v0.9.9

- Store single `AtomicI32` field instead of pair i32,AtomicBool
- Make creation faster by skipping intermediate `Value` layer
Add new `RegistryKey::id()` method to return underlying identifier

.github/workflows/coverage.yml

@@ -10,14 +10,14 @@ jobs:
       options: --security-opt seccomp=unconfined
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
 
-      - name: Generate code coverage
+      - name: Generate coverage report
         run: |
-          cargo tarpaulin --verbose --features lua54,vendored,async,send,serialize,macros --out xml --exclude-files benches --exclude-files build --exclude-files mlua_derive --exclude-files src/ffi --exclude-files tests
+          cargo tarpaulin --out xml --tests --exclude-files benches/* --exclude-files mlua-sys/src/*/*
 
-      - name: Upload to codecov.io
-        uses: codecov/codecov-action@v1
+      - name: Upload report to codecov.io
+        uses: codecov/codecov-action@v3
         with:
           token: ${{secrets.CODECOV_TOKEN}}
           fail_ci_if_error: false

.github/workflows/main.yml

@@ -7,98 +7,94 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-latest, windows-latest]
+        os: [ubuntu-22.04, macos-latest, windows-latest]
         rust: [stable]
-        lua: [lua54, lua53, lua52, lua51, luajit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
         include:
-        - os: ubuntu-20.04
-          target: x86_64-unknown-linux-gnu
-        - os: macos-latest
-          target: x86_64-apple-darwin
-        - os: windows-latest
-          target: x86_64-pc-windows-msvc
+          - os: ubuntu-22.04
+            target: x86_64-unknown-linux-gnu
+          - os: macos-latest
+            target: x86_64-apple-darwin
+          - os: windows-latest
+            target: x86_64-pc-windows-msvc
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: ${{ matrix.rust }}
-        target: ${{ matrix.target }}
-        override: true
-    - uses: Swatinem/rust-cache@v1
-    - name: Build ${{ matrix.lua }} vendored
-      run: |
-        cargo build --features "${{ matrix.lua }},vendored"
-        cargo build --features "${{ matrix.lua }},vendored,async,send,serialize,macros"
-      shell: bash
-    - name: Build ${{ matrix.lua }} pkg-config
-      if: ${{ matrix.os == 'ubuntu-20.04' && matrix.lua != 'lua54' }}
-      run: |
-        sudo apt-get update
-        sudo apt-get install -y --no-install-recommends liblua5.3-dev liblua5.2-dev liblua5.1-0-dev libluajit-5.1-dev
-        cargo build --features "${{ matrix.lua }}"
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: ${{ matrix.rust }}
+          target: ${{ matrix.target }}
+      - uses: Swatinem/rust-cache@v2
+      - name: Build ${{ matrix.lua }} vendored
+        run: |
+          cargo build --features "${{ matrix.lua }},vendored"
+          cargo build --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+        shell: bash
+      - name: Build ${{ matrix.lua }} pkg-config
+        if: ${{ matrix.os == 'ubuntu-22.04' }}
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends liblua5.4-dev liblua5.3-dev liblua5.2-dev liblua5.1-0-dev libluajit-5.1-dev
+          cargo build --features "${{ matrix.lua }}"
 
   build_aarch64_cross_macos:
     name: Cross-compile to aarch64-apple-darwin
-    runs-on: macos-11.0
+    runs-on: macos-latest
     needs: build
     strategy:
       matrix:
         lua: [lua54, lua53, lua52, lua51, luajit]
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: stable
-        target: aarch64-apple-darwin
-        override: true
-    - name: Cross-compile
-      run: cargo build --target aarch64-apple-darwin --features "${{ matrix.lua }},vendored,async,send,serialize,macros"
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+          target: aarch64-apple-darwin
+      - name: Cross-compile
+        run: cargo build --target aarch64-apple-darwin --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
 
   build_aarch64_cross_ubuntu:
     name: Cross-compile to aarch64-unknown-linux-gnu
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     needs: build
     strategy:
       matrix:
         lua: [lua54, lua53, lua52, lua51, luajit]
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: stable
-        target: aarch64-unknown-linux-gnu
-        override: true
-    - name: Install ARM compiler toolchain
-      run: |
-        sudo apt-get update
-        sudo apt-get install -y --no-install-recommends gcc-aarch64-linux-gnu libc6-dev-arm64-cross
-      shell: bash
-    - name: Cross-compile
-      run: cargo build --target aarch64-unknown-linux-gnu --features "${{ matrix.lua }},vendored,async,send,serialize,macros"
-      shell: bash
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+          target: aarch64-unknown-linux-gnu
+      - name: Install ARM compiler toolchain
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends gcc-aarch64-linux-gnu libc6-dev-arm64-cross
+        shell: bash
+      - name: Cross-compile
+        run: cargo build --target aarch64-unknown-linux-gnu --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+        shell: bash
 
   build_armv7_cross_ubuntu:
     name: Cross-compile to armv7-unknown-linux-gnueabihf
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     needs: build
     strategy:
       matrix:
         lua: [lua54, lua53, lua52, lua51]
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: stable
-        target: armv7-unknown-linux-gnueabihf
-        override: true
-    - name: Install ARM compiler toolchain
-      run: |
-        sudo apt-get update
-        sudo apt-get install -y --no-install-recommends gcc-arm-linux-gnueabihf libc-dev-armhf-cross
-      shell: bash
-    - name: Cross-compile
-      run: cargo build --target armv7-unknown-linux-gnueabihf --features "${{ matrix.lua }},vendored,async,send,serialize,macros"
-      shell: bash
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+          target: armv7-unknown-linux-gnueabihf
+      - name: Install ARM compiler toolchain
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends gcc-arm-linux-gnueabihf libc-dev-armhf-cross
+        shell: bash
+      - name: Cross-compile
+        run: cargo build --target armv7-unknown-linux-gnueabihf --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"
+        shell: bash
 
   test:
     name: Test
@@ -106,35 +102,35 @@ jobs:
     needs: build
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-latest, windows-latest]
+        os: [ubuntu-22.04, macos-latest, windows-latest]
         rust: [stable, nightly]
-        lua: [lua54, lua53, lua52, lua51, luajit, luajit52]
+        lua: [lua54, lua53, lua52, lua51, luajit, luajit52, luau, luau-jit, luau-vector4]
         include:
-        - os: ubuntu-20.04
-          target: x86_64-unknown-linux-gnu
-        - os: macos-latest
-          target: x86_64-apple-darwin
-        - os: windows-latest
-          target: x86_64-pc-windows-msvc
+          - os: ubuntu-22.04
+            target: x86_64-unknown-linux-gnu
+          - os: macos-latest
+            target: x86_64-apple-darwin
+          - os: windows-latest
+            target: x86_64-pc-windows-msvc
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: ${{ matrix.rust }}
-        target: ${{ matrix.target }}
-        override: true
-    - uses: Swatinem/rust-cache@v1
-    - name: Run ${{ matrix.lua }} tests
-      run: |
-        cargo test --features "${{ matrix.lua }},vendored"
-        cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros"
-      shell: bash
-    - name: Run compile tests (macos lua54)
-      if: ${{ matrix.os == 'macos-latest' && matrix.lua == 'lua54' }}
-      run: |
-        TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored" -- --ignored
-        TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros" -- --ignored
-      shell: bash
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: ${{ matrix.rust }}
+          target: ${{ matrix.target }}
+      - uses: Swatinem/rust-cache@v2
+      - name: Run ${{ matrix.lua }} tests
+        run: |
+          cargo test --features "${{ matrix.lua }},vendored"
+          cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
+          cargo test --features "${{ matrix.lua }},vendored,async,serialize,macros,parking_lot,unstable"
+        shell: bash
+      - name: Run compile tests (macos lua54)
+        if: ${{ matrix.os == 'macos-latest' && matrix.lua == 'lua54' }}
+        run: |
+          TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored" -- --ignored
+          TRYBUILD=overwrite cargo test --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable" -- --ignored
+        shell: bash
 
   test_with_sanitizer:
     name: Test with address sanitizer
@@ -142,25 +138,25 @@ jobs:
     needs: build
     strategy:
       matrix:
-        os: [ubuntu-20.04]
+        os: [ubuntu-22.04]
         rust: [nightly]
-        lua: [lua54, lua53, lua52, lua51, luajit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
         include:
-        - os: ubuntu-20.04
-          target: x86_64-unknown-linux-gnu
+          - os: ubuntu-22.04
+            target: x86_64-unknown-linux-gnu
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: ${{ matrix.rust }}
-        target: ${{ matrix.target }}
-        override: true
-    - uses: Swatinem/rust-cache@v1
-    - name: Run ${{ matrix.lua }} tests with address sanitizer
-      run: |
-        RUSTFLAGS="-Z sanitizer=address" \
-          cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serialize,macros" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
-      shell: bash
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: ${{ matrix.rust }}
+          target: ${{ matrix.target }}
+      - uses: Swatinem/rust-cache@v2
+      - name: Run ${{ matrix.lua }} tests with address sanitizer
+        run: |
+            cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable" --target x86_64-unknown-linux-gnu -- --skip test_too_many_recursions
+        shell: bash
+        env:
+          RUSTFLAGS: -Z sanitizer=address
 
   test_modules:
     name: Test modules
@@ -168,27 +164,26 @@ jobs:
     needs: build
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-latest]
+        os: [ubuntu-22.04, macos-latest]
         rust: [stable]
-        lua: [lua54, lua53, lua52, lua51, luajit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau]
         include:
-        - os: ubuntu-20.04
-          target: x86_64-unknown-linux-gnu
-        - os: macos-latest
-          target: x86_64-apple-darwin
+          - os: ubuntu-22.04
+            target: x86_64-unknown-linux-gnu
+          - os: macos-latest
+            target: x86_64-apple-darwin
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: ${{ matrix.rust }}
-        target: ${{ matrix.target }}
-        override: true
-    - uses: Swatinem/rust-cache@v1
-    - name: Run ${{ matrix.lua }} module tests
-      run: |
-        (cd examples/module && cargo build --release --features "${{ matrix.lua }},vendored")
-        (cd tests/module && cargo test --release --features "${{ matrix.lua }},vendored")
-      shell: bash
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: ${{ matrix.rust }}
+          target: ${{ matrix.target }}
+      - uses: Swatinem/rust-cache@v2
+      - name: Run ${{ matrix.lua }} module tests
+        run: |
+          (cd tests/module && cargo build --release --features "${{ matrix.lua }}")
+          (cd tests/module/loader && cargo test --release --features "${{ matrix.lua }},vendored")
+        shell: bash
 
   test_modules_windows:
     name: Test modules on Windows
@@ -201,42 +196,63 @@ jobs:
       run:
         shell: msys2 {0}
     steps:
-    - uses: msys2/setup-msys2@v2
-    - uses: actions/checkout@v2
-    - name: Install Rust & Lua
-      run: |
-        pacman -S --noconfirm mingw-w64-x86_64-rust mingw-w64-x86_64-lua mingw-w64-x86_64-luajit mingw-w64-x86_64-pkg-config
-    - name: Run ${{ matrix.lua }} module tests
-      run: |
-        (cd examples/module && cargo build --release --features "${{ matrix.lua }}")
-        (cd tests/module && cargo test --release --features "${{ matrix.lua }}")
+      - uses: msys2/setup-msys2@v2
+      - uses: actions/checkout@v4
+      - name: Install Rust & Lua
+        run: |
+          pacman -S --noconfirm mingw-w64-x86_64-rust mingw-w64-x86_64-lua mingw-w64-x86_64-luajit mingw-w64-x86_64-pkg-config
+      - name: Run ${{ matrix.lua }} module tests
+        run: |
+          (cd tests/module && cargo build --release --features "${{ matrix.lua }}")
+          (cd tests/module/loader && cargo test --release --features "${{ matrix.lua }}")
+
+  test_wasm32_emscripten:
+    name: Test on wasm32-unknown-emscripten
+    runs-on: ubuntu-22.04
+    needs: build
+    strategy:
+      matrix:
+        lua: [lua54, lua53, lua52, lua51, luau]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+          target: wasm32-unknown-emscripten
+      - name: Install Emscripten
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends emscripten
+      - name: Run ${{ matrix.lua }} tests
+        run: |
+          cargo test --tests --features "${{ matrix.lua }},vendored"
+          cargo test --tests --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot"
+          cargo test --tests --features "${{ matrix.lua }},vendored,async,serialize,macros,parking_lot,unstable"
 
   rustfmt:
     name: Rustfmt
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     steps:
-    - uses: actions/checkout@v2
-    - uses: actions-rs/toolchain@v1
-      with:
-        toolchain: stable
-        components: rustfmt
-        override: true
-    - run: cargo fmt -- --check
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          toolchain: stable
+          components: rustfmt
+      - run: cargo fmt -- --check
 
   clippy:
-    name: Clippy check
-    runs-on: ubuntu-20.04
+    name: Clippy
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
-        lua: [lua54, lua53, lua52, lua51, luajit]
+        lua: [lua54, lua53, lua52, lua51, luajit, luau, luau-jit, luau-vector4]
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions-rs/toolchain@v1
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
         with:
-            toolchain: nightly
-            components: clippy
-            override: true
-      - uses: actions-rs/clippy-check@v1
+          toolchain: nightly
+          components: clippy
+      - uses: giraffate/clippy-action@v1
         with:
-          token: ${{ secrets.GITHUB_TOKEN }}
-          args: --features "${{ matrix.lua }},vendored,async,send,serialize,macros"
+          reporter: 'github-pr-review'
+          clippy_flags: --features "${{ matrix.lua }},vendored,async,send,serialize,macros,parking_lot,unstable"

.gitignore

@@ -4,3 +4,4 @@ Cargo.lock
 
 .vscode/
 .DS_Store
+.stignore

CHANGELOG.md

@@ -1,3 +1,295 @@
+## v0.9.9
+
+- Minimal Luau updated to 0.629
+- Fixed bug when attempting to reset or resume already running coroutines (#416).
+- Added `RegistryKey::id()` method to get the underlying Lua registry key id.
+
+## v0.9.8
+
+- Fixed serializing same table multiple times (#408)
+- Use `mlua-sys` v0.6 (to support Luau 0.624+)
+- Fixed cross compilation of windows dlls from unix (#394)
+
+## v0.9.7
+
+- Implemented `IntoLua` for `RegistryKey`
+- Mark `__idiv` metamethod as available for luau
+- Added `Function::deep_clone()` method (Luau)
+- Added `SerializeOptions::detect_serde_json_arbitrary_precision` option
+- Added `Lua::create_buffer()` method (Luau)
+- Support serializing buffer type as a byte slice (Luau)
+- Perf: Implemented `push_into_stack`/`from_stack` for `Option<T>`
+- Added `Lua::create_ser_any_userdata()` method
+
+## v0.9.6
+
+- Added `to_pointer` function to `Function`/`Table`/`Thread`
+- Implemented `IntoLua` for `&Value`
+- Implemented `FromLua` for `RegistryKey`
+- Faster (~5%) table array traversal during serialization
+- Some performance improvements for bool/int types
+
+## v0.9.5
+
+- Minimal Luau updated to 0.609
+- Luau max stack size increased to 1M (from 100K)
+- Implemented `IntoLua` for refs to `String`/`Table`/`Function`/`AnyUserData`/`Thread` + `RegistryKey`
+- Implemented `IntoLua` and `FromLua` for `OwnedThread`/`OwnedString`
+- Fixed `FromLua` derive proc macro to cover more cases
+
+## v0.9.4
+
+- Fixed loading all-in-one modules under mixed states (eg. main state and coroutines)
+
+## v0.9.3
+
+- WebAssembly support (`wasm32-unknown-emscripten` target)
+- Performance improvements (faster Lua function calls for lua51/jit/luau)
+
+## v0.9.2
+
+- Added binary modules support to Luau
+- Added Luau package module (uses `StdLib::PACKAGE`) with loaders (follows lua5.1 interface)
+- Added support of Luau 0.601+ buffer type (represented as userdata in Rust)
+- LuaJIT `cdata` type is also represented as userdata in Rust (instead of panic)
+- Vendored LuaJIT switched to rolling vanilla (from openresty)
+- Added `Table::for_each` method for fast table pairs traversal (faster than `pairs`)
+- Performance improvements around table traversal (and faster serialization)
+- Bug fixes and improvements
+
+## v0.9.1
+
+- impl Default for Lua
+- impl IntoLuaMulti for `std::result::Result<(), E>`
+- Fix using wrong userdata index after processing Variadic args (#311)
+
+## v0.9.0
+
+Changes since v0.9.0-rc.3
+
+- Improved non-static (scoped) userdata support
+- Added `Scope::create_any_userdata()` method
+- Added `Lua::set_vector_metatable()` method (`unstable` feature flag)
+- Added `OwnedThread` type (`unstable` feature flag)
+- Minimal Luau updated to 0.590
+- Added new option `sort_keys` to `DeserializeOptions` (`Lua::from_value()` method)
+- Changed `Table::raw_len()` output type to `usize`
+- Helper functions for `Value` (eg: `Value::as_number()`/`Value::as_string`/etc)
+- Performance improvements
+
+## v0.9.0-rc.3
+
+- Minimal Luau updated to 0.588
+
+## v0.9.0-rc.2
+
+- Added `#[derive(FromLua)]` macro to opt-in into `FromLua<T> where T: 'static + Clone` (userdata type).
+- Support vendored module mode for windows (raw-dylib linking, Rust 1.71+)
+- `module` and `vendored` features are now mutually exclusive
+- Use `C-unwind` ABI (Rust 1.71+)
+- Changed `AsChunk` trait to support capturing wrapped Lua types
+
+## v0.9.0-rc.1
+
+- `UserDataMethods::add_async_method()` takes `&T` instead of cloning `T`
+- Implemented `PartialEq<[T]>` for tables
+- Added Luau 4-dimensional vectors support (`luau-vector4` feature)
+- `Table::sequence_values()` iterator no longer uses any metamethods (`Table::raw_sequence_values()` is deprecated)
+- Added `Table:is_empty()` function that checks both hash and array parts
+- Refactored Debug interface
+- Re-exported `ffi` (`mlua-sys`) crate for easier writing of unsafe code
+- Refactored Lua 5.4 warnings interface
+- Take `&str` as function name in `TableExt` and `AnyUserDataExt` traits
+- Added module attribule `skip_memory_check` to improve performance
+- Added `AnyUserData::wrap()` to provide more easy way of creating _any_ userdata in Lua
+
+## v0.9.0-beta.3
+
+- Added `OwnedAnyUserData::take()`
+- Switch to `DeserializeOwned`
+- Overwrite error context when called multiple times
+- New feature flag `luau-jit` to enable (experimental) Luau codegen backend
+- Set `__name` field in userdata metatable
+- Added `Value::to_string()` method similar to `luaL_tolstring`
+- Lua 5.4.6
+- Application data container now allows to mutably and immutably borrow different types at the same time
+- Performance optimizations
+- Support getting and setting environment for Lua functions.
+- Added `UserDataFields::add_field()` method to add static fields to UserData
+
+Breaking changes:
+- Require environment to be a `Table` instead of `Value` in Chunks.
+- `AsChunk::env()` renamed to `AsChunk::environment()`
+
+## v0.9.0-beta.2
+
+New features:
+- Added `Thread::set_hook()` function to set hook on threads
+- Added pretty print to the Debug formatting to Lua `Value` and `Table`
+- ffi layer moved to `mlua-sys` crate
+- Added OwnedString (unstable)
+
+Breaking changes:
+- Refactor `HookTriggers` (make it const)
+
+## v0.9.0-beta.1
+
+New features:
+- Owned Lua types (unstable feature flag)
+- New functions `Function::wrap`/`Function::wrap_mut`/`Function::wrap_async`
+- `Lua::register_userdata_type()` to register a custom userdata types (without requiring `UserData` trait)
+- `Lua::create_any_userdata()`
+- Added `create_userdata_ref`/`create_userdata_ref_mut` for scopes
+- Added `AnyUserDataExt` trait with auxiliary functions for `AnyUserData`
+- Added `UserDataRef` and `UserDataRefMut` type wrapped that implement `FromLua`
+- Improved error handling:
+  * Improved error reporting when calling Rust functions from Lua.
+  * Added `Error::BadArgument` to help identify bad argument position or name
+  * Added `ErrorContext` extension trait to attach additional context to `Error`
+
+Breaking changes:
+- Refactored `AsChunk` trait
+- `ToLua`/`ToLuaMulti` renamed to `IntoLua`/`IntoLuaMulti`
+- Renamed `to_lua_err` to `into_lua_err`
+- Removed `FromLua` impl for `T: UserData+Clone`
+- Removed `Lua::async_scope`
+- Added `&Lua` arg to Luau interrupt callback
+
+Other:
+- Better Debug for String
+- Allow deserializing values from serializable UserData using `Lua::from_value()` method
+- Added `Table::clear()` method
+- Added `Error::downcast_ref()` method
+- Support setting memory limit for Lua 5.1/JIT/Luau
+- Support setting module name in `#[lua_module(name = "...")]` macro
+- Minor fixes and improvements
+
+## v0.8.10
+
+- Update to Luau 0.590 (luau0-src to 0.7.x)
+- Fix loading luau code starting with \t
+- Pin lua-src and luajit-src versions
+
+## v0.8.9
+
+- Update minimal (vendored) Lua 5.4 to 5.4.6
+- Use `lua_closethread` instead of `lua_resetthread` in vendored mode (Lua 5.4.6)
+- Allow deserializing Lua null into unit (`()`) or unit struct.
+
+## v0.8.8
+
+- Fix potential deadlock when trying to reuse dropped registry keys.
+- Optimize userdata methods call when __index and fields_getters are nil
+
+## v0.8.7
+
+- Minimum Luau updated to 0.555 (`LUAI_MAXCSTACK` limit increased to 100000)
+- `_VERSION` in Luau now includes version number
+- Fixed lifetime of `DebugNames` in `Debug::names()` and `DebugSource` in `Debug::source()`
+- Fixed subtraction overflow when calculating index for `MultiValue::get()`
+
+## v0.8.6
+
+- Fixed bug when recycled Registry slot can be set to Nil
+
+## v0.8.5
+
+- Fixed potential unsoundness when using `Layout::from_size_align_unchecked` and Rust 1.65+
+- Performance optimizations around string and table creation in standalone mode
+- Added fast track path to Table `get`/`set`/`len` methods without metatable
+- Added new methods `push`/`pop`/`raw_push`/`raw_pop` to Table
+- Fix getting caller information from `Lua::load`
+- Better checks and tests when trying to modify a Luau readonly table
+
+## v0.8.4
+
+- Minimal Luau updated to 0.548
+
+## v0.8.3
+
+- Close to-be-closed variables for Lua 5.4 when using call_async functions (#192)
+- Fixed Lua assertion when inspecting another thread stack. (#195)
+- Use more reliable way to create LuaJIT VM (which can fail if use Rust allocator on non-x86 platforms)
+
+## v0.8.2
+
+- Performance optimizations in handling UserData
+- Minimal Luau updated to 0.536
+- Fixed bug in `Function::bind` when passing empty binds and no arguments (#189)
+
+## v0.8.1
+
+- Added `Lua::create_proxy` for accessing to UserData static fields and functions without instance
+- Added `Table::to_pointer()` and `String::to_pointer()` functions
+- Bugfixes and improvements (#176 #179)
+
+## v0.8.0
+Changes since 0.7.4
+- Roblox Luau support
+- Removed C glue
+- Added async support to `__index` and `__newindex` metamethods
+- Added `Function::info()` to get information about functions (#149).
+- Added `parking_lot` dependency under feature flag (for `UserData`)
+- `Hash` implementation for Lua String
+- Added `Value::to_pointer()` function
+- Performance improvements
+
+Breaking changes:
+- Refactored `AsChunk` trait (added implementation for `Path` and `PathBuf`).
+
+## v0.8.0-beta.5
+
+- Lua sources no longer needed to build modules
+- Added `__iter` metamethod for Luau
+- Added `Value::to_pointer()` function
+- Added `Function::coverage` for Luau to obtain coverage report
+- Bugfixes and improvements (#153 #161 #168)
+
+## v0.8.0-beta.4
+
+- Removed `&Lua` from `Lua::set_interrupt` as it's not safe (introduced in v0.8.0-beta.3)
+- Enabled `Lua::gc_inc` for Luau
+- Luau `debug` module marked as safe (enabled by default)
+- Implemented `Hash` for Lua String
+- Support mode options in `collectgarbage` for Luau
+- Added ability to set global Luau compiler (used for loading all chunks).
+- Refactored `AsChunk` trait (breaking changes).
+  `AsChunk` now implemented for `Path` and `PathBuf` to load lua files from fs.
+- Added `parking_lot` dependency and feature flag (for `UserData`)
+- Added `Function::info()` to get information about functions (#149).
+- Bugfixes and improvements (#104 #142)
+
+## v0.8.0-beta.3
+
+- Luau vector constructor
+- Luau sandboxing support
+- Luau interrupts (yieldable)
+- More Luau compiler options (mutable globals)
+- Other performance improvements
+
+## v0.8.0-beta.2
+
+- Luau vector datatype support
+- Luau readonly table attribute
+- Other Luau improvements
+
+## v0.8.0-beta.1
+
+- Roblox Luau support
+- Refactored ffi module. C glue is no longer required
+- Added async support to `__index` and `__newindex` metamethods
+
+## v0.7.4
+
+- Improved `Lua::create_registry_value` to reuse previously expired registry keys.
+  No need to call `Lua::expire_registry_values` when creating/dropping registry values.
+- Added `Lua::replace_registry_value` to change value of an existing Registry Key
+- Async calls optimization
+
+## v0.7.3
+
+- Fixed cross-compilation issue (introduced in 84a174c)
+
 ## v0.7.2
 
 - Allow `pkg-config` to omit include paths if they equals to standard (#114).

Cargo.toml

@@ -1,81 +1,97 @@
 [package]
 name = "mlua"
-version = "0.7.2" # remember to update html_root_url and mlua_derive
-authors = ["Aleksandr Orlenko <zxteam@pm.me>", "kyren <catherine@chucklefish.org>"]
-edition = "2018"
+version = "0.9.9" # remember to update mlua_derive
+authors = ["Aleksandr Orlenko <zxteam@pm.me>", "kyren <catherine@kyju.org>"]
+rust-version = "1.71"
+edition = "2021"
 repository = "https://github.com/khvzak/mlua"
 documentation = "https://docs.rs/mlua"
 readme = "README.md"
-keywords = ["lua", "luajit", "async", "futures", "scripting"]
+keywords = ["lua", "luajit", "luau", "async", "scripting"]
 categories = ["api-bindings", "asynchronous"]
 license = "MIT"
-links = "lua"
-build = "build/main.rs"
 description = """
-High level bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT)
+High level bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox Luau
 with async/await features and support of writing native Lua modules in Rust.
 """
 
 [package.metadata.docs.rs]
-features = ["lua54", "vendored", "async", "send", "serialize", "macros"]
+features = ["lua54", "vendored", "async", "send", "serialize", "macros", "parking_lot", "unstable"]
 rustdoc-args = ["--cfg", "docsrs"]
 
 [workspace]
 members = [
     "mlua_derive",
-    "examples/module",
-    "tests/module",
+    "mlua-sys",
 ]
 
 [features]
-lua54 = []
-lua53 = []
-lua52 = []
-lua51 = []
-luajit = []
-luajit52 = ["luajit"]
-vendored = ["lua-src", "luajit-src"]
-module = ["mlua_derive"]
-async = ["futures-core", "futures-task", "futures-util"]
+lua54 = ["ffi/lua54"]
+lua53 = ["ffi/lua53"]
+lua52 = ["ffi/lua52"]
+lua51 = ["ffi/lua51"]
+luajit = ["ffi/luajit"]
+luajit52 = ["luajit", "ffi/luajit52"]
+luau = ["ffi/luau", "dep:libloading"]
+luau-jit = ["luau", "ffi/luau-codegen"]
+luau-vector4 = ["luau", "ffi/luau-vector4"]
+vendored = ["ffi/vendored"]
+module = ["dep:mlua_derive", "ffi/module"]
+async = ["dep:futures-util"]
 send = []
-serialize = ["serde", "erased-serde"]
+serialize = ["dep:serde", "dep:erased-serde", "dep:serde-value"]
 macros = ["mlua_derive/macros"]
+unstable = []
 
 [dependencies]
-mlua_derive = { version = "=0.6.0", optional = true, path = "mlua_derive" }
-bstr = { version = "0.2", features = ["std"], default_features = false }
+mlua_derive = { version = "=0.9.3", optional = true, path = "mlua_derive" }
+bstr = { version = "1.0", features = ["std"], default-features = false }
 once_cell = { version = "1.0" }
 num-traits = { version = "0.2.14" }
-rustc-hash = "1.0"
-futures-core = { version = "0.3.5", optional = true }
-futures-task = { version = "0.3.5", optional = true }
-futures-util = { version = "0.3.5", optional = true }
+rustc-hash = "2.0"
+futures-util = { version = "0.3", optional = true, default-features = false, features = ["std"] }
 serde = { version = "1.0", optional = true }
-erased-serde = { version = "0.3", optional = true }
+erased-serde = { version = "0.4", optional = true }
+serde-value = { version = "0.7", optional = true }
+parking_lot = { version = "0.12", optional = true }
 
-[build-dependencies]
-cc = { version = "1.0" }
-pkg-config = { version = "0.3.17" }
-lua-src = { version = ">= 540.0.0, < 550.0.0", optional = true }
-luajit-src = { version = ">= 210.3.1, < 220.0.0", optional = true }
+ffi = { package = "mlua-sys", version = "0.6.1", path = "mlua-sys" }
+
+[target.'cfg(unix)'.dependencies]
+libloading = { version = "0.8", optional = true }
 
 [dev-dependencies]
-rustyline = "9.0"
-criterion = { version = "0.3.4", features = ["html_reports", "async_tokio"] }
 trybuild = "1.0"
 futures = "0.3.5"
-hyper = { version = "0.14", features = ["client", "server"] }
-reqwest = { version = "0.11", features = ["json"] }
-tokio = { version = "1.0", features = ["full"] }
-futures-timer = "3.0"
-serde_json = "1.0"
+hyper = { version = "1.2", features = ["full"] }
+hyper-util = { version = "0.1.3", features = ["full"] }
+http-body-util = "0.1.1"
+reqwest = { version = "0.12", features = ["json"] }
+tokio = { version = "1.0", features = ["macros", "rt", "time"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = { version = "1.0", features = ["arbitrary_precision"] }
 maplit = "1.0"
+tempfile = "3"
+static_assertions = "1.0"
+
+[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
+criterion = { version = "0.5", features = ["async_tokio"] }
+rustyline = "14.0"
+tokio = { version = "1.0", features = ["full"] }
+
+[lints.rust]
+unexpected_cfgs = { level = "allow", check-cfg = ['cfg(tarpaulin_include)'] }
 
 [[bench]]
 name = "benchmark"
 harness = false
 required-features = ["async"]
 
+[[bench]]
+name = "serde"
+harness = false
+required-features = ["serialize"]
+
 [[example]]
 name = "async_http_client"
 required-features = ["async", "macros"]

FAQ.md

@@ -0,0 +1,21 @@
+# mlua FAQ
+
+This file is for general questions that don't fit into the README or crate docs.
+
+## Loading a C module fails with error `undefined symbol: lua_xxx`. How to fix?
+
+Add the following rustflags to your [.cargo/config](http://doc.crates.io/config.html) in order to properly export Lua symbols:
+
+```toml
+[target.x86_64-unknown-linux-gnu]
+rustflags = ["-C", "link-args=-rdynamic"]
+
+[target.x86_64-apple-darwin]
+rustflags = ["-C", "link-args=-rdynamic"]
+```
+
+## I want to add support for a Lua VM fork to mlua. Do you accept pull requests?
+
+Adding new feature flag to support a Lua VM fork is a major step that requires huge effort to maintain it.
+Regular updates, testing, checking compatibility, etc.
+That's why I don't plan to support new Lua VM forks or other languages in mlua.

README.md

@@ -7,20 +7,31 @@
 [crates.io]: https://crates.io/crates/mlua
 [API Documentation]: https://docs.rs/mlua/badge.svg
 [docs.rs]: https://docs.rs/mlua
-[Coverage Status]: https://codecov.io/gh/khvzak/mlua/branch/master/graph/badge.svg?token=99339FS1CG
-[codecov.io]: https://codecov.io/gh/khvzak/mlua
-[MSRV]: https://img.shields.io/badge/rust-1.53+-brightgreen.svg?&logo=rust
+[Coverage Status]: https://codecov.io/gh/mlua-rs/mlua/branch/master/graph/badge.svg?token=99339FS1CG
+[codecov.io]: https://codecov.io/gh/mlua-rs/mlua
+[MSRV]: https://img.shields.io/badge/rust-1.71+-brightgreen.svg?&logo=rust
 
-[Guided Tour](examples/guided_tour.rs)
+[Guided Tour] | [Benchmarks] | [FAQ]
+
+[Guided Tour]: examples/guided_tour.rs
+[Benchmarks]: https://github.com/khvzak/script-bench-rs
+[FAQ]: FAQ.md
+
+> **Note**
+>
+> See v0.9 [release notes](https://github.com/khvzak/mlua/blob/master/docs/release_notes/v0.9.md).
 
 `mlua` is bindings to [Lua](https://www.lua.org) programming language for Rust with a goal to provide
 _safe_ (as far as it's possible), high level, easy to use, practical and flexible API.
 
-Started as `rlua` fork, `mlua` supports Lua 5.4, 5.3, 5.2 and 5.1 including LuaJIT (2.0.5 and 2.1 beta) and allows to write native Lua modules in Rust as well as use Lua in a standalone mode.
+Started as `rlua` fork, `mlua` supports Lua 5.4, 5.3, 5.2, 5.1 (including LuaJIT) and [Roblox Luau] and allows to write native Lua modules in Rust as well as use Lua in a standalone mode.
 
 `mlua` tested on Windows/macOS/Linux including module mode in [GitHub Actions] on `x86_64` platform and cross-compilation to `aarch64` (other targets are also supported).
 
+WebAssembly (WASM) is supported through `wasm32-unknown-emscripten` target for all Lua versions excluding JIT.
+
 [GitHub Actions]: https://github.com/khvzak/mlua/actions
+[Roblox Luau]: https://luau-lang.org
 
 ## Usage
 
@@ -35,28 +46,37 @@ Below is a list of the available feature flags. By default `mlua` does not enabl
 * `lua51`: activate Lua [5.1] support
 * `luajit`: activate [LuaJIT] support
 * `luajit52`: activate [LuaJIT] support with partial compatibility with Lua 5.2
+* `luau`: activate [Luau] support (auto vendored mode)
+* `luau-jit`: activate [Luau] support with JIT backend.
+* `luau-vector4`: activate [Luau] support with 4-dimensional vector.
 * `vendored`: build static Lua(JIT) library from sources during `mlua` compilation using [lua-src] or [luajit-src] crates
 * `module`: enable module mode (building loadable `cdylib` library for Lua)
 * `async`: enable async/await support (any executor can be used, eg. [tokio] or [async-std])
 * `send`: make `mlua::Lua` transferable across thread boundaries (adds [`Send`] requirement to `mlua::Function` and `mlua::UserData`)
 * `serialize`: add serialization and deserialization support to `mlua` types using [serde] framework
 * `macros`: enable procedural macros (such as `chunk!`)
+* `parking_lot`: support UserData types wrapped in [parking_lot]'s primitives (`Arc<Mutex>` and `Arc<RwLock>`)
+* `unstable`: enable **unstable** features. The public API of these features may break between releases.
 
 [5.4]: https://www.lua.org/manual/5.4/manual.html
 [5.3]: https://www.lua.org/manual/5.3/manual.html
 [5.2]: https://www.lua.org/manual/5.2/manual.html
 [5.1]: https://www.lua.org/manual/5.1/manual.html
 [LuaJIT]: https://luajit.org/
+[Luau]: https://github.com/Roblox/luau
 [lua-src]: https://github.com/khvzak/lua-src-rs
 [luajit-src]: https://github.com/khvzak/luajit-src-rs
 [tokio]: https://github.com/tokio-rs/tokio
 [async-std]: https://github.com/async-rs/async-std
 [`Send`]: https://doc.rust-lang.org/std/marker/trait.Send.html
 [serde]: https://github.com/serde-rs/serde
+[parking_lot]: https://github.com/Amanieu/parking_lot
 
 ### Async/await support
 
-`mlua` supports async/await for all Lua versions. This works using Lua [coroutines](https://www.lua.org/manual/5.3/manual.html#2.6) and require running [Thread](https://docs.rs/mlua/latest/mlua/struct.Thread.html) along with enabling `feature = "async"` in `Cargo.toml`.
+`mlua` supports async/await for all Lua versions including Luau.
+
+This works using Lua [coroutines](https://www.lua.org/manual/5.3/manual.html#2.6) and require running [Thread](https://docs.rs/mlua/latest/mlua/struct.Thread.html) along with enabling `feature = "async"` in `Cargo.toml`.
 
 **Examples**:
 - [HTTP Client](examples/async_http_client.rs)
@@ -64,6 +84,20 @@ Below is a list of the available feature flags. By default `mlua` does not enabl
 - [HTTP Server](examples/async_http_server.rs)
 - [TCP Server](examples/async_tcp_server.rs)
 
+
+**shell command examples**:
+```shell
+# async http client (hyper)
+cargo run --example async_http_client --features=lua54,async,macros
+
+# async http client (reqwest)
+cargo run --example async_http_reqwest --features=lua54,async,macros,serialize
+
+# async http server
+cargo run --example async_http_server --features=lua54,async,macros
+curl -v http://localhost:3000
+```
+
 ### Serialization (serde) support
 
 With `serialize` feature flag enabled, `mlua` allows you to serialize/deserialize any type that implements [`serde::Serialize`] and [`serde::Deserialize`] into/from [`mlua::Value`]. In addition `mlua` provides [`serde::Serialize`] trait implementation for it (including `UserData` support).
@@ -76,16 +110,16 @@ With `serialize` feature flag enabled, `mlua` allows you to serialize/deserializ
 
 ### Compiling
 
-You have to enable one of the features `lua54`, `lua53`, `lua52`, `lua51` or `luajit(52)`, according to the chosen Lua version.
+You have to enable one of the features: `lua54`, `lua53`, `lua52`, `lua51`, `luajit(52)` or `luau`, according to the chosen Lua version.
 
 By default `mlua` uses `pkg-config` tool to find lua includes and libraries for the chosen Lua version.
 In most cases it works as desired, although sometimes could be more preferable to use a custom lua library.
-To achieve this, mlua supports `LUA_INC`, `LUA_LIB`, `LUA_LIB_NAME` and `LUA_LINK` environment variables.
+To achieve this, mlua supports `LUA_LIB`, `LUA_LIB_NAME` and `LUA_LINK` environment variables.
 `LUA_LINK` is optional and may be `dylib` (a dynamic library) or `static` (a static library, `.a` archive).
 
 An example how to use them:
 ``` sh
-my_project $ LUA_INC=$HOME/tmp/lua-5.2.4/src LUA_LIB=$HOME/tmp/lua-5.2.4/src LUA_LIB_NAME=lua LUA_LINK=static cargo build
+my_project $ LUA_LIB=$HOME/tmp/lua-5.2.4/src LUA_LIB_NAME=lua LUA_LINK=static cargo build
 ```
 
 `mlua` also supports vendored lua/luajit using the auxiliary crates [lua-src](https://crates.io/crates/lua-src) and
@@ -99,7 +133,7 @@ Add to `Cargo.toml` :
 
 ``` toml
 [dependencies]
-mlua = { version = "0.7", features = ["lua54", "vendored"] }
+mlua = { version = "0.9.9", features = ["lua54", "vendored"] }
 ```
 
 `main.rs`
@@ -134,7 +168,7 @@ Add to `Cargo.toml` :
 crate-type = ["cdylib"]
 
 [dependencies]
-mlua = { version = "0.7", features = ["lua54", "vendored", "module"] }
+mlua = { version = "0.9.9", features = ["lua54", "module"] }
 ```
 
 `lib.rs` :
@@ -179,13 +213,11 @@ rustflags = [
 ]
 ```
 On Linux you can build modules normally with `cargo build --release`.
-Vendored and non-vendored builds are supported for these OS.
 
-On Windows `vendored` mode for modules is not supported since you need to link to a Lua dll.
-Easiest way is to use either MinGW64 (as part of [MSYS2](https://github.com/msys2/msys2) package) with `pkg-config` or
-MSVC with `LUA_INC` / `LUA_LIB` / `LUA_LIB_NAME` environment variables.
+On Windows the target module will be linked with `lua5x.dll` library (depending on your feature flags).
+Your main application should provide this library.
 
-More details about compiling and linking Lua modules can be found on the [Building Modules](http://lua-users.org/wiki/BuildingModules) page.
+Module builds don't require Lua lib or headers to be installed on the system.
 
 ### Publishing to luarocks.org
 
@@ -249,6 +281,14 @@ If you encounter them, a bug report would be very welcome:
 
   + If you detect that, after catching a panic or during a Drop triggered from a panic, a `Lua` or handle method is triggering other bugs or there is a Lua stack space leak, this is a bug. `mlua` instances are supposed to remain fully usable in the face of user generated panics. This guarantee does not extend to panics marked with "mlua internal error" simply because that is already indicative of a separate bug.
 
+## Sandboxing
+
+Please check the [Luau Sandboxing] page if you are interested in running untrusted Lua scripts in controlled environment.
+
+`mlua` provides `Lua::sandbox` method for enabling sandbox mode (Luau only).
+
+[Luau Sandboxing]: https://luau-lang.org/sandbox
+
 ## License
 
 This project is licensed under the [MIT license](LICENSE)

benches/benchmark.rs

@@ -1,5 +1,7 @@
-use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
+use std::sync::atomic::{AtomicUsize, Ordering};
 use std::time::Duration;
+
+use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
 use tokio::runtime::Runtime;
 use tokio::task;
 
@@ -10,10 +12,10 @@ fn collect_gc_twice(lua: &Lua) {
     lua.gc_collect().unwrap();
 }
 
-fn create_table(c: &mut Criterion) {
+fn table_create_empty(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("create [table empty]", |b| {
+    c.bench_function("table [create empty]", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
@@ -24,71 +26,55 @@ fn create_table(c: &mut Criterion) {
     });
 }
 
-fn create_array(c: &mut Criterion) {
+fn table_create_array(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("create [array] 10", |b| {
+    c.bench_function("table [create array]", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                let table = lua.create_table().unwrap();
-                for i in 1..=10 {
-                    table.set(i, i).unwrap();
-                }
+                lua.create_sequence_from(1..=10).unwrap();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn create_string_table(c: &mut Criterion) {
+fn table_create_hash(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("create [table string] 10", |b| {
+    c.bench_function("table [create hash]", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                let table = lua.create_table().unwrap();
-                for &s in &["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"] {
-                    let s = lua.create_string(s).unwrap();
-                    table.set(s.clone(), s).unwrap();
-                }
+                lua.create_table_from(
+                    ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"]
+                        .into_iter()
+                        .map(|s| (s, s)),
+                )
+                .unwrap();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn create_function(c: &mut Criterion) {
+fn table_get_set(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("create [function] 10", |b| {
+    c.bench_function("table [get and set]", |b| {
         b.iter_batched(
-            || collect_gc_twice(&lua),
-            |_| {
-                for i in 0..10 {
-                    lua.create_function(move |_, ()| Ok(i)).unwrap();
-                }
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn call_lua_function(c: &mut Criterion) {
-    let lua = Lua::new();
-
-    c.bench_function("call Lua function [sum] 3 10", |b| {
-        b.iter_batched_ref(
             || {
                 collect_gc_twice(&lua);
-                lua.load("function(a, b, c) return a + b + c end")
-                    .eval::<LuaFunction>()
-                    .unwrap()
+                lua.create_table().unwrap()
             },
-            |function| {
-                for i in 0..10 {
-                    let _result: i64 = function.call((i, i + 1, i + 2)).unwrap();
+            |table| {
+                for (i, s) in ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"]
+                    .into_iter()
+                    .enumerate()
+                {
+                    table.raw_set(s, i).unwrap();
+                    assert_eq!(table.raw_get::<_, usize>(s).unwrap(), i);
                 }
             },
             BatchSize::SmallInput,
@@ -96,170 +82,318 @@ fn call_lua_function(c: &mut Criterion) {
     });
 }
 
-fn call_sum_callback(c: &mut Criterion) {
+fn table_traversal_pairs(c: &mut Criterion) {
     let lua = Lua::new();
-    let callback = lua
-        .create_function(|_, (a, b, c): (i64, i64, i64)| Ok(a + b + c))
+
+    c.bench_function("table [traversal pairs]", |b| {
+        b.iter_batched(
+            || lua.globals(),
+            |globals| {
+                for kv in globals.pairs::<String, LuaValue>() {
+                    let (_k, _v) = kv.unwrap();
+                }
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn table_traversal_for_each(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    c.bench_function("table [traversal for_each]", |b| {
+        b.iter_batched(
+            || lua.globals(),
+            |globals| globals.for_each::<String, LuaValue>(|_k, _v| Ok(())),
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn table_traversal_sequence(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    let table = lua.create_sequence_from(1..1000).unwrap();
+
+    c.bench_function("table [traversal sequence]", |b| {
+        b.iter_batched(
+            || table.clone(),
+            |table| {
+                for v in table.sequence_values::<i32>() {
+                    let _i = v.unwrap();
+                }
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn function_create(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    c.bench_function("function [create Rust]", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                lua.create_function(|_, ()| Ok(123)).unwrap();
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn function_call_sum(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    let sum = lua
+        .create_function(|_, (a, b, c): (i64, i64, i64)| Ok(a + b - c))
         .unwrap();
-    lua.globals().set("callback", callback).unwrap();
 
-    c.bench_function("call Rust callback [sum] 3 10", |b| {
-        b.iter_batched_ref(
-            || {
-                collect_gc_twice(&lua);
-                lua.load("function() for i = 1,10 do callback(i, i+1, i+2) end end")
-                    .eval::<LuaFunction>()
-                    .unwrap()
-            },
-            |function| {
-                function.call::<_, ()>(()).unwrap();
+    c.bench_function("function [call Rust sum]", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                assert_eq!(sum.call::<_, i64>((10, 20, 30)).unwrap(), 0);
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn call_async_sum_callback(c: &mut Criterion) {
-    let options = LuaOptions::new().thread_cache_size(1024);
-    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
-    let callback = lua
-        .create_async_function(|_, (a, b, c): (i64, i64, i64)| async move {
-            task::yield_now().await;
-            Ok(a + b + c)
-        })
-        .unwrap();
-    lua.globals().set("callback", callback).unwrap();
-
-    c.bench_function("call async Rust callback [sum] 3 10", |b| {
-        let rt = Runtime::new().unwrap();
-        b.to_async(rt).iter_batched(
-            || {
-                collect_gc_twice(&lua);
-                lua.load("function() for i = 1,10 do callback(i, i+1, i+2) end end")
-                    .eval::<LuaFunction>()
-                    .unwrap()
-            },
-            |function| async move {
-                function.call_async::<_, ()>(()).await.unwrap();
-            },
-            BatchSize::SmallInput,
-        );
-    });
-}
-
-fn call_concat_callback(c: &mut Criterion) {
+fn function_call_lua_sum(c: &mut Criterion) {
     let lua = Lua::new();
-    let callback = lua
+
+    let sum = lua
+        .load("function(a, b, c) return a + b - c end")
+        .eval::<LuaFunction>()
+        .unwrap();
+
+    c.bench_function("function [call Lua sum]", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                assert_eq!(sum.call::<_, i64>((10, 20, 30)).unwrap(), 0);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn function_call_concat(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    let concat = lua
         .create_function(|_, (a, b): (LuaString, LuaString)| {
             Ok(format!("{}{}", a.to_str()?, b.to_str()?))
         })
         .unwrap();
-    lua.globals().set("callback", callback).unwrap();
+    let i = AtomicUsize::new(0);
 
-    c.bench_function("call Rust callback [concat string] 10", |b| {
-        b.iter_batched_ref(
+    c.bench_function("function [call Rust concat string]", |b| {
+        b.iter_batched(
             || {
                 collect_gc_twice(&lua);
-                lua.load("function() for i = 1,10 do callback('a', tostring(i)) end end")
-                    .eval::<LuaFunction>()
-                    .unwrap()
+                i.fetch_add(1, Ordering::Relaxed)
             },
-            |function| {
-                function.call::<_, ()>(()).unwrap();
+            |i| {
+                assert_eq!(
+                    concat.call::<_, LuaString>(("num:", i)).unwrap(),
+                    format!("num:{i}")
+                );
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn create_registry_values(c: &mut Criterion) {
+fn function_call_lua_concat(c: &mut Criterion) {
     let lua = Lua::new();
 
-    c.bench_function("create [registry value] 10", |b| {
+    let concat = lua
+        .load("function(a, b) return a..b end")
+        .eval::<LuaFunction>()
+        .unwrap();
+    let i = AtomicUsize::new(0);
+
+    c.bench_function("function [call Lua concat string]", |b| {
+        b.iter_batched(
+            || {
+                collect_gc_twice(&lua);
+                i.fetch_add(1, Ordering::Relaxed)
+            },
+            |i| {
+                assert_eq!(
+                    concat.call::<_, LuaString>(("num:", i)).unwrap(),
+                    format!("num:{i}")
+                );
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn function_async_call_sum(c: &mut Criterion) {
+    let options = LuaOptions::new().thread_pool_size(1024);
+    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
+
+    let sum = lua
+        .create_async_function(|_, (a, b, c): (i64, i64, i64)| async move {
+            task::yield_now().await;
+            Ok(a + b - c)
+        })
+        .unwrap();
+
+    c.bench_function("function [async call Rust sum]", |b| {
+        let rt = Runtime::new().unwrap();
+        b.to_async(rt).iter_batched(
+            || collect_gc_twice(&lua),
+            |_| async {
+                assert_eq!(sum.call_async::<_, i64>((10, 20, 30)).await.unwrap(), 0);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn registry_value_create(c: &mut Criterion) {
+    let lua = Lua::new();
+    lua.gc_stop();
+
+    c.bench_function("registry value [create]", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| lua.create_registry_value("hello").unwrap(),
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn registry_value_get(c: &mut Criterion) {
+    let lua = Lua::new();
+    lua.gc_stop();
+
+    let value = lua.create_registry_value("hello").unwrap();
+
+    c.bench_function("registry value [get]", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                for _ in 0..10 {
-                    lua.create_registry_value(lua.pack(true).unwrap()).unwrap();
-                }
-                lua.expire_registry_values();
+                assert_eq!(lua.registry_value::<LuaString>(&value).unwrap(), "hello");
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn create_userdata(c: &mut Criterion) {
-    struct UserData(i64);
+fn userdata_create(c: &mut Criterion) {
+    struct UserData(#[allow(unused)] i64);
     impl LuaUserData for UserData {}
 
     let lua = Lua::new();
 
-    c.bench_function("create [table userdata] 10", |b| {
+    c.bench_function("userdata [create]", |b| {
         b.iter_batched(
             || collect_gc_twice(&lua),
             |_| {
-                let table: LuaTable = lua.create_table().unwrap();
-                for i in 1..11 {
-                    table.set(i, UserData(i)).unwrap();
-                }
+                lua.create_userdata(UserData(123)).unwrap();
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn call_userdata_method(c: &mut Criterion) {
-    struct UserData(i64);
+fn userdata_call_index(c: &mut Criterion) {
+    struct UserData(#[allow(unused)] i64);
     impl LuaUserData for UserData {
         fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
-            methods.add_method("method", |_, this, ()| Ok(this.0));
+            methods.add_meta_method(LuaMetaMethod::Index, move |_, _, key: LuaString| Ok(key));
         }
     }
 
     let lua = Lua::new();
-    lua.globals().set("userdata", UserData(10)).unwrap();
+    let ud = lua.create_userdata(UserData(123)).unwrap();
+    let index = lua
+        .load("function(ud) return ud.test end")
+        .eval::<LuaFunction>()
+        .unwrap();
 
-    c.bench_function("call [userdata method] 10", |b| {
-        b.iter_batched_ref(
-            || {
-                collect_gc_twice(&lua);
-                lua.load("function() for i = 1,10 do userdata:method() end end")
-                    .eval::<LuaFunction>()
-                    .unwrap()
-            },
-            |function| {
-                function.call::<_, ()>(()).unwrap();
+    c.bench_function("userdata [call index]", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                assert_eq!(index.call::<_, LuaString>(&ud).unwrap(), "test");
             },
             BatchSize::SmallInput,
         );
     });
 }
 
-fn call_async_userdata_method(c: &mut Criterion) {
-    #[derive(Clone, Copy)]
+fn userdata_call_method(c: &mut Criterion) {
     struct UserData(i64);
     impl LuaUserData for UserData {
         fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
-            methods.add_async_method("method", |_, this, ()| async move { Ok(this.0) });
+            methods.add_method("add", |_, this, i: i64| Ok(this.0 + i));
         }
     }
 
-    let options = LuaOptions::new().thread_cache_size(1024);
-    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
-    lua.globals().set("userdata", UserData(10)).unwrap();
+    let lua = Lua::new();
+    let ud = lua.create_userdata(UserData(123)).unwrap();
+    let method = lua
+        .load("function(ud, i) return ud:add(i) end")
+        .eval::<LuaFunction>()
+        .unwrap();
+    let i = AtomicUsize::new(0);
 
-    c.bench_function("call async [userdata method] 10", |b| {
+    c.bench_function("userdata [call method]", |b| {
+        b.iter_batched(
+            || {
+                collect_gc_twice(&lua);
+                i.fetch_add(1, Ordering::Relaxed)
+            },
+            |i| {
+                assert_eq!(method.call::<_, usize>((&ud, i)).unwrap(), 123 + i);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn userdata_async_call_method(c: &mut Criterion) {
+    struct UserData(i64);
+    impl LuaUserData for UserData {
+        fn add_methods<'lua, M: LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
+            methods.add_async_method("add", |_, this, i: i64| async move {
+                task::yield_now().await;
+                Ok(this.0 + i)
+            });
+        }
+    }
+
+    let options = LuaOptions::new().thread_pool_size(1024);
+    let lua = Lua::new_with(LuaStdLib::ALL_SAFE, options).unwrap();
+    let ud = lua.create_userdata(UserData(123)).unwrap();
+    let method = lua
+        .load("function(ud, i) return ud:add(i) end")
+        .eval::<LuaFunction>()
+        .unwrap();
+    let i = AtomicUsize::new(0);
+
+    c.bench_function("userdata [async call method] 10", |b| {
         let rt = Runtime::new().unwrap();
         b.to_async(rt).iter_batched(
             || {
                 collect_gc_twice(&lua);
-                lua.load("function() for i = 1,10 do userdata:method() end end")
-                    .eval::<LuaFunction>()
-                    .unwrap()
+                (
+                    method.clone(),
+                    ud.clone(),
+                    i.fetch_add(1, Ordering::Relaxed),
+                )
             },
-            |function| async move {
-                function.call_async::<_, ()>(()).await.unwrap();
+            |(method, ud, i)| async move {
+                assert_eq!(
+                    method.call_async::<_, usize>((ud, i)).await.unwrap(),
+                    123 + i
+                );
             },
             BatchSize::SmallInput,
         );
@@ -269,22 +403,32 @@ fn call_async_userdata_method(c: &mut Criterion) {
 criterion_group! {
     name = benches;
     config = Criterion::default()
-        .sample_size(300)
+        .sample_size(500)
         .measurement_time(Duration::from_secs(10))
         .noise_threshold(0.02);
     targets =
-        create_table,
-        create_array,
-        create_string_table,
-        create_function,
-        call_lua_function,
-        call_sum_callback,
-        call_async_sum_callback,
-        call_concat_callback,
-        create_registry_values,
-        create_userdata,
-        call_userdata_method,
-        call_async_userdata_method,
+        table_create_empty,
+        table_create_array,
+        table_create_hash,
+        table_get_set,
+        table_traversal_pairs,
+        table_traversal_for_each,
+        table_traversal_sequence,
+
+        function_create,
+        function_call_sum,
+        function_call_lua_sum,
+        function_call_concat,
+        function_call_lua_concat,
+        function_async_call_sum,
+
+        registry_value_create,
+        registry_value_get,
+
+        userdata_create,
+        userdata_call_index,
+        userdata_call_method,
+        userdata_async_call_method,
 }
 
 criterion_main!(benches);

benches/serde.rs

@@ -0,0 +1,90 @@
+use std::time::Duration;
+
+use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
+
+use mlua::prelude::*;
+
+fn collect_gc_twice(lua: &Lua) {
+    lua.gc_collect().unwrap();
+    lua.gc_collect().unwrap();
+}
+
+fn encode_json(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    let encode = lua
+        .create_function(|_, t: LuaValue| Ok(serde_json::to_string(&t).unwrap()))
+        .unwrap();
+    let table = lua
+        .load(
+            r#"{
+        name = "Clark Kent",
+        address = {
+            city = "Smallville",
+            state = "Kansas",
+            country = "USA",
+        },
+        age = 22,
+        parents = {"Jonathan Kent", "Martha Kent"},
+        superman = true,
+        interests = {"flying", "saving the world", "kryptonite"},
+    }"#,
+        )
+        .eval::<LuaTable>()
+        .unwrap();
+
+    c.bench_function("serialize json", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                encode.call::<_, LuaString>(&table).unwrap();
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+fn decode_json(c: &mut Criterion) {
+    let lua = Lua::new();
+
+    let decode = lua
+        .create_function(|lua, s: String| {
+            lua.to_value(&serde_json::from_str::<serde_json::Value>(&s).unwrap())
+        })
+        .unwrap();
+    let json = r#"{
+        "name": "Clark Kent",
+        "address": {
+            "city": "Smallville",
+            "state": "Kansas",
+            "country": "USA"
+        },
+        "age": 22,
+        "parents": ["Jonathan Kent", "Martha Kent"],
+        "superman": true,
+        "interests": ["flying", "saving the world", "kryptonite"]
+    }"#;
+
+    c.bench_function("deserialize json", |b| {
+        b.iter_batched(
+            || collect_gc_twice(&lua),
+            |_| {
+                decode.call::<_, LuaTable>(json).unwrap();
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
+criterion_group! {
+    name = benches;
+    config = Criterion::default()
+        .sample_size(500)
+        .measurement_time(Duration::from_secs(10))
+        .noise_threshold(0.02);
+    targets =
+        encode_json,
+        decode_json,
+}
+
+criterion_main!(benches);

build/find_dummy.rs

@@ -1,5 +0,0 @@
-use std::path::PathBuf;
-
-pub fn probe_lua() -> PathBuf {
-    unreachable!()
-}

build/find_normal.rs

@@ -1,91 +0,0 @@
-use std::env;
-use std::ops::Bound;
-use std::path::PathBuf;
-
-fn get_env_var(name: &str) -> String {
-    match env::var(name) {
-        Ok(val) => val,
-        Err(env::VarError::NotPresent) => String::new(),
-        Err(err) => panic!("cannot get {}: {}", name, err),
-    }
-}
-
-pub fn probe_lua() -> Option<PathBuf> {
-    let include_dir = get_env_var("LUA_INC");
-    let lib_dir = get_env_var("LUA_LIB");
-    let lua_lib = get_env_var("LUA_LIB_NAME");
-
-    println!("cargo:rerun-if-env-changed=LUA_INC");
-    println!("cargo:rerun-if-env-changed=LUA_LIB");
-    println!("cargo:rerun-if-env-changed=LUA_LIB_NAME");
-    println!("cargo:rerun-if-env-changed=LUA_LINK");
-
-    let need_lua_lib = cfg!(any(not(feature = "module"), target_os = "windows"));
-
-    if !include_dir.is_empty() {
-        if need_lua_lib {
-            if lib_dir.is_empty() {
-                panic!("LUA_LIB is not set");
-            }
-            if lua_lib.is_empty() {
-                panic!("LUA_LIB_NAME is not set");
-            }
-
-            let mut link_lib = "";
-            if get_env_var("LUA_LINK") == "static" {
-                link_lib = "static=";
-            };
-            println!("cargo:rustc-link-search=native={}", lib_dir);
-            println!("cargo:rustc-link-lib={}{}", link_lib, lua_lib);
-        }
-        return Some(PathBuf::from(include_dir));
-    }
-
-    // Find using `pkg-config`
-
-    #[cfg(feature = "lua54")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.4", "5.5", "lua5.4", "5.4");
-    #[cfg(feature = "lua53")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.3", "5.4", "lua5.3", "5.3");
-    #[cfg(feature = "lua52")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.2", "5.3", "lua5.2", "5.2");
-    #[cfg(feature = "lua51")]
-    let (incl_bound, excl_bound, alt_probe, ver) = ("5.1", "5.2", "lua5.1", "5.1");
-
-    #[cfg(any(
-        feature = "lua54",
-        feature = "lua53",
-        feature = "lua52",
-        feature = "lua51"
-    ))]
-    {
-        let mut lua = pkg_config::Config::new()
-            .range_version((Bound::Included(incl_bound), Bound::Excluded(excl_bound)))
-            .cargo_metadata(need_lua_lib)
-            .probe("lua");
-
-        if lua.is_err() {
-            lua = pkg_config::Config::new()
-                .cargo_metadata(need_lua_lib)
-                .probe(alt_probe);
-        }
-
-        lua.expect(&format!("cannot find Lua {} using `pkg-config`", ver))
-            .include_paths
-            .get(0)
-            .cloned()
-    }
-
-    #[cfg(feature = "luajit")]
-    {
-        let lua = pkg_config::Config::new()
-            .range_version((Bound::Included("2.0.5"), Bound::Unbounded))
-            .cargo_metadata(need_lua_lib)
-            .probe("luajit");
-
-        lua.expect("cannot find LuaJIT using `pkg-config`")
-            .include_paths
-            .get(0)
-            .cloned()
-    }
-}

build/main.rs

@@ -1,258 +0,0 @@
-#![allow(unreachable_code)]
-
-use std::env;
-use std::fs::File;
-use std::io::{Error, ErrorKind, Result, Write};
-use std::path::{Path, PathBuf};
-use std::process::Command;
-
-#[cfg_attr(
-    all(
-        feature = "vendored",
-        any(
-            feature = "lua54",
-            feature = "lua53",
-            feature = "lua52",
-            feature = "lua51",
-            feature = "luajit"
-        )
-    ),
-    path = "find_vendored.rs"
-)]
-#[cfg_attr(
-    all(
-        not(feature = "vendored"),
-        any(
-            feature = "lua54",
-            feature = "lua53",
-            feature = "lua52",
-            feature = "lua51",
-            feature = "luajit"
-        )
-    ),
-    path = "find_normal.rs"
-)]
-#[cfg_attr(
-    not(any(
-        feature = "lua54",
-        feature = "lua53",
-        feature = "lua52",
-        feature = "lua51",
-        feature = "luajit"
-    )),
-    path = "find_dummy.rs"
-)]
-mod find;
-
-trait CommandExt {
-    fn execute(&mut self) -> Result<()>;
-}
-
-impl CommandExt for Command {
-    /// Execute the command and return an error if it exited with a failure status.
-    fn execute(&mut self) -> Result<()> {
-        self.status()
-            .and_then(|status| {
-                if status.success() {
-                    Ok(())
-                } else {
-                    Err(Error::new(ErrorKind::Other, "non-zero exit code"))
-                }
-            })
-            .map_err(|_| {
-                Error::new(
-                    ErrorKind::Other,
-                    format!("The command {:?} did not run successfully.", self),
-                )
-            })
-    }
-}
-
-// `include_path` is optional as Lua headers can be also found in compiler standard paths
-fn build_glue(include_path: Option<impl AsRef<Path>>) {
-    let build_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
-
-    let mut config = cc::Build::new();
-    if let Some(include_path) = include_path {
-        config.include(include_path.as_ref());
-    }
-
-    // Compile and run glue.c
-    let glue = build_dir.join("glue");
-
-    config
-        .get_compiler()
-        .to_command()
-        .arg("src/ffi/glue/glue.c")
-        .arg("-o")
-        .arg(&glue)
-        .execute()
-        .unwrap();
-
-    Command::new(glue)
-        .arg(build_dir.join("glue.rs"))
-        .execute()
-        .unwrap();
-}
-
-// When cross-compiling, we cannot use `build_glue` as we cannot run the generated
-// executable.  Instead, let's take a stab at synthesizing the likely values.
-// If you're cross-compiling and using a non-vendored library then there is a chance
-// that the values selected here may be incorrect, but we have no way to determine
-// that here.
-fn generate_glue() -> Result<()> {
-    let build_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());
-    let mut glue = File::create(build_dir.join("glue.rs"))?;
-    writeln!(
-        glue,
-        "/* This file was generated by build/main.rs; do not modify by hand */"
-    )?;
-    writeln!(glue, "use std::os::raw::*;")?;
-
-    writeln!(glue, "/* luaconf.h */")?;
-    let pointer_bit_width: usize = env::var("CARGO_CFG_TARGET_POINTER_WIDTH")
-        .unwrap()
-        .parse()
-        .unwrap();
-    writeln!(
-        glue,
-        "pub const LUA_EXTRASPACE: c_int = {} / 8;",
-        pointer_bit_width
-    )?;
-
-    // This is generally hardcoded to this size
-    writeln!(glue, "pub const LUA_IDSIZE: c_int = 60;")?;
-
-    // Unless the target is restricted, the defaults are 64 bit
-    writeln!(glue, "pub type LUA_NUMBER = c_double;")?;
-    writeln!(glue, "pub type LUA_INTEGER = i64;")?;
-    writeln!(glue, "pub type LUA_UNSIGNED = u64;")?;
-
-    writeln!(glue, "/* lua.h */")?;
-    let version = if cfg!(any(feature = "luajit", feature = "lua51")) {
-        (5, 1, 0)
-    } else if cfg!(feature = "lua52") {
-        (5, 2, 0)
-    } else if cfg!(feature = "lua53") {
-        (5, 3, 0)
-    } else if cfg!(feature = "lua54") {
-        (5, 4, 0)
-    } else {
-        unreachable!();
-    };
-    writeln!(
-        glue,
-        "pub const LUA_VERSION_NUM: c_int = {};",
-        (version.0 * 100) + version.1
-    )?;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    writeln!(
-        glue,
-        "pub const LUA_REGISTRYINDEX: c_int = -{} - 1000;",
-        if pointer_bit_width >= 32 {
-            1_000_000
-        } else {
-            15_000
-        }
-    )?;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    writeln!(glue, "pub const LUA_REGISTRYINDEX: c_int = -10000;")?;
-
-    // These two are only defined in lua 5.1
-    writeln!(glue, "pub const LUA_ENVIRONINDEX: c_int = -10001;")?;
-    writeln!(glue, "pub const LUA_GLOBALSINDEX: c_int = -10002;")?;
-
-    writeln!(glue, "/* lauxlib.h */")?;
-    // This is only defined in lua 5.3 and up, but we can always generate its value here,
-    // even if we don't use it.
-    // This matches the default definition in lauxlib.h
-    writeln!(glue, "pub const LUAL_NUMSIZES: c_int = std::mem::size_of::<LUA_INTEGER>() as c_int * 16 + std::mem::size_of::<LUA_NUMBER>() as c_int;")?;
-
-    writeln!(glue, "/* lualib.h */")?;
-    write!(
-        glue,
-        r#"
-#[cfg(feature = "luajit")]
-pub const LUA_BITLIBNAME: &str = "bit";
-#[cfg(not(feature = "luajit"))]
-pub const LUA_BITLIBNAME: &str = "bit32";
-
-pub const LUA_COLIBNAME: &str = "coroutine";
-pub const LUA_DBLIBNAME: &str = "debug";
-pub const LUA_IOLIBNAME: &str = "io";
-pub const LUA_LOADLIBNAME: &str = "package";
-pub const LUA_MATHLIBNAME: &str = "math";
-pub const LUA_OSLIBNAME: &str = "os";
-pub const LUA_STRLIBNAME: &str = "string";
-pub const LUA_TABLIBNAME: &str = "table";
-pub const LUA_UTF8LIBNAME: &str = "utf8";
-
-pub const LUA_JITLIBNAME: &str = "jit";
-pub const LUA_FFILIBNAME: &str = "ffi";
-"#
-    )?;
-
-    Ok(())
-}
-
-fn main() {
-    #[cfg(not(any(
-        feature = "lua54",
-        feature = "lua53",
-        feature = "lua52",
-        feature = "lua51",
-        feature = "luajit"
-    )))]
-    compile_error!(
-        "You must enable one of the features: lua54, lua53, lua52, lua51, luajit, luajit52"
-    );
-
-    #[cfg(all(
-        feature = "lua54",
-        any(
-            feature = "lua53",
-            feature = "lua52",
-            feature = "lua51",
-            feature = "luajit"
-        )
-    ))]
-    compile_error!(
-        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52"
-    );
-
-    #[cfg(all(
-        feature = "lua53",
-        any(feature = "lua52", feature = "lua51", feature = "luajit")
-    ))]
-    compile_error!(
-        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52"
-    );
-
-    #[cfg(all(feature = "lua52", any(feature = "lua51", feature = "luajit")))]
-    compile_error!(
-        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52"
-    );
-
-    #[cfg(all(feature = "lua51", feature = "luajit"))]
-    compile_error!(
-        "You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52"
-    );
-
-    // We don't support "vendored module" mode on windows
-    #[cfg(all(feature = "vendored", feature = "module", target_os = "windows"))]
-    compile_error!(
-        "Vendored (static) builds are not supported for modules on Windows.\n"
-            + "Please, use `pkg-config` or custom mode to link to a Lua dll."
-    );
-
-    if env::var("TARGET").unwrap() != env::var("HOST").unwrap() {
-        generate_glue().unwrap();
-    } else {
-        let include_dir = find::probe_lua();
-        build_glue(include_dir);
-        println!("cargo:rerun-if-changed=src/ffi/glue/glue.c");
-    }
-
-    println!("cargo:rerun-if-changed=build");
-}

docs/release_notes/v0.9.md

@@ -0,0 +1,361 @@
+## mlua v0.9 release notes
+
+The v0.9 version of mlua is a major release that includes a number of API changes and improvements. This release is a stepping stone towards the v1.0.
+This document highlights the most important changes. For a full list of changes, see the [CHANGELOG].
+
+[CHANGELOG]: https://github.com/khvzak/mlua/blob/master/CHANGELOG.md
+
+### New features
+
+#### 1. New Any UserData API
+
+This is a long awaited feature that allows to register in Lua foreign types that cannot implement `UserData` trait because of the Rust orphan rules.
+
+Now you can register any type that implements [`Any`] trait as a userdata type.
+
+Consider the following example:
+
+```rust
+lua.register_userdata_type::<std::string::String>(|reg| {
+    reg.add_method("len", |_, this, ()| Ok(this.len()));
+
+    reg.add_method_mut("push", |_, this, s: String| {
+        this.push_str(&s);
+        Ok(())
+    });
+
+    reg.add_meta_method(MetaMethod::ToString, |lua, this, ()| lua.create_string(this));
+})?;
+
+let s = lua.create_any_userdata("hello".to_string())?;
+lua.load(chunk! {
+    print("s:len() is " .. $s:len())
+    $s:push(" world")
+    // Prints: hello, world
+    print($s)
+})
+.exec()?;
+```
+
+In this example we registered [`std::string::String`] as a userdata type with a set of methods and then created an instance of this type in Lua.
+
+It's _not_ required to register a type before using the `Lua::create_any_userdata()` method, instead an empty metatable will be created for you.
+You can also register the same type multiple times with different methods. Any previously created instances will share the old metatable, while new instances will have the new one.
+
+The new set of API is called `any_userdata` because it allows to register types that implements [`Any`] trait.
+
+[`std::string::String`]: https://doc.rust-lang.org/stable/std/string/struct.String.html
+[`Any`]: https://doc.rust-lang.org/stable/std/any/trait.Any.html
+
+#### 2. Scope support for the new any userdata types
+
+When you need to create non-static userdata instances in Lua, the usual way is use `Lua::scope()` helper to make them scoped. When out of scope, any scoped objects will be automatically
+dropped. The only downside of this approach is that every new instance will have a new metatable. This is not very fast if you need to create a lot of instances.
+
+With the new Any UserData API, you can place non-static references `&T` where `T: 'static` into a scope and they will share a single static metatable.
+
+```rust
+lua.register_userdata_type::<std::string::String>(|reg| {
+    reg.add_method_mut("replace", |_, this, (pat, to): (String, String)| {
+        *this = this.replace(&pat, &to);
+        Ok(())
+    });
+
+    reg.add_meta_method(MetaMethod::ToString, |lua, this, ()| lua.create_string(this));
+})?;
+
+let mut s = "hello, world".to_string();
+
+lua.scope(|scope| {
+    // This userdata instance holds only a mutable reference to our string
+    let ud = scope.create_any_userdata_ref_mut(&mut s)?;
+    lua.load(chunk! {
+        $ud:replace("world", "user")
+    })
+    .exec()
+})?;
+
+// Prints: hello, user!
+println!("{s}!");
+```
+
+#### 3. Owned types (`unstable`)
+
+One of the common questions was how to embed a Lua type into Rust struct to use it later. It was non-trivial to do because of the `'lua` lifetime attached to every Lua value.
+
+In v0.9 mlua introduces "owned" types `OwnedTable`/`OwnedFunction`/`OwnedString`/`OwnedAnyUserData`/ `OwnedThread`that are `'static` (no lifetime attached).
+
+```rust
+let lua = Lua::new();
+
+struct MyStruct {
+    table: OwnedTable,
+    func: OwnedFunction,
+}
+
+let my_struct = MyStruct {
+    table: lua.globals().into_owned(),
+    func: lua
+        .create_function(|_, t: Table| Ok(format!("{t:#?}")))?
+        .into_owned(),
+};
+
+// It's safe to drop Lua!
+drop(lua);
+
+let result = my_struct.func.call::<_, String>(my_struct.table)?;
+println!("{result}");
+```
+
+Prior to v0.9, it was possible to do by creating a reference to the Lua value in registry using `Lua::create_registry_value()`
+and retrieving value later using `Lua::registry_value()` method.
+
+All owned handles hold a *strong* reference to the current Lua instance.
+Be warned, if you place them into a Lua type (eg. `UserData` or a Rust callback), it is *very easy*
+to accidentally cause reference cycles that would prevent destroying Lua instance.
+
+Please note this functionality is available under the `unstable` feature flag and not available when the `send` feature is enabled.
+
+#### New ffi module
+
+In v0.9 release the internal `ffi` module has been moved into the new [`mlua-sys`] crate and became available for public use.
+This crate provides unified Lua FFI API (targeting Lua 5.4) using a (limited) compatibility layer for older versions.
+
+mlua re-exports the `ffi` module aliasing the `mlua-sys` crate and provides (unsafe) functionality to work with raw Lua state:
+
+```rust
+unsafe {
+    unsafe extern "C-unwind" fn lua_add(state: *mut mlua::lua_State) -> i32 {
+        let a = mlua::ffi::luaL_checkinteger(state, 1);
+        let b = mlua::ffi::luaL_checkinteger(state, 2);
+        mlua::ffi::lua_pushinteger(state, a + b);
+        1
+    }
+
+    let add = lua.create_c_function(lua_add)?;
+    assert_eq!(add.call::<_, i32>((2, 3))?, 5);
+}
+```
+
+[`mlua-sys`]: https://crates.io/crates/mlua-sys
+
+#### Luau JIT support
+
+mlua brings support for the new [Luau] JIT backend under the `luau-jit` feature flag.
+
+It will automatically trigger JIT compilation for new Lua chunks. To disable it, just call `lua.enable_jit(false)` before loading Lua code
+(but any previously compiled chunks will remain JIT-compiled).
+
+[Luau]: https://luau-lang.org
+
+### Improvements
+
+#### 1. Better error reporting
+
+When calling a Rust function from Lua and passing wrong arguments, previous mlua versions reported a error message without any context or reference to the particular argument.
+
+In v0.9 it reports a error message with the argument index and expected type:
+
+```rust
+let func = lua.create_function(|_, _a: i32| Ok(()))?;
+lua.load(chunk! {
+    local ok, err = pcall($func, "not a number")
+    // Prints: bad argument #1: error converting Lua string to i32 (expected number or string coercible to number)
+    print(err)
+})
+.exec()?;
+```
+
+Similar changes have been made for userdata functions and methods:
+
+```rust
+lua.register_userdata_type::<&'static str>(|reg| {
+    reg.add_method("len", |_, this, ()| Ok(this.len()));
+})?;
+
+let s = lua.create_any_userdata("hello")?;
+lua.load(chunk! {
+    local ok, err = pcall($s.len, 123)
+    // Prints: bad argument `self` to `&str.len`: error converting Lua integer to userdata
+    print(err)
+})
+.exec()?;
+```
+
+#### 2. Error context
+
+Similar to the [`anyhow`] Error type, now it's possible to attach context to Lua errors:
+
+```rust
+let read = lua.create_function(|lua, path: String| {
+    let bytes = std::fs::read(&path)
+        .into_lua_err()
+        .context(format!("Failed to open `{path}`"))?;
+    Ok(lua.create_string(bytes))
+})?;
+
+lua.load(chunk! {
+    local ok, err = pcall($read, "/nonexistent")
+    /// Prints:
+    /// Failed to open /nonexistent
+    /// No such file or directory (os error 2)
+    /// stack traceback:
+    /// ...
+    print(err)
+})
+.exec()?;
+```
+
+[`anyhow`]: https://crates.io/crates/anyhow
+
+#### 4. New methods `Function::wrap`/`AnyUserData::wrap`
+
+Sometimes it's useful to have `IntoLua` trait implementation for a Rust function or type `T: Any` without needing to call `Lua::create_function()`/`Lua::create_any_userdata()` methods.
+Since v0.9 you can call the new methods `Function::wrap()`/`AnyUserData::wrap()` that allows to do this. They return an abstract type that `impl IntoLua`:
+
+```rust
+lua.globals().set("print_rust", Function::wrap(|_, s: String| Ok(println!("{}", s))))?;
+lua.globals().set("rust_ud", AnyUserData::wrap("hello"))?;
+```
+
+In addition there are also `Function::wrap_mut()`/`Function::wrap_async()` methods that allow to wrap mutable and async functions respectively.
+
+For a `T: 'UserData + 'static` the `IntoLua` trait is still always implemented.
+
+#### `UserDataRef` and `UserDataRefMut` type wrappers
+
+The new wrappers `UserDataRef` and `UserDataRefMut` are receivers for userdata type `T` and borrow underlying instance for the lifetime of the wrapper.
+
+```rust
+lua.globals()
+    .set("ud", AnyUserData::wrap("hello".to_string()))?;
+
+let mut ud_mut: UserDataRefMut<String> = lua.globals().get("ud")?;
+ud_mut.push_str(", Rust");
+drop(ud_mut);
+
+let ud_ref: UserDataRef<String> = lua.globals().get("ud")?;
+// Prints: hello, Rust
+println!("{}", *ud_ref);
+```
+
+In the previous mlua versions the same functionality can be achieved by receiving `AnyUserData` and calling `AnyUserData::borrow()`/`AnyUserData::borrow_mut()` methods.
+
+The new wrappers are identical to Rust [`Ref`]/[`RefMut`] types.
+
+[`Ref`]: https://doc.rust-lang.org/std/cell/struct.Ref.html
+[`RefMut`]: https://doc.rust-lang.org/std/cell/struct.RefMut.html
+
+#### New `AnyUserDataExt` trait
+
+Similar to the `TableExt` trait, the `AnyUserDataExt` provides a set of extra methods for the `AnyUserData` type.
+
+1) `AnyUserDataExt::get()/set()` to get/set a value by key from the userdata, assuming it has `__index` metamethod.
+
+2) `AnyUserDataExt::call()` to call the userdata as a function assuming it has `__call` metamethod.
+
+3) `AnyUserData::call_method(name, ...)` to call the userdata method, assuming it has `__index` metamethod and the associated function.
+
+#### Pretty formatting Lua values
+
+`mlua::Value` implements a new format `:#?` that allows to (recursively) pretty print Lua values:
+
+```rust
+println!("{:#?}", lua.globals());
+```
+
+Prints:
+```
+{
+  ["_G"] = table: 0x7fa2d0706260,
+  ["_VERSION"] = "Lua 5.4",
+  ["assert"] = function: 0x10451d11d,
+  ["collectgarbage"] = function: 0x10451d198,
+  ["coroutine"] = {
+    ["close"] = function: 0x10451e28f,
+    ...
+  },
+  ["dofile"] = function: 0x10451d37c,
+  ...
+}
+```
+
+In addition a new method `Value::to_string()` has been added to convert `Value` to a string (using `__tostring` metamethod if available).
+
+#### Environment for Lua functions
+
+Any Lua functions have an associated environment table that is used to resolve global variables. By default it sets to a Lua globals table.
+
+In the new release it's possible to get or update a function environment using `Function::environment()` or `Function::set_environment()` methods respectively.
+
+```rust
+let f = lua.load("return a").into_function()?;
+
+assert_eq!(f.environment(), Some(lua.globals()));
+
+lua.globals().set("a", 1)?;
+assert_eq!(f.call::<_, i32>(())?, 1);
+
+f.set_environment(lua.create_table_from([("a", "hello")])?)?;
+assert_eq!(f.call::<_, mlua::String>(())?, "hello");
+```
+
+#### Performance optimizations
+
+The new mlua version has a number of performance improvements. Please check the [benchmarks results] to see how mlua compares to rlua and rhai.
+
+[benchmarks results]: https://github.com/khvzak/script-bench-rs
+
+### Changes in `module` mode
+
+#### New attributes
+
+The `lua_module` macro now support the following attributes:
+
+- `name=...` - sets name of the module (defaults to the name of the function).
+
+Eg.:
+
+```rust
+#[mlua::lua_module(name = "alt_module")]
+fn my_module(lua: &Lua) -> LuaResult<LuaTable> {
+    lua.create_table()
+}
+```
+
+Under the hood a new function `luaopen_alt_module` will be created for the Lua module loader.
+
+- `skip_memory_check` - skip memory allocation checks for some operations.
+
+In module mode, mlua runs in unknown environment and cannot say are there any memory limits or not. As result, some operations that require memory allocation runs in
+protected mode. Setting this attribute will improve performance of such operations with risk of having uncaught exceptions and memory leaks.
+
+#### Improved Windows target
+
+In previous mlua versions, building a Lua module for Windows requires having Lua development libraries installed on the system.
+In contrast, on Linux and macOS, modules can be built without any external dependencies using the `-undefined=dynamic_lookup` linker flag.
+
+With Rust 1.71+ it's now possible to lift this restriction for Windows as well. You can build modules normally and they will be linked with
+`lua54.dll`/`lua53.dll`/`lua52.dll`/`lua51.dll` depending on the enabled Lua version.
+
+You still need to have the dll although, linked to application where the module will be loaded.
+
+### Breaking changes
+
+1) `ToLua`/`ToLuaMulti` traits have been renamed to `IntoLua`/`IntoLuaMulti` respectively (with the methods called `into_lua`/`into_lua_multi`).
+
+The main reason for this change is following the Rust self [convention](https://rust-lang.github.io/rust-clippy/master/index.html#/wrong_self_convention).
+
+2) Removed `FromLua` implementation for `T: UserData + Clone`.
+
+During the usage of mlua, it was found that this implementation is not very useful and prevents custom `FromLua` implementations for `T: UserData`.
+It should be a developer decision to opt-in `FromLua` for their `T` if needed rather than having enabled it unconditionally.
+
+To opt-in `FromLua` for `T: Clone` you can use a simple `#[derive(FromLua)]` macro (requires `feature = "macros"`):
+
+```rust
+#[derive(Clone, Copy, mlua::FromLua)]
+struct MyUserData(i32);
+```
+
+`T` is not required to implement `UserData` because of the new relaxed restrictions on userdata types.

examples/async_http_client.rs

@@ -1,33 +1,36 @@
 use std::collections::HashMap;
 
-use hyper::body::{Body as HyperBody, HttpBody as _};
-use hyper::Client as HyperClient;
+use http_body_util::BodyExt as _;
+use hyper::body::Incoming;
+use hyper_util::client::legacy::Client as HyperClient;
+use hyper_util::rt::TokioExecutor;
 
-use mlua::{chunk, AnyUserData, ExternalResult, Lua, Result, UserData, UserDataMethods};
+use mlua::{chunk, ExternalResult, Lua, Result, UserData, UserDataMethods};
 
-struct BodyReader(HyperBody);
+struct BodyReader(Incoming);
 
 impl UserData for BodyReader {
     fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-        methods.add_async_function("read", |lua, reader: AnyUserData| async move {
-            let mut reader = reader.borrow_mut::<Self>()?;
-            if let Some(bytes) = reader.0.data().await {
-                let bytes = bytes.to_lua_err()?;
-                return Some(lua.create_string(&bytes)).transpose();
+        // Every call returns a next chunk
+        methods.add_async_method_mut("read", |lua, reader, ()| async move {
+            if let Some(bytes) = reader.0.frame().await {
+                if let Some(bytes) = bytes.into_lua_err()?.data_ref() {
+                    return Some(lua.create_string(&bytes)).transpose();
+                }
             }
             Ok(None)
         });
     }
 }
 
-#[tokio::main]
+#[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<()> {
     let lua = Lua::new();
 
     let fetch_url = lua.create_async_function(|lua, uri: String| async move {
-        let client = HyperClient::new();
-        let uri = uri.parse().to_lua_err()?;
-        let resp = client.get(uri).await.to_lua_err()?;
+        let client = HyperClient::builder(TokioExecutor::new()).build_http::<String>();
+        let uri = uri.parse().into_lua_err()?;
+        let resp = client.get(uri).await.into_lua_err()?;
 
         let lua_resp = lua.create_table()?;
         lua_resp.set("status", resp.status().as_u16())?;
@@ -37,7 +40,7 @@ async fn main() -> Result<()> {
             headers
                 .entry(key.as_str())
                 .or_insert(Vec::new())
-                .push(value.to_str().to_lua_err()?);
+                .push(value.to_str().into_lua_err()?);
         }
 
         lua_resp.set("headers", headers)?;
@@ -56,11 +59,11 @@ async fn main() -> Result<()> {
                 end
             end
             repeat
-                local body = res.body:read()
-                if body then
-                    print(body)
+                local chunk = res.body:read()
+                if chunk then
+                    print(chunk)
                 end
-            until not body
+            until not chunk
         })
         .into_function()?;
 

examples/async_http_reqwest.rs

@@ -1,33 +1,27 @@
-use mlua::{chunk, ExternalResult, Lua, LuaSerdeExt, Result};
+use mlua::{chunk, ExternalResult, Lua, LuaSerdeExt, Result, Value};
 
-#[tokio::main]
+#[tokio::main(flavor = "current_thread")]
 async fn main() -> Result<()> {
     let lua = Lua::new();
 
-    let null = lua.null();
-
     let fetch_json = lua.create_async_function(|lua, uri: String| async move {
         let resp = reqwest::get(&uri)
             .await
             .and_then(|resp| resp.error_for_status())
-            .to_lua_err()?;
-        let json = resp.json::<serde_json::Value>().await.to_lua_err()?;
+            .into_lua_err()?;
+        let json = resp.json::<serde_json::Value>().await.into_lua_err()?;
         lua.to_value(&json)
     })?;
 
+    let dbg = lua.create_function(|_, value: Value| {
+        println!("{value:#?}");
+        Ok(())
+    })?;
+
     let f = lua
         .load(chunk! {
-            function print_r(t, indent)
-                local indent = indent or ""
-                for k, v in pairs(t) do
-                    io.write(indent, tostring(k))
-                    if type(v) == "table" then io.write(":\n") print_r(v, indent.."  ")
-                    else io.write(": ", v == $null and "null" or tostring(v), "\n") end
-                end
-            end
-
             local res = $fetch_json(...)
-            print_r(res)
+            $dbg(res)
         })
         .into_function()?;
 

examples/async_http_server.rs

@@ -1,43 +1,63 @@
+use std::convert::Infallible;
 use std::future::Future;
 use std::net::SocketAddr;
-use std::pin::Pin;
 use std::rc::Rc;
-use std::task::{Context, Poll};
 
-use hyper::server::conn::AddrStream;
-use hyper::service::Service;
-use hyper::{Body, Request, Response, Server};
+use futures::future::LocalBoxFuture;
+use http_body_util::{combinators::BoxBody, BodyExt as _, Empty, Full};
+use hyper::body::{Bytes, Incoming};
+use hyper::{Request, Response};
+use hyper_util::rt::TokioIo;
+use hyper_util::server::conn::auto::Builder as ServerConnBuilder;
+use tokio::net::TcpListener;
+use tokio::task::LocalSet;
 
 use mlua::{
-    chunk, Error as LuaError, Function, Lua, String as LuaString, Table, UserData, UserDataMethods,
+    chunk, Error as LuaError, Function, Lua, RegistryKey, String as LuaString, Table, UserData,
+    UserDataMethods,
 };
 
-struct LuaRequest(SocketAddr, Request<Body>);
+/// Wrapper around incoming request that implements UserData
+struct LuaRequest(SocketAddr, Request<Incoming>);
 
 impl UserData for LuaRequest {
     fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-        methods.add_method("remote_addr", |_lua, req, ()| Ok((req.0).to_string()));
-        methods.add_method("method", |_lua, req, ()| Ok((req.1).method().to_string()));
+        methods.add_method("remote_addr", |_, req, ()| Ok((req.0).to_string()));
+        methods.add_method("method", |_, req, ()| Ok((req.1).method().to_string()));
+        methods.add_method("path", |_, req, ()| Ok(req.1.uri().path().to_string()));
     }
 }
 
-pub struct Svc(Rc<Lua>, SocketAddr);
+/// Service that handles incoming requests
+#[derive(Clone)]
+pub struct Svc {
+    lua: Rc<Lua>,
+    handler: Rc<RegistryKey>,
+    peer_addr: SocketAddr,
+}
 
-impl Service<Request<Body>> for Svc {
-    type Response = Response<Body>;
-    type Error = LuaError;
-    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;
-
-    fn poll_ready(&mut self, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
+impl Svc {
+    pub fn new(lua: Rc<Lua>, handler: Rc<RegistryKey>, peer_addr: SocketAddr) -> Self {
+        Self {
+            lua,
+            handler,
+            peer_addr,
+        }
     }
+}
 
-    fn call(&mut self, req: Request<Body>) -> Self::Future {
+impl hyper::service::Service<Request<Incoming>> for Svc {
+    type Response = Response<BoxBody<Bytes, Infallible>>;
+    type Error = LuaError;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
+
+    fn call(&self, req: Request<Incoming>) -> Self::Future {
         // If handler returns an error then generate 5xx response
-        let lua = self.0.clone();
-        let lua_req = LuaRequest(self.1, req);
+        let lua = self.lua.clone();
+        let handler_key = self.handler.clone();
+        let lua_req = LuaRequest(self.peer_addr, req);
         Box::pin(async move {
-            let handler: Function = lua.named_registry_value("http_handler")?;
+            let handler: Function = lua.registry_value(&handler_key)?;
             match handler.call_async::<_, Table>(lua_req).await {
                 Ok(lua_resp) => {
                     let status = lua_resp.get::<_, Option<u16>>("status")?.unwrap_or(200);
@@ -51,10 +71,11 @@ impl Service<Request<Body>> for Svc {
                         }
                     }
 
+                    // Set body
                     let body = lua_resp
                         .get::<_, Option<LuaString>>("body")?
-                        .map(|b| Body::from(b.as_bytes().to_vec()))
-                        .unwrap_or_else(Body::empty);
+                        .map(|b| Full::new(Bytes::copy_from_slice(b.as_bytes())).boxed())
+                        .unwrap_or_else(|| Empty::<Bytes>::new().boxed());
 
                     Ok(resp.body(body).unwrap())
                 }
@@ -62,7 +83,7 @@ impl Service<Request<Body>> for Svc {
                     eprintln!("{}", err);
                     Ok(Response::builder()
                         .status(500)
-                        .body(Body::from("Internal Server Error"))
+                        .body(Full::new(Bytes::from("Internal Server Error")).boxed())
                         .unwrap())
                 }
             }
@@ -75,13 +96,14 @@ async fn main() {
     let lua = Rc::new(Lua::new());
 
     // Create Lua handler function
-    let handler: Function = lua
+    let handler: RegistryKey = lua
         .load(chunk! {
             function(req)
                 return {
                     status = 200,
                     headers = {
                         ["X-Req-Method"] = req:method(),
+                        ["X-Req-Path"] = req:path(),
                         ["X-Remote-Addr"] = req:remote_addr(),
                     },
                     body = "Hello from Lua!\n"
@@ -89,37 +111,35 @@ async fn main() {
             end
         })
         .eval()
-        .expect("cannot create Lua handler");
+        .expect("Failed to create Lua handler");
+    let handler = Rc::new(handler);
 
-    // Store it in the Registry
-    lua.set_named_registry_value("http_handler", handler)
-        .expect("cannot store Lua handler");
+    let listen_addr = "127.0.0.1:3000";
+    let listener = TcpListener::bind(listen_addr).await.unwrap();
+    println!("Listening on http://{listen_addr}");
 
-    let addr = ([127, 0, 0, 1], 3000).into();
-    let server = Server::bind(&addr).executor(LocalExec).serve(MakeSvc(lua));
+    let local = LocalSet::new();
+    loop {
+        let (stream, peer_addr) = match listener.accept().await {
+            Ok(x) => x,
+            Err(err) => {
+                eprintln!("Failed to accept connection: {err}");
+                continue;
+            }
+        };
 
-    println!("Listening on http://{}", addr);
-
-    // Create `LocalSet` to spawn !Send futures
-    let local = tokio::task::LocalSet::new();
-    local.run_until(server).await.expect("cannot run server")
-}
-
-struct MakeSvc(Rc<Lua>);
-
-impl Service<&AddrStream> for MakeSvc {
-    type Response = Svc;
-    type Error = hyper::Error;
-    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;
-
-    fn poll_ready(&mut self, _: &mut Context) -> Poll<Result<(), Self::Error>> {
-        Poll::Ready(Ok(()))
-    }
-
-    fn call(&mut self, stream: &AddrStream) -> Self::Future {
-        let lua = self.0.clone();
-        let remote_addr = stream.remote_addr();
-        Box::pin(async move { Ok(Svc(lua, remote_addr)) })
+        let svc = Svc::new(lua.clone(), handler.clone(), peer_addr);
+        local
+            .run_until(async move {
+                let result = ServerConnBuilder::new(LocalExec)
+                    .http1()
+                    .serve_connection(TokioIo::new(stream), svc)
+                    .await;
+                if let Err(err) = result {
+                    eprintln!("Error serving connection: {err:?}");
+                }
+            })
+            .await;
     }
 }
 
@@ -128,7 +148,7 @@ struct LocalExec;
 
 impl<F> hyper::rt::Executor<F> for LocalExec
 where
-    F: std::future::Future + 'static, // not requiring `Send`
+    F: Future + 'static, // not requiring `Send`
 {
     fn execute(&self, fut: F) {
         tokio::task::spawn_local(fut);

examples/async_tcp_server.rs

@@ -6,9 +6,7 @@ use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::{TcpListener, TcpStream};
 use tokio::task;
 
-use mlua::{
-    chunk, AnyUserData, Function, Lua, RegistryKey, String as LuaString, UserData, UserDataMethods,
-};
+use mlua::{chunk, Function, Lua, RegistryKey, String as LuaString, UserData, UserDataMethods};
 
 struct LuaTcpStream(TcpStream);
 
@@ -18,28 +16,19 @@ impl UserData for LuaTcpStream {
             Ok(this.0.peer_addr()?.to_string())
         });
 
-        methods.add_async_function(
-            "read",
-            |lua, (this, size): (AnyUserData, usize)| async move {
-                let mut this = this.borrow_mut::<Self>()?;
-                let mut buf = vec![0; size];
-                let n = this.0.read(&mut buf).await?;
-                buf.truncate(n);
-                lua.create_string(&buf)
-            },
-        );
+        methods.add_async_method_mut("read", |lua, this, size| async move {
+            let mut buf = vec![0; size];
+            let n = this.0.read(&mut buf).await?;
+            buf.truncate(n);
+            lua.create_string(&buf)
+        });
 
-        methods.add_async_function(
-            "write",
-            |_, (this, data): (AnyUserData, LuaString)| async move {
-                let mut this = this.borrow_mut::<Self>()?;
-                let n = this.0.write(&data.as_bytes()).await?;
-                Ok(n)
-            },
-        );
+        methods.add_async_method_mut("write", |_, this, data: LuaString| async move {
+            let n = this.0.write(&data.as_bytes()).await?;
+            Ok(n)
+        });
 
-        methods.add_async_function("close", |_, this: AnyUserData| async move {
-            let mut this = this.borrow_mut::<Self>()?;
+        methods.add_async_method_mut("close", |_, this, ()| async move {
             this.0.shutdown().await?;
             Ok(())
         });

examples/guided_tour.rs

@@ -1,7 +1,9 @@
 use std::f32;
 use std::iter::FromIterator;
 
-use mlua::{chunk, Function, Lua, MetaMethod, Result, UserData, UserDataMethods, Variadic};
+use mlua::{
+    chunk, FromLua, Function, Lua, MetaMethod, Result, UserData, UserDataMethods, Value, Variadic,
+};
 
 fn main() -> Result<()> {
     // You can create a new Lua state with `Lua::new()`. This loads the default Lua std library
@@ -22,7 +24,7 @@ fn main() -> Result<()> {
 
     // You can load and evaluate Lua code. The returned type of `Lua::load` is a builder
     // that allows you to change settings before running Lua code. Here, we are using it to set
-    // the name of the laoded chunk to "example code", which will be used when Lua error
+    // the name of the loaded chunk to "example code", which will be used when Lua error
     // messages are printed.
 
     lua.load(
@@ -30,7 +32,7 @@ fn main() -> Result<()> {
             global = 'foo'..'bar'
         "#,
     )
-    .set_name("example code")?
+    .set_name("example code")
     .exec()?;
     assert_eq!(globals.get::<_, String>("global")?, "foobar");
 
@@ -87,7 +89,7 @@ fn main() -> Result<()> {
     let print: Function = globals.get("print")?;
     print.call::<_, ()>("hello from rust")?;
 
-    // This API generally handles variadics using tuples. This is one way to call a function with
+    // This API generally handles variadic using tuples. This is one way to call a function with
     // multiple parameters:
 
     print.call::<_, ()>(("hello", "again", "from", "rust"))?;
@@ -98,7 +100,7 @@ fn main() -> Result<()> {
         ["hello", "yet", "again", "from", "rust"].iter().cloned(),
     ))?;
 
-    // You can bind rust functions to Lua as well. Callbacks receive the Lua state inself as their
+    // You can bind rust functions to Lua as well. Callbacks receive the Lua state itself as their
     // first parameter, and the arguments given to the function as the second parameter. The type
     // of the arguments can be anything that is convertible from the parameters given by Lua, in
     // this case, the function expects two string sequences.
@@ -151,6 +153,16 @@ fn main() -> Result<()> {
     #[derive(Copy, Clone)]
     struct Vec2(f32, f32);
 
+    // We can implement `FromLua` trait for our `Vec2` to return a copy
+    impl<'lua> FromLua<'lua> for Vec2 {
+        fn from_lua(value: Value<'lua>, _: &'lua Lua) -> Result<Self> {
+            match value {
+                Value::UserData(ud) => Ok(*ud.borrow::<Self>()?),
+                _ => unreachable!(),
+            }
+        }
+    }
+
     impl UserData for Vec2 {
         fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
             methods.add_method("magnitude", |_, vec, ()| {

examples/module/Cargo.toml

@@ -2,18 +2,19 @@
 name = "rust_module"
 version = "0.0.0"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
-edition = "2018"
+edition = "2021"
 
 [lib]
 crate-type = ["cdylib"]
 
+[workspace]
+
 [features]
 lua54 = ["mlua/lua54"]
 lua53 = ["mlua/lua53"]
 lua52 = ["mlua/lua52"]
 lua51 = ["mlua/lua51"]
 luajit = ["mlua/luajit"]
-vendored = ["mlua/vendored"]
 
 [dependencies]
 mlua = { path = "../..", features = ["module"] }

examples/module/src/lib.rs

@@ -8,32 +8,10 @@ fn used_memory(lua: &Lua, _: ()) -> LuaResult<usize> {
     Ok(lua.used_memory())
 }
 
-fn check_userdata(_: &Lua, ud: MyUserData) -> LuaResult<i32> {
-    Ok(ud.0)
-}
-
 #[mlua::lua_module]
 fn rust_module(lua: &Lua) -> LuaResult<LuaTable> {
     let exports = lua.create_table()?;
     exports.set("sum", lua.create_function(sum)?)?;
     exports.set("used_memory", lua.create_function(used_memory)?)?;
-    exports.set("check_userdata", lua.create_function(check_userdata)?)?;
     Ok(exports)
 }
-
-#[derive(Clone, Copy)]
-struct MyUserData(i32);
-
-impl LuaUserData for MyUserData {}
-
-#[mlua::lua_module]
-fn rust_module_second(lua: &Lua) -> LuaResult<LuaTable> {
-    let exports = lua.create_table()?;
-    exports.set("userdata", lua.create_userdata(MyUserData(123))?)?;
-    Ok(exports)
-}
-
-#[mlua::lua_module]
-fn rust_module_error(_: &Lua) -> LuaResult<LuaTable> {
-    Err("custom module error".to_lua_err())
-}

examples/repl.rs

@@ -1,11 +1,11 @@
 //! This example shows a simple read-evaluate-print-loop (REPL).
 
 use mlua::{Error, Lua, MultiValue};
-use rustyline::Editor;
+use rustyline::DefaultEditor;
 
 fn main() {
     let lua = Lua::new();
-    let mut editor = Editor::<()>::new();
+    let mut editor = DefaultEditor::new().expect("Failed to create editor");
 
     loop {
         let mut prompt = "> ";
@@ -19,12 +19,12 @@ fn main() {
 
             match lua.load(&line).eval::<MultiValue>() {
                 Ok(values) => {
-                    editor.add_history_entry(line);
+                    editor.add_history_entry(line).unwrap();
                     println!(
                         "{}",
                         values
                             .iter()
-                            .map(|value| format!("{:?}", value))
+                            .map(|value| format!("{:#?}", value))
                             .collect::<Vec<_>>()
                             .join("\t")
                     );

mlua-sys/Cargo.toml

@@ -0,0 +1,46 @@
+[package]
+name = "mlua-sys"
+version = "0.6.1"
+authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
+rust-version = "1.71"
+edition = "2021"
+repository = "https://github.com/khvzak/mlua"
+documentation = "https://docs.rs/mlua-sys"
+readme = "README.md"
+categories = ["external-ffi-bindings"]
+license = "MIT"
+links = "lua"
+build = "build/main.rs"
+description = """
+Low level (FFI) bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox Luau
+"""
+
+[package.metadata.docs.rs]
+features = ["lua54", "vendored"]
+rustdoc-args = ["--cfg", "docsrs"]
+
+[features]
+lua54 = []
+lua53 = []
+lua52 = []
+lua51 = []
+luajit = []
+luajit52 = ["luajit"]
+luau = ["luau0-src"]
+luau-codegen = ["luau"]
+luau-vector4 = ["luau"]
+vendored = ["lua-src", "luajit-src"]
+module = []
+
+[dependencies]
+
+[build-dependencies]
+cc = "1.0"
+cfg-if = "1.0"
+pkg-config = "0.3.17"
+lua-src = { version = ">= 546.0.2, < 546.1.0", optional = true }
+luajit-src = { version = ">= 210.5.0, < 210.6.0", optional = true }
+luau0-src = { version = "0.10.0", optional = true }
+
+[lints.rust]
+unexpected_cfgs = { level = "allow", check-cfg = ['cfg(raw_dylib)'] }

mlua-sys/README.md

@@ -0,0 +1,8 @@
+# mlua-sys
+
+Low level (FFI) bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox [Luau].
+
+Intended to be consumed by the [mlua] crate.
+
+[Luau]: https://github.com/Roblox/luau
+[mlua]: https://crates.io/crates/mlua

mlua-sys/build/find_normal.rs

@@ -0,0 +1,58 @@
+#![allow(dead_code)]
+
+use std::env;
+use std::ops::Bound;
+
+pub fn probe_lua() {
+    let target_arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
+
+    if target_arch == "wasm32" && cfg!(not(feature = "vendored")) {
+        panic!("Please enable `vendored` feature to build for wasm32");
+    }
+
+    let lib_dir = env::var("LUA_LIB").unwrap_or_default();
+    let lua_lib = env::var("LUA_LIB_NAME").unwrap_or_default();
+
+    println!("cargo:rerun-if-env-changed=LUA_LIB");
+    println!("cargo:rerun-if-env-changed=LUA_LIB_NAME");
+    println!("cargo:rerun-if-env-changed=LUA_LINK");
+
+    if !lua_lib.is_empty() {
+        if !lib_dir.is_empty() {
+            println!("cargo:rustc-link-search=native={lib_dir}");
+        }
+        let mut link_lib = "";
+        if env::var("LUA_LINK").as_deref() == Ok("static") {
+            link_lib = "static=";
+        };
+        println!("cargo:rustc-link-lib={link_lib}{lua_lib}");
+        return;
+    }
+
+    // Find using `pkg-config`
+
+    #[cfg(feature = "lua54")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.4", "5.5", Some("lua5.4"), "5.4");
+    #[cfg(feature = "lua53")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.3", "5.4", Some("lua5.3"), "5.3");
+    #[cfg(feature = "lua52")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.2", "5.3", Some("lua5.2"), "5.2");
+    #[cfg(feature = "lua51")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("5.1", "5.2", Some("lua5.1"), "5.1");
+    #[cfg(feature = "luajit")]
+    let (incl_bound, excl_bound, alt_probe, ver) = ("2.0.4", "2.2", None, "JIT");
+
+    #[rustfmt::skip]
+    let mut lua = pkg_config::Config::new()
+        .range_version((Bound::Included(incl_bound), Bound::Excluded(excl_bound)))
+        .cargo_metadata(true)
+        .probe(if cfg!(feature = "luajit") { "luajit" } else { "lua" });
+
+    if lua.is_err() && alt_probe.is_some() {
+        lua = pkg_config::Config::new()
+            .cargo_metadata(true)
+            .probe(alt_probe.unwrap());
+    }
+
+    lua.unwrap_or_else(|err| panic!("cannot find Lua{ver} using `pkg-config`: {err}"));
+}

mlua-sys/build/find_vendored.rs

@@ -1,25 +1,29 @@
-use std::path::PathBuf;
+#![allow(dead_code)]
 
-pub fn probe_lua() -> Option<PathBuf> {
+pub fn probe_lua() {
     #[cfg(feature = "lua54")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua54);
+
     #[cfg(feature = "lua53")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua53);
+
     #[cfg(feature = "lua52")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua52);
+
     #[cfg(feature = "lua51")]
     let artifacts = lua_src::Build::new().build(lua_src::Lua51);
+
     #[cfg(feature = "luajit")]
-    let artifacts = {
-        let mut builder = luajit_src::Build::new();
-        if cfg!(feature = "luajit52") {
-            builder.lua52compat(true);
-        }
-        builder.build()
-    };
+    let artifacts = luajit_src::Build::new()
+        .lua52compat(cfg!(feature = "luajit52"))
+        .build();
+
+    #[cfg(feature = "luau")]
+    let artifacts = luau0_src::Build::new()
+        .enable_codegen(cfg!(feature = "luau-codegen"))
+        .set_max_cstack_size(1000000)
+        .set_vector_size(if cfg!(feature = "luau-vector4") { 4 } else { 3 })
+        .build();
 
-    #[cfg(not(feature = "module"))]
     artifacts.print_cargo_metadata();
-
-    Some(artifacts.include_dir().to_owned())
 }

mlua-sys/build/main.rs

@@ -0,0 +1,19 @@
+cfg_if::cfg_if! {
+    if #[cfg(all(feature = "lua54", not(any(feature = "lua53", feature = "lua52", feature = "lua51", feature = "luajit", feature = "luau"))))] {
+        include!("main_inner.rs");
+    } else if #[cfg(all(feature = "lua53", not(any(feature = "lua54", feature = "lua52", feature = "lua51", feature = "luajit", feature = "luau"))))] {
+        include!("main_inner.rs");
+    } else if #[cfg(all(feature = "lua52", not(any(feature = "lua54", feature = "lua53", feature = "lua51", feature = "luajit", feature = "luau"))))] {
+        include!("main_inner.rs");
+    } else if #[cfg(all(feature = "lua51", not(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "luajit", feature = "luau"))))] {
+        include!("main_inner.rs");
+    } else if #[cfg(all(feature = "luajit", not(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "lua51", feature = "luau"))))] {
+        include!("main_inner.rs");
+    } else if #[cfg(all(feature = "luau", not(any(feature = "lua54", feature = "lua53", feature = "lua52", feature = "lua51", feature = "luajit"))))] {
+        include!("main_inner.rs");
+    } else {
+        fn main() {
+            compile_error!("You can enable only one of the features: lua54, lua53, lua52, lua51, luajit, luajit52, luau");
+        }
+    }
+}

mlua-sys/build/main_inner.rs

@@ -0,0 +1,35 @@
+use std::env;
+
+cfg_if::cfg_if! {
+    if #[cfg(any(feature = "luau", feature = "vendored"))] {
+        #[path = "find_vendored.rs"]
+        mod find;
+    } else {
+        #[path = "find_normal.rs"]
+        mod find;
+    }
+}
+
+fn main() {
+    #[cfg(all(feature = "luau", feature = "module", windows))]
+    compile_error!("Luau does not support `module` mode on Windows");
+
+    #[cfg(all(feature = "module", feature = "vendored"))]
+    compile_error!("`vendored` and `module` features are mutually exclusive");
+
+    println!("cargo:rerun-if-changed=build");
+
+    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
+    if target_os == "windows" && cfg!(feature = "module") {
+        if !std::env::var("LUA_LIB_NAME").unwrap_or_default().is_empty() {
+            // Don't use raw-dylib linking
+            find::probe_lua();
+            return;
+        }
+
+        println!("cargo:rustc-cfg=raw_dylib");
+    }
+
+    #[cfg(not(feature = "module"))]
+    find::probe_lua();
+}

mlua-sys/src/lib.rs

@@ -0,0 +1,108 @@
+//! Low level bindings to Lua 5.4/5.3/5.2/5.1 (including LuaJIT) and Roblox Luau.
+
+#![allow(non_camel_case_types, non_snake_case, dead_code)]
+#![allow(clippy::missing_safety_doc)]
+#![doc(test(attr(deny(warnings))))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+
+use std::os::raw::c_int;
+
+#[cfg(any(feature = "lua54", doc))]
+pub use lua54::*;
+
+#[cfg(any(feature = "lua53", doc))]
+pub use lua53::*;
+
+#[cfg(any(feature = "lua52", doc))]
+pub use lua52::*;
+
+#[cfg(any(feature = "lua51", feature = "luajit", doc))]
+pub use lua51::*;
+
+#[cfg(any(feature = "luau", doc))]
+pub use luau::*;
+
+#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+#[doc(hidden)]
+pub const LUA_MAX_UPVALUES: c_int = 255;
+
+#[cfg(any(feature = "lua51", feature = "luajit"))]
+#[doc(hidden)]
+pub const LUA_MAX_UPVALUES: c_int = 60;
+
+#[cfg(feature = "luau")]
+#[doc(hidden)]
+pub const LUA_MAX_UPVALUES: c_int = 200;
+
+// I believe `luaL_traceback` < 5.4 requires this much free stack to not error.
+// 5.4 uses `luaL_Buffer`
+#[doc(hidden)]
+pub const LUA_TRACEBACK_STACK: c_int = 11;
+
+// Copied from https://github.com/rust-lang/rust/blob/master/library/std/src/sys/pal/common/alloc.rs
+// The minimum alignment guaranteed by the architecture. This value is used to
+// add fast paths for low alignment values.
+#[cfg(any(
+    target_arch = "x86",
+    target_arch = "arm",
+    target_arch = "m68k",
+    target_arch = "csky",
+    target_arch = "mips",
+    target_arch = "mips32r6",
+    target_arch = "powerpc",
+    target_arch = "powerpc64",
+    target_arch = "sparc",
+    target_arch = "wasm32",
+    target_arch = "hexagon",
+    all(
+        target_arch = "riscv32",
+        not(any(target_os = "espidf", target_os = "zkvm"))
+    ),
+    all(target_arch = "xtensa", not(target_os = "espidf")),
+))]
+#[doc(hidden)]
+pub const SYS_MIN_ALIGN: usize = 8;
+#[cfg(any(
+    target_arch = "x86_64",
+    target_arch = "aarch64",
+    target_arch = "arm64ec",
+    target_arch = "loongarch64",
+    target_arch = "mips64",
+    target_arch = "mips64r6",
+    target_arch = "s390x",
+    target_arch = "sparc64",
+    target_arch = "riscv64",
+    target_arch = "wasm64",
+))]
+#[doc(hidden)]
+pub const SYS_MIN_ALIGN: usize = 16;
+// The allocator on the esp-idf and zkvm platforms guarantee 4 byte alignment.
+#[cfg(any(
+    all(target_arch = "riscv32", any(target_os = "espidf", target_os = "zkvm")),
+    all(target_arch = "xtensa", target_os = "espidf"),
+))]
+#[doc(hidden)]
+pub const SYS_MIN_ALIGN: usize = 4;
+
+#[macro_use]
+mod macros;
+
+#[cfg(any(feature = "lua54", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "lua54")))]
+pub mod lua54;
+
+#[cfg(any(feature = "lua53", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "lua53")))]
+pub mod lua53;
+
+#[cfg(any(feature = "lua52", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "lua52")))]
+pub mod lua52;
+
+#[cfg(any(feature = "lua51", feature = "luajit", doc))]
+#[cfg_attr(docsrs, doc(cfg(any(feature = "lua51", feature = "luajit"))))]
+pub mod lua51;
+
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+pub mod luau;

mlua-sys/src/lua51/compat.rs

@@ -1,69 +1,15 @@
-// The MIT License (MIT)
-//
-// Copyright (c) 2019-2021 A. Orlenko
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
+//! MLua compatibility layer for Lua 5.1/JIT
+//!
+//! Based on github.com/keplerproject/lua-compat-5.3
 
-// Based on github.com/keplerproject/lua-compat-5.3
-
-#![allow(clippy::needless_return)]
-
-use std::ffi::CStr;
 use std::mem;
 use std::os::raw::{c_char, c_int, c_void};
 use std::ptr;
 
-use super::lauxlib::{
-    luaL_callmeta, luaL_error, luaL_getmetafield_old, luaL_loadbuffer, luaL_newmetatable_old,
-};
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-use super::lauxlib::{luaL_Reg, luaL_checktype, luaL_getmetatable};
-
-#[cfg(feature = "lua52")]
-use super::lauxlib::{luaL_checkstack, luaL_getsubtable};
-
-use super::lua::{
-    self, lua_CFunction, lua_Debug, lua_Integer, lua_Number, lua_State, lua_Writer, lua_call,
-    lua_createtable, lua_dump_old, lua_error, lua_getfield_old, lua_getstack, lua_gettable_old,
-    lua_gettop, lua_insert, lua_isstring, lua_istable, lua_newuserdata, lua_pop, lua_pushboolean,
-    lua_pushcfunction, lua_pushfstring, lua_pushinteger, lua_pushliteral, lua_pushlstring_old,
-    lua_pushnil, lua_pushnumber, lua_pushthread, lua_pushvalue, lua_rawget_old, lua_rawgeti_old,
-    lua_rawset, lua_replace, lua_setfield, lua_setglobal, lua_setmetatable, lua_settable,
-    lua_toboolean, lua_tointeger, lua_tolstring, lua_tonumber, lua_topointer, lua_tostring,
-    lua_touserdata, lua_type, lua_typename,
-};
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-use super::lua::{
-    lua_checkstack, lua_concat, lua_equal, lua_getfenv, lua_getinfo, lua_getmetatable,
-    lua_isnumber, lua_lessthan, lua_newtable, lua_next, lua_objlen, lua_pushcclosure,
-    lua_pushlightuserdata, lua_pushstring_old, lua_rawequal, lua_remove, lua_resume_old,
-    lua_setfenv, lua_settop, LUA_OPADD, LUA_OPUNM,
-};
-
-#[cfg(feature = "lua52")]
-use super::lua::{
-    lua_absindex, lua_getglobal_old, lua_getuservalue_old, lua_pushstring, lua_rawgetp_old,
-    lua_rawsetp, lua_tonumberx,
-};
+use super::lauxlib::*;
+use super::lua::*;
 
+#[inline(always)]
 unsafe fn compat53_reverse(L: *mut lua_State, mut a: c_int, mut b: c_int) {
     while a < b {
         lua_pushvalue(L, a);
@@ -125,10 +71,9 @@ unsafe fn compat53_checkmode(
         );
         return err;
     }
-    lua::LUA_OK
+    LUA_OK
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 unsafe fn compat53_findfield(L: *mut lua_State, objidx: c_int, level: c_int) -> c_int {
     if level == 0 || lua_istable(L, -1) == 0 {
         return 0; // not found
@@ -137,7 +82,7 @@ unsafe fn compat53_findfield(L: *mut lua_State, objidx: c_int, level: c_int) ->
     lua_pushnil(L); // start 'next' loop
     while lua_next(L, -2) != 0 {
         // for each pair in table
-        if lua_type(L, -2) == lua::LUA_TSTRING {
+        if lua_type(L, -2) == LUA_TSTRING {
             // ignore non-string keys
             if lua_rawequal(L, objidx, -1) != 0 {
                 // found object?
@@ -154,25 +99,23 @@ unsafe fn compat53_findfield(L: *mut lua_State, objidx: c_int, level: c_int) ->
         }
         lua_pop(L, 1); // remove value
     }
-    return 0; // not found
+    0 // not found
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 unsafe fn compat53_pushglobalfuncname(L: *mut lua_State, ar: *mut lua_Debug) -> c_int {
     let top = lua_gettop(L);
     lua_getinfo(L, cstr!("f"), ar); // push function
-    lua_pushvalue(L, lua::LUA_GLOBALSINDEX);
+    lua_pushvalue(L, LUA_GLOBALSINDEX);
     if compat53_findfield(L, top + 1, 2) != 0 {
         lua_copy(L, -1, top + 1); // move name to proper place
         lua_pop(L, 2); // remove pushed values
-        return 1;
+        1
     } else {
         lua_settop(L, top); // remove function and global table
-        return 0;
+        0
     }
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 unsafe fn compat53_pushfuncname(L: *mut lua_State, ar: *mut lua_Debug) {
     if *(*ar).namewhat != b'\0' as c_char {
         // is there a name?
@@ -197,75 +140,27 @@ unsafe fn compat53_pushfuncname(L: *mut lua_State, ar: *mut lua_Debug) {
     }
 }
 
-unsafe fn compat53_call_lua(L: *mut lua_State, code: &str, nargs: c_int, nret: c_int) {
-    lua_rawgetp(L, lua::LUA_REGISTRYINDEX, code.as_ptr() as *const c_void);
-    if lua_type(L, -1) != lua::LUA_TFUNCTION {
-        lua_pop(L, 1);
-        if luaL_loadbuffer(
-            L,
-            code.as_ptr() as *const c_char,
-            code.as_bytes().len(),
-            cstr!("=none"),
-        ) != 0
-        {
-            lua_error(L);
-        }
-        lua_pushvalue(L, -1);
-        lua_rawsetp(L, lua::LUA_REGISTRYINDEX, code.as_ptr() as *const c_void);
-    }
-    lua_insert(L, -nargs - 1);
-    lua_call(L, nargs, nret);
-}
-
 //
 // lua ported functions
 //
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[inline(always)]
-pub fn lua_upvalueindex(i: c_int) -> c_int {
-    lua::LUA_GLOBALSINDEX - i
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_absindex(L: *mut lua_State, mut idx: c_int) -> c_int {
-    if idx < 0 && idx > lua::LUA_REGISTRYINDEX {
+    if idx < 0 && idx > LUA_REGISTRYINDEX {
         idx += lua_gettop(L) + 1;
     }
     idx
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-static COMPAT53_ARITH_CODE: &str = r#"
-local op,a,b=...
-if op == 0 then return a+b
-elseif op == 1 then return a-b
-elseif op == 2 then return a*b
-elseif op == 3 then return a/b
-elseif op == 4 then return a%b
-elseif op == 5 then return a^b
-elseif op == 6 then return -a
-end
-"#;
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-pub unsafe fn lua_arith(L: *mut lua_State, op: c_int) {
-    #[allow(clippy::manual_range_contains)]
-    if op < LUA_OPADD || op > LUA_OPUNM {
-        luaL_error(L, cstr!("invalid 'op' argument for lua_arith"));
-    }
-    luaL_checkstack(L, 5, cstr!("not enough stack slots"));
-    if op == LUA_OPUNM {
-        lua_pushvalue(L, -1);
-    }
-    lua_pushnumber(L, op as lua_Number);
-    lua_insert(L, -3);
-    compat53_call_lua(L, COMPAT53_ARITH_CODE, 3, 1);
-}
-
 pub unsafe fn lua_rotate(L: *mut lua_State, mut idx: c_int, mut n: c_int) {
     idx = lua_absindex(L, idx);
+    if n > 0 {
+        // Faster version
+        for _ in 0..n {
+            lua_insert(L, idx);
+        }
+        return;
+    }
     let n_elems = lua_gettop(L) - idx + 1;
     if n < 0 {
         n += n_elems;
@@ -279,7 +174,6 @@ pub unsafe fn lua_rotate(L: *mut lua_State, mut idx: c_int, mut n: c_int) {
     }
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_copy(L: *mut lua_State, fromidx: c_int, toidx: c_int) {
     let abs_to = lua_absindex(L, toidx);
@@ -290,32 +184,30 @@ pub unsafe fn lua_copy(L: *mut lua_State, fromidx: c_int, toidx: c_int) {
 
 #[inline(always)]
 pub unsafe fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int {
-    if lua_type(L, idx) == lua::LUA_TNUMBER {
+    if lua_type(L, idx) == LUA_TNUMBER {
         let n = lua_tonumber(L, idx);
         let i = lua_tointeger(L, idx);
         if (n - i as lua_Number).abs() < lua_Number::EPSILON {
             return 1;
         }
     }
-    return 0;
+    0
+}
+
+#[inline(always)]
+pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
+    lua_tointegerx(L, i, ptr::null_mut())
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_tonumberx(L: *mut lua_State, i: c_int, isnum: *mut c_int) -> lua_Number {
     let n = lua_tonumber(L, i);
     if !isnum.is_null() {
-        *isnum = if n != 0.0 || lua_isnumber(L, i) != 0 {
-            1
-        } else {
-            0
-        };
+        *isnum = (n != 0.0 || lua_isnumber(L, i) != 0) as c_int;
     }
-    return n;
+    n
 }
 
-// Implemented for Lua 5.2 as well
-// See https://github.com/keplerproject/lua-compat-5.3/issues/40
 #[inline(always)]
 pub unsafe fn lua_tointegerx(L: *mut lua_State, i: c_int, isnum: *mut c_int) -> lua_Integer {
     let mut ok = 0;
@@ -330,80 +222,45 @@ pub unsafe fn lua_tointegerx(L: *mut lua_State, i: c_int, isnum: *mut c_int) ->
     if !isnum.is_null() {
         *isnum = 0;
     }
-    return 0;
+    0
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize {
     lua_objlen(L, idx)
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[inline(always)]
-pub unsafe fn lua_compare(L: *mut lua_State, mut idx1: c_int, mut idx2: c_int, op: c_int) -> c_int {
-    match op {
-        lua::LUA_OPEQ => lua_equal(L, idx1, idx2),
-        lua::LUA_OPLT => lua_lessthan(L, idx1, idx2),
-        lua::LUA_OPLE => {
-            luaL_checkstack(L, 5, cstr!("not enough stack slots"));
-            idx1 = lua_absindex(L, idx1);
-            idx2 = lua_absindex(L, idx2);
-            lua_pushvalue(L, idx1);
-            lua_pushvalue(L, idx2);
-            compat53_call_lua(L, "local a,b=...\nreturn a<=b\n", 2, 1);
-            let result = lua_toboolean(L, -1);
-            lua_pop(L, 1);
-            result
-        }
-        _ => luaL_error(L, cstr!("invalid 'op' argument for lua_compare")),
-    }
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_pushlstring(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char {
     if l == 0 {
-        lua_pushlstring_old(L, cstr!(""), 0);
+        lua_pushlstring_(L, cstr!(""), 0);
     } else {
-        lua_pushlstring_old(L, s, l);
+        lua_pushlstring_(L, s, l);
     }
     lua_tostring(L, -1)
 }
 
-#[cfg(feature = "lua52")]
-#[inline(always)]
-pub unsafe fn lua_pushlstring(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char {
-    if l == 0 {
-        lua_pushlstring_old(L, cstr!(""), 0)
-    } else {
-        lua_pushlstring_old(L, s, l)
-    }
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_pushstring(L: *mut lua_State, s: *const c_char) -> *const c_char {
-    lua_pushstring_old(L, s);
+    lua_pushstring_(L, s);
     lua_tostring(L, -1)
 }
 
-#[cfg(feature = "lua52")]
 #[inline(always)]
 pub unsafe fn lua_getglobal(L: *mut lua_State, var: *const c_char) -> c_int {
-    lua_getglobal_old(L, var);
+    lua_getglobal_(L, var);
     lua_type(L, -1)
 }
 
 #[inline(always)]
 pub unsafe fn lua_gettable(L: *mut lua_State, idx: c_int) -> c_int {
-    lua_gettable_old(L, idx);
+    lua_gettable_(L, idx);
     lua_type(L, -1)
 }
 
 #[inline(always)]
 pub unsafe fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int {
-    lua_getfield_old(L, idx, k);
+    lua_getfield_(L, idx, k);
     lua_type(L, -1)
 }
 
@@ -411,54 +268,35 @@ pub unsafe fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c
 pub unsafe fn lua_geti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) -> c_int {
     idx = lua_absindex(L, idx);
     lua_pushinteger(L, n);
-    lua_gettable(L, idx);
-    lua_type(L, -1)
+    lua_gettable(L, idx)
 }
 
-// A new version which returns c_int
 #[inline(always)]
 pub unsafe fn lua_rawget(L: *mut lua_State, idx: c_int) -> c_int {
-    lua_rawget_old(L, idx);
+    lua_rawget_(L, idx);
     lua_type(L, -1)
 }
 
-// A new version which returns c_int
 #[inline(always)]
 pub unsafe fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int {
-    lua_rawgeti_old(L, idx, n);
+    let n = n.try_into().expect("cannot convert index to lua_Integer");
+    lua_rawgeti_(L, idx, n);
     lua_type(L, -1)
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int {
     let abs_i = lua_absindex(L, idx);
     lua_pushlightuserdata(L, p as *mut c_void);
-    lua_rawget(L, abs_i);
-    lua_type(L, -1)
+    lua_rawget(L, abs_i)
 }
 
-#[cfg(feature = "lua52")]
-#[inline(always)]
-pub unsafe fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int {
-    lua_rawgetp_old(L, idx, p);
-    lua_type(L, -1)
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int {
     lua_getfenv(L, idx);
     lua_type(L, -1)
 }
 
-#[cfg(feature = "lua52")]
-#[inline(always)]
-pub unsafe fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int {
-    lua_getuservalue_old(L, idx);
-    lua_type(L, -1)
-}
-
 #[inline(always)]
 pub unsafe fn lua_seti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) {
     luaL_checkstack(L, 1, cstr!("not enough stack slots available"));
@@ -468,7 +306,12 @@ pub unsafe fn lua_seti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) {
     lua_settable(L, idx);
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
+#[inline(always)]
+pub unsafe fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer) {
+    let n = n.try_into().expect("cannot convert index from lua_Integer");
+    lua_rawseti_(L, idx, n)
+}
+
 #[inline(always)]
 pub unsafe fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void) {
     let abs_i = lua_absindex(L, idx);
@@ -478,10 +321,9 @@ pub unsafe fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void) {
     lua_rawset(L, abs_i);
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_setuservalue(L: *mut lua_State, idx: c_int) {
-    luaL_checktype(L, -1, lua::LUA_TTABLE);
+    luaL_checktype(L, -1, LUA_TTABLE);
     lua_setfenv(L, idx);
 }
 
@@ -492,28 +334,21 @@ pub unsafe fn lua_dump(
     data: *mut c_void,
     _strip: c_int,
 ) -> c_int {
-    lua_dump_old(L, writer, data)
+    lua_dump_(L, writer, data)
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[inline(always)]
-pub unsafe fn lua_resume(L: *mut lua_State, _from: *mut lua_State, narg: c_int) -> c_int {
-    lua_resume_old(L, narg)
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_len(L: *mut lua_State, idx: c_int) {
     match lua_type(L, idx) {
-        lua::LUA_TSTRING => {
+        LUA_TSTRING => {
             lua_pushnumber(L, lua_objlen(L, idx) as lua_Number);
         }
-        lua::LUA_TTABLE => {
+        LUA_TTABLE => {
             if luaL_callmeta(L, idx, cstr!("__len")) == 0 {
                 lua_pushnumber(L, lua_objlen(L, idx) as lua_Number);
             }
         }
-        lua::LUA_TUSERDATA if luaL_callmeta(L, idx, cstr!("__len")) != 0 => {}
+        LUA_TUSERDATA if luaL_callmeta(L, idx, cstr!("__len")) != 0 => {}
         _ => {
             luaL_error(
                 L,
@@ -524,88 +359,32 @@ pub unsafe fn lua_len(L: *mut lua_State, idx: c_int) {
     }
 }
 
-#[inline(always)]
-pub unsafe fn lua_stringtonumber(L: *mut lua_State, s: *const c_char) -> usize {
-    use std::str::FromStr;
-
-    let cs = CStr::from_ptr(s);
-    if let Ok(rs) = cs.to_str() {
-        if let Ok(n) = f64::from_str(rs.trim()) {
-            lua_pushnumber(L, n as lua_Number);
-            return cs.to_bytes_with_nul().len();
-        }
-    }
-    0
-}
-
-#[allow(clippy::branches_sharing_code)]
-pub unsafe fn lua_getextraspace(L: *mut lua_State) -> *mut c_void {
-    use super::glue::LUA_EXTRASPACE;
-
-    luaL_checkstack(L, 4, cstr!("not enough stack slots available"));
-    lua_pushliteral(L, "__compat53_extraspace");
-    lua_pushvalue(L, -1);
-    lua_rawget(L, lua::LUA_REGISTRYINDEX);
-    if lua_istable(L, -1) == 0 {
-        lua_pop(L, 1);
-        lua_createtable(L, 0, 2);
-        lua_createtable(L, 0, 1);
-        lua_pushliteral(L, "k");
-        lua_setfield(L, -2, cstr!("__mode"));
-        lua_setmetatable(L, -2);
-        lua_pushvalue(L, -2);
-        lua_pushvalue(L, -2);
-        lua_rawset(L, lua::LUA_REGISTRYINDEX);
-    }
-    lua_replace(L, -2);
-    let is_main = lua_pushthread(L);
-    lua_rawget(L, -2);
-    let mut _ptr = lua_touserdata(L, -1);
-    if _ptr.is_null() {
-        lua_pop(L, 1);
-        _ptr = lua_newuserdata(L, LUA_EXTRASPACE as usize);
-        if is_main != 0 {
-            // mem::size_of::<c_void>() == 1
-            ptr::write_bytes(_ptr, 0, LUA_EXTRASPACE as usize);
-            lua_pushthread(L);
-            lua_pushvalue(L, -2);
-            lua_rawset(L, -4);
-            lua_pushboolean(L, 1);
-            lua_pushvalue(L, -2);
-            lua_rawset(L, -4);
-        } else {
-            lua_pushboolean(L, 1);
-            lua_rawget(L, -3);
-            let mptr = lua_touserdata(L, -1);
-            if !mptr.is_null() {
-                ptr::copy_nonoverlapping(mptr, _ptr, LUA_EXTRASPACE as usize)
-            } else {
-                ptr::write_bytes(_ptr, 0, LUA_EXTRASPACE as usize);
-            }
-            lua_pop(L, 1);
-            lua_pushthread(L);
-            lua_pushvalue(L, -2);
-            lua_rawset(L, -4);
-        }
-    }
-    lua_pop(L, 2);
-    return _ptr;
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn lua_pushglobaltable(L: *mut lua_State) {
-    lua_pushvalue(L, lua::LUA_GLOBALSINDEX);
+    lua_pushvalue(L, LUA_GLOBALSINDEX);
+}
+
+#[inline(always)]
+pub unsafe fn lua_resume(
+    L: *mut lua_State,
+    _from: *mut lua_State,
+    narg: c_int,
+    nres: *mut c_int,
+) -> c_int {
+    let ret = lua_resume_(L, narg);
+    if (ret == LUA_OK || ret == LUA_YIELD) && !(nres.is_null()) {
+        *nres = lua_gettop(L);
+    }
+    ret
 }
 
 //
 // lauxlib ported functions
 //
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char) {
-    if lua_checkstack(L, sz + lua::LUA_MINSTACK) == 0 {
+    if lua_checkstack(L, sz + LUA_MINSTACK) == 0 {
         if !msg.is_null() {
             luaL_error(L, cstr!("stack overflow (%s)"), msg);
         } else {
@@ -615,23 +394,19 @@ pub unsafe fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char)
     }
 }
 
-pub unsafe fn luaL_checkversion(_L: *mut lua_State) {
-    // Void
-}
-
 #[inline(always)]
 pub unsafe fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int {
-    if luaL_getmetafield_old(L, obj, e) != 0 {
+    if luaL_getmetafield_(L, obj, e) != 0 {
         lua_type(L, -1)
     } else {
-        lua::LUA_TNIL
+        LUA_TNIL
     }
 }
 
 #[inline(always)]
 pub unsafe fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int {
-    if luaL_newmetatable_old(L, tname) != 0 {
-        lua_pushstring(L, tname);
+    if luaL_newmetatable_(L, tname) != 0 {
+        lua_pushstring_(L, tname);
         lua_setfield(L, -2, cstr!("__name"));
         1
     } else {
@@ -639,7 +414,6 @@ pub unsafe fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_in
     }
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn luaL_loadbufferx(
     L: *mut lua_State,
@@ -648,32 +422,30 @@ pub unsafe fn luaL_loadbufferx(
     name: *const c_char,
     mode: *const c_char,
 ) -> c_int {
-    let status = if sz > 0 && *buff as u8 == lua::LUA_SIGNATURE[0] {
-        compat53_checkmode(L, mode, cstr!("binary"), lua::LUA_ERRSYNTAX)
+    let status = if sz > 0 && *buff as u8 == LUA_SIGNATURE[0] {
+        compat53_checkmode(L, mode, cstr!("binary"), LUA_ERRSYNTAX)
     } else {
-        compat53_checkmode(L, mode, cstr!("text"), lua::LUA_ERRSYNTAX)
+        compat53_checkmode(L, mode, cstr!("text"), LUA_ERRSYNTAX)
     };
-    if status != lua::LUA_OK {
+    if status != LUA_OK {
         return status;
     }
     luaL_loadbuffer(L, buff, sz, name)
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn luaL_len(L: *mut lua_State, idx: c_int) -> lua_Integer {
     let mut isnum = 0;
     luaL_checkstack(L, 1, cstr!("not enough stack slots"));
     lua_len(L, idx);
     let res = lua_tointegerx(L, -1, &mut isnum);
-    lua::lua_pop(L, 1);
+    lua_pop(L, 1);
     if isnum == 0 {
         luaL_error(L, cstr!("object length is not an integer"));
     }
     res
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 pub unsafe fn luaL_traceback(
     L: *mut lua_State,
     L1: *mut lua_State,
@@ -713,33 +485,33 @@ pub unsafe fn luaL_traceback(
     lua_concat(L, lua_gettop(L) - top);
 }
 
-pub unsafe fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char {
+pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize) -> *const c_char {
+    idx = lua_absindex(L, idx);
     if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
-        let t = lua_type(L, idx);
-        match t {
-            lua::LUA_TNIL => {
+        match lua_type(L, idx) {
+            LUA_TNIL => {
                 lua_pushliteral(L, "nil");
             }
-            lua::LUA_TSTRING | lua::LUA_TNUMBER => {
+            LUA_TSTRING | LUA_TNUMBER => {
                 lua_pushvalue(L, idx);
             }
-            lua::LUA_TBOOLEAN => {
+            LUA_TBOOLEAN => {
                 if lua_toboolean(L, idx) == 0 {
                     lua_pushliteral(L, "false");
                 } else {
                     lua_pushliteral(L, "true");
                 }
             }
-            _ => {
+            t => {
                 let tt = luaL_getmetafield(L, idx, cstr!("__name"));
-                let name = if tt == lua::LUA_TSTRING {
+                let name = if tt == LUA_TSTRING {
                     lua_tostring(L, -1)
                 } else {
                     lua_typename(L, t)
                 };
                 lua_pushfstring(L, cstr!("%s: %p"), name, lua_topointer(L, idx));
-                if tt != lua::LUA_TNIL {
-                    lua_replace(L, -2);
+                if tt != LUA_TNIL {
+                    lua_replace(L, -2); // remove '__name'
                 }
             }
         };
@@ -749,7 +521,6 @@ pub unsafe fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) ->
     lua_tolstring(L, -1, len)
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 #[inline(always)]
 pub unsafe fn luaL_setmetatable(L: *mut lua_State, tname: *const c_char) {
     luaL_checkstack(L, 1, cstr!("not enough stack slots"));
@@ -757,57 +528,19 @@ pub unsafe fn luaL_setmetatable(L: *mut lua_State, tname: *const c_char) {
     lua_setmetatable(L, -2);
 }
 
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[inline(always)]
-pub unsafe fn luaL_testudata(L: *mut lua_State, i: c_int, tname: *const c_char) -> *mut c_void {
-    let mut p = lua_touserdata(L, i);
-    luaL_checkstack(L, 2, cstr!("not enough stack slots"));
-    if p.is_null() || lua_getmetatable(L, i) == 0 {
-        return ptr::null_mut();
-    } else {
-        luaL_getmetatable(L, tname);
-        let res = lua_rawequal(L, -1, -2);
-        lua_pop(L, 2);
-        if res == 0 {
-            p = ptr::null_mut();
-        }
-    }
-    return p;
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[inline(always)]
-pub unsafe fn luaL_setfuncs(L: *mut lua_State, mut l: *const luaL_Reg, nup: c_int) {
-    luaL_checkstack(L, nup + 1, cstr!("too many upvalues"));
-    while !(*l).name.is_null() {
-        // fill the table with given functions
-        l = l.offset(1);
-        lua_pushstring(L, (*l).name);
-        for _ in 0..nup {
-            // copy upvalues to the top
-            lua_pushvalue(L, -(nup + 1));
-        }
-        lua_pushcclosure(L, (*l).func, nup); // closure with those upvalues
-        lua_settable(L, -(nup + 3)); // table must be below the upvalues, the name and the closure
-    }
-    lua_pop(L, nup); // remove upvalues
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
 pub unsafe fn luaL_getsubtable(L: *mut lua_State, idx: c_int, fname: *const c_char) -> c_int {
     let abs_i = lua_absindex(L, idx);
     luaL_checkstack(L, 3, cstr!("not enough stack slots"));
-    lua_pushstring(L, fname);
-    lua_gettable(L, abs_i);
-    if lua_istable(L, -1) != 0 {
+    lua_pushstring_(L, fname);
+    if lua_gettable(L, abs_i) == LUA_TTABLE {
         return 1;
     }
     lua_pop(L, 1);
     lua_newtable(L);
-    lua_pushstring(L, fname);
+    lua_pushstring_(L, fname);
     lua_pushvalue(L, -2);
     lua_settable(L, abs_i);
-    return 0;
+    0
 }
 
 pub unsafe fn luaL_requiref(
@@ -817,12 +550,12 @@ pub unsafe fn luaL_requiref(
     glb: c_int,
 ) {
     luaL_checkstack(L, 3, cstr!("not enough stack slots available"));
-    luaL_getsubtable(L, lua::LUA_REGISTRYINDEX, cstr!("_LOADED"));
-    if lua_getfield(L, -1, modname) == lua::LUA_TNIL {
+    luaL_getsubtable(L, LUA_REGISTRYINDEX, cstr!("_LOADED"));
+    if lua_getfield(L, -1, modname) == LUA_TNIL {
         lua_pop(L, 1);
         lua_pushcfunction(L, openf);
         lua_pushstring(L, modname);
-        #[cfg(any(feature = "lua52", feature = "lua51"))]
+        #[cfg(feature = "lua51")]
         {
             lua_call(L, 1, 1);
             lua_pushvalue(L, -1);
@@ -834,11 +567,10 @@ pub unsafe fn luaL_requiref(
             lua_getfield(L, -1, modname);
         }
     }
-    if cfg!(any(feature = "lua52", feature = "lua51")) && glb != 0 {
+    if glb != 0 {
         lua_pushvalue(L, -1);
         lua_setglobal(L, modname);
-    }
-    if cfg!(feature = "luajit") && glb == 0 {
+    } else {
         lua_pushnil(L);
         lua_setglobal(L, modname);
     }

mlua-sys/src/lua51/lauxlib.rs

@@ -0,0 +1,147 @@
+//! Contains definitions from `lauxlib.h`.
+
+use std::os::raw::{c_char, c_int, c_void};
+use std::ptr;
+
+use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State};
+
+// Extra error code for 'luaL_load'
+pub const LUA_ERRFILE: c_int = lua::LUA_ERRERR + 1;
+
+#[repr(C)]
+pub struct luaL_Reg {
+    pub name: *const c_char,
+    pub func: lua_CFunction,
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_register(L: *mut lua_State, libname: *const c_char, l: *const luaL_Reg);
+    #[link_name = "luaL_getmetafield"]
+    pub fn luaL_getmetafield_(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    pub fn luaL_callmeta(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    pub fn luaL_typerror(L: *mut lua_State, narg: c_int, tname: *const c_char) -> c_int;
+    pub fn luaL_argerror(L: *mut lua_State, narg: c_int, extramsg: *const c_char) -> c_int;
+    pub fn luaL_checklstring(L: *mut lua_State, narg: c_int, l: *mut usize) -> *const c_char;
+    pub fn luaL_optlstring(
+        L: *mut lua_State,
+        narg: c_int,
+        def: *const c_char,
+        l: *mut usize,
+    ) -> *const c_char;
+    pub fn luaL_checknumber(L: *mut lua_State, narg: c_int) -> lua_Number;
+    pub fn luaL_optnumber(L: *mut lua_State, narg: c_int, def: lua_Number) -> lua_Number;
+    pub fn luaL_checkinteger(L: *mut lua_State, narg: c_int) -> lua_Integer;
+    pub fn luaL_optinteger(L: *mut lua_State, narg: c_int, def: lua_Integer) -> lua_Integer;
+    #[link_name = "luaL_checkstack"]
+    pub fn luaL_checkstack_(L: *mut lua_State, sz: c_int, msg: *const c_char);
+    pub fn luaL_checktype(L: *mut lua_State, narg: c_int, t: c_int);
+    pub fn luaL_checkany(L: *mut lua_State, narg: c_int);
+
+    #[link_name = "luaL_newmetatable"]
+    pub fn luaL_newmetatable_(L: *mut lua_State, tname: *const c_char) -> c_int;
+    pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+
+    pub fn luaL_where(L: *mut lua_State, lvl: c_int);
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+
+    pub fn luaL_checkoption(
+        L: *mut lua_State,
+        narg: c_int,
+        def: *const c_char,
+        lst: *const *const c_char,
+    ) -> c_int;
+}
+
+// Pre-defined references
+pub const LUA_NOREF: c_int = -2;
+pub const LUA_REFNIL: c_int = -1;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
+    pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
+
+    pub fn luaL_loadfile(L: *mut lua_State, filename: *const c_char) -> c_int;
+    pub fn luaL_loadbuffer(
+        L: *mut lua_State,
+        buff: *const c_char,
+        sz: usize,
+        name: *const c_char,
+    ) -> c_int;
+    pub fn luaL_loadstring(L: *mut lua_State, s: *const c_char) -> c_int;
+
+    pub fn luaL_newstate() -> *mut lua_State;
+
+    pub fn luaL_gsub(
+        L: *mut lua_State,
+        s: *const c_char,
+        p: *const c_char,
+        r: *const c_char,
+    ) -> *const c_char;
+
+    pub fn luaL_findtable(
+        L: *mut lua_State,
+        idx: c_int,
+        fname: *const c_char,
+        szhint: c_int,
+    ) -> *const c_char;
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+
+#[inline(always)]
+pub unsafe fn luaL_argcheck(L: *mut lua_State, cond: c_int, narg: c_int, extramsg: *const c_char) {
+    if cond == 0 {
+        luaL_argerror(L, narg, extramsg);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_checkstring(L: *mut lua_State, n: c_int) -> *const c_char {
+    luaL_checklstring(L, n, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_optstring(L: *mut lua_State, n: c_int, d: *const c_char) -> *const c_char {
+    luaL_optlstring(L, n, d, ptr::null_mut())
+}
+
+// Deprecated from 5.3: luaL_checkint, luaL_optint, luaL_checklong, luaL_optlong
+
+#[inline(always)]
+pub unsafe fn luaL_typename(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua::lua_typename(L, lua::lua_type(L, i))
+}
+
+pub unsafe fn luaL_dofile(L: *mut lua_State, filename: *const c_char) -> c_int {
+    let status = luaL_loadfile(L, filename);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_dostring(L: *mut lua_State, s: *const c_char) -> c_int {
+    let status = luaL_loadstring(L, s);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_getmetatable(L: *mut lua_State, n: *const c_char) {
+    lua::lua_getfield_(L, lua::LUA_REGISTRYINDEX, n);
+}
+
+// TODO: luaL_opt
+
+//
+// TODO: Generic Buffer Manipulation
+//

mlua-sys/src/lua51/lua.rs

@@ -0,0 +1,407 @@
+//! Contains definitions from `lua.h`.
+
+use std::marker::{PhantomData, PhantomPinned};
+use std::os::raw::{c_char, c_double, c_int, c_void};
+use std::ptr;
+
+// Mark for precompiled code (`<esc>Lua`)
+#[cfg(not(feature = "luajit"))]
+pub const LUA_SIGNATURE: &[u8] = b"\x1bLua";
+#[cfg(feature = "luajit")]
+pub const LUA_SIGNATURE: &[u8] = b"\x1bLJ";
+
+// Option for multiple returns in 'lua_pcall' and 'lua_call'
+pub const LUA_MULTRET: c_int = -1;
+
+//
+// Pseudo-indices
+//
+pub const LUA_REGISTRYINDEX: c_int = -10000;
+pub const LUA_ENVIRONINDEX: c_int = -10001;
+pub const LUA_GLOBALSINDEX: c_int = -10002;
+
+pub const fn lua_upvalueindex(i: c_int) -> c_int {
+    LUA_GLOBALSINDEX - i
+}
+
+//
+// Thread status
+//
+pub const LUA_OK: c_int = 0;
+pub const LUA_YIELD: c_int = 1;
+pub const LUA_ERRRUN: c_int = 2;
+pub const LUA_ERRSYNTAX: c_int = 3;
+pub const LUA_ERRMEM: c_int = 4;
+pub const LUA_ERRERR: c_int = 5;
+
+/// A raw Lua state associated with a thread.
+#[repr(C)]
+pub struct lua_State {
+    _data: [u8; 0],
+    _marker: PhantomData<(*mut u8, PhantomPinned)>,
+}
+
+//
+// Basic types
+//
+pub const LUA_TNONE: c_int = -1;
+
+pub const LUA_TNIL: c_int = 0;
+pub const LUA_TBOOLEAN: c_int = 1;
+pub const LUA_TLIGHTUSERDATA: c_int = 2;
+pub const LUA_TNUMBER: c_int = 3;
+pub const LUA_TSTRING: c_int = 4;
+pub const LUA_TTABLE: c_int = 5;
+pub const LUA_TFUNCTION: c_int = 6;
+pub const LUA_TUSERDATA: c_int = 7;
+pub const LUA_TTHREAD: c_int = 8;
+
+/// Type produced by LuaJIT FFI module
+#[cfg(feature = "luajit")]
+pub const LUA_TCDATA: c_int = 10;
+
+/// Minimum Lua stack available to a C function
+pub const LUA_MINSTACK: c_int = 20;
+
+/// A Lua number, usually equivalent to `f64`
+pub type lua_Number = c_double;
+
+/// A Lua integer, usually equivalent to `i64`
+#[cfg(target_pointer_width = "32")]
+pub type lua_Integer = i32;
+#[cfg(target_pointer_width = "64")]
+pub type lua_Integer = i64;
+
+/// Type for native C functions that can be passed to Lua.
+pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+
+// Type for functions that read/write blocks when loading/dumping Lua chunks
+#[rustfmt::skip]
+pub type lua_Reader =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
+#[rustfmt::skip]
+pub type lua_Writer =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+
+/// Type for memory-allocation functions
+#[rustfmt::skip]
+pub type lua_Alloc =
+    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // State manipulation
+    //
+    pub fn lua_newstate(f: lua_Alloc, ud: *mut c_void) -> *mut lua_State;
+    pub fn lua_close(L: *mut lua_State);
+    pub fn lua_newthread(L: *mut lua_State) -> *mut lua_State;
+
+    pub fn lua_atpanic(L: *mut lua_State, panicf: lua_CFunction) -> lua_CFunction;
+
+    //
+    // Basic stack manipulation
+    //
+    pub fn lua_gettop(L: *mut lua_State) -> c_int;
+    pub fn lua_settop(L: *mut lua_State, idx: c_int);
+    pub fn lua_pushvalue(L: *mut lua_State, idx: c_int);
+    pub fn lua_remove(L: *mut lua_State, idx: c_int);
+    pub fn lua_insert(L: *mut lua_State, idx: c_int);
+    pub fn lua_replace(L: *mut lua_State, idx: c_int);
+    pub fn lua_checkstack(L: *mut lua_State, sz: c_int) -> c_int;
+
+    pub fn lua_xmove(from: *mut lua_State, to: *mut lua_State, n: c_int);
+
+    //
+    // Access functions (stack -> C)
+    //
+    pub fn lua_isnumber(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isstring(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_iscfunction(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isuserdata(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_type(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_typename(L: *mut lua_State, tp: c_int) -> *const c_char;
+
+    pub fn lua_equal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+    pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+    pub fn lua_lessthan(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+
+    pub fn lua_tonumber(L: *mut lua_State, idx: c_int) -> lua_Number;
+    #[link_name = "lua_tointeger"]
+    pub fn lua_tointeger_(L: *mut lua_State, idx: c_int) -> lua_Integer;
+    pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn lua_objlen(L: *mut lua_State, idx: c_int) -> usize;
+    pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> Option<lua_CFunction>;
+    pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
+    pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
+    pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
+
+    //
+    // Push functions (C -> stack)
+    //
+    pub fn lua_pushnil(L: *mut lua_State);
+    pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
+    pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
+    #[link_name = "lua_pushlstring"]
+    pub fn lua_pushlstring_(L: *mut lua_State, s: *const c_char, l: usize);
+    #[link_name = "lua_pushstring"]
+    pub fn lua_pushstring_(L: *mut lua_State, s: *const c_char);
+    // lua_pushvfstring
+    pub fn lua_pushfstring(L: *mut lua_State, fmt: *const c_char, ...) -> *const c_char;
+    pub fn lua_pushcclosure(L: *mut lua_State, f: lua_CFunction, n: c_int);
+    pub fn lua_pushboolean(L: *mut lua_State, b: c_int);
+    pub fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void);
+    pub fn lua_pushthread(L: *mut lua_State) -> c_int;
+
+    //
+    // Get functions (Lua -> stack)
+    //
+    #[link_name = "lua_gettable"]
+    pub fn lua_gettable_(L: *mut lua_State, idx: c_int);
+    #[link_name = "lua_getfield"]
+    pub fn lua_getfield_(L: *mut lua_State, idx: c_int, k: *const c_char);
+    #[link_name = "lua_rawget"]
+    pub fn lua_rawget_(L: *mut lua_State, idx: c_int);
+    #[link_name = "lua_rawgeti"]
+    pub fn lua_rawgeti_(L: *mut lua_State, idx: c_int, n: c_int);
+    pub fn lua_createtable(L: *mut lua_State, narr: c_int, nrec: c_int);
+    pub fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void;
+    pub fn lua_getmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_getfenv(L: *mut lua_State, idx: c_int);
+
+    //
+    // Set functions (stack -> Lua)
+    //
+    pub fn lua_settable(L: *mut lua_State, idx: c_int);
+    pub fn lua_setfield(L: *mut lua_State, idx: c_int, k: *const c_char);
+    pub fn lua_rawset(L: *mut lua_State, idx: c_int);
+    #[link_name = "lua_rawseti"]
+    pub fn lua_rawseti_(L: *mut lua_State, idx: c_int, n: c_int);
+    pub fn lua_setmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_setfenv(L: *mut lua_State, idx: c_int) -> c_int;
+
+    //
+    // 'load' and 'call' functions (load and run Lua code)
+    //
+    pub fn lua_call(L: *mut lua_State, nargs: c_int, nresults: c_int);
+    pub fn lua_pcall(L: *mut lua_State, nargs: c_int, nresults: c_int, errfunc: c_int) -> c_int;
+    pub fn lua_cpcall(L: *mut lua_State, f: lua_CFunction, ud: *mut c_void) -> c_int;
+    pub fn lua_load(
+        L: *mut lua_State,
+        reader: lua_Reader,
+        data: *mut c_void,
+        chunkname: *const c_char,
+    ) -> c_int;
+
+    #[link_name = "lua_dump"]
+    pub fn lua_dump_(L: *mut lua_State, writer: lua_Writer, data: *mut c_void) -> c_int;
+
+    //
+    // Coroutine functions
+    //
+    pub fn lua_yield(L: *mut lua_State, nresults: c_int) -> c_int;
+    #[link_name = "lua_resume"]
+    pub fn lua_resume_(L: *mut lua_State, narg: c_int) -> c_int;
+    pub fn lua_status(L: *mut lua_State) -> c_int;
+}
+
+//
+// Garbage-collection function and options
+//
+pub const LUA_GCSTOP: c_int = 0;
+pub const LUA_GCRESTART: c_int = 1;
+pub const LUA_GCCOLLECT: c_int = 2;
+pub const LUA_GCCOUNT: c_int = 3;
+pub const LUA_GCCOUNTB: c_int = 4;
+pub const LUA_GCSTEP: c_int = 5;
+pub const LUA_GCSETPAUSE: c_int = 6;
+pub const LUA_GCSETSTEPMUL: c_int = 7;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
+}
+
+//
+// Miscellaneous functions
+//
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
+extern "C-unwind" {
+    #[link_name = "lua_error"]
+    fn lua_error_(L: *mut lua_State) -> c_int;
+    pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_concat(L: *mut lua_State, n: c_int);
+    pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
+    pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
+}
+
+// lua_error does not return but is declared to return int, and Rust translates
+// ! to void which can cause link-time errors if the platform linker is aware
+// of return types and requires they match (for example: wasm does this).
+#[inline(always)]
+pub unsafe fn lua_error(L: *mut lua_State) -> ! {
+    lua_error_(L);
+    unreachable!();
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+#[inline(always)]
+pub unsafe fn lua_pop(L: *mut lua_State, n: c_int) {
+    lua_settop(L, -n - 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_newtable(L: *mut lua_State) {
+    lua_createtable(L, 0, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_register(L: *mut lua_State, n: *const c_char, f: lua_CFunction) {
+    lua_pushcfunction(L, f);
+    lua_setglobal(L, n)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcfunction(L: *mut lua_State, f: lua_CFunction) {
+    lua_pushcclosure(L, f, 0)
+}
+
+// TODO: lua_strlen
+
+#[inline(always)]
+pub unsafe fn lua_isfunction(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TFUNCTION) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_istable(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTABLE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_islightuserdata(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TLIGHTUSERDATA) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNIL) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isboolean(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TBOOLEAN) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isthread(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTHREAD) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnone(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNONE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) <= LUA_TNIL) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) {
+    use std::ffi::CString;
+    let c_str = CString::new(s).unwrap();
+    lua_pushlstring_(L, c_str.as_ptr(), c_str.as_bytes().len())
+}
+
+#[inline(always)]
+pub unsafe fn lua_setglobal(L: *mut lua_State, var: *const c_char) {
+    lua_setfield(L, LUA_GLOBALSINDEX, var)
+}
+
+#[inline(always)]
+pub unsafe fn lua_getglobal_(L: *mut lua_State, var: *const c_char) {
+    lua_getfield_(L, LUA_GLOBALSINDEX, var)
+}
+
+#[inline(always)]
+pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
+    if lua_islightuserdata(L, idx) != 0 {
+        return lua_touserdata(L, idx);
+    }
+    ptr::null_mut()
+}
+
+#[inline(always)]
+pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua_tolstring(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_xpush(from: *mut lua_State, to: *mut lua_State, idx: c_int) {
+    lua_pushvalue(from, idx);
+    lua_xmove(from, to, 1);
+}
+
+//
+// Debug API
+//
+
+// Maximum size for the description of the source of a function in debug information.
+const LUA_IDSIZE: usize = 60;
+
+// Event codes
+pub const LUA_HOOKCALL: c_int = 0;
+pub const LUA_HOOKRET: c_int = 1;
+pub const LUA_HOOKLINE: c_int = 2;
+pub const LUA_HOOKCOUNT: c_int = 3;
+pub const LUA_HOOKTAILCALL: c_int = 4;
+
+// Event masks
+pub const LUA_MASKCALL: c_int = 1 << (LUA_HOOKCALL as usize);
+pub const LUA_MASKRET: c_int = 1 << (LUA_HOOKRET as usize);
+pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
+pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
+
+/// Type for functions to be called on debug events.
+pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_setlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_getupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+    pub fn lua_setupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+
+    pub fn lua_sethook(
+        L: *mut lua_State,
+        func: Option<lua_Hook>,
+        mask: c_int,
+        count: c_int,
+    ) -> c_int;
+    pub fn lua_gethook(L: *mut lua_State) -> Option<lua_Hook>;
+    pub fn lua_gethookmask(L: *mut lua_State) -> c_int;
+    pub fn lua_gethookcount(L: *mut lua_State) -> c_int;
+}
+
+#[repr(C)]
+pub struct lua_Debug {
+    pub event: c_int,
+    pub name: *const c_char,
+    pub namewhat: *const c_char,
+    pub what: *const c_char,
+    pub source: *const c_char,
+    pub currentline: c_int,
+    pub nups: c_int,
+    pub linedefined: c_int,
+    pub lastlinedefined: c_int,
+    pub short_src: [c_char; LUA_IDSIZE],
+    // lua.h mentions this is for private use
+    i_ci: c_int,
+}

mlua-sys/src/lua51/lualib.rs

@@ -0,0 +1,43 @@
+//! Contains definitions from `lualib.h`.
+
+use std::os::raw::c_int;
+
+use super::lua::lua_State;
+
+pub const LUA_COLIBNAME: &str = "coroutine";
+pub const LUA_TABLIBNAME: &str = "table";
+pub const LUA_IOLIBNAME: &str = "io";
+pub const LUA_OSLIBNAME: &str = "os";
+pub const LUA_STRLIBNAME: &str = "string";
+pub const LUA_MATHLIBNAME: &str = "math";
+pub const LUA_DBLIBNAME: &str = "debug";
+pub const LUA_LOADLIBNAME: &str = "package";
+
+#[cfg(feature = "luajit")]
+pub const LUA_BITLIBNAME: &str = "bit";
+#[cfg(feature = "luajit")]
+pub const LUA_JITLIBNAME: &str = "jit";
+#[cfg(feature = "luajit")]
+pub const LUA_FFILIBNAME: &str = "ffi";
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua51", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaopen_base(L: *mut lua_State) -> c_int;
+    pub fn luaopen_table(L: *mut lua_State) -> c_int;
+    pub fn luaopen_io(L: *mut lua_State) -> c_int;
+    pub fn luaopen_os(L: *mut lua_State) -> c_int;
+    pub fn luaopen_string(L: *mut lua_State) -> c_int;
+    pub fn luaopen_math(L: *mut lua_State) -> c_int;
+    pub fn luaopen_debug(L: *mut lua_State) -> c_int;
+    pub fn luaopen_package(L: *mut lua_State) -> c_int;
+
+    #[cfg(feature = "luajit")]
+    pub fn luaopen_bit(L: *mut lua_State) -> c_int;
+    #[cfg(feature = "luajit")]
+    pub fn luaopen_jit(L: *mut lua_State) -> c_int;
+    #[cfg(feature = "luajit")]
+    pub fn luaopen_ffi(L: *mut lua_State) -> c_int;
+
+    // open all builtin libraries
+    pub fn luaL_openlibs(L: *mut lua_State);
+}

mlua-sys/src/lua51/mod.rs

@@ -0,0 +1,11 @@
+//! Low level bindings to Lua 5.1.
+
+pub use compat::*;
+pub use lauxlib::*;
+pub use lua::*;
+pub use lualib::*;
+
+pub mod compat;
+pub mod lauxlib;
+pub mod lua;
+pub mod lualib;

mlua-sys/src/lua52/compat.rs

@@ -0,0 +1,264 @@
+//! MLua compatibility layer for Lua 5.2
+//!
+//! Based on github.com/keplerproject/lua-compat-5.3
+
+use std::os::raw::{c_char, c_int, c_void};
+use std::ptr;
+
+use super::lauxlib::*;
+use super::lua::*;
+
+#[inline(always)]
+unsafe fn compat53_reverse(L: *mut lua_State, mut a: c_int, mut b: c_int) {
+    while a < b {
+        lua_pushvalue(L, a);
+        lua_pushvalue(L, b);
+        lua_replace(L, a);
+        lua_replace(L, b);
+        a += 1;
+        b -= 1;
+    }
+}
+
+//
+// lua ported functions
+//
+
+pub unsafe fn lua_rotate(L: *mut lua_State, mut idx: c_int, mut n: c_int) {
+    idx = lua_absindex(L, idx);
+    if n > 0 {
+        // Faster version
+        for _ in 0..n {
+            lua_insert(L, idx);
+        }
+        return;
+    }
+    let n_elems = lua_gettop(L) - idx + 1;
+    if n < 0 {
+        n += n_elems;
+    }
+    if n > 0 && n < n_elems {
+        luaL_checkstack(L, 2, cstr!("not enough stack slots available"));
+        n = n_elems - n;
+        compat53_reverse(L, idx, idx + n - 1);
+        compat53_reverse(L, idx + n, idx + n_elems - 1);
+        compat53_reverse(L, idx, idx + n_elems - 1);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int {
+    if lua_type(L, idx) == LUA_TNUMBER {
+        let n = lua_tonumber(L, idx);
+        let i = lua_tointeger(L, idx);
+        if (n - i as lua_Number).abs() < lua_Number::EPSILON {
+            return 1;
+        }
+    }
+    0
+}
+
+#[inline(always)]
+pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
+    lua_tointegerx(L, i, ptr::null_mut())
+}
+
+// Implemented for Lua 5.2 as well
+// See https://github.com/keplerproject/lua-compat-5.3/issues/40
+#[inline(always)]
+pub unsafe fn lua_tointegerx(L: *mut lua_State, i: c_int, isnum: *mut c_int) -> lua_Integer {
+    let mut ok = 0;
+    let n = lua_tonumberx(L, i, &mut ok);
+    let n_int = n as lua_Integer;
+    if ok != 0 && (n - n_int as lua_Number).abs() < lua_Number::EPSILON {
+        if !isnum.is_null() {
+            *isnum = 1;
+        }
+        return n_int;
+    }
+    if !isnum.is_null() {
+        *isnum = 0;
+    }
+    0
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushlstring(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char {
+    if l == 0 {
+        lua_pushlstring_(L, cstr!(""), 0)
+    } else {
+        lua_pushlstring_(L, s, l)
+    }
+}
+
+#[inline(always)]
+pub unsafe fn lua_getglobal(L: *mut lua_State, var: *const c_char) -> c_int {
+    lua_getglobal_(L, var);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_gettable(L: *mut lua_State, idx: c_int) -> c_int {
+    lua_gettable_(L, idx);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int {
+    lua_getfield_(L, idx, k);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_geti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) -> c_int {
+    idx = lua_absindex(L, idx);
+    lua_pushinteger(L, n);
+    lua_gettable(L, idx)
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawget(L: *mut lua_State, idx: c_int) -> c_int {
+    lua_rawget_(L, idx);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int {
+    let n = n.try_into().expect("cannot convert index to lua_Integer");
+    lua_rawgeti_(L, idx, n);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int {
+    lua_rawgetp_(L, idx, p);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int {
+    lua_getuservalue_(L, idx);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_seti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) {
+    luaL_checkstack(L, 1, cstr!("not enough stack slots available"));
+    idx = lua_absindex(L, idx);
+    lua_pushinteger(L, n);
+    lua_insert(L, -2);
+    lua_settable(L, idx);
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer) {
+    let n = n.try_into().expect("cannot convert index from lua_Integer");
+    lua_rawseti_(L, idx, n)
+}
+
+#[inline(always)]
+pub unsafe fn lua_dump(
+    L: *mut lua_State,
+    writer: lua_Writer,
+    data: *mut c_void,
+    _strip: c_int,
+) -> c_int {
+    lua_dump_(L, writer, data)
+}
+
+#[inline(always)]
+pub unsafe fn lua_resume(
+    L: *mut lua_State,
+    from: *mut lua_State,
+    narg: c_int,
+    nres: *mut c_int,
+) -> c_int {
+    let ret = lua_resume_(L, from, narg);
+    if (ret == LUA_OK || ret == LUA_YIELD) && !(nres.is_null()) {
+        *nres = lua_gettop(L);
+    }
+    ret
+}
+
+//
+// lauxlib ported functions
+//
+
+#[inline(always)]
+pub unsafe fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int {
+    if luaL_getmetafield_(L, obj, e) != 0 {
+        lua_type(L, -1)
+    } else {
+        LUA_TNIL
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int {
+    if luaL_newmetatable_(L, tname) != 0 {
+        lua_pushstring(L, tname);
+        lua_setfield(L, -2, cstr!("__name"));
+        1
+    } else {
+        0
+    }
+}
+
+pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize) -> *const c_char {
+    idx = lua_absindex(L, idx);
+    if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
+        match lua_type(L, idx) {
+            LUA_TNIL => {
+                lua_pushliteral(L, "nil");
+            }
+            LUA_TSTRING | LUA_TNUMBER => {
+                lua_pushvalue(L, idx);
+            }
+            LUA_TBOOLEAN => {
+                if lua_toboolean(L, idx) == 0 {
+                    lua_pushliteral(L, "false");
+                } else {
+                    lua_pushliteral(L, "true");
+                }
+            }
+            t => {
+                let tt = luaL_getmetafield(L, idx, cstr!("__name"));
+                let name = if tt == LUA_TSTRING {
+                    lua_tostring(L, -1)
+                } else {
+                    lua_typename(L, t)
+                };
+                lua_pushfstring(L, cstr!("%s: %p"), name, lua_topointer(L, idx));
+                if tt != LUA_TNIL {
+                    lua_replace(L, -2); // remove '__name'
+                }
+            }
+        };
+    } else if lua_isstring(L, -1) == 0 {
+        luaL_error(L, cstr!("'__tostring' must return a string"));
+    }
+    lua_tolstring(L, -1, len)
+}
+
+pub unsafe fn luaL_requiref(
+    L: *mut lua_State,
+    modname: *const c_char,
+    openf: lua_CFunction,
+    glb: c_int,
+) {
+    luaL_checkstack(L, 3, cstr!("not enough stack slots available"));
+    luaL_getsubtable(L, LUA_REGISTRYINDEX, cstr!("_LOADED"));
+    if lua_getfield(L, -1, modname) == LUA_TNIL {
+        lua_pop(L, 1);
+        lua_pushcfunction(L, openf);
+        lua_pushstring(L, modname);
+        lua_call(L, 1, 1);
+        lua_pushvalue(L, -1);
+        lua_setfield(L, -3, modname);
+    }
+    if glb != 0 {
+        lua_pushvalue(L, -1);
+        lua_setglobal(L, modname);
+    }
+    lua_replace(L, -2);
+}

mlua-sys/src/lua52/lauxlib.rs

@@ -0,0 +1,187 @@
+//! Contains definitions from `lauxlib.h`.
+
+use std::os::raw::{c_char, c_int, c_void};
+use std::ptr;
+
+use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State, lua_Unsigned};
+
+// Extra error code for 'luaL_load'
+pub const LUA_ERRFILE: c_int = lua::LUA_ERRERR + 1;
+
+#[repr(C)]
+pub struct luaL_Reg {
+    pub name: *const c_char,
+    pub func: lua_CFunction,
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number);
+
+    #[link_name = "luaL_getmetafield"]
+    pub fn luaL_getmetafield_(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    pub fn luaL_callmeta(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    #[link_name = "luaL_tolstring"]
+    pub fn luaL_tolstring_(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn luaL_argerror(L: *mut lua_State, arg: c_int, extramsg: *const c_char) -> c_int;
+    pub fn luaL_checklstring(L: *mut lua_State, arg: c_int, l: *mut usize) -> *const c_char;
+    pub fn luaL_optlstring(
+        L: *mut lua_State,
+        arg: c_int,
+        def: *const c_char,
+        l: *mut usize,
+    ) -> *const c_char;
+    pub fn luaL_checknumber(L: *mut lua_State, arg: c_int) -> lua_Number;
+    pub fn luaL_optnumber(L: *mut lua_State, arg: c_int, def: lua_Number) -> lua_Number;
+    pub fn luaL_checkinteger(L: *mut lua_State, arg: c_int) -> lua_Integer;
+    pub fn luaL_optinteger(L: *mut lua_State, arg: c_int, def: lua_Integer) -> lua_Integer;
+    pub fn luaL_checkunsigned(L: *mut lua_State, arg: c_int) -> lua_Unsigned;
+    pub fn luaL_optunsigned(L: *mut lua_State, arg: c_int, def: lua_Unsigned) -> lua_Unsigned;
+
+    pub fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char);
+    pub fn luaL_checktype(L: *mut lua_State, arg: c_int, t: c_int);
+    pub fn luaL_checkany(L: *mut lua_State, arg: c_int);
+
+    #[link_name = "luaL_newmetatable"]
+    pub fn luaL_newmetatable_(L: *mut lua_State, tname: *const c_char) -> c_int;
+    pub fn luaL_setmetatable(L: *mut lua_State, tname: *const c_char);
+    pub fn luaL_testudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+    pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+
+    pub fn luaL_where(L: *mut lua_State, lvl: c_int);
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+
+    pub fn luaL_checkoption(
+        L: *mut lua_State,
+        arg: c_int,
+        def: *const c_char,
+        lst: *const *const c_char,
+    ) -> c_int;
+
+    pub fn luaL_fileresult(L: *mut lua_State, stat: c_int, fname: *const c_char) -> c_int;
+    pub fn luaL_execresult(L: *mut lua_State, stat: c_int) -> c_int;
+}
+
+// Pre-defined references
+pub const LUA_NOREF: c_int = -2;
+pub const LUA_REFNIL: c_int = -1;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
+    pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
+
+    pub fn luaL_loadfilex(L: *mut lua_State, filename: *const c_char, mode: *const c_char)
+        -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
+    luaL_loadfilex(L, f, ptr::null())
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_loadbufferx(
+        L: *mut lua_State,
+        buff: *const c_char,
+        sz: usize,
+        name: *const c_char,
+        mode: *const c_char,
+    ) -> c_int;
+    pub fn luaL_loadstring(L: *mut lua_State, s: *const c_char) -> c_int;
+
+    pub fn luaL_newstate() -> *mut lua_State;
+
+    pub fn luaL_len(L: *mut lua_State, idx: c_int) -> lua_Integer;
+
+    pub fn luaL_gsub(
+        L: *mut lua_State,
+        s: *const c_char,
+        p: *const c_char,
+        r: *const c_char,
+    ) -> *const c_char;
+
+    pub fn luaL_setfuncs(L: *mut lua_State, l: *const luaL_Reg, nup: c_int);
+
+    pub fn luaL_getsubtable(L: *mut lua_State, idx: c_int, fname: *const c_char) -> c_int;
+
+    pub fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const c_char, level: c_int);
+
+    #[link_name = "luaL_requiref"]
+    pub fn luaL_requiref_(
+        L: *mut lua_State,
+        modname: *const c_char,
+        openf: lua_CFunction,
+        glb: c_int,
+    );
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+
+// TODO: luaL_newlibtable, luaL_newlib
+
+#[inline(always)]
+pub unsafe fn luaL_argcheck(L: *mut lua_State, cond: c_int, arg: c_int, extramsg: *const c_char) {
+    if cond == 0 {
+        luaL_argerror(L, arg, extramsg);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_checkstring(L: *mut lua_State, n: c_int) -> *const c_char {
+    luaL_checklstring(L, n, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_optstring(L: *mut lua_State, n: c_int, d: *const c_char) -> *const c_char {
+    luaL_optlstring(L, n, d, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_typename(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua::lua_typename(L, lua::lua_type(L, i))
+}
+
+#[inline(always)]
+pub unsafe fn luaL_dofile(L: *mut lua_State, filename: *const c_char) -> c_int {
+    let status = luaL_loadfile(L, filename);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_dostring(L: *mut lua_State, s: *const c_char) -> c_int {
+    let status = luaL_loadstring(L, s);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_getmetatable(L: *mut lua_State, n: *const c_char) {
+    lua::lua_getfield_(L, lua::LUA_REGISTRYINDEX, n);
+}
+
+// luaL_opt would be implemented here but it is undocumented, so it's omitted
+
+#[inline(always)]
+pub unsafe fn luaL_loadbuffer(
+    L: *mut lua_State,
+    s: *const c_char,
+    sz: usize,
+    n: *const c_char,
+) -> c_int {
+    luaL_loadbufferx(L, s, sz, n, ptr::null())
+}
+
+//
+// TODO: Generic Buffer Manipulation
+//

mlua-sys/src/lua52/lua.rs

@@ -0,0 +1,502 @@
+//! Contains definitions from `lua.h`.
+
+use std::marker::{PhantomData, PhantomPinned};
+use std::os::raw::{c_char, c_double, c_int, c_uchar, c_uint, c_void};
+use std::ptr;
+
+// Mark for precompiled code (`<esc>Lua`)
+pub const LUA_SIGNATURE: &[u8] = b"\x1bLua";
+
+// Option for multiple returns in 'lua_pcall' and 'lua_call'
+pub const LUA_MULTRET: c_int = -1;
+
+// Size of the Lua stack
+pub const LUAI_MAXSTACK: c_int = 1000000;
+
+//
+// Pseudo-indices
+//
+pub const LUA_REGISTRYINDEX: c_int = -LUAI_MAXSTACK - 1000;
+
+pub const fn lua_upvalueindex(i: c_int) -> c_int {
+    LUA_REGISTRYINDEX - i
+}
+
+//
+// Thread status
+//
+pub const LUA_OK: c_int = 0;
+pub const LUA_YIELD: c_int = 1;
+pub const LUA_ERRRUN: c_int = 2;
+pub const LUA_ERRSYNTAX: c_int = 3;
+pub const LUA_ERRMEM: c_int = 4;
+pub const LUA_ERRGCMM: c_int = 5;
+pub const LUA_ERRERR: c_int = 6;
+
+/// A raw Lua state associated with a thread.
+#[repr(C)]
+pub struct lua_State {
+    _data: [u8; 0],
+    _marker: PhantomData<(*mut u8, PhantomPinned)>,
+}
+
+//
+// Basic types
+//
+pub const LUA_TNONE: c_int = -1;
+
+pub const LUA_TNIL: c_int = 0;
+pub const LUA_TBOOLEAN: c_int = 1;
+pub const LUA_TLIGHTUSERDATA: c_int = 2;
+pub const LUA_TNUMBER: c_int = 3;
+pub const LUA_TSTRING: c_int = 4;
+pub const LUA_TTABLE: c_int = 5;
+pub const LUA_TFUNCTION: c_int = 6;
+pub const LUA_TUSERDATA: c_int = 7;
+pub const LUA_TTHREAD: c_int = 8;
+
+pub const LUA_NUMTAGS: c_int = 9;
+
+/// Minimum Lua stack available to a C function
+pub const LUA_MINSTACK: c_int = 20;
+
+// Predefined values in the registry
+pub const LUA_RIDX_MAINTHREAD: lua_Integer = 1;
+pub const LUA_RIDX_GLOBALS: lua_Integer = 2;
+pub const LUA_RIDX_LAST: lua_Integer = LUA_RIDX_GLOBALS;
+
+/// A Lua number, usually equivalent to `f64`
+pub type lua_Number = c_double;
+
+/// A Lua integer, usually equivalent to `i64`
+#[cfg(target_pointer_width = "32")]
+pub type lua_Integer = i32;
+#[cfg(target_pointer_width = "64")]
+pub type lua_Integer = i64;
+
+/// A Lua unsigned integer, equivalent to `u32` in Lua 5.2
+pub type lua_Unsigned = c_uint;
+
+/// Type for native C functions that can be passed to Lua
+pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+
+// Type for functions that read/write blocks when loading/dumping Lua chunks
+#[rustfmt::skip]
+pub type lua_Reader =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
+#[rustfmt::skip]
+pub type lua_Writer =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+
+/// Type for memory-allocation functions
+#[rustfmt::skip]
+pub type lua_Alloc =
+    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // State manipulation
+    //
+    pub fn lua_newstate(f: lua_Alloc, ud: *mut c_void) -> *mut lua_State;
+    pub fn lua_close(L: *mut lua_State);
+    pub fn lua_newthread(L: *mut lua_State) -> *mut lua_State;
+
+    pub fn lua_atpanic(L: *mut lua_State, panicf: lua_CFunction) -> lua_CFunction;
+
+    pub fn lua_version(L: *mut lua_State) -> *const lua_Number;
+
+    //
+    // Basic stack manipulation
+    //
+    pub fn lua_absindex(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_gettop(L: *mut lua_State) -> c_int;
+    pub fn lua_settop(L: *mut lua_State, idx: c_int);
+    pub fn lua_pushvalue(L: *mut lua_State, idx: c_int);
+    pub fn lua_remove(L: *mut lua_State, idx: c_int);
+    pub fn lua_insert(L: *mut lua_State, idx: c_int);
+    pub fn lua_replace(L: *mut lua_State, idx: c_int);
+    pub fn lua_copy(L: *mut lua_State, fromidx: c_int, toidx: c_int);
+    pub fn lua_checkstack(L: *mut lua_State, sz: c_int) -> c_int;
+
+    pub fn lua_xmove(from: *mut lua_State, to: *mut lua_State, n: c_int);
+
+    //
+    // Access functions (stack -> C)
+    //
+    pub fn lua_isnumber(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isstring(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_iscfunction(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isuserdata(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_type(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_typename(L: *mut lua_State, tp: c_int) -> *const c_char;
+
+    pub fn lua_tonumberx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Number;
+    #[link_name = "lua_tointegerx"]
+    pub fn lua_tointegerx_(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Integer;
+    pub fn lua_tounsignedx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Unsigned;
+    pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize;
+    pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> Option<lua_CFunction>;
+    pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
+    pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
+    pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
+}
+
+//
+// Comparison and arithmetic functions
+//
+pub const LUA_OPADD: c_int = 0;
+pub const LUA_OPSUB: c_int = 1;
+pub const LUA_OPMUL: c_int = 2;
+pub const LUA_OPDIV: c_int = 3;
+pub const LUA_OPMOD: c_int = 4;
+pub const LUA_OPPOW: c_int = 5;
+pub const LUA_OPUNM: c_int = 6;
+
+pub const LUA_OPEQ: c_int = 0;
+pub const LUA_OPLT: c_int = 1;
+pub const LUA_OPLE: c_int = 2;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_arith(L: *mut lua_State, op: c_int);
+    pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+    pub fn lua_compare(L: *mut lua_State, idx1: c_int, idx2: c_int, op: c_int) -> c_int;
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Push functions (C -> stack)
+    //
+    pub fn lua_pushnil(L: *mut lua_State);
+    pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
+    pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
+    pub fn lua_pushunsigned(L: *mut lua_State, n: lua_Unsigned);
+    #[link_name = "lua_pushlstring"]
+    pub fn lua_pushlstring_(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char;
+    pub fn lua_pushstring(L: *mut lua_State, s: *const c_char) -> *const c_char;
+    // lua_pushvfstring
+    pub fn lua_pushfstring(L: *mut lua_State, fmt: *const c_char, ...) -> *const c_char;
+    pub fn lua_pushcclosure(L: *mut lua_State, f: lua_CFunction, n: c_int);
+    pub fn lua_pushboolean(L: *mut lua_State, b: c_int);
+    pub fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void);
+    pub fn lua_pushthread(L: *mut lua_State) -> c_int;
+
+    //
+    // Get functions (Lua -> stack)
+    //
+    #[link_name = "lua_getglobal"]
+    pub fn lua_getglobal_(L: *mut lua_State, name: *const c_char);
+    #[link_name = "lua_gettable"]
+    pub fn lua_gettable_(L: *mut lua_State, idx: c_int);
+    #[link_name = "lua_getfield"]
+    pub fn lua_getfield_(L: *mut lua_State, idx: c_int, k: *const c_char);
+    #[link_name = "lua_rawget"]
+    pub fn lua_rawget_(L: *mut lua_State, idx: c_int);
+    #[link_name = "lua_rawgeti"]
+    pub fn lua_rawgeti_(L: *mut lua_State, idx: c_int, n: c_int);
+    #[link_name = "lua_rawgetp"]
+    pub fn lua_rawgetp_(L: *mut lua_State, idx: c_int, p: *const c_void);
+    pub fn lua_createtable(L: *mut lua_State, narr: c_int, nrec: c_int);
+    pub fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void;
+    pub fn lua_getmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    #[link_name = "lua_getuservalue"]
+    pub fn lua_getuservalue_(L: *mut lua_State, idx: c_int);
+
+    //
+    // Set functions (stack -> Lua)
+    //
+    pub fn lua_setglobal(L: *mut lua_State, var: *const c_char);
+    pub fn lua_settable(L: *mut lua_State, idx: c_int);
+    pub fn lua_setfield(L: *mut lua_State, idx: c_int, k: *const c_char);
+    pub fn lua_rawset(L: *mut lua_State, idx: c_int);
+    #[link_name = "lua_rawseti"]
+    pub fn lua_rawseti_(L: *mut lua_State, idx: c_int, n: c_int);
+    pub fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void);
+    pub fn lua_setmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_setuservalue(L: *mut lua_State, idx: c_int);
+
+    //
+    // 'load' and 'call' functions (load and run Lua code)
+    //
+    pub fn lua_callk(
+        L: *mut lua_State,
+        nargs: c_int,
+        nresults: c_int,
+        ctx: c_int,
+        k: Option<lua_CFunction>,
+    );
+    pub fn lua_pcallk(
+        L: *mut lua_State,
+        nargs: c_int,
+        nresults: c_int,
+        errfunc: c_int,
+        ctx: c_int,
+        k: Option<lua_CFunction>,
+    ) -> c_int;
+
+    pub fn lua_getctx(L: *mut lua_State, ctx: *mut c_int) -> c_int;
+
+    pub fn lua_load(
+        L: *mut lua_State,
+        reader: lua_Reader,
+        data: *mut c_void,
+        chunkname: *const c_char,
+        mode: *const c_char,
+    ) -> c_int;
+    #[link_name = "lua_dump"]
+    pub fn lua_dump_(L: *mut lua_State, writer: lua_Writer, data: *mut c_void) -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn lua_call(L: *mut lua_State, n: c_int, r: c_int) {
+    lua_callk(L, n, r, 0, None)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_int {
+    lua_pcallk(L, n, r, f, 0, None)
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Coroutine functions
+    //
+    pub fn lua_yieldk(
+        L: *mut lua_State,
+        nresults: c_int,
+        ctx: c_int,
+        k: Option<lua_CFunction>,
+    ) -> c_int;
+    #[link_name = "lua_resume"]
+    pub fn lua_resume_(L: *mut lua_State, from: *mut lua_State, narg: c_int) -> c_int;
+    pub fn lua_status(L: *mut lua_State) -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn lua_yield(L: *mut lua_State, n: c_int) -> c_int {
+    lua_yieldk(L, n, 0, None)
+}
+
+//
+// Garbage-collection function and options
+//
+pub const LUA_GCSTOP: c_int = 0;
+pub const LUA_GCRESTART: c_int = 1;
+pub const LUA_GCCOLLECT: c_int = 2;
+pub const LUA_GCCOUNT: c_int = 3;
+pub const LUA_GCCOUNTB: c_int = 4;
+pub const LUA_GCSTEP: c_int = 5;
+pub const LUA_GCSETPAUSE: c_int = 6;
+pub const LUA_GCSETSTEPMUL: c_int = 7;
+pub const LUA_GCSETMAJORINC: c_int = 8;
+pub const LUA_GCISRUNNING: c_int = 9;
+pub const LUA_GCGEN: c_int = 10;
+pub const LUA_GCINC: c_int = 11;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Miscellaneous functions
+    //
+    #[link_name = "lua_error"]
+    fn lua_error_(L: *mut lua_State) -> c_int;
+    pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_concat(L: *mut lua_State, n: c_int);
+    pub fn lua_len(L: *mut lua_State, idx: c_int);
+    pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
+    pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
+}
+
+// lua_error does not return but is declared to return int, and Rust translates
+// ! to void which can cause link-time errors if the platform linker is aware
+// of return types and requires they match (for example: wasm does this).
+#[inline(always)]
+pub unsafe fn lua_error(L: *mut lua_State) -> ! {
+    lua_error_(L);
+    unreachable!();
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+#[inline(always)]
+pub unsafe fn lua_tonumber(L: *mut lua_State, i: c_int) -> lua_Number {
+    lua_tonumberx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_tointeger_(L: *mut lua_State, i: c_int) -> lua_Integer {
+    lua_tointegerx_(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_tounsigned(L: *mut lua_State, i: c_int) -> lua_Unsigned {
+    lua_tounsignedx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pop(L: *mut lua_State, n: c_int) {
+    lua_settop(L, -n - 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_newtable(L: *mut lua_State) {
+    lua_createtable(L, 0, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_register(L: *mut lua_State, n: *const c_char, f: lua_CFunction) {
+    lua_pushcfunction(L, f);
+    lua_setglobal(L, n)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcfunction(L: *mut lua_State, f: lua_CFunction) {
+    lua_pushcclosure(L, f, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_isfunction(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TFUNCTION) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_istable(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTABLE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_islightuserdata(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TLIGHTUSERDATA) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNIL) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isboolean(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TBOOLEAN) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isthread(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTHREAD) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnone(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNONE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) <= 0) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) -> *const c_char {
+    use std::ffi::CString;
+    let c_str = CString::new(s).unwrap();
+    lua_pushlstring_(L, c_str.as_ptr(), c_str.as_bytes().len())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushglobaltable(L: *mut lua_State) {
+    lua_rawgeti_(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS as _)
+}
+
+#[inline(always)]
+pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
+    if lua_islightuserdata(L, idx) != 0 {
+        return lua_touserdata(L, idx);
+    }
+    ptr::null_mut()
+}
+
+#[inline(always)]
+pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua_tolstring(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_xpush(from: *mut lua_State, to: *mut lua_State, idx: c_int) {
+    lua_pushvalue(from, idx);
+    lua_xmove(from, to, 1);
+}
+
+//
+// Debug API
+//
+
+// Maximum size for the description of the source of a function in debug information.
+const LUA_IDSIZE: usize = 60;
+
+// Event codes
+pub const LUA_HOOKCALL: c_int = 0;
+pub const LUA_HOOKRET: c_int = 1;
+pub const LUA_HOOKLINE: c_int = 2;
+pub const LUA_HOOKCOUNT: c_int = 3;
+pub const LUA_HOOKTAILCALL: c_int = 4;
+
+// Event masks
+pub const LUA_MASKCALL: c_int = 1 << (LUA_HOOKCALL as usize);
+pub const LUA_MASKRET: c_int = 1 << (LUA_HOOKRET as usize);
+pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
+pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
+
+/// Type for functions to be called on debug events.
+pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_setlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_getupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+    pub fn lua_setupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+
+    pub fn lua_upvalueid(L: *mut lua_State, fidx: c_int, n: c_int) -> *mut c_void;
+    pub fn lua_upvaluejoin(L: *mut lua_State, fidx1: c_int, n1: c_int, fidx2: c_int, n2: c_int);
+
+    pub fn lua_sethook(
+        L: *mut lua_State,
+        func: Option<lua_Hook>,
+        mask: c_int,
+        count: c_int,
+    ) -> c_int;
+    pub fn lua_gethook(L: *mut lua_State) -> Option<lua_Hook>;
+    pub fn lua_gethookmask(L: *mut lua_State) -> c_int;
+    pub fn lua_gethookcount(L: *mut lua_State) -> c_int;
+}
+
+#[repr(C)]
+pub struct lua_Debug {
+    pub event: c_int,
+    pub name: *const c_char,
+    pub namewhat: *const c_char,
+    pub what: *const c_char,
+    pub source: *const c_char,
+    pub currentline: c_int,
+    pub linedefined: c_int,
+    pub lastlinedefined: c_int,
+    pub nups: c_uchar,
+    pub nparams: c_uchar,
+    pub isvararg: c_char,
+    pub istailcall: c_char,
+    pub short_src: [c_char; LUA_IDSIZE],
+    // lua.h mentions this is for private use
+    i_ci: *mut c_void,
+}

mlua-sys/src/lua52/lualib.rs

@@ -0,0 +1,32 @@
+//! Contains definitions from `lualib.h`.
+
+use std::os::raw::c_int;
+
+use super::lua::lua_State;
+
+pub const LUA_COLIBNAME: &str = "coroutine";
+pub const LUA_TABLIBNAME: &str = "table";
+pub const LUA_IOLIBNAME: &str = "io";
+pub const LUA_OSLIBNAME: &str = "os";
+pub const LUA_STRLIBNAME: &str = "string";
+pub const LUA_BITLIBNAME: &str = "bit32";
+pub const LUA_MATHLIBNAME: &str = "math";
+pub const LUA_DBLIBNAME: &str = "debug";
+pub const LUA_LOADLIBNAME: &str = "package";
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua52", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaopen_base(L: *mut lua_State) -> c_int;
+    pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
+    pub fn luaopen_table(L: *mut lua_State) -> c_int;
+    pub fn luaopen_io(L: *mut lua_State) -> c_int;
+    pub fn luaopen_os(L: *mut lua_State) -> c_int;
+    pub fn luaopen_string(L: *mut lua_State) -> c_int;
+    pub fn luaopen_bit32(L: *mut lua_State) -> c_int;
+    pub fn luaopen_math(L: *mut lua_State) -> c_int;
+    pub fn luaopen_debug(L: *mut lua_State) -> c_int;
+    pub fn luaopen_package(L: *mut lua_State) -> c_int;
+
+    // open all builtin libraries
+    pub fn luaL_openlibs(L: *mut lua_State);
+}

mlua-sys/src/lua52/mod.rs

@@ -0,0 +1,11 @@
+//! Low level bindings to Lua 5.2.
+
+pub use compat::*;
+pub use lauxlib::*;
+pub use lua::*;
+pub use lualib::*;
+
+pub mod compat;
+pub mod lauxlib;
+pub mod lua;
+pub mod lualib;

mlua-sys/src/lua53/compat.rs

@@ -0,0 +1,19 @@
+//! MLua compatibility layer for Lua 5.3
+
+use std::os::raw::c_int;
+
+use super::lua::*;
+
+#[inline(always)]
+pub unsafe fn lua_resume(
+    L: *mut lua_State,
+    from: *mut lua_State,
+    narg: c_int,
+    nres: *mut c_int,
+) -> c_int {
+    let ret = lua_resume_(L, from, narg);
+    if (ret == LUA_OK || ret == LUA_YIELD) && !(nres.is_null()) {
+        *nres = lua_gettop(L);
+    }
+    ret
+}

mlua-sys/src/lua53/lauxlib.rs

@@ -0,0 +1,193 @@
+//! Contains definitions from `lauxlib.h`.
+
+use std::os::raw::{c_char, c_int, c_void};
+use std::ptr;
+
+use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State};
+
+// Extra error code for 'luaL_loadfilex'
+pub const LUA_ERRFILE: c_int = lua::LUA_ERRERR + 1;
+
+// Key, in the registry, for table of loaded modules
+pub const LUA_LOADED_TABLE: &str = "_LOADED";
+
+// Key, in the registry, for table of preloaded loaders
+pub const LUA_PRELOAD_TABLE: &str = "_PRELOAD";
+
+#[repr(C)]
+pub struct luaL_Reg {
+    pub name: *const c_char,
+    pub func: lua_CFunction,
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number, sz: usize);
+
+    pub fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    pub fn luaL_callmeta(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    #[link_name = "luaL_tolstring"]
+    pub fn luaL_tolstring_(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn luaL_argerror(L: *mut lua_State, arg: c_int, extramsg: *const c_char) -> c_int;
+    pub fn luaL_checklstring(L: *mut lua_State, arg: c_int, l: *mut usize) -> *const c_char;
+    pub fn luaL_optlstring(
+        L: *mut lua_State,
+        arg: c_int,
+        def: *const c_char,
+        l: *mut usize,
+    ) -> *const c_char;
+    pub fn luaL_checknumber(L: *mut lua_State, arg: c_int) -> lua_Number;
+    pub fn luaL_optnumber(L: *mut lua_State, arg: c_int, def: lua_Number) -> lua_Number;
+    pub fn luaL_checkinteger(L: *mut lua_State, arg: c_int) -> lua_Integer;
+    pub fn luaL_optinteger(L: *mut lua_State, arg: c_int, def: lua_Integer) -> lua_Integer;
+
+    pub fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char);
+    pub fn luaL_checktype(L: *mut lua_State, arg: c_int, t: c_int);
+    pub fn luaL_checkany(L: *mut lua_State, arg: c_int);
+
+    pub fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int;
+    pub fn luaL_setmetatable(L: *mut lua_State, tname: *const c_char);
+    pub fn luaL_testudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+    pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+
+    pub fn luaL_where(L: *mut lua_State, lvl: c_int);
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+
+    pub fn luaL_checkoption(
+        L: *mut lua_State,
+        arg: c_int,
+        def: *const c_char,
+        lst: *const *const c_char,
+    ) -> c_int;
+
+    pub fn luaL_fileresult(L: *mut lua_State, stat: c_int, fname: *const c_char) -> c_int;
+    pub fn luaL_execresult(L: *mut lua_State, stat: c_int) -> c_int;
+}
+
+// Pre-defined references
+pub const LUA_NOREF: c_int = -2;
+pub const LUA_REFNIL: c_int = -1;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
+    pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
+
+    pub fn luaL_loadfilex(L: *mut lua_State, filename: *const c_char, mode: *const c_char)
+        -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
+    luaL_loadfilex(L, f, ptr::null())
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_loadbufferx(
+        L: *mut lua_State,
+        buff: *const c_char,
+        sz: usize,
+        name: *const c_char,
+        mode: *const c_char,
+    ) -> c_int;
+    pub fn luaL_loadstring(L: *mut lua_State, s: *const c_char) -> c_int;
+
+    pub fn luaL_newstate() -> *mut lua_State;
+
+    pub fn luaL_len(L: *mut lua_State, idx: c_int) -> lua_Integer;
+
+    pub fn luaL_gsub(
+        L: *mut lua_State,
+        s: *const c_char,
+        p: *const c_char,
+        r: *const c_char,
+    ) -> *const c_char;
+
+    pub fn luaL_setfuncs(L: *mut lua_State, l: *const luaL_Reg, nup: c_int);
+
+    pub fn luaL_getsubtable(L: *mut lua_State, idx: c_int, fname: *const c_char) -> c_int;
+
+    pub fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const c_char, level: c_int);
+
+    pub fn luaL_requiref(
+        L: *mut lua_State,
+        modname: *const c_char,
+        openf: lua_CFunction,
+        glb: c_int,
+    );
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+
+// TODO: luaL_newlibtable, luaL_newlib
+
+#[inline(always)]
+pub unsafe fn luaL_argcheck(L: *mut lua_State, cond: c_int, arg: c_int, extramsg: *const c_char) {
+    if cond == 0 {
+        luaL_argerror(L, arg, extramsg);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_checkstring(L: *mut lua_State, n: c_int) -> *const c_char {
+    luaL_checklstring(L, n, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_optstring(L: *mut lua_State, n: c_int, d: *const c_char) -> *const c_char {
+    luaL_optlstring(L, n, d, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_typename(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua::lua_typename(L, lua::lua_type(L, i))
+}
+
+#[inline(always)]
+pub unsafe fn luaL_dofile(L: *mut lua_State, filename: *const c_char) -> c_int {
+    let status = luaL_loadfile(L, filename);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_dostring(L: *mut lua_State, s: *const c_char) -> c_int {
+    let status = luaL_loadstring(L, s);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_getmetatable(L: *mut lua_State, n: *const c_char) {
+    lua::lua_getfield(L, lua::LUA_REGISTRYINDEX, n);
+}
+
+#[inline(always)]
+pub unsafe fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char {
+    luaL_tolstring_(L, lua::lua_absindex(L, idx), len)
+}
+
+// luaL_opt would be implemented here but it is undocumented, so it's omitted
+
+#[inline(always)]
+pub unsafe fn luaL_loadbuffer(
+    L: *mut lua_State,
+    s: *const c_char,
+    sz: usize,
+    n: *const c_char,
+) -> c_int {
+    luaL_loadbufferx(L, s, sz, n, ptr::null())
+}
+
+//
+// TODO: Generic Buffer Manipulation
+//

mlua-sys/src/lua53/lua.rs

@@ -0,0 +1,521 @@
+//! Contains definitions from `lua.h`.
+
+use std::marker::{PhantomData, PhantomPinned};
+use std::mem;
+use std::os::raw::{c_char, c_double, c_int, c_uchar, c_void};
+use std::ptr;
+
+// Mark for precompiled code (`<esc>Lua`)
+pub const LUA_SIGNATURE: &[u8] = b"\x1bLua";
+
+// Option for multiple returns in 'lua_pcall' and 'lua_call'
+pub const LUA_MULTRET: c_int = -1;
+
+// Size of the Lua stack
+pub const LUAI_MAXSTACK: c_int = 1000000;
+
+// Size of a raw memory area associated with  a Lua state with very fast access.
+pub const LUA_EXTRASPACE: usize = mem::size_of::<*const ()>();
+
+//
+// Pseudo-indices
+//
+pub const LUA_REGISTRYINDEX: c_int = -LUAI_MAXSTACK - 1000;
+
+pub const fn lua_upvalueindex(i: c_int) -> c_int {
+    LUA_REGISTRYINDEX - i
+}
+
+//
+// Thread status
+//
+pub const LUA_OK: c_int = 0;
+pub const LUA_YIELD: c_int = 1;
+pub const LUA_ERRRUN: c_int = 2;
+pub const LUA_ERRSYNTAX: c_int = 3;
+pub const LUA_ERRMEM: c_int = 4;
+pub const LUA_ERRGCMM: c_int = 5;
+pub const LUA_ERRERR: c_int = 6;
+
+/// A raw Lua state associated with a thread.
+#[repr(C)]
+pub struct lua_State {
+    _data: [u8; 0],
+    _marker: PhantomData<(*mut u8, PhantomPinned)>,
+}
+
+//
+// Basic types
+//
+pub const LUA_TNONE: c_int = -1;
+
+pub const LUA_TNIL: c_int = 0;
+pub const LUA_TBOOLEAN: c_int = 1;
+pub const LUA_TLIGHTUSERDATA: c_int = 2;
+pub const LUA_TNUMBER: c_int = 3;
+pub const LUA_TSTRING: c_int = 4;
+pub const LUA_TTABLE: c_int = 5;
+pub const LUA_TFUNCTION: c_int = 6;
+pub const LUA_TUSERDATA: c_int = 7;
+pub const LUA_TTHREAD: c_int = 8;
+
+pub const LUA_NUMTAGS: c_int = 9;
+
+/// Minimum Lua stack available to a C function
+pub const LUA_MINSTACK: c_int = 20;
+
+// Predefined values in the registry
+pub const LUA_RIDX_MAINTHREAD: lua_Integer = 1;
+pub const LUA_RIDX_GLOBALS: lua_Integer = 2;
+pub const LUA_RIDX_LAST: lua_Integer = LUA_RIDX_GLOBALS;
+
+/// A Lua number, usually equivalent to `f64`
+pub type lua_Number = c_double;
+
+/// A Lua integer, usually equivalent to `i64`
+pub type lua_Integer = i64;
+
+/// A Lua unsigned integer, usually equivalent to `u64`
+pub type lua_Unsigned = u64;
+
+/// Type for continuation-function contexts
+pub type lua_KContext = isize;
+
+/// Type for native C functions that can be passed to Lua
+pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+
+/// Type for continuation functions
+pub type lua_KFunction =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, status: c_int, ctx: lua_KContext) -> c_int;
+
+// Type for functions that read/write blocks when loading/dumping Lua chunks
+#[rustfmt::skip]
+pub type lua_Reader =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
+#[rustfmt::skip]
+pub type lua_Writer =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+
+/// Type for memory-allocation functions
+#[rustfmt::skip]
+pub type lua_Alloc =
+    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // State manipulation
+    //
+    pub fn lua_newstate(f: lua_Alloc, ud: *mut c_void) -> *mut lua_State;
+    pub fn lua_close(L: *mut lua_State);
+    pub fn lua_newthread(L: *mut lua_State) -> *mut lua_State;
+
+    pub fn lua_atpanic(L: *mut lua_State, panicf: lua_CFunction) -> lua_CFunction;
+
+    pub fn lua_version(L: *mut lua_State) -> *const lua_Number;
+
+    //
+    // Basic stack manipulation
+    //
+    pub fn lua_absindex(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_gettop(L: *mut lua_State) -> c_int;
+    pub fn lua_settop(L: *mut lua_State, idx: c_int);
+    pub fn lua_pushvalue(L: *mut lua_State, idx: c_int);
+    pub fn lua_rotate(L: *mut lua_State, idx: c_int, n: c_int);
+    pub fn lua_copy(L: *mut lua_State, fromidx: c_int, toidx: c_int);
+    pub fn lua_checkstack(L: *mut lua_State, sz: c_int) -> c_int;
+
+    pub fn lua_xmove(from: *mut lua_State, to: *mut lua_State, n: c_int);
+
+    //
+    // Access functions (stack -> C)
+    //
+    pub fn lua_isnumber(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isstring(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_iscfunction(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isuserdata(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_type(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_typename(L: *mut lua_State, tp: c_int) -> *const c_char;
+
+    pub fn lua_tonumberx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Number;
+    pub fn lua_tointegerx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Integer;
+    pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize;
+    pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> Option<lua_CFunction>;
+    pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
+    pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
+    pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
+}
+
+//
+// Comparison and arithmetic functions
+//
+pub const LUA_OPADD: c_int = 0;
+pub const LUA_OPSUB: c_int = 1;
+pub const LUA_OPMUL: c_int = 2;
+pub const LUA_OPMOD: c_int = 3;
+pub const LUA_OPPOW: c_int = 4;
+pub const LUA_OPDIV: c_int = 5;
+pub const LUA_OPIDIV: c_int = 6;
+pub const LUA_OPBAND: c_int = 7;
+pub const LUA_OPBOR: c_int = 8;
+pub const LUA_OPBXOR: c_int = 9;
+pub const LUA_OPSHL: c_int = 10;
+pub const LUA_OPSHR: c_int = 11;
+pub const LUA_OPUNM: c_int = 12;
+pub const LUA_OPBNOT: c_int = 13;
+
+pub const LUA_OPEQ: c_int = 0;
+pub const LUA_OPLT: c_int = 1;
+pub const LUA_OPLE: c_int = 2;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_arith(L: *mut lua_State, op: c_int);
+    pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+    pub fn lua_compare(L: *mut lua_State, idx1: c_int, idx2: c_int, op: c_int) -> c_int;
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Push functions (C -> stack)
+    //
+    pub fn lua_pushnil(L: *mut lua_State);
+    pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
+    pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
+    pub fn lua_pushlstring(L: *mut lua_State, s: *const c_char, len: usize) -> *const c_char;
+    pub fn lua_pushstring(L: *mut lua_State, s: *const c_char) -> *const c_char;
+    // lua_pushvfstring
+    pub fn lua_pushfstring(L: *mut lua_State, fmt: *const c_char, ...) -> *const c_char;
+    pub fn lua_pushcclosure(L: *mut lua_State, f: lua_CFunction, n: c_int);
+    pub fn lua_pushboolean(L: *mut lua_State, b: c_int);
+    pub fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void);
+    pub fn lua_pushthread(L: *mut lua_State) -> c_int;
+
+    //
+    // Get functions (Lua -> stack)
+    //
+    pub fn lua_getglobal(L: *mut lua_State, name: *const c_char) -> c_int;
+    pub fn lua_gettable(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int;
+    pub fn lua_geti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int;
+    pub fn lua_rawget(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int;
+    pub fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int;
+
+    pub fn lua_createtable(L: *mut lua_State, narr: c_int, nrec: c_int);
+    pub fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void;
+    pub fn lua_getmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int;
+
+    //
+    // Set functions (stack -> Lua)
+    //
+    pub fn lua_setglobal(L: *mut lua_State, name: *const c_char);
+    pub fn lua_settable(L: *mut lua_State, idx: c_int);
+    pub fn lua_setfield(L: *mut lua_State, idx: c_int, k: *const c_char);
+    pub fn lua_seti(L: *mut lua_State, idx: c_int, n: lua_Integer);
+    pub fn lua_rawset(L: *mut lua_State, idx: c_int);
+    pub fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer);
+    pub fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void);
+    pub fn lua_setmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_setuservalue(L: *mut lua_State, idx: c_int);
+
+    //
+    // 'load' and 'call' functions (load and run Lua code)
+    //
+    pub fn lua_callk(
+        L: *mut lua_State,
+        nargs: c_int,
+        nresults: c_int,
+        ctx: lua_KContext,
+        k: Option<lua_KFunction>,
+    );
+    pub fn lua_pcallk(
+        L: *mut lua_State,
+        nargs: c_int,
+        nresults: c_int,
+        errfunc: c_int,
+        ctx: lua_KContext,
+        k: Option<lua_KFunction>,
+    ) -> c_int;
+
+    pub fn lua_load(
+        L: *mut lua_State,
+        reader: lua_Reader,
+        data: *mut c_void,
+        chunkname: *const c_char,
+        mode: *const c_char,
+    ) -> c_int;
+
+    pub fn lua_dump(
+        L: *mut lua_State,
+        writer: lua_Writer,
+        data: *mut c_void,
+        strip: c_int,
+    ) -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn lua_call(L: *mut lua_State, n: c_int, r: c_int) {
+    lua_callk(L, n, r, 0, None)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_int {
+    lua_pcallk(L, n, r, f, 0, None)
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Coroutine functions
+    //
+    pub fn lua_yieldk(
+        L: *mut lua_State,
+        nresults: c_int,
+        ctx: lua_KContext,
+        k: Option<lua_KFunction>,
+    ) -> c_int;
+    #[link_name = "lua_resume"]
+    pub fn lua_resume_(L: *mut lua_State, from: *mut lua_State, narg: c_int) -> c_int;
+    pub fn lua_status(L: *mut lua_State) -> c_int;
+    pub fn lua_isyieldable(L: *mut lua_State) -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn lua_yield(L: *mut lua_State, n: c_int) -> c_int {
+    lua_yieldk(L, n, 0, None)
+}
+
+//
+// Garbage-collection function and options
+//
+pub const LUA_GCSTOP: c_int = 0;
+pub const LUA_GCRESTART: c_int = 1;
+pub const LUA_GCCOLLECT: c_int = 2;
+pub const LUA_GCCOUNT: c_int = 3;
+pub const LUA_GCCOUNTB: c_int = 4;
+pub const LUA_GCSTEP: c_int = 5;
+pub const LUA_GCSETPAUSE: c_int = 6;
+pub const LUA_GCSETSTEPMUL: c_int = 7;
+pub const LUA_GCISRUNNING: c_int = 9;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Miscellaneous functions
+    //
+    #[link_name = "lua_error"]
+    fn lua_error_(L: *mut lua_State) -> c_int;
+    pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_concat(L: *mut lua_State, n: c_int);
+    pub fn lua_len(L: *mut lua_State, idx: c_int);
+    pub fn lua_stringtonumber(L: *mut lua_State, s: *const c_char) -> usize;
+    pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
+    pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
+}
+
+// lua_error does not return but is declared to return int, and Rust translates
+// ! to void which can cause link-time errors if the platform linker is aware
+// of return types and requires they match (for example: wasm does this).
+#[inline(always)]
+pub unsafe fn lua_error(L: *mut lua_State) -> ! {
+    lua_error_(L);
+    unreachable!();
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+#[inline(always)]
+pub unsafe fn lua_getextraspace(L: *mut lua_State) -> *mut c_void {
+    (L as *mut c_char).sub(LUA_EXTRASPACE) as *mut c_void
+}
+
+#[inline(always)]
+pub unsafe fn lua_tonumber(L: *mut lua_State, i: c_int) -> lua_Number {
+    lua_tonumberx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
+    lua_tointegerx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pop(L: *mut lua_State, n: c_int) {
+    lua_settop(L, -n - 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_newtable(L: *mut lua_State) {
+    lua_createtable(L, 0, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_register(L: *mut lua_State, n: *const c_char, f: lua_CFunction) {
+    lua_pushcfunction(L, f);
+    lua_setglobal(L, n)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcfunction(L: *mut lua_State, f: lua_CFunction) {
+    lua_pushcclosure(L, f, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_isfunction(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TFUNCTION) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_istable(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTABLE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_islightuserdata(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TLIGHTUSERDATA) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNIL) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isboolean(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TBOOLEAN) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isthread(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTHREAD) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnone(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNONE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) <= 0) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) -> *const c_char {
+    use std::ffi::CString;
+    let c_str = CString::new(s).unwrap();
+    lua_pushlstring(L, c_str.as_ptr(), c_str.as_bytes().len())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushglobaltable(L: *mut lua_State) -> c_int {
+    lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS)
+}
+
+#[inline(always)]
+pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
+    if lua_islightuserdata(L, idx) != 0 {
+        return lua_touserdata(L, idx);
+    }
+    ptr::null_mut()
+}
+
+#[inline(always)]
+pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua_tolstring(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_insert(L: *mut lua_State, idx: c_int) {
+    lua_rotate(L, idx, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_remove(L: *mut lua_State, idx: c_int) {
+    lua_rotate(L, idx, -1);
+    lua_pop(L, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_replace(L: *mut lua_State, idx: c_int) {
+    lua_copy(L, -1, idx);
+    lua_pop(L, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_xpush(from: *mut lua_State, to: *mut lua_State, idx: c_int) {
+    lua_pushvalue(from, idx);
+    lua_xmove(from, to, 1);
+}
+
+//
+// Debug API
+//
+
+// Maximum size for the description of the source of a function in debug information.
+const LUA_IDSIZE: usize = 60;
+
+// Event codes
+pub const LUA_HOOKCALL: c_int = 0;
+pub const LUA_HOOKRET: c_int = 1;
+pub const LUA_HOOKLINE: c_int = 2;
+pub const LUA_HOOKCOUNT: c_int = 3;
+pub const LUA_HOOKTAILCALL: c_int = 4;
+
+// Event masks
+pub const LUA_MASKCALL: c_int = 1 << (LUA_HOOKCALL as usize);
+pub const LUA_MASKRET: c_int = 1 << (LUA_HOOKRET as usize);
+pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
+pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
+
+/// Type for functions to be called on debug events.
+pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_setlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_getupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+    pub fn lua_setupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+
+    pub fn lua_upvalueid(L: *mut lua_State, fidx: c_int, n: c_int) -> *mut c_void;
+    pub fn lua_upvaluejoin(L: *mut lua_State, fidx1: c_int, n1: c_int, fidx2: c_int, n2: c_int);
+
+    pub fn lua_sethook(L: *mut lua_State, func: Option<lua_Hook>, mask: c_int, count: c_int);
+    pub fn lua_gethook(L: *mut lua_State) -> Option<lua_Hook>;
+    pub fn lua_gethookmask(L: *mut lua_State) -> c_int;
+    pub fn lua_gethookcount(L: *mut lua_State) -> c_int;
+}
+
+#[repr(C)]
+pub struct lua_Debug {
+    pub event: c_int,
+    pub name: *const c_char,
+    pub namewhat: *const c_char,
+    pub what: *const c_char,
+    pub source: *const c_char,
+    pub currentline: c_int,
+    pub linedefined: c_int,
+    pub lastlinedefined: c_int,
+    pub nups: c_uchar,
+    pub nparams: c_uchar,
+    pub isvararg: c_char,
+    pub istailcall: c_char,
+    pub short_src: [c_char; LUA_IDSIZE],
+    // lua.h mentions this is for private use
+    i_ci: *mut c_void,
+}

mlua-sys/src/lua53/lualib.rs

@@ -0,0 +1,34 @@
+//! Contains definitions from `lualib.h`.
+
+use std::os::raw::c_int;
+
+use super::lua::lua_State;
+
+pub const LUA_COLIBNAME: &str = "coroutine";
+pub const LUA_TABLIBNAME: &str = "table";
+pub const LUA_IOLIBNAME: &str = "io";
+pub const LUA_OSLIBNAME: &str = "os";
+pub const LUA_STRLIBNAME: &str = "string";
+pub const LUA_UTF8LIBNAME: &str = "utf8";
+pub const LUA_BITLIBNAME: &str = "bit32";
+pub const LUA_MATHLIBNAME: &str = "math";
+pub const LUA_DBLIBNAME: &str = "debug";
+pub const LUA_LOADLIBNAME: &str = "package";
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua53", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaopen_base(L: *mut lua_State) -> c_int;
+    pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
+    pub fn luaopen_table(L: *mut lua_State) -> c_int;
+    pub fn luaopen_io(L: *mut lua_State) -> c_int;
+    pub fn luaopen_os(L: *mut lua_State) -> c_int;
+    pub fn luaopen_string(L: *mut lua_State) -> c_int;
+    pub fn luaopen_utf8(L: *mut lua_State) -> c_int;
+    pub fn luaopen_bit32(L: *mut lua_State) -> c_int;
+    pub fn luaopen_math(L: *mut lua_State) -> c_int;
+    pub fn luaopen_debug(L: *mut lua_State) -> c_int;
+    pub fn luaopen_package(L: *mut lua_State) -> c_int;
+
+    // open all builtin libraries
+    pub fn luaL_openlibs(L: *mut lua_State);
+}

mlua-sys/src/lua53/mod.rs

@@ -0,0 +1,11 @@
+//! Low level bindings to Lua 5.3.
+
+pub use compat::*;
+pub use lauxlib::*;
+pub use lua::*;
+pub use lualib::*;
+
+pub mod compat;
+pub mod lauxlib;
+pub mod lua;
+pub mod lualib;

mlua-sys/src/lua54/lauxlib.rs

@@ -0,0 +1,189 @@
+//! Contains definitions from `lauxlib.h`.
+
+use std::os::raw::{c_char, c_int, c_void};
+use std::ptr;
+
+use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State};
+
+// Extra error code for 'luaL_loadfilex'
+pub const LUA_ERRFILE: c_int = lua::LUA_ERRERR + 1;
+
+// Key, in the registry, for table of loaded modules
+pub const LUA_LOADED_TABLE: &str = "_LOADED";
+
+// Key, in the registry, for table of preloaded loaders
+pub const LUA_PRELOAD_TABLE: &str = "_PRELOAD";
+
+#[repr(C)]
+pub struct luaL_Reg {
+    pub name: *const c_char,
+    pub func: lua_CFunction,
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number, sz: usize);
+
+    pub fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    pub fn luaL_callmeta(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    pub fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn luaL_argerror(L: *mut lua_State, arg: c_int, extramsg: *const c_char) -> c_int;
+    pub fn luaL_checklstring(L: *mut lua_State, arg: c_int, l: *mut usize) -> *const c_char;
+    pub fn luaL_optlstring(
+        L: *mut lua_State,
+        arg: c_int,
+        def: *const c_char,
+        l: *mut usize,
+    ) -> *const c_char;
+    pub fn luaL_checknumber(L: *mut lua_State, arg: c_int) -> lua_Number;
+    pub fn luaL_optnumber(L: *mut lua_State, arg: c_int, def: lua_Number) -> lua_Number;
+    pub fn luaL_checkinteger(L: *mut lua_State, arg: c_int) -> lua_Integer;
+    pub fn luaL_optinteger(L: *mut lua_State, arg: c_int, def: lua_Integer) -> lua_Integer;
+
+    pub fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char);
+    pub fn luaL_checktype(L: *mut lua_State, arg: c_int, t: c_int);
+    pub fn luaL_checkany(L: *mut lua_State, arg: c_int);
+
+    pub fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int;
+    pub fn luaL_setmetatable(L: *mut lua_State, tname: *const c_char);
+    pub fn luaL_testudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+    pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+
+    pub fn luaL_where(L: *mut lua_State, lvl: c_int);
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> c_int;
+
+    pub fn luaL_checkoption(
+        L: *mut lua_State,
+        arg: c_int,
+        def: *const c_char,
+        lst: *const *const c_char,
+    ) -> c_int;
+
+    pub fn luaL_fileresult(L: *mut lua_State, stat: c_int, fname: *const c_char) -> c_int;
+    pub fn luaL_execresult(L: *mut lua_State, stat: c_int) -> c_int;
+}
+
+// Pre-defined references
+pub const LUA_NOREF: c_int = -2;
+pub const LUA_REFNIL: c_int = -1;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
+    pub fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int);
+
+    pub fn luaL_loadfilex(L: *mut lua_State, filename: *const c_char, mode: *const c_char)
+        -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
+    luaL_loadfilex(L, f, ptr::null())
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaL_loadbufferx(
+        L: *mut lua_State,
+        buff: *const c_char,
+        sz: usize,
+        name: *const c_char,
+        mode: *const c_char,
+    ) -> c_int;
+    pub fn luaL_loadstring(L: *mut lua_State, s: *const c_char) -> c_int;
+
+    pub fn luaL_newstate() -> *mut lua_State;
+
+    pub fn luaL_len(L: *mut lua_State, idx: c_int) -> lua_Integer;
+
+    // TODO: luaL_addgsub
+
+    pub fn luaL_gsub(
+        L: *mut lua_State,
+        s: *const c_char,
+        p: *const c_char,
+        r: *const c_char,
+    ) -> *const c_char;
+
+    pub fn luaL_setfuncs(L: *mut lua_State, l: *const luaL_Reg, nup: c_int);
+
+    pub fn luaL_getsubtable(L: *mut lua_State, idx: c_int, fname: *const c_char) -> c_int;
+
+    pub fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const c_char, level: c_int);
+
+    pub fn luaL_requiref(
+        L: *mut lua_State,
+        modname: *const c_char,
+        openf: lua_CFunction,
+        glb: c_int,
+    );
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+
+// TODO: luaL_newlibtable, luaL_newlib
+
+#[inline(always)]
+pub unsafe fn luaL_argcheck(L: *mut lua_State, cond: c_int, arg: c_int, extramsg: *const c_char) {
+    if cond == 0 {
+        luaL_argerror(L, arg, extramsg);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_checkstring(L: *mut lua_State, n: c_int) -> *const c_char {
+    luaL_checklstring(L, n, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_optstring(L: *mut lua_State, n: c_int, d: *const c_char) -> *const c_char {
+    luaL_optlstring(L, n, d, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_typename(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua::lua_typename(L, lua::lua_type(L, i))
+}
+
+#[inline(always)]
+pub unsafe fn luaL_dofile(L: *mut lua_State, filename: *const c_char) -> c_int {
+    let status = luaL_loadfile(L, filename);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_dostring(L: *mut lua_State, s: *const c_char) -> c_int {
+    let status = luaL_loadstring(L, s);
+    if status == 0 {
+        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
+    } else {
+        status
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_getmetatable(L: *mut lua_State, n: *const c_char) {
+    lua::lua_getfield(L, lua::LUA_REGISTRYINDEX, n);
+}
+
+// luaL_opt would be implemented here but it is undocumented, so it's omitted
+
+#[inline(always)]
+pub unsafe fn luaL_loadbuffer(
+    L: *mut lua_State,
+    s: *const c_char,
+    sz: usize,
+    n: *const c_char,
+) -> c_int {
+    luaL_loadbufferx(L, s, sz, n, ptr::null())
+}
+
+//
+// TODO: Generic Buffer Manipulation
+//

mlua-sys/src/lua54/lua.rs

@@ -0,0 +1,572 @@
+//! Contains definitions from `lua.h`.
+
+use std::marker::{PhantomData, PhantomPinned};
+use std::mem;
+use std::os::raw::{c_char, c_double, c_int, c_uchar, c_ushort, c_void};
+use std::ptr;
+
+// Mark for precompiled code (`<esc>Lua`)
+pub const LUA_SIGNATURE: &[u8] = b"\x1bLua";
+
+// Option for multiple returns in 'lua_pcall' and 'lua_call'
+pub const LUA_MULTRET: c_int = -1;
+
+// Size of the Lua stack
+pub const LUAI_MAXSTACK: c_int = 1000000;
+
+// Size of a raw memory area associated with  a Lua state with very fast access.
+pub const LUA_EXTRASPACE: usize = mem::size_of::<*const ()>();
+
+//
+// Pseudo-indices
+//
+pub const LUA_REGISTRYINDEX: c_int = -LUAI_MAXSTACK - 1000;
+
+pub const fn lua_upvalueindex(i: c_int) -> c_int {
+    LUA_REGISTRYINDEX - i
+}
+
+//
+// Thread status
+//
+pub const LUA_OK: c_int = 0;
+pub const LUA_YIELD: c_int = 1;
+pub const LUA_ERRRUN: c_int = 2;
+pub const LUA_ERRSYNTAX: c_int = 3;
+pub const LUA_ERRMEM: c_int = 4;
+pub const LUA_ERRERR: c_int = 5;
+
+/// A raw Lua state associated with a thread.
+#[repr(C)]
+pub struct lua_State {
+    _data: [u8; 0],
+    _marker: PhantomData<(*mut u8, PhantomPinned)>,
+}
+
+//
+// Basic types
+//
+pub const LUA_TNONE: c_int = -1;
+
+pub const LUA_TNIL: c_int = 0;
+pub const LUA_TBOOLEAN: c_int = 1;
+pub const LUA_TLIGHTUSERDATA: c_int = 2;
+pub const LUA_TNUMBER: c_int = 3;
+pub const LUA_TSTRING: c_int = 4;
+pub const LUA_TTABLE: c_int = 5;
+pub const LUA_TFUNCTION: c_int = 6;
+pub const LUA_TUSERDATA: c_int = 7;
+pub const LUA_TTHREAD: c_int = 8;
+
+pub const LUA_NUMTYPES: c_int = 9;
+
+/// Minimum Lua stack available to a C function
+pub const LUA_MINSTACK: c_int = 20;
+
+// Predefined values in the registry
+pub const LUA_RIDX_MAINTHREAD: lua_Integer = 1;
+pub const LUA_RIDX_GLOBALS: lua_Integer = 2;
+pub const LUA_RIDX_LAST: lua_Integer = LUA_RIDX_GLOBALS;
+
+/// A Lua number, usually equivalent to `f64`
+pub type lua_Number = c_double;
+
+/// A Lua integer, usually equivalent to `i64`
+pub type lua_Integer = i64;
+
+/// A Lua unsigned integer, usually equivalent to `u64`
+pub type lua_Unsigned = u64;
+
+/// Type for continuation-function contexts
+pub type lua_KContext = isize;
+
+/// Type for native C functions that can be passed to Lua
+pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+
+/// Type for continuation functions
+pub type lua_KFunction =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, status: c_int, ctx: lua_KContext) -> c_int;
+
+// Type for functions that read/write blocks when loading/dumping Lua chunks
+#[rustfmt::skip]
+pub type lua_Reader =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
+#[rustfmt::skip]
+pub type lua_Writer =
+    unsafe extern "C-unwind" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
+
+/// Type for memory-allocation functions
+#[rustfmt::skip]
+pub type lua_Alloc =
+    unsafe extern "C-unwind" fn(ud: *mut c_void, ptr: *mut c_void, osize: usize, nsize: usize) -> *mut c_void;
+
+/// Type for warning functions
+pub type lua_WarnFunction =
+    unsafe extern "C-unwind" fn(ud: *mut c_void, msg: *const c_char, tocont: c_int);
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // State manipulation
+    //
+    pub fn lua_newstate(f: lua_Alloc, ud: *mut c_void) -> *mut lua_State;
+    pub fn lua_close(L: *mut lua_State);
+    pub fn lua_newthread(L: *mut lua_State) -> *mut lua_State;
+    // Deprecated in Lua 5.4.6
+    pub fn lua_resetthread(L: *mut lua_State) -> c_int;
+    #[cfg(feature = "vendored")]
+    pub fn lua_closethread(L: *mut lua_State, from: *mut lua_State) -> c_int;
+
+    pub fn lua_atpanic(L: *mut lua_State, panicf: lua_CFunction) -> lua_CFunction;
+
+    pub fn lua_version(L: *mut lua_State) -> lua_Number;
+
+    //
+    // Basic stack manipulation
+    //
+    pub fn lua_absindex(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_gettop(L: *mut lua_State) -> c_int;
+    pub fn lua_settop(L: *mut lua_State, idx: c_int);
+    pub fn lua_pushvalue(L: *mut lua_State, idx: c_int);
+    pub fn lua_rotate(L: *mut lua_State, idx: c_int, n: c_int);
+    pub fn lua_copy(L: *mut lua_State, fromidx: c_int, toidx: c_int);
+    pub fn lua_checkstack(L: *mut lua_State, sz: c_int) -> c_int;
+
+    pub fn lua_xmove(from: *mut lua_State, to: *mut lua_State, n: c_int);
+
+    //
+    // Access functions (stack -> C)
+    //
+    pub fn lua_isnumber(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isstring(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_iscfunction(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isuserdata(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_type(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_typename(L: *mut lua_State, tp: c_int) -> *const c_char;
+
+    pub fn lua_tonumberx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Number;
+    pub fn lua_tointegerx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Integer;
+    pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    #[link_name = "lua_rawlen"]
+    fn lua_rawlen_(L: *mut lua_State, idx: c_int) -> lua_Unsigned;
+    pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> Option<lua_CFunction>;
+    pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
+    pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
+    pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
+}
+
+// lua_rawlen's return type changed from size_t to lua_Unsigned int in Lua 5.4.
+// This adapts the crate API to the new Lua ABI.
+#[inline(always)]
+pub unsafe fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize {
+    lua_rawlen_(L, idx) as usize
+}
+
+//
+// Comparison and arithmetic functions
+//
+pub const LUA_OPADD: c_int = 0;
+pub const LUA_OPSUB: c_int = 1;
+pub const LUA_OPMUL: c_int = 2;
+pub const LUA_OPMOD: c_int = 3;
+pub const LUA_OPPOW: c_int = 4;
+pub const LUA_OPDIV: c_int = 5;
+pub const LUA_OPIDIV: c_int = 6;
+pub const LUA_OPBAND: c_int = 7;
+pub const LUA_OPBOR: c_int = 8;
+pub const LUA_OPBXOR: c_int = 9;
+pub const LUA_OPSHL: c_int = 10;
+pub const LUA_OPSHR: c_int = 11;
+pub const LUA_OPUNM: c_int = 12;
+pub const LUA_OPBNOT: c_int = 13;
+
+pub const LUA_OPEQ: c_int = 0;
+pub const LUA_OPLT: c_int = 1;
+pub const LUA_OPLE: c_int = 2;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_arith(L: *mut lua_State, op: c_int);
+    pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+    pub fn lua_compare(L: *mut lua_State, idx1: c_int, idx2: c_int, op: c_int) -> c_int;
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Push functions (C -> stack)
+    //
+    pub fn lua_pushnil(L: *mut lua_State);
+    pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
+    pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
+    pub fn lua_pushlstring(L: *mut lua_State, s: *const c_char, len: usize) -> *const c_char;
+    pub fn lua_pushstring(L: *mut lua_State, s: *const c_char) -> *const c_char;
+    // lua_pushvfstring
+    pub fn lua_pushfstring(L: *mut lua_State, fmt: *const c_char, ...) -> *const c_char;
+    pub fn lua_pushcclosure(L: *mut lua_State, f: lua_CFunction, n: c_int);
+    pub fn lua_pushboolean(L: *mut lua_State, b: c_int);
+    pub fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void);
+    pub fn lua_pushthread(L: *mut lua_State) -> c_int;
+
+    //
+    // Get functions (Lua -> stack)
+    //
+    pub fn lua_getglobal(L: *mut lua_State, name: *const c_char) -> c_int;
+    pub fn lua_gettable(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int;
+    pub fn lua_geti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int;
+    pub fn lua_rawget(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int;
+    pub fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int;
+
+    pub fn lua_createtable(L: *mut lua_State, narr: c_int, nrec: c_int);
+    pub fn lua_newuserdatauv(L: *mut lua_State, sz: usize, nuvalue: c_int) -> *mut c_void;
+    pub fn lua_getmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_getiuservalue(L: *mut lua_State, idx: c_int, n: c_int) -> c_int;
+
+    //
+    // Set functions (stack -> Lua)
+    //
+    pub fn lua_setglobal(L: *mut lua_State, name: *const c_char);
+    pub fn lua_settable(L: *mut lua_State, idx: c_int);
+    pub fn lua_setfield(L: *mut lua_State, idx: c_int, k: *const c_char);
+    pub fn lua_seti(L: *mut lua_State, idx: c_int, n: lua_Integer);
+    pub fn lua_rawset(L: *mut lua_State, idx: c_int);
+    pub fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer);
+    pub fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void);
+    pub fn lua_setmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_setiuservalue(L: *mut lua_State, idx: c_int, n: c_int) -> c_int;
+
+    //
+    // 'load' and 'call' functions (load and run Lua code)
+    //
+    pub fn lua_callk(
+        L: *mut lua_State,
+        nargs: c_int,
+        nresults: c_int,
+        ctx: lua_KContext,
+        k: Option<lua_KFunction>,
+    );
+    pub fn lua_pcallk(
+        L: *mut lua_State,
+        nargs: c_int,
+        nresults: c_int,
+        errfunc: c_int,
+        ctx: lua_KContext,
+        k: Option<lua_KFunction>,
+    ) -> c_int;
+
+    pub fn lua_load(
+        L: *mut lua_State,
+        reader: lua_Reader,
+        data: *mut c_void,
+        chunkname: *const c_char,
+        mode: *const c_char,
+    ) -> c_int;
+
+    pub fn lua_dump(
+        L: *mut lua_State,
+        writer: lua_Writer,
+        data: *mut c_void,
+        strip: c_int,
+    ) -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn lua_call(L: *mut lua_State, n: c_int, r: c_int) {
+    lua_callk(L, n, r, 0, None)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_int {
+    lua_pcallk(L, n, r, f, 0, None)
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Coroutine functions
+    //
+    pub fn lua_yieldk(
+        L: *mut lua_State,
+        nresults: c_int,
+        ctx: lua_KContext,
+        k: Option<lua_KFunction>,
+    ) -> c_int;
+    pub fn lua_resume(
+        L: *mut lua_State,
+        from: *mut lua_State,
+        narg: c_int,
+        nres: *mut c_int,
+    ) -> c_int;
+    pub fn lua_status(L: *mut lua_State) -> c_int;
+    pub fn lua_isyieldable(L: *mut lua_State) -> c_int;
+}
+
+#[inline(always)]
+pub unsafe fn lua_yield(L: *mut lua_State, n: c_int) -> c_int {
+    lua_yieldk(L, n, 0, None)
+}
+
+//
+// Warning-related functions
+//
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_setwarnf(L: *mut lua_State, f: Option<lua_WarnFunction>, ud: *mut c_void);
+    pub fn lua_warning(L: *mut lua_State, msg: *const c_char, tocont: c_int);
+}
+
+//
+// Garbage-collection function and options
+//
+pub const LUA_GCSTOP: c_int = 0;
+pub const LUA_GCRESTART: c_int = 1;
+pub const LUA_GCCOLLECT: c_int = 2;
+pub const LUA_GCCOUNT: c_int = 3;
+pub const LUA_GCCOUNTB: c_int = 4;
+pub const LUA_GCSTEP: c_int = 5;
+pub const LUA_GCSETPAUSE: c_int = 6;
+pub const LUA_GCSETSTEPMUL: c_int = 7;
+pub const LUA_GCISRUNNING: c_int = 9;
+pub const LUA_GCGEN: c_int = 10;
+pub const LUA_GCINC: c_int = 11;
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_gc(L: *mut lua_State, what: c_int, ...) -> c_int;
+}
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    //
+    // Miscellaneous functions
+    //
+    #[link_name = "lua_error"]
+    fn lua_error_(L: *mut lua_State) -> c_int;
+    pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_concat(L: *mut lua_State, n: c_int);
+    pub fn lua_len(L: *mut lua_State, idx: c_int);
+    pub fn lua_stringtonumber(L: *mut lua_State, s: *const c_char) -> usize;
+    pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
+    pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
+
+    pub fn lua_toclose(L: *mut lua_State, idx: c_int);
+    pub fn lua_closeslot(L: *mut lua_State, idx: c_int);
+}
+
+// lua_error does not return but is declared to return int, and Rust translates
+// ! to void which can cause link-time errors if the platform linker is aware
+// of return types and requires they match (for example: wasm does this).
+#[inline(always)]
+pub unsafe fn lua_error(L: *mut lua_State) -> ! {
+    lua_error_(L);
+    unreachable!();
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+#[inline(always)]
+pub unsafe fn lua_getextraspace(L: *mut lua_State) -> *mut c_void {
+    (L as *mut c_char).sub(LUA_EXTRASPACE) as *mut c_void
+}
+
+#[inline(always)]
+pub unsafe fn lua_tonumber(L: *mut lua_State, i: c_int) -> lua_Number {
+    lua_tonumberx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
+    lua_tointegerx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pop(L: *mut lua_State, n: c_int) {
+    lua_settop(L, -n - 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_newtable(L: *mut lua_State) {
+    lua_createtable(L, 0, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_register(L: *mut lua_State, n: *const c_char, f: lua_CFunction) {
+    lua_pushcfunction(L, f);
+    lua_setglobal(L, n)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcfunction(L: *mut lua_State, f: lua_CFunction) {
+    lua_pushcclosure(L, f, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_isfunction(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TFUNCTION) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_istable(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTABLE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_islightuserdata(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TLIGHTUSERDATA) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNIL) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isboolean(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TBOOLEAN) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isthread(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTHREAD) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnone(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNONE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) <= 0) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) -> *const c_char {
+    use std::ffi::CString;
+    let c_str = CString::new(s).unwrap();
+    lua_pushlstring(L, c_str.as_ptr(), c_str.as_bytes().len())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushglobaltable(L: *mut lua_State) -> c_int {
+    lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS)
+}
+
+#[inline(always)]
+pub unsafe fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void {
+    if lua_islightuserdata(L, idx) != 0 {
+        return lua_touserdata(L, idx);
+    }
+    ptr::null_mut()
+}
+
+#[inline(always)]
+pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua_tolstring(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_insert(L: *mut lua_State, idx: c_int) {
+    lua_rotate(L, idx, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_remove(L: *mut lua_State, idx: c_int) {
+    lua_rotate(L, idx, -1);
+    lua_pop(L, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_replace(L: *mut lua_State, idx: c_int) {
+    lua_copy(L, -1, idx);
+    lua_pop(L, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_xpush(from: *mut lua_State, to: *mut lua_State, idx: c_int) {
+    lua_pushvalue(from, idx);
+    lua_xmove(from, to, 1);
+}
+
+#[inline(always)]
+pub unsafe fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void {
+    lua_newuserdatauv(L, sz, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int {
+    lua_getiuservalue(L, idx, 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_setuservalue(L: *mut lua_State, idx: c_int) -> c_int {
+    lua_setiuservalue(L, idx, 1)
+}
+
+//
+// Debug API
+//
+
+// Maximum size for the description of the source of a function in debug information.
+const LUA_IDSIZE: usize = 60;
+
+// Event codes
+pub const LUA_HOOKCALL: c_int = 0;
+pub const LUA_HOOKRET: c_int = 1;
+pub const LUA_HOOKLINE: c_int = 2;
+pub const LUA_HOOKCOUNT: c_int = 3;
+pub const LUA_HOOKTAILCALL: c_int = 4;
+
+// Event masks
+pub const LUA_MASKCALL: c_int = 1 << (LUA_HOOKCALL as usize);
+pub const LUA_MASKRET: c_int = 1 << (LUA_HOOKRET as usize);
+pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
+pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
+
+/// Type for functions to be called on debug events.
+pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
+    pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_setlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
+    pub fn lua_getupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+    pub fn lua_setupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+
+    pub fn lua_upvalueid(L: *mut lua_State, fidx: c_int, n: c_int) -> *mut c_void;
+    pub fn lua_upvaluejoin(L: *mut lua_State, fidx1: c_int, n1: c_int, fidx2: c_int, n2: c_int);
+
+    pub fn lua_sethook(L: *mut lua_State, func: Option<lua_Hook>, mask: c_int, count: c_int);
+    pub fn lua_gethook(L: *mut lua_State) -> Option<lua_Hook>;
+    pub fn lua_gethookmask(L: *mut lua_State) -> c_int;
+    pub fn lua_gethookcount(L: *mut lua_State) -> c_int;
+}
+
+#[repr(C)]
+pub struct lua_Debug {
+    pub event: c_int,
+    pub name: *const c_char,
+    pub namewhat: *const c_char,
+    pub what: *const c_char,
+    pub source: *const c_char,
+    pub srclen: usize,
+    pub currentline: c_int,
+    pub linedefined: c_int,
+    pub lastlinedefined: c_int,
+    pub nups: c_uchar,
+    pub nparams: c_uchar,
+    pub isvararg: c_char,
+    pub istailcall: c_char,
+    pub ftransfer: c_ushort,
+    pub ntransfer: c_ushort,
+    pub short_src: [c_char; LUA_IDSIZE],
+    // lua.h mentions this is for private use
+    i_ci: *mut c_void,
+}

mlua-sys/src/lua54/lualib.rs

@@ -0,0 +1,32 @@
+//! Contains definitions from `lualib.h`.
+
+use std::os::raw::c_int;
+
+use super::lua::lua_State;
+
+pub const LUA_COLIBNAME: &str = "coroutine";
+pub const LUA_TABLIBNAME: &str = "table";
+pub const LUA_IOLIBNAME: &str = "io";
+pub const LUA_OSLIBNAME: &str = "os";
+pub const LUA_STRLIBNAME: &str = "string";
+pub const LUA_UTF8LIBNAME: &str = "utf8";
+pub const LUA_MATHLIBNAME: &str = "math";
+pub const LUA_DBLIBNAME: &str = "debug";
+pub const LUA_LOADLIBNAME: &str = "package";
+
+#[cfg_attr(all(windows, raw_dylib), link(name = "lua54", kind = "raw-dylib"))]
+extern "C-unwind" {
+    pub fn luaopen_base(L: *mut lua_State) -> c_int;
+    pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
+    pub fn luaopen_table(L: *mut lua_State) -> c_int;
+    pub fn luaopen_io(L: *mut lua_State) -> c_int;
+    pub fn luaopen_os(L: *mut lua_State) -> c_int;
+    pub fn luaopen_string(L: *mut lua_State) -> c_int;
+    pub fn luaopen_utf8(L: *mut lua_State) -> c_int;
+    pub fn luaopen_math(L: *mut lua_State) -> c_int;
+    pub fn luaopen_debug(L: *mut lua_State) -> c_int;
+    pub fn luaopen_package(L: *mut lua_State) -> c_int;
+
+    // open all builtin libraries
+    pub fn luaL_openlibs(L: *mut lua_State);
+}

mlua-sys/src/lua54/mod.rs

@@ -0,0 +1,9 @@
+//! Low level bindings to Lua 5.4.
+
+pub use lauxlib::*;
+pub use lua::*;
+pub use lualib::*;
+
+pub mod lauxlib;
+pub mod lua;
+pub mod lualib;

mlua-sys/src/luau/compat.rs

@@ -0,0 +1,521 @@
+//! MLua compatibility layer for Roblox Luau.
+//!
+//! Based on github.com/keplerproject/lua-compat-5.3
+
+use std::ffi::CStr;
+use std::mem;
+use std::os::raw::{c_char, c_int, c_void};
+use std::ptr;
+
+use super::lauxlib::*;
+use super::lua::*;
+use super::luacode::*;
+
+unsafe fn compat53_reverse(L: *mut lua_State, mut a: c_int, mut b: c_int) {
+    while a < b {
+        lua_pushvalue(L, a);
+        lua_pushvalue(L, b);
+        lua_replace(L, a);
+        lua_replace(L, b);
+        a += 1;
+        b -= 1;
+    }
+}
+
+const COMPAT53_LEVELS1: c_int = 12; // size of the first part of the stack
+const COMPAT53_LEVELS2: c_int = 10; // size of the second part of the stack
+
+unsafe fn compat53_findfield(L: *mut lua_State, objidx: c_int, level: c_int) -> c_int {
+    if level == 0 || lua_istable(L, -1) == 0 {
+        return 0; // not found
+    }
+
+    lua_pushnil(L); // start 'next' loop
+    while lua_next(L, -2) != 0 {
+        // for each pair in table
+        if lua_type(L, -2) == LUA_TSTRING {
+            // ignore non-string keys
+            if lua_rawequal(L, objidx, -1) != 0 {
+                // found object?
+                lua_pop(L, 1); // remove value (but keep name)
+                return 1;
+            } else if compat53_findfield(L, objidx, level - 1) != 0 {
+                // try recursively
+                lua_remove(L, -2); // remove table (but keep name)
+                lua_pushliteral(L, ".");
+                lua_insert(L, -2); // place '.' between the two names
+                lua_concat(L, 3);
+                return 1;
+            }
+        }
+        lua_pop(L, 1); // remove value
+    }
+    0 // not found
+}
+
+unsafe fn compat53_pushglobalfuncname(
+    L: *mut lua_State,
+    level: c_int,
+    ar: *mut lua_Debug,
+) -> c_int {
+    let top = lua_gettop(L);
+    // push function
+    lua_getinfo(L, level, cstr!("f"), ar);
+    lua_pushvalue(L, LUA_GLOBALSINDEX);
+    if compat53_findfield(L, top + 1, 2) != 0 {
+        lua_copy(L, -1, top + 1); // move name to proper place
+        lua_pop(L, 2); // remove pushed values
+        1
+    } else {
+        lua_settop(L, top); // remove function and global table
+        0
+    }
+}
+
+unsafe fn compat53_pushfuncname(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) {
+    if !(*ar).name.is_null() {
+        // is there a name?
+        lua_pushfstring(L, cstr!("function '%s'"), (*ar).name);
+    } else if compat53_pushglobalfuncname(L, level, ar) != 0 {
+        lua_pushfstring(L, cstr!("function '%s'"), lua_tostring(L, -1));
+        lua_remove(L, -2); // remove name
+    } else {
+        lua_pushliteral(L, "?");
+    }
+}
+
+//
+// lua ported functions
+//
+
+pub unsafe fn lua_rotate(L: *mut lua_State, mut idx: c_int, mut n: c_int) {
+    idx = lua_absindex(L, idx);
+    if n > 0 {
+        // Faster version
+        for _ in 0..n {
+            lua_insert(L, idx);
+        }
+        return;
+    }
+    let n_elems = lua_gettop(L) - idx + 1;
+    if n < 0 {
+        n += n_elems;
+    }
+    if n > 0 && n < n_elems {
+        luaL_checkstack(L, 2, cstr!("not enough stack slots available"));
+        n = n_elems - n;
+        compat53_reverse(L, idx, idx + n - 1);
+        compat53_reverse(L, idx + n, idx + n_elems - 1);
+        compat53_reverse(L, idx, idx + n_elems - 1);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn lua_copy(L: *mut lua_State, fromidx: c_int, toidx: c_int) {
+    let abs_to = lua_absindex(L, toidx);
+    luaL_checkstack(L, 1, cstr!("not enough stack slots"));
+    lua_pushvalue(L, fromidx);
+    lua_replace(L, abs_to);
+}
+
+#[inline(always)]
+pub unsafe fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int {
+    if lua_type(L, idx) == LUA_TNUMBER {
+        let n = lua_tonumber(L, idx);
+        let i = lua_tointeger(L, idx);
+        if (n - i as lua_Number).abs() < lua_Number::EPSILON {
+            return 1;
+        }
+    }
+    0
+}
+
+#[inline(always)]
+pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
+    lua_tointegerx(L, i, ptr::null_mut())
+}
+
+pub unsafe fn lua_tointegerx(L: *mut lua_State, i: c_int, isnum: *mut c_int) -> lua_Integer {
+    let mut ok = 0;
+    let n = lua_tonumberx(L, i, &mut ok);
+    let n_int = n as lua_Integer;
+    if ok != 0 && (n - n_int as lua_Number).abs() < lua_Number::EPSILON {
+        if !isnum.is_null() {
+            *isnum = 1;
+        }
+        return n_int;
+    }
+    if !isnum.is_null() {
+        *isnum = 0;
+    }
+    0
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize {
+    lua_objlen(L, idx)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushlstring(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char {
+    if l == 0 {
+        lua_pushlstring_(L, cstr!(""), 0);
+    } else {
+        lua_pushlstring_(L, s, l);
+    }
+    lua_tostring(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushstring(L: *mut lua_State, s: *const c_char) -> *const c_char {
+    lua_pushstring_(L, s);
+    lua_tostring(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_geti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) -> c_int {
+    idx = lua_absindex(L, idx);
+    lua_pushinteger(L, n);
+    lua_gettable(L, idx)
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int {
+    lua_rawgeti_(L, idx, n)
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int {
+    let abs_i = lua_absindex(L, idx);
+    lua_pushlightuserdata(L, p as *mut c_void);
+    lua_rawget(L, abs_i)
+}
+
+#[inline(always)]
+pub unsafe fn lua_getuservalue(L: *mut lua_State, mut idx: c_int) -> c_int {
+    luaL_checkstack(L, 2, cstr!("not enough stack slots available"));
+    idx = lua_absindex(L, idx);
+    lua_pushliteral(L, "__mlua_uservalues");
+    if lua_rawget(L, LUA_REGISTRYINDEX) != LUA_TTABLE {
+        return LUA_TNIL;
+    }
+    lua_pushvalue(L, idx);
+    lua_rawget(L, -2);
+    lua_remove(L, -2);
+    lua_type(L, -1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_seti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) {
+    luaL_checkstack(L, 1, cstr!("not enough stack slots available"));
+    idx = lua_absindex(L, idx);
+    lua_pushinteger(L, n);
+    lua_insert(L, -2);
+    lua_settable(L, idx);
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer) {
+    lua_rawseti_(L, idx, n)
+}
+
+#[inline(always)]
+pub unsafe fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void) {
+    let abs_i = lua_absindex(L, idx);
+    luaL_checkstack(L, 1, cstr!("not enough stack slots"));
+    lua_pushlightuserdata(L, p as *mut c_void);
+    lua_insert(L, -2);
+    lua_rawset(L, abs_i);
+}
+
+#[inline(always)]
+pub unsafe fn lua_setuservalue(L: *mut lua_State, mut idx: c_int) {
+    luaL_checkstack(L, 4, cstr!("not enough stack slots available"));
+    idx = lua_absindex(L, idx);
+    lua_pushliteral(L, "__mlua_uservalues");
+    lua_pushvalue(L, -1);
+    if lua_rawget(L, LUA_REGISTRYINDEX) != LUA_TTABLE {
+        lua_pop(L, 1);
+        lua_createtable(L, 0, 2); // main table
+        lua_createtable(L, 0, 1); // metatable
+        lua_pushliteral(L, "k");
+        lua_setfield(L, -2, cstr!("__mode"));
+        lua_setmetatable(L, -2);
+        lua_pushvalue(L, -2);
+        lua_pushvalue(L, -2);
+        lua_rawset(L, LUA_REGISTRYINDEX);
+    }
+    lua_replace(L, -2);
+    lua_pushvalue(L, idx);
+    lua_pushvalue(L, -3);
+    lua_remove(L, -4);
+    lua_rawset(L, -3);
+    lua_pop(L, 1);
+}
+
+#[inline(always)]
+pub unsafe fn lua_len(L: *mut lua_State, idx: c_int) {
+    match lua_type(L, idx) {
+        LUA_TSTRING => {
+            lua_pushnumber(L, lua_objlen(L, idx) as lua_Number);
+        }
+        LUA_TTABLE => {
+            if luaL_callmeta(L, idx, cstr!("__len")) == 0 {
+                lua_pushnumber(L, lua_objlen(L, idx) as lua_Number);
+            }
+        }
+        LUA_TUSERDATA if luaL_callmeta(L, idx, cstr!("__len")) != 0 => {}
+        _ => {
+            luaL_error(
+                L,
+                cstr!("attempt to get length of a %s value"),
+                lua_typename(L, lua_type(L, idx)),
+            );
+        }
+    }
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushglobaltable(L: *mut lua_State) {
+    lua_pushvalue(L, LUA_GLOBALSINDEX);
+}
+
+#[inline(always)]
+pub unsafe fn lua_resume(
+    L: *mut lua_State,
+    from: *mut lua_State,
+    narg: c_int,
+    nres: *mut c_int,
+) -> c_int {
+    let ret = lua_resume_(L, from, narg);
+    if (ret == LUA_OK || ret == LUA_YIELD) && !(nres.is_null()) {
+        *nres = lua_gettop(L);
+    }
+    ret
+}
+
+//
+// lauxlib ported functions
+//
+
+#[inline(always)]
+pub unsafe fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char) {
+    if lua_checkstack(L, sz + LUA_MINSTACK) == 0 {
+        if !msg.is_null() {
+            luaL_error(L, cstr!("stack overflow (%s)"), msg);
+        } else {
+            lua_pushliteral(L, "stack overflow");
+            lua_error(L);
+        }
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int {
+    if luaL_getmetafield_(L, obj, e) != 0 {
+        lua_type(L, -1)
+    } else {
+        LUA_TNIL
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int {
+    if luaL_newmetatable_(L, tname) != 0 {
+        lua_pushstring(L, tname);
+        lua_setfield(L, -2, cstr!("__type"));
+        1
+    } else {
+        0
+    }
+}
+
+pub unsafe fn luaL_loadbufferx(
+    L: *mut lua_State,
+    data: *const c_char,
+    mut size: usize,
+    name: *const c_char,
+    mode: *const c_char,
+) -> c_int {
+    extern "C" {
+        fn free(p: *mut c_void);
+    }
+
+    let chunk_is_text = size == 0 || (*data as u8) >= b'\t';
+    if !mode.is_null() {
+        let modeb = CStr::from_ptr(mode).to_bytes();
+        if !chunk_is_text && !modeb.contains(&b'b') {
+            lua_pushfstring(
+                L,
+                cstr!("attempt to load a binary chunk (mode is '%s')"),
+                mode,
+            );
+            return LUA_ERRSYNTAX;
+        } else if chunk_is_text && !modeb.contains(&b't') {
+            lua_pushfstring(
+                L,
+                cstr!("attempt to load a text chunk (mode is '%s')"),
+                mode,
+            );
+            return LUA_ERRSYNTAX;
+        }
+    }
+
+    if chunk_is_text {
+        let data = luau_compile_(data, size, ptr::null_mut(), &mut size);
+        let ok = luau_load(L, name, data, size, 0) == 0;
+        free(data as *mut c_void);
+        if !ok {
+            return LUA_ERRSYNTAX;
+        }
+    } else if luau_load(L, name, data, size, 0) != 0 {
+        return LUA_ERRSYNTAX;
+    }
+    LUA_OK
+}
+
+#[inline(always)]
+pub unsafe fn luaL_loadbuffer(
+    L: *mut lua_State,
+    data: *const c_char,
+    size: usize,
+    name: *const c_char,
+) -> c_int {
+    luaL_loadbufferx(L, data, size, name, ptr::null())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_len(L: *mut lua_State, idx: c_int) -> lua_Integer {
+    let mut isnum = 0;
+    luaL_checkstack(L, 1, cstr!("not enough stack slots"));
+    lua_len(L, idx);
+    let res = lua_tointegerx(L, -1, &mut isnum);
+    lua_pop(L, 1);
+    if isnum == 0 {
+        luaL_error(L, cstr!("object length is not an integer"));
+    }
+    res
+}
+
+pub unsafe fn luaL_traceback(
+    L: *mut lua_State,
+    L1: *mut lua_State,
+    msg: *const c_char,
+    mut level: c_int,
+) {
+    let mut ar: lua_Debug = mem::zeroed();
+    let top = lua_gettop(L);
+    let numlevels = lua_stackdepth(L);
+    let mark = if numlevels > COMPAT53_LEVELS1 + COMPAT53_LEVELS2 {
+        COMPAT53_LEVELS1
+    } else {
+        0
+    };
+
+    if !msg.is_null() {
+        lua_pushfstring(L, cstr!("%s\n"), msg);
+    }
+    lua_pushliteral(L, "stack traceback:");
+    while lua_getinfo(L1, level, cstr!(""), &mut ar) != 0 {
+        if level + 1 == mark {
+            // too many levels?
+            lua_pushliteral(L, "\n\t..."); // add a '...'
+            level = numlevels - COMPAT53_LEVELS2; // and skip to last ones
+        } else {
+            lua_getinfo(L1, level, cstr!("sln"), &mut ar);
+            lua_pushfstring(L, cstr!("\n\t%s:"), ar.short_src);
+            if ar.currentline > 0 {
+                lua_pushfstring(L, cstr!("%d:"), ar.currentline);
+            }
+            lua_pushliteral(L, " in ");
+            compat53_pushfuncname(L, level, &mut ar);
+            lua_concat(L, lua_gettop(L) - top);
+        }
+        level += 1;
+    }
+    lua_concat(L, lua_gettop(L) - top);
+}
+
+pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize) -> *const c_char {
+    idx = lua_absindex(L, idx);
+    if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
+        match lua_type(L, idx) {
+            LUA_TNIL => {
+                lua_pushliteral(L, "nil");
+            }
+            LUA_TSTRING | LUA_TNUMBER => {
+                lua_pushvalue(L, idx);
+            }
+            LUA_TBOOLEAN => {
+                if lua_toboolean(L, idx) == 0 {
+                    lua_pushliteral(L, "false");
+                } else {
+                    lua_pushliteral(L, "true");
+                }
+            }
+            t => {
+                let tt = luaL_getmetafield(L, idx, cstr!("__type"));
+                let name = if tt == LUA_TSTRING {
+                    lua_tostring(L, -1)
+                } else {
+                    lua_typename(L, t)
+                };
+                lua_pushfstring(L, cstr!("%s: %p"), name, lua_topointer(L, idx));
+                if tt != LUA_TNIL {
+                    lua_replace(L, -2); // remove '__type'
+                }
+            }
+        };
+    } else if lua_isstring(L, -1) == 0 {
+        luaL_error(L, cstr!("'__tostring' must return a string"));
+    }
+    lua_tolstring(L, -1, len)
+}
+
+#[inline(always)]
+pub unsafe fn luaL_setmetatable(L: *mut lua_State, tname: *const c_char) {
+    luaL_checkstack(L, 1, cstr!("not enough stack slots"));
+    luaL_getmetatable(L, tname);
+    lua_setmetatable(L, -2);
+}
+
+pub unsafe fn luaL_getsubtable(L: *mut lua_State, idx: c_int, fname: *const c_char) -> c_int {
+    let abs_i = lua_absindex(L, idx);
+    luaL_checkstack(L, 3, cstr!("not enough stack slots"));
+    lua_pushstring_(L, fname);
+    if lua_gettable(L, abs_i) == LUA_TTABLE {
+        return 1;
+    }
+    lua_pop(L, 1);
+    lua_newtable(L);
+    lua_pushstring_(L, fname);
+    lua_pushvalue(L, -2);
+    lua_settable(L, abs_i);
+    0
+}
+
+pub unsafe fn luaL_requiref(
+    L: *mut lua_State,
+    modname: *const c_char,
+    openf: lua_CFunction,
+    glb: c_int,
+) {
+    luaL_checkstack(L, 3, cstr!("not enough stack slots available"));
+    luaL_getsubtable(L, LUA_REGISTRYINDEX, cstr!("_LOADED"));
+    if lua_getfield(L, -1, modname) == LUA_TNIL {
+        lua_pop(L, 1);
+        lua_pushcfunction(L, openf);
+        lua_pushstring(L, modname);
+        lua_call(L, 1, 1);
+        lua_pushvalue(L, -1);
+        lua_setfield(L, -3, modname);
+    }
+    if glb != 0 {
+        lua_pushvalue(L, -1);
+        lua_setglobal(L, modname);
+    } else {
+        lua_pushnil(L);
+        lua_setglobal(L, modname);
+    }
+    lua_replace(L, -2);
+}

mlua-sys/src/luau/lauxlib.rs

@@ -0,0 +1,204 @@
+//! Contains definitions from `lualib.h`.
+
+use std::os::raw::{c_char, c_float, c_int, c_void};
+use std::ptr;
+
+use super::lua::{
+    self, lua_CFunction, lua_Integer, lua_Number, lua_State, lua_Unsigned, LUA_REGISTRYINDEX,
+};
+
+#[repr(C)]
+pub struct luaL_Reg {
+    pub name: *const c_char,
+    pub func: lua_CFunction,
+}
+
+extern "C-unwind" {
+    pub fn luaL_register(L: *mut lua_State, libname: *const c_char, l: *const luaL_Reg);
+    #[link_name = "luaL_getmetafield"]
+    pub fn luaL_getmetafield_(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    pub fn luaL_callmeta(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
+    #[link_name = "luaL_typeerrorL"]
+    pub fn luaL_typeerror(L: *mut lua_State, narg: c_int, tname: *const c_char) -> !;
+    #[link_name = "luaL_argerrorL"]
+    pub fn luaL_argerror(L: *mut lua_State, narg: c_int, extramsg: *const c_char) -> !;
+    pub fn luaL_checklstring(L: *mut lua_State, narg: c_int, l: *mut usize) -> *const c_char;
+    pub fn luaL_optlstring(
+        L: *mut lua_State,
+        narg: c_int,
+        def: *const c_char,
+        l: *mut usize,
+    ) -> *const c_char;
+    pub fn luaL_checknumber(L: *mut lua_State, narg: c_int) -> lua_Number;
+    pub fn luaL_optnumber(L: *mut lua_State, narg: c_int, def: lua_Number) -> lua_Number;
+
+    pub fn luaL_checkboolean(L: *mut lua_State, narg: c_int) -> c_int;
+    pub fn luaL_optboolean(L: *mut lua_State, narg: c_int, def: c_int) -> c_int;
+
+    pub fn luaL_checkinteger(L: *mut lua_State, narg: c_int) -> lua_Integer;
+    pub fn luaL_optinteger(L: *mut lua_State, narg: c_int, def: lua_Integer) -> lua_Integer;
+    pub fn luaL_checkunsigned(L: *mut lua_State, narg: c_int) -> lua_Unsigned;
+    pub fn luaL_optunsigned(L: *mut lua_State, narg: c_int, def: lua_Unsigned) -> lua_Unsigned;
+
+    pub fn luaL_checkvector(L: *mut lua_State, narg: c_int) -> *const c_float;
+    pub fn luaL_optvector(L: *mut lua_State, narg: c_int, def: *const c_float) -> *const c_float;
+
+    #[link_name = "luaL_checkstack"]
+    pub fn luaL_checkstack_(L: *mut lua_State, sz: c_int, msg: *const c_char);
+    pub fn luaL_checktype(L: *mut lua_State, narg: c_int, t: c_int);
+    pub fn luaL_checkany(L: *mut lua_State, narg: c_int);
+
+    #[link_name = "luaL_newmetatable"]
+    pub fn luaL_newmetatable_(L: *mut lua_State, tname: *const c_char) -> c_int;
+    pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
+
+    pub fn luaL_checkbuffer(L: *mut lua_State, narg: c_int, len: *mut usize) -> *mut c_void;
+
+    pub fn luaL_where(L: *mut lua_State, lvl: c_int);
+
+    #[link_name = "luaL_errorL"]
+    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> !;
+
+    pub fn luaL_checkoption(
+        L: *mut lua_State,
+        narg: c_int,
+        def: *const c_char,
+        lst: *const *const c_char,
+    ) -> c_int;
+
+    #[link_name = "luaL_tolstring"]
+    pub fn luaL_tolstring_(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+
+    pub fn luaL_newstate() -> *mut lua_State;
+
+    // TODO: luaL_findtable
+
+    pub fn luaL_typename(L: *mut lua_State, idx: c_int) -> *const c_char;
+
+    // sandbox libraries and globals
+    #[link_name = "luaL_sandbox"]
+    pub fn luaL_sandbox_(L: *mut lua_State);
+    pub fn luaL_sandboxthread(L: *mut lua_State);
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+
+#[inline(always)]
+pub unsafe fn luaL_argcheck(L: *mut lua_State, cond: c_int, arg: c_int, extramsg: *const c_char) {
+    if cond == 0 {
+        luaL_argerror(L, arg, extramsg);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_argexpected(L: *mut lua_State, cond: c_int, arg: c_int, tname: *const c_char) {
+    if cond == 0 {
+        luaL_typeerror(L, arg, tname);
+    }
+}
+
+#[inline(always)]
+pub unsafe fn luaL_checkstring(L: *mut lua_State, n: c_int) -> *const c_char {
+    luaL_checklstring(L, n, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn luaL_optstring(L: *mut lua_State, n: c_int, d: *const c_char) -> *const c_char {
+    luaL_optlstring(L, n, d, ptr::null_mut())
+}
+
+// TODO: luaL_opt
+
+#[inline(always)]
+pub unsafe fn luaL_getmetatable(L: *mut lua_State, n: *const c_char) -> c_int {
+    lua::lua_getfield(L, LUA_REGISTRYINDEX, n)
+}
+
+#[inline(always)]
+pub unsafe fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int {
+    assert_eq!(t, LUA_REGISTRYINDEX);
+    let r = lua::lua_ref(L, -1);
+    lua::lua_pop(L, 1);
+    r
+}
+
+#[inline(always)]
+pub unsafe fn luaL_unref(L: *mut lua_State, t: c_int, r#ref: c_int) {
+    assert_eq!(t, LUA_REGISTRYINDEX);
+    lua::lua_unref(L, r#ref)
+}
+
+pub unsafe fn luaL_sandbox(L: *mut lua_State, enabled: c_int) {
+    use super::lua::*;
+
+    // set all libraries to read-only
+    lua_pushnil(L);
+    while lua_next(L, LUA_GLOBALSINDEX) != 0 {
+        if lua_istable(L, -1) != 0 {
+            lua_setreadonly(L, -1, enabled);
+        }
+        lua_pop(L, 1);
+    }
+
+    // set all builtin metatables to read-only
+    lua_pushliteral(L, "");
+    if lua_getmetatable(L, -1) != 0 {
+        lua_setreadonly(L, -1, enabled);
+        lua_pop(L, 2);
+    } else {
+        lua_pop(L, 1);
+    }
+
+    // set globals to readonly and activate safeenv since the env is immutable
+    lua_setreadonly(L, LUA_GLOBALSINDEX, enabled);
+    lua_setsafeenv(L, LUA_GLOBALSINDEX, enabled);
+}
+
+//
+// Generic Buffer Manipulation
+//
+
+/// Buffer size used for on-stack string operations. This limit depends on native stack size.
+pub const LUA_BUFFERSIZE: usize = 512;
+
+#[repr(C)]
+pub struct luaL_Strbuf {
+    p: *mut c_char,   // current position in buffer
+    end: *mut c_char, // end of the current buffer
+    L: *mut lua_State,
+    storage: *mut c_void, // TString
+    buffer: [c_char; LUA_BUFFERSIZE],
+}
+
+// For compatibility
+pub type luaL_Buffer = luaL_Strbuf;
+
+extern "C-unwind" {
+    pub fn luaL_buffinit(L: *mut lua_State, B: *mut luaL_Strbuf);
+    pub fn luaL_buffinitsize(L: *mut lua_State, B: *mut luaL_Strbuf, size: usize) -> *mut c_char;
+    pub fn luaL_prepbuffsize(B: *mut luaL_Strbuf, size: usize) -> *mut c_char;
+    pub fn luaL_addlstring(B: *mut luaL_Strbuf, s: *const c_char, l: usize);
+    pub fn luaL_addvalue(B: *mut luaL_Strbuf);
+    pub fn luaL_addvalueany(B: *mut luaL_Strbuf, idx: c_int);
+    pub fn luaL_pushresult(B: *mut luaL_Strbuf);
+    pub fn luaL_pushresultsize(B: *mut luaL_Strbuf, size: usize);
+}
+
+pub unsafe fn luaL_addchar(B: *mut luaL_Strbuf, c: c_char) {
+    if (*B).p >= (*B).end {
+        luaL_prepbuffsize(B, 1);
+    }
+    *(*B).p = c;
+    (*B).p = (*B).p.add(1);
+}
+
+pub unsafe fn luaL_addstring(B: *mut luaL_Strbuf, s: *const c_char) {
+    // Calculate length of s
+    let mut len = 0;
+    while *s.add(len) != 0 {
+        len += 1;
+    }
+    luaL_addlstring(B, s, len);
+}

mlua-sys/src/luau/lua.rs

@@ -0,0 +1,562 @@
+//! Contains definitions from `lua.h`.
+
+use std::marker::{PhantomData, PhantomPinned};
+use std::os::raw::{c_char, c_double, c_float, c_int, c_uint, c_void};
+use std::{mem, ptr};
+
+// Option for multiple returns in 'lua_pcall' and 'lua_call'
+pub const LUA_MULTRET: c_int = -1;
+
+// Max number of Lua stack slots
+const LUAI_MAXCSTACK: c_int = 1000000;
+
+// Number of valid Lua userdata tags
+const LUA_UTAG_LIMIT: c_int = 128;
+
+// Number of valid Lua lightuserdata tags
+const LUA_LUTAG_LIMIT: c_int = 128;
+
+//
+// Pseudo-indices
+//
+pub const LUA_REGISTRYINDEX: c_int = -LUAI_MAXCSTACK - 2000;
+pub const LUA_ENVIRONINDEX: c_int = -LUAI_MAXCSTACK - 2001;
+pub const LUA_GLOBALSINDEX: c_int = -LUAI_MAXCSTACK - 2002;
+
+pub const fn lua_upvalueindex(i: c_int) -> c_int {
+    LUA_GLOBALSINDEX - i
+}
+
+//
+// Thread status
+//
+pub const LUA_OK: c_int = 0;
+pub const LUA_YIELD: c_int = 1;
+pub const LUA_ERRRUN: c_int = 2;
+pub const LUA_ERRSYNTAX: c_int = 3;
+pub const LUA_ERRMEM: c_int = 4;
+pub const LUA_ERRERR: c_int = 5;
+
+/// A raw Lua state associated with a thread.
+#[repr(C)]
+pub struct lua_State {
+    _data: [u8; 0],
+    _marker: PhantomData<(*mut u8, PhantomPinned)>,
+}
+
+//
+// Basic types
+//
+pub const LUA_TNONE: c_int = -1;
+
+pub const LUA_TNIL: c_int = 0;
+pub const LUA_TBOOLEAN: c_int = 1;
+
+pub const LUA_TLIGHTUSERDATA: c_int = 2;
+pub const LUA_TNUMBER: c_int = 3;
+pub const LUA_TVECTOR: c_int = 4;
+
+pub const LUA_TSTRING: c_int = 5;
+pub const LUA_TTABLE: c_int = 6;
+pub const LUA_TFUNCTION: c_int = 7;
+pub const LUA_TUSERDATA: c_int = 8;
+pub const LUA_TTHREAD: c_int = 9;
+pub const LUA_TBUFFER: c_int = 10;
+
+/// Guaranteed number of Lua stack slots available to a C function.
+pub const LUA_MINSTACK: c_int = 20;
+
+/// A Lua number, usually equivalent to `f64`.
+pub type lua_Number = c_double;
+
+/// A Lua integer, equivalent to `i32`.
+pub type lua_Integer = c_int;
+
+/// A Lua unsigned integer, equivalent to `u32`.
+pub type lua_Unsigned = c_uint;
+
+/// Type for native C functions that can be passed to Lua.
+pub type lua_CFunction = unsafe extern "C-unwind" fn(L: *mut lua_State) -> c_int;
+pub type lua_Continuation = unsafe extern "C-unwind" fn(L: *mut lua_State, status: c_int) -> c_int;
+
+/// Type for userdata destructor functions.
+pub type lua_Udestructor = unsafe extern "C-unwind" fn(*mut c_void);
+pub type lua_Destructor = unsafe extern "C-unwind" fn(L: *mut lua_State, *mut c_void);
+
+/// Type for memory-allocation functions.
+pub type lua_Alloc = unsafe extern "C-unwind" fn(
+    ud: *mut c_void,
+    ptr: *mut c_void,
+    osize: usize,
+    nsize: usize,
+) -> *mut c_void;
+
+/// Returns Luau release version (eg. `0.xxx`).
+pub const fn luau_version() -> Option<&'static str> {
+    option_env!("LUAU_VERSION")
+}
+
+extern "C-unwind" {
+    //
+    // State manipulation
+    //
+    pub fn lua_newstate(f: lua_Alloc, ud: *mut c_void) -> *mut lua_State;
+    pub fn lua_close(L: *mut lua_State);
+    pub fn lua_newthread(L: *mut lua_State) -> *mut lua_State;
+    pub fn lua_mainthread(L: *mut lua_State) -> *mut lua_State;
+    pub fn lua_resetthread(L: *mut lua_State);
+    pub fn lua_isthreadreset(L: *mut lua_State) -> c_int;
+
+    //
+    // Basic stack manipulation
+    //
+    pub fn lua_absindex(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_gettop(L: *mut lua_State) -> c_int;
+    pub fn lua_settop(L: *mut lua_State, idx: c_int);
+    pub fn lua_pushvalue(L: *mut lua_State, idx: c_int);
+    pub fn lua_remove(L: *mut lua_State, idx: c_int);
+    pub fn lua_insert(L: *mut lua_State, idx: c_int);
+    pub fn lua_replace(L: *mut lua_State, idx: c_int);
+    pub fn lua_checkstack(L: *mut lua_State, sz: c_int) -> c_int;
+    pub fn lua_rawcheckstack(L: *mut lua_State, sz: c_int);
+
+    pub fn lua_xmove(from: *mut lua_State, to: *mut lua_State, n: c_int);
+    pub fn lua_xpush(from: *mut lua_State, to: *mut lua_State, idx: c_int);
+
+    //
+    // Access functions (stack -> C)
+    //
+    pub fn lua_isnumber(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isstring(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_iscfunction(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isLfunction(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_isuserdata(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_type(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_typename(L: *mut lua_State, tp: c_int) -> *const c_char;
+
+    pub fn lua_equal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+    pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+    pub fn lua_lessthan(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
+
+    pub fn lua_tonumberx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Number;
+    #[link_name = "lua_tointegerx"]
+    pub fn lua_tointegerx_(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Integer;
+    pub fn lua_tounsignedx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Unsigned;
+    pub fn lua_tovector(L: *mut lua_State, idx: c_int) -> *const c_float;
+    pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
+    pub fn lua_tostringatom(L: *mut lua_State, idx: c_int, atom: *mut c_int) -> *const c_char;
+    pub fn lua_namecallatom(L: *mut lua_State, atom: *mut c_int) -> *const c_char;
+    pub fn lua_objlen(L: *mut lua_State, idx: c_int) -> usize;
+    pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> Option<lua_CFunction>;
+    pub fn lua_tolightuserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
+    pub fn lua_tolightuserdatatagged(L: *mut lua_State, idx: c_int, tag: c_int) -> *mut c_void;
+    pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
+    pub fn lua_touserdatatagged(L: *mut lua_State, idx: c_int, tag: c_int) -> *mut c_void;
+    pub fn lua_userdatatag(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_lightuserdatatag(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
+    pub fn lua_tobuffer(L: *mut lua_State, idx: c_int, len: *mut usize) -> *mut c_void;
+    pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
+
+    //
+    // Push functions (C -> stack)
+    //
+    pub fn lua_pushnil(L: *mut lua_State);
+    pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
+    pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
+    pub fn lua_pushunsigned(L: *mut lua_State, n: lua_Unsigned);
+    #[cfg(not(feature = "luau-vector4"))]
+    pub fn lua_pushvector(L: *mut lua_State, x: c_float, y: c_float, z: c_float);
+    #[cfg(feature = "luau-vector4")]
+    pub fn lua_pushvector(L: *mut lua_State, x: c_float, y: c_float, z: c_float, w: c_float);
+    #[link_name = "lua_pushlstring"]
+    pub fn lua_pushlstring_(L: *mut lua_State, s: *const c_char, l: usize);
+    #[link_name = "lua_pushstring"]
+    pub fn lua_pushstring_(L: *mut lua_State, s: *const c_char);
+    // lua_pushvfstring
+    #[link_name = "lua_pushfstringL"]
+    pub fn lua_pushfstring(L: *mut lua_State, fmt: *const c_char, ...) -> *const c_char;
+    pub fn lua_pushcclosurek(
+        L: *mut lua_State,
+        f: lua_CFunction,
+        debugname: *const c_char,
+        nup: c_int,
+        cont: Option<lua_Continuation>,
+    );
+    pub fn lua_pushboolean(L: *mut lua_State, b: c_int);
+    pub fn lua_pushthread(L: *mut lua_State) -> c_int;
+
+    pub fn lua_pushlightuserdatatagged(L: *mut lua_State, p: *mut c_void, tag: c_int);
+    pub fn lua_newuserdatatagged(L: *mut lua_State, sz: usize, tag: c_int) -> *mut c_void;
+    pub fn lua_newuserdatadtor(L: *mut lua_State, sz: usize, dtor: lua_Udestructor) -> *mut c_void;
+
+    pub fn lua_newbuffer(L: *mut lua_State, sz: usize) -> *mut c_void;
+
+    //
+    // Get functions (Lua -> stack)
+    //
+    pub fn lua_gettable(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int;
+    pub fn lua_rawgetfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int;
+    pub fn lua_rawget(L: *mut lua_State, idx: c_int) -> c_int;
+    #[link_name = "lua_rawgeti"]
+    pub fn lua_rawgeti_(L: *mut lua_State, idx: c_int, n: c_int) -> c_int;
+    pub fn lua_createtable(L: *mut lua_State, narr: c_int, nrec: c_int);
+
+    pub fn lua_setreadonly(L: *mut lua_State, idx: c_int, enabled: c_int);
+    pub fn lua_getreadonly(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_setsafeenv(L: *mut lua_State, idx: c_int, enabled: c_int);
+
+    pub fn lua_getmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_getfenv(L: *mut lua_State, idx: c_int);
+
+    //
+    // Set functions (stack -> Lua)
+    //
+    pub fn lua_settable(L: *mut lua_State, idx: c_int);
+    pub fn lua_setfield(L: *mut lua_State, idx: c_int, k: *const c_char);
+    pub fn lua_rawset(L: *mut lua_State, idx: c_int);
+    #[link_name = "lua_rawseti"]
+    pub fn lua_rawseti_(L: *mut lua_State, idx: c_int, n: c_int);
+    pub fn lua_setmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
+    pub fn lua_setfenv(L: *mut lua_State, idx: c_int) -> c_int;
+
+    //
+    // `load' and `call' functions (load and run Luau bytecode)
+    //
+    pub fn luau_load(
+        L: *mut lua_State,
+        chunkname: *const c_char,
+        data: *const c_char,
+        size: usize,
+        env: c_int,
+    ) -> c_int;
+    pub fn lua_call(L: *mut lua_State, nargs: c_int, nresults: c_int);
+    pub fn lua_pcall(L: *mut lua_State, nargs: c_int, nresults: c_int, errfunc: c_int) -> c_int;
+
+    //
+    // Coroutine functions
+    //
+    pub fn lua_yield(L: *mut lua_State, nresults: c_int) -> c_int;
+    pub fn lua_break(L: *mut lua_State) -> c_int;
+    #[link_name = "lua_resume"]
+    pub fn lua_resume_(L: *mut lua_State, from: *mut lua_State, narg: c_int) -> c_int;
+    pub fn lua_resumeerror(L: *mut lua_State, from: *mut lua_State) -> c_int;
+    pub fn lua_status(L: *mut lua_State) -> c_int;
+    pub fn lua_isyieldable(L: *mut lua_State) -> c_int;
+    pub fn lua_getthreaddata(L: *mut lua_State) -> *mut c_void;
+    pub fn lua_setthreaddata(L: *mut lua_State, data: *mut c_void);
+}
+
+//
+// Garbage-collection function and options
+//
+pub const LUA_GCSTOP: c_int = 0;
+pub const LUA_GCRESTART: c_int = 1;
+pub const LUA_GCCOLLECT: c_int = 2;
+pub const LUA_GCCOUNT: c_int = 3;
+pub const LUA_GCCOUNTB: c_int = 4;
+pub const LUA_GCISRUNNING: c_int = 5;
+pub const LUA_GCSTEP: c_int = 6;
+pub const LUA_GCSETGOAL: c_int = 7;
+pub const LUA_GCSETSTEPMUL: c_int = 8;
+pub const LUA_GCSETSTEPSIZE: c_int = 9;
+
+extern "C-unwind" {
+    pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
+}
+
+//
+// Memory statistics
+//
+extern "C-unwind" {
+    pub fn lua_setmemcat(L: *mut lua_State, category: c_int);
+    pub fn lua_totalbytes(L: *mut lua_State, category: c_int) -> usize;
+}
+
+//
+// Miscellaneous functions
+//
+extern "C-unwind" {
+    pub fn lua_error(L: *mut lua_State) -> !;
+    pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_rawiter(L: *mut lua_State, idx: c_int, iter: c_int) -> c_int;
+    pub fn lua_concat(L: *mut lua_State, n: c_int);
+    // TODO: lua_encodepointer
+    pub fn lua_clock() -> c_double;
+    pub fn lua_setuserdatatag(L: *mut lua_State, idx: c_int, tag: c_int);
+    pub fn lua_setuserdatadtor(L: *mut lua_State, tag: c_int, dtor: Option<lua_Destructor>);
+    pub fn lua_getuserdatadtor(L: *mut lua_State, tag: c_int) -> Option<lua_Destructor>;
+    pub fn lua_setuserdatametatable(L: *mut lua_State, tag: c_int, idx: c_int);
+    pub fn lua_getuserdatametatable(L: *mut lua_State, tag: c_int);
+    pub fn lua_setlightuserdataname(L: *mut lua_State, tag: c_int, name: *const c_char);
+    pub fn lua_getlightuserdataname(L: *mut lua_State, tag: c_int) -> *const c_char;
+    pub fn lua_clonefunction(L: *mut lua_State, idx: c_int);
+    pub fn lua_cleartable(L: *mut lua_State, idx: c_int);
+    pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
+}
+
+//
+// Reference system, can be used to pin objects
+//
+pub const LUA_NOREF: c_int = -1;
+pub const LUA_REFNIL: c_int = 0;
+
+extern "C-unwind" {
+    pub fn lua_ref(L: *mut lua_State, idx: c_int) -> c_int;
+    pub fn lua_unref(L: *mut lua_State, r#ref: c_int);
+}
+
+//
+// Some useful macros (implemented as Rust functions)
+//
+
+#[inline(always)]
+pub unsafe fn lua_tonumber(L: *mut lua_State, i: c_int) -> lua_Number {
+    lua_tonumberx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_tointeger_(L: *mut lua_State, i: c_int) -> lua_Integer {
+    lua_tointegerx_(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_tounsigned(L: *mut lua_State, i: c_int) -> lua_Unsigned {
+    lua_tounsignedx(L, i, ptr::null_mut())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pop(L: *mut lua_State, n: c_int) {
+    lua_settop(L, -n - 1)
+}
+
+#[inline(always)]
+pub unsafe fn lua_newtable(L: *mut lua_State) {
+    lua_createtable(L, 0, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void {
+    lua_newuserdatatagged(L, sz, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_newuserdata_t<T>(L: *mut lua_State) -> *mut T {
+    unsafe extern "C-unwind" fn destructor<T>(ud: *mut c_void) {
+        ptr::drop_in_place(ud as *mut T);
+    }
+
+    lua_newuserdatadtor(L, mem::size_of::<T>(), destructor::<T>) as *mut T
+}
+
+// TODO: lua_strlen
+
+#[inline(always)]
+pub unsafe fn lua_isfunction(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TFUNCTION) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_istable(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTABLE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_islightuserdata(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TLIGHTUSERDATA) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNIL) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isboolean(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TBOOLEAN) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isvector(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TVECTOR) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isthread(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TTHREAD) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isbuffer(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TBUFFER) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnone(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) == LUA_TNONE) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
+    (lua_type(L, n) <= LUA_TNIL) as c_int
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) {
+    use std::ffi::CString;
+    let c_str = CString::new(s).unwrap();
+    lua_pushlstring_(L, c_str.as_ptr(), c_str.as_bytes().len())
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcfunction(L: *mut lua_State, f: lua_CFunction) {
+    lua_pushcclosurek(L, f, ptr::null(), 0, None)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcfunctiond(L: *mut lua_State, f: lua_CFunction, debugname: *const c_char) {
+    lua_pushcclosurek(L, f, debugname, 0, None)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcclosure(L: *mut lua_State, f: lua_CFunction, nup: c_int) {
+    lua_pushcclosurek(L, f, ptr::null(), nup, None)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushcclosured(
+    L: *mut lua_State,
+    f: lua_CFunction,
+    debugname: *const c_char,
+    nup: c_int,
+) {
+    lua_pushcclosurek(L, f, debugname, nup, None)
+}
+
+#[inline(always)]
+pub unsafe fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void) {
+    lua_pushlightuserdatatagged(L, p, 0)
+}
+
+#[inline(always)]
+pub unsafe fn lua_setglobal(L: *mut lua_State, var: *const c_char) {
+    lua_setfield(L, LUA_GLOBALSINDEX, var)
+}
+
+#[inline(always)]
+pub unsafe fn lua_getglobal(L: *mut lua_State, var: *const c_char) -> c_int {
+    lua_getfield(L, LUA_GLOBALSINDEX, var)
+}
+
+#[inline(always)]
+pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
+    lua_tolstring(L, i, ptr::null_mut())
+}
+
+//
+// Debug API
+//
+
+// Maximum size for the description of the source of a function in debug information.
+const LUA_IDSIZE: usize = 256;
+
+/// Type for functions to be called on debug events.
+pub type lua_Hook = unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug);
+
+pub type lua_Coverage = unsafe extern "C-unwind" fn(
+    context: *mut c_void,
+    function: *const c_char,
+    linedefined: c_int,
+    depth: c_int,
+    hits: *const c_int,
+    size: usize,
+);
+
+extern "C-unwind" {
+    pub fn lua_stackdepth(L: *mut lua_State) -> c_int;
+    pub fn lua_getinfo(
+        L: *mut lua_State,
+        level: c_int,
+        what: *const c_char,
+        ar: *mut lua_Debug,
+    ) -> c_int;
+    pub fn lua_getargument(L: *mut lua_State, level: c_int, n: c_int) -> c_int;
+    pub fn lua_getlocal(L: *mut lua_State, level: c_int, n: c_int) -> *const c_char;
+    pub fn lua_setlocal(L: *mut lua_State, level: c_int, n: c_int) -> *const c_char;
+    pub fn lua_getupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+    pub fn lua_setupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
+
+    pub fn lua_singlestep(L: *mut lua_State, enabled: c_int);
+    pub fn lua_breakpoint(
+        L: *mut lua_State,
+        funcindex: c_int,
+        line: c_int,
+        enabled: c_int,
+    ) -> c_int;
+
+    pub fn lua_getcoverage(
+        L: *mut lua_State,
+        funcindex: c_int,
+        context: *mut c_void,
+        callback: lua_Coverage,
+    );
+
+    pub fn lua_debugtrace(L: *mut lua_State) -> *const c_char;
+}
+
+#[repr(C)]
+pub struct lua_Debug {
+    pub name: *const c_char,
+    pub what: *const c_char,
+    pub source: *const c_char,
+    pub short_src: *const c_char,
+    pub linedefined: c_int,
+    pub currentline: c_int,
+    pub nupvals: u8,
+    pub nparams: u8,
+    pub isvararg: c_char,
+    pub userdata: *mut c_void,
+    pub ssbuf: [c_char; LUA_IDSIZE],
+}
+
+//
+// Callbacks that can be used to reconfigure behavior of the VM dynamically.
+// These are shared between all coroutines.
+//
+
+#[repr(C)]
+#[non_exhaustive]
+pub struct lua_Callbacks {
+    /// arbitrary userdata pointer that is never overwritten by Luau
+    pub userdata: *mut c_void,
+
+    /// gets called at safepoints (loop back edges, call/ret, gc) if set
+    pub interrupt: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, gc: c_int)>,
+    /// gets called when an unprotected error is raised (if longjmp is used)
+    pub panic: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, errcode: c_int)>,
+
+    /// gets called when L is created (LP == parent) or destroyed (LP == NULL)
+    pub userthread: Option<unsafe extern "C-unwind" fn(LP: *mut lua_State, L: *mut lua_State)>,
+    /// gets called when a string is created; returned atom can be retrieved via tostringatom
+    pub useratom: Option<unsafe extern "C-unwind" fn(s: *const c_char, l: usize) -> i16>,
+
+    /// gets called when BREAK instruction is encountered
+    pub debugbreak: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
+    /// gets called after each instruction in single step mode
+    pub debugstep: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
+    /// gets called when thread execution is interrupted by break in another thread
+    pub debuginterrupt: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, ar: *mut lua_Debug)>,
+    /// gets called when protected call results in an error
+    pub debugprotectederror: Option<unsafe extern "C-unwind" fn(L: *mut lua_State)>,
+}
+
+extern "C" {
+    pub fn lua_callbacks(L: *mut lua_State) -> *mut lua_Callbacks;
+}
+
+// Functions from customization lib
+extern "C" {
+    pub fn luau_setfflag(name: *const c_char, value: c_int) -> c_int;
+}

mlua-sys/src/luau/luacode.rs

@@ -0,0 +1,62 @@
+//! Contains definitions from `luacode.h`.
+
+use std::os::raw::{c_char, c_int, c_void};
+use std::{ptr, slice};
+
+#[repr(C)]
+#[non_exhaustive]
+pub struct lua_CompileOptions {
+    pub optimizationLevel: c_int,
+    pub debugLevel: c_int,
+    pub typeInfoLevel: c_int,
+    pub coverageLevel: c_int,
+    pub vectorLib: *const c_char,
+    pub vectorCtor: *const c_char,
+    pub vectorType: *const c_char,
+    pub mutableGlobals: *const *const c_char,
+    pub userdataTypes: *const *const c_char,
+}
+
+impl Default for lua_CompileOptions {
+    fn default() -> Self {
+        Self {
+            optimizationLevel: 1,
+            debugLevel: 1,
+            typeInfoLevel: 0,
+            coverageLevel: 0,
+            vectorLib: ptr::null(),
+            vectorCtor: ptr::null(),
+            vectorType: ptr::null(),
+            mutableGlobals: ptr::null(),
+            userdataTypes: ptr::null(),
+        }
+    }
+}
+
+extern "C-unwind" {
+    #[link_name = "luau_compile"]
+    pub fn luau_compile_(
+        source: *const c_char,
+        size: usize,
+        options: *mut lua_CompileOptions,
+        outsize: *mut usize,
+    ) -> *mut c_char;
+}
+
+extern "C" {
+    fn free(p: *mut c_void);
+}
+
+pub unsafe fn luau_compile(source: &[u8], mut options: lua_CompileOptions) -> Vec<u8> {
+    let mut outsize = 0;
+    let data_ptr = luau_compile_(
+        source.as_ptr() as *const c_char,
+        source.len(),
+        &mut options,
+        &mut outsize,
+    );
+    assert!(!data_ptr.is_null(), "luau_compile failed");
+    let data = slice::from_raw_parts(data_ptr as *mut u8, outsize).to_vec();
+    free(data_ptr as *mut c_void);
+    data
+}

mlua-sys/src/luau/luacodegen.rs

@@ -0,0 +1,11 @@
+//! Contains definitions from `luacodegen.h`.
+
+use std::os::raw::c_int;
+
+use super::lua::lua_State;
+
+extern "C-unwind" {
+    pub fn luau_codegen_supported() -> c_int;
+    pub fn luau_codegen_create(state: *mut lua_State);
+    pub fn luau_codegen_compile(state: *mut lua_State, idx: c_int);
+}

mlua-sys/src/luau/lualib.rs

@@ -0,0 +1,31 @@
+//! Contains definitions from `lualib.h`.
+
+use std::os::raw::c_int;
+
+use super::lua::lua_State;
+
+pub const LUA_COLIBNAME: &str = "coroutine";
+pub const LUA_TABLIBNAME: &str = "table";
+pub const LUA_OSLIBNAME: &str = "os";
+pub const LUA_STRLIBNAME: &str = "string";
+pub const LUA_BITLIBNAME: &str = "bit32";
+pub const LUA_BUFFERLIBNAME: &str = "buffer";
+pub const LUA_UTF8LIBNAME: &str = "utf8";
+pub const LUA_MATHLIBNAME: &str = "math";
+pub const LUA_DBLIBNAME: &str = "debug";
+
+extern "C-unwind" {
+    pub fn luaopen_base(L: *mut lua_State) -> c_int;
+    pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
+    pub fn luaopen_table(L: *mut lua_State) -> c_int;
+    pub fn luaopen_os(L: *mut lua_State) -> c_int;
+    pub fn luaopen_string(L: *mut lua_State) -> c_int;
+    pub fn luaopen_bit32(L: *mut lua_State) -> c_int;
+    pub fn luaopen_buffer(L: *mut lua_State) -> c_int;
+    pub fn luaopen_utf8(L: *mut lua_State) -> c_int;
+    pub fn luaopen_math(L: *mut lua_State) -> c_int;
+    pub fn luaopen_debug(L: *mut lua_State) -> c_int;
+
+    // open all builtin libraries
+    pub fn luaL_openlibs(L: *mut lua_State);
+}

mlua-sys/src/luau/mod.rs

@@ -0,0 +1,15 @@
+//! Low level bindings to Luau.
+
+pub use compat::*;
+pub use lauxlib::*;
+pub use lua::*;
+pub use luacode::*;
+pub use luacodegen::*;
+pub use lualib::*;
+
+pub mod compat;
+pub mod lauxlib;
+pub mod lua;
+pub mod luacode;
+pub mod luacodegen;
+pub mod lualib;

mlua-sys/src/macros.rs

@@ -0,0 +1,7 @@
+#[allow(unused_macros)]
+macro_rules! cstr {
+    ($s:expr) => {
+        concat!($s, "\0") as *const str as *const [::std::os::raw::c_char]
+            as *const ::std::os::raw::c_char
+    };
+}

mlua_derive/Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "mlua_derive"
-version = "0.6.0"
+version = "0.9.3"
 authors = ["Aleksandr Orlenko <zxteam@pm.me>"]
-edition = "2018"
+edition = "2021"
 description = "Procedural macros for the mlua crate."
 repository = "https://github.com/khvzak/mlua"
 keywords = ["lua", "mlua"]
@@ -18,7 +18,7 @@ macros = ["proc-macro-error", "itertools", "regex", "once_cell"]
 quote = "1.0"
 proc-macro2 = { version = "1.0", features = ["span-locations"] }
 proc-macro-error = { version = "1.0", optional = true }
-syn = { version = "1.0", features = ["full"] }
-itertools = { version = "0.10", optional = true }
+syn = { version = "2.0", features = ["full"] }
+itertools = { version = "0.12", optional = true }
 regex = { version = "1.4", optional = true }
-once_cell = { version = "1.5", optional = true }
+once_cell = { version = "1.0", optional = true }

mlua_derive/src/from_lua.rs

@@ -0,0 +1,33 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, DeriveInput};
+
+pub fn from_lua(input: TokenStream) -> TokenStream {
+    let DeriveInput {
+        ident, generics, ..
+    } = parse_macro_input!(input as DeriveInput);
+
+    let ident_str = ident.to_string();
+    let (impl_generics, ty_generics, _) = generics.split_for_impl();
+    let where_clause = match &generics.where_clause {
+        Some(where_clause) => quote! { #where_clause, Self: 'static + Clone },
+        None => quote! { where Self: 'static + Clone },
+    };
+
+    quote! {
+      impl #impl_generics ::mlua::FromLua<'_> for #ident #ty_generics #where_clause {
+        #[inline]
+        fn from_lua(value: ::mlua::Value<'_>, _: &'_ ::mlua::Lua) -> ::mlua::Result<Self> {
+          match value {
+            ::mlua::Value::UserData(ud) => Ok(ud.borrow::<Self>()?.clone()),
+            _ => Err(::mlua::Error::FromLuaConversionError {
+                from: value.type_name(),
+                to: #ident_str,
+                message: None,
+            }),
+          }
+        }
+      }
+    }
+    .into()
+}

mlua_derive/src/lib.rs

@@ -1,7 +1,8 @@
 use proc_macro::TokenStream;
 use proc_macro2::{Ident, Span};
 use quote::quote;
-use syn::{parse_macro_input, AttributeArgs, Error, ItemFn};
+use syn::meta::ParseNestedMeta;
+use syn::{parse_macro_input, ItemFn, LitStr, Result};
 
 #[cfg(feature = "macros")]
 use {
@@ -9,30 +10,63 @@ use {
     proc_macro_error::proc_macro_error,
 };
 
+#[derive(Default)]
+struct ModuleAttributes {
+    name: Option<Ident>,
+    skip_memory_check: bool,
+}
+
+impl ModuleAttributes {
+    fn parse(&mut self, meta: ParseNestedMeta) -> Result<()> {
+        if meta.path.is_ident("name") {
+            match meta.value() {
+                Ok(value) => {
+                    self.name = Some(value.parse::<LitStr>()?.parse()?);
+                }
+                Err(_) => {
+                    return Err(meta.error("`name` attribute must have a value"));
+                }
+            }
+        } else if meta.path.is_ident("skip_memory_check") {
+            if meta.value().is_ok() {
+                return Err(meta.error("`skip_memory_check` attribute have no values"));
+            }
+            self.skip_memory_check = true;
+        } else {
+            return Err(meta.error("unsupported module attribute"));
+        }
+        Ok(())
+    }
+}
+
 #[proc_macro_attribute]
 pub fn lua_module(attr: TokenStream, item: TokenStream) -> TokenStream {
-    let args = parse_macro_input!(attr as AttributeArgs);
-    let func = parse_macro_input!(item as ItemFn);
-
-    if !args.is_empty() {
-        let err = Error::new(Span::call_site(), "the macro does not support arguments")
-            .to_compile_error();
-        return err.into();
+    let mut args = ModuleAttributes::default();
+    if !attr.is_empty() {
+        let args_parser = syn::meta::parser(|meta| args.parse(meta));
+        parse_macro_input!(attr with args_parser);
     }
 
-    let func_name = func.sig.ident.clone();
-    let ext_entrypoint_name = Ident::new(&format!("luaopen_{}", func_name), Span::call_site());
+    let func = parse_macro_input!(item as ItemFn);
+    let func_name = &func.sig.ident;
+    let module_name = args.name.unwrap_or_else(|| func_name.clone());
+    let ext_entrypoint_name = Ident::new(&format!("luaopen_{module_name}"), Span::call_site());
+    let skip_memory_check = if args.skip_memory_check {
+        quote! { lua.skip_memory_check(true); }
+    } else {
+        quote! {}
+    };
 
     let wrapped = quote! {
-        ::mlua::require_module_feature!();
+        mlua::require_module_feature!();
 
         #func
 
         #[no_mangle]
-        unsafe extern "C" fn #ext_entrypoint_name(state: *mut ::mlua::lua_State) -> ::std::os::raw::c_int {
-            ::mlua::Lua::init_from_ptr(state)
-                .entrypoint1(#func_name)
-                .expect("cannot initialize module")
+        unsafe extern "C-unwind" fn #ext_entrypoint_name(state: *mut mlua::lua_State) -> ::std::os::raw::c_int {
+            let lua = mlua::Lua::init_from_ptr(state);
+            #skip_memory_check
+            lua.entrypoint1(state, #func_name)
         }
     };
 
@@ -61,28 +95,22 @@ pub fn chunk(input: TokenStream) -> TokenStream {
     });
 
     let wrapped_code = quote! {{
-        use ::mlua::{AsChunk, ChunkMode, Lua, Result, Value};
+        use mlua::{AsChunk, ChunkMode, Lua, Result, Table};
+        use ::std::borrow::Cow;
+        use ::std::cell::Cell;
+        use ::std::io::Result as IoResult;
         use ::std::marker::PhantomData;
-        use ::std::sync::Mutex;
 
-        fn annotate<'a, F: FnOnce(&'a Lua) -> Result<Value<'a>>>(f: F) -> F { f }
+        struct InnerChunk<'lua, F: FnOnce(&'lua Lua) -> Result<Table<'lua>>>(Cell<Option<F>>, PhantomData<&'lua ()>);
 
-        struct InnerChunk<'a, F: FnOnce(&'a Lua) -> Result<Value<'a>>>(Mutex<Option<F>>, PhantomData<&'a ()>);
-
-        impl<'lua, F> AsChunk<'lua> for InnerChunk<'lua, F>
+        impl<'lua, F> AsChunk<'lua, 'static> for InnerChunk<'lua, F>
         where
-            F: FnOnce(&'lua Lua) -> Result<Value<'lua>>,
+            F: FnOnce(&'lua Lua) -> Result<Table<'lua>>,
         {
-            fn source(&self) -> &[u8] {
-                (#source).as_bytes()
-            }
-
-            fn env(&self, lua: &'lua Lua) -> Result<Option<Value<'lua>>> {
+            fn environment(&self, lua: &'lua Lua) -> Result<Option<Table<'lua>>> {
                 if #caps_len > 0 {
-                    if let Ok(mut make_env) = self.0.lock() {
-                        if let Some(make_env) = make_env.take() {
-                            return make_env(lua).map(Some);
-                        }
+                    if let Some(make_env) = self.0.take() {
+                        return make_env(lua).map(Some);
                     }
                 }
                 Ok(None)
@@ -91,9 +119,15 @@ pub fn chunk(input: TokenStream) -> TokenStream {
             fn mode(&self) -> Option<ChunkMode> {
                 Some(ChunkMode::Text)
             }
+
+            fn source(self) -> IoResult<Cow<'static, [u8]>> {
+                Ok(Cow::Borrowed((#source).as_bytes()))
+            }
         }
 
-        let make_env = annotate(move |lua: &Lua| -> Result<Value> {
+        fn annotate<'a, F: FnOnce(&'a Lua) -> Result<Table<'a>>>(f: F) -> F { f }
+
+        let make_env = annotate(move |lua: &Lua| -> Result<Table> {
             let globals = lua.globals();
             let env = lua.create_table()?;
             let meta = lua.create_table()?;
@@ -104,16 +138,24 @@ pub fn chunk(input: TokenStream) -> TokenStream {
             #(#caps)*
 
             env.set_metatable(Some(meta));
-            Ok(Value::Table(env))
+            Ok(env)
         });
 
-        &InnerChunk(Mutex::new(Some(make_env)), PhantomData)
+        InnerChunk(Cell::new(Some(make_env)), PhantomData)
     }};
 
     wrapped_code.into()
 }
 
+#[cfg(feature = "macros")]
+#[proc_macro_derive(FromLua)]
+pub fn from_lua(input: TokenStream) -> TokenStream {
+    from_lua::from_lua(input)
+}
+
 #[cfg(feature = "macros")]
 mod chunk;
 #[cfg(feature = "macros")]
+mod from_lua;
+#[cfg(feature = "macros")]
 mod token;

mlua_derive/src/token.rs

@@ -1,7 +1,6 @@
 use std::{
     cmp::{Eq, PartialEq},
     fmt::{self, Display, Formatter},
-    iter::IntoIterator,
     vec::IntoIter,
 };
 
@@ -59,7 +58,7 @@ fn parse_pos(span: &Span) -> Option<(usize, usize)> {
 
     static RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"bytes\(([0-9]+)\.\.([0-9]+)\)").unwrap());
 
-    match RE.captures(&format!("{:?}", span)) {
+    match RE.captures(&format!("{span:?}")) {
         Some(caps) => match (caps.get(1), caps.get(2)) {
             (Some(start), Some(end)) => Some((
                 match start.as_str().parse() {

src/chunk.rs

@@ -0,0 +1,553 @@
+use std::borrow::Cow;
+use std::collections::HashMap;
+use std::ffi::CString;
+use std::io::Result as IoResult;
+use std::path::{Path, PathBuf};
+use std::string::String as StdString;
+
+use crate::error::{Error, ErrorContext, Result};
+use crate::function::Function;
+use crate::lua::Lua;
+use crate::table::Table;
+use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti};
+
+/// Trait for types [loadable by Lua] and convertible to a [`Chunk`]
+///
+/// [loadable by Lua]: https://www.lua.org/manual/5.4/manual.html#3.3.2
+/// [`Chunk`]: crate::Chunk
+pub trait AsChunk<'lua, 'a> {
+    /// Returns optional chunk name
+    fn name(&self) -> Option<StdString> {
+        None
+    }
+
+    /// Returns optional chunk [environment]
+    ///
+    /// [environment]: https://www.lua.org/manual/5.4/manual.html#2.2
+    fn environment(&self, lua: &'lua Lua) -> Result<Option<Table<'lua>>> {
+        let _lua = lua; // suppress warning
+        Ok(None)
+    }
+
+    /// Returns optional chunk mode (text or binary)
+    fn mode(&self) -> Option<ChunkMode> {
+        None
+    }
+
+    /// Returns chunk data (can be text or binary)
+    fn source(self) -> IoResult<Cow<'a, [u8]>>;
+}
+
+impl<'a> AsChunk<'_, 'a> for &'a str {
+    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+        Ok(Cow::Borrowed(self.as_ref()))
+    }
+}
+
+impl AsChunk<'_, 'static> for StdString {
+    fn source(self) -> IoResult<Cow<'static, [u8]>> {
+        Ok(Cow::Owned(self.into_bytes()))
+    }
+}
+
+impl<'a> AsChunk<'_, 'a> for &'a StdString {
+    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+        Ok(Cow::Borrowed(self.as_bytes()))
+    }
+}
+
+impl<'a> AsChunk<'_, 'a> for &'a [u8] {
+    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+        Ok(Cow::Borrowed(self))
+    }
+}
+
+impl AsChunk<'_, 'static> for Vec<u8> {
+    fn source(self) -> IoResult<Cow<'static, [u8]>> {
+        Ok(Cow::Owned(self))
+    }
+}
+
+impl<'a> AsChunk<'_, 'a> for &'a Vec<u8> {
+    fn source(self) -> IoResult<Cow<'a, [u8]>> {
+        Ok(Cow::Borrowed(self.as_ref()))
+    }
+}
+
+impl AsChunk<'_, 'static> for &Path {
+    fn name(&self) -> Option<StdString> {
+        Some(format!("@{}", self.display()))
+    }
+
+    fn source(self) -> IoResult<Cow<'static, [u8]>> {
+        std::fs::read(self).map(Cow::Owned)
+    }
+}
+
+impl AsChunk<'_, 'static> for PathBuf {
+    fn name(&self) -> Option<StdString> {
+        Some(format!("@{}", self.display()))
+    }
+
+    fn source(self) -> IoResult<Cow<'static, [u8]>> {
+        std::fs::read(self).map(Cow::Owned)
+    }
+}
+
+/// Returned from [`Lua::load`] and is used to finalize loading and executing Lua main chunks.
+///
+/// [`Lua::load`]: crate::Lua::load
+#[must_use = "`Chunk`s do nothing unless one of `exec`, `eval`, `call`, or `into_function` are called on them"]
+pub struct Chunk<'lua, 'a> {
+    pub(crate) lua: &'lua Lua,
+    pub(crate) name: StdString,
+    pub(crate) env: Result<Option<Table<'lua>>>,
+    pub(crate) mode: Option<ChunkMode>,
+    pub(crate) source: IoResult<Cow<'a, [u8]>>,
+    #[cfg(feature = "luau")]
+    pub(crate) compiler: Option<Compiler>,
+}
+
+/// Represents chunk mode (text or binary).
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ChunkMode {
+    Text,
+    Binary,
+}
+
+/// Luau compiler
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+#[derive(Clone, Debug)]
+pub struct Compiler {
+    optimization_level: u8,
+    debug_level: u8,
+    type_info_level: u8,
+    coverage_level: u8,
+    vector_lib: Option<String>,
+    vector_ctor: Option<String>,
+    vector_type: Option<String>,
+    mutable_globals: Vec<String>,
+    userdata_types: Vec<String>,
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl Default for Compiler {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl Compiler {
+    /// Creates Luau compiler instance with default options
+    pub const fn new() -> Self {
+        // Defaults are taken from luacode.h
+        Compiler {
+            optimization_level: 1,
+            debug_level: 1,
+            type_info_level: 0,
+            coverage_level: 0,
+            vector_lib: None,
+            vector_ctor: None,
+            vector_type: None,
+            mutable_globals: Vec::new(),
+            userdata_types: Vec::new(),
+        }
+    }
+
+    /// Sets Luau compiler optimization level.
+    ///
+    /// Possible values:
+    /// * 0 - no optimization
+    /// * 1 - baseline optimization level that doesn't prevent debuggability (default)
+    /// * 2 - includes optimizations that harm debuggability such as inlining
+    #[must_use]
+    pub const fn set_optimization_level(mut self, level: u8) -> Self {
+        self.optimization_level = level;
+        self
+    }
+
+    /// Sets Luau compiler debug level.
+    ///
+    /// Possible values:
+    /// * 0 - no debugging support
+    /// * 1 - line info & function names only; sufficient for backtraces (default)
+    /// * 2 - full debug info with local & upvalue names; necessary for debugger
+    #[must_use]
+    pub const fn set_debug_level(mut self, level: u8) -> Self {
+        self.debug_level = level;
+        self
+    }
+
+    /// Sets Luau type information level used to guide native code generation decisions.
+    ///
+    /// Possible values:
+    /// * 0 - generate for native modules (default)
+    /// * 1 - generate for all modules
+    pub const fn set_type_info_level(mut self, level: u8) -> Self {
+        self.type_info_level = level;
+        self
+    }
+
+    /// Sets Luau compiler code coverage level.
+    ///
+    /// Possible values:
+    /// * 0 - no code coverage support (default)
+    /// * 1 - statement coverage
+    /// * 2 - statement and expression coverage (verbose)
+    #[must_use]
+    pub const fn set_coverage_level(mut self, level: u8) -> Self {
+        self.coverage_level = level;
+        self
+    }
+
+    #[doc(hidden)]
+    #[must_use]
+    pub fn set_vector_lib(mut self, lib: impl Into<String>) -> Self {
+        self.vector_lib = Some(lib.into());
+        self
+    }
+
+    #[doc(hidden)]
+    #[must_use]
+    pub fn set_vector_ctor(mut self, ctor: impl Into<String>) -> Self {
+        self.vector_ctor = Some(ctor.into());
+        self
+    }
+
+    #[doc(hidden)]
+    #[must_use]
+    pub fn set_vector_type(mut self, r#type: impl Into<String>) -> Self {
+        self.vector_type = Some(r#type.into());
+        self
+    }
+
+    /// Sets a list of globals that are mutable.
+    ///
+    /// It disables the import optimization for fields accessed through these.
+    #[must_use]
+    pub fn set_mutable_globals(mut self, globals: Vec<String>) -> Self {
+        self.mutable_globals = globals;
+        self
+    }
+
+    /// Sets a list of userdata types that will be included in the type information.
+    #[must_use]
+    pub fn set_userdata_types(mut self, types: Vec<String>) -> Self {
+        self.userdata_types = types;
+        self
+    }
+
+    /// Compiles the `source` into bytecode.
+    pub fn compile(&self, source: impl AsRef<[u8]>) -> Vec<u8> {
+        use std::os::raw::c_int;
+        use std::ptr;
+
+        let vector_lib = self.vector_lib.clone();
+        let vector_lib = vector_lib.and_then(|lib| CString::new(lib).ok());
+        let vector_lib = vector_lib.as_ref();
+        let vector_ctor = self.vector_ctor.clone();
+        let vector_ctor = vector_ctor.and_then(|ctor| CString::new(ctor).ok());
+        let vector_ctor = vector_ctor.as_ref();
+        let vector_type = self.vector_type.clone();
+        let vector_type = vector_type.and_then(|t| CString::new(t).ok());
+        let vector_type = vector_type.as_ref();
+
+        macro_rules! vec2cstring_ptr {
+            ($name:ident, $name_ptr:ident) => {
+                let $name = self
+                    .$name
+                    .iter()
+                    .map(|name| CString::new(name.clone()).ok())
+                    .collect::<Option<Vec<_>>>()
+                    .unwrap_or_default();
+                let mut $name = $name.iter().map(|s| s.as_ptr()).collect::<Vec<_>>();
+                let mut $name_ptr = ptr::null();
+                if !$name.is_empty() {
+                    $name.push(ptr::null());
+                    $name_ptr = $name.as_ptr();
+                }
+            };
+        }
+
+        vec2cstring_ptr!(mutable_globals, mutable_globals_ptr);
+        vec2cstring_ptr!(userdata_types, userdata_types_ptr);
+
+        unsafe {
+            let mut options = ffi::lua_CompileOptions::default();
+            options.optimizationLevel = self.optimization_level as c_int;
+            options.debugLevel = self.debug_level as c_int;
+            options.typeInfoLevel = self.type_info_level as c_int;
+            options.coverageLevel = self.coverage_level as c_int;
+            options.vectorLib = vector_lib.map_or(ptr::null(), |s| s.as_ptr());
+            options.vectorCtor = vector_ctor.map_or(ptr::null(), |s| s.as_ptr());
+            options.vectorType = vector_type.map_or(ptr::null(), |s| s.as_ptr());
+            options.mutableGlobals = mutable_globals_ptr;
+            options.userdataTypes = userdata_types_ptr;
+            ffi::luau_compile(source.as_ref(), options)
+        }
+    }
+}
+
+impl<'lua, 'a> Chunk<'lua, 'a> {
+    /// Sets the name of this chunk, which results in more informative error traces.
+    pub fn set_name(mut self, name: impl Into<String>) -> Self {
+        self.name = name.into();
+        self
+    }
+
+    /// Sets the environment of the loaded chunk to the given value.
+    ///
+    /// In Lua >=5.2 main chunks always have exactly one upvalue, and this upvalue is used as the `_ENV`
+    /// variable inside the chunk. By default this value is set to the global environment.
+    ///
+    /// Calling this method changes the `_ENV` upvalue to the value provided, and variables inside
+    /// the chunk will refer to the given environment rather than the global one.
+    ///
+    /// All global variables (including the standard library!) are looked up in `_ENV`, so it may be
+    /// necessary to populate the environment in order for scripts using custom environments to be
+    /// useful.
+    pub fn set_environment<V: IntoLua<'lua>>(mut self, env: V) -> Self {
+        self.env = env
+            .into_lua(self.lua)
+            .and_then(|val| self.lua.unpack(val))
+            .context("bad environment value");
+        self
+    }
+
+    /// Sets whether the chunk is text or binary (autodetected by default).
+    ///
+    /// Be aware, Lua does not check the consistency of the code inside binary chunks.
+    /// Running maliciously crafted bytecode can crash the interpreter.
+    pub fn set_mode(mut self, mode: ChunkMode) -> Self {
+        self.mode = Some(mode);
+        self
+    }
+
+    /// Sets or overwrites a Luau compiler used for this chunk.
+    ///
+    /// See [`Compiler`] for details and possible options.
+    ///
+    /// Requires `feature = "luau"`
+    #[cfg(any(feature = "luau", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    pub fn set_compiler(mut self, compiler: Compiler) -> Self {
+        self.compiler = Some(compiler);
+        self
+    }
+
+    /// Execute this chunk of code.
+    ///
+    /// This is equivalent to calling the chunk function with no arguments and no return values.
+    pub fn exec(self) -> Result<()> {
+        self.call::<_, ()>(())?;
+        Ok(())
+    }
+
+    /// Asynchronously execute this chunk of code.
+    ///
+    /// See [`exec`] for more details.
+    ///
+    /// Requires `feature = "async"`
+    ///
+    /// [`exec`]: #method.exec
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    pub async fn exec_async(self) -> Result<()> {
+        self.call_async(()).await
+    }
+
+    /// Evaluate the chunk as either an expression or block.
+    ///
+    /// If the chunk can be parsed as an expression, this loads and executes the chunk and returns
+    /// the value that it evaluates to. Otherwise, the chunk is interpreted as a block as normal,
+    /// and this is equivalent to calling `exec`.
+    pub fn eval<R: FromLuaMulti<'lua>>(self) -> Result<R> {
+        // Bytecode is always interpreted as a statement.
+        // For source code, first try interpreting the lua as an expression by adding
+        // "return", then as a statement. This is the same thing the
+        // actual lua repl does.
+        if self.detect_mode() == ChunkMode::Binary {
+            self.call(())
+        } else if let Ok(function) = self.to_expression() {
+            function.call(())
+        } else {
+            self.call(())
+        }
+    }
+
+    /// Asynchronously evaluate the chunk as either an expression or block.
+    ///
+    /// See [`eval`] for more details.
+    ///
+    /// Requires `feature = "async"`
+    ///
+    /// [`eval`]: #method.eval
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    pub async fn eval_async<R>(self) -> Result<R>
+    where
+        R: FromLuaMulti<'lua> + 'lua,
+    {
+        if self.detect_mode() == ChunkMode::Binary {
+            self.call_async(()).await
+        } else if let Ok(function) = self.to_expression() {
+            function.call_async(()).await
+        } else {
+            self.call_async(()).await
+        }
+    }
+
+    /// Load the chunk function and call it with the given arguments.
+    ///
+    /// This is equivalent to `into_function` and calling the resulting function.
+    pub fn call<A: IntoLuaMulti<'lua>, R: FromLuaMulti<'lua>>(self, args: A) -> Result<R> {
+        self.into_function()?.call(args)
+    }
+
+    /// Load the chunk function and asynchronously call it with the given arguments.
+    ///
+    /// See [`call`] for more details.
+    ///
+    /// Requires `feature = "async"`
+    ///
+    /// [`call`]: #method.call
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    pub async fn call_async<A, R>(self, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua,
+    {
+        self.into_function()?.call_async(args).await
+    }
+
+    /// Load this chunk into a regular `Function`.
+    ///
+    /// This simply compiles the chunk without actually executing it.
+    #[cfg_attr(not(feature = "luau"), allow(unused_mut))]
+    pub fn into_function(mut self) -> Result<Function<'lua>> {
+        #[cfg(feature = "luau")]
+        if self.compiler.is_some() {
+            // We don't need to compile source if no compiler set
+            self.compile();
+        }
+
+        let name = Self::convert_name(self.name)?;
+        self.lua
+            .load_chunk(Some(&name), self.env?, self.mode, self.source?.as_ref())
+    }
+
+    /// Compiles the chunk and changes mode to binary.
+    ///
+    /// It does nothing if the chunk is already binary.
+    fn compile(&mut self) {
+        if let Ok(ref source) = self.source {
+            if self.detect_mode() == ChunkMode::Text {
+                #[cfg(feature = "luau")]
+                {
+                    let data = self
+                        .compiler
+                        .get_or_insert_with(Default::default)
+                        .compile(source);
+                    self.source = Ok(Cow::Owned(data));
+                    self.mode = Some(ChunkMode::Binary);
+                }
+                #[cfg(not(feature = "luau"))]
+                if let Ok(func) = self.lua.load_chunk(None, None, None, source.as_ref()) {
+                    let data = func.dump(false);
+                    self.source = Ok(Cow::Owned(data));
+                    self.mode = Some(ChunkMode::Binary);
+                }
+            }
+        }
+    }
+
+    /// Fetches compiled bytecode of this chunk from the cache.
+    ///
+    /// If not found, compiles the source code and stores it on the cache.
+    pub(crate) fn try_cache(mut self) -> Self {
+        struct ChunksCache(HashMap<Vec<u8>, Vec<u8>>);
+
+        // Try to fetch compiled chunk from cache
+        let mut text_source = None;
+        if let Ok(ref source) = self.source {
+            if self.detect_mode() == ChunkMode::Text {
+                if let Some(cache) = self.lua.app_data_ref::<ChunksCache>() {
+                    if let Some(data) = cache.0.get(source.as_ref()) {
+                        self.source = Ok(Cow::Owned(data.clone()));
+                        self.mode = Some(ChunkMode::Binary);
+                        return self;
+                    }
+                }
+                text_source = Some(source.as_ref().to_vec());
+            }
+        }
+
+        // Compile and cache the chunk
+        if let Some(text_source) = text_source {
+            self.compile();
+            if let Ok(ref binary_source) = self.source {
+                if self.detect_mode() == ChunkMode::Binary {
+                    if let Some(mut cache) = self.lua.app_data_mut::<ChunksCache>() {
+                        cache.0.insert(text_source, binary_source.as_ref().to_vec());
+                    } else {
+                        let mut cache = ChunksCache(HashMap::new());
+                        cache.0.insert(text_source, binary_source.as_ref().to_vec());
+                        let _ = self.lua.try_set_app_data(cache);
+                    }
+                }
+            }
+        }
+
+        self
+    }
+
+    fn to_expression(&self) -> Result<Function<'lua>> {
+        // We assume that mode is Text
+        let source = self.source.as_ref();
+        let source = source.map_err(Error::runtime)?;
+        let source = Self::expression_source(source);
+        // We don't need to compile source if no compiler options set
+        #[cfg(feature = "luau")]
+        let source = self
+            .compiler
+            .as_ref()
+            .map(|c| c.compile(&source))
+            .unwrap_or(source);
+
+        let name = Self::convert_name(self.name.clone())?;
+        self.lua
+            .load_chunk(Some(&name), self.env.clone()?, None, &source)
+    }
+
+    fn detect_mode(&self) -> ChunkMode {
+        match (self.mode, &self.source) {
+            (Some(mode), _) => mode,
+            (None, Ok(source)) => {
+                #[cfg(not(feature = "luau"))]
+                if source.starts_with(ffi::LUA_SIGNATURE) {
+                    return ChunkMode::Binary;
+                }
+                #[cfg(feature = "luau")]
+                if *source.first().unwrap_or(&u8::MAX) < b'\n' {
+                    return ChunkMode::Binary;
+                }
+                ChunkMode::Text
+            }
+            (None, Err(_)) => ChunkMode::Text, // any value is fine
+        }
+    }
+
+    fn convert_name(name: String) -> Result<CString> {
+        CString::new(name).map_err(|err| Error::runtime(format!("invalid name: {err}")))
+    }
+
+    fn expression_source(source: &[u8]) -> Vec<u8> {
+        let mut buf = Vec::with_capacity(b"return ".len() + source.len());
+        buf.extend(b"return ");
+        buf.extend(source);
+        buf
+    }
+}

src/error.rs

@@ -1,5 +1,3 @@
-#![allow(clippy::wrong_self_convention)]
-
 use std::error::Error as StdError;
 use std::fmt;
 use std::io::Error as IoError;
@@ -9,6 +7,8 @@ use std::str::Utf8Error;
 use std::string::String as StdString;
 use std::sync::Arc;
 
+use crate::private::Sealed;
+
 /// Error type returned by `mlua` methods.
 #[derive(Debug, Clone)]
 #[non_exhaustive]
@@ -37,7 +37,8 @@ pub enum Error {
     /// Lua garbage collector error, aka `LUA_ERRGCMM`.
     ///
     /// The Lua VM returns this error when there is an error running a `__gc` metamethod.
-    #[cfg(any(feature = "lua53", feature = "lua52"))]
+    #[cfg(any(feature = "lua53", feature = "lua52", doc))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua53", feature = "lua52"))))]
     GarbageCollectorError(StdString),
     /// Potentially unsafe action in safe mode.
     SafetyError(StdString),
@@ -46,11 +47,6 @@ pub enum Error {
     /// This error can only happen when Lua state was not created by us and does not have the
     /// custom allocator attached.
     MemoryLimitNotAvailable,
-    /// Main thread is not available.
-    ///
-    /// This error can only happen in Lua5.1/LuaJIT module mode, when module loaded within a coroutine.
-    /// These Lua versions does not have `LUA_RIDX_MAINTHREAD` registry key.
-    MainThreadNotAvailable,
     /// A mutable callback has triggered Lua code that has called the same mutable callback again.
     ///
     /// This is an error because a mutable callback can only be borrowed mutably once.
@@ -68,8 +64,22 @@ pub enum Error {
     /// called with a huge number of arguments, or a rust callback returns a huge number of return
     /// values.
     StackError,
-    /// Too many arguments to `Function::bind`
+    /// Too many arguments to `Function::bind`.
     BindError,
+    /// Bad argument received from Lua (usually when calling a function).
+    ///
+    /// This error can help to identify the argument that caused the error
+    /// (which is stored in the corresponding field).
+    BadArgument {
+        /// Function that was called.
+        to: Option<StdString>,
+        /// Argument position (usually starts from 1).
+        pos: usize,
+        /// Argument name.
+        name: Option<StdString>,
+        /// Underlying error returned when converting argument to a Lua value.
+        cause: Arc<Error>,
+    },
     /// A Rust value could not be converted to a Lua value.
     ToLuaConversionError {
         /// Name of the Rust type that could not be converted.
@@ -91,7 +101,7 @@ pub enum Error {
     /// [`Thread::resume`] was called on an inactive coroutine.
     ///
     /// A coroutine is inactive if its main function has returned or if an error has occurred inside
-    /// the coroutine.
+    /// the coroutine. Already running coroutines are also marked as inactive (unresumable).
     ///
     /// [`Thread::status`] can be used to check if the coroutine can be resumed without causing this
     /// error.
@@ -115,7 +125,7 @@ pub enum Error {
     ///
     /// [`AnyUserData`]: crate::AnyUserData
     UserDataDestructed,
-    /// An [`AnyUserData`] immutable borrow failed because it is already borrowed mutably.
+    /// An [`AnyUserData`] immutable borrow failed.
     ///
     /// This error can occur when a method on a [`UserData`] type calls back into Lua, which then
     /// tries to call a method on the same [`UserData`] type. Consider restructuring your API to
@@ -124,7 +134,7 @@ pub enum Error {
     /// [`AnyUserData`]: crate::AnyUserData
     /// [`UserData`]: crate::UserData
     UserDataBorrowError,
-    /// An [`AnyUserData`] mutable borrow failed because it is already borrowed.
+    /// An [`AnyUserData`] mutable borrow failed.
     ///
     /// This error can occur when a method on a [`UserData`] type calls back into Lua, which then
     /// tries to call a method on the same [`UserData`] type. Consider restructuring your API to
@@ -141,8 +151,11 @@ pub enum Error {
     ///
     /// [`MetaMethod`]: crate::MetaMethod
     MetaMethodTypeError {
+        /// Name of the metamethod.
         method: StdString,
+        /// Passed value type.
         type_name: &'static str,
+        /// A string containing more detailed error information.
         message: Option<StdString>,
     },
     /// A [`RegistryKey`] produced from a different Lua state was used.
@@ -177,6 +190,13 @@ pub enum Error {
     /// error. The Rust code that originally invoked the Lua code then receives a `CallbackError`,
     /// from which the original error (and a stack traceback) can be recovered.
     ExternalError(Arc<dyn StdError + Send + Sync>),
+    /// An error with additional context.
+    WithContext {
+        /// A string containing additional context.
+        context: StdString,
+        /// Underlying error.
+        cause: Arc<Error>,
+    },
 }
 
 /// A specialized `Result` type used by `mlua`'s API.
@@ -186,24 +206,21 @@ pub type Result<T> = StdResult<T, Error>;
 impl fmt::Display for Error {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            Error::SyntaxError { ref message, .. } => write!(fmt, "syntax error: {}", message),
-            Error::RuntimeError(ref msg) => write!(fmt, "runtime error: {}", msg),
+            Error::SyntaxError { ref message, .. } => write!(fmt, "syntax error: {message}"),
+            Error::RuntimeError(ref msg) => write!(fmt, "runtime error: {msg}"),
             Error::MemoryError(ref msg) => {
-                write!(fmt, "memory error: {}", msg)
+                write!(fmt, "memory error: {msg}")
             }
             #[cfg(any(feature = "lua53", feature = "lua52"))]
             Error::GarbageCollectorError(ref msg) => {
-                write!(fmt, "garbage collector error: {}", msg)
+                write!(fmt, "garbage collector error: {msg}")
             }
             Error::SafetyError(ref msg) => {
-                write!(fmt, "safety error: {}", msg)
+                write!(fmt, "safety error: {msg}")
             },
             Error::MemoryLimitNotAvailable => {
                 write!(fmt, "setting memory limit is not available")
             }
-            Error::MainThreadNotAvailable => {
-                write!(fmt, "main thread is not available in Lua 5.1")
-            }
             Error::RecursiveMutCallback => write!(fmt, "mutable callback called recursively"),
             Error::CallbackDestructed => write!(
                 fmt,
@@ -217,44 +234,55 @@ impl fmt::Display for Error {
                 fmt,
                 "too many arguments to Function::bind"
             ),
+            Error::BadArgument { ref to, pos, ref name, ref cause } => {
+                if let Some(name) = name {
+                    write!(fmt, "bad argument `{name}`")?;
+                } else {
+                    write!(fmt, "bad argument #{pos}")?;
+                }
+                if let Some(to) = to {
+                    write!(fmt, " to `{to}`")?;
+                }
+                write!(fmt, ": {cause}")
+            },
             Error::ToLuaConversionError { from, to, ref message } => {
-                write!(fmt, "error converting {} to Lua {}", from, to)?;
+                write!(fmt, "error converting {from} to Lua {to}")?;
                 match *message {
                     None => Ok(()),
-                    Some(ref message) => write!(fmt, " ({})", message),
+                    Some(ref message) => write!(fmt, " ({message})"),
                 }
             }
             Error::FromLuaConversionError { from, to, ref message } => {
-                write!(fmt, "error converting Lua {} to {}", from, to)?;
+                write!(fmt, "error converting Lua {from} to {to}")?;
                 match *message {
                     None => Ok(()),
-                    Some(ref message) => write!(fmt, " ({})", message),
+                    Some(ref message) => write!(fmt, " ({message})"),
                 }
             }
             Error::CoroutineInactive => write!(fmt, "cannot resume inactive coroutine"),
             Error::UserDataTypeMismatch => write!(fmt, "userdata is not expected type"),
             Error::UserDataDestructed => write!(fmt, "userdata has been destructed"),
-            Error::UserDataBorrowError => write!(fmt, "userdata already mutably borrowed"),
-            Error::UserDataBorrowMutError => write!(fmt, "userdata already borrowed"),
-            Error::MetaMethodRestricted(ref method) => write!(fmt, "metamethod {} is restricted", method),
+            Error::UserDataBorrowError => write!(fmt, "error borrowing userdata"),
+            Error::UserDataBorrowMutError => write!(fmt, "error mutably borrowing userdata"),
+            Error::MetaMethodRestricted(ref method) => write!(fmt, "metamethod {method} is restricted"),
             Error::MetaMethodTypeError { ref method, type_name, ref message } => {
-                write!(fmt, "metamethod {} has unsupported type {}", method, type_name)?;
+                write!(fmt, "metamethod {method} has unsupported type {type_name}")?;
                 match *message {
                     None => Ok(()),
-                    Some(ref message) => write!(fmt, " ({})", message),
+                    Some(ref message) => write!(fmt, " ({message})"),
                 }
             }
             Error::MismatchedRegistryKey => {
                 write!(fmt, "RegistryKey used from different Lua state")
             }
             Error::CallbackError { ref cause, ref traceback } => {
-                writeln!(fmt, "callback error")?;
                 // Trace errors down to the root
                 let (mut cause, mut full_traceback) = (cause, None);
                 while let Error::CallbackError { cause: ref cause2, traceback: ref traceback2 } = **cause {
                     cause = cause2;
                     full_traceback = Some(traceback2);
                 }
+                writeln!(fmt, "{cause}")?;
                 if let Some(full_traceback) = full_traceback {
                     let traceback = traceback.trim_start_matches("stack traceback:");
                     let traceback = traceback.trim_start().trim_end();
@@ -268,20 +296,24 @@ impl fmt::Display for Error {
                 } else {
                     writeln!(fmt, "{}", traceback.trim_end())?;
                 }
-                write!(fmt, "caused by: {}", cause)
+                Ok(())
             }
             Error::PreviouslyResumedPanic => {
                 write!(fmt, "previously resumed panic returned again")
             }
             #[cfg(feature = "serialize")]
             Error::SerializeError(ref err) => {
-                write!(fmt, "serialize error: {}", err)
+                write!(fmt, "serialize error: {err}")
             },
             #[cfg(feature = "serialize")]
             Error::DeserializeError(ref err) => {
-                write!(fmt, "deserialize error: {}", err)
+                write!(fmt, "deserialize error: {err}")
             },
-            Error::ExternalError(ref err) => write!(fmt, "{}", err),
+            Error::ExternalError(ref err) => write!(fmt, "{err}"),
+            Error::WithContext { ref context, ref cause } => {
+                writeln!(fmt, "{context}")?;
+                write!(fmt, "{cause}")
+            }
         }
     }
 }
@@ -295,53 +327,147 @@ impl StdError for Error {
             // Given that we include source to fmt::Display implementation for `CallbackError`, this call returns nothing.
             Error::CallbackError { .. } => None,
             Error::ExternalError(ref err) => err.source(),
+            Error::WithContext { ref cause, .. } => match cause.as_ref() {
+                Error::ExternalError(err) => err.source(),
+                _ => None,
+            },
             _ => None,
         }
     }
 }
 
 impl Error {
-    pub fn external<T: Into<Box<dyn StdError + Send + Sync>>>(err: T) -> Error {
+    /// Creates a new `RuntimeError` with the given message.
+    #[inline]
+    pub fn runtime<S: fmt::Display>(message: S) -> Self {
+        Error::RuntimeError(message.to_string())
+    }
+
+    /// Wraps an external error object.
+    #[inline]
+    pub fn external<T: Into<Box<dyn StdError + Send + Sync>>>(err: T) -> Self {
         Error::ExternalError(err.into().into())
     }
+
+    /// Attempts to downcast the external error object to a concrete type by reference.
+    pub fn downcast_ref<T>(&self) -> Option<&T>
+    where
+        T: StdError + 'static,
+    {
+        match self {
+            Error::ExternalError(err) => err.downcast_ref(),
+            Error::WithContext { cause, .. } => match cause.as_ref() {
+                Error::ExternalError(err) => err.downcast_ref(),
+                _ => None,
+            },
+            _ => None,
+        }
+    }
+
+    pub(crate) fn bad_self_argument(to: &str, cause: Error) -> Self {
+        Error::BadArgument {
+            to: Some(to.to_string()),
+            pos: 1,
+            name: Some("self".to_string()),
+            cause: Arc::new(cause),
+        }
+    }
+
+    pub(crate) fn from_lua_conversion<'a>(
+        from: &'static str,
+        to: &'static str,
+        message: impl Into<Option<&'a str>>,
+    ) -> Self {
+        Error::FromLuaConversionError {
+            from,
+            to,
+            message: message.into().map(|s| s.into()),
+        }
+    }
 }
 
+/// Trait for converting [`std::error::Error`] into Lua [`Error`].
 pub trait ExternalError {
-    fn to_lua_err(self) -> Error;
+    fn into_lua_err(self) -> Error;
 }
 
 impl<E: Into<Box<dyn StdError + Send + Sync>>> ExternalError for E {
-    fn to_lua_err(self) -> Error {
+    fn into_lua_err(self) -> Error {
         Error::external(self)
     }
 }
 
+/// Trait for converting [`std::result::Result`] into Lua [`Result`].
 pub trait ExternalResult<T> {
-    fn to_lua_err(self) -> Result<T>;
+    fn into_lua_err(self) -> Result<T>;
 }
 
 impl<T, E> ExternalResult<T> for StdResult<T, E>
 where
     E: ExternalError,
 {
-    fn to_lua_err(self) -> Result<T> {
-        self.map_err(|e| e.to_lua_err())
+    fn into_lua_err(self) -> Result<T> {
+        self.map_err(|e| e.into_lua_err())
     }
 }
 
-impl std::convert::From<AddrParseError> for Error {
+/// Provides the `context` method for [`Error`] and `Result<T, Error>`.
+pub trait ErrorContext: Sealed {
+    /// Wraps the error value with additional context.
+    fn context<C: fmt::Display>(self, context: C) -> Self;
+
+    /// Wrap the error value with additional context that is evaluated lazily
+    /// only once an error does occur.
+    fn with_context<C: fmt::Display>(self, f: impl FnOnce(&Error) -> C) -> Self;
+}
+
+impl ErrorContext for Error {
+    fn context<C: fmt::Display>(self, context: C) -> Self {
+        let context = context.to_string();
+        match self {
+            Error::WithContext { cause, .. } => Error::WithContext { context, cause },
+            _ => Error::WithContext {
+                context,
+                cause: Arc::new(self),
+            },
+        }
+    }
+
+    fn with_context<C: fmt::Display>(self, f: impl FnOnce(&Error) -> C) -> Self {
+        let context = f(&self).to_string();
+        match self {
+            Error::WithContext { cause, .. } => Error::WithContext { context, cause },
+            _ => Error::WithContext {
+                context,
+                cause: Arc::new(self),
+            },
+        }
+    }
+}
+
+impl<T> ErrorContext for StdResult<T, Error> {
+    fn context<C: fmt::Display>(self, context: C) -> Self {
+        self.map_err(|err| err.context(context))
+    }
+
+    fn with_context<C: fmt::Display>(self, f: impl FnOnce(&Error) -> C) -> Self {
+        self.map_err(|err| err.with_context(f))
+    }
+}
+
+impl From<AddrParseError> for Error {
     fn from(err: AddrParseError) -> Self {
         Error::external(err)
     }
 }
 
-impl std::convert::From<IoError> for Error {
+impl From<IoError> for Error {
     fn from(err: IoError) -> Self {
         Error::external(err)
     }
 }
 
-impl std::convert::From<Utf8Error> for Error {
+impl From<Utf8Error> for Error {
     fn from(err: Utf8Error) -> Self {
         Error::external(err)
     }

src/ffi/glue/glue.c

@@ -1,289 +0,0 @@
-// The MIT License (MIT)
-//
-// Copyright (c) 2019-2021 A. Orlenko
-// Copyright (c) 2014 J.C. Moyer
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <lauxlib.h>
-#include <lua.h>
-#include <lualib.h>
-
-#ifndef LUA_EXTRASPACE
-#define LUA_EXTRASPACE (sizeof(void*))
-#endif
-
-// Macros taken from https://gcc.gnu.org/onlinedocs/cpp/Stringification.html
-#define xstr(s) str(s)
-#define str(s) #s
-
-typedef struct rs_item {
-  int type;
-  const char *name;
-  union {
-    int int_val;
-    const char *str_val;
-    LUA_INTEGER lua_int_val;
-  };
-} rs_item;
-
-
-#define TY_INT 0
-#define RS_INT(name, val)                                                      \
-  { TY_INT, name, .int_val = val }
-
-#if LUA_VERSION_NUM >= 503
-#define TY_LUAINT 1
-#define RS_LUAINT(name, val)                                                   \
-  { TY_LUAINT, name, .lua_int_val = val }
-#endif
-
-#define TY_STR 2
-#define RS_STR(name, val)                                                      \
-  { TY_STR, name, .str_val = val }
-
-#define TY_TYPE 3
-#define RS_TYPE(name, val)                                                     \
-  { TY_TYPE, name, .str_val = val }
-
-#define TY_COMMENT 4
-#define RS_COMMENT(val)                                                        \
-  { TY_COMMENT, NULL, .str_val = val }
-
-#define TY_RAW 5
-#define RS_RAW(val)                                                            \
-  { TY_RAW, NULL, .str_val = val }
-
-const char *rs_int_type(int width) {
-  switch (width) {
-  default:
-  case 2:
-    return "i16";
-  case 4:
-    return "i32";
-  case 8:
-    return "i64";
-  case 16:
-    return "i128";
-  }
-}
-
-const char *rs_uint_type(int width) {
-  switch (width) {
-  default:
-  case 2:
-    return "u16";
-  case 4:
-    return "u32";
-  case 8:
-    return "u64";
-  case 16:
-    return "u128";
-  }
-}
-
-int try_write(char **str, char c, size_t n, size_t *written, size_t szstr) {
-  if (szstr - *written < n) {
-    return 0;
-  }
-  for (; n; n--, *written++)
-    *(*str)++ = c;
-  return 1;
-}
-
-// converts \ in a string to \\ so that it can be used as a rust string literal
-// ensures that `out` will always have a null terminating character
-size_t escape(const char *in, char *out, size_t szout) {
-  size_t written = 0;
-  char cur;
-
-  while ((cur = *in++)) {
-    switch (cur) {
-    case '\\':
-      if (!try_write(&out, cur, 2, &written, szout))
-        goto finalize;
-      break;
-    default:
-      if (!try_write(&out, cur, 1, &written, szout))
-        goto finalize;
-      break;
-    }
-  }
-
-finalize:
-  if (written + 1 <= szout) {
-    *out++ = '\0';
-    written++;
-  }
-  return written;
-}
-
-int write_int_item(FILE *f, const char *name, int value) {
-  return fprintf(f, "pub const %s: c_int = %d;\n", name, value);
-}
-
-#if LUA_VERSION_NUM >= 503
-int write_lua_int_item(FILE *f, const char *name, LUA_INTEGER value) {
-  return fprintf(f, "pub const %s: LUA_INTEGER = " LUA_INTEGER_FMT ";\n", name,
-                 value);
-}
-#endif
-
-int write_str_item(FILE *f, const char *name, const char *value) {
-  size_t len = strlen(value);
-  size_t bufsz = len * 2 + 1;
-  char *buf = malloc(bufsz);
-  int ret;
-  escape(value, buf, bufsz);
-  ret = fprintf(f, "pub const %s: &str = \"%s\";\n", name, buf);
-  free(buf);
-  return ret;
-}
-
-int write_type(FILE *f, const char *name, const char *value) {
-  return fprintf(f, "pub type %s = %s;\n", name, value);
-}
-
-int write_comment(FILE *f, const char *value) {
-  return fprintf(f, "/* %s */\n", value);
-}
-
-int write_raw(FILE *f, const char *value) { return fputs(value, f) >= 0; }
-
-int write_item(FILE *f, const rs_item *c) {
-  switch (c->type) {
-  case TY_INT:
-    return write_int_item(f, c->name, c->int_val);
-#if LUA_VERSION_NUM >= 503
-  case TY_LUAINT:
-    return write_lua_int_item(f, c->name, c->lua_int_val);
-#endif
-  case TY_STR:
-    return write_str_item(f, c->name, c->str_val);
-  case TY_TYPE:
-    return write_type(f, c->name, c->str_val);
-  case TY_COMMENT:
-    return write_comment(f, c->str_val);
-  case TY_RAW:
-    return write_raw(f, c->str_val);
-  default:
-    return 0;
-  }
-}
-
-int write_items_(FILE *f, const rs_item items[], size_t num) {
-  size_t i;
-  for (i = 0; i < num; i++) {
-    if (!write_item(f, &items[i]))
-      return 0;
-  }
-  return 1;
-}
-
-#define write_items(f, cs) write_items_(f, cs, sizeof(cs) / sizeof(cs[0]))
-
-int main(int argc, const char **argv) {
-  if (argc <= 1) {
-    printf("usage: %s <filename>\n", argv[0]);
-    return EXIT_FAILURE;
-  }
-
-  const char *filename = argv[1];
-
-  FILE *f = fopen(filename, "w");
-
-  if (!f) {
-    printf("could not open file: errno = %d\n", errno);
-    return EXIT_FAILURE;
-  }
-
-  const rs_item glue_entries[] = {
-      RS_COMMENT("this file was generated by glue.c; do not modify it by hand"),
-      RS_RAW("use std::os::raw::*;\n"),
-
-      // == luaconf.h ==========================================================
-
-      RS_COMMENT("luaconf.h"),
-      RS_INT("LUA_EXTRASPACE", LUA_EXTRASPACE),
-      RS_INT("LUA_IDSIZE", LUA_IDSIZE),
-      RS_TYPE("LUA_NUMBER",
-              sizeof(LUA_NUMBER) > sizeof(float) ? "c_double" : "c_float"),
-      RS_TYPE("LUA_INTEGER", rs_int_type(sizeof(LUA_INTEGER))),
-#if LUA_VERSION_NUM >= 502
-      RS_TYPE("LUA_UNSIGNED", rs_uint_type(sizeof(LUA_UNSIGNED))),
-#else
-      RS_TYPE("LUA_UNSIGNED", rs_uint_type(sizeof(size_t))),
-#endif
-
-      // == lua.h ==============================================================
-
-      RS_COMMENT("lua.h"),
-      RS_INT("LUA_VERSION_NUM", LUA_VERSION_NUM),
-      RS_INT("LUA_REGISTRYINDEX", LUA_REGISTRYINDEX),
-#if LUA_VERSION_NUM == 501
-      RS_INT("LUA_ENVIRONINDEX", LUA_ENVIRONINDEX),
-      RS_INT("LUA_GLOBALSINDEX", LUA_GLOBALSINDEX),
-#endif
-
-      // == lauxlib.h ==========================================================
-
-      RS_COMMENT("lauxlib.h"),
-#if LUA_VERSION_NUM >= 503
-      RS_INT("LUAL_NUMSIZES", LUAL_NUMSIZES),
-#endif
-
-      // == lualib.h ===========================================================
-
-      RS_COMMENT("lualib.h"),
-      RS_STR("LUA_COLIBNAME", LUA_COLIBNAME),
-      RS_STR("LUA_TABLIBNAME", LUA_TABLIBNAME),
-      RS_STR("LUA_IOLIBNAME", LUA_IOLIBNAME),
-      RS_STR("LUA_OSLIBNAME", LUA_OSLIBNAME),
-      RS_STR("LUA_STRLIBNAME", LUA_STRLIBNAME),
-#ifdef LUA_UTF8LIBNAME
-      RS_STR("LUA_UTF8LIBNAME", LUA_UTF8LIBNAME),
-#endif
-#ifdef LUA_BITLIBNAME
-      RS_STR("LUA_BITLIBNAME", LUA_BITLIBNAME),
-#endif
-      RS_STR("LUA_MATHLIBNAME", LUA_MATHLIBNAME),
-      RS_STR("LUA_DBLIBNAME", LUA_DBLIBNAME),
-      RS_STR("LUA_LOADLIBNAME", LUA_LOADLIBNAME),
-#ifdef LUA_JITLIBNAME
-      RS_STR("LUA_JITLIBNAME", LUA_JITLIBNAME),
-#endif
-#ifdef LUA_FFILIBNAME
-      RS_STR("LUA_FFILIBNAME", LUA_FFILIBNAME),
-#endif
-  };
-
-  if (!write_items(f, glue_entries)) {
-    printf("%s: error generating %s; aborting\n", argv[0], filename);
-    return EXIT_FAILURE;
-  }
-
-  fclose(f);
-
-  return EXIT_SUCCESS;
-}

src/ffi/lauxlib.rs

@@ -1,306 +0,0 @@
-// The MIT License (MIT)
-//
-// Copyright (c) 2019-2021 A. Orlenko
-// Copyright (c) 2014 J.C. Moyer
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-//! Contains definitions from `lauxlib.h`.
-
-use std::os::raw::{c_char, c_int, c_long, c_void};
-use std::ptr;
-
-use super::lua::{self, lua_CFunction, lua_Integer, lua_Number, lua_State};
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use super::glue::LUAL_NUMSIZES;
-
-#[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-pub use super::compat53::{luaL_getmetafield, luaL_newmetatable, luaL_requiref, luaL_tolstring};
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-pub use super::compat53::{
-    luaL_checkstack, luaL_checkversion, luaL_getsubtable, luaL_len, luaL_loadbufferx,
-    luaL_setfuncs, luaL_setmetatable, luaL_testudata, luaL_traceback,
-};
-
-// extra error code for 'luaL_load'
-pub const LUA_ERRFILE: c_int = lua::LUA_ERRERR + 1;
-
-#[repr(C)]
-pub struct luaL_Reg {
-    pub name: *const c_char,
-    pub func: lua_CFunction,
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn luaL_checkversion(L: *mut lua_State) {
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    luaL_checkversion_(
-        L,
-        lua::LUA_VERSION_NUM as lua_Number,
-        LUAL_NUMSIZES as usize,
-    );
-    #[cfg(feature = "lua52")]
-    luaL_checkversion_(L, lua::LUA_VERSION_NUM as lua_Number);
-}
-
-extern "C" {
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number, sz: usize);
-    #[cfg(feature = "lua52")]
-    pub fn luaL_checkversion_(L: *mut lua_State, ver: lua_Number);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "luaL_getmetafield"]
-    pub fn luaL_getmetafield_old(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
-
-    pub fn luaL_callmeta(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int;
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn luaL_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
-    pub fn luaL_argerror(L: *mut lua_State, arg: c_int, l: *const c_char) -> c_int;
-    pub fn luaL_checklstring(L: *mut lua_State, arg: c_int, l: *mut usize) -> *const c_char;
-    pub fn luaL_optlstring(
-        L: *mut lua_State,
-        arg: c_int,
-        def: *const c_char,
-        l: *mut usize,
-    ) -> *const c_char;
-    pub fn luaL_checknumber(L: *mut lua_State, arg: c_int) -> lua_Number;
-    pub fn luaL_optnumber(L: *mut lua_State, arg: c_int, def: lua_Number) -> lua_Number;
-    pub fn luaL_checkinteger(L: *mut lua_State, arg: c_int) -> lua_Integer;
-    pub fn luaL_optinteger(L: *mut lua_State, arg: c_int, def: lua_Integer) -> lua_Integer;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_checkstack(L: *mut lua_State, sz: c_int, msg: *const c_char);
-    pub fn luaL_checktype(L: *mut lua_State, arg: c_int, t: c_int);
-    pub fn luaL_checkany(L: *mut lua_State, arg: c_int);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "luaL_newmetatable"]
-    pub fn luaL_newmetatable_old(L: *mut lua_State, tname: *const c_char) -> c_int;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_setmetatable(L: *mut lua_State, tname: *const c_char);
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_testudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
-    pub fn luaL_checkudata(L: *mut lua_State, ud: c_int, tname: *const c_char) -> *mut c_void;
-
-    pub fn luaL_where(L: *mut lua_State, lvl: c_int);
-    pub fn luaL_error(L: *mut lua_State, fmt: *const c_char, ...) -> !;
-
-    // TODO: test this
-    pub fn luaL_checkoption(
-        L: *mut lua_State,
-        arg: c_int,
-        def: *const c_char,
-        lst: *const *const c_char,
-    ) -> c_int;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_fileresult(L: *mut lua_State, stat: c_int, fname: *const c_char) -> c_int;
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_execresult(L: *mut lua_State, stat: c_int) -> c_int;
-}
-
-// pre-defined references
-pub const LUA_NOREF: c_int = -2;
-pub const LUA_REFNIL: c_int = -1;
-
-extern "C" {
-    pub fn luaL_ref(L: *mut lua_State, t: c_int) -> c_int;
-    pub fn luaL_unref(L: *mut lua_State, t: c_int, r: c_int);
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_loadfilex(L: *mut lua_State, filename: *const c_char, mode: *const c_char)
-        -> c_int;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn luaL_loadfile(L: *mut lua_State, filename: *const c_char) -> c_int;
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn luaL_loadfile(L: *mut lua_State, f: *const c_char) -> c_int {
-    luaL_loadfilex(L, f, ptr::null())
-}
-
-extern "C" {
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_loadbufferx(
-        L: *mut lua_State,
-        buff: *const c_char,
-        sz: usize,
-        name: *const c_char,
-        mode: *const c_char,
-    ) -> c_int;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn luaL_loadbuffer(
-        L: *mut lua_State,
-        buff: *const c_char,
-        sz: usize,
-        name: *const c_char,
-    ) -> c_int;
-    pub fn luaL_loadstring(L: *mut lua_State, s: *const c_char) -> c_int;
-
-    pub fn luaL_newstate() -> *mut lua_State;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_len(L: *mut lua_State, idx: c_int) -> lua_Integer;
-
-    // TODO (lua54): luaL_addgsub
-
-    pub fn luaL_gsub(
-        L: *mut lua_State,
-        s: *const c_char,
-        p: *const c_char,
-        r: *const c_char,
-    ) -> *const c_char;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_setfuncs(L: *mut lua_State, l: *const luaL_Reg, nup: c_int);
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_getsubtable(L: *mut lua_State, idx: c_int, fname: *const c_char) -> c_int;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaL_traceback(L: *mut lua_State, L1: *mut lua_State, msg: *const c_char, level: c_int);
-
-    // Skip Lua 5.2 implementation in favor of the compat53 one
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn luaL_requiref(
-        L: *mut lua_State,
-        modname: *const c_char,
-        openf: lua_CFunction,
-        glb: c_int,
-    );
-}
-
-#[inline(always)]
-#[allow(unused_variables)]
-pub unsafe fn luaL_newlibtable(L: *mut lua_State, l: *const luaL_Reg) {
-    // TODO: figure out how to pass an appropriate hint for the second param
-    // this involves correcting the second parameter's type; in C this is
-    // sizeof(l)/sizeof(l[0])
-    lua::lua_createtable(L, 0, 0)
-}
-
-#[inline(always)]
-pub unsafe fn luaL_newlib(L: *mut lua_State, l: *const luaL_Reg) {
-    luaL_checkversion(L);
-    luaL_newlibtable(L, l);
-    luaL_setfuncs(L, l, 0)
-}
-
-#[inline(always)]
-pub unsafe fn luaL_argcheck(L: *mut lua_State, cond: c_int, arg: c_int, extramsg: *const c_char) {
-    if cond == 0 {
-        luaL_argerror(L, arg, extramsg);
-    }
-}
-
-#[inline(always)]
-pub unsafe fn luaL_checkstring(L: *mut lua_State, n: c_int) -> *const c_char {
-    luaL_checklstring(L, n, ptr::null_mut())
-}
-
-#[inline(always)]
-pub unsafe fn luaL_optstring(L: *mut lua_State, n: c_int, d: *const c_char) -> *const c_char {
-    luaL_optlstring(L, n, d, ptr::null_mut())
-}
-
-// From 5.3 user manual:
-// Macros to project non-default integer types (luaL_checkint, luaL_optint,
-// luaL_checklong, luaL_optlong) were deprecated. Use their equivalent over
-// lua_Integer with a type cast (or, when possible, use lua_Integer in your
-// code).
-#[inline(always)]
-//#[deprecated]
-pub unsafe fn luaL_checkint(L: *mut lua_State, n: c_int) -> c_int {
-    luaL_checkinteger(L, n) as c_int
-}
-
-#[inline(always)]
-//#[deprecated]
-pub unsafe fn luaL_optint(L: *mut lua_State, n: c_int, d: c_int) -> c_int {
-    luaL_optinteger(L, n, d as lua_Integer) as c_int
-}
-
-#[inline(always)]
-//#[deprecated]
-pub unsafe fn luaL_checklong(L: *mut lua_State, n: c_int) -> c_long {
-    luaL_checkinteger(L, n) as c_long
-}
-
-#[inline(always)]
-//#[deprecated]
-pub unsafe fn luaL_optlong(L: *mut lua_State, n: c_int, d: c_long) -> c_long {
-    luaL_optinteger(L, n, d as lua_Integer) as c_long
-}
-
-#[inline(always)]
-pub unsafe fn luaL_typename(L: *mut lua_State, i: c_int) -> *const c_char {
-    lua::lua_typename(L, lua::lua_type(L, i))
-}
-
-#[inline(always)]
-pub unsafe fn luaL_dofile(L: *mut lua_State, filename: *const c_char) -> c_int {
-    let status = luaL_loadfile(L, filename);
-    if status == 0 {
-        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
-    } else {
-        status
-    }
-}
-
-#[inline(always)]
-pub unsafe fn luaL_dostring(L: *mut lua_State, s: *const c_char) -> c_int {
-    let status = luaL_loadstring(L, s);
-    if status == 0 {
-        lua::lua_pcall(L, 0, lua::LUA_MULTRET, 0)
-    } else {
-        status
-    }
-}
-
-#[inline(always)]
-pub unsafe fn luaL_getmetatable(L: *mut lua_State, n: *const c_char) {
-    lua::lua_getfield(L, lua::LUA_REGISTRYINDEX, n);
-}
-
-// luaL_opt would be implemented here but it is undocumented, so it's omitted
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn luaL_loadbuffer(
-    L: *mut lua_State,
-    s: *const c_char,
-    sz: usize,
-    n: *const c_char,
-) -> c_int {
-    luaL_loadbufferx(L, s, sz, n, ptr::null())
-}
-
-// TODO: Add buffer API
-
-// omitted: old module system compatibility (removed in 5.4)

src/ffi/lua.rs

@@ -1,835 +0,0 @@
-// The MIT License (MIT)
-//
-// Copyright (c) 2019-2021 A. Orlenko
-// Copyright (c) 2014 J.C. Moyer
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-//! Contains definitions from `lua.h`.
-
-use std::marker::{PhantomData, PhantomPinned};
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-use std::os::raw::c_uchar;
-use std::os::raw::{c_char, c_int, c_void};
-#[cfg(feature = "lua54")]
-use std::os::raw::{c_uint, c_ushort};
-use std::ptr;
-
-use super::luaconf;
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-pub use super::glue::{LUA_ENVIRONINDEX, LUA_GLOBALSINDEX};
-pub use super::glue::{LUA_REGISTRYINDEX, LUA_VERSION_NUM};
-
-#[cfg(not(feature = "luajit"))]
-pub const LUA_SIGNATURE: &[u8] = b"\x1bLua";
-#[cfg(feature = "luajit")]
-pub const LUA_SIGNATURE: &[u8] = b"\x1bLJ";
-
-// option for multiple returns in 'lua_pcall' and 'lua_call'
-pub const LUA_MULTRET: c_int = -1;
-
-#[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-pub use super::compat53::{
-    lua_dump, lua_getextraspace, lua_getfield, lua_geti, lua_gettable, lua_getuservalue,
-    lua_isinteger, lua_pushlstring, lua_rawget, lua_rawgeti, lua_rawgetp, lua_rotate, lua_seti,
-    lua_stringtonumber, lua_tointegerx,
-};
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-pub use super::compat53::{
-    lua_absindex, lua_arith, lua_compare, lua_copy, lua_len, lua_pushglobaltable, lua_pushstring,
-    lua_rawlen, lua_rawsetp, lua_resume as lua_resume_53, lua_setuservalue, lua_tonumberx,
-    lua_upvalueindex,
-};
-
-#[cfg(feature = "lua52")]
-pub use super::compat53::lua_getglobal;
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub const fn lua_upvalueindex(i: c_int) -> c_int {
-    LUA_REGISTRYINDEX - i
-}
-
-// thread status
-pub const LUA_OK: c_int = 0;
-pub const LUA_YIELD: c_int = 1;
-pub const LUA_ERRRUN: c_int = 2;
-pub const LUA_ERRSYNTAX: c_int = 3;
-pub const LUA_ERRMEM: c_int = 4;
-#[cfg(any(feature = "lua53", feature = "lua52"))]
-pub const LUA_ERRGCMM: c_int = 5;
-#[cfg(any(feature = "lua54", feature = "lua51", feature = "luajit"))]
-pub const LUA_ERRERR: c_int = 5;
-#[cfg(any(feature = "lua53", feature = "lua52"))]
-pub const LUA_ERRERR: c_int = 6;
-
-/// A raw Lua state associated with a thread.
-#[repr(C)]
-pub struct lua_State {
-    _data: [u8; 0],
-    _marker: PhantomData<(*mut u8, PhantomPinned)>,
-}
-
-// basic types
-pub const LUA_TNONE: c_int = -1;
-
-pub const LUA_TNIL: c_int = 0;
-pub const LUA_TBOOLEAN: c_int = 1;
-pub const LUA_TLIGHTUSERDATA: c_int = 2;
-pub const LUA_TNUMBER: c_int = 3;
-pub const LUA_TSTRING: c_int = 4;
-pub const LUA_TTABLE: c_int = 5;
-pub const LUA_TFUNCTION: c_int = 6;
-pub const LUA_TUSERDATA: c_int = 7;
-pub const LUA_TTHREAD: c_int = 8;
-
-#[cfg(feature = "lua54")]
-pub const LUA_NUMTYPES: c_int = 9;
-#[cfg(any(feature = "lua53", feature = "lua52"))]
-pub const LUA_NUMTAGS: c_int = 9;
-
-// minimum stack available to a C function
-pub const LUA_MINSTACK: c_int = 20;
-
-// predefined values in the registry
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-pub const LUA_RIDX_MAINTHREAD: lua_Integer = 1;
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-pub const LUA_RIDX_GLOBALS: lua_Integer = 2;
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-pub const LUA_RIDX_LAST: lua_Integer = LUA_RIDX_GLOBALS;
-
-// I believe `luaL_traceback` < 5.4 requires this much free stack to not error.
-// 5.4 uses `luaL_Buffer`
-pub const LUA_TRACEBACK_STACK: c_int = 11;
-
-/// A Lua number, usually equivalent to `f64`.
-pub type lua_Number = luaconf::LUA_NUMBER;
-
-/// A Lua integer, usually equivalent to `i64`.
-pub type lua_Integer = luaconf::LUA_INTEGER;
-
-/// A Lua unsigned integer, usually equivalent to `u64`.
-pub type lua_Unsigned = luaconf::LUA_UNSIGNED;
-
-// type for continuation-function contexts
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub type lua_KContext = luaconf::LUA_KCONTEXT;
-
-/// Type for native C functions that can be passed to Lua.
-pub type lua_CFunction = unsafe extern "C" fn(L: *mut lua_State) -> c_int;
-
-// Type for continuation functions
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub type lua_KFunction =
-    unsafe extern "C" fn(L: *mut lua_State, status: c_int, ctx: lua_KContext) -> c_int;
-
-// Type for functions that read/write blocks when loading/dumping Lua chunks
-pub type lua_Reader =
-    unsafe extern "C" fn(L: *mut lua_State, ud: *mut c_void, sz: *mut usize) -> *const c_char;
-pub type lua_Writer =
-    unsafe extern "C" fn(L: *mut lua_State, p: *const c_void, sz: usize, ud: *mut c_void) -> c_int;
-
-// Type for memory-allocation functions.
-pub type lua_Alloc = unsafe extern "C" fn(
-    ud: *mut c_void,
-    ptr: *mut c_void,
-    osize: usize,
-    nsize: usize,
-) -> *mut c_void;
-
-// Type for warning functions
-#[cfg(feature = "lua54")]
-pub type lua_WarnFunction =
-    unsafe extern "C" fn(ud: *mut c_void, msg: *const c_char, tocont: c_int);
-
-extern "C" {
-    // state manipulation
-    pub fn lua_newstate(f: lua_Alloc, ud: *mut c_void) -> *mut lua_State;
-    pub fn lua_close(L: *mut lua_State);
-    pub fn lua_newthread(L: *mut lua_State) -> *mut lua_State;
-
-    #[cfg(feature = "lua54")]
-    #[link_name = "lua_resetthread"]
-    pub fn lua_resetthread_54(L: *mut lua_State) -> c_int;
-    #[cfg(all(feature = "luajit", feature = "vendored"))]
-    #[link_name = "lua_resetthread"]
-    pub fn lua_resetthread_jit(L: *mut lua_State, th: *mut lua_State);
-
-    pub fn lua_atpanic(L: *mut lua_State, panicf: lua_CFunction) -> lua_CFunction;
-
-    #[cfg(feature = "lua54")]
-    pub fn lua_version(L: *mut lua_State) -> lua_Number;
-    #[cfg(feature = "lua53")]
-    pub fn lua_version(L: *mut lua_State) -> *const lua_Number;
-
-    // basic stack manipulation
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_absindex(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_gettop(L: *mut lua_State) -> c_int;
-    pub fn lua_settop(L: *mut lua_State, idx: c_int);
-    pub fn lua_pushvalue(L: *mut lua_State, idx: c_int);
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    pub fn lua_remove(L: *mut lua_State, idx: c_int);
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    pub fn lua_insert(L: *mut lua_State, idx: c_int);
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    pub fn lua_replace(L: *mut lua_State, idx: c_int);
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_rotate(L: *mut lua_State, idx: c_int, n: c_int);
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_copy(L: *mut lua_State, fromidx: c_int, toidx: c_int);
-    pub fn lua_checkstack(L: *mut lua_State, sz: c_int) -> c_int;
-
-    pub fn lua_xmove(from: *mut lua_State, to: *mut lua_State, n: c_int);
-
-    // access functions (stack -> C)
-    pub fn lua_isnumber(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_isstring(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_iscfunction(L: *mut lua_State, idx: c_int) -> c_int;
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_isuserdata(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_type(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_typename(L: *mut lua_State, tp: c_int) -> *const c_char;
-
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_tonumber(L: *mut lua_State, idx: c_int) -> lua_Number;
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_tonumberx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Number;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_tointeger(L: *mut lua_State, idx: c_int) -> lua_Integer;
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_tointegerx(L: *mut lua_State, idx: c_int, isnum: *mut c_int) -> lua_Integer;
-    pub fn lua_toboolean(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_tolstring(L: *mut lua_State, idx: c_int, len: *mut usize) -> *const c_char;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_objlen(L: *mut lua_State, idx: c_int) -> usize;
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_rawlen(L: *mut lua_State, idx: c_int) -> usize;
-    pub fn lua_tocfunction(L: *mut lua_State, idx: c_int) -> lua_CFunction;
-    pub fn lua_touserdata(L: *mut lua_State, idx: c_int) -> *mut c_void;
-    pub fn lua_tothread(L: *mut lua_State, idx: c_int) -> *mut lua_State;
-    pub fn lua_topointer(L: *mut lua_State, idx: c_int) -> *const c_void;
-}
-
-#[cfg(any(feature = "lua54", all(feature = "luajit", feature = "vendored")))]
-pub unsafe fn lua_resetthread(_L: *mut lua_State, th: *mut lua_State) -> c_int {
-    #[cfg(all(feature = "luajit", feature = "vendored"))]
-    {
-        lua_resetthread_jit(_L, th);
-        LUA_OK
-    }
-    #[cfg(feature = "lua54")]
-    lua_resetthread_54(th)
-}
-
-// Comparison and arithmetic functions
-pub const LUA_OPADD: c_int = 0;
-pub const LUA_OPSUB: c_int = 1;
-pub const LUA_OPMUL: c_int = 2;
-
-#[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-pub const LUA_OPDIV: c_int = 3;
-#[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-pub const LUA_OPMOD: c_int = 4;
-#[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-pub const LUA_OPPOW: c_int = 5;
-#[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-pub const LUA_OPUNM: c_int = 6;
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPMOD: c_int = 3;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPPOW: c_int = 4;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPDIV: c_int = 5;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPIDIV: c_int = 6;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPBAND: c_int = 7;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPBOR: c_int = 8;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPBXOR: c_int = 9;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPSHL: c_int = 10;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPSHR: c_int = 11;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPUNM: c_int = 12;
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub const LUA_OPBNOT: c_int = 13;
-
-extern "C" {
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_arith(L: *mut lua_State, op: c_int);
-}
-
-pub const LUA_OPEQ: c_int = 0;
-pub const LUA_OPLT: c_int = 1;
-pub const LUA_OPLE: c_int = 2;
-
-extern "C" {
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_equal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
-    pub fn lua_rawequal(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_lessthan(L: *mut lua_State, idx1: c_int, idx2: c_int) -> c_int;
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_compare(L: *mut lua_State, idx1: c_int, idx2: c_int, op: c_int) -> c_int;
-}
-
-// push functions (C -> stack)
-extern "C" {
-    pub fn lua_pushnil(L: *mut lua_State);
-    pub fn lua_pushnumber(L: *mut lua_State, n: lua_Number);
-    pub fn lua_pushinteger(L: *mut lua_State, n: lua_Integer);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_pushlstring(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_pushlstring"]
-    pub fn lua_pushlstring_old(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_pushstring(L: *mut lua_State, s: *const c_char) -> *const c_char;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_pushstring"]
-    pub fn lua_pushstring_old(L: *mut lua_State, s: *const c_char) -> *const c_char;
-
-    // TODO: omitted:
-    // lua_pushvfstring
-    pub fn lua_pushfstring(L: *mut lua_State, fmt: *const c_char, ...) -> *const c_char;
-    pub fn lua_pushcclosure(L: *mut lua_State, f: lua_CFunction, n: c_int);
-    pub fn lua_pushboolean(L: *mut lua_State, b: c_int);
-    pub fn lua_pushlightuserdata(L: *mut lua_State, p: *mut c_void);
-    pub fn lua_pushthread(L: *mut lua_State) -> c_int;
-}
-
-// get functions (Lua -> stack)
-extern "C" {
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_getglobal(L: *mut lua_State, var: *const c_char) -> c_int;
-    #[cfg(feature = "lua52")]
-    #[link_name = "lua_getglobal"]
-    pub fn lua_getglobal_old(L: *mut lua_State, var: *const c_char);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_gettable(L: *mut lua_State, idx: c_int) -> c_int;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_gettable"]
-    pub fn lua_gettable_old(L: *mut lua_State, idx: c_int);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_getfield"]
-    pub fn lua_getfield_old(L: *mut lua_State, idx: c_int, k: *const c_char);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_geti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int;
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_rawget(L: *mut lua_State, idx: c_int) -> c_int;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_rawget"]
-    pub fn lua_rawget_old(L: *mut lua_State, idx: c_int);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_rawgeti"]
-    pub fn lua_rawgeti_old(L: *mut lua_State, idx: c_int, n: lua_Integer);
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int;
-    #[cfg(feature = "lua52")]
-    #[link_name = "lua_rawgetp"]
-    pub fn lua_rawgetp_old(L: *mut lua_State, idx: c_int, p: *const c_void);
-
-    pub fn lua_createtable(L: *mut lua_State, narr: c_int, nrec: c_int);
-    #[cfg(feature = "lua54")]
-    pub fn lua_newuserdatauv(L: *mut lua_State, sz: usize, nuvalue: c_int) -> *mut c_void;
-    #[cfg(any(
-        feature = "lua53",
-        feature = "lua52",
-        feature = "lua51",
-        feature = "luajit"
-    ))]
-    pub fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void;
-    pub fn lua_getmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
-
-    #[cfg(feature = "lua54")]
-    pub fn lua_getiuservalue(L: *mut lua_State, idx: c_int, n: c_int) -> c_int;
-    #[cfg(feature = "lua53")]
-    pub fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int;
-    #[cfg(feature = "lua52")]
-    #[link_name = "lua_getuservalue"]
-    pub fn lua_getuservalue_old(L: *mut lua_State, idx: c_int);
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_getfenv(L: *mut lua_State, idx: c_int);
-}
-
-#[cfg(feature = "lua54")]
-#[inline(always)]
-pub unsafe fn lua_newuserdata(L: *mut lua_State, sz: usize) -> *mut c_void {
-    lua_newuserdatauv(L, sz, 1)
-}
-
-#[cfg(feature = "lua54")]
-#[inline(always)]
-pub unsafe fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int {
-    lua_getiuservalue(L, idx, 1)
-}
-
-// set functions (stack -> Lua)
-extern "C" {
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_setglobal(L: *mut lua_State, var: *const c_char);
-    pub fn lua_settable(L: *mut lua_State, idx: c_int);
-    pub fn lua_setfield(L: *mut lua_State, idx: c_int, k: *const c_char);
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_seti(L: *mut lua_State, idx: c_int, n: lua_Integer);
-    pub fn lua_rawset(L: *mut lua_State, idx: c_int);
-    pub fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer);
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_rawsetp(L: *mut lua_State, idx: c_int, p: *const c_void);
-    pub fn lua_setmetatable(L: *mut lua_State, objindex: c_int) -> c_int;
-    #[cfg(feature = "lua54")]
-    pub fn lua_setiuservalue(L: *mut lua_State, idx: c_int, n: c_int) -> c_int;
-    #[cfg(any(feature = "lua53", feature = "lua52"))]
-    pub fn lua_setuservalue(L: *mut lua_State, idx: c_int);
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_setfenv(L: *mut lua_State, idx: c_int) -> c_int;
-}
-
-#[cfg(feature = "lua54")]
-#[inline(always)]
-pub unsafe fn lua_setuservalue(L: *mut lua_State, idx: c_int) {
-    lua_setiuservalue(L, idx, 1);
-}
-
-// 'load' and 'call' functions (load and run Lua code)
-extern "C" {
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_callk(
-        L: *mut lua_State,
-        nargs: c_int,
-        nresults: c_int,
-        ctx: lua_KContext,
-        k: Option<lua_KFunction>,
-    );
-    #[cfg(feature = "lua52")]
-    pub fn lua_callk(
-        L: *mut lua_State,
-        nargs: c_int,
-        nresults: c_int,
-        ctx: c_int,
-        k: Option<lua_CFunction>,
-    );
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_pcallk(
-        L: *mut lua_State,
-        nargs: c_int,
-        nresults: c_int,
-        errfunc: c_int,
-        ctx: lua_KContext,
-        k: Option<lua_KFunction>,
-    ) -> c_int;
-    #[cfg(feature = "lua52")]
-    pub fn lua_pcallk(
-        L: *mut lua_State,
-        nargs: c_int,
-        nresults: c_int,
-        errfunc: c_int,
-        ctx: c_int,
-        k: Option<lua_CFunction>,
-    ) -> c_int;
-
-    #[cfg(feature = "lua52")]
-    pub fn lua_getctx(L: *mut lua_State, ctx: *mut c_int) -> c_int;
-
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_call(L: *mut lua_State, nargs: c_int, nresults: c_int);
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_pcall(L: *mut lua_State, nargs: c_int, nresults: c_int, errfunc: c_int) -> c_int;
-
-    // TODO
-    pub fn lua_load(
-        L: *mut lua_State,
-        reader: lua_Reader,
-        dt: *mut c_void,
-        chunkname: *const c_char,
-        mode: *const c_char,
-    ) -> c_int;
-
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_dump(
-        L: *mut lua_State,
-        writer: lua_Writer,
-        data: *mut c_void,
-        strip: c_int,
-    ) -> c_int;
-    #[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_dump"]
-    pub fn lua_dump_old(L: *mut lua_State, writer: lua_Writer, data: *mut c_void) -> c_int;
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn lua_call(L: *mut lua_State, n: c_int, r: c_int) {
-    lua_callk(L, n, r, 0, None)
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn lua_pcall(L: *mut lua_State, n: c_int, r: c_int, f: c_int) -> c_int {
-    lua_pcallk(L, n, r, f, 0, None)
-}
-
-// coroutine functions
-extern "C" {
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_yieldk(
-        L: *mut lua_State,
-        nresults: c_int,
-        ctx: lua_KContext,
-        k: Option<lua_KFunction>,
-    ) -> c_int;
-    #[cfg(feature = "lua52")]
-    pub fn lua_yieldk(
-        L: *mut lua_State,
-        nresults: c_int,
-        ctx: c_int,
-        k: Option<lua_CFunction>,
-    ) -> c_int;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    pub fn lua_yield(L: *mut lua_State, nresults: c_int) -> c_int;
-
-    #[cfg(feature = "lua54")]
-    pub fn lua_resume(
-        L: *mut lua_State,
-        from: *mut lua_State,
-        narg: c_int,
-        nres: *mut c_int,
-    ) -> c_int;
-    #[cfg(any(feature = "lua53", feature = "lua52"))]
-    #[link_name = "lua_resume"]
-    pub fn lua_resume_53(L: *mut lua_State, from: *mut lua_State, narg: c_int) -> c_int;
-    #[cfg(any(feature = "lua51", feature = "luajit"))]
-    #[link_name = "lua_resume"]
-    pub fn lua_resume_old(L: *mut lua_State, narg: c_int) -> c_int;
-
-    pub fn lua_status(L: *mut lua_State) -> c_int;
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_isyieldable(L: *mut lua_State) -> c_int;
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn lua_yield(L: *mut lua_State, n: c_int) -> c_int {
-    lua_yieldk(L, n, 0, None)
-}
-
-#[cfg(any(
-    feature = "lua53",
-    feature = "lua52",
-    feature = "lua51",
-    feature = "luajit"
-))]
-#[inline(always)]
-pub unsafe fn lua_resume(
-    L: *mut lua_State,
-    from: *mut lua_State,
-    narg: c_int,
-    nres: *mut c_int,
-) -> c_int {
-    let ret = lua_resume_53(L, from, narg);
-    if ret == LUA_OK || ret == LUA_YIELD {
-        *nres = lua_gettop(L);
-    }
-    ret
-}
-
-// warning-related functions
-#[cfg(feature = "lua54")]
-extern "C" {
-    pub fn lua_setwarnf(L: *mut lua_State, f: Option<lua_WarnFunction>, ud: *mut c_void);
-    pub fn lua_warning(L: *mut lua_State, msg: *const c_char, tocont: c_int);
-}
-
-// garbage-collection function and options
-pub const LUA_GCSTOP: c_int = 0;
-pub const LUA_GCRESTART: c_int = 1;
-pub const LUA_GCCOLLECT: c_int = 2;
-pub const LUA_GCCOUNT: c_int = 3;
-pub const LUA_GCCOUNTB: c_int = 4;
-pub const LUA_GCSTEP: c_int = 5;
-pub const LUA_GCSETPAUSE: c_int = 6;
-pub const LUA_GCSETSTEPMUL: c_int = 7;
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-pub const LUA_GCISRUNNING: c_int = 9;
-#[cfg(feature = "lua54")]
-pub const LUA_GCGEN: c_int = 10;
-#[cfg(feature = "lua54")]
-pub const LUA_GCINC: c_int = 11;
-
-extern "C" {
-    #[cfg(feature = "lua54")]
-    pub fn lua_gc(L: *mut lua_State, what: c_int, ...) -> c_int;
-    #[cfg(any(
-        feature = "lua53",
-        feature = "lua52",
-        feature = "lua51",
-        feature = "luajit"
-    ))]
-    pub fn lua_gc(L: *mut lua_State, what: c_int, data: c_int) -> c_int;
-}
-
-// miscellaneous functions
-extern "C" {
-    pub fn lua_error(L: *mut lua_State) -> !;
-    pub fn lua_next(L: *mut lua_State, idx: c_int) -> c_int;
-    pub fn lua_concat(L: *mut lua_State, n: c_int);
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_len(L: *mut lua_State, idx: c_int);
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn lua_stringtonumber(L: *mut lua_State, s: *const c_char) -> usize;
-    pub fn lua_getallocf(L: *mut lua_State, ud: *mut *mut c_void) -> lua_Alloc;
-    pub fn lua_setallocf(L: *mut lua_State, f: lua_Alloc, ud: *mut c_void);
-    #[cfg(feature = "lua54")]
-    pub fn lua_toclose(L: *mut lua_State, idx: c_int);
-}
-
-// some useful macros
-// here, implemented as Rust functions
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-#[inline(always)]
-pub unsafe fn lua_getextraspace(L: *mut lua_State) -> *mut c_void {
-    (L as *mut c_char).offset(-super::glue::LUA_EXTRASPACE as isize) as *mut c_void
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn lua_tonumber(L: *mut lua_State, i: c_int) -> lua_Number {
-    lua_tonumberx(L, i, ptr::null_mut())
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
-    lua_tointegerx(L, i, ptr::null_mut())
-}
-
-#[inline(always)]
-pub unsafe fn lua_pop(L: *mut lua_State, n: c_int) {
-    lua_settop(L, -n - 1)
-}
-
-#[inline(always)]
-pub unsafe fn lua_newtable(L: *mut lua_State) {
-    lua_createtable(L, 0, 0)
-}
-
-#[inline(always)]
-pub unsafe fn lua_register(L: *mut lua_State, n: *const c_char, f: lua_CFunction) {
-    lua_pushcfunction(L, f);
-    lua_setglobal(L, n)
-}
-
-#[inline(always)]
-pub unsafe fn lua_pushcfunction(L: *mut lua_State, f: lua_CFunction) {
-    lua_pushcclosure(L, f, 0)
-}
-
-#[inline(always)]
-pub unsafe fn lua_isfunction(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TFUNCTION) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_istable(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TTABLE) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_islightuserdata(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TLIGHTUSERDATA) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_isnil(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TNIL) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_isboolean(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TBOOLEAN) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_isthread(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TTHREAD) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_isnone(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) == LUA_TNONE) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_isnoneornil(L: *mut lua_State, n: c_int) -> c_int {
-    (lua_type(L, n) <= 0) as c_int
-}
-
-#[inline(always)]
-pub unsafe fn lua_pushliteral(L: *mut lua_State, s: &'static str) -> *const c_char {
-    use std::ffi::CString;
-    let c_str = CString::new(s).unwrap();
-    lua_pushlstring(L, c_str.as_ptr(), c_str.as_bytes().len())
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[inline(always)]
-pub unsafe fn lua_setglobal(L: *mut lua_State, var: *const c_char) {
-    lua_setfield(L, LUA_GLOBALSINDEX, var)
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[inline(always)]
-pub unsafe fn lua_getglobal(L: *mut lua_State, var: *const c_char) -> c_int {
-    lua_getfield(L, LUA_GLOBALSINDEX, var)
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[inline(always)]
-pub unsafe fn lua_pushglobaltable(L: *mut lua_State) -> c_int {
-    lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS)
-}
-
-#[inline(always)]
-pub unsafe fn lua_tostring(L: *mut lua_State, i: c_int) -> *const c_char {
-    lua_tolstring(L, i, ptr::null_mut())
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-#[inline(always)]
-pub unsafe fn lua_insert(L: *mut lua_State, idx: c_int) {
-    lua_rotate(L, idx, 1)
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-#[inline(always)]
-pub unsafe fn lua_remove(L: *mut lua_State, idx: c_int) {
-    lua_rotate(L, idx, -1);
-    lua_pop(L, 1)
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-#[inline(always)]
-pub unsafe fn lua_replace(L: *mut lua_State, idx: c_int) {
-    lua_copy(L, -1, idx);
-    lua_pop(L, 1)
-}
-
-// Debug API
-// Event codes
-pub const LUA_HOOKCALL: c_int = 0;
-pub const LUA_HOOKRET: c_int = 1;
-pub const LUA_HOOKLINE: c_int = 2;
-pub const LUA_HOOKCOUNT: c_int = 3;
-pub const LUA_HOOKTAILCALL: c_int = 4;
-
-// Event masks
-pub const LUA_MASKCALL: c_int = 1 << (LUA_HOOKCALL as usize);
-pub const LUA_MASKRET: c_int = 1 << (LUA_HOOKRET as usize);
-pub const LUA_MASKLINE: c_int = 1 << (LUA_HOOKLINE as usize);
-pub const LUA_MASKCOUNT: c_int = 1 << (LUA_HOOKCOUNT as usize);
-
-/// Type for functions to be called on debug events.
-pub type lua_Hook = unsafe extern "C" fn(L: *mut lua_State, ar: *mut lua_Debug);
-
-extern "C" {
-    pub fn lua_getstack(L: *mut lua_State, level: c_int, ar: *mut lua_Debug) -> c_int;
-    pub fn lua_getinfo(L: *mut lua_State, what: *const c_char, ar: *mut lua_Debug) -> c_int;
-    pub fn lua_getlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
-    pub fn lua_setlocal(L: *mut lua_State, ar: *const lua_Debug, n: c_int) -> *const c_char;
-    pub fn lua_getupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
-    pub fn lua_setupvalue(L: *mut lua_State, funcindex: c_int, n: c_int) -> *const c_char;
-
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_upvalueid(L: *mut lua_State, fidx: c_int, n: c_int) -> *mut c_void;
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn lua_upvaluejoin(L: *mut lua_State, fidx1: c_int, n1: c_int, fidx2: c_int, n2: c_int);
-
-    pub fn lua_sethook(L: *mut lua_State, func: Option<lua_Hook>, mask: c_int, count: c_int);
-    pub fn lua_gethook(L: *mut lua_State) -> Option<lua_Hook>;
-    pub fn lua_gethookmask(L: *mut lua_State) -> c_int;
-    pub fn lua_gethookcount(L: *mut lua_State) -> c_int;
-
-    #[cfg(feature = "lua54")]
-    pub fn lua_setcstacklimit(L: *mut lua_State, limit: c_uint) -> c_int;
-}
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-#[repr(C)]
-pub struct lua_Debug {
-    pub event: c_int,
-    pub name: *const c_char,
-    pub namewhat: *const c_char,
-    pub what: *const c_char,
-    pub source: *const c_char,
-    #[cfg(feature = "lua54")]
-    pub srclen: usize,
-    pub currentline: c_int,
-    pub linedefined: c_int,
-    pub lastlinedefined: c_int,
-    pub nups: c_uchar,
-    pub nparams: c_uchar,
-    pub isvararg: c_char,
-    pub istailcall: c_char,
-    #[cfg(feature = "lua54")]
-    pub ftransfer: c_ushort,
-    #[cfg(feature = "lua54")]
-    pub ntransfer: c_ushort,
-    pub short_src: [c_char; luaconf::LUA_IDSIZE as usize],
-    // lua.h mentions this is for private use
-    i_ci: *mut c_void,
-}
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-#[repr(C)]
-pub struct lua_Debug {
-    pub event: c_int,
-    pub name: *const c_char,
-    pub namewhat: *const c_char,
-    pub what: *const c_char,
-    pub source: *const c_char,
-    pub currentline: c_int,
-    pub nups: c_int,
-    pub linedefined: c_int,
-    pub lastlinedefined: c_int,
-    pub short_src: [c_char; luaconf::LUA_IDSIZE as usize],
-    // lua.h mentions this is for private use
-    i_ci: c_int,
-}

src/ffi/luaconf.rs

@@ -1,36 +0,0 @@
-// The MIT License (MIT)
-//
-// Copyright (c) 2019-2021 A. Orlenko
-// Copyright (c) 2014 J.C. Moyer
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-//! Contains definitions from `luaconf.h`.
-
-pub use super::glue::LUA_INTEGER;
-pub use super::glue::LUA_NUMBER;
-pub use super::glue::LUA_UNSIGNED;
-
-pub use super::glue::LUA_IDSIZE;
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use super::glue::LUAL_NUMSIZES;
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub type LUA_KCONTEXT = isize; // intptr_t

src/ffi/lualib.rs

@@ -1,67 +0,0 @@
-// The MIT License (MIT)
-//
-// Copyright (c) 2019-2021 A. Orlenko
-// Copyright (c) 2014 J.C. Moyer
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-//! Contains definitions from `lualib.h`.
-
-use std::os::raw::c_int;
-
-use super::lua::lua_State;
-
-pub use super::glue::{
-    LUA_COLIBNAME, LUA_DBLIBNAME, LUA_IOLIBNAME, LUA_LOADLIBNAME, LUA_MATHLIBNAME, LUA_OSLIBNAME,
-    LUA_STRLIBNAME, LUA_TABLIBNAME,
-};
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use super::glue::LUA_UTF8LIBNAME;
-
-#[cfg(any(feature = "lua52", feature = "luajit"))]
-pub use super::glue::LUA_BITLIBNAME;
-
-#[cfg(feature = "luajit")]
-pub use super::glue::{LUA_FFILIBNAME, LUA_JITLIBNAME};
-
-extern "C" {
-    pub fn luaopen_base(L: *mut lua_State) -> c_int;
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-    pub fn luaopen_coroutine(L: *mut lua_State) -> c_int;
-    pub fn luaopen_table(L: *mut lua_State) -> c_int;
-    pub fn luaopen_io(L: *mut lua_State) -> c_int;
-    pub fn luaopen_os(L: *mut lua_State) -> c_int;
-    pub fn luaopen_string(L: *mut lua_State) -> c_int;
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
-    pub fn luaopen_utf8(L: *mut lua_State) -> c_int;
-    #[cfg(feature = "lua52")]
-    pub fn luaopen_bit32(L: *mut lua_State) -> c_int;
-    pub fn luaopen_math(L: *mut lua_State) -> c_int;
-    pub fn luaopen_debug(L: *mut lua_State) -> c_int;
-    pub fn luaopen_package(L: *mut lua_State) -> c_int;
-    #[cfg(feature = "luajit")]
-    pub fn luaopen_bit(L: *mut lua_State) -> c_int;
-    #[cfg(feature = "luajit")]
-    pub fn luaopen_jit(L: *mut lua_State) -> c_int;
-    #[cfg(feature = "luajit")]
-    pub fn luaopen_ffi(L: *mut lua_State) -> c_int;
-
-    pub fn luaL_openlibs(L: *mut lua_State);
-}

src/ffi/mod.rs

@@ -1,315 +0,0 @@
-// The MIT License (MIT)
-//
-// Copyright (c) 2019-2021 A. Orlenko
-// Copyright (c) 2014 J.C. Moyer
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-//! Low level bindings to Lua.
-
-#![allow(non_camel_case_types, non_snake_case, dead_code)]
-
-use std::os::raw::c_int;
-
-// This is more or less in the order it appears in the Lua manual, with the
-// exception of constants, which appear scattered throughout the manual text.
-
-// C API types
-pub use self::lua::{
-    lua_Alloc, lua_CFunction, lua_Debug, lua_Hook, lua_Integer, lua_Number, lua_Reader, lua_State,
-    lua_Unsigned, lua_Writer,
-};
-
-#[cfg(feature = "lua54")]
-pub use self::lua::lua_WarnFunction;
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use self::lua::{lua_KContext, lua_KFunction};
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-pub use self::lua::{lua_getfenv, lua_setfenv};
-
-// C API functions
-pub use self::lua::{
-    lua_absindex,
-    lua_arith,
-    lua_atpanic,
-    lua_call,
-    lua_checkstack,
-    lua_close,
-    lua_compare,
-    lua_concat,
-    lua_copy,
-    lua_createtable,
-    lua_dump,
-    lua_error,
-    lua_gc,
-    lua_getallocf,
-    lua_getextraspace,
-    lua_getfield,
-    lua_getglobal,
-    lua_gethook,
-    lua_gethookcount,
-    lua_gethookmask,
-    lua_geti,
-    lua_getinfo,
-    lua_getlocal,
-    lua_getmetatable,
-    lua_getstack,
-    lua_gettable,
-    lua_gettop,
-    lua_getupvalue,
-    lua_getuservalue,
-    lua_insert,
-    lua_isboolean,
-    lua_iscfunction,
-    lua_isfunction,
-    lua_isinteger,
-    lua_islightuserdata,
-    lua_isnil,
-    lua_isnone,
-    lua_isnoneornil,
-    lua_isnumber,
-    lua_isstring,
-    lua_istable,
-    lua_isthread,
-    lua_isuserdata,
-    lua_len,
-    lua_load,
-    lua_newstate,
-    lua_newtable,
-    lua_newthread,
-    lua_newuserdata,
-    lua_next,
-    lua_pcall,
-    lua_pop,
-    lua_pushboolean,
-    lua_pushcclosure,
-    lua_pushcfunction,
-    lua_pushfstring,
-    lua_pushglobaltable,
-    lua_pushinteger,
-    lua_pushlightuserdata,
-    lua_pushliteral,
-    lua_pushlstring,
-    lua_pushnil,
-    lua_pushnumber,
-    lua_pushstring,
-    lua_pushthread,
-    lua_pushvalue,
-    // omitted: lua_pushvfstring
-    lua_rawequal,
-    lua_rawget,
-    lua_rawgeti,
-    lua_rawgetp,
-    lua_rawlen,
-    lua_rawset,
-    lua_rawseti,
-    lua_rawsetp,
-    lua_register,
-    lua_remove,
-    lua_replace,
-    lua_resume,
-    lua_rotate,
-    lua_setallocf,
-    lua_setfield,
-    lua_setglobal,
-    lua_sethook,
-    lua_seti,
-    lua_setlocal,
-    lua_setmetatable,
-    lua_settable,
-    lua_settop,
-    lua_setupvalue,
-    lua_setuservalue,
-    lua_status,
-    lua_stringtonumber,
-    lua_toboolean,
-    lua_tocfunction,
-    lua_tointeger,
-    lua_tointegerx,
-    lua_tolstring,
-    lua_tonumber,
-    lua_tonumberx,
-    lua_topointer,
-    lua_tostring,
-    lua_tothread,
-    lua_touserdata,
-    lua_type,
-    lua_typename,
-    lua_upvalueindex,
-    lua_xmove,
-    lua_yield,
-};
-
-#[cfg(feature = "lua54")]
-pub use self::lua::{
-    lua_getiuservalue, lua_newuserdatauv, lua_setcstacklimit, lua_setiuservalue, lua_setwarnf,
-    lua_toclose, lua_warning,
-};
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use self::lua::{lua_isyieldable, lua_version};
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-pub use self::lua::{lua_callk, lua_pcallk, lua_upvalueid, lua_upvaluejoin, lua_yieldk};
-
-#[cfg(any(feature = "lua54", all(feature = "luajit", feature = "vendored")))]
-pub use self::lua::lua_resetthread;
-
-// auxiliary library types
-pub use self::lauxlib::luaL_Reg;
-
-// auxiliary library functions
-pub use self::lauxlib::{
-    luaL_argcheck, luaL_argerror, luaL_callmeta, luaL_checkany, luaL_checkint, luaL_checkinteger,
-    luaL_checklong, luaL_checklstring, luaL_checknumber, luaL_checkoption, luaL_checkstack,
-    luaL_checkstring, luaL_checktype, luaL_checkudata, luaL_checkversion, luaL_dofile,
-    luaL_dostring, luaL_error, luaL_getmetafield, luaL_getmetatable, luaL_getsubtable, luaL_gsub,
-    luaL_len, luaL_loadbuffer, luaL_loadbufferx, luaL_loadfile, luaL_loadstring, luaL_newlib,
-    luaL_newlibtable, luaL_newmetatable, luaL_newstate, luaL_optint, luaL_optinteger, luaL_optlong,
-    luaL_optlstring, luaL_optnumber, luaL_optstring, luaL_ref, luaL_requiref, luaL_setfuncs,
-    luaL_setmetatable, luaL_testudata, luaL_tolstring, luaL_traceback, luaL_typename, luaL_unref,
-    luaL_where,
-};
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-pub use self::lauxlib::{luaL_execresult, luaL_fileresult, luaL_loadfilex};
-
-// lualib.h functions
-pub use self::lualib::{
-    luaL_openlibs, luaopen_base, luaopen_debug, luaopen_io, luaopen_math, luaopen_os,
-    luaopen_package, luaopen_string, luaopen_table,
-};
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use self::lualib::{luaopen_coroutine, luaopen_utf8};
-
-#[cfg(feature = "lua52")]
-pub use self::lualib::{luaopen_bit32, luaopen_coroutine};
-
-#[cfg(feature = "luajit")]
-pub use self::lualib::{luaopen_bit, luaopen_ffi, luaopen_jit};
-
-// constants from lua.h
-pub use self::lua::{
-    LUA_ERRERR, LUA_ERRMEM, LUA_ERRRUN, LUA_ERRSYNTAX, LUA_GCCOLLECT, LUA_GCCOUNT, LUA_GCCOUNTB,
-    LUA_GCRESTART, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL, LUA_GCSTEP, LUA_GCSTOP, LUA_HOOKCALL,
-    LUA_HOOKCOUNT, LUA_HOOKLINE, LUA_HOOKRET, LUA_HOOKTAILCALL, LUA_MASKCALL, LUA_MASKCOUNT,
-    LUA_MASKLINE, LUA_MASKRET, LUA_MINSTACK, LUA_MULTRET, LUA_OK, LUA_OPADD, LUA_OPDIV, LUA_OPEQ,
-    LUA_OPLE, LUA_OPLT, LUA_OPMOD, LUA_OPMUL, LUA_OPPOW, LUA_OPSUB, LUA_OPUNM, LUA_REGISTRYINDEX,
-    LUA_SIGNATURE, LUA_TBOOLEAN, LUA_TFUNCTION, LUA_TLIGHTUSERDATA, LUA_TNIL, LUA_TNONE,
-    LUA_TNUMBER, LUA_TRACEBACK_STACK, LUA_TSTRING, LUA_TTABLE, LUA_TTHREAD, LUA_TUSERDATA,
-    LUA_YIELD,
-};
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use self::lua::{
-    LUA_OPBAND, LUA_OPBNOT, LUA_OPBOR, LUA_OPBXOR, LUA_OPIDIV, LUA_OPSHL, LUA_OPSHR,
-};
-
-#[cfg(feature = "lua54")]
-pub use self::lua::{LUA_GCGEN, LUA_GCINC};
-
-#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-pub use self::lua::{LUA_GCISRUNNING, LUA_RIDX_GLOBALS, LUA_RIDX_MAINTHREAD};
-
-#[cfg(any(feature = "lua53", feature = "lua52"))]
-pub use self::lua::LUA_ERRGCMM;
-
-#[cfg(any(feature = "lua51", feature = "luajit"))]
-pub use self::lua::{LUA_ENVIRONINDEX, LUA_GLOBALSINDEX};
-
-// constants from lauxlib.h
-pub use self::lauxlib::{LUA_ERRFILE, LUA_NOREF, LUA_REFNIL};
-
-// constants from lualib.h
-pub use self::lualib::{
-    LUA_COLIBNAME, LUA_DBLIBNAME, LUA_IOLIBNAME, LUA_LOADLIBNAME, LUA_MATHLIBNAME, LUA_OSLIBNAME,
-    LUA_STRLIBNAME, LUA_TABLIBNAME,
-};
-
-#[cfg(any(feature = "lua54", feature = "lua53"))]
-pub use self::lualib::LUA_UTF8LIBNAME;
-
-#[cfg(any(feature = "lua52", feature = "luajit"))]
-pub use self::lualib::LUA_BITLIBNAME;
-
-#[cfg(feature = "luajit")]
-pub use self::lualib::{LUA_FFILIBNAME, LUA_JITLIBNAME};
-
-// Not actually defined in lua.h / luaconf.h
-pub const LUA_MAX_UPVALUES: c_int = 255;
-
-// Copied from https://github.com/rust-lang/rust/blob/master/library/std/src/sys/common/alloc.rs
-#[cfg(all(any(
-    target_arch = "x86",
-    target_arch = "arm",
-    target_arch = "mips",
-    target_arch = "powerpc",
-    target_arch = "powerpc64",
-    target_arch = "sparc",
-    target_arch = "asmjs",
-    target_arch = "wasm32",
-    target_arch = "hexagon",
-    target_arch = "riscv32"
-)))]
-pub const SYS_MIN_ALIGN: usize = 8;
-#[cfg(all(any(
-    target_arch = "x86_64",
-    target_arch = "aarch64",
-    target_arch = "mips64",
-    target_arch = "s390x",
-    target_arch = "sparc64",
-    target_arch = "riscv64"
-)))]
-pub const SYS_MIN_ALIGN: usize = 16;
-
-// Hack to avoid stripping a few unused Lua symbols that could be imported
-// by C modules in unsafe mode
-pub(crate) fn keep_lua_symbols() {
-    let mut symbols: Vec<*const extern "C" fn()> = Vec::new();
-    symbols.push(lua_atpanic as _);
-    symbols.push(lua_isuserdata as _);
-    symbols.push(lua_tocfunction as _);
-    symbols.push(luaL_loadstring as _);
-    symbols.push(luaL_openlibs as _);
-    if cfg!(any(any(
-        feature = "lua54",
-        feature = "lua53",
-        feature = "lua52"
-    ))) {
-        symbols.push(lua_getglobal as _);
-        symbols.push(lua_setglobal as _);
-    }
-}
-
-#[allow(unused_imports, dead_code, non_camel_case_types)]
-#[allow(clippy::unreadable_literal)]
-mod glue {
-    include!(concat!(env!("OUT_DIR"), "/glue.rs"));
-}
-
-#[cfg(any(feature = "lua52", feature = "lua51", feature = "luajit"))]
-mod compat53;
-
-mod lauxlib;
-mod lua;
-mod luaconf;
-mod lualib;

src/function.rs

@@ -1,20 +1,86 @@
+use std::cell::RefCell;
+use std::mem;
 use std::os::raw::{c_int, c_void};
 use std::ptr;
 use std::slice;
 
 use crate::error::{Error, Result};
-use crate::ffi;
-use crate::types::LuaRef;
-use crate::util::{assert_stack, check_stack, error_traceback, pop_error, StackGuard};
-use crate::value::{FromLuaMulti, ToLuaMulti};
+use crate::lua::Lua;
+use crate::table::Table;
+use crate::types::{Callback, LuaRef, MaybeSend};
+use crate::util::{
+    assert_stack, check_stack, linenumber_to_usize, pop_error, ptr_to_lossy_str, ptr_to_str,
+    StackGuard,
+};
+use crate::value::{FromLuaMulti, IntoLua, IntoLuaMulti, Value};
 
 #[cfg(feature = "async")]
-use {futures_core::future::LocalBoxFuture, futures_util::future};
+use {
+    crate::types::AsyncCallback,
+    futures_util::future::{self, Future},
+};
 
 /// Handle to an internal Lua function.
 #[derive(Clone, Debug)]
 pub struct Function<'lua>(pub(crate) LuaRef<'lua>);
 
+/// Owned handle to an internal Lua function.
+///
+/// The owned handle holds a *strong* reference to the current Lua instance.
+/// Be warned, if you place it into a Lua type (eg. [`UserData`] or a Rust callback), it is *very easy*
+/// to accidentally cause reference cycles that would prevent destroying Lua instance.
+///
+/// [`UserData`]: crate::UserData
+#[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
+#[derive(Clone, Debug)]
+pub struct OwnedFunction(pub(crate) crate::types::LuaOwnedRef);
+
+#[cfg(feature = "unstable")]
+impl OwnedFunction {
+    /// Get borrowed handle to the underlying Lua function.
+    #[cfg_attr(feature = "send", allow(unused))]
+    pub const fn to_ref(&self) -> Function {
+        Function(self.0.to_ref())
+    }
+}
+
+/// Contains information about a function.
+///
+/// Please refer to the [`Lua Debug Interface`] for more information.
+///
+/// [`Lua Debug Interface`]: https://www.lua.org/manual/5.4/manual.html#4.7
+#[derive(Clone, Debug)]
+pub struct FunctionInfo {
+    /// A (reasonable) name of the function (`None` if the name cannot be found).
+    pub name: Option<String>,
+    /// Explains the `name` field (can be `global`/`local`/`method`/`field`/`upvalue`/etc).
+    ///
+    /// Always `None` for Luau.
+    pub name_what: Option<&'static str>,
+    /// A string `Lua` if the function is a Lua function, `C` if it is a C function, `main` if it is the main part of a chunk.
+    pub what: &'static str,
+    /// Source of the chunk that created the function.
+    pub source: Option<String>,
+    /// A "printable" version of `source`, to be used in error messages.
+    pub short_src: Option<String>,
+    /// The line number where the definition of the function starts.
+    pub line_defined: Option<usize>,
+    /// The line number where the definition of the function ends (not set by Luau).
+    pub last_line_defined: Option<usize>,
+}
+
+/// Luau function coverage snapshot.
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct CoverageInfo {
+    pub function: Option<String>,
+    pub line_defined: i32,
+    pub depth: i32,
+    pub hits: Vec<i32>,
+}
+
 impl<'lua> Function<'lua> {
     /// Calls the function, passing `args` as function arguments.
     ///
@@ -56,39 +122,31 @@ impl<'lua> Function<'lua> {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn call<A: ToLuaMulti<'lua>, R: FromLuaMulti<'lua>>(&self, args: A) -> Result<R> {
+    pub fn call<A: IntoLuaMulti<'lua>, R: FromLuaMulti<'lua>>(&self, args: A) -> Result<R> {
         let lua = self.0.lua;
+        let state = lua.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            check_stack(state, 2)?;
 
-        let mut args = args.to_lua_multi(lua)?;
-        let nargs = args.len() as c_int;
-
-        let results = unsafe {
-            let _sg = StackGuard::new(lua.state);
-            check_stack(lua.state, nargs + 3)?;
-
-            ffi::lua_pushcfunction(lua.state, error_traceback);
-            let stack_start = ffi::lua_gettop(lua.state);
+            // Push error handler
+            lua.push_error_traceback();
+            let stack_start = ffi::lua_gettop(state);
+            // Push function and the arguments
             lua.push_ref(&self.0);
-            for arg in args.drain_all() {
-                lua.push_value(arg)?;
-            }
-            let ret = ffi::lua_pcall(lua.state, nargs, ffi::LUA_MULTRET, stack_start);
+            let nargs = args.push_into_stack_multi(lua)?;
+            // Call the function
+            let ret = ffi::lua_pcall(state, nargs, ffi::LUA_MULTRET, stack_start);
             if ret != ffi::LUA_OK {
-                return Err(pop_error(lua.state, ret));
+                return Err(pop_error(state, ret));
             }
-            let nresults = ffi::lua_gettop(lua.state) - stack_start;
-            let mut results = args; // Reuse MultiValue container
-            assert_stack(lua.state, 2);
-            for _ in 0..nresults {
-                results.push_front(lua.pop_value());
-            }
-            ffi::lua_pop(lua.state, 1);
-            results
-        };
-        R::from_lua_multi(results, lua)
+            // Get the results
+            let nresults = ffi::lua_gettop(state) - stack_start;
+            R::from_stack_multi(nresults, lua)
+        }
     }
 
-    /// Returns a Feature that, when polled, calls `self`, passing `args` as function arguments,
+    /// Returns a future that, when polled, calls `self`, passing `args` as function arguments,
     /// and drives the execution.
     ///
     /// Internally it wraps the function to an [`AsyncThread`].
@@ -99,14 +157,13 @@ impl<'lua> Function<'lua> {
     ///
     /// ```
     /// use std::time::Duration;
-    /// use futures_timer::Delay;
     /// # use mlua::{Lua, Result};
     /// # #[tokio::main]
     /// # async fn main() -> Result<()> {
     /// # let lua = Lua::new();
     ///
     /// let sleep = lua.create_async_function(move |_lua, n: u64| async move {
-    ///     Delay::new(Duration::from_millis(n)).await;
+    ///     tokio::time::sleep(Duration::from_millis(n)).await;
     ///     Ok(())
     /// })?;
     ///
@@ -119,21 +176,18 @@ impl<'lua> Function<'lua> {
     /// [`AsyncThread`]: crate::AsyncThread
     #[cfg(feature = "async")]
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-    pub fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
+    pub fn call_async<A, R>(&self, args: A) -> impl Future<Output = Result<R>> + 'lua
     where
-        'lua: 'fut,
-        A: ToLuaMulti<'lua>,
-        R: FromLuaMulti<'lua> + 'fut,
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua,
     {
         let lua = self.0.lua;
-        match lua.create_recycled_thread(self.clone()) {
-            Ok(t) => {
-                let mut t = t.into_async(args);
-                t.set_recyclable(true);
-                Box::pin(t)
-            }
-            Err(e) => Box::pin(future::err(e)),
-        }
+        let thread_res = lua.create_recycled_thread(self).map(|th| {
+            let mut th = th.into_async(args);
+            th.set_recyclable(true);
+            th
+        });
+        async move { thread_res?.await }
     }
 
     /// Returns a function that, when called, calls `self`, passing `args` as the first set of
@@ -163,50 +217,188 @@ impl<'lua> Function<'lua> {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn bind<A: ToLuaMulti<'lua>>(&self, args: A) -> Result<Function<'lua>> {
-        unsafe extern "C" fn bind_call_impl(state: *mut ffi::lua_State) -> c_int {
+    pub fn bind<A: IntoLuaMulti<'lua>>(&self, args: A) -> Result<Function<'lua>> {
+        unsafe extern "C-unwind" fn args_wrapper_impl(state: *mut ffi::lua_State) -> c_int {
             let nargs = ffi::lua_gettop(state);
-            let nbinds = ffi::lua_tointeger(state, ffi::lua_upvalueindex(2)) as c_int;
-            ffi::luaL_checkstack(state, nbinds + 2, ptr::null());
-
-            ffi::lua_settop(state, nargs + nbinds + 1);
-            ffi::lua_rotate(state, -(nargs + nbinds + 1), nbinds + 1);
-
-            ffi::lua_pushvalue(state, ffi::lua_upvalueindex(1));
-            ffi::lua_replace(state, 1);
+            let nbinds = ffi::lua_tointeger(state, ffi::lua_upvalueindex(1)) as c_int;
+            ffi::luaL_checkstack(state, nbinds, ptr::null());
 
             for i in 0..nbinds {
-                ffi::lua_pushvalue(state, ffi::lua_upvalueindex(i + 3));
-                ffi::lua_replace(state, i + 2);
+                ffi::lua_pushvalue(state, ffi::lua_upvalueindex(i + 2));
+            }
+            if nargs > 0 {
+                ffi::lua_rotate(state, 1, nbinds);
             }
 
-            ffi::lua_call(state, nargs + nbinds, ffi::LUA_MULTRET);
-            ffi::lua_gettop(state)
+            nargs + nbinds
         }
 
         let lua = self.0.lua;
+        let state = lua.state();
 
-        let args = args.to_lua_multi(lua)?;
+        let args = args.into_lua_multi(lua)?;
         let nargs = args.len() as c_int;
 
-        if nargs + 2 > ffi::LUA_MAX_UPVALUES {
+        if nargs == 0 {
+            return Ok(self.clone());
+        }
+
+        if nargs + 1 > ffi::LUA_MAX_UPVALUES {
             return Err(Error::BindError);
         }
 
-        unsafe {
-            let _sg = StackGuard::new(lua.state);
-            check_stack(lua.state, nargs + 5)?;
+        let args_wrapper = unsafe {
+            let _sg = StackGuard::new(state);
+            check_stack(state, nargs + 3)?;
 
-            lua.push_ref(&self.0);
-            ffi::lua_pushinteger(lua.state, nargs as ffi::lua_Integer);
+            ffi::lua_pushinteger(state, nargs as ffi::lua_Integer);
             for arg in args {
                 lua.push_value(arg)?;
             }
-            protect_lua!(lua.state, nargs + 2, 1, fn(state) {
-                ffi::lua_pushcclosure(state, bind_call_impl, ffi::lua_gettop(state));
+            protect_lua!(state, nargs + 1, 1, fn(state) {
+                ffi::lua_pushcclosure(state, args_wrapper_impl, ffi::lua_gettop(state));
             })?;
 
-            Ok(Function(lua.pop_ref()))
+            Function(lua.pop_ref())
+        };
+
+        lua.load(
+            r#"
+            local func, args_wrapper = ...
+            return function(...)
+                return func(args_wrapper(...))
+            end
+            "#,
+        )
+        .try_cache()
+        .set_name("__mlua_bind")
+        .call((self.clone(), args_wrapper))
+    }
+
+    /// Returns the environment of the Lua function.
+    ///
+    /// By default Lua functions shares a global environment.
+    ///
+    /// This function always returns `None` for Rust/C functions.
+    pub fn environment(&self) -> Option<Table> {
+        let lua = self.0.lua;
+        let state = lua.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            assert_stack(state, 1);
+
+            lua.push_ref(&self.0);
+            if ffi::lua_iscfunction(state, -1) != 0 {
+                return None;
+            }
+
+            #[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
+            ffi::lua_getfenv(state, -1);
+            #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+            for i in 1..=255 {
+                // Traverse upvalues until we find the _ENV one
+                match ffi::lua_getupvalue(state, -1, i) {
+                    s if s.is_null() => break,
+                    s if std::ffi::CStr::from_ptr(s as _).to_bytes() == b"_ENV" => break,
+                    _ => ffi::lua_pop(state, 1),
+                }
+            }
+
+            if ffi::lua_type(state, -1) != ffi::LUA_TTABLE {
+                return None;
+            }
+            Some(Table(lua.pop_ref()))
+        }
+    }
+
+    /// Sets the environment of the Lua function.
+    ///
+    /// The environment is a table that is used as the global environment for the function.
+    /// Returns `true` if environment successfully changed, `false` otherwise.
+    ///
+    /// This function does nothing for Rust/C functions.
+    pub fn set_environment(&self, env: Table) -> Result<bool> {
+        let lua = self.0.lua;
+        let state = lua.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            check_stack(state, 2)?;
+
+            lua.push_ref(&self.0);
+            if ffi::lua_iscfunction(state, -1) != 0 {
+                return Ok(false);
+            }
+
+            #[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
+            {
+                lua.push_ref(&env.0);
+                ffi::lua_setfenv(state, -2);
+            }
+            #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+            for i in 1..=255 {
+                match ffi::lua_getupvalue(state, -1, i) {
+                    s if s.is_null() => return Ok(false),
+                    s if std::ffi::CStr::from_ptr(s as _).to_bytes() == b"_ENV" => {
+                        ffi::lua_pop(state, 1);
+                        // Create an anonymous function with the new environment
+                        let f_with_env = lua
+                            .load("return _ENV")
+                            .set_environment(env)
+                            .try_cache()
+                            .into_function()?;
+                        lua.push_ref(&f_with_env.0);
+                        ffi::lua_upvaluejoin(state, -2, i, -1, 1);
+                        break;
+                    }
+                    _ => ffi::lua_pop(state, 1),
+                }
+            }
+
+            Ok(true)
+        }
+    }
+
+    /// Returns information about the function.
+    ///
+    /// Corresponds to the `>Sn` what mask for [`lua_getinfo`] when applied to the function.
+    ///
+    /// [`lua_getinfo`]: https://www.lua.org/manual/5.4/manual.html#lua_getinfo
+    pub fn info(&self) -> FunctionInfo {
+        let lua = self.0.lua;
+        let state = lua.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            assert_stack(state, 1);
+
+            let mut ar: ffi::lua_Debug = mem::zeroed();
+            lua.push_ref(&self.0);
+            #[cfg(not(feature = "luau"))]
+            let res = ffi::lua_getinfo(state, cstr!(">Sn"), &mut ar);
+            #[cfg(feature = "luau")]
+            let res = ffi::lua_getinfo(state, -1, cstr!("sn"), &mut ar);
+            mlua_assert!(res != 0, "lua_getinfo failed with `>Sn`");
+
+            FunctionInfo {
+                name: ptr_to_lossy_str(ar.name).map(|s| s.into_owned()),
+                #[cfg(not(feature = "luau"))]
+                name_what: match ptr_to_str(ar.namewhat) {
+                    Some("") => None,
+                    val => val,
+                },
+                #[cfg(feature = "luau")]
+                name_what: None,
+                what: ptr_to_str(ar.what).unwrap_or("main"),
+                source: ptr_to_lossy_str(ar.source).map(|s| s.into_owned()),
+                #[cfg(not(feature = "luau"))]
+                short_src: ptr_to_lossy_str(ar.short_src.as_ptr()).map(|s| s.into_owned()),
+                #[cfg(feature = "luau")]
+                short_src: ptr_to_lossy_str(ar.short_src).map(|s| s.into_owned()),
+                line_defined: linenumber_to_usize(ar.linedefined),
+                #[cfg(not(feature = "luau"))]
+                last_line_defined: linenumber_to_usize(ar.lastlinedefined),
+                #[cfg(feature = "luau")]
+                last_line_defined: None,
+            }
         }
     }
 
@@ -214,8 +406,14 @@ impl<'lua> Function<'lua> {
     ///
     /// If `strip` is true, the binary representation may not include all debug information
     /// about the function, to save space.
+    ///
+    /// For Luau a [Compiler] can be used to compile Lua chunks to bytecode.
+    ///
+    /// [Compiler]: crate::chunk::Compiler
+    #[cfg(not(feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub fn dump(&self, strip: bool) -> Vec<u8> {
-        unsafe extern "C" fn writer(
+        unsafe extern "C-unwind" fn writer(
             _state: *mut ffi::lua_State,
             buf: *const c_void,
             buf_len: usize,
@@ -228,20 +426,112 @@ impl<'lua> Function<'lua> {
         }
 
         let lua = self.0.lua;
+        let state = lua.state();
         let mut data: Vec<u8> = Vec::new();
         unsafe {
-            let _sg = StackGuard::new(lua.state);
-            assert_stack(lua.state, 1);
+            let _sg = StackGuard::new(state);
+            assert_stack(state, 1);
 
             lua.push_ref(&self.0);
             let data_ptr = &mut data as *mut Vec<u8> as *mut c_void;
-            let strip = if strip { 1 } else { 0 };
-            ffi::lua_dump(lua.state, writer, data_ptr, strip);
-            ffi::lua_pop(lua.state, 1);
+            ffi::lua_dump(state, writer, data_ptr, strip as i32);
+            ffi::lua_pop(state, 1);
         }
 
         data
     }
+
+    /// Retrieves recorded coverage information about this Lua function including inner calls.
+    ///
+    /// This function takes a callback as an argument and calls it providing [`CoverageInfo`] snapshot
+    /// per each executed inner function.
+    ///
+    /// Recording of coverage information is controlled by [`Compiler::set_coverage_level`] option.
+    ///
+    /// Requires `feature = "luau"`
+    ///
+    /// [`Compiler::set_coverage_level`]: crate::chunk::Compiler::set_coverage_level
+    #[cfg(any(feature = "luau", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    pub fn coverage<F>(&self, mut func: F)
+    where
+        F: FnMut(CoverageInfo),
+    {
+        use std::ffi::CStr;
+        use std::os::raw::c_char;
+
+        unsafe extern "C-unwind" fn callback<F: FnMut(CoverageInfo)>(
+            data: *mut c_void,
+            function: *const c_char,
+            line_defined: c_int,
+            depth: c_int,
+            hits: *const c_int,
+            size: usize,
+        ) {
+            let function = if !function.is_null() {
+                Some(CStr::from_ptr(function).to_string_lossy().to_string())
+            } else {
+                None
+            };
+            let rust_callback = &mut *(data as *mut F);
+            rust_callback(CoverageInfo {
+                function,
+                line_defined,
+                depth,
+                hits: slice::from_raw_parts(hits, size).to_vec(),
+            });
+        }
+
+        let lua = self.0.lua;
+        let state = lua.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            assert_stack(state, 1);
+
+            lua.push_ref(&self.0);
+            let func_ptr = &mut func as *mut F as *mut c_void;
+            ffi::lua_getcoverage(state, -1, func_ptr, callback::<F>);
+        }
+    }
+
+    /// Converts this function to a generic C pointer.
+    ///
+    /// There is no way to convert the pointer back to its original value.
+    ///
+    /// Typically this function is used only for hashing and debug information.
+    #[inline]
+    pub fn to_pointer(&self) -> *const c_void {
+        self.0.to_pointer()
+    }
+
+    /// Creates a deep clone of the Lua function.
+    ///
+    /// Copies the function prototype and all its upvalues to the
+    /// newly created function.
+    ///
+    /// This function returns shallow clone (same handle) for Rust/C functions.
+    /// Requires `feature = "luau"`
+    #[cfg(feature = "luau")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    pub fn deep_clone(&self) -> Self {
+        let ref_thread = self.0.lua.ref_thread();
+        unsafe {
+            if ffi::lua_iscfunction(ref_thread, self.0.index) != 0 {
+                return self.clone();
+            }
+
+            ffi::lua_clonefunction(ref_thread, self.0.index);
+            Function(self.0.lua.pop_ref_thread())
+        }
+    }
+
+    /// Convert this handle to owned version.
+    #[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
+    #[inline]
+    pub fn into_owned(self) -> OwnedFunction {
+        OwnedFunction(self.0.into_owned())
+    }
 }
 
 impl<'lua> PartialEq for Function<'lua> {
@@ -249,3 +539,118 @@ impl<'lua> PartialEq for Function<'lua> {
         self.0 == other.0
     }
 }
+
+// Additional shortcuts
+#[cfg(feature = "unstable")]
+impl OwnedFunction {
+    /// Calls the function, passing `args` as function arguments.
+    ///
+    /// This is a shortcut for [`Function::call()`].
+    #[inline]
+    pub fn call<'lua, A, R>(&'lua self, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>,
+    {
+        self.to_ref().call(args)
+    }
+
+    /// Returns a future that, when polled, calls `self`, passing `args` as function arguments,
+    /// and drives the execution.
+    ///
+    /// This is a shortcut for [`Function::call_async()`].
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    #[inline]
+    pub async fn call_async<'lua, A, R>(&'lua self, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua,
+    {
+        self.to_ref().call_async(args).await
+    }
+}
+
+pub(crate) struct WrappedFunction<'lua>(pub(crate) Callback<'lua, 'static>);
+
+#[cfg(feature = "async")]
+pub(crate) struct WrappedAsyncFunction<'lua>(pub(crate) AsyncCallback<'lua, 'static>);
+
+impl<'lua> Function<'lua> {
+    /// Wraps a Rust function or closure, returning an opaque type that implements [`IntoLua`] trait.
+    #[inline]
+    pub fn wrap<A, R, F>(func: F) -> impl IntoLua<'lua>
+    where
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+        F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+    {
+        WrappedFunction(Box::new(move |lua, nargs| unsafe {
+            let args = A::from_stack_args(nargs, 1, None, lua)?;
+            func(lua, args)?.push_into_stack_multi(lua)
+        }))
+    }
+
+    /// Wraps a Rust mutable closure, returning an opaque type that implements [`IntoLua`] trait.
+    #[inline]
+    pub fn wrap_mut<A, R, F>(func: F) -> impl IntoLua<'lua>
+    where
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+        F: FnMut(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+    {
+        let func = RefCell::new(func);
+        WrappedFunction(Box::new(move |lua, nargs| unsafe {
+            let mut func = func
+                .try_borrow_mut()
+                .map_err(|_| Error::RecursiveMutCallback)?;
+            let args = A::from_stack_args(nargs, 1, None, lua)?;
+            func(lua, args)?.push_into_stack_multi(lua)
+        }))
+    }
+
+    /// Wraps a Rust async function or closure, returning an opaque type that implements [`IntoLua`] trait.
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    pub fn wrap_async<A, R, F, FR>(func: F) -> impl IntoLua<'lua>
+    where
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+        F: Fn(&'lua Lua, A) -> FR + MaybeSend + 'static,
+        FR: Future<Output = Result<R>> + 'lua,
+    {
+        WrappedAsyncFunction(Box::new(move |lua, args| unsafe {
+            let args = match A::from_lua_args(args, 1, None, lua) {
+                Ok(args) => args,
+                Err(e) => return Box::pin(future::err(e)),
+            };
+            let fut = func(lua, args);
+            Box::pin(async move { fut.await?.push_into_stack_multi(lua) })
+        }))
+    }
+}
+
+impl<'lua> IntoLua<'lua> for WrappedFunction<'lua> {
+    #[inline]
+    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+        lua.create_callback(self.0).map(Value::Function)
+    }
+}
+
+#[cfg(feature = "async")]
+impl<'lua> IntoLua<'lua> for WrappedAsyncFunction<'lua> {
+    #[inline]
+    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>> {
+        lua.create_async_callback(self.0).map(Value::Function)
+    }
+}
+
+#[cfg(test)]
+mod assertions {
+    use super::*;
+
+    static_assertions::assert_not_impl_any!(Function: Send);
+
+    #[cfg(all(feature = "unstable", not(feature = "send")))]
+    static_assertions::assert_not_impl_any!(OwnedFunction: Send);
+}

src/hook.rs

@@ -1,10 +1,13 @@
+use std::borrow::Cow;
 use std::cell::UnsafeCell;
-use std::ffi::CStr;
+#[cfg(not(feature = "luau"))]
 use std::ops::{BitOr, BitOrAssign};
-use std::os::raw::{c_char, c_int};
+use std::os::raw::c_int;
+
+use ffi::lua_Debug;
 
-use crate::ffi::{self, lua_Debug};
 use crate::lua::Lua;
+use crate::util::{linenumber_to_usize, ptr_to_lossy_str, ptr_to_str};
 
 /// Contains information about currently executing Lua code.
 ///
@@ -18,9 +21,12 @@ use crate::lua::Lua;
 pub struct Debug<'lua> {
     lua: &'lua Lua,
     ar: ActivationRecord,
+    #[cfg(feature = "luau")]
+    level: c_int,
 }
 
 impl<'lua> Debug<'lua> {
+    #[cfg(not(feature = "luau"))]
     pub(crate) fn new(lua: &'lua Lua, ar: *mut lua_Debug) -> Self {
         Debug {
             lua,
@@ -28,10 +34,12 @@ impl<'lua> Debug<'lua> {
         }
     }
 
-    pub(crate) fn new_owned(lua: &'lua Lua, ar: lua_Debug) -> Self {
+    pub(crate) fn new_owned(lua: &'lua Lua, _level: c_int, ar: lua_Debug) -> Self {
         Debug {
             lua,
             ar: ActivationRecord::Owned(UnsafeCell::new(ar)),
+            #[cfg(feature = "luau")]
+            level: _level,
         }
     }
 
@@ -41,6 +49,8 @@ impl<'lua> Debug<'lua> {
     /// from a function that did a tail call.
     ///
     /// [Lua 5.1]: https://www.lua.org/manual/5.1/manual.html#pdf-LUA_HOOKTAILRET
+    #[cfg(not(feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub fn event(&self) -> DebugEvent {
         unsafe {
             match (*self.ar.get()).event {
@@ -55,32 +65,58 @@ impl<'lua> Debug<'lua> {
     }
 
     /// Corresponds to the `n` what mask.
-    pub fn names(&self) -> DebugNames<'lua> {
+    pub fn names(&self) -> DebugNames {
         unsafe {
+            #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state, cstr!("n"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state(), cstr!("n"), self.ar.get()) != 0,
                 "lua_getinfo failed with `n`"
             );
+            #[cfg(feature = "luau")]
+            mlua_assert!(
+                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("n"), self.ar.get()) != 0,
+                "lua_getinfo failed with `n`"
+            );
+
             DebugNames {
-                name: ptr_to_str((*self.ar.get()).name),
-                name_what: ptr_to_str((*self.ar.get()).namewhat),
+                name: ptr_to_lossy_str((*self.ar.get()).name),
+                #[cfg(not(feature = "luau"))]
+                name_what: match ptr_to_str((*self.ar.get()).namewhat) {
+                    Some("") => None,
+                    val => val,
+                },
+                #[cfg(feature = "luau")]
+                name_what: None,
             }
         }
     }
 
     /// Corresponds to the `S` what mask.
-    pub fn source(&self) -> DebugSource<'lua> {
+    pub fn source(&self) -> DebugSource {
         unsafe {
+            #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state, cstr!("S"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state(), cstr!("S"), self.ar.get()) != 0,
                 "lua_getinfo failed with `S`"
             );
+            #[cfg(feature = "luau")]
+            mlua_assert!(
+                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("s"), self.ar.get()) != 0,
+                "lua_getinfo failed with `s`"
+            );
+
             DebugSource {
-                source: ptr_to_str((*self.ar.get()).source),
-                short_src: ptr_to_str((*self.ar.get()).short_src.as_ptr()),
-                line_defined: (*self.ar.get()).linedefined as i32,
-                last_line_defined: (*self.ar.get()).lastlinedefined as i32,
-                what: ptr_to_str((*self.ar.get()).what),
+                source: ptr_to_lossy_str((*self.ar.get()).source),
+                #[cfg(not(feature = "luau"))]
+                short_src: ptr_to_lossy_str((*self.ar.get()).short_src.as_ptr()),
+                #[cfg(feature = "luau")]
+                short_src: ptr_to_lossy_str((*self.ar.get()).short_src),
+                line_defined: linenumber_to_usize((*self.ar.get()).linedefined),
+                #[cfg(not(feature = "luau"))]
+                last_line_defined: linenumber_to_usize((*self.ar.get()).lastlinedefined),
+                #[cfg(feature = "luau")]
+                last_line_defined: None,
+                what: ptr_to_str((*self.ar.get()).what).unwrap_or("main"),
             }
         }
     }
@@ -88,20 +124,29 @@ impl<'lua> Debug<'lua> {
     /// Corresponds to the `l` what mask. Returns the current line.
     pub fn curr_line(&self) -> i32 {
         unsafe {
+            #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state, cstr!("l"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state(), cstr!("l"), self.ar.get()) != 0,
                 "lua_getinfo failed with `l`"
             );
-            (*self.ar.get()).currentline as i32
+            #[cfg(feature = "luau")]
+            mlua_assert!(
+                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("l"), self.ar.get()) != 0,
+                "lua_getinfo failed with `l`"
+            );
+
+            (*self.ar.get()).currentline
         }
     }
 
     /// Corresponds to the `t` what mask. Returns true if the hook is in a function tail call, false
     /// otherwise.
+    #[cfg(not(feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub fn is_tail_call(&self) -> bool {
         unsafe {
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state, cstr!("t"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state(), cstr!("t"), self.ar.get()) != 0,
                 "lua_getinfo failed with `t`"
             );
             (*self.ar.get()).currentline != 0
@@ -111,22 +156,38 @@ impl<'lua> Debug<'lua> {
     /// Corresponds to the `u` what mask.
     pub fn stack(&self) -> DebugStack {
         unsafe {
+            #[cfg(not(feature = "luau"))]
             mlua_assert!(
-                ffi::lua_getinfo(self.lua.state, cstr!("u"), self.ar.get()) != 0,
+                ffi::lua_getinfo(self.lua.state(), cstr!("u"), self.ar.get()) != 0,
                 "lua_getinfo failed with `u`"
             );
-            DebugStack {
-                num_ups: (*self.ar.get()).nups as i32,
+            #[cfg(feature = "luau")]
+            mlua_assert!(
+                ffi::lua_getinfo(self.lua.state(), self.level, cstr!("a"), self.ar.get()) != 0,
+                "lua_getinfo failed with `a`"
+            );
+
+            #[cfg(not(feature = "luau"))]
+            let stack = DebugStack {
+                num_ups: (*self.ar.get()).nups as _,
                 #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
-                num_params: (*self.ar.get()).nparams as i32,
+                num_params: (*self.ar.get()).nparams as _,
                 #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
                 is_vararg: (*self.ar.get()).isvararg != 0,
-            }
+            };
+            #[cfg(feature = "luau")]
+            let stack = DebugStack {
+                num_ups: (*self.ar.get()).nupvals as i32,
+                num_params: (*self.ar.get()).nparams as i32,
+                is_vararg: (*self.ar.get()).isvararg != 0,
+            };
+            stack
         }
     }
 }
 
 enum ActivationRecord {
+    #[cfg(not(feature = "luau"))]
     Borrowed(*mut lua_Debug),
     Owned(UnsafeCell<lua_Debug>),
 }
@@ -135,6 +196,7 @@ impl ActivationRecord {
     #[inline]
     fn get(&self) -> *mut lua_Debug {
         match self {
+            #[cfg(not(feature = "luau"))]
             ActivationRecord::Borrowed(x) => *x,
             ActivationRecord::Owned(x) => x.get(),
         }
@@ -154,31 +216,52 @@ pub enum DebugEvent {
 
 #[derive(Clone, Debug)]
 pub struct DebugNames<'a> {
-    pub name: Option<&'a [u8]>,
-    pub name_what: Option<&'a [u8]>,
+    /// A (reasonable) name of the function (`None` if the name cannot be found).
+    pub name: Option<Cow<'a, str>>,
+    /// Explains the `name` field (can be `global`/`local`/`method`/`field`/`upvalue`/etc).
+    ///
+    /// Always `None` for Luau.
+    pub name_what: Option<&'static str>,
 }
 
 #[derive(Clone, Debug)]
 pub struct DebugSource<'a> {
-    pub source: Option<&'a [u8]>,
-    pub short_src: Option<&'a [u8]>,
-    pub line_defined: i32,
-    pub last_line_defined: i32,
-    pub what: Option<&'a [u8]>,
+    /// Source of the chunk that created the function.
+    pub source: Option<Cow<'a, str>>,
+    /// A "printable" version of `source`, to be used in error messages.
+    pub short_src: Option<Cow<'a, str>>,
+    /// The line number where the definition of the function starts.
+    pub line_defined: Option<usize>,
+    /// The line number where the definition of the function ends (not set by Luau).
+    pub last_line_defined: Option<usize>,
+    /// A string `Lua` if the function is a Lua function, `C` if it is a C function, `main` if it is the main part of a chunk.
+    pub what: &'static str,
 }
 
 #[derive(Copy, Clone, Debug)]
 pub struct DebugStack {
     pub num_ups: i32,
-    /// Requires `feature = "lua54/lua53/lua52"`
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+    /// Requires `feature = "lua54/lua53/lua52/luau"`
+    #[cfg(any(
+        feature = "lua54",
+        feature = "lua53",
+        feature = "lua52",
+        feature = "luau"
+    ))]
     pub num_params: i32,
-    /// Requires `feature = "lua54/lua53/lua52"`
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+    /// Requires `feature = "lua54/lua53/lua52/luau"`
+    #[cfg(any(
+        feature = "lua54",
+        feature = "lua53",
+        feature = "lua52",
+        feature = "luau"
+    ))]
     pub is_vararg: bool,
 }
 
 /// Determines when a hook function will be called by Lua.
+#[cfg(not(feature = "luau"))]
+#[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
 #[derive(Clone, Copy, Debug, Default)]
 pub struct HookTriggers {
     /// Before a function call.
@@ -196,49 +279,61 @@ pub struct HookTriggers {
     pub every_nth_instruction: Option<u32>,
 }
 
+#[cfg(not(feature = "luau"))]
 impl HookTriggers {
-    /// Returns a new instance of `HookTriggers` with [`on_calls`] trigger set.
+    /// An instance of `HookTriggers` with `on_calls` trigger set.
+    pub const ON_CALLS: Self = HookTriggers::new().on_calls();
+
+    /// An instance of `HookTriggers` with `on_returns` trigger set.
+    pub const ON_RETURNS: Self = HookTriggers::new().on_returns();
+
+    /// An instance of `HookTriggers` with `every_line` trigger set.
+    pub const EVERY_LINE: Self = HookTriggers::new().every_line();
+
+    /// Returns a new instance of `HookTriggers` with all triggers disabled.
+    pub const fn new() -> Self {
+        HookTriggers {
+            on_calls: false,
+            on_returns: false,
+            every_line: false,
+            every_nth_instruction: None,
+        }
+    }
+
+    /// Returns an instance of `HookTriggers` with [`on_calls`] trigger set.
     ///
     /// [`on_calls`]: #structfield.on_calls
-    pub fn on_calls() -> Self {
-        HookTriggers {
-            on_calls: true,
-            ..Default::default()
-        }
+    pub const fn on_calls(mut self) -> Self {
+        self.on_calls = true;
+        self
     }
 
-    /// Returns a new instance of `HookTriggers` with [`on_returns`] trigger set.
+    /// Returns an instance of `HookTriggers` with [`on_returns`] trigger set.
     ///
     /// [`on_returns`]: #structfield.on_returns
-    pub fn on_returns() -> Self {
-        HookTriggers {
-            on_returns: true,
-            ..Default::default()
-        }
+    pub const fn on_returns(mut self) -> Self {
+        self.on_returns = true;
+        self
     }
 
-    /// Returns a new instance of `HookTriggers` with [`every_line`] trigger set.
+    /// Returns an instance of `HookTriggers` with [`every_line`] trigger set.
     ///
     /// [`every_line`]: #structfield.every_line
-    pub fn every_line() -> Self {
-        HookTriggers {
-            every_line: true,
-            ..Default::default()
-        }
+    pub const fn every_line(mut self) -> Self {
+        self.every_line = true;
+        self
     }
 
-    /// Returns a new instance of `HookTriggers` with [`every_nth_instruction`] trigger set.
+    /// Returns an instance of `HookTriggers` with [`every_nth_instruction`] trigger set.
     ///
     /// [`every_nth_instruction`]: #structfield.every_nth_instruction
-    pub fn every_nth_instruction(n: u32) -> Self {
-        HookTriggers {
-            every_nth_instruction: Some(n),
-            ..Default::default()
-        }
+    pub const fn every_nth_instruction(mut self, n: u32) -> Self {
+        self.every_nth_instruction = Some(n);
+        self
     }
 
     // Compute the mask to pass to `lua_sethook`.
-    pub(crate) fn mask(&self) -> c_int {
+    pub(crate) const fn mask(&self) -> c_int {
         let mut mask: c_int = 0;
         if self.on_calls {
             mask |= ffi::LUA_MASKCALL
@@ -257,11 +352,15 @@ impl HookTriggers {
 
     // Returns the `count` parameter to pass to `lua_sethook`, if applicable. Otherwise, zero is
     // returned.
-    pub(crate) fn count(&self) -> c_int {
-        self.every_nth_instruction.unwrap_or(0) as c_int
+    pub(crate) const fn count(&self) -> c_int {
+        match self.every_nth_instruction {
+            Some(n) => n as c_int,
+            None => 0,
+        }
     }
 }
 
+#[cfg(not(feature = "luau"))]
 impl BitOr for HookTriggers {
     type Output = Self;
 
@@ -276,16 +375,9 @@ impl BitOr for HookTriggers {
     }
 }
 
+#[cfg(not(feature = "luau"))]
 impl BitOrAssign for HookTriggers {
     fn bitor_assign(&mut self, rhs: Self) {
         *self = *self | rhs;
     }
 }
-
-unsafe fn ptr_to_str<'a>(input: *const c_char) -> Option<&'a [u8]> {
-    if input.is_null() {
-        None
-    } else {
-        Some(CStr::from_ptr(input).to_bytes())
-    }
-}

src/lib.rs

@@ -10,10 +10,10 @@
 //!
 //! # Converting data
 //!
-//! The [`ToLua`] and [`FromLua`] traits allow conversion from Rust types to Lua values and vice
+//! The [`IntoLua`] and [`FromLua`] traits allow conversion from Rust types to Lua values and vice
 //! versa. They are implemented for many data structures found in Rust's standard library.
 //!
-//! For more general conversions, the [`ToLuaMulti`] and [`FromLuaMulti`] traits allow converting
+//! For more general conversions, the [`IntoLuaMulti`] and [`FromLuaMulti`] traits allow converting
 //! between Rust types and *any number* of Lua values.
 //!
 //! Most code in `mlua` is generic over implementors of those traits, so in most places the normal
@@ -54,9 +54,9 @@
 //! [executing]: crate::Chunk::exec
 //! [evaluating]: crate::Chunk::eval
 //! [globals]: crate::Lua::globals
-//! [`ToLua`]: crate::ToLua
+//! [`IntoLua`]: crate::IntoLua
 //! [`FromLua`]: crate::FromLua
-//! [`ToLuaMulti`]: crate::ToLuaMulti
+//! [`IntoLuaMulti`]: crate::IntoLuaMulti
 //! [`FromLuaMulti`]: crate::FromLuaMulti
 //! [`Function`]: crate::Function
 //! [`UserData`]: crate::UserData
@@ -71,22 +71,23 @@
 //! [`serde::Serialize`]: https://docs.serde.rs/serde/ser/trait.Serialize.html
 //! [`serde::Deserialize`]: https://docs.serde.rs/serde/de/trait.Deserialize.html
 
-// mlua types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/mlua/0.7.2")]
 // Deny warnings inside doc tests / examples. When this isn't present, rustdoc doesn't show *any*
 // warnings at all.
-#![doc(test(attr(deny(warnings))))]
+#![doc(test(attr(warn(warnings))))] // FIXME: Remove this when rust-lang/rust#123748 is fixed
 #![cfg_attr(docsrs, feature(doc_cfg))]
 
 #[macro_use]
 mod macros;
 
+mod chunk;
 mod conversion;
 mod error;
-mod ffi;
 mod function;
 mod hook;
 mod lua;
+#[cfg(feature = "luau")]
+mod luau;
+mod memory;
 mod multi;
 mod scope;
 mod stdlib;
@@ -95,28 +96,45 @@ mod table;
 mod thread;
 mod types;
 mod userdata;
+mod userdata_ext;
+mod userdata_impl;
 mod util;
 mod value;
 
 pub mod prelude;
 
-pub use crate::{ffi::lua_CFunction, ffi::lua_State};
+pub use ffi::{self, lua_CFunction, lua_State};
 
-pub use crate::error::{Error, ExternalError, ExternalResult, Result};
-pub use crate::function::Function;
-pub use crate::hook::{Debug, DebugEvent, DebugNames, DebugSource, DebugStack, HookTriggers};
-pub use crate::lua::{AsChunk, Chunk, ChunkMode, GCMode, Lua, LuaOptions};
+pub use crate::chunk::{AsChunk, Chunk, ChunkMode};
+pub use crate::error::{Error, ErrorContext, ExternalError, ExternalResult, Result};
+pub use crate::function::{Function, FunctionInfo};
+pub use crate::hook::{Debug, DebugEvent, DebugNames, DebugSource, DebugStack};
+pub use crate::lua::{GCMode, Lua, LuaOptions};
 pub use crate::multi::Variadic;
 pub use crate::scope::Scope;
 pub use crate::stdlib::StdLib;
 pub use crate::string::String;
 pub use crate::table::{Table, TableExt, TablePairs, TableSequence};
 pub use crate::thread::{Thread, ThreadStatus};
-pub use crate::types::{Integer, LightUserData, Number, RegistryKey};
+pub use crate::types::{AppDataRef, AppDataRefMut, Integer, LightUserData, Number, RegistryKey};
 pub use crate::userdata::{
     AnyUserData, MetaMethod, UserData, UserDataFields, UserDataMetatable, UserDataMethods,
+    UserDataRef, UserDataRefMut,
+};
+pub use crate::userdata_ext::AnyUserDataExt;
+pub use crate::userdata_impl::UserDataRegistry;
+pub use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, MultiValue, Nil, Value};
+
+#[cfg(not(feature = "luau"))]
+pub use crate::hook::HookTriggers;
+
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+pub use crate::{
+    chunk::Compiler,
+    function::CoverageInfo,
+    types::{Vector, VmState},
 };
-pub use crate::value::{FromLua, FromLuaMulti, MultiValue, Nil, ToLua, ToLuaMulti, Value};
 
 #[cfg(feature = "async")]
 pub use crate::thread::AsyncThread;
@@ -131,17 +149,24 @@ pub use crate::serde::{
 #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
 pub mod serde;
 
-#[cfg(any(feature = "mlua_derive"))]
+#[cfg(feature = "mlua_derive")]
 #[allow(unused_imports)]
 #[macro_use]
 extern crate mlua_derive;
 
+// Unstable features
+#[cfg(feature = "unstable")]
+pub use crate::{
+    function::OwnedFunction, string::OwnedString, table::OwnedTable, thread::OwnedThread,
+    userdata::OwnedAnyUserData,
+};
+
 /// Create a type that implements [`AsChunk`] and can capture Rust variables.
 ///
 /// This macro allows to write Lua code directly in Rust code.
 ///
 /// Rust variables can be referenced from Lua using `$` prefix, as shown in the example below.
-/// User's Rust types needs to implement [`UserData`] or [`ToLua`] traits.
+/// User's Rust types needs to implement [`UserData`] or [`IntoLua`] traits.
 ///
 /// Captured variables are **moved** into the chunk.
 ///
@@ -187,11 +212,19 @@ extern crate mlua_derive;
 ///
 /// [`AsChunk`]: crate::AsChunk
 /// [`UserData`]: crate::UserData
-/// [`ToLua`]: crate::ToLua
-#[cfg(any(feature = "macros"))]
+/// [`IntoLua`]: crate::IntoLua
+#[cfg(feature = "macros")]
 #[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
 pub use mlua_derive::chunk;
 
+/// Derive [`FromLua`] for a Rust type.
+///
+/// Current implementation generate code that takes [`UserData`] value, borrow it (of the Rust type)
+/// and clone.
+#[cfg(feature = "macros")]
+#[cfg_attr(docsrs, doc(cfg(feature = "macros")))]
+pub use mlua_derive::FromLua;
+
 /// Registers Lua module entrypoint.
 ///
 /// You can register multiple entrypoints as required.
@@ -209,6 +242,43 @@ pub use mlua_derive::chunk;
 ///
 /// Internally in the code above the compiler defines C function `luaopen_my_module`.
 ///
+/// You can also pass options to the attribute:
+///
+/// * name - name of the module, defaults to the name of the function
+///
+/// ```ignore
+/// #[mlua::lua_module(name = "alt_module")]
+/// fn my_module(lua: &Lua) -> Result<Table> {
+///     ...
+/// }
+/// ```
+///
+/// * skip_memory_check - skip memory allocation checks for some operations.
+///
+/// In module mode, mlua runs in unknown environment and cannot say are there any memory
+/// limits or not. As result, some operations that require memory allocation runs in
+/// protected mode. Setting this attribute will improve performance of such operations
+/// with risk of having uncaught exceptions and memory leaks.
+///
+/// ```ignore
+/// #[mlua::lua_module(skip_memory_check)]
+/// fn my_module(lua: &Lua) -> Result<Table> {
+///     ...
+/// }
+/// ```
+///
 #[cfg(any(feature = "module", docsrs))]
 #[cfg_attr(docsrs, doc(cfg(feature = "module")))]
 pub use mlua_derive::lua_module;
+
+pub(crate) mod private {
+    use super::*;
+
+    pub trait Sealed {}
+
+    impl Sealed for Error {}
+    impl<T> Sealed for std::result::Result<T, Error> {}
+    impl Sealed for Lua {}
+    impl Sealed for Table<'_> {}
+    impl Sealed for AnyUserData<'_> {}
+}

src/luau/mod.rs

@@ -0,0 +1,88 @@
+use std::ffi::CStr;
+use std::os::raw::{c_float, c_int};
+
+use crate::error::Result;
+use crate::lua::Lua;
+
+// Since Luau has some missing standard functions, we re-implement them here
+
+impl Lua {
+    pub(crate) unsafe fn configure_luau(&self) -> Result<()> {
+        let globals = self.globals();
+
+        globals.raw_set(
+            "collectgarbage",
+            self.create_c_function(lua_collectgarbage)?,
+        )?;
+        globals.raw_set("vector", self.create_c_function(lua_vector)?)?;
+
+        // Set `_VERSION` global to include version number
+        // The environment variable `LUAU_VERSION` set by the build script
+        if let Some(version) = ffi::luau_version() {
+            globals.raw_set("_VERSION", format!("Luau {version}"))?;
+        }
+
+        Ok(())
+    }
+
+    pub(crate) fn disable_c_modules(&self) -> Result<()> {
+        package::disable_dylibs(self);
+        Ok(())
+    }
+}
+
+unsafe extern "C-unwind" fn lua_collectgarbage(state: *mut ffi::lua_State) -> c_int {
+    let option = ffi::luaL_optstring(state, 1, cstr!("collect"));
+    let option = CStr::from_ptr(option);
+    let arg = ffi::luaL_optinteger(state, 2, 0);
+    match option.to_str() {
+        Ok("collect") => {
+            ffi::lua_gc(state, ffi::LUA_GCCOLLECT, 0);
+            0
+        }
+        Ok("stop") => {
+            ffi::lua_gc(state, ffi::LUA_GCSTOP, 0);
+            0
+        }
+        Ok("restart") => {
+            ffi::lua_gc(state, ffi::LUA_GCRESTART, 0);
+            0
+        }
+        Ok("count") => {
+            let kbytes = ffi::lua_gc(state, ffi::LUA_GCCOUNT, 0) as ffi::lua_Number;
+            let kbytes_rem = ffi::lua_gc(state, ffi::LUA_GCCOUNTB, 0) as ffi::lua_Number;
+            ffi::lua_pushnumber(state, kbytes + kbytes_rem / 1024.0);
+            1
+        }
+        Ok("step") => {
+            let res = ffi::lua_gc(state, ffi::LUA_GCSTEP, arg);
+            ffi::lua_pushboolean(state, res);
+            1
+        }
+        Ok("isrunning") => {
+            let res = ffi::lua_gc(state, ffi::LUA_GCISRUNNING, 0);
+            ffi::lua_pushboolean(state, res);
+            1
+        }
+        _ => ffi::luaL_error(state, cstr!("collectgarbage called with invalid option")),
+    }
+}
+
+// Luau vector datatype constructor
+unsafe extern "C-unwind" fn lua_vector(state: *mut ffi::lua_State) -> c_int {
+    let x = ffi::luaL_checknumber(state, 1) as c_float;
+    let y = ffi::luaL_checknumber(state, 2) as c_float;
+    let z = ffi::luaL_checknumber(state, 3) as c_float;
+    #[cfg(feature = "luau-vector4")]
+    let w = ffi::luaL_checknumber(state, 4) as c_float;
+
+    #[cfg(not(feature = "luau-vector4"))]
+    ffi::lua_pushvector(state, x, y, z);
+    #[cfg(feature = "luau-vector4")]
+    ffi::lua_pushvector(state, x, y, z, w);
+    1
+}
+
+pub(crate) use package::register_package_module;
+
+mod package;

src/luau/package.rs

@@ -0,0 +1,269 @@
+use std::ffi::CStr;
+use std::fmt::Write;
+use std::os::raw::c_int;
+use std::path::{PathBuf, MAIN_SEPARATOR_STR};
+use std::string::String as StdString;
+use std::{env, fs};
+
+use crate::chunk::ChunkMode;
+use crate::error::Result;
+use crate::lua::Lua;
+use crate::table::Table;
+use crate::types::RegistryKey;
+use crate::value::{IntoLua, Value};
+
+#[cfg(unix)]
+use {libloading::Library, rustc_hash::FxHashMap};
+
+//
+// Luau package module
+//
+
+#[cfg(unix)]
+const TARGET_MLUA_LUAU_ABI_VERSION: u32 = 1;
+
+#[cfg(all(unix, feature = "module"))]
+#[no_mangle]
+#[used]
+pub static MLUA_LUAU_ABI_VERSION: u32 = TARGET_MLUA_LUAU_ABI_VERSION;
+
+// We keep reference to the `package` table in registry under this key
+struct PackageKey(RegistryKey);
+
+// We keep reference to the loaded dylibs in application data
+#[cfg(unix)]
+struct LoadedDylibs(FxHashMap<PathBuf, Library>);
+
+#[cfg(unix)]
+impl std::ops::Deref for LoadedDylibs {
+    type Target = FxHashMap<PathBuf, Library>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+#[cfg(unix)]
+impl std::ops::DerefMut for LoadedDylibs {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+pub(crate) fn register_package_module(lua: &Lua) -> Result<()> {
+    // Create the package table and store it in app_data for later use (bypassing globals lookup)
+    let package = lua.create_table()?;
+    lua.set_app_data(PackageKey(lua.create_registry_value(package.clone())?));
+
+    // Set `package.path`
+    let mut search_path = env::var("LUAU_PATH")
+        .or_else(|_| env::var("LUA_PATH"))
+        .unwrap_or_default();
+    if search_path.is_empty() {
+        search_path = "?.luau;?.lua".to_string();
+    }
+    package.raw_set("path", search_path)?;
+
+    // Set `package.cpath`
+    #[cfg(unix)]
+    {
+        let mut search_cpath = env::var("LUAU_CPATH")
+            .or_else(|_| env::var("LUA_CPATH"))
+            .unwrap_or_default();
+        if search_cpath.is_empty() {
+            if cfg!(any(target_os = "macos", target_os = "ios")) {
+                search_cpath = "?.dylib".to_string();
+            } else {
+                search_cpath = "?.so".to_string();
+            }
+        }
+        package.raw_set("cpath", search_cpath)?;
+    }
+
+    // Set `package.loaded` (table with a list of loaded modules)
+    let loaded = lua.create_table()?;
+    package.raw_set("loaded", loaded.clone())?;
+    lua.set_named_registry_value("_LOADED", loaded)?;
+
+    // Set `package.loaders`
+    let loaders = lua.create_sequence_from([lua.create_function(lua_loader)?])?;
+    package.raw_set("loaders", loaders.clone())?;
+    #[cfg(unix)]
+    {
+        loaders.push(lua.create_function(dylib_loader)?)?;
+        lua.set_app_data(LoadedDylibs(FxHashMap::default()));
+    }
+    lua.set_named_registry_value("_LOADERS", loaders)?;
+
+    // Register the module and `require` function in globals
+    let globals = lua.globals();
+    globals.raw_set("package", package)?;
+    globals.raw_set("require", unsafe { lua.create_c_function(lua_require)? })?;
+
+    Ok(())
+}
+
+#[allow(unused_variables)]
+pub(crate) fn disable_dylibs(lua: &Lua) {
+    // Presence of `LoadedDylibs` in app data is used as a flag
+    // to check whether binary modules are enabled
+    #[cfg(unix)]
+    lua.remove_app_data::<LoadedDylibs>();
+}
+
+unsafe extern "C-unwind" fn lua_require(state: *mut ffi::lua_State) -> c_int {
+    ffi::lua_settop(state, 1);
+    let name = ffi::luaL_checkstring(state, 1);
+    ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("_LOADED")); // _LOADED is at index 2
+    if ffi::lua_rawgetfield(state, 2, name) != ffi::LUA_TNIL {
+        return 1; // module is already loaded
+    }
+    ffi::lua_pop(state, 1); // remove nil
+
+    // load the module
+    let err_buf = ffi::lua_newuserdata_t::<StdString>(state);
+    err_buf.write(StdString::new());
+    ffi::luaL_getsubtable(state, ffi::LUA_REGISTRYINDEX, cstr!("_LOADERS")); // _LOADERS is at index 3
+    for i in 1.. {
+        if ffi::lua_rawgeti(state, -1, i) == ffi::LUA_TNIL {
+            // no more loaders?
+            if (*err_buf).is_empty() {
+                ffi::luaL_error(state, cstr!("module '%s' not found"), name);
+            } else {
+                let bytes = (*err_buf).as_bytes();
+                let extra = ffi::lua_pushlstring(state, bytes.as_ptr() as *const _, bytes.len());
+                ffi::luaL_error(state, cstr!("module '%s' not found:%s"), name, extra);
+            }
+        }
+        ffi::lua_pushvalue(state, 1); // name arg
+        ffi::lua_call(state, 1, 2); // call loader
+        match ffi::lua_type(state, -2) {
+            ffi::LUA_TFUNCTION => break, // loader found
+            ffi::LUA_TSTRING => {
+                // error message
+                let msg = ffi::lua_tostring(state, -2);
+                let msg = CStr::from_ptr(msg).to_string_lossy();
+                _ = write!(&mut *err_buf, "\n\t{msg}");
+            }
+            _ => {}
+        }
+        ffi::lua_pop(state, 2); // remove both results
+    }
+    ffi::lua_pushvalue(state, 1); // name is 1st argument to module loader
+    ffi::lua_rotate(state, -2, 1); // loader data <-> name
+
+    // stack: ...; loader function; module name; loader data
+    ffi::lua_call(state, 2, 1);
+    // stack: ...; result from loader function
+    if ffi::lua_isnil(state, -1) != 0 {
+        ffi::lua_pop(state, 1);
+        ffi::lua_pushboolean(state, 1); // use true as result
+    }
+    ffi::lua_pushvalue(state, -1); // make copy of entrypoint result
+    ffi::lua_setfield(state, 2, name); /* _LOADED[name] = returned value */
+    1
+}
+
+/// Searches for the given `name` in the given `path`.
+///
+/// `path` is a string containing a sequence of templates separated by semicolons.
+fn package_searchpath(name: &str, search_path: &str, try_prefix: bool) -> Option<PathBuf> {
+    let mut names = vec![name.replace('.', MAIN_SEPARATOR_STR)];
+    if try_prefix && name.contains('.') {
+        let prefix = name.split_once('.').map(|(prefix, _)| prefix).unwrap();
+        names.push(prefix.to_string());
+    }
+    for path in search_path.split(';') {
+        for name in &names {
+            let file_path = PathBuf::from(path.replace('?', name));
+            if let Ok(true) = fs::metadata(&file_path).map(|m| m.is_file()) {
+                return Some(file_path);
+            }
+        }
+    }
+    None
+}
+
+//
+// Module loaders
+//
+
+/// Tries to load a lua (text) file
+fn lua_loader(lua: &Lua, modname: StdString) -> Result<Value> {
+    let package = {
+        let key = lua.app_data_ref::<PackageKey>().unwrap();
+        lua.registry_value::<Table>(&key.0)
+    }?;
+    let search_path = package.get::<_, StdString>("path").unwrap_or_default();
+
+    if let Some(file_path) = package_searchpath(&modname, &search_path, false) {
+        match fs::read(&file_path) {
+            Ok(buf) => {
+                return lua
+                    .load(&buf)
+                    .set_name(&format!("={}", file_path.display()))
+                    .set_mode(ChunkMode::Text)
+                    .into_function()
+                    .map(Value::Function);
+            }
+            Err(err) => {
+                return format!("cannot open '{}': {err}", file_path.display()).into_lua(lua);
+            }
+        }
+    }
+
+    Ok(Value::Nil)
+}
+
+/// Tries to load a dynamic library
+#[cfg(unix)]
+fn dylib_loader(lua: &Lua, modname: StdString) -> Result<Value> {
+    let package = {
+        let key = lua.app_data_ref::<PackageKey>().unwrap();
+        lua.registry_value::<Table>(&key.0)
+    }?;
+    let search_cpath = package.get::<_, StdString>("cpath").unwrap_or_default();
+
+    let find_symbol = |lib: &Library| unsafe {
+        if let Ok(entry) = lib.get::<ffi::lua_CFunction>(format!("luaopen_{modname}\0").as_bytes())
+        {
+            return lua.create_c_function(*entry).map(Value::Function);
+        }
+        // Try all in one mode
+        if let Ok(entry) = lib.get::<ffi::lua_CFunction>(
+            format!("luaopen_{}\0", modname.replace('.', "_")).as_bytes(),
+        ) {
+            return lua.create_c_function(*entry).map(Value::Function);
+        }
+        "cannot find module entrypoint".into_lua(lua)
+    };
+
+    if let Some(file_path) = package_searchpath(&modname, &search_cpath, true) {
+        let file_path = file_path.canonicalize()?;
+        // Load the library and check for symbol
+        unsafe {
+            let mut loaded_dylibs = match lua.app_data_mut::<LoadedDylibs>() {
+                Some(loaded_dylibs) => loaded_dylibs,
+                None => return "dynamic libraries are disabled in safe mode".into_lua(lua),
+            };
+            // Check if it's already loaded
+            if let Some(lib) = loaded_dylibs.get(&file_path) {
+                return find_symbol(lib);
+            }
+            if let Ok(lib) = Library::new(&file_path) {
+                // Check version
+                let mod_version = lib.get::<*const u32>(b"MLUA_LUAU_ABI_VERSION");
+                let mod_version = mod_version.map(|v| **v).unwrap_or_default();
+                if mod_version != TARGET_MLUA_LUAU_ABI_VERSION {
+                    let err = format!("wrong module ABI version (expected {TARGET_MLUA_LUAU_ABI_VERSION}, got {mod_version})");
+                    return err.into_lua(lua);
+                }
+                let symbol = find_symbol(&lib);
+                loaded_dylibs.insert(file_path, lib);
+                return symbol;
+            }
+        }
+    }
+
+    Ok(Value::Nil)
+}

src/macros.rs

@@ -101,9 +101,15 @@ macro_rules! protect_lua {
     };
 
     ($state:expr, $nargs:expr, $nresults:expr, fn($state_inner:ident) $code:expr) => {{
-        unsafe extern "C" fn do_call($state_inner: *mut ffi::lua_State) -> ::std::os::raw::c_int {
+        use ::std::os::raw::c_int;
+        unsafe extern "C-unwind" fn do_call($state_inner: *mut ffi::lua_State) -> c_int {
             $code;
-            $nresults
+            let nresults = $nresults;
+            if nresults == ::ffi::LUA_MULTRET {
+                ffi::lua_gettop($state_inner)
+            } else {
+                nresults
+            }
         }
 
         crate::util::protect_lua_call($state, $nargs, do_call)

src/memory.rs

@@ -0,0 +1,147 @@
+use std::alloc::{self, Layout};
+use std::os::raw::c_void;
+use std::ptr;
+
+pub(crate) static ALLOCATOR: ffi::lua_Alloc = allocator;
+
+#[repr(C)]
+#[derive(Default)]
+pub(crate) struct MemoryState {
+    used_memory: isize,
+    memory_limit: isize,
+    // Can be set to temporary ignore the memory limit.
+    // This is used when calling `lua_pushcfunction` for lua5.1/jit/luau.
+    ignore_limit: bool,
+    // Indicates that the memory limit was reached on the last allocation.
+    #[cfg(feature = "luau")]
+    limit_reached: bool,
+}
+
+impl MemoryState {
+    #[inline]
+    pub(crate) unsafe fn get(state: *mut ffi::lua_State) -> *mut Self {
+        let mut mem_state = ptr::null_mut();
+        #[cfg(feature = "luau")]
+        {
+            ffi::lua_getallocf(state, &mut mem_state);
+            mlua_assert!(!mem_state.is_null(), "Luau state has no allocator userdata");
+        }
+        #[cfg(not(feature = "luau"))]
+        if ffi::lua_getallocf(state, &mut mem_state) != ALLOCATOR {
+            mem_state = ptr::null_mut();
+        }
+        mem_state as *mut MemoryState
+    }
+
+    #[inline]
+    pub(crate) fn used_memory(&self) -> usize {
+        self.used_memory as usize
+    }
+
+    #[inline]
+    pub(crate) fn memory_limit(&self) -> usize {
+        self.memory_limit as usize
+    }
+
+    #[inline]
+    pub(crate) fn set_memory_limit(&mut self, limit: usize) -> usize {
+        let prev_limit = self.memory_limit;
+        self.memory_limit = limit as isize;
+        prev_limit as usize
+    }
+
+    // This function is used primarily for calling `lua_pushcfunction` in lua5.1/jit/luau
+    // to bypass the memory limit (if set).
+    #[cfg(any(feature = "lua51", feature = "luajit", feature = "luau"))]
+    #[inline]
+    pub(crate) unsafe fn relax_limit_with(state: *mut ffi::lua_State, f: impl FnOnce()) {
+        let mem_state = Self::get(state);
+        if !mem_state.is_null() {
+            (*mem_state).ignore_limit = true;
+            f();
+            (*mem_state).ignore_limit = false;
+        } else {
+            f();
+        }
+    }
+
+    // Does nothing apart from calling `f()`, we don't need to bypass any limits
+    #[cfg(any(feature = "lua52", feature = "lua53", feature = "lua54"))]
+    #[inline]
+    pub(crate) unsafe fn relax_limit_with(_state: *mut ffi::lua_State, f: impl FnOnce()) {
+        f();
+    }
+
+    // Returns `true` if the memory limit was reached on the last memory operation
+    #[cfg(feature = "luau")]
+    #[inline]
+    pub(crate) unsafe fn limit_reached(state: *mut ffi::lua_State) -> bool {
+        (*Self::get(state)).limit_reached
+    }
+}
+
+unsafe extern "C-unwind" fn allocator(
+    extra: *mut c_void,
+    ptr: *mut c_void,
+    osize: usize,
+    nsize: usize,
+) -> *mut c_void {
+    let mem_state = &mut *(extra as *mut MemoryState);
+    #[cfg(feature = "luau")]
+    {
+        // Reset the flag
+        mem_state.limit_reached = false;
+    }
+
+    if nsize == 0 {
+        // Free memory
+        if !ptr.is_null() {
+            let layout = Layout::from_size_align_unchecked(osize, ffi::SYS_MIN_ALIGN);
+            alloc::dealloc(ptr as *mut u8, layout);
+            mem_state.used_memory -= osize as isize;
+        }
+        return ptr::null_mut();
+    }
+
+    // Do not allocate more than isize::MAX
+    if nsize > isize::MAX as usize {
+        return ptr::null_mut();
+    }
+
+    // Are we fit to the memory limits?
+    let mut mem_diff = nsize as isize;
+    if !ptr.is_null() {
+        mem_diff -= osize as isize;
+    }
+    let mem_limit = mem_state.memory_limit;
+    let new_used_memory = mem_state.used_memory + mem_diff;
+    if mem_limit > 0 && new_used_memory > mem_limit && !mem_state.ignore_limit {
+        #[cfg(feature = "luau")]
+        {
+            mem_state.limit_reached = true;
+        }
+        return ptr::null_mut();
+    }
+    mem_state.used_memory += mem_diff;
+
+    if ptr.is_null() {
+        // Allocate new memory
+        let new_layout = match Layout::from_size_align(nsize, ffi::SYS_MIN_ALIGN) {
+            Ok(layout) => layout,
+            Err(_) => return ptr::null_mut(),
+        };
+        let new_ptr = alloc::alloc(new_layout) as *mut c_void;
+        if new_ptr.is_null() {
+            alloc::handle_alloc_error(new_layout);
+        }
+        return new_ptr;
+    }
+
+    // Reallocate memory
+    let old_layout = Layout::from_size_align_unchecked(osize, ffi::SYS_MIN_ALIGN);
+    let new_ptr = alloc::realloc(ptr as *mut u8, old_layout, nsize) as *mut c_void;
+    if new_ptr.is_null() {
+        alloc::handle_alloc_error(old_layout);
+    }
+    new_ptr
+}

src/multi.rs

@@ -1,52 +1,134 @@
-#![allow(clippy::wrong_self_convention)]
-
-use std::iter::FromIterator;
 use std::ops::{Deref, DerefMut};
+use std::os::raw::c_int;
 use std::result::Result as StdResult;
 
 use crate::error::Result;
 use crate::lua::Lua;
-use crate::value::{FromLua, FromLuaMulti, MultiValue, Nil, ToLua, ToLuaMulti};
+use crate::util::check_stack;
+use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, MultiValue, Nil};
 
 /// Result is convertible to `MultiValue` following the common Lua idiom of returning the result
 /// on success, or in the case of an error, returning `nil` and an error message.
-impl<'lua, T: ToLua<'lua>, E: ToLua<'lua>> ToLuaMulti<'lua> for StdResult<T, E> {
-    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-        let mut result = MultiValue::new_or_cached(lua);
+impl<'lua, T: IntoLua<'lua>, E: IntoLua<'lua>> IntoLuaMulti<'lua> for StdResult<T, E> {
+    #[inline]
+    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+        let mut result = MultiValue::with_lua_and_capacity(lua, 2);
         match self {
-            Ok(v) => result.push_front(v.to_lua(lua)?),
+            Ok(v) => result.push_front(v.into_lua(lua)?),
             Err(e) => {
-                result.push_front(e.to_lua(lua)?);
+                result.push_front(e.into_lua(lua)?);
                 result.push_front(Nil);
             }
         }
         Ok(result)
     }
+
+    #[inline]
+    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
+        match self {
+            Ok(v) => v.push_into_stack(lua).map(|_| 1),
+            Err(e) => {
+                let state = lua.state();
+                check_stack(state, 3)?;
+                ffi::lua_pushnil(state);
+                e.push_into_stack(lua)?;
+                Ok(2)
+            }
+        }
+    }
 }
 
-impl<'lua, T: ToLua<'lua>> ToLuaMulti<'lua> for T {
-    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-        let mut v = MultiValue::new_or_cached(lua);
-        v.push_front(self.to_lua(lua)?);
+impl<'lua, E: IntoLua<'lua>> IntoLuaMulti<'lua> for StdResult<(), E> {
+    #[inline]
+    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+        match self {
+            Ok(_) => return Ok(MultiValue::new()),
+            Err(e) => {
+                let mut result = MultiValue::with_lua_and_capacity(lua, 2);
+                result.push_front(e.into_lua(lua)?);
+                result.push_front(Nil);
+                Ok(result)
+            }
+        }
+    }
+
+    #[inline]
+    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
+        match self {
+            Ok(_) => Ok(0),
+            Err(e) => {
+                let state = lua.state();
+                check_stack(state, 3)?;
+                ffi::lua_pushnil(state);
+                e.push_into_stack(lua)?;
+                Ok(2)
+            }
+        }
+    }
+}
+
+impl<'lua, T: IntoLua<'lua>> IntoLuaMulti<'lua> for T {
+    #[inline]
+    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+        let mut v = MultiValue::with_lua_and_capacity(lua, 1);
+        v.push_front(self.into_lua(lua)?);
         Ok(v)
     }
+
+    #[inline]
+    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
+        self.push_into_stack(lua)?;
+        Ok(1)
+    }
 }
 
 impl<'lua, T: FromLua<'lua>> FromLuaMulti<'lua> for T {
+    #[inline]
     fn from_lua_multi(mut values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
-        let res = T::from_lua(values.pop_front().unwrap_or(Nil), lua);
-        lua.cache_multivalue(values);
-        res
+        T::from_lua(values.pop_front().unwrap_or(Nil), lua)
+    }
+
+    #[inline]
+    fn from_lua_args(
+        mut args: MultiValue<'lua>,
+        i: usize,
+        to: Option<&str>,
+        lua: &'lua Lua,
+    ) -> Result<Self> {
+        T::from_lua_arg(args.pop_front().unwrap_or(Nil), i, to, lua)
+    }
+
+    #[inline]
+    unsafe fn from_stack_multi(nvals: c_int, lua: &'lua Lua) -> Result<Self> {
+        if nvals == 0 {
+            return T::from_lua(Nil, lua);
+        }
+        T::from_stack(-nvals, lua)
+    }
+
+    #[inline]
+    unsafe fn from_stack_args(
+        nargs: c_int,
+        i: usize,
+        to: Option<&str>,
+        lua: &'lua Lua,
+    ) -> Result<Self> {
+        if nargs == 0 {
+            return T::from_lua_arg(Nil, i, to, lua);
+        }
+        T::from_stack_arg(-nargs, i, to, lua)
     }
 }
 
-impl<'lua> ToLuaMulti<'lua> for MultiValue<'lua> {
-    fn to_lua_multi(self, _: &'lua Lua) -> Result<MultiValue<'lua>> {
+impl<'lua> IntoLuaMulti<'lua> for MultiValue<'lua> {
+    #[inline]
+    fn into_lua_multi(self, _: &'lua Lua) -> Result<MultiValue<'lua>> {
         Ok(self)
     }
 }
 
 impl<'lua> FromLuaMulti<'lua> for MultiValue<'lua> {
+    #[inline]
     fn from_lua_multi(values: MultiValue<'lua>, _: &'lua Lua) -> Result<Self> {
         Ok(values)
     }
@@ -83,7 +165,7 @@ pub struct Variadic<T>(Vec<T>);
 
 impl<T> Variadic<T> {
     /// Creates an empty `Variadic` wrapper containing no values.
-    pub fn new() -> Variadic<T> {
+    pub const fn new() -> Variadic<T> {
         Variadic(Vec::new())
     }
 }
@@ -123,68 +205,141 @@ impl<T> DerefMut for Variadic<T> {
     }
 }
 
-impl<'lua, T: ToLua<'lua>> ToLuaMulti<'lua> for Variadic<T> {
-    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-        let mut values = MultiValue::new_or_cached(lua);
-        values.refill(self.0.into_iter().map(|e| e.to_lua(lua)))?;
+impl<'lua, T: IntoLua<'lua>> IntoLuaMulti<'lua> for Variadic<T> {
+    #[inline]
+    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+        let mut values = MultiValue::with_lua_and_capacity(lua, self.0.len());
+        values.refill(self.0.into_iter().map(|e| e.into_lua(lua)))?;
         Ok(values)
     }
 }
 
 impl<'lua, T: FromLua<'lua>> FromLuaMulti<'lua> for Variadic<T> {
+    #[inline]
     fn from_lua_multi(mut values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
-        let res = values
+        values
             .drain_all()
             .map(|e| T::from_lua(e, lua))
             .collect::<Result<Vec<T>>>()
-            .map(Variadic);
-        lua.cache_multivalue(values);
-        res
+            .map(Variadic)
     }
 }
 
 macro_rules! impl_tuple {
     () => (
-        impl<'lua> ToLuaMulti<'lua> for () {
-            fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
-                Ok(MultiValue::new_or_cached(lua))
+        impl<'lua> IntoLuaMulti<'lua> for () {
+            #[inline]
+            fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+                Ok(MultiValue::with_lua_and_capacity(lua, 0))
+            }
+
+            #[inline]
+            unsafe fn push_into_stack_multi(self, _lua: &'lua Lua) -> Result<c_int> {
+                Ok(0)
             }
         }
 
         impl<'lua> FromLuaMulti<'lua> for () {
-            fn from_lua_multi(values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
-                lua.cache_multivalue(values);
+            #[inline]
+            fn from_lua_multi(_values: MultiValue<'lua>, _lua: &'lua Lua) -> Result<Self> {
+                Ok(())
+            }
+
+            #[inline]
+            unsafe fn from_stack_multi(nvals: c_int, lua: &'lua Lua) -> Result<Self> {
+                if nvals > 0 {
+                    ffi::lua_pop(lua.state(), nvals);
+                }
                 Ok(())
             }
         }
     );
 
     ($last:ident $($name:ident)*) => (
-        impl<'lua, $($name,)* $last> ToLuaMulti<'lua> for ($($name,)* $last,)
-            where $($name: ToLua<'lua>,)*
-                  $last: ToLuaMulti<'lua>
+        impl<'lua, $($name,)* $last> IntoLuaMulti<'lua> for ($($name,)* $last,)
+            where $($name: IntoLua<'lua>,)*
+                  $last: IntoLuaMulti<'lua>
         {
-            #[allow(unused_mut)]
-            #[allow(non_snake_case)]
-            fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
+            #[allow(unused_mut, non_snake_case)]
+            #[inline]
+            fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>> {
                 let ($($name,)* $last,) = self;
 
-                let mut results = $last.to_lua_multi(lua)?;
-                push_reverse!(results, $($name.to_lua(lua)?,)*);
+                let mut results = $last.into_lua_multi(lua)?;
+                push_reverse!(results, $($name.into_lua(lua)?,)*);
                 Ok(results)
             }
+
+            #[allow(non_snake_case)]
+            #[inline]
+            unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
+                let ($($name,)* $last,) = self;
+                let mut nresults = 0;
+                $(
+                    _ = $name;
+                    nresults += 1;
+                )*
+                check_stack(lua.state(), nresults + 1)?;
+                $(
+                    $name.push_into_stack(lua)?;
+                )*
+                nresults += $last.push_into_stack_multi(lua)?;
+                Ok(nresults)
+            }
         }
 
         impl<'lua, $($name,)* $last> FromLuaMulti<'lua> for ($($name,)* $last,)
             where $($name: FromLua<'lua>,)*
                   $last: FromLuaMulti<'lua>
         {
-            #[allow(unused_mut)]
-            #[allow(non_snake_case)]
+            #[allow(unused_mut, non_snake_case)]
+            #[inline]
             fn from_lua_multi(mut values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self> {
-                $(let $name = values.pop_front().unwrap_or(Nil);)*
+                $(let $name = FromLua::from_lua(values.pop_front().unwrap_or(Nil), lua)?;)*
                 let $last = FromLuaMulti::from_lua_multi(values, lua)?;
-                Ok(($(FromLua::from_lua($name, lua)?,)* $last,))
+                Ok(($($name,)* $last,))
+            }
+
+            #[allow(unused_mut, non_snake_case)]
+            #[inline]
+            fn from_lua_args(mut args: MultiValue<'lua>, mut i: usize, to: Option<&str>, lua: &'lua Lua) -> Result<Self> {
+                $(
+                    let $name = FromLua::from_lua_arg(args.pop_front().unwrap_or(Nil), i, to, lua)?;
+                    i += 1;
+                )*
+                let $last = FromLuaMulti::from_lua_args(args, i, to, lua)?;
+                Ok(($($name,)* $last,))
+            }
+
+            #[allow(unused_mut, non_snake_case)]
+            #[inline]
+            unsafe fn from_stack_multi(mut nvals: c_int, lua: &'lua Lua) -> Result<Self> {
+                $(
+                    let $name = if nvals > 0 {
+                        nvals -= 1;
+                        FromLua::from_stack(-(nvals + 1), lua)
+                    } else {
+                        FromLua::from_lua(Nil, lua)
+                    }?;
+                )*
+                let $last = FromLuaMulti::from_stack_multi(nvals, lua)?;
+                Ok(($($name,)* $last,))
+            }
+
+            #[allow(unused_mut, non_snake_case)]
+            #[inline]
+            unsafe fn from_stack_args(mut nargs: c_int, mut i: usize, to: Option<&str>, lua: &'lua Lua) -> Result<Self> {
+                $(
+                    let $name = if nargs > 0 {
+                        nargs -= 1;
+                        FromLua::from_stack_arg(-(nargs + 1), i, to, lua)
+                    } else {
+                        FromLua::from_lua_arg(Nil, i, to, lua)
+                    }?;
+                    i += 1;
+                )*
+                let $last = FromLuaMulti::from_stack_args(nargs, i, to, lua)?;
+                Ok(($($name,)* $last,))
             }
         }
     );

src/prelude.rs

@@ -2,19 +2,29 @@
 
 #[doc(no_inline)]
 pub use crate::{
-    AnyUserData as LuaAnyUserData, Chunk as LuaChunk, Error as LuaError,
-    ExternalError as LuaExternalError, ExternalResult as LuaExternalResult, FromLua, FromLuaMulti,
-    Function as LuaFunction, GCMode as LuaGCMode, Integer as LuaInteger,
-    LightUserData as LuaLightUserData, Lua, LuaOptions, MetaMethod as LuaMetaMethod,
+    AnyUserData as LuaAnyUserData, AnyUserDataExt as LuaAnyUserDataExt, Chunk as LuaChunk,
+    Error as LuaError, ErrorContext as LuaErrorContext, ExternalError as LuaExternalError,
+    ExternalResult as LuaExternalResult, FromLua, FromLuaMulti, Function as LuaFunction,
+    FunctionInfo as LuaFunctionInfo, GCMode as LuaGCMode, Integer as LuaInteger, IntoLua,
+    IntoLuaMulti, LightUserData as LuaLightUserData, Lua, LuaOptions, MetaMethod as LuaMetaMethod,
     MultiValue as LuaMultiValue, Nil as LuaNil, Number as LuaNumber, RegistryKey as LuaRegistryKey,
     Result as LuaResult, StdLib as LuaStdLib, String as LuaString, Table as LuaTable,
     TableExt as LuaTableExt, TablePairs as LuaTablePairs, TableSequence as LuaTableSequence,
-    Thread as LuaThread, ThreadStatus as LuaThreadStatus, ToLua, ToLuaMulti,
-    UserData as LuaUserData, UserDataFields as LuaUserDataFields,
-    UserDataMetatable as LuaUserDataMetatable, UserDataMethods as LuaUserDataMethods,
+    Thread as LuaThread, ThreadStatus as LuaThreadStatus, UserData as LuaUserData,
+    UserDataFields as LuaUserDataFields, UserDataMetatable as LuaUserDataMetatable,
+    UserDataMethods as LuaUserDataMethods, UserDataRef as LuaUserDataRef,
+    UserDataRefMut as LuaUserDataRefMut, UserDataRegistry as LuaUserDataRegistry,
     Value as LuaValue,
 };
 
+#[cfg(not(feature = "luau"))]
+#[doc(no_inline)]
+pub use crate::HookTriggers as LuaHookTriggers;
+
+#[cfg(feature = "luau")]
+#[doc(no_inline)]
+pub use crate::{CoverageInfo as LuaCoverageInfo, Vector as LuaVector, VmState as LuaVmState};
+
 #[cfg(feature = "async")]
 #[doc(no_inline)]
 pub use crate::AsyncThread as LuaAsyncThread;
@@ -25,3 +35,10 @@ pub use crate::{
     DeserializeOptions as LuaDeserializeOptions, LuaSerdeExt,
     SerializeOptions as LuaSerializeOptions,
 };
+
+#[cfg(feature = "unstable")]
+#[doc(no_inline)]
+pub use crate::{
+    OwnedAnyUserData as LuaOwnedAnyUserData, OwnedFunction as LuaOwnedFunction,
+    OwnedString as LuaOwnedString, OwnedTable as LuaOwnedTable, OwnedThread as LuaOwnedThread,
+};

src/serde/de.rs

@@ -1,14 +1,15 @@
 use std::cell::RefCell;
 use std::os::raw::c_void;
 use std::rc::Rc;
+use std::result::Result as StdResult;
 use std::string::String as StdString;
 
 use rustc_hash::FxHashSet;
 use serde::de::{self, IntoDeserializer};
 
 use crate::error::{Error, Result};
-use crate::ffi;
 use crate::table::{Table, TablePairs, TableSequence};
+use crate::userdata::AnyUserData;
 use crate::value::Value;
 
 /// A struct for deserializing Lua values into Rust values.
@@ -23,14 +24,14 @@ pub struct Deserializer<'lua> {
 #[derive(Debug, Clone, Copy)]
 #[non_exhaustive]
 pub struct Options {
-    /// If true, an attempt to serialize types such as [`Thread`], [`UserData`], [`LightUserData`]
+    /// If true, an attempt to serialize types such as [`Function`], [`Thread`], [`LightUserData`]
     /// and [`Error`] will cause an error.
     /// Otherwise these types skipped when iterating or serialized as unit type.
     ///
     /// Default: **true**
     ///
+    /// [`Function`]: crate::Function
     /// [`Thread`]: crate::Thread
-    /// [`UserData`]: crate::UserData
     /// [`LightUserData`]: crate::LightUserData
     /// [`Error`]: crate::Error
     pub deny_unsupported_types: bool,
@@ -41,6 +42,11 @@ pub struct Options {
     ///
     /// Default: **true**
     pub deny_recursive_tables: bool,
+
+    /// If true, keys in tables will be iterated in sorted order.
+    ///
+    /// Default: **false**
+    pub sort_keys: bool,
 }
 
 impl Default for Options {
@@ -55,6 +61,7 @@ impl Options {
         Options {
             deny_unsupported_types: true,
             deny_recursive_tables: true,
+            sort_keys: false,
         }
     }
 
@@ -71,10 +78,19 @@ impl Options {
     ///
     /// [`deny_recursive_tables`]: #structfield.deny_recursive_tables
     #[must_use]
-    pub fn deny_recursive_tables(mut self, enabled: bool) -> Self {
+    pub const fn deny_recursive_tables(mut self, enabled: bool) -> Self {
         self.deny_recursive_tables = enabled;
         self
     }
+
+    /// Sets [`sort_keys`] option.
+    ///
+    /// [`sort_keys`]: #structfield.sort_keys
+    #[must_use]
+    pub const fn sort_keys(mut self, enabled: bool) -> Self {
+        self.sort_keys = enabled;
+        self
+    }
 }
 
 impl<'lua> Deserializer<'lua> {
@@ -120,6 +136,8 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
             Value::Integer(i) => visitor.visit_i64(i.into()),
             #[allow(clippy::useless_conversion)]
             Value::Number(n) => visitor.visit_f64(n.into()),
+            #[cfg(feature = "luau")]
+            Value::Vector(_) => self.deserialize_seq(visitor),
             Value::String(s) => match s.to_str() {
                 Ok(s) => visitor.visit_str(s),
                 Err(_) => visitor.visit_bytes(s.as_bytes()),
@@ -127,16 +145,25 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
             Value::Table(ref t) if t.raw_len() > 0 || t.is_array() => self.deserialize_seq(visitor),
             Value::Table(_) => self.deserialize_map(visitor),
             Value::LightUserData(ud) if ud.0.is_null() => visitor.visit_none(),
+            Value::UserData(ud) if ud.is_serializable() => {
+                serde_userdata(ud, |value| value.deserialize_any(visitor))
+            }
+            #[cfg(feature = "luau")]
+            Value::UserData(ud) if ud.1 == crate::types::SubtypeId::Buffer => unsafe {
+                let mut size = 0usize;
+                let buf = ffi::lua_tobuffer(ud.0.lua.ref_thread(), ud.0.index, &mut size);
+                mlua_assert!(!buf.is_null(), "invalid Luau buffer");
+                let buf = std::slice::from_raw_parts(buf as *const u8, size);
+                visitor.visit_bytes(buf)
+            },
             Value::Function(_)
             | Value::Thread(_)
             | Value::UserData(_)
             | Value::LightUserData(_)
             | Value::Error(_) => {
                 if self.options.deny_unsupported_types {
-                    Err(de::Error::custom(format!(
-                        "unsupported value type `{}`",
-                        self.value.type_name()
-                    )))
+                    let msg = format!("unsupported value type `{}`", self.value.type_name());
+                    Err(de::Error::custom(msg))
                 } else {
                     visitor.visit_unit()
                 }
@@ -159,8 +186,8 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
     #[inline]
     fn deserialize_enum<V>(
         self,
-        _name: &str,
-        _variants: &'static [&'static str],
+        name: &'static str,
+        variants: &'static [&'static str],
         visitor: V,
     ) -> Result<V::Value>
     where
@@ -187,13 +214,18 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                         &"map with a single key",
                     ));
                 }
-                if check_value_if_skip(&value, self.options, &self.visited)? {
+                let skip = check_value_for_skip(&value, self.options, &self.visited)
+                    .map_err(|err| Error::DeserializeError(err.to_string()))?;
+                if skip {
                     return Err(de::Error::custom("bad enum value"));
                 }
 
                 (variant, Some(value), Some(_guard))
             }
             Value::String(variant) => (variant.to_str()?.to_owned(), None, None),
+            Value::UserData(ud) if ud.is_serializable() => {
+                return serde_userdata(ud, |value| value.deserialize_enum(name, variants, visitor));
+            }
             _ => return Err(de::Error::custom("bad enum value")),
         };
 
@@ -211,12 +243,22 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
         V: de::Visitor<'de>,
     {
         match self.value {
+            #[cfg(feature = "luau")]
+            Value::Vector(vec) => {
+                let mut deserializer = VecDeserializer {
+                    vec,
+                    next: 0,
+                    options: self.options,
+                    visited: self.visited,
+                };
+                visitor.visit_seq(&mut deserializer)
+            }
             Value::Table(t) => {
                 let _guard = RecursionGuard::new(&t, &self.visited);
 
-                let len = t.raw_len() as usize;
+                let len = t.raw_len();
                 let mut deserializer = SeqDeserializer {
-                    seq: t.raw_sequence_values(),
+                    seq: t.sequence_values(),
                     options: self.options,
                     visited: self.visited,
                 };
@@ -230,6 +272,9 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                     ))
                 }
             }
+            Value::UserData(ud) if ud.is_serializable() => {
+                serde_userdata(ud, |value| value.deserialize_seq(visitor))
+            }
             value => Err(de::Error::invalid_type(
                 de::Unexpected::Other(value.type_name()),
                 &"table",
@@ -268,7 +313,7 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                 let _guard = RecursionGuard::new(&t, &self.visited);
 
                 let mut deserializer = MapDeserializer {
-                    pairs: t.pairs(),
+                    pairs: MapPairs::new(t, self.options.sort_keys)?,
                     value: None,
                     options: self.options,
                     visited: self.visited,
@@ -285,6 +330,9 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
                     ))
                 }
             }
+            Value::UserData(ud) if ud.is_serializable() => {
+                serde_userdata(ud, |value| value.deserialize_map(visitor))
+            }
             value => Err(de::Error::invalid_type(
                 de::Unexpected::Other(value.type_name()),
                 &"table",
@@ -305,10 +353,44 @@ impl<'lua, 'de> serde::Deserializer<'de> for Deserializer<'lua> {
         self.deserialize_map(visitor)
     }
 
+    #[inline]
+    fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        match self.value {
+            Value::UserData(ud) if ud.is_serializable() => {
+                serde_userdata(ud, |value| value.deserialize_newtype_struct(name, visitor))
+            }
+            _ => visitor.visit_newtype_struct(self),
+        }
+    }
+
+    #[inline]
+    fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        match self.value {
+            Value::LightUserData(ud) if ud.0.is_null() => visitor.visit_unit(),
+            _ => self.deserialize_any(visitor),
+        }
+    }
+
+    #[inline]
+    fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
+    where
+        V: de::Visitor<'de>,
+    {
+        match self.value {
+            Value::LightUserData(ud) if ud.0.is_null() => visitor.visit_unit(),
+            _ => self.deserialize_any(visitor),
+        }
+    }
+
     serde::forward_to_deserialize_any! {
         bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string bytes
-        byte_buf unit unit_struct newtype_struct
-        identifier ignored_any
+        byte_buf identifier ignored_any
     }
 }
 
@@ -329,7 +411,9 @@ impl<'lua, 'de> de::SeqAccess<'de> for SeqDeserializer<'lua> {
             match self.seq.next() {
                 Some(value) => {
                     let value = value?;
-                    if check_value_if_skip(&value, self.options, &self.visited)? {
+                    let skip = check_value_for_skip(&value, self.options, &self.visited)
+                        .map_err(|err| Error::DeserializeError(err.to_string()))?;
+                    if skip {
                         continue;
                     }
                     let visited = Rc::clone(&self.visited);
@@ -349,8 +433,83 @@ impl<'lua, 'de> de::SeqAccess<'de> for SeqDeserializer<'lua> {
     }
 }
 
+#[cfg(feature = "luau")]
+struct VecDeserializer {
+    vec: crate::types::Vector,
+    next: usize,
+    options: Options,
+    visited: Rc<RefCell<FxHashSet<*const c_void>>>,
+}
+
+#[cfg(feature = "luau")]
+impl<'de> de::SeqAccess<'de> for VecDeserializer {
+    type Error = Error;
+
+    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
+    where
+        T: de::DeserializeSeed<'de>,
+    {
+        match self.vec.0.get(self.next) {
+            Some(&n) => {
+                self.next += 1;
+                let visited = Rc::clone(&self.visited);
+                let deserializer =
+                    Deserializer::from_parts(Value::Number(n as _), self.options, visited);
+                seed.deserialize(deserializer).map(Some)
+            }
+            None => Ok(None),
+        }
+    }
+
+    fn size_hint(&self) -> Option<usize> {
+        Some(crate::types::Vector::SIZE)
+    }
+}
+
+pub(crate) enum MapPairs<'lua> {
+    Iter(TablePairs<'lua, Value<'lua>, Value<'lua>>),
+    Vec(Vec<(Value<'lua>, Value<'lua>)>),
+}
+
+impl<'lua> MapPairs<'lua> {
+    pub(crate) fn new(t: Table<'lua>, sort_keys: bool) -> Result<Self> {
+        if sort_keys {
+            let mut pairs = t.pairs::<Value, Value>().collect::<Result<Vec<_>>>()?;
+            pairs.sort_by(|(a, _), (b, _)| b.cmp(a)); // reverse order as we pop values from the end
+            Ok(MapPairs::Vec(pairs))
+        } else {
+            Ok(MapPairs::Iter(t.pairs::<Value, Value>()))
+        }
+    }
+
+    pub(crate) fn count(self) -> usize {
+        match self {
+            MapPairs::Iter(iter) => iter.count(),
+            MapPairs::Vec(vec) => vec.len(),
+        }
+    }
+
+    pub(crate) fn size_hint(&self) -> (usize, Option<usize>) {
+        match self {
+            MapPairs::Iter(iter) => iter.size_hint(),
+            MapPairs::Vec(vec) => (vec.len(), Some(vec.len())),
+        }
+    }
+}
+
+impl<'lua> Iterator for MapPairs<'lua> {
+    type Item = Result<(Value<'lua>, Value<'lua>)>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self {
+            MapPairs::Iter(iter) => iter.next(),
+            MapPairs::Vec(vec) => vec.pop().map(Ok),
+        }
+    }
+}
+
 struct MapDeserializer<'lua> {
-    pairs: TablePairs<'lua, Value<'lua>, Value<'lua>>,
+    pairs: MapPairs<'lua>,
     value: Option<Value<'lua>>,
     options: Options,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
@@ -368,9 +527,11 @@ impl<'lua, 'de> de::MapAccess<'de> for MapDeserializer<'lua> {
             match self.pairs.next() {
                 Some(item) => {
                     let (key, value) = item?;
-                    if check_value_if_skip(&key, self.options, &self.visited)?
-                        || check_value_if_skip(&value, self.options, &self.visited)?
-                    {
+                    let skip_key = check_value_for_skip(&key, self.options, &self.visited)
+                        .map_err(|err| Error::DeserializeError(err.to_string()))?;
+                    let skip_value = check_value_for_skip(&value, self.options, &self.visited)
+                        .map_err(|err| Error::DeserializeError(err.to_string()))?;
+                    if skip_key || skip_value {
                         continue;
                     }
                     self.processed += 1;
@@ -499,18 +660,16 @@ impl<'lua, 'de> de::VariantAccess<'de> for VariantDeserializer<'lua> {
 
 // Adds `ptr` to the `visited` map and removes on drop
 // Used to track recursive tables but allow to traverse same tables multiple times
-struct RecursionGuard {
+pub(crate) struct RecursionGuard {
     ptr: *const c_void,
     visited: Rc<RefCell<FxHashSet<*const c_void>>>,
 }
 
 impl RecursionGuard {
     #[inline]
-    fn new(table: &Table, visited: &Rc<RefCell<FxHashSet<*const c_void>>>) -> Self {
+    pub(crate) fn new(table: &Table, visited: &Rc<RefCell<FxHashSet<*const c_void>>>) -> Self {
         let visited = Rc::clone(visited);
-        let lua = table.0.lua;
-        let ptr =
-            unsafe { lua.ref_thread_exec(|refthr| ffi::lua_topointer(refthr, table.0.index)) };
+        let ptr = table.to_pointer();
         visited.borrow_mut().insert(ptr);
         RecursionGuard { ptr, visited }
     }
@@ -523,23 +682,22 @@ impl Drop for RecursionGuard {
 }
 
 // Checks `options` and decides should we emit an error or skip next element
-fn check_value_if_skip(
+pub(crate) fn check_value_for_skip(
     value: &Value,
     options: Options,
     visited: &RefCell<FxHashSet<*const c_void>>,
-) -> Result<bool> {
+) -> StdResult<bool, &'static str> {
     match value {
         Value::Table(table) => {
-            let lua = table.0.lua;
-            let ptr =
-                unsafe { lua.ref_thread_exec(|refthr| ffi::lua_topointer(refthr, table.0.index)) };
+            let ptr = table.to_pointer();
             if visited.borrow().contains(&ptr) {
                 if options.deny_recursive_tables {
-                    return Err(de::Error::custom("recursive table detected"));
+                    return Err("recursive table detected");
                 }
                 return Ok(true); // skip
             }
         }
+        Value::UserData(ud) if ud.is_serializable() => {}
         Value::Function(_)
         | Value::Thread(_)
         | Value::UserData(_)
@@ -553,3 +711,11 @@ fn check_value_if_skip(
     }
     Ok(false) // do not skip
 }
+
+fn serde_userdata<V>(
+    ud: AnyUserData,
+    f: impl FnOnce(serde_value::Value) -> std::result::Result<V, serde_value::DeserializerError>,
+) -> Result<V> {
+    let value = serde_value::to_value(ud).map_err(|err| Error::SerializeError(err.to_string()))?;
+    f(value).map_err(|err| Error::DeserializeError(err.to_string()))
+}

src/serde/mod.rs

@@ -1,20 +1,19 @@
 //! (De)Serialization support using serde.
 
 use std::os::raw::c_void;
-use std::ptr;
 
-use serde::{Deserialize, Serialize};
+use serde::{de::DeserializeOwned, ser::Serialize};
 
 use crate::error::Result;
-use crate::ffi;
 use crate::lua::Lua;
+use crate::private::Sealed;
 use crate::table::Table;
-use crate::types::LightUserData;
-use crate::util::{assert_stack, check_stack, StackGuard};
+use crate::util::check_stack;
 use crate::value::Value;
 
 /// Trait for serializing/deserializing Lua values using Serde.
-pub trait LuaSerdeExt<'lua> {
+#[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+pub trait LuaSerdeExt: Sealed {
     /// A special value (lightuserdata) to encode/decode optional (none) values.
     ///
     /// Requires `feature = "serialize"`
@@ -36,7 +35,7 @@ pub trait LuaSerdeExt<'lua> {
     ///     Ok(())
     /// }
     /// ```
-    fn null(&'lua self) -> Value<'lua>;
+    fn null(&self) -> Value;
 
     /// A metatable attachable to a Lua table to systematically encode it as Array (instead of Map).
     /// As result, encoded Array will contain only sequence part of the table, with the same length
@@ -67,7 +66,7 @@ pub trait LuaSerdeExt<'lua> {
     ///     Ok(())
     /// }
     /// ```
-    fn array_metatable(&'lua self) -> Table<'lua>;
+    fn array_metatable(&self) -> Table;
 
     /// Converts `T` into a [`Value`] instance.
     ///
@@ -100,7 +99,7 @@ pub trait LuaSerdeExt<'lua> {
     ///     "#).exec()
     /// }
     /// ```
-    fn to_value<T: Serialize + ?Sized>(&'lua self, t: &T) -> Result<Value<'lua>>;
+    fn to_value<'lua, T: Serialize + ?Sized>(&'lua self, t: &T) -> Result<Value<'lua>>;
 
     /// Converts `T` into a [`Value`] instance with options.
     ///
@@ -125,7 +124,7 @@ pub trait LuaSerdeExt<'lua> {
     ///     "#).exec()
     /// }
     /// ```
-    fn to_value_with<T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
+    fn to_value_with<'lua, T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
     where
         T: Serialize + ?Sized;
 
@@ -157,7 +156,8 @@ pub trait LuaSerdeExt<'lua> {
     ///     Ok(())
     /// }
     /// ```
-    fn from_value<T: Deserialize<'lua>>(&'lua self, value: Value<'lua>) -> Result<T>;
+    #[allow(clippy::wrong_self_convention)]
+    fn from_value<T: DeserializeOwned>(&self, value: Value) -> Result<T>;
 
     /// Deserializes a [`Value`] into any serde deserializable object with options.
     ///
@@ -188,53 +188,47 @@ pub trait LuaSerdeExt<'lua> {
     ///     Ok(())
     /// }
     /// ```
-    fn from_value_with<T: Deserialize<'lua>>(
-        &'lua self,
-        value: Value<'lua>,
-        options: de::Options,
-    ) -> Result<T>;
+    #[allow(clippy::wrong_self_convention)]
+    fn from_value_with<T: DeserializeOwned>(&self, value: Value, options: de::Options)
+        -> Result<T>;
 }
 
-impl<'lua> LuaSerdeExt<'lua> for Lua {
-    fn null(&'lua self) -> Value<'lua> {
-        Value::LightUserData(LightUserData(ptr::null_mut()))
+impl LuaSerdeExt for Lua {
+    fn null(&self) -> Value {
+        Value::NULL
     }
 
-    fn array_metatable(&'lua self) -> Table<'lua> {
+    fn array_metatable(&self) -> Table {
         unsafe {
-            let _sg = StackGuard::new(self.state);
-            assert_stack(self.state, 1);
-
-            push_array_metatable(self.state);
-
-            Table(self.pop_ref())
+            push_array_metatable(self.ref_thread());
+            Table(self.pop_ref_thread())
         }
     }
 
-    fn to_value<T>(&'lua self, t: &T) -> Result<Value<'lua>>
+    fn to_value<'lua, T>(&'lua self, t: &T) -> Result<Value<'lua>>
     where
         T: Serialize + ?Sized,
     {
         t.serialize(ser::Serializer::new(self))
     }
 
-    fn to_value_with<T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
+    fn to_value_with<'lua, T>(&'lua self, t: &T, options: ser::Options) -> Result<Value<'lua>>
     where
         T: Serialize + ?Sized,
     {
         t.serialize(ser::Serializer::new_with_options(self, options))
     }
 
-    fn from_value<T>(&'lua self, value: Value<'lua>) -> Result<T>
+    fn from_value<T>(&self, value: Value) -> Result<T>
     where
-        T: Deserialize<'lua>,
+        T: DeserializeOwned,
     {
         T::deserialize(de::Deserializer::new(value))
     }
 
-    fn from_value_with<T>(&'lua self, value: Value<'lua>, options: de::Options) -> Result<T>
+    fn from_value_with<T>(&self, value: Value, options: de::Options) -> Result<T>
     where
-        T: Deserialize<'lua>,
+        T: DeserializeOwned,
     {
         T::deserialize(de::Deserializer::new_with_options(value, options))
     }
@@ -256,7 +250,7 @@ pub(crate) unsafe fn init_metatables(state: *mut ffi::lua_State) -> Result<()> {
 }
 
 pub(crate) unsafe fn push_array_metatable(state: *mut ffi::lua_State) {
-    let array_metatable_key = &ARRAY_METATABLE_REGISTRY_KEY as *const u8 as *mut c_void;
+    let array_metatable_key = &ARRAY_METATABLE_REGISTRY_KEY as *const u8 as *const c_void;
     ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, array_metatable_key);
 }
 

src/serde/ser.rs

@@ -1,16 +1,10 @@
-use std::os::raw::c_int;
-
 use serde::{ser, Serialize};
 
 use super::LuaSerdeExt;
 use crate::error::{Error, Result};
-use crate::ffi;
 use crate::lua::Lua;
-use crate::string::String;
 use crate::table::Table;
-use crate::types::Integer;
-use crate::util::{check_stack, StackGuard};
-use crate::value::{ToLua, Value};
+use crate::value::{IntoLua, Value};
 
 /// A struct for serializing Rust values into Lua values.
 #[derive(Debug)]
@@ -48,6 +42,12 @@ pub struct Options {
     /// [`null`]: crate::LuaSerdeExt::null
     /// [`Nil`]: crate::Value::Nil
     pub serialize_unit_to_null: bool,
+
+    /// If true, serialize `serde_json::Number` with arbitrary_precision to a Lua number.
+    /// Otherwise it will be serialized as an object (what serde does).
+    ///
+    /// Default: **false**
+    pub detect_serde_json_arbitrary_precision: bool,
 }
 
 impl Default for Options {
@@ -63,6 +63,7 @@ impl Options {
             set_array_metatable: true,
             serialize_none_to_null: true,
             serialize_unit_to_null: true,
+            detect_serde_json_arbitrary_precision: false,
         }
     }
 
@@ -92,6 +93,20 @@ impl Options {
         self.serialize_unit_to_null = enabled;
         self
     }
+
+    /// Sets [`detect_serde_json_arbitrary_precision`] option.
+    ///
+    /// This option is used to serialize `serde_json::Number` with arbitrary precision to a Lua number.
+    /// Otherwise it will be serialized as an object (what serde does).
+    ///
+    /// This option is disabled by default.
+    ///
+    /// [`detect_serde_json_arbitrary_precision`]: #structfield.detect_serde_json_arbitrary_precision
+    #[must_use]
+    pub const fn detect_serde_json_arbitrary_precision(mut self, enabled: bool) -> Self {
+        self.detect_serde_json_arbitrary_precision = enabled;
+        self
+    }
 }
 
 impl<'lua> Serializer<'lua> {
@@ -110,7 +125,7 @@ macro_rules! lua_serialize_number {
     ($name:ident, $t:ty) => {
         #[inline]
         fn $name(self, value: $t) -> Result<Value<'lua>> {
-            value.to_lua(self.lua)
+            value.into_lua(self.lua)
         }
     };
 }
@@ -121,12 +136,12 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 
     // Associated types for keeping track of additional state while serializing
     // compound data structures like sequences and maps.
-    type SerializeSeq = SerializeVec<'lua>;
-    type SerializeTuple = SerializeVec<'lua>;
-    type SerializeTupleStruct = SerializeVec<'lua>;
+    type SerializeSeq = SerializeSeq<'lua>;
+    type SerializeTuple = SerializeSeq<'lua>;
+    type SerializeTupleStruct = SerializeSeq<'lua>;
     type SerializeTupleVariant = SerializeTupleVariant<'lua>;
     type SerializeMap = SerializeMap<'lua>;
-    type SerializeStruct = SerializeMap<'lua>;
+    type SerializeStruct = SerializeStruct<'lua>;
     type SerializeStructVariant = SerializeStructVariant<'lua>;
 
     #[inline]
@@ -236,13 +251,11 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 
     #[inline]
     fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
-        let len = len.unwrap_or(0) as c_int;
-        let table = self.lua.create_table_with_capacity(len, 0)?;
+        let table = self.lua.create_table_with_capacity(len.unwrap_or(0), 0)?;
         if self.options.set_array_metatable {
             table.set_metatable(Some(self.lua.array_metatable()));
         }
-        let options = self.options;
-        Ok(SerializeVec { table, options })
+        Ok(SerializeSeq::new(table, self.options))
     }
 
     #[inline]
@@ -253,9 +266,14 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
     #[inline]
     fn serialize_tuple_struct(
         self,
-        _name: &'static str,
+        name: &'static str,
         len: usize,
     ) -> Result<Self::SerializeTupleStruct> {
+        #[cfg(feature = "luau")]
+        if name == "Vector" && len == crate::types::Vector::SIZE {
+            return Ok(SerializeSeq::new_vector(self.lua, self.options));
+        }
+        _ = name;
         self.serialize_seq(Some(len))
     }
 
@@ -268,7 +286,7 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
         _len: usize,
     ) -> Result<Self::SerializeTupleVariant> {
         Ok(SerializeTupleVariant {
-            name: self.lua.create_string(variant)?,
+            variant,
             table: self.lua.create_table()?,
             options: self.options,
         })
@@ -276,17 +294,31 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
 
     #[inline]
     fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap> {
-        let len = len.unwrap_or(0) as c_int;
         Ok(SerializeMap {
             key: None,
-            table: self.lua.create_table_with_capacity(0, len)?,
+            table: self.lua.create_table_with_capacity(0, len.unwrap_or(0))?,
             options: self.options,
         })
     }
 
     #[inline]
-    fn serialize_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
-        self.serialize_map(Some(len))
+    fn serialize_struct(self, name: &'static str, len: usize) -> Result<Self::SerializeStruct> {
+        if self.options.detect_serde_json_arbitrary_precision
+            && name == "$serde_json::private::Number"
+            && len == 1
+        {
+            return Ok(SerializeStruct {
+                lua: self.lua,
+                inner: None,
+                options: self.options,
+            });
+        }
+
+        Ok(SerializeStruct {
+            lua: self.lua,
+            inner: Some(Value::Table(self.lua.create_table_with_capacity(0, len)?)),
+            options: self.options,
+        })
     }
 
     #[inline]
@@ -298,20 +330,48 @@ impl<'lua> ser::Serializer for Serializer<'lua> {
         len: usize,
     ) -> Result<Self::SerializeStructVariant> {
         Ok(SerializeStructVariant {
-            name: self.lua.create_string(variant)?,
-            table: self.lua.create_table_with_capacity(0, len as c_int)?,
+            variant,
+            table: self.lua.create_table_with_capacity(0, len)?,
             options: self.options,
         })
     }
 }
 
 #[doc(hidden)]
-pub struct SerializeVec<'lua> {
-    table: Table<'lua>,
+pub struct SerializeSeq<'lua> {
+    lua: &'lua Lua,
+    #[cfg(feature = "luau")]
+    vector: Option<crate::types::Vector>,
+    table: Option<Table<'lua>>,
+    next: usize,
     options: Options,
 }
 
-impl<'lua> ser::SerializeSeq for SerializeVec<'lua> {
+impl<'lua> SerializeSeq<'lua> {
+    const fn new(table: Table<'lua>, options: Options) -> Self {
+        Self {
+            lua: table.0.lua,
+            #[cfg(feature = "luau")]
+            vector: None,
+            table: Some(table),
+            next: 0,
+            options,
+        }
+    }
+
+    #[cfg(feature = "luau")]
+    const fn new_vector(lua: &'lua Lua, options: Options) -> Self {
+        Self {
+            lua,
+            vector: Some(crate::types::Vector::zero()),
+            table: None,
+            next: 0,
+            options,
+        }
+    }
+}
+
+impl<'lua> ser::SerializeSeq for SerializeSeq<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -319,27 +379,19 @@ impl<'lua> ser::SerializeSeq for SerializeVec<'lua> {
     where
         T: Serialize + ?Sized,
     {
-        let lua = self.table.0.lua;
-        let value = lua.to_value_with(value, self.options)?;
-        unsafe {
-            let _sg = StackGuard::new(lua.state);
-            check_stack(lua.state, 4)?;
-
-            lua.push_ref(&self.table.0);
-            lua.push_value(value)?;
-            protect_lua!(lua.state, 2, 0, fn(state) {
-                let len = ffi::lua_rawlen(state, -2) as Integer;
-                ffi::lua_rawseti(state, -2, len + 1);
-            })
-        }
+        let value = self.lua.to_value_with(value, self.options)?;
+        let table = self.table.as_ref().unwrap();
+        table.raw_seti(self.next + 1, value)?;
+        self.next += 1;
+        Ok(())
     }
 
     fn end(self) -> Result<Value<'lua>> {
-        Ok(Value::Table(self.table))
+        Ok(Value::Table(self.table.unwrap()))
     }
 }
 
-impl<'lua> ser::SerializeTuple for SerializeVec<'lua> {
+impl<'lua> ser::SerializeTuple for SerializeSeq<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -355,7 +407,7 @@ impl<'lua> ser::SerializeTuple for SerializeVec<'lua> {
     }
 }
 
-impl<'lua> ser::SerializeTupleStruct for SerializeVec<'lua> {
+impl<'lua> ser::SerializeTupleStruct for SerializeSeq<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -363,17 +415,29 @@ impl<'lua> ser::SerializeTupleStruct for SerializeVec<'lua> {
     where
         T: Serialize + ?Sized,
     {
+        #[cfg(feature = "luau")]
+        if let Some(vector) = self.vector.as_mut() {
+            let value = self.lua.to_value_with(value, self.options)?;
+            let value = self.lua.unpack(value)?;
+            vector.0[self.next] = value;
+            self.next += 1;
+            return Ok(());
+        }
         ser::SerializeSeq::serialize_element(self, value)
     }
 
     fn end(self) -> Result<Value<'lua>> {
+        #[cfg(feature = "luau")]
+        if let Some(vector) = self.vector {
+            return Ok(Value::Vector(vector));
+        }
         ser::SerializeSeq::end(self)
     }
 }
 
 #[doc(hidden)]
 pub struct SerializeTupleVariant<'lua> {
-    name: String<'lua>,
+    variant: &'static str,
     table: Table<'lua>,
     options: Options,
 }
@@ -387,15 +451,13 @@ impl<'lua> ser::SerializeTupleVariant for SerializeTupleVariant<'lua> {
         T: Serialize + ?Sized,
     {
         let lua = self.table.0.lua;
-        let idx = self.table.raw_len() + 1;
-        self.table
-            .raw_insert(idx, lua.to_value_with(value, self.options)?)
+        self.table.raw_push(lua.to_value_with(value, self.options)?)
     }
 
     fn end(self) -> Result<Value<'lua>> {
         let lua = self.table.0.lua;
         let table = lua.create_table()?;
-        table.raw_set(self.name, self.table)?;
+        table.raw_set(self.variant, self.table)?;
         Ok(Value::Table(table))
     }
 }
@@ -438,7 +500,14 @@ impl<'lua> ser::SerializeMap for SerializeMap<'lua> {
     }
 }
 
-impl<'lua> ser::SerializeStruct for SerializeMap<'lua> {
+#[doc(hidden)]
+pub struct SerializeStruct<'lua> {
+    lua: &'lua Lua,
+    inner: Option<Value<'lua>>,
+    options: Options,
+}
+
+impl<'lua> ser::SerializeStruct for SerializeStruct<'lua> {
     type Ok = Value<'lua>;
     type Error = Error;
 
@@ -446,18 +515,44 @@ impl<'lua> ser::SerializeStruct for SerializeMap<'lua> {
     where
         T: Serialize + ?Sized,
     {
-        ser::SerializeMap::serialize_key(self, key)?;
-        ser::SerializeMap::serialize_value(self, value)
+        match self.inner {
+            Some(Value::Table(ref table)) => {
+                table.raw_set(key, self.lua.to_value_with(value, self.options)?)?;
+            }
+            None if self.options.detect_serde_json_arbitrary_precision => {
+                // A special case for `serde_json::Number` with arbitrary precision.
+                assert_eq!(key, "$serde_json::private::Number");
+                self.inner = Some(self.lua.to_value_with(value, self.options)?);
+            }
+            _ => unreachable!(),
+        }
+        Ok(())
     }
 
     fn end(self) -> Result<Value<'lua>> {
-        ser::SerializeMap::end(self)
+        match self.inner {
+            Some(table @ Value::Table(_)) => Ok(table),
+            Some(value) if self.options.detect_serde_json_arbitrary_precision => {
+                let number_s = value.as_str().expect("not an arbitrary precision number");
+                if number_s.contains(['.', 'e', 'E']) {
+                    if let Ok(number) = number_s.parse().map(Value::Number) {
+                        return Ok(number);
+                    }
+                }
+                Ok(number_s
+                    .parse()
+                    .map(Value::Integer)
+                    .or_else(|_| number_s.parse().map(Value::Number))
+                    .unwrap_or(value))
+            }
+            _ => unreachable!(),
+        }
     }
 }
 
 #[doc(hidden)]
 pub struct SerializeStructVariant<'lua> {
-    name: String<'lua>,
+    variant: &'static str,
     table: Table<'lua>,
     options: Options,
 }
@@ -478,8 +573,8 @@ impl<'lua> ser::SerializeStructVariant for SerializeStructVariant<'lua> {
 
     fn end(self) -> Result<Value<'lua>> {
         let lua = self.table.0.lua;
-        let table = lua.create_table()?;
-        table.raw_set(self.name, self.table)?;
+        let table = lua.create_table_with_capacity(0, 1)?;
+        table.raw_set(self.variant, self.table)?;
         Ok(Value::Table(table))
     }
 }

src/stdlib.rs

@@ -1,5 +1,4 @@
 use std::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign};
-use std::u32;
 
 /// Flags describing the set of lua standard libraries to load.
 #[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
@@ -8,42 +7,66 @@ pub struct StdLib(u32);
 impl StdLib {
     /// [`coroutine`](https://www.lua.org/manual/5.4/manual.html#6.2) library
     ///
-    /// Requires `feature = "lua54/lua53/lua52"`
-    #[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
+    /// Requires `feature = "lua54/lua53/lua52/luau"`
+    #[cfg(any(
+        feature = "lua54",
+        feature = "lua53",
+        feature = "lua52",
+        feature = "luau"
+    ))]
     pub const COROUTINE: StdLib = StdLib(1);
+
     /// [`table`](https://www.lua.org/manual/5.4/manual.html#6.6) library
     pub const TABLE: StdLib = StdLib(1 << 1);
+
     /// [`io`](https://www.lua.org/manual/5.4/manual.html#6.8) library
+    #[cfg(not(feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
     pub const IO: StdLib = StdLib(1 << 2);
+
     /// [`os`](https://www.lua.org/manual/5.4/manual.html#6.9) library
     pub const OS: StdLib = StdLib(1 << 3);
+
     /// [`string`](https://www.lua.org/manual/5.4/manual.html#6.4) library
     pub const STRING: StdLib = StdLib(1 << 4);
+
     /// [`utf8`](https://www.lua.org/manual/5.4/manual.html#6.5) library
     ///
-    /// Requires `feature = "lua54/lua53"`
-    #[cfg(any(feature = "lua54", feature = "lua53"))]
+    /// Requires `feature = "lua54/lua53/luau"`
+    #[cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))]
     pub const UTF8: StdLib = StdLib(1 << 5);
+
     /// [`bit`](https://www.lua.org/manual/5.2/manual.html#6.7) library
     ///
-    /// Requires `feature = "lua52/luajit"`
-    #[cfg(any(feature = "lua52", feature = "luajit", doc))]
+    /// Requires `feature = "lua52/luajit/luau"`
+    #[cfg(any(feature = "lua52", feature = "luajit", feature = "luau", doc))]
     pub const BIT: StdLib = StdLib(1 << 6);
+
     /// [`math`](https://www.lua.org/manual/5.4/manual.html#6.7) library
     pub const MATH: StdLib = StdLib(1 << 7);
+
     /// [`package`](https://www.lua.org/manual/5.4/manual.html#6.3) library
     pub const PACKAGE: StdLib = StdLib(1 << 8);
+
+    /// [`buffer`](https://luau-lang.org/library#buffer-library) library
+    #[cfg(any(feature = "luau", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    pub const BUFFER: StdLib = StdLib(1 << 9);
+
     /// [`jit`](http://luajit.org/ext_jit.html) library
     ///
     /// Requires `feature = "luajit"`
     #[cfg(any(feature = "luajit", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luajit")))]
     pub const JIT: StdLib = StdLib(1 << 9);
 
     /// (**unsafe**) [`ffi`](http://luajit.org/ext_ffi.html) library
     ///
     /// Requires `feature = "luajit"`
     #[cfg(any(feature = "luajit", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luajit")))]
     pub const FFI: StdLib = StdLib(1 << 30);
+
     /// (**unsafe**) [`debug`](https://www.lua.org/manual/5.4/manual.html#6.10) library
     pub const DEBUG: StdLib = StdLib(1 << 31);
 
@@ -52,7 +75,10 @@ impl StdLib {
     /// (**unsafe**) All standard libraries
     pub const ALL: StdLib = StdLib(u32::MAX);
     /// The safe subset of the standard libraries
+    #[cfg(not(feature = "luau"))]
     pub const ALL_SAFE: StdLib = StdLib((1 << 30) - 1);
+    #[cfg(feature = "luau")]
+    pub const ALL_SAFE: StdLib = StdLib(u32::MAX);
 
     pub fn contains(self, lib: Self) -> bool {
         (self & lib).0 != 0

src/string.rs

@@ -1,6 +1,8 @@
-use std::borrow::Cow;
+use std::borrow::{Borrow, Cow};
+use std::hash::{Hash, Hasher};
+use std::os::raw::c_void;
 use std::string::String as StdString;
-use std::{slice, str};
+use std::{fmt, slice, str};
 
 #[cfg(feature = "serialize")]
 use {
@@ -9,16 +11,35 @@ use {
 };
 
 use crate::error::{Error, Result};
-use crate::ffi;
 use crate::types::LuaRef;
-use crate::util::{assert_stack, StackGuard};
 
 /// Handle to an internal Lua string.
 ///
 /// Unlike Rust strings, Lua strings may not be valid UTF-8.
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct String<'lua>(pub(crate) LuaRef<'lua>);
 
+/// Owned handle to an internal Lua string.
+///
+/// The owned handle holds a *strong* reference to the current Lua instance.
+/// Be warned, if you place it into a Lua type (eg. [`UserData`] or a Rust callback), it is *very easy*
+/// to accidentally cause reference cycles that would prevent destroying Lua instance.
+///
+/// [`UserData`]: crate::UserData
+#[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
+#[derive(Clone)]
+pub struct OwnedString(pub(crate) crate::types::LuaOwnedRef);
+
+#[cfg(feature = "unstable")]
+impl OwnedString {
+    /// Get borrowed handle to the underlying Lua string.
+    #[cfg_attr(feature = "send", allow(unused))]
+    pub const fn to_ref(&self) -> String {
+        String(self.0.to_ref())
+    }
+}
+
 impl<'lua> String<'lua> {
     /// Get a `&str` slice if the Lua string is valid UTF-8.
     ///
@@ -38,6 +59,7 @@ impl<'lua> String<'lua> {
     /// # Ok(())
     /// # }
     /// ```
+    #[inline]
     pub fn to_str(&self) -> Result<&str> {
         str::from_utf8(self.as_bytes()).map_err(|e| Error::FromLuaConversionError {
             from: "string",
@@ -64,6 +86,7 @@ impl<'lua> String<'lua> {
     /// # Ok(())
     /// # }
     /// ```
+    #[inline]
     pub fn to_string_lossy(&self) -> Cow<'_, str> {
         StdString::from_utf8_lossy(self.as_bytes())
     }
@@ -85,6 +108,7 @@ impl<'lua> String<'lua> {
     /// # Ok(())
     /// # }
     /// ```
+    #[inline]
     pub fn as_bytes(&self) -> &[u8] {
         let nulled = self.as_bytes_with_nul();
         &nulled[..nulled.len() - 1]
@@ -92,25 +116,68 @@ impl<'lua> String<'lua> {
 
     /// Get the bytes that make up this string, including the trailing nul byte.
     pub fn as_bytes_with_nul(&self) -> &[u8] {
-        let lua = self.0.lua;
+        let ref_thread = self.0.lua.ref_thread();
         unsafe {
-            let _sg = StackGuard::new(lua.state);
-            assert_stack(lua.state, 1);
-
-            lua.push_ref(&self.0);
             mlua_debug_assert!(
-                ffi::lua_type(lua.state, -1) == ffi::LUA_TSTRING,
+                ffi::lua_type(ref_thread, self.0.index) == ffi::LUA_TSTRING,
                 "string ref is not string type"
             );
 
             let mut size = 0;
             // This will not trigger a 'm' error, because the reference is guaranteed to be of
             // string type
-            let data = ffi::lua_tolstring(lua.state, -1, &mut size);
+            let data = ffi::lua_tolstring(ref_thread, self.0.index, &mut size);
 
             slice::from_raw_parts(data as *const u8, size + 1)
         }
     }
+
+    /// Converts this string to a generic C pointer.
+    ///
+    /// There is no way to convert the pointer back to its original value.
+    ///
+    /// Typically this function is used only for hashing and debug information.
+    #[inline]
+    pub fn to_pointer(&self) -> *const c_void {
+        self.0.to_pointer()
+    }
+
+    /// Convert this handle to owned version.
+    #[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
+    #[inline]
+    pub fn into_owned(self) -> OwnedString {
+        OwnedString(self.0.into_owned())
+    }
+}
+
+impl<'lua> fmt::Debug for String<'lua> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let bytes = self.as_bytes();
+        // Check if the string is valid utf8
+        if let Ok(s) = str::from_utf8(bytes) {
+            return s.fmt(f);
+        }
+
+        // Format as bytes
+        write!(f, "b\"")?;
+        for &b in bytes {
+            // https://doc.rust-lang.org/reference/tokens.html#byte-escapes
+            match b {
+                b'\n' => write!(f, "\\n")?,
+                b'\r' => write!(f, "\\r")?,
+                b'\t' => write!(f, "\\t")?,
+                b'\\' | b'"' => write!(f, "\\{}", b as char)?,
+                b'\0' => write!(f, "\\0")?,
+                // ASCII printable
+                0x20..=0x7e => write!(f, "{}", b as char)?,
+                _ => write!(f, "\\x{b:02x}")?,
+            }
+        }
+        write!(f, "\"")?;
+
+        Ok(())
+    }
 }
 
 impl<'lua> AsRef<[u8]> for String<'lua> {
@@ -119,6 +186,12 @@ impl<'lua> AsRef<[u8]> for String<'lua> {
     }
 }
 
+impl<'lua> Borrow<[u8]> for String<'lua> {
+    fn borrow(&self) -> &[u8] {
+        self.as_bytes()
+    }
+}
+
 // Lua strings are basically &[u8] slices, so implement PartialEq for anything resembling that.
 //
 // This makes our `String` comparable with `Vec<u8>`, `[u8]`, `&str`, `String` and `mlua::String`
@@ -129,13 +202,21 @@ impl<'lua> AsRef<[u8]> for String<'lua> {
 // in other ways.
 impl<'lua, T> PartialEq<T> for String<'lua>
 where
-    T: AsRef<[u8]>,
+    T: AsRef<[u8]> + ?Sized,
 {
     fn eq(&self, other: &T) -> bool {
         self.as_bytes() == other.as_ref()
     }
 }
 
+impl<'lua> Eq for String<'lua> {}
+
+impl<'lua> Hash for String<'lua> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.as_bytes().hash(state);
+    }
+}
+
 #[cfg(feature = "serialize")]
 impl<'lua> Serialize for String<'lua> {
     fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
@@ -148,3 +229,41 @@ impl<'lua> Serialize for String<'lua> {
         }
     }
 }
+
+// Additional shortcuts
+#[cfg(feature = "unstable")]
+impl OwnedString {
+    /// Get a `&str` slice if the Lua string is valid UTF-8.
+    ///
+    /// This is a shortcut for [`String::to_str()`].
+    #[inline]
+    pub fn to_str(&self) -> Result<&str> {
+        let s = self.to_ref();
+        // Reattach lifetime to &self
+        unsafe { std::mem::transmute(s.to_str()) }
+    }
+
+    /// Get the bytes that make up this string.
+    ///
+    /// This is a shortcut for [`String::as_bytes()`].
+    #[inline]
+    pub fn as_bytes(&self) -> &[u8] {
+        let s = self.to_ref();
+        // Reattach lifetime to &self
+        unsafe { std::mem::transmute(s.as_bytes()) }
+    }
+}
+
+#[cfg(feature = "unstable")]
+impl fmt::Debug for OwnedString {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.to_ref().fmt(f)
+    }
+}
+
+#[cfg(test)]
+mod assertions {
+    use super::*;
+
+    static_assertions::assert_not_impl_any!(String: Send);
+}

src/thread.rs

@@ -1,32 +1,32 @@
-use std::cmp;
-use std::os::raw::c_int;
+use std::os::raw::{c_int, c_void};
 
 use crate::error::{Error, Result};
-use crate::ffi;
+#[allow(unused)]
+use crate::lua::Lua;
 use crate::types::LuaRef;
-use crate::util::{check_stack, error_traceback, pop_error, StackGuard};
-use crate::value::{FromLuaMulti, ToLuaMulti};
+use crate::util::{check_stack, error_traceback_thread, pop_error, StackGuard};
+use crate::value::{FromLuaMulti, IntoLuaMulti};
 
-#[cfg(any(feature = "lua54", all(feature = "luajit", feature = "vendored")))]
-use crate::function::Function;
+#[cfg(not(feature = "luau"))]
+use crate::{
+    hook::{Debug, HookTriggers},
+    types::MaybeSend,
+};
 
 #[cfg(feature = "async")]
 use {
-    crate::{
-        lua::{Lua, ASYNC_POLL_PENDING},
-        value::{MultiValue, Value},
-    },
-    futures_core::{future::Future, stream::Stream},
+    crate::value::MultiValue,
+    futures_util::stream::Stream,
     std::{
-        cell::RefCell,
+        future::Future,
         marker::PhantomData,
-        os::raw::c_void,
         pin::Pin,
+        ptr::NonNull,
         task::{Context, Poll, Waker},
     },
 };
 
-/// Status of a Lua thread (or coroutine).
+/// Status of a Lua thread (coroutine).
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub enum ThreadStatus {
     /// The thread was just created, or is suspended because it has called `coroutine.yield`.
@@ -41,27 +41,61 @@ pub enum ThreadStatus {
     Error,
 }
 
-/// Handle to an internal Lua thread (or coroutine).
+/// Handle to an internal Lua thread (coroutine).
 #[derive(Clone, Debug)]
-pub struct Thread<'lua>(pub(crate) LuaRef<'lua>);
+pub struct Thread<'lua>(pub(crate) LuaRef<'lua>, pub(crate) *mut ffi::lua_State);
+
+/// Owned handle to an internal Lua thread (coroutine).
+///
+/// The owned handle holds a *strong* reference to the current Lua instance.
+/// Be warned, if you place it into a Lua type (eg. [`UserData`] or a Rust callback), it is *very easy*
+/// to accidentally cause reference cycles that would prevent destroying Lua instance.
+///
+/// [`UserData`]: crate::UserData
+#[cfg(feature = "unstable")]
+#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
+#[derive(Clone, Debug)]
+pub struct OwnedThread(
+    pub(crate) crate::types::LuaOwnedRef,
+    pub(crate) *mut ffi::lua_State,
+);
+
+#[cfg(feature = "unstable")]
+impl OwnedThread {
+    /// Get borrowed handle to the underlying Lua table.
+    #[cfg_attr(feature = "send", allow(unused))]
+    pub const fn to_ref(&self) -> Thread {
+        Thread(self.0.to_ref(), self.1)
+    }
+}
 
 /// Thread (coroutine) representation as an async [`Future`] or [`Stream`].
 ///
 /// Requires `feature = "async"`
 ///
-/// [`Future`]: futures_core::future::Future
-/// [`Stream`]: futures_core::stream::Stream
+/// [`Future`]: std::future::Future
+/// [`Stream`]: futures_util::stream::Stream
 #[cfg(feature = "async")]
 #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
-#[derive(Debug)]
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct AsyncThread<'lua, R> {
     thread: Thread<'lua>,
-    args0: RefCell<Option<Result<MultiValue<'lua>>>>,
+    init_args: Option<Result<MultiValue<'lua>>>,
     ret: PhantomData<R>,
     recycle: bool,
 }
 
 impl<'lua> Thread<'lua> {
+    #[inline(always)]
+    pub(crate) fn new(r#ref: LuaRef<'lua>) -> Self {
+        let state = unsafe { ffi::lua_tothread(r#ref.lua.ref_thread(), r#ref.index) };
+        Thread(r#ref, state)
+    }
+
+    const fn state(&self) -> *mut ffi::lua_State {
+        self.1
+    }
+
     /// Resumes execution of this thread.
     ///
     /// Equivalent to `coroutine.resume`.
@@ -105,57 +139,68 @@ impl<'lua> Thread<'lua> {
     /// ```
     pub fn resume<A, R>(&self, args: A) -> Result<R>
     where
-        A: ToLuaMulti<'lua>,
+        A: IntoLuaMulti<'lua>,
         R: FromLuaMulti<'lua>,
     {
+        if self.status() != ThreadStatus::Resumable {
+            return Err(Error::CoroutineInactive);
+        }
+
         let lua = self.0.lua;
-        let mut args = args.to_lua_multi(lua)?;
-        let nargs = args.len() as c_int;
-        let results = unsafe {
-            let _sg = StackGuard::new(lua.state);
-            check_stack(lua.state, cmp::max(nargs + 1, 3))?;
+        let state = lua.state();
+        let thread_state = self.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            let _thread_sg = StackGuard::with_top(thread_state, 0);
 
-            let thread_state =
-                lua.ref_thread_exec(|ref_thread| ffi::lua_tothread(ref_thread, self.0.index));
+            let nresults = self.resume_inner(args)?;
+            check_stack(state, nresults + 1)?;
+            ffi::lua_xmove(thread_state, state, nresults);
 
-            let status = ffi::lua_status(thread_state);
-            if status != ffi::LUA_YIELD && ffi::lua_gettop(thread_state) == 0 {
-                return Err(Error::CoroutineInactive);
-            }
+            R::from_stack_multi(nresults, lua)
+        }
+    }
 
+    /// Resumes execution of this thread.
+    ///
+    /// It's similar to `resume()` but leaves `nresults` values on the thread stack.
+    unsafe fn resume_inner<A: IntoLuaMulti<'lua>>(&self, args: A) -> Result<c_int> {
+        let lua = self.0.lua;
+        let state = lua.state();
+        let thread_state = self.state();
+
+        let nargs = args.push_into_stack_multi(lua)?;
+        if nargs > 0 {
             check_stack(thread_state, nargs)?;
-            for arg in args.drain_all() {
-                lua.push_value(arg)?;
-            }
-            ffi::lua_xmove(lua.state, thread_state, nargs);
+            ffi::lua_xmove(state, thread_state, nargs);
+        }
 
-            let mut nresults = 0;
-
-            let ret = ffi::lua_resume(thread_state, lua.state, nargs, &mut nresults as *mut c_int);
-            if ret != ffi::LUA_OK && ret != ffi::LUA_YIELD {
-                protect_lua!(lua.state, 0, 0, |_| error_traceback(thread_state))?;
+        let mut nresults = 0;
+        let ret = ffi::lua_resume(thread_state, state, nargs, &mut nresults as *mut c_int);
+        if ret != ffi::LUA_OK && ret != ffi::LUA_YIELD {
+            if ret == ffi::LUA_ERRMEM {
+                // Don't call error handler for memory errors
                 return Err(pop_error(thread_state, ret));
             }
+            check_stack(state, 3)?;
+            protect_lua!(state, 0, 1, |state| error_traceback_thread(
+                state,
+                thread_state
+            ))?;
+            return Err(pop_error(state, ret));
+        }
 
-            let mut results = args; // Reuse MultiValue container
-            check_stack(lua.state, nresults + 2)?; // 2 is extra for `lua.pop_value()` below
-            ffi::lua_xmove(thread_state, lua.state, nresults);
-
-            for _ in 0..nresults {
-                results.push_front(lua.pop_value());
-            }
-            results
-        };
-        R::from_lua_multi(results, lua)
+        Ok(nresults)
     }
 
     /// Gets the status of the thread.
     pub fn status(&self) -> ThreadStatus {
-        let lua = self.0.lua;
+        let thread_state = self.state();
+        if thread_state == self.0.lua.state() {
+            // The coroutine is currently running
+            return ThreadStatus::Unresumable;
+        }
         unsafe {
-            let thread_state =
-                lua.ref_thread_exec(|ref_thread| ffi::lua_tothread(ref_thread, self.0.index));
-
             let status = ffi::lua_status(thread_state);
             if status != ffi::LUA_OK && status != ffi::LUA_YIELD {
                 ThreadStatus::Error
@@ -167,38 +212,65 @@ impl<'lua> Thread<'lua> {
         }
     }
 
+    /// Sets a 'hook' function that will periodically be called as Lua code executes.
+    ///
+    /// This function is similar or [`Lua::set_hook()`] except that it sets for the thread.
+    /// To remove a hook call [`Lua::remove_hook()`].
+    #[cfg(not(feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(not(feature = "luau"))))]
+    pub fn set_hook<F>(&self, triggers: HookTriggers, callback: F)
+    where
+        F: Fn(&Lua, Debug) -> Result<()> + MaybeSend + 'static,
+    {
+        let lua = self.0.lua;
+        unsafe {
+            lua.set_thread_hook(self.state(), triggers, callback);
+        }
+    }
+
     /// Resets a thread
     ///
     /// In [Lua 5.4]: cleans its call stack and closes all pending to-be-closed variables.
     /// Returns a error in case of either the original error that stopped the thread or errors
     /// in closing methods.
     ///
-    /// In [LuaJIT]: resets to the initial state of a newly created Lua thread.
+    /// In Luau: resets to the initial state of a newly created Lua thread.
     /// Lua threads in arbitrary states (like yielded or errored) can be reset properly.
     ///
     /// Sets a Lua function for the thread afterwards.
     ///
-    /// Requires `feature = "lua54"` OR `feature = "luajit,vendored"`
+    /// Requires `feature = "lua54"` OR `feature = "luau"`.
     ///
-    /// [Lua 5.4]: https://www.lua.org/manual/5.4/manual.html#lua_resetthread
-    /// [LuaJIT]: https://github.com/openresty/luajit2#lua_resetthread
-    #[cfg(any(feature = "lua54", all(feature = "luajit", feature = "vendored")))]
-    pub fn reset(&self, func: Function<'lua>) -> Result<()> {
+    /// [Lua 5.4]: https://www.lua.org/manual/5.4/manual.html#lua_closethread
+    #[cfg(any(feature = "lua54", feature = "luau"))]
+    #[cfg_attr(docsrs, doc(cfg(any(feature = "lua54", feature = "luau"))))]
+    pub fn reset(&self, func: crate::function::Function<'lua>) -> Result<()> {
         let lua = self.0.lua;
+        let thread_state = self.state();
+        if thread_state == lua.state() {
+            return Err(Error::runtime("cannot reset a running thread"));
+        }
         unsafe {
-            let _sg = StackGuard::new(lua.state);
-            check_stack(lua.state, 2)?;
-
-            lua.push_ref(&self.0);
-            let thread_state = ffi::lua_tothread(lua.state, -1);
-
-            let ret = ffi::lua_resetthread(lua.state, thread_state);
-            if ret != ffi::LUA_OK {
-                return Err(pop_error(thread_state, ret));
+            #[cfg(all(feature = "lua54", not(feature = "vendored")))]
+            let status = ffi::lua_resetthread(thread_state);
+            #[cfg(all(feature = "lua54", feature = "vendored"))]
+            let status = ffi::lua_closethread(thread_state, lua.state());
+            #[cfg(feature = "lua54")]
+            if status != ffi::LUA_OK {
+                return Err(pop_error(thread_state, status));
             }
+            #[cfg(feature = "luau")]
+            ffi::lua_resetthread(thread_state);
 
-            lua.push_ref(&func.0);
-            ffi::lua_xmove(lua.state, thread_state, 1);
+            // Push function to the top of the thread stack
+            ffi::lua_xpush(lua.ref_thread(), thread_state, func.0.index);
+
+            #[cfg(feature = "luau")]
+            {
+                // Inherit `LUA_GLOBALSINDEX` from the main thread
+                ffi::lua_xpush(lua.main_state(), thread_state, ffi::LUA_GLOBALSINDEX);
+                ffi::lua_replace(thread_state, ffi::LUA_GLOBALSINDEX);
+            }
 
             Ok(())
         }
@@ -216,8 +288,8 @@ impl<'lua> Thread<'lua> {
     ///
     /// Requires `feature = "async"`
     ///
-    /// [`Future`]: futures_core::future::Future
-    /// [`Stream`]: futures_core::stream::Stream
+    /// [`Future`]: std::future::Future
+    /// [`Stream`]: futures_util::stream::Stream
     /// [`resume()`]: https://www.lua.org/manual/5.4/manual.html#lua_resume
     ///
     /// # Examples
@@ -253,17 +325,80 @@ impl<'lua> Thread<'lua> {
     #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
     pub fn into_async<A, R>(self, args: A) -> AsyncThread<'lua, R>
     where
-        A: ToLuaMulti<'lua>,
+        A: IntoLuaMulti<'lua>,
         R: FromLuaMulti<'lua>,
     {
-        let args = args.to_lua_multi(self.0.lua);
+        let args = args.into_lua_multi(self.0.lua);
         AsyncThread {
             thread: self,
-            args0: RefCell::new(Some(args)),
+            init_args: Some(args),
             ret: PhantomData,
             recycle: false,
         }
     }
+
+    /// Enables sandbox mode on this thread.
+    ///
+    /// Under the hood replaces the global environment table with a new table,
+    /// that performs writes locally and proxies reads to caller's global environment.
+    ///
+    /// This mode ideally should be used together with the global sandbox mode [`Lua::sandbox()`].
+    ///
+    /// Please note that Luau links environment table with chunk when loading it into Lua state.
+    /// Therefore you need to load chunks into a thread to link with the thread environment.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use mlua::{Lua, Result};
+    /// # fn main() -> Result<()> {
+    /// let lua = Lua::new();
+    /// let thread = lua.create_thread(lua.create_function(|lua2, ()| {
+    ///     lua2.load("var = 123").exec()?;
+    ///     assert_eq!(lua2.globals().get::<_, u32>("var")?, 123);
+    ///     Ok(())
+    /// })?)?;
+    /// thread.sandbox()?;
+    /// thread.resume(())?;
+    ///
+    /// // The global environment should be unchanged
+    /// assert_eq!(lua.globals().get::<_, Option<u32>>("var")?, None);
+    /// # Ok(())
+    /// # }
+    /// ```
+    ///
+    /// Requires `feature = "luau"`
+    #[cfg(any(feature = "luau", docsrs))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    #[doc(hidden)]
+    pub fn sandbox(&self) -> Result<()> {
+        let lua = self.0.lua;
+        let state = lua.state();
+        let thread_state = self.state();
+        unsafe {
+            check_stack(thread_state, 3)?;
+            check_stack(state, 3)?;
+            protect_lua!(state, 0, 0, |_| ffi::luaL_sandboxthread(thread_state))
+        }
+    }
+
+    /// Converts this thread to a generic C pointer.
+    ///
+    /// There is no way to convert the pointer back to its original value.
+    ///
+    /// Typically this function is used only for hashing and debug information.
+    #[inline]
+    pub fn to_pointer(&self) -> *const c_void {
+        self.0.to_pointer()
+    }
+
+    /// Convert this handle to owned version.
+    #[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
+    #[inline]
+    pub fn into_owned(self) -> OwnedThread {
+        OwnedThread(self.0.into_owned(), self.1)
+    }
 }
 
 impl<'lua> PartialEq for Thread<'lua> {
@@ -272,6 +407,26 @@ impl<'lua> PartialEq for Thread<'lua> {
     }
 }
 
+// Additional shortcuts
+#[cfg(feature = "unstable")]
+impl OwnedThread {
+    /// Resumes execution of this thread.
+    ///
+    /// See [`Thread::resume()`] for more details.
+    pub fn resume<'lua, A, R>(&'lua self, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>,
+    {
+        self.to_ref().resume(args)
+    }
+
+    /// Gets the status of the thread.
+    pub fn status(&self) -> ThreadStatus {
+        self.to_ref().status()
+    }
+}
+
 #[cfg(feature = "async")]
 impl<'lua, R> AsyncThread<'lua, R> {
     #[inline]
@@ -281,11 +436,23 @@ impl<'lua, R> AsyncThread<'lua, R> {
 }
 
 #[cfg(feature = "async")]
-#[cfg(any(feature = "lua54", all(feature = "luajit", feature = "vendored")))]
+#[cfg(any(feature = "lua54", feature = "luau"))]
 impl<'lua, R> Drop for AsyncThread<'lua, R> {
     fn drop(&mut self) {
         if self.recycle {
-            self.thread.0.lua.recycle_thread(&mut self.thread);
+            unsafe {
+                let lua = self.thread.0.lua;
+                // For Lua 5.4 this also closes all pending to-be-closed variables
+                if !lua.recycle_thread(&mut self.thread) {
+                    #[cfg(feature = "lua54")]
+                    if self.thread.status() == ThreadStatus::Error {
+                        #[cfg(not(feature = "vendored"))]
+                        ffi::lua_resetthread(self.thread.state());
+                        #[cfg(feature = "vendored")]
+                        ffi::lua_closethread(self.thread.state(), lua.state());
+                    }
+                }
+            }
         }
     }
 }
@@ -298,26 +465,36 @@ where
     type Item = Result<R>;
 
     fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        let lua = self.thread.0.lua;
-
-        match self.thread.status() {
-            ThreadStatus::Resumable => {}
-            _ => return Poll::Ready(None),
-        };
-
-        let _wg = WakerGuard::new(lua, cx.waker().clone());
-        let ret: MultiValue = if let Some(args) = self.args0.borrow_mut().take() {
-            self.thread.resume(args?)?
-        } else {
-            self.thread.resume(())?
-        };
-
-        if is_poll_pending(&ret) {
-            return Poll::Pending;
+        if self.thread.status() != ThreadStatus::Resumable {
+            return Poll::Ready(None);
         }
 
-        cx.waker().wake_by_ref();
-        Poll::Ready(Some(R::from_lua_multi(ret, lua)))
+        let lua = self.thread.0.lua;
+        let state = lua.state();
+        let thread_state = self.thread.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            let _thread_sg = StackGuard::with_top(thread_state, 0);
+            let _wg = WakerGuard::new(lua, cx.waker());
+
+            // This is safe as we are not moving the whole struct
+            let this = self.get_unchecked_mut();
+            let nresults = if let Some(args) = this.init_args.take() {
+                this.thread.resume_inner(args?)?
+            } else {
+                this.thread.resume_inner(())?
+            };
+
+            if nresults == 1 && is_poll_pending(thread_state) {
+                return Poll::Pending;
+            }
+
+            check_stack(state, nresults + 1)?;
+            ffi::lua_xmove(thread_state, state, nresults);
+
+            cx.waker().wake_by_ref();
+            Poll::Ready(Some(R::from_stack_multi(nresults, lua)))
+        }
     }
 }
 
@@ -329,67 +506,80 @@ where
     type Output = Result<R>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        if self.thread.status() != ThreadStatus::Resumable {
+            return Poll::Ready(Err(Error::CoroutineInactive));
+        }
+
         let lua = self.thread.0.lua;
+        let state = lua.state();
+        let thread_state = self.thread.state();
+        unsafe {
+            let _sg = StackGuard::new(state);
+            let _thread_sg = StackGuard::with_top(thread_state, 0);
+            let _wg = WakerGuard::new(lua, cx.waker());
 
-        match self.thread.status() {
-            ThreadStatus::Resumable => {}
-            _ => return Poll::Ready(Err(Error::CoroutineInactive)),
-        };
+            // This is safe as we are not moving the whole struct
+            let this = self.get_unchecked_mut();
+            let nresults = if let Some(args) = this.init_args.take() {
+                this.thread.resume_inner(args?)?
+            } else {
+                this.thread.resume_inner(())?
+            };
 
-        let _wg = WakerGuard::new(lua, cx.waker().clone());
-        let ret: MultiValue = if let Some(args) = self.args0.borrow_mut().take() {
-            self.thread.resume(args?)?
-        } else {
-            self.thread.resume(())?
-        };
+            if nresults == 1 && is_poll_pending(thread_state) {
+                return Poll::Pending;
+            }
 
-        if is_poll_pending(&ret) {
-            return Poll::Pending;
+            if ffi::lua_status(thread_state) == ffi::LUA_YIELD {
+                // Ignore value returned via yield()
+                cx.waker().wake_by_ref();
+                return Poll::Pending;
+            }
+
+            check_stack(state, nresults + 1)?;
+            ffi::lua_xmove(thread_state, state, nresults);
+
+            Poll::Ready(R::from_stack_multi(nresults, lua))
         }
-
-        if let ThreadStatus::Resumable = self.thread.status() {
-            // Ignore value returned via yield()
-            cx.waker().wake_by_ref();
-            return Poll::Pending;
-        }
-
-        Poll::Ready(R::from_lua_multi(ret, lua))
     }
 }
 
 #[cfg(feature = "async")]
 #[inline(always)]
-fn is_poll_pending(val: &MultiValue) -> bool {
-    match val.iter().enumerate().last() {
-        Some((0, Value::LightUserData(ud))) => {
-            ud.0 == &ASYNC_POLL_PENDING as *const u8 as *mut c_void
-        }
-        _ => false,
-    }
+unsafe fn is_poll_pending(state: *mut ffi::lua_State) -> bool {
+    ffi::lua_tolightuserdata(state, -1) == Lua::poll_pending().0
 }
 
 #[cfg(feature = "async")]
-struct WakerGuard<'lua> {
+struct WakerGuard<'lua, 'a> {
     lua: &'lua Lua,
-    prev: Option<Waker>,
+    prev: NonNull<Waker>,
+    _phantom: PhantomData<&'a ()>,
 }
 
 #[cfg(feature = "async")]
-impl<'lua> WakerGuard<'lua> {
+impl<'lua, 'a> WakerGuard<'lua, 'a> {
     #[inline]
-    pub fn new(lua: &Lua, waker: Waker) -> Result<WakerGuard> {
-        unsafe {
-            let prev = lua.set_waker(Some(waker));
-            Ok(WakerGuard { lua, prev })
-        }
+    pub fn new(lua: &'lua Lua, waker: &'a Waker) -> Result<WakerGuard<'lua, 'a>> {
+        let prev = unsafe { lua.set_waker(NonNull::from(waker)) };
+        Ok(WakerGuard {
+            lua,
+            prev,
+            _phantom: PhantomData,
+        })
     }
 }
 
 #[cfg(feature = "async")]
-impl<'lua> Drop for WakerGuard<'lua> {
+impl<'lua, 'a> Drop for WakerGuard<'lua, 'a> {
     fn drop(&mut self) {
-        unsafe {
-            self.lua.set_waker(self.prev.take());
-        }
+        unsafe { self.lua.set_waker(self.prev) };
     }
 }
+
+#[cfg(test)]
+mod assertions {
+    use super::*;
+
+    static_assertions::assert_not_impl_any!(Thread: Send);
+}

src/types.rs

@@ -1,65 +1,92 @@
+use std::any::{Any, TypeId};
+use std::cell::{Cell, Ref, RefCell, RefMut, UnsafeCell};
 use std::hash::{Hash, Hasher};
+use std::ops::{Deref, DerefMut};
 use std::os::raw::{c_int, c_void};
+use std::result::Result as StdResult;
+use std::sync::atomic::{AtomicI32, Ordering};
 use std::sync::{Arc, Mutex};
 use std::{fmt, mem, ptr};
 
-#[cfg(feature = "lua54")]
-use std::ffi::CStr;
-
-#[cfg(feature = "async")]
-use futures_core::future::LocalBoxFuture;
+use rustc_hash::FxHashMap;
 
 use crate::error::Result;
-use crate::ffi;
+#[cfg(not(feature = "luau"))]
 use crate::hook::Debug;
-use crate::lua::Lua;
-use crate::util::{assert_stack, StackGuard};
-use crate::value::MultiValue;
+use crate::lua::{ExtraData, Lua};
+
+#[cfg(feature = "async")]
+use {crate::value::MultiValue, futures_util::future::LocalBoxFuture};
+
+#[cfg(feature = "unstable")]
+use {crate::lua::LuaInner, std::marker::PhantomData};
+
+#[cfg(all(feature = "luau", feature = "serialize"))]
+use serde::ser::{Serialize, SerializeTupleStruct, Serializer};
 
 /// Type of Lua integer numbers.
 pub type Integer = ffi::lua_Integer;
 /// Type of Lua floating point numbers.
 pub type Number = ffi::lua_Number;
 
+// Represents different subtypes wrapped to AnyUserData
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub(crate) enum SubtypeId {
+    None,
+    #[cfg(feature = "luau")]
+    Buffer,
+    #[cfg(feature = "luajit")]
+    CData,
+}
+
 /// A "light" userdata value. Equivalent to an unmanaged raw pointer.
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct LightUserData(pub *mut c_void);
 
-pub(crate) type Callback<'lua, 'a> =
-    Box<dyn Fn(&'lua Lua, MultiValue<'lua>) -> Result<MultiValue<'lua>> + 'a>;
+pub(crate) type Callback<'lua, 'a> = Box<dyn Fn(&'lua Lua, c_int) -> Result<c_int> + 'a>;
 
-pub(crate) struct CallbackUpvalue<'lua> {
-    pub(crate) lua: Lua,
-    pub(crate) func: Callback<'lua, 'static>,
+pub(crate) struct Upvalue<T> {
+    pub(crate) data: T,
+    pub(crate) extra: Arc<UnsafeCell<ExtraData>>,
 }
 
+pub(crate) type CallbackUpvalue = Upvalue<Callback<'static, 'static>>;
+
 #[cfg(feature = "async")]
 pub(crate) type AsyncCallback<'lua, 'a> =
-    Box<dyn Fn(&'lua Lua, MultiValue<'lua>) -> LocalBoxFuture<'lua, Result<MultiValue<'lua>>> + 'a>;
+    Box<dyn Fn(&'lua Lua, MultiValue<'lua>) -> LocalBoxFuture<'lua, Result<c_int>> + 'a>;
 
 #[cfg(feature = "async")]
-pub(crate) struct AsyncCallbackUpvalue<'lua> {
-    pub(crate) lua: Lua,
-    pub(crate) func: AsyncCallback<'lua, 'static>,
-}
+pub(crate) type AsyncCallbackUpvalue = Upvalue<AsyncCallback<'static, 'static>>;
 
 #[cfg(feature = "async")]
-pub(crate) struct AsyncPollUpvalue<'lua> {
-    pub(crate) lua: Lua,
-    pub(crate) fut: LocalBoxFuture<'lua, Result<MultiValue<'lua>>>,
+pub(crate) type AsyncPollUpvalue = Upvalue<LocalBoxFuture<'static, Result<c_int>>>;
+
+/// Type to set next Luau VM action after executing interrupt function.
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+pub enum VmState {
+    Continue,
+    Yield,
 }
 
-#[cfg(feature = "send")]
-pub(crate) type HookCallback = Arc<Mutex<dyn FnMut(&Lua, Debug) -> Result<()> + Send>>;
+#[cfg(all(feature = "send", not(feature = "luau")))]
+pub(crate) type HookCallback = Arc<dyn Fn(&Lua, Debug) -> Result<()> + Send>;
 
-#[cfg(not(feature = "send"))]
-pub(crate) type HookCallback = Arc<Mutex<dyn FnMut(&Lua, Debug) -> Result<()>>>;
+#[cfg(all(not(feature = "send"), not(feature = "luau")))]
+pub(crate) type HookCallback = Arc<dyn Fn(&Lua, Debug) -> Result<()>>;
+
+#[cfg(all(feature = "luau", feature = "send"))]
+pub(crate) type InterruptCallback = Arc<dyn Fn(&Lua) -> Result<VmState> + Send>;
+
+#[cfg(all(feature = "luau", not(feature = "send")))]
+pub(crate) type InterruptCallback = Arc<dyn Fn(&Lua) -> Result<VmState>>;
 
 #[cfg(all(feature = "send", feature = "lua54"))]
-pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &CStr, bool) -> Result<()> + Send>;
+pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &str, bool) -> Result<()> + Send>;
 
 #[cfg(all(not(feature = "send"), feature = "lua54"))]
-pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &CStr, bool) -> Result<()>>;
+pub(crate) type WarnCallback = Box<dyn Fn(&Lua, &str, bool) -> Result<()>>;
 
 #[cfg(feature = "send")]
 pub trait MaybeSend: Send {}
@@ -71,7 +98,93 @@ pub trait MaybeSend {}
 #[cfg(not(feature = "send"))]
 impl<T> MaybeSend for T {}
 
-pub(crate) struct DestructedUserdataMT;
+/// A Luau vector type.
+///
+/// By default vectors are 3-dimensional, but can be 4-dimensional
+/// if the `luau-vector4` feature is enabled.
+#[cfg(any(feature = "luau", doc))]
+#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+#[derive(Debug, Default, Clone, Copy, PartialEq)]
+pub struct Vector(pub(crate) [f32; Self::SIZE]);
+
+#[cfg(any(feature = "luau", doc))]
+impl fmt::Display for Vector {
+    #[rustfmt::skip]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        #[cfg(not(feature = "luau-vector4"))]
+        return write!(f, "vector({}, {}, {})", self.x(), self.y(), self.z());
+        #[cfg(feature = "luau-vector4")]
+        return write!(f, "vector({}, {}, {}, {})", self.x(), self.y(), self.z(), self.w());
+    }
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl Vector {
+    pub(crate) const SIZE: usize = if cfg!(feature = "luau-vector4") { 4 } else { 3 };
+
+    /// Creates a new vector.
+    #[cfg(not(feature = "luau-vector4"))]
+    pub const fn new(x: f32, y: f32, z: f32) -> Self {
+        Self([x, y, z])
+    }
+
+    /// Creates a new vector.
+    #[cfg(feature = "luau-vector4")]
+    pub const fn new(x: f32, y: f32, z: f32, w: f32) -> Self {
+        Self([x, y, z, w])
+    }
+
+    /// Creates a new vector with all components set to `0.0`.
+    #[doc(hidden)]
+    pub const fn zero() -> Self {
+        Self([0.0; Self::SIZE])
+    }
+
+    /// Returns 1st component of the vector.
+    pub const fn x(&self) -> f32 {
+        self.0[0]
+    }
+
+    /// Returns 2nd component of the vector.
+    pub const fn y(&self) -> f32 {
+        self.0[1]
+    }
+
+    /// Returns 3rd component of the vector.
+    pub const fn z(&self) -> f32 {
+        self.0[2]
+    }
+
+    /// Returns 4th component of the vector.
+    #[cfg(any(feature = "luau-vector4", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau-vector4")))]
+    pub const fn w(&self) -> f32 {
+        self.0[3]
+    }
+}
+
+#[cfg(all(feature = "luau", feature = "serialize"))]
+impl Serialize for Vector {
+    fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
+        let mut ts = serializer.serialize_tuple_struct("Vector", Self::SIZE)?;
+        ts.serialize_field(&self.x())?;
+        ts.serialize_field(&self.y())?;
+        ts.serialize_field(&self.z())?;
+        #[cfg(feature = "luau-vector4")]
+        ts.serialize_field(&self.w())?;
+        ts.end()
+    }
+}
+
+#[cfg(any(feature = "luau", doc))]
+impl PartialEq<[f32; Self::SIZE]> for Vector {
+    #[inline]
+    fn eq(&self, other: &[f32; Self::SIZE]) -> bool {
+        self.0 == *other
+    }
+}
+
+pub(crate) struct DestructedUserdata;
 
 /// An auto generated key into the Lua registry.
 ///
@@ -82,34 +195,34 @@ pub(crate) struct DestructedUserdataMT;
 /// Be warned, If you place this into Lua via a [`UserData`] type or a rust callback, it is *very
 /// easy* to accidentally cause reference cycles that the Lua garbage collector cannot resolve.
 /// Instead of placing a [`RegistryKey`] into a [`UserData`] type, prefer instead to use
-/// [`AnyUserData::set_user_value`] / [`AnyUserData::get_user_value`].
+/// [`AnyUserData::set_user_value`] / [`AnyUserData::user_value`].
 ///
 /// [`UserData`]: crate::UserData
 /// [`RegistryKey`]: crate::RegistryKey
 /// [`Lua::remove_registry_value`]: crate::Lua::remove_registry_value
 /// [`Lua::expire_registry_values`]: crate::Lua::expire_registry_values
 /// [`AnyUserData::set_user_value`]: crate::AnyUserData::set_user_value
-/// [`AnyUserData::get_user_value`]: crate::AnyUserData::get_user_value
+/// [`AnyUserData::user_value`]: crate::AnyUserData::user_value
 pub struct RegistryKey {
-    pub(crate) registry_id: c_int,
+    pub(crate) registry_id: AtomicI32,
     pub(crate) unref_list: Arc<Mutex<Option<Vec<c_int>>>>,
 }
 
 impl fmt::Debug for RegistryKey {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "RegistryKey({})", self.registry_id)
+        write!(f, "RegistryKey({})", self.id())
     }
 }
 
 impl Hash for RegistryKey {
     fn hash<H: Hasher>(&self, state: &mut H) {
-        self.registry_id.hash(state)
+        self.id().hash(state)
     }
 }
 
 impl PartialEq for RegistryKey {
     fn eq(&self, other: &RegistryKey) -> bool {
-        self.registry_id == other.registry_id && Arc::ptr_eq(&self.unref_list, &other.unref_list)
+        self.id() == other.id() && Arc::ptr_eq(&self.unref_list, &other.unref_list)
     }
 }
 
@@ -117,17 +230,41 @@ impl Eq for RegistryKey {}
 
 impl Drop for RegistryKey {
     fn drop(&mut self) {
-        let mut unref_list = mlua_expect!(self.unref_list.lock(), "unref list poisoned");
-        if let Some(list) = unref_list.as_mut() {
-            list.push(self.registry_id);
+        let registry_id = self.id();
+        // We don't need to collect nil slot
+        if registry_id > ffi::LUA_REFNIL {
+            let mut unref_list = mlua_expect!(self.unref_list.lock(), "unref list poisoned");
+            if let Some(list) = unref_list.as_mut() {
+                list.push(registry_id);
+            }
         }
     }
 }
 
 impl RegistryKey {
-    // Destroys the RegistryKey without adding to the drop list
-    pub(crate) fn take(self) -> c_int {
-        let registry_id = self.registry_id;
+    /// Creates a new instance of `RegistryKey`
+    pub(crate) const fn new(id: c_int, unref_list: Arc<Mutex<Option<Vec<c_int>>>>) -> Self {
+        RegistryKey {
+            registry_id: AtomicI32::new(id),
+            unref_list,
+        }
+    }
+
+    /// Returns the underlying Lua reference of this `RegistryKey`
+    #[inline(always)]
+    pub fn id(&self) -> c_int {
+        self.registry_id.load(Ordering::Relaxed)
+    }
+
+    /// Sets the unique Lua reference key of this `RegistryKey`
+    #[inline(always)]
+    pub(crate) fn set_id(&self, id: c_int) {
+        self.registry_id.store(id, Ordering::Relaxed);
+    }
+
+    /// Destroys the `RegistryKey` without adding to the unref list
+    pub(crate) fn take(self) -> i32 {
+        let registry_id = self.id();
         unsafe {
             ptr::read(&self.unref_list);
             mem::forget(self);
@@ -139,11 +276,36 @@ impl RegistryKey {
 pub(crate) struct LuaRef<'lua> {
     pub(crate) lua: &'lua Lua,
     pub(crate) index: c_int,
+    pub(crate) drop: bool,
+}
+
+impl<'lua> LuaRef<'lua> {
+    pub(crate) const fn new(lua: &'lua Lua, index: c_int) -> Self {
+        LuaRef {
+            lua,
+            index,
+            drop: true,
+        }
+    }
+
+    #[inline]
+    pub(crate) fn to_pointer(&self) -> *const c_void {
+        unsafe { ffi::lua_topointer(self.lua.ref_thread(), self.index) }
+    }
+
+    #[cfg(feature = "unstable")]
+    #[inline]
+    pub(crate) fn into_owned(self) -> LuaOwnedRef {
+        assert!(self.drop, "Cannot turn non-drop reference into owned");
+        let owned_ref = LuaOwnedRef::new(self.lua.clone(), self.index);
+        mem::forget(self);
+        owned_ref
+    }
 }
 
 impl<'lua> fmt::Debug for LuaRef<'lua> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "Ref({})", self.index)
+        write!(f, "Ref({:p})", self.to_pointer())
     }
 }
 
@@ -155,21 +317,222 @@ impl<'lua> Clone for LuaRef<'lua> {
 
 impl<'lua> Drop for LuaRef<'lua> {
     fn drop(&mut self) {
-        if self.index > 0 {
-            self.lua.drop_ref(self);
+        if self.drop {
+            self.lua.drop_ref_index(self.index);
         }
     }
 }
 
 impl<'lua> PartialEq for LuaRef<'lua> {
     fn eq(&self, other: &Self) -> bool {
-        let lua = self.lua;
-        unsafe {
-            let _sg = StackGuard::new(lua.state);
-            assert_stack(lua.state, 2);
-            lua.push_ref(self);
-            lua.push_ref(other);
-            ffi::lua_rawequal(lua.state, -1, -2) == 1
+        let ref_thread = self.lua.ref_thread();
+        assert!(
+            ref_thread == other.lua.ref_thread(),
+            "Lua instance passed Value created from a different main Lua state"
+        );
+        unsafe { ffi::lua_rawequal(ref_thread, self.index, other.index) == 1 }
+    }
+}
+
+#[cfg(feature = "unstable")]
+pub(crate) struct LuaOwnedRef {
+    pub(crate) inner: Arc<LuaInner>,
+    pub(crate) index: c_int,
+    _non_send: PhantomData<*const ()>,
+}
+
+#[cfg(feature = "unstable")]
+impl fmt::Debug for LuaOwnedRef {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "OwnedRef({:p})", self.to_ref().to_pointer())
+    }
+}
+
+#[cfg(feature = "unstable")]
+impl Clone for LuaOwnedRef {
+    fn clone(&self) -> Self {
+        self.to_ref().clone().into_owned()
+    }
+}
+
+#[cfg(feature = "unstable")]
+impl Drop for LuaOwnedRef {
+    fn drop(&mut self) {
+        let lua: &Lua = unsafe { mem::transmute(&self.inner) };
+        lua.drop_ref_index(self.index);
+    }
+}
+
+#[cfg(feature = "unstable")]
+impl LuaOwnedRef {
+    pub(crate) const fn new(inner: Arc<LuaInner>, index: c_int) -> Self {
+        LuaOwnedRef {
+            inner,
+            index,
+            _non_send: PhantomData,
+        }
+    }
+
+    pub(crate) const fn to_ref(&self) -> LuaRef {
+        LuaRef {
+            lua: unsafe { mem::transmute(&self.inner) },
+            index: self.index,
+            drop: false,
         }
     }
 }
+
+#[derive(Debug, Default)]
+pub(crate) struct AppData {
+    #[cfg(not(feature = "send"))]
+    container: UnsafeCell<FxHashMap<TypeId, RefCell<Box<dyn Any>>>>,
+    #[cfg(feature = "send")]
+    container: UnsafeCell<FxHashMap<TypeId, RefCell<Box<dyn Any + Send>>>>,
+    borrow: Cell<usize>,
+}
+
+impl AppData {
+    #[track_caller]
+    pub(crate) fn insert<T: MaybeSend + 'static>(&self, data: T) -> Option<T> {
+        match self.try_insert(data) {
+            Ok(data) => data,
+            Err(_) => panic!("cannot mutably borrow app data container"),
+        }
+    }
+
+    pub(crate) fn try_insert<T: MaybeSend + 'static>(&self, data: T) -> StdResult<Option<T>, T> {
+        if self.borrow.get() != 0 {
+            return Err(data);
+        }
+        // SAFETY: we checked that there are no other references to the container
+        Ok(unsafe { &mut *self.container.get() }
+            .insert(TypeId::of::<T>(), RefCell::new(Box::new(data)))
+            .and_then(|data| data.into_inner().downcast::<T>().ok().map(|data| *data)))
+    }
+
+    #[track_caller]
+    pub(crate) fn borrow<T: 'static>(&self) -> Option<AppDataRef<T>> {
+        let data = unsafe { &*self.container.get() }
+            .get(&TypeId::of::<T>())?
+            .borrow();
+        self.borrow.set(self.borrow.get() + 1);
+        Some(AppDataRef {
+            data: Ref::filter_map(data, |data| data.downcast_ref()).ok()?,
+            borrow: &self.borrow,
+        })
+    }
+
+    #[track_caller]
+    pub(crate) fn borrow_mut<T: 'static>(&self) -> Option<AppDataRefMut<T>> {
+        let data = unsafe { &*self.container.get() }
+            .get(&TypeId::of::<T>())?
+            .borrow_mut();
+        self.borrow.set(self.borrow.get() + 1);
+        Some(AppDataRefMut {
+            data: RefMut::filter_map(data, |data| data.downcast_mut()).ok()?,
+            borrow: &self.borrow,
+        })
+    }
+
+    #[track_caller]
+    pub(crate) fn remove<T: 'static>(&self) -> Option<T> {
+        if self.borrow.get() != 0 {
+            panic!("cannot mutably borrow app data container");
+        }
+        // SAFETY: we checked that there are no other references to the container
+        unsafe { &mut *self.container.get() }
+            .remove(&TypeId::of::<T>())?
+            .into_inner()
+            .downcast::<T>()
+            .ok()
+            .map(|data| *data)
+    }
+}
+
+/// A wrapper type for an immutably borrowed value from an app data container.
+///
+/// This type is similar to [`Ref`].
+pub struct AppDataRef<'a, T: ?Sized + 'a> {
+    data: Ref<'a, T>,
+    borrow: &'a Cell<usize>,
+}
+
+impl<T: ?Sized> Drop for AppDataRef<'_, T> {
+    fn drop(&mut self) {
+        self.borrow.set(self.borrow.get() - 1);
+    }
+}
+
+impl<T: ?Sized> Deref for AppDataRef<'_, T> {
+    type Target = T;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.data
+    }
+}
+
+impl<T: ?Sized + fmt::Display> fmt::Display for AppDataRef<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        (**self).fmt(f)
+    }
+}
+
+impl<T: ?Sized + fmt::Debug> fmt::Debug for AppDataRef<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        (**self).fmt(f)
+    }
+}
+
+/// A wrapper type for a mutably borrowed value from an app data container.
+///
+/// This type is similar to [`RefMut`].
+pub struct AppDataRefMut<'a, T: ?Sized + 'a> {
+    data: RefMut<'a, T>,
+    borrow: &'a Cell<usize>,
+}
+
+impl<T: ?Sized> Drop for AppDataRefMut<'_, T> {
+    fn drop(&mut self) {
+        self.borrow.set(self.borrow.get() - 1);
+    }
+}
+
+impl<T: ?Sized> Deref for AppDataRefMut<'_, T> {
+    type Target = T;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        &self.data
+    }
+}
+
+impl<T: ?Sized> DerefMut for AppDataRefMut<'_, T> {
+    #[inline]
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.data
+    }
+}
+
+impl<T: ?Sized + fmt::Display> fmt::Display for AppDataRefMut<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        (**self).fmt(f)
+    }
+}
+
+impl<T: ?Sized + fmt::Debug> fmt::Debug for AppDataRefMut<'_, T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        (**self).fmt(f)
+    }
+}
+
+#[cfg(test)]
+mod assertions {
+    use super::*;
+
+    static_assertions::assert_impl_all!(RegistryKey: Send, Sync);
+    static_assertions::assert_not_impl_any!(LuaRef: Send);
+
+    #[cfg(feature = "unstable")]
+    static_assertions::assert_not_impl_any!(LuaOwnedRef: Send);
+}

src/userdata_ext.rs

@@ -0,0 +1,190 @@
+use crate::error::{Error, Result};
+use crate::private::Sealed;
+use crate::userdata::{AnyUserData, MetaMethod};
+use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, Value};
+
+#[cfg(feature = "async")]
+use futures_util::future::{self, LocalBoxFuture};
+
+/// An extension trait for [`AnyUserData`] that provides a variety of convenient functionality.
+pub trait AnyUserDataExt<'lua>: Sealed {
+    /// Gets the value associated to `key` from the userdata, assuming it has `__index` metamethod.
+    fn get<K: IntoLua<'lua>, V: FromLua<'lua>>(&self, key: K) -> Result<V>;
+
+    /// Sets the value associated to `key` in the userdata, assuming it has `__newindex` metamethod.
+    fn set<K: IntoLua<'lua>, V: IntoLua<'lua>>(&self, key: K, value: V) -> Result<()>;
+
+    /// Calls the userdata as a function assuming it has `__call` metamethod.
+    ///
+    /// The metamethod is called with the userdata as its first argument, followed by the passed arguments.
+    fn call<A, R>(&self, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>;
+
+    /// Asynchronously calls the userdata as a function assuming it has `__call` metamethod.
+    ///
+    /// The metamethod is called with the userdata as its first argument, followed by the passed arguments.
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua;
+
+    /// Calls the userdata method, assuming it has `__index` metamethod
+    /// and a function associated to `name`.
+    fn call_method<A, R>(&self, name: &str, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>;
+
+    /// Gets the function associated to `key` from the table and asynchronously executes it,
+    /// passing the table itself along with `args` as function arguments and returning Future.
+    ///
+    /// Requires `feature = "async"`
+    ///
+    /// This might invoke the `__index` metamethod.
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    fn call_async_method<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua;
+
+    /// Gets the function associated to `key` from the table and executes it,
+    /// passing `args` as function arguments.
+    ///
+    /// This is a shortcut for
+    /// `table.get::<_, Function>(key)?.call(args)`
+    ///
+    /// This might invoke the `__index` metamethod.
+    fn call_function<A, R>(&self, name: &str, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>;
+
+    /// Gets the function associated to `key` from the table and asynchronously executes it,
+    /// passing `args` as function arguments and returning Future.
+    ///
+    /// Requires `feature = "async"`
+    ///
+    /// This might invoke the `__index` metamethod.
+    #[cfg(feature = "async")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "async")))]
+    fn call_async_function<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua;
+}
+
+impl<'lua> AnyUserDataExt<'lua> for AnyUserData<'lua> {
+    fn get<K: IntoLua<'lua>, V: FromLua<'lua>>(&self, key: K) -> Result<V> {
+        let metatable = self.get_metatable()?;
+        match metatable.get::<Value>(MetaMethod::Index)? {
+            Value::Table(table) => table.raw_get(key),
+            Value::Function(func) => func.call((self.clone(), key)),
+            _ => Err(Error::runtime("attempt to index a userdata value")),
+        }
+    }
+
+    fn set<K: IntoLua<'lua>, V: IntoLua<'lua>>(&self, key: K, value: V) -> Result<()> {
+        let metatable = self.get_metatable()?;
+        match metatable.get::<Value>(MetaMethod::NewIndex)? {
+            Value::Table(table) => table.raw_set(key, value),
+            Value::Function(func) => func.call((self.clone(), key, value)),
+            _ => Err(Error::runtime("attempt to index a userdata value")),
+        }
+    }
+
+    fn call<A, R>(&self, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>,
+    {
+        let metatable = self.get_metatable()?;
+        match metatable.get::<Value>(MetaMethod::Call)? {
+            Value::Function(func) => func.call((self.clone(), args)),
+            _ => Err(Error::runtime("attempt to call a userdata value")),
+        }
+    }
+
+    #[cfg(feature = "async")]
+    fn call_async<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua,
+    {
+        let metatable = match self.get_metatable() {
+            Ok(metatable) => metatable,
+            Err(err) => return Box::pin(future::err(err)),
+        };
+        match metatable.get::<Value>(MetaMethod::Call) {
+            Ok(Value::Function(func)) => {
+                let mut args = match args.into_lua_multi(self.0.lua) {
+                    Ok(args) => args,
+                    Err(e) => return Box::pin(future::err(e)),
+                };
+                args.push_front(Value::UserData(self.clone()));
+                Box::pin(async move { func.call_async(args).await })
+            }
+            Ok(_) => Box::pin(future::err(Error::runtime(
+                "attempt to call a userdata value",
+            ))),
+            Err(err) => Box::pin(future::err(err)),
+        }
+    }
+
+    fn call_method<A, R>(&self, name: &str, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>,
+    {
+        self.call_function(name, (self.clone(), args))
+    }
+
+    #[cfg(feature = "async")]
+    fn call_async_method<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua,
+    {
+        self.call_async_function(name, (self.clone(), args))
+    }
+
+    fn call_function<A, R>(&self, name: &str, args: A) -> Result<R>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua>,
+    {
+        match self.get(name)? {
+            Value::Function(func) => func.call(args),
+            val => {
+                let msg = format!("attempt to call a {} value", val.type_name());
+                Err(Error::runtime(msg))
+            }
+        }
+    }
+
+    #[cfg(feature = "async")]
+    fn call_async_function<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
+    where
+        A: IntoLuaMulti<'lua>,
+        R: FromLuaMulti<'lua> + 'lua,
+    {
+        match self.get(name) {
+            Ok(Value::Function(func)) => {
+                let args = match args.into_lua_multi(self.0.lua) {
+                    Ok(args) => args,
+                    Err(e) => return Box::pin(future::err(e)),
+                };
+                Box::pin(async move { func.call_async(args).await })
+            }
+            Ok(val) => {
+                let msg = format!("attempt to call a {} value", val.type_name());
+                Box::pin(future::err(Error::runtime(msg)))
+            }
+            Err(err) => Box::pin(future::err(err)),
+        }
+    }
+}

src/userdata_impl.rs

@@ -0,0 +1,797 @@
+#![allow(clippy::await_holding_refcell_ref, clippy::await_holding_lock)]
+
+use std::any::TypeId;
+use std::cell::{Ref, RefCell, RefMut};
+use std::marker::PhantomData;
+use std::os::raw::c_int;
+use std::string::String as StdString;
+use std::sync::{Arc, Mutex, RwLock};
+
+use crate::error::{Error, Result};
+use crate::lua::Lua;
+use crate::types::{Callback, MaybeSend};
+use crate::userdata::{
+    AnyUserData, MetaMethod, UserData, UserDataCell, UserDataFields, UserDataMethods,
+};
+use crate::util::{get_userdata, short_type_name};
+use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, Value};
+
+#[cfg(not(feature = "send"))]
+use std::rc::Rc;
+
+#[cfg(feature = "async")]
+use {crate::types::AsyncCallback, futures_util::future, std::future::Future};
+
+/// Handle to registry for userdata methods and metamethods.
+pub struct UserDataRegistry<'lua, T: 'static> {
+    // Fields
+    pub(crate) fields: Vec<(String, Callback<'lua, 'static>)>,
+    pub(crate) field_getters: Vec<(String, Callback<'lua, 'static>)>,
+    pub(crate) field_setters: Vec<(String, Callback<'lua, 'static>)>,
+    pub(crate) meta_fields: Vec<(String, Callback<'lua, 'static>)>,
+
+    // Methods
+    pub(crate) methods: Vec<(String, Callback<'lua, 'static>)>,
+    #[cfg(feature = "async")]
+    pub(crate) async_methods: Vec<(String, AsyncCallback<'lua, 'static>)>,
+    pub(crate) meta_methods: Vec<(String, Callback<'lua, 'static>)>,
+    #[cfg(feature = "async")]
+    pub(crate) async_meta_methods: Vec<(String, AsyncCallback<'lua, 'static>)>,
+
+    _type: PhantomData<T>,
+}
+
+impl<'lua, T: 'static> UserDataRegistry<'lua, T> {
+    pub(crate) const fn new() -> Self {
+        UserDataRegistry {
+            fields: Vec::new(),
+            field_getters: Vec::new(),
+            field_setters: Vec::new(),
+            meta_fields: Vec::new(),
+            methods: Vec::new(),
+            #[cfg(feature = "async")]
+            async_methods: Vec::new(),
+            meta_methods: Vec::new(),
+            #[cfg(feature = "async")]
+            async_meta_methods: Vec::new(),
+            _type: PhantomData,
+        }
+    }
+
+    fn box_method<M, A, R>(name: &str, method: M) -> Callback<'lua, 'static>
+    where
+        M: Fn(&'lua Lua, &T, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = get_function_name::<T>(name);
+        macro_rules! try_self_arg {
+            ($res:expr) => {
+                $res.map_err(|err| Error::bad_self_argument(&name, err))?
+            };
+            ($res:expr, $err:expr) => {
+                $res.map_err(|_| Error::bad_self_argument(&name, $err))?
+            };
+        }
+
+        Box::new(move |lua, nargs| unsafe {
+            if nargs == 0 {
+                let err = Error::from_lua_conversion("missing argument", "userdata", None);
+                try_self_arg!(Err(err));
+            }
+            let state = lua.state();
+            // Find absolute "self" index before processing args
+            let index = ffi::lua_absindex(state, -nargs);
+            // Self was at position 1, so we pass 2 here
+            let args = A::from_stack_args(nargs - 1, 2, Some(&name), lua);
+
+            match try_self_arg!(lua.get_userdata_type_id(index)) {
+                Some(id) if id == TypeId::of::<T>() => {
+                    let ud = try_self_arg!(get_userdata_ref::<T>(state, index));
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<T>>() => {
+                    let ud = try_self_arg!(get_userdata_ref::<Rc<T>>(state, index));
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
+                    let ud = try_self_arg!(get_userdata_ref::<Rc<RefCell<T>>>(state, index));
+                    let ud = try_self_arg!(ud.try_borrow(), Error::UserDataBorrowError);
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                Some(id) if id == TypeId::of::<Arc<T>>() => {
+                    let ud = try_self_arg!(get_userdata_ref::<Arc<T>>(state, index));
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
+                    let ud = try_self_arg!(get_userdata_ref::<Arc<Mutex<T>>>(state, index));
+                    let ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowError);
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => {
+                    let ud = get_userdata_ref::<Arc<parking_lot::Mutex<T>>>(state, index);
+                    let ud = try_self_arg!(ud);
+                    let ud = try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowError));
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
+                    let ud = try_self_arg!(get_userdata_ref::<Arc<RwLock<T>>>(state, index));
+                    let ud = try_self_arg!(ud.try_read(), Error::UserDataBorrowError);
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => {
+                    let ud = get_userdata_ref::<Arc<parking_lot::RwLock<T>>>(state, index);
+                    let ud = try_self_arg!(ud);
+                    let ud = try_self_arg!(ud.try_read().ok_or(Error::UserDataBorrowError));
+                    method(lua, &ud, args?)?.push_into_stack_multi(lua)
+                }
+                _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
+            }
+        })
+    }
+
+    fn box_method_mut<M, A, R>(name: &str, method: M) -> Callback<'lua, 'static>
+    where
+        M: FnMut(&'lua Lua, &mut T, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = get_function_name::<T>(name);
+        macro_rules! try_self_arg {
+            ($res:expr) => {
+                $res.map_err(|err| Error::bad_self_argument(&name, err))?
+            };
+            ($res:expr, $err:expr) => {
+                $res.map_err(|_| Error::bad_self_argument(&name, $err))?
+            };
+        }
+
+        let method = RefCell::new(method);
+        Box::new(move |lua, nargs| unsafe {
+            let mut method = method
+                .try_borrow_mut()
+                .map_err(|_| Error::RecursiveMutCallback)?;
+            if nargs == 0 {
+                let err = Error::from_lua_conversion("missing argument", "userdata", None);
+                try_self_arg!(Err(err));
+            }
+            let state = lua.state();
+            // Find absolute "self" index before processing args
+            let index = ffi::lua_absindex(state, -nargs);
+            // Self was at position 1, so we pass 2 here
+            let args = A::from_stack_args(nargs - 1, 2, Some(&name), lua);
+
+            match try_self_arg!(lua.get_userdata_type_id(index)) {
+                Some(id) if id == TypeId::of::<T>() => {
+                    let mut ud = try_self_arg!(get_userdata_mut::<T>(state, index));
+                    method(lua, &mut ud, args?)?.push_into_stack_multi(lua)
+                }
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<T>>() => Err(Error::UserDataBorrowMutError),
+                #[cfg(not(feature = "send"))]
+                Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
+                    let ud = try_self_arg!(get_userdata_mut::<Rc<RefCell<T>>>(state, index));
+                    let mut ud = try_self_arg!(ud.try_borrow_mut(), Error::UserDataBorrowMutError);
+                    method(lua, &mut ud, args?)?.push_into_stack_multi(lua)
+                }
+                Some(id) if id == TypeId::of::<Arc<T>>() => Err(Error::UserDataBorrowMutError),
+                Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
+                    let ud = try_self_arg!(get_userdata_mut::<Arc<Mutex<T>>>(state, index));
+                    let mut ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowMutError);
+                    method(lua, &mut ud, args?)?.push_into_stack_multi(lua)
+                }
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => {
+                    let ud = get_userdata_mut::<Arc<parking_lot::Mutex<T>>>(state, index);
+                    let ud = try_self_arg!(ud);
+                    let mut ud = try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowMutError));
+                    method(lua, &mut ud, args?)?.push_into_stack_multi(lua)
+                }
+                Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
+                    let ud = try_self_arg!(get_userdata_mut::<Arc<RwLock<T>>>(state, index));
+                    let mut ud = try_self_arg!(ud.try_write(), Error::UserDataBorrowMutError);
+                    method(lua, &mut ud, args?)?.push_into_stack_multi(lua)
+                }
+                #[cfg(feature = "parking_lot")]
+                Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => {
+                    let ud = get_userdata_mut::<Arc<parking_lot::RwLock<T>>>(state, index);
+                    let ud = try_self_arg!(ud);
+                    let mut ud = try_self_arg!(ud.try_write().ok_or(Error::UserDataBorrowMutError));
+                    method(lua, &mut ud, args?)?.push_into_stack_multi(lua)
+                }
+                _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
+            }
+        })
+    }
+
+    #[cfg(feature = "async")]
+    fn box_async_method<'s, M, A, MR, R>(name: &str, method: M) -> AsyncCallback<'lua, 'static>
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = Arc::new(get_function_name::<T>(name));
+        let method = Arc::new(method);
+
+        Box::new(move |lua, mut args| unsafe {
+            let name = name.clone();
+            let method = method.clone();
+            macro_rules! try_self_arg {
+                ($res:expr) => {
+                    $res.map_err(|err| Error::bad_self_argument(&name, err))?
+                };
+                ($res:expr, $err:expr) => {
+                    $res.map_err(|_| Error::bad_self_argument(&name, $err))?
+                };
+            }
+
+            Box::pin(async move {
+                let this = args.pop_front().ok_or_else(|| {
+                    Error::from_lua_conversion("missing argument", "userdata", None)
+                });
+                let this = try_self_arg!(AnyUserData::from_lua(try_self_arg!(this), lua));
+                let args = A::from_lua_args(args, 2, Some(&name), lua);
+
+                let (ref_thread, index) = (lua.ref_thread(), this.0.index);
+                match try_self_arg!(this.type_id()) {
+                    Some(id) if id == TypeId::of::<T>() => {
+                        let ud = try_self_arg!(get_userdata_ref::<T>(ref_thread, index));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<T>>() => {
+                        let ud = try_self_arg!(get_userdata_ref::<Rc<T>>(ref_thread, index));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
+                        let ud =
+                            try_self_arg!(get_userdata_ref::<Rc<RefCell<T>>>(ref_thread, index));
+                        let ud = try_self_arg!(ud.try_borrow(), Error::UserDataBorrowError);
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    Some(id) if id == TypeId::of::<Arc<T>>() => {
+                        let ud = try_self_arg!(get_userdata_ref::<Arc<T>>(ref_thread, index));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
+                        let ud =
+                            try_self_arg!(get_userdata_ref::<Arc<Mutex<T>>>(ref_thread, index));
+                        let ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowError);
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => {
+                        let ud = get_userdata_ref::<Arc<parking_lot::Mutex<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let ud = try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowError));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
+                        let ud =
+                            try_self_arg!(get_userdata_ref::<Arc<RwLock<T>>>(ref_thread, index));
+                        let ud = try_self_arg!(ud.try_read(), Error::UserDataBorrowError);
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => {
+                        let ud = get_userdata_ref::<Arc<parking_lot::RwLock<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let ud = try_self_arg!(ud.try_read().ok_or(Error::UserDataBorrowError));
+                        let ud = std::mem::transmute::<&T, &T>(&ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
+                }
+            })
+        })
+    }
+
+    #[cfg(feature = "async")]
+    fn box_async_method_mut<'s, M, A, MR, R>(name: &str, method: M) -> AsyncCallback<'lua, 'static>
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = Arc::new(get_function_name::<T>(name));
+        let method = Arc::new(method);
+
+        Box::new(move |lua, mut args| unsafe {
+            let name = name.clone();
+            let method = method.clone();
+            macro_rules! try_self_arg {
+                ($res:expr) => {
+                    $res.map_err(|err| Error::bad_self_argument(&name, err))?
+                };
+                ($res:expr, $err:expr) => {
+                    $res.map_err(|_| Error::bad_self_argument(&name, $err))?
+                };
+            }
+
+            Box::pin(async move {
+                let this = args.pop_front().ok_or_else(|| {
+                    Error::from_lua_conversion("missing argument", "userdata", None)
+                });
+                let this = try_self_arg!(AnyUserData::from_lua(try_self_arg!(this), lua));
+                let args = A::from_lua_args(args, 2, Some(&name), lua);
+
+                let (ref_thread, index) = (lua.ref_thread(), this.0.index);
+                match try_self_arg!(this.type_id()) {
+                    Some(id) if id == TypeId::of::<T>() => {
+                        let mut ud = try_self_arg!(get_userdata_mut::<T>(ref_thread, index));
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
+                        Err(Error::UserDataBorrowMutError)
+                    }
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Rc<RefCell<T>>>() => {
+                        let ud =
+                            try_self_arg!(get_userdata_mut::<Rc<RefCell<T>>>(ref_thread, index));
+                        let mut ud =
+                            try_self_arg!(ud.try_borrow_mut(), Error::UserDataBorrowMutError);
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(not(feature = "send"))]
+                    Some(id) if id == TypeId::of::<Arc<T>>() => Err(Error::UserDataBorrowMutError),
+                    Some(id) if id == TypeId::of::<Arc<Mutex<T>>>() => {
+                        let ud =
+                            try_self_arg!(get_userdata_mut::<Arc<Mutex<T>>>(ref_thread, index));
+                        let mut ud = try_self_arg!(ud.try_lock(), Error::UserDataBorrowMutError);
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::Mutex<T>>>() => {
+                        let ud = get_userdata_mut::<Arc<parking_lot::Mutex<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let mut ud =
+                            try_self_arg!(ud.try_lock().ok_or(Error::UserDataBorrowMutError));
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    Some(id) if id == TypeId::of::<Arc<RwLock<T>>>() => {
+                        let ud =
+                            try_self_arg!(get_userdata_mut::<Arc<RwLock<T>>>(ref_thread, index));
+                        let mut ud = try_self_arg!(ud.try_write(), Error::UserDataBorrowMutError);
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    #[cfg(feature = "parking_lot")]
+                    Some(id) if id == TypeId::of::<Arc<parking_lot::RwLock<T>>>() => {
+                        let ud = get_userdata_mut::<Arc<parking_lot::RwLock<T>>>(ref_thread, index);
+                        let ud = try_self_arg!(ud);
+                        let mut ud =
+                            try_self_arg!(ud.try_write().ok_or(Error::UserDataBorrowMutError));
+                        let ud = std::mem::transmute::<&mut T, &mut T>(&mut ud);
+                        method(lua, ud, args?).await?.push_into_stack_multi(lua)
+                    }
+                    _ => Err(Error::bad_self_argument(&name, Error::UserDataTypeMismatch)),
+                }
+            })
+        })
+    }
+
+    fn box_function<F, A, R>(name: &str, function: F) -> Callback<'lua, 'static>
+    where
+        F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = get_function_name::<T>(name);
+        Box::new(move |lua, nargs| unsafe {
+            let args = A::from_stack_args(nargs, 1, Some(&name), lua)?;
+            function(lua, args)?.push_into_stack_multi(lua)
+        })
+    }
+
+    fn box_function_mut<F, A, R>(name: &str, function: F) -> Callback<'lua, 'static>
+    where
+        F: FnMut(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = get_function_name::<T>(name);
+        let function = RefCell::new(function);
+        Box::new(move |lua, nargs| unsafe {
+            let function = &mut *function
+                .try_borrow_mut()
+                .map_err(|_| Error::RecursiveMutCallback)?;
+            let args = A::from_stack_args(nargs, 1, Some(&name), lua)?;
+            function(lua, args)?.push_into_stack_multi(lua)
+        })
+    }
+
+    #[cfg(feature = "async")]
+    fn box_async_function<F, A, FR, R>(name: &str, function: F) -> AsyncCallback<'lua, 'static>
+    where
+        F: Fn(&'lua Lua, A) -> FR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        FR: Future<Output = Result<R>> + 'lua,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = get_function_name::<T>(name);
+        Box::new(move |lua, args| unsafe {
+            let args = match A::from_lua_args(args, 1, Some(&name), lua) {
+                Ok(args) => args,
+                Err(e) => return Box::pin(future::err(e)),
+            };
+            let fut = function(lua, args);
+            Box::pin(async move { fut.await?.push_into_stack_multi(lua) })
+        })
+    }
+
+    pub(crate) fn check_meta_field<V>(lua: &'lua Lua, name: &str, value: V) -> Result<Value<'lua>>
+    where
+        V: IntoLua<'lua>,
+    {
+        let value = value.into_lua(lua)?;
+        if name == MetaMethod::Index || name == MetaMethod::NewIndex {
+            match value {
+                Value::Nil | Value::Table(_) | Value::Function(_) => {}
+                _ => {
+                    return Err(Error::MetaMethodTypeError {
+                        method: name.to_string(),
+                        type_name: value.type_name(),
+                        message: Some("expected nil, table or function".to_string()),
+                    })
+                }
+            }
+        }
+        value.into_lua(lua)
+    }
+}
+
+// Returns function name for the type `T`, without the module path
+fn get_function_name<T>(name: &str) -> StdString {
+    format!("{}.{name}", short_type_name::<T>())
+}
+
+impl<'lua, T: 'static> UserDataFields<'lua, T> for UserDataRegistry<'lua, T> {
+    fn add_field<V>(&mut self, name: impl AsRef<str>, value: V)
+    where
+        V: IntoLua<'lua> + Clone + 'static,
+    {
+        let name = name.as_ref().to_string();
+        self.fields.push((
+            name,
+            Box::new(move |lua, _| unsafe { value.clone().push_into_stack_multi(lua) }),
+        ));
+    }
+
+    fn add_field_method_get<M, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        M: Fn(&'lua Lua, &T) -> Result<R> + MaybeSend + 'static,
+        R: IntoLua<'lua>,
+    {
+        let name = name.as_ref();
+        let method = Self::box_method(name, move |lua, data, ()| method(lua, data));
+        self.field_getters.push((name.into(), method));
+    }
+
+    fn add_field_method_set<M, A>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        M: FnMut(&'lua Lua, &mut T, A) -> Result<()> + MaybeSend + 'static,
+        A: FromLua<'lua>,
+    {
+        let name = name.as_ref();
+        let method = Self::box_method_mut(name, method);
+        self.field_setters.push((name.into(), method));
+    }
+
+    fn add_field_function_get<F, R>(&mut self, name: impl AsRef<str>, function: F)
+    where
+        F: Fn(&'lua Lua, AnyUserData<'lua>) -> Result<R> + MaybeSend + 'static,
+        R: IntoLua<'lua>,
+    {
+        let name = name.as_ref();
+        let func = Self::box_function(name, function);
+        self.field_getters.push((name.into(), func));
+    }
+
+    fn add_field_function_set<F, A>(&mut self, name: impl AsRef<str>, mut function: F)
+    where
+        F: FnMut(&'lua Lua, AnyUserData<'lua>, A) -> Result<()> + MaybeSend + 'static,
+        A: FromLua<'lua>,
+    {
+        let name = name.as_ref();
+        let func = Self::box_function_mut(name, move |lua, (data, val)| function(lua, data, val));
+        self.field_setters.push((name.into(), func));
+    }
+
+    fn add_meta_field<V>(&mut self, name: impl AsRef<str>, value: V)
+    where
+        V: IntoLua<'lua> + Clone + 'static,
+    {
+        let name = name.as_ref().to_string();
+        let name2 = name.clone();
+        self.meta_fields.push((
+            name,
+            Box::new(move |lua, _| unsafe {
+                Self::check_meta_field(lua, &name2, value.clone())?.push_into_stack_multi(lua)
+            }),
+        ));
+    }
+
+    fn add_meta_field_with<F, R>(&mut self, name: impl AsRef<str>, f: F)
+    where
+        F: Fn(&'lua Lua) -> Result<R> + MaybeSend + 'static,
+        R: IntoLua<'lua>,
+    {
+        let name = name.as_ref().to_string();
+        let name2 = name.clone();
+        self.meta_fields.push((
+            name,
+            Box::new(move |lua, _| unsafe {
+                Self::check_meta_field(lua, &name2, f(lua)?)?.push_into_stack_multi(lua)
+            }),
+        ));
+    }
+
+    // Below are internal methods
+
+    fn append_fields_from<S>(&mut self, other: UserDataRegistry<'lua, S>) {
+        self.fields.extend(other.fields);
+        self.field_getters.extend(other.field_getters);
+        self.field_setters.extend(other.field_setters);
+        self.meta_fields.extend(other.meta_fields);
+    }
+}
+
+impl<'lua, T: 'static> UserDataMethods<'lua, T> for UserDataRegistry<'lua, T> {
+    fn add_method<M, A, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        M: Fn(&'lua Lua, &T, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.methods
+            .push((name.into(), Self::box_method(name, method)));
+    }
+
+    fn add_method_mut<M, A, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        M: FnMut(&'lua Lua, &mut T, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.methods
+            .push((name.into(), Self::box_method_mut(name, method)));
+    }
+
+    #[cfg(feature = "async")]
+    fn add_async_method<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_methods
+            .push((name.into(), Self::box_async_method(name, method)));
+    }
+
+    #[cfg(feature = "async")]
+    fn add_async_method_mut<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_methods
+            .push((name.into(), Self::box_async_method_mut(name, method)));
+    }
+
+    fn add_function<F, A, R>(&mut self, name: impl AsRef<str>, function: F)
+    where
+        F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.methods
+            .push((name.into(), Self::box_function(name, function)));
+    }
+
+    fn add_function_mut<F, A, R>(&mut self, name: impl AsRef<str>, function: F)
+    where
+        F: FnMut(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.methods
+            .push((name.into(), Self::box_function_mut(name, function)));
+    }
+
+    #[cfg(feature = "async")]
+    fn add_async_function<F, A, FR, R>(&mut self, name: impl AsRef<str>, function: F)
+    where
+        F: Fn(&'lua Lua, A) -> FR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        FR: Future<Output = Result<R>> + 'lua,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_methods
+            .push((name.into(), Self::box_async_function(name, function)));
+    }
+
+    fn add_meta_method<M, A, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        M: Fn(&'lua Lua, &T, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.meta_methods
+            .push((name.into(), Self::box_method(name, method)));
+    }
+
+    fn add_meta_method_mut<M, A, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        M: FnMut(&'lua Lua, &mut T, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.meta_methods
+            .push((name.into(), Self::box_method_mut(name, method)));
+    }
+
+    #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
+    fn add_async_meta_method<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_meta_methods
+            .push((name.into(), Self::box_async_method(name, method)));
+    }
+
+    #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
+    fn add_async_meta_method_mut<'s, M, A, MR, R>(&mut self, name: impl AsRef<str>, method: M)
+    where
+        'lua: 's,
+        T: 'static,
+        M: Fn(&'lua Lua, &'s mut T, A) -> MR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        MR: Future<Output = Result<R>> + 's,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_meta_methods
+            .push((name.into(), Self::box_async_method_mut(name, method)));
+    }
+
+    fn add_meta_function<F, A, R>(&mut self, name: impl AsRef<str>, function: F)
+    where
+        F: Fn(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.meta_methods
+            .push((name.into(), Self::box_function(name, function)));
+    }
+
+    fn add_meta_function_mut<F, A, R>(&mut self, name: impl AsRef<str>, function: F)
+    where
+        F: FnMut(&'lua Lua, A) -> Result<R> + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.meta_methods
+            .push((name.into(), Self::box_function_mut(name, function)));
+    }
+
+    #[cfg(all(feature = "async", not(any(feature = "lua51", feature = "luau"))))]
+    fn add_async_meta_function<F, A, FR, R>(&mut self, name: impl AsRef<str>, function: F)
+    where
+        F: Fn(&'lua Lua, A) -> FR + MaybeSend + 'static,
+        A: FromLuaMulti<'lua>,
+        FR: Future<Output = Result<R>> + 'lua,
+        R: IntoLuaMulti<'lua>,
+    {
+        let name = name.as_ref();
+        self.async_meta_methods
+            .push((name.into(), Self::box_async_function(name, function)));
+    }
+
+    // Below are internal methods used in generated code
+
+    fn append_methods_from<S>(&mut self, other: UserDataRegistry<'lua, S>) {
+        self.methods.extend(other.methods);
+        #[cfg(feature = "async")]
+        self.async_methods.extend(other.async_methods);
+        self.meta_methods.extend(other.meta_methods);
+        #[cfg(feature = "async")]
+        self.async_meta_methods.extend(other.async_meta_methods);
+    }
+}
+
+#[inline]
+unsafe fn get_userdata_ref<'a, T>(state: *mut ffi::lua_State, index: c_int) -> Result<Ref<'a, T>> {
+    (*get_userdata::<UserDataCell<T>>(state, index)).try_borrow()
+}
+
+#[inline]
+unsafe fn get_userdata_mut<'a, T>(
+    state: *mut ffi::lua_State,
+    index: c_int,
+) -> Result<RefMut<'a, T>> {
+    (*get_userdata::<UserDataCell<T>>(state, index)).try_borrow_mut()
+}
+
+macro_rules! lua_userdata_impl {
+    ($type:ty) => {
+        impl<T: UserData + 'static> UserData for $type {
+            fn add_fields<'lua, F: UserDataFields<'lua, Self>>(fields: &mut F) {
+                let mut orig_fields = UserDataRegistry::new();
+                T::add_fields(&mut orig_fields);
+                fields.append_fields_from(orig_fields);
+            }
+
+            fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
+                let mut orig_methods = UserDataRegistry::new();
+                T::add_methods(&mut orig_methods);
+                methods.append_methods_from(orig_methods);
+            }
+        }
+    };
+}
+
+#[cfg(not(feature = "send"))]
+lua_userdata_impl!(Rc<T>);
+#[cfg(not(feature = "send"))]
+lua_userdata_impl!(Rc<RefCell<T>>);
+
+lua_userdata_impl!(Arc<T>);
+lua_userdata_impl!(Arc<Mutex<T>>);
+lua_userdata_impl!(Arc<RwLock<T>>);
+#[cfg(feature = "parking_lot")]
+lua_userdata_impl!(Arc<parking_lot::Mutex<T>>);
+#[cfg(feature = "parking_lot")]
+lua_userdata_impl!(Arc<parking_lot::RwLock<T>>);
+
+// A special proxy object for UserData
+pub(crate) struct UserDataProxy<T>(pub(crate) PhantomData<T>);
+
+lua_userdata_impl!(UserDataProxy<T>);

src/util/mod.rs

@@ -1,15 +1,20 @@
 use std::any::{Any, TypeId};
+use std::borrow::Cow;
+use std::ffi::CStr;
 use std::fmt::Write;
+use std::mem::MaybeUninit;
 use std::os::raw::{c_char, c_int, c_void};
 use std::panic::{catch_unwind, resume_unwind, AssertUnwindSafe};
 use std::sync::Arc;
-use std::{mem, ptr, slice};
+use std::{ptr, slice, str};
 
 use once_cell::sync::Lazy;
 use rustc_hash::FxHashMap;
 
 use crate::error::{Error, Result};
-use crate::ffi;
+use crate::memory::MemoryState;
+
+pub(crate) use short_names::short_type_name;
 
 static METATABLE_CACHE: Lazy<FxHashMap<TypeId, u8>> = Lazy::new(|| {
     let mut map = FxHashMap::with_capacity_and_hasher(32, Default::default());
@@ -45,7 +50,6 @@ pub unsafe fn check_stack(state: *mut ffi::lua_State, amount: c_int) -> Result<(
 pub struct StackGuard {
     state: *mut ffi::lua_State,
     top: c_int,
-    extra: c_int,
 }
 
 impl StackGuard {
@@ -57,18 +61,12 @@ impl StackGuard {
         StackGuard {
             state,
             top: ffi::lua_gettop(state),
-            extra: 0,
         }
     }
 
-    // Similar to `new`, but checks and keeps `extra` elements from top of the stack on Drop.
-    #[inline]
-    pub unsafe fn new_extra(state: *mut ffi::lua_State, extra: c_int) -> StackGuard {
-        StackGuard {
-            state,
-            top: ffi::lua_gettop(state),
-            extra,
-        }
+    // Same as `new()`, but allows specifying the expected stack size at the end of the scope.
+    pub const fn with_top(state: *mut ffi::lua_State, top: c_int) -> StackGuard {
+        StackGuard { state, top }
     }
 }
 
@@ -76,14 +74,11 @@ impl Drop for StackGuard {
     fn drop(&mut self) {
         unsafe {
             let top = ffi::lua_gettop(self.state);
-            if top < self.top + self.extra {
+            if top < self.top {
                 mlua_panic!("{} too many stack values popped", self.top - top)
             }
-            if top > self.top + self.extra {
-                if self.extra > 0 {
-                    ffi::lua_rotate(self.state, self.top + 1, self.extra);
-                }
-                ffi::lua_settop(self.state, self.top + self.extra);
+            if top > self.top {
+                ffi::lua_settop(self.state, self.top);
             }
         }
     }
@@ -98,12 +93,14 @@ impl Drop for StackGuard {
 pub unsafe fn protect_lua_call(
     state: *mut ffi::lua_State,
     nargs: c_int,
-    f: unsafe extern "C" fn(*mut ffi::lua_State) -> c_int,
+    f: unsafe extern "C-unwind" fn(*mut ffi::lua_State) -> c_int,
 ) -> Result<()> {
     let stack_start = ffi::lua_gettop(state) - nargs;
 
-    ffi::lua_pushcfunction(state, error_traceback);
-    ffi::lua_pushcfunction(state, f);
+    MemoryState::relax_limit_with(state, || {
+        ffi::lua_pushcfunction(state, error_traceback);
+        ffi::lua_pushcfunction(state, f);
+    });
     if nargs > 0 {
         ffi::lua_rotate(state, stack_start + 1, 2);
     }
@@ -135,26 +132,21 @@ where
     F: Fn(*mut ffi::lua_State) -> R,
     R: Copy,
 {
-    union URes<R: Copy> {
-        uninit: (),
-        init: R,
-    }
-
     struct Params<F, R: Copy> {
         function: F,
-        result: URes<R>,
+        result: MaybeUninit<R>,
         nresults: c_int,
     }
 
-    unsafe extern "C" fn do_call<F, R>(state: *mut ffi::lua_State) -> c_int
+    unsafe extern "C-unwind" fn do_call<F, R>(state: *mut ffi::lua_State) -> c_int
     where
-        R: Copy,
         F: Fn(*mut ffi::lua_State) -> R,
+        R: Copy,
     {
         let params = ffi::lua_touserdata(state, -1) as *mut Params<F, R>;
         ffi::lua_pop(state, 1);
 
-        (*params).result.init = ((*params).function)(state);
+        (*params).result.write(((*params).function)(state));
 
         if (*params).nresults == ffi::LUA_MULTRET {
             ffi::lua_gettop(state)
@@ -165,15 +157,17 @@ where
 
     let stack_start = ffi::lua_gettop(state) - nargs;
 
-    ffi::lua_pushcfunction(state, error_traceback);
-    ffi::lua_pushcfunction(state, do_call::<F, R>);
+    MemoryState::relax_limit_with(state, || {
+        ffi::lua_pushcfunction(state, error_traceback);
+        ffi::lua_pushcfunction(state, do_call::<F, R>);
+    });
     if nargs > 0 {
         ffi::lua_rotate(state, stack_start + 1, 2);
     }
 
     let mut params = Params {
         function: f,
-        result: URes { uninit: () },
+        result: MaybeUninit::uninit(),
         nresults,
     };
 
@@ -184,7 +178,7 @@ where
     if ret == ffi::LUA_OK {
         // `LUA_OK` is only returned when the `do_call` function has completed successfully, so
         // `params.result` is definitely initialized.
-        Ok(params.result.init)
+        Ok(params.result.assume_init())
     } else {
         Err(pop_error(state, ret))
     }
@@ -202,7 +196,7 @@ pub unsafe fn pop_error(state: *mut ffi::lua_State, err_code: c_int) -> Error {
         "pop_error called with non-error return code"
     );
 
-    match get_gc_userdata::<WrappedFailure>(state, -1).as_mut() {
+    match get_gc_userdata::<WrappedFailure>(state, -1, ptr::null()).as_mut() {
         Some(WrappedFailure::Error(err)) => {
             ffi::lua_pop(state, 1);
             err.clone()
@@ -245,30 +239,54 @@ pub unsafe fn pop_error(state: *mut ffi::lua_State, err_code: c_int) -> Error {
     }
 }
 
-// Uses 3 stack spaces, does not call checkstack.
-#[inline]
-pub unsafe fn push_string<S: AsRef<[u8]> + ?Sized>(
-    state: *mut ffi::lua_State,
-    s: &S,
-) -> Result<()> {
-    let s = s.as_ref();
-    protect_lua!(state, 0, 1, |state| {
+// Uses 3 (or 1 if unprotected) stack spaces, does not call checkstack.
+#[inline(always)]
+pub unsafe fn push_string(state: *mut ffi::lua_State, s: &[u8], protect: bool) -> Result<()> {
+    // Always use protected mode if the string is too long
+    if protect || s.len() > (1 << 30) {
+        protect_lua!(state, 0, 1, |state| {
+            ffi::lua_pushlstring(state, s.as_ptr() as *const c_char, s.len());
+        })
+    } else {
         ffi::lua_pushlstring(state, s.as_ptr() as *const c_char, s.len());
-    })
+        Ok(())
+    }
+}
+
+// Uses 3 stack spaces (when protect), does not call checkstack.
+#[cfg(feature = "luau")]
+#[inline(always)]
+pub unsafe fn push_buffer(state: *mut ffi::lua_State, b: &[u8], protect: bool) -> Result<()> {
+    let data = if protect {
+        protect_lua!(state, 0, 1, |state| ffi::lua_newbuffer(state, b.len()))?
+    } else {
+        ffi::lua_newbuffer(state, b.len())
+    };
+    let buf = slice::from_raw_parts_mut(data as *mut u8, b.len());
+    buf.copy_from_slice(b);
+    Ok(())
 }
 
 // Uses 3 stack spaces, does not call checkstack.
 #[inline]
-pub unsafe fn push_table(state: *mut ffi::lua_State, narr: c_int, nrec: c_int) -> Result<()> {
-    protect_lua!(state, 0, 1, |state| ffi::lua_createtable(state, narr, nrec))
+pub unsafe fn push_table(
+    state: *mut ffi::lua_State,
+    narr: usize,
+    nrec: usize,
+    protect: bool,
+) -> Result<()> {
+    let narr: c_int = narr.try_into().unwrap_or(c_int::MAX);
+    let nrec: c_int = nrec.try_into().unwrap_or(c_int::MAX);
+    if protect {
+        protect_lua!(state, 0, 1, |state| ffi::lua_createtable(state, narr, nrec))
+    } else {
+        ffi::lua_createtable(state, narr, nrec);
+        Ok(())
+    }
 }
 
 // Uses 4 stack spaces, does not call checkstack.
-pub unsafe fn rawset_field<S>(state: *mut ffi::lua_State, table: c_int, field: &S) -> Result<()>
-where
-    S: AsRef<[u8]> + ?Sized,
-{
-    let field = field.as_ref();
+pub unsafe fn rawset_field(state: *mut ffi::lua_State, table: c_int, field: &str) -> Result<()> {
     ffi::lua_pushvalue(state, table);
     protect_lua!(state, 2, 0, |state| {
         ffi::lua_pushlstring(state, field.as_ptr() as *const c_char, field.len());
@@ -279,10 +297,21 @@ where
 
 // Internally uses 3 stack spaces, does not call checkstack.
 #[inline]
-pub unsafe fn push_userdata<T>(state: *mut ffi::lua_State, t: T) -> Result<()> {
-    let ud = protect_lua!(state, 0, 1, |state| {
-        ffi::lua_newuserdata(state, mem::size_of::<T>()) as *mut T
-    })?;
+pub unsafe fn push_userdata<T>(state: *mut ffi::lua_State, t: T, protect: bool) -> Result<()> {
+    #[cfg(not(feature = "luau"))]
+    let ud = if protect {
+        protect_lua!(state, 0, 1, |state| {
+            ffi::lua_newuserdata(state, std::mem::size_of::<T>()) as *mut T
+        })?
+    } else {
+        ffi::lua_newuserdata(state, std::mem::size_of::<T>()) as *mut T
+    };
+    #[cfg(feature = "luau")]
+    let ud = if protect {
+        protect_lua!(state, 0, 1, |state| { ffi::lua_newuserdata_t::<T>(state) })?
+    } else {
+        ffi::lua_newuserdata_t::<T>(state)
+    };
     ptr::write(ud, t);
     Ok(())
 }
@@ -290,10 +319,19 @@ pub unsafe fn push_userdata<T>(state: *mut ffi::lua_State, t: T) -> Result<()> {
 // Internally uses 3 stack spaces, does not call checkstack.
 #[cfg(feature = "lua54")]
 #[inline]
-pub unsafe fn push_userdata_uv<T>(state: *mut ffi::lua_State, t: T, nuvalue: c_int) -> Result<()> {
-    let ud = protect_lua!(state, 0, 1, |state| {
-        ffi::lua_newuserdatauv(state, mem::size_of::<T>(), nuvalue) as *mut T
-    })?;
+pub unsafe fn push_userdata_uv<T>(
+    state: *mut ffi::lua_State,
+    t: T,
+    nuvalue: c_int,
+    protect: bool,
+) -> Result<()> {
+    let ud = if protect {
+        protect_lua!(state, 0, 1, |state| {
+            ffi::lua_newuserdatauv(state, std::mem::size_of::<T>(), nuvalue) as *mut T
+        })?
+    } else {
+        ffi::lua_newuserdatauv(state, std::mem::size_of::<T>(), nuvalue) as *mut T
+    };
     ptr::write(ud, t);
     Ok(())
 }
@@ -316,35 +354,194 @@ pub unsafe fn take_userdata<T>(state: *mut ffi::lua_State) -> T {
     // after the first call to __gc.
     get_destructed_userdata_metatable(state);
     ffi::lua_setmetatable(state, -2);
-    let ud = get_userdata(state, -1);
+    let ud = get_userdata::<T>(state, -1);
+
+    // Update userdata tag to disable destructor and mark as destructed
+    #[cfg(feature = "luau")]
+    ffi::lua_setuserdatatag(state, -1, 1);
+
     ffi::lua_pop(state, 1);
     ptr::read(ud)
 }
 
 // Pushes the userdata and attaches a metatable with __gc method.
 // Internally uses 3 stack spaces, does not call checkstack.
-pub unsafe fn push_gc_userdata<T: Any>(state: *mut ffi::lua_State, t: T) -> Result<()> {
-    push_userdata(state, t)?;
+pub unsafe fn push_gc_userdata<T: Any>(
+    state: *mut ffi::lua_State,
+    t: T,
+    protect: bool,
+) -> Result<()> {
+    push_userdata(state, t, protect)?;
     get_gc_metatable::<T>(state);
     ffi::lua_setmetatable(state, -2);
     Ok(())
 }
 
 // Uses 2 stack spaces, does not call checkstack
-pub unsafe fn get_gc_userdata<T: Any>(state: *mut ffi::lua_State, index: c_int) -> *mut T {
+pub unsafe fn get_gc_userdata<T: Any>(
+    state: *mut ffi::lua_State,
+    index: c_int,
+    mt_ptr: *const c_void,
+) -> *mut T {
     let ud = ffi::lua_touserdata(state, index) as *mut T;
     if ud.is_null() || ffi::lua_getmetatable(state, index) == 0 {
         return ptr::null_mut();
     }
-    get_gc_metatable::<T>(state);
-    let res = ffi::lua_rawequal(state, -1, -2);
-    ffi::lua_pop(state, 2);
-    if res == 0 {
-        return ptr::null_mut();
+    if !mt_ptr.is_null() {
+        let ud_mt_ptr = ffi::lua_topointer(state, -1);
+        ffi::lua_pop(state, 1);
+        if !ptr::eq(ud_mt_ptr, mt_ptr) {
+            return ptr::null_mut();
+        }
+    } else {
+        get_gc_metatable::<T>(state);
+        let res = ffi::lua_rawequal(state, -1, -2);
+        ffi::lua_pop(state, 2);
+        if res == 0 {
+            return ptr::null_mut();
+        }
     }
     ud
 }
 
+unsafe extern "C-unwind" fn lua_error_impl(state: *mut ffi::lua_State) -> c_int {
+    ffi::lua_error(state);
+}
+
+unsafe extern "C-unwind" fn lua_isfunction_impl(state: *mut ffi::lua_State) -> c_int {
+    ffi::lua_pushboolean(state, ffi::lua_isfunction(state, -1));
+    1
+}
+
+unsafe extern "C-unwind" fn lua_istable_impl(state: *mut ffi::lua_State) -> c_int {
+    ffi::lua_pushboolean(state, ffi::lua_istable(state, -1));
+    1
+}
+
+unsafe fn init_userdata_metatable_index(state: *mut ffi::lua_State) -> Result<()> {
+    let index_key = &USERDATA_METATABLE_INDEX as *const u8 as *const _;
+    if ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, index_key) == ffi::LUA_TFUNCTION {
+        return Ok(());
+    }
+    ffi::lua_pop(state, 1);
+
+    // Create and cache `__index` generator
+    let code = cstr!(
+        r#"
+            local error, isfunction, istable = ...
+            return function (__index, field_getters, methods)
+                -- Common case: has field getters and index is a table
+                if field_getters ~= nil and methods == nil and istable(__index) then
+                    return function (self, key)
+                        local field_getter = field_getters[key]
+                        if field_getter ~= nil then
+                            return field_getter(self)
+                        end
+                        return __index[key]
+                    end
+                end
+
+                return function (self, key)
+                    if field_getters ~= nil then
+                        local field_getter = field_getters[key]
+                        if field_getter ~= nil then
+                            return field_getter(self)
+                        end
+                    end
+
+                    if methods ~= nil then
+                        local method = methods[key]
+                        if method ~= nil then
+                            return method
+                        end
+                    end
+
+                    if isfunction(__index) then
+                        return __index(self, key)
+                    elseif __index == nil then
+                        error("attempt to get an unknown field '"..key.."'")
+                    else
+                        return __index[key]
+                    end
+                end
+            end
+    "#
+    );
+    let code_len = CStr::from_ptr(code).to_bytes().len();
+    protect_lua!(state, 0, 1, |state| {
+        let ret = ffi::luaL_loadbuffer(state, code, code_len, cstr!("__mlua_index"));
+        if ret != ffi::LUA_OK {
+            ffi::lua_error(state);
+        }
+        ffi::lua_pushcfunction(state, lua_error_impl);
+        ffi::lua_pushcfunction(state, lua_isfunction_impl);
+        ffi::lua_pushcfunction(state, lua_istable_impl);
+        ffi::lua_call(state, 3, 1);
+
+        #[cfg(feature = "luau-jit")]
+        if ffi::luau_codegen_supported() != 0 {
+            ffi::luau_codegen_compile(state, -1);
+        }
+
+        // Store in the registry
+        ffi::lua_pushvalue(state, -1);
+        ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, index_key);
+    })
+}
+
+pub unsafe fn init_userdata_metatable_newindex(state: *mut ffi::lua_State) -> Result<()> {
+    let newindex_key = &USERDATA_METATABLE_NEWINDEX as *const u8 as *const _;
+    if ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, newindex_key) == ffi::LUA_TFUNCTION {
+        return Ok(());
+    }
+    ffi::lua_pop(state, 1);
+
+    // Create and cache `__newindex` generator
+    let code = cstr!(
+        r#"
+            local error, isfunction = ...
+            return function (__newindex, field_setters)
+                return function (self, key, value)
+                    if field_setters ~= nil then
+                        local field_setter = field_setters[key]
+                        if field_setter ~= nil then
+                            field_setter(self, value)
+                            return
+                        end
+                    end
+
+                    if isfunction(__newindex) then
+                        __newindex(self, key, value)
+                    elseif __newindex == nil then
+                        error("attempt to set an unknown field '"..key.."'")
+                    else
+                        __newindex[key] = value
+                    end
+                end
+            end
+    "#
+    );
+    let code_len = CStr::from_ptr(code).to_bytes().len();
+    protect_lua!(state, 0, 1, |state| {
+        let ret = ffi::luaL_loadbuffer(state, code, code_len, cstr!("__mlua_newindex"));
+        if ret != ffi::LUA_OK {
+            ffi::lua_error(state);
+        }
+        ffi::lua_pushcfunction(state, lua_error_impl);
+        ffi::lua_pushcfunction(state, lua_isfunction_impl);
+        ffi::lua_call(state, 2, 1);
+
+        #[cfg(feature = "luau-jit")]
+        if ffi::luau_codegen_supported() != 0 {
+            ffi::luau_codegen_compile(state, -1);
+        }
+
+        // Store in the registry
+        ffi::lua_pushvalue(state, -1);
+        ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, newindex_key);
+    })
+}
+
 // Populates the given table with the appropriate members to be a userdata metatable for the given type.
 // This function takes the given table at the `metatable` index, and adds an appropriate `__gc` member
 // to it for the given type and a `__metatable` entry to protect the table from script access.
@@ -353,106 +550,22 @@ pub unsafe fn get_gc_userdata<T: Any>(state: *mut ffi::lua_State, index: c_int)
 // captured `__index` if no matches found.
 // The same is also applicable for `__newindex` metamethod and `field_setters` table.
 // Internally uses 9 stack spaces and does not call checkstack.
-pub unsafe fn init_userdata_metatable<T>(
+pub unsafe fn init_userdata_metatable(
     state: *mut ffi::lua_State,
     metatable: c_int,
     field_getters: Option<c_int>,
     field_setters: Option<c_int>,
     methods: Option<c_int>,
+    extra_init: Option<fn(*mut ffi::lua_State) -> Result<()>>,
 ) -> Result<()> {
-    // Wrapper to lookup in `field_getters` first, then `methods`, ending original `__index`.
-    // Used only if `field_getters` or `methods` set.
-    unsafe extern "C" fn meta_index_impl(state: *mut ffi::lua_State) -> c_int {
-        // stack: self, key
-        ffi::luaL_checkstack(state, 2, ptr::null());
-
-        // lookup in `field_getters` table
-        if ffi::lua_isnil(state, ffi::lua_upvalueindex(2)) == 0 {
-            ffi::lua_pushvalue(state, -1); // `key` arg
-            if ffi::lua_rawget(state, ffi::lua_upvalueindex(2)) != ffi::LUA_TNIL {
-                ffi::lua_insert(state, -3); // move function
-                ffi::lua_pop(state, 1); // remove `key`
-                ffi::lua_call(state, 1, 1);
-                return 1;
-            }
-            ffi::lua_pop(state, 1); // pop the nil value
-        }
-        // lookup in `methods` table
-        if ffi::lua_isnil(state, ffi::lua_upvalueindex(3)) == 0 {
-            ffi::lua_pushvalue(state, -1); // `key` arg
-            if ffi::lua_rawget(state, ffi::lua_upvalueindex(3)) != ffi::LUA_TNIL {
-                ffi::lua_insert(state, -3);
-                ffi::lua_pop(state, 2);
-                return 1;
-            }
-            ffi::lua_pop(state, 1); // pop the nil value
-        }
-
-        // lookup in `__index`
-        ffi::lua_pushvalue(state, ffi::lua_upvalueindex(1));
-        match ffi::lua_type(state, -1) {
-            ffi::LUA_TNIL => {
-                ffi::lua_pop(state, 1); // pop the nil value
-                let field = ffi::lua_tostring(state, -1);
-                ffi::luaL_error(state, cstr!("attempt to get an unknown field '%s'"), field);
-            }
-            ffi::LUA_TTABLE => {
-                ffi::lua_insert(state, -2);
-                ffi::lua_gettable(state, -2);
-            }
-            ffi::LUA_TFUNCTION => {
-                ffi::lua_insert(state, -3);
-                ffi::lua_call(state, 2, 1);
-            }
-            _ => unreachable!(),
-        }
-
-        1
-    }
-
-    // Similar to `meta_index_impl`, checks `field_setters` table first, then `__newindex` metamethod.
-    // Used only if `field_setters` set.
-    unsafe extern "C" fn meta_newindex_impl(state: *mut ffi::lua_State) -> c_int {
-        // stack: self, key, value
-        ffi::luaL_checkstack(state, 2, ptr::null());
-
-        // lookup in `field_setters` table
-        ffi::lua_pushvalue(state, -2); // `key` arg
-        if ffi::lua_rawget(state, ffi::lua_upvalueindex(2)) != ffi::LUA_TNIL {
-            ffi::lua_remove(state, -3); // remove `key`
-            ffi::lua_insert(state, -3); // move function
-            ffi::lua_call(state, 2, 0);
-            return 0;
-        }
-        ffi::lua_pop(state, 1); // pop the nil value
-
-        // lookup in `__newindex`
-        ffi::lua_pushvalue(state, ffi::lua_upvalueindex(1));
-        match ffi::lua_type(state, -1) {
-            ffi::LUA_TNIL => {
-                ffi::lua_pop(state, 1); // pop the nil value
-                let field = ffi::lua_tostring(state, -2);
-                ffi::luaL_error(state, cstr!("attempt to set an unknown field '%s'"), field);
-            }
-            ffi::LUA_TTABLE => {
-                ffi::lua_insert(state, -3);
-                ffi::lua_settable(state, -3);
-            }
-            ffi::LUA_TFUNCTION => {
-                ffi::lua_insert(state, -4);
-                ffi::lua_call(state, 3, 0);
-            }
-            _ => unreachable!(),
-        }
-
-        0
-    }
-
     ffi::lua_pushvalue(state, metatable);
 
     if field_getters.is_some() || methods.is_some() {
-        push_string(state, "__index")?;
-        let index_type = ffi::lua_rawget(state, -2);
+        // Push `__index` generator function
+        init_userdata_metatable_index(state)?;
+
+        push_string(state, b"__index", true)?;
+        let index_type = ffi::lua_rawget(state, -3);
         match index_type {
             ffi::LUA_TNIL | ffi::LUA_TTABLE | ffi::LUA_TFUNCTION => {
                 for &idx in &[field_getters, methods] {
@@ -462,9 +575,9 @@ pub unsafe fn init_userdata_metatable<T>(
                         ffi::lua_pushnil(state);
                     }
                 }
-                protect_lua!(state, 3, 1, fn(state) {
-                    ffi::lua_pushcclosure(state, meta_index_impl, 3);
-                })?;
+
+                // Generate `__index`
+                protect_lua!(state, 4, 1, fn(state) ffi::lua_call(state, 3, 1))?;
             }
             _ => mlua_panic!("improper __index type {}", index_type),
         }
@@ -473,14 +586,16 @@ pub unsafe fn init_userdata_metatable<T>(
     }
 
     if let Some(field_setters) = field_setters {
-        push_string(state, "__newindex")?;
-        let newindex_type = ffi::lua_rawget(state, -2);
+        // Push `__newindex` generator function
+        init_userdata_metatable_newindex(state)?;
+
+        push_string(state, b"__newindex", true)?;
+        let newindex_type = ffi::lua_rawget(state, -3);
         match newindex_type {
             ffi::LUA_TNIL | ffi::LUA_TTABLE | ffi::LUA_TFUNCTION => {
                 ffi::lua_pushvalue(state, field_setters);
-                protect_lua!(state, 2, 1, fn(state) {
-                    ffi::lua_pushcclosure(state, meta_newindex_impl, 2);
-                })?;
+                // Generate `__newindex`
+                protect_lua!(state, 3, 1, fn(state) ffi::lua_call(state, 2, 1))?;
             }
             _ => mlua_panic!("improper __newindex type {}", newindex_type),
         }
@@ -488,8 +603,10 @@ pub unsafe fn init_userdata_metatable<T>(
         rawset_field(state, -2, "__newindex")?;
     }
 
-    ffi::lua_pushcfunction(state, userdata_destructor::<T>);
-    rawset_field(state, -2, "__gc")?;
+    // Additional initialization
+    if let Some(extra_init) = extra_init {
+        extra_init(state)?;
+    }
 
     ffi::lua_pushboolean(state, 0);
     rawset_field(state, -2, "__metatable")?;
@@ -499,7 +616,8 @@ pub unsafe fn init_userdata_metatable<T>(
     Ok(())
 }
 
-pub unsafe extern "C" fn userdata_destructor<T>(state: *mut ffi::lua_State) -> c_int {
+#[cfg(not(feature = "luau"))]
+pub unsafe extern "C-unwind" fn userdata_destructor<T>(state: *mut ffi::lua_State) -> c_int {
     // It's probably NOT a good idea to catch Rust panics in finalizer
     // Lua 5.4 ignores it, other versions generates `LUA_ERRGCMM` without calling message handler
     take_userdata::<T>(state);
@@ -533,7 +651,7 @@ where
 
     // We cannot shadow Rust errors with Lua ones, we pre-allocate enough memory
     // to store a wrapped error or panic *before* we proceed.
-    let ud = ffi::lua_newuserdata(state, mem::size_of::<WrappedFailure>());
+    let ud = WrappedFailure::new_userdata(state);
     ffi::lua_rotate(state, 1, 1);
 
     match catch_unwind(AssertUnwindSafe(|| f(nargs))) {
@@ -544,8 +662,6 @@ where
         Ok(Err(err)) => {
             ffi::lua_settop(state, 1);
 
-            let wrapped_error = ud as *mut WrappedFailure;
-
             // Build `CallbackError` with traceback
             let traceback = if ffi::lua_checkstack(state, ffi::LUA_TRACEBACK_STACK) != 0 {
                 ffi::luaL_traceback(state, state, ptr::null(), 0);
@@ -556,10 +672,8 @@ where
                 "<not enough stack space for traceback>".to_string()
             };
             let cause = Arc::new(err);
-            ptr::write(
-                wrapped_error,
-                WrappedFailure::Error(Error::CallbackError { traceback, cause }),
-            );
+            let wrapped_error = WrappedFailure::Error(Error::CallbackError { traceback, cause });
+            ptr::write(ud, wrapped_error);
             get_gc_metatable::<WrappedFailure>(state);
             ffi::lua_setmetatable(state, -2);
 
@@ -567,7 +681,7 @@ where
         }
         Err(p) => {
             ffi::lua_settop(state, 1);
-            ptr::write(ud as *mut WrappedFailure, WrappedFailure::Panic(Some(p)));
+            ptr::write(ud, WrappedFailure::Panic(Some(p)));
             get_gc_metatable::<WrappedFailure>(state);
             ffi::lua_setmetatable(state, -2);
             ffi::lua_error(state)
@@ -575,14 +689,21 @@ where
     }
 }
 
-pub unsafe extern "C" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
+pub unsafe extern "C-unwind" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
+    // Luau calls error handler for memory allocation errors, skip it
+    // See https://github.com/Roblox/luau/issues/880
+    #[cfg(feature = "luau")]
+    if MemoryState::limit_reached(state) {
+        return 0;
+    }
+
     if ffi::lua_checkstack(state, 2) == 0 {
         // If we don't have enough stack space to even check the error type, do
         // nothing so we don't risk shadowing a rust panic.
         return 1;
     }
 
-    if get_gc_userdata::<WrappedFailure>(state, -1).is_null() {
+    if get_gc_userdata::<WrappedFailure>(state, -1, ptr::null()).is_null() {
         let s = ffi::luaL_tolstring(state, -1, ptr::null_mut());
         if ffi::lua_checkstack(state, ffi::LUA_TRACEBACK_STACK) != 0 {
             ffi::luaL_traceback(state, state, s, 0);
@@ -593,8 +714,22 @@ pub unsafe extern "C" fn error_traceback(state: *mut ffi::lua_State) -> c_int {
     1
 }
 
+// A variant of `error_traceback` that can safely inspect another (yielded) thread stack
+pub unsafe fn error_traceback_thread(state: *mut ffi::lua_State, thread: *mut ffi::lua_State) {
+    // Move error object to the main thread to safely call `__tostring` metamethod if present
+    ffi::lua_xmove(thread, state, 1);
+
+    if get_gc_userdata::<WrappedFailure>(state, -1, ptr::null()).is_null() {
+        let s = ffi::luaL_tolstring(state, -1, ptr::null_mut());
+        if ffi::lua_checkstack(state, ffi::LUA_TRACEBACK_STACK) != 0 {
+            ffi::luaL_traceback(state, thread, s, 0);
+            ffi::lua_remove(state, -2);
+        }
+    }
+}
+
 // A variant of `pcall` that does not allow Lua to catch Rust panics from `callback_error`.
-pub unsafe extern "C" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
+pub unsafe extern "C-unwind" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
     ffi::luaL_checkstack(state, 2, ptr::null());
 
     let top = ffi::lua_gettop(state);
@@ -609,7 +744,7 @@ pub unsafe extern "C" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
         ffi::lua_gettop(state)
     } else {
         if let Some(WrappedFailure::Panic(_)) =
-            get_gc_userdata::<WrappedFailure>(state, -1).as_ref()
+            get_gc_userdata::<WrappedFailure>(state, -1, ptr::null()).as_ref()
         {
             ffi::lua_error(state);
         }
@@ -620,12 +755,12 @@ pub unsafe extern "C" fn safe_pcall(state: *mut ffi::lua_State) -> c_int {
 }
 
 // A variant of `xpcall` that does not allow Lua to catch Rust panics from `callback_error`.
-pub unsafe extern "C" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
-    unsafe extern "C" fn xpcall_msgh(state: *mut ffi::lua_State) -> c_int {
+pub unsafe extern "C-unwind" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
+    unsafe extern "C-unwind" fn xpcall_msgh(state: *mut ffi::lua_State) -> c_int {
         ffi::luaL_checkstack(state, 2, ptr::null());
 
         if let Some(WrappedFailure::Panic(_)) =
-            get_gc_userdata::<WrappedFailure>(state, -1).as_ref()
+            get_gc_userdata::<WrappedFailure>(state, -1, ptr::null()).as_ref()
         {
             1
         } else {
@@ -655,7 +790,7 @@ pub unsafe extern "C" fn safe_xpcall(state: *mut ffi::lua_State) -> c_int {
         ffi::lua_gettop(state) - 1
     } else {
         if let Some(WrappedFailure::Panic(_)) =
-            get_gc_userdata::<WrappedFailure>(state, -1).as_ref()
+            get_gc_userdata::<WrappedFailure>(state, -1, ptr::null()).as_ref()
         {
             ffi::lua_error(state);
         }
@@ -686,6 +821,8 @@ pub unsafe fn get_main_state(state: *mut ffi::lua_State) -> Option<*mut ffi::lua
             None
         }
     }
+    #[cfg(feature = "luau")]
+    Some(ffi::lua_mainthread(state))
 }
 
 // Initialize the internal (with __gc method) metatable for a type T.
@@ -696,10 +833,13 @@ pub unsafe fn init_gc_metatable<T: Any>(
 ) -> Result<()> {
     check_stack(state, 6)?;
 
-    push_table(state, 0, 3)?;
+    push_table(state, 0, 3, true)?;
 
-    ffi::lua_pushcfunction(state, userdata_destructor::<T>);
-    rawset_field(state, -2, "__gc")?;
+    #[cfg(not(feature = "luau"))]
+    {
+        ffi::lua_pushcfunction(state, userdata_destructor::<T>);
+        rawset_field(state, -2, "__gc")?;
+    }
 
     ffi::lua_pushboolean(state, 0);
     rawset_field(state, -2, "__metatable")?;
@@ -730,11 +870,11 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
 
     // Create error and panic metatables
 
-    unsafe extern "C" fn error_tostring(state: *mut ffi::lua_State) -> c_int {
+    unsafe extern "C-unwind" fn error_tostring(state: *mut ffi::lua_State) -> c_int {
         callback_error(state, |_| {
             check_stack(state, 3)?;
 
-            let err_buf = match get_gc_userdata::<WrappedFailure>(state, -1).as_ref() {
+            let err_buf = match get_gc_userdata::<WrappedFailure>(state, -1, ptr::null()).as_ref() {
                 Some(WrappedFailure::Error(error)) => {
                     let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
                     ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key);
@@ -745,7 +885,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
                     // Depending on how the API is used and what error types scripts are given, it may
                     // be possible to make this consume arbitrary amounts of memory (for example, some
                     // kind of recursive error structure?)
-                    let _ = write!(&mut (*err_buf), "{}", error);
+                    let _ = write!(&mut (*err_buf), "{error}");
                     Ok(err_buf)
                 }
                 Some(WrappedFailure::Panic(Some(ref panic))) => {
@@ -756,9 +896,9 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
                     ffi::lua_pop(state, 2);
 
                     if let Some(msg) = panic.downcast_ref::<&str>() {
-                        let _ = write!(&mut (*err_buf), "{}", msg);
+                        let _ = write!(&mut (*err_buf), "{msg}");
                     } else if let Some(msg) = panic.downcast_ref::<String>() {
-                        let _ = write!(&mut (*err_buf), "{}", msg);
+                        let _ = write!(&mut (*err_buf), "{msg}");
                     } else {
                         let _ = write!(&mut (*err_buf), "<panic>");
                     };
@@ -771,7 +911,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
                 }
             }?;
 
-            push_string(state, &*err_buf)?;
+            push_string(state, (*err_buf).as_bytes(), true)?;
             (*err_buf).clear();
 
             Ok(1)
@@ -788,11 +928,11 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
 
     // Create destructed userdata metatable
 
-    unsafe extern "C" fn destructed_error(state: *mut ffi::lua_State) -> c_int {
+    unsafe extern "C-unwind" fn destructed_error(state: *mut ffi::lua_State) -> c_int {
         callback_error(state, |_| Err(Error::CallbackDestructed))
     }
 
-    push_table(state, 0, 26)?;
+    push_table(state, 0, 26, true)?;
     ffi::lua_pushcfunction(state, destructed_error);
     for &method in &[
         "__add",
@@ -802,7 +942,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
         "__mod",
         "__pow",
         "__unm",
-        #[cfg(any(feature = "lua54", feature = "lua53"))]
+        #[cfg(any(feature = "lua54", feature = "lua53", feature = "luau"))]
         "__idiv",
         #[cfg(any(feature = "lua54", feature = "lua53"))]
         "__band",
@@ -834,6 +974,8 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
         "__pairs",
         #[cfg(any(feature = "lua53", feature = "lua52", feature = "luajit52"))]
         "__ipairs",
+        #[cfg(feature = "luau")]
+        "__iter",
         #[cfg(feature = "lua54")]
         "__close",
     ] {
@@ -849,7 +991,7 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
 
     // Create error print buffer
     init_gc_metatable::<String>(state, None)?;
-    push_gc_userdata(state, String::new())?;
+    push_gc_userdata(state, String::new(), true)?;
     protect_lua!(state, 1, 0, fn(state) {
         let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
         ffi::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key);
@@ -859,10 +1001,22 @@ pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<()> {
 }
 
 pub(crate) enum WrappedFailure {
+    None,
     Error(Error),
     Panic(Option<Box<dyn Any + Send + 'static>>),
 }
 
+impl WrappedFailure {
+    pub(crate) unsafe fn new_userdata(state: *mut ffi::lua_State) -> *mut Self {
+        #[cfg(feature = "luau")]
+        let ud = ffi::lua_newuserdata_t::<Self>(state);
+        #[cfg(not(feature = "luau"))]
+        let ud = ffi::lua_newuserdata(state, std::mem::size_of::<Self>()) as *mut Self;
+        ptr::write(ud, WrappedFailure::None);
+        ud
+    }
+}
+
 // Converts the given lua value to a string in a reasonable format without causing a Lua error or
 // panicking.
 pub(crate) unsafe fn to_string(state: *mut ffi::lua_State, index: c_int) -> String {
@@ -882,6 +1036,16 @@ pub(crate) unsafe fn to_string(state: *mut ffi::lua_State, index: c_int) -> Stri
                 i.to_string()
             }
         }
+        #[cfg(feature = "luau")]
+        ffi::LUA_TVECTOR => {
+            let v = ffi::lua_tovector(state, index);
+            mlua_debug_assert!(!v.is_null(), "vector is null");
+            let (x, y, z) = (*v, *v.add(1), *v.add(2));
+            #[cfg(not(feature = "luau-vector4"))]
+            return format!("vector({x}, {y}, {z})");
+            #[cfg(feature = "luau-vector4")]
+            return format!("vector({x}, {y}, {z}, {w})", w = *v.add(3));
+        }
         ffi::LUA_TSTRING => {
             let mut size = 0;
             // This will not trigger a 'm' error, because the reference is guaranteed to be of
@@ -893,6 +1057,10 @@ pub(crate) unsafe fn to_string(state: *mut ffi::lua_State, index: c_int) -> Stri
         ffi::LUA_TFUNCTION => format!("<function {:?}>", ffi::lua_topointer(state, index)),
         ffi::LUA_TUSERDATA => format!("<userdata {:?}>", ffi::lua_topointer(state, index)),
         ffi::LUA_TTHREAD => format!("<thread {:?}>", ffi::lua_topointer(state, index)),
+        #[cfg(feature = "luau")]
+        ffi::LUA_TBUFFER => format!("<buffer {:?}>", ffi::lua_topointer(state, index)),
+        #[cfg(feature = "luajit")]
+        ffi::LUA_TCDATA => format!("<cdata {:?}>", ffi::lua_topointer(state, index)),
         _ => "<unknown>".to_string(),
     }
 }
@@ -902,5 +1070,30 @@ pub(crate) unsafe fn get_destructed_userdata_metatable(state: *mut ffi::lua_Stat
     ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, key);
 }
 
+pub(crate) unsafe fn ptr_to_str<'a>(input: *const c_char) -> Option<&'a str> {
+    if input.is_null() {
+        return None;
+    }
+    str::from_utf8(CStr::from_ptr(input).to_bytes()).ok()
+}
+
+pub(crate) unsafe fn ptr_to_lossy_str<'a>(input: *const c_char) -> Option<Cow<'a, str>> {
+    if input.is_null() {
+        return None;
+    }
+    Some(String::from_utf8_lossy(CStr::from_ptr(input).to_bytes()))
+}
+
+pub(crate) fn linenumber_to_usize(n: c_int) -> Option<usize> {
+    match n {
+        n if n < 0 => None,
+        n => Some(n as usize),
+    }
+}
+
 static DESTRUCTED_USERDATA_METATABLE: u8 = 0;
 static ERROR_PRINT_BUFFER_KEY: u8 = 0;
+static USERDATA_METATABLE_INDEX: u8 = 0;
+static USERDATA_METATABLE_NEWINDEX: u8 = 0;
+
+mod short_names;

src/util/short_names.rs

@@ -0,0 +1,85 @@
+//! Mostly copied from [bevy_utils]
+//!
+//! [bevy_utils]: https://github.com/bevyengine/bevy/blob/main/crates/bevy_utils/src/short_names.rs
+
+use std::any::type_name;
+
+/// Returns a short version of a type name `T` without all module paths.
+///
+/// The short name of a type is its full name as returned by
+/// [`std::any::type_name`], but with the prefix of all paths removed. For
+/// example, the short name of `alloc::vec::Vec<core::option::Option<u32>>`
+/// would be `Vec<Option<u32>>`.
+pub(crate) fn short_type_name<T: ?Sized>() -> String {
+    let full_name = type_name::<T>();
+
+    // Generics result in nested paths within <..> blocks.
+    // Consider "core::option::Option<alloc::string::String>".
+    // To tackle this, we parse the string from left to right, collapsing as we go.
+    let mut index: usize = 0;
+    let end_of_string = full_name.len();
+    let mut parsed_name = String::new();
+
+    while index < end_of_string {
+        let rest_of_string = full_name.get(index..end_of_string).unwrap_or_default();
+
+        // Collapse everything up to the next special character,
+        // then skip over it
+        if let Some(special_character_index) = rest_of_string
+            .find(|c: char| [' ', '<', '>', '(', ')', '[', ']', ',', ';'].contains(&c))
+        {
+            let segment_to_collapse = rest_of_string
+                .get(0..special_character_index)
+                .unwrap_or_default();
+            parsed_name += collapse_type_name(segment_to_collapse);
+            // Insert the special character
+            let special_character =
+                &rest_of_string[special_character_index..=special_character_index];
+            parsed_name.push_str(special_character);
+
+            match special_character {
+                ">" | ")" | "]"
+                    if rest_of_string[special_character_index + 1..].starts_with("::") =>
+                {
+                    parsed_name.push_str("::");
+                    // Move the index past the "::"
+                    index += special_character_index + 3;
+                }
+                // Move the index just past the special character
+                _ => index += special_character_index + 1,
+            }
+        } else {
+            // If there are no special characters left, we're done!
+            parsed_name += collapse_type_name(rest_of_string);
+            index = end_of_string;
+        }
+    }
+    parsed_name
+}
+
+#[inline(always)]
+fn collapse_type_name(string: &str) -> &str {
+    string.rsplit("::").next().unwrap()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::short_type_name;
+    use std::collections::HashMap;
+
+    #[test]
+    fn tests() {
+        assert_eq!(short_type_name::<String>(), "String");
+        assert_eq!(short_type_name::<Option<String>>(), "Option<String>");
+        assert_eq!(short_type_name::<(String, &str)>(), "(String, &str)");
+        assert_eq!(short_type_name::<[i32; 3]>(), "[i32; 3]");
+        assert_eq!(
+            short_type_name::<HashMap<String, Option<[i32; 3]>>>(),
+            "HashMap<String, Option<[i32; 3]>>"
+        );
+        assert_eq!(
+            short_type_name::<dyn Fn(i32) -> i32>(),
+            "dyn Fn(i32) -> i32"
+        );
+    }
+}

src/value.rs

@@ -1,10 +1,21 @@
-use std::iter::{self, FromIterator};
-use std::{slice, str, vec};
+use std::borrow::Cow;
+use std::cmp::Ordering;
+use std::collections::HashSet;
+use std::iter;
+use std::ops::Index;
+use std::os::raw::{c_int, c_void};
+use std::string::String as StdString;
+use std::sync::Arc;
+use std::{fmt, mem, ptr, slice, str, vec};
+
+use num_traits::FromPrimitive;
 
 #[cfg(feature = "serialize")]
 use {
+    crate::table::SerializableTable,
+    rustc_hash::FxHashSet,
     serde::ser::{self, Serialize, Serializer},
-    std::result::Result as StdResult,
+    std::{cell::RefCell, rc::Rc, result::Result as StdResult},
 };
 
 use crate::error::{Error, Result};
@@ -13,13 +24,14 @@ use crate::lua::Lua;
 use crate::string::String;
 use crate::table::Table;
 use crate::thread::Thread;
-use crate::types::{Integer, LightUserData, Number};
+use crate::types::{Integer, LightUserData, Number, SubtypeId};
 use crate::userdata::AnyUserData;
+use crate::util::{check_stack, StackGuard};
 
 /// A dynamically typed Lua value. The `String`, `Table`, `Function`, `Thread`, and `UserData`
 /// variants contain handle types into the internal Lua state. It is a logic error to mix handle
 /// types between separate `Lua` instances, and doing so will result in a panic.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub enum Value<'lua> {
     /// The Lua value `nil`.
     Nil,
@@ -33,6 +45,10 @@ pub enum Value<'lua> {
     Integer(Integer),
     /// A floating point number.
     Number(Number),
+    /// A Luau vector.
+    #[cfg(any(feature = "luau", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    Vector(crate::types::Vector),
     /// An interned string, managed by Lua.
     ///
     /// Unlike Rust strings, Lua strings may not be valid UTF-8.
@@ -53,6 +69,12 @@ pub enum Value<'lua> {
 pub use self::Value::Nil;
 
 impl<'lua> Value<'lua> {
+    /// A special value (lightuserdata) to represent null value.
+    ///
+    /// It can be used in Lua tables without downsides of `nil`.
+    pub const NULL: Value<'static> = Value::LightUserData(LightUserData(ptr::null_mut()));
+
+    /// Returns type name of this value.
     pub const fn type_name(&self) -> &'static str {
         match *self {
             Value::Nil => "nil",
@@ -60,11 +82,17 @@ impl<'lua> Value<'lua> {
             Value::LightUserData(_) => "lightuserdata",
             Value::Integer(_) => "integer",
             Value::Number(_) => "number",
+            #[cfg(feature = "luau")]
+            Value::Vector(_) => "vector",
             Value::String(_) => "string",
             Value::Table(_) => "table",
             Value::Function(_) => "function",
             Value::Thread(_) => "thread",
-            Value::UserData(_) => "userdata",
+            Value::UserData(AnyUserData(_, SubtypeId::None)) => "userdata",
+            #[cfg(feature = "luau")]
+            Value::UserData(AnyUserData(_, SubtypeId::Buffer)) => "buffer",
+            #[cfg(feature = "luajit")]
+            Value::UserData(AnyUserData(_, SubtypeId::CData)) => "cdata",
             Value::Error(_) => "error",
         }
     }
@@ -83,7 +111,437 @@ impl<'lua> Value<'lua> {
         match (self, other.as_ref()) {
             (Value::Table(a), Value::Table(b)) => a.equals(b),
             (Value::UserData(a), Value::UserData(b)) => a.equals(b),
-            _ => Ok(self == other.as_ref()),
+            (a, b) => Ok(a == b),
+        }
+    }
+
+    /// Converts the value to a generic C pointer.
+    ///
+    /// The value can be a userdata, a table, a thread, a string, or a function; otherwise it returns NULL.
+    /// Different objects will give different pointers.
+    /// There is no way to convert the pointer back to its original value.
+    ///
+    /// Typically this function is used only for hashing and debug information.
+    #[inline]
+    pub fn to_pointer(&self) -> *const c_void {
+        match self {
+            Value::LightUserData(ud) => ud.0,
+            Value::String(String(r))
+            | Value::Table(Table(r))
+            | Value::Function(Function(r))
+            | Value::Thread(Thread(r, ..))
+            | Value::UserData(AnyUserData(r, ..)) => r.to_pointer(),
+            _ => ptr::null(),
+        }
+    }
+
+    /// Converts the value to a string.
+    ///
+    /// If the value has a metatable with a `__tostring` method, then it will be called to get the result.
+    pub fn to_string(&self) -> Result<StdString> {
+        match self {
+            Value::Nil => Ok("nil".to_string()),
+            Value::Boolean(b) => Ok(b.to_string()),
+            Value::LightUserData(ud) if ud.0.is_null() => Ok("null".to_string()),
+            Value::LightUserData(ud) => Ok(format!("lightuserdata: {:p}", ud.0)),
+            Value::Integer(i) => Ok(i.to_string()),
+            Value::Number(n) => Ok(n.to_string()),
+            #[cfg(feature = "luau")]
+            Value::Vector(v) => Ok(v.to_string()),
+            Value::String(s) => Ok(s.to_str()?.to_string()),
+            Value::Table(Table(r))
+            | Value::Function(Function(r))
+            | Value::Thread(Thread(r, ..))
+            | Value::UserData(AnyUserData(r, ..)) => unsafe {
+                let state = r.lua.state();
+                let _guard = StackGuard::new(state);
+                check_stack(state, 3)?;
+
+                r.lua.push_ref(r);
+                protect_lua!(state, 1, 1, fn(state) {
+                    ffi::luaL_tolstring(state, -1, ptr::null_mut());
+                })?;
+                Ok(String(r.lua.pop_ref()).to_str()?.to_string())
+            },
+            Value::Error(err) => Ok(err.to_string()),
+        }
+    }
+
+    /// Returns `true` if the value is a [`Nil`].
+    #[inline]
+    pub fn is_nil(&self) -> bool {
+        self == &Nil
+    }
+
+    /// Returns `true` if the value is a [`NULL`].
+    #[inline]
+    pub fn is_null(&self) -> bool {
+        self == &Self::NULL
+    }
+
+    /// Returns `true` if the value is a boolean.
+    #[inline]
+    pub fn is_boolean(&self) -> bool {
+        self.as_boolean().is_some()
+    }
+
+    /// Cast the value to boolean.
+    ///
+    /// If the value is a Boolean, returns it or `None` otherwise.
+    #[inline]
+    pub fn as_boolean(&self) -> Option<bool> {
+        match *self {
+            Value::Boolean(b) => Some(b),
+            _ => None,
+        }
+    }
+
+    /// Returns `true` if the value is a [`LightUserData`].
+    #[inline]
+    pub fn is_light_userdata(&self) -> bool {
+        self.as_light_userdata().is_some()
+    }
+
+    /// Cast the value to [`LightUserData`].
+    ///
+    /// If the value is a [`LightUserData`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_light_userdata(&self) -> Option<LightUserData> {
+        match *self {
+            Value::LightUserData(l) => Some(l),
+            _ => None,
+        }
+    }
+
+    /// Returns `true` if the value is an [`Integer`].
+    #[inline]
+    pub fn is_integer(&self) -> bool {
+        self.as_integer().is_some()
+    }
+
+    /// Cast the value to [`Integer`].
+    ///
+    /// If the value is a Lua [`Integer`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_integer(&self) -> Option<Integer> {
+        match *self {
+            Value::Integer(i) => Some(i),
+            _ => None,
+        }
+    }
+
+    /// Cast the value to `i32`.
+    ///
+    /// If the value is a Lua [`Integer`], try to convert it to `i32` or return `None` otherwise.
+    #[inline]
+    pub fn as_i32(&self) -> Option<i32> {
+        #[allow(clippy::useless_conversion)]
+        self.as_integer().and_then(|i| i32::try_from(i).ok())
+    }
+
+    /// Cast the value to `u32`.
+    ///
+    /// If the value is a Lua [`Integer`], try to convert it to `u32` or return `None` otherwise.
+    #[inline]
+    pub fn as_u32(&self) -> Option<u32> {
+        self.as_integer().and_then(|i| u32::try_from(i).ok())
+    }
+
+    /// Cast the value to `i64`.
+    ///
+    /// If the value is a Lua [`Integer`], try to convert it to `i64` or return `None` otherwise.
+    #[inline]
+    pub fn as_i64(&self) -> Option<i64> {
+        self.as_integer().map(i64::from)
+    }
+
+    /// Cast the value to `u64`.
+    ///
+    /// If the value is a Lua [`Integer`], try to convert it to `u64` or return `None` otherwise.
+    #[inline]
+    pub fn as_u64(&self) -> Option<u64> {
+        self.as_integer().and_then(|i| u64::try_from(i).ok())
+    }
+
+    /// Cast the value to `isize`.
+    ///
+    /// If the value is a Lua [`Integer`], try to convert it to `isize` or return `None` otherwise.
+    #[inline]
+    pub fn as_isize(&self) -> Option<isize> {
+        self.as_integer().and_then(|i| isize::try_from(i).ok())
+    }
+
+    /// Cast the value to `usize`.
+    ///
+    /// If the value is a Lua [`Integer`], try to convert it to `usize` or return `None` otherwise.
+    #[inline]
+    pub fn as_usize(&self) -> Option<usize> {
+        self.as_integer().and_then(|i| usize::try_from(i).ok())
+    }
+
+    /// Returns `true` if the value is a Lua [`Number`].
+    #[inline]
+    pub fn is_number(&self) -> bool {
+        self.as_number().is_some()
+    }
+
+    /// Cast the value to [`Number`].
+    ///
+    /// If the value is a Lua [`Number`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_number(&self) -> Option<Number> {
+        match *self {
+            Value::Number(n) => Some(n),
+            _ => None,
+        }
+    }
+
+    /// Cast the value to `f32`.
+    ///
+    /// If the value is a Lua [`Number`], try to convert it to `f32` or return `None` otherwise.
+    #[inline]
+    pub fn as_f32(&self) -> Option<f32> {
+        self.as_number().and_then(f32::from_f64)
+    }
+
+    /// Cast the value to `f64`.
+    ///
+    /// If the value is a Lua [`Number`], try to convert it to `f64` or return `None` otherwise.
+    #[inline]
+    pub fn as_f64(&self) -> Option<f64> {
+        self.as_number()
+    }
+
+    /// Returns `true` if the value is a Lua [`String`].
+    #[inline]
+    pub fn is_string(&self) -> bool {
+        self.as_string().is_some()
+    }
+
+    /// Cast the value to Lua [`String`].
+    ///
+    /// If the value is a Lua [`String`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_string(&self) -> Option<&String> {
+        match self {
+            Value::String(s) => Some(s),
+            _ => None,
+        }
+    }
+
+    /// Cast the value to [`str`].
+    ///
+    /// If the value is a Lua [`String`], try to convert it to [`str`] or return `None` otherwise.
+    #[inline]
+    pub fn as_str(&self) -> Option<&str> {
+        self.as_string().and_then(|s| s.to_str().ok())
+    }
+
+    /// Cast the value to [`Cow<str>`].
+    ///
+    /// If the value is a Lua [`String`], converts it to [`Cow<str>`] or returns `None` otherwise.
+    #[inline]
+    pub fn as_string_lossy(&self) -> Option<Cow<str>> {
+        self.as_string().map(|s| s.to_string_lossy())
+    }
+
+    /// Returns `true` if the value is a Lua [`Table`].
+    #[inline]
+    pub fn is_table(&self) -> bool {
+        self.as_table().is_some()
+    }
+
+    /// Cast the value to [`Table`].
+    ///
+    /// If the value is a Lua [`Table`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_table(&self) -> Option<&Table> {
+        match self {
+            Value::Table(t) => Some(t),
+            _ => None,
+        }
+    }
+
+    /// Returns `true` if the value is a Lua [`Thread`].
+    #[inline]
+    pub fn is_thread(&self) -> bool {
+        self.as_thread().is_some()
+    }
+
+    /// Cast the value to [`Thread`].
+    ///
+    /// If the value is a Lua [`Thread`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_thread(&self) -> Option<&Thread> {
+        match self {
+            Value::Thread(t) => Some(t),
+            _ => None,
+        }
+    }
+
+    /// Returns `true` if the value is a Lua [`Function`].
+    #[inline]
+    pub fn is_function(&self) -> bool {
+        self.as_function().is_some()
+    }
+
+    /// Cast the value to [`Function`].
+    ///
+    /// If the value is a Lua [`Function`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_function(&self) -> Option<&Function> {
+        match self {
+            Value::Function(f) => Some(f),
+            _ => None,
+        }
+    }
+
+    /// Returns `true` if the value is an [`AnyUserData`].
+    #[inline]
+    pub fn is_userdata(&self) -> bool {
+        self.as_userdata().is_some()
+    }
+
+    /// Cast the value to [`AnyUserData`].
+    ///
+    /// If the value is an [`AnyUserData`], returns it or `None` otherwise.
+    #[inline]
+    pub fn as_userdata(&self) -> Option<&AnyUserData> {
+        match self {
+            Value::UserData(ud) => Some(ud),
+            _ => None,
+        }
+    }
+
+    /// Returns `true` if the value is a Buffer wrapped in [`AnyUserData`].
+    #[cfg(any(feature = "luau", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
+    #[doc(hidden)]
+    #[inline]
+    pub fn is_buffer(&self) -> bool {
+        self.as_userdata()
+            .map(|ud| ud.1 == SubtypeId::Buffer)
+            .unwrap_or_default()
+    }
+
+    /// Returns `true` if the value is a CData wrapped in [`AnyUserData`].
+    #[cfg(any(feature = "luajit", doc))]
+    #[cfg_attr(docsrs, doc(cfg(feature = "luajit")))]
+    #[doc(hidden)]
+    #[inline]
+    pub fn is_cdata(&self) -> bool {
+        self.as_userdata()
+            .map(|ud| ud.1 == SubtypeId::CData)
+            .unwrap_or_default()
+    }
+
+    /// Wrap reference to this Value into [`SerializableValue`].
+    ///
+    /// This allows customizing serialization behavior using serde.
+    #[cfg(feature = "serialize")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+    #[doc(hidden)]
+    pub fn to_serializable(&self) -> SerializableValue<'_, 'lua> {
+        SerializableValue::new(self, Default::default(), None)
+    }
+
+    // Compares two values.
+    // Used to sort values for Debug printing.
+    pub(crate) fn cmp(&self, other: &Self) -> Ordering {
+        fn cmp_num(a: Number, b: Number) -> Ordering {
+            match (a, b) {
+                _ if a < b => Ordering::Less,
+                _ if a > b => Ordering::Greater,
+                _ => Ordering::Equal,
+            }
+        }
+
+        match (self, other) {
+            // Nil
+            (Value::Nil, Value::Nil) => Ordering::Equal,
+            (Value::Nil, _) => Ordering::Less,
+            (_, Value::Nil) => Ordering::Greater,
+            // Null (a special case)
+            (Value::LightUserData(ud1), Value::LightUserData(ud2)) if ud1 == ud2 => Ordering::Equal,
+            (Value::LightUserData(ud1), _) if ud1.0.is_null() => Ordering::Less,
+            (_, Value::LightUserData(ud2)) if ud2.0.is_null() => Ordering::Greater,
+            // Boolean
+            (Value::Boolean(a), Value::Boolean(b)) => a.cmp(b),
+            (Value::Boolean(_), _) => Ordering::Less,
+            (_, Value::Boolean(_)) => Ordering::Greater,
+            // Integer && Number
+            (Value::Integer(a), Value::Integer(b)) => a.cmp(b),
+            (&Value::Integer(a), &Value::Number(b)) => cmp_num(a as Number, b),
+            (&Value::Number(a), &Value::Integer(b)) => cmp_num(a, b as Number),
+            (&Value::Number(a), &Value::Number(b)) => cmp_num(a, b),
+            (Value::Integer(_) | Value::Number(_), _) => Ordering::Less,
+            (_, Value::Integer(_) | Value::Number(_)) => Ordering::Greater,
+            // String
+            (Value::String(a), Value::String(b)) => a.as_bytes().cmp(b.as_bytes()),
+            (Value::String(_), _) => Ordering::Less,
+            (_, Value::String(_)) => Ordering::Greater,
+            // Other variants can be randomly ordered
+            (a, b) => a.to_pointer().cmp(&b.to_pointer()),
+        }
+    }
+
+    pub(crate) fn fmt_pretty(
+        &self,
+        fmt: &mut fmt::Formatter,
+        recursive: bool,
+        ident: usize,
+        visited: &mut HashSet<*const c_void>,
+    ) -> fmt::Result {
+        match self {
+            Value::Nil => write!(fmt, "nil"),
+            Value::Boolean(b) => write!(fmt, "{b}"),
+            Value::LightUserData(ud) if ud.0.is_null() => write!(fmt, "null"),
+            Value::LightUserData(ud) => write!(fmt, "lightuserdata: {:?}", ud.0),
+            Value::Integer(i) => write!(fmt, "{i}"),
+            Value::Number(n) => write!(fmt, "{n}"),
+            #[cfg(feature = "luau")]
+            Value::Vector(v) => write!(fmt, "{v}"),
+            Value::String(s) => write!(fmt, "{s:?}"),
+            Value::Table(t) if recursive && !visited.contains(&t.to_pointer()) => {
+                t.fmt_pretty(fmt, ident, visited)
+            }
+            t @ Value::Table(_) => write!(fmt, "table: {:?}", t.to_pointer()),
+            f @ Value::Function(_) => write!(fmt, "function: {:?}", f.to_pointer()),
+            t @ Value::Thread(_) => write!(fmt, "thread: {:?}", t.to_pointer()),
+            u @ Value::UserData(ud) => {
+                // Try `__name/__type` first then `__tostring`
+                let name = ud.type_name().ok().flatten();
+                let s = name
+                    .map(|name| format!("{name}: {:?}", u.to_pointer()))
+                    .or_else(|| u.to_string().ok())
+                    .unwrap_or_else(|| format!("userdata: {:?}", u.to_pointer()));
+                write!(fmt, "{s}")
+            }
+            Value::Error(e) if recursive => write!(fmt, "{e:?}"),
+            Value::Error(_) => write!(fmt, "error"),
+        }
+    }
+}
+
+impl fmt::Debug for Value<'_> {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        if fmt.alternate() {
+            return self.fmt_pretty(fmt, true, 0, &mut HashSet::new());
+        }
+        match self {
+            Value::Nil => write!(fmt, "Nil"),
+            Value::Boolean(b) => write!(fmt, "Boolean({b})"),
+            Value::LightUserData(ud) => write!(fmt, "{ud:?}"),
+            Value::Integer(i) => write!(fmt, "Integer({i})"),
+            Value::Number(n) => write!(fmt, "Number({n})"),
+            #[cfg(feature = "luau")]
+            Value::Vector(v) => write!(fmt, "{v:?}"),
+            Value::String(s) => write!(fmt, "String({s:?})"),
+            Value::Table(t) => write!(fmt, "{t:?}"),
+            Value::Function(f) => write!(fmt, "{f:?}"),
+            Value::Thread(t) => write!(fmt, "{t:?}"),
+            Value::UserData(ud) => write!(fmt, "{ud:?}"),
+            Value::Error(e) => write!(fmt, "Error({e:?})"),
         }
     }
 }
@@ -98,6 +556,8 @@ impl<'lua> PartialEq for Value<'lua> {
             (Value::Integer(a), Value::Number(b)) => *a as Number == *b,
             (Value::Number(a), Value::Integer(b)) => *a == *b as Number,
             (Value::Number(a), Value::Number(b)) => *a == *b,
+            #[cfg(feature = "luau")]
+            (Value::Vector(v1), Value::Vector(v2)) => v1 == v2,
             (Value::String(a), Value::String(b)) => a == b,
             (Value::Table(a), Value::Table(b)) => a == b,
             (Value::Function(a), Value::Function(b)) => a == b,
@@ -115,58 +575,218 @@ impl<'lua> AsRef<Value<'lua>> for Value<'lua> {
     }
 }
 
+/// A wrapped [`Value`] with customized serialization behavior.
+#[cfg(feature = "serialize")]
+#[cfg_attr(docsrs, doc(cfg(feature = "serialize")))]
+pub struct SerializableValue<'a, 'lua> {
+    value: &'a Value<'lua>,
+    options: crate::serde::de::Options,
+    // In many cases we don't need `visited` map, so don't allocate memory by default
+    visited: Option<Rc<RefCell<FxHashSet<*const c_void>>>>,
+}
+
 #[cfg(feature = "serialize")]
 impl<'lua> Serialize for Value<'lua> {
+    #[inline]
+    fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
+        SerializableValue::new(self, Default::default(), None).serialize(serializer)
+    }
+}
+
+#[cfg(feature = "serialize")]
+impl<'a, 'lua> SerializableValue<'a, 'lua> {
+    #[inline]
+    pub(crate) fn new(
+        value: &'a Value<'lua>,
+        options: crate::serde::de::Options,
+        visited: Option<&Rc<RefCell<FxHashSet<*const c_void>>>>,
+    ) -> Self {
+        if let Value::Table(_) = value {
+            return Self {
+                value,
+                options,
+                // We need to always initialize the `visited` map for Tables
+                visited: visited.cloned().or_else(|| Some(Default::default())),
+            };
+        }
+        Self {
+            value,
+            options,
+            visited: None,
+        }
+    }
+
+    /// If true, an attempt to serialize types such as [`Function`], [`Thread`], [`LightUserData`]
+    /// and [`Error`] will cause an error.
+    /// Otherwise these types skipped when iterating or serialized as unit type.
+    ///
+    /// Default: **true**
+    #[must_use]
+    pub const fn deny_unsupported_types(mut self, enabled: bool) -> Self {
+        self.options.deny_unsupported_types = enabled;
+        self
+    }
+
+    /// If true, an attempt to serialize a recursive table (table that refers to itself)
+    /// will cause an error.
+    /// Otherwise subsequent attempts to serialize the same table will be ignored.
+    ///
+    /// Default: **true**
+    #[must_use]
+    pub const fn deny_recursive_tables(mut self, enabled: bool) -> Self {
+        self.options.deny_recursive_tables = enabled;
+        self
+    }
+
+    /// If true, keys in tables will be iterated (and serialized) in sorted order.
+    ///
+    /// Default: **false**
+    #[must_use]
+    pub const fn sort_keys(mut self, enabled: bool) -> Self {
+        self.options.sort_keys = enabled;
+        self
+    }
+}
+
+#[cfg(feature = "serialize")]
+impl<'a, 'lua> Serialize for SerializableValue<'a, 'lua> {
     fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
     where
         S: Serializer,
     {
-        match self {
+        match self.value {
             Value::Nil => serializer.serialize_unit(),
             Value::Boolean(b) => serializer.serialize_bool(*b),
             #[allow(clippy::useless_conversion)]
             Value::Integer(i) => serializer.serialize_i64((*i).into()),
-            #[allow(clippy::useless_conversion)]
-            Value::Number(n) => serializer.serialize_f64((*n).into()),
+            Value::Number(n) => serializer.serialize_f64(*n),
+            #[cfg(feature = "luau")]
+            Value::Vector(v) => v.serialize(serializer),
             Value::String(s) => s.serialize(serializer),
-            Value::Table(t) => t.serialize(serializer),
-            Value::UserData(ud) => ud.serialize(serializer),
+            Value::Table(t) => {
+                let visited = self.visited.as_ref().unwrap().clone();
+                SerializableTable::new(t, self.options, visited).serialize(serializer)
+            }
             Value::LightUserData(ud) if ud.0.is_null() => serializer.serialize_none(),
-            Value::Error(_) | Value::LightUserData(_) | Value::Function(_) | Value::Thread(_) => {
-                let msg = format!("cannot serialize <{}>", self.type_name());
-                Err(ser::Error::custom(msg))
+            Value::UserData(ud) if ud.is_serializable() || self.options.deny_unsupported_types => {
+                ud.serialize(serializer)
+            }
+            Value::Function(_)
+            | Value::Thread(_)
+            | Value::UserData(_)
+            | Value::LightUserData(_)
+            | Value::Error(_) => {
+                if self.options.deny_unsupported_types {
+                    let msg = format!("cannot serialize <{}>", self.value.type_name());
+                    Err(ser::Error::custom(msg))
+                } else {
+                    serializer.serialize_unit()
+                }
             }
         }
     }
 }
 
 /// Trait for types convertible to `Value`.
-pub trait ToLua<'lua> {
+pub trait IntoLua<'lua>: Sized {
     /// Performs the conversion.
-    fn to_lua(self, lua: &'lua Lua) -> Result<Value<'lua>>;
+    fn into_lua(self, lua: &'lua Lua) -> Result<Value<'lua>>;
+
+    /// Pushes the value into the Lua stack.
+    ///
+    /// # Safety
+    /// This method does not check Lua stack space.
+    #[doc(hidden)]
+    #[inline]
+    unsafe fn push_into_stack(self, lua: &'lua Lua) -> Result<()> {
+        lua.push_value(self.into_lua(lua)?)
+    }
 }
 
 /// Trait for types convertible from `Value`.
 pub trait FromLua<'lua>: Sized {
     /// Performs the conversion.
-    fn from_lua(lua_value: Value<'lua>, lua: &'lua Lua) -> Result<Self>;
+    fn from_lua(value: Value<'lua>, lua: &'lua Lua) -> Result<Self>;
+
+    /// Performs the conversion for an argument (eg. function argument).
+    ///
+    /// `i` is the argument index (position),
+    /// `to` is a function name that received the argument.
+    #[doc(hidden)]
+    #[inline]
+    fn from_lua_arg(arg: Value<'lua>, i: usize, to: Option<&str>, lua: &'lua Lua) -> Result<Self> {
+        Self::from_lua(arg, lua).map_err(|err| Error::BadArgument {
+            to: to.map(|s| s.to_string()),
+            pos: i,
+            name: None,
+            cause: Arc::new(err),
+        })
+    }
+
+    /// Performs the conversion for a value in the Lua stack at index `idx`.
+    #[doc(hidden)]
+    #[inline]
+    unsafe fn from_stack(idx: c_int, lua: &'lua Lua) -> Result<Self> {
+        Self::from_lua(lua.stack_value(idx), lua)
+    }
+
+    /// Same as `from_lua_arg` but for a value in the Lua stack at index `idx`.
+    #[doc(hidden)]
+    #[inline]
+    unsafe fn from_stack_arg(
+        idx: c_int,
+        i: usize,
+        to: Option<&str>,
+        lua: &'lua Lua,
+    ) -> Result<Self> {
+        Self::from_stack(idx, lua).map_err(|err| Error::BadArgument {
+            to: to.map(|s| s.to_string()),
+            pos: i,
+            name: None,
+            cause: Arc::new(err),
+        })
+    }
 }
 
 /// Multiple Lua values used for both argument passing and also for multiple return values.
 #[derive(Debug, Clone)]
-pub struct MultiValue<'lua>(Vec<Value<'lua>>);
+pub struct MultiValue<'lua> {
+    vec: Vec<Value<'lua>>,
+    lua: Option<&'lua Lua>,
+}
+
+impl Drop for MultiValue<'_> {
+    fn drop(&mut self) {
+        if let Some(lua) = self.lua {
+            let vec = mem::take(&mut self.vec);
+            lua.push_multivalue_to_pool(vec);
+        }
+    }
+}
 
 impl<'lua> MultiValue<'lua> {
     /// Creates an empty `MultiValue` containing no values.
-    #[inline]
-    pub fn new() -> MultiValue<'lua> {
-        MultiValue(Vec::new())
+    pub const fn new() -> MultiValue<'lua> {
+        MultiValue {
+            vec: Vec::new(),
+            lua: None,
+        }
     }
 
-    /// Similar to `new` but can return previously used container with allocated capacity.
+    /// Similar to `new` but can reuse previously used container with allocated capacity.
     #[inline]
-    pub(crate) fn new_or_cached(lua: &'lua Lua) -> MultiValue<'lua> {
-        lua.new_or_cached_multivalue()
+    pub(crate) fn with_lua_and_capacity(lua: &'lua Lua, capacity: usize) -> MultiValue<'lua> {
+        let vec = lua
+            .pop_multivalue_from_pool()
+            .map(|mut vec| {
+                vec.reserve(capacity);
+                vec
+            })
+            .unwrap_or_else(|| Vec::with_capacity(capacity));
+        MultiValue {
+            vec,
+            lua: Some(lua),
+        }
     }
 }
 
@@ -189,8 +809,10 @@ impl<'lua> IntoIterator for MultiValue<'lua> {
     type IntoIter = iter::Rev<vec::IntoIter<Value<'lua>>>;
 
     #[inline]
-    fn into_iter(self) -> Self::IntoIter {
-        self.0.into_iter().rev()
+    fn into_iter(mut self) -> Self::IntoIter {
+        let vec = mem::take(&mut self.vec);
+        mem::forget(self);
+        vec.into_iter().rev()
     }
 }
 
@@ -200,62 +822,83 @@ impl<'a, 'lua> IntoIterator for &'a MultiValue<'lua> {
 
     #[inline]
     fn into_iter(self) -> Self::IntoIter {
-        (&self.0).iter().rev()
+        self.vec.iter().rev()
+    }
+}
+
+impl<'lua> Index<usize> for MultiValue<'lua> {
+    type Output = Value<'lua>;
+
+    #[inline]
+    fn index(&self, index: usize) -> &Self::Output {
+        if let Some(result) = self.get(index) {
+            result
+        } else {
+            panic!(
+                "index out of bounds: the len is {} but the index is {}",
+                self.len(),
+                index
+            )
+        }
     }
 }
 
 impl<'lua> MultiValue<'lua> {
     #[inline]
-    pub fn from_vec(mut v: Vec<Value<'lua>>) -> MultiValue<'lua> {
-        v.reverse();
-        MultiValue(v)
+    pub fn from_vec(mut vec: Vec<Value<'lua>>) -> MultiValue<'lua> {
+        vec.reverse();
+        MultiValue { vec, lua: None }
     }
 
     #[inline]
-    pub fn into_vec(self) -> Vec<Value<'lua>> {
-        let mut v = self.0;
-        v.reverse();
-        v
+    pub fn into_vec(mut self) -> Vec<Value<'lua>> {
+        let mut vec = mem::take(&mut self.vec);
+        mem::forget(self);
+        vec.reverse();
+        vec
     }
 
     #[inline]
-    pub(crate) fn reserve(&mut self, size: usize) {
-        self.0.reserve(size);
+    pub fn get(&self, index: usize) -> Option<&Value<'lua>> {
+        if index < self.vec.len() {
+            return self.vec.get(self.vec.len() - index - 1);
+        }
+        None
     }
 
     #[inline]
-    pub(crate) fn push_front(&mut self, value: Value<'lua>) {
-        self.0.push(value);
+    pub fn pop_front(&mut self) -> Option<Value<'lua>> {
+        self.vec.pop()
     }
 
     #[inline]
-    pub(crate) fn pop_front(&mut self) -> Option<Value<'lua>> {
-        self.0.pop()
+    pub fn push_front(&mut self, value: Value<'lua>) {
+        self.vec.push(value);
     }
 
     #[inline]
     pub fn clear(&mut self) {
-        self.0.clear();
+        self.vec.clear();
     }
 
     #[inline]
     pub fn len(&self) -> usize {
-        self.0.len()
+        self.vec.len()
     }
 
     #[inline]
     pub fn is_empty(&self) -> bool {
-        self.0.is_empty()
+        self.vec.is_empty()
     }
 
     #[inline]
     pub fn iter(&self) -> iter::Rev<slice::Iter<Value<'lua>>> {
-        self.0.iter().rev()
+        self.vec.iter().rev()
     }
 
     #[inline]
     pub(crate) fn drain_all(&mut self) -> iter::Rev<vec::Drain<Value<'lua>>> {
-        self.0.drain(..).rev()
+        self.vec.drain(..).rev()
     }
 
     #[inline]
@@ -263,22 +906,39 @@ impl<'lua> MultiValue<'lua> {
         &mut self,
         iter: impl IntoIterator<Item = Result<Value<'lua>>>,
     ) -> Result<()> {
-        self.0.clear();
+        self.vec.clear();
         for value in iter {
-            self.0.push(value?);
+            self.vec.push(value?);
         }
-        self.0.reverse();
+        self.vec.reverse();
         Ok(())
     }
 }
 
 /// Trait for types convertible to any number of Lua values.
 ///
-/// This is a generalization of `ToLua`, allowing any number of resulting Lua values instead of just
-/// one. Any type that implements `ToLua` will automatically implement this trait.
-pub trait ToLuaMulti<'lua> {
+/// This is a generalization of `IntoLua`, allowing any number of resulting Lua values instead of just
+/// one. Any type that implements `IntoLua` will automatically implement this trait.
+pub trait IntoLuaMulti<'lua>: Sized {
     /// Performs the conversion.
-    fn to_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>>;
+    fn into_lua_multi(self, lua: &'lua Lua) -> Result<MultiValue<'lua>>;
+
+    /// Pushes the values into the Lua stack.
+    ///
+    /// Returns number of pushed values.
+    #[doc(hidden)]
+    #[inline]
+    unsafe fn push_into_stack_multi(self, lua: &'lua Lua) -> Result<c_int> {
+        let mut values = self.into_lua_multi(lua)?;
+        let len: c_int = values.len().try_into().unwrap();
+        unsafe {
+            check_stack(lua.state(), len + 1)?;
+            for v in values.drain_all() {
+                lua.push_value(v)?;
+            }
+        }
+        Ok(len)
+    }
 }
 
 /// Trait for types that can be created from an arbitrary number of Lua values.
@@ -293,4 +953,56 @@ pub trait FromLuaMulti<'lua>: Sized {
     /// assigning values. Similarly, if not enough values are given, conversions should assume that
     /// any missing values are nil.
     fn from_lua_multi(values: MultiValue<'lua>, lua: &'lua Lua) -> Result<Self>;
+
+    /// Performs the conversion for a list of arguments.
+    ///
+    /// `i` is an index (position) of the first argument,
+    /// `to` is a function name that received the arguments.
+    #[doc(hidden)]
+    #[inline]
+    fn from_lua_args(
+        args: MultiValue<'lua>,
+        i: usize,
+        to: Option<&str>,
+        lua: &'lua Lua,
+    ) -> Result<Self> {
+        let _ = (i, to);
+        Self::from_lua_multi(args, lua)
+    }
+
+    /// Performs the conversion for a number of values in the Lua stack.
+    #[doc(hidden)]
+    #[inline]
+    unsafe fn from_stack_multi(nvals: c_int, lua: &'lua Lua) -> Result<Self> {
+        let mut values = MultiValue::with_lua_and_capacity(lua, nvals as usize);
+        for idx in 1..=nvals {
+            values.push_front(lua.stack_value(-idx));
+        }
+        if nvals > 0 {
+            // It's safe to clear the stack as all references moved to ref thread
+            ffi::lua_pop(lua.state(), nvals);
+        }
+        Self::from_lua_multi(values, lua)
+    }
+
+    /// Same as `from_lua_args` but for a number of values in the Lua stack.
+    #[doc(hidden)]
+    #[inline]
+    unsafe fn from_stack_args(
+        nargs: c_int,
+        i: usize,
+        to: Option<&str>,
+        lua: &'lua Lua,
+    ) -> Result<Self> {
+        let _ = (i, to);
+        Self::from_stack_multi(nargs, lua)
+    }
+}
+
+#[cfg(test)]
+mod assertions {
+    use super::*;
+
+    static_assertions::assert_not_impl_any!(Value: Send);
+    static_assertions::assert_not_impl_any!(MultiValue: Send);
 }

tarpaulin.toml

@@ -0,0 +1,8 @@
+[lua54_coverage]
+features = "lua54,vendored,async,serialize,macros,unstable"
+
+[lua51_coverage]
+features = "lua51,vendored,async,serialize,macros,unstable"
+
+[luau_coverage]
+features = "luau,async,serialize,macros,unstable"

tests/async.rs

@@ -1,21 +1,26 @@
 #![cfg(feature = "async")]
 
-use std::cell::Cell;
-use std::rc::Rc;
-use std::sync::{
-    atomic::{AtomicI64, AtomicU64, Ordering},
-    Arc,
-};
+use std::sync::{Arc, Mutex};
 use std::time::Duration;
 
-use futures_timer::Delay;
 use futures_util::stream::TryStreamExt;
 
 use mlua::{
-    Error, Function, Lua, LuaOptions, MetaMethod, Result, StdLib, Table, TableExt, Thread,
+    AnyUserDataExt, Error, Function, Lua, LuaOptions, MultiValue, Result, StdLib, Table, TableExt,
     UserData, UserDataMethods, Value,
 };
 
+#[cfg(not(target_arch = "wasm32"))]
+async fn sleep_ms(ms: u64) {
+    tokio::time::sleep(Duration::from_millis(ms)).await;
+}
+
+#[cfg(target_arch = "wasm32")]
+async fn sleep_ms(_ms: u64) {
+    // I was unable to make sleep() work in wasm32-emscripten target
+    tokio::task::yield_now().await;
+}
+
 #[tokio::test]
 async fn test_async_function() -> Result<()> {
     let lua = Lua::new();
@@ -30,12 +35,25 @@ async fn test_async_function() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn test_async_function_wrap() -> Result<()> {
+    let lua = Lua::new();
+
+    let f = Function::wrap_async(|_, s: String| async move { Ok(s) });
+    lua.globals().set("f", f)?;
+
+    let res: String = lua.load(r#"f("hello")"#).eval_async().await?;
+    assert_eq!(res, "hello");
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn test_async_sleep() -> Result<()> {
     let lua = Lua::new();
 
     let sleep = lua.create_async_function(move |_lua, n: u64| async move {
-        Delay::new(Duration::from_millis(n)).await;
+        sleep_ms(n).await;
         Ok(format!("elapsed:{}ms", n))
     })?;
     lua.globals().set("sleep", sleep)?;
@@ -51,7 +69,7 @@ async fn test_async_call() -> Result<()> {
     let lua = Lua::new();
 
     let hello = lua.create_async_function(|_lua, name: String| async move {
-        Delay::new(Duration::from_millis(10)).await;
+        sleep_ms(10).await;
         Ok(format!("hello, {}!", name))
     })?;
 
@@ -71,11 +89,33 @@ async fn test_async_call() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn test_async_call_many_returns() -> Result<()> {
+    let lua = Lua::new();
+
+    let hello = lua.create_async_function(|_lua, ()| async move {
+        sleep_ms(10).await;
+        Ok(("a", "b", "c", 1))
+    })?;
+
+    let vals = hello.call_async::<_, MultiValue>(()).await?;
+    assert_eq!(vals.len(), 4);
+    assert_eq!(vals[0].to_string()?, "a");
+    assert_eq!(vals[1].to_string()?, "b");
+    assert_eq!(vals[2].to_string()?, "c");
+    assert_eq!(vals[3], Value::Integer(1));
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn test_async_bind_call() -> Result<()> {
     let lua = Lua::new();
 
-    let sum = lua.create_async_function(|_lua, (a, b): (i64, i64)| async move { Ok(a + b) })?;
+    let sum = lua.create_async_function(|_lua, (a, b): (i64, i64)| async move {
+        tokio::task::yield_now().await;
+        Ok(a + b)
+    })?;
 
     let plus_10 = sum.bind(10)?;
     lua.globals().set("plus_10", plus_10)?;
@@ -91,7 +131,7 @@ async fn test_async_handle_yield() -> Result<()> {
     let lua = Lua::new();
 
     let sum = lua.create_async_function(|_lua, (a, b): (i64, i64)| async move {
-        Delay::new(Duration::from_millis(10)).await;
+        sleep_ms(10).await;
         Ok(a + b)
     })?;
 
@@ -149,10 +189,10 @@ async fn test_async_return_async_closure() -> Result<()> {
     let lua = Lua::new();
 
     let f = lua.create_async_function(|lua, a: i64| async move {
-        Delay::new(Duration::from_millis(10)).await;
+        sleep_ms(10).await;
 
         let g = lua.create_async_function(move |_, b: i64| async move {
-            Delay::new(Duration::from_millis(10)).await;
+            sleep_ms(10).await;
             return Ok(a + b);
         })?;
 
@@ -171,6 +211,38 @@ async fn test_async_return_async_closure() -> Result<()> {
     Ok(())
 }
 
+#[cfg(feature = "lua54")]
+#[tokio::test]
+async fn test_async_lua54_to_be_closed() -> Result<()> {
+    let lua = Lua::new();
+
+    let globals = lua.globals();
+    globals.set("close_count", 0)?;
+
+    let code = r#"
+        local t <close> = setmetatable({}, {
+            __close = function()
+                close_count = close_count + 1
+            end
+        })
+        error "test"
+    "#;
+    let f = lua.load(code).into_function()?;
+
+    // Test close using call_async
+    let _ = f.call_async::<_, ()>(()).await;
+    assert_eq!(globals.get::<_, usize>("close_count")?, 1);
+
+    // Don't close by default when awaiting async threads
+    let co = lua.create_thread(f.clone())?;
+    let _ = co.clone().into_async::<_, ()>(()).await;
+    assert_eq!(globals.get::<_, usize>("close_count")?, 1);
+    let _ = co.reset(f);
+    assert_eq!(globals.get::<_, usize>("close_count")?, 2);
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn test_async_thread_stream() -> Result<()> {
     let lua = Lua::new();
@@ -210,7 +282,7 @@ async fn test_async_thread() -> Result<()> {
     let f = lua.create_async_function(move |_lua, ()| {
         let cnt3 = cnt2.clone();
         async move {
-            Delay::new(Duration::from_millis(*cnt3.as_ref())).await;
+            sleep_ms(*cnt3.as_ref()).await;
             Ok("done")
         }
     })?;
@@ -226,92 +298,152 @@ async fn test_async_thread() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn test_async_thread_capture() -> Result<()> {
+    let lua = Lua::new();
+
+    let f = lua.create_async_function(move |_lua, v: Value| async move {
+        tokio::task::yield_now().await;
+        drop(v);
+        Ok(())
+    })?;
+
+    let thread = lua.create_thread(f)?;
+    // After first resume, `v: Value` is captured in the coroutine
+    thread.resume::<_, ()>("abc").unwrap();
+    drop(thread);
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn test_async_table() -> Result<()> {
-    let options = LuaOptions::new().thread_cache_size(4);
+    let options = LuaOptions::new().thread_pool_size(4);
     let lua = Lua::new_with(StdLib::ALL_SAFE, options)?;
 
     let table = lua.create_table()?;
     table.set("val", 10)?;
 
     let get_value = lua.create_async_function(|_, table: Table| async move {
-        Delay::new(Duration::from_millis(10)).await;
+        sleep_ms(10).await;
         table.get::<_, i64>("val")
     })?;
     table.set("get_value", get_value)?;
 
     let set_value = lua.create_async_function(|_, (table, n): (Table, i64)| async move {
-        Delay::new(Duration::from_millis(10)).await;
+        sleep_ms(10).await;
         table.set("val", n)
     })?;
     table.set("set_value", set_value)?;
 
     let sleep = lua.create_async_function(|_, n| async move {
-        Delay::new(Duration::from_millis(n)).await;
+        sleep_ms(n).await;
         Ok(format!("elapsed:{}ms", n))
     })?;
     table.set("sleep", sleep)?;
 
     assert_eq!(
-        table
-            .call_async_method::<_, _, i64>("get_value", ())
-            .await?,
+        table.call_async_method::<_, i64>("get_value", ()).await?,
         10
     );
     table.call_async_method("set_value", 15).await?;
     assert_eq!(
-        table
-            .call_async_method::<_, _, i64>("get_value", ())
-            .await?,
+        table.call_async_method::<_, i64>("get_value", ()).await?,
         15
     );
     assert_eq!(
-        table
-            .call_async_function::<_, _, String>("sleep", 7)
-            .await?,
+        table.call_async_function::<_, String>("sleep", 7).await?,
         "elapsed:7ms"
     );
 
     Ok(())
 }
 
+#[tokio::test]
+async fn test_async_thread_pool() -> Result<()> {
+    let options = LuaOptions::new().thread_pool_size(4);
+    let lua = Lua::new_with(StdLib::ALL_SAFE, options)?;
+
+    let error_f = lua.create_async_function(|_, ()| async move {
+        sleep_ms(10).await;
+        Err::<(), _>(Error::runtime("test"))
+    })?;
+
+    let sleep = lua.create_async_function(|_, n| async move {
+        sleep_ms(n).await;
+        Ok(format!("elapsed:{}ms", n))
+    })?;
+
+    assert!(error_f.call_async::<_, ()>(()).await.is_err());
+    // Next call should use cached thread
+    assert_eq!(sleep.call_async::<_, String>(3).await?, "elapsed:3ms");
+
+    Ok(())
+}
+
 #[tokio::test]
 async fn test_async_userdata() -> Result<()> {
-    #[derive(Clone)]
-    struct MyUserData(Arc<AtomicU64>);
+    struct MyUserData(u64);
 
     impl UserData for MyUserData {
         fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
             methods.add_async_method("get_value", |_, data, ()| async move {
-                Delay::new(Duration::from_millis(10)).await;
-                Ok(data.0.load(Ordering::Relaxed))
+                sleep_ms(10).await;
+                Ok(data.0)
             });
 
-            methods.add_async_method("set_value", |_, data, n| async move {
-                Delay::new(Duration::from_millis(10)).await;
-                data.0.store(n, Ordering::Relaxed);
+            methods.add_async_method_mut("set_value", |_, data, n| async move {
+                sleep_ms(10).await;
+                data.0 = n;
                 Ok(())
             });
 
             methods.add_async_function("sleep", |_, n| async move {
-                Delay::new(Duration::from_millis(n)).await;
+                sleep_ms(n).await;
                 Ok(format!("elapsed:{}ms", n))
             });
 
-            #[cfg(not(feature = "lua51"))]
-            methods.add_async_meta_method(MetaMethod::Call, |_, data, ()| async move {
-                let n = data.0.load(Ordering::Relaxed);
-                Delay::new(Duration::from_millis(n)).await;
+            #[cfg(not(any(feature = "lua51", feature = "luau")))]
+            methods.add_async_meta_method(mlua::MetaMethod::Call, |_, data, ()| async move {
+                let n = data.0;
+                sleep_ms(n).await;
                 Ok(format!("elapsed:{}ms", n))
             });
+
+            #[cfg(not(any(feature = "lua51", feature = "luau")))]
+            methods.add_async_meta_method(
+                mlua::MetaMethod::Index,
+                |_, data, key: String| async move {
+                    sleep_ms(10).await;
+                    match key.as_str() {
+                        "ms" => Ok(Some(data.0 as f64)),
+                        "s" => Ok(Some((data.0 as f64) / 1000.0)),
+                        _ => Ok(None),
+                    }
+                },
+            );
+
+            #[cfg(not(any(feature = "lua51", feature = "luau")))]
+            methods.add_async_meta_method_mut(
+                mlua::MetaMethod::NewIndex,
+                |_, data, (key, value): (String, f64)| async move {
+                    sleep_ms(10).await;
+                    match key.as_str() {
+                        "ms" => data.0 = value as u64,
+                        "s" => data.0 = (value * 1000.0) as u64,
+                        _ => return Err(Error::external(format!("key '{}' not found", key))),
+                    }
+                    Ok(())
+                },
+            );
         }
     }
 
     let lua = Lua::new();
     let globals = lua.globals();
 
-    let userdata = lua.create_userdata(MyUserData(Arc::new(AtomicU64::new(11))))?;
-    globals.set("userdata", userdata.clone())?;
+    let userdata = lua.create_userdata(MyUserData(11))?;
+    globals.set("userdata", &userdata)?;
 
     lua.load(
         r#"
@@ -324,133 +456,93 @@ async fn test_async_userdata() -> Result<()> {
     .exec_async()
     .await?;
 
-    #[cfg(not(feature = "lua51"))]
+    #[cfg(not(any(feature = "lua51", feature = "luau")))]
     lua.load(
         r#"
         userdata:set_value(15)
         assert(userdata() == "elapsed:15ms")
+
+        userdata.ms = 2000
+        assert(userdata.s == 2)
+
+        userdata.s = 15
+        assert(userdata.ms == 15000)
     "#,
     )
     .exec_async()
     .await?;
 
-    Ok(())
-}
+    userdata.call_async_method("set_value", 24).await?;
+    let n: u64 = userdata.call_async_method("get_value", ()).await?;
+    assert_eq!(n, 24);
+    userdata.call_async_function("sleep", 15).await?;
 
-#[tokio::test]
-async fn test_async_scope() -> Result<()> {
-    let ref lua = Lua::new();
-
-    let ref rc = Rc::new(Cell::new(0));
-
-    let fut = lua.async_scope(|scope| async move {
-        let f = scope.create_async_function(move |_, n: u64| {
-            let rc2 = rc.clone();
-            async move {
-                rc2.set(42);
-                Delay::new(Duration::from_millis(n)).await;
-                assert_eq!(Rc::strong_count(&rc2), 2);
-                Ok(())
-            }
-        })?;
-
-        lua.globals().set("f", f.clone())?;
-
-        assert_eq!(Rc::strong_count(rc), 1);
-        let _ = f.call_async::<u64, ()>(10).await?;
-        assert_eq!(Rc::strong_count(rc), 1);
-
-        // Create future in partialy polled state (Poll::Pending)
-        let g = lua.create_thread(f)?;
-        g.resume::<u64, ()>(10)?;
-        lua.globals().set("g", g)?;
-        assert_eq!(Rc::strong_count(rc), 2);
-
-        Ok(())
-    });
-
-    assert_eq!(Rc::strong_count(rc), 1);
-    let _ = fut.await?;
-    assert_eq!(Rc::strong_count(rc), 1);
-
-    match lua
-        .globals()
-        .get::<_, Function>("f")?
-        .call_async::<_, ()>(10)
-        .await
-    {
-        Err(Error::CallbackError { ref cause, .. }) => match cause.as_ref() {
-            Error::CallbackDestructed => {}
-            e => panic!("expected `CallbackDestructed` error cause, got {:?}", e),
-        },
-        r => panic!("improper return for destructed function: {:?}", r),
-    };
-
-    match lua.globals().get::<_, Thread>("g")?.resume::<_, Value>(()) {
-        Err(Error::CallbackError { ref cause, .. }) => match cause.as_ref() {
-            Error::CallbackDestructed => {}
-            e => panic!("expected `CallbackDestructed` error cause, got {:?}", e),
-        },
-        r => panic!("improper return for destructed function: {:?}", r),
-    };
+    #[cfg(not(any(feature = "lua51", feature = "luau")))]
+    assert_eq!(userdata.call_async::<_, String>(()).await?, "elapsed:24ms");
 
     Ok(())
 }
 
 #[tokio::test]
-async fn test_async_scope_userdata() -> Result<()> {
-    #[derive(Clone)]
-    struct MyUserData(Arc<AtomicI64>);
+async fn test_async_thread_error() -> Result<()> {
+    struct MyUserData;
 
     impl UserData for MyUserData {
         fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
-            methods.add_async_method("get_value", |_, data, ()| async move {
-                Delay::new(Duration::from_millis(10)).await;
-                Ok(data.0.load(Ordering::Relaxed))
-            });
-
-            methods.add_async_method("set_value", |_, data, n| async move {
-                Delay::new(Duration::from_millis(10)).await;
-                data.0.store(n, Ordering::Relaxed);
-                Ok(())
-            });
-
-            methods.add_async_function("sleep", |_, n| async move {
-                Delay::new(Duration::from_millis(n)).await;
-                Ok(format!("elapsed:{}ms", n))
-            });
+            methods.add_meta_method("__tostring", |_, _this, ()| Ok("myuserdata error"))
         }
     }
 
-    let ref lua = Lua::new();
-
-    let ref arc = Arc::new(AtomicI64::new(11));
-
-    lua.async_scope(|scope| async move {
-        let ud = scope.create_userdata(MyUserData(arc.clone()))?;
-        lua.globals().set("userdata", ud)?;
-        lua.load(
-            r#"
-            assert(userdata:get_value() == 11)
-            userdata:set_value(12)
-            assert(userdata.sleep(5) == "elapsed:5ms")
-            assert(userdata:get_value() == 12)
-        "#,
-        )
-        .exec_async()
-        .await
-    })
-    .await?;
-
-    assert_eq!(Arc::strong_count(arc), 1);
-
-    match lua.load("userdata:get_value()").exec_async().await {
-        Err(Error::CallbackError { ref cause, .. }) => match cause.as_ref() {
-            Error::CallbackDestructed => {}
-            e => panic!("expected `CallbackDestructed` error cause, got {:?}", e),
-        },
-        r => panic!("improper return for destructed userdata: {:?}", r),
-    };
+    let lua = Lua::new();
+    let result = lua
+        .load("function x(...) error(...) end x(...)")
+        .set_name("chunk")
+        .call_async::<_, ()>(MyUserData)
+        .await;
+    assert!(
+        matches!(result, Err(Error::RuntimeError(cause)) if cause.contains("myuserdata error")),
+        "improper error traceback from dead thread"
+    );
+
+    Ok(())
+}
+
+#[cfg(all(feature = "unstable", not(feature = "send")))]
+#[tokio::test]
+async fn test_owned_async_call() -> Result<()> {
+    let lua = Lua::new();
+
+    let hello = lua
+        .create_async_function(|_, name: String| async move {
+            sleep_ms(10).await;
+            Ok(format!("hello, {}!", name))
+        })?
+        .into_owned();
+    drop(lua);
+
+    assert_eq!(hello.call_async::<_, String>("alex").await?, "hello, alex!");
+
+    Ok(())
+}
+
+#[tokio::test]
+async fn test_async_terminate() -> Result<()> {
+    let lua = Lua::new();
+
+    let mutex = Arc::new(Mutex::new(0u32));
+    let mutex2 = mutex.clone();
+    let func = lua.create_async_function(move |_, ()| {
+        let mutex = mutex2.clone();
+        async move {
+            let _guard = mutex.lock();
+            sleep_ms(100).await;
+            Ok(())
+        }
+    })?;
+
+    let _ = tokio::time::timeout(Duration::from_millis(30), func.call_async::<_, ()>(())).await;
+    lua.gc_collect()?;
+    assert!(mutex.try_lock().is_ok());
 
     Ok(())
 }

tests/chunk.rs

@@ -0,0 +1,71 @@
+use std::fs;
+use std::io;
+
+use mlua::{Lua, Result};
+
+#[test]
+fn test_chunk_path() -> Result<()> {
+    let lua = Lua::new();
+
+    if cfg!(target_arch = "wasm32") {
+        // TODO: figure out why emscripten fails on file operations
+        // Also see https://github.com/rust-lang/rust/issues/119250
+        return Ok(());
+    }
+
+    let temp_dir = tempfile::tempdir().unwrap();
+    fs::write(
+        temp_dir.path().join("module.lua"),
+        r#"
+        return 321
+    "#,
+    )?;
+    let i: i32 = lua.load(&*temp_dir.path().join("module.lua")).eval()?;
+    assert_eq!(i, 321);
+
+    match lua.load(&*temp_dir.path().join("module2.lua")).exec() {
+        Err(err) if err.downcast_ref::<io::Error>().unwrap().kind() == io::ErrorKind::NotFound => {}
+        res => panic!("expected io::Error, got {:?}", res),
+    };
+
+    Ok(())
+}
+
+#[test]
+#[cfg(feature = "macros")]
+fn test_chunk_macro() -> Result<()> {
+    let lua = Lua::new();
+
+    let name = "Rustacean";
+    let table = vec![1];
+
+    let data = lua.create_table()?;
+    data.raw_set("num", 1)?;
+
+    let ud = mlua::AnyUserData::wrap("hello");
+    let f = mlua::Function::wrap(|_lua, ()| Ok(()));
+
+    lua.globals().set("g", 123)?;
+
+    let string = String::new();
+    let str = string.as_str();
+
+    lua.load(mlua::chunk! {
+        assert($name == "Rustacean")
+        assert(type($table) == "table")
+        assert($table[1] == 1)
+        assert(type($data) == "table")
+        assert($data.num == 1)
+        assert(type($ud) == "userdata")
+        assert(type($f) == "function")
+        assert(type($str) == "string")
+        assert($str == "")
+        assert(g == 123)
+        s = 321
+    })
+    .exec()?;
+
+    assert_eq!(lua.globals().get::<_, i32>("s")?, 321);
+
+    Ok(())
+}

tests/compile.rs

@@ -15,7 +15,11 @@ fn test_compilation() {
     t.compile_fail("tests/compile/static_callback_args.rs");
 
     #[cfg(feature = "async")]
-    t.compile_fail("tests/compile/async_nonstatic_userdata.rs");
+    {
+        t.compile_fail("tests/compile/async_any_userdata_method.rs");
+        t.compile_fail("tests/compile/async_nonstatic_userdata.rs");
+        t.compile_fail("tests/compile/async_userdata_method.rs");
+    }
 
     #[cfg(feature = "send")]
     t.compile_fail("tests/compile/non_send.rs");

tests/compile/async_any_userdata_method.rs

@@ -0,0 +1,14 @@
+use mlua::{UserDataMethods, Lua};
+
+fn main() {
+    let lua = Lua::new();
+
+    lua.register_userdata_type::<String>(|reg| {
+        let s = String::new();
+        let mut s = &s;
+        reg.add_async_method("t", |_, this: &String, ()| async {
+            s = this;
+            Ok(())
+        });
+    }).unwrap();
+}

tests/compile/async_any_userdata_method.stderr

@@ -0,0 +1,83 @@
+error: lifetime may not live long enough
+  --> tests/compile/async_any_userdata_method.rs:9:58
+   |
+9  |           reg.add_async_method("t", |_, this: &String, ()| async {
+   |  ___________________________________----------------------_^
+   | |                                   |                    |
+   | |                                   |                    return type of closure `{async block@$DIR/tests/compile/async_any_userdata_method.rs:9:58: 12:10}` contains a lifetime `'2`
+   | |                                   lifetime `'1` represents this closure's body
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |_________^ returning this value requires that `'1` must outlive `'2`
+   |
+   = note: closure implements `Fn`, so references to captured variables can't escape the closure
+
+error[E0596]: cannot borrow `s` as mutable, as it is a captured variable in a `Fn` closure
+  --> tests/compile/async_any_userdata_method.rs:9:58
+   |
+9  |           reg.add_async_method("t", |_, this: &String, ()| async {
+   |  __________________________________________________________^
+10 | |             s = this;
+   | |             - mutable borrow occurs due to use of `s` in closure
+11 | |             Ok(())
+12 | |         });
+   | |_________^ cannot borrow as mutable
+
+error[E0597]: `s` does not live long enough
+  --> tests/compile/async_any_userdata_method.rs:8:21
+   |
+7  |           let s = String::new();
+   |               - binding `s` declared here
+8  |           let mut s = &s;
+   |                       ^^ borrowed value does not live long enough
+9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |__________- argument requires that `s` is borrowed for `'static`
+13 |       }).unwrap();
+   |       - `s` dropped here while still borrowed
+
+error[E0521]: borrowed data escapes outside of closure
+  --> tests/compile/async_any_userdata_method.rs:9:9
+   |
+6  |       lua.register_userdata_type::<String>(|reg| {
+   |                                             ---
+   |                                             |
+   |                                             `reg` is a reference that is only valid in the closure body
+   |                                             has type `&mut LuaUserDataRegistry<'1, std::string::String>`
+...
+9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |          ^
+   | |          |
+   | |__________`reg` escapes the closure body here
+   |            argument requires that `'1` must outlive `'static`
+   |
+   = note: requirement occurs because of a mutable reference to `LuaUserDataRegistry<'_, std::string::String>`
+   = note: mutable references are invariant over their type parameter
+   = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
+
+error[E0373]: closure may outlive the current function, but it borrows `s`, which is owned by the current function
+  --> tests/compile/async_any_userdata_method.rs:9:35
+   |
+9  |         reg.add_async_method("t", |_, this: &String, ()| async {
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^ may outlive borrowed value `s`
+10 |             s = this;
+   |             - `s` is borrowed here
+   |
+note: function requires argument type to outlive `'static`
+  --> tests/compile/async_any_userdata_method.rs:9:9
+   |
+9  | /         reg.add_async_method("t", |_, this: &String, ()| async {
+10 | |             s = this;
+11 | |             Ok(())
+12 | |         });
+   | |__________^
+help: to force the closure to take ownership of `s` (and any other referenced variables), use the `move` keyword
+   |
+9  |         reg.add_async_method("t", move |_, this: &String, ()| async {
+   |                                   ++++

tests/compile/async_nonstatic_userdata.rs

@@ -1,8 +1,6 @@
-use mlua::{Lua, UserData, UserDataMethods};
+use mlua::{UserData, UserDataMethods};
 
 fn main() {
-    let ref lua = Lua::new();
-
     #[derive(Clone)]
     struct MyUserData<'a>(&'a i64);