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Fix async userdata __index, __newindex metamethods

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This commit is contained in:
Tarik02
2022-03-19 16:07:51 +02:00
committed by Alex Orlenko
parent c85616137a
commit d4f8dce597
3 changed files with 201 additions and 99 deletions
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src/util.rs
+117 -97
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@@ -9,7 +9,7 @@ use once_cell::sync::Lazy;
use rustc_hash::FxHashMap;
use crate::error::{Error, Result};
use crate::ffi;
use crate::ffi::{self, lua_error};
static METATABLE_CACHE: Lazy<FxHashMap<TypeId, u8>> = Lazy::new(|| {
let mut map = FxHashMap::with_capacity_and_hasher(32, Default::default());
@@ -345,6 +345,112 @@ pub unsafe fn get_gc_userdata<T: Any>(state: *mut ffi::lua_State, index: c_int)
ud
}
unsafe extern "C" fn isfunction_impl(state: *mut ffi::lua_State) -> c_int {
// stack: var
ffi::luaL_checkstack(state, 1, ptr::null());
let t = ffi::lua_type(state, -1);
ffi::lua_pop(state, 1);
ffi::lua_pushboolean(state, if t == ffi::LUA_TFUNCTION { 1 } else { 0 });
1
}
unsafe extern "C" fn error_impl(state: *mut ffi::lua_State) -> c_int {
// stack: message
ffi::luaL_checkstack(state, 1, ptr::null());
lua_error(state);
}
pub unsafe fn init_userdata_metatable_index(state: *mut ffi::lua_State) -> Result<()> {
protect_lua!(state, 0, 1, |state| {
let ret = ffi::luaL_dostring(
state,
cstr!(
r#"
return function (isfunction, error)
return function (__index, field_getters, methods)
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
end
"#
),
);
if ret != ffi::LUA_OK {
ffi::lua_error(state);
}
ffi::lua_pushcfunction(state, isfunction_impl);
ffi::lua_pushcfunction(state, error_impl);
ffi::lua_call(state, 2, 1);
})?;
Ok(())
}
pub unsafe fn init_userdata_metatable_newindex(state: *mut ffi::lua_State) -> Result<()> {
protect_lua!(state, 0, 1, |state| {
let ret = ffi::luaL_dostring(
state,
cstr!(
r#"
return function (isfunction, error)
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
end
"#
),
);
if ret != ffi::LUA_OK {
ffi::lua_error(state);
}
ffi::lua_pushcfunction(state, isfunction_impl);
ffi::lua_pushcfunction(state, error_impl);
ffi::lua_call(state, 2, 1);
})?;
Ok(())
}
// 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.
@@ -360,99 +466,13 @@ pub unsafe fn init_userdata_metatable<T>(
field_setters: Option<c_int>,
methods: Option<c_int>,
) -> 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() {
init_userdata_metatable_index(state)?;
push_string(state, "__index")?;
let index_type = ffi::lua_rawget(state, -2);
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 +482,8 @@ 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);
})?;
protect_lua!(state, 4, 1, |state| ffi::lua_call(state, 3, 1))?;
}
_ => mlua_panic!("improper __index type {}", index_type),
}
@@ -473,14 +492,15 @@ pub unsafe fn init_userdata_metatable<T>(
}
if let Some(field_setters) = field_setters {
init_userdata_metatable_newindex(state)?;
push_string(state, "__newindex")?;
let newindex_type = ffi::lua_rawget(state, -2);
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);
})?;
protect_lua!(state, 3, 1, |state| ffi::lua_call(state, 2, 1))?;
}
_ => mlua_panic!("improper __newindex type {}", newindex_type),
}