Files
mlua-rs-mlua/mlua-sys/src/luau/lua.rs
T
Alex Orlenko 12e61e01f6 Restrict access to Luau VM from UserData destructors.
It's unsafe to make almost any Lua calls when userdata destructor is running.
This can cause recursive GC run and crash.
See https://github.com/luau-lang/luau/pull/510 for some details.
2025-04-05 10:31:39 +01:00

548 lines
20 KiB
Rust

//! Contains definitions from `lua.h`.
use std::ffi::CStr;
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, 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`.
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 (no unwinding).
pub type lua_Destructor = unsafe extern "C" fn(L: *mut lua_State, *mut c_void);
/// Type for memory-allocation functions (no unwinding).
pub type lua_Alloc =
unsafe extern "C" 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) -> c_int;
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);
#[link_name = "lua_pushinteger"]
pub fn lua_pushinteger_(L: *mut lua_State, n: c_int);
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_newuserdatataggedwithmetatable(L: *mut lua_State, sz: usize, tag: c_int) -> *mut c_void;
pub fn lua_newuserdatadtor(L: *mut lua_State, sz: usize, dtor: lua_Destructor) -> *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);
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, idx: c_int) -> lua_Number {
lua_tonumberx(L, idx, ptr::null_mut())
}
#[inline(always)]
pub unsafe fn lua_tointeger_(L: *mut lua_State, idx: c_int) -> c_int {
lua_tointegerx_(L, idx, 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, data: T) -> *mut T {
unsafe extern "C" fn destructor<T>(_: *mut lua_State, ud: *mut c_void) {
ptr::drop_in_place(ud as *mut T);
}
let ud_ptr = lua_newuserdatadtor(L, const { mem::size_of::<T>() }, destructor::<T>) as *mut T;
ptr::write(ud_ptr, data);
ud_ptr
}
// 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 CStr) {
lua_pushstring_(L, s.as_ptr());
}
#[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)>,
/// gets called when memory is allocated
pub onallocate: Option<unsafe extern "C-unwind" fn(L: *mut lua_State, osize: usize, nsize: usize)>,
}
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;
pub fn lua_getmetatablepointer(L: *mut lua_State, idx: c_int) -> *const c_void;
}