mlua/src/ffi/lua52/compat.rs
2022-03-20 20:30:20 +00:00

259 lines
6.7 KiB
Rust

//! MLua compatibility layer for Lua 5.2
//!
//! Based on github.com/keplerproject/lua-compat-5.3
use std::convert::TryInto;
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);
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, idx: c_int, len: *mut usize) -> *const c_char {
if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
let t = lua_type(L, idx);
match t {
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");
}
}
_ => {
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);
}
}
};
} 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);
}