mlua_sys/lua52/
compat.rs

1//! MLua compatibility layer for Lua 5.2
2//!
3//! Based on github.com/keplerproject/lua-compat-5.3
4
5use std::os::raw::{c_char, c_int, c_void};
6use std::ptr;
7
8use super::lauxlib::*;
9use super::lua::*;
10
11#[inline(always)]
12unsafe fn compat53_reverse(L: *mut lua_State, mut a: c_int, mut b: c_int) {
13    while a < b {
14        lua_pushvalue(L, a);
15        lua_pushvalue(L, b);
16        lua_replace(L, a);
17        lua_replace(L, b);
18        a += 1;
19        b -= 1;
20    }
21}
22
23//
24// lua ported functions
25//
26
27pub unsafe fn lua_rotate(L: *mut lua_State, mut idx: c_int, mut n: c_int) {
28    idx = lua_absindex(L, idx);
29    if n > 0 {
30        // Faster version
31        for _ in 0..n {
32            lua_insert(L, idx);
33        }
34        return;
35    }
36    let n_elems = lua_gettop(L) - idx + 1;
37    if n < 0 {
38        n += n_elems;
39    }
40    if n > 0 && n < n_elems {
41        luaL_checkstack(L, 2, cstr!("not enough stack slots available"));
42        n = n_elems - n;
43        compat53_reverse(L, idx, idx + n - 1);
44        compat53_reverse(L, idx + n, idx + n_elems - 1);
45        compat53_reverse(L, idx, idx + n_elems - 1);
46    }
47}
48
49#[inline(always)]
50pub unsafe fn lua_isinteger(L: *mut lua_State, idx: c_int) -> c_int {
51    if lua_type(L, idx) == LUA_TNUMBER {
52        let n = lua_tonumber(L, idx);
53        let i = lua_tointeger(L, idx);
54        // Lua 5.3+ returns "false" for `-0.0`
55        if n.to_bits() == (i as lua_Number).to_bits() {
56            return 1;
57        }
58    }
59    0
60}
61
62#[inline(always)]
63pub unsafe fn lua_tointeger(L: *mut lua_State, i: c_int) -> lua_Integer {
64    lua_tointegerx(L, i, ptr::null_mut())
65}
66
67// Implemented for Lua 5.2 as well
68// See https://github.com/keplerproject/lua-compat-5.3/issues/40
69#[inline(always)]
70pub unsafe fn lua_tointegerx(L: *mut lua_State, i: c_int, isnum: *mut c_int) -> lua_Integer {
71    let mut ok = 0;
72    let n = lua_tonumberx(L, i, &mut ok);
73    let n_int = n as lua_Integer;
74    if ok != 0 && (n - n_int as lua_Number).abs() < lua_Number::EPSILON {
75        if !isnum.is_null() {
76            *isnum = 1;
77        }
78        return n_int;
79    }
80    if !isnum.is_null() {
81        *isnum = 0;
82    }
83    0
84}
85
86#[inline(always)]
87pub unsafe fn lua_pushlstring(L: *mut lua_State, s: *const c_char, l: usize) -> *const c_char {
88    if l == 0 {
89        lua_pushlstring_(L, cstr!(""), 0)
90    } else {
91        lua_pushlstring_(L, s, l)
92    }
93}
94
95#[inline(always)]
96pub unsafe fn lua_getglobal(L: *mut lua_State, var: *const c_char) -> c_int {
97    lua_getglobal_(L, var);
98    lua_type(L, -1)
99}
100
101#[inline(always)]
102pub unsafe fn lua_gettable(L: *mut lua_State, idx: c_int) -> c_int {
103    lua_gettable_(L, idx);
104    lua_type(L, -1)
105}
106
107#[inline(always)]
108pub unsafe fn lua_getfield(L: *mut lua_State, idx: c_int, k: *const c_char) -> c_int {
109    lua_getfield_(L, idx, k);
110    lua_type(L, -1)
111}
112
113#[inline(always)]
114pub unsafe fn lua_geti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) -> c_int {
115    idx = lua_absindex(L, idx);
116    lua_pushinteger(L, n);
117    lua_gettable(L, idx)
118}
119
120#[inline(always)]
121pub unsafe fn lua_rawget(L: *mut lua_State, idx: c_int) -> c_int {
122    lua_rawget_(L, idx);
123    lua_type(L, -1)
124}
125
126#[inline(always)]
127pub unsafe fn lua_rawgeti(L: *mut lua_State, idx: c_int, n: lua_Integer) -> c_int {
128    let n = n.try_into().expect("cannot convert index to lua_Integer");
129    lua_rawgeti_(L, idx, n);
130    lua_type(L, -1)
131}
132
133#[inline(always)]
134pub unsafe fn lua_rawgetp(L: *mut lua_State, idx: c_int, p: *const c_void) -> c_int {
135    lua_rawgetp_(L, idx, p);
136    lua_type(L, -1)
137}
138
139#[inline(always)]
140pub unsafe fn lua_getuservalue(L: *mut lua_State, idx: c_int) -> c_int {
141    lua_getuservalue_(L, idx);
142    lua_type(L, -1)
143}
144
145#[inline(always)]
146pub unsafe fn lua_seti(L: *mut lua_State, mut idx: c_int, n: lua_Integer) {
147    luaL_checkstack(L, 1, cstr!("not enough stack slots available"));
148    idx = lua_absindex(L, idx);
149    lua_pushinteger(L, n);
150    lua_insert(L, -2);
151    lua_settable(L, idx);
152}
153
154#[inline(always)]
155pub unsafe fn lua_rawseti(L: *mut lua_State, idx: c_int, n: lua_Integer) {
156    let n = n.try_into().expect("cannot convert index from lua_Integer");
157    lua_rawseti_(L, idx, n)
158}
159
160#[inline(always)]
161pub unsafe fn lua_dump(L: *mut lua_State, writer: lua_Writer, data: *mut c_void, _strip: c_int) -> c_int {
162    lua_dump_(L, writer, data)
163}
164
165#[inline(always)]
166pub unsafe fn lua_resume(L: *mut lua_State, from: *mut lua_State, narg: c_int, nres: *mut c_int) -> c_int {
167    let ret = lua_resume_(L, from, narg);
168    if (ret == LUA_OK || ret == LUA_YIELD) && !(nres.is_null()) {
169        *nres = lua_gettop(L);
170    }
171    ret
172}
173
174//
175// lauxlib ported functions
176//
177
178#[inline(always)]
179pub unsafe fn luaL_getmetafield(L: *mut lua_State, obj: c_int, e: *const c_char) -> c_int {
180    if luaL_getmetafield_(L, obj, e) != 0 {
181        lua_type(L, -1)
182    } else {
183        LUA_TNIL
184    }
185}
186
187#[inline(always)]
188pub unsafe fn luaL_newmetatable(L: *mut lua_State, tname: *const c_char) -> c_int {
189    if luaL_newmetatable_(L, tname) != 0 {
190        lua_pushstring(L, tname);
191        lua_setfield(L, -2, cstr!("__name"));
192        1
193    } else {
194        0
195    }
196}
197
198pub unsafe fn luaL_tolstring(L: *mut lua_State, mut idx: c_int, len: *mut usize) -> *const c_char {
199    idx = lua_absindex(L, idx);
200    if luaL_callmeta(L, idx, cstr!("__tostring")) == 0 {
201        match lua_type(L, idx) {
202            LUA_TNIL => {
203                lua_pushliteral(L, c"nil");
204            }
205            LUA_TSTRING | LUA_TNUMBER => {
206                lua_pushvalue(L, idx);
207            }
208            LUA_TBOOLEAN => {
209                if lua_toboolean(L, idx) == 0 {
210                    lua_pushliteral(L, c"false");
211                } else {
212                    lua_pushliteral(L, c"true");
213                }
214            }
215            t => {
216                let tt = luaL_getmetafield(L, idx, cstr!("__name"));
217                let name = if tt == LUA_TSTRING {
218                    lua_tostring(L, -1)
219                } else {
220                    lua_typename(L, t)
221                };
222                lua_pushfstring(L, cstr!("%s: %p"), name, lua_topointer(L, idx));
223                if tt != LUA_TNIL {
224                    lua_replace(L, -2); // remove '__name'
225                }
226            }
227        };
228    } else if lua_isstring(L, -1) == 0 {
229        luaL_error(L, cstr!("'__tostring' must return a string"));
230    }
231    lua_tolstring(L, -1, len)
232}
233
234pub unsafe fn luaL_requiref(L: *mut lua_State, modname: *const c_char, openf: lua_CFunction, glb: c_int) {
235    luaL_checkstack(L, 3, cstr!("not enough stack slots available"));
236    luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
237    if lua_getfield(L, -1, modname) == LUA_TNIL {
238        lua_pop(L, 1);
239        lua_pushcfunction(L, openf);
240        lua_pushstring(L, modname);
241        lua_call(L, 1, 1);
242        lua_pushvalue(L, -1);
243        lua_setfield(L, -3, modname);
244    }
245    if glb != 0 {
246        lua_pushvalue(L, -1);
247        lua_setglobal(L, modname);
248    }
249    lua_replace(L, -2);
250}
251
252pub unsafe fn luaL_loadbufferenv(
253    L: *mut lua_State,
254    data: *const c_char,
255    size: usize,
256    name: *const c_char,
257    mode: *const c_char,
258    mut env: c_int,
259) -> c_int {
260    if env != 0 {
261        env = lua_absindex(L, env);
262    }
263    let status = luaL_loadbufferx(L, data, size, name, mode);
264    if status == LUA_OK && env != 0 {
265        lua_pushvalue(L, env);
266        lua_setupvalue(L, -2, 1);
267    }
268    status
269}
mlua_sys/lua52/compat.rs

mlua_sys/lua52/
compat.rs
