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lbaselib.cpp
468 lines (407 loc) · 12 KB
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lbaselib.cpp
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// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
// This code is based on Lua 5.x implementation licensed under MIT License; see lua_LICENSE.txt for details
#include "lualib.h"
#include "lstate.h"
#include "lapi.h"
#include "ldo.h"
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
static void writestring(const char* s, size_t l)
{
fwrite(s, 1, l, stdout);
}
static int luaB_print(lua_State* L)
{
int n = lua_gettop(L); /* number of arguments */
for (int i = 1; i <= n; i++)
{
size_t l;
const char* s = luaL_tolstring(L, i, &l); /* convert to string using __tostring et al */
if (i > 1)
writestring("\t", 1);
writestring(s, l);
lua_pop(L, 1); /* pop result */
}
writestring("\n", 1);
return 0;
}
static int luaB_tonumber(lua_State* L)
{
int base = luaL_optinteger(L, 2, 10);
if (base == 10)
{ /* standard conversion */
int isnum = 0;
double n = lua_tonumberx(L, 1, &isnum);
if (isnum)
{
lua_pushnumber(L, n);
return 1;
}
luaL_checkany(L, 1); /* error if we don't have any argument */
}
else
{
const char* s1 = luaL_checkstring(L, 1);
luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
char* s2;
unsigned long long n;
n = strtoull(s1, &s2, base);
if (s1 != s2)
{ /* at least one valid digit? */
while (isspace((unsigned char)(*s2)))
s2++; /* skip trailing spaces */
if (*s2 == '\0')
{ /* no invalid trailing characters? */
lua_pushnumber(L, (double)n);
return 1;
}
}
}
lua_pushnil(L); /* else not a number */
return 1;
}
static int luaB_error(lua_State* L)
{
int level = luaL_optinteger(L, 2, 1);
lua_settop(L, 1);
if (lua_isstring(L, 1) && level > 0)
{ /* add extra information? */
luaL_where(L, level);
lua_pushvalue(L, 1);
lua_concat(L, 2);
}
lua_error(L);
}
static int luaB_getmetatable(lua_State* L)
{
luaL_checkany(L, 1);
if (!lua_getmetatable(L, 1))
{
lua_pushnil(L);
return 1; /* no metatable */
}
luaL_getmetafield(L, 1, "__metatable");
return 1; /* returns either __metatable field (if present) or metatable */
}
static int luaB_setmetatable(lua_State* L)
{
int t = lua_type(L, 2);
luaL_checktype(L, 1, LUA_TTABLE);
luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
if (luaL_getmetafield(L, 1, "__metatable"))
luaL_error(L, "cannot change a protected metatable");
lua_settop(L, 2);
lua_setmetatable(L, 1);
return 1;
}
static void getfunc(lua_State* L, int opt)
{
if (lua_isfunction(L, 1))
lua_pushvalue(L, 1);
else
{
lua_Debug ar;
int level = opt ? luaL_optinteger(L, 1, 1) : luaL_checkinteger(L, 1);
luaL_argcheck(L, level >= 0, 1, "level must be non-negative");
if (lua_getinfo(L, level, "f", &ar) == 0)
luaL_argerror(L, 1, "invalid level");
if (lua_isnil(L, -1))
luaL_error(L, "no function environment for tail call at level %d", level);
}
}
static int luaB_getfenv(lua_State* L)
{
getfunc(L, 1);
if (lua_iscfunction(L, -1)) /* is a C function? */
lua_pushvalue(L, LUA_GLOBALSINDEX); /* return the thread's global env. */
else
lua_getfenv(L, -1);
lua_setsafeenv(L, -1, false);
return 1;
}
static int luaB_setfenv(lua_State* L)
{
luaL_checktype(L, 2, LUA_TTABLE);
getfunc(L, 0);
lua_pushvalue(L, 2);
lua_setsafeenv(L, -1, false);
if (lua_isnumber(L, 1) && lua_tonumber(L, 1) == 0)
{
/* change environment of current thread */
lua_pushthread(L);
lua_insert(L, -2);
lua_setfenv(L, -2);
return 0;
}
else if (lua_iscfunction(L, -2) || lua_setfenv(L, -2) == 0)
luaL_error(L, "'setfenv' cannot change environment of given object");
return 1;
}
static int luaB_rawequal(lua_State* L)
{
luaL_checkany(L, 1);
luaL_checkany(L, 2);
lua_pushboolean(L, lua_rawequal(L, 1, 2));
return 1;
}
static int luaB_rawget(lua_State* L)
{
luaL_checktype(L, 1, LUA_TTABLE);
luaL_checkany(L, 2);
lua_settop(L, 2);
lua_rawget(L, 1);
return 1;
}
static int luaB_rawset(lua_State* L)
{
luaL_checktype(L, 1, LUA_TTABLE);
luaL_checkany(L, 2);
luaL_checkany(L, 3);
lua_settop(L, 3);
lua_rawset(L, 1);
return 1;
}
static int luaB_gcinfo(lua_State* L)
{
lua_pushinteger(L, lua_gc(L, LUA_GCCOUNT, 0));
return 1;
}
static int luaB_type(lua_State* L)
{
luaL_checkany(L, 1);
lua_pushstring(L, luaL_typename(L, 1));
return 1;
}
static int luaB_typeof(lua_State* L)
{
luaL_checkany(L, 1);
const TValue* obj = luaA_toobject(L, 1);
lua_pushstring(L, luaT_objtypename(L, obj));
return 1;
}
int luaB_next(lua_State* L)
{
luaL_checktype(L, 1, LUA_TTABLE);
lua_settop(L, 2); /* create a 2nd argument if there isn't one */
if (lua_next(L, 1))
return 2;
else
{
lua_pushnil(L);
return 1;
}
}
static int luaB_pairs(lua_State* L)
{
luaL_checktype(L, 1, LUA_TTABLE);
lua_pushvalue(L, lua_upvalueindex(1)); /* return generator, */
lua_pushvalue(L, 1); /* state, */
lua_pushnil(L); /* and initial value */
return 3;
}
int luaB_inext(lua_State* L)
{
int i = luaL_checkinteger(L, 2);
luaL_checktype(L, 1, LUA_TTABLE);
i++; /* next value */
lua_pushinteger(L, i);
lua_rawgeti(L, 1, i);
return (lua_isnil(L, -1)) ? 0 : 2;
}
static int luaB_ipairs(lua_State* L)
{
luaL_checktype(L, 1, LUA_TTABLE);
lua_pushvalue(L, lua_upvalueindex(1)); /* return generator, */
lua_pushvalue(L, 1); /* state, */
lua_pushinteger(L, 0); /* and initial value */
return 3;
}
static int luaB_assert(lua_State* L)
{
luaL_checkany(L, 1);
if (!lua_toboolean(L, 1))
luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
return lua_gettop(L);
}
static int luaB_select(lua_State* L)
{
int n = lua_gettop(L);
if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#')
{
lua_pushinteger(L, n - 1);
return 1;
}
else
{
int i = luaL_checkinteger(L, 1);
if (i < 0)
i = n + i;
else if (i > n)
i = n;
luaL_argcheck(L, 1 <= i, 1, "index out of range");
return n - i;
}
}
static void luaB_pcallrun(lua_State* L, void* ud)
{
StkId func = (StkId)ud;
luaD_call(L, func, LUA_MULTRET);
}
static int luaB_pcally(lua_State* L)
{
luaL_checkany(L, 1);
StkId func = L->base;
// any errors from this point on are handled by continuation
L->ci->flags |= LUA_CALLINFO_HANDLE;
// maintain yieldable invariant (baseCcalls <= nCcalls)
L->baseCcalls++;
int status = luaD_pcall(L, luaB_pcallrun, func, savestack(L, func), 0);
L->baseCcalls--;
// necessary to accomodate functions that return lots of values
expandstacklimit(L, L->top);
// yielding means we need to propagate yield; resume will call continuation function later
if (status == 0 && (L->status == LUA_YIELD || L->status == LUA_BREAK))
return -1; // -1 is a marker for yielding from C
// immediate return (error or success)
lua_rawcheckstack(L, 1);
lua_pushboolean(L, status == 0);
lua_insert(L, 1);
return lua_gettop(L); // return status + all results
}
static int luaB_pcallcont(lua_State* L, int status)
{
if (status == 0)
{
lua_rawcheckstack(L, 1);
lua_pushboolean(L, true);
lua_insert(L, 1); // insert status before all results
return lua_gettop(L);
}
else
{
lua_rawcheckstack(L, 1);
lua_pushboolean(L, false);
lua_insert(L, -2); // insert status before error object
return 2;
}
}
static int luaB_xpcally(lua_State* L)
{
luaL_checktype(L, 2, LUA_TFUNCTION);
/* swap function & error function */
lua_pushvalue(L, 1);
lua_pushvalue(L, 2);
lua_replace(L, 1);
lua_replace(L, 2);
/* at this point the stack looks like err, f, args */
// any errors from this point on are handled by continuation
L->ci->flags |= LUA_CALLINFO_HANDLE;
StkId errf = L->base;
StkId func = L->base + 1;
// maintain yieldable invariant (baseCcalls <= nCcalls)
L->baseCcalls++;
int status = luaD_pcall(L, luaB_pcallrun, func, savestack(L, func), savestack(L, errf));
L->baseCcalls--;
// necessary to accomodate functions that return lots of values
expandstacklimit(L, L->top);
// yielding means we need to propagate yield; resume will call continuation function later
if (status == 0 && (L->status == LUA_YIELD || L->status == LUA_BREAK))
return -1; // -1 is a marker for yielding from C
// immediate return (error or success)
lua_rawcheckstack(L, 1);
lua_pushboolean(L, status == 0);
lua_replace(L, 1); // replace error function with status
return lua_gettop(L); // return status + all results
}
static void luaB_xpcallerr(lua_State* L, void* ud)
{
StkId func = (StkId)ud;
luaD_call(L, func, 1);
}
static int luaB_xpcallcont(lua_State* L, int status)
{
if (status == 0)
{
lua_rawcheckstack(L, 1);
lua_pushboolean(L, true);
lua_replace(L, 1); // replace error function with status
return lua_gettop(L); /* return status + all results */
}
else
{
lua_rawcheckstack(L, 3);
lua_pushboolean(L, false);
lua_pushvalue(L, 1); // push error function on top of the stack
lua_pushvalue(L, -3); // push error object (that was on top of the stack before)
StkId res = L->top - 3;
StkId errf = L->top - 2;
// note: we pass res as errfunc as a short cut; if errf generates an error, we'll try to execute res (boolean) and fail
luaD_pcall(L, luaB_xpcallerr, errf, savestack(L, errf), savestack(L, res));
return 2;
}
}
static int luaB_tostring(lua_State* L)
{
luaL_checkany(L, 1);
luaL_tolstring(L, 1, NULL);
return 1;
}
static int luaB_newproxy(lua_State* L)
{
int t = lua_type(L, 1);
luaL_argexpected(L, t == LUA_TNONE || t == LUA_TNIL || t == LUA_TBOOLEAN, 1, "nil or boolean");
bool needsmt = lua_toboolean(L, 1);
lua_newuserdata(L, 0);
if (needsmt)
{
lua_newtable(L);
lua_setmetatable(L, -2);
}
return 1;
}
static const luaL_Reg base_funcs[] = {
{"assert", luaB_assert},
{"error", luaB_error},
{"gcinfo", luaB_gcinfo},
{"getfenv", luaB_getfenv},
{"getmetatable", luaB_getmetatable},
{"next", luaB_next},
{"newproxy", luaB_newproxy},
{"print", luaB_print},
{"rawequal", luaB_rawequal},
{"rawget", luaB_rawget},
{"rawset", luaB_rawset},
{"select", luaB_select},
{"setfenv", luaB_setfenv},
{"setmetatable", luaB_setmetatable},
{"tonumber", luaB_tonumber},
{"tostring", luaB_tostring},
{"type", luaB_type},
{"typeof", luaB_typeof},
{NULL, NULL},
};
static void auxopen(lua_State* L, const char* name, lua_CFunction f, lua_CFunction u)
{
lua_pushcfunction(L, u, NULL);
lua_pushcclosure(L, f, name, 1);
lua_setfield(L, -2, name);
}
int luaopen_base(lua_State* L)
{
/* set global _G */
lua_pushvalue(L, LUA_GLOBALSINDEX);
lua_setglobal(L, "_G");
/* open lib into global table */
luaL_register(L, "_G", base_funcs);
lua_pushliteral(L, "Luau");
lua_setglobal(L, "_VERSION"); /* set global _VERSION */
/* `ipairs' and `pairs' need auxiliary functions as upvalues */
auxopen(L, "ipairs", luaB_ipairs, luaB_inext);
auxopen(L, "pairs", luaB_pairs, luaB_next);
lua_pushcclosurek(L, luaB_pcally, "pcall", 0, luaB_pcallcont);
lua_setfield(L, -2, "pcall");
lua_pushcclosurek(L, luaB_xpcally, "xpcall", 0, luaB_xpcallcont);
lua_setfield(L, -2, "xpcall");
return 1;
}