Mesen-SX/Lua/lbaselib.c

/*
** $Id: lbaselib.c,v 1.314 2016/09/05 19:06:34 roberto Exp $
** Basic library
** See Copyright Notice in lua.h
*/

#define lbaselib_c
#define LUA_LIB

#include "lprefix.h"


#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"


static int luaB_print(lua_State* L)
{
	int n = lua_gettop(L); /* number of arguments */
	int i;
	lua_getglobal(L, "tostring");
	for (i = 1; i <= n; i++)
	{
		const char* s;
		size_t l;
		lua_pushvalue(L, -1); /* function to be called */
		lua_pushvalue(L, i); /* value to print */
		lua_call(L, 1, 1);
		s = lua_tolstring(L, -1, &l); /* get result */
		if (s == NULL)
			return luaL_error(L, "'tostring' must return a string to 'print'");
		if (i > 1)
			lua_writestring("\t", 1);
		lua_writestring(s, l);
		lua_pop(L, 1); /* pop result */
	}
	lua_writeline();
	return 0;
}


#define SPACECHARS	" \f\n\r\t\v"

static const char* b_str2int(const char* s, int base, lua_Integer* pn)
{
	lua_Unsigned n = 0;
	int neg = 0;
	s += strspn(s, SPACECHARS); /* skip initial spaces */
	if (*s == '-')
	{
		s++;
		neg = 1;
	} /* handle signal */
	else if (*s == '+') s++;
	if (!isalnum((unsigned char)*s)) /* no digit? */
		return NULL;
	do
	{
		int digit = (isdigit((unsigned char)*s))
			            ? *s - '0'
			            : (toupper((unsigned char)*s) - 'A') + 10;
		if (digit >= base) return NULL; /* invalid numeral */
		n = n * base + digit;
		s++;
	}
	while (isalnum((unsigned char)*s));
	s += strspn(s, SPACECHARS); /* skip trailing spaces */
	*pn = (lua_Integer)((neg) ? (0u - n) : n);
	return s;
}


static int luaB_tonumber(lua_State* L)
{
	if (lua_isnoneornil(L, 2))
	{
		/* standard conversion? */
		luaL_checkany(L, 1);
		if (lua_type(L, 1) == LUA_TNUMBER)
		{
			/* already a number? */
			lua_settop(L, 1); /* yes; return it */
			return 1;
		}
		else
		{
			size_t l;
			const char* s = lua_tolstring(L, 1, &l);
			if (s != NULL && lua_stringtonumber(L, s) == l + 1)
				return 1; /* successful conversion to number */
			/* else not a number */
		}
	}
	else
	{
		size_t l;
		const char* s;
		lua_Integer n = 0; /* to avoid warnings */
		lua_Integer base = luaL_checkinteger(L, 2);
		luaL_checktype(L, 1, LUA_TSTRING); /* no numbers as strings */
		s = lua_tolstring(L, 1, &l);
		luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
		if (b_str2int(s, (int)base, &n) == s + l)
		{
			lua_pushinteger(L, n);
			return 1;
		} /* else not a number */
	} /* else not a number */
	lua_pushnil(L); /* not a number */
	return 1;
}


static int luaB_error(lua_State* L)
{
	int level = (int)luaL_optinteger(L, 2, 1);
	lua_settop(L, 1);
	if (lua_type(L, 1) == LUA_TSTRING && level > 0)
	{
		luaL_where(L, level); /* add extra information */
		lua_pushvalue(L, 1);
		lua_concat(L, 2);
	}
	return 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_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
	              "nil or table expected");
	if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
		return luaL_error(L, "cannot change a protected metatable");
	lua_settop(L, 2);
	lua_setmetatable(L, 1);
	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_rawlen(lua_State* L)
{
	int t = lua_type(L, 1);
	luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
	              "table or string expected");
	lua_pushinteger(L, lua_rawlen(L, 1));
	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_collectgarbage(lua_State* L)
{
	static const char* const opts[] = {
		"stop", "restart", "collect",
		"count", "step", "setpause", "setstepmul",
		"isrunning", NULL
	};
	static const int optsnum[] = {
		LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
		LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
		LUA_GCISRUNNING
	};
	int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
	int ex = (int)luaL_optinteger(L, 2, 0);
	int res = lua_gc(L, o, ex);
	switch (o)
	{
	case LUA_GCCOUNT:
		{
			int b = lua_gc(L, LUA_GCCOUNTB, 0);
			lua_pushnumber(L, (lua_Number)res + ((lua_Number)b / 1024));
			return 1;
		}
	case LUA_GCSTEP:
	case LUA_GCISRUNNING:
		{
			lua_pushboolean(L, res);
			return 1;
		}
	default:
		{
			lua_pushinteger(L, res);
			return 1;
		}
	}
}


static int luaB_type(lua_State* L)
{
	int t = lua_type(L, 1);
	luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
	lua_pushstring(L, lua_typename(L, t));
	return 1;
}


static int pairsmeta(lua_State* L, const char* method, int iszero,
                     lua_CFunction iter)
{
	luaL_checkany(L, 1);
	if (luaL_getmetafield(L, 1, method) == LUA_TNIL)
	{
		/* no metamethod? */
		lua_pushcfunction(L, iter); /* will return generator, */
		lua_pushvalue(L, 1); /* state, */
		if (iszero) lua_pushinteger(L, 0); /* and initial value */
		else lua_pushnil(L);
	}
	else
	{
		lua_pushvalue(L, 1); /* argument 'self' to metamethod */
		lua_call(L, 1, 3); /* get 3 values from metamethod */
	}
	return 3;
}


static 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)
{
	return pairsmeta(L, "__pairs", 0, luaB_next);
}


/*
** Traversal function for 'ipairs'
*/
static int ipairsaux(lua_State* L)
{
	lua_Integer i = luaL_checkinteger(L, 2) + 1;
	lua_pushinteger(L, i);
	return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
}


/*
** 'ipairs' function. Returns 'ipairsaux', given "table", 0.
** (The given "table" may not be a table.)
*/
static int luaB_ipairs(lua_State* L)
{
#if defined(LUA_COMPAT_IPAIRS)
  return pairsmeta(L, "__ipairs", 1, ipairsaux);
#else
	luaL_checkany(L, 1);
	lua_pushcfunction(L, ipairsaux); /* iteration function */
	lua_pushvalue(L, 1); /* state */
	lua_pushinteger(L, 0); /* initial value */
	return 3;
#endif
}


static int load_aux(lua_State* L, int status, int envidx)
{
	if (status == LUA_OK)
	{
		if (envidx != 0)
		{
			/* 'env' parameter? */
			lua_pushvalue(L, envidx); /* environment for loaded function */
			if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
				lua_pop(L, 1); /* remove 'env' if not used by previous call */
		}
		return 1;
	}
	else
	{
		/* error (message is on top of the stack) */
		lua_pushnil(L);
		lua_insert(L, -2); /* put before error message */
		return 2; /* return nil plus error message */
	}
}


static int luaB_loadfile(lua_State* L)
{
	const char* fname = luaL_optstring(L, 1, NULL);
	const char* mode = luaL_optstring(L, 2, NULL);
	int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
	int status = luaL_loadfilex(L, fname, mode);
	return load_aux(L, status, env);
}


/*
** {======================================================
** Generic Read function
** =======================================================
*/


/*
** reserved slot, above all arguments, to hold a copy of the returned
** string to avoid it being collected while parsed. 'load' has four
** optional arguments (chunk, source name, mode, and environment).
*/
#define RESERVEDSLOT	5


/*
** Reader for generic 'load' function: 'lua_load' uses the
** stack for internal stuff, so the reader cannot change the
** stack top. Instead, it keeps its resulting string in a
** reserved slot inside the stack.
*/
static const char* generic_reader(lua_State* L, void* ud, size_t* size)
{
	(void)(ud); /* not used */
	luaL_checkstack(L, 2, "too many nested functions");
	lua_pushvalue(L, 1); /* get function */
	lua_call(L, 0, 1); /* call it */
	if (lua_isnil(L, -1))
	{
		lua_pop(L, 1); /* pop result */
		*size = 0;
		return NULL;
	}
	else if (!lua_isstring(L, -1))
		luaL_error(L, "reader function must return a string");
	lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
	return lua_tolstring(L, RESERVEDSLOT, size);
}


static int luaB_load(lua_State* L)
{
	int status;
	size_t l;
	const char* s = lua_tolstring(L, 1, &l);
	const char* mode = luaL_optstring(L, 3, "bt");
	int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
	if (s != NULL)
	{
		/* loading a string? */
		const char* chunkname = luaL_optstring(L, 2, s);
		status = luaL_loadbufferx(L, s, l, chunkname, mode);
	}
	else
	{
		/* loading from a reader function */
		const char* chunkname = luaL_optstring(L, 2, "=(load)");
		luaL_checktype(L, 1, LUA_TFUNCTION);
		lua_settop(L, RESERVEDSLOT); /* create reserved slot */
		status = lua_load(L, generic_reader, NULL, chunkname, mode);
	}
	return load_aux(L, status, env);
}

/* }====================================================== */


static int dofilecont(lua_State* L, int d1, lua_KContext d2)
{
	(void)d1;
	(void)d2; /* only to match 'lua_Kfunction' prototype */
	return lua_gettop(L) - 1;
}


static int luaB_dofile(lua_State* L)
{
	const char* fname = luaL_optstring(L, 1, NULL);
	lua_settop(L, 1);
	if (luaL_loadfile(L, fname) != LUA_OK)
		return lua_error(L);
	lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
	return dofilecont(L, 0, 0);
}


static int luaB_assert(lua_State* L)
{
	if (lua_toboolean(L, 1)) /* condition is true? */
		return lua_gettop(L); /* return all arguments */
	else
	{
		/* error */
		luaL_checkany(L, 1); /* there must be a condition */
		lua_remove(L, 1); /* remove it */
		lua_pushliteral(L, "assertion failed!"); /* default message */
		lua_settop(L, 1); /* leave only message (default if no other one) */
		return luaB_error(L); /* call 'error' */
	}
}


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
	{
		lua_Integer 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 - (int)i;
	}
}


/*
** Continuation function for 'pcall' and 'xpcall'. Both functions
** already pushed a 'true' before doing the call, so in case of success
** 'finishpcall' only has to return everything in the stack minus
** 'extra' values (where 'extra' is exactly the number of items to be
** ignored).
*/
static int finishpcall(lua_State* L, int status, lua_KContext extra)
{
	if (status != LUA_OK && status != LUA_YIELD)
	{
		/* error? */
		lua_pushboolean(L, 0); /* first result (false) */
		lua_pushvalue(L, -2); /* error message */
		return 2; /* return false, msg */
	}
	else
		return lua_gettop(L) - (int)extra; /* return all results */
}


static int luaB_pcall(lua_State* L)
{
	int status;
	luaL_checkany(L, 1);
	lua_pushboolean(L, 1); /* first result if no errors */
	lua_insert(L, 1); /* put it in place */
	status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
	return finishpcall(L, status, 0);
}


/*
** Do a protected call with error handling. After 'lua_rotate', the
** stack will have <f, err, true, f, [args...]>; so, the function passes
** 2 to 'finishpcall' to skip the 2 first values when returning results.
*/
static int luaB_xpcall(lua_State* L)
{
	int status;
	int n = lua_gettop(L);
	luaL_checktype(L, 2, LUA_TFUNCTION); /* check error function */
	lua_pushboolean(L, 1); /* first result */
	lua_pushvalue(L, 1); /* function */
	lua_rotate(L, 3, 2); /* move them below function's arguments */
	status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
	return finishpcall(L, status, 2);
}


static int luaB_tostring(lua_State* L)
{
	luaL_checkany(L, 1);
	luaL_tolstring(L, 1, NULL);
	return 1;
}


static const luaL_Reg base_funcs[] = {
	{"assert", luaB_assert},
	{"collectgarbage", luaB_collectgarbage},
	{"dofile", luaB_dofile},
	{"error", luaB_error},
	{"getmetatable", luaB_getmetatable},
	{"ipairs", luaB_ipairs},
	{"loadfile", luaB_loadfile},
	{"load", luaB_load},
#if defined(LUA_COMPAT_LOADSTRING)
  {"loadstring", luaB_load},
#endif
	{"next", luaB_next},
	{"pairs", luaB_pairs},
	{"pcall", luaB_pcall},
	{"print", luaB_print},
	{"rawequal", luaB_rawequal},
	{"rawlen", luaB_rawlen},
	{"rawget", luaB_rawget},
	{"rawset", luaB_rawset},
	{"select", luaB_select},
	{"setmetatable", luaB_setmetatable},
	{"tonumber", luaB_tonumber},
	{"tostring", luaB_tostring},
	{"type", luaB_type},
	{"xpcall", luaB_xpcall},
	/* placeholders */
	{"_G", NULL},
	{"_VERSION", NULL},
	{NULL, NULL}
};


LUAMOD_API int luaopen_base(lua_State* L)
{
	/* open lib into global table */
	lua_pushglobaltable(L);
	luaL_setfuncs(L, base_funcs, 0);
	/* set global _G */
	lua_pushvalue(L, -1);
	lua_setfield(L, -2, "_G");
	/* set global _VERSION */
	lua_pushliteral(L, LUA_VERSION);
	lua_setfield(L, -2, "_VERSION");
	return 1;
}