Mesen-SX/Lua/lobject.c

/*
** $Id: lobject.c,v 2.113 2016/12/22 13:08:50 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/

#define lobject_c
#define LUA_CORE

#include "lprefix.h"


#include <locale.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lctype.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"


LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};


/*
** converts an integer to a "floating point byte", represented as
** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
** eeeee != 0 and (xxx) otherwise.
*/
int luaO_int2fb(unsigned int x)
{
	int e = 0; /* exponent */
	if (x < 8) return x;
	while (x >= (8 << 4))
	{
		/* coarse steps */
		x = (x + 0xf) >> 4; /* x = ceil(x / 16) */
		e += 4;
	}
	while (x >= (8 << 1))
	{
		/* fine steps */
		x = (x + 1) >> 1; /* x = ceil(x / 2) */
		e++;
	}
	return ((e + 1) << 3) | (cast_int(x) - 8);
}


/* converts back */
int luaO_fb2int(int x)
{
	return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
}


/*
** Computes ceil(log2(x))
*/
int luaO_ceillog2(unsigned int x)
{
	static const lu_byte log_2[256] = {
		/* log_2[i] = ceil(log2(i - 1)) */
		0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
		6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
		8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
		8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
		8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
		8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
	};
	int l = 0;
	x--;
	while (x >= 256)
	{
		l += 8;
		x >>= 8;
	}
	return l + log_2[x];
}


static lua_Integer intarith(lua_State* L, int op, lua_Integer v1,
                            lua_Integer v2)
{
	switch (op)
	{
	case LUA_OPADD: return intop(+, v1, v2);
	case LUA_OPSUB: return intop(-, v1, v2);
	case LUA_OPMUL: return intop(*, v1, v2);
	case LUA_OPMOD: return luaV_mod(L, v1, v2);
	case LUA_OPIDIV: return luaV_div(L, v1, v2);
	case LUA_OPBAND: return intop(&, v1, v2);
	case LUA_OPBOR: return intop(|, v1, v2);
	case LUA_OPBXOR: return intop(^, v1, v2);
	case LUA_OPSHL: return luaV_shiftl(v1, v2);
	case LUA_OPSHR: return luaV_shiftl(v1, -v2);
	case LUA_OPUNM: return intop(-, 0, v1);
	case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
	default: lua_assert(0);
		return 0;
	}
}


static lua_Number numarith(lua_State* L, int op, lua_Number v1,
                           lua_Number v2)
{
	switch (op)
	{
	case LUA_OPADD: return luai_numadd(L, v1, v2);
	case LUA_OPSUB: return luai_numsub(L, v1, v2);
	case LUA_OPMUL: return luai_nummul(L, v1, v2);
	case LUA_OPDIV: return luai_numdiv(L, v1, v2);
	case LUA_OPPOW: return luai_numpow(L, v1, v2);
	case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
	case LUA_OPUNM: return luai_numunm(L, v1);
	case LUA_OPMOD:
		{
			lua_Number m;
			luai_nummod(L, v1, v2, m);
			return m;
		}
	default: lua_assert(0);
		return 0;
	}
}


void luaO_arith(lua_State* L, int op, const TValue* p1, const TValue* p2,
                TValue* res)
{
	switch (op)
	{
	case LUA_OPBAND:
	case LUA_OPBOR:
	case LUA_OPBXOR:
	case LUA_OPSHL:
	case LUA_OPSHR:
	case LUA_OPBNOT:
		{
			/* operate only on integers */
			lua_Integer i1;
			lua_Integer i2;
			if (tointeger(p1, &i1) && tointeger(p2, &i2))
			{
				setivalue(res, intarith(L, op, i1, i2));
				return;
			}
			else break; /* go to the end */
		}
	case LUA_OPDIV:
	case LUA_OPPOW:
		{
			/* operate only on floats */
			lua_Number n1;
			lua_Number n2;
			if (tonumber(p1, &n1) && tonumber(p2, &n2))
			{
				setfltvalue(res, numarith(L, op, n1, n2));
				return;
			}
			else break; /* go to the end */
		}
	default:
		{
			/* other operations */
			lua_Number n1;
			lua_Number n2;
			if (ttisinteger(p1) && ttisinteger(p2))
			{
				setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
				return;
			}
			else if (tonumber(p1, &n1) && tonumber(p2, &n2))
			{
				setfltvalue(res, numarith(L, op, n1, n2));
				return;
			}
			else break; /* go to the end */
		}
	}
	/* could not perform raw operation; try metamethod */
	lua_assert(L != NULL); /* should not fail when folding (compile time) */
	luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
}


int luaO_hexavalue(int c)
{
	if (lisdigit(c)) return c - '0';
	else return (ltolower(c) - 'a') + 10;
}


static int isneg(const char** s)
{
	if (**s == '-')
	{
		(*s)++;
		return 1;
	}
	else if (**s == '+') (*s)++;
	return 0;
}


/*
** {==================================================================
** Lua's implementation for 'lua_strx2number'
** ===================================================================
*/

#if !defined(lua_strx2number)

/* maximum number of significant digits to read (to avoid overflows
   even with single floats) */
#define MAXSIGDIG	30

/*
** convert an hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number(const char* s, char** endptr)
{
	int dot = lua_getlocaledecpoint();
	lua_Number r = 0.0; /* result (accumulator) */
	int sigdig = 0; /* number of significant digits */
	int nosigdig = 0; /* number of non-significant digits */
	int e = 0; /* exponent correction */
	int neg; /* 1 if number is negative */
	int hasdot = 0; /* true after seen a dot */
	*endptr = cast(char *, s); /* nothing is valid yet */
	while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
	neg = isneg(&s); /* check signal */
	if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
		return 0.0; /* invalid format (no '0x') */
	for (s += 2; ; s++)
	{
		/* skip '0x' and read numeral */
		if (*s == dot)
		{
			if (hasdot) break; /* second dot? stop loop */
			else hasdot = 1;
		}
		else if (lisxdigit(cast_uchar(*s)))
		{
			if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
				nosigdig++;
			else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
				r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
			else e++; /* too many digits; ignore, but still count for exponent */
			if (hasdot) e--; /* decimal digit? correct exponent */
		}
		else break; /* neither a dot nor a digit */
	}
	if (nosigdig + sigdig == 0) /* no digits? */
		return 0.0; /* invalid format */
	*endptr = cast(char *, s); /* valid up to here */
	e *= 4; /* each digit multiplies/divides value by 2^4 */
	if (*s == 'p' || *s == 'P')
	{
		/* exponent part? */
		int exp1 = 0; /* exponent value */
		int neg1; /* exponent signal */
		s++; /* skip 'p' */
		neg1 = isneg(&s); /* signal */
		if (!lisdigit(cast_uchar(*s)))
			return 0.0; /* invalid; must have at least one digit */
		while (lisdigit(cast_uchar(*s))) /* read exponent */
			exp1 = exp1 * 10 + *(s++) - '0';
		if (neg1) exp1 = -exp1;
		e += exp1;
		*endptr = cast(char *, s); /* valid up to here */
	}
	if (neg) r = -r;
	return l_mathop(ldexp)(r, e);
}

#endif
/* }====================================================== */


/* maximum length of a numeral */
#if !defined (L_MAXLENNUM)
#define L_MAXLENNUM	200
#endif

static const char* l_str2dloc(const char* s, lua_Number* result, int mode)
{
	char* endptr;
	*result = (mode == 'x')
		          ? lua_strx2number(s, &endptr) /* try to convert */
		          : lua_str2number(s, &endptr);
	if (endptr == s) return NULL; /* nothing recognized? */
	while (lisspace(cast_uchar(*endptr))) endptr++; /* skip trailing spaces */
	return (*endptr == '\0') ? endptr : NULL; /* OK if no trailing characters */
}


/*
** Convert string 's' to a Lua number (put in 'result'). Return NULL
** on fail or the address of the ending '\0' on success.
** 'pmode' points to (and 'mode' contains) special things in the string:
** - 'x'/'X' means an hexadecimal numeral
** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
** - '.' just optimizes the search for the common case (nothing special)
** This function accepts both the current locale or a dot as the radix
** mark. If the convertion fails, it may mean number has a dot but
** locale accepts something else. In that case, the code copies 's'
** to a buffer (because 's' is read-only), changes the dot to the
** current locale radix mark, and tries to convert again.
*/
static const char* l_str2d(const char* s, lua_Number* result)
{
	const char* endptr;
	const char* pmode = strpbrk(s, ".xXnN");
	int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
	if (mode == 'n') /* reject 'inf' and 'nan' */
		return NULL;
	endptr = l_str2dloc(s, result, mode); /* try to convert */
	if (endptr == NULL)
	{
		/* failed? may be a different locale */
		char buff[L_MAXLENNUM + 1];
		const char* pdot = strchr(s, '.');
		if (strlen(s) > L_MAXLENNUM || pdot == NULL)
			return NULL; /* string too long or no dot; fail */
		strcpy(buff, s); /* copy string to buffer */
		buff[pdot - s] = lua_getlocaledecpoint(); /* correct decimal point */
		endptr = l_str2dloc(buff, result, mode); /* try again */
		if (endptr != NULL)
			endptr = s + (endptr - buff); /* make relative to 's' */
	}
	return endptr;
}


#define MAXBY10		cast(lua_Unsigned, LUA_MAXINTEGER / 10)
#define MAXLASTD	cast_int(LUA_MAXINTEGER % 10)

static const char* l_str2int(const char* s, lua_Integer* result)
{
	lua_Unsigned a = 0;
	int empty = 1;
	int neg;
	while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
	neg = isneg(&s);
	if (s[0] == '0' &&
		(s[1] == 'x' || s[1] == 'X'))
	{
		/* hex? */
		s += 2; /* skip '0x' */
		for (; lisxdigit(cast_uchar(*s)); s++)
		{
			a = a * 16 + luaO_hexavalue(*s);
			empty = 0;
		}
	}
	else
	{
		/* decimal */
		for (; lisdigit(cast_uchar(*s)); s++)
		{
			int d = *s - '0';
			if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg)) /* overflow? */
				return NULL; /* do not accept it (as integer) */
			a = a * 10 + d;
			empty = 0;
		}
	}
	while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */
	if (empty || *s != '\0') return NULL; /* something wrong in the numeral */
	else
	{
		*result = l_castU2S((neg) ? 0u - a : a);
		return s;
	}
}


size_t luaO_str2num(const char* s, TValue* o)
{
	lua_Integer i;
	lua_Number n;
	const char* e;
	if ((e = l_str2int(s, &i)) != NULL)
	{
		/* try as an integer */
		setivalue(o, i);
	}
	else if ((e = l_str2d(s, &n)) != NULL)
	{
		/* else try as a float */
		setfltvalue(o, n);
	}
	else
		return 0; /* conversion failed */
	return (e - s) + 1; /* success; return string size */
}


int luaO_utf8esc(char* buff, unsigned long x)
{
	int n = 1; /* number of bytes put in buffer (backwards) */
	lua_assert(x <= 0x10FFFF);
	if (x < 0x80) /* ascii? */
		buff[UTF8BUFFSZ - 1] = cast(char, x);
	else
	{
		/* need continuation bytes */
		unsigned int mfb = 0x3f; /* maximum that fits in first byte */
		do
		{
			/* add continuation bytes */
			buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
			x >>= 6; /* remove added bits */
			mfb >>= 1; /* now there is one less bit available in first byte */
		}
		while (x > mfb); /* still needs continuation byte? */
		buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */
	}
	return n;
}


/* maximum length of the conversion of a number to a string */
#define MAXNUMBER2STR	50


/*
** Convert a number object to a string
*/
void luaO_tostring(lua_State* L, StkId obj)
{
	char buff[MAXNUMBER2STR];
	size_t len;
	lua_assert(ttisnumber(obj));
	if (ttisinteger(obj))
		len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
	else
	{
		len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
#if !defined(LUA_COMPAT_FLOATSTRING)
		if (buff[strspn(buff, "-0123456789")] == '\0')
		{
			/* looks like an int? */
			buff[len++] = lua_getlocaledecpoint();
			buff[len++] = '0'; /* adds '.0' to result */
		}
#endif
	}
	setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
}


static void pushstr(lua_State* L, const char* str, size_t l)
{
	setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
	luaD_inctop(L);
}


/*
** this function handles only '%d', '%c', '%f', '%p', and '%s'
   conventional formats, plus Lua-specific '%I' and '%U'
*/
const char* luaO_pushvfstring(lua_State* L, const char* fmt, va_list argp)
{
	int n = 0;
	for (;;)
	{
		const char* e = strchr(fmt, '%');
		if (e == NULL) break;
		pushstr(L, fmt, e - fmt);
		switch (*(e + 1))
		{
		case 's':
			{
				/* zero-terminated string */
				const char* s = va_arg(argp, char *);
				if (s == NULL) s = "(null)";
				pushstr(L, s, strlen(s));
				break;
			}
		case 'c':
			{
				/* an 'int' as a character */
				char buff = cast(char, va_arg(argp, int));
				if (lisprint(cast_uchar(buff)))
					pushstr(L, &buff, 1);
				else /* non-printable character; print its code */
					luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
				break;
			}
		case 'd':
			{
				/* an 'int' */
				setivalue(L->top, va_arg(argp, int));
				goto top2str;
			}
		case 'I':
			{
				/* a 'lua_Integer' */
				setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
				goto top2str;
			}
		case 'f':
			{
				/* a 'lua_Number' */
				setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
			top2str: /* convert the top element to a string */
				luaD_inctop(L);
				luaO_tostring(L, L->top - 1);
				break;
			}
		case 'p':
			{
				/* a pointer */
				char buff[4 * sizeof(void*) + 8]; /* should be enough space for a '%p' */
				int l = l_sprintf(buff, sizeof(buff), "%p", va_arg(argp, void *));
				pushstr(L, buff, l);
				break;
			}
		case 'U':
			{
				/* an 'int' as a UTF-8 sequence */
				char buff[UTF8BUFFSZ];
				int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
				pushstr(L, buff + UTF8BUFFSZ - l, l);
				break;
			}
		case '%':
			{
				pushstr(L, "%", 1);
				break;
			}
		default:
			{
				luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
				              *(e + 1));
			}
		}
		n += 2;
		fmt = e + 2;
	}
	luaD_checkstack(L, 1);
	pushstr(L, fmt, strlen(fmt));
	if (n > 0) luaV_concat(L, n + 1);
	return svalue(L->top - 1);
}


const char* luaO_pushfstring(lua_State* L, const char* fmt, ...)
{
	const char* msg;
	va_list argp;
	va_start(argp, fmt);
	msg = luaO_pushvfstring(L, fmt, argp);
	va_end(argp);
	return msg;
}


/* number of chars of a literal string without the ending \0 */
#define LL(x)	(sizeof(x)/sizeof(char) - 1)

#define RETS	"..."
#define PRE	"[string \""
#define POS	"\"]"

#define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )

void luaO_chunkid(char* out, const char* source, size_t bufflen)
{
	size_t l = strlen(source);
	if (*source == '=')
	{
		/* 'literal' source */
		if (l <= bufflen) /* small enough? */
			memcpy(out, source + 1, l * sizeof(char));
		else
		{
			/* truncate it */
			addstr(out, source + 1, bufflen - 1);
			*out = '\0';
		}
	}
	else if (*source == '@')
	{
		/* file name */
		if (l <= bufflen) /* small enough? */
			memcpy(out, source + 1, l * sizeof(char));
		else
		{
			/* add '...' before rest of name */
			addstr(out, RETS, LL(RETS));
			bufflen -= LL(RETS);
			memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
		}
	}
	else
	{
		/* string; format as [string "source"] */
		const char* nl = strchr(source, '\n'); /* find first new line (if any) */
		addstr(out, PRE, LL(PRE)); /* add prefix */
		bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */
		if (l < bufflen && nl == NULL)
		{
			/* small one-line source? */
			addstr(out, source, l); /* keep it */
		}
		else
		{
			if (nl != NULL) l = nl - source; /* stop at first newline */
			if (l > bufflen) l = bufflen;
			addstr(out, source, l);
			addstr(out, RETS, LL(RETS));
		}
		memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
	}
}