lua/lobject.c
2013-04-25 10:53:13 -03:00

314 lines
8.5 KiB
C

/*
** $Id: lobject.c,v 2.59 2013/04/16 18:46:28 roberto Exp roberto $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define lobject_c
#define LUA_CORE
#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 >= 0x10) {
x = (x+1) >> 1;
e++;
}
return ((e+1) << 3) | (cast_int(x) - 8);
}
/* converts back */
int luaO_fb2int (int x) {
int e = (x >> 3) & 0x1f;
if (e == 0) return x;
else return ((x & 7) + 8) << (e - 1);
}
int luaO_ceillog2 (unsigned int x) {
static const lu_byte log_2[256] = {
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];
}
lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2) {
switch (op) {
case LUA_OPADD: return luai_numadd(NULL, v1, v2);
case LUA_OPSUB: return luai_numsub(NULL, v1, v2);
case LUA_OPMUL: return luai_nummul(NULL, v1, v2);
case LUA_OPDIV: return luai_numdiv(NULL, v1, v2);
case LUA_OPMOD: return luai_nummod(NULL, v1, v2);
case LUA_OPPOW: return luai_numpow(NULL, v1, v2);
case LUA_OPUNM: return luai_numunm(NULL, v1);
default: lua_assert(0); return 0;
}
}
int luaO_hexavalue (int c) {
if (lisdigit(c)) return c - '0';
else return ltolower(c) - 'a' + 10;
}
#if !defined(lua_strx2number)
#include <math.h>
static int isneg (const char **s) {
if (**s == '-') { (*s)++; return 1; }
else if (**s == '+') (*s)++;
return 0;
}
static lua_Number readhexa (const char **s, lua_Number r, int *count) {
for (; lisxdigit(cast_uchar(**s)); (*s)++) { /* read integer part */
r = (r * cast_num(16.0)) + cast_num(luaO_hexavalue(cast_uchar(**s)));
(*count)++;
}
return r;
}
/*
** convert an hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number (const char *s, char **endptr) {
lua_Number r = 0.0;
int e = 0, i = 0;
int neg = 0; /* 1 if number is negative */
*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') */
s += 2; /* skip '0x' */
r = readhexa(&s, r, &i); /* read integer part */
if (*s == '.') {
s++; /* skip dot */
r = readhexa(&s, r, &e); /* read fractional part */
}
if (i == 0 && e == 0)
return 0.0; /* invalid format (no digit) */
e *= -4; /* each fractional digit divides value by 2^-4 */
*endptr = cast(char *, s); /* valid up to here */
if (*s == 'p' || *s == 'P') { /* exponent part? */
int exp1 = 0;
int neg1;
s++; /* skip 'p' */
neg1 = isneg(&s); /* signal */
if (!lisdigit(cast_uchar(*s)))
goto ret; /* 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 */
ret:
if (neg) r = -r;
return l_mathop(ldexp)(r, e);
}
#endif
int luaO_str2d (const char *s, size_t len, lua_Number *result) {
char *endptr;
if (strpbrk(s, "nN")) /* reject 'inf' and 'nan' */
return 0;
else if (strpbrk(s, "xX")) /* hexa? */
*result = lua_strx2number(s, &endptr);
else
*result = lua_str2number(s, &endptr);
if (endptr == s) return 0; /* nothing recognized */
while (lisspace(cast_uchar(*endptr))) endptr++;
return (endptr == s + len); /* OK if no trailing characters */
}
int luaO_str2int (const char *s, lua_Integer *result) {
lua_Unsigned a = 0;
if (s[0] == '0' &&
(s[1] == 'x' || s[1] == 'X')) { /* hexa? */
s += 2; /* skip '0x' */
for (; lisxdigit(cast_uchar(*s)); s++)
a = a * 16 + luaO_hexavalue(cast_uchar(*s));
}
else { /* decimal */
for (; lisdigit(cast_uchar(*s)); s++)
a = a * 10 + luaO_hexavalue(cast_uchar(*s));
}
if (*s != '\0') return 0; /* something wrong in the numeral */
else {
*result = cast(lua_Integer, a);
return 1;
}
}
static void pushstr (lua_State *L, const char *str, size_t l) {
setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
}
/* this function handles only `%d', `%c', %f, %p, and `%s' formats */
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;
luaD_checkstack(L, 2); /* fmt + item */
pushstr(L, fmt, e - fmt);
switch (*(e+1)) {
case 's': {
const char *s = va_arg(argp, char *);
if (s == NULL) s = "(null)";
pushstr(L, s, strlen(s));
break;
}
case 'c': {
char buff;
buff = cast(char, va_arg(argp, int));
pushstr(L, &buff, 1);
break;
}
case 'd': {
setnvalue(L->top++, cast_num(va_arg(argp, int)));
break;
}
case 'I': {
char buff[LUA_MAXINTEGER2STR];
lua_Integer i = cast(lua_Integer, va_arg(argp, lua_Integer));
int l = lua_integer2str(buff, i);
pushstr(L, buff, l);
break;
}
case 'f': {
setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
break;
}
case 'p': {
char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
int l = sprintf(buff, "%p", va_arg(argp, void *));
pushstr(L, buff, l);
break;
}
case '%': {
pushstr(L, "%", 1);
break;
}
default: {
luaG_runerror(L,
"invalid option " LUA_QL("%%%c") " to " LUA_QL("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));
}
}