lobject.c
(5.1.5)
/*
** $Id: lobject.c,v 2.22.1.1 2007/12/27 13:02:25 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/
#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define lobject_c
#define LUA_CORE
#include "lua.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"
const TValue luaO_nilobject_ = {{NULL}, LUA_TNIL};
/*
** 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; /* expoent */
while (x >= 16) {
x = (x+1) >> 1;
e++;
}
if (x < 8) return x;
else return ((e+1) << 3) | (cast_int(x) - 8);
}
/* converts back */
int luaO_fb2int (int x) {
int e = (x >> 3) & 31;
if (e == 0) return x;
else return ((x & 7)+8) << (e - 1);
}
int luaO_log2 (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 = -1;
while (x >= 256) { l += 8; x >>= 8; }
return l + log_2[x];
}
int luaO_rawequalObj (const TValue *t1, const TValue *t2) {
if (ttype(t1) != ttype(t2)) return 0;
else switch (ttype(t1)) {
case LUA_TNIL:
return 1;
case LUA_TNUMBER:
return luai_numeq(nvalue(t1), nvalue(t2));
case LUA_TBOOLEAN:
return bvalue(t1) == bvalue(t2); /* boolean true must be 1 !! */
case LUA_TLIGHTUSERDATA:
return pvalue(t1) == pvalue(t2);
default:
lua_assert(iscollectable(t1));
return gcvalue(t1) == gcvalue(t2);
}
}
int luaO_str2d (const char *s, lua_Number *result) {
char *endptr;
*result = lua_str2number(s, &endptr);
if (endptr == s) return 0; /* conversion failed */
if (*endptr == 'x' || *endptr == 'X') /* maybe an hexadecimal constant? */
*result = cast_num(strtoul(s, &endptr, 16));
if (*endptr == '\0') return 1; /* most common case */
while (isspace(cast(unsigned char, *endptr))) endptr++;
if (*endptr != '\0') return 0; /* invalid trailing characters? */
return 1;
}
static void pushstr (lua_State *L, const char *str) {
setsvalue2s(L, L->top, luaS_new(L, str));
incr_top(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 = 1;
pushstr(L, "");
for (;;) {
const char *e = strchr(fmt, '%');
if (e == NULL) break;
setsvalue2s(L, L->top, luaS_newlstr(L, fmt, e-fmt));
incr_top(L);
switch (*(e+1)) {
case 's': {
const char *s = va_arg(argp, char *);
if (s == NULL) s = "(null)";
pushstr(L, s);
break;
}
case 'c': {
char buff[2];
buff[0] = cast(char, va_arg(argp, int));
buff[1] = '\0';
pushstr(L, buff);
break;
}
case 'd': {
setnvalue(L->top, cast_num(va_arg(argp, int)));
incr_top(L);
break;
}
case 'f': {
setnvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
incr_top(L);
break;
}
case 'p': {
char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
sprintf(buff, "%p", va_arg(argp, void *));
pushstr(L, buff);
break;
}
case '%': {
pushstr(L, "%");
break;
}
default: {
char buff[3];
buff[0] = '%';
buff[1] = *(e+1);
buff[2] = '\0';
pushstr(L, buff);
break;
}
}
n += 2;
fmt = e+2;
}
pushstr(L, fmt);
luaV_concat(L, n+1, cast_int(L->top - L->base) - 1);
L->top -= n;
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;
}
void luaO_chunkid (char *out, const char *source, size_t bufflen) {
if (*source == '=') {
strncpy(out, source+1, bufflen); /* remove first char */
out[bufflen-1] = '\0'; /* ensures null termination */
}
else { /* out = "source", or "...source" */
if (*source == '@') {
size_t l;
source++; /* skip the `@' */
bufflen -= sizeof(" '...' ");
l = strlen(source);
strcpy(out, "");
if (l > bufflen) {
source += (l-bufflen); /* get last part of file name */
strcat(out, "...");
}
strcat(out, source);
}
else { /* out = [string "string"] */
size_t len = strcspn(source, "\n\r"); /* stop at first newline */
bufflen -= sizeof(" [string \"...\"] ");
if (len > bufflen) len = bufflen;
strcpy(out, "[string \"");
if (source[len] != '\0') { /* must truncate? */
strncat(out, source, len);
strcat(out, "...");
}
else
strcat(out, source);
strcat(out, "\"]");
}
}
}