lobject.c
上传用户:yisoukefu
上传日期:2020-08-09
资源大小:39506k
文件大小:5k
- /*
- ** $Id: lobject.c,v 2.22 2006/02/10 17:43:52 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 == ' ') return 1; /* most common case */
- while (isspace(cast(unsigned char, *endptr))) endptr++;
- if (*endptr != ' ') 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] = ' ';
- 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] = ' ';
- 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] = ' '; /* 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, "nr"); /* stop at first newline */
- bufflen -= sizeof(" [string "..."] ");
- if (len > bufflen) len = bufflen;
- strcpy(out, "[string "");
- if (source[len] != ' ') { /* must truncate? */
- strncat(out, source, len);
- strcat(out, "...");
- }
- else
- strcat(out, source);
- strcat(out, ""]");
- }
- }
- }