lobject.c

   1 /*
   2 ** $Id: lobject.c,v 2.22.1.1 2007/12/27 13:02:25 roberto Exp $
   3 ** Some generic functions over Lua objects
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #if 0
   8 #include <ctype.h>
   9 #include <stdarg.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #endif
  14
  15 #define lobject_c
  16 #define LUA_CORE
  17
  18 #include "lua.h"
  19
  20 #include "ldo.h"
  21 #include "lmem.h"
  22 #include "lobject.h"
  23 #include "lstate.h"
  24 #include "lstring.h"
  25 #include "lvm.h"
  26
  27
  28
  29 const TValue luaO_nilobject_ = {{NULL}, LUA_TNIL};
  30
  31
  32 /*
  33 ** converts an integer to a "floating point byte", represented as
  34 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
  35 ** eeeee != 0 and (xxx) otherwise.
  36 */
  37 int luaO_int2fb (unsigned int x) {
  38   int e = 0;  /* expoent */
  39   while (x >= 16) {
  40     x = (x+1) >> 1;
  41     e++;
  42   }
  43   if (x < 8) return x;
  44   else return ((e+1) << 3) | (cast_int(x) - 8);
  45 }
  46
  47
  48 /* converts back */
  49 int luaO_fb2int (int x) {
  50   int e = (x >> 3) & 31;
  51   if (e == 0) return x;
  52   else return ((x & 7)+8) << (e - 1);
  53 }
  54
  55
  56 int luaO_log2 (unsigned int x) {
  57   static const lu_byte log_2[256] = {
  58     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,
  59     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,
  60     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,
  61     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,
  62     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  63     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  64     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  65     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
  66   };
  67   int l = -1;
  68   while (x >= 256) { l += 8; x >>= 8; }
  69   return l + log_2[x];
  70
  71 }
  72
  73
  74 int luaO_rawequalObj (const TValue *t1, const TValue *t2) {
  75   if (ttype(t1) != ttype(t2)) return 0;
  76   else switch (ttype(t1)) {
  77     case LUA_TNIL:
  78       return 1;
  79     case LUA_TNUMBER:
  80       return luai_numeq(nvalue(t1), nvalue(t2));
  81     case LUA_TBOOLEAN:
  82       return bvalue(t1) == bvalue(t2);  /* boolean true must be 1 !! */
  83     case LUA_TLIGHTUSERDATA:
  84       return pvalue(t1) == pvalue(t2);
  85     default:
  86       lua_assert(iscollectable(t1));
  87       return gcvalue(t1) == gcvalue(t2);
  88   }
  89 }
  90
  91
  92 int luaO_str2d (const char *s, lua_Number *result) {
  93   char *endptr;
  94   *result = lua_str2number(s, &endptr);
  95   if (endptr == s) return 0;  /* conversion failed */
  96   if (*endptr == 'x' || *endptr == 'X')  /* maybe an hexadecimal constant? */
  97     *result = cast_num(strtoul(s, &endptr, 16));
  98   if (*endptr == '\0') return 1;  /* most common case */
  99   while (isspace(cast(unsigned char, *endptr))) endptr++;
 100   if (*endptr != '\0') return 0;  /* invalid trailing characters? */
 101   return 1;
 102 }
 103
 104
 105
 106 static void pushstr (lua_State *L, const char *str) {
 107   setsvalue2s(L, L->top, luaS_new(L, str));
 108   incr_top(L);
 109 }
 110
 111
 112 /* this function handles only `%d', `%c', %f, %p, and `%s' formats */
 113 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
 114   int n = 1;
 115   pushstr(L, "");
 116   for (;;) {
 117     const char *e = strchr(fmt, '%');
 118     if (e == NULL) break;
 119     setsvalue2s(L, L->top, luaS_newlstr(L, fmt, e-fmt));
 120     incr_top(L);
 121     switch (*(e+1)) {
 122       case 's': {
 123         const char *s = va_arg(argp, char *);
 124         if (s == NULL) s = "(null)";
 125         pushstr(L, s);
 126         break;
 127       }
 128       case 'c': {
 129         char buff[2];
 130         buff[0] = cast(char, va_arg(argp, int));
 131         buff[1] = '\0';
 132         pushstr(L, buff);
 133         break;
 134       }
 135       case 'd': {
 136         setnvalue(L->top, cast_num(va_arg(argp, int)));
 137         incr_top(L);
 138         break;
 139       }
 140       case 'f': {
 141         setnvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
 142         incr_top(L);
 143         break;
 144       }
 145       case 'p': {
 146         char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
 147         snprintf(buff, sizeof (buff), "%p", va_arg(argp, void *));
 148         pushstr(L, buff);
 149         break;
 150       }
 151       case '%': {
 152         pushstr(L, "%");
 153         break;
 154       }
 155       default: {
 156         char buff[3];
 157         buff[0] = '%';
 158         buff[1] = *(e+1);
 159         buff[2] = '\0';
 160         pushstr(L, buff);
 161         break;
 162       }
 163     }
 164     n += 2;
 165     fmt = e+2;
 166   }
 167   pushstr(L, fmt);
 168   luaV_concat(L, n+1, cast_int(L->top - L->base) - 1);
 169   L->top -= n;
 170   return svalue(L->top - 1);
 171 }
 172
 173
 174 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
 175   const char *msg;
 176   va_list argp;
 177   va_start(argp, fmt);
 178   msg = luaO_pushvfstring(L, fmt, argp);
 179   va_end(argp);
 180   return msg;
 181 }
 182
 183
 184 void luaO_chunkid (char *out, const char *source, size_t bufflen) {
 185   if (*source == '=') {
 186     strncpy(out, source+1, bufflen);  /* remove first char */
 187     out[bufflen-1] = '\0';  /* ensures null termination */
 188   }
 189   else {  /* out = "source", or "...source" */
 190     if (*source == '@') {
 191       size_t l;
 192       source++;  /* skip the `@' */
 193       bufflen -= sizeof(" '...' ");
 194       l = strlen(source);
 195       strcpy(out, "");
 196       if (l > bufflen) {
 197         source += (l-bufflen);  /* get last part of file name */
 198         strcat(out, "...");
 199       }
 200       strcat(out, source);
 201     }
 202     else {  /* out = [string "string"] */
 203       size_t len = strcspn(source, "\n\r");  /* stop at first newline */
 204       bufflen -= sizeof(" [string \"...\"] ");
 205       if (len > bufflen) len = bufflen;
 206       strcpy(out, "[string \"");
 207       if (source[len] != '\0') {  /* must truncate? */
 208         strncat(out, source, len);
 209         strcat(out, "...");
 210       }
 211       else
 212         strcat(out, source);
 213       strcat(out, "\"]");
 214     }
 215   }
 216 }