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