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  1. /*
  2. ** $Id: lobject.c,v 2.58.1.1 2013/04/12 18:48:47 roberto Exp $
  3. ** Some generic functions over Lua objects
  4. ** See Copyright Notice in lua.h
  5. */
  6.  
  7. #include <stdarg.h>
  8. #include <stdio.h>
  9. #include <stdlib.h>
  10. #include <string.h>
  11.  
  12. #define lobject_c
  13. #define LUA_CORE
  14.  
  15. #include "lua.h"
  16.  
  17. #include "lctype.h"
  18. #include "ldebug.h"
  19. #include "ldo.h"
  20. #include "lmem.h"
  21. #include "lobject.h"
  22. #include "lstate.h"
  23. #include "lstring.h"
  24. #include "lvm.h"
  25.  
  26.  
  27.  
  28. LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
  29.  
  30.  
  31. /*
  32. ** converts an integer to a "floating point byte", represented as
  33. ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
  34. ** eeeee != 0 and (xxx) otherwise.
  35. */
  36. int luaO_int2fb (unsigned int x) {
  37.   int e = 0;  /* exponent */
  38.   if (x < 8) return x;
  39.   while (x >= 0x10) {
  40.     x = (x+1) >> 1;
  41.     e++;
  42.   }
  43.   return ((e+1) << 3) | (cast_int(x) - 8);
  44. }
  45.  
  46.  
  47. /* converts back */
  48. int luaO_fb2int (int x) {
  49.   int e = (x >> 3) & 0x1f;
  50.   if (e == 0) return x;
  51.   else return ((x & 7) + 8) << (e - 1);
  52. }
  53.  
  54.  
  55. int luaO_ceillog2 (unsigned int x) {
  56.   static const lu_byte log_2[256] = {
  57.     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,
  58.     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,
  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.     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.     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  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.     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
  65.   };
  66.   int l = 0;
  67.   x--;
  68.   while (x >= 256) { l += 8; x >>= 8; }
  69.   return l + log_2[x];
  70. }
  71.  
  72.  
  73. lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2) {
  74.   switch (op) {
  75.     case LUA_OPADD: return luai_numadd(NULL, v1, v2);
  76.     case LUA_OPSUB: return luai_numsub(NULL, v1, v2);
  77.     case LUA_OPMUL: return luai_nummul(NULL, v1, v2);
  78.     case LUA_OPDIV: return luai_numdiv(NULL, v1, v2);
  79.     case LUA_OPMOD: return luai_nummod(NULL, v1, v2);
  80.     case LUA_OPPOW: return luai_numpow(NULL, v1, v2);
  81.     case LUA_OPUNM: return luai_numunm(NULL, v1);
  82.     default: lua_assert(0); return 0;
  83.   }
  84. }
  85.  
  86.  
  87. int luaO_hexavalue (int c) {
  88.   if (lisdigit(c)) return c - '0';
  89.   else return ltolower(c) - 'a' + 10;
  90. }
  91.  
  92.  
  93. #if !defined(lua_strx2number)
  94.  
  95. #include <math.h>
  96.  
  97.  
  98. static int isneg (const char **s) {
  99.   if (**s == '-') { (*s)++; return 1; }
  100.   else if (**s == '+') (*s)++;
  101.   return 0;
  102. }
  103.  
  104.  
  105. static lua_Number readhexa (const char **s, lua_Number r, int *count) {
  106.   for (; lisxdigit(cast_uchar(**s)); (*s)++) {  /* read integer part */
  107.     r = (r * cast_num(16.0)) + cast_num(luaO_hexavalue(cast_uchar(**s)));
  108.     (*count)++;
  109.   }
  110.   return r;
  111. }
  112.  
  113.  
  114. /*
  115. ** convert an hexadecimal numeric string to a number, following
  116. ** C99 specification for 'strtod'
  117. */
  118. static lua_Number lua_strx2number (const char *s, char **endptr) {
  119.   lua_Number r = 0.0;
  120.   int e = 0, i = 0;
  121.   int neg = 0;  /* 1 if number is negative */
  122.   *endptr = cast(char *, s);  /* nothing is valid yet */
  123.   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
  124.   neg = isneg(&s);  /* check signal */
  125.   if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
  126.     return 0.0;  /* invalid format (no '0x') */
  127.   s += 2;  /* skip '0x' */
  128.   r = readhexa(&s, r, &i);  /* read integer part */
  129.   if (*s == '.') {
  130.     s++;  /* skip dot */
  131.     r = readhexa(&s, r, &e);  /* read fractional part */
  132.   }
  133.   if (i == 0 && e == 0)
  134.     return 0.0;  /* invalid format (no digit) */
  135.   e *= -4;  /* each fractional digit divides value by 2^-4 */
  136.   *endptr = cast(char *, s);  /* valid up to here */
  137.   if (*s == 'p' || *s == 'P') {  /* exponent part? */
  138.     int exp1 = 0;
  139.     int neg1;
  140.     s++;  /* skip 'p' */
  141.     neg1 = isneg(&s);  /* signal */
  142.     if (!lisdigit(cast_uchar(*s)))
  143.       goto ret;  /* must have at least one digit */
  144.     while (lisdigit(cast_uchar(*s)))  /* read exponent */
  145.       exp1 = exp1 * 10 + *(s++) - '0';
  146.     if (neg1) exp1 = -exp1;
  147.     e += exp1;
  148.   }
  149.   *endptr = cast(char *, s);  /* valid up to here */
  150.  ret:
  151.   if (neg) r = -r;
  152.   return l_mathop(ldexp)(r, e);
  153. }
  154.  
  155. #endif
  156.  
  157.  
  158. int luaO_str2d (const char *s, size_t len, lua_Number *result) {
  159.   char *endptr;
  160.   if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
  161.     return 0;
  162.   else if (strpbrk(s, "xX"))  /* hexa? */
  163.     *result = lua_strx2number(s, &endptr);
  164.   else
  165.     *result = lua_str2number(s, &endptr);
  166.   if (endptr == s) return 0;  /* nothing recognized */
  167.   while (lisspace(cast_uchar(*endptr))) endptr++;
  168.   return (endptr == s + len);  /* OK if no trailing characters */
  169. }
  170.  
  171.  
  172.  
  173. static void pushstr (lua_State *L, const char *str, size_t l) {
  174.   setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
  175. }
  176.  
  177.  
  178. /* this function handles only `%d', `%c', %f, %p, and `%s' formats */
  179. const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  180.   int n = 0;
  181.   for (;;) {
  182.     const char *e = strchr(fmt, '%');
  183.     if (e == NULL) break;
  184.     luaD_checkstack(L, 2);  /* fmt + item */
  185.     pushstr(L, fmt, e - fmt);
  186.     switch (*(e+1)) {
  187.       case 's': {
  188.         const char *s = va_arg(argp, char *);
  189.         if (s == NULL) s = "(null)";
  190.         pushstr(L, s, strlen(s));
  191.         break;
  192.       }
  193.       case 'c': {
  194.         char buff;
  195.         buff = cast(char, va_arg(argp, int));
  196.         pushstr(L, &buff, 1);
  197.         break;
  198.       }
  199.       case 'd': {
  200.         setnvalue(L->top++, cast_num(va_arg(argp, int)));
  201.         break;
  202.       }
  203.       case 'f': {
  204.         setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
  205.         break;
  206.       }
  207.       case 'p': {
  208.         char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
  209.         int l = sprintf(buff, "%p", va_arg(argp, void *));
  210.         pushstr(L, buff, l);
  211.         break;
  212.       }
  213.       case '%': {
  214.         pushstr(L, "%", 1);
  215.         break;
  216.       }
  217.       default: {
  218.         luaG_runerror(L,
  219.             "invalid option " LUA_QL("%%%c") " to " LUA_QL("lua_pushfstring"),
  220.             *(e + 1));
  221.       }
  222.     }
  223.     n += 2;
  224.     fmt = e+2;
  225.   }
  226.   luaD_checkstack(L, 1);
  227.   pushstr(L, fmt, strlen(fmt));
  228.   if (n > 0) luaV_concat(L, n + 1);
  229.   return svalue(L->top - 1);
  230. }
  231.  
  232.  
  233. const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
  234.   const char *msg;
  235.   va_list argp;
  236.   va_start(argp, fmt);
  237.   msg = luaO_pushvfstring(L, fmt, argp);
  238.   va_end(argp);
  239.   return msg;
  240. }
  241.  
  242.  
  243. /* number of chars of a literal string without the ending \0 */
  244. #define LL(x)   (sizeof(x)/sizeof(char) - 1)
  245.  
  246. #define RETS    "..."
  247. #define PRE     "[string \""
  248. #define POS     "\"]"
  249.  
  250. #define addstr(a,b,l)   ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
  251.  
  252. void luaO_chunkid (char *out, const char *source, size_t bufflen) {
  253.   size_t l = strlen(source);
  254.   if (*source == '=') {  /* 'literal' source */
  255.     if (l <= bufflen)  /* small enough? */
  256.       memcpy(out, source + 1, l * sizeof(char));
  257.     else {  /* truncate it */
  258.       addstr(out, source + 1, bufflen - 1);
  259.       *out = '\0';
  260.     }
  261.   }
  262.   else if (*source == '@') {  /* file name */
  263.     if (l <= bufflen)  /* small enough? */
  264.       memcpy(out, source + 1, l * sizeof(char));
  265.     else {  /* add '...' before rest of name */
  266.       addstr(out, RETS, LL(RETS));
  267.       bufflen -= LL(RETS);
  268.       memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
  269.     }
  270.   }
  271.   else {  /* string; format as [string "source"] */
  272.     const char *nl = strchr(source, '\n');  /* find first new line (if any) */
  273.     addstr(out, PRE, LL(PRE));  /* add prefix */
  274.     bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
  275.     if (l < bufflen && nl == NULL) {  /* small one-line source? */
  276.       addstr(out, source, l);  /* keep it */
  277.     }
  278.     else {
  279.       if (nl != NULL) l = nl - source;  /* stop at first newline */
  280.       if (l > bufflen) l = bufflen;
  281.       addstr(out, source, l);
  282.       addstr(out, RETS, LL(RETS));
  283.     }
  284.     memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
  285.   }
  286. }
  287.  
  288.