module/lua/lobject.c

   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 #define lobject_c
   8 #define LUA_CORE
   9
  10 #include <sys/lua/lua.h>
  11
  12 #include "lctype.h"
  13 #include "ldebug.h"
  14 #include "ldo.h"
  15 #include "lmem.h"
  16 #include "lobject.h"
  17 #include "lstate.h"
  18 #include "lstring.h"
  19 #include "lvm.h"
  20
  21
  22
  23 LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
  24
  25
  26 /*
  27 ** converts an integer to a "floating point byte", represented as
  28 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
  29 ** eeeee != 0 and (xxx) otherwise.
  30 */
  31 int luaO_int2fb (unsigned int x) {
  32   int e = 0;  /* exponent */
  33   if (x < 8) return x;
  34   while (x >= 0x10) {
  35     x = (x+1) >> 1;
  36     e++;
  37   }
  38   return ((e+1) << 3) | (cast_int(x) - 8);
  39 }
  40
  41
  42 /* converts back */
  43 int luaO_fb2int (int x) {
  44   int e = (x >> 3) & 0x1f;
  45   if (e == 0) return x;
  46   else return ((x & 7) + 8) << (e - 1);
  47 }
  48
  49
  50 int luaO_ceillog2 (unsigned int x) {
  51   static const lu_byte log_2[256] = {
  52     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,
  53     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,
  54     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,
  55     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,
  56     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  57     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  58     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
  59     8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
  60   };
  61   int l = 0;
  62   x--;
  63   while (x >= 256) { l += 8; x >>= 8; }
  64   return l + log_2[x];
  65 }
  66
  67
  68 lua_Number luaO_arith (int op, lua_Number v1, lua_Number v2) {
  69   switch (op) {
  70     case LUA_OPADD: return luai_numadd(NULL, v1, v2);
  71     case LUA_OPSUB: return luai_numsub(NULL, v1, v2);
  72     case LUA_OPMUL: return luai_nummul(NULL, v1, v2);
  73     case LUA_OPDIV: return luai_numdiv(NULL, v1, v2);
  74     case LUA_OPMOD: return luai_nummod(NULL, v1, v2);
  75     case LUA_OPPOW: return luai_numpow(NULL, v1, v2);
  76     case LUA_OPUNM: return luai_numunm(NULL, v1);
  77     default: lua_assert(0); return 0;
  78   }
  79 }
  80
  81
  82 int luaO_hexavalue (int c) {
  83   if (lisdigit(c)) return c - '0';
  84   else return ltolower(c) - 'a' + 10;
  85 }
  86
  87
  88 #if !defined(lua_strx2number)
  89
  90
  91
  92 static int isneg (const char **s) {
  93   if (**s == '-') { (*s)++; return 1; }
  94   else if (**s == '+') (*s)++;
  95   return 0;
  96 }
  97
  98
  99 static lua_Number readhexa (const char **s, lua_Number r, int *count) {
 100   for (; lisxdigit(cast_uchar(**s)); (*s)++) {  /* read integer part */
 101     r = (r * cast_num(16.0)) + cast_num(luaO_hexavalue(cast_uchar(**s)));
 102     (*count)++;
 103   }
 104   return r;
 105 }
 106
 107
 108 /*
 109 ** convert an hexadecimal numeric string to a number, following
 110 ** C99 specification for 'strtod'
 111 */
 112 static lua_Number lua_strx2number (const char *s, char **endptr) {
 113   lua_Number r = 0.0;
 114   int e = 0, i = 0;
 115   int neg = 0;  /* 1 if number is negative */
 116   *endptr = cast(char *, s);  /* nothing is valid yet */
 117   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
 118   neg = isneg(&s);  /* check signal */
 119   if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
 120     return 0.0;  /* invalid format (no '0x') */
 121   s += 2;  /* skip '0x' */
 122   r = readhexa(&s, r, &i);  /* read integer part */
 123   if (*s == '.') {
 124     s++;  /* skip dot */
 125     r = readhexa(&s, r, &e);  /* read fractional part */
 126   }
 127   if (i == 0 && e == 0)
 128     return 0.0;  /* invalid format (no digit) */
 129   e *= -4;  /* each fractional digit divides value by 2^-4 */
 130   *endptr = cast(char *, s);  /* valid up to here */
 131   if (*s == 'p' || *s == 'P') {  /* exponent part? */
 132     int exp1 = 0;
 133     int neg1;
 134     s++;  /* skip 'p' */
 135     neg1 = isneg(&s);  /* signal */
 136     if (!lisdigit(cast_uchar(*s)))
 137       goto ret;  /* must have at least one digit */
 138     while (lisdigit(cast_uchar(*s)))  /* read exponent */
 139       exp1 = exp1 * 10 + *(s++) - '0';
 140     if (neg1) exp1 = -exp1;
 141     e += exp1;
 142   }
 143   *endptr = cast(char *, s);  /* valid up to here */
 144  ret:
 145   if (neg) r = -r;
 146   return ((e >= 0) ? (r * (1ULL << e)) : (r / (1ULL << -e)));
 147 }
 148
 149 #endif
 150
 151
 152 int luaO_str2d (const char *s, size_t len, lua_Number *result) {
 153   char *endptr;
 154   if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
 155     return 0;
 156   else if (strpbrk(s, "xX"))  /* hexa? */
 157     *result = lua_strx2number(s, &endptr);
 158   else
 159     *result = lua_str2number(s, &endptr);
 160   if (endptr == s) return 0;  /* nothing recognized */
 161   while (lisspace(cast_uchar(*endptr))) endptr++;
 162   return (endptr == s + len);  /* OK if no trailing characters */
 163 }
 164
 165
 166
 167 static void pushstr (lua_State *L, const char *str, size_t l) {
 168   setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
 169 }
 170
 171
 172 /* this function handles only `%d', `%c', %f, %p, and `%s' formats */
 173 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
 174   int n = 0;
 175   for (;;) {
 176     const char *e = strchr(fmt, '%');
 177     if (e == NULL) break;
 178     luaD_checkstack(L, 2);  /* fmt + item */
 179     pushstr(L, fmt, e - fmt);
 180     switch (*(e+1)) {
 181       case 's': {
 182         const char *s = va_arg(argp, char *);
 183         if (s == NULL) s = "(null)";
 184         pushstr(L, s, strlen(s));
 185         break;
 186       }
 187       case 'c': {
 188         char buff;
 189         buff = cast(char, va_arg(argp, int));
 190         pushstr(L, &buff, 1);
 191         break;
 192       }
 193       case 'd': {
 194         setnvalue(L->top++, cast_num(va_arg(argp, int)));
 195         break;
 196       }
 197       case 'f': {
 198         setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
 199         break;
 200       }
 201       case 'p': {
 202         char buff[4*sizeof(void *) + 8]; /* should be enough space for a `%p' */
 203         int l = lcompat_sprintf(buff, sizeof(buff), "%p", va_arg(argp, void *));
 204         pushstr(L, buff, l);
 205         break;
 206       }
 207       case '%': {
 208         pushstr(L, "%", 1);
 209         break;
 210       }
 211       default: {
 212         luaG_runerror(L,
 213             "invalid option " LUA_QL("%%%c") " to " LUA_QL("lua_pushfstring"),
 214             *(e + 1));
 215       }
 216     }
 217     n += 2;
 218     fmt = e+2;
 219   }
 220   luaD_checkstack(L, 1);
 221   pushstr(L, fmt, strlen(fmt));
 222   if (n > 0) luaV_concat(L, n + 1);
 223   return svalue(L->top - 1);
 224 }
 225
 226
 227 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
 228   const char *msg;
 229   va_list argp;
 230   va_start(argp, fmt);
 231   msg = luaO_pushvfstring(L, fmt, argp);
 232   va_end(argp);
 233   return msg;
 234 }
 235
 236
 237 /* number of chars of a literal string without the ending \0 */
 238 #define LL(x)   (sizeof(x)/sizeof(char) - 1)
 239
 240 #define RETS    "..."
 241 #define PRE     "[string \""
 242 #define POS     "\"]"
 243
 244 #define addstr(a,b,l)   ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
 245
 246 void luaO_chunkid (char *out, const char *source, size_t bufflen) {
 247   size_t l = strlen(source);
 248   if (*source == '=') {  /* 'literal' source */
 249     if (l <= bufflen)  /* small enough? */
 250       memcpy(out, source + 1, l * sizeof(char));
 251     else {  /* truncate it */
 252       addstr(out, source + 1, bufflen - 1);
 253       *out = '\0';
 254     }
 255   }
 256   else if (*source == '@') {  /* file name */
 257     if (l <= bufflen)  /* small enough? */
 258       memcpy(out, source + 1, l * sizeof(char));
 259     else {  /* add '...' before rest of name */
 260       addstr(out, RETS, LL(RETS));
 261       bufflen -= LL(RETS);
 262       memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
 263     }
 264   }
 265   else {  /* string; format as [string "source"] */
 266     const char *nl = strchr(source, '\n');  /* find first new line (if any) */
 267     addstr(out, PRE, LL(PRE));  /* add prefix */
 268     bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
 269     if (l < bufflen && nl == NULL) {  /* small one-line source? */
 270       addstr(out, source, l);  /* keep it */
 271     }
 272     else {
 273       if (nl != NULL) l = nl - source;  /* stop at first newline */
 274       if (l > bufflen) l = bufflen;
 275       addstr(out, source, l);
 276       addstr(out, RETS, LL(RETS));
 277     }
 278     memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
 279   }
 280 }