external/mit/lua/dist/src/lobject.c

   1 /*      $NetBSD: lobject.c,v 1.5 2015/10/08 13:21:00 mbalmer Exp $      */
   2
   3 /*
   4 ** Id: lobject.c,v 2.104 2015/04/11 18:30:08 roberto Exp
   5 ** Some generic functions over Lua objects
   6 ** See Copyright Notice in lua.h
   7 */
   8
   9 #define lobject_c
  10 #define LUA_CORE
  11
  12 #include "lprefix.h"
  13
  14
  15 #ifndef _KERNEL
  16 #include <locale.h>
  17 #include <math.h>
  18 #include <stdarg.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #endif
  23
  24 #include "lua.h"
  25
  26 #include "lctype.h"
  27 #include "ldebug.h"
  28 #include "ldo.h"
  29 #include "lmem.h"
  30 #include "lobject.h"
  31 #include "lstate.h"
  32 #include "lstring.h"
  33 #include "lvm.h"
  34
  35
  36
  37 LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
  38
  39
  40 /*
  41 ** converts an integer to a "floating point byte", represented as
  42 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
  43 ** eeeee != 0 and (xxx) otherwise.
  44 */
  45 int luaO_int2fb (unsigned int x) {
  46   int e = 0;  /* exponent */
  47   if (x < 8) return x;
  48   while (x >= (8 << 4)) {  /* coarse steps */
  49     x = (x + 0xf) >> 4;  /* x = ceil(x / 16) */
  50     e += 4;
  51   }
  52   while (x >= (8 << 1)) {  /* fine steps */
  53     x = (x + 1) >> 1;  /* x = ceil(x / 2) */
  54     e++;
  55   }
  56   return ((e+1) << 3) | (cast_int(x) - 8);
  57 }
  58
  59
  60 /* converts back */
  61 int luaO_fb2int (int x) {
  62   int e = (x >> 3) & 0x1f;
  63   if (e == 0) return x;
  64   else return ((x & 7) + 8) << (e - 1);
  65 }
  66
  67
  68 /*
  69 ** Computes ceil(log2(x))
  70 */
  71 int luaO_ceillog2 (unsigned int x) {
  72   static const lu_byte log_2[256] = {  /* log_2[i] = ceil(log2(i - 1)) */
  73     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,
  74     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,
  75     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,
  76     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,
  77     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,
  78     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,
  79     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,
  80     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
  81   };
  82   int l = 0;
  83   x--;
  84   while (x >= 256) { l += 8; x >>= 8; }
  85   return l + log_2[x];
  86 }
  87
  88
  89 static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
  90                                                    lua_Integer v2) {
  91   switch (op) {
  92     case LUA_OPADD: return intop(+, v1, v2);
  93     case LUA_OPSUB:return intop(-, v1, v2);
  94     case LUA_OPMUL:return intop(*, v1, v2);
  95     case LUA_OPMOD: return luaV_mod(L, v1, v2);
  96     case LUA_OPIDIV: return luaV_div(L, v1, v2);
  97     case LUA_OPBAND: return intop(&, v1, v2);
  98     case LUA_OPBOR: return intop(|, v1, v2);
  99     case LUA_OPBXOR: return intop(^, v1, v2);
 100     case LUA_OPSHL: return luaV_shiftl(v1, v2);
 101     case LUA_OPSHR: return luaV_shiftl(v1, -v2);
 102     case LUA_OPUNM: return intop(-, 0, v1);
 103     case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
 104     default: lua_assert(0); return 0;
 105   }
 106 }
 107
 108
 109 #ifndef _KERNEL
 110 static lua_Number numarith (lua_State *L, int op, lua_Number v1,
 111                                                   lua_Number v2) {
 112   switch (op) {
 113     case LUA_OPADD: return luai_numadd(L, v1, v2);
 114     case LUA_OPSUB: return luai_numsub(L, v1, v2);
 115     case LUA_OPMUL: return luai_nummul(L, v1, v2);
 116     case LUA_OPDIV: return luai_numdiv(L, v1, v2);
 117     case LUA_OPPOW: return luai_numpow(L, v1, v2);
 118     case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
 119     case LUA_OPUNM: return luai_numunm(L, v1);
 120     case LUA_OPMOD: {
 121       lua_Number m;
 122       luai_nummod(L, v1, v2, m);
 123       return m;
 124     }
 125     default: lua_assert(0); return 0;
 126   }
 127 }
 128 #endif
 129
 130
 131 void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
 132                  TValue *res) {
 133   switch (op) {
 134     case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
 135     case LUA_OPSHL: case LUA_OPSHR:
 136     case LUA_OPBNOT: {  /* operate only on integers */
 137       lua_Integer i1; lua_Integer i2;
 138       if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
 139         setivalue(res, intarith(L, op, i1, i2));
 140         return;
 141       }
 142       else break;  /* go to the end */
 143     }
 144 #ifndef _KERNEL
 145     case LUA_OPDIV: case LUA_OPPOW: {  /* operate only on floats */
 146       lua_Number n1; lua_Number n2;
 147       if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
 148         setfltvalue(res, numarith(L, op, n1, n2));
 149         return;
 150       }
 151       else break;  /* go to the end */
 152     }
 153 #endif
 154     default: {  /* other operations */
 155 #ifndef _KERNEL
 156       lua_Number n1; lua_Number n2;
 157       if (ttisinteger(p1) && ttisinteger(p2)) {
 158         setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
 159         return;
 160       }
 161       else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
 162         setfltvalue(res, numarith(L, op, n1, n2));
 163         return;
 164       }
 165 #else /* _KERNEL */
 166       lua_Integer i1; lua_Integer i2;
 167       if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
 168         setivalue(res, intarith(L, op, i1, i2));
 169         return;
 170       }
 171 #endif
 172       else break;  /* go to the end */
 173     }
 174   }
 175   /* could not perform raw operation; try metamethod */
 176   lua_assert(L != NULL);  /* should not fail when folding (compile time) */
 177   luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
 178 }
 179
 180
 181 int luaO_hexavalue (int c) {
 182   if (lisdigit(c)) return c - '0';
 183   else return (ltolower(c) - 'a') + 10;
 184 }
 185
 186
 187 static int isneg (const char **s) {
 188   if (**s == '-') { (*s)++; return 1; }
 189   else if (**s == '+') (*s)++;
 190   return 0;
 191 }
 192
 193
 194
 195 #ifndef _KERNEL
 196 /*
 197 ** {==================================================================
 198 ** Lua's implementation for 'lua_strx2number'
 199 ** ===================================================================
 200 */
 201
 202 #if !defined(lua_strx2number)
 203
 204 /* maximum number of significant digits to read (to avoid overflows
 205    even with single floats) */
 206 #define MAXSIGDIG       30
 207
 208 /*
 209 ** convert an hexadecimal numeric string to a number, following
 210 ** C99 specification for 'strtod'
 211 */
 212 static lua_Number lua_strx2number (const char *s, char **endptr) {
 213   int dot = lua_getlocaledecpoint();
 214   lua_Number r = 0.0;  /* result (accumulator) */
 215   int sigdig = 0;  /* number of significant digits */
 216   int nosigdig = 0;  /* number of non-significant digits */
 217   int e = 0;  /* exponent correction */
 218   int neg;  /* 1 if number is negative */
 219   int hasdot = 0;  /* true after seen a dot */
 220   *endptr = cast(char *, s);  /* nothing is valid yet */
 221   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
 222   neg = isneg(&s);  /* check signal */
 223   if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
 224     return 0.0;  /* invalid format (no '0x') */
 225   for (s += 2; ; s++) {  /* skip '0x' and read numeral */
 226     if (*s == dot) {
 227       if (hasdot) break;  /* second dot? stop loop */
 228       else hasdot = 1;
 229     }
 230     else if (lisxdigit(cast_uchar(*s))) {
 231       if (sigdig == 0 && *s == '0')  /* non-significant digit (zero)? */
 232         nosigdig++;
 233       else if (++sigdig <= MAXSIGDIG)  /* can read it without overflow? */
 234           r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
 235       else e++; /* too many digits; ignore, but still count for exponent */
 236       if (hasdot) e--;  /* decimal digit? correct exponent */
 237     }
 238     else break;  /* neither a dot nor a digit */
 239   }
 240   if (nosigdig + sigdig == 0)  /* no digits? */
 241     return 0.0;  /* invalid format */
 242   *endptr = cast(char *, s);  /* valid up to here */
 243   e *= 4;  /* each digit multiplies/divides value by 2^4 */
 244   if (*s == 'p' || *s == 'P') {  /* exponent part? */
 245     int exp1 = 0;  /* exponent value */
 246     int neg1;  /* exponent signal */
 247     s++;  /* skip 'p' */
 248     neg1 = isneg(&s);  /* signal */
 249     if (!lisdigit(cast_uchar(*s)))
 250       return 0.0;  /* invalid; must have at least one digit */
 251     while (lisdigit(cast_uchar(*s)))  /* read exponent */
 252       exp1 = exp1 * 10 + *(s++) - '0';
 253     if (neg1) exp1 = -exp1;
 254     e += exp1;
 255     *endptr = cast(char *, s);  /* valid up to here */
 256   }
 257   if (neg) r = -r;
 258   return l_mathop(ldexp)(r, e);
 259 }
 260
 261 #endif
 262 /* }====================================================== */
 263
 264
 265 static const char *l_str2d (const char *s, lua_Number *result) {
 266   char *endptr;
 267   if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
 268     return NULL;
 269   else if (strpbrk(s, "xX"))  /* hex? */
 270     *result = lua_strx2number(s, &endptr);
 271   else
 272     *result = lua_str2number(s, &endptr);
 273   if (endptr == s) return NULL;  /* nothing recognized */
 274   while (lisspace(cast_uchar(*endptr))) endptr++;
 275   return (*endptr == '\0' ? endptr : NULL);  /* OK if no trailing characters */
 276 }
 277 #endif /* _KERNEL */
 278
 279
 280 static const char *l_str2int (const char *s, lua_Integer *result) {
 281   lua_Unsigned a = 0;
 282   int empty = 1;
 283   int neg;
 284   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
 285   neg = isneg(&s);
 286   if (s[0] == '0' &&
 287       (s[1] == 'x' || s[1] == 'X')) {  /* hex? */
 288     s += 2;  /* skip '0x' */
 289     for (; lisxdigit(cast_uchar(*s)); s++) {
 290       a = a * 16 + luaO_hexavalue(*s);
 291       empty = 0;
 292     }
 293   }
 294   else {  /* decimal */
 295     for (; lisdigit(cast_uchar(*s)); s++) {
 296       a = a * 10 + *s - '0';
 297       empty = 0;
 298     }
 299   }
 300   while (lisspace(cast_uchar(*s))) s++;  /* skip trailing spaces */
 301   if (empty || *s != '\0') return NULL;  /* something wrong in the numeral */
 302   else {
 303     *result = l_castU2S((neg) ? 0u - a : a);
 304     return s;
 305   }
 306 }
 307
 308
 309 size_t luaO_str2num (const char *s, TValue *o) {
 310 #ifndef _KERNEL
 311   lua_Integer i; lua_Number n;
 312 #else /* _KERNEL */
 313   lua_Integer i;
 314 #endif
 315   const char *e;
 316   if ((e = l_str2int(s, &i)) != NULL) {  /* try as an integer */
 317     setivalue(o, i);
 318   }
 319 #ifndef _KERNEL
 320   else if ((e = l_str2d(s, &n)) != NULL) {  /* else try as a float */
 321     setfltvalue(o, n);
 322   }
 323 #endif
 324   else
 325     return 0;  /* conversion failed */
 326   return (e - s) + 1;  /* success; return string size */
 327 }
 328
 329
 330 int luaO_utf8esc (char *buff, unsigned long x) {
 331   int n = 1;  /* number of bytes put in buffer (backwards) */
 332   lua_assert(x <= 0x10FFFF);
 333   if (x < 0x80)  /* ascii? */
 334     buff[UTF8BUFFSZ - 1] = cast(char, x);
 335   else {  /* need continuation bytes */
 336     unsigned int mfb = 0x3f;  /* maximum that fits in first byte */
 337     do {  /* add continuation bytes */
 338       buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
 339       x >>= 6;  /* remove added bits */
 340       mfb >>= 1;  /* now there is one less bit available in first byte */
 341     } while (x > mfb);  /* still needs continuation byte? */
 342     buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x);  /* add first byte */
 343   }
 344   return n;
 345 }
 346
 347
 348 /* maximum length of the conversion of a number to a string */
 349 #define MAXNUMBER2STR   50
 350
 351
 352 /*
 353 ** Convert a number object to a string
 354 */
 355 void luaO_tostring (lua_State *L, StkId obj) {
 356   char buff[MAXNUMBER2STR];
 357   size_t len;
 358   lua_assert(ttisnumber(obj));
 359 #ifndef _KERNEL
 360   if (ttisinteger(obj))
 361     len = lua_integer2str(buff, ivalue(obj));
 362   else {
 363     len = lua_number2str(buff, fltvalue(obj));
 364 #if !defined(LUA_COMPAT_FLOATSTRING)
 365     if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */
 366       buff[len++] = lua_getlocaledecpoint();
 367       buff[len++] = '0';  /* adds '.0' to result */
 368     }
 369 #endif
 370   }
 371 #else /* _KERNEL */
 372   lua_assert(ttisinteger(obj));
 373   len = lua_integer2str(buff, ivalue(obj));
 374 #endif
 375   setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
 376 }
 377
 378
 379 static void pushstr (lua_State *L, const char *str, size_t l) {
 380   setsvalue2s(L, L->top++, luaS_newlstr(L, str, l));
 381 }
 382
 383
 384 /* this function handles only '%d', '%c', '%f', '%p', and '%s'
 385    conventional formats, plus Lua-specific '%I' and '%U' */
 386 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
 387   int n = 0;
 388   for (;;) {
 389     const char *e = strchr(fmt, '%');
 390     if (e == NULL) break;
 391     luaD_checkstack(L, 2);  /* fmt + item */
 392     pushstr(L, fmt, e - fmt);
 393     switch (*(e+1)) {
 394       case 's': {
 395         const char *s = va_arg(argp, char *);
 396         if (s == NULL) s = "(null)";
 397         pushstr(L, s, strlen(s));
 398         break;
 399       }
 400       case 'c': {
 401         char buff = cast(char, va_arg(argp, int));
 402         if (lisprint(cast_uchar(buff)))
 403           pushstr(L, &buff, 1);
 404         else  /* non-printable character; print its code */
 405           luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
 406         break;
 407       }
 408       case 'd': {
 409         setivalue(L->top++, va_arg(argp, int));
 410         luaO_tostring(L, L->top - 1);
 411         break;
 412       }
 413       case 'I': {
 414         setivalue(L->top++, cast(lua_Integer, va_arg(argp, l_uacInt)));
 415         luaO_tostring(L, L->top - 1);
 416         break;
 417       }
 418 #ifndef _KERNEL
 419       case 'f': {
 420         setfltvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
 421         luaO_tostring(L, L->top - 1);
 422         break;
 423       }
 424 #endif
 425       case 'p': {
 426         char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
 427         int l = sprintf(buff, "%p", va_arg(argp, void *));
 428         pushstr(L, buff, l);
 429         break;
 430       }
 431       case 'U': {
 432         char buff[UTF8BUFFSZ];
 433         int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
 434         pushstr(L, buff + UTF8BUFFSZ - l, l);
 435         break;
 436       }
 437       case '%': {
 438         pushstr(L, "%", 1);
 439         break;
 440       }
 441       default: {
 442         luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
 443                          *(e + 1));
 444       }
 445     }
 446     n += 2;
 447     fmt = e+2;
 448   }
 449   luaD_checkstack(L, 1);
 450   pushstr(L, fmt, strlen(fmt));
 451   if (n > 0) luaV_concat(L, n + 1);
 452   return svalue(L->top - 1);
 453 }
 454
 455
 456 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
 457   const char *msg;
 458   va_list argp;
 459   va_start(argp, fmt);
 460   msg = luaO_pushvfstring(L, fmt, argp);
 461   va_end(argp);
 462   return msg;
 463 }
 464
 465
 466 /* number of chars of a literal string without the ending \0 */
 467 #define LL(x)   (sizeof(x)/sizeof(char) - 1)
 468
 469 #define RETS    "..."
 470 #define PRE     "[string \""
 471 #define POS     "\"]"
 472
 473 #define addstr(a,b,l)   ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
 474
 475 void luaO_chunkid (char *out, const char *source, size_t bufflen) {
 476   size_t l = strlen(source);
 477   if (*source == '=') {  /* 'literal' source */
 478     if (l <= bufflen)  /* small enough? */
 479       memcpy(out, source + 1, l * sizeof(char));
 480     else {  /* truncate it */
 481       addstr(out, source + 1, bufflen - 1);
 482       *out = '\0';
 483     }
 484   }
 485   else if (*source == '@') {  /* file name */
 486     if (l <= bufflen)  /* small enough? */
 487       memcpy(out, source + 1, l * sizeof(char));
 488     else {  /* add '...' before rest of name */
 489       addstr(out, RETS, LL(RETS));
 490       bufflen -= LL(RETS);
 491       memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
 492     }
 493   }
 494   else {  /* string; format as [string "source"] */
 495     const char *nl = strchr(source, '\n');  /* find first new line (if any) */
 496     addstr(out, PRE, LL(PRE));  /* add prefix */
 497     bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
 498     if (l < bufflen && nl == NULL) {  /* small one-line source? */
 499       addstr(out, source, l);  /* keep it */
 500     }
 501     else {
 502       if (nl != NULL) l = nl - source;  /* stop at first newline */
 503       if (l > bufflen) l = bufflen;
 504       addstr(out, source, l);
 505       addstr(out, RETS, LL(RETS));
 506     }
 507     memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
 508   }
 509 }
 510