lobject.cc (16512B)
1 /* 2 ** $Id: lobject.c,v 2.113.1.1 2017/04/19 17:29:57 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 "lprefix.h" 11 12 13 #include <locale.h> 14 #include <math.h> 15 #include <stdarg.h> 16 #include <stdio.h> 17 #include <stdlib.h> 18 #include <string.h> 19 20 #include "lua.h" 21 22 #include "lctype.h" 23 #include "ldebug.h" 24 #include "ldo.h" 25 #include "lmem.h" 26 #include "lobject.h" 27 #include "lstate.h" 28 #include "lstring.h" 29 #include "lvm.h" 30 31 32 33 LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT}; 34 35 36 /* 37 ** converts an integer to a "floating point byte", represented as 38 ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if 39 ** eeeee != 0 and (xxx) otherwise. 40 */ 41 int luaO_int2fb (unsigned int x) { 42 int e = 0; /* exponent */ 43 if (x < 8) return x; 44 while (x >= (8 << 4)) { /* coarse steps */ 45 x = (x + 0xf) >> 4; /* x = ceil(x / 16) */ 46 e += 4; 47 } 48 while (x >= (8 << 1)) { /* fine steps */ 49 x = (x + 1) >> 1; /* x = ceil(x / 2) */ 50 e++; 51 } 52 return ((e+1) << 3) | (cast_int(x) - 8); 53 } 54 55 56 /* converts back */ 57 int luaO_fb2int (int x) { 58 return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1); 59 } 60 61 62 /* 63 ** Computes ceil(log2(x)) 64 */ 65 int luaO_ceillog2 (unsigned int x) { 66 static const lu_byte log_2[256] = { /* log_2[i] = ceil(log2(i - 1)) */ 67 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, 68 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, 69 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, 70 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, 71 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, 72 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, 73 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, 74 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 75 }; 76 int l = 0; 77 x--; 78 while (x >= 256) { l += 8; x >>= 8; } 79 return l + log_2[x]; 80 } 81 82 83 static lua_Integer intarith (lua_State *L, int op, lua_Integer v1, 84 lua_Integer v2) { 85 switch (op) { 86 case LUA_OPADD: return intop(+, v1, v2); 87 case LUA_OPSUB:return intop(-, v1, v2); 88 case LUA_OPMUL:return intop(*, v1, v2); 89 case LUA_OPMOD: return luaV_mod(L, v1, v2); 90 case LUA_OPIDIV: return luaV_div(L, v1, v2); 91 case LUA_OPBAND: return intop(&, v1, v2); 92 case LUA_OPBOR: return intop(|, v1, v2); 93 case LUA_OPBXOR: return intop(^, v1, v2); 94 case LUA_OPSHL: return luaV_shiftl(v1, v2); 95 case LUA_OPSHR: return luaV_shiftl(v1, -v2); 96 case LUA_OPUNM: return intop(-, 0, v1); 97 case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1); 98 default: lua_assert(0); return 0; 99 } 100 } 101 102 103 static lua_Number numarith (lua_State *L, int op, lua_Number v1, 104 lua_Number v2) { 105 switch (op) { 106 case LUA_OPADD: return luai_numadd(L, v1, v2); 107 case LUA_OPSUB: return luai_numsub(L, v1, v2); 108 case LUA_OPMUL: return luai_nummul(L, v1, v2); 109 case LUA_OPDIV: return luai_numdiv(L, v1, v2); 110 case LUA_OPPOW: return luai_numpow(L, v1, v2); 111 case LUA_OPIDIV: return luai_numidiv(L, v1, v2); 112 case LUA_OPUNM: return luai_numunm(L, v1); 113 case LUA_OPMOD: { 114 lua_Number m; 115 luai_nummod(L, v1, v2, m); 116 return m; 117 } 118 default: lua_assert(0); return 0; 119 } 120 } 121 122 123 void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2, 124 TValue *res) { 125 switch (op) { 126 case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR: 127 case LUA_OPSHL: case LUA_OPSHR: 128 case LUA_OPBNOT: { /* operate only on integers */ 129 lua_Integer i1; lua_Integer i2; 130 if (tointeger(p1, &i1) && tointeger(p2, &i2)) { 131 setivalue(res, intarith(L, op, i1, i2)); 132 return; 133 } 134 else break; /* go to the end */ 135 } 136 case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */ 137 lua_Number n1; lua_Number n2; 138 if (tonumber(p1, &n1) && tonumber(p2, &n2)) { 139 setfltvalue(res, numarith(L, op, n1, n2)); 140 return; 141 } 142 else break; /* go to the end */ 143 } 144 default: { /* other operations */ 145 lua_Number n1; lua_Number n2; 146 if (ttisinteger(p1) && ttisinteger(p2)) { 147 setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2))); 148 return; 149 } 150 else if (tonumber(p1, &n1) && tonumber(p2, &n2)) { 151 setfltvalue(res, numarith(L, op, n1, n2)); 152 return; 153 } 154 else break; /* go to the end */ 155 } 156 } 157 /* could not perform raw operation; try metamethod */ 158 lua_assert(L != NULL); /* should not fail when folding (compile time) */ 159 luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD)); 160 } 161 162 163 int luaO_hexavalue (int c) { 164 if (lisdigit(c)) return c - '0'; 165 else return (ltolower(c) - 'a') + 10; 166 } 167 168 169 static int isneg (const char **s) { 170 if (**s == '-') { (*s)++; return 1; } 171 else if (**s == '+') (*s)++; 172 return 0; 173 } 174 175 176 177 /* 178 ** {================================================================== 179 ** Lua's implementation for 'lua_strx2number' 180 ** =================================================================== 181 */ 182 183 #if !defined(lua_strx2number) 184 185 /* maximum number of significant digits to read (to avoid overflows 186 even with single floats) */ 187 #define MAXSIGDIG 30 188 189 /* 190 ** convert an hexadecimal numeric string to a number, following 191 ** C99 specification for 'strtod' 192 */ 193 static lua_Number lua_strx2number (const char *s, char **endptr) { 194 int dot = lua_getlocaledecpoint(); 195 lua_Number r = 0.0; /* result (accumulator) */ 196 int sigdig = 0; /* number of significant digits */ 197 int nosigdig = 0; /* number of non-significant digits */ 198 int e = 0; /* exponent correction */ 199 int neg; /* 1 if number is negative */ 200 int hasdot = 0; /* true after seen a dot */ 201 *endptr = cast(char *, s); /* nothing is valid yet */ 202 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ 203 neg = isneg(&s); /* check signal */ 204 if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */ 205 return 0.0; /* invalid format (no '0x') */ 206 for (s += 2; ; s++) { /* skip '0x' and read numeral */ 207 if (*s == dot) { 208 if (hasdot) break; /* second dot? stop loop */ 209 else hasdot = 1; 210 } 211 else if (lisxdigit(cast_uchar(*s))) { 212 if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */ 213 nosigdig++; 214 else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */ 215 r = (r * cast_num(16.0)) + luaO_hexavalue(*s); 216 else e++; /* too many digits; ignore, but still count for exponent */ 217 if (hasdot) e--; /* decimal digit? correct exponent */ 218 } 219 else break; /* neither a dot nor a digit */ 220 } 221 if (nosigdig + sigdig == 0) /* no digits? */ 222 return 0.0; /* invalid format */ 223 *endptr = cast(char *, s); /* valid up to here */ 224 e *= 4; /* each digit multiplies/divides value by 2^4 */ 225 if (*s == 'p' || *s == 'P') { /* exponent part? */ 226 int exp1 = 0; /* exponent value */ 227 int neg1; /* exponent signal */ 228 s++; /* skip 'p' */ 229 neg1 = isneg(&s); /* signal */ 230 if (!lisdigit(cast_uchar(*s))) 231 return 0.0; /* invalid; must have at least one digit */ 232 while (lisdigit(cast_uchar(*s))) /* read exponent */ 233 exp1 = exp1 * 10 + *(s++) - '0'; 234 if (neg1) exp1 = -exp1; 235 e += exp1; 236 *endptr = cast(char *, s); /* valid up to here */ 237 } 238 if (neg) r = -r; 239 return l_mathop(ldexp)(r, e); 240 } 241 242 #endif 243 /* }====================================================== */ 244 245 246 /* maximum length of a numeral */ 247 #if !defined (L_MAXLENNUM) 248 #define L_MAXLENNUM 200 249 #endif 250 251 static const char *l_str2dloc (const char *s, lua_Number *result, int mode) { 252 char *endptr; 253 *result = (mode == 'x') ? lua_strx2number(s, &endptr) /* try to convert */ 254 : lua_str2number(s, &endptr); 255 if (endptr == s) return NULL; /* nothing recognized? */ 256 while (lisspace(cast_uchar(*endptr))) endptr++; /* skip trailing spaces */ 257 return (*endptr == '\0') ? endptr : NULL; /* OK if no trailing characters */ 258 } 259 260 261 /* 262 ** Convert string 's' to a Lua number (put in 'result'). Return NULL 263 ** on fail or the address of the ending '\0' on success. 264 ** 'pmode' points to (and 'mode' contains) special things in the string: 265 ** - 'x'/'X' means an hexadecimal numeral 266 ** - 'n'/'N' means 'inf' or 'nan' (which should be rejected) 267 ** - '.' just optimizes the search for the common case (nothing special) 268 ** This function accepts both the current locale or a dot as the radix 269 ** mark. If the convertion fails, it may mean number has a dot but 270 ** locale accepts something else. In that case, the code copies 's' 271 ** to a buffer (because 's' is read-only), changes the dot to the 272 ** current locale radix mark, and tries to convert again. 273 */ 274 static const char *l_str2d (const char *s, lua_Number *result) { 275 const char *endptr; 276 const char *pmode = strpbrk(s, ".xXnN"); 277 int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0; 278 if (mode == 'n') /* reject 'inf' and 'nan' */ 279 return NULL; 280 endptr = l_str2dloc(s, result, mode); /* try to convert */ 281 if (endptr == NULL) { /* failed? may be a different locale */ 282 char buff[L_MAXLENNUM + 1]; 283 const char *pdot = strchr(s, '.'); 284 if (strlen(s) > L_MAXLENNUM || pdot == NULL) 285 return NULL; /* string too long or no dot; fail */ 286 strcpy(buff, s); /* copy string to buffer */ 287 buff[pdot - s] = lua_getlocaledecpoint(); /* correct decimal point */ 288 endptr = l_str2dloc(buff, result, mode); /* try again */ 289 if (endptr != NULL) 290 endptr = s + (endptr - buff); /* make relative to 's' */ 291 } 292 return endptr; 293 } 294 295 296 #define MAXBY10 cast(lua_Unsigned, LUA_MAXINTEGER / 10) 297 #define MAXLASTD cast_int(LUA_MAXINTEGER % 10) 298 299 static const char *l_str2int (const char *s, lua_Integer *result) { 300 lua_Unsigned a = 0; 301 int empty = 1; 302 int neg; 303 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ 304 neg = isneg(&s); 305 if (s[0] == '0' && 306 (s[1] == 'x' || s[1] == 'X')) { /* hex? */ 307 s += 2; /* skip '0x' */ 308 for (; lisxdigit(cast_uchar(*s)); s++) { 309 a = a * 16 + luaO_hexavalue(*s); 310 empty = 0; 311 } 312 } 313 else { /* decimal */ 314 for (; lisdigit(cast_uchar(*s)); s++) { 315 int d = *s - '0'; 316 if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg)) /* overflow? */ 317 return NULL; /* do not accept it (as integer) */ 318 a = a * 10 + d; 319 empty = 0; 320 } 321 } 322 while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */ 323 if (empty || *s != '\0') return NULL; /* something wrong in the numeral */ 324 else { 325 *result = l_castU2S((neg) ? 0u - a : a); 326 return s; 327 } 328 } 329 330 331 size_t luaO_str2num (const char *s, TValue *o) { 332 lua_Integer i; lua_Number n; 333 const char *e; 334 if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */ 335 setivalue(o, i); 336 } 337 else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */ 338 setfltvalue(o, n); 339 } 340 else 341 return 0; /* conversion failed */ 342 return (e - s) + 1; /* success; return string size */ 343 } 344 345 346 int luaO_utf8esc (char *buff, unsigned long x) { 347 int n = 1; /* number of bytes put in buffer (backwards) */ 348 lua_assert(x <= 0x10FFFF); 349 if (x < 0x80) /* ascii? */ 350 buff[UTF8BUFFSZ - 1] = cast(char, x); 351 else { /* need continuation bytes */ 352 unsigned int mfb = 0x3f; /* maximum that fits in first byte */ 353 do { /* add continuation bytes */ 354 buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f)); 355 x >>= 6; /* remove added bits */ 356 mfb >>= 1; /* now there is one less bit available in first byte */ 357 } while (x > mfb); /* still needs continuation byte? */ 358 buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */ 359 } 360 return n; 361 } 362 363 364 /* maximum length of the conversion of a number to a string */ 365 #define MAXNUMBER2STR 50 366 367 368 /* 369 ** Convert a number object to a string 370 */ 371 void luaO_tostring (lua_State *L, StkId obj) { 372 char buff[MAXNUMBER2STR]; 373 size_t len; 374 lua_assert(ttisnumber(obj)); 375 if (ttisinteger(obj)) 376 len = lua_integer2str(buff, sizeof(buff), ivalue(obj)); 377 else { 378 len = lua_number2str(buff, sizeof(buff), fltvalue(obj)); 379 #if !defined(LUA_COMPAT_FLOATSTRING) 380 if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */ 381 buff[len++] = lua_getlocaledecpoint(); 382 buff[len++] = '0'; /* adds '.0' to result */ 383 } 384 #endif 385 } 386 setsvalue2s(L, obj, luaS_newlstr(L, buff, len)); 387 } 388 389 390 static void pushstr (lua_State *L, const char *str, size_t l) { 391 setsvalue2s(L, L->top, luaS_newlstr(L, str, l)); 392 luaD_inctop(L); 393 } 394 395 396 /* 397 ** this function handles only '%d', '%c', '%f', '%p', and '%s' 398 conventional formats, plus Lua-specific '%I' and '%U' 399 */ 400 const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) { 401 int n = 0; 402 for (;;) { 403 const char *e = strchr(fmt, '%'); 404 if (e == NULL) break; 405 pushstr(L, fmt, e - fmt); 406 switch (*(e+1)) { 407 case 's': { /* zero-terminated string */ 408 const char *s = va_arg(argp, char *); 409 if (s == NULL) s = "(null)"; 410 pushstr(L, s, strlen(s)); 411 break; 412 } 413 case 'c': { /* an 'int' as a character */ 414 char buff = cast(char, va_arg(argp, int)); 415 if (lisprint(cast_uchar(buff))) 416 pushstr(L, &buff, 1); 417 else /* non-printable character; print its code */ 418 luaO_pushfstring(L, "<\\%d>", cast_uchar(buff)); 419 break; 420 } 421 case 'd': { /* an 'int' */ 422 setivalue(L->top, va_arg(argp, int)); 423 goto top2str; 424 } 425 case 'I': { /* a 'lua_Integer' */ 426 setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt))); 427 goto top2str; 428 } 429 case 'f': { /* a 'lua_Number' */ 430 setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber))); 431 top2str: /* convert the top element to a string */ 432 luaD_inctop(L); 433 luaO_tostring(L, L->top - 1); 434 break; 435 } 436 case 'p': { /* a pointer */ 437 char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */ 438 void *p = va_arg(argp, void *); 439 int l = lua_pointer2str(buff, sizeof(buff), p); 440 pushstr(L, buff, l); 441 break; 442 } 443 case 'U': { /* an 'int' as a UTF-8 sequence */ 444 char buff[UTF8BUFFSZ]; 445 int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long))); 446 pushstr(L, buff + UTF8BUFFSZ - l, l); 447 break; 448 } 449 case '%': { 450 pushstr(L, "%", 1); 451 break; 452 } 453 default: { 454 luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'", 455 *(e + 1)); 456 } 457 } 458 n += 2; 459 fmt = e+2; 460 } 461 luaD_checkstack(L, 1); 462 pushstr(L, fmt, strlen(fmt)); 463 if (n > 0) luaV_concat(L, n + 1); 464 return svalue(L->top - 1); 465 } 466 467 468 const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) { 469 const char *msg; 470 va_list argp; 471 va_start(argp, fmt); 472 msg = luaO_pushvfstring(L, fmt, argp); 473 va_end(argp); 474 return msg; 475 } 476 477 478 /* number of chars of a literal string without the ending \0 */ 479 #define LL(x) (sizeof(x)/sizeof(char) - 1) 480 481 #define RETS "..." 482 #define PRE "[string \"" 483 #define POS "\"]" 484 485 #define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) ) 486 487 void luaO_chunkid (char *out, const char *source, size_t bufflen) { 488 size_t l = strlen(source); 489 if (*source == '=') { /* 'literal' source */ 490 if (l <= bufflen) /* small enough? */ 491 memcpy(out, source + 1, l * sizeof(char)); 492 else { /* truncate it */ 493 addstr(out, source + 1, bufflen - 1); 494 *out = '\0'; 495 } 496 } 497 else if (*source == '@') { /* file name */ 498 if (l <= bufflen) /* small enough? */ 499 memcpy(out, source + 1, l * sizeof(char)); 500 else { /* add '...' before rest of name */ 501 addstr(out, RETS, LL(RETS)); 502 bufflen -= LL(RETS); 503 memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char)); 504 } 505 } 506 else { /* string; format as [string "source"] */ 507 const char *nl = strchr(source, '\n'); /* find first new line (if any) */ 508 addstr(out, PRE, LL(PRE)); /* add prefix */ 509 bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */ 510 if (l < bufflen && nl == NULL) { /* small one-line source? */ 511 addstr(out, source, l); /* keep it */ 512 } 513 else { 514 if (nl != NULL) l = nl - source; /* stop at first newline */ 515 if (l > bufflen) l = bufflen; 516 addstr(out, source, l); 517 addstr(out, RETS, LL(RETS)); 518 } 519 memcpy(out, POS, (LL(POS) + 1) * sizeof(char)); 520 } 521 } 522