1 /* $NetBSD: lvm.c,v 1.8 2015/10/11 09:21:15 mbalmer Exp $ */ 2 3 /* 4 ** Id: lvm.c,v 2.245 2015/06/09 15:53:35 roberto Exp 5 ** Lua virtual machine 6 ** See Copyright Notice in lua.h 7 */ 8 9 #define lvm_c 10 #define LUA_CORE 11 12 #include "lprefix.h" 13 14 #ifndef _KERNEL 15 #include <float.h> 16 #include <limits.h> 17 #include <math.h> 18 #include <stdio.h> 19 #include <stdlib.h> 20 #include <string.h> 21 #endif 22 23 #include "lua.h" 24 25 #include "ldebug.h" 26 #include "ldo.h" 27 #include "lfunc.h" 28 #include "lgc.h" 29 #include "lobject.h" 30 #include "lopcodes.h" 31 #include "lstate.h" 32 #include "lstring.h" 33 #include "ltable.h" 34 #include "ltm.h" 35 #include "lvm.h" 36 37 38 /* limit for table tag-method chains (to avoid loops) */ 39 #define MAXTAGLOOP 2000 40 41 42 #ifndef _KERNEL 43 /* 44 ** 'l_intfitsf' checks whether a given integer can be converted to a 45 ** float without rounding. Used in comparisons. Left undefined if 46 ** all integers fit in a float precisely. 47 */ 48 #if !defined(l_intfitsf) 49 50 /* number of bits in the mantissa of a float */ 51 #define NBM (l_mathlim(MANT_DIG)) 52 53 /* 54 ** Check whether some integers may not fit in a float, that is, whether 55 ** (maxinteger >> NBM) > 0 (that implies (1 << NBM) <= maxinteger). 56 ** (The shifts are done in parts to avoid shifting by more than the size 57 ** of an integer. In a worst case, NBM == 113 for long double and 58 ** sizeof(integer) == 32.) 59 */ 60 #if ((((LUA_MAXINTEGER >> (NBM / 4)) >> (NBM / 4)) >> (NBM / 4)) \ 61 >> (NBM - (3 * (NBM / 4)))) > 0 62 63 #define l_intfitsf(i) \ 64 (-((lua_Integer)1 << NBM) <= (i) && (i) <= ((lua_Integer)1 << NBM)) 65 66 #endif 67 68 #endif 69 #endif /*_KERNEL */ 70 71 #ifndef _KERNEL 72 /* 73 ** Try to convert a value to a float. The float case is already handled 74 ** by the macro 'tonumber'. 75 */ 76 int luaV_tonumber_ (const TValue *obj, lua_Number *n) { 77 TValue v; 78 if (ttisinteger(obj)) { 79 *n = cast_num(ivalue(obj)); 80 return 1; 81 } 82 else if (cvt2num(obj) && /* string convertible to number? */ 83 luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) { 84 *n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */ 85 return 1; 86 } 87 else 88 return 0; /* conversion failed */ 89 } 90 #endif 91 92 93 /* 94 ** try to convert a value to an integer, rounding according to 'mode': 95 ** mode == 0: accepts only integral values 96 ** mode == 1: takes the floor of the number 97 ** mode == 2: takes the ceil of the number 98 */ 99 int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode) { 100 TValue v; 101 again: 102 #ifndef _KERNEL 103 if (ttisfloat(obj)) { 104 lua_Number n = fltvalue(obj); 105 lua_Number f = l_floor(n); 106 if (n != f) { /* not an integral value? */ 107 if (mode == 0) return 0; /* fails if mode demands integral value */ 108 else if (mode > 1) /* needs ceil? */ 109 f += 1; /* convert floor to ceil (remember: n != f) */ 110 } 111 return lua_numbertointeger(f, p); 112 } 113 else if (ttisinteger(obj)) { 114 #else /* _KERNEL */ 115 if (ttisinteger(obj)) { 116 UNUSED(mode); 117 #endif 118 *p = ivalue(obj); 119 return 1; 120 } 121 else if (cvt2num(obj) && 122 luaO_str2num(svalue(obj), &v) == vslen(obj) + 1) { 123 obj = &v; 124 goto again; /* convert result from 'luaO_str2num' to an integer */ 125 } 126 return 0; /* conversion failed */ 127 } 128 129 130 #ifndef _KERNEL 131 /* 132 ** Try to convert a 'for' limit to an integer, preserving the 133 ** semantics of the loop. 134 ** (The following explanation assumes a non-negative step; it is valid 135 ** for negative steps mutatis mutandis.) 136 ** If the limit can be converted to an integer, rounding down, that is 137 ** it. 138 ** Otherwise, check whether the limit can be converted to a number. If 139 ** the number is too large, it is OK to set the limit as LUA_MAXINTEGER, 140 ** which means no limit. If the number is too negative, the loop 141 ** should not run, because any initial integer value is larger than the 142 ** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects 143 ** the extreme case when the initial value is LUA_MININTEGER, in which 144 ** case the LUA_MININTEGER limit would still run the loop once. 145 */ 146 static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step, 147 int *stopnow) { 148 *stopnow = 0; /* usually, let loops run */ 149 if (!luaV_tointeger(obj, p, (step < 0 ? 2 : 1))) { /* not fit in integer? */ 150 lua_Number n; /* try to convert to float */ 151 if (!tonumber(obj, &n)) /* cannot convert to float? */ 152 return 0; /* not a number */ 153 if (luai_numlt(0, n)) { /* if true, float is larger than max integer */ 154 *p = LUA_MAXINTEGER; 155 if (step < 0) *stopnow = 1; 156 } 157 else { /* float is smaller than min integer */ 158 *p = LUA_MININTEGER; 159 if (step >= 0) *stopnow = 1; 160 } 161 } 162 return 1; 163 } 164 #endif 165 166 167 /* 168 ** Main function for table access (invoking metamethods if needed). 169 ** Compute 'val = t[key]' 170 */ 171 void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) { 172 int loop; /* counter to avoid infinite loops */ 173 for (loop = 0; loop < MAXTAGLOOP; loop++) { 174 const TValue *tm; 175 if (ttistable(t)) { /* 't' is a table? */ 176 Table *h = hvalue(t); 177 const TValue *res = luaH_get(h, key); /* do a primitive get */ 178 if (!ttisnil(res) || /* result is not nil? */ 179 (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */ 180 setobj2s(L, val, res); /* result is the raw get */ 181 return; 182 } 183 /* else will try metamethod */ 184 } 185 else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX))) 186 luaG_typeerror(L, t, "index"); /* no metamethod */ 187 if (ttisfunction(tm)) { /* metamethod is a function */ 188 luaT_callTM(L, tm, t, key, val, 1); 189 return; 190 } 191 t = tm; /* else repeat access over 'tm' */ 192 } 193 luaG_runerror(L, "gettable chain too long; possible loop"); 194 } 195 196 197 /* 198 ** Main function for table assignment (invoking metamethods if needed). 199 ** Compute 't[key] = val' 200 */ 201 void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) { 202 int loop; /* counter to avoid infinite loops */ 203 for (loop = 0; loop < MAXTAGLOOP; loop++) { 204 const TValue *tm; 205 if (ttistable(t)) { /* 't' is a table? */ 206 Table *h = hvalue(t); 207 TValue *oldval = cast(TValue *, luaH_get(h, key)); 208 /* if previous value is not nil, there must be a previous entry 209 in the table; a metamethod has no relevance */ 210 if (!ttisnil(oldval) || 211 /* previous value is nil; must check the metamethod */ 212 ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL && 213 /* no metamethod; is there a previous entry in the table? */ 214 (oldval != luaO_nilobject || 215 /* no previous entry; must create one. (The next test is 216 always true; we only need the assignment.) */ 217 (oldval = luaH_newkey(L, h, key), 1)))) { 218 /* no metamethod and (now) there is an entry with given key */ 219 setobj2t(L, oldval, val); /* assign new value to that entry */ 220 invalidateTMcache(h); 221 luaC_barrierback(L, h, val); 222 return; 223 } 224 /* else will try the metamethod */ 225 } 226 else /* not a table; check metamethod */ 227 if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX))) 228 luaG_typeerror(L, t, "index"); 229 /* try the metamethod */ 230 if (ttisfunction(tm)) { 231 luaT_callTM(L, tm, t, key, val, 0); 232 return; 233 } 234 t = tm; /* else repeat assignment over 'tm' */ 235 } 236 luaG_runerror(L, "settable chain too long; possible loop"); 237 } 238 239 240 /* 241 ** Compare two strings 'ls' x 'rs', returning an integer smaller-equal- 242 ** -larger than zero if 'ls' is smaller-equal-larger than 'rs'. 243 ** The code is a little tricky because it allows '\0' in the strings 244 ** and it uses 'strcoll' (to respect locales) for each segments 245 ** of the strings. 246 */ 247 static int l_strcmp (const TString *ls, const TString *rs) { 248 const char *l = getstr(ls); 249 size_t ll = tsslen(ls); 250 const char *r = getstr(rs); 251 size_t lr = tsslen(rs); 252 for (;;) { /* for each segment */ 253 int temp = strcoll(l, r); 254 if (temp != 0) /* not equal? */ 255 return temp; /* done */ 256 else { /* strings are equal up to a '\0' */ 257 size_t len = strlen(l); /* index of first '\0' in both strings */ 258 if (len == lr) /* 'rs' is finished? */ 259 return (len == ll) ? 0 : 1; /* check 'ls' */ 260 else if (len == ll) /* 'ls' is finished? */ 261 return -1; /* 'ls' is smaller than 'rs' ('rs' is not finished) */ 262 /* both strings longer than 'len'; go on comparing after the '\0' */ 263 len++; 264 l += len; ll -= len; r += len; lr -= len; 265 } 266 } 267 } 268 269 270 /* 271 ** Check whether integer 'i' is less than float 'f'. If 'i' has an 272 ** exact representation as a float ('l_intfitsf'), compare numbers as 273 ** floats. Otherwise, if 'f' is outside the range for integers, result 274 ** is trivial. Otherwise, compare them as integers. (When 'i' has no 275 ** float representation, either 'f' is "far away" from 'i' or 'f' has 276 ** no precision left for a fractional part; either way, how 'f' is 277 ** truncated is irrelevant.) When 'f' is NaN, comparisons must result 278 ** in false. 279 */ 280 static int LTintfloat (lua_Integer i, lua_Number f) { 281 #if defined(l_intfitsf) 282 if (!l_intfitsf(i)) { 283 if (f >= -cast_num(LUA_MININTEGER)) /* -minint == maxint + 1 */ 284 return 1; /* f >= maxint + 1 > i */ 285 else if (f > cast_num(LUA_MININTEGER)) /* minint < f <= maxint ? */ 286 return (i < cast(lua_Integer, f)); /* compare them as integers */ 287 else /* f <= minint <= i (or 'f' is NaN) --> not(i < f) */ 288 return 0; 289 } 290 #endif 291 return luai_numlt(cast_num(i), f); /* compare them as floats */ 292 } 293 294 295 /* 296 ** Check whether integer 'i' is less than or equal to float 'f'. 297 ** See comments on previous function. 298 */ 299 static int LEintfloat (lua_Integer i, lua_Number f) { 300 #if defined(l_intfitsf) 301 if (!l_intfitsf(i)) { 302 if (f >= -cast_num(LUA_MININTEGER)) /* -minint == maxint + 1 */ 303 return 1; /* f >= maxint + 1 > i */ 304 else if (f >= cast_num(LUA_MININTEGER)) /* minint <= f <= maxint ? */ 305 return (i <= cast(lua_Integer, f)); /* compare them as integers */ 306 else /* f < minint <= i (or 'f' is NaN) --> not(i <= f) */ 307 return 0; 308 } 309 #endif 310 return luai_numle(cast_num(i), f); /* compare them as floats */ 311 } 312 313 314 /* 315 ** Return 'l < r', for numbers. 316 */ 317 static int LTnum (const TValue *l, const TValue *r) { 318 #ifdef _KERNEL 319 lua_Integer li = ivalue(l); 320 return li < ivalue(r); /* both must be integers */ 321 #else 322 if (ttisinteger(l)) { 323 lua_Integer li = ivalue(l); 324 if (ttisinteger(r)) 325 return li < ivalue(r); /* both are integers */ 326 else /* 'l' is int and 'r' is float */ 327 return LTintfloat(li, fltvalue(r)); /* l < r ? */ 328 } 329 else { 330 lua_Number lf = fltvalue(l); /* 'l' must be float */ 331 if (ttisfloat(r)) 332 return luai_numlt(lf, fltvalue(r)); /* both are float */ 333 else if (luai_numisnan(lf)) /* 'r' is int and 'l' is float */ 334 return 0; /* NaN < i is always false */ 335 else /* without NaN, (l < r) <--> not(r <= l) */ 336 return !LEintfloat(ivalue(r), lf); /* not (r <= l) ? */ 337 } 338 #endif 339 } 340 341 342 /* 343 ** Return 'l <= r', for numbers. 344 */ 345 static int LEnum (const TValue *l, const TValue *r) { 346 #ifdef _KERNEL 347 lua_Integer li = ivalue(l); 348 return li <= ivalue(r); /* both must be integers */ 349 #else 350 if (ttisinteger(l)) { 351 lua_Integer li = ivalue(l); 352 if (ttisinteger(r)) 353 return li <= ivalue(r); /* both are integers */ 354 else /* 'l' is int and 'r' is float */ 355 return LEintfloat(li, fltvalue(r)); /* l <= r ? */ 356 } 357 else { 358 lua_Number lf = fltvalue(l); /* 'l' must be float */ 359 if (ttisfloat(r)) 360 return luai_numle(lf, fltvalue(r)); /* both are float */ 361 else if (luai_numisnan(lf)) /* 'r' is int and 'l' is float */ 362 return 0; /* NaN <= i is always false */ 363 else /* without NaN, (l <= r) <--> not(r < l) */ 364 return !LTintfloat(ivalue(r), lf); /* not (r < l) ? */ 365 } 366 #endif 367 } 368 369 370 /* 371 ** Main operation less than; return 'l < r'. 372 */ 373 int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) { 374 int res; 375 if (ttisnumber(l) && ttisnumber(r)) /* both operands are numbers? */ 376 return LTnum(l, r); 377 else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ 378 return l_strcmp(tsvalue(l), tsvalue(r)) < 0; 379 else if ((res = luaT_callorderTM(L, l, r, TM_LT)) < 0) /* no metamethod? */ 380 luaG_ordererror(L, l, r); /* error */ 381 return res; 382 } 383 384 385 /* 386 ** Main operation less than or equal to; return 'l <= r'. If it needs 387 ** a metamethod and there is no '__le', try '__lt', based on 388 ** l <= r iff !(r < l) (assuming a total order). If the metamethod 389 ** yields during this substitution, the continuation has to know 390 ** about it (to negate the result of r<l); bit CIST_LEQ in the call 391 ** status keeps that information. 392 */ 393 int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) { 394 int res; 395 if (ttisnumber(l) && ttisnumber(r)) /* both operands are numbers? */ 396 return LEnum(l, r); 397 else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ 398 return l_strcmp(tsvalue(l), tsvalue(r)) <= 0; 399 else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0) /* try 'le' */ 400 return res; 401 else { /* try 'lt': */ 402 L->ci->callstatus |= CIST_LEQ; /* mark it is doing 'lt' for 'le' */ 403 res = luaT_callorderTM(L, r, l, TM_LT); 404 L->ci->callstatus ^= CIST_LEQ; /* clear mark */ 405 if (res < 0) 406 luaG_ordererror(L, l, r); 407 return !res; /* result is negated */ 408 } 409 } 410 411 412 /* 413 ** Main operation for equality of Lua values; return 't1 == t2'. 414 ** L == NULL means raw equality (no metamethods) 415 */ 416 int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) { 417 const TValue *tm; 418 if (ttype(t1) != ttype(t2)) { /* not the same variant? */ 419 #ifndef _KERNEL 420 if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER) 421 return 0; /* only numbers can be equal with different variants */ 422 else { /* two numbers with different variants */ 423 lua_Integer i1, i2; /* compare them as integers */ 424 return (tointeger(t1, &i1) && tointeger(t2, &i2) && i1 == i2); 425 } 426 #else /* _KERNEL */ 427 return 0; /* numbers have only the integer variant */ 428 #endif 429 } 430 /* values have same type and same variant */ 431 switch (ttype(t1)) { 432 case LUA_TNIL: return 1; 433 case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2)); 434 #ifndef _KERNEL 435 case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2)); 436 #endif 437 case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */ 438 case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2); 439 case LUA_TLCF: return fvalue(t1) == fvalue(t2); 440 case LUA_TSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2)); 441 case LUA_TLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2)); 442 case LUA_TUSERDATA: { 443 if (uvalue(t1) == uvalue(t2)) return 1; 444 else if (L == NULL) return 0; 445 tm = fasttm(L, uvalue(t1)->metatable, TM_EQ); 446 if (tm == NULL) 447 tm = fasttm(L, uvalue(t2)->metatable, TM_EQ); 448 break; /* will try TM */ 449 } 450 case LUA_TTABLE: { 451 if (hvalue(t1) == hvalue(t2)) return 1; 452 else if (L == NULL) return 0; 453 tm = fasttm(L, hvalue(t1)->metatable, TM_EQ); 454 if (tm == NULL) 455 tm = fasttm(L, hvalue(t2)->metatable, TM_EQ); 456 break; /* will try TM */ 457 } 458 default: 459 return gcvalue(t1) == gcvalue(t2); 460 } 461 if (tm == NULL) /* no TM? */ 462 return 0; /* objects are different */ 463 luaT_callTM(L, tm, t1, t2, L->top, 1); /* call TM */ 464 return !l_isfalse(L->top); 465 } 466 467 468 /* macro used by 'luaV_concat' to ensure that element at 'o' is a string */ 469 #define tostring(L,o) \ 470 (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1))) 471 472 #define isemptystr(o) (ttisshrstring(o) && tsvalue(o)->shrlen == 0) 473 474 /* 475 ** Main operation for concatenation: concat 'total' values in the stack, 476 ** from 'L->top - total' up to 'L->top - 1'. 477 */ 478 void luaV_concat (lua_State *L, int total) { 479 lua_assert(total >= 2); 480 do { 481 StkId top = L->top; 482 int n = 2; /* number of elements handled in this pass (at least 2) */ 483 if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1)) 484 luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT); 485 else if (isemptystr(top - 1)) /* second operand is empty? */ 486 cast_void(tostring(L, top - 2)); /* result is first operand */ 487 else if (isemptystr(top - 2)) { /* first operand is an empty string? */ 488 setobjs2s(L, top - 2, top - 1); /* result is second op. */ 489 } 490 else { 491 /* at least two non-empty string values; get as many as possible */ 492 size_t tl = vslen(top - 1); 493 char *buffer; 494 int i; 495 /* collect total length */ 496 for (i = 1; i < total && tostring(L, top-i-1); i++) { 497 size_t l = vslen(top - i - 1); 498 if (l >= (MAX_SIZE/sizeof(char)) - tl) 499 luaG_runerror(L, "string length overflow"); 500 tl += l; 501 } 502 buffer = luaZ_openspace(L, &G(L)->buff, tl); 503 tl = 0; 504 n = i; 505 do { /* copy all strings to buffer */ 506 size_t l = vslen(top - i); 507 memcpy(buffer+tl, svalue(top-i), l * sizeof(char)); 508 tl += l; 509 } while (--i > 0); 510 setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); /* create result */ 511 } 512 total -= n-1; /* got 'n' strings to create 1 new */ 513 L->top -= n-1; /* popped 'n' strings and pushed one */ 514 } while (total > 1); /* repeat until only 1 result left */ 515 } 516 517 518 /* 519 ** Main operation 'ra' = #rb'. 520 */ 521 void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) { 522 const TValue *tm; 523 switch (ttype(rb)) { 524 case LUA_TTABLE: { 525 Table *h = hvalue(rb); 526 tm = fasttm(L, h->metatable, TM_LEN); 527 if (tm) break; /* metamethod? break switch to call it */ 528 setivalue(ra, luaH_getn(h)); /* else primitive len */ 529 return; 530 } 531 case LUA_TSHRSTR: { 532 setivalue(ra, tsvalue(rb)->shrlen); 533 return; 534 } 535 case LUA_TLNGSTR: { 536 setivalue(ra, tsvalue(rb)->u.lnglen); 537 return; 538 } 539 default: { /* try metamethod */ 540 tm = luaT_gettmbyobj(L, rb, TM_LEN); 541 if (ttisnil(tm)) /* no metamethod? */ 542 luaG_typeerror(L, rb, "get length of"); 543 break; 544 } 545 } 546 luaT_callTM(L, tm, rb, rb, ra, 1); 547 } 548 549 550 /* 551 ** Integer division; return 'm // n', that is, floor(m/n). 552 ** C division truncates its result (rounds towards zero). 553 ** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer, 554 ** otherwise 'floor(q) == trunc(q) - 1'. 555 */ 556 lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) { 557 if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ 558 if (n == 0) 559 luaG_runerror(L, "attempt to divide by zero"); 560 return intop(-, 0, m); /* n==-1; avoid overflow with 0x80000...//-1 */ 561 } 562 else { 563 lua_Integer q = m / n; /* perform C division */ 564 if ((m ^ n) < 0 && m % n != 0) /* 'm/n' would be negative non-integer? */ 565 q -= 1; /* correct result for different rounding */ 566 return q; 567 } 568 } 569 570 571 /* 572 ** Integer modulus; return 'm % n'. (Assume that C '%' with 573 ** negative operands follows C99 behavior. See previous comment 574 ** about luaV_div.) 575 */ 576 lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) { 577 if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ 578 if (n == 0) 579 luaG_runerror(L, "attempt to perform 'n%%0'"); 580 return 0; /* m % -1 == 0; avoid overflow with 0x80000...%-1 */ 581 } 582 else { 583 lua_Integer r = m % n; 584 if (r != 0 && (m ^ n) < 0) /* 'm/n' would be non-integer negative? */ 585 r += n; /* correct result for different rounding */ 586 return r; 587 } 588 } 589 590 591 /* number of bits in an integer */ 592 #define NBITS cast_int(sizeof(lua_Integer) * CHAR_BIT) 593 594 /* 595 ** Shift left operation. (Shift right just negates 'y'.) 596 */ 597 lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) { 598 if (y < 0) { /* shift right? */ 599 if (y <= -NBITS) return 0; 600 else return intop(>>, x, -y); 601 } 602 else { /* shift left */ 603 if (y >= NBITS) return 0; 604 else return intop(<<, x, y); 605 } 606 } 607 608 609 /* 610 ** check whether cached closure in prototype 'p' may be reused, that is, 611 ** whether there is a cached closure with the same upvalues needed by 612 ** new closure to be created. 613 */ 614 static LClosure *getcached (Proto *p, UpVal **encup, StkId base) { 615 LClosure *c = p->cache; 616 if (c != NULL) { /* is there a cached closure? */ 617 int nup = p->sizeupvalues; 618 Upvaldesc *uv = p->upvalues; 619 int i; 620 for (i = 0; i < nup; i++) { /* check whether it has right upvalues */ 621 TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v; 622 if (c->upvals[i]->v != v) 623 return NULL; /* wrong upvalue; cannot reuse closure */ 624 } 625 } 626 return c; /* return cached closure (or NULL if no cached closure) */ 627 } 628 629 630 /* 631 ** create a new Lua closure, push it in the stack, and initialize 632 ** its upvalues. Note that the closure is not cached if prototype is 633 ** already black (which means that 'cache' was already cleared by the 634 ** GC). 635 */ 636 static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base, 637 StkId ra) { 638 int nup = p->sizeupvalues; 639 Upvaldesc *uv = p->upvalues; 640 int i; 641 LClosure *ncl = luaF_newLclosure(L, nup); 642 ncl->p = p; 643 setclLvalue(L, ra, ncl); /* anchor new closure in stack */ 644 for (i = 0; i < nup; i++) { /* fill in its upvalues */ 645 if (uv[i].instack) /* upvalue refers to local variable? */ 646 ncl->upvals[i] = luaF_findupval(L, base + uv[i].idx); 647 else /* get upvalue from enclosing function */ 648 ncl->upvals[i] = encup[uv[i].idx]; 649 ncl->upvals[i]->refcount++; 650 /* new closure is white, so we do not need a barrier here */ 651 } 652 if (!isblack(p)) /* cache will not break GC invariant? */ 653 p->cache = ncl; /* save it on cache for reuse */ 654 } 655 656 657 /* 658 ** finish execution of an opcode interrupted by an yield 659 */ 660 void luaV_finishOp (lua_State *L) { 661 CallInfo *ci = L->ci; 662 StkId base = ci->u.l.base; 663 Instruction inst = *(ci->u.l.savedpc - 1); /* interrupted instruction */ 664 OpCode op = GET_OPCODE(inst); 665 switch (op) { /* finish its execution */ 666 #ifndef _KERNEL 667 case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV: case OP_IDIV: 668 #else 669 case OP_ADD: case OP_SUB: case OP_MUL: case OP_IDIV: 670 #endif 671 case OP_BAND: case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: 672 #ifndef _KERNEL 673 case OP_MOD: case OP_POW: 674 #else 675 case OP_MOD: 676 #endif 677 case OP_UNM: case OP_BNOT: case OP_LEN: 678 case OP_GETTABUP: case OP_GETTABLE: case OP_SELF: { 679 setobjs2s(L, base + GETARG_A(inst), --L->top); 680 break; 681 } 682 case OP_LE: case OP_LT: case OP_EQ: { 683 int res = !l_isfalse(L->top - 1); 684 L->top--; 685 if (ci->callstatus & CIST_LEQ) { /* "<=" using "<" instead? */ 686 lua_assert(op == OP_LE); 687 ci->callstatus ^= CIST_LEQ; /* clear mark */ 688 res = !res; /* negate result */ 689 } 690 lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP); 691 if (res != GETARG_A(inst)) /* condition failed? */ 692 ci->u.l.savedpc++; /* skip jump instruction */ 693 break; 694 } 695 case OP_CONCAT: { 696 StkId top = L->top - 1; /* top when 'luaT_trybinTM' was called */ 697 int b = GETARG_B(inst); /* first element to concatenate */ 698 int total = cast_int(top - 1 - (base + b)); /* yet to concatenate */ 699 setobj2s(L, top - 2, top); /* put TM result in proper position */ 700 if (total > 1) { /* are there elements to concat? */ 701 L->top = top - 1; /* top is one after last element (at top-2) */ 702 luaV_concat(L, total); /* concat them (may yield again) */ 703 } 704 /* move final result to final position */ 705 setobj2s(L, ci->u.l.base + GETARG_A(inst), L->top - 1); 706 L->top = ci->top; /* restore top */ 707 break; 708 } 709 case OP_TFORCALL: { 710 lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP); 711 L->top = ci->top; /* correct top */ 712 break; 713 } 714 case OP_CALL: { 715 if (GETARG_C(inst) - 1 >= 0) /* nresults >= 0? */ 716 L->top = ci->top; /* adjust results */ 717 break; 718 } 719 case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE: 720 break; 721 default: lua_assert(0); 722 } 723 } 724 725 726 727 728 /* 729 ** {================================================================== 730 ** Function 'luaV_execute': main interpreter loop 731 ** =================================================================== 732 */ 733 734 735 /* 736 ** some macros for common tasks in 'luaV_execute' 737 */ 738 739 #if !defined(luai_runtimecheck) 740 #define luai_runtimecheck(L, c) /* void */ 741 #endif 742 743 744 #define RA(i) (base+GETARG_A(i)) 745 /* to be used after possible stack reallocation */ 746 #define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i)) 747 #define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i)) 748 #define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \ 749 ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i)) 750 #define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \ 751 ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i)) 752 #define KBx(i) \ 753 (k + (GETARG_Bx(i) != 0 ? GETARG_Bx(i) - 1 : GETARG_Ax(*ci->u.l.savedpc++))) 754 755 756 /* execute a jump instruction */ 757 #define dojump(ci,i,e) \ 758 { int a = GETARG_A(i); \ 759 if (a > 0) luaF_close(L, ci->u.l.base + a - 1); \ 760 ci->u.l.savedpc += GETARG_sBx(i) + e; } 761 762 /* for test instructions, execute the jump instruction that follows it */ 763 #define donextjump(ci) { i = *ci->u.l.savedpc; dojump(ci, i, 1); } 764 765 766 #define Protect(x) { {x;}; base = ci->u.l.base; } 767 768 #define checkGC(L,c) \ 769 Protect( luaC_condGC(L,{L->top = (c); /* limit of live values */ \ 770 luaC_step(L); \ 771 L->top = ci->top;}) /* restore top */ \ 772 luai_threadyield(L); ) 773 774 775 #define vmdispatch(o) switch(o) 776 #define vmcase(l) case l: 777 #define vmbreak break 778 779 void luaV_execute (lua_State *L) { 780 CallInfo *ci = L->ci; 781 LClosure *cl; 782 TValue *k; 783 StkId base; 784 newframe: /* reentry point when frame changes (call/return) */ 785 lua_assert(ci == L->ci); 786 cl = clLvalue(ci->func); 787 k = cl->p->k; 788 base = ci->u.l.base; 789 /* main loop of interpreter */ 790 for (;;) { 791 Instruction i = *(ci->u.l.savedpc++); 792 StkId ra; 793 if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) && 794 (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) { 795 Protect(luaG_traceexec(L)); 796 } 797 /* WARNING: several calls may realloc the stack and invalidate 'ra' */ 798 ra = RA(i); 799 lua_assert(base == ci->u.l.base); 800 lua_assert(base <= L->top && L->top < L->stack + L->stacksize); 801 vmdispatch (GET_OPCODE(i)) { 802 vmcase(OP_MOVE) { 803 setobjs2s(L, ra, RB(i)); 804 vmbreak; 805 } 806 vmcase(OP_LOADK) { 807 TValue *rb = k + GETARG_Bx(i); 808 setobj2s(L, ra, rb); 809 vmbreak; 810 } 811 vmcase(OP_LOADKX) { 812 TValue *rb; 813 lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG); 814 rb = k + GETARG_Ax(*ci->u.l.savedpc++); 815 setobj2s(L, ra, rb); 816 vmbreak; 817 } 818 vmcase(OP_LOADBOOL) { 819 setbvalue(ra, GETARG_B(i)); 820 if (GETARG_C(i)) ci->u.l.savedpc++; /* skip next instruction (if C) */ 821 vmbreak; 822 } 823 vmcase(OP_LOADNIL) { 824 int b = GETARG_B(i); 825 do { 826 setnilvalue(ra++); 827 } while (b--); 828 vmbreak; 829 } 830 vmcase(OP_GETUPVAL) { 831 int b = GETARG_B(i); 832 setobj2s(L, ra, cl->upvals[b]->v); 833 vmbreak; 834 } 835 vmcase(OP_GETTABUP) { 836 int b = GETARG_B(i); 837 Protect(luaV_gettable(L, cl->upvals[b]->v, RKC(i), ra)); 838 vmbreak; 839 } 840 vmcase(OP_GETTABLE) { 841 Protect(luaV_gettable(L, RB(i), RKC(i), ra)); 842 vmbreak; 843 } 844 vmcase(OP_SETTABUP) { 845 int a = GETARG_A(i); 846 Protect(luaV_settable(L, cl->upvals[a]->v, RKB(i), RKC(i))); 847 vmbreak; 848 } 849 vmcase(OP_SETUPVAL) { 850 UpVal *uv = cl->upvals[GETARG_B(i)]; 851 setobj(L, uv->v, ra); 852 luaC_upvalbarrier(L, uv); 853 vmbreak; 854 } 855 vmcase(OP_SETTABLE) { 856 Protect(luaV_settable(L, ra, RKB(i), RKC(i))); 857 vmbreak; 858 } 859 vmcase(OP_NEWTABLE) { 860 int b = GETARG_B(i); 861 int c = GETARG_C(i); 862 Table *t = luaH_new(L); 863 sethvalue(L, ra, t); 864 if (b != 0 || c != 0) 865 luaH_resize(L, t, luaO_fb2int(b), luaO_fb2int(c)); 866 checkGC(L, ra + 1); 867 vmbreak; 868 } 869 vmcase(OP_SELF) { 870 StkId rb = RB(i); 871 setobjs2s(L, ra+1, rb); 872 Protect(luaV_gettable(L, rb, RKC(i), ra)); 873 vmbreak; 874 } 875 vmcase(OP_ADD) { 876 TValue *rb = RKB(i); 877 TValue *rc = RKC(i); 878 #ifndef _KERNEL 879 lua_Number nb; lua_Number nc; 880 if (ttisinteger(rb) && ttisinteger(rc)) { 881 lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); 882 setivalue(ra, intop(+, ib, ic)); 883 } 884 else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { 885 setfltvalue(ra, luai_numadd(L, nb, nc)); 886 } 887 #else /* _KERNEL */ 888 lua_Integer ib; lua_Integer ic; 889 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 890 setivalue(ra, intop(+, ib, ic)); 891 } 892 #endif 893 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_ADD)); } 894 vmbreak; 895 } 896 vmcase(OP_SUB) { 897 TValue *rb = RKB(i); 898 TValue *rc = RKC(i); 899 #ifndef _KERNEL 900 lua_Number nb; lua_Number nc; 901 if (ttisinteger(rb) && ttisinteger(rc)) { 902 lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); 903 setivalue(ra, intop(-, ib, ic)); 904 } 905 else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { 906 setfltvalue(ra, luai_numsub(L, nb, nc)); 907 } 908 #else /* _KERNEL */ 909 lua_Integer ib; lua_Integer ic; 910 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 911 setivalue(ra, intop(-, ib, ic)); 912 } 913 #endif 914 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SUB)); } 915 vmbreak; 916 } 917 vmcase(OP_MUL) { 918 TValue *rb = RKB(i); 919 TValue *rc = RKC(i); 920 #ifndef _KERNEL 921 lua_Number nb; lua_Number nc; 922 if (ttisinteger(rb) && ttisinteger(rc)) { 923 lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); 924 setivalue(ra, intop(*, ib, ic)); 925 } 926 else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { 927 setfltvalue(ra, luai_nummul(L, nb, nc)); 928 } 929 #else /* _KERNEL */ 930 lua_Integer ib; lua_Integer ic; 931 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 932 setivalue(ra, intop(*, ib, ic)); 933 } 934 #endif 935 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MUL)); } 936 vmbreak; 937 } 938 #ifndef _KERNEL 939 vmcase(OP_DIV) { /* float division (always with floats) */ 940 TValue *rb = RKB(i); 941 TValue *rc = RKC(i); 942 lua_Number nb; lua_Number nc; 943 if (tonumber(rb, &nb) && tonumber(rc, &nc)) { 944 setfltvalue(ra, luai_numdiv(L, nb, nc)); 945 } 946 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_DIV)); } 947 vmbreak; 948 } 949 #endif 950 vmcase(OP_BAND) { 951 TValue *rb = RKB(i); 952 TValue *rc = RKC(i); 953 lua_Integer ib; lua_Integer ic; 954 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 955 setivalue(ra, intop(&, ib, ic)); 956 } 957 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BAND)); } 958 vmbreak; 959 } 960 vmcase(OP_BOR) { 961 TValue *rb = RKB(i); 962 TValue *rc = RKC(i); 963 lua_Integer ib; lua_Integer ic; 964 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 965 setivalue(ra, intop(|, ib, ic)); 966 } 967 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BOR)); } 968 vmbreak; 969 } 970 vmcase(OP_BXOR) { 971 TValue *rb = RKB(i); 972 TValue *rc = RKC(i); 973 lua_Integer ib; lua_Integer ic; 974 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 975 setivalue(ra, intop(^, ib, ic)); 976 } 977 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BXOR)); } 978 vmbreak; 979 } 980 vmcase(OP_SHL) { 981 TValue *rb = RKB(i); 982 TValue *rc = RKC(i); 983 lua_Integer ib; lua_Integer ic; 984 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 985 setivalue(ra, luaV_shiftl(ib, ic)); 986 } 987 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHL)); } 988 vmbreak; 989 } 990 vmcase(OP_SHR) { 991 TValue *rb = RKB(i); 992 TValue *rc = RKC(i); 993 lua_Integer ib; lua_Integer ic; 994 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 995 setivalue(ra, luaV_shiftl(ib, -ic)); 996 } 997 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHR)); } 998 vmbreak; 999 } 1000 vmcase(OP_MOD) { 1001 TValue *rb = RKB(i); 1002 TValue *rc = RKC(i); 1003 #ifndef _KERNEL 1004 lua_Number nb; lua_Number nc; 1005 if (ttisinteger(rb) && ttisinteger(rc)) { 1006 lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); 1007 setivalue(ra, luaV_mod(L, ib, ic)); 1008 } 1009 else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { 1010 lua_Number m; 1011 luai_nummod(L, nb, nc, m); 1012 setfltvalue(ra, m); 1013 } 1014 #else /* _KERNEL */ 1015 lua_Integer ib; lua_Integer ic; 1016 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 1017 setivalue(ra, luaV_mod(L, ib, ic)); 1018 } 1019 #endif 1020 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MOD)); } 1021 vmbreak; 1022 } 1023 vmcase(OP_IDIV) { /* floor division */ 1024 TValue *rb = RKB(i); 1025 TValue *rc = RKC(i); 1026 #ifndef _KERNEL 1027 lua_Number nb; lua_Number nc; 1028 if (ttisinteger(rb) && ttisinteger(rc)) { 1029 lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); 1030 setivalue(ra, luaV_div(L, ib, ic)); 1031 } 1032 else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { 1033 setfltvalue(ra, luai_numidiv(L, nb, nc)); 1034 } 1035 #else /* _KERNEL */ 1036 lua_Integer ib; lua_Integer ic; 1037 if (tointeger(rb, &ib) && tointeger(rc, &ic)) { 1038 setivalue(ra, luaV_div(L, ib, ic)); 1039 } 1040 #endif 1041 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_IDIV)); } 1042 vmbreak; 1043 } 1044 #ifndef _KERNEL 1045 vmcase(OP_POW) { 1046 TValue *rb = RKB(i); 1047 TValue *rc = RKC(i); 1048 lua_Number nb; lua_Number nc; 1049 if (tonumber(rb, &nb) && tonumber(rc, &nc)) { 1050 setfltvalue(ra, luai_numpow(L, nb, nc)); 1051 } 1052 else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_POW)); } 1053 vmbreak; 1054 } 1055 #endif 1056 vmcase(OP_UNM) { 1057 TValue *rb = RB(i); 1058 #ifndef _KERNEL 1059 lua_Number nb; 1060 if (ttisinteger(rb)) { 1061 lua_Integer ib = ivalue(rb); 1062 setivalue(ra, intop(-, 0, ib)); 1063 } 1064 else if (tonumber(rb, &nb)) { 1065 setfltvalue(ra, luai_numunm(L, nb)); 1066 } 1067 #else /* _KERNEL */ 1068 lua_Integer ib; 1069 if (tointeger(rb, &ib)) { 1070 setivalue(ra, intop(-, 0, ib)); 1071 } 1072 #endif 1073 else { 1074 Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM)); 1075 } 1076 vmbreak; 1077 } 1078 vmcase(OP_BNOT) { 1079 TValue *rb = RB(i); 1080 lua_Integer ib; 1081 if (tointeger(rb, &ib)) { 1082 setivalue(ra, intop(^, ~l_castS2U(0), ib)); 1083 } 1084 else { 1085 Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT)); 1086 } 1087 vmbreak; 1088 } 1089 vmcase(OP_NOT) { 1090 TValue *rb = RB(i); 1091 int res = l_isfalse(rb); /* next assignment may change this value */ 1092 setbvalue(ra, res); 1093 vmbreak; 1094 } 1095 vmcase(OP_LEN) { 1096 Protect(luaV_objlen(L, ra, RB(i))); 1097 vmbreak; 1098 } 1099 vmcase(OP_CONCAT) { 1100 int b = GETARG_B(i); 1101 int c = GETARG_C(i); 1102 StkId rb; 1103 L->top = base + c + 1; /* mark the end of concat operands */ 1104 Protect(luaV_concat(L, c - b + 1)); 1105 ra = RA(i); /* 'luav_concat' may invoke TMs and move the stack */ 1106 rb = base + b; 1107 setobjs2s(L, ra, rb); 1108 checkGC(L, (ra >= rb ? ra + 1 : rb)); 1109 L->top = ci->top; /* restore top */ 1110 vmbreak; 1111 } 1112 vmcase(OP_JMP) { 1113 dojump(ci, i, 0); 1114 vmbreak; 1115 } 1116 vmcase(OP_EQ) { 1117 TValue *rb = RKB(i); 1118 TValue *rc = RKC(i); 1119 Protect( 1120 if (cast_int(luaV_equalobj(L, rb, rc)) != GETARG_A(i)) 1121 ci->u.l.savedpc++; 1122 else 1123 donextjump(ci); 1124 ) 1125 vmbreak; 1126 } 1127 vmcase(OP_LT) { 1128 Protect( 1129 if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i)) 1130 ci->u.l.savedpc++; 1131 else 1132 donextjump(ci); 1133 ) 1134 vmbreak; 1135 } 1136 vmcase(OP_LE) { 1137 Protect( 1138 if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i)) 1139 ci->u.l.savedpc++; 1140 else 1141 donextjump(ci); 1142 ) 1143 vmbreak; 1144 } 1145 vmcase(OP_TEST) { 1146 if (GETARG_C(i) ? l_isfalse(ra) : !l_isfalse(ra)) 1147 ci->u.l.savedpc++; 1148 else 1149 donextjump(ci); 1150 vmbreak; 1151 } 1152 vmcase(OP_TESTSET) { 1153 TValue *rb = RB(i); 1154 if (GETARG_C(i) ? l_isfalse(rb) : !l_isfalse(rb)) 1155 ci->u.l.savedpc++; 1156 else { 1157 setobjs2s(L, ra, rb); 1158 donextjump(ci); 1159 } 1160 vmbreak; 1161 } 1162 vmcase(OP_CALL) { 1163 int b = GETARG_B(i); 1164 int nresults = GETARG_C(i) - 1; 1165 if (b != 0) L->top = ra+b; /* else previous instruction set top */ 1166 if (luaD_precall(L, ra, nresults)) { /* C function? */ 1167 if (nresults >= 0) L->top = ci->top; /* adjust results */ 1168 base = ci->u.l.base; 1169 } 1170 else { /* Lua function */ 1171 ci = L->ci; 1172 ci->callstatus |= CIST_REENTRY; 1173 goto newframe; /* restart luaV_execute over new Lua function */ 1174 } 1175 vmbreak; 1176 } 1177 vmcase(OP_TAILCALL) { 1178 int b = GETARG_B(i); 1179 if (b != 0) L->top = ra+b; /* else previous instruction set top */ 1180 lua_assert(GETARG_C(i) - 1 == LUA_MULTRET); 1181 if (luaD_precall(L, ra, LUA_MULTRET)) /* C function? */ 1182 base = ci->u.l.base; 1183 else { 1184 /* tail call: put called frame (n) in place of caller one (o) */ 1185 CallInfo *nci = L->ci; /* called frame */ 1186 CallInfo *oci = nci->previous; /* caller frame */ 1187 StkId nfunc = nci->func; /* called function */ 1188 StkId ofunc = oci->func; /* caller function */ 1189 /* last stack slot filled by 'precall' */ 1190 StkId lim = nci->u.l.base + getproto(nfunc)->numparams; 1191 int aux; 1192 /* close all upvalues from previous call */ 1193 if (cl->p->sizep > 0) luaF_close(L, oci->u.l.base); 1194 /* move new frame into old one */ 1195 for (aux = 0; nfunc + aux < lim; aux++) 1196 setobjs2s(L, ofunc + aux, nfunc + aux); 1197 oci->u.l.base = ofunc + (nci->u.l.base - nfunc); /* correct base */ 1198 oci->top = L->top = ofunc + (L->top - nfunc); /* correct top */ 1199 oci->u.l.savedpc = nci->u.l.savedpc; 1200 oci->callstatus |= CIST_TAIL; /* function was tail called */ 1201 ci = L->ci = oci; /* remove new frame */ 1202 lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize); 1203 goto newframe; /* restart luaV_execute over new Lua function */ 1204 } 1205 vmbreak; 1206 } 1207 vmcase(OP_RETURN) { 1208 int b = GETARG_B(i); 1209 if (cl->p->sizep > 0) luaF_close(L, base); 1210 b = luaD_poscall(L, ra, (b != 0 ? b - 1 : L->top - ra)); 1211 if (!(ci->callstatus & CIST_REENTRY)) /* 'ci' still the called one */ 1212 return; /* external invocation: return */ 1213 else { /* invocation via reentry: continue execution */ 1214 ci = L->ci; 1215 if (b) L->top = ci->top; 1216 lua_assert(isLua(ci)); 1217 lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL); 1218 goto newframe; /* restart luaV_execute over new Lua function */ 1219 } 1220 } 1221 vmcase(OP_FORLOOP) { 1222 #ifndef _KERNEL 1223 if (ttisinteger(ra)) { /* integer loop? */ 1224 #endif 1225 lua_Integer step = ivalue(ra + 2); 1226 lua_Integer idx = ivalue(ra) + step; /* increment index */ 1227 lua_Integer limit = ivalue(ra + 1); 1228 if ((0 < step) ? (idx <= limit) : (limit <= idx)) { 1229 ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ 1230 chgivalue(ra, idx); /* update internal index... */ 1231 setivalue(ra + 3, idx); /* ...and external index */ 1232 } 1233 #ifndef _KERNEL 1234 } 1235 else { /* floating loop */ 1236 lua_Number step = fltvalue(ra + 2); 1237 lua_Number idx = luai_numadd(L, fltvalue(ra), step); /* inc. index */ 1238 lua_Number limit = fltvalue(ra + 1); 1239 if (luai_numlt(0, step) ? luai_numle(idx, limit) 1240 : luai_numle(limit, idx)) { 1241 ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ 1242 chgfltvalue(ra, idx); /* update internal index... */ 1243 setfltvalue(ra + 3, idx); /* ...and external index */ 1244 } 1245 } 1246 #endif 1247 vmbreak; 1248 } 1249 vmcase(OP_FORPREP) { 1250 TValue *init = ra; 1251 TValue *plimit = ra + 1; 1252 TValue *pstep = ra + 2; 1253 lua_Integer ilimit; 1254 #ifndef _KERNEL 1255 int stopnow; 1256 if (ttisinteger(init) && ttisinteger(pstep) && 1257 forlimit(plimit, &ilimit, ivalue(pstep), &stopnow)) { 1258 /* all values are integer */ 1259 lua_Integer initv = (stopnow ? 0 : ivalue(init)); 1260 setivalue(plimit, ilimit); 1261 setivalue(init, initv - ivalue(pstep)); 1262 } 1263 else { /* try making all values floats */ 1264 lua_Number ninit; lua_Number nlimit; lua_Number nstep; 1265 if (!tonumber(plimit, &nlimit)) 1266 luaG_runerror(L, "'for' limit must be a number"); 1267 setfltvalue(plimit, nlimit); 1268 if (!tonumber(pstep, &nstep)) 1269 luaG_runerror(L, "'for' step must be a number"); 1270 setfltvalue(pstep, nstep); 1271 if (!tonumber(init, &ninit)) 1272 luaG_runerror(L, "'for' initial value must be a number"); 1273 setfltvalue(init, luai_numsub(L, ninit, nstep)); 1274 } 1275 #else /* _KERNEL */ 1276 lua_Integer initv; lua_Integer step; 1277 if (!tointeger(plimit, &ilimit)) 1278 luaG_runerror(L, "'for' limit must be a number"); 1279 setivalue(plimit, ilimit); 1280 if (!tointeger(pstep, &step)) 1281 luaG_runerror(L, "'for' step must be a number"); 1282 setivalue(pstep, step); 1283 if (!tointeger(init, &initv)) 1284 luaG_runerror(L, "'for' initial value must be a number"); 1285 setivalue(init, initv - step); 1286 #endif 1287 ci->u.l.savedpc += GETARG_sBx(i); 1288 vmbreak; 1289 } 1290 vmcase(OP_TFORCALL) { 1291 StkId cb = ra + 3; /* call base */ 1292 setobjs2s(L, cb+2, ra+2); 1293 setobjs2s(L, cb+1, ra+1); 1294 setobjs2s(L, cb, ra); 1295 L->top = cb + 3; /* func. + 2 args (state and index) */ 1296 Protect(luaD_call(L, cb, GETARG_C(i), 1)); 1297 L->top = ci->top; 1298 i = *(ci->u.l.savedpc++); /* go to next instruction */ 1299 ra = RA(i); 1300 lua_assert(GET_OPCODE(i) == OP_TFORLOOP); 1301 goto l_tforloop; 1302 } 1303 vmcase(OP_TFORLOOP) { 1304 l_tforloop: 1305 if (!ttisnil(ra + 1)) { /* continue loop? */ 1306 setobjs2s(L, ra, ra + 1); /* save control variable */ 1307 ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ 1308 } 1309 vmbreak; 1310 } 1311 vmcase(OP_SETLIST) { 1312 int n = GETARG_B(i); 1313 int c = GETARG_C(i); 1314 unsigned int last; 1315 Table *h; 1316 if (n == 0) n = cast_int(L->top - ra) - 1; 1317 if (c == 0) { 1318 lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG); 1319 c = GETARG_Ax(*ci->u.l.savedpc++); 1320 } 1321 luai_runtimecheck(L, ttistable(ra)); 1322 h = hvalue(ra); 1323 last = ((c-1)*LFIELDS_PER_FLUSH) + n; 1324 if (last > h->sizearray) /* needs more space? */ 1325 luaH_resizearray(L, h, last); /* pre-allocate it at once */ 1326 for (; n > 0; n--) { 1327 TValue *val = ra+n; 1328 luaH_setint(L, h, last--, val); 1329 luaC_barrierback(L, h, val); 1330 } 1331 L->top = ci->top; /* correct top (in case of previous open call) */ 1332 vmbreak; 1333 } 1334 vmcase(OP_CLOSURE) { 1335 Proto *p = cl->p->p[GETARG_Bx(i)]; 1336 LClosure *ncl = getcached(p, cl->upvals, base); /* cached closure */ 1337 if (ncl == NULL) /* no match? */ 1338 pushclosure(L, p, cl->upvals, base, ra); /* create a new one */ 1339 else 1340 setclLvalue(L, ra, ncl); /* push cashed closure */ 1341 checkGC(L, ra + 1); 1342 vmbreak; 1343 } 1344 vmcase(OP_VARARG) { 1345 int b = GETARG_B(i) - 1; 1346 int j; 1347 int n = cast_int(base - ci->func) - cl->p->numparams - 1; 1348 if (b < 0) { /* B == 0? */ 1349 b = n; /* get all var. arguments */ 1350 Protect(luaD_checkstack(L, n)); 1351 ra = RA(i); /* previous call may change the stack */ 1352 L->top = ra + n; 1353 } 1354 for (j = 0; j < b; j++) { 1355 if (j < n) { 1356 setobjs2s(L, ra + j, base - n + j); 1357 } 1358 else { 1359 setnilvalue(ra + j); 1360 } 1361 } 1362 vmbreak; 1363 } 1364 vmcase(OP_EXTRAARG) { 1365 lua_assert(0); 1366 vmbreak; 1367 } 1368 } 1369 } 1370 } 1371 1372 /* }================================================================== */ 1373 1374