1/* $NetBSD: lcode.c,v 1.14 2023/06/08 21:12:08 nikita Exp $ */ 2 3/* 4** Id: lcode.c 5** Code generator for Lua 6** See Copyright Notice in lua.h 7*/ 8 9#define lcode_c 10#define LUA_CORE 11 12#include "lprefix.h" 13 14 15#ifndef _KERNEL 16#include <float.h> 17#include <limits.h> 18#include <math.h> 19#include <stdlib.h> 20#endif /* _KERNEL */ 21 22#include "lua.h" 23 24#include "lcode.h" 25#include "ldebug.h" 26#include "ldo.h" 27#include "lgc.h" 28#include "llex.h" 29#include "lmem.h" 30#include "lobject.h" 31#include "lopcodes.h" 32#include "lparser.h" 33#include "lstring.h" 34#include "ltable.h" 35#include "lvm.h" 36 37 38/* Maximum number of registers in a Lua function (must fit in 8 bits) */ 39#define MAXREGS 255 40 41 42#define hasjumps(e) ((e)->t != (e)->f) 43 44 45static int codesJ (FuncState *fs, OpCode o, int sj, int k); 46 47 48 49/* semantic error */ 50l_noret luaK_semerror (LexState *ls, const char *msg) { 51 ls->t.token = 0; /* remove "near <token>" from final message */ 52 luaX_syntaxerror(ls, msg); 53} 54 55 56/* 57** If expression is a numeric constant, fills 'v' with its value 58** and returns 1. Otherwise, returns 0. 59*/ 60static int tonumeral (const expdesc *e, TValue *v) { 61 if (hasjumps(e)) 62 return 0; /* not a numeral */ 63 switch (e->k) { 64 case VKINT: 65 if (v) setivalue(v, e->u.ival); 66 return 1; 67#ifndef _KERNEL 68 case VKFLT: 69 if (v) setfltvalue(v, e->u.nval); 70 return 1; 71#endif /* _KERNEL */ 72 default: return 0; 73 } 74} 75 76 77/* 78** Get the constant value from a constant expression 79*/ 80static TValue *const2val (FuncState *fs, const expdesc *e) { 81 lua_assert(e->k == VCONST); 82 return &fs->ls->dyd->actvar.arr[e->u.info].k; 83} 84 85 86/* 87** If expression is a constant, fills 'v' with its value 88** and returns 1. Otherwise, returns 0. 89*/ 90int luaK_exp2const (FuncState *fs, const expdesc *e, TValue *v) { 91 if (hasjumps(e)) 92 return 0; /* not a constant */ 93 switch (e->k) { 94 case VFALSE: 95 setbfvalue(v); 96 return 1; 97 case VTRUE: 98 setbtvalue(v); 99 return 1; 100 case VNIL: 101 setnilvalue(v); 102 return 1; 103 case VKSTR: { 104 setsvalue(fs->ls->L, v, e->u.strval); 105 return 1; 106 } 107 case VCONST: { 108 setobj(fs->ls->L, v, const2val(fs, e)); 109 return 1; 110 } 111 default: return tonumeral(e, v); 112 } 113} 114 115 116/* 117** Return the previous instruction of the current code. If there 118** may be a jump target between the current instruction and the 119** previous one, return an invalid instruction (to avoid wrong 120** optimizations). 121*/ 122static Instruction *previousinstruction (FuncState *fs) { 123 static const Instruction invalidinstruction = ~(Instruction)0; 124 if (fs->pc > fs->lasttarget) 125 return &fs->f->code[fs->pc - 1]; /* previous instruction */ 126 else 127 return cast(Instruction*, &invalidinstruction); 128} 129 130 131/* 132** Create a OP_LOADNIL instruction, but try to optimize: if the previous 133** instruction is also OP_LOADNIL and ranges are compatible, adjust 134** range of previous instruction instead of emitting a new one. (For 135** instance, 'local a; local b' will generate a single opcode.) 136*/ 137void luaK_nil (FuncState *fs, int from, int n) { 138 int l = from + n - 1; /* last register to set nil */ 139 Instruction *previous = previousinstruction(fs); 140 if (GET_OPCODE(*previous) == OP_LOADNIL) { /* previous is LOADNIL? */ 141 int pfrom = GETARG_A(*previous); /* get previous range */ 142 int pl = pfrom + GETARG_B(*previous); 143 if ((pfrom <= from && from <= pl + 1) || 144 (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */ 145 if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */ 146 if (pl > l) l = pl; /* l = max(l, pl) */ 147 SETARG_A(*previous, from); 148 SETARG_B(*previous, l - from); 149 return; 150 } /* else go through */ 151 } 152 luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */ 153} 154 155 156/* 157** Gets the destination address of a jump instruction. Used to traverse 158** a list of jumps. 159*/ 160static int getjump (FuncState *fs, int pc) { 161 int offset = GETARG_sJ(fs->f->code[pc]); 162 if (offset == NO_JUMP) /* point to itself represents end of list */ 163 return NO_JUMP; /* end of list */ 164 else 165 return (pc+1)+offset; /* turn offset into absolute position */ 166} 167 168 169/* 170** Fix jump instruction at position 'pc' to jump to 'dest'. 171** (Jump addresses are relative in Lua) 172*/ 173static void fixjump (FuncState *fs, int pc, int dest) { 174 Instruction *jmp = &fs->f->code[pc]; 175 int offset = dest - (pc + 1); 176 lua_assert(dest != NO_JUMP); 177 if (!(-OFFSET_sJ <= offset && offset <= MAXARG_sJ - OFFSET_sJ)) 178 luaX_syntaxerror(fs->ls, "control structure too long"); 179 lua_assert(GET_OPCODE(*jmp) == OP_JMP); 180 SETARG_sJ(*jmp, offset); 181} 182 183 184/* 185** Concatenate jump-list 'l2' into jump-list 'l1' 186*/ 187void luaK_concat (FuncState *fs, int *l1, int l2) { 188 if (l2 == NO_JUMP) return; /* nothing to concatenate? */ 189 else if (*l1 == NO_JUMP) /* no original list? */ 190 *l1 = l2; /* 'l1' points to 'l2' */ 191 else { 192 int list = *l1; 193 int next; 194 while ((next = getjump(fs, list)) != NO_JUMP) /* find last element */ 195 list = next; 196 fixjump(fs, list, l2); /* last element links to 'l2' */ 197 } 198} 199 200 201/* 202** Create a jump instruction and return its position, so its destination 203** can be fixed later (with 'fixjump'). 204*/ 205int luaK_jump (FuncState *fs) { 206 return codesJ(fs, OP_JMP, NO_JUMP, 0); 207} 208 209 210/* 211** Code a 'return' instruction 212*/ 213void luaK_ret (FuncState *fs, int first, int nret) { 214 OpCode op; 215 switch (nret) { 216 case 0: op = OP_RETURN0; break; 217 case 1: op = OP_RETURN1; break; 218 default: op = OP_RETURN; break; 219 } 220 luaK_codeABC(fs, op, first, nret + 1, 0); 221} 222 223 224/* 225** Code a "conditional jump", that is, a test or comparison opcode 226** followed by a jump. Return jump position. 227*/ 228static int condjump (FuncState *fs, OpCode op, int A, int B, int C, int k) { 229 luaK_codeABCk(fs, op, A, B, C, k); 230 return luaK_jump(fs); 231} 232 233 234/* 235** returns current 'pc' and marks it as a jump target (to avoid wrong 236** optimizations with consecutive instructions not in the same basic block). 237*/ 238int luaK_getlabel (FuncState *fs) { 239 fs->lasttarget = fs->pc; 240 return fs->pc; 241} 242 243 244/* 245** Returns the position of the instruction "controlling" a given 246** jump (that is, its condition), or the jump itself if it is 247** unconditional. 248*/ 249static Instruction *getjumpcontrol (FuncState *fs, int pc) { 250 Instruction *pi = &fs->f->code[pc]; 251 if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1)))) 252 return pi-1; 253 else 254 return pi; 255} 256 257 258/* 259** Patch destination register for a TESTSET instruction. 260** If instruction in position 'node' is not a TESTSET, return 0 ("fails"). 261** Otherwise, if 'reg' is not 'NO_REG', set it as the destination 262** register. Otherwise, change instruction to a simple 'TEST' (produces 263** no register value) 264*/ 265static int patchtestreg (FuncState *fs, int node, int reg) { 266 Instruction *i = getjumpcontrol(fs, node); 267 if (GET_OPCODE(*i) != OP_TESTSET) 268 return 0; /* cannot patch other instructions */ 269 if (reg != NO_REG && reg != GETARG_B(*i)) 270 SETARG_A(*i, reg); 271 else { 272 /* no register to put value or register already has the value; 273 change instruction to simple test */ 274 *i = CREATE_ABCk(OP_TEST, GETARG_B(*i), 0, 0, GETARG_k(*i)); 275 } 276 return 1; 277} 278 279 280/* 281** Traverse a list of tests ensuring no one produces a value 282*/ 283static void removevalues (FuncState *fs, int list) { 284 for (; list != NO_JUMP; list = getjump(fs, list)) 285 patchtestreg(fs, list, NO_REG); 286} 287 288 289/* 290** Traverse a list of tests, patching their destination address and 291** registers: tests producing values jump to 'vtarget' (and put their 292** values in 'reg'), other tests jump to 'dtarget'. 293*/ 294static void patchlistaux (FuncState *fs, int list, int vtarget, int reg, 295 int dtarget) { 296 while (list != NO_JUMP) { 297 int next = getjump(fs, list); 298 if (patchtestreg(fs, list, reg)) 299 fixjump(fs, list, vtarget); 300 else 301 fixjump(fs, list, dtarget); /* jump to default target */ 302 list = next; 303 } 304} 305 306 307/* 308** Path all jumps in 'list' to jump to 'target'. 309** (The assert means that we cannot fix a jump to a forward address 310** because we only know addresses once code is generated.) 311*/ 312void luaK_patchlist (FuncState *fs, int list, int target) { 313 lua_assert(target <= fs->pc); 314 patchlistaux(fs, list, target, NO_REG, target); 315} 316 317 318void luaK_patchtohere (FuncState *fs, int list) { 319 int hr = luaK_getlabel(fs); /* mark "here" as a jump target */ 320 luaK_patchlist(fs, list, hr); 321} 322 323 324/* limit for difference between lines in relative line info. */ 325#define LIMLINEDIFF 0x80 326 327 328/* 329** Save line info for a new instruction. If difference from last line 330** does not fit in a byte, of after that many instructions, save a new 331** absolute line info; (in that case, the special value 'ABSLINEINFO' 332** in 'lineinfo' signals the existence of this absolute information.) 333** Otherwise, store the difference from last line in 'lineinfo'. 334*/ 335static void savelineinfo (FuncState *fs, Proto *f, int line) { 336 int linedif = line - fs->previousline; 337 int pc = fs->pc - 1; /* last instruction coded */ 338 if (abs(linedif) >= LIMLINEDIFF || fs->iwthabs++ >= MAXIWTHABS) { 339 luaM_growvector(fs->ls->L, f->abslineinfo, fs->nabslineinfo, 340 f->sizeabslineinfo, AbsLineInfo, MAX_INT, "lines"); 341 f->abslineinfo[fs->nabslineinfo].pc = pc; 342 f->abslineinfo[fs->nabslineinfo++].line = line; 343 linedif = ABSLINEINFO; /* signal that there is absolute information */ 344 fs->iwthabs = 1; /* restart counter */ 345 } 346 luaM_growvector(fs->ls->L, f->lineinfo, pc, f->sizelineinfo, ls_byte, 347 MAX_INT, "opcodes"); 348 f->lineinfo[pc] = linedif; 349 fs->previousline = line; /* last line saved */ 350} 351 352 353/* 354** Remove line information from the last instruction. 355** If line information for that instruction is absolute, set 'iwthabs' 356** above its max to force the new (replacing) instruction to have 357** absolute line info, too. 358*/ 359static void removelastlineinfo (FuncState *fs) { 360 Proto *f = fs->f; 361 int pc = fs->pc - 1; /* last instruction coded */ 362 if (f->lineinfo[pc] != ABSLINEINFO) { /* relative line info? */ 363 fs->previousline -= f->lineinfo[pc]; /* correct last line saved */ 364 fs->iwthabs--; /* undo previous increment */ 365 } 366 else { /* absolute line information */ 367 lua_assert(f->abslineinfo[fs->nabslineinfo - 1].pc == pc); 368 fs->nabslineinfo--; /* remove it */ 369 fs->iwthabs = MAXIWTHABS + 1; /* force next line info to be absolute */ 370 } 371} 372 373 374/* 375** Remove the last instruction created, correcting line information 376** accordingly. 377*/ 378static void removelastinstruction (FuncState *fs) { 379 removelastlineinfo(fs); 380 fs->pc--; 381} 382 383 384/* 385** Emit instruction 'i', checking for array sizes and saving also its 386** line information. Return 'i' position. 387*/ 388int luaK_code (FuncState *fs, Instruction i) { 389 Proto *f = fs->f; 390 /* put new instruction in code array */ 391 luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction, 392 MAX_INT, "opcodes"); 393 f->code[fs->pc++] = i; 394 savelineinfo(fs, f, fs->ls->lastline); 395 return fs->pc - 1; /* index of new instruction */ 396} 397 398 399/* 400** Format and emit an 'iABC' instruction. (Assertions check consistency 401** of parameters versus opcode.) 402*/ 403int luaK_codeABCk (FuncState *fs, OpCode o, int a, int b, int c, int k) { 404 lua_assert(getOpMode(o) == iABC); 405 lua_assert(a <= MAXARG_A && b <= MAXARG_B && 406 c <= MAXARG_C && (k & ~1) == 0); 407 return luaK_code(fs, CREATE_ABCk(o, a, b, c, k)); 408} 409 410 411/* 412** Format and emit an 'iABx' instruction. 413*/ 414int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) { 415 lua_assert(getOpMode(o) == iABx); 416 lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx); 417 return luaK_code(fs, CREATE_ABx(o, a, bc)); 418} 419 420 421/* 422** Format and emit an 'iAsBx' instruction. 423*/ 424int luaK_codeAsBx (FuncState *fs, OpCode o, int a, int bc) { 425 unsigned int b = bc + OFFSET_sBx; 426 lua_assert(getOpMode(o) == iAsBx); 427 lua_assert(a <= MAXARG_A && b <= MAXARG_Bx); 428 return luaK_code(fs, CREATE_ABx(o, a, b)); 429} 430 431 432/* 433** Format and emit an 'isJ' instruction. 434*/ 435static int codesJ (FuncState *fs, OpCode o, int sj, int k) { 436 unsigned int j = sj + OFFSET_sJ; 437 lua_assert(getOpMode(o) == isJ); 438 lua_assert(j <= MAXARG_sJ && (k & ~1) == 0); 439 return luaK_code(fs, CREATE_sJ(o, j, k)); 440} 441 442 443/* 444** Emit an "extra argument" instruction (format 'iAx') 445*/ 446static int codeextraarg (FuncState *fs, int a) { 447 lua_assert(a <= MAXARG_Ax); 448 return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a)); 449} 450 451 452/* 453** Emit a "load constant" instruction, using either 'OP_LOADK' 454** (if constant index 'k' fits in 18 bits) or an 'OP_LOADKX' 455** instruction with "extra argument". 456*/ 457static int luaK_codek (FuncState *fs, int reg, int k) { 458 if (k <= MAXARG_Bx) 459 return luaK_codeABx(fs, OP_LOADK, reg, k); 460 else { 461 int p = luaK_codeABx(fs, OP_LOADKX, reg, 0); 462 codeextraarg(fs, k); 463 return p; 464 } 465} 466 467 468/* 469** Check register-stack level, keeping track of its maximum size 470** in field 'maxstacksize' 471*/ 472void luaK_checkstack (FuncState *fs, int n) { 473 int newstack = fs->freereg + n; 474 if (newstack > fs->f->maxstacksize) { 475 if (newstack >= MAXREGS) 476 luaX_syntaxerror(fs->ls, 477 "function or expression needs too many registers"); 478 fs->f->maxstacksize = cast_byte(newstack); 479 } 480} 481 482 483/* 484** Reserve 'n' registers in register stack 485*/ 486void luaK_reserveregs (FuncState *fs, int n) { 487 luaK_checkstack(fs, n); 488 fs->freereg += n; 489} 490 491 492/* 493** Free register 'reg', if it is neither a constant index nor 494** a local variable. 495) 496*/ 497static void freereg (FuncState *fs, int reg) { 498 if (reg >= luaY_nvarstack(fs)) { 499 fs->freereg--; 500 lua_assert(reg == fs->freereg); 501 } 502} 503 504 505/* 506** Free two registers in proper order 507*/ 508static void freeregs (FuncState *fs, int r1, int r2) { 509 if (r1 > r2) { 510 freereg(fs, r1); 511 freereg(fs, r2); 512 } 513 else { 514 freereg(fs, r2); 515 freereg(fs, r1); 516 } 517} 518 519 520/* 521** Free register used by expression 'e' (if any) 522*/ 523static void freeexp (FuncState *fs, expdesc *e) { 524 if (e->k == VNONRELOC) 525 freereg(fs, e->u.info); 526} 527 528 529/* 530** Free registers used by expressions 'e1' and 'e2' (if any) in proper 531** order. 532*/ 533static void freeexps (FuncState *fs, expdesc *e1, expdesc *e2) { 534 int r1 = (e1->k == VNONRELOC) ? e1->u.info : -1; 535 int r2 = (e2->k == VNONRELOC) ? e2->u.info : -1; 536 freeregs(fs, r1, r2); 537} 538 539 540/* 541** Add constant 'v' to prototype's list of constants (field 'k'). 542** Use scanner's table to cache position of constants in constant list 543** and try to reuse constants. Because some values should not be used 544** as keys (nil cannot be a key, integer keys can collapse with float 545** keys), the caller must provide a useful 'key' for indexing the cache. 546** Note that all functions share the same table, so entering or exiting 547** a function can make some indices wrong. 548*/ 549static int addk (FuncState *fs, TValue *key, TValue *v) { 550 TValue val; 551 lua_State *L = fs->ls->L; 552 Proto *f = fs->f; 553 const TValue *idx = luaH_get(fs->ls->h, key); /* query scanner table */ 554 int k, oldsize; 555 if (ttisinteger(idx)) { /* is there an index there? */ 556 k = cast_int(ivalue(idx)); 557 /* correct value? (warning: must distinguish floats from integers!) */ 558 if (k < fs->nk && ttypetag(&f->k[k]) == ttypetag(v) && 559 luaV_rawequalobj(&f->k[k], v)) 560 return k; /* reuse index */ 561 } 562 /* constant not found; create a new entry */ 563 oldsize = f->sizek; 564 k = fs->nk; 565 /* numerical value does not need GC barrier; 566 table has no metatable, so it does not need to invalidate cache */ 567 setivalue(&val, k); 568 luaH_finishset(L, fs->ls->h, key, idx, &val); 569 luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants"); 570 while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]); 571 setobj(L, &f->k[k], v); 572 fs->nk++; 573 luaC_barrier(L, f, v); 574 return k; 575} 576 577 578/* 579** Add a string to list of constants and return its index. 580*/ 581static int stringK (FuncState *fs, TString *s) { 582 TValue o; 583 setsvalue(fs->ls->L, &o, s); 584 return addk(fs, &o, &o); /* use string itself as key */ 585} 586 587 588/* 589** Add an integer to list of constants and return its index. 590*/ 591static int luaK_intK (FuncState *fs, lua_Integer n) { 592 TValue o; 593 setivalue(&o, n); 594 return addk(fs, &o, &o); /* use integer itself as key */ 595} 596 597 598#ifndef _KERNEL 599/* 600** Add a float to list of constants and return its index. Floats 601** with integral values need a different key, to avoid collision 602** with actual integers. To that, we add to the number its smaller 603** power-of-two fraction that is still significant in its scale. 604** For doubles, that would be 1/2^52. 605** (This method is not bulletproof: there may be another float 606** with that value, and for floats larger than 2^53 the result is 607** still an integer. At worst, this only wastes an entry with 608** a duplicate.) 609*/ 610static int luaK_numberK (FuncState *fs, lua_Number r) { 611 TValue o; 612 lua_Integer ik; 613 setfltvalue(&o, r); 614 if (!luaV_flttointeger(r, &ik, F2Ieq)) /* not an integral value? */ 615 return addk(fs, &o, &o); /* use number itself as key */ 616 else { /* must build an alternative key */ 617 const int nbm = l_floatatt(MANT_DIG); 618 const lua_Number q = l_mathop(ldexp)(l_mathop(1.0), -nbm + 1); 619 const lua_Number k = (ik == 0) ? q : r + r*q; /* new key */ 620 TValue kv; 621 setfltvalue(&kv, k); 622 /* result is not an integral value, unless value is too large */ 623 lua_assert(!luaV_flttointeger(k, &ik, F2Ieq) || 624 l_mathop(fabs)(r) >= l_mathop(1e6)); 625 return addk(fs, &kv, &o); 626 } 627} 628#endif /* _KERNEL */ 629 630 631/* 632** Add a false to list of constants and return its index. 633*/ 634static int boolF (FuncState *fs) { 635 TValue o; 636 setbfvalue(&o); 637 return addk(fs, &o, &o); /* use boolean itself as key */ 638} 639 640 641/* 642** Add a true to list of constants and return its index. 643*/ 644static int boolT (FuncState *fs) { 645 TValue o; 646 setbtvalue(&o); 647 return addk(fs, &o, &o); /* use boolean itself as key */ 648} 649 650 651/* 652** Add nil to list of constants and return its index. 653*/ 654static int nilK (FuncState *fs) { 655 TValue k, v; 656 setnilvalue(&v); 657 /* cannot use nil as key; instead use table itself to represent nil */ 658 sethvalue(fs->ls->L, &k, fs->ls->h); 659 return addk(fs, &k, &v); 660} 661 662 663/* 664** Check whether 'i' can be stored in an 'sC' operand. Equivalent to 665** (0 <= int2sC(i) && int2sC(i) <= MAXARG_C) but without risk of 666** overflows in the hidden addition inside 'int2sC'. 667*/ 668static int fitsC (lua_Integer i) { 669 return (l_castS2U(i) + OFFSET_sC <= cast_uint(MAXARG_C)); 670} 671 672 673/* 674** Check whether 'i' can be stored in an 'sBx' operand. 675*/ 676static int fitsBx (lua_Integer i) { 677 return (-OFFSET_sBx <= i && i <= MAXARG_Bx - OFFSET_sBx); 678} 679 680 681void luaK_int (FuncState *fs, int reg, lua_Integer i) { 682 if (fitsBx(i)) 683 luaK_codeAsBx(fs, OP_LOADI, reg, cast_int(i)); 684 else 685 luaK_codek(fs, reg, luaK_intK(fs, i)); 686} 687 688 689#ifndef _KERNEL 690static void luaK_float (FuncState *fs, int reg, lua_Number f) { 691 lua_Integer fi; 692 if (luaV_flttointeger(f, &fi, F2Ieq) && fitsBx(fi)) 693 luaK_codeAsBx(fs, OP_LOADF, reg, cast_int(fi)); 694 else 695 luaK_codek(fs, reg, luaK_numberK(fs, f)); 696} 697#endif /* _KERNEL */ 698 699 700/* 701** Convert a constant in 'v' into an expression description 'e' 702*/ 703static void const2exp (TValue *v, expdesc *e) { 704 switch (ttypetag(v)) { 705 case LUA_VNUMINT: 706 e->k = VKINT; e->u.ival = ivalue(v); 707 break; 708#ifndef _KERNEL 709 case LUA_VNUMFLT: 710 e->k = VKFLT; e->u.nval = fltvalue(v); 711 break; 712#endif /* _KERNEL */ 713 case LUA_VFALSE: 714 e->k = VFALSE; 715 break; 716 case LUA_VTRUE: 717 e->k = VTRUE; 718 break; 719 case LUA_VNIL: 720 e->k = VNIL; 721 break; 722 case LUA_VSHRSTR: case LUA_VLNGSTR: 723 e->k = VKSTR; e->u.strval = tsvalue(v); 724 break; 725 default: lua_assert(0); 726 } 727} 728 729 730/* 731** Fix an expression to return the number of results 'nresults'. 732** 'e' must be a multi-ret expression (function call or vararg). 733*/ 734void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) { 735 Instruction *pc = &getinstruction(fs, e); 736 if (e->k == VCALL) /* expression is an open function call? */ 737 SETARG_C(*pc, nresults + 1); 738 else { 739 lua_assert(e->k == VVARARG); 740 SETARG_C(*pc, nresults + 1); 741 SETARG_A(*pc, fs->freereg); 742 luaK_reserveregs(fs, 1); 743 } 744} 745 746 747/* 748** Convert a VKSTR to a VK 749*/ 750static void str2K (FuncState *fs, expdesc *e) { 751 lua_assert(e->k == VKSTR); 752 e->u.info = stringK(fs, e->u.strval); 753 e->k = VK; 754} 755 756 757/* 758** Fix an expression to return one result. 759** If expression is not a multi-ret expression (function call or 760** vararg), it already returns one result, so nothing needs to be done. 761** Function calls become VNONRELOC expressions (as its result comes 762** fixed in the base register of the call), while vararg expressions 763** become VRELOC (as OP_VARARG puts its results where it wants). 764** (Calls are created returning one result, so that does not need 765** to be fixed.) 766*/ 767void luaK_setoneret (FuncState *fs, expdesc *e) { 768 if (e->k == VCALL) { /* expression is an open function call? */ 769 /* already returns 1 value */ 770 lua_assert(GETARG_C(getinstruction(fs, e)) == 2); 771 e->k = VNONRELOC; /* result has fixed position */ 772 e->u.info = GETARG_A(getinstruction(fs, e)); 773 } 774 else if (e->k == VVARARG) { 775 SETARG_C(getinstruction(fs, e), 2); 776 e->k = VRELOC; /* can relocate its simple result */ 777 } 778} 779 780 781/* 782** Ensure that expression 'e' is not a variable (nor a <const>). 783** (Expression still may have jump lists.) 784*/ 785void luaK_dischargevars (FuncState *fs, expdesc *e) { 786 switch (e->k) { 787 case VCONST: { 788 const2exp(const2val(fs, e), e); 789 break; 790 } 791 case VLOCAL: { /* already in a register */ 792 e->u.info = e->u.var.ridx; 793 e->k = VNONRELOC; /* becomes a non-relocatable value */ 794 break; 795 } 796 case VUPVAL: { /* move value to some (pending) register */ 797 e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0); 798 e->k = VRELOC; 799 break; 800 } 801 case VINDEXUP: { 802 e->u.info = luaK_codeABC(fs, OP_GETTABUP, 0, e->u.ind.t, e->u.ind.idx); 803 e->k = VRELOC; 804 break; 805 } 806 case VINDEXI: { 807 freereg(fs, e->u.ind.t); 808 e->u.info = luaK_codeABC(fs, OP_GETI, 0, e->u.ind.t, e->u.ind.idx); 809 e->k = VRELOC; 810 break; 811 } 812 case VINDEXSTR: { 813 freereg(fs, e->u.ind.t); 814 e->u.info = luaK_codeABC(fs, OP_GETFIELD, 0, e->u.ind.t, e->u.ind.idx); 815 e->k = VRELOC; 816 break; 817 } 818 case VINDEXED: { 819 freeregs(fs, e->u.ind.t, e->u.ind.idx); 820 e->u.info = luaK_codeABC(fs, OP_GETTABLE, 0, e->u.ind.t, e->u.ind.idx); 821 e->k = VRELOC; 822 break; 823 } 824 case VVARARG: case VCALL: { 825 luaK_setoneret(fs, e); 826 break; 827 } 828 default: break; /* there is one value available (somewhere) */ 829 } 830} 831 832 833/* 834** Ensure expression value is in register 'reg', making 'e' a 835** non-relocatable expression. 836** (Expression still may have jump lists.) 837*/ 838static void discharge2reg (FuncState *fs, expdesc *e, int reg) { 839 luaK_dischargevars(fs, e); 840 switch (e->k) { 841 case VNIL: { 842 luaK_nil(fs, reg, 1); 843 break; 844 } 845 case VFALSE: { 846 luaK_codeABC(fs, OP_LOADFALSE, reg, 0, 0); 847 break; 848 } 849 case VTRUE: { 850 luaK_codeABC(fs, OP_LOADTRUE, reg, 0, 0); 851 break; 852 } 853 case VKSTR: { 854 str2K(fs, e); 855 } /* FALLTHROUGH */ 856 case VK: { 857 luaK_codek(fs, reg, e->u.info); 858 break; 859 } 860#ifndef _KERNEL 861 case VKFLT: { 862 luaK_float(fs, reg, e->u.nval); 863 break; 864 } 865#endif /* _KERNEL */ 866 case VKINT: { 867 luaK_int(fs, reg, e->u.ival); 868 break; 869 } 870 case VRELOC: { 871 Instruction *pc = &getinstruction(fs, e); 872 SETARG_A(*pc, reg); /* instruction will put result in 'reg' */ 873 break; 874 } 875 case VNONRELOC: { 876 if (reg != e->u.info) 877 luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0); 878 break; 879 } 880 default: { 881 lua_assert(e->k == VJMP); 882 return; /* nothing to do... */ 883 } 884 } 885 e->u.info = reg; 886 e->k = VNONRELOC; 887} 888 889 890/* 891** Ensure expression value is in a register, making 'e' a 892** non-relocatable expression. 893** (Expression still may have jump lists.) 894*/ 895static void discharge2anyreg (FuncState *fs, expdesc *e) { 896 if (e->k != VNONRELOC) { /* no fixed register yet? */ 897 luaK_reserveregs(fs, 1); /* get a register */ 898 discharge2reg(fs, e, fs->freereg-1); /* put value there */ 899 } 900} 901 902 903static int code_loadbool (FuncState *fs, int A, OpCode op) { 904 luaK_getlabel(fs); /* those instructions may be jump targets */ 905 return luaK_codeABC(fs, op, A, 0, 0); 906} 907 908 909/* 910** check whether list has any jump that do not produce a value 911** or produce an inverted value 912*/ 913static int need_value (FuncState *fs, int list) { 914 for (; list != NO_JUMP; list = getjump(fs, list)) { 915 Instruction i = *getjumpcontrol(fs, list); 916 if (GET_OPCODE(i) != OP_TESTSET) return 1; 917 } 918 return 0; /* not found */ 919} 920 921 922/* 923** Ensures final expression result (which includes results from its 924** jump lists) is in register 'reg'. 925** If expression has jumps, need to patch these jumps either to 926** its final position or to "load" instructions (for those tests 927** that do not produce values). 928*/ 929static void exp2reg (FuncState *fs, expdesc *e, int reg) { 930 discharge2reg(fs, e, reg); 931 if (e->k == VJMP) /* expression itself is a test? */ 932 luaK_concat(fs, &e->t, e->u.info); /* put this jump in 't' list */ 933 if (hasjumps(e)) { 934 int final; /* position after whole expression */ 935 int p_f = NO_JUMP; /* position of an eventual LOAD false */ 936 int p_t = NO_JUMP; /* position of an eventual LOAD true */ 937 if (need_value(fs, e->t) || need_value(fs, e->f)) { 938 int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs); 939 p_f = code_loadbool(fs, reg, OP_LFALSESKIP); /* skip next inst. */ 940 p_t = code_loadbool(fs, reg, OP_LOADTRUE); 941 /* jump around these booleans if 'e' is not a test */ 942 luaK_patchtohere(fs, fj); 943 } 944 final = luaK_getlabel(fs); 945 patchlistaux(fs, e->f, final, reg, p_f); 946 patchlistaux(fs, e->t, final, reg, p_t); 947 } 948 e->f = e->t = NO_JUMP; 949 e->u.info = reg; 950 e->k = VNONRELOC; 951} 952 953 954/* 955** Ensures final expression result is in next available register. 956*/ 957void luaK_exp2nextreg (FuncState *fs, expdesc *e) { 958 luaK_dischargevars(fs, e); 959 freeexp(fs, e); 960 luaK_reserveregs(fs, 1); 961 exp2reg(fs, e, fs->freereg - 1); 962} 963 964 965/* 966** Ensures final expression result is in some (any) register 967** and return that register. 968*/ 969int luaK_exp2anyreg (FuncState *fs, expdesc *e) { 970 luaK_dischargevars(fs, e); 971 if (e->k == VNONRELOC) { /* expression already has a register? */ 972 if (!hasjumps(e)) /* no jumps? */ 973 return e->u.info; /* result is already in a register */ 974 if (e->u.info >= luaY_nvarstack(fs)) { /* reg. is not a local? */ 975 exp2reg(fs, e, e->u.info); /* put final result in it */ 976 return e->u.info; 977 } 978 /* else expression has jumps and cannot change its register 979 to hold the jump values, because it is a local variable. 980 Go through to the default case. */ 981 } 982 luaK_exp2nextreg(fs, e); /* default: use next available register */ 983 return e->u.info; 984} 985 986 987/* 988** Ensures final expression result is either in a register 989** or in an upvalue. 990*/ 991void luaK_exp2anyregup (FuncState *fs, expdesc *e) { 992 if (e->k != VUPVAL || hasjumps(e)) 993 luaK_exp2anyreg(fs, e); 994} 995 996 997/* 998** Ensures final expression result is either in a register 999** or it is a constant. 1000*/ 1001void luaK_exp2val (FuncState *fs, expdesc *e) { 1002 if (hasjumps(e)) 1003 luaK_exp2anyreg(fs, e); 1004 else 1005 luaK_dischargevars(fs, e); 1006} 1007 1008 1009/* 1010** Try to make 'e' a K expression with an index in the range of R/K 1011** indices. Return true iff succeeded. 1012*/ 1013static int luaK_exp2K (FuncState *fs, expdesc *e) { 1014 if (!hasjumps(e)) { 1015 int info; 1016 switch (e->k) { /* move constants to 'k' */ 1017 case VTRUE: info = boolT(fs); break; 1018 case VFALSE: info = boolF(fs); break; 1019 case VNIL: info = nilK(fs); break; 1020 case VKINT: info = luaK_intK(fs, e->u.ival); break; 1021#ifndef _KERNEL 1022 case VKFLT: info = luaK_numberK(fs, e->u.nval); break; 1023#endif /* _KERNEL */ 1024 case VKSTR: info = stringK(fs, e->u.strval); break; 1025 case VK: info = e->u.info; break; 1026 default: return 0; /* not a constant */ 1027 } 1028 if (info <= MAXINDEXRK) { /* does constant fit in 'argC'? */ 1029 e->k = VK; /* make expression a 'K' expression */ 1030 e->u.info = info; 1031 return 1; 1032 } 1033 } 1034 /* else, expression doesn't fit; leave it unchanged */ 1035 return 0; 1036} 1037 1038 1039/* 1040** Ensures final expression result is in a valid R/K index 1041** (that is, it is either in a register or in 'k' with an index 1042** in the range of R/K indices). 1043** Returns 1 iff expression is K. 1044*/ 1045int luaK_exp2RK (FuncState *fs, expdesc *e) { 1046 if (luaK_exp2K(fs, e)) 1047 return 1; 1048 else { /* not a constant in the right range: put it in a register */ 1049 luaK_exp2anyreg(fs, e); 1050 return 0; 1051 } 1052} 1053 1054 1055static void codeABRK (FuncState *fs, OpCode o, int a, int b, 1056 expdesc *ec) { 1057 int k = luaK_exp2RK(fs, ec); 1058 luaK_codeABCk(fs, o, a, b, ec->u.info, k); 1059} 1060 1061 1062/* 1063** Generate code to store result of expression 'ex' into variable 'var'. 1064*/ 1065void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) { 1066 switch (var->k) { 1067 case VLOCAL: { 1068 freeexp(fs, ex); 1069 exp2reg(fs, ex, var->u.var.ridx); /* compute 'ex' into proper place */ 1070 return; 1071 } 1072 case VUPVAL: { 1073 int e = luaK_exp2anyreg(fs, ex); 1074 luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0); 1075 break; 1076 } 1077 case VINDEXUP: { 1078 codeABRK(fs, OP_SETTABUP, var->u.ind.t, var->u.ind.idx, ex); 1079 break; 1080 } 1081 case VINDEXI: { 1082 codeABRK(fs, OP_SETI, var->u.ind.t, var->u.ind.idx, ex); 1083 break; 1084 } 1085 case VINDEXSTR: { 1086 codeABRK(fs, OP_SETFIELD, var->u.ind.t, var->u.ind.idx, ex); 1087 break; 1088 } 1089 case VINDEXED: { 1090 codeABRK(fs, OP_SETTABLE, var->u.ind.t, var->u.ind.idx, ex); 1091 break; 1092 } 1093 default: lua_assert(0); /* invalid var kind to store */ 1094 } 1095 freeexp(fs, ex); 1096} 1097 1098 1099/* 1100** Emit SELF instruction (convert expression 'e' into 'e:key(e,'). 1101*/ 1102void luaK_self (FuncState *fs, expdesc *e, expdesc *key) { 1103 int ereg; 1104 luaK_exp2anyreg(fs, e); 1105 ereg = e->u.info; /* register where 'e' was placed */ 1106 freeexp(fs, e); 1107 e->u.info = fs->freereg; /* base register for op_self */ 1108 e->k = VNONRELOC; /* self expression has a fixed register */ 1109 luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */ 1110 codeABRK(fs, OP_SELF, e->u.info, ereg, key); 1111 freeexp(fs, key); 1112} 1113 1114 1115/* 1116** Negate condition 'e' (where 'e' is a comparison). 1117*/ 1118static void negatecondition (FuncState *fs, expdesc *e) { 1119 Instruction *pc = getjumpcontrol(fs, e->u.info); 1120 lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET && 1121 GET_OPCODE(*pc) != OP_TEST); 1122 SETARG_k(*pc, (GETARG_k(*pc) ^ 1)); 1123} 1124 1125 1126/* 1127** Emit instruction to jump if 'e' is 'cond' (that is, if 'cond' 1128** is true, code will jump if 'e' is true.) Return jump position. 1129** Optimize when 'e' is 'not' something, inverting the condition 1130** and removing the 'not'. 1131*/ 1132static int jumponcond (FuncState *fs, expdesc *e, int cond) { 1133 if (e->k == VRELOC) { 1134 Instruction ie = getinstruction(fs, e); 1135 if (GET_OPCODE(ie) == OP_NOT) { 1136 removelastinstruction(fs); /* remove previous OP_NOT */ 1137 return condjump(fs, OP_TEST, GETARG_B(ie), 0, 0, !cond); 1138 } 1139 /* else go through */ 1140 } 1141 discharge2anyreg(fs, e); 1142 freeexp(fs, e); 1143 return condjump(fs, OP_TESTSET, NO_REG, e->u.info, 0, cond); 1144} 1145 1146 1147/* 1148** Emit code to go through if 'e' is true, jump otherwise. 1149*/ 1150void luaK_goiftrue (FuncState *fs, expdesc *e) { 1151 int pc; /* pc of new jump */ 1152 luaK_dischargevars(fs, e); 1153 switch (e->k) { 1154 case VJMP: { /* condition? */ 1155 negatecondition(fs, e); /* jump when it is false */ 1156 pc = e->u.info; /* save jump position */ 1157 break; 1158 } 1159#ifndef _KERNEL 1160 case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: { 1161#else /* _KERNEL */ 1162 case VK: case VKINT: case VKSTR: case VTRUE: { 1163#endif /* _KERNEL */ 1164 pc = NO_JUMP; /* always true; do nothing */ 1165 break; 1166 } 1167 default: { 1168 pc = jumponcond(fs, e, 0); /* jump when false */ 1169 break; 1170 } 1171 } 1172 luaK_concat(fs, &e->f, pc); /* insert new jump in false list */ 1173 luaK_patchtohere(fs, e->t); /* true list jumps to here (to go through) */ 1174 e->t = NO_JUMP; 1175} 1176 1177 1178/* 1179** Emit code to go through if 'e' is false, jump otherwise. 1180*/ 1181void luaK_goiffalse (FuncState *fs, expdesc *e) { 1182 int pc; /* pc of new jump */ 1183 luaK_dischargevars(fs, e); 1184 switch (e->k) { 1185 case VJMP: { 1186 pc = e->u.info; /* already jump if true */ 1187 break; 1188 } 1189 case VNIL: case VFALSE: { 1190 pc = NO_JUMP; /* always false; do nothing */ 1191 break; 1192 } 1193 default: { 1194 pc = jumponcond(fs, e, 1); /* jump if true */ 1195 break; 1196 } 1197 } 1198 luaK_concat(fs, &e->t, pc); /* insert new jump in 't' list */ 1199 luaK_patchtohere(fs, e->f); /* false list jumps to here (to go through) */ 1200 e->f = NO_JUMP; 1201} 1202 1203 1204/* 1205** Code 'not e', doing constant folding. 1206*/ 1207static void codenot (FuncState *fs, expdesc *e) { 1208 switch (e->k) { 1209 case VNIL: case VFALSE: { 1210 e->k = VTRUE; /* true == not nil == not false */ 1211 break; 1212 } 1213#ifndef _KERNEL 1214 case VK: case VKFLT: case VKINT: case VKSTR: case VTRUE: { 1215#else /* _KERNEL */ 1216 case VK: case VKINT: case VKSTR: case VTRUE: { 1217#endif /* _KERNEL */ 1218 e->k = VFALSE; /* false == not "x" == not 0.5 == not 1 == not true */ 1219 break; 1220 } 1221 case VJMP: { 1222 negatecondition(fs, e); 1223 break; 1224 } 1225 case VRELOC: 1226 case VNONRELOC: { 1227 discharge2anyreg(fs, e); 1228 freeexp(fs, e); 1229 e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0); 1230 e->k = VRELOC; 1231 break; 1232 } 1233 default: lua_assert(0); /* cannot happen */ 1234 } 1235 /* interchange true and false lists */ 1236 { int temp = e->f; e->f = e->t; e->t = temp; } 1237 removevalues(fs, e->f); /* values are useless when negated */ 1238 removevalues(fs, e->t); 1239} 1240 1241 1242/* 1243** Check whether expression 'e' is a small literal string 1244*/ 1245static int isKstr (FuncState *fs, expdesc *e) { 1246 return (e->k == VK && !hasjumps(e) && e->u.info <= MAXARG_B && 1247 ttisshrstring(&fs->f->k[e->u.info])); 1248} 1249 1250/* 1251** Check whether expression 'e' is a literal integer. 1252*/ 1253int luaK_isKint (expdesc *e) { 1254 return (e->k == VKINT && !hasjumps(e)); 1255} 1256 1257 1258/* 1259** Check whether expression 'e' is a literal integer in 1260** proper range to fit in register C 1261*/ 1262static int isCint (expdesc *e) { 1263 return luaK_isKint(e) && (l_castS2U(e->u.ival) <= l_castS2U(MAXARG_C)); 1264} 1265 1266 1267/* 1268** Check whether expression 'e' is a literal integer in 1269** proper range to fit in register sC 1270*/ 1271static int isSCint (expdesc *e) { 1272 return luaK_isKint(e) && fitsC(e->u.ival); 1273} 1274 1275 1276/* 1277** Check whether expression 'e' is a literal integer or float in 1278** proper range to fit in a register (sB or sC). 1279*/ 1280static int isSCnumber (expdesc *e, int *pi, int *isfloat) { 1281 lua_Integer i; 1282 if (e->k == VKINT) 1283 i = e->u.ival; 1284#ifndef _KERNEL 1285 else if (e->k == VKFLT && luaV_flttointeger(e->u.nval, &i, F2Ieq)) 1286 *isfloat = 1; 1287#endif /* _KERNEL */ 1288 else 1289 return 0; /* not a number */ 1290 if (!hasjumps(e) && fitsC(i)) { 1291 *pi = int2sC(cast_int(i)); 1292 return 1; 1293 } 1294 else 1295 return 0; 1296} 1297 1298 1299/* 1300** Create expression 't[k]'. 't' must have its final result already in a 1301** register or upvalue. Upvalues can only be indexed by literal strings. 1302** Keys can be literal strings in the constant table or arbitrary 1303** values in registers. 1304*/ 1305void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) { 1306 if (k->k == VKSTR) 1307 str2K(fs, k); 1308 lua_assert(!hasjumps(t) && 1309 (t->k == VLOCAL || t->k == VNONRELOC || t->k == VUPVAL)); 1310 if (t->k == VUPVAL && !isKstr(fs, k)) /* upvalue indexed by non 'Kstr'? */ 1311 luaK_exp2anyreg(fs, t); /* put it in a register */ 1312 if (t->k == VUPVAL) { 1313 t->u.ind.t = t->u.info; /* upvalue index */ 1314 t->u.ind.idx = k->u.info; /* literal string */ 1315 t->k = VINDEXUP; 1316 } 1317 else { 1318 /* register index of the table */ 1319 t->u.ind.t = (t->k == VLOCAL) ? t->u.var.ridx: t->u.info; 1320 if (isKstr(fs, k)) { 1321 t->u.ind.idx = k->u.info; /* literal string */ 1322 t->k = VINDEXSTR; 1323 } 1324 else if (isCint(k)) { 1325 t->u.ind.idx = cast_int(k->u.ival); /* int. constant in proper range */ 1326 t->k = VINDEXI; 1327 } 1328 else { 1329 t->u.ind.idx = luaK_exp2anyreg(fs, k); /* register */ 1330 t->k = VINDEXED; 1331 } 1332 } 1333} 1334 1335 1336/* 1337** Return false if folding can raise an error. 1338** Bitwise operations need operands convertible to integers; division 1339** operations cannot have 0 as divisor. 1340*/ 1341static int validop (int op, TValue *v1, TValue *v2) { 1342 switch (op) { 1343 case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR: 1344 case LUA_OPSHL: case LUA_OPSHR: case LUA_OPBNOT: { /* conversion errors */ 1345 lua_Integer i; 1346 return (luaV_tointegerns(v1, &i, LUA_FLOORN2I) && 1347 luaV_tointegerns(v2, &i, LUA_FLOORN2I)); 1348 } 1349#ifndef _KERNEL 1350 case LUA_OPDIV: case LUA_OPIDIV: case LUA_OPMOD: /* division by 0 */ 1351#else /* _KERNEL */ 1352 case LUA_OPIDIV: case LUA_OPMOD: /* division by 0 */ 1353#endif /* _KERNEL */ 1354 return (nvalue(v2) != 0); 1355 default: return 1; /* everything else is valid */ 1356 } 1357} 1358 1359 1360/* 1361** Try to "constant-fold" an operation; return 1 iff successful. 1362** (In this case, 'e1' has the final result.) 1363*/ 1364static int constfolding (FuncState *fs, int op, expdesc *e1, 1365 const expdesc *e2) { 1366 TValue v1, v2, res; 1367 if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2)) 1368 return 0; /* non-numeric operands or not safe to fold */ 1369 luaO_rawarith(fs->ls->L, op, &v1, &v2, &res); /* does operation */ 1370 if (ttisinteger(&res)) { 1371 e1->k = VKINT; 1372 e1->u.ival = ivalue(&res); 1373 } 1374 else { /* folds neither NaN nor 0.0 (to avoid problems with -0.0) */ 1375#ifndef _KERNEL 1376 lua_Number n = fltvalue(&res); 1377 if (luai_numisnan(n) || n == 0) 1378 return 0; 1379 e1->k = VKFLT; 1380 e1->u.nval = n; 1381#else /* _KERNEL */ 1382 return 0; /* if it is not integer, we must fail */ 1383#endif /* _KERNEL */ 1384 } 1385 return 1; 1386} 1387 1388 1389/* 1390** Convert a BinOpr to an OpCode (ORDER OPR - ORDER OP) 1391*/ 1392l_sinline OpCode binopr2op (BinOpr opr, BinOpr baser, OpCode base) { 1393 lua_assert(baser <= opr && 1394 ((baser == OPR_ADD && opr <= OPR_SHR) || 1395 (baser == OPR_LT && opr <= OPR_LE))); 1396 return cast(OpCode, (cast_int(opr) - cast_int(baser)) + cast_int(base)); 1397} 1398 1399 1400/* 1401** Convert a UnOpr to an OpCode (ORDER OPR - ORDER OP) 1402*/ 1403l_sinline OpCode unopr2op (UnOpr opr) { 1404 return cast(OpCode, (cast_int(opr) - cast_int(OPR_MINUS)) + 1405 cast_int(OP_UNM)); 1406} 1407 1408 1409/* 1410** Convert a BinOpr to a tag method (ORDER OPR - ORDER TM) 1411*/ 1412l_sinline TMS binopr2TM (BinOpr opr) { 1413 lua_assert(OPR_ADD <= opr && opr <= OPR_SHR); 1414 return cast(TMS, (cast_int(opr) - cast_int(OPR_ADD)) + cast_int(TM_ADD)); 1415} 1416 1417 1418/* 1419** Emit code for unary expressions that "produce values" 1420** (everything but 'not'). 1421** Expression to produce final result will be encoded in 'e'. 1422*/ 1423static void codeunexpval (FuncState *fs, OpCode op, expdesc *e, int line) { 1424 int r = luaK_exp2anyreg(fs, e); /* opcodes operate only on registers */ 1425 freeexp(fs, e); 1426 e->u.info = luaK_codeABC(fs, op, 0, r, 0); /* generate opcode */ 1427 e->k = VRELOC; /* all those operations are relocatable */ 1428 luaK_fixline(fs, line); 1429} 1430 1431 1432/* 1433** Emit code for binary expressions that "produce values" 1434** (everything but logical operators 'and'/'or' and comparison 1435** operators). 1436** Expression to produce final result will be encoded in 'e1'. 1437*/ 1438static void finishbinexpval (FuncState *fs, expdesc *e1, expdesc *e2, 1439 OpCode op, int v2, int flip, int line, 1440 OpCode mmop, TMS event) { 1441 int v1 = luaK_exp2anyreg(fs, e1); 1442 int pc = luaK_codeABCk(fs, op, 0, v1, v2, 0); 1443 freeexps(fs, e1, e2); 1444 e1->u.info = pc; 1445 e1->k = VRELOC; /* all those operations are relocatable */ 1446 luaK_fixline(fs, line); 1447 luaK_codeABCk(fs, mmop, v1, v2, event, flip); /* to call metamethod */ 1448 luaK_fixline(fs, line); 1449} 1450 1451 1452/* 1453** Emit code for binary expressions that "produce values" over 1454** two registers. 1455*/ 1456static void codebinexpval (FuncState *fs, BinOpr opr, 1457 expdesc *e1, expdesc *e2, int line) { 1458 OpCode op = binopr2op(opr, OPR_ADD, OP_ADD); 1459 int v2 = luaK_exp2anyreg(fs, e2); /* make sure 'e2' is in a register */ 1460 /* 'e1' must be already in a register or it is a constant */ 1461 lua_assert((VNIL <= e1->k && e1->k <= VKSTR) || 1462 e1->k == VNONRELOC || e1->k == VRELOC); 1463 lua_assert(OP_ADD <= op && op <= OP_SHR); 1464 finishbinexpval(fs, e1, e2, op, v2, 0, line, OP_MMBIN, binopr2TM(opr)); 1465} 1466 1467 1468/* 1469** Code binary operators with immediate operands. 1470*/ 1471static void codebini (FuncState *fs, OpCode op, 1472 expdesc *e1, expdesc *e2, int flip, int line, 1473 TMS event) { 1474 int v2 = int2sC(cast_int(e2->u.ival)); /* immediate operand */ 1475 lua_assert(e2->k == VKINT); 1476 finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINI, event); 1477} 1478 1479 1480/* 1481** Code binary operators with K operand. 1482*/ 1483static void codebinK (FuncState *fs, BinOpr opr, 1484 expdesc *e1, expdesc *e2, int flip, int line) { 1485 TMS event = binopr2TM(opr); 1486 int v2 = e2->u.info; /* K index */ 1487 OpCode op = binopr2op(opr, OPR_ADD, OP_ADDK); 1488 finishbinexpval(fs, e1, e2, op, v2, flip, line, OP_MMBINK, event); 1489} 1490 1491 1492/* Try to code a binary operator negating its second operand. 1493** For the metamethod, 2nd operand must keep its original value. 1494*/ 1495static int finishbinexpneg (FuncState *fs, expdesc *e1, expdesc *e2, 1496 OpCode op, int line, TMS event) { 1497 if (!luaK_isKint(e2)) 1498 return 0; /* not an integer constant */ 1499 else { 1500 lua_Integer i2 = e2->u.ival; 1501 if (!(fitsC(i2) && fitsC(-i2))) 1502 return 0; /* not in the proper range */ 1503 else { /* operating a small integer constant */ 1504 int v2 = cast_int(i2); 1505 finishbinexpval(fs, e1, e2, op, int2sC(-v2), 0, line, OP_MMBINI, event); 1506 /* correct metamethod argument */ 1507 SETARG_B(fs->f->code[fs->pc - 1], int2sC(v2)); 1508 return 1; /* successfully coded */ 1509 } 1510 } 1511} 1512 1513 1514static void swapexps (expdesc *e1, expdesc *e2) { 1515 expdesc temp = *e1; *e1 = *e2; *e2 = temp; /* swap 'e1' and 'e2' */ 1516} 1517 1518 1519/* 1520** Code binary operators with no constant operand. 1521*/ 1522static void codebinNoK (FuncState *fs, BinOpr opr, 1523 expdesc *e1, expdesc *e2, int flip, int line) { 1524 if (flip) 1525 swapexps(e1, e2); /* back to original order */ 1526 codebinexpval(fs, opr, e1, e2, line); /* use standard operators */ 1527} 1528 1529 1530/* 1531** Code arithmetic operators ('+', '-', ...). If second operand is a 1532** constant in the proper range, use variant opcodes with K operands. 1533*/ 1534static void codearith (FuncState *fs, BinOpr opr, 1535 expdesc *e1, expdesc *e2, int flip, int line) { 1536 if (tonumeral(e2, NULL) && luaK_exp2K(fs, e2)) /* K operand? */ 1537 codebinK(fs, opr, e1, e2, flip, line); 1538 else /* 'e2' is neither an immediate nor a K operand */ 1539 codebinNoK(fs, opr, e1, e2, flip, line); 1540} 1541 1542 1543/* 1544** Code commutative operators ('+', '*'). If first operand is a 1545** numeric constant, change order of operands to try to use an 1546** immediate or K operator. 1547*/ 1548static void codecommutative (FuncState *fs, BinOpr op, 1549 expdesc *e1, expdesc *e2, int line) { 1550 int flip = 0; 1551 if (tonumeral(e1, NULL)) { /* is first operand a numeric constant? */ 1552 swapexps(e1, e2); /* change order */ 1553 flip = 1; 1554 } 1555 if (op == OPR_ADD && isSCint(e2)) /* immediate operand? */ 1556 codebini(fs, OP_ADDI, e1, e2, flip, line, TM_ADD); 1557 else 1558 codearith(fs, op, e1, e2, flip, line); 1559} 1560 1561 1562/* 1563** Code bitwise operations; they are all commutative, so the function 1564** tries to put an integer constant as the 2nd operand (a K operand). 1565*/ 1566static void codebitwise (FuncState *fs, BinOpr opr, 1567 expdesc *e1, expdesc *e2, int line) { 1568 int flip = 0; 1569 if (e1->k == VKINT) { 1570 swapexps(e1, e2); /* 'e2' will be the constant operand */ 1571 flip = 1; 1572 } 1573 if (e2->k == VKINT && luaK_exp2K(fs, e2)) /* K operand? */ 1574 codebinK(fs, opr, e1, e2, flip, line); 1575 else /* no constants */ 1576 codebinNoK(fs, opr, e1, e2, flip, line); 1577} 1578 1579 1580/* 1581** Emit code for order comparisons. When using an immediate operand, 1582** 'isfloat' tells whether the original value was a float. 1583*/ 1584static void codeorder (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) { 1585 int r1, r2; 1586 int im; 1587 int isfloat = 0; 1588 OpCode op; 1589 if (isSCnumber(e2, &im, &isfloat)) { 1590 /* use immediate operand */ 1591 r1 = luaK_exp2anyreg(fs, e1); 1592 r2 = im; 1593 op = binopr2op(opr, OPR_LT, OP_LTI); 1594 } 1595 else if (isSCnumber(e1, &im, &isfloat)) { 1596 /* transform (A < B) to (B > A) and (A <= B) to (B >= A) */ 1597 r1 = luaK_exp2anyreg(fs, e2); 1598 r2 = im; 1599 op = binopr2op(opr, OPR_LT, OP_GTI); 1600 } 1601 else { /* regular case, compare two registers */ 1602 r1 = luaK_exp2anyreg(fs, e1); 1603 r2 = luaK_exp2anyreg(fs, e2); 1604 op = binopr2op(opr, OPR_LT, OP_LT); 1605 } 1606 freeexps(fs, e1, e2); 1607 e1->u.info = condjump(fs, op, r1, r2, isfloat, 1); 1608 e1->k = VJMP; 1609} 1610 1611 1612/* 1613** Emit code for equality comparisons ('==', '~='). 1614** 'e1' was already put as RK by 'luaK_infix'. 1615*/ 1616static void codeeq (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) { 1617 int r1, r2; 1618 int im; 1619 int isfloat = 0; /* not needed here, but kept for symmetry */ 1620 OpCode op; 1621 if (e1->k != VNONRELOC) { 1622 lua_assert(e1->k == VK || e1->k == VKINT || e1->k == VKFLT); 1623 swapexps(e1, e2); 1624 } 1625 r1 = luaK_exp2anyreg(fs, e1); /* 1st expression must be in register */ 1626 if (isSCnumber(e2, &im, &isfloat)) { 1627 op = OP_EQI; 1628 r2 = im; /* immediate operand */ 1629 } 1630 else if (luaK_exp2RK(fs, e2)) { /* 2nd expression is constant? */ 1631 op = OP_EQK; 1632 r2 = e2->u.info; /* constant index */ 1633 } 1634 else { 1635 op = OP_EQ; /* will compare two registers */ 1636 r2 = luaK_exp2anyreg(fs, e2); 1637 } 1638 freeexps(fs, e1, e2); 1639 e1->u.info = condjump(fs, op, r1, r2, isfloat, (opr == OPR_EQ)); 1640 e1->k = VJMP; 1641} 1642 1643 1644/* 1645** Apply prefix operation 'op' to expression 'e'. 1646*/ 1647void luaK_prefix (FuncState *fs, UnOpr opr, expdesc *e, int line) { 1648 static const expdesc ef = {VKINT, {0}, NO_JUMP, NO_JUMP}; 1649 luaK_dischargevars(fs, e); 1650 switch (opr) { 1651 case OPR_MINUS: case OPR_BNOT: /* use 'ef' as fake 2nd operand */ 1652 if (constfolding(fs, opr + LUA_OPUNM, e, &ef)) 1653 break; 1654 /* else */ /* FALLTHROUGH */ 1655 case OPR_LEN: 1656 codeunexpval(fs, unopr2op(opr), e, line); 1657 break; 1658 case OPR_NOT: codenot(fs, e); break; 1659 default: lua_assert(0); 1660 } 1661} 1662 1663 1664/* 1665** Process 1st operand 'v' of binary operation 'op' before reading 1666** 2nd operand. 1667*/ 1668void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) { 1669 luaK_dischargevars(fs, v); 1670 switch (op) { 1671 case OPR_AND: { 1672 luaK_goiftrue(fs, v); /* go ahead only if 'v' is true */ 1673 break; 1674 } 1675 case OPR_OR: { 1676 luaK_goiffalse(fs, v); /* go ahead only if 'v' is false */ 1677 break; 1678 } 1679 case OPR_CONCAT: { 1680 luaK_exp2nextreg(fs, v); /* operand must be on the stack */ 1681 break; 1682 } 1683 case OPR_ADD: case OPR_SUB: 1684#ifndef _KERNEL 1685 case OPR_MUL: case OPR_DIV: case OPR_IDIV: 1686 case OPR_MOD: case OPR_POW: 1687#else /* _KERNEL */ 1688 case OPR_MUL: case OPR_IDIV: 1689 case OPR_MOD: 1690#endif /* _KERNEL */ 1691 case OPR_BAND: case OPR_BOR: case OPR_BXOR: 1692 case OPR_SHL: case OPR_SHR: { 1693 if (!tonumeral(v, NULL)) 1694 luaK_exp2anyreg(fs, v); 1695 /* else keep numeral, which may be folded or used as an immediate 1696 operand */ 1697 break; 1698 } 1699 case OPR_EQ: case OPR_NE: { 1700 if (!tonumeral(v, NULL)) 1701 luaK_exp2RK(fs, v); 1702 /* else keep numeral, which may be an immediate operand */ 1703 break; 1704 } 1705 case OPR_LT: case OPR_LE: 1706 case OPR_GT: case OPR_GE: { 1707 int dummy, dummy2; 1708 if (!isSCnumber(v, &dummy, &dummy2)) 1709 luaK_exp2anyreg(fs, v); 1710 /* else keep numeral, which may be an immediate operand */ 1711 break; 1712 } 1713 default: lua_assert(0); 1714 } 1715} 1716 1717/* 1718** Create code for '(e1 .. e2)'. 1719** For '(e1 .. e2.1 .. e2.2)' (which is '(e1 .. (e2.1 .. e2.2))', 1720** because concatenation is right associative), merge both CONCATs. 1721*/ 1722static void codeconcat (FuncState *fs, expdesc *e1, expdesc *e2, int line) { 1723 Instruction *ie2 = previousinstruction(fs); 1724 if (GET_OPCODE(*ie2) == OP_CONCAT) { /* is 'e2' a concatenation? */ 1725 int n = GETARG_B(*ie2); /* # of elements concatenated in 'e2' */ 1726 lua_assert(e1->u.info + 1 == GETARG_A(*ie2)); 1727 freeexp(fs, e2); 1728 SETARG_A(*ie2, e1->u.info); /* correct first element ('e1') */ 1729 SETARG_B(*ie2, n + 1); /* will concatenate one more element */ 1730 } 1731 else { /* 'e2' is not a concatenation */ 1732 luaK_codeABC(fs, OP_CONCAT, e1->u.info, 2, 0); /* new concat opcode */ 1733 freeexp(fs, e2); 1734 luaK_fixline(fs, line); 1735 } 1736} 1737 1738 1739/* 1740** Finalize code for binary operation, after reading 2nd operand. 1741*/ 1742void luaK_posfix (FuncState *fs, BinOpr opr, 1743 expdesc *e1, expdesc *e2, int line) { 1744 luaK_dischargevars(fs, e2); 1745 if (foldbinop(opr) && constfolding(fs, opr + LUA_OPADD, e1, e2)) 1746 return; /* done by folding */ 1747 switch (opr) { 1748 case OPR_AND: { 1749 lua_assert(e1->t == NO_JUMP); /* list closed by 'luaK_infix' */ 1750 luaK_concat(fs, &e2->f, e1->f); 1751 *e1 = *e2; 1752 break; 1753 } 1754 case OPR_OR: { 1755 lua_assert(e1->f == NO_JUMP); /* list closed by 'luaK_infix' */ 1756 luaK_concat(fs, &e2->t, e1->t); 1757 *e1 = *e2; 1758 break; 1759 } 1760 case OPR_CONCAT: { /* e1 .. e2 */ 1761 luaK_exp2nextreg(fs, e2); 1762 codeconcat(fs, e1, e2, line); 1763 break; 1764 } 1765 case OPR_ADD: case OPR_MUL: { 1766 codecommutative(fs, opr, e1, e2, line); 1767 break; 1768 } 1769 case OPR_SUB: { 1770 if (finishbinexpneg(fs, e1, e2, OP_ADDI, line, TM_SUB)) 1771 break; /* coded as (r1 + -I) */ 1772 /* ELSE */ 1773 } /* FALLTHROUGH */ 1774#ifndef _KERNEL 1775 case OPR_DIV: case OPR_IDIV: case OPR_MOD: case OPR_POW: { 1776#else /* _KERNEL */ 1777 case OPR_IDIV: case OPR_MOD: { 1778#endif 1779 codearith(fs, opr, e1, e2, 0, line); 1780 break; 1781 } 1782 case OPR_BAND: case OPR_BOR: case OPR_BXOR: { 1783 codebitwise(fs, opr, e1, e2, line); 1784 break; 1785 } 1786 case OPR_SHL: { 1787 if (isSCint(e1)) { 1788 swapexps(e1, e2); 1789 codebini(fs, OP_SHLI, e1, e2, 1, line, TM_SHL); /* I << r2 */ 1790 } 1791 else if (finishbinexpneg(fs, e1, e2, OP_SHRI, line, TM_SHL)) { 1792 /* coded as (r1 >> -I) */; 1793 } 1794 else /* regular case (two registers) */ 1795 codebinexpval(fs, opr, e1, e2, line); 1796 break; 1797 } 1798 case OPR_SHR: { 1799 if (isSCint(e2)) 1800 codebini(fs, OP_SHRI, e1, e2, 0, line, TM_SHR); /* r1 >> I */ 1801 else /* regular case (two registers) */ 1802 codebinexpval(fs, opr, e1, e2, line); 1803 break; 1804 } 1805 case OPR_EQ: case OPR_NE: { 1806 codeeq(fs, opr, e1, e2); 1807 break; 1808 } 1809 case OPR_GT: case OPR_GE: { 1810 /* '(a > b)' <=> '(b < a)'; '(a >= b)' <=> '(b <= a)' */ 1811 swapexps(e1, e2); 1812 opr = cast(BinOpr, (opr - OPR_GT) + OPR_LT); 1813 } /* FALLTHROUGH */ 1814 case OPR_LT: case OPR_LE: { 1815 codeorder(fs, opr, e1, e2); 1816 break; 1817 } 1818 default: lua_assert(0); 1819 } 1820} 1821 1822 1823/* 1824** Change line information associated with current position, by removing 1825** previous info and adding it again with new line. 1826*/ 1827void luaK_fixline (FuncState *fs, int line) { 1828 removelastlineinfo(fs); 1829 savelineinfo(fs, fs->f, line); 1830} 1831 1832 1833void luaK_settablesize (FuncState *fs, int pc, int ra, int asize, int hsize) { 1834 Instruction *inst = &fs->f->code[pc]; 1835 int rb = (hsize != 0) ? luaO_ceillog2(hsize) + 1 : 0; /* hash size */ 1836 int extra = asize / (MAXARG_C + 1); /* higher bits of array size */ 1837 int rc = asize % (MAXARG_C + 1); /* lower bits of array size */ 1838 int k = (extra > 0); /* true iff needs extra argument */ 1839 *inst = CREATE_ABCk(OP_NEWTABLE, ra, rb, rc, k); 1840 *(inst + 1) = CREATE_Ax(OP_EXTRAARG, extra); 1841} 1842 1843 1844/* 1845** Emit a SETLIST instruction. 1846** 'base' is register that keeps table; 1847** 'nelems' is #table plus those to be stored now; 1848** 'tostore' is number of values (in registers 'base + 1',...) to add to 1849** table (or LUA_MULTRET to add up to stack top). 1850*/ 1851void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) { 1852 lua_assert(tostore != 0 && tostore <= LFIELDS_PER_FLUSH); 1853 if (tostore == LUA_MULTRET) 1854 tostore = 0; 1855 if (nelems <= MAXARG_C) 1856 luaK_codeABC(fs, OP_SETLIST, base, tostore, nelems); 1857 else { 1858 int extra = nelems / (MAXARG_C + 1); 1859 nelems %= (MAXARG_C + 1); 1860 luaK_codeABCk(fs, OP_SETLIST, base, tostore, nelems, 1); 1861 codeextraarg(fs, extra); 1862 } 1863 fs->freereg = base + 1; /* free registers with list values */ 1864} 1865 1866 1867/* 1868** return the final target of a jump (skipping jumps to jumps) 1869*/ 1870static int finaltarget (Instruction *code, int i) { 1871 int count; 1872 for (count = 0; count < 100; count++) { /* avoid infinite loops */ 1873 Instruction pc = code[i]; 1874 if (GET_OPCODE(pc) != OP_JMP) 1875 break; 1876 else 1877 i += GETARG_sJ(pc) + 1; 1878 } 1879 return i; 1880} 1881 1882 1883/* 1884** Do a final pass over the code of a function, doing small peephole 1885** optimizations and adjustments. 1886*/ 1887void luaK_finish (FuncState *fs) { 1888 int i; 1889 Proto *p = fs->f; 1890 for (i = 0; i < fs->pc; i++) { 1891 Instruction *pc = &p->code[i]; 1892 lua_assert(i == 0 || isOT(*(pc - 1)) == isIT(*pc)); 1893 switch (GET_OPCODE(*pc)) { 1894 case OP_RETURN0: case OP_RETURN1: { 1895 if (!(fs->needclose || p->is_vararg)) 1896 break; /* no extra work */ 1897 /* else use OP_RETURN to do the extra work */ 1898 SET_OPCODE(*pc, OP_RETURN); 1899 } /* FALLTHROUGH */ 1900 case OP_RETURN: case OP_TAILCALL: { 1901 if (fs->needclose) 1902 SETARG_k(*pc, 1); /* signal that it needs to close */ 1903 if (p->is_vararg) 1904 SETARG_C(*pc, p->numparams + 1); /* signal that it is vararg */ 1905 break; 1906 } 1907 case OP_JMP: { 1908 int target = finaltarget(p->code, i); 1909 fixjump(fs, i, target); 1910 break; 1911 } 1912 default: break; 1913 } 1914 } 1915} 1916