| 1 | /* |
| 2 | ** $Id: lcode.c,v 2.62 2012/08/16 17:34:28 roberto Exp $ |
| 3 | ** Code generator for Lua |
| 4 | ** See Copyright Notice in lua.h |
| 5 | */ |
| 6 | |
| 7 | |
| 8 | #include <stdlib.h> |
| 9 | |
| 10 | #define lcode_c |
| 11 | #define LUA_CORE |
| 12 | |
| 13 | #include "lua.h" |
| 14 | |
| 15 | #include "lcode.h" |
| 16 | #include "ldebug.h" |
| 17 | #include "ldo.h" |
| 18 | #include "lgc.h" |
| 19 | #include "llex.h" |
| 20 | #include "lmem.h" |
| 21 | #include "lobject.h" |
| 22 | #include "lopcodes.h" |
| 23 | #include "lparser.h" |
| 24 | #include "lstring.h" |
| 25 | #include "ltable.h" |
| 26 | #include "lvm.h" |
| 27 | |
| 28 | |
| 29 | #define hasjumps(e) ((e)->t != (e)->f) |
| 30 | |
| 31 | |
| 32 | static int isnumeral(expdesc *e) { |
| 33 | return (e->k == VKNUM && e->t == NO_JUMP && e->f == NO_JUMP); |
| 34 | } |
| 35 | |
| 36 | |
| 37 | void luaK_nil (FuncState *fs, int from, int n) { |
| 38 | Instruction *previous; |
| 39 | int l = from + n - 1; /* last register to set nil */ |
| 40 | if (fs->pc > fs->lasttarget) { /* no jumps to current position? */ |
| 41 | previous = &fs->f->code[fs->pc-1]; |
| 42 | if (GET_OPCODE(*previous) == OP_LOADNIL) { |
| 43 | int pfrom = GETARG_A(*previous); |
| 44 | int pl = pfrom + GETARG_B(*previous); |
| 45 | if ((pfrom <= from && from <= pl + 1) || |
| 46 | (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */ |
| 47 | if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */ |
| 48 | if (pl > l) l = pl; /* l = max(l, pl) */ |
| 49 | SETARG_A(*previous, from); |
| 50 | SETARG_B(*previous, l - from); |
| 51 | return; |
| 52 | } |
| 53 | } /* else go through */ |
| 54 | } |
| 55 | luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */ |
| 56 | } |
| 57 | |
| 58 | |
| 59 | int luaK_jump (FuncState *fs) { |
| 60 | int jpc = fs->jpc; /* save list of jumps to here */ |
| 61 | int j; |
| 62 | fs->jpc = NO_JUMP; |
| 63 | j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP); |
| 64 | luaK_concat(fs, &j, jpc); /* keep them on hold */ |
| 65 | return j; |
| 66 | } |
| 67 | |
| 68 | |
| 69 | void luaK_ret (FuncState *fs, int first, int nret) { |
| 70 | luaK_codeABC(fs, OP_RETURN, first, nret+1, 0); |
| 71 | } |
| 72 | |
| 73 | |
| 74 | static int condjump (FuncState *fs, OpCode op, int A, int B, int C) { |
| 75 | luaK_codeABC(fs, op, A, B, C); |
| 76 | return luaK_jump(fs); |
| 77 | } |
| 78 | |
| 79 | |
| 80 | static void fixjump (FuncState *fs, int pc, int dest) { |
| 81 | Instruction *jmp = &fs->f->code[pc]; |
| 82 | int offset = dest-(pc+1); |
| 83 | lua_assert(dest != NO_JUMP); |
| 84 | if (abs(offset) > MAXARG_sBx) |
| 85 | luaX_syntaxerror(fs->ls, "control structure too long"); |
| 86 | SETARG_sBx(*jmp, offset); |
| 87 | } |
| 88 | |
| 89 | |
| 90 | /* |
| 91 | ** returns current `pc' and marks it as a jump target (to avoid wrong |
| 92 | ** optimizations with consecutive instructions not in the same basic block). |
| 93 | */ |
| 94 | int luaK_getlabel (FuncState *fs) { |
| 95 | fs->lasttarget = fs->pc; |
| 96 | return fs->pc; |
| 97 | } |
| 98 | |
| 99 | |
| 100 | static int getjump (FuncState *fs, int pc) { |
| 101 | int offset = GETARG_sBx(fs->f->code[pc]); |
| 102 | if (offset == NO_JUMP) /* point to itself represents end of list */ |
| 103 | return NO_JUMP; /* end of list */ |
| 104 | else |
| 105 | return (pc+1)+offset; /* turn offset into absolute position */ |
| 106 | } |
| 107 | |
| 108 | |
| 109 | static Instruction *getjumpcontrol (FuncState *fs, int pc) { |
| 110 | Instruction *pi = &fs->f->code[pc]; |
| 111 | if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1)))) |
| 112 | return pi-1; |
| 113 | else |
| 114 | return pi; |
| 115 | } |
| 116 | |
| 117 | |
| 118 | /* |
| 119 | ** check whether list has any jump that do not produce a value |
| 120 | ** (or produce an inverted value) |
| 121 | */ |
| 122 | static int need_value (FuncState *fs, int list) { |
| 123 | for (; list != NO_JUMP; list = getjump(fs, list)) { |
| 124 | Instruction i = *getjumpcontrol(fs, list); |
| 125 | if (GET_OPCODE(i) != OP_TESTSET) return 1; |
| 126 | } |
| 127 | return 0; /* not found */ |
| 128 | } |
| 129 | |
| 130 | |
| 131 | static int patchtestreg (FuncState *fs, int node, int reg) { |
| 132 | Instruction *i = getjumpcontrol(fs, node); |
| 133 | if (GET_OPCODE(*i) != OP_TESTSET) |
| 134 | return 0; /* cannot patch other instructions */ |
| 135 | if (reg != NO_REG && reg != GETARG_B(*i)) |
| 136 | SETARG_A(*i, reg); |
| 137 | else /* no register to put value or register already has the value */ |
| 138 | *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i)); |
| 139 | |
| 140 | return 1; |
| 141 | } |
| 142 | |
| 143 | |
| 144 | static void removevalues (FuncState *fs, int list) { |
| 145 | for (; list != NO_JUMP; list = getjump(fs, list)) |
| 146 | patchtestreg(fs, list, NO_REG); |
| 147 | } |
| 148 | |
| 149 | |
| 150 | static void patchlistaux (FuncState *fs, int list, int vtarget, int reg, |
| 151 | int dtarget) { |
| 152 | while (list != NO_JUMP) { |
| 153 | int next = getjump(fs, list); |
| 154 | if (patchtestreg(fs, list, reg)) |
| 155 | fixjump(fs, list, vtarget); |
| 156 | else |
| 157 | fixjump(fs, list, dtarget); /* jump to default target */ |
| 158 | list = next; |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | |
| 163 | static void dischargejpc (FuncState *fs) { |
| 164 | patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc); |
| 165 | fs->jpc = NO_JUMP; |
| 166 | } |
| 167 | |
| 168 | |
| 169 | void luaK_patchlist (FuncState *fs, int list, int target) { |
| 170 | if (target == fs->pc) |
| 171 | luaK_patchtohere(fs, list); |
| 172 | else { |
| 173 | lua_assert(target < fs->pc); |
| 174 | patchlistaux(fs, list, target, NO_REG, target); |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | |
| 179 | LUAI_FUNC void luaK_patchclose (FuncState *fs, int list, int level) { |
| 180 | level++; /* argument is +1 to reserve 0 as non-op */ |
| 181 | while (list != NO_JUMP) { |
| 182 | int next = getjump(fs, list); |
| 183 | lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP && |
| 184 | (GETARG_A(fs->f->code[list]) == 0 || |
| 185 | GETARG_A(fs->f->code[list]) >= level)); |
| 186 | SETARG_A(fs->f->code[list], level); |
| 187 | list = next; |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | |
| 192 | void luaK_patchtohere (FuncState *fs, int list) { |
| 193 | luaK_getlabel(fs); |
| 194 | luaK_concat(fs, &fs->jpc, list); |
| 195 | } |
| 196 | |
| 197 | |
| 198 | void luaK_concat (FuncState *fs, int *l1, int l2) { |
| 199 | if (l2 == NO_JUMP) return; |
| 200 | else if (*l1 == NO_JUMP) |
| 201 | *l1 = l2; |
| 202 | else { |
| 203 | int list = *l1; |
| 204 | int next; |
| 205 | while ((next = getjump(fs, list)) != NO_JUMP) /* find last element */ |
| 206 | list = next; |
| 207 | fixjump(fs, list, l2); |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | |
| 212 | static int luaK_code (FuncState *fs, Instruction i) { |
| 213 | Proto *f = fs->f; |
| 214 | dischargejpc(fs); /* `pc' will change */ |
| 215 | /* put new instruction in code array */ |
| 216 | luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction, |
| 217 | MAX_INT, "opcodes"); |
| 218 | f->code[fs->pc] = i; |
| 219 | /* save corresponding line information */ |
| 220 | luaM_growvector(fs->ls->L, f->lineinfo, fs->pc, f->sizelineinfo, int, |
| 221 | MAX_INT, "opcodes"); |
| 222 | f->lineinfo[fs->pc] = fs->ls->lastline; |
| 223 | return fs->pc++; |
| 224 | } |
| 225 | |
| 226 | |
| 227 | int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) { |
| 228 | lua_assert(getOpMode(o) == iABC); |
| 229 | lua_assert(getBMode(o) != OpArgN || b == 0); |
| 230 | lua_assert(getCMode(o) != OpArgN || c == 0); |
| 231 | lua_assert(a <= MAXARG_A && b <= MAXARG_B && c <= MAXARG_C); |
| 232 | return luaK_code(fs, CREATE_ABC(o, a, b, c)); |
| 233 | } |
| 234 | |
| 235 | |
| 236 | int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) { |
| 237 | lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx); |
| 238 | lua_assert(getCMode(o) == OpArgN); |
| 239 | lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx); |
| 240 | return luaK_code(fs, CREATE_ABx(o, a, bc)); |
| 241 | } |
| 242 | |
| 243 | |
| 244 | static int codeextraarg (FuncState *fs, int a) { |
| 245 | lua_assert(a <= MAXARG_Ax); |
| 246 | return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a)); |
| 247 | } |
| 248 | |
| 249 | |
| 250 | int luaK_codek (FuncState *fs, int reg, int k) { |
| 251 | if (k <= MAXARG_Bx) |
| 252 | return luaK_codeABx(fs, OP_LOADK, reg, k); |
| 253 | else { |
| 254 | int p = luaK_codeABx(fs, OP_LOADKX, reg, 0); |
| 255 | codeextraarg(fs, k); |
| 256 | return p; |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | |
| 261 | void luaK_checkstack (FuncState *fs, int n) { |
| 262 | int newstack = fs->freereg + n; |
| 263 | if (newstack > fs->f->maxstacksize) { |
| 264 | if (newstack >= MAXSTACK) |
| 265 | luaX_syntaxerror(fs->ls, "function or expression too complex"); |
| 266 | fs->f->maxstacksize = cast_byte(newstack); |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | |
| 271 | void luaK_reserveregs (FuncState *fs, int n) { |
| 272 | luaK_checkstack(fs, n); |
| 273 | fs->freereg += n; |
| 274 | } |
| 275 | |
| 276 | |
| 277 | static void freereg (FuncState *fs, int reg) { |
| 278 | if (!ISK(reg) && reg >= fs->nactvar) { |
| 279 | fs->freereg--; |
| 280 | lua_assert(reg == fs->freereg); |
| 281 | } |
| 282 | } |
| 283 | |
| 284 | |
| 285 | static void freeexp (FuncState *fs, expdesc *e) { |
| 286 | if (e->k == VNONRELOC) |
| 287 | freereg(fs, e->u.info); |
| 288 | } |
| 289 | |
| 290 | |
| 291 | static int addk (FuncState *fs, TValue *key, TValue *v) { |
| 292 | lua_State *L = fs->ls->L; |
| 293 | TValue *idx = luaH_set(L, fs->h, key); |
| 294 | Proto *f = fs->f; |
| 295 | int k, oldsize; |
| 296 | if (ttisnumber(idx)) { |
| 297 | lua_Number n = nvalue(idx); |
| 298 | lua_number2int(k, n); |
| 299 | if (luaV_rawequalobj(&f->k[k], v)) |
| 300 | return k; |
| 301 | /* else may be a collision (e.g., between 0.0 and "\0\0\0\0\0\0\0\0"); |
| 302 | go through and create a new entry for this value */ |
| 303 | } |
| 304 | /* constant not found; create a new entry */ |
| 305 | oldsize = f->sizek; |
| 306 | k = fs->nk; |
| 307 | /* numerical value does not need GC barrier; |
| 308 | table has no metatable, so it does not need to invalidate cache */ |
| 309 | setnvalue(idx, cast_num(k)); |
| 310 | luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants"); |
| 311 | while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]); |
| 312 | setobj(L, &f->k[k], v); |
| 313 | fs->nk++; |
| 314 | luaC_barrier(L, f, v); |
| 315 | return k; |
| 316 | } |
| 317 | |
| 318 | |
| 319 | int luaK_stringK (FuncState *fs, TString *s) { |
| 320 | TValue o; |
| 321 | setsvalue(fs->ls->L, &o, s); |
| 322 | return addk(fs, &o, &o); |
| 323 | } |
| 324 | |
| 325 | |
| 326 | int luaK_numberK (FuncState *fs, lua_Number r) { |
| 327 | int n; |
| 328 | lua_State *L = fs->ls->L; |
| 329 | TValue o; |
| 330 | setnvalue(&o, r); |
| 331 | if (r == 0 || luai_numisnan(NULL, r)) { /* handle -0 and NaN */ |
| 332 | /* use raw representation as key to avoid numeric problems */ |
| 333 | setsvalue(L, L->top++, luaS_newlstr(L, (char *)&r, sizeof(r))); |
| 334 | n = addk(fs, L->top - 1, &o); |
| 335 | L->top--; |
| 336 | } |
| 337 | else |
| 338 | n = addk(fs, &o, &o); /* regular case */ |
| 339 | return n; |
| 340 | } |
| 341 | |
| 342 | |
| 343 | static int boolK (FuncState *fs, int b) { |
| 344 | TValue o; |
| 345 | setbvalue(&o, b); |
| 346 | return addk(fs, &o, &o); |
| 347 | } |
| 348 | |
| 349 | |
| 350 | static int nilK (FuncState *fs) { |
| 351 | TValue k, v; |
| 352 | setnilvalue(&v); |
| 353 | /* cannot use nil as key; instead use table itself to represent nil */ |
| 354 | sethvalue(fs->ls->L, &k, fs->h); |
| 355 | return addk(fs, &k, &v); |
| 356 | } |
| 357 | |
| 358 | |
| 359 | void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) { |
| 360 | if (e->k == VCALL) { /* expression is an open function call? */ |
| 361 | SETARG_C(getcode(fs, e), nresults+1); |
| 362 | } |
| 363 | else if (e->k == VVARARG) { |
| 364 | SETARG_B(getcode(fs, e), nresults+1); |
| 365 | SETARG_A(getcode(fs, e), fs->freereg); |
| 366 | luaK_reserveregs(fs, 1); |
| 367 | } |
| 368 | } |
| 369 | |
| 370 | |
| 371 | void luaK_setoneret (FuncState *fs, expdesc *e) { |
| 372 | if (e->k == VCALL) { /* expression is an open function call? */ |
| 373 | e->k = VNONRELOC; |
| 374 | e->u.info = GETARG_A(getcode(fs, e)); |
| 375 | } |
| 376 | else if (e->k == VVARARG) { |
| 377 | SETARG_B(getcode(fs, e), 2); |
| 378 | e->k = VRELOCABLE; /* can relocate its simple result */ |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | |
| 383 | void luaK_dischargevars (FuncState *fs, expdesc *e) { |
| 384 | switch (e->k) { |
| 385 | case VLOCAL: { |
| 386 | e->k = VNONRELOC; |
| 387 | break; |
| 388 | } |
| 389 | case VUPVAL: { |
| 390 | e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0); |
| 391 | e->k = VRELOCABLE; |
| 392 | break; |
| 393 | } |
| 394 | case VINDEXED: { |
| 395 | OpCode op = OP_GETTABUP; /* assume 't' is in an upvalue */ |
| 396 | freereg(fs, e->u.ind.idx); |
| 397 | if (e->u.ind.vt == VLOCAL) { /* 't' is in a register? */ |
| 398 | freereg(fs, e->u.ind.t); |
| 399 | op = OP_GETTABLE; |
| 400 | } |
| 401 | e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx); |
| 402 | e->k = VRELOCABLE; |
| 403 | break; |
| 404 | } |
| 405 | case VVARARG: |
| 406 | case VCALL: { |
| 407 | luaK_setoneret(fs, e); |
| 408 | break; |
| 409 | } |
| 410 | default: break; /* there is one value available (somewhere) */ |
| 411 | } |
| 412 | } |
| 413 | |
| 414 | |
| 415 | static int code_label (FuncState *fs, int A, int b, int jump) { |
| 416 | luaK_getlabel(fs); /* those instructions may be jump targets */ |
| 417 | return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump); |
| 418 | } |
| 419 | |
| 420 | |
| 421 | static void discharge2reg (FuncState *fs, expdesc *e, int reg) { |
| 422 | luaK_dischargevars(fs, e); |
| 423 | switch (e->k) { |
| 424 | case VNIL: { |
| 425 | luaK_nil(fs, reg, 1); |
| 426 | break; |
| 427 | } |
| 428 | case VFALSE: case VTRUE: { |
| 429 | luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0); |
| 430 | break; |
| 431 | } |
| 432 | case VK: { |
| 433 | luaK_codek(fs, reg, e->u.info); |
| 434 | break; |
| 435 | } |
| 436 | case VKNUM: { |
| 437 | luaK_codek(fs, reg, luaK_numberK(fs, e->u.nval)); |
| 438 | break; |
| 439 | } |
| 440 | case VRELOCABLE: { |
| 441 | Instruction *pc = &getcode(fs, e); |
| 442 | SETARG_A(*pc, reg); |
| 443 | break; |
| 444 | } |
| 445 | case VNONRELOC: { |
| 446 | if (reg != e->u.info) |
| 447 | luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0); |
| 448 | break; |
| 449 | } |
| 450 | default: { |
| 451 | lua_assert(e->k == VVOID || e->k == VJMP); |
| 452 | return; /* nothing to do... */ |
| 453 | } |
| 454 | } |
| 455 | e->u.info = reg; |
| 456 | e->k = VNONRELOC; |
| 457 | } |
| 458 | |
| 459 | |
| 460 | static void discharge2anyreg (FuncState *fs, expdesc *e) { |
| 461 | if (e->k != VNONRELOC) { |
| 462 | luaK_reserveregs(fs, 1); |
| 463 | discharge2reg(fs, e, fs->freereg-1); |
| 464 | } |
| 465 | } |
| 466 | |
| 467 | |
| 468 | static void exp2reg (FuncState *fs, expdesc *e, int reg) { |
| 469 | discharge2reg(fs, e, reg); |
| 470 | if (e->k == VJMP) |
| 471 | luaK_concat(fs, &e->t, e->u.info); /* put this jump in `t' list */ |
| 472 | if (hasjumps(e)) { |
| 473 | int final; /* position after whole expression */ |
| 474 | int p_f = NO_JUMP; /* position of an eventual LOAD false */ |
| 475 | int p_t = NO_JUMP; /* position of an eventual LOAD true */ |
| 476 | if (need_value(fs, e->t) || need_value(fs, e->f)) { |
| 477 | int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs); |
| 478 | p_f = code_label(fs, reg, 0, 1); |
| 479 | p_t = code_label(fs, reg, 1, 0); |
| 480 | luaK_patchtohere(fs, fj); |
| 481 | } |
| 482 | final = luaK_getlabel(fs); |
| 483 | patchlistaux(fs, e->f, final, reg, p_f); |
| 484 | patchlistaux(fs, e->t, final, reg, p_t); |
| 485 | } |
| 486 | e->f = e->t = NO_JUMP; |
| 487 | e->u.info = reg; |
| 488 | e->k = VNONRELOC; |
| 489 | } |
| 490 | |
| 491 | |
| 492 | void luaK_exp2nextreg (FuncState *fs, expdesc *e) { |
| 493 | luaK_dischargevars(fs, e); |
| 494 | freeexp(fs, e); |
| 495 | luaK_reserveregs(fs, 1); |
| 496 | exp2reg(fs, e, fs->freereg - 1); |
| 497 | } |
| 498 | |
| 499 | |
| 500 | int luaK_exp2anyreg (FuncState *fs, expdesc *e) { |
| 501 | luaK_dischargevars(fs, e); |
| 502 | if (e->k == VNONRELOC) { |
| 503 | if (!hasjumps(e)) return e->u.info; /* exp is already in a register */ |
| 504 | if (e->u.info >= fs->nactvar) { /* reg. is not a local? */ |
| 505 | exp2reg(fs, e, e->u.info); /* put value on it */ |
| 506 | return e->u.info; |
| 507 | } |
| 508 | } |
| 509 | luaK_exp2nextreg(fs, e); /* default */ |
| 510 | return e->u.info; |
| 511 | } |
| 512 | |
| 513 | |
| 514 | void luaK_exp2anyregup (FuncState *fs, expdesc *e) { |
| 515 | if (e->k != VUPVAL || hasjumps(e)) |
| 516 | luaK_exp2anyreg(fs, e); |
| 517 | } |
| 518 | |
| 519 | |
| 520 | void luaK_exp2val (FuncState *fs, expdesc *e) { |
| 521 | if (hasjumps(e)) |
| 522 | luaK_exp2anyreg(fs, e); |
| 523 | else |
| 524 | luaK_dischargevars(fs, e); |
| 525 | } |
| 526 | |
| 527 | |
| 528 | int luaK_exp2RK (FuncState *fs, expdesc *e) { |
| 529 | luaK_exp2val(fs, e); |
| 530 | switch (e->k) { |
| 531 | case VTRUE: |
| 532 | case VFALSE: |
| 533 | case VNIL: { |
| 534 | if (fs->nk <= MAXINDEXRK) { /* constant fits in RK operand? */ |
| 535 | e->u.info = (e->k == VNIL) ? nilK(fs) : boolK(fs, (e->k == VTRUE)); |
| 536 | e->k = VK; |
| 537 | return RKASK(e->u.info); |
| 538 | } |
| 539 | else break; |
| 540 | } |
| 541 | case VKNUM: { |
| 542 | e->u.info = luaK_numberK(fs, e->u.nval); |
| 543 | e->k = VK; |
| 544 | /* go through */ |
| 545 | } |
| 546 | case VK: { |
| 547 | if (e->u.info <= MAXINDEXRK) /* constant fits in argC? */ |
| 548 | return RKASK(e->u.info); |
| 549 | else break; |
| 550 | } |
| 551 | default: break; |
| 552 | } |
| 553 | /* not a constant in the right range: put it in a register */ |
| 554 | return luaK_exp2anyreg(fs, e); |
| 555 | } |
| 556 | |
| 557 | |
| 558 | void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) { |
| 559 | switch (var->k) { |
| 560 | case VLOCAL: { |
| 561 | freeexp(fs, ex); |
| 562 | exp2reg(fs, ex, var->u.info); |
| 563 | return; |
| 564 | } |
| 565 | case VUPVAL: { |
| 566 | int e = luaK_exp2anyreg(fs, ex); |
| 567 | luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0); |
| 568 | break; |
| 569 | } |
| 570 | case VINDEXED: { |
| 571 | OpCode op = (var->u.ind.vt == VLOCAL) ? OP_SETTABLE : OP_SETTABUP; |
| 572 | int e = luaK_exp2RK(fs, ex); |
| 573 | luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e); |
| 574 | break; |
| 575 | } |
| 576 | default: { |
| 577 | lua_assert(0); /* invalid var kind to store */ |
| 578 | break; |
| 579 | } |
| 580 | } |
| 581 | freeexp(fs, ex); |
| 582 | } |
| 583 | |
| 584 | |
| 585 | void luaK_self (FuncState *fs, expdesc *e, expdesc *key) { |
| 586 | int ereg; |
| 587 | luaK_exp2anyreg(fs, e); |
| 588 | ereg = e->u.info; /* register where 'e' was placed */ |
| 589 | freeexp(fs, e); |
| 590 | e->u.info = fs->freereg; /* base register for op_self */ |
| 591 | e->k = VNONRELOC; |
| 592 | luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */ |
| 593 | luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key)); |
| 594 | freeexp(fs, key); |
| 595 | } |
| 596 | |
| 597 | |
| 598 | static void invertjump (FuncState *fs, expdesc *e) { |
| 599 | Instruction *pc = getjumpcontrol(fs, e->u.info); |
| 600 | lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET && |
| 601 | GET_OPCODE(*pc) != OP_TEST); |
| 602 | SETARG_A(*pc, !(GETARG_A(*pc))); |
| 603 | } |
| 604 | |
| 605 | |
| 606 | static int jumponcond (FuncState *fs, expdesc *e, int cond) { |
| 607 | if (e->k == VRELOCABLE) { |
| 608 | Instruction ie = getcode(fs, e); |
| 609 | if (GET_OPCODE(ie) == OP_NOT) { |
| 610 | fs->pc--; /* remove previous OP_NOT */ |
| 611 | return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond); |
| 612 | } |
| 613 | /* else go through */ |
| 614 | } |
| 615 | discharge2anyreg(fs, e); |
| 616 | freeexp(fs, e); |
| 617 | return condjump(fs, OP_TESTSET, NO_REG, e->u.info, cond); |
| 618 | } |
| 619 | |
| 620 | |
| 621 | void luaK_goiftrue (FuncState *fs, expdesc *e) { |
| 622 | int pc; /* pc of last jump */ |
| 623 | luaK_dischargevars(fs, e); |
| 624 | switch (e->k) { |
| 625 | case VJMP: { |
| 626 | invertjump(fs, e); |
| 627 | pc = e->u.info; |
| 628 | break; |
| 629 | } |
| 630 | case VK: case VKNUM: case VTRUE: { |
| 631 | pc = NO_JUMP; /* always true; do nothing */ |
| 632 | break; |
| 633 | } |
| 634 | default: { |
| 635 | pc = jumponcond(fs, e, 0); |
| 636 | break; |
| 637 | } |
| 638 | } |
| 639 | luaK_concat(fs, &e->f, pc); /* insert last jump in `f' list */ |
| 640 | luaK_patchtohere(fs, e->t); |
| 641 | e->t = NO_JUMP; |
| 642 | } |
| 643 | |
| 644 | |
| 645 | void luaK_goiffalse (FuncState *fs, expdesc *e) { |
| 646 | int pc; /* pc of last jump */ |
| 647 | luaK_dischargevars(fs, e); |
| 648 | switch (e->k) { |
| 649 | case VJMP: { |
| 650 | pc = e->u.info; |
| 651 | break; |
| 652 | } |
| 653 | case VNIL: case VFALSE: { |
| 654 | pc = NO_JUMP; /* always false; do nothing */ |
| 655 | break; |
| 656 | } |
| 657 | default: { |
| 658 | pc = jumponcond(fs, e, 1); |
| 659 | break; |
| 660 | } |
| 661 | } |
| 662 | luaK_concat(fs, &e->t, pc); /* insert last jump in `t' list */ |
| 663 | luaK_patchtohere(fs, e->f); |
| 664 | e->f = NO_JUMP; |
| 665 | } |
| 666 | |
| 667 | |
| 668 | static void codenot (FuncState *fs, expdesc *e) { |
| 669 | luaK_dischargevars(fs, e); |
| 670 | switch (e->k) { |
| 671 | case VNIL: case VFALSE: { |
| 672 | e->k = VTRUE; |
| 673 | break; |
| 674 | } |
| 675 | case VK: case VKNUM: case VTRUE: { |
| 676 | e->k = VFALSE; |
| 677 | break; |
| 678 | } |
| 679 | case VJMP: { |
| 680 | invertjump(fs, e); |
| 681 | break; |
| 682 | } |
| 683 | case VRELOCABLE: |
| 684 | case VNONRELOC: { |
| 685 | discharge2anyreg(fs, e); |
| 686 | freeexp(fs, e); |
| 687 | e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0); |
| 688 | e->k = VRELOCABLE; |
| 689 | break; |
| 690 | } |
| 691 | default: { |
| 692 | lua_assert(0); /* cannot happen */ |
| 693 | break; |
| 694 | } |
| 695 | } |
| 696 | /* interchange true and false lists */ |
| 697 | { int temp = e->f; e->f = e->t; e->t = temp; } |
| 698 | removevalues(fs, e->f); |
| 699 | removevalues(fs, e->t); |
| 700 | } |
| 701 | |
| 702 | |
| 703 | void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) { |
| 704 | lua_assert(!hasjumps(t)); |
| 705 | t->u.ind.t = t->u.info; |
| 706 | t->u.ind.idx = luaK_exp2RK(fs, k); |
| 707 | t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL |
| 708 | : check_exp(vkisinreg(t->k), VLOCAL); |
| 709 | t->k = VINDEXED; |
| 710 | } |
| 711 | |
| 712 | |
| 713 | static int constfolding (OpCode op, expdesc *e1, expdesc *e2) { |
| 714 | lua_Number r; |
| 715 | if (!isnumeral(e1) || !isnumeral(e2)) return 0; |
| 716 | if ((op == OP_DIV || op == OP_MOD) && e2->u.nval == 0) |
| 717 | return 0; /* do not attempt to divide by 0 */ |
| 718 | r = luaO_arith(op - OP_ADD + LUA_OPADD, e1->u.nval, e2->u.nval); |
| 719 | e1->u.nval = r; |
| 720 | return 1; |
| 721 | } |
| 722 | |
| 723 | |
| 724 | static void codearith (FuncState *fs, OpCode op, |
| 725 | expdesc *e1, expdesc *e2, int line) { |
| 726 | if (constfolding(op, e1, e2)) |
| 727 | return; |
| 728 | else { |
| 729 | int o2 = (op != OP_UNM && op != OP_LEN) ? luaK_exp2RK(fs, e2) : 0; |
| 730 | int o1 = luaK_exp2RK(fs, e1); |
| 731 | if (o1 > o2) { |
| 732 | freeexp(fs, e1); |
| 733 | freeexp(fs, e2); |
| 734 | } |
| 735 | else { |
| 736 | freeexp(fs, e2); |
| 737 | freeexp(fs, e1); |
| 738 | } |
| 739 | e1->u.info = luaK_codeABC(fs, op, 0, o1, o2); |
| 740 | e1->k = VRELOCABLE; |
| 741 | luaK_fixline(fs, line); |
| 742 | } |
| 743 | } |
| 744 | |
| 745 | |
| 746 | static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1, |
| 747 | expdesc *e2) { |
| 748 | int o1 = luaK_exp2RK(fs, e1); |
| 749 | int o2 = luaK_exp2RK(fs, e2); |
| 750 | freeexp(fs, e2); |
| 751 | freeexp(fs, e1); |
| 752 | if (cond == 0 && op != OP_EQ) { |
| 753 | int temp; /* exchange args to replace by `<' or `<=' */ |
| 754 | temp = o1; o1 = o2; o2 = temp; /* o1 <==> o2 */ |
| 755 | cond = 1; |
| 756 | } |
| 757 | e1->u.info = condjump(fs, op, cond, o1, o2); |
| 758 | e1->k = VJMP; |
| 759 | } |
| 760 | |
| 761 | |
| 762 | void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) { |
| 763 | expdesc e2; |
| 764 | e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0; |
| 765 | switch (op) { |
| 766 | case OPR_MINUS: { |
| 767 | if (isnumeral(e)) /* minus constant? */ |
| 768 | e->u.nval = luai_numunm(NULL, e->u.nval); /* fold it */ |
| 769 | else { |
| 770 | luaK_exp2anyreg(fs, e); |
| 771 | codearith(fs, OP_UNM, e, &e2, line); |
| 772 | } |
| 773 | break; |
| 774 | } |
| 775 | case OPR_NOT: codenot(fs, e); break; |
| 776 | case OPR_LEN: { |
| 777 | luaK_exp2anyreg(fs, e); /* cannot operate on constants */ |
| 778 | codearith(fs, OP_LEN, e, &e2, line); |
| 779 | break; |
| 780 | } |
| 781 | default: lua_assert(0); |
| 782 | } |
| 783 | } |
| 784 | |
| 785 | |
| 786 | void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) { |
| 787 | switch (op) { |
| 788 | case OPR_AND: { |
| 789 | luaK_goiftrue(fs, v); |
| 790 | break; |
| 791 | } |
| 792 | case OPR_OR: { |
| 793 | luaK_goiffalse(fs, v); |
| 794 | break; |
| 795 | } |
| 796 | case OPR_CONCAT: { |
| 797 | luaK_exp2nextreg(fs, v); /* operand must be on the `stack' */ |
| 798 | break; |
| 799 | } |
| 800 | case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV: |
| 801 | case OPR_MOD: case OPR_POW: { |
| 802 | if (!isnumeral(v)) luaK_exp2RK(fs, v); |
| 803 | break; |
| 804 | } |
| 805 | default: { |
| 806 | luaK_exp2RK(fs, v); |
| 807 | break; |
| 808 | } |
| 809 | } |
| 810 | } |
| 811 | |
| 812 | |
| 813 | void luaK_posfix (FuncState *fs, BinOpr op, |
| 814 | expdesc *e1, expdesc *e2, int line) { |
| 815 | switch (op) { |
| 816 | case OPR_AND: { |
| 817 | lua_assert(e1->t == NO_JUMP); /* list must be closed */ |
| 818 | luaK_dischargevars(fs, e2); |
| 819 | luaK_concat(fs, &e2->f, e1->f); |
| 820 | *e1 = *e2; |
| 821 | break; |
| 822 | } |
| 823 | case OPR_OR: { |
| 824 | lua_assert(e1->f == NO_JUMP); /* list must be closed */ |
| 825 | luaK_dischargevars(fs, e2); |
| 826 | luaK_concat(fs, &e2->t, e1->t); |
| 827 | *e1 = *e2; |
| 828 | break; |
| 829 | } |
| 830 | case OPR_CONCAT: { |
| 831 | luaK_exp2val(fs, e2); |
| 832 | if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) { |
| 833 | lua_assert(e1->u.info == GETARG_B(getcode(fs, e2))-1); |
| 834 | freeexp(fs, e1); |
| 835 | SETARG_B(getcode(fs, e2), e1->u.info); |
| 836 | e1->k = VRELOCABLE; e1->u.info = e2->u.info; |
| 837 | } |
| 838 | else { |
| 839 | luaK_exp2nextreg(fs, e2); /* operand must be on the 'stack' */ |
| 840 | codearith(fs, OP_CONCAT, e1, e2, line); |
| 841 | } |
| 842 | break; |
| 843 | } |
| 844 | case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV: |
| 845 | case OPR_MOD: case OPR_POW: { |
| 846 | codearith(fs, cast(OpCode, op - OPR_ADD + OP_ADD), e1, e2, line); |
| 847 | break; |
| 848 | } |
| 849 | case OPR_EQ: case OPR_LT: case OPR_LE: { |
| 850 | codecomp(fs, cast(OpCode, op - OPR_EQ + OP_EQ), 1, e1, e2); |
| 851 | break; |
| 852 | } |
| 853 | case OPR_NE: case OPR_GT: case OPR_GE: { |
| 854 | codecomp(fs, cast(OpCode, op - OPR_NE + OP_EQ), 0, e1, e2); |
| 855 | break; |
| 856 | } |
| 857 | default: lua_assert(0); |
| 858 | } |
| 859 | } |
| 860 | |
| 861 | |
| 862 | void luaK_fixline (FuncState *fs, int line) { |
| 863 | fs->f->lineinfo[fs->pc - 1] = line; |
| 864 | } |
| 865 | |
| 866 | |
| 867 | void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) { |
| 868 | int c = (nelems - 1)/LFIELDS_PER_FLUSH + 1; |
| 869 | int b = (tostore == LUA_MULTRET) ? 0 : tostore; |
| 870 | lua_assert(tostore != 0); |
| 871 | if (c <= MAXARG_C) |
| 872 | luaK_codeABC(fs, OP_SETLIST, base, b, c); |
| 873 | else if (c <= MAXARG_Ax) { |
| 874 | luaK_codeABC(fs, OP_SETLIST, base, b, 0); |
| 875 | codeextraarg(fs, c); |
| 876 | } |
| 877 | else |
| 878 | luaX_syntaxerror(fs->ls, "constructor too long"); |
| 879 | fs->freereg = base + 1; /* free registers with list values */ |
| 880 | } |
| 881 | |