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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 |