1 /*
2 ** $Id: lcode.c,v 2.62.1.1 2013/04/12 18:48:47 roberto Exp $
3 ** Code generator for Lua
4 ** See Copyright Notice in lua.h
5 */
6
7 #include <sys/zfs_context.h>
8
9 #define lcode_c
10 #define LUA_CORE
11
12 #include "lua.h"
13
14 #include "lcode.h"
15 #include "ldebug.h"
16 #include "ldo.h"
17 #include "lgc.h"
18 #include "llex.h"
19 #include "lmem.h"
20 #include "lobject.h"
21 #include "lopcodes.h"
22 #include "lparser.h"
23 #include "lstring.h"
24 #include "ltable.h"
25 #include "lvm.h"
26
27
28 #define hasjumps(e) ((e)->t != (e)->f)
29
30
isnumeral(expdesc * e)31 static int isnumeral(expdesc *e) {
32 return (e->k == VKNUM && e->t == NO_JUMP && e->f == NO_JUMP);
33 }
34
35
luaK_nil(FuncState * fs,int from,int n)36 void luaK_nil (FuncState *fs, int from, int n) {
37 Instruction *previous;
38 int l = from + n - 1; /* last register to set nil */
39 if (fs->pc > fs->lasttarget) { /* no jumps to current position? */
40 previous = &fs->f->code[fs->pc-1];
41 if (GET_OPCODE(*previous) == OP_LOADNIL) {
42 int pfrom = GETARG_A(*previous);
43 int pl = pfrom + GETARG_B(*previous);
44 if ((pfrom <= from && from <= pl + 1) ||
45 (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */
46 if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */
47 if (pl > l) l = pl; /* l = max(l, pl) */
48 SETARG_A(*previous, from);
49 SETARG_B(*previous, l - from);
50 return;
51 }
52 } /* else go through */
53 }
54 luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */
55 }
56
57
luaK_jump(FuncState * fs)58 int luaK_jump (FuncState *fs) {
59 int jpc = fs->jpc; /* save list of jumps to here */
60 int j;
61 fs->jpc = NO_JUMP;
62 j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
63 luaK_concat(fs, &j, jpc); /* keep them on hold */
64 return j;
65 }
66
67
luaK_ret(FuncState * fs,int first,int nret)68 void luaK_ret (FuncState *fs, int first, int nret) {
69 luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
70 }
71
72
condjump(FuncState * fs,OpCode op,int A,int B,int C)73 static int condjump (FuncState *fs, OpCode op, int A, int B, int C) {
74 luaK_codeABC(fs, op, A, B, C);
75 return luaK_jump(fs);
76 }
77
78
fixjump(FuncState * fs,int pc,int dest)79 static void fixjump (FuncState *fs, int pc, int dest) {
80 Instruction *jmp = &fs->f->code[pc];
81 int offset = dest-(pc+1);
82 lua_assert(dest != NO_JUMP);
83 if (abs(offset) > MAXARG_sBx)
84 luaX_syntaxerror(fs->ls, "control structure too long");
85 SETARG_sBx(*jmp, offset);
86 }
87
88
89 /*
90 ** returns current `pc' and marks it as a jump target (to avoid wrong
91 ** optimizations with consecutive instructions not in the same basic block).
92 */
luaK_getlabel(FuncState * fs)93 int luaK_getlabel (FuncState *fs) {
94 fs->lasttarget = fs->pc;
95 return fs->pc;
96 }
97
98
getjump(FuncState * fs,int pc)99 static int getjump (FuncState *fs, int pc) {
100 int offset = GETARG_sBx(fs->f->code[pc]);
101 if (offset == NO_JUMP) /* point to itself represents end of list */
102 return NO_JUMP; /* end of list */
103 else
104 return (pc+1)+offset; /* turn offset into absolute position */
105 }
106
107
getjumpcontrol(FuncState * fs,int pc)108 static Instruction *getjumpcontrol (FuncState *fs, int pc) {
109 Instruction *pi = &fs->f->code[pc];
110 if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1))))
111 return pi-1;
112 else
113 return pi;
114 }
115
116
117 /*
118 ** check whether list has any jump that do not produce a value
119 ** (or produce an inverted value)
120 */
need_value(FuncState * fs,int list)121 static int need_value (FuncState *fs, int list) {
122 for (; list != NO_JUMP; list = getjump(fs, list)) {
123 Instruction i = *getjumpcontrol(fs, list);
124 if (GET_OPCODE(i) != OP_TESTSET) return 1;
125 }
126 return 0; /* not found */
127 }
128
129
patchtestreg(FuncState * fs,int node,int reg)130 static int patchtestreg (FuncState *fs, int node, int reg) {
131 Instruction *i = getjumpcontrol(fs, node);
132 if (GET_OPCODE(*i) != OP_TESTSET)
133 return 0; /* cannot patch other instructions */
134 if (reg != NO_REG && reg != GETARG_B(*i))
135 SETARG_A(*i, reg);
136 else /* no register to put value or register already has the value */
137 *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i));
138
139 return 1;
140 }
141
142
removevalues(FuncState * fs,int list)143 static void removevalues (FuncState *fs, int list) {
144 for (; list != NO_JUMP; list = getjump(fs, list))
145 patchtestreg(fs, list, NO_REG);
146 }
147
148
patchlistaux(FuncState * fs,int list,int vtarget,int reg,int dtarget)149 static void patchlistaux (FuncState *fs, int list, int vtarget, int reg,
150 int dtarget) {
151 while (list != NO_JUMP) {
152 int next = getjump(fs, list);
153 if (patchtestreg(fs, list, reg))
154 fixjump(fs, list, vtarget);
155 else
156 fixjump(fs, list, dtarget); /* jump to default target */
157 list = next;
158 }
159 }
160
161
dischargejpc(FuncState * fs)162 static void dischargejpc (FuncState *fs) {
163 patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
164 fs->jpc = NO_JUMP;
165 }
166
167
luaK_patchlist(FuncState * fs,int list,int target)168 void luaK_patchlist (FuncState *fs, int list, int target) {
169 if (target == fs->pc)
170 luaK_patchtohere(fs, list);
171 else {
172 lua_assert(target < fs->pc);
173 patchlistaux(fs, list, target, NO_REG, target);
174 }
175 }
176
177
luaK_patchclose(FuncState * fs,int list,int level)178 LUAI_FUNC void luaK_patchclose (FuncState *fs, int list, int level) {
179 level++; /* argument is +1 to reserve 0 as non-op */
180 while (list != NO_JUMP) {
181 int next = getjump(fs, list);
182 lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP &&
183 (GETARG_A(fs->f->code[list]) == 0 ||
184 GETARG_A(fs->f->code[list]) >= level));
185 SETARG_A(fs->f->code[list], level);
186 list = next;
187 }
188 }
189
190
luaK_patchtohere(FuncState * fs,int list)191 void luaK_patchtohere (FuncState *fs, int list) {
192 luaK_getlabel(fs);
193 luaK_concat(fs, &fs->jpc, list);
194 }
195
196
luaK_concat(FuncState * fs,int * l1,int l2)197 void luaK_concat (FuncState *fs, int *l1, int l2) {
198 if (l2 == NO_JUMP) return;
199 else if (*l1 == NO_JUMP)
200 *l1 = l2;
201 else {
202 int list = *l1;
203 int next;
204 while ((next = getjump(fs, list)) != NO_JUMP) /* find last element */
205 list = next;
206 fixjump(fs, list, l2);
207 }
208 }
209
210
luaK_code(FuncState * fs,Instruction i)211 static int luaK_code (FuncState *fs, Instruction i) {
212 Proto *f = fs->f;
213 dischargejpc(fs); /* `pc' will change */
214 /* put new instruction in code array */
215 luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction,
216 MAX_INT, "opcodes");
217 f->code[fs->pc] = i;
218 /* save corresponding line information */
219 luaM_growvector(fs->ls->L, f->lineinfo, fs->pc, f->sizelineinfo, int,
220 MAX_INT, "opcodes");
221 f->lineinfo[fs->pc] = fs->ls->lastline;
222 return fs->pc++;
223 }
224
225
luaK_codeABC(FuncState * fs,OpCode o,int a,int b,int c)226 int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) {
227 lua_assert(getOpMode(o) == iABC);
228 lua_assert(getBMode(o) != OpArgN || b == 0);
229 lua_assert(getCMode(o) != OpArgN || c == 0);
230 lua_assert(a <= MAXARG_A && b <= MAXARG_B && c <= MAXARG_C);
231 return luaK_code(fs, CREATE_ABC(o, a, b, c));
232 }
233
234
luaK_codeABx(FuncState * fs,OpCode o,int a,unsigned int bc)235 int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) {
236 lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx);
237 lua_assert(getCMode(o) == OpArgN);
238 lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx);
239 return luaK_code(fs, CREATE_ABx(o, a, bc));
240 }
241
242
codeextraarg(FuncState * fs,int a)243 static int codeextraarg (FuncState *fs, int a) {
244 lua_assert(a <= MAXARG_Ax);
245 return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a));
246 }
247
248
luaK_codek(FuncState * fs,int reg,int k)249 int luaK_codek (FuncState *fs, int reg, int k) {
250 if (k <= MAXARG_Bx)
251 return luaK_codeABx(fs, OP_LOADK, reg, k);
252 else {
253 int p = luaK_codeABx(fs, OP_LOADKX, reg, 0);
254 codeextraarg(fs, k);
255 return p;
256 }
257 }
258
259
luaK_checkstack(FuncState * fs,int n)260 void luaK_checkstack (FuncState *fs, int n) {
261 int newstack = fs->freereg + n;
262 if (newstack > fs->f->maxstacksize) {
263 if (newstack >= MAXSTACK)
264 luaX_syntaxerror(fs->ls, "function or expression too complex");
265 fs->f->maxstacksize = cast_byte(newstack);
266 }
267 }
268
269
luaK_reserveregs(FuncState * fs,int n)270 void luaK_reserveregs (FuncState *fs, int n) {
271 luaK_checkstack(fs, n);
272 fs->freereg += n;
273 }
274
275
freereg(FuncState * fs,int reg)276 static void freereg (FuncState *fs, int reg) {
277 if (!ISK(reg) && reg >= fs->nactvar) {
278 fs->freereg--;
279 lua_assert(reg == fs->freereg);
280 }
281 }
282
283
freeexp(FuncState * fs,expdesc * e)284 static void freeexp (FuncState *fs, expdesc *e) {
285 if (e->k == VNONRELOC)
286 freereg(fs, e->u.info);
287 }
288
289
addk(FuncState * fs,TValue * key,TValue * v)290 static int addk (FuncState *fs, TValue *key, TValue *v) {
291 lua_State *L = fs->ls->L;
292 TValue *idx = luaH_set(L, fs->h, key);
293 Proto *f = fs->f;
294 int k, oldsize;
295 if (ttisnumber(idx)) {
296 lua_Number n = nvalue(idx);
297 lua_number2int(k, n);
298 if (luaV_rawequalobj(&f->k[k], v))
299 return k;
300 /* else may be a collision (e.g., between 0.0 and "\0\0\0\0\0\0\0\0");
301 go through and create a new entry for this value */
302 }
303 /* constant not found; create a new entry */
304 oldsize = f->sizek;
305 k = fs->nk;
306 /* numerical value does not need GC barrier;
307 table has no metatable, so it does not need to invalidate cache */
308 setnvalue(idx, cast_num(k));
309 luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants");
310 while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]);
311 setobj(L, &f->k[k], v);
312 fs->nk++;
313 luaC_barrier(L, f, v);
314 return k;
315 }
316
317
luaK_stringK(FuncState * fs,TString * s)318 int luaK_stringK (FuncState *fs, TString *s) {
319 TValue o;
320 setsvalue(fs->ls->L, &o, s);
321 return addk(fs, &o, &o);
322 }
323
324
luaK_numberK(FuncState * fs,lua_Number r)325 int luaK_numberK (FuncState *fs, lua_Number r) {
326 int n;
327 lua_State *L = fs->ls->L;
328 TValue o;
329 setnvalue(&o, r);
330 if (r == 0 || luai_numisnan(NULL, r)) { /* handle -0 and NaN */
331 /* use raw representation as key to avoid numeric problems */
332 setsvalue(L, L->top++, luaS_newlstr(L, (char *)&r, sizeof(r)));
333 n = addk(fs, L->top - 1, &o);
334 L->top--;
335 }
336 else
337 n = addk(fs, &o, &o); /* regular case */
338 return n;
339 }
340
341
boolK(FuncState * fs,int b)342 static int boolK (FuncState *fs, int b) {
343 TValue o;
344 setbvalue(&o, b);
345 return addk(fs, &o, &o);
346 }
347
348
nilK(FuncState * fs)349 static int nilK (FuncState *fs) {
350 TValue k, v;
351 setnilvalue(&v);
352 /* cannot use nil as key; instead use table itself to represent nil */
353 sethvalue(fs->ls->L, &k, fs->h);
354 return addk(fs, &k, &v);
355 }
356
357
luaK_setreturns(FuncState * fs,expdesc * e,int nresults)358 void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) {
359 if (e->k == VCALL) { /* expression is an open function call? */
360 SETARG_C(getcode(fs, e), nresults+1);
361 }
362 else if (e->k == VVARARG) {
363 SETARG_B(getcode(fs, e), nresults+1);
364 SETARG_A(getcode(fs, e), fs->freereg);
365 luaK_reserveregs(fs, 1);
366 }
367 }
368
369
luaK_setoneret(FuncState * fs,expdesc * e)370 void luaK_setoneret (FuncState *fs, expdesc *e) {
371 if (e->k == VCALL) { /* expression is an open function call? */
372 e->k = VNONRELOC;
373 e->u.info = GETARG_A(getcode(fs, e));
374 }
375 else if (e->k == VVARARG) {
376 SETARG_B(getcode(fs, e), 2);
377 e->k = VRELOCABLE; /* can relocate its simple result */
378 }
379 }
380
381
luaK_dischargevars(FuncState * fs,expdesc * e)382 void luaK_dischargevars (FuncState *fs, expdesc *e) {
383 switch (e->k) {
384 case VLOCAL: {
385 e->k = VNONRELOC;
386 break;
387 }
388 case VUPVAL: {
389 e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0);
390 e->k = VRELOCABLE;
391 break;
392 }
393 case VINDEXED: {
394 OpCode op = OP_GETTABUP; /* assume 't' is in an upvalue */
395 freereg(fs, e->u.ind.idx);
396 if (e->u.ind.vt == VLOCAL) { /* 't' is in a register? */
397 freereg(fs, e->u.ind.t);
398 op = OP_GETTABLE;
399 }
400 e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx);
401 e->k = VRELOCABLE;
402 break;
403 }
404 case VVARARG:
405 case VCALL: {
406 luaK_setoneret(fs, e);
407 break;
408 }
409 default: break; /* there is one value available (somewhere) */
410 }
411 }
412
413
code_label(FuncState * fs,int A,int b,int jump)414 static int code_label (FuncState *fs, int A, int b, int jump) {
415 luaK_getlabel(fs); /* those instructions may be jump targets */
416 return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump);
417 }
418
419
discharge2reg(FuncState * fs,expdesc * e,int reg)420 static void discharge2reg (FuncState *fs, expdesc *e, int reg) {
421 luaK_dischargevars(fs, e);
422 switch (e->k) {
423 case VNIL: {
424 luaK_nil(fs, reg, 1);
425 break;
426 }
427 case VFALSE: case VTRUE: {
428 luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0);
429 break;
430 }
431 case VK: {
432 luaK_codek(fs, reg, e->u.info);
433 break;
434 }
435 case VKNUM: {
436 luaK_codek(fs, reg, luaK_numberK(fs, e->u.nval));
437 break;
438 }
439 case VRELOCABLE: {
440 Instruction *pc = &getcode(fs, e);
441 SETARG_A(*pc, reg);
442 break;
443 }
444 case VNONRELOC: {
445 if (reg != e->u.info)
446 luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0);
447 break;
448 }
449 default: {
450 lua_assert(e->k == VVOID || e->k == VJMP);
451 return; /* nothing to do... */
452 }
453 }
454 e->u.info = reg;
455 e->k = VNONRELOC;
456 }
457
458
discharge2anyreg(FuncState * fs,expdesc * e)459 static void discharge2anyreg (FuncState *fs, expdesc *e) {
460 if (e->k != VNONRELOC) {
461 luaK_reserveregs(fs, 1);
462 discharge2reg(fs, e, fs->freereg-1);
463 }
464 }
465
466
exp2reg(FuncState * fs,expdesc * e,int reg)467 static void exp2reg (FuncState *fs, expdesc *e, int reg) {
468 discharge2reg(fs, e, reg);
469 if (e->k == VJMP)
470 luaK_concat(fs, &e->t, e->u.info); /* put this jump in `t' list */
471 if (hasjumps(e)) {
472 int final; /* position after whole expression */
473 int p_f = NO_JUMP; /* position of an eventual LOAD false */
474 int p_t = NO_JUMP; /* position of an eventual LOAD true */
475 if (need_value(fs, e->t) || need_value(fs, e->f)) {
476 int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs);
477 p_f = code_label(fs, reg, 0, 1);
478 p_t = code_label(fs, reg, 1, 0);
479 luaK_patchtohere(fs, fj);
480 }
481 final = luaK_getlabel(fs);
482 patchlistaux(fs, e->f, final, reg, p_f);
483 patchlistaux(fs, e->t, final, reg, p_t);
484 }
485 e->f = e->t = NO_JUMP;
486 e->u.info = reg;
487 e->k = VNONRELOC;
488 }
489
490
luaK_exp2nextreg(FuncState * fs,expdesc * e)491 void luaK_exp2nextreg (FuncState *fs, expdesc *e) {
492 luaK_dischargevars(fs, e);
493 freeexp(fs, e);
494 luaK_reserveregs(fs, 1);
495 exp2reg(fs, e, fs->freereg - 1);
496 }
497
498
luaK_exp2anyreg(FuncState * fs,expdesc * e)499 int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
500 luaK_dischargevars(fs, e);
501 if (e->k == VNONRELOC) {
502 if (!hasjumps(e)) return e->u.info; /* exp is already in a register */
503 if (e->u.info >= fs->nactvar) { /* reg. is not a local? */
504 exp2reg(fs, e, e->u.info); /* put value on it */
505 return e->u.info;
506 }
507 }
508 luaK_exp2nextreg(fs, e); /* default */
509 return e->u.info;
510 }
511
512
luaK_exp2anyregup(FuncState * fs,expdesc * e)513 void luaK_exp2anyregup (FuncState *fs, expdesc *e) {
514 if (e->k != VUPVAL || hasjumps(e))
515 luaK_exp2anyreg(fs, e);
516 }
517
518
luaK_exp2val(FuncState * fs,expdesc * e)519 void luaK_exp2val (FuncState *fs, expdesc *e) {
520 if (hasjumps(e))
521 luaK_exp2anyreg(fs, e);
522 else
523 luaK_dischargevars(fs, e);
524 }
525
526
luaK_exp2RK(FuncState * fs,expdesc * e)527 int luaK_exp2RK (FuncState *fs, expdesc *e) {
528 luaK_exp2val(fs, e);
529 switch (e->k) {
530 case VTRUE:
531 case VFALSE:
532 case VNIL: {
533 if (fs->nk <= MAXINDEXRK) { /* constant fits in RK operand? */
534 e->u.info = (e->k == VNIL) ? nilK(fs) : boolK(fs, (e->k == VTRUE));
535 e->k = VK;
536 return RKASK(e->u.info);
537 }
538 else break;
539 }
540 case VKNUM: {
541 e->u.info = luaK_numberK(fs, e->u.nval);
542 e->k = VK;
543 /* go through */
544 }
545 case VK: {
546 if (e->u.info <= MAXINDEXRK) /* constant fits in argC? */
547 return RKASK(e->u.info);
548 else break;
549 }
550 default: break;
551 }
552 /* not a constant in the right range: put it in a register */
553 return luaK_exp2anyreg(fs, e);
554 }
555
556
luaK_storevar(FuncState * fs,expdesc * var,expdesc * ex)557 void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) {
558 switch (var->k) {
559 case VLOCAL: {
560 freeexp(fs, ex);
561 exp2reg(fs, ex, var->u.info);
562 return;
563 }
564 case VUPVAL: {
565 int e = luaK_exp2anyreg(fs, ex);
566 luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0);
567 break;
568 }
569 case VINDEXED: {
570 OpCode op = (var->u.ind.vt == VLOCAL) ? OP_SETTABLE : OP_SETTABUP;
571 int e = luaK_exp2RK(fs, ex);
572 luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e);
573 break;
574 }
575 default: {
576 lua_assert(0); /* invalid var kind to store */
577 break;
578 }
579 }
580 freeexp(fs, ex);
581 }
582
583
luaK_self(FuncState * fs,expdesc * e,expdesc * key)584 void luaK_self (FuncState *fs, expdesc *e, expdesc *key) {
585 int ereg;
586 luaK_exp2anyreg(fs, e);
587 ereg = e->u.info; /* register where 'e' was placed */
588 freeexp(fs, e);
589 e->u.info = fs->freereg; /* base register for op_self */
590 e->k = VNONRELOC;
591 luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */
592 luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key));
593 freeexp(fs, key);
594 }
595
596
invertjump(FuncState * fs,expdesc * e)597 static void invertjump (FuncState *fs, expdesc *e) {
598 Instruction *pc = getjumpcontrol(fs, e->u.info);
599 lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET &&
600 GET_OPCODE(*pc) != OP_TEST);
601 SETARG_A(*pc, !(GETARG_A(*pc)));
602 }
603
604
jumponcond(FuncState * fs,expdesc * e,int cond)605 static int jumponcond (FuncState *fs, expdesc *e, int cond) {
606 if (e->k == VRELOCABLE) {
607 Instruction ie = getcode(fs, e);
608 if (GET_OPCODE(ie) == OP_NOT) {
609 fs->pc--; /* remove previous OP_NOT */
610 return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond);
611 }
612 /* else go through */
613 }
614 discharge2anyreg(fs, e);
615 freeexp(fs, e);
616 return condjump(fs, OP_TESTSET, NO_REG, e->u.info, cond);
617 }
618
619
luaK_goiftrue(FuncState * fs,expdesc * e)620 void luaK_goiftrue (FuncState *fs, expdesc *e) {
621 int pc; /* pc of last jump */
622 luaK_dischargevars(fs, e);
623 switch (e->k) {
624 case VJMP: {
625 invertjump(fs, e);
626 pc = e->u.info;
627 break;
628 }
629 case VK: case VKNUM: case VTRUE: {
630 pc = NO_JUMP; /* always true; do nothing */
631 break;
632 }
633 default: {
634 pc = jumponcond(fs, e, 0);
635 break;
636 }
637 }
638 luaK_concat(fs, &e->f, pc); /* insert last jump in `f' list */
639 luaK_patchtohere(fs, e->t);
640 e->t = NO_JUMP;
641 }
642
643
luaK_goiffalse(FuncState * fs,expdesc * e)644 void luaK_goiffalse (FuncState *fs, expdesc *e) {
645 int pc; /* pc of last jump */
646 luaK_dischargevars(fs, e);
647 switch (e->k) {
648 case VJMP: {
649 pc = e->u.info;
650 break;
651 }
652 case VNIL: case VFALSE: {
653 pc = NO_JUMP; /* always false; do nothing */
654 break;
655 }
656 default: {
657 pc = jumponcond(fs, e, 1);
658 break;
659 }
660 }
661 luaK_concat(fs, &e->t, pc); /* insert last jump in `t' list */
662 luaK_patchtohere(fs, e->f);
663 e->f = NO_JUMP;
664 }
665
666
codenot(FuncState * fs,expdesc * e)667 static void codenot (FuncState *fs, expdesc *e) {
668 luaK_dischargevars(fs, e);
669 switch (e->k) {
670 case VNIL: case VFALSE: {
671 e->k = VTRUE;
672 break;
673 }
674 case VK: case VKNUM: case VTRUE: {
675 e->k = VFALSE;
676 break;
677 }
678 case VJMP: {
679 invertjump(fs, e);
680 break;
681 }
682 case VRELOCABLE:
683 case VNONRELOC: {
684 discharge2anyreg(fs, e);
685 freeexp(fs, e);
686 e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0);
687 e->k = VRELOCABLE;
688 break;
689 }
690 default: {
691 lua_assert(0); /* cannot happen */
692 break;
693 }
694 }
695 /* interchange true and false lists */
696 { int temp = e->f; e->f = e->t; e->t = temp; }
697 removevalues(fs, e->f);
698 removevalues(fs, e->t);
699 }
700
701
luaK_indexed(FuncState * fs,expdesc * t,expdesc * k)702 void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) {
703 lua_assert(!hasjumps(t));
704 t->u.ind.t = t->u.info;
705 t->u.ind.idx = luaK_exp2RK(fs, k);
706 t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL
707 : check_exp(vkisinreg(t->k), VLOCAL);
708 t->k = VINDEXED;
709 }
710
711
constfolding(OpCode op,expdesc * e1,expdesc * e2)712 static int constfolding (OpCode op, expdesc *e1, expdesc *e2) {
713 lua_Number r;
714 if (!isnumeral(e1) || !isnumeral(e2)) return 0;
715 if ((op == OP_DIV || op == OP_MOD) && e2->u.nval == 0)
716 return 0; /* do not attempt to divide by 0 */
717 /*
718 * Patched: check for MIN_INT / -1
719 */
720 if (op == OP_DIV && e1->u.nval == INT64_MIN && e2->u.nval == -1)
721 return 0;
722 r = luaO_arith(op - OP_ADD + LUA_OPADD, e1->u.nval, e2->u.nval);
723 e1->u.nval = r;
724 return 1;
725 }
726
727
codearith(FuncState * fs,OpCode op,expdesc * e1,expdesc * e2,int line)728 static void codearith (FuncState *fs, OpCode op,
729 expdesc *e1, expdesc *e2, int line) {
730 if (constfolding(op, e1, e2))
731 return;
732 else {
733 int o2 = (op != OP_UNM && op != OP_LEN) ? luaK_exp2RK(fs, e2) : 0;
734 int o1 = luaK_exp2RK(fs, e1);
735 if (o1 > o2) {
736 freeexp(fs, e1);
737 freeexp(fs, e2);
738 }
739 else {
740 freeexp(fs, e2);
741 freeexp(fs, e1);
742 }
743 e1->u.info = luaK_codeABC(fs, op, 0, o1, o2);
744 e1->k = VRELOCABLE;
745 luaK_fixline(fs, line);
746 }
747 }
748
749
codecomp(FuncState * fs,OpCode op,int cond,expdesc * e1,expdesc * e2)750 static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1,
751 expdesc *e2) {
752 int o1 = luaK_exp2RK(fs, e1);
753 int o2 = luaK_exp2RK(fs, e2);
754 freeexp(fs, e2);
755 freeexp(fs, e1);
756 if (cond == 0 && op != OP_EQ) {
757 int temp; /* exchange args to replace by `<' or `<=' */
758 temp = o1; o1 = o2; o2 = temp; /* o1 <==> o2 */
759 cond = 1;
760 }
761 e1->u.info = condjump(fs, op, cond, o1, o2);
762 e1->k = VJMP;
763 }
764
765
luaK_prefix(FuncState * fs,UnOpr op,expdesc * e,int line)766 void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) {
767 expdesc e2;
768 e2.t = e2.f = NO_JUMP; e2.k = VKNUM; e2.u.nval = 0;
769 switch (op) {
770 case OPR_MINUS: {
771 if (isnumeral(e)) /* minus constant? */
772 e->u.nval = luai_numunm(NULL, e->u.nval); /* fold it */
773 else {
774 luaK_exp2anyreg(fs, e);
775 codearith(fs, OP_UNM, e, &e2, line);
776 }
777 break;
778 }
779 case OPR_NOT: codenot(fs, e); break;
780 case OPR_LEN: {
781 luaK_exp2anyreg(fs, e); /* cannot operate on constants */
782 codearith(fs, OP_LEN, e, &e2, line);
783 break;
784 }
785 default: lua_assert(0);
786 }
787 }
788
789
luaK_infix(FuncState * fs,BinOpr op,expdesc * v)790 void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) {
791 switch (op) {
792 case OPR_AND: {
793 luaK_goiftrue(fs, v);
794 break;
795 }
796 case OPR_OR: {
797 luaK_goiffalse(fs, v);
798 break;
799 }
800 case OPR_CONCAT: {
801 luaK_exp2nextreg(fs, v); /* operand must be on the `stack' */
802 break;
803 }
804 case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
805 case OPR_MOD: case OPR_POW: {
806 if (!isnumeral(v)) luaK_exp2RK(fs, v);
807 break;
808 }
809 default: {
810 luaK_exp2RK(fs, v);
811 break;
812 }
813 }
814 }
815
816
luaK_posfix(FuncState * fs,BinOpr op,expdesc * e1,expdesc * e2,int line)817 void luaK_posfix (FuncState *fs, BinOpr op,
818 expdesc *e1, expdesc *e2, int line) {
819 switch (op) {
820 case OPR_AND: {
821 lua_assert(e1->t == NO_JUMP); /* list must be closed */
822 luaK_dischargevars(fs, e2);
823 luaK_concat(fs, &e2->f, e1->f);
824 *e1 = *e2;
825 break;
826 }
827 case OPR_OR: {
828 lua_assert(e1->f == NO_JUMP); /* list must be closed */
829 luaK_dischargevars(fs, e2);
830 luaK_concat(fs, &e2->t, e1->t);
831 *e1 = *e2;
832 break;
833 }
834 case OPR_CONCAT: {
835 luaK_exp2val(fs, e2);
836 if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) {
837 lua_assert(e1->u.info == GETARG_B(getcode(fs, e2))-1);
838 freeexp(fs, e1);
839 SETARG_B(getcode(fs, e2), e1->u.info);
840 e1->k = VRELOCABLE; e1->u.info = e2->u.info;
841 }
842 else {
843 luaK_exp2nextreg(fs, e2); /* operand must be on the 'stack' */
844 codearith(fs, OP_CONCAT, e1, e2, line);
845 }
846 break;
847 }
848 case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV:
849 case OPR_MOD: case OPR_POW: {
850 codearith(fs, cast(OpCode, op - OPR_ADD + OP_ADD), e1, e2, line);
851 break;
852 }
853 case OPR_EQ: case OPR_LT: case OPR_LE: {
854 codecomp(fs, cast(OpCode, op - OPR_EQ + OP_EQ), 1, e1, e2);
855 break;
856 }
857 case OPR_NE: case OPR_GT: case OPR_GE: {
858 codecomp(fs, cast(OpCode, op - OPR_NE + OP_EQ), 0, e1, e2);
859 break;
860 }
861 default: lua_assert(0);
862 }
863 }
864
865
luaK_fixline(FuncState * fs,int line)866 void luaK_fixline (FuncState *fs, int line) {
867 fs->f->lineinfo[fs->pc - 1] = line;
868 }
869
870
luaK_setlist(FuncState * fs,int base,int nelems,int tostore)871 void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) {
872 int c = (nelems - 1)/LFIELDS_PER_FLUSH + 1;
873 int b = (tostore == LUA_MULTRET) ? 0 : tostore;
874 lua_assert(tostore != 0);
875 if (c <= MAXARG_C)
876 luaK_codeABC(fs, OP_SETLIST, base, b, c);
877 else if (c <= MAXARG_Ax) {
878 luaK_codeABC(fs, OP_SETLIST, base, b, 0);
879 codeextraarg(fs, c);
880 }
881 else
882 luaX_syntaxerror(fs->ls, "constructor too long");
883 fs->freereg = base + 1; /* free registers with list values */
884 }
885
886