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1/*
2** Lua parser (source code -> bytecode).
3** Copyright (C) 2005-2009 Mike Pall. See Copyright Notice in luajit.h
4**
5** Major portions taken verbatim or adapted from the Lua interpreter.
6** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
7*/
8
9#define lj_parse_c
10#define LUA_CORE
11
12#include "lj_obj.h"
13#include "lj_gc.h"
14#include "lj_err.h"
15#include "lj_str.h"
16#include "lj_tab.h"
17#include "lj_func.h"
18#include "lj_state.h"
19#include "lj_bc.h"
20#include "lj_lex.h"
21#include "lj_parse.h"
22#include "lj_vm.h"
23#include "lj_vmevent.h"
24
25/* -- Parser structures and definitions ----------------------------------- */
26
27/* Expression kinds. */
28typedef enum {
29 /* Constant expressions must be first and in this order: */
30 VKNIL,
31 VKFALSE,
32 VKTRUE,
33 VKSTR, /* sval = string value */
34 VKNUM, /* nval = numerical value */
35 VKLAST = VKNUM,
36 /* Non-constant expressions follow: */
37 VLOCAL, /* info = local register */
38 VUPVAL, /* info = upvalue index */
39 VGLOBAL, /* sval = string value */
40 VINDEXED, /* info = table register, aux = index reg/byte/string const */
41 VJMP, /* info = instruction PC */
42 VRELOCABLE, /* info = instruction PC */
43 VNONRELOC, /* info = result register */
44 VCALL, /* info = instruction PC, aux = base */
45 VVOID
46} ExpKind;
47
48/* Expression descriptor. */
49typedef struct ExpDesc {
50 union {
51 struct { uint32_t info, aux; } s;
52 TValue nval;
53 GCstr *sval;
54 } u;
55 ExpKind k;
56 BCPos t; /* true condition exit list */
57 BCPos f; /* false condition exit list */
58} ExpDesc;
59
60/* Tests for expression types */
61#define isK(e) ((uint32_t)((e)->k) <= VKLAST)
62#define isnumK(e) ((e)->k == VKNUM)
63#define isstrK(e) ((e)->k == VKSTR)
64#define expnumV(e) check_exp(isnumK((e)), numV(&(e)->u.nval))
65
66#define hasjumps(e) ((e)->t != (e)->f)
67#define isKexp(e) (isK(e) && !hasjumps(e))
68#define isnumKexp(e) (isnumK(e) && !hasjumps(e))
69
70#define priKk(k) check_exp((k) <= VKTRUE, (k) - VKNIL)
71#define priK(e) priKk((e)->k)
72
73/* Per-function linked list of blocks. */
74typedef struct FuncBlock {
75 struct FuncBlock *previous; /* chain */
76 BCPos breaklist; /* list of jumps out of this loop */
77 uint8_t nactvar; /* # active locals outside the breakable structure */
78 uint8_t upval; /* true if some variable in the block is an upvalue */
79 uint8_t isbreakable; /* true if `block' is a loop */
80} FuncBlock;
81
82typedef struct UpValDesc {
83 uint8_t k;
84 uint8_t info;
85} UpValDesc;
86
87/* Per-function state. */
88typedef struct FuncState {
89 GCproto *pt; /* current function header */
90 GCtab *kt; /* table to find (and reuse) elements in `k' */
91 struct FuncState *prev; /* enclosing function */
92 struct LexState *ls; /* lexical state */
93 struct lua_State *L; /* copy of the Lua state */
94 struct FuncBlock *bl; /* chain of current blocks */
95 BCPos pc; /* next bytecode position */
96 BCPos lasttarget; /* PC of last jump target */
97 BCPos jpc; /* list of pending jumps to PC */
98 BCReg freereg; /* first free register */
99 BCReg nkn, nkgc; /* number of lua_Number/GCobj constants */
100 uint16_t nlocvars; /* number of elements in `locvars' */
101 uint8_t nactvar; /* number of active local variables */
102 uint8_t nuv; /* number of upvalues */
103 UpValDesc upvalues[LJ_MAX_UPVAL]; /* upvalues */
104 uint16_t actvar[LJ_MAX_LOCVAR]; /* declared-variable stack */
105} FuncState;
106
107/* Binary and unary operators. ORDER OPR */
108typedef enum BinOpr {
109 OPR_ADD, OPR_SUB, OPR_MUL, OPR_DIV, OPR_MOD, OPR_POW, /* ORDER ARITH */
110 OPR_CONCAT,
111 OPR_NE, OPR_EQ,
112 OPR_LT, OPR_GE, OPR_LE, OPR_GT,
113 OPR_AND, OPR_OR,
114 OPR_NOBINOPR
115} BinOpr;
116
117LJ_STATIC_ASSERT((int)BC_ISGE-(int)BC_ISLT == (int)OPR_GE-(int)OPR_LT);
118LJ_STATIC_ASSERT((int)BC_ISLE-(int)BC_ISLT == (int)OPR_LE-(int)OPR_LT);
119LJ_STATIC_ASSERT((int)BC_ISGT-(int)BC_ISLT == (int)OPR_GT-(int)OPR_LT);
120LJ_STATIC_ASSERT((int)BC_SUBVV-(int)BC_ADDVV == (int)OPR_SUB-(int)OPR_ADD);
121LJ_STATIC_ASSERT((int)BC_MULVV-(int)BC_ADDVV == (int)OPR_MUL-(int)OPR_ADD);
122LJ_STATIC_ASSERT((int)BC_DIVVV-(int)BC_ADDVV == (int)OPR_DIV-(int)OPR_ADD);
123LJ_STATIC_ASSERT((int)BC_MODVV-(int)BC_ADDVV == (int)OPR_MOD-(int)OPR_ADD);
124
125typedef enum UnOpr { OPR_MINUS, OPR_NOT, OPR_LEN, OPR_NOUNOPR } UnOpr;
126
127/* -- Error handling ------------------------------------------------------ */
128
129LJ_NORET LJ_NOINLINE static void err_syntax(LexState *ls, ErrMsg em)
130{
131 lj_lex_error(ls, ls->token, em);
132}
133
134LJ_NORET LJ_NOINLINE static void err_token(LexState *ls, LexToken token)
135{
136 lj_lex_error(ls, ls->token, LJ_ERR_XTOKEN, lj_lex_token2str(ls, token));
137}
138
139LJ_NORET static void err_limit(FuncState *fs, uint32_t limit, const char *what)
140{
141 if (fs->pt->linedefined == 0)
142 lj_lex_error(fs->ls, 0, LJ_ERR_XLIMM, limit, what);
143 else
144 lj_lex_error(fs->ls, 0, LJ_ERR_XLIMF, fs->pt->linedefined, limit, what);
145}
146
147#define checklimit(fs, v, l, m) if ((v) >= (l)) err_limit(fs, l, m)
148#define checklimitgt(fs, v, l, m) if ((v) > (l)) err_limit(fs, l, m)
149#define checkcond(ls, c, em) { if (!(c)) err_syntax(ls, em); }
150
151/* -- Code emitter: branches ---------------------------------------------- */
152
153static BCPos getjump(FuncState *fs, BCPos pc)
154{
155 ptrdiff_t delta = bc_j(fs->pt->bc[pc]);
156 if ((BCPos)delta == NO_JMP)
157 return NO_JMP;
158 else
159 return (BCPos)(((ptrdiff_t)pc+1)+delta);
160}
161
162static int need_value(FuncState *fs, BCPos list)
163{
164 for (; list != NO_JMP; list = getjump(fs, list)) {
165 BCOp op = bc_op(fs->pt->bc[list >= 1 ? list-1 : list]);
166 if (!(op == BC_ISTC || op == BC_ISFC)) return 1;
167 }
168 return 0; /* Not found. */
169}
170
171static int patchtestreg(FuncState *fs, BCPos pc, BCReg reg)
172{
173 BCIns *i = &fs->pt->bc[pc >= 1 ? pc-1 : pc];
174 BCOp op = bc_op(*i);
175 if (!(op == BC_ISTC || op == BC_ISFC))
176 return 0; /* cannot patch other instructions */
177 if (reg != NO_REG && reg != bc_d(*i)) {
178 setbc_a(i, reg);
179 } else { /* no register to put value or register already has the value */
180 setbc_op(i, op+(BC_IST-BC_ISTC));
181 setbc_a(i, 0);
182 }
183 return 1;
184}
185
186static void removevalues(FuncState *fs, BCPos list)
187{
188 for (; list != NO_JMP; list = getjump(fs, list))
189 patchtestreg(fs, list, NO_REG);
190}
191
192static void fixjump(FuncState *fs, BCPos pc, BCPos dest)
193{
194 BCIns *jmp = &fs->pt->bc[pc];
195 BCPos offset = dest-(pc+1)+BCBIAS_J;
196 lua_assert(dest != NO_JMP);
197 if (offset > BCMAX_D)
198 err_syntax(fs->ls, LJ_ERR_XJUMP);
199 setbc_d(jmp, offset);
200}
201
202static void concatjumps(FuncState *fs, BCPos *l1, BCPos l2)
203{
204 if (l2 == NO_JMP) return;
205 else if (*l1 == NO_JMP) {
206 *l1 = l2;
207 } else {
208 BCPos list = *l1;
209 BCPos next;
210 while ((next = getjump(fs, list)) != NO_JMP) /* find last element */
211 list = next;
212 fixjump(fs, list, l2);
213 }
214}
215
216static void patchlistaux(FuncState *fs, BCPos list, BCPos vtarget,
217 BCReg reg, BCPos dtarget)
218{
219 while (list != NO_JMP) {
220 BCPos next = getjump(fs, list);
221 if (patchtestreg(fs, list, reg))
222 fixjump(fs, list, vtarget);
223 else
224 fixjump(fs, list, dtarget); /* jump to default target */
225 list = next;
226 }
227}
228
229static void patchtohere(FuncState *fs, BCPos list)
230{
231 fs->lasttarget = fs->pc;
232 concatjumps(fs, &fs->jpc, list);
233}
234
235static void patchlist(FuncState *fs, BCPos list, BCPos target)
236{
237 if (target == fs->pc) {
238 patchtohere(fs, list);
239 } else {
240 lua_assert(target < fs->pc);
241 patchlistaux(fs, list, target, NO_REG, target);
242 }
243}
244
245/* -- Code emitter: instructions ------------------------------------------ */
246
247static BCPos emitINS(FuncState *fs, BCIns i)
248{
249 GCproto *pt;
250 patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc);
251 fs->jpc = NO_JMP;
252 pt = fs->pt;
253 if (LJ_UNLIKELY(fs->pc >= pt->sizebc)) {
254 checklimit(fs, fs->pc, LJ_MAX_BCINS, "bytecode instructions");
255 lj_mem_growvec(fs->L, pt->bc, pt->sizebc, LJ_MAX_BCINS, BCIns);
256 lj_mem_growvec(fs->L, pt->lineinfo, pt->sizelineinfo, LJ_MAX_BCINS, BCLine);
257 }
258 pt->bc[fs->pc] = i;
259 pt->lineinfo[fs->pc] = fs->ls->lastline;
260 return fs->pc++;
261}
262
263#define emitABC(fs, o, a, b, c) emitINS(fs, BCINS_ABC(o, a, b, c))
264#define emitAD(fs, o, a, d) emitINS(fs, BCINS_AD(o, a, d))
265#define emitAJ(fs, o, a, j) emitINS(fs, BCINS_AJ(o, a, j))
266
267#define bcptr(fs, e) (&(fs)->pt->bc[(e)->u.s.info])
268
269static BCPos emit_jump(FuncState *fs)
270{
271 BCPos jpc = fs->jpc; /* save list of jumps to here */
272 BCPos j = fs->pc - 1;
273 fs->jpc = NO_JMP;
274 if ((int32_t)j >= (int32_t)fs->lasttarget && bc_op(fs->pt->bc[j]) == BC_UCLO)
275 setbc_j(&fs->pt->bc[j], NO_JMP);
276 else
277 j = emitAJ(fs, BC_JMP, fs->freereg, NO_JMP);
278 concatjumps(fs, &j, jpc); /* keep them on hold */
279 return j;
280}
281
282/* -- Code emitter: constants --------------------------------------------- */
283
284static BCReg numK(FuncState *fs, ExpDesc *e)
285{
286 lua_State *L = fs->L;
287 TValue *val;
288 lua_assert(isnumK(e));
289 val = lj_tab_set(L, fs->kt, &e->u.nval);
290 if (tvisnum(val))
291 return val->u32.lo;
292 val->u64 = fs->nkn;
293 return fs->nkn++;
294}
295
296static BCReg gcK(FuncState *fs, GCobj *gc, int itype)
297{
298 lua_State *L = fs->L;
299 TValue o, *val;
300 setgcV(L, &o, &gc->gch, itype);
301 val = lj_tab_set(L, fs->kt, &o);
302 if (tvisnum(val))
303 return val->u32.lo;
304 val->u64 = fs->nkgc;
305 return fs->nkgc++;
306}
307
308static BCReg strK(FuncState *fs, ExpDesc *e)
309{
310 lua_assert(isstrK(e) || e->k == VGLOBAL);
311 return gcK(fs, obj2gco(e->u.sval), LJ_TSTR);
312}
313
314GCstr *lj_parse_keepstr(LexState *ls, const char *str, size_t len)
315{
316 lua_State *L = ls->L;
317 GCstr *s = lj_str_new(L, str, len);
318 TValue *tv = lj_tab_setstr(L, ls->fs->kt, s);
319 if (tvisnil(tv)) setboolV(tv, 1); /* Anchor string to avoid GC. */
320 return s;
321}
322
323static void keep_token(LexState *ls)
324{
325 if (ls->token == TK_name || ls->token == TK_string) {
326 TValue *tv = lj_tab_setstr(ls->L, ls->fs->kt, strV(&ls->tokenval));
327 if (tvisnil(tv)) setboolV(tv, 1); /* Anchor string to avoid GC. */
328 }
329}
330
331static void nilK(FuncState *fs, BCReg from, BCReg n)
332{
333 BCIns *pr;
334 if (fs->pc > fs->lasttarget) { /* no jumps to current position? */
335 BCReg pfrom, pto;
336 pr = &fs->pt->bc[fs->pc-1];
337 pfrom = bc_a(*pr);
338 switch (bc_op(*pr)) {
339 case BC_KPRI:
340 if (bc_d(*pr) != ~LJ_TNIL) break;
341 if (from == pfrom) {
342 if (n == 1) return;
343 } else if (from == pfrom+1) {
344 from = pfrom;
345 n++;
346 } else {
347 break;
348 }
349 fs->pc--;
350 break;
351 case BC_KNIL:
352 pto = bc_d(*pr);
353 if (pfrom <= from && from <= pto+1) { /* can connect both? */
354 if (from+n-1 > pto)
355 setbc_d(pr, from+n-1);
356 return;
357 }
358 break;
359 default:
360 break;
361 }
362 }
363 emitINS(fs, n == 1 ? BCINS_AD(BC_KPRI, from, priKk(VKNIL))
364 : BCINS_AD(BC_KNIL, from, from+n-1));
365}
366
367/* -- Code emitter: registers --------------------------------------------- */
368
369static void checkframe(FuncState *fs, BCReg n)
370{
371 BCReg sz = fs->freereg + n;
372 if (sz > fs->pt->framesize) {
373 if (sz >= LJ_MAX_SLOTS)
374 err_syntax(fs->ls, LJ_ERR_XSLOTS);
375 fs->pt->framesize = cast_byte(sz);
376 }
377}
378
379static void reserveregs(FuncState *fs, BCReg n)
380{
381 checkframe(fs, n);
382 fs->freereg += n;
383}
384
385static void freereg(FuncState *fs, BCReg reg)
386{
387 if (reg >= fs->nactvar) {
388 fs->freereg--;
389 lua_assert(reg == fs->freereg);
390 }
391}
392
393static void freeexp(FuncState *fs, ExpDesc *e)
394{
395 if (e->k == VNONRELOC)
396 freereg(fs, e->u.s.info);
397}
398
399/* -- Code emitter: expressions ------------------------------------------- */
400
401static void dischargevars(FuncState *fs, ExpDesc *e)
402{
403 BCIns ins;
404 switch (e->k) {
405 case VUPVAL:
406 ins = BCINS_AD(BC_UGET, 0, e->u.s.info);
407 break;
408 case VGLOBAL:
409 ins = BCINS_AD(BC_GGET, 0, strK(fs, e));
410 break;
411 case VINDEXED: {
412 /* TGET[VSB] key = reg, string const or byte const */
413 BCReg rc = e->u.s.aux;
414 if ((int32_t)rc < 0) {
415 ins = BCINS_ABC(BC_TGETS, 0, e->u.s.info, ~rc);
416 } else if (rc > BCMAX_C) {
417 ins = BCINS_ABC(BC_TGETB, 0, e->u.s.info, rc-(BCMAX_C+1));
418 } else {
419 freereg(fs, rc);
420 ins = BCINS_ABC(BC_TGETV, 0, e->u.s.info, rc);
421 }
422 freereg(fs, e->u.s.info);
423 break;
424 }
425 case VCALL:
426 e->u.s.info = e->u.s.aux;
427 /* fallthrough */
428 case VLOCAL:
429 e->k = VNONRELOC;
430 /* fallthrough */
431 default:
432 return;
433 }
434 e->u.s.info = emitINS(fs, ins);
435 e->k = VRELOCABLE;
436}
437
438static void discharge2reg(FuncState *fs, ExpDesc *e, BCReg reg)
439{
440 BCIns ins;
441 dischargevars(fs, e);
442 switch (e->k) {
443 case VKNIL: case VKFALSE: case VKTRUE:
444 ins = BCINS_AD(BC_KPRI, reg, priK(e));
445 break;
446 case VKSTR:
447 ins = BCINS_AD(BC_KSTR, reg, strK(fs, e));
448 break;
449 case VKNUM: {
450 lua_Number n = expnumV(e);
451 int32_t k = lj_num2int(n);
452 if (checki16(k) && n == cast_num(k))
453 ins = BCINS_AD(BC_KSHORT, reg, (BCReg)(uint16_t)k);
454 else
455 ins = BCINS_AD(BC_KNUM, reg, numK(fs, e));
456 break;
457 }
458 case VRELOCABLE:
459 setbc_a(bcptr(fs, e), reg);
460 goto noins;
461 case VNONRELOC:
462 if (reg == e->u.s.info)
463 goto noins;
464 ins = BCINS_AD(BC_MOV, reg, e->u.s.info);
465 break;
466 default:
467 lua_assert(e->k == VVOID || e->k == VJMP);
468 return; /* nothing to do... */
469 }
470 emitINS(fs, ins);
471noins:
472 e->u.s.info = reg;
473 e->k = VNONRELOC;
474}
475
476static void exp2reg(FuncState *fs, ExpDesc *e, BCReg reg)
477{
478 discharge2reg(fs, e, reg);
479 if (e->k == VJMP)
480 concatjumps(fs, &e->t, e->u.s.info); /* put this jump in `t' list */
481 if (hasjumps(e)) {
482 BCPos final; /* position after whole expression */
483 BCPos p_f = NO_JMP; /* position of an eventual LOAD false */
484 BCPos p_t = NO_JMP; /* position of an eventual LOAD true */
485 if (need_value(fs, e->t) || need_value(fs, e->f)) {
486 BCPos fj = (e->k == VJMP) ? NO_JMP : emit_jump(fs);
487 p_f = emitAD(fs, BC_KPRI, reg, priKk(VKFALSE));
488 emitAJ(fs, BC_JMP, fs->freereg, 1);
489 p_t = emitAD(fs, BC_KPRI, reg, priKk(VKTRUE));
490 patchtohere(fs, fj);
491 }
492 final = fs->pc;
493 fs->lasttarget = final;
494 patchlistaux(fs, e->f, final, reg, p_f);
495 patchlistaux(fs, e->t, final, reg, p_t);
496 }
497 e->f = e->t = NO_JMP;
498 e->u.s.info = reg;
499 e->k = VNONRELOC;
500}
501
502static void exp2nextreg(FuncState *fs, ExpDesc *e)
503{
504 dischargevars(fs, e);
505 freeexp(fs, e);
506 reserveregs(fs, 1);
507 exp2reg(fs, e, fs->freereg - 1);
508}
509
510static BCReg exp2anyreg(FuncState *fs, ExpDesc *e)
511{
512 dischargevars(fs, e);
513 if (e->k == VNONRELOC) {
514 if (!hasjumps(e)) return e->u.s.info; /* exp is already in a register */
515 if (e->u.s.info >= fs->nactvar) { /* reg. is not a local? */
516 exp2reg(fs, e, e->u.s.info); /* put value on it */
517 return e->u.s.info;
518 }
519 }
520 exp2nextreg(fs, e); /* default */
521 return e->u.s.info;
522}
523
524static void exp2val(FuncState *fs, ExpDesc *e)
525{
526 if (hasjumps(e))
527 exp2anyreg(fs, e);
528 else
529 dischargevars(fs, e);
530}
531
532static void storevar(FuncState *fs, ExpDesc *var, ExpDesc *e)
533{
534 BCIns ins;
535 switch (var->k) {
536 case VLOCAL:
537 freeexp(fs, e);
538 exp2reg(fs, e, var->u.s.info);
539 return;
540 case VUPVAL:
541 exp2val(fs, e);
542 switch (e->k) {
543 case VKNIL: case VKFALSE: case VKTRUE:
544 ins = BCINS_AD(BC_USETP, var->u.s.info, priK(e));
545 break;
546 case VKSTR:
547 ins = BCINS_AD(BC_USETS, var->u.s.info, strK(fs, e));
548 break;
549 case VKNUM:
550 ins = BCINS_AD(BC_USETN, var->u.s.info, numK(fs, e));
551 break;
552 default:
553 ins = BCINS_AD(BC_USETV, var->u.s.info, exp2anyreg(fs, e));
554 break;
555 }
556 break;
557 case VGLOBAL: {
558 BCReg ra = exp2anyreg(fs, e);
559 ins = BCINS_AD(BC_GSET, ra, strK(fs, var));
560 break;
561 }
562 case VINDEXED: {
563 /* TSET[VSB] key = reg, string const or byte const */
564 BCReg ra = exp2anyreg(fs, e);
565 BCReg rc = var->u.s.aux;
566 if ((int32_t)rc < 0) {
567 ins = BCINS_ABC(BC_TSETS, ra, var->u.s.info, ~rc);
568 } else if (rc > BCMAX_C) {
569 ins = BCINS_ABC(BC_TSETB, ra, var->u.s.info, rc-(BCMAX_C+1));
570 } else {
571 /* Free late alloced key reg to avoid assert on free of value reg. */
572 /* This can only happen when called from constructor(). */
573 lua_assert(e->k != VNONRELOC || ra < fs->nactvar ||
574 rc < ra || (freereg(fs, rc),1));
575 ins = BCINS_ABC(BC_TSETV, ra, var->u.s.info, rc);
576 }
577 break;
578 }
579 default:
580 lua_assert(0); /* invalid var kind to store */
581 return;
582 }
583 emitINS(fs, ins);
584 freeexp(fs, e);
585}
586
587static void indexexp(FuncState *fs, ExpDesc *t, ExpDesc *e)
588{
589 /* already called: exp2val(fs, e) */
590 t->k = VINDEXED;
591 if (isnumK(e)) {
592 lua_Number n = expnumV(e);
593 int32_t k = lj_num2int(n);
594 if (checku8(k) && n == cast_num(k)) {
595 t->u.s.aux = BCMAX_C+1+(uint32_t)k; /* 256..511: const byte key */
596 return;
597 }
598 } else if (isstrK(e)) {
599 BCReg idx = strK(fs, e);
600 if (idx <= BCMAX_C) {
601 t->u.s.aux = ~idx; /* -256..-1: const string key */
602 return;
603 }
604 }
605 t->u.s.aux = exp2anyreg(fs, e); /* 0..255: register */
606}
607
608static void methodexp(FuncState *fs, ExpDesc *e, ExpDesc *key)
609{
610 BCReg idx, func, tab = exp2anyreg(fs, e);
611 freeexp(fs, e);
612 func = fs->freereg;
613 emitAD(fs, BC_MOV, func+1, tab);
614 lua_assert(isstrK(key));
615 idx = strK(fs, key);
616 if (idx <= BCMAX_C) {
617 reserveregs(fs, 2);
618 emitABC(fs, BC_TGETS, func, tab, idx);
619 } else {
620 reserveregs(fs, 3);
621 emitAD(fs, BC_KSTR, func+2, idx);
622 emitABC(fs, BC_TGETV, func, tab, func+2);
623 fs->freereg--;
624 }
625 e->u.s.info = func;
626 e->k = VNONRELOC;
627}
628
629/* -- Code emitter: conditionals ------------------------------------------ */
630
631static void invertjump(FuncState *fs, ExpDesc *e)
632{
633 BCIns *i = bcptr(fs, e) - 1;
634 setbc_op(i, bc_op(*i)^1);
635}
636
637static BCPos jumponcond(FuncState *fs, ExpDesc *e, int cond)
638{
639 if (e->k == VRELOCABLE) {
640 BCIns *i = bcptr(fs, e);
641 if (bc_op(*i) == BC_NOT) {
642 *i = BCINS_AD(cond ? BC_ISF : BC_IST, 0, bc_d(*i));
643 return emit_jump(fs);
644 }
645 /* else go through */
646 }
647 if (e->k != VNONRELOC) {
648 reserveregs(fs, 1);
649 discharge2reg(fs, e, fs->freereg-1);
650 }
651 freeexp(fs, e);
652 emitAD(fs, cond ? BC_ISTC : BC_ISFC, NO_REG, e->u.s.info);
653 return emit_jump(fs);
654}
655
656static void goiftrue(FuncState *fs, ExpDesc *e)
657{
658 BCPos pc; /* PC of last jump. */
659 dischargevars(fs, e);
660 switch (e->k) {
661 case VKSTR: case VKNUM: case VKTRUE:
662 pc = NO_JMP; /* always true; do nothing */
663 break;
664 case VJMP:
665 invertjump(fs, e);
666 pc = e->u.s.info;
667 break;
668 case VKFALSE:
669 if (!hasjumps(e)) {
670 pc = emit_jump(fs); /* always jump */
671 break;
672 }
673 /* fallthrough */
674 default:
675 pc = jumponcond(fs, e, 0);
676 break;
677 }
678 concatjumps(fs, &e->f, pc); /* insert last jump in `f' list */
679 patchtohere(fs, e->t);
680 e->t = NO_JMP;
681}
682
683static void goiffalse(FuncState *fs, ExpDesc *e)
684{
685 BCPos pc; /* PC of last jump. */
686 dischargevars(fs, e);
687 switch (e->k) {
688 case VKNIL: case VKFALSE:
689 pc = NO_JMP; /* always false; do nothing */
690 break;
691 case VJMP:
692 pc = e->u.s.info;
693 break;
694 case VKTRUE:
695 if (!hasjumps(e)) {
696 pc = emit_jump(fs); /* always jump */
697 break;
698 }
699 /* fallthrough */
700 default:
701 pc = jumponcond(fs, e, 1);
702 break;
703 }
704 concatjumps(fs, &e->t, pc); /* insert last jump in `t' list */
705 patchtohere(fs, e->f);
706 e->f = NO_JMP;
707}
708
709/* -- Code emitter: operators --------------------------------------------- */
710
711static int foldarith(BinOpr opr, ExpDesc *e1, ExpDesc *e2)
712{
713 TValue o;
714 if (!isnumKexp(e1) || !isnumKexp(e2)) return 0;
715 setnumV(&o, lj_vm_foldarith(expnumV(e1), expnumV(e2), (int)opr-OPR_ADD));
716 if (tvisnan(&o) || tvismzero(&o)) return 0; /* Avoid NaN and -0 as consts. */
717 setnumV(&e1->u.nval, numV(&o));
718 return 1;
719}
720
721static void codearith(FuncState *fs, BinOpr opr, ExpDesc *e1, ExpDesc *e2)
722{
723 BCReg rb, rc, t;
724 uint32_t op;
725 if (foldarith(opr, e1, e2))
726 return;
727 if (opr == OPR_POW) {
728 op = BC_POW;
729 rc = exp2anyreg(fs, e2);
730 rb = exp2anyreg(fs, e1);
731 } else {
732 op = opr-OPR_ADD+BC_ADDVV;
733 /* must discharge 2nd operand first since VINDEXED might free regs */
734 exp2val(fs, e2);
735 if (isnumK(e2) && (rc = numK(fs, e2)) <= BCMAX_C)
736 op -= BC_ADDVV-BC_ADDVN;
737 else
738 rc = exp2anyreg(fs, e2);
739 /* emit_prebinop discharges 1st operand, but may need to use KNUM/KSHORT */
740 lua_assert(isnumK(e1) || e1->k == VNONRELOC);
741 exp2val(fs, e1);
742 /* avoid two consts to satisfy bytecode constraints */
743 if (isnumK(e1) && !isnumK(e2) && (t = numK(fs, e1)) <= BCMAX_B) {
744 rb = rc; rc = t; op -= BC_ADDVV-BC_ADDNV;
745 } else {
746 rb = exp2anyreg(fs, e1);
747 }
748 }
749 /* using freeexp might cause asserts if the order is wrong */
750 if (e1->k == VNONRELOC && e1->u.s.info >= fs->nactvar) fs->freereg--;
751 if (e2->k == VNONRELOC && e2->u.s.info >= fs->nactvar) fs->freereg--;
752 e1->u.s.info = emitABC(fs, op, 0, rb, rc);
753 e1->k = VRELOCABLE;
754}
755
756static void codecomp(FuncState *fs, BinOpr opr, ExpDesc *e1, ExpDesc *e2)
757{
758 ExpDesc *eret = e1;
759 BCIns ins;
760 exp2val(fs, e1);
761 if (opr == OPR_EQ || opr == OPR_NE) {
762 BCOp op = opr == OPR_EQ ? BC_ISEQV : BC_ISNEV;
763 BCReg ra;
764 if (isK(e1)) { e1 = e2; e2 = eret; } /* need constant in 2nd arg */
765 ra = exp2anyreg(fs, e1); /* first arg must be in a reg */
766 exp2val(fs, e2);
767 switch (e2->k) {
768 case VKNIL: case VKFALSE: case VKTRUE:
769 ins = BCINS_AD(op+(BC_ISEQP-BC_ISEQV), ra, priK(e2));
770 break;
771 case VKSTR:
772 ins = BCINS_AD(op+(BC_ISEQS-BC_ISEQV), ra, strK(fs, e2));
773 break;
774 case VKNUM:
775 ins = BCINS_AD(op+(BC_ISEQN-BC_ISEQV), ra, numK(fs, e2));
776 break;
777 default:
778 ins = BCINS_AD(op, ra, exp2anyreg(fs, e2));
779 break;
780 }
781 } else {
782 uint32_t op = opr-OPR_LT+BC_ISLT;
783 BCReg ra;
784 if ((op-BC_ISLT) & 1) { /* GT -> LT, GE -> LE */
785 e1 = e2; e2 = eret; /* swap operands */
786 op = ((op-BC_ISLT)^3)+BC_ISLT;
787 }
788 ra = exp2anyreg(fs, e1);
789 ins = BCINS_AD(op, ra, exp2anyreg(fs, e2));
790 }
791 /* using freeexp might cause asserts if the order is wrong */
792 if (e1->k == VNONRELOC && e1->u.s.info >= fs->nactvar) fs->freereg--;
793 if (e2->k == VNONRELOC && e2->u.s.info >= fs->nactvar) fs->freereg--;
794 emitINS(fs, ins);
795 eret->u.s.info = emit_jump(fs);
796 eret->k = VJMP;
797}
798
799static void emit_unop(FuncState *fs, UnOpr uop, ExpDesc *e)
800{
801 BCOp op = BC_LEN;
802 switch (uop) {
803 case OPR_MINUS:
804 if (isnumKexp(e) && expnumV(e) != 0) { /* Avoid const-folding to -0. */
805 setnumV(&e->u.nval, -expnumV(e));
806 return;
807 }
808 op = BC_UNM;
809 /* fallthrough */
810 case OPR_LEN:
811 exp2anyreg(fs, e);
812 break;
813 case OPR_NOT:
814 /* interchange true and false lists */
815 { BCPos temp = e->f; e->f = e->t; e->t = temp; }
816 removevalues(fs, e->f);
817 removevalues(fs, e->t);
818 dischargevars(fs, e);
819 switch (e->k) {
820 case VKNIL: case VKFALSE:
821 e->k = VKTRUE;
822 return;
823 case VKSTR: case VKNUM: case VKTRUE:
824 e->k = VKFALSE;
825 return;
826 case VJMP:
827 invertjump(fs, e);
828 return;
829 case VRELOCABLE:
830 reserveregs(fs, 1);
831 setbc_a(bcptr(fs, e), fs->freereg-1);
832 e->u.s.info = fs->freereg-1;
833 e->k = VNONRELOC;
834 break;
835 case VNONRELOC:
836 break;
837 default: lua_assert(0); return;
838 }
839 op = BC_NOT;
840 break;
841 default: lua_assert(0); return;
842 }
843 freeexp(fs, e);
844 e->u.s.info = emitAD(fs, op, 0, e->u.s.info);
845 e->k = VRELOCABLE;
846}
847
848static void prepare_binop(FuncState *fs, BinOpr op, ExpDesc *e)
849{
850 switch (op) {
851 case OPR_AND:
852 goiftrue(fs, e);
853 break;
854 case OPR_OR:
855 goiffalse(fs, e);
856 break;
857 case OPR_CONCAT:
858 exp2nextreg(fs, e); /* operand must be on the `stack' */
859 break;
860 case OPR_EQ: case OPR_NE:
861 if (!isKexp(e)) exp2anyreg(fs, e);
862 break;
863 default:
864 if (!isnumKexp(e)) exp2anyreg(fs, e);
865 break;
866 }
867}
868
869static void emit_binop(FuncState *fs, BinOpr op, ExpDesc *e1, ExpDesc *e2)
870{
871 switch (op) {
872 case OPR_AND:
873 lua_assert(e1->t == NO_JMP); /* list must be closed */
874 dischargevars(fs, e2);
875 concatjumps(fs, &e2->f, e1->f);
876 *e1 = *e2;
877 break;
878 case OPR_OR:
879 lua_assert(e1->f == NO_JMP); /* list must be closed */
880 dischargevars(fs, e2);
881 concatjumps(fs, &e2->t, e1->t);
882 *e1 = *e2;
883 break;
884 case OPR_CONCAT:
885 exp2val(fs, e2);
886 if (e2->k == VRELOCABLE && bc_op(*bcptr(fs, e2)) == BC_CAT) {
887 lua_assert(e1->u.s.info == bc_b(*bcptr(fs, e2))-1);
888 freeexp(fs, e1);
889 setbc_b(bcptr(fs, e2), e1->u.s.info);
890 e1->u.s.info = e2->u.s.info;
891 } else {
892 exp2nextreg(fs, e2);
893 freeexp(fs, e2);
894 freeexp(fs, e1);
895 e1->u.s.info = emitABC(fs, BC_CAT, 0, e1->u.s.info, e2->u.s.info);
896 }
897 e1->k = VRELOCABLE;
898 break;
899 case OPR_ADD: case OPR_SUB: case OPR_MUL:
900 case OPR_DIV: case OPR_MOD: case OPR_POW:
901 codearith(fs, op, e1, e2);
902 break;
903 case OPR_EQ: case OPR_NE:
904 case OPR_LT: case OPR_LE: case OPR_GT: case OPR_GE:
905 codecomp(fs, op, e1, e2);
906 break;
907 default: lua_assert(0); break;
908 }
909}
910
911/* -- Lexer support ------------------------------------------------------- */
912
913static int testnext(LexState *ls, LexToken tok)
914{
915 if (ls->token == tok) {
916 lj_lex_next(ls);
917 return 1;
918 }
919 return 0;
920}
921
922static void checknext(LexState *ls, LexToken tok)
923{
924 if (ls->token != tok)
925 err_token(ls, tok);
926 lj_lex_next(ls);
927}
928
929static void checkmatch(LexState *ls, LexToken what, LexToken who, BCLine line)
930{
931 if (!testnext(ls, what)) {
932 if (line == ls->linenumber) {
933 err_token(ls, what);
934 } else {
935 const char *swhat = lj_lex_token2str(ls, what);
936 const char *swho = lj_lex_token2str(ls, who);
937 lj_lex_error(ls, ls->token, LJ_ERR_XMATCH, swhat, swho, line);
938 }
939 }
940}
941
942static GCstr *str_checkname(LexState *ls)
943{
944 GCstr *s;
945 if (ls->token != TK_name)
946 err_token(ls, TK_name);
947 s = strV(&ls->tokenval);
948 lj_lex_next(ls);
949 return s;
950}
951
952static void init_exp(ExpDesc *e, ExpKind k, uint32_t info)
953{
954 e->k = k;
955 e->u.s.info = info;
956 e->f = e->t = NO_JMP;
957}
958
959static void checkname(LexState *ls, ExpDesc *e)
960{
961 init_exp(e, VKSTR, 0);
962 e->u.sval = str_checkname(ls);
963}
964
965/* -- Variable handling --------------------------------------------------- */
966
967#define getlocvar(fs, i) ((fs)->pt->varinfo[(fs)->actvar[(i)]])
968
969static BCReg registerlocalvar(LexState *ls, GCstr *name)
970{
971 FuncState *fs = ls->fs;
972 GCproto *pt = fs->pt;
973 if (LJ_UNLIKELY(fs->nlocvars >= pt->sizevarinfo)) {
974 MSize oldsize = pt->sizevarinfo;
975 checklimit(fs, fs->nlocvars, 32767, "local variables");
976 lj_mem_growvec(fs->L, pt->varinfo, pt->sizevarinfo, 32767, VarInfo);
977 while (oldsize < pt->sizevarinfo) pt->varinfo[oldsize++].name = NULL;
978 }
979 pt->varinfo[fs->nlocvars].name = name;
980 lj_gc_objbarrier(ls->L, pt, name);
981 return fs->nlocvars++;
982}
983
984static void new_localvar(LexState *ls, GCstr *name, BCReg n)
985{
986 FuncState *fs = ls->fs;
987 checklimit(fs, fs->nactvar+n, LJ_MAX_LOCVAR, "local variables");
988 fs->actvar[fs->nactvar+n] = cast(uint16_t, registerlocalvar(ls, name));
989}
990
991#define new_localvarliteral(ls,v,n) \
992 new_localvar(ls, lj_parse_keepstr(ls, "" v, sizeof(v)-1), n)
993
994static void adjustlocalvars(LexState *ls, BCReg nvars)
995{
996 FuncState *fs = ls->fs;
997 fs->nactvar = cast_byte(fs->nactvar + nvars);
998 for (; nvars; nvars--)
999 getlocvar(fs, fs->nactvar - nvars).startpc = fs->pc;
1000}
1001
1002static void removevars(LexState *ls, BCReg tolevel)
1003{
1004 FuncState *fs = ls->fs;
1005 while (fs->nactvar > tolevel)
1006 getlocvar(fs, --fs->nactvar).endpc = fs->pc;
1007}
1008
1009static uint32_t indexupvalue(FuncState *fs, GCstr *name, ExpDesc *v)
1010{
1011 uint32_t i;
1012 GCproto *pt = fs->pt;
1013 for (i = 0; i < fs->nuv; i++) {
1014 if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->u.s.info) {
1015 lua_assert(pt->uvname[i] == name);
1016 return i;
1017 }
1018 }
1019 /* Not found, create a new upvalue for this name. */
1020 if (LJ_UNLIKELY(fs->nuv >= pt->sizeuvname)) {
1021 MSize oldsize = pt->sizeuvname;
1022 checklimit(fs, fs->nuv, LJ_MAX_UPVAL, "upvalues");
1023 lj_mem_growvec(fs->L, pt->uvname, pt->sizeuvname, LJ_MAX_UPVAL, GCstr *);
1024 while (oldsize < pt->sizeuvname) pt->uvname[oldsize++] = NULL;
1025 }
1026 pt->uvname[fs->nuv] = name;
1027 lj_gc_objbarrier(fs->L, pt, name);
1028 lua_assert(v->k == VLOCAL || v->k == VUPVAL);
1029 fs->upvalues[fs->nuv].k = cast_byte(v->k);
1030 fs->upvalues[fs->nuv].info = cast_byte(v->u.s.info);
1031 return fs->nuv++;
1032}
1033
1034static BCReg searchvar(FuncState *fs, GCstr *n)
1035{
1036 int i;
1037 for (i = fs->nactvar-1; i >= 0; i--) {
1038 if (n == getlocvar(fs, i).name)
1039 return (BCReg)i;
1040 }
1041 return (BCReg)-1; /* Not found. */
1042}
1043
1044static void markupval(FuncState *fs, BCReg level)
1045{
1046 FuncBlock *bl = fs->bl;
1047 while (bl && bl->nactvar > level) bl = bl->previous;
1048 if (bl) bl->upval = 1;
1049}
1050
1051static int singlevaraux(FuncState *fs, GCstr *name, ExpDesc *e, int first)
1052{
1053 if (fs == NULL) { /* no more levels? */
1054 init_exp(e, VGLOBAL, 0); /* default is global variable */
1055 e->u.sval = name;
1056 return 1;
1057 } else {
1058 BCReg reg = searchvar(fs, name); /* look up at current level */
1059 if ((int32_t)reg >= 0) {
1060 init_exp(e, VLOCAL, reg);
1061 if (!first)
1062 markupval(fs, reg); /* local will be used as an upval */
1063 return 0;
1064 } else { /* not found at current level; try upper one */
1065 if (singlevaraux(fs->prev, name, e, 0)) /* global? */
1066 return 1;
1067 e->u.s.info = indexupvalue(fs, name, e); /* else was local or upvalue */
1068 e->k = VUPVAL; /* upvalue in this level */
1069 return 0;
1070 }
1071 }
1072}
1073
1074#define singlevar(ls, e) singlevaraux((ls)->fs, str_checkname(ls), (e), 1)
1075
1076static void adjust_assign(LexState *ls, BCReg nvars, BCReg nexps, ExpDesc *e)
1077{
1078 FuncState *fs = ls->fs;
1079 int32_t extra = (int32_t)nvars - (int32_t)nexps;
1080 if (e->k == VCALL) {
1081 extra++; /* includes call itself */
1082 if (extra < 0) extra = 0;
1083 setbc_b(bcptr(fs, e), extra+1);
1084 if (extra > 1) reserveregs(fs, (BCReg)extra-1);
1085 } else {
1086 if (e->k != VVOID) exp2nextreg(fs, e); /* close last expression */
1087 if (extra > 0) {
1088 BCReg reg = fs->freereg;
1089 reserveregs(fs, (BCReg)extra);
1090 nilK(fs, reg, (BCReg)extra);
1091 }
1092 }
1093}
1094
1095/* -- Function handling --------------------------------------------------- */
1096
1097/* Forward declaration. */
1098static void chunk(LexState *ls);
1099
1100static void open_func(LexState *ls, FuncState *fs)
1101{
1102 lua_State *L = ls->L;
1103 GCproto *pt = lj_func_newproto(L);
1104 fs->pt = pt;
1105 fs->prev = ls->fs; /* linked list of funcstates */
1106 fs->ls = ls;
1107 fs->L = L;
1108 ls->fs = fs;
1109 fs->pc = 0;
1110 fs->lasttarget = 0;
1111 fs->jpc = NO_JMP;
1112 fs->freereg = 0;
1113 fs->nkgc = 0;
1114 fs->nkn = 0;
1115 fs->nlocvars = 0;
1116 fs->nactvar = 0;
1117 fs->nuv = 0;
1118 fs->bl = NULL;
1119 pt->chunkname = ls->chunkname;
1120 pt->framesize = 2; /* registers 0/1 are always valid */
1121 fs->kt = lj_tab_new(L, 0, 0);
1122 /* anchor table of constants and prototype (to avoid being collected) */
1123 settabV(L, L->top, fs->kt);
1124 incr_top(L);
1125 setprotoV(L, L->top, pt);
1126 incr_top(L);
1127}
1128
1129static void collectk(FuncState *fs, GCproto *pt)
1130{
1131 GCtab *kt;
1132 TValue *array;
1133 Node *node;
1134 BCReg nkgc;
1135 MSize i, hmask, sizek;
1136 GCRef *kstart;
1137 checklimitgt(fs, fs->nkn, BCMAX_D+1, "constants");
1138 checklimitgt(fs, fs->nkgc, BCMAX_D+1, "constants");
1139 nkgc = round_nkgc(fs->nkgc);
1140 sizek = (MSize)(nkgc*sizeof(MRef) + fs->nkn*sizeof(lua_Number));
1141 kstart = lj_mem_newt(fs->L, sizek, GCRef);
1142 if (nkgc) setgcrefnull(kstart[0]); /* May be uninitialized otherwise. */
1143 pt->k.gc = kstart + nkgc;
1144 pt->sizekn = fs->nkn;
1145 pt->sizekgc = fs->nkgc;
1146 kt = fs->kt;
1147 array = tvref(kt->array);
1148 for (i = 0; i < kt->asize; i++)
1149 if (tvisnum(&array[i]))
1150 pt->k.n[array[i].u32.lo] = cast_num(i);
1151 node = noderef(kt->node);
1152 hmask = kt->hmask;
1153 for (i = 0; i <= hmask; i++) {
1154 Node *n = &node[i];
1155 if (tvisnum(&n->val)) {
1156 ptrdiff_t kidx = (ptrdiff_t)n->val.u32.lo;
1157 if (tvisnum(&n->key)) {
1158 pt->k.n[kidx] = numV(&n->key);
1159 } else {
1160 GCobj *o = gcV(&n->key);
1161 setgcref(pt->k.gc[~kidx], o);
1162 lj_gc_objbarrier(fs->L, pt, o);
1163 }
1164 }
1165 }
1166}
1167
1168static void collectuv(FuncState *fs, GCproto *pt)
1169{
1170 uint32_t i;
1171 pt->uv = lj_mem_newvec(fs->L, fs->nuv, int16_t);
1172 pt->sizeuv = fs->nuv;
1173 for (i = 0; i < pt->sizeuv; i++) {
1174 uint32_t v = fs->upvalues[i].info;
1175 if (fs->upvalues[i].k == VUPVAL) v = ~v;
1176 pt->uv[i] = (int16_t)v;
1177 }
1178}
1179
1180static void finalret(FuncState *fs, GCproto *pt)
1181{
1182 BCPos lastpc = fs->pc;
1183 if (lastpc > fs->lasttarget) {
1184 switch (bc_op(pt->bc[lastpc-1])) {
1185 case BC_CALLMT: case BC_CALLT:
1186 case BC_RETM: case BC_RET: case BC_RET0: case BC_RET1:
1187 goto suppress_return; /* already got a return */
1188 default: break;
1189 }
1190 }
1191 if (fs->pt->flags & PROTO_HAS_FNEW)
1192 emitAJ(fs, BC_UCLO, 0, 0);
1193 emitAD(fs, BC_RET0, 0, 1); /* final return */
1194suppress_return:
1195 /* may need to fixup returns encoded before first function was created */
1196 if (fs->pt->flags & PROTO_FIXUP_RETURN) {
1197 BCPos pc;
1198 for (pc = 0; pc < lastpc; pc++) {
1199 BCIns i = pt->bc[pc];
1200 BCPos offset;
1201 switch (bc_op(i)) {
1202 case BC_CALLMT: case BC_CALLT:
1203 case BC_RETM: case BC_RET: case BC_RET0: case BC_RET1:
1204 offset = emitINS(fs, i)-(pc+1)+BCBIAS_J; /* copy return ins */
1205 if (offset > BCMAX_D)
1206 err_syntax(fs->ls, LJ_ERR_XFIXUP);
1207 pt->bc[pc] = BCINS_AD(BC_UCLO, 0, offset); /* replace w/ UCLO+branch */
1208 break;
1209 case BC_UCLO: return; /* we're done */
1210 default: break;
1211 }
1212 }
1213 }
1214}
1215
1216static void close_func(LexState *ls)
1217{
1218 lua_State *L = ls->L;
1219 FuncState *fs = ls->fs;
1220 GCproto *pt = fs->pt;
1221 removevars(ls, 0);
1222 finalret(fs, pt);
1223 lj_mem_reallocvec(L, pt->bc, pt->sizebc, fs->pc, BCIns);
1224 pt->sizebc = fs->pc;
1225 collectk(fs, pt);
1226 collectuv(fs, pt);
1227 lj_mem_reallocvec(L, pt->lineinfo, pt->sizelineinfo, fs->pc, BCLine);
1228 pt->sizelineinfo = fs->pc;
1229 lj_mem_reallocvec(L, pt->varinfo, pt->sizevarinfo, fs->nlocvars, VarInfo);
1230 pt->sizevarinfo = fs->nlocvars;
1231 lj_mem_reallocvec(L, pt->uvname, pt->sizeuvname, fs->nuv, GCstr *);
1232 pt->sizeuvname = fs->nuv;
1233 lua_assert(fs->bl == NULL);
1234 lj_vmevent_send(L, BC,
1235 setprotoV(L, L->top++, pt);
1236 );
1237 ls->fs = fs->prev;
1238 L->top -= 2; /* Remove table and prototype from the stack. */
1239 lua_assert(ls->fs != NULL || ls->token == TK_eof);
1240 keep_token(ls); /* Re-anchor last token. */
1241}
1242
1243GCproto *lj_parse(LexState *ls)
1244{
1245 struct FuncState fs;
1246 ls->level = 0;
1247 open_func(ls, &fs);
1248 fs.pt->flags |= PROTO_IS_VARARG; /* Main chunk is always a vararg func. */
1249 lj_lex_next(ls); /* Read-ahead first token. */
1250 chunk(ls);
1251 if (ls->token != TK_eof)
1252 err_token(ls, TK_eof);
1253 fs.pt->lastlinedefined = ls->linenumber;
1254 close_func(ls);
1255 lua_assert(fs.prev == NULL);
1256 lua_assert(fs.pt->sizeuv == 0);
1257 lua_assert(ls->fs == NULL);
1258 return fs.pt;
1259}
1260
1261/* -- Expressions --------------------------------------------------------- */
1262
1263/* forward declaration */
1264static void expr(LexState *ls, ExpDesc *v);
1265
1266static void field(LexState *ls, ExpDesc *v)
1267{
1268 /* field -> ['.' | ':'] NAME */
1269 FuncState *fs = ls->fs;
1270 ExpDesc key;
1271 exp2anyreg(fs, v);
1272 lj_lex_next(ls); /* skip the dot or colon */
1273 checkname(ls, &key);
1274 indexexp(fs, v, &key);
1275}
1276
1277static void yindex(LexState *ls, ExpDesc *v)
1278{
1279 /* index -> '[' expr ']' */
1280 lj_lex_next(ls); /* skip the '[' */
1281 expr(ls, v);
1282 exp2val(ls->fs, v);
1283 checknext(ls, ']');
1284}
1285
1286static void kexp2tv(TValue *v, ExpDesc *e)
1287{
1288 switch (e->k) {
1289 case VKNIL: case VKFALSE: case VKTRUE: v->it = ~(int32_t)e->k; break;
1290 case VKSTR:
1291 setgcref(v->gcr, obj2gco(e->u.sval)); v->it = LJ_TSTR; break;
1292 case VKNUM: setnumV(v, expnumV(e)); break;
1293 default: lua_assert(0); break;
1294 }
1295}
1296
1297static void constructor(LexState *ls, ExpDesc *e)
1298{
1299 FuncState *fs = ls->fs;
1300 BCLine line = ls->linenumber;
1301 GCtab *t = NULL;
1302 int vcall = 0, needarr = 0;
1303 int32_t narr = 1; /* first array index */
1304 uint32_t nhash = 0; /* number of hash entries */
1305 BCReg freg = fs->freereg;
1306 BCPos pc = emitAD(fs, BC_TNEW, freg, 0);
1307 init_exp(e, VNONRELOC, freg);
1308 reserveregs(fs, 1);
1309 freg++;
1310 checknext(ls, '{');
1311 while (ls->token != '}') {
1312 ExpDesc key, val;
1313 vcall = 0;
1314 if (ls->token == '[') {
1315 yindex(ls, &key); /* already calls exp2val */
1316 if (!isK(&key)) indexexp(fs, e, &key);
1317 if (isnumK(&key) && expnumV(&key) == 0) needarr = 1; else nhash++;
1318 checknext(ls, '=');
1319 } else if (ls->token == TK_name && lj_lex_lookahead(ls) == '=') {
1320 checkname(ls, &key);
1321 checknext(ls, '=');
1322 nhash++;
1323 } else {
1324 init_exp(&key, VKNUM, 0);
1325 setintV(&key.u.nval, narr);
1326 narr++;
1327 needarr = vcall = 1;
1328 }
1329 expr(ls, &val);
1330 if (isKexp(&val) && isK(&key) && key.k != VKNIL) {
1331 TValue k;
1332 if (!t) { /* create template table on demand */
1333 BCReg kidx;
1334 t = lj_tab_new(fs->L, 0, 0);
1335 kidx = gcK(fs, obj2gco(t), LJ_TTAB);
1336 fs->pt->bc[pc] = BCINS_AD(BC_TDUP, freg-1, kidx);
1337 }
1338 vcall = 0;
1339 kexp2tv(&k, &key);
1340 kexp2tv(lj_tab_set(fs->L, t, &k), &val);
1341 if (val.k == VKSTR)
1342 lj_gc_objbarriert(fs->L, t, val.u.sval);
1343 } else {
1344 if (isK(&key)) indexexp(fs, e, &key);
1345 if (val.k != VCALL) vcall = 0;
1346 storevar(fs, e, &val);
1347 }
1348 fs->freereg = freg;
1349 if (!testnext(ls, ',') && !testnext(ls, ';')) break;
1350 }
1351 checkmatch(ls, '}', '{', line);
1352 if (vcall) {
1353 BCIns *i = &fs->pt->bc[fs->pc-1];
1354 ExpDesc en;
1355 lua_assert(bc_a(*i)==freg && bc_op(*i) == (narr>256?BC_TSETV:BC_TSETB));
1356 init_exp(&en, VKNUM, 0);
1357 setintV(&en.u.nval, narr-1);
1358 if (narr > 256) { fs->pc--; i--; }
1359 *i = BCINS_AD(BC_TSETM, freg, numK(fs, &en));
1360 setbc_b(i-1, 0);
1361 }
1362 if (pc == fs->pc-1) { /* make expr relocable if possible */
1363 e->u.s.info = pc;
1364 fs->freereg--;
1365 e->k = VRELOCABLE;
1366 } else {
1367 e->k = VNONRELOC; /* indexexp may have changed it */
1368 }
1369 if (!t) { /* Construct TNEW RD: hhhhhaaaaaaaaaaa. */
1370 if (!needarr) narr = 0;
1371 else if (narr < 3) narr = 3;
1372 else if (narr > 0x7ff) narr = 0x7ff;
1373 setbc_d(&fs->pt->bc[pc], (uint32_t)narr | (hsize2hbits(nhash) << 11));
1374 }
1375}
1376
1377static void parlist(LexState *ls)
1378{
1379 /* parlist -> [ param { `,' param } ] */
1380 FuncState *fs = ls->fs;
1381 GCproto *pt = fs->pt;
1382 BCReg nparams = 0;
1383 if (ls->token != ')') { /* is `parlist' not empty? */
1384 do {
1385 switch (ls->token) {
1386 case TK_name: /* param -> NAME */
1387 new_localvar(ls, str_checkname(ls), nparams++);
1388 break;
1389 case TK_dots: /* param -> `...' */
1390 lj_lex_next(ls);
1391 pt->flags |= PROTO_IS_VARARG;
1392 break;
1393 default:
1394 err_syntax(ls, LJ_ERR_XPARAM);
1395 break;
1396 }
1397 } while (!(pt->flags & PROTO_IS_VARARG) && testnext(ls, ','));
1398 }
1399 adjustlocalvars(ls, nparams);
1400 pt->numparams = cast_byte(fs->nactvar);
1401 reserveregs(fs, fs->nactvar); /* reserve register for parameters */
1402}
1403
1404static void body(LexState *ls, ExpDesc *e, int needself, BCLine line)
1405{
1406 /* body -> `(' parlist `)' chunk END */
1407 FuncState *fs, new_fs;
1408 BCReg kidx;
1409 open_func(ls, &new_fs);
1410 new_fs.pt->linedefined = line;
1411 checknext(ls, '(');
1412 if (needself) {
1413 new_localvarliteral(ls, "self", 0);
1414 adjustlocalvars(ls, 1);
1415 }
1416 parlist(ls);
1417 checknext(ls, ')');
1418 chunk(ls);
1419 new_fs.pt->lastlinedefined = ls->linenumber;
1420 checkmatch(ls, TK_end, TK_function, line);
1421 close_func(ls);
1422 fs = ls->fs;
1423 kidx = gcK(fs, obj2gco(new_fs.pt), LJ_TPROTO);
1424 init_exp(e, VRELOCABLE, emitAD(fs, BC_FNEW, 0, kidx));
1425 if (!(fs->pt->flags & PROTO_HAS_FNEW)) {
1426 if (fs->pt->flags & PROTO_HAS_RETURN)
1427 fs->pt->flags |= PROTO_FIXUP_RETURN;
1428 fs->pt->flags |= PROTO_HAS_FNEW;
1429 }
1430}
1431
1432static BCReg explist1(LexState *ls, ExpDesc *v)
1433{
1434 /* explist1 -> expr { `,' expr } */
1435 BCReg n = 1; /* at least one expression */
1436 expr(ls, v);
1437 while (testnext(ls, ',')) {
1438 exp2nextreg(ls->fs, v);
1439 expr(ls, v);
1440 n++;
1441 }
1442 return n;
1443}
1444
1445static void funcargs(LexState *ls, ExpDesc *e)
1446{
1447 FuncState *fs = ls->fs;
1448 ExpDesc args;
1449 BCIns ins;
1450 BCReg base;
1451 BCLine line = ls->linenumber;
1452 switch (ls->token) {
1453 case '(': { /* funcargs -> `(' [ explist1 ] `)' */
1454 if (line != ls->lastline)
1455 err_syntax(ls, LJ_ERR_XAMBIG);
1456 lj_lex_next(ls);
1457 if (ls->token == ')') { /* arg list is empty? */
1458 args.k = VVOID;
1459 } else {
1460 explist1(ls, &args);
1461 if (args.k == VCALL)
1462 setbc_b(bcptr(fs, &args), 0);
1463 }
1464 checkmatch(ls, ')', '(', line);
1465 break;
1466 }
1467 case '{': { /* funcargs -> constructor */
1468 constructor(ls, &args);
1469 break;
1470 }
1471 case TK_string: { /* funcargs -> STRING */
1472 init_exp(&args, VKSTR, 0);
1473 args.u.sval = strV(&ls->tokenval);
1474 lj_lex_next(ls); /* must use `seminfo' before `next' */
1475 break;
1476 }
1477 default: {
1478 err_syntax(ls, LJ_ERR_XFUNARG);
1479 return;
1480 }
1481 }
1482 lua_assert(e->k == VNONRELOC);
1483 base = e->u.s.info; /* base register for call */
1484 if (args.k == VCALL) {
1485 ins = BCINS_ABC(BC_CALLM, base, 2, args.u.s.aux - base - 1);
1486 } else {
1487 if (args.k != VVOID)
1488 exp2nextreg(fs, &args); /* close last argument */
1489 ins = BCINS_ABC(BC_CALL, base, 2, fs->freereg - base);
1490 }
1491 init_exp(e, VCALL, emitINS(fs, ins));
1492 e->u.s.aux = base;
1493 fs->pt->lineinfo[fs->pc - 1] = line;
1494 fs->freereg = base+1; /* call removes function and arguments and leaves
1495 (unless changed) one result */
1496}
1497
1498static void prefixexp(LexState *ls, ExpDesc *v)
1499{
1500 /* prefixexp -> NAME | '(' expr ')' */
1501 switch (ls->token) {
1502 case '(': {
1503 BCLine line = ls->linenumber;
1504 lj_lex_next(ls);
1505 expr(ls, v);
1506 checkmatch(ls, ')', '(', line);
1507 dischargevars(ls->fs, v);
1508 return;
1509 }
1510 case TK_name: {
1511 singlevar(ls, v);
1512 return;
1513 }
1514 default: {
1515 err_syntax(ls, LJ_ERR_XSYMBOL);
1516 return;
1517 }
1518 }
1519}
1520
1521static void primaryexp(LexState *ls, ExpDesc *v)
1522{
1523 /* primaryexp ->
1524 prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */
1525 FuncState *fs = ls->fs;
1526 prefixexp(ls, v);
1527 for (;;) {
1528 switch (ls->token) {
1529 case '.': /* field */
1530 field(ls, v);
1531 break;
1532 case '[': { /* `[' exp1 `]' */
1533 ExpDesc key;
1534 exp2anyreg(fs, v);
1535 yindex(ls, &key);
1536 indexexp(fs, v, &key);
1537 break;
1538 }
1539 case ':': { /* `:' NAME funcargs */
1540 ExpDesc key;
1541 lj_lex_next(ls);
1542 checkname(ls, &key);
1543 methodexp(fs, v, &key);
1544 funcargs(ls, v);
1545 break;
1546 }
1547 case '(': case TK_string: case '{': /* funcargs */
1548 exp2nextreg(fs, v);
1549 funcargs(ls, v);
1550 break;
1551 default: return;
1552 }
1553 }
1554}
1555
1556static void simpleexp(LexState *ls, ExpDesc *v)
1557{
1558 /* simpleexp -> NUMBER | STRING | NIL | true | false | ... |
1559 constructor | FUNCTION body | primaryexp */
1560 switch (ls->token) {
1561 case TK_number:
1562 init_exp(v, VKNUM, 0);
1563 setnumV(&v->u.nval, numV(&ls->tokenval));
1564 break;
1565 case TK_string:
1566 init_exp(v, VKSTR, 0);
1567 v->u.sval = strV(&ls->tokenval);
1568 break;
1569 case TK_nil:
1570 init_exp(v, VKNIL, 0);
1571 break;
1572 case TK_true:
1573 init_exp(v, VKTRUE, 0);
1574 break;
1575 case TK_false:
1576 init_exp(v, VKFALSE, 0);
1577 break;
1578 case TK_dots: { /* vararg */
1579 FuncState *fs = ls->fs;
1580 BCReg base;
1581 checkcond(ls, fs->pt->flags & PROTO_IS_VARARG, LJ_ERR_XDOTS);
1582 reserveregs(fs, 1);
1583 base = fs->freereg-1;
1584 init_exp(v, VCALL, emitABC(fs, BC_VARG, base, 2, 1));
1585 v->u.s.aux = base;
1586 break;
1587 }
1588 case '{': /* constructor */
1589 constructor(ls, v);
1590 return;
1591 case TK_function:
1592 lj_lex_next(ls);
1593 body(ls, v, 0, ls->linenumber);
1594 return;
1595 default:
1596 primaryexp(ls, v);
1597 return;
1598 }
1599 lj_lex_next(ls);
1600}
1601
1602static void enterlevel(LexState *ls)
1603{
1604 if (++ls->level >= LJ_MAX_XLEVEL)
1605 lj_lex_error(ls, 0, LJ_ERR_XLEVELS);
1606}
1607
1608#define leavelevel(ls) ((ls)->level--)
1609
1610static UnOpr getunopr(LexToken tok)
1611{
1612 switch (tok) {
1613 case TK_not: return OPR_NOT;
1614 case '-': return OPR_MINUS;
1615 case '#': return OPR_LEN;
1616 default: return OPR_NOUNOPR;
1617 }
1618}
1619
1620static BinOpr getbinopr(LexToken tok)
1621{
1622 switch (tok) {
1623 case '+': return OPR_ADD;
1624 case '-': return OPR_SUB;
1625 case '*': return OPR_MUL;
1626 case '/': return OPR_DIV;
1627 case '%': return OPR_MOD;
1628 case '^': return OPR_POW;
1629 case TK_concat: return OPR_CONCAT;
1630 case TK_ne: return OPR_NE;
1631 case TK_eq: return OPR_EQ;
1632 case '<': return OPR_LT;
1633 case TK_le: return OPR_LE;
1634 case '>': return OPR_GT;
1635 case TK_ge: return OPR_GE;
1636 case TK_and: return OPR_AND;
1637 case TK_or: return OPR_OR;
1638 default: return OPR_NOBINOPR;
1639 }
1640}
1641
1642static const struct {
1643 uint8_t left; /* left priority for each binary operator */
1644 uint8_t right; /* right priority */
1645} priority[] = { /* ORDER OPR */
1646 {6,6}, {6,6}, {7,7}, {7,7}, {7,7}, /* ADD SUB MUL DIV MOD */
1647 {10,9}, {5,4}, /* POW CONCAT (right associative) */
1648 {3,3}, {3,3}, /* EQ NE */
1649 {3,3}, {3,3}, {3,3}, {3,3}, /* LT GE GT LE */
1650 {2,2}, {1,1} /* AND OR */
1651};
1652
1653#define UNARY_PRIORITY 8 /* priority for unary operators */
1654
1655/*
1656** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
1657** where `binop' is any binary operator with a priority higher than `limit'
1658*/
1659static BinOpr subexpr(LexState *ls, ExpDesc *v, uint32_t limit)
1660{
1661 BinOpr op;
1662 UnOpr uop;
1663 enterlevel(ls);
1664 uop = getunopr(ls->token);
1665 if (uop != OPR_NOUNOPR) {
1666 lj_lex_next(ls);
1667 subexpr(ls, v, UNARY_PRIORITY);
1668 emit_unop(ls->fs, uop, v);
1669 } else {
1670 simpleexp(ls, v);
1671 }
1672 /* expand while operators have priorities higher than `limit' */
1673 op = getbinopr(ls->token);
1674 while (op != OPR_NOBINOPR && priority[op].left > limit) {
1675 ExpDesc v2;
1676 BinOpr nextop;
1677 lj_lex_next(ls);
1678 prepare_binop(ls->fs, op, v);
1679 /* read sub-expression with higher priority */
1680 nextop = subexpr(ls, &v2, priority[op].right);
1681 emit_binop(ls->fs, op, v, &v2);
1682 op = nextop;
1683 }
1684 leavelevel(ls);
1685 return op; /* return first untreated operator */
1686}
1687
1688static void expr(LexState *ls, ExpDesc *v)
1689{
1690 subexpr(ls, v, 0);
1691}
1692
1693static BCPos condexpr(LexState *ls)
1694{
1695 /* cond -> exp */
1696 ExpDesc v;
1697 expr(ls, &v); /* read condition */
1698 if (v.k == VKNIL) v.k = VKFALSE; /* `falses' are all equal here */
1699 goiftrue(ls->fs, &v);
1700 return v.f;
1701}
1702
1703/* -- Scope handling ------------------------------------------------------ */
1704
1705static void enterblock(FuncState *fs, FuncBlock *bl, int isbreakable)
1706{
1707 bl->breaklist = NO_JMP;
1708 bl->isbreakable = (uint8_t)isbreakable;
1709 bl->nactvar = fs->nactvar;
1710 bl->upval = 0;
1711 bl->previous = fs->bl;
1712 fs->bl = bl;
1713 lua_assert(fs->freereg == fs->nactvar);
1714}
1715
1716static void leaveblock(FuncState *fs)
1717{
1718 FuncBlock *bl = fs->bl;
1719 fs->bl = bl->previous;
1720 removevars(fs->ls, bl->nactvar);
1721 fs->freereg = fs->nactvar; /* free registers */
1722 lua_assert(bl->nactvar == fs->nactvar);
1723 /* a block either controls scope or breaks (never both) */
1724 lua_assert(!bl->isbreakable || !bl->upval);
1725 if (bl->upval)
1726 emitAJ(fs, BC_UCLO, bl->nactvar, 0);
1727 else /* avoid in upval case, it clears lasttarget and kills UCLO+JMP join */
1728 patchtohere(fs, bl->breaklist);
1729}
1730
1731static void block(LexState *ls)
1732{
1733 /* block -> chunk */
1734 FuncState *fs = ls->fs;
1735 FuncBlock bl;
1736 enterblock(fs, &bl, 0);
1737 chunk(ls);
1738 lua_assert(bl.breaklist == NO_JMP);
1739 leaveblock(fs);
1740}
1741
1742/* -- Statements ---------------------------------------------------------- */
1743
1744/*
1745** structure to chain all variables in the left-hand side of an
1746** assignment
1747*/
1748struct LHS_assign {
1749 ExpDesc v; /* variable (global, local, upvalue, or indexed) */
1750 struct LHS_assign *prev;
1751};
1752
1753/*
1754** check whether, in an assignment to a local variable, the local variable
1755** is needed in a previous assignment (to a table). If so, save original
1756** local value in a safe place and use this safe copy in the previous
1757** assignment.
1758*/
1759static void check_conflict(LexState *ls, struct LHS_assign *lh,
1760 const ExpDesc *v)
1761{
1762 FuncState *fs = ls->fs;
1763 BCReg reg = fs->freereg; /* eventual position to save local variable */
1764 int conflict = 0;
1765 for (; lh; lh = lh->prev) {
1766 if (lh->v.k == VINDEXED) {
1767 if (lh->v.u.s.info == v->u.s.info) { /* conflict? */
1768 conflict = 1;
1769 lh->v.u.s.info = reg; /* previous assignment will use safe copy */
1770 }
1771 if (lh->v.u.s.aux == v->u.s.info) { /* conflict? */
1772 conflict = 1;
1773 lh->v.u.s.aux = reg; /* previous assignment will use safe copy */
1774 }
1775 }
1776 }
1777 if (conflict) {
1778 emitAD(fs, BC_MOV, reg, v->u.s.info); /* make copy */
1779 reserveregs(fs, 1);
1780 }
1781}
1782
1783static void assignment(LexState *ls, struct LHS_assign *lh, BCReg nvars)
1784{
1785 ExpDesc e;
1786 checkcond(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED, LJ_ERR_XSYNTAX);
1787 if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
1788 struct LHS_assign nv;
1789 nv.prev = lh;
1790 primaryexp(ls, &nv.v);
1791 if (nv.v.k == VLOCAL)
1792 check_conflict(ls, lh, &nv.v);
1793 checklimit(ls->fs, ls->level + nvars, LJ_MAX_XLEVEL, "variable names");
1794 assignment(ls, &nv, nvars+1);
1795 } else { /* assignment -> `=' explist1 */
1796 BCReg nexps;
1797 checknext(ls, '=');
1798 nexps = explist1(ls, &e);
1799 if (nexps == nvars) {
1800 if (e.k == VCALL) {
1801 if (bc_op(*bcptr(ls->fs, &e)) == BC_VARG) {
1802 ls->fs->freereg--;
1803 e.k = VRELOCABLE;
1804 } else {
1805 e.u.s.info = e.u.s.aux;
1806 e.k = VNONRELOC;
1807 }
1808 }
1809 storevar(ls->fs, &lh->v, &e);
1810 return;
1811 }
1812 adjust_assign(ls, nvars, nexps, &e);
1813 if (nexps > nvars)
1814 ls->fs->freereg -= nexps - nvars; /* remove extra values */
1815 }
1816 init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
1817 storevar(ls->fs, &lh->v, &e);
1818}
1819
1820static void breakstat(LexState *ls)
1821{
1822 FuncState *fs = ls->fs;
1823 FuncBlock *bl = fs->bl;
1824 int upval = 0;
1825 while (bl && !bl->isbreakable) {
1826 upval |= bl->upval;
1827 bl = bl->previous;
1828 }
1829 if (!bl)
1830 err_syntax(ls, LJ_ERR_XBREAK);
1831 if (upval)
1832 emitAJ(fs, BC_UCLO, bl->nactvar, 0);
1833 concatjumps(fs, &bl->breaklist, emit_jump(fs));
1834}
1835
1836static void whilestat(LexState *ls, BCLine line)
1837{
1838 /* whilestat -> WHILE cond DO block END */
1839 FuncState *fs = ls->fs;
1840 BCPos start, loop, condexit;
1841 FuncBlock bl;
1842 lj_lex_next(ls); /* skip WHILE */
1843 start = fs->lasttarget = fs->pc;
1844 condexit = condexpr(ls);
1845 enterblock(fs, &bl, 1);
1846 checknext(ls, TK_do);
1847 loop = emitAD(fs, BC_LOOP, fs->nactvar, 0);
1848 block(ls);
1849 patchlist(fs, emit_jump(fs), start);
1850 checkmatch(ls, TK_end, TK_while, line);
1851 leaveblock(fs);
1852 patchtohere(fs, condexit); /* false conditions finish the loop */
1853 fixjump(fs, loop, fs->pc);
1854}
1855
1856static void repeatstat(LexState *ls, BCLine line)
1857{
1858 /* repeatstat -> REPEAT block UNTIL cond */
1859 FuncState *fs = ls->fs;
1860 BCPos loop = fs->lasttarget = fs->pc;
1861 BCPos condexit;
1862 FuncBlock bl1, bl2;
1863 enterblock(fs, &bl1, 1); /* loop block */
1864 enterblock(fs, &bl2, 0); /* scope block */
1865 lj_lex_next(ls); /* skip REPEAT */
1866 emitAD(fs, BC_LOOP, fs->nactvar, 0);
1867 chunk(ls);
1868 checkmatch(ls, TK_until, TK_repeat, line);
1869 condexit = condexpr(ls); /* read condition (inside scope block) */
1870 if (!bl2.upval) { /* no upvalues? */
1871 leaveblock(fs); /* finish scope */
1872 } else { /* complete semantics when there are upvalues */
1873 breakstat(ls); /* if condition then break */
1874 patchtohere(fs, condexit); /* else... */
1875 leaveblock(fs); /* finish scope... */
1876 condexit = emit_jump(fs); /* and repeat */
1877 }
1878 patchlist(fs, condexit, loop); /* close the loop */
1879 fixjump(fs, loop, fs->pc);
1880 leaveblock(fs); /* finish loop */
1881}
1882
1883static void exp1(LexState *ls)
1884{
1885 ExpDesc e;
1886 expr(ls, &e);
1887 exp2nextreg(ls->fs, &e);
1888}
1889
1890static void forbody(LexState *ls, BCReg base, BCLine line, BCReg nvars,
1891 int isnum)
1892{
1893 /* forbody -> DO block */
1894 FuncBlock bl;
1895 FuncState *fs = ls->fs;
1896 BCPos loop, loopend;
1897 adjustlocalvars(ls, 3); /* control variables */
1898 checknext(ls, TK_do);
1899 loop = isnum ? emitAJ(fs, BC_FORI, base, NO_JMP) :
1900 emitAJ(fs, BC_JMP, fs->freereg, NO_JMP);
1901 enterblock(fs, &bl, 0); /* scope for declared variables */
1902 adjustlocalvars(ls, nvars);
1903 reserveregs(fs, nvars);
1904 block(ls);
1905 leaveblock(fs); /* end of scope for declared variables */
1906 if (isnum) {
1907 loopend = emitAJ(fs, BC_FORL, base, NO_JMP);
1908 fixjump(fs, loop, fs->pc);
1909 } else {
1910 fixjump(fs, loop, fs->pc);
1911 emitABC(fs, BC_ITERC, base+3, nvars+1, 2+1);
1912 loopend = emitAJ(fs, BC_ITERL, base+3, NO_JMP);
1913 fs->pt->lineinfo[loopend-1] = line;
1914 }
1915 fs->pt->lineinfo[loopend] = line; /* pretend last op starts the loop */
1916 fixjump(fs, loopend, loop+1);
1917}
1918
1919static void fornum(LexState *ls, GCstr *varname, BCLine line)
1920{
1921 /* fornum -> NAME = exp1,exp1[,exp1] forbody */
1922 FuncState *fs = ls->fs;
1923 BCReg base = fs->freereg;
1924 new_localvarliteral(ls, "(for index)", FORL_IDX);
1925 new_localvarliteral(ls, "(for limit)", FORL_STOP);
1926 new_localvarliteral(ls, "(for step)", FORL_STEP);
1927 new_localvar(ls, varname, FORL_EXT);
1928 checknext(ls, '=');
1929 exp1(ls); /* initial value */
1930 checknext(ls, ',');
1931 exp1(ls); /* limit */
1932 if (testnext(ls, ',')) {
1933 exp1(ls); /* optional step */
1934 } else { /* default step = 1 */
1935 emitAD(fs, BC_KSHORT, fs->freereg, 1);
1936 reserveregs(fs, 1);
1937 }
1938 forbody(ls, base, line, 1, 1);
1939}
1940
1941static void forlist(LexState *ls, GCstr *indexname)
1942{
1943 /* forlist -> NAME {,NAME} IN explist1 forbody */
1944 FuncState *fs = ls->fs;
1945 ExpDesc e;
1946 BCReg nvars = 0;
1947 BCLine line;
1948 BCReg base = fs->freereg;
1949 /* create control variables */
1950 new_localvarliteral(ls, "(for generator)", nvars++);
1951 new_localvarliteral(ls, "(for state)", nvars++);
1952 new_localvarliteral(ls, "(for control)", nvars++);
1953 /* create declared variables */
1954 new_localvar(ls, indexname, nvars++);
1955 while (testnext(ls, ','))
1956 new_localvar(ls, str_checkname(ls), nvars++);
1957 checknext(ls, TK_in);
1958 line = ls->linenumber;
1959 adjust_assign(ls, 3, explist1(ls, &e), &e);
1960 checkframe(fs, 3); /* extra space to call generator */
1961 forbody(ls, base, line, nvars - 3, 0);
1962}
1963
1964static void forstat(LexState *ls, BCLine line)
1965{
1966 /* forstat -> FOR (fornum | forlist) END */
1967 FuncState *fs = ls->fs;
1968 GCstr *varname;
1969 FuncBlock bl;
1970 enterblock(fs, &bl, 1); /* scope for loop and control variables */
1971 lj_lex_next(ls); /* skip `for' */
1972 varname = str_checkname(ls); /* first variable name */
1973 switch (ls->token) {
1974 case '=': fornum(ls, varname, line); break;
1975 case ',': case TK_in: forlist(ls, varname); break;
1976 default: err_syntax(ls, LJ_ERR_XFOR);
1977 }
1978 checkmatch(ls, TK_end, TK_for, line);
1979 leaveblock(fs); /* loop scope (`break' jumps to this point) */
1980}
1981
1982static BCPos test_then_block(LexState *ls)
1983{
1984 /* test_then_block -> [IF | ELSEIF] cond THEN block */
1985 BCPos condexit;
1986 lj_lex_next(ls); /* skip IF or ELSEIF */
1987 condexit = condexpr(ls);
1988 checknext(ls, TK_then);
1989 block(ls); /* `then' part */
1990 return condexit;
1991}
1992
1993static void ifstat(LexState *ls, BCLine line)
1994{
1995 /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
1996 FuncState *fs = ls->fs;
1997 BCPos flist;
1998 BCPos escapelist = NO_JMP;
1999 flist = test_then_block(ls); /* IF cond THEN block */
2000 while (ls->token == TK_elseif) {
2001 concatjumps(fs, &escapelist, emit_jump(fs));
2002 patchtohere(fs, flist);
2003 flist = test_then_block(ls); /* ELSEIF cond THEN block */
2004 }
2005 if (ls->token == TK_else) {
2006 concatjumps(fs, &escapelist, emit_jump(fs));
2007 patchtohere(fs, flist);
2008 lj_lex_next(ls); /* skip ELSE (after patch, for correct line info) */
2009 block(ls); /* `else' part */
2010 } else {
2011 concatjumps(fs, &escapelist, flist);
2012 }
2013 patchtohere(fs, escapelist);
2014 checkmatch(ls, TK_end, TK_if, line);
2015}
2016
2017static void localfunc(LexState *ls)
2018{
2019 ExpDesc v, b;
2020 FuncState *fs = ls->fs;
2021 new_localvar(ls, str_checkname(ls), 0);
2022 init_exp(&v, VLOCAL, fs->freereg);
2023 reserveregs(fs, 1);
2024 adjustlocalvars(ls, 1);
2025 body(ls, &b, 0, ls->linenumber);
2026 storevar(fs, &v, &b);
2027 /* debug information will only see the variable after this point! */
2028 getlocvar(fs, fs->nactvar - 1).startpc = fs->pc;
2029}
2030
2031static void localstat(LexState *ls)
2032{
2033 /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */
2034 BCReg nvars = 0;
2035 BCReg nexps;
2036 ExpDesc e;
2037 do {
2038 new_localvar(ls, str_checkname(ls), nvars++);
2039 } while (testnext(ls, ','));
2040 if (testnext(ls, '=')) {
2041 nexps = explist1(ls, &e);
2042 } else {
2043 e.k = VVOID;
2044 nexps = 0;
2045 }
2046 adjust_assign(ls, nvars, nexps, &e);
2047 adjustlocalvars(ls, nvars);
2048}
2049
2050static int func_name(LexState *ls, ExpDesc *v)
2051{
2052 /* func_name -> NAME {field} [`:' NAME] */
2053 int needself = 0;
2054 singlevar(ls, v);
2055 while (ls->token == '.')
2056 field(ls, v);
2057 if (ls->token == ':') {
2058 needself = 1;
2059 field(ls, v);
2060 }
2061 return needself;
2062}
2063
2064static void funcstat(LexState *ls, BCLine line)
2065{
2066 /* funcstat -> FUNCTION func_name body */
2067 FuncState *fs;
2068 int needself;
2069 ExpDesc v, b;
2070 lj_lex_next(ls); /* skip FUNCTION */
2071 needself = func_name(ls, &v);
2072 body(ls, &b, needself, line);
2073 fs = ls->fs;
2074 storevar(fs, &v, &b);
2075 fs->pt->lineinfo[fs->pc - 1] = line;
2076}
2077
2078static void exprstat(LexState *ls)
2079{
2080 /* stat -> func | assignment */
2081 FuncState *fs = ls->fs;
2082 struct LHS_assign v;
2083 primaryexp(ls, &v.v);
2084 if (v.v.k == VCALL) { /* stat -> func */
2085 setbc_b(bcptr(fs, &v.v), 1); /* call statement uses no results */
2086 } else { /* stat -> assignment */
2087 v.prev = NULL;
2088 assignment(ls, &v, 1);
2089 }
2090}
2091
2092static int block_follow(LexToken token)
2093{
2094 switch (token) {
2095 case TK_else: case TK_elseif: case TK_end: case TK_until: case TK_eof:
2096 return 1;
2097 default:
2098 return 0;
2099 }
2100}
2101
2102static void retstat(LexState *ls)
2103{
2104 /* stat -> RETURN explist */
2105 BCIns ins;
2106 FuncState *fs = ls->fs;
2107 lj_lex_next(ls); /* skip RETURN */
2108 fs->pt->flags |= PROTO_HAS_RETURN;
2109 if (block_follow(ls->token) || ls->token == ';') {
2110 ins = BCINS_AD(BC_RET0, 0, 1); /* return no values */
2111 } else {
2112 ExpDesc e;
2113 BCReg nret = explist1(ls, &e); /* optional return values */
2114 if (nret == 1) {
2115 if (e.k == VCALL) {
2116 BCIns *i = bcptr(fs, &e);
2117 /* It doesn't pay off to add BC_VARGT just for 'return ...'. */
2118 if (bc_op(*i) == BC_VARG) goto notailcall;
2119 fs->pc--;
2120 ins = BCINS_AD(bc_op(*i)-BC_CALL+BC_CALLT, bc_a(*i), bc_c(*i));
2121 } else {
2122 ins = BCINS_AD(BC_RET1, exp2anyreg(fs, &e), 2);
2123 }
2124 } else {
2125 if (e.k == VCALL) {
2126 notailcall:
2127 setbc_b(bcptr(fs, &e), 0);
2128 ins = BCINS_AD(BC_RETM, fs->nactvar, e.u.s.aux - fs->nactvar);
2129 } else {
2130 exp2nextreg(fs, &e); /* values must go to the `stack' */
2131 ins = BCINS_AD(BC_RET, fs->nactvar, nret+1);
2132 }
2133 }
2134 }
2135 if (fs->pt->flags & PROTO_HAS_FNEW)
2136 emitAJ(fs, BC_UCLO, 0, 0);
2137 emitINS(fs, ins);
2138}
2139
2140static int statement(LexState *ls)
2141{
2142 BCLine line = ls->linenumber; /* may be needed for error messages */
2143 switch (ls->token) {
2144 case TK_if:
2145 ifstat(ls, line);
2146 return 0;
2147 case TK_while:
2148 whilestat(ls, line);
2149 return 0;
2150 case TK_do:
2151 lj_lex_next(ls); /* skip DO */
2152 block(ls);
2153 checkmatch(ls, TK_end, TK_do, line);
2154 return 0;
2155 case TK_for:
2156 forstat(ls, line);
2157 return 0;
2158 case TK_repeat:
2159 repeatstat(ls, line);
2160 return 0;
2161 case TK_function:
2162 funcstat(ls, line);
2163 return 0;
2164 case TK_local:
2165 lj_lex_next(ls); /* skip LOCAL */
2166 if (testnext(ls, TK_function)) /* local function? */
2167 localfunc(ls);
2168 else
2169 localstat(ls);
2170 return 0;
2171 case TK_return:
2172 retstat(ls);
2173 return 1; /* must be last statement */
2174 case TK_break:
2175 lj_lex_next(ls); /* skip BREAK */
2176 breakstat(ls);
2177 return 1; /* must be last statement */
2178 default:
2179 exprstat(ls);
2180 return 0;
2181 }
2182}
2183
2184static void chunk(LexState *ls)
2185{
2186 /* chunk -> { stat [`;'] } */
2187 int islast = 0;
2188 enterlevel(ls);
2189 while (!islast && !block_follow(ls->token)) {
2190 islast = statement(ls);
2191 testnext(ls, ';');
2192 lua_assert(ls->fs->pt->framesize >= ls->fs->freereg &&
2193 ls->fs->freereg >= ls->fs->nactvar);
2194 ls->fs->freereg = ls->fs->nactvar; /* free registers */
2195 }
2196 leavelevel(ls);
2197}
2198
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-03-17 19:45:24 +0000