A modern Music Player Daemon based on Rockbox open source high quality audio player
tsiry-sandratraina.com
libadwaita
audio
rust
zig
deno
mpris
rockbox
mpd
1/*
2** $Id: lparser.c,v 2.42.1.4 2011/10/21 19:31:42 roberto Exp $
3** Lua Parser
4** See Copyright Notice in lua.h
5*/
6
7
8#include <string.h>
9
10#define lparser_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 "lfunc.h"
19#include "llex.h"
20#include "lmem.h"
21#include "lobject.h"
22#include "lopcodes.h"
23#include "lparser.h"
24#include "lstate.h"
25#include "lstring.h"
26#include "ltable.h"
27
28
29
30#define hasmultret(k) ((k) == VCALL || (k) == VVARARG)
31
32#define getlocvar(fs, i) ((fs)->f->locvars[(fs)->actvar[i]])
33
34#define luaY_checklimit(fs,v,l,m) if ((v)>(l)) errorlimit(fs,l,m)
35
36
37/*
38** nodes for block list (list of active blocks)
39*/
40typedef struct BlockCnt {
41 struct BlockCnt *previous; /* chain */
42 int breaklist; /* list of jumps out of this loop */
43 lu_byte nactvar; /* # active locals outside the breakable structure */
44 lu_byte upval; /* true if some variable in the block is an upvalue */
45 lu_byte isbreakable; /* true if `block' is a loop */
46} BlockCnt;
47
48
49
50/*
51** prototypes for recursive non-terminal functions
52*/
53static void chunk (LexState *ls);
54static void expr (LexState *ls, expdesc *v);
55
56
57static void anchor_token (LexState *ls) {
58 if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) {
59 TString *ts = ls->t.seminfo.ts;
60 luaX_newstring(ls, getstr(ts), ts->tsv.len);
61 }
62}
63
64
65static void error_expected (LexState *ls, int token) {
66 luaX_syntaxerror(ls,
67 luaO_pushfstring(ls->L, LUA_QS " expected", luaX_token2str(ls, token)));
68}
69
70
71static void errorlimit (FuncState *fs, int limit, const char *what) {
72 const char *msg = (fs->f->linedefined == 0) ?
73 luaO_pushfstring(fs->L, "main function has more than %d %s", limit, what) :
74 luaO_pushfstring(fs->L, "function at line %d has more than %d %s",
75 fs->f->linedefined, limit, what);
76 luaX_lexerror(fs->ls, msg, 0);
77}
78
79
80static int testnext (LexState *ls, int c) {
81 if (ls->t.token == c) {
82 luaX_next(ls);
83 return 1;
84 }
85 else return 0;
86}
87
88
89static void check (LexState *ls, int c) {
90 if (ls->t.token != c)
91 error_expected(ls, c);
92}
93
94static void checknext (LexState *ls, int c) {
95 check(ls, c);
96 luaX_next(ls);
97}
98
99
100#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); }
101
102
103
104static void check_match (LexState *ls, int what, int who, int where) {
105 if (!testnext(ls, what)) {
106 if (where == ls->linenumber)
107 error_expected(ls, what);
108 else {
109 luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
110 LUA_QS " expected (to close " LUA_QS " at line %d)",
111 luaX_token2str(ls, what), luaX_token2str(ls, who), where));
112 }
113 }
114}
115
116
117static TString *str_checkname (LexState *ls) {
118 TString *ts;
119 check(ls, TK_NAME);
120 ts = ls->t.seminfo.ts;
121 luaX_next(ls);
122 return ts;
123}
124
125
126static void init_exp (expdesc *e, expkind k, int i) {
127 e->f = e->t = NO_JUMP;
128 e->k = k;
129 e->u.s.info = i;
130}
131
132
133static void codestring (LexState *ls, expdesc *e, TString *s) {
134 init_exp(e, VK, luaK_stringK(ls->fs, s));
135}
136
137
138static void checkname(LexState *ls, expdesc *e) {
139 codestring(ls, e, str_checkname(ls));
140}
141
142
143static int registerlocalvar (LexState *ls, TString *varname) {
144 FuncState *fs = ls->fs;
145 Proto *f = fs->f;
146 int oldsize = f->sizelocvars;
147 luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
148 LocVar, SHRT_MAX, "too many local variables");
149 while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL;
150 f->locvars[fs->nlocvars].varname = varname;
151 luaC_objbarrier(ls->L, f, varname);
152 return fs->nlocvars++;
153}
154
155
156#define new_localvarliteral(ls,v,n) \
157 new_localvar(ls, luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char))-1), n)
158
159
160static void new_localvar (LexState *ls, TString *name, int n) {
161 FuncState *fs = ls->fs;
162 luaY_checklimit(fs, fs->nactvar+n+1, LUAI_MAXVARS, "local variables");
163 fs->actvar[fs->nactvar+n] = cast(unsigned short, registerlocalvar(ls, name));
164}
165
166
167static void adjustlocalvars (LexState *ls, int nvars) {
168 FuncState *fs = ls->fs;
169 fs->nactvar = cast_byte(fs->nactvar + nvars);
170 for (; nvars; nvars--) {
171 getlocvar(fs, fs->nactvar - nvars).startpc = fs->pc;
172 }
173}
174
175
176static void removevars (LexState *ls, int tolevel) {
177 FuncState *fs = ls->fs;
178 while (fs->nactvar > tolevel)
179 getlocvar(fs, --fs->nactvar).endpc = fs->pc;
180}
181
182
183static int indexupvalue (FuncState *fs, TString *name, expdesc *v) {
184 int i;
185 Proto *f = fs->f;
186 int oldsize = f->sizeupvalues;
187 for (i=0; i<f->nups; i++) {
188 if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->u.s.info) {
189 lua_assert(f->upvalues[i] == name);
190 return i;
191 }
192 }
193 /* new one */
194 luaY_checklimit(fs, f->nups + 1, LUAI_MAXUPVALUES, "upvalues");
195 luaM_growvector(fs->L, f->upvalues, f->nups, f->sizeupvalues,
196 TString *, MAX_INT, "");
197 while (oldsize < f->sizeupvalues) f->upvalues[oldsize++] = NULL;
198 f->upvalues[f->nups] = name;
199 luaC_objbarrier(fs->L, f, name);
200 lua_assert(v->k == VLOCAL || v->k == VUPVAL);
201 fs->upvalues[f->nups].k = cast_byte(v->k);
202 fs->upvalues[f->nups].info = cast_byte(v->u.s.info);
203 return f->nups++;
204}
205
206
207static int searchvar (FuncState *fs, TString *n) {
208 int i;
209 for (i=fs->nactvar-1; i >= 0; i--) {
210 if (n == getlocvar(fs, i).varname)
211 return i;
212 }
213 return -1; /* not found */
214}
215
216
217static void markupval (FuncState *fs, int level) {
218 BlockCnt *bl = fs->bl;
219 while (bl && bl->nactvar > level) bl = bl->previous;
220 if (bl) bl->upval = 1;
221}
222
223
224static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
225 if (fs == NULL) { /* no more levels? */
226 init_exp(var, VGLOBAL, NO_REG); /* default is global variable */
227 return VGLOBAL;
228 }
229 else {
230 int v = searchvar(fs, n); /* look up at current level */
231 if (v >= 0) {
232 init_exp(var, VLOCAL, v);
233 if (!base)
234 markupval(fs, v); /* local will be used as an upval */
235 return VLOCAL;
236 }
237 else { /* not found at current level; try upper one */
238 if (singlevaraux(fs->prev, n, var, 0) == VGLOBAL)
239 return VGLOBAL;
240 var->u.s.info = indexupvalue(fs, n, var); /* else was LOCAL or UPVAL */
241 var->k = VUPVAL; /* upvalue in this level */
242 return VUPVAL;
243 }
244 }
245}
246
247
248static void singlevar (LexState *ls, expdesc *var) {
249 TString *varname = str_checkname(ls);
250 FuncState *fs = ls->fs;
251 if (singlevaraux(fs, varname, var, 1) == VGLOBAL)
252 var->u.s.info = luaK_stringK(fs, varname); /* info points to global name */
253}
254
255
256static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
257 FuncState *fs = ls->fs;
258 int extra = nvars - nexps;
259 if (hasmultret(e->k)) {
260 extra++; /* includes call itself */
261 if (extra < 0) extra = 0;
262 luaK_setreturns(fs, e, extra); /* last exp. provides the difference */
263 if (extra > 1) luaK_reserveregs(fs, extra-1);
264 }
265 else {
266 if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */
267 if (extra > 0) {
268 int reg = fs->freereg;
269 luaK_reserveregs(fs, extra);
270 luaK_nil(fs, reg, extra);
271 }
272 }
273}
274
275
276static void enterlevel (LexState *ls) {
277 if (++ls->L->nCcalls > LUAI_MAXCCALLS)
278 luaX_lexerror(ls, "chunk has too many syntax levels", 0);
279}
280
281
282#define leavelevel(ls) ((ls)->L->nCcalls--)
283
284
285static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isbreakable) {
286 bl->breaklist = NO_JUMP;
287 bl->isbreakable = isbreakable;
288 bl->nactvar = fs->nactvar;
289 bl->upval = 0;
290 bl->previous = fs->bl;
291 fs->bl = bl;
292 lua_assert(fs->freereg == fs->nactvar);
293}
294
295
296static void leaveblock (FuncState *fs) {
297 BlockCnt *bl = fs->bl;
298 fs->bl = bl->previous;
299 removevars(fs->ls, bl->nactvar);
300 if (bl->upval)
301 luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
302 /* a block either controls scope or breaks (never both) */
303 lua_assert(!bl->isbreakable || !bl->upval);
304 lua_assert(bl->nactvar == fs->nactvar);
305 fs->freereg = fs->nactvar; /* free registers */
306 luaK_patchtohere(fs, bl->breaklist);
307}
308
309
310static void pushclosure (LexState *ls, FuncState *func, expdesc *v) {
311 FuncState *fs = ls->fs;
312 Proto *f = fs->f;
313 int oldsize = f->sizep;
314 int i;
315 luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *,
316 MAXARG_Bx, "constant table overflow");
317 while (oldsize < f->sizep) f->p[oldsize++] = NULL;
318 f->p[fs->np++] = func->f;
319 luaC_objbarrier(ls->L, f, func->f);
320 init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
321 for (i=0; i<func->f->nups; i++) {
322 OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
323 luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0);
324 }
325}
326
327
328static void open_func (LexState *ls, FuncState *fs) {
329 lua_State *L = ls->L;
330 Proto *f = luaF_newproto(L);
331 fs->f = f;
332 fs->prev = ls->fs; /* linked list of funcstates */
333 fs->ls = ls;
334 fs->L = L;
335 ls->fs = fs;
336 fs->pc = 0;
337 fs->lasttarget = -1;
338 fs->jpc = NO_JUMP;
339 fs->freereg = 0;
340 fs->nk = 0;
341 fs->np = 0;
342 fs->nlocvars = 0;
343 fs->nactvar = 0;
344 fs->bl = NULL;
345 f->source = ls->source;
346 f->maxstacksize = 2; /* registers 0/1 are always valid */
347#ifdef LUA_OPTIMIZE_DEBUG
348 fs->lastline = 0;
349 fs->lastlineOffset = 0;
350 fs->lineinfoLastPC = -1;
351#endif
352 fs->h = luaH_new(L, 0, 0);
353 /* anchor table of constants and prototype (to avoid being collected) */
354 sethvalue2s(L, L->top, fs->h);
355 incr_top(L);
356 setptvalue2s(L, L->top, f);
357 incr_top(L);
358}
359
360
361static void close_func (LexState *ls) {
362 if (!ls || !ls->fs || !ls->fs->f)
363 return;
364 lua_State *L = ls->L;
365 FuncState *fs = ls->fs;
366 Proto *f = fs->f;
367 removevars(ls, 0);
368 luaK_ret(fs, 0, 0); /* final return */
369 luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
370 f->sizecode = fs->pc;
371#ifdef LUA_OPTIMIZE_DEBUG
372 f->packedlineinfo[fs->lastlineOffset+1]=0;
373 luaM_reallocvector(L, f->packedlineinfo, f->sizelineinfo,
374 fs->lastlineOffset+2, unsigned char);
375 f->sizelineinfo = fs->lastlineOffset + 2;
376#else
377 luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
378 f->sizelineinfo = fs->pc;
379#endif
380 luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue);
381 f->sizek = fs->nk;
382 luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *);
383 f->sizep = fs->np;
384 luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar);
385 f->sizelocvars = fs->nlocvars;
386 luaM_reallocvector(L, f->upvalues, f->sizeupvalues, f->nups, TString *);
387 f->sizeupvalues = f->nups;
388 lua_assert(luaG_checkcode(f));
389 lua_assert(fs->bl == NULL);
390 ls->fs = fs->prev;
391 /* last token read was anchored in defunct function; must reanchor it */
392 if (fs) anchor_token(ls);
393 L->top -= 2; /* remove table and prototype from the stack */
394}
395
396#ifdef LUA_OPTIMIZE_DEBUG
397static void compile_stripdebug(lua_State *L, Proto *f) {
398 int level;
399#ifdef LUA_OPTIMIZE_DEBUG_USER
400 lua_pushlightuserdata(L, &luaG_stripdebug);
401 lua_gettable(L, LUA_REGISTRYINDEX);
402 level = lua_isnil(L, -1) ? LUA_OPTIMIZE_DEBUG : lua_tointeger(L, -1);
403 lua_pop(L, 1);
404#else
405 level = LUA_OPTIMIZE_DEBUG;
406#endif
407
408 if (level > 1) {
409 luaG_stripdebug(L, f, level, 16);
410 }
411}
412#endif
413
414Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, const char *name) {
415 struct LexState lexstate;
416 struct FuncState funcstate;
417 TString *tname = luaS_new(L, name);
418 setsvalue2s(L, L->top, tname); /* protect name */
419 incr_top(L);
420 lexstate.buff = buff;
421 luaX_setinput(L, &lexstate, z, tname);
422 open_func(&lexstate, &funcstate);
423 funcstate.f->is_vararg = VARARG_ISVARARG; /* main func. is always vararg */
424 luaX_next(&lexstate); /* read first token */
425 chunk(&lexstate);
426 check(&lexstate, TK_EOS);
427 close_func(&lexstate);
428 L->top--; /* remove 'name' from stack */
429#ifdef LUA_OPTIMIZE_DEBUG
430 compile_stripdebug(L, funcstate.f);
431#endif
432 lua_assert(funcstate.prev == NULL);
433 lua_assert(funcstate.f->nups == 0);
434 lua_assert(lexstate.fs == NULL);
435 return funcstate.f;
436}
437
438
439/*============================================================*/
440/* GRAMMAR RULES */
441/*============================================================*/
442
443
444static void field (LexState *ls, expdesc *v) {
445 /* field -> ['.' | ':'] NAME */
446 FuncState *fs = ls->fs;
447 expdesc key;
448 luaK_exp2anyreg(fs, v);
449 luaX_next(ls); /* skip the dot or colon */
450 checkname(ls, &key);
451 luaK_indexed(fs, v, &key);
452}
453
454
455static void yindex (LexState *ls, expdesc *v) {
456 /* index -> '[' expr ']' */
457 luaX_next(ls); /* skip the '[' */
458 expr(ls, v);
459 luaK_exp2val(ls->fs, v);
460 checknext(ls, ']');
461}
462
463
464/*
465** {======================================================================
466** Rules for Constructors
467** =======================================================================
468*/
469
470
471struct ConsControl {
472 expdesc v; /* last list item read */
473 expdesc *t; /* table descriptor */
474 int nh; /* total number of `record' elements */
475 int na; /* total number of array elements */
476 int tostore; /* number of array elements pending to be stored */
477};
478
479
480static void recfield (LexState *ls, struct ConsControl *cc) {
481 /* recfield -> (NAME | `['exp1`]') = exp1 */
482 FuncState *fs = ls->fs;
483 int reg = ls->fs->freereg;
484 expdesc key, val;
485 int rkkey;
486 if (ls->t.token == TK_NAME) {
487 luaY_checklimit(fs, cc->nh, MAX_INT, "items in a constructor");
488 checkname(ls, &key);
489 }
490 else /* ls->t.token == '[' */
491 yindex(ls, &key);
492 cc->nh++;
493 checknext(ls, '=');
494 rkkey = luaK_exp2RK(fs, &key);
495 expr(ls, &val);
496 luaK_codeABC(fs, OP_SETTABLE, cc->t->u.s.info, rkkey, luaK_exp2RK(fs, &val));
497 fs->freereg = reg; /* free registers */
498}
499
500
501static void closelistfield (FuncState *fs, struct ConsControl *cc) {
502 if (cc->v.k == VVOID) return; /* there is no list item */
503 luaK_exp2nextreg(fs, &cc->v);
504 cc->v.k = VVOID;
505 if (cc->tostore == LFIELDS_PER_FLUSH) {
506 luaK_setlist(fs, cc->t->u.s.info, cc->na, cc->tostore); /* flush */
507 cc->tostore = 0; /* no more items pending */
508 }
509}
510
511
512static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
513 if (cc->tostore == 0) return;
514 if (hasmultret(cc->v.k)) {
515 luaK_setmultret(fs, &cc->v);
516 luaK_setlist(fs, cc->t->u.s.info, cc->na, LUA_MULTRET);
517 cc->na--; /* do not count last expression (unknown number of elements) */
518 }
519 else {
520 if (cc->v.k != VVOID)
521 luaK_exp2nextreg(fs, &cc->v);
522 luaK_setlist(fs, cc->t->u.s.info, cc->na, cc->tostore);
523 }
524}
525
526
527static void listfield (LexState *ls, struct ConsControl *cc) {
528 expr(ls, &cc->v);
529 luaY_checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
530 cc->na++;
531 cc->tostore++;
532}
533
534
535static void constructor (LexState *ls, expdesc *t) {
536 /* constructor -> ?? */
537 FuncState *fs = ls->fs;
538 int line = ls->linenumber;
539 int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0);
540 struct ConsControl cc;
541 cc.na = cc.nh = cc.tostore = 0;
542 cc.t = t;
543 init_exp(t, VRELOCABLE, pc);
544 init_exp(&cc.v, VVOID, 0); /* no value (yet) */
545 luaK_exp2nextreg(ls->fs, t); /* fix it at stack top (for gc) */
546 checknext(ls, '{');
547 do {
548 lua_assert(cc.v.k == VVOID || cc.tostore > 0);
549 if (ls->t.token == '}') break;
550 closelistfield(fs, &cc);
551 switch(ls->t.token) {
552 case TK_NAME: { /* may be listfields or recfields */
553 luaX_lookahead(ls);
554 if (ls->lookahead.token != '=') /* expression? */
555 listfield(ls, &cc);
556 else
557 recfield(ls, &cc);
558 break;
559 }
560 case '[': { /* constructor_item -> recfield */
561 recfield(ls, &cc);
562 break;
563 }
564 default: { /* constructor_part -> listfield */
565 listfield(ls, &cc);
566 break;
567 }
568 }
569 } while (testnext(ls, ',') || testnext(ls, ';'));
570 check_match(ls, '}', '{', line);
571 lastlistfield(fs, &cc);
572 SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
573 SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */
574}
575
576/* }====================================================================== */
577
578
579
580static void parlist (LexState *ls) {
581 /* parlist -> [ param { `,' param } ] */
582 FuncState *fs = ls->fs;
583 Proto *f = fs->f;
584 int nparams = 0;
585 f->is_vararg = 0;
586 if (ls->t.token != ')') { /* is `parlist' not empty? */
587 do {
588 switch (ls->t.token) {
589 case TK_NAME: { /* param -> NAME */
590 new_localvar(ls, str_checkname(ls), nparams++);
591 break;
592 }
593 case TK_DOTS: { /* param -> `...' */
594 luaX_next(ls);
595#if defined(LUA_COMPAT_VARARG)
596 /* use `arg' as default name */
597 new_localvarliteral(ls, "arg", nparams++);
598 f->is_vararg = VARARG_HASARG | VARARG_NEEDSARG;
599#endif
600 f->is_vararg |= VARARG_ISVARARG;
601 break;
602 }
603 default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected");
604 }
605 } while (!f->is_vararg && testnext(ls, ','));
606 }
607 adjustlocalvars(ls, nparams);
608 //f->numparams = cast_byte(fs->nactvar - (f->is_vararg & VARARG_HASARG));
609#if defined(LUA_COMPAT_VARARG)
610 f->numparams = cast_byte(fs->nactvar - (f->is_vararg & VARARG_HASARG));
611#else
612 f->numparams = cast_byte(fs->nactvar);
613#endif
614 luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */
615}
616
617
618static void body (LexState *ls, expdesc *e, int needself, int line) {
619 /* body -> `(' parlist `)' chunk END */
620 FuncState new_fs;
621 open_func(ls, &new_fs);
622 new_fs.f->linedefined = line;
623 checknext(ls, '(');
624 if (needself) {
625 new_localvarliteral(ls, "self", 0);
626 adjustlocalvars(ls, 1);
627 }
628 parlist(ls);
629 checknext(ls, ')');
630 chunk(ls);
631 new_fs.f->lastlinedefined = ls->linenumber;
632 check_match(ls, TK_END, TK_FUNCTION, line);
633 close_func(ls);
634 pushclosure(ls, &new_fs, e);
635}
636
637
638static int explist1 (LexState *ls, expdesc *v) {
639 /* explist1 -> expr { `,' expr } */
640 int n = 1; /* at least one expression */
641 expr(ls, v);
642 while (testnext(ls, ',')) {
643 luaK_exp2nextreg(ls->fs, v);
644 expr(ls, v);
645 n++;
646 }
647 return n;
648}
649
650
651static void funcargs (LexState *ls, expdesc *f) {
652 FuncState *fs = ls->fs;
653 expdesc args;
654 int base, nparams;
655 int line = ls->linenumber;
656 switch (ls->t.token) {
657 case '(': { /* funcargs -> `(' [ explist1 ] `)' */
658 if (line != ls->lastline)
659 luaX_syntaxerror(ls,"ambiguous syntax (function call x new statement)");
660 luaX_next(ls);
661 if (ls->t.token == ')') /* arg list is empty? */
662 args.k = VVOID;
663 else {
664 explist1(ls, &args);
665 luaK_setmultret(fs, &args);
666 }
667 check_match(ls, ')', '(', line);
668 break;
669 }
670 case '{': { /* funcargs -> constructor */
671 constructor(ls, &args);
672 break;
673 }
674 case TK_STRING: { /* funcargs -> STRING */
675 codestring(ls, &args, ls->t.seminfo.ts);
676 luaX_next(ls); /* must use `seminfo' before `next' */
677 break;
678 }
679 default: {
680 luaX_syntaxerror(ls, "function arguments expected");
681 return;
682 }
683 }
684 lua_assert(f->k == VNONRELOC);
685 base = f->u.s.info; /* base register for call */
686 if (hasmultret(args.k))
687 nparams = LUA_MULTRET; /* open call */
688 else {
689 if (args.k != VVOID)
690 luaK_exp2nextreg(fs, &args); /* close last argument */
691 nparams = fs->freereg - (base+1);
692 }
693 init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2));
694 luaK_fixline(fs, line);
695 fs->freereg = base+1; /* call remove function and arguments and leaves
696 (unless changed) one result */
697}
698
699
700
701
702/*
703** {======================================================================
704** Expression parsing
705** =======================================================================
706*/
707
708
709static void prefixexp (LexState *ls, expdesc *v) {
710 /* prefixexp -> NAME | '(' expr ')' */
711 switch (ls->t.token) {
712 case '(': {
713 int line = ls->linenumber;
714 luaX_next(ls);
715 expr(ls, v);
716 check_match(ls, ')', '(', line);
717 luaK_dischargevars(ls->fs, v);
718 return;
719 }
720 case TK_NAME: {
721 singlevar(ls, v);
722 return;
723 }
724 default: {
725 luaX_syntaxerror(ls, "unexpected symbol");
726 return;
727 }
728 }
729}
730
731
732static void primaryexp (LexState *ls, expdesc *v) {
733 /* primaryexp ->
734 prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */
735 FuncState *fs = ls->fs;
736 prefixexp(ls, v);
737 for (;;) {
738 switch (ls->t.token) {
739 case '.': { /* field */
740 field(ls, v);
741 break;
742 }
743 case '[': { /* `[' exp1 `]' */
744 expdesc key;
745 luaK_exp2anyreg(fs, v);
746 yindex(ls, &key);
747 luaK_indexed(fs, v, &key);
748 break;
749 }
750 case ':': { /* `:' NAME funcargs */
751 expdesc key;
752 luaX_next(ls);
753 checkname(ls, &key);
754 luaK_self(fs, v, &key);
755 funcargs(ls, v);
756 break;
757 }
758 case '(': case TK_STRING: case '{': { /* funcargs */
759 luaK_exp2nextreg(fs, v);
760 funcargs(ls, v);
761 break;
762 }
763 default: return;
764 }
765 }
766}
767
768
769static void simpleexp (LexState *ls, expdesc *v) {
770 /* simpleexp -> NUMBER | STRING | NIL | true | false | ... |
771 constructor | FUNCTION body | primaryexp */
772 switch (ls->t.token) {
773 case TK_NUMBER: {
774 init_exp(v, VKNUM, 0);
775 v->u.nval = ls->t.seminfo.r;
776 break;
777 }
778 case TK_STRING: {
779 codestring(ls, v, ls->t.seminfo.ts);
780 break;
781 }
782 case TK_NIL: {
783 init_exp(v, VNIL, 0);
784 break;
785 }
786 case TK_TRUE: {
787 init_exp(v, VTRUE, 0);
788 break;
789 }
790 case TK_FALSE: {
791 init_exp(v, VFALSE, 0);
792 break;
793 }
794 case TK_DOTS: { /* vararg */
795 FuncState *fs = ls->fs;
796 check_condition(ls, fs->f->is_vararg,
797 "cannot use " LUA_QL("...") " outside a vararg function");
798 fs->f->is_vararg &= ~VARARG_NEEDSARG; /* don't need 'arg' */
799 init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
800 break;
801 }
802 case '{': { /* constructor */
803 constructor(ls, v);
804 return;
805 }
806 case TK_FUNCTION: {
807 luaX_next(ls);
808 body(ls, v, 0, ls->linenumber);
809 return;
810 }
811 default: {
812 primaryexp(ls, v);
813 return;
814 }
815 }
816 luaX_next(ls);
817}
818
819
820static UnOpr getunopr (int op) {
821 switch (op) {
822 case TK_NOT: return OPR_NOT;
823 case '-': return OPR_MINUS;
824 case '#': return OPR_LEN;
825 default: return OPR_NOUNOPR;
826 }
827}
828
829
830static BinOpr getbinopr (int op) {
831 switch (op) {
832 case '+': return OPR_ADD;
833 case '-': return OPR_SUB;
834 case '*': return OPR_MUL;
835 case '/': return OPR_DIV;
836 case '%': return OPR_MOD;
837 case '^': return OPR_POW;
838 case TK_CONCAT: return OPR_CONCAT;
839 case TK_NE: return OPR_NE;
840 case TK_EQ: return OPR_EQ;
841 case '<': return OPR_LT;
842 case TK_LE: return OPR_LE;
843 case '>': return OPR_GT;
844 case TK_GE: return OPR_GE;
845 case TK_AND: return OPR_AND;
846 case TK_OR: return OPR_OR;
847 default: return OPR_NOBINOPR;
848 }
849}
850
851
852static const struct {
853 lu_byte left; /* left priority for each binary operator */
854 lu_byte right; /* right priority */
855} priority[] = { /* ORDER OPR */
856 {6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `/' `%' */
857 {10, 9}, {5, 4}, /* power and concat (right associative) */
858 {3, 3}, {3, 3}, /* equality and inequality */
859 {3, 3}, {3, 3}, {3, 3}, {3, 3}, /* order */
860 {2, 2}, {1, 1} /* logical (and/or) */
861};
862
863#define UNARY_PRIORITY 8 /* priority for unary operators */
864
865
866/*
867** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
868** where `binop' is any binary operator with a priority higher than `limit'
869*/
870static BinOpr subexpr (LexState *ls, expdesc *v, unsigned int limit) {
871 BinOpr op;
872 UnOpr uop;
873 enterlevel(ls);
874 uop = getunopr(ls->t.token);
875 if (uop != OPR_NOUNOPR) {
876 luaX_next(ls);
877 subexpr(ls, v, UNARY_PRIORITY);
878 luaK_prefix(ls->fs, uop, v);
879 }
880 else simpleexp(ls, v);
881 /* expand while operators have priorities higher than `limit' */
882 op = getbinopr(ls->t.token);
883 while (op != OPR_NOBINOPR && priority[op].left > limit) {
884 expdesc v2;
885 BinOpr nextop;
886 luaX_next(ls);
887 luaK_infix(ls->fs, op, v);
888 /* read sub-expression with higher priority */
889 nextop = subexpr(ls, &v2, priority[op].right);
890 luaK_posfix(ls->fs, op, v, &v2);
891 op = nextop;
892 }
893 leavelevel(ls);
894 return op; /* return first untreated operator */
895}
896
897
898static void expr (LexState *ls, expdesc *v) {
899 subexpr(ls, v, 0);
900}
901
902/* }==================================================================== */
903
904
905
906/*
907** {======================================================================
908** Rules for Statements
909** =======================================================================
910*/
911
912
913static int block_follow (int token) {
914 switch (token) {
915 case TK_ELSE: case TK_ELSEIF: case TK_END:
916 case TK_UNTIL: case TK_EOS:
917 return 1;
918 default: return 0;
919 }
920}
921
922
923static void block (LexState *ls) {
924 /* block -> chunk */
925 FuncState *fs = ls->fs;
926 BlockCnt bl;
927 enterblock(fs, &bl, 0);
928 chunk(ls);
929 lua_assert(bl.breaklist == NO_JUMP);
930 leaveblock(fs);
931}
932
933
934/*
935** structure to chain all variables in the left-hand side of an
936** assignment
937*/
938struct LHS_assign {
939 struct LHS_assign *prev;
940 expdesc v; /* variable (global, local, upvalue, or indexed) */
941};
942
943
944/*
945** check whether, in an assignment to a local variable, the local variable
946** is needed in a previous assignment (to a table). If so, save original
947** local value in a safe place and use this safe copy in the previous
948** assignment.
949*/
950static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
951 FuncState *fs = ls->fs;
952 int extra = fs->freereg; /* eventual position to save local variable */
953 int conflict = 0;
954 for (; lh; lh = lh->prev) {
955 if (lh->v.k == VINDEXED) {
956 if (lh->v.u.s.info == v->u.s.info) { /* conflict? */
957 conflict = 1;
958 lh->v.u.s.info = extra; /* previous assignment will use safe copy */
959 }
960 if (lh->v.u.s.aux == v->u.s.info) { /* conflict? */
961 conflict = 1;
962 lh->v.u.s.aux = extra; /* previous assignment will use safe copy */
963 }
964 }
965 }
966 if (conflict) {
967 luaK_codeABC(fs, OP_MOVE, fs->freereg, v->u.s.info, 0); /* make copy */
968 luaK_reserveregs(fs, 1);
969 }
970}
971
972
973static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
974 expdesc e;
975 check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
976 "syntax error");
977 if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
978 struct LHS_assign nv;
979 nv.prev = lh;
980 primaryexp(ls, &nv.v);
981 if (nv.v.k == VLOCAL)
982 check_conflict(ls, lh, &nv.v);
983 luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls,
984 "variables in assignment");
985 assignment(ls, &nv, nvars+1);
986 }
987 else { /* assignment -> `=' explist1 */
988 int nexps;
989 checknext(ls, '=');
990 nexps = explist1(ls, &e);
991 if (nexps != nvars) {
992 adjust_assign(ls, nvars, nexps, &e);
993 if (nexps > nvars)
994 ls->fs->freereg -= nexps - nvars; /* remove extra values */
995 }
996 else {
997 luaK_setoneret(ls->fs, &e); /* close last expression */
998 luaK_storevar(ls->fs, &lh->v, &e);
999 return; /* avoid default */
1000 }
1001 }
1002 init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
1003 luaK_storevar(ls->fs, &lh->v, &e);
1004}
1005
1006
1007static int cond (LexState *ls) {
1008 /* cond -> exp */
1009 expdesc v;
1010 expr(ls, &v); /* read condition */
1011 if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */
1012 luaK_goiftrue(ls->fs, &v);
1013 return v.f;
1014}
1015
1016
1017static void breakstat (LexState *ls) {
1018 FuncState *fs = ls->fs;
1019 BlockCnt *bl = fs->bl;
1020 int upval = 0;
1021 while (bl && !bl->isbreakable) {
1022 upval |= bl->upval;
1023 bl = bl->previous;
1024 }
1025 if (!bl)
1026 luaX_syntaxerror(ls, "no loop to break");
1027 if (upval)
1028 luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
1029 luaK_concat(fs, &bl->breaklist, luaK_jump(fs));
1030}
1031
1032
1033static void whilestat (LexState *ls, int line) {
1034 /* whilestat -> WHILE cond DO block END */
1035 FuncState *fs = ls->fs;
1036 int whileinit;
1037 int condexit;
1038 BlockCnt bl;
1039 luaX_next(ls); /* skip WHILE */
1040 whileinit = luaK_getlabel(fs);
1041 condexit = cond(ls);
1042 enterblock(fs, &bl, 1);
1043 checknext(ls, TK_DO);
1044 block(ls);
1045 luaK_patchlist(fs, luaK_jump(fs), whileinit);
1046 check_match(ls, TK_END, TK_WHILE, line);
1047 leaveblock(fs);
1048 luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
1049}
1050
1051
1052static void repeatstat (LexState *ls, int line) {
1053 /* repeatstat -> REPEAT block UNTIL cond */
1054 int condexit;
1055 FuncState *fs = ls->fs;
1056 int repeat_init = luaK_getlabel(fs);
1057 BlockCnt bl1, bl2;
1058 enterblock(fs, &bl1, 1); /* loop block */
1059 enterblock(fs, &bl2, 0); /* scope block */
1060 luaX_next(ls); /* skip REPEAT */
1061 chunk(ls);
1062 check_match(ls, TK_UNTIL, TK_REPEAT, line);
1063 condexit = cond(ls); /* read condition (inside scope block) */
1064 if (!bl2.upval) { /* no upvalues? */
1065 leaveblock(fs); /* finish scope */
1066 luaK_patchlist(ls->fs, condexit, repeat_init); /* close the loop */
1067 }
1068 else { /* complete semantics when there are upvalues */
1069 breakstat(ls); /* if condition then break */
1070 luaK_patchtohere(ls->fs, condexit); /* else... */
1071 leaveblock(fs); /* finish scope... */
1072 luaK_patchlist(ls->fs, luaK_jump(fs), repeat_init); /* and repeat */
1073 }
1074 leaveblock(fs); /* finish loop */
1075}
1076
1077
1078static int exp1 (LexState *ls) {
1079 expdesc e;
1080 int k;
1081 expr(ls, &e);
1082 k = e.k;
1083 luaK_exp2nextreg(ls->fs, &e);
1084 return k;
1085}
1086
1087
1088static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
1089 /* forbody -> DO block */
1090 BlockCnt bl;
1091 FuncState *fs = ls->fs;
1092 int prep, endfor;
1093 adjustlocalvars(ls, 3); /* control variables */
1094 checknext(ls, TK_DO);
1095 prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
1096 enterblock(fs, &bl, 0); /* scope for declared variables */
1097 adjustlocalvars(ls, nvars);
1098 luaK_reserveregs(fs, nvars);
1099 block(ls);
1100 leaveblock(fs); /* end of scope for declared variables */
1101 luaK_patchtohere(fs, prep);
1102 endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
1103 luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars);
1104 luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
1105 luaK_patchlist(fs, (isnum ? endfor : luaK_jump(fs)), prep + 1);
1106}
1107
1108
1109static void fornum (LexState *ls, TString *varname, int line) {
1110 /* fornum -> NAME = exp1,exp1[,exp1] forbody */
1111 FuncState *fs = ls->fs;
1112 int base = fs->freereg;
1113 new_localvarliteral(ls, "(for index)", 0);
1114 new_localvarliteral(ls, "(for limit)", 1);
1115 new_localvarliteral(ls, "(for step)", 2);
1116 new_localvar(ls, varname, 3);
1117 checknext(ls, '=');
1118 exp1(ls); /* initial value */
1119 checknext(ls, ',');
1120 exp1(ls); /* limit */
1121 if (testnext(ls, ','))
1122 exp1(ls); /* optional step */
1123 else { /* default step = 1 */
1124 luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1));
1125 luaK_reserveregs(fs, 1);
1126 }
1127 forbody(ls, base, line, 1, 1);
1128}
1129
1130
1131static void forlist (LexState *ls, TString *indexname) {
1132 /* forlist -> NAME {,NAME} IN explist1 forbody */
1133 FuncState *fs = ls->fs;
1134 expdesc e;
1135 int nvars = 0;
1136 int line;
1137 int base = fs->freereg;
1138 /* create control variables */
1139 new_localvarliteral(ls, "(for generator)", nvars++);
1140 new_localvarliteral(ls, "(for state)", nvars++);
1141 new_localvarliteral(ls, "(for control)", nvars++);
1142 /* create declared variables */
1143 new_localvar(ls, indexname, nvars++);
1144 while (testnext(ls, ','))
1145 new_localvar(ls, str_checkname(ls), nvars++);
1146 checknext(ls, TK_IN);
1147 line = ls->linenumber;
1148 adjust_assign(ls, 3, explist1(ls, &e), &e);
1149 luaK_checkstack(fs, 3); /* extra space to call generator */
1150 forbody(ls, base, line, nvars - 3, 0);
1151}
1152
1153
1154static void forstat (LexState *ls, int line) {
1155 /* forstat -> FOR (fornum | forlist) END */
1156 FuncState *fs = ls->fs;
1157 TString *varname;
1158 BlockCnt bl;
1159 enterblock(fs, &bl, 1); /* scope for loop and control variables */
1160 luaX_next(ls); /* skip `for' */
1161 varname = str_checkname(ls); /* first variable name */
1162 switch (ls->t.token) {
1163 case '=': fornum(ls, varname, line); break;
1164 case ',': case TK_IN: forlist(ls, varname); break;
1165 default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected");
1166 }
1167 check_match(ls, TK_END, TK_FOR, line);
1168 leaveblock(fs); /* loop scope (`break' jumps to this point) */
1169}
1170
1171
1172static int test_then_block (LexState *ls) {
1173 /* test_then_block -> [IF | ELSEIF] cond THEN block */
1174 int condexit;
1175 luaX_next(ls); /* skip IF or ELSEIF */
1176 condexit = cond(ls);
1177 checknext(ls, TK_THEN);
1178 block(ls); /* `then' part */
1179 return condexit;
1180}
1181
1182
1183static void ifstat (LexState *ls, int line) {
1184 /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
1185 FuncState *fs = ls->fs;
1186 int flist;
1187 int escapelist = NO_JUMP;
1188 flist = test_then_block(ls); /* IF cond THEN block */
1189 while (ls->t.token == TK_ELSEIF) {
1190 luaK_concat(fs, &escapelist, luaK_jump(fs));
1191 luaK_patchtohere(fs, flist);
1192 flist = test_then_block(ls); /* ELSEIF cond THEN block */
1193 }
1194 if (ls->t.token == TK_ELSE) {
1195 luaK_concat(fs, &escapelist, luaK_jump(fs));
1196 luaK_patchtohere(fs, flist);
1197 luaX_next(ls); /* skip ELSE (after patch, for correct line info) */
1198 block(ls); /* `else' part */
1199 }
1200 else
1201 luaK_concat(fs, &escapelist, flist);
1202 luaK_patchtohere(fs, escapelist);
1203 check_match(ls, TK_END, TK_IF, line);
1204}
1205
1206
1207static void localfunc (LexState *ls) {
1208 expdesc v, b;
1209 FuncState *fs = ls->fs;
1210 new_localvar(ls, str_checkname(ls), 0);
1211 init_exp(&v, VLOCAL, fs->freereg);
1212 luaK_reserveregs(fs, 1);
1213 adjustlocalvars(ls, 1);
1214 body(ls, &b, 0, ls->linenumber);
1215 luaK_storevar(fs, &v, &b);
1216 /* debug information will only see the variable after this point! */
1217 getlocvar(fs, fs->nactvar - 1).startpc = fs->pc;
1218}
1219
1220
1221static void localstat (LexState *ls) {
1222 /* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */
1223 int nvars = 0;
1224 int nexps;
1225 expdesc e;
1226 do {
1227 new_localvar(ls, str_checkname(ls), nvars++);
1228 } while (testnext(ls, ','));
1229 if (testnext(ls, '='))
1230 nexps = explist1(ls, &e);
1231 else {
1232 e.k = VVOID;
1233 nexps = 0;
1234 }
1235 adjust_assign(ls, nvars, nexps, &e);
1236 adjustlocalvars(ls, nvars);
1237}
1238
1239
1240static int funcname (LexState *ls, expdesc *v) {
1241 /* funcname -> NAME {field} [`:' NAME] */
1242 int needself = 0;
1243 singlevar(ls, v);
1244 while (ls->t.token == '.')
1245 field(ls, v);
1246 if (ls->t.token == ':') {
1247 needself = 1;
1248 field(ls, v);
1249 }
1250 return needself;
1251}
1252
1253
1254static void funcstat (LexState *ls, int line) {
1255 /* funcstat -> FUNCTION funcname body */
1256 int needself;
1257 expdesc v, b;
1258 luaX_next(ls); /* skip FUNCTION */
1259 needself = funcname(ls, &v);
1260 body(ls, &b, needself, line);
1261 luaK_storevar(ls->fs, &v, &b);
1262 luaK_fixline(ls->fs, line); /* definition `happens' in the first line */
1263}
1264
1265
1266static void exprstat (LexState *ls) {
1267 /* stat -> func | assignment */
1268 FuncState *fs = ls->fs;
1269 struct LHS_assign v;
1270 primaryexp(ls, &v.v);
1271 if (v.v.k == VCALL) /* stat -> func */
1272 SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */
1273 else { /* stat -> assignment */
1274 v.prev = NULL;
1275 assignment(ls, &v, 1);
1276 }
1277}
1278
1279
1280static void retstat (LexState *ls) {
1281 /* stat -> RETURN explist */
1282 FuncState *fs = ls->fs;
1283 expdesc e;
1284 int first, nret; /* registers with returned values */
1285 luaX_next(ls); /* skip RETURN */
1286 if (block_follow(ls->t.token) || ls->t.token == ';')
1287 first = nret = 0; /* return no values */
1288 else {
1289 nret = explist1(ls, &e); /* optional return values */
1290 if (hasmultret(e.k)) {
1291 luaK_setmultret(fs, &e);
1292 if (e.k == VCALL && nret == 1) { /* tail call? */
1293 SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
1294 lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
1295 }
1296 first = fs->nactvar;
1297 nret = LUA_MULTRET; /* return all values */
1298 }
1299 else {
1300 if (nret == 1) /* only one single value? */
1301 first = luaK_exp2anyreg(fs, &e);
1302 else {
1303 luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
1304 first = fs->nactvar; /* return all `active' values */
1305 lua_assert(nret == fs->freereg - first);
1306 }
1307 }
1308 }
1309 luaK_ret(fs, first, nret);
1310}
1311
1312
1313static int statement (LexState *ls) {
1314 int line = ls->linenumber; /* may be needed for error messages */
1315 switch (ls->t.token) {
1316 case TK_IF: { /* stat -> ifstat */
1317 ifstat(ls, line);
1318 return 0;
1319 }
1320 case TK_WHILE: { /* stat -> whilestat */
1321 whilestat(ls, line);
1322 return 0;
1323 }
1324 case TK_DO: { /* stat -> DO block END */
1325 luaX_next(ls); /* skip DO */
1326 block(ls);
1327 check_match(ls, TK_END, TK_DO, line);
1328 return 0;
1329 }
1330 case TK_FOR: { /* stat -> forstat */
1331 forstat(ls, line);
1332 return 0;
1333 }
1334 case TK_REPEAT: { /* stat -> repeatstat */
1335 repeatstat(ls, line);
1336 return 0;
1337 }
1338 case TK_FUNCTION: {
1339 funcstat(ls, line); /* stat -> funcstat */
1340 return 0;
1341 }
1342 case TK_LOCAL: { /* stat -> localstat */
1343 luaX_next(ls); /* skip LOCAL */
1344 if (testnext(ls, TK_FUNCTION)) /* local function? */
1345 localfunc(ls);
1346 else
1347 localstat(ls);
1348 return 0;
1349 }
1350 case TK_RETURN: { /* stat -> retstat */
1351 retstat(ls);
1352 return 1; /* must be last statement */
1353 }
1354 case TK_BREAK: { /* stat -> breakstat */
1355 luaX_next(ls); /* skip BREAK */
1356 breakstat(ls);
1357 return 1; /* must be last statement */
1358 }
1359 default: {
1360 exprstat(ls);
1361 return 0; /* to avoid warnings */
1362 }
1363 }
1364}
1365
1366
1367static void chunk (LexState *ls) {
1368 /* chunk -> { stat [`;'] } */
1369 int islast = 0;
1370 enterlevel(ls);
1371 while (!islast && !block_follow(ls->t.token)) {
1372 islast = statement(ls);
1373 testnext(ls, ';');
1374 lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg &&
1375 ls->fs->freereg >= ls->fs->nactvar);
1376 ls->fs->freereg = ls->fs->nactvar; /* free registers */
1377 }
1378 leavelevel(ls);
1379}
1380
1381/* }====================================================================== */