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- Committer: Bazaar Package Importer
- Author(s): Robert Millan
- Date: 2009-07-25 19:00:53 UTC
- mfrom: (1.6.3 upstream)
- mto: (17.4.13 sid)
- mto: This revision was merged to the branch mainline in revision 53.
- Revision ID: james.westby@ubuntu.com-20090725190053-uv3lm6ya3zxs77ep
Import upstream version 1.96+20090725
- files added:
- include/grub/i386/pc/vbeblit.h
- script/lua
- files removed:
- commands/keystatus.c
- video/fb
- files modified:
- ChangeLog
added
removed
script/lua/lparser.c
1
/*
2
** $Id: lparser.c,v 2.42.1.3 2007/12/28 15:32:23 roberto Exp $
3
** Lua Parser
4
** See Copyright Notice in lua.h
5
*/
6
7
#if 0
8
#include <string.h>
9
#endif
10
11
#define lparser_c
12
#define LUA_CORE
13
14
#include "lua.h"
15
16
#include "lcode.h"
17
#include "ldebug.h"
18
#include "ldo.h"
19
#include "lfunc.h"
20
#include "llex.h"
21
#include "lmem.h"
22
#include "lobject.h"
23
#include "lopcodes.h"
24
#include "lparser.h"
25
#include "lstate.h"
26
#include "lstring.h"
27
#include "ltable.h"
28
29
30
31
#define hasmultret(k) ((k) == VCALL || (k) == VVARARG)
32
33
#define getlocvar(fs, i) ((fs)->f->locvars[(fs)->actvar[i]])
34
35
#define luaY_checklimit(fs,v,l,m) if ((v)>(l)) errorlimit(fs,l,m)
36
37
38
/*
39
** nodes for block list (list of active blocks)
40
*/
41
typedef struct BlockCnt {
42
struct BlockCnt *previous; /* chain */
43
int breaklist; /* list of jumps out of this loop */
44
lu_byte nactvar; /* # active locals outside the breakable structure */
45
lu_byte upval; /* true if some variable in the block is an upvalue */
46
lu_byte isbreakable; /* true if `block' is a loop */
47
} BlockCnt;
48
49
50
51
/*
52
** prototypes for recursive non-terminal functions
53
*/
54
static void chunk (LexState *ls);
55
static void expr (LexState *ls, expdesc *v);
56
57
58
static void anchor_token (LexState *ls) {
59
if (ls->t.token == TK_NAME || ls->t.token == TK_STRING) {
60
TString *ts = ls->t.seminfo.ts;
61
luaX_newstring(ls, getstr(ts), ts->tsv.len);
62
}
63
}
64
65
66
static void error_expected (LexState *ls, int token) {
67
luaX_syntaxerror(ls,
68
luaO_pushfstring(ls->L, LUA_QS " expected", luaX_token2str(ls, token)));
69
}
70
71
72
static void errorlimit (FuncState *fs, int limit, const char *what) {
73
const char *msg = (fs->f->linedefined == 0) ?
74
luaO_pushfstring(fs->L, "main function has more than %d %s", limit, what) :
75
luaO_pushfstring(fs->L, "function at line %d has more than %d %s",
76
fs->f->linedefined, limit, what);
77
luaX_lexerror(fs->ls, msg, 0);
78
}
79
80
81
static int testnext (LexState *ls, int c) {
82
if (ls->t.token == c) {
83
luaX_next(ls);
84
return 1;
85
}
86
else return 0;
87
}
88
89
90
static void check (LexState *ls, int c) {
91
if (ls->t.token != c)
92
error_expected(ls, c);
93
}
94
95
static void checknext (LexState *ls, int c) {
96
check(ls, c);
97
luaX_next(ls);
98
}
99
100
101
#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); }
102
103
104
105
static void check_match (LexState *ls, int what, int who, int where) {
106
if (!testnext(ls, what)) {
107
if (where == ls->linenumber)
108
error_expected(ls, what);
109
else {
110
luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
111
LUA_QS " expected (to close " LUA_QS " at line %d)",
112
luaX_token2str(ls, what), luaX_token2str(ls, who), where));
113
}
114
}
115
}
116
117
118
static TString *str_checkname (LexState *ls) {
119
TString *ts;
120
check(ls, TK_NAME);
121
ts = ls->t.seminfo.ts;
122
luaX_next(ls);
123
return ts;
124
}
125
126
127
static void init_exp (expdesc *e, expkind k, int i) {
128
e->f = e->t = NO_JUMP;
129
e->k = k;
130
e->u.s.info = i;
131
}
132
133
134
static void codestring (LexState *ls, expdesc *e, TString *s) {
135
init_exp(e, VK, luaK_stringK(ls->fs, s));
136
}
137
138
139
static void checkname(LexState *ls, expdesc *e) {
140
codestring(ls, e, str_checkname(ls));
141
}
142
143
144
static int registerlocalvar (LexState *ls, TString *varname) {
145
FuncState *fs = ls->fs;
146
Proto *f = fs->f;
147
int oldsize = f->sizelocvars;
148
luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars,
149
LocVar, SHRT_MAX, "too many local variables");
150
while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL;
151
f->locvars[fs->nlocvars].varname = varname;
152
luaC_objbarrier(ls->L, f, varname);
153
return fs->nlocvars++;
154
}
155
156
157
#define new_localvarliteral(ls,v,n) \
158
new_localvar(ls, luaX_newstring(ls, "" v, (sizeof(v)/sizeof(char))-1), n)
159
160
161
static void new_localvar (LexState *ls, TString *name, int n) {
162
FuncState *fs = ls->fs;
163
luaY_checklimit(fs, fs->nactvar+n+1, LUAI_MAXVARS, "local variables");
164
fs->actvar[fs->nactvar+n] = cast(unsigned short, registerlocalvar(ls, name));
165
}
166
167
168
static void adjustlocalvars (LexState *ls, int nvars) {
169
FuncState *fs = ls->fs;
170
fs->nactvar = cast_byte(fs->nactvar + nvars);
171
for (; nvars; nvars--) {
172
getlocvar(fs, fs->nactvar - nvars).startpc = fs->pc;
173
}
174
}
175
176
177
static void removevars (LexState *ls, int tolevel) {
178
FuncState *fs = ls->fs;
179
while (fs->nactvar > tolevel)
180
getlocvar(fs, --fs->nactvar).endpc = fs->pc;
181
}
182
183
184
static int indexupvalue (FuncState *fs, TString *name, expdesc *v) {
185
int i;
186
Proto *f = fs->f;
187
int oldsize = f->sizeupvalues;
188
for (i=0; i<f->nups; i++) {
189
if (fs->upvalues[i].k == v->k && fs->upvalues[i].info == v->u.s.info) {
190
lua_assert(f->upvalues[i] == name);
191
return i;
192
}
193
}
194
/* new one */
195
luaY_checklimit(fs, f->nups + 1, LUAI_MAXUPVALUES, "upvalues");
196
luaM_growvector(fs->L, f->upvalues, f->nups, f->sizeupvalues,
197
TString *, MAX_INT, "");
198
while (oldsize < f->sizeupvalues) f->upvalues[oldsize++] = NULL;
199
f->upvalues[f->nups] = name;
200
luaC_objbarrier(fs->L, f, name);
201
lua_assert(v->k == VLOCAL || v->k == VUPVAL);
202
fs->upvalues[f->nups].k = cast_byte(v->k);
203
fs->upvalues[f->nups].info = cast_byte(v->u.s.info);
204
return f->nups++;
205
}
206
207
208
static int searchvar (FuncState *fs, TString *n) {
209
int i;
210
for (i=fs->nactvar-1; i >= 0; i--) {
211
if (n == getlocvar(fs, i).varname)
212
return i;
213
}
214
return -1; /* not found */
215
}
216
217
218
static void markupval (FuncState *fs, int level) {
219
BlockCnt *bl = fs->bl;
220
while (bl && bl->nactvar > level) bl = bl->previous;
221
if (bl) bl->upval = 1;
222
}
223
224
225
static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) {
226
if (fs == NULL) { /* no more levels? */
227
init_exp(var, VGLOBAL, NO_REG); /* default is global variable */
228
return VGLOBAL;
229
}
230
else {
231
int v = searchvar(fs, n); /* look up at current level */
232
if (v >= 0) {
233
init_exp(var, VLOCAL, v);
234
if (!base)
235
markupval(fs, v); /* local will be used as an upval */
236
return VLOCAL;
237
}
238
else { /* not found at current level; try upper one */
239
if (singlevaraux(fs->prev, n, var, 0) == VGLOBAL)
240
return VGLOBAL;
241
var->u.s.info = indexupvalue(fs, n, var); /* else was LOCAL or UPVAL */
242
var->k = VUPVAL; /* upvalue in this level */
243
return VUPVAL;
244
}
245
}
246
}
247
248
249
static void singlevar (LexState *ls, expdesc *var) {
250
TString *varname = str_checkname(ls);
251
FuncState *fs = ls->fs;
252
if (singlevaraux(fs, varname, var, 1) == VGLOBAL)
253
var->u.s.info = luaK_stringK(fs, varname); /* info points to global name */
254
}
255
256
257
static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) {
258
FuncState *fs = ls->fs;
259
int extra = nvars - nexps;
260
if (hasmultret(e->k)) {
261
extra++; /* includes call itself */
262
if (extra < 0) extra = 0;
263
luaK_setreturns(fs, e, extra); /* last exp. provides the difference */
264
if (extra > 1) luaK_reserveregs(fs, extra-1);
265
}
266
else {
267
if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */
268
if (extra > 0) {
269
int reg = fs->freereg;
270
luaK_reserveregs(fs, extra);
271
luaK_nil(fs, reg, extra);
272
}
273
}
274
}
275
276
277
static void enterlevel (LexState *ls) {
278
if (++ls->L->nCcalls > LUAI_MAXCCALLS)
279
luaX_lexerror(ls, "chunk has too many syntax levels", 0);
280
}
281
282
283
#define leavelevel(ls) ((ls)->L->nCcalls--)
284
285
286
static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isbreakable) {
287
bl->breaklist = NO_JUMP;
288
bl->isbreakable = isbreakable;
289
bl->nactvar = fs->nactvar;
290
bl->upval = 0;
291
bl->previous = fs->bl;
292
fs->bl = bl;
293
lua_assert(fs->freereg == fs->nactvar);
294
}
295
296
297
static void leaveblock (FuncState *fs) {
298
BlockCnt *bl = fs->bl;
299
fs->bl = bl->previous;
300
removevars(fs->ls, bl->nactvar);
301
if (bl->upval)
302
luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
303
/* a block either controls scope or breaks (never both) */
304
lua_assert(!bl->isbreakable || !bl->upval);
305
lua_assert(bl->nactvar == fs->nactvar);
306
fs->freereg = fs->nactvar; /* free registers */
307
luaK_patchtohere(fs, bl->breaklist);
308
}
309
310
311
static void pushclosure (LexState *ls, FuncState *func, expdesc *v) {
312
FuncState *fs = ls->fs;
313
Proto *f = fs->f;
314
int oldsize = f->sizep;
315
int i;
316
luaM_growvector(ls->L, f->p, fs->np, f->sizep, Proto *,
317
MAXARG_Bx, "constant table overflow");
318
while (oldsize < f->sizep) f->p[oldsize++] = NULL;
319
f->p[fs->np++] = func->f;
320
luaC_objbarrier(ls->L, f, func->f);
321
init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np-1));
322
for (i=0; i<func->f->nups; i++) {
323
OpCode o = (func->upvalues[i].k == VLOCAL) ? OP_MOVE : OP_GETUPVAL;
324
luaK_codeABC(fs, o, 0, func->upvalues[i].info, 0);
325
}
326
}
327
328
329
static void open_func (LexState *ls, FuncState *fs) {
330
lua_State *L = ls->L;
331
Proto *f = luaF_newproto(L);
332
fs->f = f;
333
fs->prev = ls->fs; /* linked list of funcstates */
334
fs->ls = ls;
335
fs->L = L;
336
ls->fs = fs;
337
fs->pc = 0;
338
fs->lasttarget = -1;
339
fs->jpc = NO_JUMP;
340
fs->freereg = 0;
341
fs->nk = 0;
342
fs->np = 0;
343
fs->nlocvars = 0;
344
fs->nactvar = 0;
345
fs->bl = NULL;
346
f->source = ls->source;
347
f->maxstacksize = 2; /* registers 0/1 are always valid */
348
fs->h = luaH_new(L, 0, 0);
349
/* anchor table of constants and prototype (to avoid being collected) */
350
sethvalue2s(L, L->top, fs->h);
351
incr_top(L);
352
setptvalue2s(L, L->top, f);
353
incr_top(L);
354
}
355
356
357
static void close_func (LexState *ls) {
358
lua_State *L = ls->L;
359
FuncState *fs = ls->fs;
360
Proto *f = fs->f;
361
removevars(ls, 0);
362
luaK_ret(fs, 0, 0); /* final return */
363
luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction);
364
f->sizecode = fs->pc;
365
luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int);
366
f->sizelineinfo = fs->pc;
367
luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue);
368
f->sizek = fs->nk;
369
luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *);
370
f->sizep = fs->np;
371
luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar);
372
f->sizelocvars = fs->nlocvars;
373
luaM_reallocvector(L, f->upvalues, f->sizeupvalues, f->nups, TString *);
374
f->sizeupvalues = f->nups;
375
lua_assert(luaG_checkcode(f));
376
lua_assert(fs->bl == NULL);
377
ls->fs = fs->prev;
378
L->top -= 2; /* remove table and prototype from the stack */
379
/* last token read was anchored in defunct function; must reanchor it */
380
if (fs) anchor_token(ls);
381
}
382
383
384
Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, const char *name) {
385
struct LexState lexstate;
386
struct FuncState funcstate;
387
lexstate.buff = buff;
388
luaX_setinput(L, &lexstate, z, luaS_new(L, name));
389
open_func(&lexstate, &funcstate);
390
funcstate.f->is_vararg = VARARG_ISVARARG; /* main func. is always vararg */
391
luaX_next(&lexstate); /* read first token */
392
chunk(&lexstate);
393
check(&lexstate, TK_EOS);
394
close_func(&lexstate);
395
lua_assert(funcstate.prev == NULL);
396
lua_assert(funcstate.f->nups == 0);
397
lua_assert(lexstate.fs == NULL);
398
return funcstate.f;
399
}
400
401
402
403
/*============================================================*/
404
/* GRAMMAR RULES */
405
/*============================================================*/
406
407
408
static void field (LexState *ls, expdesc *v) {
409
/* field -> ['.' | ':'] NAME */
410
FuncState *fs = ls->fs;
411
expdesc key;
412
luaK_exp2anyreg(fs, v);
413
luaX_next(ls); /* skip the dot or colon */
414
checkname(ls, &key);
415
luaK_indexed(fs, v, &key);
416
}
417
418
419
static void yindex (LexState *ls, expdesc *v) {
420
/* index -> '[' expr ']' */
421
luaX_next(ls); /* skip the '[' */
422
expr(ls, v);
423
luaK_exp2val(ls->fs, v);
424
checknext(ls, ']');
425
}
426
427
428
/*
429
** {======================================================================
430
** Rules for Constructors
431
** =======================================================================
432
*/
433
434
435
struct ConsControl {
436
expdesc v; /* last list item read */
437
expdesc *t; /* table descriptor */
438
int nh; /* total number of `record' elements */
439
int na; /* total number of array elements */
440
int tostore; /* number of array elements pending to be stored */
441
};
442
443
444
static void recfield (LexState *ls, struct ConsControl *cc) {
445
/* recfield -> (NAME | `['exp1`]') = exp1 */
446
FuncState *fs = ls->fs;
447
int reg = ls->fs->freereg;
448
expdesc key, val;
449
int rkkey;
450
if (ls->t.token == TK_NAME) {
451
luaY_checklimit(fs, cc->nh, MAX_INT, "items in a constructor");
452
checkname(ls, &key);
453
}
454
else /* ls->t.token == '[' */
455
yindex(ls, &key);
456
cc->nh++;
457
checknext(ls, '=');
458
rkkey = luaK_exp2RK(fs, &key);
459
expr(ls, &val);
460
luaK_codeABC(fs, OP_SETTABLE, cc->t->u.s.info, rkkey, luaK_exp2RK(fs, &val));
461
fs->freereg = reg; /* free registers */
462
}
463
464
465
static void closelistfield (FuncState *fs, struct ConsControl *cc) {
466
if (cc->v.k == VVOID) return; /* there is no list item */
467
luaK_exp2nextreg(fs, &cc->v);
468
cc->v.k = VVOID;
469
if (cc->tostore == LFIELDS_PER_FLUSH) {
470
luaK_setlist(fs, cc->t->u.s.info, cc->na, cc->tostore); /* flush */
471
cc->tostore = 0; /* no more items pending */
472
}
473
}
474
475
476
static void lastlistfield (FuncState *fs, struct ConsControl *cc) {
477
if (cc->tostore == 0) return;
478
if (hasmultret(cc->v.k)) {
479
luaK_setmultret(fs, &cc->v);
480
luaK_setlist(fs, cc->t->u.s.info, cc->na, LUA_MULTRET);
481
cc->na--; /* do not count last expression (unknown number of elements) */
482
}
483
else {
484
if (cc->v.k != VVOID)
485
luaK_exp2nextreg(fs, &cc->v);
486
luaK_setlist(fs, cc->t->u.s.info, cc->na, cc->tostore);
487
}
488
}
489
490
491
static void listfield (LexState *ls, struct ConsControl *cc) {
492
expr(ls, &cc->v);
493
luaY_checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor");
494
cc->na++;
495
cc->tostore++;
496
}
497
498
499
static void constructor (LexState *ls, expdesc *t) {
500
/* constructor -> ?? */
501
FuncState *fs = ls->fs;
502
int line = ls->linenumber;
503
int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0);
504
struct ConsControl cc;
505
cc.na = cc.nh = cc.tostore = 0;
506
cc.t = t;
507
init_exp(t, VRELOCABLE, pc);
508
init_exp(&cc.v, VVOID, 0); /* no value (yet) */
509
luaK_exp2nextreg(ls->fs, t); /* fix it at stack top (for gc) */
510
checknext(ls, '{');
511
do {
512
lua_assert(cc.v.k == VVOID || cc.tostore > 0);
513
if (ls->t.token == '}') break;
514
closelistfield(fs, &cc);
515
switch(ls->t.token) {
516
case TK_NAME: { /* may be listfields or recfields */
517
luaX_lookahead(ls);
518
if (ls->lookahead.token != '=') /* expression? */
519
listfield(ls, &cc);
520
else
521
recfield(ls, &cc);
522
break;
523
}
524
case '[': { /* constructor_item -> recfield */
525
recfield(ls, &cc);
526
break;
527
}
528
default: { /* constructor_part -> listfield */
529
listfield(ls, &cc);
530
break;
531
}
532
}
533
} while (testnext(ls, ',') || testnext(ls, ';'));
534
check_match(ls, '}', '{', line);
535
lastlistfield(fs, &cc);
536
SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */
537
SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */
538
}
539
540
/* }====================================================================== */
541
542
543
544
static void parlist (LexState *ls) {
545
/* parlist -> [ param { `,' param } ] */
546
FuncState *fs = ls->fs;
547
Proto *f = fs->f;
548
int nparams = 0;
549
f->is_vararg = 0;
550
if (ls->t.token != ')') { /* is `parlist' not empty? */
551
do {
552
switch (ls->t.token) {
553
case TK_NAME: { /* param -> NAME */
554
new_localvar(ls, str_checkname(ls), nparams++);
555
break;
556
}
557
case TK_DOTS: { /* param -> `...' */
558
luaX_next(ls);
559
#if defined(LUA_COMPAT_VARARG)
560
/* use `arg' as default name */
561
new_localvarliteral(ls, "arg", nparams++);
562
f->is_vararg = VARARG_HASARG | VARARG_NEEDSARG;
563
#endif
564
f->is_vararg |= VARARG_ISVARARG;
565
break;
566
}
567
default: luaX_syntaxerror(ls, "<name> or " LUA_QL("...") " expected");
568
}
569
} while (!f->is_vararg && testnext(ls, ','));
570
}
571
adjustlocalvars(ls, nparams);
572
f->numparams = cast_byte(fs->nactvar - (f->is_vararg & VARARG_HASARG));
573
luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */
574
}
575
576
577
static void body (LexState *ls, expdesc *e, int needself, int line) {
578
/* body -> `(' parlist `)' chunk END */
579
FuncState new_fs;
580
open_func(ls, &new_fs);
581
new_fs.f->linedefined = line;
582
checknext(ls, '(');
583
if (needself) {
584
new_localvarliteral(ls, "self", 0);
585
adjustlocalvars(ls, 1);
586
}
587
parlist(ls);
588
checknext(ls, ')');
589
chunk(ls);
590
new_fs.f->lastlinedefined = ls->linenumber;
591
check_match(ls, TK_END, TK_FUNCTION, line);
592
close_func(ls);
593
pushclosure(ls, &new_fs, e);
594
}
595
596
597
static int explist1 (LexState *ls, expdesc *v) {
598
/* explist1 -> expr { `,' expr } */
599
int n = 1; /* at least one expression */
600
expr(ls, v);
601
while (testnext(ls, ',')) {
602
luaK_exp2nextreg(ls->fs, v);
603
expr(ls, v);
604
n++;
605
}
606
return n;
607
}
608
609
610
static void funcargs (LexState *ls, expdesc *f) {
611
FuncState *fs = ls->fs;
612
expdesc args;
613
int base, nparams;
614
int line = ls->linenumber;
615
switch (ls->t.token) {
616
case '(': { /* funcargs -> `(' [ explist1 ] `)' */
617
if (line != ls->lastline)
618
luaX_syntaxerror(ls,"ambiguous syntax (function call x new statement)");
619
luaX_next(ls);
620
if (ls->t.token == ')') /* arg list is empty? */
621
args.k = VVOID;
622
else {
623
explist1(ls, &args);
624
luaK_setmultret(fs, &args);
625
}
626
check_match(ls, ')', '(', line);
627
break;
628
}
629
case '{': { /* funcargs -> constructor */
630
constructor(ls, &args);
631
break;
632
}
633
case TK_STRING: { /* funcargs -> STRING */
634
codestring(ls, &args, ls->t.seminfo.ts);
635
luaX_next(ls); /* must use `seminfo' before `next' */
636
break;
637
}
638
default: {
639
luaX_syntaxerror(ls, "function arguments expected");
640
return;
641
}
642
}
643
lua_assert(f->k == VNONRELOC);
644
base = f->u.s.info; /* base register for call */
645
if (hasmultret(args.k))
646
nparams = LUA_MULTRET; /* open call */
647
else {
648
if (args.k != VVOID)
649
luaK_exp2nextreg(fs, &args); /* close last argument */
650
nparams = fs->freereg - (base+1);
651
}
652
init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2));
653
luaK_fixline(fs, line);
654
fs->freereg = base+1; /* call remove function and arguments and leaves
655
(unless changed) one result */
656
}
657
658
659
660
661
/*
662
** {======================================================================
663
** Expression parsing
664
** =======================================================================
665
*/
666
667
668
static void prefixexp (LexState *ls, expdesc *v) {
669
/* prefixexp -> NAME | '(' expr ')' */
670
switch (ls->t.token) {
671
case '(': {
672
int line = ls->linenumber;
673
luaX_next(ls);
674
expr(ls, v);
675
check_match(ls, ')', '(', line);
676
luaK_dischargevars(ls->fs, v);
677
return;
678
}
679
case TK_NAME: {
680
singlevar(ls, v);
681
return;
682
}
683
default: {
684
luaX_syntaxerror(ls, "unexpected symbol");
685
return;
686
}
687
}
688
}
689
690
691
static void primaryexp (LexState *ls, expdesc *v) {
692
/* primaryexp ->
693
prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */
694
FuncState *fs = ls->fs;
695
prefixexp(ls, v);
696
for (;;) {
697
switch (ls->t.token) {
698
case '.': { /* field */
699
field(ls, v);
700
break;
701
}
702
case '[': { /* `[' exp1 `]' */
703
expdesc key;
704
luaK_exp2anyreg(fs, v);
705
yindex(ls, &key);
706
luaK_indexed(fs, v, &key);
707
break;
708
}
709
case ':': { /* `:' NAME funcargs */
710
expdesc key;
711
luaX_next(ls);
712
checkname(ls, &key);
713
luaK_self(fs, v, &key);
714
funcargs(ls, v);
715
break;
716
}
717
case '(': case TK_STRING: case '{': { /* funcargs */
718
luaK_exp2nextreg(fs, v);
719
funcargs(ls, v);
720
break;
721
}
722
default: return;
723
}
724
}
725
}
726
727
728
static void simpleexp (LexState *ls, expdesc *v) {
729
/* simpleexp -> NUMBER | STRING | NIL | true | false | ... |
730
constructor | FUNCTION body | primaryexp */
731
switch (ls->t.token) {
732
case TK_NUMBER: {
733
init_exp(v, VKNUM, 0);
734
v->u.nval = ls->t.seminfo.r;
735
break;
736
}
737
case TK_STRING: {
738
codestring(ls, v, ls->t.seminfo.ts);
739
break;
740
}
741
case TK_NIL: {
742
init_exp(v, VNIL, 0);
743
break;
744
}
745
case TK_TRUE: {
746
init_exp(v, VTRUE, 0);
747
break;
748
}
749
case TK_FALSE: {
750
init_exp(v, VFALSE, 0);
751
break;
752
}
753
case TK_DOTS: { /* vararg */
754
FuncState *fs = ls->fs;
755
check_condition(ls, fs->f->is_vararg,
756
"cannot use " LUA_QL("...") " outside a vararg function");
757
fs->f->is_vararg &= ~VARARG_NEEDSARG; /* don't need 'arg' */
758
init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
759
break;
760
}
761
case '{': { /* constructor */
762
constructor(ls, v);
763
return;
764
}
765
case TK_FUNCTION: {
766
luaX_next(ls);
767
body(ls, v, 0, ls->linenumber);
768
return;
769
}
770
default: {
771
primaryexp(ls, v);
772
return;
773
}
774
}
775
luaX_next(ls);
776
}
777
778
779
static UnOpr getunopr (int op) {
780
switch (op) {
781
case TK_NOT: return OPR_NOT;
782
case '-': return OPR_MINUS;
783
case '#': return OPR_LEN;
784
default: return OPR_NOUNOPR;
785
}
786
}
787
788
789
static BinOpr getbinopr (int op) {
790
switch (op) {
791
case '+': return OPR_ADD;
792
case '-': return OPR_SUB;
793
case '*': return OPR_MUL;
794
case '/': return OPR_DIV;
795
case '%': return OPR_MOD;
796
case '^': return OPR_POW;
797
case TK_CONCAT: return OPR_CONCAT;
798
case TK_NE: return OPR_NE;
799
case TK_EQ: return OPR_EQ;
800
case '<': return OPR_LT;
801
case TK_LE: return OPR_LE;
802
case '>': return OPR_GT;
803
case TK_GE: return OPR_GE;
804
case TK_AND: return OPR_AND;
805
case TK_OR: return OPR_OR;
806
default: return OPR_NOBINOPR;
807
}
808
}
809
810
811
static const struct {
812
lu_byte left; /* left priority for each binary operator */
813
lu_byte right; /* right priority */
814
} priority[] = { /* ORDER OPR */
815
{6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `/' `%' */
816
{10, 9}, {5, 4}, /* power and concat (right associative) */
817
{3, 3}, {3, 3}, /* equality and inequality */
818
{3, 3}, {3, 3}, {3, 3}, {3, 3}, /* order */
819
{2, 2}, {1, 1} /* logical (and/or) */
820
};
821
822
#define UNARY_PRIORITY 8 /* priority for unary operators */
823
824
825
/*
826
** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
827
** where `binop' is any binary operator with a priority higher than `limit'
828
*/
829
static BinOpr subexpr (LexState *ls, expdesc *v, unsigned int limit) {
830
BinOpr op;
831
UnOpr uop;
832
enterlevel(ls);
833
uop = getunopr(ls->t.token);
834
if (uop != OPR_NOUNOPR) {
835
luaX_next(ls);
836
subexpr(ls, v, UNARY_PRIORITY);
837
luaK_prefix(ls->fs, uop, v);
838
}
839
else simpleexp(ls, v);
840
/* expand while operators have priorities higher than `limit' */
841
op = getbinopr(ls->t.token);
842
while (op != OPR_NOBINOPR && priority[op].left > limit) {
843
expdesc v2;
844
BinOpr nextop;
845
luaX_next(ls);
846
luaK_infix(ls->fs, op, v);
847
/* read sub-expression with higher priority */
848
nextop = subexpr(ls, &v2, priority[op].right);
849
luaK_posfix(ls->fs, op, v, &v2);
850
op = nextop;
851
}
852
leavelevel(ls);
853
return op; /* return first untreated operator */
854
}
855
856
857
static void expr (LexState *ls, expdesc *v) {
858
subexpr(ls, v, 0);
859
}
860
861
/* }==================================================================== */
862
863
864
865
/*
866
** {======================================================================
867
** Rules for Statements
868
** =======================================================================
869
*/
870
871
872
static int block_follow (int token) {
873
switch (token) {
874
case TK_ELSE: case TK_ELSEIF: case TK_END:
875
case TK_UNTIL: case TK_EOS:
876
return 1;
877
default: return 0;
878
}
879
}
880
881
882
static void block (LexState *ls) {
883
/* block -> chunk */
884
FuncState *fs = ls->fs;
885
BlockCnt bl;
886
enterblock(fs, &bl, 0);
887
chunk(ls);
888
lua_assert(bl.breaklist == NO_JUMP);
889
leaveblock(fs);
890
}
891
892
893
/*
894
** structure to chain all variables in the left-hand side of an
895
** assignment
896
*/
897
struct LHS_assign {
898
struct LHS_assign *prev;
899
expdesc v; /* variable (global, local, upvalue, or indexed) */
900
};
901
902
903
/*
904
** check whether, in an assignment to a local variable, the local variable
905
** is needed in a previous assignment (to a table). If so, save original
906
** local value in a safe place and use this safe copy in the previous
907
** assignment.
908
*/
909
static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) {
910
FuncState *fs = ls->fs;
911
int extra = fs->freereg; /* eventual position to save local variable */
912
int conflict = 0;
913
for (; lh; lh = lh->prev) {
914
if (lh->v.k == VINDEXED) {
915
if (lh->v.u.s.info == v->u.s.info) { /* conflict? */
916
conflict = 1;
917
lh->v.u.s.info = extra; /* previous assignment will use safe copy */
918
}
919
if (lh->v.u.s.aux == v->u.s.info) { /* conflict? */
920
conflict = 1;
921
lh->v.u.s.aux = extra; /* previous assignment will use safe copy */
922
}
923
}
924
}
925
if (conflict) {
926
luaK_codeABC(fs, OP_MOVE, fs->freereg, v->u.s.info, 0); /* make copy */
927
luaK_reserveregs(fs, 1);
928
}
929
}
930
931
932
static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) {
933
expdesc e;
934
check_condition(ls, VLOCAL <= lh->v.k && lh->v.k <= VINDEXED,
935
"syntax error");
936
if (testnext(ls, ',')) { /* assignment -> `,' primaryexp assignment */
937
struct LHS_assign nv;
938
nv.prev = lh;
939
primaryexp(ls, &nv.v);
940
if (nv.v.k == VLOCAL)
941
check_conflict(ls, lh, &nv.v);
942
luaY_checklimit(ls->fs, nvars, LUAI_MAXCCALLS - ls->L->nCcalls,
943
"variables in assignment");
944
assignment(ls, &nv, nvars+1);
945
}
946
else { /* assignment -> `=' explist1 */
947
int nexps;
948
checknext(ls, '=');
949
nexps = explist1(ls, &e);
950
if (nexps != nvars) {
951
adjust_assign(ls, nvars, nexps, &e);
952
if (nexps > nvars)
953
ls->fs->freereg -= nexps - nvars; /* remove extra values */
954
}
955
else {
956
luaK_setoneret(ls->fs, &e); /* close last expression */
957
luaK_storevar(ls->fs, &lh->v, &e);
958
return; /* avoid default */
959
}
960
}
961
init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */
962
luaK_storevar(ls->fs, &lh->v, &e);
963
}
964
965
966
static int cond (LexState *ls) {
967
/* cond -> exp */
968
expdesc v;
969
expr(ls, &v); /* read condition */
970
if (v.k == VNIL) v.k = VFALSE; /* `falses' are all equal here */
971
luaK_goiftrue(ls->fs, &v);
972
return v.f;
973
}
974
975
976
static void breakstat (LexState *ls) {
977
FuncState *fs = ls->fs;
978
BlockCnt *bl = fs->bl;
979
int upval = 0;
980
while (bl && !bl->isbreakable) {
981
upval |= bl->upval;
982
bl = bl->previous;
983
}
984
if (!bl)
985
luaX_syntaxerror(ls, "no loop to break");
986
if (upval)
987
luaK_codeABC(fs, OP_CLOSE, bl->nactvar, 0, 0);
988
luaK_concat(fs, &bl->breaklist, luaK_jump(fs));
989
}
990
991
992
static void whilestat (LexState *ls, int line) {
993
/* whilestat -> WHILE cond DO block END */
994
FuncState *fs = ls->fs;
995
int whileinit;
996
int condexit;
997
BlockCnt bl;
998
luaX_next(ls); /* skip WHILE */
999
whileinit = luaK_getlabel(fs);
1000
condexit = cond(ls);
1001
enterblock(fs, &bl, 1);
1002
checknext(ls, TK_DO);
1003
block(ls);
1004
luaK_patchlist(fs, luaK_jump(fs), whileinit);
1005
check_match(ls, TK_END, TK_WHILE, line);
1006
leaveblock(fs);
1007
luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
1008
}
1009
1010
1011
static void repeatstat (LexState *ls, int line) {
1012
/* repeatstat -> REPEAT block UNTIL cond */
1013
int condexit;
1014
FuncState *fs = ls->fs;
1015
int repeat_init = luaK_getlabel(fs);
1016
BlockCnt bl1, bl2;
1017
enterblock(fs, &bl1, 1); /* loop block */
1018
enterblock(fs, &bl2, 0); /* scope block */
1019
luaX_next(ls); /* skip REPEAT */
1020
chunk(ls);
1021
check_match(ls, TK_UNTIL, TK_REPEAT, line);
1022
condexit = cond(ls); /* read condition (inside scope block) */
1023
if (!bl2.upval) { /* no upvalues? */
1024
leaveblock(fs); /* finish scope */
1025
luaK_patchlist(ls->fs, condexit, repeat_init); /* close the loop */
1026
}
1027
else { /* complete semantics when there are upvalues */
1028
breakstat(ls); /* if condition then break */
1029
luaK_patchtohere(ls->fs, condexit); /* else... */
1030
leaveblock(fs); /* finish scope... */
1031
luaK_patchlist(ls->fs, luaK_jump(fs), repeat_init); /* and repeat */
1032
}
1033
leaveblock(fs); /* finish loop */
1034
}
1035
1036
1037
static int exp1 (LexState *ls) {
1038
expdesc e;
1039
int k;
1040
expr(ls, &e);
1041
k = e.k;
1042
luaK_exp2nextreg(ls->fs, &e);
1043
return k;
1044
}
1045
1046
1047
static void forbody (LexState *ls, int base, int line, int nvars, int isnum) {
1048
/* forbody -> DO block */
1049
BlockCnt bl;
1050
FuncState *fs = ls->fs;
1051
int prep, endfor;
1052
adjustlocalvars(ls, 3); /* control variables */
1053
checknext(ls, TK_DO);
1054
prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs);
1055
enterblock(fs, &bl, 0); /* scope for declared variables */
1056
adjustlocalvars(ls, nvars);
1057
luaK_reserveregs(fs, nvars);
1058
block(ls);
1059
leaveblock(fs); /* end of scope for declared variables */
1060
luaK_patchtohere(fs, prep);
1061
endfor = (isnum) ? luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP) :
1062
luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars);
1063
luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
1064
luaK_patchlist(fs, (isnum ? endfor : luaK_jump(fs)), prep + 1);
1065
}
1066
1067
1068
static void fornum (LexState *ls, TString *varname, int line) {
1069
/* fornum -> NAME = exp1,exp1[,exp1] forbody */
1070
FuncState *fs = ls->fs;
1071
int base = fs->freereg;
1072
new_localvarliteral(ls, "(for index)", 0);
1073
new_localvarliteral(ls, "(for limit)", 1);
1074
new_localvarliteral(ls, "(for step)", 2);
1075
new_localvar(ls, varname, 3);
1076
checknext(ls, '=');
1077
exp1(ls); /* initial value */
1078
checknext(ls, ',');
1079
exp1(ls); /* limit */
1080
if (testnext(ls, ','))
1081
exp1(ls); /* optional step */
1082
else { /* default step = 1 */
1083
luaK_codeABx(fs, OP_LOADK, fs->freereg, luaK_numberK(fs, 1));
1084
luaK_reserveregs(fs, 1);
1085
}
1086
forbody(ls, base, line, 1, 1);
1087
}
1088
1089
1090
static void forlist (LexState *ls, TString *indexname) {
1091
/* forlist -> NAME {,NAME} IN explist1 forbody */
1092
FuncState *fs = ls->fs;
1093
expdesc e;
1094
int nvars = 0;
1095
int line;
1096
int base = fs->freereg;
1097
/* create control variables */
1098
new_localvarliteral(ls, "(for generator)", nvars++);
1099
new_localvarliteral(ls, "(for state)", nvars++);
1100
new_localvarliteral(ls, "(for control)", nvars++);
1101
/* create declared variables */
1102
new_localvar(ls, indexname, nvars++);
1103
while (testnext(ls, ','))
1104
new_localvar(ls, str_checkname(ls), nvars++);
1105
checknext(ls, TK_IN);
1106
line = ls->linenumber;
1107
adjust_assign(ls, 3, explist1(ls, &e), &e);
1108
luaK_checkstack(fs, 3); /* extra space to call generator */
1109
forbody(ls, base, line, nvars - 3, 0);
1110
}
1111
1112
1113
static void forstat (LexState *ls, int line) {
1114
/* forstat -> FOR (fornum | forlist) END */
1115
FuncState *fs = ls->fs;
1116
TString *varname;
1117
BlockCnt bl;
1118
enterblock(fs, &bl, 1); /* scope for loop and control variables */
1119
luaX_next(ls); /* skip `for' */
1120
varname = str_checkname(ls); /* first variable name */
1121
switch (ls->t.token) {
1122
case '=': fornum(ls, varname, line); break;
1123
case ',': case TK_IN: forlist(ls, varname); break;
1124
default: luaX_syntaxerror(ls, LUA_QL("=") " or " LUA_QL("in") " expected");
1125
}
1126
check_match(ls, TK_END, TK_FOR, line);
1127
leaveblock(fs); /* loop scope (`break' jumps to this point) */
1128
}
1129
1130
1131
static int test_then_block (LexState *ls) {
1132
/* test_then_block -> [IF | ELSEIF] cond THEN block */
1133
int condexit;
1134
luaX_next(ls); /* skip IF or ELSEIF */
1135
condexit = cond(ls);
1136
checknext(ls, TK_THEN);
1137
block(ls); /* `then' part */
1138
return condexit;
1139
}
1140
1141
1142
static void ifstat (LexState *ls, int line) {
1143
/* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */
1144
FuncState *fs = ls->fs;
1145
int flist;
1146
int escapelist = NO_JUMP;
1147
flist = test_then_block(ls); /* IF cond THEN block */
1148
while (ls->t.token == TK_ELSEIF) {
1149
luaK_concat(fs, &escapelist, luaK_jump(fs));
1150
luaK_patchtohere(fs, flist);
1151
flist = test_then_block(ls); /* ELSEIF cond THEN block */
1152
}
1153
if (ls->t.token == TK_ELSE) {
1154
luaK_concat(fs, &escapelist, luaK_jump(fs));
1155
luaK_patchtohere(fs, flist);
1156
luaX_next(ls); /* skip ELSE (after patch, for correct line info) */
1157
block(ls); /* `else' part */
1158
}
1159
else
1160
luaK_concat(fs, &escapelist, flist);
1161
luaK_patchtohere(fs, escapelist);
1162
check_match(ls, TK_END, TK_IF, line);
1163
}
1164
1165
1166
static void localfunc (LexState *ls) {
1167
expdesc v, b;
1168
FuncState *fs = ls->fs;
1169
new_localvar(ls, str_checkname(ls), 0);
1170
init_exp(&v, VLOCAL, fs->freereg);
1171
luaK_reserveregs(fs, 1);
1172
adjustlocalvars(ls, 1);
1173
body(ls, &b, 0, ls->linenumber);
1174
luaK_storevar(fs, &v, &b);
1175
/* debug information will only see the variable after this point! */
1176
getlocvar(fs, fs->nactvar - 1).startpc = fs->pc;
1177
}
1178
1179
1180
static void localstat (LexState *ls) {
1181
/* stat -> LOCAL NAME {`,' NAME} [`=' explist1] */
1182
int nvars = 0;
1183
int nexps;
1184
expdesc e;
1185
do {
1186
new_localvar(ls, str_checkname(ls), nvars++);
1187
} while (testnext(ls, ','));
1188
if (testnext(ls, '='))
1189
nexps = explist1(ls, &e);
1190
else {
1191
e.k = VVOID;
1192
nexps = 0;
1193
}
1194
adjust_assign(ls, nvars, nexps, &e);
1195
adjustlocalvars(ls, nvars);
1196
}
1197
1198
1199
static int funcname (LexState *ls, expdesc *v) {
1200
/* funcname -> NAME {field} [`:' NAME] */
1201
int needself = 0;
1202
singlevar(ls, v);
1203
while (ls->t.token == '.')
1204
field(ls, v);
1205
if (ls->t.token == ':') {
1206
needself = 1;
1207
field(ls, v);
1208
}
1209
return needself;
1210
}
1211
1212
1213
static void funcstat (LexState *ls, int line) {
1214
/* funcstat -> FUNCTION funcname body */
1215
int needself;
1216
expdesc v, b;
1217
luaX_next(ls); /* skip FUNCTION */
1218
needself = funcname(ls, &v);
1219
body(ls, &b, needself, line);
1220
luaK_storevar(ls->fs, &v, &b);
1221
luaK_fixline(ls->fs, line); /* definition `happens' in the first line */
1222
}
1223
1224
1225
static void exprstat (LexState *ls) {
1226
/* stat -> func | assignment */
1227
FuncState *fs = ls->fs;
1228
struct LHS_assign v;
1229
primaryexp(ls, &v.v);
1230
if (v.v.k == VCALL) /* stat -> func */
1231
SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */
1232
else { /* stat -> assignment */
1233
v.prev = NULL;
1234
assignment(ls, &v, 1);
1235
}
1236
}
1237
1238
1239
static void retstat (LexState *ls) {
1240
/* stat -> RETURN explist */
1241
FuncState *fs = ls->fs;
1242
expdesc e;
1243
int first, nret; /* registers with returned values */
1244
luaX_next(ls); /* skip RETURN */
1245
if (block_follow(ls->t.token) || ls->t.token == ';')
1246
first = nret = 0; /* return no values */
1247
else {
1248
nret = explist1(ls, &e); /* optional return values */
1249
if (hasmultret(e.k)) {
1250
luaK_setmultret(fs, &e);
1251
if (e.k == VCALL && nret == 1) { /* tail call? */
1252
SET_OPCODE(getcode(fs,&e), OP_TAILCALL);
1253
lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar);
1254
}
1255
first = fs->nactvar;
1256
nret = LUA_MULTRET; /* return all values */
1257
}
1258
else {
1259
if (nret == 1) /* only one single value? */
1260
first = luaK_exp2anyreg(fs, &e);
1261
else {
1262
luaK_exp2nextreg(fs, &e); /* values must go to the `stack' */
1263
first = fs->nactvar; /* return all `active' values */
1264
lua_assert(nret == fs->freereg - first);
1265
}
1266
}
1267
}
1268
luaK_ret(fs, first, nret);
1269
}
1270
1271
1272
static int statement (LexState *ls) {
1273
int line = ls->linenumber; /* may be needed for error messages */
1274
switch (ls->t.token) {
1275
case TK_IF: { /* stat -> ifstat */
1276
ifstat(ls, line);
1277
return 0;
1278
}
1279
case TK_WHILE: { /* stat -> whilestat */
1280
whilestat(ls, line);
1281
return 0;
1282
}
1283
case TK_DO: { /* stat -> DO block END */
1284
luaX_next(ls); /* skip DO */
1285
block(ls);
1286
check_match(ls, TK_END, TK_DO, line);
1287
return 0;
1288
}
1289
case TK_FOR: { /* stat -> forstat */
1290
forstat(ls, line);
1291
return 0;
1292
}
1293
case TK_REPEAT: { /* stat -> repeatstat */
1294
repeatstat(ls, line);
1295
return 0;
1296
}
1297
case TK_FUNCTION: {
1298
funcstat(ls, line); /* stat -> funcstat */
1299
return 0;
1300
}
1301
case TK_LOCAL: { /* stat -> localstat */
1302
luaX_next(ls); /* skip LOCAL */
1303
if (testnext(ls, TK_FUNCTION)) /* local function? */
1304
localfunc(ls);
1305
else
1306
localstat(ls);
1307
return 0;
1308
}
1309
case TK_RETURN: { /* stat -> retstat */
1310
retstat(ls);
1311
return 1; /* must be last statement */
1312
}
1313
case TK_BREAK: { /* stat -> breakstat */
1314
luaX_next(ls); /* skip BREAK */
1315
breakstat(ls);
1316
return 1; /* must be last statement */
1317
}
1318
default: {
1319
exprstat(ls);
1320
return 0; /* to avoid warnings */
1321
}
1322
}
1323
}
1324
1325
1326
static void chunk (LexState *ls) {
1327
/* chunk -> { stat [`;'] } */
1328
int islast = 0;
1329
enterlevel(ls);
1330
while (!islast && !block_follow(ls->t.token)) {
1331
islast = statement(ls);
1332
testnext(ls, ';');
1333
lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg &&
1334
ls->fs->freereg >= ls->fs->nactvar);
1335
ls->fs->freereg = ls->fs->nactvar; /* free registers */
1336
}
1337
leavelevel(ls);
1338
}
1339
1340
/* }====================================================================== */
Loggerhead is a web-based interface for Breezy
Version: 2.0.1