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[wxWidgets.git] / src / regex / regcomp.c
1 #include <sys/types.h>
2 #include <stdio.h>
3 #include <string.h>
4 #include <ctype.h>
5 #include <limits.h>
6 #include <stdlib.h>
7 #include "regex.h"
8
9 #include "utils.h"
10 #include "regex2.h"
11
12 #include "cclass.h"
13 #include "cname.h"
14
15 /*
16 * parse structure, passed up and down to avoid global variables and
17 * other clumsinesses
18 */
19 struct parse {
20 char *next; /* next character in RE */
21 char *end; /* end of string (-> NUL normally) */
22 int error; /* has an error been seen? */
23 sop *strip; /* malloced strip */
24 sopno ssize; /* malloced strip size (allocated) */
25 sopno slen; /* malloced strip length (used) */
26 int ncsalloc; /* number of csets allocated */
27 struct re_guts *g;
28 # define NPAREN 10 /* we need to remember () 1-9 for back refs */
29 sopno pbegin[NPAREN]; /* -> ( ([0] unused) */
30 sopno pend[NPAREN]; /* -> ) ([0] unused) */
31 };
32
33 #include "regcomp.ih"
34
35 static char nuls[10]; /* place to point scanner in event of error */
36
37 /*
38 * macros for use with parse structure
39 * BEWARE: these know that the parse structure is named `p' !!!
40 */
41 #define PEEK() (*p->next)
42 #define PEEK2() (*(p->next+1))
43 #define MORE() (p->next < p->end)
44 #define MORE2() (p->next+1 < p->end)
45 #define SEE(c) (MORE() && PEEK() == (c))
46 #define SEETWO(a, b) (MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
47 #define EAT(c) ((SEE(c)) ? (NEXT(), 1) : 0)
48 #define EATTWO(a, b) ((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
49 #define NEXT() (p->next++)
50 #define NEXT2() (p->next += 2)
51 #define NEXTn(n) (p->next += (n))
52 #define GETNEXT() (*p->next++)
53 #define SETERROR(e) seterr(p, (e))
54 #define REQUIRE(co, e) ((void)((co) || SETERROR(e)))
55 #define MUSTSEE(c, e) (REQUIRE(MORE() && PEEK() == (c), e))
56 #define MUSTEAT(c, e) (REQUIRE(MORE() && GETNEXT() == (c), e))
57 #define MUSTNOTSEE(c, e) (REQUIRE(!MORE() || PEEK() != (c), e))
58 #define EMIT(op, sopnd) doemit(p, (sop)(op), (size_t)(sopnd))
59 #define INSERT(op, pos) doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
60 #define AHEAD(pos) dofwd(p, pos, HERE()-(pos))
61 #define ASTERN(sop, pos) EMIT(sop, HERE()-pos)
62 #define HERE() (p->slen)
63 #define THERE() (p->slen - 1)
64 #define THERETHERE() (p->slen - 2)
65 #define DROP(n) (p->slen -= (n))
66
67 #ifndef NDEBUG
68 static int never = 0; /* for use in asserts; shuts lint up */
69 #else
70 #define never 0 /* some <assert.h>s have bugs too */
71 #endif
72
73 /*
74 - regcomp - interface for parser and compilation
75 = extern int regcomp(regex_t *, const char *, int);
76 = #define REG_BASIC 0000
77 = #define REG_EXTENDED 0001
78 = #define REG_ICASE 0002
79 = #define REG_NOSUB 0004
80 = #define REG_NEWLINE 0010
81 = #define REG_NOSPEC 0020
82 = #define REG_PEND 0040
83 = #define REG_DUMP 0200
84 */
85 int /* 0 success, otherwise REG_something */
86 regcomp(preg, pattern, cflags)
87 regex_t *preg;
88 const char *pattern;
89 int cflags;
90 {
91 struct parse pa;
92 register struct re_guts *g;
93 register struct parse *p = &pa;
94 register int i;
95 register size_t len;
96 #ifdef REDEBUG
97 # define GOODFLAGS(f) (f)
98 #else
99 # define GOODFLAGS(f) ((f)&~REG_DUMP)
100 #endif
101
102 cflags = GOODFLAGS(cflags);
103 if ((cflags&REG_EXTENDED) && (cflags&REG_NOSPEC))
104 return(REG_INVARG);
105
106 if (cflags&REG_PEND) {
107 if (preg->re_endp < pattern)
108 return(REG_INVARG);
109 len = preg->re_endp - pattern;
110 } else
111 len = strlen((char *)pattern);
112
113 /* do the mallocs early so failure handling is easy */
114 g = (struct re_guts *)malloc(sizeof(struct re_guts) +
115 (NC-1)*sizeof(cat_t));
116 if (g == NULL)
117 return(REG_ESPACE);
118 p->ssize = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */
119 p->strip = (sop *)malloc(p->ssize * sizeof(sop));
120 p->slen = 0;
121 if (p->strip == NULL) {
122 free((char *)g);
123 return(REG_ESPACE);
124 }
125
126 /* set things up */
127 p->g = g;
128 p->next = (char *)pattern; /* convenience; we do not modify it */
129 p->end = p->next + len;
130 p->error = 0;
131 p->ncsalloc = 0;
132 for (i = 0; i < NPAREN; i++) {
133 p->pbegin[i] = 0;
134 p->pend[i] = 0;
135 }
136 g->csetsize = NC;
137 g->sets = NULL;
138 g->setbits = NULL;
139 g->ncsets = 0;
140 g->cflags = cflags;
141 g->iflags = 0;
142 g->nbol = 0;
143 g->neol = 0;
144 g->must = NULL;
145 g->mlen = 0;
146 g->nsub = 0;
147 g->ncategories = 1; /* category 0 is "everything else" */
148 g->categories = &g->catspace[-(CHAR_MIN)];
149 (void) memset((char *)g->catspace, 0, NC*sizeof(cat_t));
150 g->backrefs = 0;
151
152 /* do it */
153 EMIT(OEND, 0);
154 g->firststate = THERE();
155 if (cflags&REG_EXTENDED)
156 p_ere(p, OUT);
157 else if (cflags&REG_NOSPEC)
158 p_str(p);
159 else
160 p_bre(p, OUT, OUT);
161 EMIT(OEND, 0);
162 g->laststate = THERE();
163
164 /* tidy up loose ends and fill things in */
165 categorize(p, g);
166 stripsnug(p, g);
167 findmust(p, g);
168 g->nplus = pluscount(p, g);
169 g->magic = MAGIC2;
170 preg->re_nsub = g->nsub;
171 preg->re_g = g;
172 preg->re_magic = MAGIC1;
173 #ifndef REDEBUG
174 /* not debugging, so can't rely on the assert() in regexec() */
175 if (g->iflags&BAD)
176 SETERROR(REG_ASSERT);
177 #endif
178
179 /* win or lose, we're done */
180 if (p->error != 0) /* lose */
181 regfree(preg);
182 return(p->error);
183 }
184
185 /*
186 - p_ere - ERE parser top level, concatenation and alternation
187 == static void p_ere(register struct parse *p, int stop);
188 */
189 static void
190 p_ere(p, stop)
191 register struct parse *p;
192 int stop; /* character this ERE should end at */
193 {
194 register char c;
195 register sopno prevback;
196 register sopno prevfwd;
197 register sopno conc;
198 register int first = 1; /* is this the first alternative? */
199
200 for (;;) {
201 /* do a bunch of concatenated expressions */
202 conc = HERE();
203 while (MORE() && (c = PEEK()) != '|' && c != stop)
204 p_ere_exp(p);
205 REQUIRE(HERE() != conc, REG_EMPTY); /* require nonempty */
206
207 if (!EAT('|'))
208 break; /* NOTE BREAK OUT */
209
210 if (first) {
211 INSERT(OCH_, conc); /* offset is wrong */
212 prevfwd = conc;
213 prevback = conc;
214 first = 0;
215 }
216 ASTERN(OOR1, prevback);
217 prevback = THERE();
218 AHEAD(prevfwd); /* fix previous offset */
219 prevfwd = HERE();
220 EMIT(OOR2, 0); /* offset is very wrong */
221 }
222
223 if (!first) { /* tail-end fixups */
224 AHEAD(prevfwd);
225 ASTERN(O_CH, prevback);
226 }
227
228 assert(!MORE() || SEE(stop));
229 }
230
231 /*
232 - p_ere_exp - parse one subERE, an atom possibly followed by a repetition op
233 == static void p_ere_exp(register struct parse *p);
234 */
235 static void
236 p_ere_exp(p)
237 register struct parse *p;
238 {
239 register char c;
240 register sopno pos;
241 register int count;
242 register int count2;
243 register sopno subno;
244 int wascaret = 0;
245
246 assert(MORE()); /* caller should have ensured this */
247 c = GETNEXT();
248
249 pos = HERE();
250 switch (c) {
251 case '(':
252 REQUIRE(MORE(), REG_EPAREN);
253 p->g->nsub++;
254 subno = p->g->nsub;
255 if (subno < NPAREN)
256 p->pbegin[subno] = HERE();
257 EMIT(OLPAREN, subno);
258 if (!SEE(')'))
259 p_ere(p, ')');
260 if (subno < NPAREN) {
261 p->pend[subno] = HERE();
262 assert(p->pend[subno] != 0);
263 }
264 EMIT(ORPAREN, subno);
265 MUSTEAT(')', REG_EPAREN);
266 break;
267 #ifndef POSIX_MISTAKE
268 case ')': /* happens only if no current unmatched ( */
269 /*
270 * You may ask, why the ifndef? Because I didn't notice
271 * this until slightly too late for 1003.2, and none of the
272 * other 1003.2 regular-expression reviewers noticed it at
273 * all. So an unmatched ) is legal POSIX, at least until
274 * we can get it fixed.
275 */
276 SETERROR(REG_EPAREN);
277 break;
278 #endif
279 case '^':
280 EMIT(OBOL, 0);
281 p->g->iflags |= USEBOL;
282 p->g->nbol++;
283 wascaret = 1;
284 break;
285 case '$':
286 EMIT(OEOL, 0);
287 p->g->iflags |= USEEOL;
288 p->g->neol++;
289 break;
290 case '|':
291 SETERROR(REG_EMPTY);
292 break;
293 case '*':
294 case '+':
295 case '?':
296 SETERROR(REG_BADRPT);
297 break;
298 case '.':
299 if (p->g->cflags&REG_NEWLINE)
300 nonnewline(p);
301 else
302 EMIT(OANY, 0);
303 break;
304 case '[':
305 p_bracket(p);
306 break;
307 case '\\':
308 REQUIRE(MORE(), REG_EESCAPE);
309 c = GETNEXT();
310 ordinary(p, c);
311 break;
312 case '{': /* okay as ordinary except if digit follows */
313 REQUIRE(!MORE() || !isdigit(PEEK()), REG_BADRPT);
314 /* FALLTHROUGH */
315 default:
316 ordinary(p, c);
317 break;
318 }
319
320 if (!MORE())
321 return;
322 c = PEEK();
323 /* we call { a repetition if followed by a digit */
324 if (!( c == '*' || c == '+' || c == '?' ||
325 (c == '{' && MORE2() && isdigit(PEEK2())) ))
326 return; /* no repetition, we're done */
327 NEXT();
328
329 REQUIRE(!wascaret, REG_BADRPT);
330 switch (c) {
331 case '*': /* implemented as +? */
332 /* this case does not require the (y|) trick, noKLUDGE */
333 INSERT(OPLUS_, pos);
334 ASTERN(O_PLUS, pos);
335 INSERT(OQUEST_, pos);
336 ASTERN(O_QUEST, pos);
337 break;
338 case '+':
339 INSERT(OPLUS_, pos);
340 ASTERN(O_PLUS, pos);
341 break;
342 case '?':
343 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
344 INSERT(OCH_, pos); /* offset slightly wrong */
345 ASTERN(OOR1, pos); /* this one's right */
346 AHEAD(pos); /* fix the OCH_ */
347 EMIT(OOR2, 0); /* offset very wrong... */
348 AHEAD(THERE()); /* ...so fix it */
349 ASTERN(O_CH, THERETHERE());
350 break;
351 case '{':
352 count = p_count(p);
353 if (EAT(',')) {
354 if (isdigit(PEEK())) {
355 count2 = p_count(p);
356 REQUIRE(count <= count2, REG_BADBR);
357 } else /* single number with comma */
358 count2 = INFINITY;
359 } else /* just a single number */
360 count2 = count;
361 repeat(p, pos, count, count2);
362 if (!EAT('}')) { /* error heuristics */
363 while (MORE() && PEEK() != '}')
364 NEXT();
365 REQUIRE(MORE(), REG_EBRACE);
366 SETERROR(REG_BADBR);
367 }
368 break;
369 }
370
371 if (!MORE())
372 return;
373 c = PEEK();
374 if (!( c == '*' || c == '+' || c == '?' ||
375 (c == '{' && MORE2() && isdigit(PEEK2())) ) )
376 return;
377 SETERROR(REG_BADRPT);
378 }
379
380 /*
381 - p_str - string (no metacharacters) "parser"
382 == static void p_str(register struct parse *p);
383 */
384 static void
385 p_str(p)
386 register struct parse *p;
387 {
388 REQUIRE(MORE(), REG_EMPTY);
389 while (MORE())
390 ordinary(p, GETNEXT());
391 }
392
393 /*
394 - p_bre - BRE parser top level, anchoring and concatenation
395 == static void p_bre(register struct parse *p, register int end1, \
396 == register int end2);
397 * Giving end1 as OUT essentially eliminates the end1/end2 check.
398 *
399 * This implementation is a bit of a kludge, in that a trailing $ is first
400 * taken as an ordinary character and then revised to be an anchor. The
401 * only undesirable side effect is that '$' gets included as a character
402 * category in such cases. This is fairly harmless; not worth fixing.
403 * The amount of lookahead needed to avoid this kludge is excessive.
404 */
405 static void
406 p_bre(p, end1, end2)
407 register struct parse *p;
408 register int end1; /* first terminating character */
409 register int end2; /* second terminating character */
410 {
411 register sopno start = HERE();
412 register int first = 1; /* first subexpression? */
413 register int wasdollar = 0;
414
415 if (EAT('^')) {
416 EMIT(OBOL, 0);
417 p->g->iflags |= USEBOL;
418 p->g->nbol++;
419 }
420 while (MORE() && !SEETWO(end1, end2)) {
421 wasdollar = p_simp_re(p, first);
422 first = 0;
423 }
424 if (wasdollar) { /* oops, that was a trailing anchor */
425 DROP(1);
426 EMIT(OEOL, 0);
427 p->g->iflags |= USEEOL;
428 p->g->neol++;
429 }
430
431 REQUIRE(HERE() != start, REG_EMPTY); /* require nonempty */
432 }
433
434 /*
435 - p_simp_re - parse a simple RE, an atom possibly followed by a repetition
436 == static int p_simp_re(register struct parse *p, int starordinary);
437 */
438 static int /* was the simple RE an unbackslashed $? */
439 p_simp_re(p, starordinary)
440 register struct parse *p;
441 int starordinary; /* is a leading * an ordinary character? */
442 {
443 register int c;
444 register int count;
445 register int count2;
446 register sopno pos;
447 register int i;
448 register sopno subno;
449 # define BACKSL (1<<CHAR_BIT)
450
451 pos = HERE(); /* repetion op, if any, covers from here */
452
453 assert(MORE()); /* caller should have ensured this */
454 c = GETNEXT();
455 if (c == '\\') {
456 REQUIRE(MORE(), REG_EESCAPE);
457 c = BACKSL | (unsigned char)GETNEXT();
458 }
459 switch (c) {
460 case '.':
461 if (p->g->cflags&REG_NEWLINE)
462 nonnewline(p);
463 else
464 EMIT(OANY, 0);
465 break;
466 case '[':
467 p_bracket(p);
468 break;
469 case BACKSL|'{':
470 SETERROR(REG_BADRPT);
471 break;
472 case BACKSL|'(':
473 p->g->nsub++;
474 subno = p->g->nsub;
475 if (subno < NPAREN)
476 p->pbegin[subno] = HERE();
477 EMIT(OLPAREN, subno);
478 /* the MORE here is an error heuristic */
479 if (MORE() && !SEETWO('\\', ')'))
480 p_bre(p, '\\', ')');
481 if (subno < NPAREN) {
482 p->pend[subno] = HERE();
483 assert(p->pend[subno] != 0);
484 }
485 EMIT(ORPAREN, subno);
486 REQUIRE(EATTWO('\\', ')'), REG_EPAREN);
487 break;
488 case BACKSL|')': /* should not get here -- must be user */
489 case BACKSL|'}':
490 SETERROR(REG_EPAREN);
491 break;
492 case BACKSL|'1':
493 case BACKSL|'2':
494 case BACKSL|'3':
495 case BACKSL|'4':
496 case BACKSL|'5':
497 case BACKSL|'6':
498 case BACKSL|'7':
499 case BACKSL|'8':
500 case BACKSL|'9':
501 i = (c&~BACKSL) - '0';
502 assert(i < NPAREN);
503 if (p->pend[i] != 0) {
504 assert(i <= p->g->nsub);
505 EMIT(OBACK_, i);
506 assert(p->pbegin[i] != 0);
507 assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
508 assert(OP(p->strip[p->pend[i]]) == ORPAREN);
509 (void) dupl(p, p->pbegin[i]+1, p->pend[i]);
510 EMIT(O_BACK, i);
511 } else
512 SETERROR(REG_ESUBREG);
513 p->g->backrefs = 1;
514 break;
515 case '*':
516 REQUIRE(starordinary, REG_BADRPT);
517 /* FALLTHROUGH */
518 default:
519 ordinary(p, (char)c); /* takes off BACKSL, if any */
520 break;
521 }
522
523 if (EAT('*')) { /* implemented as +? */
524 /* this case does not require the (y|) trick, noKLUDGE */
525 INSERT(OPLUS_, pos);
526 ASTERN(O_PLUS, pos);
527 INSERT(OQUEST_, pos);
528 ASTERN(O_QUEST, pos);
529 } else if (EATTWO('\\', '{')) {
530 count = p_count(p);
531 if (EAT(',')) {
532 if (MORE() && isdigit(PEEK())) {
533 count2 = p_count(p);
534 REQUIRE(count <= count2, REG_BADBR);
535 } else /* single number with comma */
536 count2 = INFINITY;
537 } else /* just a single number */
538 count2 = count;
539 repeat(p, pos, count, count2);
540 if (!EATTWO('\\', '}')) { /* error heuristics */
541 while (MORE() && !SEETWO('\\', '}'))
542 NEXT();
543 REQUIRE(MORE(), REG_EBRACE);
544 SETERROR(REG_BADBR);
545 }
546 } else if (c == (unsigned char)'$') /* $ (but not \$) ends it */
547 return(1);
548
549 return(0);
550 }
551
552 /*
553 - p_count - parse a repetition count
554 == static int p_count(register struct parse *p);
555 */
556 static int /* the value */
557 p_count(p)
558 register struct parse *p;
559 {
560 register int count = 0;
561 register int ndigits = 0;
562
563 while (MORE() && isdigit(PEEK()) && count <= DUPMAX) {
564 count = count*10 + (GETNEXT() - '0');
565 ndigits++;
566 }
567
568 REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
569 return(count);
570 }
571
572 /*
573 - p_bracket - parse a bracketed character list
574 == static void p_bracket(register struct parse *p);
575 *
576 * Note a significant property of this code: if the allocset() did SETERROR,
577 * no set operations are done.
578 */
579 static void
580 p_bracket(p)
581 register struct parse *p;
582 {
583 register cset *cs = allocset(p);
584 register int invert = 0;
585
586 /* Dept of Truly Sickening Special-Case Kludges */
587 if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) {
588 EMIT(OBOW, 0);
589 NEXTn(6);
590 return;
591 }
592 if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) {
593 EMIT(OEOW, 0);
594 NEXTn(6);
595 return;
596 }
597
598 if (EAT('^'))
599 invert++; /* make note to invert set at end */
600 if (EAT(']'))
601 CHadd(cs, ']');
602 else if (EAT('-'))
603 CHadd(cs, '-');
604 while (MORE() && PEEK() != ']' && !SEETWO('-', ']'))
605 p_b_term(p, cs);
606 if (EAT('-'))
607 CHadd(cs, '-');
608 MUSTEAT(']', REG_EBRACK);
609
610 if (p->error != 0) /* don't mess things up further */
611 return;
612
613 if (p->g->cflags&REG_ICASE) {
614 register int i;
615 register int ci;
616
617 for (i = p->g->csetsize - 1; i >= 0; i--)
618 if (CHIN(cs, i) && isalpha(i)) {
619 ci = othercase(i);
620 if (ci != i)
621 CHadd(cs, ci);
622 }
623 if (cs->multis != NULL)
624 mccase(p, cs);
625 }
626 if (invert) {
627 register int i;
628
629 for (i = p->g->csetsize - 1; i >= 0; i--)
630 if (CHIN(cs, i))
631 CHsub(cs, i);
632 else
633 CHadd(cs, i);
634 if (p->g->cflags&REG_NEWLINE)
635 CHsub(cs, '\n');
636 if (cs->multis != NULL)
637 mcinvert(p, cs);
638 }
639
640 assert(cs->multis == NULL); /* xxx */
641
642 if (nch(p, cs) == 1) { /* optimize singleton sets */
643 ordinary(p, firstch(p, cs));
644 freeset(p, cs);
645 } else
646 EMIT(OANYOF, freezeset(p, cs));
647 }
648
649 /*
650 - p_b_term - parse one term of a bracketed character list
651 == static void p_b_term(register struct parse *p, register cset *cs);
652 */
653 static void
654 p_b_term(p, cs)
655 register struct parse *p;
656 register cset *cs;
657 {
658 register char c;
659 register char start, finish;
660 register int i;
661
662 /* classify what we've got */
663 switch ((MORE()) ? PEEK() : '\0') {
664 case '[':
665 c = (MORE2()) ? PEEK2() : '\0';
666 break;
667 case '-':
668 SETERROR(REG_ERANGE);
669 return; /* NOTE RETURN */
670 break;
671 default:
672 c = '\0';
673 break;
674 }
675
676 switch (c) {
677 case ':': /* character class */
678 NEXT2();
679 REQUIRE(MORE(), REG_EBRACK);
680 c = PEEK();
681 REQUIRE(c != '-' && c != ']', REG_ECTYPE);
682 p_b_cclass(p, cs);
683 REQUIRE(MORE(), REG_EBRACK);
684 REQUIRE(EATTWO(':', ']'), REG_ECTYPE);
685 break;
686 case '=': /* equivalence class */
687 NEXT2();
688 REQUIRE(MORE(), REG_EBRACK);
689 c = PEEK();
690 REQUIRE(c != '-' && c != ']', REG_ECOLLATE);
691 p_b_eclass(p, cs);
692 REQUIRE(MORE(), REG_EBRACK);
693 REQUIRE(EATTWO('=', ']'), REG_ECOLLATE);
694 break;
695 default: /* symbol, ordinary character, or range */
696 /* xxx revision needed for multichar stuff */
697 start = p_b_symbol(p);
698 if (SEE('-') && MORE2() && PEEK2() != ']') {
699 /* range */
700 NEXT();
701 if (EAT('-'))
702 finish = '-';
703 else
704 finish = p_b_symbol(p);
705 } else
706 finish = start;
707 /* xxx what about signed chars here... */
708 REQUIRE(start <= finish, REG_ERANGE);
709 for (i = start; i <= finish; i++)
710 CHadd(cs, i);
711 break;
712 }
713 }
714
715 /*
716 - p_b_cclass - parse a character-class name and deal with it
717 == static void p_b_cclass(register struct parse *p, register cset *cs);
718 */
719 static void
720 p_b_cclass(p, cs)
721 register struct parse *p;
722 register cset *cs;
723 {
724 register char *sp = p->next;
725 register struct cclass *cp;
726 register size_t len;
727 register char *u;
728 register char c;
729
730 while (MORE() && isalpha(PEEK()))
731 NEXT();
732 len = p->next - sp;
733 for (cp = cclasses; cp->name != NULL; cp++)
734 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
735 break;
736 if (cp->name == NULL) {
737 /* oops, didn't find it */
738 SETERROR(REG_ECTYPE);
739 return;
740 }
741
742 u = cp->chars;
743 while ((c = *u++) != '\0')
744 CHadd(cs, c);
745 for (u = cp->multis; *u != '\0'; u += strlen(u) + 1)
746 MCadd(p, cs, u);
747 }
748
749 /*
750 - p_b_eclass - parse an equivalence-class name and deal with it
751 == static void p_b_eclass(register struct parse *p, register cset *cs);
752 *
753 * This implementation is incomplete. xxx
754 */
755 static void
756 p_b_eclass(p, cs)
757 register struct parse *p;
758 register cset *cs;
759 {
760 register char c;
761
762 c = p_b_coll_elem(p, '=');
763 CHadd(cs, c);
764 }
765
766 /*
767 - p_b_symbol - parse a character or [..]ed multicharacter collating symbol
768 == static char p_b_symbol(register struct parse *p);
769 */
770 static char /* value of symbol */
771 p_b_symbol(p)
772 register struct parse *p;
773 {
774 register char value;
775
776 REQUIRE(MORE(), REG_EBRACK);
777 if (!EATTWO('[', '.'))
778 return(GETNEXT());
779
780 /* collating symbol */
781 value = p_b_coll_elem(p, '.');
782 REQUIRE(EATTWO('.', ']'), REG_ECOLLATE);
783 return(value);
784 }
785
786 /*
787 - p_b_coll_elem - parse a collating-element name and look it up
788 == static char p_b_coll_elem(register struct parse *p, int endc);
789 */
790 static char /* value of collating element */
791 p_b_coll_elem(p, endc)
792 register struct parse *p;
793 int endc; /* name ended by endc,']' */
794 {
795 register char *sp = p->next;
796 register struct cname *cp;
797 register int len;
798
799 while (MORE() && !SEETWO(endc, ']'))
800 NEXT();
801 if (!MORE()) {
802 SETERROR(REG_EBRACK);
803 return(0);
804 }
805 len = p->next - sp;
806 for (cp = cnames; cp->name != NULL; cp++)
807 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
808 return(cp->code); /* known name */
809 if (len == 1)
810 return(*sp); /* single character */
811 SETERROR(REG_ECOLLATE); /* neither */
812 return(0);
813 }
814
815 /*
816 - othercase - return the case counterpart of an alphabetic
817 == static char othercase(int ch);
818 */
819 static char /* if no counterpart, return ch */
820 othercase(ch)
821 int ch;
822 {
823 assert(isalpha(ch));
824 if (isupper(ch))
825 return(tolower(ch));
826 else if (islower(ch))
827 return(toupper(ch));
828 else /* peculiar, but could happen */
829 return(ch);
830 }
831
832 /*
833 - bothcases - emit a dualcase version of a two-case character
834 == static void bothcases(register struct parse *p, int ch);
835 *
836 * Boy, is this implementation ever a kludge...
837 */
838 static void
839 bothcases(p, ch)
840 register struct parse *p;
841 int ch;
842 {
843 register char *oldnext = p->next;
844 register char *oldend = p->end;
845 char bracket[3];
846
847 assert(othercase(ch) != ch); /* p_bracket() would recurse */
848 p->next = bracket;
849 p->end = bracket+2;
850 bracket[0] = ch;
851 bracket[1] = ']';
852 bracket[2] = '\0';
853 p_bracket(p);
854 assert(p->next == bracket+2);
855 p->next = oldnext;
856 p->end = oldend;
857 }
858
859 /*
860 - ordinary - emit an ordinary character
861 == static void ordinary(register struct parse *p, register int ch);
862 */
863 static void
864 ordinary(p, ch)
865 register struct parse *p;
866 register int ch;
867 {
868 register cat_t *cap = p->g->categories;
869
870 if ((p->g->cflags&REG_ICASE) && isalpha(ch) && othercase(ch) != ch)
871 bothcases(p, ch);
872 else {
873 EMIT(OCHAR, (unsigned char)ch);
874 if (cap[ch] == 0)
875 cap[ch] = p->g->ncategories++;
876 }
877 }
878
879 /*
880 - nonnewline - emit REG_NEWLINE version of OANY
881 == static void nonnewline(register struct parse *p);
882 *
883 * Boy, is this implementation ever a kludge...
884 */
885 static void
886 nonnewline(p)
887 register struct parse *p;
888 {
889 register char *oldnext = p->next;
890 register char *oldend = p->end;
891 char bracket[4];
892
893 p->next = bracket;
894 p->end = bracket+3;
895 bracket[0] = '^';
896 bracket[1] = '\n';
897 bracket[2] = ']';
898 bracket[3] = '\0';
899 p_bracket(p);
900 assert(p->next == bracket+3);
901 p->next = oldnext;
902 p->end = oldend;
903 }
904
905 /*
906 - repeat - generate code for a bounded repetition, recursively if needed
907 == static void repeat(register struct parse *p, sopno start, int from, int to);
908 */
909 static void
910 repeat(p, start, from, to)
911 register struct parse *p;
912 sopno start; /* operand from here to end of strip */
913 int from; /* repeated from this number */
914 int to; /* to this number of times (maybe INFINITY) */
915 {
916 register sopno finish = HERE();
917 # define N 2
918 # define INF 3
919 # define REP(f, t) ((f)*8 + (t))
920 # define MAP(n) (((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N)
921 register sopno copy;
922
923 if (p->error != 0) /* head off possible runaway recursion */
924 return;
925
926 assert(from <= to);
927
928 switch (REP(MAP(from), MAP(to))) {
929 case REP(0, 0): /* must be user doing this */
930 DROP(finish-start); /* drop the operand */
931 break;
932 case REP(0, 1): /* as x{1,1}? */
933 case REP(0, N): /* as x{1,n}? */
934 case REP(0, INF): /* as x{1,}? */
935 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
936 INSERT(OCH_, start); /* offset is wrong... */
937 repeat(p, start+1, 1, to);
938 ASTERN(OOR1, start);
939 AHEAD(start); /* ... fix it */
940 EMIT(OOR2, 0);
941 AHEAD(THERE());
942 ASTERN(O_CH, THERETHERE());
943 break;
944 case REP(1, 1): /* trivial case */
945 /* done */
946 break;
947 case REP(1, N): /* as x?x{1,n-1} */
948 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
949 INSERT(OCH_, start);
950 ASTERN(OOR1, start);
951 AHEAD(start);
952 EMIT(OOR2, 0); /* offset very wrong... */
953 AHEAD(THERE()); /* ...so fix it */
954 ASTERN(O_CH, THERETHERE());
955 copy = dupl(p, start+1, finish+1);
956 assert(copy == finish+4);
957 repeat(p, copy, 1, to-1);
958 break;
959 case REP(1, INF): /* as x+ */
960 INSERT(OPLUS_, start);
961 ASTERN(O_PLUS, start);
962 break;
963 case REP(N, N): /* as xx{m-1,n-1} */
964 copy = dupl(p, start, finish);
965 repeat(p, copy, from-1, to-1);
966 break;
967 case REP(N, INF): /* as xx{n-1,INF} */
968 copy = dupl(p, start, finish);
969 repeat(p, copy, from-1, to);
970 break;
971 default: /* "can't happen" */
972 SETERROR(REG_ASSERT); /* just in case */
973 break;
974 }
975 }
976
977 /*
978 - seterr - set an error condition
979 == static int seterr(register struct parse *p, int e);
980 */
981 static int /* useless but makes type checking happy */
982 seterr(p, e)
983 register struct parse *p;
984 int e;
985 {
986 if (p->error == 0) /* keep earliest error condition */
987 p->error = e;
988 p->next = nuls; /* try to bring things to a halt */
989 p->end = nuls;
990 return(0); /* make the return value well-defined */
991 }
992
993 /*
994 - allocset - allocate a set of characters for []
995 == static cset *allocset(register struct parse *p);
996 */
997 static cset *
998 allocset(p)
999 register struct parse *p;
1000 {
1001 register int no = p->g->ncsets++;
1002 register size_t nc;
1003 register size_t nbytes;
1004 register cset *cs;
1005 register size_t css = (size_t)p->g->csetsize;
1006 register int i;
1007
1008 if (no >= p->ncsalloc) { /* need another column of space */
1009 p->ncsalloc += CHAR_BIT;
1010 nc = p->ncsalloc;
1011 assert(nc % CHAR_BIT == 0);
1012 nbytes = nc / CHAR_BIT * css;
1013 if (p->g->sets == NULL)
1014 p->g->sets = (cset *)malloc(nc * sizeof(cset));
1015 else
1016 p->g->sets = (cset *)realloc((char *)p->g->sets,
1017 nc * sizeof(cset));
1018 if (p->g->setbits == NULL)
1019 p->g->setbits = (uch *)malloc(nbytes);
1020 else {
1021 p->g->setbits = (uch *)realloc((char *)p->g->setbits,
1022 nbytes);
1023 /* xxx this isn't right if setbits is now NULL */
1024 for (i = 0; i < no; i++)
1025 p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT);
1026 }
1027 if (p->g->sets != NULL && p->g->setbits != NULL)
1028 (void) memset((char *)p->g->setbits + (nbytes - css),
1029 0, css);
1030 else {
1031 no = 0;
1032 SETERROR(REG_ESPACE);
1033 /* caller's responsibility not to do set ops */
1034 }
1035 }
1036
1037 assert(p->g->sets != NULL); /* xxx */
1038 cs = &p->g->sets[no];
1039 cs->ptr = p->g->setbits + css*((no)/CHAR_BIT);
1040 cs->mask = 1 << ((no) % CHAR_BIT);
1041 cs->hash = 0;
1042 cs->smultis = 0;
1043 cs->multis = NULL;
1044
1045 return(cs);
1046 }
1047
1048 /*
1049 - freeset - free a now-unused set
1050 == static void freeset(register struct parse *p, register cset *cs);
1051 */
1052 static void
1053 freeset(p, cs)
1054 register struct parse *p;
1055 register cset *cs;
1056 {
1057 register size_t i;
1058 register cset *top = &p->g->sets[p->g->ncsets];
1059 register size_t css = (size_t)p->g->csetsize;
1060
1061 for (i = 0; i < css; i++)
1062 CHsub(cs, i);
1063 if (cs == top-1) /* recover only the easy case */
1064 p->g->ncsets--;
1065 }
1066
1067 /*
1068 - freezeset - final processing on a set of characters
1069 == static int freezeset(register struct parse *p, register cset *cs);
1070 *
1071 * The main task here is merging identical sets. This is usually a waste
1072 * of time (although the hash code minimizes the overhead), but can win
1073 * big if REG_ICASE is being used. REG_ICASE, by the way, is why the hash
1074 * is done using addition rather than xor -- all ASCII [aA] sets xor to
1075 * the same value!
1076 */
1077 static int /* set number */
1078 freezeset(p, cs)
1079 register struct parse *p;
1080 register cset *cs;
1081 {
1082 register uch h = cs->hash;
1083 register size_t i;
1084 register cset *top = &p->g->sets[p->g->ncsets];
1085 register cset *cs2;
1086 register size_t css = (size_t)p->g->csetsize;
1087
1088 /* look for an earlier one which is the same */
1089 for (cs2 = &p->g->sets[0]; cs2 < top; cs2++)
1090 if (cs2->hash == h && cs2 != cs) {
1091 /* maybe */
1092 for (i = 0; i < css; i++)
1093 if (!!CHIN(cs2, i) != !!CHIN(cs, i))
1094 break; /* no */
1095 if (i == css)
1096 break; /* yes */
1097 }
1098
1099 if (cs2 < top) { /* found one */
1100 freeset(p, cs);
1101 cs = cs2;
1102 }
1103
1104 return((int)(cs - p->g->sets));
1105 }
1106
1107 /*
1108 - firstch - return first character in a set (which must have at least one)
1109 == static int firstch(register struct parse *p, register cset *cs);
1110 */
1111 static int /* character; there is no "none" value */
1112 firstch(p, cs)
1113 register struct parse *p;
1114 register cset *cs;
1115 {
1116 register size_t i;
1117 register size_t css = (size_t)p->g->csetsize;
1118
1119 for (i = 0; i < css; i++)
1120 if (CHIN(cs, i))
1121 return((char)i);
1122 assert(never);
1123 return(0); /* arbitrary */
1124 }
1125
1126 /*
1127 - nch - number of characters in a set
1128 == static int nch(register struct parse *p, register cset *cs);
1129 */
1130 static int
1131 nch(p, cs)
1132 register struct parse *p;
1133 register cset *cs;
1134 {
1135 register size_t i;
1136 register size_t css = (size_t)p->g->csetsize;
1137 register int n = 0;
1138
1139 for (i = 0; i < css; i++)
1140 if (CHIN(cs, i))
1141 n++;
1142 return(n);
1143 }
1144
1145 /*
1146 - mcadd - add a collating element to a cset
1147 == static void mcadd(register struct parse *p, register cset *cs, \
1148 == register char *cp);
1149 */
1150 static void
1151 mcadd(p, cs, cp)
1152 register struct parse *p;
1153 register cset *cs;
1154 register char *cp;
1155 {
1156 register size_t oldend = cs->smultis;
1157
1158 cs->smultis += strlen(cp) + 1;
1159 if (cs->multis == NULL)
1160 cs->multis = malloc(cs->smultis);
1161 else
1162 cs->multis = realloc(cs->multis, cs->smultis);
1163 if (cs->multis == NULL) {
1164 SETERROR(REG_ESPACE);
1165 return;
1166 }
1167
1168 (void) strcpy(cs->multis + oldend - 1, cp);
1169 cs->multis[cs->smultis - 1] = '\0';
1170 }
1171
1172 /* these functions don't seem to be used (yet?), suppress warnings */
1173 #if 0
1174 /*
1175 - mcsub - subtract a collating element from a cset
1176 == static void mcsub(register cset *cs, register char *cp);
1177 */
1178 static void
1179 mcsub(cs, cp)
1180 register cset *cs;
1181 register char *cp;
1182 {
1183 register char *fp = mcfind(cs, cp);
1184 register size_t len = strlen(fp);
1185
1186 assert(fp != NULL);
1187 (void) memmove(fp, fp + len + 1,
1188 cs->smultis - (fp + len + 1 - cs->multis));
1189 cs->smultis -= len;
1190
1191 if (cs->smultis == 0) {
1192 free(cs->multis);
1193 cs->multis = NULL;
1194 return;
1195 }
1196
1197 cs->multis = realloc(cs->multis, cs->smultis);
1198 assert(cs->multis != NULL);
1199 }
1200
1201 /*
1202 - mcin - is a collating element in a cset?
1203 == static int mcin(register cset *cs, register char *cp);
1204 */
1205 static int
1206 mcin(cs, cp)
1207 register cset *cs;
1208 register char *cp;
1209 {
1210 return(mcfind(cs, cp) != NULL);
1211 }
1212
1213 /*
1214 - mcfind - find a collating element in a cset
1215 == static char *mcfind(register cset *cs, register char *cp);
1216 */
1217 static char *
1218 mcfind(cs, cp)
1219 register cset *cs;
1220 register char *cp;
1221 {
1222 register char *p;
1223
1224 if (cs->multis == NULL)
1225 return(NULL);
1226 for (p = cs->multis; *p != '\0'; p += strlen(p) + 1)
1227 if (strcmp(cp, p) == 0)
1228 return(p);
1229 return(NULL);
1230 }
1231 #endif /* 0 */
1232
1233 /*
1234 - mcinvert - invert the list of collating elements in a cset
1235 == static void mcinvert(register struct parse *p, register cset *cs);
1236 *
1237 * This would have to know the set of possibilities. Implementation
1238 * is deferred.
1239 */
1240 static void
1241 mcinvert(p, cs)
1242 register struct parse *p;
1243 register cset *cs;
1244 {
1245 assert(cs->multis == NULL); /* xxx */
1246 }
1247
1248 /*
1249 - mccase - add case counterparts of the list of collating elements in a cset
1250 == static void mccase(register struct parse *p, register cset *cs);
1251 *
1252 * This would have to know the set of possibilities. Implementation
1253 * is deferred.
1254 */
1255 static void
1256 mccase(p, cs)
1257 register struct parse *p;
1258 register cset *cs;
1259 {
1260 assert(cs->multis == NULL); /* xxx */
1261 }
1262
1263 /*
1264 - isinsets - is this character in any sets?
1265 == static int isinsets(register struct re_guts *g, int c);
1266 */
1267 static int /* predicate */
1268 isinsets(g, c)
1269 register struct re_guts *g;
1270 int c;
1271 {
1272 register uch *col;
1273 register int i;
1274 register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
1275 register unsigned uc = (unsigned char)c;
1276
1277 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
1278 if (col[uc] != 0)
1279 return(1);
1280 return(0);
1281 }
1282
1283 /*
1284 - samesets - are these two characters in exactly the same sets?
1285 == static int samesets(register struct re_guts *g, int c1, int c2);
1286 */
1287 static int /* predicate */
1288 samesets(g, c1, c2)
1289 register struct re_guts *g;
1290 int c1;
1291 int c2;
1292 {
1293 register uch *col;
1294 register int i;
1295 register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
1296 register unsigned uc1 = (unsigned char)c1;
1297 register unsigned uc2 = (unsigned char)c2;
1298
1299 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
1300 if (col[uc1] != col[uc2])
1301 return(0);
1302 return(1);
1303 }
1304
1305 /*
1306 - categorize - sort out character categories
1307 == static void categorize(struct parse *p, register struct re_guts *g);
1308 */
1309 static void
1310 categorize(p, g)
1311 struct parse *p;
1312 register struct re_guts *g;
1313 {
1314 register cat_t *cats = g->categories;
1315 register int c;
1316 register int c2;
1317 register cat_t cat;
1318
1319 /* avoid making error situations worse */
1320 if (p->error != 0)
1321 return;
1322
1323 for (c = CHAR_MIN; c <= CHAR_MAX; c++)
1324 if (cats[c] == 0 && isinsets(g, c)) {
1325 cat = g->ncategories++;
1326 cats[c] = cat;
1327 for (c2 = c+1; c2 <= CHAR_MAX; c2++)
1328 if (cats[c2] == 0 && samesets(g, c, c2))
1329 cats[c2] = cat;
1330 }
1331 }
1332
1333 /*
1334 - dupl - emit a duplicate of a bunch of sops
1335 == static sopno dupl(register struct parse *p, sopno start, sopno finish);
1336 */
1337 static sopno /* start of duplicate */
1338 dupl(p, start, finish)
1339 register struct parse *p;
1340 sopno start; /* from here */
1341 sopno finish; /* to this less one */
1342 {
1343 register sopno ret = HERE();
1344 register sopno len = finish - start;
1345
1346 assert(finish >= start);
1347 if (len == 0)
1348 return(ret);
1349 enlarge(p, p->ssize + len); /* this many unexpected additions */
1350 assert(p->ssize >= p->slen + len);
1351 (void) memcpy((char *)(p->strip + p->slen),
1352 (char *)(p->strip + start), (size_t)len*sizeof(sop));
1353 p->slen += len;
1354 return(ret);
1355 }
1356
1357 /*
1358 - doemit - emit a strip operator
1359 == static void doemit(register struct parse *p, sop op, size_t opnd);
1360 *
1361 * It might seem better to implement this as a macro with a function as
1362 * hard-case backup, but it's just too big and messy unless there are
1363 * some changes to the data structures. Maybe later.
1364 */
1365 static void
1366 doemit(p, op, opnd)
1367 register struct parse *p;
1368 sop op;
1369 size_t opnd;
1370 {
1371 /* avoid making error situations worse */
1372 if (p->error != 0)
1373 return;
1374
1375 /* deal with oversize operands ("can't happen", more or less) */
1376 assert(opnd < 1<<OPSHIFT);
1377
1378 /* deal with undersized strip */
1379 if (p->slen >= p->ssize)
1380 enlarge(p, (p->ssize+1) / 2 * 3); /* +50% */
1381 assert(p->slen < p->ssize);
1382
1383 /* finally, it's all reduced to the easy case */
1384 p->strip[p->slen++] = SOP(op, opnd);
1385 }
1386
1387 /*
1388 - doinsert - insert a sop into the strip
1389 == static void doinsert(register struct parse *p, sop op, size_t opnd, sopno pos);
1390 */
1391 static void
1392 doinsert(p, op, opnd, pos)
1393 register struct parse *p;
1394 sop op;
1395 size_t opnd;
1396 sopno pos;
1397 {
1398 register sopno sn;
1399 register sop s;
1400 register int i;
1401
1402 /* avoid making error situations worse */
1403 if (p->error != 0)
1404 return;
1405
1406 sn = HERE();
1407 EMIT(op, opnd); /* do checks, ensure space */
1408 assert(HERE() == sn+1);
1409 s = p->strip[sn];
1410
1411 /* adjust paren pointers */
1412 assert(pos > 0);
1413 for (i = 1; i < NPAREN; i++) {
1414 if (p->pbegin[i] >= pos) {
1415 p->pbegin[i]++;
1416 }
1417 if (p->pend[i] >= pos) {
1418 p->pend[i]++;
1419 }
1420 }
1421
1422 memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos],
1423 (HERE()-pos-1)*sizeof(sop));
1424 p->strip[pos] = s;
1425 }
1426
1427 /*
1428 - dofwd - complete a forward reference
1429 == static void dofwd(register struct parse *p, sopno pos, sop value);
1430 */
1431 static void
1432 dofwd(p, pos, value)
1433 register struct parse *p;
1434 register sopno pos;
1435 sop value;
1436 {
1437 /* avoid making error situations worse */
1438 if (p->error != 0)
1439 return;
1440
1441 assert(value < 1<<OPSHIFT);
1442 p->strip[pos] = OP(p->strip[pos]) | value;
1443 }
1444
1445 /*
1446 - enlarge - enlarge the strip
1447 == static void enlarge(register struct parse *p, sopno size);
1448 */
1449 static void
1450 enlarge(p, size)
1451 register struct parse *p;
1452 register sopno size;
1453 {
1454 register sop *sp;
1455
1456 if (p->ssize >= size)
1457 return;
1458
1459 sp = (sop *)realloc(p->strip, size*sizeof(sop));
1460 if (sp == NULL) {
1461 SETERROR(REG_ESPACE);
1462 return;
1463 }
1464 p->strip = sp;
1465 p->ssize = size;
1466 }
1467
1468 /*
1469 - stripsnug - compact the strip
1470 == static void stripsnug(register struct parse *p, register struct re_guts *g);
1471 */
1472 static void
1473 stripsnug(p, g)
1474 register struct parse *p;
1475 register struct re_guts *g;
1476 {
1477 g->nstates = p->slen;
1478 g->strip = (sop *)realloc((char *)p->strip, p->slen * sizeof(sop));
1479 if (g->strip == NULL) {
1480 SETERROR(REG_ESPACE);
1481 g->strip = p->strip;
1482 }
1483 }
1484
1485 /*
1486 - findmust - fill in must and mlen with longest mandatory literal string
1487 == static void findmust(register struct parse *p, register struct re_guts *g);
1488 *
1489 * This algorithm could do fancy things like analyzing the operands of |
1490 * for common subsequences. Someday. This code is simple and finds most
1491 * of the interesting cases.
1492 *
1493 * Note that must and mlen got initialized during setup.
1494 */
1495 static void
1496 findmust(p, g)
1497 struct parse *p;
1498 register struct re_guts *g;
1499 {
1500 register sop *scan;
1501 sop *start;
1502 register sop *newstart;
1503 register sopno newlen;
1504 register sop s;
1505 register char *cp;
1506 register sopno i;
1507
1508 /* avoid making error situations worse */
1509 if (p->error != 0)
1510 return;
1511
1512 /* find the longest OCHAR sequence in strip */
1513 newlen = 0;
1514 scan = g->strip + 1;
1515 do {
1516 s = *scan++;
1517 switch (OP(s)) {
1518 case OCHAR: /* sequence member */
1519 if (newlen == 0) /* new sequence */
1520 newstart = scan - 1;
1521 newlen++;
1522 break;
1523 case OPLUS_: /* things that don't break one */
1524 case OLPAREN:
1525 case ORPAREN:
1526 break;
1527 case OQUEST_: /* things that must be skipped */
1528 case OCH_:
1529 scan--;
1530 do {
1531 scan += OPND(s);
1532 s = *scan;
1533 /* assert() interferes w debug printouts */
1534 if (OP(s) != O_QUEST && OP(s) != O_CH &&
1535 OP(s) != OOR2) {
1536 g->iflags |= BAD;
1537 return;
1538 }
1539 } while (OP(s) != O_QUEST && OP(s) != O_CH);
1540 /* fallthrough */
1541 default: /* things that break a sequence */
1542 if (newlen > g->mlen) { /* ends one */
1543 start = newstart;
1544 g->mlen = newlen;
1545 }
1546 newlen = 0;
1547 break;
1548 }
1549 } while (OP(s) != OEND);
1550
1551 if (g->mlen == 0) /* there isn't one */
1552 return;
1553
1554 /* turn it into a character string */
1555 g->must = malloc((size_t)g->mlen + 1);
1556 if (g->must == NULL) { /* argh; just forget it */
1557 g->mlen = 0;
1558 return;
1559 }
1560 cp = g->must;
1561 scan = start;
1562 for (i = g->mlen; i > 0; i--) {
1563 while (OP(s = *scan++) != OCHAR)
1564 continue;
1565 assert(cp < g->must + g->mlen);
1566 *cp++ = (char)OPND(s);
1567 }
1568 assert(cp == g->must + g->mlen);
1569 *cp++ = '\0'; /* just on general principles */
1570 }
1571
1572 /*
1573 - pluscount - count + nesting
1574 == static sopno pluscount(register struct parse *p, register struct re_guts *g);
1575 */
1576 static sopno /* nesting depth */
1577 pluscount(p, g)
1578 struct parse *p;
1579 register struct re_guts *g;
1580 {
1581 register sop *scan;
1582 register sop s;
1583 register sopno plusnest = 0;
1584 register sopno maxnest = 0;
1585
1586 if (p->error != 0)
1587 return(0); /* there may not be an OEND */
1588
1589 scan = g->strip + 1;
1590 do {
1591 s = *scan++;
1592 switch (OP(s)) {
1593 case OPLUS_:
1594 plusnest++;
1595 break;
1596 case O_PLUS:
1597 if (plusnest > maxnest)
1598 maxnest = plusnest;
1599 plusnest--;
1600 break;
1601 }
1602 } while (OP(s) != OEND);
1603 if (plusnest != 0)
1604 g->iflags |= BAD;
1605 return(maxnest);
1606 }
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