source: trunk/minix/lib/regex/regcomp.c@ 20

Last change on this file since 20 was 9, checked in by Mattia Monga, 14 years ago

Minix 3.1.2a
File size: 40.8 KB
Line 
1/*-
2 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
3 * Copyright (c) 1992, 1993, 1994
4 * The Regents of the University of California. All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Henry Spencer.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * @(#)regcomp.c 8.5 (Berkeley) 3/20/94
38 */
39
40#if defined(LIBC_SCCS) && !defined(lint)
41static char sccsid[] = "@(#)regcomp.c 8.5 (Berkeley) 3/20/94";
42#endif /* LIBC_SCCS and not lint */
43
44#include <sys/types.h>
45#include <stdio.h>
46#include <string.h>
47#ifdef __minix_vmd
48#include <bsd/asciictype.h>
49#else
50#include <ctype.h>
51#endif
52#include <limits.h>
53#include <stdlib.h>
54#include <regex.h>
55
56#include "utils.h"
57#include "regex2.h"
58
59#include "cclass.h"
60#include "cname.h"
61
62/*
63 * parse structure, passed up and down to avoid global variables and
64 * other clumsinesses
65 */
66struct parse {
67 char *next; /* next character in RE */
68 char *end; /* end of string (-> NUL normally) */
69 int error; /* has an error been seen? */
70 sop *strip; /* malloced strip */
71 sopno ssize; /* malloced strip size (allocated) */
72 sopno slen; /* malloced strip length (used) */
73 int ncsalloc; /* number of csets allocated */
74 struct re_guts *g;
75# define NPAREN 10 /* we need to remember () 1-9 for back refs */
76 sopno pbegin[NPAREN]; /* -> ( ([0] unused) */
77 sopno pend[NPAREN]; /* -> ) ([0] unused) */
78};
79
80/* ========= begin header generated by ./mkh ========= */
81#ifdef __cplusplus
82extern "C" {
83#endif
84
85/* === regcomp.c === */
86static void p_ere(struct parse *p, int stop);
87static void p_ere_exp(struct parse *p);
88static void p_str(struct parse *p);
89static void p_bre(struct parse *p, int end1, int end2);
90static int p_simp_re(struct parse *p, int starordinary);
91static int p_count(struct parse *p);
92static void p_bracket(struct parse *p);
93static void p_b_term(struct parse *p, cset *cs);
94static void p_b_cclass(struct parse *p, cset *cs);
95static void p_b_eclass(struct parse *p, cset *cs);
96static char p_b_symbol(struct parse *p);
97static char p_b_coll_elem(struct parse *p, int endc);
98static char othercase(int ch);
99static void bothcases(struct parse *p, int ch);
100static void ordinary(struct parse *p, int ch);
101static void nonnewline(struct parse *p);
102static void repeat(struct parse *p, sopno start, int from, int to);
103static int seterr(struct parse *p, int e);
104static cset *allocset(struct parse *p);
105static void freeset(struct parse *p, cset *cs);
106static int freezeset(struct parse *p, cset *cs);
107static int firstch(struct parse *p, cset *cs);
108static int nch(struct parse *p, cset *cs);
109static void mcadd(struct parse *p, cset *cs, char *cp);
110static void mcsub(cset *cs, char *cp);
111static int mcin(cset *cs, char *cp);
112static char *mcfind(cset *cs, char *cp);
113static void mcinvert(struct parse *p, cset *cs);
114static void mccase(struct parse *p, cset *cs);
115static int isinsets(struct re_guts *g, int c);
116static int samesets(struct re_guts *g, int c1, int c2);
117static void categorize(struct parse *p, struct re_guts *g);
118static sopno dupl(struct parse *p, sopno start, sopno finish);
119static void doemit(struct parse *p, sop op, size_t opnd);
120static void doinsert(struct parse *p, sop op, size_t opnd, sopno pos);
121static void dofwd(struct parse *p, sopno pos, sop value);
122static void enlarge(struct parse *p, sopno size);
123static void stripsnug(struct parse *p, struct re_guts *g);
124static void findmust(struct parse *p, struct re_guts *g);
125static sopno pluscount(struct parse *p, struct re_guts *g);
126
127#ifdef __cplusplus
128}
129#endif
130/* ========= end header generated by ./mkh ========= */
131
132static char nuls[10]; /* place to point scanner in event of error */
133
134/*
135 * macros for use with parse structure
136 * BEWARE: these know that the parse structure is named `p' !!!
137 */
138#define PEEK() (*p->next)
139#define PEEK2() (*(p->next+1))
140#define MORE() (p->next < p->end)
141#define MORE2() (p->next+1 < p->end)
142#define SEE(c) (MORE() && PEEK() == (c))
143#define SEETWO(a, b) (MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
144#define EAT(c) ((SEE(c)) ? (NEXT(), 1) : 0)
145#define EATTWO(a, b) ((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
146#define NEXT() (p->next++)
147#define NEXT2() (p->next += 2)
148#define NEXTn(n) (p->next += (n))
149#define GETNEXT() (*p->next++)
150#define SETERROR(e) seterr(p, (e))
151#define REQUIRE(co, e) ((co) || SETERROR(e))
152#define MUSTSEE(c, e) (REQUIRE(MORE() && PEEK() == (c), e))
153#define MUSTEAT(c, e) (REQUIRE(MORE() && GETNEXT() == (c), e))
154#define MUSTNOTSEE(c, e) (REQUIRE(!MORE() || PEEK() != (c), e))
155#define EMIT(op, sopnd) doemit(p, (sop)(op), (size_t)(sopnd))
156#define INSERT(op, pos) doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
157#define AHEAD(pos) dofwd(p, pos, HERE()-(pos))
158#define ASTERN(sop, pos) EMIT(sop, HERE()-pos)
159#define HERE() (p->slen)
160#define THERE() (p->slen - 1)
161#define THERETHERE() (p->slen - 2)
162#define DROP(n) (p->slen -= (n))
163
164#ifndef NDEBUG
165static int never = 0; /* for use in asserts; shuts lint up */
166#else
167#define never 0 /* some <assert.h>s have bugs too */
168#endif
169
170/*
171 - regcomp - interface for parser and compilation
172 = extern int regcomp(regex_t *, const char *, int);
173 = #define REG_BASIC 0000
174 = #define REG_EXTENDED 0001
175 = #define REG_ICASE 0002
176 = #define REG_NOSUB 0004
177 = #define REG_NEWLINE 0010
178 = #define REG_NOSPEC 0020
179 = #define REG_PEND 0040
180 = #define REG_DUMP 0200
181 */
182int /* 0 success, otherwise REG_something */
183regcomp(preg, pattern, cflags)
184regex_t *preg;
185const char *pattern;
186int cflags;
187{
188 struct parse pa;
189 register struct re_guts *g;
190 register struct parse *p = &pa;
191 register int i;
192 register size_t len;
193#ifdef REDEBUG
194# define GOODFLAGS(f) (f)
195#else
196# define GOODFLAGS(f) ((f)&~REG_DUMP)
197#endif
198
199 cflags = GOODFLAGS(cflags);
200 if ((cflags&REG_EXTENDED) && (cflags&REG_NOSPEC))
201 return(REG_INVARG);
202
203 if (cflags&REG_PEND) {
204 if (preg->re_endp < pattern)
205 return(REG_INVARG);
206 len = preg->re_endp - pattern;
207 } else
208 len = strlen((char *)pattern);
209
210 /* do the mallocs early so failure handling is easy */
211 g = (struct re_guts *)malloc(sizeof(struct re_guts) +
212 (NC-1)*sizeof(cat_t));
213 if (g == NULL)
214 return(REG_ESPACE);
215 p->ssize = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */
216 p->strip = (sop *)malloc(p->ssize * sizeof(sop));
217 p->slen = 0;
218 if (p->strip == NULL) {
219 free((char *)g);
220 return(REG_ESPACE);
221 }
222
223 /* set things up */
224 p->g = g;
225 p->next = (char *)pattern; /* convenience; we do not modify it */
226 p->end = p->next + len;
227 p->error = 0;
228 p->ncsalloc = 0;
229 for (i = 0; i < NPAREN; i++) {
230 p->pbegin[i] = 0;
231 p->pend[i] = 0;
232 }
233 g->csetsize = NC;
234 g->sets = NULL;
235 g->setbits = NULL;
236 g->ncsets = 0;
237 g->cflags = cflags;
238 g->iflags = 0;
239 g->nbol = 0;
240 g->neol = 0;
241 g->must = NULL;
242 g->mlen = 0;
243 g->nsub = 0;
244 g->ncategories = 1; /* category 0 is "everything else" */
245 g->categories = &g->catspace[-(CHAR_MIN)];
246 (void) memset((char *)g->catspace, 0, NC*sizeof(cat_t));
247 g->backrefs = 0;
248
249 /* do it */
250 EMIT(OEND, 0);
251 g->firststate = THERE();
252 if (cflags&REG_EXTENDED)
253 p_ere(p, OUT);
254 else if (cflags&REG_NOSPEC)
255 p_str(p);
256 else
257 p_bre(p, OUT, OUT);
258 EMIT(OEND, 0);
259 g->laststate = THERE();
260
261 /* tidy up loose ends and fill things in */
262 categorize(p, g);
263 stripsnug(p, g);
264 findmust(p, g);
265 g->nplus = pluscount(p, g);
266 g->magic = MAGIC2;
267 preg->re_nsub = g->nsub;
268 preg->re_g = g;
269 preg->re_magic = MAGIC1;
270#ifndef REDEBUG
271 /* not debugging, so can't rely on the assert() in regexec() */
272 if (g->iflags&BAD)
273 SETERROR(REG_ASSERT);
274#endif
275
276 /* win or lose, we're done */
277 if (p->error != 0) /* lose */
278 regfree(preg);
279 return(p->error);
280}
281
282/*
283 - p_ere - ERE parser top level, concatenation and alternation
284 == static void p_ere(register struct parse *p, int stop);
285 */
286static void
287p_ere(p, stop)
288register struct parse *p;
289int stop; /* character this ERE should end at */
290{
291 register char c;
292 register sopno prevback;
293 register sopno prevfwd;
294 register sopno conc;
295 register int first = 1; /* is this the first alternative? */
296
297 for (;;) {
298 /* do a bunch of concatenated expressions */
299 conc = HERE();
300 while (MORE() && (c = PEEK()) != '|' && c != stop)
301 p_ere_exp(p);
302 REQUIRE(HERE() != conc, REG_EMPTY); /* require nonempty */
303
304 if (!EAT('|'))
305 break; /* NOTE BREAK OUT */
306
307 if (first) {
308 INSERT(OCH_, conc); /* offset is wrong */
309 prevfwd = conc;
310 prevback = conc;
311 first = 0;
312 }
313 ASTERN(OOR1, prevback);
314 prevback = THERE();
315 AHEAD(prevfwd); /* fix previous offset */
316 prevfwd = HERE();
317 EMIT(OOR2, 0); /* offset is very wrong */
318 }
319
320 if (!first) { /* tail-end fixups */
321 AHEAD(prevfwd);
322 ASTERN(O_CH, prevback);
323 }
324
325 assert(!MORE() || SEE(stop));
326}
327
328/*
329 - p_ere_exp - parse one subERE, an atom possibly followed by a repetition op
330 == static void p_ere_exp(register struct parse *p);
331 */
332static void
333p_ere_exp(p)
334register struct parse *p;
335{
336 register char c;
337 register sopno pos;
338 register int count;
339 register int count2;
340 register sopno subno;
341 int wascaret = 0;
342
343 assert(MORE()); /* caller should have ensured this */
344 c = GETNEXT();
345
346 pos = HERE();
347 switch (c) {
348 case '(':
349 REQUIRE(MORE(), REG_EPAREN);
350 p->g->nsub++;
351 subno = p->g->nsub;
352 if (subno < NPAREN)
353 p->pbegin[subno] = HERE();
354 EMIT(OLPAREN, subno);
355 if (!SEE(')'))
356 p_ere(p, ')');
357 if (subno < NPAREN) {
358 p->pend[subno] = HERE();
359 assert(p->pend[subno] != 0);
360 }
361 EMIT(ORPAREN, subno);
362 MUSTEAT(')', REG_EPAREN);
363 break;
364#ifndef POSIX_MISTAKE
365 case ')': /* happens only if no current unmatched ( */
366 /*
367 * You may ask, why the ifndef? Because I didn't notice
368 * this until slightly too late for 1003.2, and none of the
369 * other 1003.2 regular-expression reviewers noticed it at
370 * all. So an unmatched ) is legal POSIX, at least until
371 * we can get it fixed.
372 */
373 SETERROR(REG_EPAREN);
374 break;
375#endif
376 case '^':
377 EMIT(OBOL, 0);
378 p->g->iflags |= USEBOL;
379 p->g->nbol++;
380 wascaret = 1;
381 break;
382 case '$':
383 EMIT(OEOL, 0);
384 p->g->iflags |= USEEOL;
385 p->g->neol++;
386 break;
387 case '|':
388 SETERROR(REG_EMPTY);
389 break;
390 case '*':
391 case '+':
392 case '?':
393 SETERROR(REG_BADRPT);
394 break;
395 case '.':
396 if (p->g->cflags&REG_NEWLINE)
397 nonnewline(p);
398 else
399 EMIT(OANY, 0);
400 break;
401 case '[':
402 p_bracket(p);
403 break;
404 case '\\':
405 REQUIRE(MORE(), REG_EESCAPE);
406 c = GETNEXT();
407 ordinary(p, c);
408 break;
409 case '{': /* okay as ordinary except if digit follows */
410 REQUIRE(!MORE() || !isdigit(PEEK()), REG_BADRPT);
411 /* FALLTHROUGH */
412 default:
413 ordinary(p, c);
414 break;
415 }
416
417 if (!MORE())
418 return;
419 c = PEEK();
420 /* we call { a repetition if followed by a digit */
421 if (!( c == '*' || c == '+' || c == '?' ||
422 (c == '{' && MORE2() && isdigit(PEEK2())) ))
423 return; /* no repetition, we're done */
424 NEXT();
425
426 REQUIRE(!wascaret, REG_BADRPT);
427 switch (c) {
428 case '*': /* implemented as +? */
429 /* this case does not require the (y|) trick, noKLUDGE */
430 INSERT(OPLUS_, pos);
431 ASTERN(O_PLUS, pos);
432 INSERT(OQUEST_, pos);
433 ASTERN(O_QUEST, pos);
434 break;
435 case '+':
436 INSERT(OPLUS_, pos);
437 ASTERN(O_PLUS, pos);
438 break;
439 case '?':
440 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
441 INSERT(OCH_, pos); /* offset slightly wrong */
442 ASTERN(OOR1, pos); /* this one's right */
443 AHEAD(pos); /* fix the OCH_ */
444 EMIT(OOR2, 0); /* offset very wrong... */
445 AHEAD(THERE()); /* ...so fix it */
446 ASTERN(O_CH, THERETHERE());
447 break;
448 case '{':
449 count = p_count(p);
450 if (EAT(',')) {
451 if (isdigit(PEEK())) {
452 count2 = p_count(p);
453 REQUIRE(count <= count2, REG_BADBR);
454 } else /* single number with comma */
455 count2 = INFINITY;
456 } else /* just a single number */
457 count2 = count;
458 repeat(p, pos, count, count2);
459 if (!EAT('}')) { /* error heuristics */
460 while (MORE() && PEEK() != '}')
461 NEXT();
462 REQUIRE(MORE(), REG_EBRACE);
463 SETERROR(REG_BADBR);
464 }
465 break;
466 }
467
468 if (!MORE())
469 return;
470 c = PEEK();
471 if (!( c == '*' || c == '+' || c == '?' ||
472 (c == '{' && MORE2() && isdigit(PEEK2())) ) )
473 return;
474 SETERROR(REG_BADRPT);
475}
476
477/*
478 - p_str - string (no metacharacters) "parser"
479 == static void p_str(register struct parse *p);
480 */
481static void
482p_str(p)
483register struct parse *p;
484{
485 REQUIRE(MORE(), REG_EMPTY);
486 while (MORE())
487 ordinary(p, GETNEXT());
488}
489
490/*
491 - p_bre - BRE parser top level, anchoring and concatenation
492 == static void p_bre(register struct parse *p, register int end1, \
493 == register int end2);
494 * Giving end1 as OUT essentially eliminates the end1/end2 check.
495 *
496 * This implementation is a bit of a kludge, in that a trailing $ is first
497 * taken as an ordinary character and then revised to be an anchor. The
498 * only undesirable side effect is that '$' gets included as a character
499 * category in such cases. This is fairly harmless; not worth fixing.
500 * The amount of lookahead needed to avoid this kludge is excessive.
501 */
502static void
503p_bre(p, end1, end2)
504register struct parse *p;
505register int end1; /* first terminating character */
506register int end2; /* second terminating character */
507{
508 register sopno start = HERE();
509 register int first = 1; /* first subexpression? */
510 register int wasdollar = 0;
511
512 if (EAT('^')) {
513 EMIT(OBOL, 0);
514 p->g->iflags |= USEBOL;
515 p->g->nbol++;
516 }
517 while (MORE() && !SEETWO(end1, end2)) {
518 wasdollar = p_simp_re(p, first);
519 first = 0;
520 }
521 if (wasdollar) { /* oops, that was a trailing anchor */
522 DROP(1);
523 EMIT(OEOL, 0);
524 p->g->iflags |= USEEOL;
525 p->g->neol++;
526 }
527
528 REQUIRE(HERE() != start, REG_EMPTY); /* require nonempty */
529}
530
531/*
532 - p_simp_re - parse a simple RE, an atom possibly followed by a repetition
533 == static int p_simp_re(register struct parse *p, int starordinary);
534 */
535static int /* was the simple RE an unbackslashed $? */
536p_simp_re(p, starordinary)
537register struct parse *p;
538int starordinary; /* is a leading * an ordinary character? */
539{
540 register int c;
541 register int count;
542 register int count2;
543 register sopno pos;
544 register int i;
545 register sopno subno;
546# define BACKSL (1<<CHAR_BIT)
547
548 pos = HERE(); /* repetion op, if any, covers from here */
549
550 assert(MORE()); /* caller should have ensured this */
551 c = GETNEXT();
552 if (c == '\\') {
553 REQUIRE(MORE(), REG_EESCAPE);
554 c = BACKSL | (unsigned char)GETNEXT();
555 }
556 switch (c) {
557 case '.':
558 if (p->g->cflags&REG_NEWLINE)
559 nonnewline(p);
560 else
561 EMIT(OANY, 0);
562 break;
563 case '[':
564 p_bracket(p);
565 break;
566 case BACKSL|'{':
567 SETERROR(REG_BADRPT);
568 break;
569 case BACKSL|'(':
570 p->g->nsub++;
571 subno = p->g->nsub;
572 if (subno < NPAREN)
573 p->pbegin[subno] = HERE();
574 EMIT(OLPAREN, subno);
575 /* the MORE here is an error heuristic */
576 if (MORE() && !SEETWO('\\', ')'))
577 p_bre(p, '\\', ')');
578 if (subno < NPAREN) {
579 p->pend[subno] = HERE();
580 assert(p->pend[subno] != 0);
581 }
582 EMIT(ORPAREN, subno);
583 REQUIRE(EATTWO('\\', ')'), REG_EPAREN);
584 break;
585 case BACKSL|')': /* should not get here -- must be user */
586 case BACKSL|'}':
587 SETERROR(REG_EPAREN);
588 break;
589 case BACKSL|'1':
590 case BACKSL|'2':
591 case BACKSL|'3':
592 case BACKSL|'4':
593 case BACKSL|'5':
594 case BACKSL|'6':
595 case BACKSL|'7':
596 case BACKSL|'8':
597 case BACKSL|'9':
598 i = (c&~BACKSL) - '0';
599 assert(i < NPAREN);
600 if (p->pend[i] != 0) {
601 assert(i <= p->g->nsub);
602 EMIT(OBACK_, i);
603 assert(p->pbegin[i] != 0);
604 assert(OP(p->strip[p->pbegin[i]]) == OLPAREN);
605 assert(OP(p->strip[p->pend[i]]) == ORPAREN);
606 (void) dupl(p, p->pbegin[i]+1, p->pend[i]);
607 EMIT(O_BACK, i);
608 } else
609 SETERROR(REG_ESUBREG);
610 p->g->backrefs = 1;
611 break;
612 case '*':
613 REQUIRE(starordinary, REG_BADRPT);
614 /* FALLTHROUGH */
615 default:
616 ordinary(p, c &~ BACKSL);
617 break;
618 }
619
620 if (EAT('*')) { /* implemented as +? */
621 /* this case does not require the (y|) trick, noKLUDGE */
622 INSERT(OPLUS_, pos);
623 ASTERN(O_PLUS, pos);
624 INSERT(OQUEST_, pos);
625 ASTERN(O_QUEST, pos);
626 } else if (EATTWO('\\', '{')) {
627 count = p_count(p);
628 if (EAT(',')) {
629 if (MORE() && isdigit(PEEK())) {
630 count2 = p_count(p);
631 REQUIRE(count <= count2, REG_BADBR);
632 } else /* single number with comma */
633 count2 = INFINITY;
634 } else /* just a single number */
635 count2 = count;
636 repeat(p, pos, count, count2);
637 if (!EATTWO('\\', '}')) { /* error heuristics */
638 while (MORE() && !SEETWO('\\', '}'))
639 NEXT();
640 REQUIRE(MORE(), REG_EBRACE);
641 SETERROR(REG_BADBR);
642 }
643 } else if (c == (unsigned char)'$') /* $ (but not \$) ends it */
644 return(1);
645
646 return(0);
647}
648
649/*
650 - p_count - parse a repetition count
651 == static int p_count(register struct parse *p);
652 */
653static int /* the value */
654p_count(p)
655register struct parse *p;
656{
657 register int count = 0;
658 register int ndigits = 0;
659
660 while (MORE() && isdigit(PEEK()) && count <= DUPMAX) {
661 count = count*10 + (GETNEXT() - '0');
662 ndigits++;
663 }
664
665 REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
666 return(count);
667}
668
669/*
670 - p_bracket - parse a bracketed character list
671 == static void p_bracket(register struct parse *p);
672 *
673 * Note a significant property of this code: if the allocset() did SETERROR,
674 * no set operations are done.
675 */
676static void
677p_bracket(p)
678register struct parse *p;
679{
680 register char c;
681 register cset *cs = allocset(p);
682 register int invert = 0;
683
684 /* Dept of Truly Sickening Special-Case Kludges */
685 if (p->next + 5 < p->end && strncmp(p->next, "[:<:]]", 6) == 0) {
686 EMIT(OBOW, 0);
687 NEXTn(6);
688 return;
689 }
690 if (p->next + 5 < p->end && strncmp(p->next, "[:>:]]", 6) == 0) {
691 EMIT(OEOW, 0);
692 NEXTn(6);
693 return;
694 }
695
696 if (EAT('^'))
697 invert++; /* make note to invert set at end */
698 if (EAT(']'))
699 CHadd(cs, ']');
700 else if (EAT('-'))
701 CHadd(cs, '-');
702 while (MORE() && PEEK() != ']' && !SEETWO('-', ']'))
703 p_b_term(p, cs);
704 if (EAT('-'))
705 CHadd(cs, '-');
706 MUSTEAT(']', REG_EBRACK);
707
708 if (p->error != 0) /* don't mess things up further */
709 return;
710
711 if (p->g->cflags&REG_ICASE) {
712 register int i;
713 register int ci;
714
715 for (i = p->g->csetsize - 1; i >= 0; i--)
716 if (CHIN(cs, i) && isalpha(i)) {
717 ci = othercase(i);
718 if (ci != i)
719 CHadd(cs, ci);
720 }
721 if (cs->multis != NULL)
722 mccase(p, cs);
723 }
724 if (invert) {
725 register int i;
726
727 for (i = p->g->csetsize - 1; i >= 0; i--)
728 if (CHIN(cs, i))
729 CHsub(cs, i);
730 else
731 CHadd(cs, i);
732 if (p->g->cflags&REG_NEWLINE)
733 CHsub(cs, '\n');
734 if (cs->multis != NULL)
735 mcinvert(p, cs);
736 }
737
738 assert(cs->multis == NULL); /* xxx */
739
740 if (nch(p, cs) == 1) { /* optimize singleton sets */
741 ordinary(p, firstch(p, cs));
742 freeset(p, cs);
743 } else
744 EMIT(OANYOF, freezeset(p, cs));
745}
746
747/*
748 - p_b_term - parse one term of a bracketed character list
749 == static void p_b_term(register struct parse *p, register cset *cs);
750 */
751static void
752p_b_term(p, cs)
753register struct parse *p;
754register cset *cs;
755{
756 register char c;
757 register char start, finish;
758 register int i;
759
760 /* classify what we've got */
761 switch ((MORE()) ? PEEK() : '\0') {
762 case '[':
763 c = (MORE2()) ? PEEK2() : '\0';
764 break;
765 case '-':
766 SETERROR(REG_ERANGE);
767 return; /* NOTE RETURN */
768 break;
769 default:
770 c = '\0';
771 break;
772 }
773
774 switch (c) {
775 case ':': /* character class */
776 NEXT2();
777 REQUIRE(MORE(), REG_EBRACK);
778 c = PEEK();
779 REQUIRE(c != '-' && c != ']', REG_ECTYPE);
780 p_b_cclass(p, cs);
781 REQUIRE(MORE(), REG_EBRACK);
782 REQUIRE(EATTWO(':', ']'), REG_ECTYPE);
783 break;
784 case '=': /* equivalence class */
785 NEXT2();
786 REQUIRE(MORE(), REG_EBRACK);
787 c = PEEK();
788 REQUIRE(c != '-' && c != ']', REG_ECOLLATE);
789 p_b_eclass(p, cs);
790 REQUIRE(MORE(), REG_EBRACK);
791 REQUIRE(EATTWO('=', ']'), REG_ECOLLATE);
792 break;
793 default: /* symbol, ordinary character, or range */
794/* xxx revision needed for multichar stuff */
795 start = p_b_symbol(p);
796 if (SEE('-') && MORE2() && PEEK2() != ']') {
797 /* range */
798 NEXT();
799 if (EAT('-'))
800 finish = '-';
801 else
802 finish = p_b_symbol(p);
803 } else
804 finish = start;
805/* xxx what about signed chars here... */
806 REQUIRE(start <= finish, REG_ERANGE);
807 for (i = start; i <= finish; i++)
808 CHadd(cs, i);
809 break;
810 }
811}
812
813/*
814 - p_b_cclass - parse a character-class name and deal with it
815 == static void p_b_cclass(register struct parse *p, register cset *cs);
816 */
817static void
818p_b_cclass(p, cs)
819register struct parse *p;
820register cset *cs;
821{
822 register char *sp = p->next;
823 register struct cclass *cp;
824 register size_t len;
825 register char *u;
826 register char c;
827
828 while (MORE() && isalpha(PEEK()))
829 NEXT();
830 len = p->next - sp;
831 for (cp = cclasses; cp->name != NULL; cp++)
832 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
833 break;
834 if (cp->name == NULL) {
835 /* oops, didn't find it */
836 SETERROR(REG_ECTYPE);
837 return;
838 }
839
840 u = cp->chars;
841 while ((c = *u++) != '\0')
842 CHadd(cs, c);
843 for (u = cp->multis; *u != '\0'; u += strlen(u) + 1)
844 MCadd(p, cs, u);
845}
846
847/*
848 - p_b_eclass - parse an equivalence-class name and deal with it
849 == static void p_b_eclass(register struct parse *p, register cset *cs);
850 *
851 * This implementation is incomplete. xxx
852 */
853static void
854p_b_eclass(p, cs)
855register struct parse *p;
856register cset *cs;
857{
858 register char c;
859
860 c = p_b_coll_elem(p, '=');
861 CHadd(cs, c);
862}
863
864/*
865 - p_b_symbol - parse a character or [..]ed multicharacter collating symbol
866 == static char p_b_symbol(register struct parse *p);
867 */
868static char /* value of symbol */
869p_b_symbol(p)
870register struct parse *p;
871{
872 register char value;
873
874 REQUIRE(MORE(), REG_EBRACK);
875 if (!EATTWO('[', '.'))
876 return(GETNEXT());
877
878 /* collating symbol */
879 value = p_b_coll_elem(p, '.');
880 REQUIRE(EATTWO('.', ']'), REG_ECOLLATE);
881 return(value);
882}
883
884/*
885 - p_b_coll_elem - parse a collating-element name and look it up
886 == static char p_b_coll_elem(register struct parse *p, int endc);
887 */
888static char /* value of collating element */
889p_b_coll_elem(p, endc)
890register struct parse *p;
891int endc; /* name ended by endc,']' */
892{
893 register char *sp = p->next;
894 register struct cname *cp;
895 register int len;
896 register char c;
897
898 while (MORE() && !SEETWO(endc, ']'))
899 NEXT();
900 if (!MORE()) {
901 SETERROR(REG_EBRACK);
902 return(0);
903 }
904 len = p->next - sp;
905 for (cp = cnames; cp->name != NULL; cp++)
906 if (strncmp(cp->name, sp, len) == 0 && cp->name[len] == '\0')
907 return(cp->code); /* known name */
908 if (len == 1)
909 return(*sp); /* single character */
910 SETERROR(REG_ECOLLATE); /* neither */
911 return(0);
912}
913
914/*
915 - othercase - return the case counterpart of an alphabetic
916 == static char othercase(int ch);
917 */
918static char /* if no counterpart, return ch */
919othercase(ch)
920int ch;
921{
922 assert(isalpha(ch));
923 if (isupper(ch))
924 return(tolower(ch));
925 else if (islower(ch))
926 return(toupper(ch));
927 else /* peculiar, but could happen */
928 return(ch);
929}
930
931/*
932 - bothcases - emit a dualcase version of a two-case character
933 == static void bothcases(register struct parse *p, int ch);
934 *
935 * Boy, is this implementation ever a kludge...
936 */
937static void
938bothcases(p, ch)
939register struct parse *p;
940int ch;
941{
942 register char *oldnext = p->next;
943 register char *oldend = p->end;
944 char bracket[3];
945
946 assert(othercase(ch) != ch); /* p_bracket() would recurse */
947 p->next = bracket;
948 p->end = bracket+2;
949 bracket[0] = ch;
950 bracket[1] = ']';
951 bracket[2] = '\0';
952 p_bracket(p);
953 assert(p->next == bracket+2);
954 p->next = oldnext;
955 p->end = oldend;
956}
957
958/*
959 - ordinary - emit an ordinary character
960 == static void ordinary(register struct parse *p, register int ch);
961 */
962static void
963ordinary(p, ch)
964register struct parse *p;
965register int ch;
966{
967 register cat_t *cap = p->g->categories;
968
969 if ((p->g->cflags&REG_ICASE) && isalpha(ch) && othercase(ch) != ch)
970 bothcases(p, ch);
971 else {
972 EMIT(OCHAR, (unsigned char)ch);
973 if (cap[ch] == 0)
974 cap[ch] = p->g->ncategories++;
975 }
976}
977
978/*
979 - nonnewline - emit REG_NEWLINE version of OANY
980 == static void nonnewline(register struct parse *p);
981 *
982 * Boy, is this implementation ever a kludge...
983 */
984static void
985nonnewline(p)
986register struct parse *p;
987{
988 register char *oldnext = p->next;
989 register char *oldend = p->end;
990 char bracket[4];
991
992 p->next = bracket;
993 p->end = bracket+3;
994 bracket[0] = '^';
995 bracket[1] = '\n';
996 bracket[2] = ']';
997 bracket[3] = '\0';
998 p_bracket(p);
999 assert(p->next == bracket+3);
1000 p->next = oldnext;
1001 p->end = oldend;
1002}
1003
1004/*
1005 - repeat - generate code for a bounded repetition, recursively if needed
1006 == static void repeat(register struct parse *p, sopno start, int from, int to);
1007 */
1008static void
1009repeat(p, start, from, to)
1010register struct parse *p;
1011sopno start; /* operand from here to end of strip */
1012int from; /* repeated from this number */
1013int to; /* to this number of times (maybe INFINITY) */
1014{
1015 register sopno finish = HERE();
1016# define N 2
1017# define INF 3
1018# define REP(f, t) ((f)*8 + (t))
1019# define MAP(n) (((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N)
1020 register sopno copy;
1021
1022 if (p->error != 0) /* head off possible runaway recursion */
1023 return;
1024
1025 assert(from <= to);
1026
1027 switch (REP(MAP(from), MAP(to))) {
1028 case REP(0, 0): /* must be user doing this */
1029 DROP(finish-start); /* drop the operand */
1030 break;
1031 case REP(0, 1): /* as x{1,1}? */
1032 case REP(0, N): /* as x{1,n}? */
1033 case REP(0, INF): /* as x{1,}? */
1034 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
1035 INSERT(OCH_, start); /* offset is wrong... */
1036 repeat(p, start+1, 1, to);
1037 ASTERN(OOR1, start);
1038 AHEAD(start); /* ... fix it */
1039 EMIT(OOR2, 0);
1040 AHEAD(THERE());
1041 ASTERN(O_CH, THERETHERE());
1042 break;
1043 case REP(1, 1): /* trivial case */
1044 /* done */
1045 break;
1046 case REP(1, N): /* as x?x{1,n-1} */
1047 /* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
1048 INSERT(OCH_, start);
1049 ASTERN(OOR1, start);
1050 AHEAD(start);
1051 EMIT(OOR2, 0); /* offset very wrong... */
1052 AHEAD(THERE()); /* ...so fix it */
1053 ASTERN(O_CH, THERETHERE());
1054 copy = dupl(p, start+1, finish+1);
1055 assert(copy == finish+4);
1056 repeat(p, copy, 1, to-1);
1057 break;
1058 case REP(1, INF): /* as x+ */
1059 INSERT(OPLUS_, start);
1060 ASTERN(O_PLUS, start);
1061 break;
1062 case REP(N, N): /* as xx{m-1,n-1} */
1063 copy = dupl(p, start, finish);
1064 repeat(p, copy, from-1, to-1);
1065 break;
1066 case REP(N, INF): /* as xx{n-1,INF} */
1067 copy = dupl(p, start, finish);
1068 repeat(p, copy, from-1, to);
1069 break;
1070 default: /* "can't happen" */
1071 SETERROR(REG_ASSERT); /* just in case */
1072 break;
1073 }
1074}
1075
1076/*
1077 - seterr - set an error condition
1078 == static int seterr(register struct parse *p, int e);
1079 */
1080static int /* useless but makes type checking happy */
1081seterr(p, e)
1082register struct parse *p;
1083int e;
1084{
1085 if (p->error == 0) /* keep earliest error condition */
1086 p->error = e;
1087 p->next = nuls; /* try to bring things to a halt */
1088 p->end = nuls;
1089 return(0); /* make the return value well-defined */
1090}
1091
1092/*
1093 - allocset - allocate a set of characters for []
1094 == static cset *allocset(register struct parse *p);
1095 */
1096static cset *
1097allocset(p)
1098register struct parse *p;
1099{
1100 register int no = p->g->ncsets++;
1101 register size_t nc;
1102 register size_t nbytes;
1103 register cset *cs;
1104 register size_t css = (size_t)p->g->csetsize;
1105 register int i;
1106
1107 if (no >= p->ncsalloc) { /* need another column of space */
1108 p->ncsalloc += CHAR_BIT;
1109 nc = p->ncsalloc;
1110 assert(nc % CHAR_BIT == 0);
1111 nbytes = nc / CHAR_BIT * css;
1112 if (p->g->sets == NULL)
1113 p->g->sets = (cset *)malloc(nc * sizeof(cset));
1114 else
1115 p->g->sets = (cset *)realloc((char *)p->g->sets,
1116 nc * sizeof(cset));
1117 if (p->g->setbits == NULL)
1118 p->g->setbits = (uch *)malloc(nbytes);
1119 else {
1120 p->g->setbits = (uch *)realloc((char *)p->g->setbits,
1121 nbytes);
1122 /* xxx this isn't right if setbits is now NULL */
1123 for (i = 0; i < no; i++)
1124 p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT);
1125 }
1126 if (p->g->sets != NULL && p->g->setbits != NULL)
1127 (void) memset((char *)p->g->setbits + (nbytes - css),
1128 0, css);
1129 else {
1130 no = 0;
1131 SETERROR(REG_ESPACE);
1132 /* caller's responsibility not to do set ops */
1133 }
1134 }
1135
1136 assert(p->g->sets != NULL); /* xxx */
1137 cs = &p->g->sets[no];
1138 cs->ptr = p->g->setbits + css*((no)/CHAR_BIT);
1139 cs->mask = 1 << ((no) % CHAR_BIT);
1140 cs->hash = 0;
1141 cs->smultis = 0;
1142 cs->multis = NULL;
1143
1144 return(cs);
1145}
1146
1147/*
1148 - freeset - free a now-unused set
1149 == static void freeset(register struct parse *p, register cset *cs);
1150 */
1151static void
1152freeset(p, cs)
1153register struct parse *p;
1154register cset *cs;
1155{
1156 register int i;
1157 register cset *top = &p->g->sets[p->g->ncsets];
1158 register size_t css = (size_t)p->g->csetsize;
1159
1160 for (i = 0; i < css; i++)
1161 CHsub(cs, i);
1162 if (cs == top-1) /* recover only the easy case */
1163 p->g->ncsets--;
1164}
1165
1166/*
1167 - freezeset - final processing on a set of characters
1168 == static int freezeset(register struct parse *p, register cset *cs);
1169 *
1170 * The main task here is merging identical sets. This is usually a waste
1171 * of time (although the hash code minimizes the overhead), but can win
1172 * big if REG_ICASE is being used. REG_ICASE, by the way, is why the hash
1173 * is done using addition rather than xor -- all ASCII [aA] sets xor to
1174 * the same value!
1175 */
1176static int /* set number */
1177freezeset(p, cs)
1178register struct parse *p;
1179register cset *cs;
1180{
1181 register uch h = cs->hash;
1182 register int i;
1183 register cset *top = &p->g->sets[p->g->ncsets];
1184 register cset *cs2;
1185 register size_t css = (size_t)p->g->csetsize;
1186
1187 /* look for an earlier one which is the same */
1188 for (cs2 = &p->g->sets[0]; cs2 < top; cs2++)
1189 if (cs2->hash == h && cs2 != cs) {
1190 /* maybe */
1191 for (i = 0; i < css; i++)
1192 if (!!CHIN(cs2, i) != !!CHIN(cs, i))
1193 break; /* no */
1194 if (i == css)
1195 break; /* yes */
1196 }
1197
1198 if (cs2 < top) { /* found one */
1199 freeset(p, cs);
1200 cs = cs2;
1201 }
1202
1203 return((int)(cs - p->g->sets));
1204}
1205
1206/*
1207 - firstch - return first character in a set (which must have at least one)
1208 == static int firstch(register struct parse *p, register cset *cs);
1209 */
1210static int /* character; there is no "none" value */
1211firstch(p, cs)
1212register struct parse *p;
1213register cset *cs;
1214{
1215 register int i;
1216 register size_t css = (size_t)p->g->csetsize;
1217
1218 for (i = 0; i < css; i++)
1219 if (CHIN(cs, i))
1220 return((char)i);
1221 assert(never);
1222 return(0); /* arbitrary */
1223}
1224
1225/*
1226 - nch - number of characters in a set
1227 == static int nch(register struct parse *p, register cset *cs);
1228 */
1229static int
1230nch(p, cs)
1231register struct parse *p;
1232register cset *cs;
1233{
1234 register int i;
1235 register size_t css = (size_t)p->g->csetsize;
1236 register int n = 0;
1237
1238 for (i = 0; i < css; i++)
1239 if (CHIN(cs, i))
1240 n++;
1241 return(n);
1242}
1243
1244/*
1245 - mcadd - add a collating element to a cset
1246 == static void mcadd(register struct parse *p, register cset *cs, \
1247 == register char *cp);
1248 */
1249static void
1250mcadd(p, cs, cp)
1251register struct parse *p;
1252register cset *cs;
1253register char *cp;
1254{
1255 register size_t oldend = cs->smultis;
1256
1257 cs->smultis += strlen(cp) + 1;
1258 if (cs->multis == NULL)
1259 cs->multis = malloc(cs->smultis);
1260 else
1261 cs->multis = realloc(cs->multis, cs->smultis);
1262 if (cs->multis == NULL) {
1263 SETERROR(REG_ESPACE);
1264 return;
1265 }
1266
1267 (void) strcpy(cs->multis + oldend - 1, cp);
1268 cs->multis[cs->smultis - 1] = '\0';
1269}
1270
1271/*
1272 - mcsub - subtract a collating element from a cset
1273 == static void mcsub(register cset *cs, register char *cp);
1274 */
1275static void
1276mcsub(cs, cp)
1277register cset *cs;
1278register char *cp;
1279{
1280 register char *fp = mcfind(cs, cp);
1281 register size_t len = strlen(fp);
1282
1283 assert(fp != NULL);
1284 (void) memmove(fp, fp + len + 1,
1285 cs->smultis - (fp + len + 1 - cs->multis));
1286 cs->smultis -= len;
1287
1288 if (cs->smultis == 0) {
1289 free(cs->multis);
1290 cs->multis = NULL;
1291 return;
1292 }
1293
1294 cs->multis = realloc(cs->multis, cs->smultis);
1295 assert(cs->multis != NULL);
1296}
1297
1298/*
1299 - mcin - is a collating element in a cset?
1300 == static int mcin(register cset *cs, register char *cp);
1301 */
1302static int
1303mcin(cs, cp)
1304register cset *cs;
1305register char *cp;
1306{
1307 return(mcfind(cs, cp) != NULL);
1308}
1309
1310/*
1311 - mcfind - find a collating element in a cset
1312 == static char *mcfind(register cset *cs, register char *cp);
1313 */
1314static char *
1315mcfind(cs, cp)
1316register cset *cs;
1317register char *cp;
1318{
1319 register char *p;
1320
1321 if (cs->multis == NULL)
1322 return(NULL);
1323 for (p = cs->multis; *p != '\0'; p += strlen(p) + 1)
1324 if (strcmp(cp, p) == 0)
1325 return(p);
1326 return(NULL);
1327}
1328
1329/*
1330 - mcinvert - invert the list of collating elements in a cset
1331 == static void mcinvert(register struct parse *p, register cset *cs);
1332 *
1333 * This would have to know the set of possibilities. Implementation
1334 * is deferred.
1335 */
1336static void
1337mcinvert(p, cs)
1338register struct parse *p;
1339register cset *cs;
1340{
1341 assert(cs->multis == NULL); /* xxx */
1342}
1343
1344/*
1345 - mccase - add case counterparts of the list of collating elements in a cset
1346 == static void mccase(register struct parse *p, register cset *cs);
1347 *
1348 * This would have to know the set of possibilities. Implementation
1349 * is deferred.
1350 */
1351static void
1352mccase(p, cs)
1353register struct parse *p;
1354register cset *cs;
1355{
1356 assert(cs->multis == NULL); /* xxx */
1357}
1358
1359/*
1360 - isinsets - is this character in any sets?
1361 == static int isinsets(register struct re_guts *g, int c);
1362 */
1363static int /* predicate */
1364isinsets(g, c)
1365register struct re_guts *g;
1366int c;
1367{
1368 register uch *col;
1369 register int i;
1370 register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
1371 register unsigned uc = (unsigned char)c;
1372
1373 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
1374 if (col[uc] != 0)
1375 return(1);
1376 return(0);
1377}
1378
1379/*
1380 - samesets - are these two characters in exactly the same sets?
1381 == static int samesets(register struct re_guts *g, int c1, int c2);
1382 */
1383static int /* predicate */
1384samesets(g, c1, c2)
1385register struct re_guts *g;
1386int c1;
1387int c2;
1388{
1389 register uch *col;
1390 register int i;
1391 register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
1392 register unsigned uc1 = (unsigned char)c1;
1393 register unsigned uc2 = (unsigned char)c2;
1394
1395 for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
1396 if (col[uc1] != col[uc2])
1397 return(0);
1398 return(1);
1399}
1400
1401/*
1402 - categorize - sort out character categories
1403 == static void categorize(struct parse *p, register struct re_guts *g);
1404 */
1405static void
1406categorize(p, g)
1407struct parse *p;
1408register struct re_guts *g;
1409{
1410 register cat_t *cats = g->categories;
1411 register int c;
1412 register int c2;
1413 register cat_t cat;
1414
1415 /* avoid making error situations worse */
1416 if (p->error != 0)
1417 return;
1418
1419 for (c = CHAR_MIN; c <= CHAR_MAX; c++)
1420 if (cats[c] == 0 && isinsets(g, c)) {
1421 cat = g->ncategories++;
1422 cats[c] = cat;
1423 for (c2 = c+1; c2 <= CHAR_MAX; c2++)
1424 if (cats[c2] == 0 && samesets(g, c, c2))
1425 cats[c2] = cat;
1426 }
1427}
1428
1429/*
1430 - dupl - emit a duplicate of a bunch of sops
1431 == static sopno dupl(register struct parse *p, sopno start, sopno finish);
1432 */
1433static sopno /* start of duplicate */
1434dupl(p, start, finish)
1435register struct parse *p;
1436sopno start; /* from here */
1437sopno finish; /* to this less one */
1438{
1439 register sopno ret = HERE();
1440 register sopno len = finish - start;
1441
1442 assert(finish >= start);
1443 if (len == 0)
1444 return(ret);
1445 enlarge(p, p->ssize + len); /* this many unexpected additions */
1446 assert(p->ssize >= p->slen + len);
1447 (void) memcpy((char *)(p->strip + p->slen),
1448 (char *)(p->strip + start), (size_t)len*sizeof(sop));
1449 p->slen += len;
1450 return(ret);
1451}
1452
1453/*
1454 - doemit - emit a strip operator
1455 == static void doemit(register struct parse *p, sop op, size_t opnd);
1456 *
1457 * It might seem better to implement this as a macro with a function as
1458 * hard-case backup, but it's just too big and messy unless there are
1459 * some changes to the data structures. Maybe later.
1460 */
1461static void
1462doemit(p, op, opnd)
1463register struct parse *p;
1464sop op;
1465size_t opnd;
1466{
1467 /* avoid making error situations worse */
1468 if (p->error != 0)
1469 return;
1470
1471 /* deal with oversize operands ("can't happen", more or less) */
1472 assert(opnd < 1<<OPSHIFT);
1473
1474 /* deal with undersized strip */
1475 if (p->slen >= p->ssize)
1476 enlarge(p, (p->ssize+1) / 2 * 3); /* +50% */
1477 assert(p->slen < p->ssize);
1478
1479 /* finally, it's all reduced to the easy case */
1480 p->strip[p->slen++] = SOP(op, opnd);
1481}
1482
1483/*
1484 - doinsert - insert a sop into the strip
1485 == static void doinsert(register struct parse *p, sop op, size_t opnd, sopno pos);
1486 */
1487static void
1488doinsert(p, op, opnd, pos)
1489register struct parse *p;
1490sop op;
1491size_t opnd;
1492sopno pos;
1493{
1494 register sopno sn;
1495 register sop s;
1496 register int i;
1497
1498 /* avoid making error situations worse */
1499 if (p->error != 0)
1500 return;
1501
1502 sn = HERE();
1503 EMIT(op, opnd); /* do checks, ensure space */
1504 assert(HERE() == sn+1);
1505 s = p->strip[sn];
1506
1507 /* adjust paren pointers */
1508 assert(pos > 0);
1509 for (i = 1; i < NPAREN; i++) {
1510 if (p->pbegin[i] >= pos) {
1511 p->pbegin[i]++;
1512 }
1513 if (p->pend[i] >= pos) {
1514 p->pend[i]++;
1515 }
1516 }
1517
1518 memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos],
1519 (HERE()-pos-1)*sizeof(sop));
1520 p->strip[pos] = s;
1521}
1522
1523/*
1524 - dofwd - complete a forward reference
1525 == static void dofwd(register struct parse *p, sopno pos, sop value);
1526 */
1527static void
1528dofwd(p, pos, value)
1529register struct parse *p;
1530register sopno pos;
1531sop value;
1532{
1533 /* avoid making error situations worse */
1534 if (p->error != 0)
1535 return;
1536
1537 assert(value < 1<<OPSHIFT);
1538 p->strip[pos] = OP(p->strip[pos]) | value;
1539}
1540
1541/*
1542 - enlarge - enlarge the strip
1543 == static void enlarge(register struct parse *p, sopno size);
1544 */
1545static void
1546enlarge(p, size)
1547register struct parse *p;
1548register sopno size;
1549{
1550 register sop *sp;
1551
1552 if (p->ssize >= size)
1553 return;
1554
1555 sp = (sop *)realloc(p->strip, size*sizeof(sop));
1556 if (sp == NULL) {
1557 SETERROR(REG_ESPACE);
1558 return;
1559 }
1560 p->strip = sp;
1561 p->ssize = size;
1562}
1563
1564/*
1565 - stripsnug - compact the strip
1566 == static void stripsnug(register struct parse *p, register struct re_guts *g);
1567 */
1568static void
1569stripsnug(p, g)
1570register struct parse *p;
1571register struct re_guts *g;
1572{
1573 g->nstates = p->slen;
1574 g->strip = (sop *)realloc((char *)p->strip, p->slen * sizeof(sop));
1575 if (g->strip == NULL) {
1576 SETERROR(REG_ESPACE);
1577 g->strip = p->strip;
1578 }
1579}
1580
1581/*
1582 - findmust - fill in must and mlen with longest mandatory literal string
1583 == static void findmust(register struct parse *p, register struct re_guts *g);
1584 *
1585 * This algorithm could do fancy things like analyzing the operands of |
1586 * for common subsequences. Someday. This code is simple and finds most
1587 * of the interesting cases.
1588 *
1589 * Note that must and mlen got initialized during setup.
1590 */
1591static void
1592findmust(p, g)
1593struct parse *p;
1594register struct re_guts *g;
1595{
1596 register sop *scan;
1597 sop *start;
1598 register sop *newstart;
1599 register sopno newlen;
1600 register sop s;
1601 register char *cp;
1602 register sopno i;
1603
1604 /* avoid making error situations worse */
1605 if (p->error != 0)
1606 return;
1607
1608 /* find the longest OCHAR sequence in strip */
1609 newlen = 0;
1610 scan = g->strip + 1;
1611 do {
1612 s = *scan++;
1613 switch (OP(s)) {
1614 case OCHAR: /* sequence member */
1615 if (newlen == 0) /* new sequence */
1616 newstart = scan - 1;
1617 newlen++;
1618 break;
1619 case OPLUS_: /* things that don't break one */
1620 case OLPAREN:
1621 case ORPAREN:
1622 break;
1623 case OQUEST_: /* things that must be skipped */
1624 case OCH_:
1625 scan--;
1626 do {
1627 scan += OPND(s);
1628 s = *scan;
1629 /* assert() interferes w debug printouts */
1630 if (OP(s) != O_QUEST && OP(s) != O_CH &&
1631 OP(s) != OOR2) {
1632 g->iflags |= BAD;
1633 return;
1634 }
1635 } while (OP(s) != O_QUEST && OP(s) != O_CH);
1636 /* fallthrough */
1637 default: /* things that break a sequence */
1638 if (newlen > g->mlen) { /* ends one */
1639 start = newstart;
1640 g->mlen = newlen;
1641 }
1642 newlen = 0;
1643 break;
1644 }
1645 } while (OP(s) != OEND);
1646
1647 if (g->mlen == 0) /* there isn't one */
1648 return;
1649
1650 /* turn it into a character string */
1651 g->must = malloc((size_t)g->mlen + 1);
1652 if (g->must == NULL) { /* argh; just forget it */
1653 g->mlen = 0;
1654 return;
1655 }
1656 cp = g->must;
1657 scan = start;
1658 for (i = g->mlen; i > 0; i--) {
1659 while (OP(s = *scan++) != OCHAR)
1660 continue;
1661 assert(cp < g->must + g->mlen);
1662 *cp++ = (char)OPND(s);
1663 }
1664 assert(cp == g->must + g->mlen);
1665 *cp++ = '\0'; /* just on general principles */
1666}
1667
1668/*
1669 - pluscount - count + nesting
1670 == static sopno pluscount(register struct parse *p, register struct re_guts *g);
1671 */
1672static sopno /* nesting depth */
1673pluscount(p, g)
1674struct parse *p;
1675register struct re_guts *g;
1676{
1677 register sop *scan;
1678 register sop s;
1679 register sopno plusnest = 0;
1680 register sopno maxnest = 0;
1681
1682 if (p->error != 0)
1683 return(0); /* there may not be an OEND */
1684
1685 scan = g->strip + 1;
1686 do {
1687 s = *scan++;
1688 switch (OP(s)) {
1689 case OPLUS_:
1690 plusnest++;
1691 break;
1692 case O_PLUS:
1693 if (plusnest > maxnest)
1694 maxnest = plusnest;
1695 plusnest--;
1696 break;
1697 }
1698 } while (OP(s) != OEND);
1699 if (plusnest != 0)
1700 g->iflags |= BAD;
1701 return(maxnest);
1702}
1703
1704/*
1705 * $PchId: regcomp.c,v 1.2 1996/03/12 19:10:15 philip Exp $
1706 */
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