Line data Source code
1 : /*
2 : * NFA utilities.
3 : * This file is #included by regcomp.c.
4 : *
5 : * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
6 : *
7 : * Development of this software was funded, in part, by Cray Research Inc.,
8 : * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
9 : * Corporation, none of whom are responsible for the results. The author
10 : * thanks all of them.
11 : *
12 : * Redistribution and use in source and binary forms -- with or without
13 : * modification -- are permitted for any purpose, provided that
14 : * redistributions in source form retain this entire copyright notice and
15 : * indicate the origin and nature of any modifications.
16 : *
17 : * I'd appreciate being given credit for this package in the documentation
18 : * of software which uses it, but that is not a requirement.
19 : *
20 : * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
21 : * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
22 : * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
23 : * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 : * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 : * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 : * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 : * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 : * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 : * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 : *
31 : * src/backend/regex/regc_nfa.c
32 : *
33 : *
34 : * One or two things that technically ought to be in here
35 : * are actually in color.c, thanks to some incestuous relationships in
36 : * the color chains.
37 : */
38 :
39 : #define NISERR() VISERR(nfa->v)
40 : #define NERR(e) VERR(nfa->v, (e))
41 :
42 :
43 : /*
44 : * newnfa - set up an NFA
45 : */
46 : static struct nfa * /* the NFA, or NULL */
47 10179 : newnfa(struct vars *v,
48 : struct colormap *cm,
49 : struct nfa *parent) /* NULL if primary NFA */
50 : {
51 : struct nfa *nfa;
52 :
53 10179 : nfa = (struct nfa *) MALLOC(sizeof(struct nfa));
54 10179 : if (nfa == NULL)
55 : {
56 0 : ERR(REG_ESPACE);
57 0 : return NULL;
58 : }
59 :
60 : /* Make the NFA minimally valid, so freenfa() will behave sanely */
61 10179 : nfa->states = NULL;
62 10179 : nfa->slast = NULL;
63 10179 : nfa->freestates = NULL;
64 10179 : nfa->freearcs = NULL;
65 10179 : nfa->lastsb = NULL;
66 10179 : nfa->lastab = NULL;
67 10179 : nfa->lastsbused = 0;
68 10179 : nfa->lastabused = 0;
69 10179 : nfa->nstates = 0;
70 10179 : nfa->cm = cm;
71 10179 : nfa->v = v;
72 10179 : nfa->bos[0] = nfa->bos[1] = COLORLESS;
73 10179 : nfa->eos[0] = nfa->eos[1] = COLORLESS;
74 10179 : nfa->flags = 0;
75 10179 : nfa->minmatchall = nfa->maxmatchall = -1;
76 10179 : nfa->parent = parent; /* Precedes newfstate so parent is valid. */
77 :
78 : /* Create required infrastructure */
79 10179 : nfa->post = newfstate(nfa, '@'); /* number 0 */
80 10179 : nfa->pre = newfstate(nfa, '>'); /* number 1 */
81 10179 : nfa->init = newstate(nfa); /* may become invalid later */
82 10179 : nfa->final = newstate(nfa);
83 10179 : if (ISERR())
84 : {
85 0 : freenfa(nfa);
86 0 : return NULL;
87 : }
88 10179 : rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->pre, nfa->init);
89 10179 : newarc(nfa, '^', 1, nfa->pre, nfa->init);
90 10179 : newarc(nfa, '^', 0, nfa->pre, nfa->init);
91 10179 : rainbow(nfa, nfa->cm, PLAIN, COLORLESS, nfa->final, nfa->post);
92 10179 : newarc(nfa, '$', 1, nfa->final, nfa->post);
93 10179 : newarc(nfa, '$', 0, nfa->final, nfa->post);
94 :
95 10179 : if (ISERR())
96 : {
97 0 : freenfa(nfa);
98 0 : return NULL;
99 : }
100 10179 : return nfa;
101 : }
102 :
103 : /*
104 : * freenfa - free an entire NFA
105 : */
106 : static void
107 10179 : freenfa(struct nfa *nfa)
108 : {
109 : struct statebatch *sb;
110 : struct statebatch *sbnext;
111 : struct arcbatch *ab;
112 : struct arcbatch *abnext;
113 :
114 21222 : for (sb = nfa->lastsb; sb != NULL; sb = sbnext)
115 : {
116 11043 : sbnext = sb->next;
117 11043 : nfa->v->spaceused -= STATEBATCHSIZE(sb->nstates);
118 11043 : FREE(sb);
119 : }
120 10179 : nfa->lastsb = NULL;
121 28455 : for (ab = nfa->lastab; ab != NULL; ab = abnext)
122 : {
123 18276 : abnext = ab->next;
124 18276 : nfa->v->spaceused -= ARCBATCHSIZE(ab->narcs);
125 18276 : FREE(ab);
126 : }
127 10179 : nfa->lastab = NULL;
128 :
129 10179 : nfa->nstates = -1;
130 10179 : FREE(nfa);
131 10179 : }
132 :
133 : /*
134 : * newstate - allocate an NFA state, with zero flag value
135 : */
136 : static struct state * /* NULL on error */
137 264404 : newstate(struct nfa *nfa)
138 : {
139 : struct state *s;
140 :
141 : /*
142 : * This is a handy place to check for operation cancel during regex
143 : * compilation, since no code path will go very long without making a new
144 : * state or arc.
145 : */
146 264404 : INTERRUPT(nfa->v->re);
147 :
148 : /* first, recycle anything that's on the freelist */
149 264404 : if (nfa->freestates != NULL)
150 : {
151 17094 : s = nfa->freestates;
152 17094 : nfa->freestates = s->next;
153 : }
154 : /* otherwise, is there anything left in the last statebatch? */
155 247310 : else if (nfa->lastsb != NULL && nfa->lastsbused < nfa->lastsb->nstates)
156 : {
157 236267 : s = &nfa->lastsb->s[nfa->lastsbused++];
158 : }
159 : /* otherwise, need to allocate a new statebatch */
160 : else
161 : {
162 : struct statebatch *newSb;
163 : size_t nstates;
164 :
165 11043 : if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE)
166 : {
167 0 : NERR(REG_ETOOBIG);
168 0 : return NULL;
169 : }
170 11043 : nstates = (nfa->lastsb != NULL) ? nfa->lastsb->nstates * 2 : FIRSTSBSIZE;
171 11043 : if (nstates > MAXSBSIZE)
172 25 : nstates = MAXSBSIZE;
173 11043 : newSb = (struct statebatch *) MALLOC(STATEBATCHSIZE(nstates));
174 11043 : if (newSb == NULL)
175 : {
176 0 : NERR(REG_ESPACE);
177 0 : return NULL;
178 : }
179 11043 : nfa->v->spaceused += STATEBATCHSIZE(nstates);
180 11043 : newSb->nstates = nstates;
181 11043 : newSb->next = nfa->lastsb;
182 11043 : nfa->lastsb = newSb;
183 11043 : nfa->lastsbused = 1;
184 11043 : s = &newSb->s[0];
185 : }
186 :
187 : assert(nfa->nstates >= 0);
188 264404 : s->no = nfa->nstates++;
189 264404 : s->flag = 0;
190 264404 : if (nfa->states == NULL)
191 10179 : nfa->states = s;
192 264404 : s->nins = 0;
193 264404 : s->ins = NULL;
194 264404 : s->nouts = 0;
195 264404 : s->outs = NULL;
196 264404 : s->tmp = NULL;
197 264404 : s->next = NULL;
198 264404 : if (nfa->slast != NULL)
199 : {
200 : assert(nfa->slast->next == NULL);
201 254225 : nfa->slast->next = s;
202 : }
203 264404 : s->prev = nfa->slast;
204 264404 : nfa->slast = s;
205 264404 : return s;
206 : }
207 :
208 : /*
209 : * newfstate - allocate an NFA state with a specified flag value
210 : */
211 : static struct state * /* NULL on error */
212 20358 : newfstate(struct nfa *nfa, int flag)
213 : {
214 : struct state *s;
215 :
216 20358 : s = newstate(nfa);
217 20358 : if (s != NULL)
218 20358 : s->flag = (char) flag;
219 20358 : return s;
220 : }
221 :
222 : /*
223 : * dropstate - delete a state's inarcs and outarcs and free it
224 : */
225 : static void
226 108677 : dropstate(struct nfa *nfa,
227 : struct state *s)
228 : {
229 : struct arc *a;
230 :
231 127470 : while ((a = s->ins) != NULL)
232 18793 : freearc(nfa, a);
233 179083 : while ((a = s->outs) != NULL)
234 70406 : freearc(nfa, a);
235 108677 : freestate(nfa, s);
236 108677 : }
237 :
238 : /*
239 : * freestate - free a state, which has no in-arcs or out-arcs
240 : */
241 : static void
242 113671 : freestate(struct nfa *nfa,
243 : struct state *s)
244 : {
245 : assert(s != NULL);
246 : assert(s->nins == 0 && s->nouts == 0);
247 :
248 113671 : s->no = FREESTATE;
249 113671 : s->flag = 0;
250 113671 : if (s->next != NULL)
251 107258 : s->next->prev = s->prev;
252 : else
253 : {
254 : assert(s == nfa->slast);
255 6413 : nfa->slast = s->prev;
256 : }
257 113671 : if (s->prev != NULL)
258 113671 : s->prev->next = s->next;
259 : else
260 : {
261 : assert(s == nfa->states);
262 0 : nfa->states = s->next;
263 : }
264 113671 : s->prev = NULL;
265 113671 : s->next = nfa->freestates; /* don't delete it, put it on the free list */
266 113671 : nfa->freestates = s;
267 113671 : }
268 :
269 : /*
270 : * newarc - set up a new arc within an NFA
271 : *
272 : * This function checks to make sure that no duplicate arcs are created.
273 : * In general we never want duplicates.
274 : *
275 : * However: in principle, a RAINBOW arc is redundant with any plain arc
276 : * (unless that arc is for a pseudocolor). But we don't try to recognize
277 : * that redundancy, either here or in allied operations such as moveins().
278 : * The pseudocolor consideration makes that more costly than it seems worth.
279 : */
280 : static void
281 960650 : newarc(struct nfa *nfa,
282 : int t,
283 : color co,
284 : struct state *from,
285 : struct state *to)
286 : {
287 : struct arc *a;
288 :
289 : assert(from != NULL && to != NULL);
290 :
291 : /*
292 : * This is a handy place to check for operation cancel during regex
293 : * compilation, since no code path will go very long without making a new
294 : * state or arc.
295 : */
296 960650 : INTERRUPT(nfa->v->re);
297 :
298 : /* check for duplicate arc, using whichever chain is shorter */
299 960650 : if (from->nouts <= to->nins)
300 : {
301 3027820 : for (a = from->outs; a != NULL; a = a->outchain)
302 2569499 : if (a->to == to && a->co == co && a->type == t)
303 85322 : return;
304 : }
305 : else
306 : {
307 38393493 : for (a = to->ins; a != NULL; a = a->inchain)
308 38062306 : if (a->from == from && a->co == co && a->type == t)
309 85820 : return;
310 : }
311 :
312 : /* no dup, so create the arc */
313 789508 : createarc(nfa, t, co, from, to);
314 : }
315 :
316 : /*
317 : * createarc - create a new arc within an NFA
318 : *
319 : * This function must *only* be used after verifying that there is no existing
320 : * identical arc (same type/color/from/to).
321 : */
322 : static void
323 8735017 : createarc(struct nfa *nfa,
324 : int t,
325 : color co,
326 : struct state *from,
327 : struct state *to)
328 : {
329 : struct arc *a;
330 :
331 8735017 : a = allocarc(nfa);
332 8735017 : if (NISERR())
333 5709 : return;
334 : assert(a != NULL);
335 :
336 8729308 : a->type = t;
337 8729308 : a->co = co;
338 8729308 : a->to = to;
339 8729308 : a->from = from;
340 :
341 : /*
342 : * Put the new arc on the beginning, not the end, of the chains; it's
343 : * simpler here, and freearc() is the same cost either way. See also the
344 : * logic in moveins() and its cohorts, as well as fixempties().
345 : */
346 8729308 : a->inchain = to->ins;
347 8729308 : a->inchainRev = NULL;
348 8729308 : if (to->ins)
349 8414758 : to->ins->inchainRev = a;
350 8729308 : to->ins = a;
351 8729308 : a->outchain = from->outs;
352 8729308 : a->outchainRev = NULL;
353 8729308 : if (from->outs)
354 8458002 : from->outs->outchainRev = a;
355 8729308 : from->outs = a;
356 :
357 8729308 : from->nouts++;
358 8729308 : to->nins++;
359 :
360 8729308 : if (COLORED(a) && nfa->parent == NULL)
361 803196 : colorchain(nfa->cm, a);
362 : }
363 :
364 : /*
365 : * allocarc - allocate a new arc within an NFA
366 : */
367 : static struct arc * /* NULL for failure */
368 8735017 : allocarc(struct nfa *nfa)
369 : {
370 : struct arc *a;
371 :
372 : /* first, recycle anything that's on the freelist */
373 8735017 : if (nfa->freearcs != NULL)
374 : {
375 697615 : a = nfa->freearcs;
376 697615 : nfa->freearcs = a->freechain;
377 : }
378 : /* otherwise, is there anything left in the last arcbatch? */
379 8037402 : else if (nfa->lastab != NULL && nfa->lastabused < nfa->lastab->narcs)
380 : {
381 8013417 : a = &nfa->lastab->a[nfa->lastabused++];
382 : }
383 : /* otherwise, need to allocate a new arcbatch */
384 : else
385 : {
386 : struct arcbatch *newAb;
387 : size_t narcs;
388 :
389 23985 : if (nfa->v->spaceused >= REG_MAX_COMPILE_SPACE)
390 : {
391 5709 : NERR(REG_ETOOBIG);
392 5709 : return NULL;
393 : }
394 18276 : narcs = (nfa->lastab != NULL) ? nfa->lastab->narcs * 2 : FIRSTABSIZE;
395 18276 : if (narcs > MAXABSIZE)
396 7529 : narcs = MAXABSIZE;
397 18276 : newAb = (struct arcbatch *) MALLOC(ARCBATCHSIZE(narcs));
398 18276 : if (newAb == NULL)
399 : {
400 0 : NERR(REG_ESPACE);
401 0 : return NULL;
402 : }
403 18276 : nfa->v->spaceused += ARCBATCHSIZE(narcs);
404 18276 : newAb->narcs = narcs;
405 18276 : newAb->next = nfa->lastab;
406 18276 : nfa->lastab = newAb;
407 18276 : nfa->lastabused = 1;
408 18276 : a = &newAb->a[0];
409 : }
410 :
411 8729308 : return a;
412 : }
413 :
414 : /*
415 : * freearc - free an arc
416 : */
417 : static void
418 812625 : freearc(struct nfa *nfa,
419 : struct arc *victim)
420 : {
421 812625 : struct state *from = victim->from;
422 812625 : struct state *to = victim->to;
423 : struct arc *predecessor;
424 :
425 : assert(victim->type != 0);
426 :
427 : /* take it off color chain if necessary */
428 812625 : if (COLORED(victim) && nfa->parent == NULL)
429 371374 : uncolorchain(nfa->cm, victim);
430 :
431 : /* take it off source's out-chain */
432 : assert(from != NULL);
433 812625 : predecessor = victim->outchainRev;
434 812625 : if (predecessor == NULL)
435 : {
436 : assert(from->outs == victim);
437 234561 : from->outs = victim->outchain;
438 : }
439 : else
440 : {
441 : assert(predecessor->outchain == victim);
442 578064 : predecessor->outchain = victim->outchain;
443 : }
444 812625 : if (victim->outchain != NULL)
445 : {
446 : assert(victim->outchain->outchainRev == victim);
447 513996 : victim->outchain->outchainRev = predecessor;
448 : }
449 812625 : from->nouts--;
450 :
451 : /* take it off target's in-chain */
452 : assert(to != NULL);
453 812625 : predecessor = victim->inchainRev;
454 812625 : if (predecessor == NULL)
455 : {
456 : assert(to->ins == victim);
457 392298 : to->ins = victim->inchain;
458 : }
459 : else
460 : {
461 : assert(predecessor->inchain == victim);
462 420327 : predecessor->inchain = victim->inchain;
463 : }
464 812625 : if (victim->inchain != NULL)
465 : {
466 : assert(victim->inchain->inchainRev == victim);
467 529541 : victim->inchain->inchainRev = predecessor;
468 : }
469 812625 : to->nins--;
470 :
471 : /* clean up and place on NFA's free list */
472 812625 : victim->type = 0;
473 812625 : victim->from = NULL; /* precautions... */
474 812625 : victim->to = NULL;
475 812625 : victim->inchain = NULL;
476 812625 : victim->inchainRev = NULL;
477 812625 : victim->outchain = NULL;
478 812625 : victim->outchainRev = NULL;
479 812625 : victim->freechain = nfa->freearcs;
480 812625 : nfa->freearcs = victim;
481 812625 : }
482 :
483 : /*
484 : * changearcsource - flip an arc to have a different from state
485 : *
486 : * Caller must have verified that there is no pre-existing duplicate arc.
487 : */
488 : static void
489 294 : changearcsource(struct arc *a, struct state *newfrom)
490 : {
491 294 : struct state *oldfrom = a->from;
492 : struct arc *predecessor;
493 :
494 : assert(oldfrom != newfrom);
495 :
496 : /* take it off old source's out-chain */
497 : assert(oldfrom != NULL);
498 294 : predecessor = a->outchainRev;
499 294 : if (predecessor == NULL)
500 : {
501 : assert(oldfrom->outs == a);
502 294 : oldfrom->outs = a->outchain;
503 : }
504 : else
505 : {
506 : assert(predecessor->outchain == a);
507 0 : predecessor->outchain = a->outchain;
508 : }
509 294 : if (a->outchain != NULL)
510 : {
511 : assert(a->outchain->outchainRev == a);
512 287 : a->outchain->outchainRev = predecessor;
513 : }
514 294 : oldfrom->nouts--;
515 :
516 294 : a->from = newfrom;
517 :
518 : /* prepend it to new source's out-chain */
519 294 : a->outchain = newfrom->outs;
520 294 : a->outchainRev = NULL;
521 294 : if (newfrom->outs)
522 294 : newfrom->outs->outchainRev = a;
523 294 : newfrom->outs = a;
524 294 : newfrom->nouts++;
525 294 : }
526 :
527 : /*
528 : * changearctarget - flip an arc to have a different to state
529 : *
530 : * Caller must have verified that there is no pre-existing duplicate arc.
531 : */
532 : static void
533 160 : changearctarget(struct arc *a, struct state *newto)
534 : {
535 160 : struct state *oldto = a->to;
536 : struct arc *predecessor;
537 :
538 : assert(oldto != newto);
539 :
540 : /* take it off old target's in-chain */
541 : assert(oldto != NULL);
542 160 : predecessor = a->inchainRev;
543 160 : if (predecessor == NULL)
544 : {
545 : assert(oldto->ins == a);
546 160 : oldto->ins = a->inchain;
547 : }
548 : else
549 : {
550 : assert(predecessor->inchain == a);
551 0 : predecessor->inchain = a->inchain;
552 : }
553 160 : if (a->inchain != NULL)
554 : {
555 : assert(a->inchain->inchainRev == a);
556 156 : a->inchain->inchainRev = predecessor;
557 : }
558 160 : oldto->nins--;
559 :
560 160 : a->to = newto;
561 :
562 : /* prepend it to new target's in-chain */
563 160 : a->inchain = newto->ins;
564 160 : a->inchainRev = NULL;
565 160 : if (newto->ins)
566 160 : newto->ins->inchainRev = a;
567 160 : newto->ins = a;
568 160 : newto->nins++;
569 160 : }
570 :
571 : /*
572 : * hasnonemptyout - Does state have a non-EMPTY out arc?
573 : */
574 : static int
575 123158 : hasnonemptyout(struct state *s)
576 : {
577 : struct arc *a;
578 :
579 137271 : for (a = s->outs; a != NULL; a = a->outchain)
580 : {
581 135291 : if (a->type != EMPTY)
582 121178 : return 1;
583 : }
584 1980 : return 0;
585 : }
586 :
587 : /*
588 : * findarc - find arc, if any, from given source with given type and color
589 : * If there is more than one such arc, the result is random.
590 : */
591 : static struct arc *
592 319 : findarc(struct state *s,
593 : int type,
594 : color co)
595 : {
596 : struct arc *a;
597 :
598 962 : for (a = s->outs; a != NULL; a = a->outchain)
599 646 : if (a->type == type && a->co == co)
600 3 : return a;
601 316 : return NULL;
602 : }
603 :
604 : /*
605 : * cparc - allocate a new arc within an NFA, copying details from old one
606 : */
607 : static void
608 753613 : cparc(struct nfa *nfa,
609 : struct arc *oa,
610 : struct state *from,
611 : struct state *to)
612 : {
613 753613 : newarc(nfa, oa->type, oa->co, from, to);
614 753613 : }
615 :
616 : /*
617 : * sortins - sort the in arcs of a state by from/color/type
618 : */
619 : static void
620 15403 : sortins(struct nfa *nfa,
621 : struct state *s)
622 : {
623 : struct arc **sortarray;
624 : struct arc *a;
625 15403 : int n = s->nins;
626 : int i;
627 :
628 15403 : if (n <= 1)
629 2 : return; /* nothing to do */
630 : /* make an array of arc pointers ... */
631 15401 : sortarray = (struct arc **) MALLOC(n * sizeof(struct arc *));
632 15401 : if (sortarray == NULL)
633 : {
634 0 : NERR(REG_ESPACE);
635 0 : return;
636 : }
637 15401 : i = 0;
638 68370 : for (a = s->ins; a != NULL; a = a->inchain)
639 52969 : sortarray[i++] = a;
640 : assert(i == n);
641 : /* ... sort the array */
642 15401 : qsort(sortarray, n, sizeof(struct arc *), sortins_cmp);
643 : /* ... and rebuild arc list in order */
644 : /* it seems worth special-casing first and last items to simplify loop */
645 15401 : a = sortarray[0];
646 15401 : s->ins = a;
647 15401 : a->inchain = sortarray[1];
648 15401 : a->inchainRev = NULL;
649 37568 : for (i = 1; i < n - 1; i++)
650 : {
651 22167 : a = sortarray[i];
652 22167 : a->inchain = sortarray[i + 1];
653 22167 : a->inchainRev = sortarray[i - 1];
654 : }
655 15401 : a = sortarray[i];
656 15401 : a->inchain = NULL;
657 15401 : a->inchainRev = sortarray[i - 1];
658 15401 : FREE(sortarray);
659 : }
660 :
661 : static int
662 37894154 : sortins_cmp(const void *a, const void *b)
663 : {
664 37894154 : const struct arc *aa = *((const struct arc *const *) a);
665 37894154 : const struct arc *bb = *((const struct arc *const *) b);
666 :
667 : /* we check the fields in the order they are most likely to be different */
668 37894154 : if (aa->from->no < bb->from->no)
669 30138905 : return -1;
670 7755249 : if (aa->from->no > bb->from->no)
671 7524363 : return 1;
672 230886 : if (aa->co < bb->co)
673 122786 : return -1;
674 108100 : if (aa->co > bb->co)
675 106488 : return 1;
676 1612 : if (aa->type < bb->type)
677 68 : return -1;
678 1544 : if (aa->type > bb->type)
679 33 : return 1;
680 1511 : return 0;
681 : }
682 :
683 : /*
684 : * sortouts - sort the out arcs of a state by to/color/type
685 : */
686 : static void
687 16 : sortouts(struct nfa *nfa,
688 : struct state *s)
689 : {
690 : struct arc **sortarray;
691 : struct arc *a;
692 16 : int n = s->nouts;
693 : int i;
694 :
695 16 : if (n <= 1)
696 0 : return; /* nothing to do */
697 : /* make an array of arc pointers ... */
698 16 : sortarray = (struct arc **) MALLOC(n * sizeof(struct arc *));
699 16 : if (sortarray == NULL)
700 : {
701 0 : NERR(REG_ESPACE);
702 0 : return;
703 : }
704 16 : i = 0;
705 484 : for (a = s->outs; a != NULL; a = a->outchain)
706 468 : sortarray[i++] = a;
707 : assert(i == n);
708 : /* ... sort the array */
709 16 : qsort(sortarray, n, sizeof(struct arc *), sortouts_cmp);
710 : /* ... and rebuild arc list in order */
711 : /* it seems worth special-casing first and last items to simplify loop */
712 16 : a = sortarray[0];
713 16 : s->outs = a;
714 16 : a->outchain = sortarray[1];
715 16 : a->outchainRev = NULL;
716 452 : for (i = 1; i < n - 1; i++)
717 : {
718 436 : a = sortarray[i];
719 436 : a->outchain = sortarray[i + 1];
720 436 : a->outchainRev = sortarray[i - 1];
721 : }
722 16 : a = sortarray[i];
723 16 : a->outchain = NULL;
724 16 : a->outchainRev = sortarray[i - 1];
725 16 : FREE(sortarray);
726 : }
727 :
728 : static int
729 2746 : sortouts_cmp(const void *a, const void *b)
730 : {
731 2746 : const struct arc *aa = *((const struct arc *const *) a);
732 2746 : const struct arc *bb = *((const struct arc *const *) b);
733 :
734 : /* we check the fields in the order they are most likely to be different */
735 2746 : if (aa->to->no < bb->to->no)
736 305 : return -1;
737 2441 : if (aa->to->no > bb->to->no)
738 80 : return 1;
739 2361 : if (aa->co < bb->co)
740 1281 : return -1;
741 1080 : if (aa->co > bb->co)
742 1058 : return 1;
743 22 : if (aa->type < bb->type)
744 1 : return -1;
745 21 : if (aa->type > bb->type)
746 7 : return 1;
747 14 : return 0;
748 : }
749 :
750 : /*
751 : * Common decision logic about whether to use arc-by-arc operations or
752 : * sort/merge. If there's just a few source arcs we cannot recoup the
753 : * cost of sorting the destination arc list, no matter how large it is.
754 : * Otherwise, limit the number of arc-by-arc comparisons to about 1000
755 : * (a somewhat arbitrary choice, but the breakeven point would probably
756 : * be machine dependent anyway).
757 : */
758 : #define BULK_ARC_OP_USE_SORT(nsrcarcs, ndestarcs) \
759 : ((nsrcarcs) < 4 ? 0 : ((nsrcarcs) > 32 || (ndestarcs) > 32))
760 :
761 : /*
762 : * moveins - move all in arcs of a state to another state
763 : *
764 : * You might think this could be done better by just updating the
765 : * existing arcs, and you would be right if it weren't for the need
766 : * for duplicate suppression, which makes it easier to just make new
767 : * ones to exploit the suppression built into newarc.
768 : *
769 : * However, if we have a whole lot of arcs to deal with, retail duplicate
770 : * checks become too slow. In that case we proceed by sorting and merging
771 : * the arc lists, and then we can indeed just update the arcs in-place.
772 : *
773 : * On the other hand, it's also true that this is frequently called with
774 : * a brand-new newState that has no existing in-arcs. In that case,
775 : * de-duplication is unnecessary, so we can just blindly move all the arcs.
776 : */
777 : static void
778 132759 : moveins(struct nfa *nfa,
779 : struct state *oldState,
780 : struct state *newState)
781 : {
782 : assert(oldState != newState);
783 :
784 132759 : if (newState->nins == 0)
785 : {
786 : /* No need for de-duplication */
787 : struct arc *a;
788 :
789 111454 : while ((a = oldState->ins) != NULL)
790 : {
791 57321 : createarc(nfa, a->type, a->co, a->from, newState);
792 57321 : freearc(nfa, a);
793 : }
794 : }
795 78626 : else if (!BULK_ARC_OP_USE_SORT(oldState->nins, newState->nins))
796 78580 : {
797 : /* With not too many arcs, just do them one at a time */
798 : struct arc *a;
799 :
800 193335 : while ((a = oldState->ins) != NULL)
801 : {
802 114755 : cparc(nfa, a, a->from, newState);
803 114755 : freearc(nfa, a);
804 : }
805 : }
806 : else
807 : {
808 : /*
809 : * With many arcs, use a sort-merge approach. Note changearctarget()
810 : * will put the arc onto the front of newState's chain, so it does not
811 : * break our walk through the sorted part of the chain.
812 : */
813 : struct arc *oa;
814 : struct arc *na;
815 :
816 : /*
817 : * Because we bypass newarc() in this code path, we'd better include a
818 : * cancel check.
819 : */
820 46 : INTERRUPT(nfa->v->re);
821 :
822 46 : sortins(nfa, oldState);
823 46 : sortins(nfa, newState);
824 46 : if (NISERR())
825 0 : return; /* might have failed to sort */
826 46 : oa = oldState->ins;
827 46 : na = newState->ins;
828 1699 : while (oa != NULL && na != NULL)
829 : {
830 1607 : struct arc *a = oa;
831 :
832 1607 : switch (sortins_cmp(&oa, &na))
833 : {
834 83 : case -1:
835 : /* newState does not have anything matching oa */
836 83 : oa = oa->inchain;
837 :
838 : /*
839 : * Rather than doing createarc+freearc, we can just unlink
840 : * and relink the existing arc struct.
841 : */
842 83 : changearctarget(a, newState);
843 83 : break;
844 236 : case 0:
845 : /* match, advance in both lists */
846 236 : oa = oa->inchain;
847 236 : na = na->inchain;
848 : /* ... and drop duplicate arc from oldState */
849 236 : freearc(nfa, a);
850 236 : break;
851 1288 : case +1:
852 : /* advance only na; oa might have a match later */
853 1288 : na = na->inchain;
854 1288 : break;
855 1607 : default:
856 : assert(NOTREACHED);
857 : }
858 : }
859 123 : while (oa != NULL)
860 : {
861 : /* newState does not have anything matching oa */
862 77 : struct arc *a = oa;
863 :
864 77 : oa = oa->inchain;
865 77 : changearctarget(a, newState);
866 : }
867 : }
868 :
869 : assert(oldState->nins == 0);
870 : assert(oldState->ins == NULL);
871 : }
872 :
873 : /*
874 : * copyins - copy in arcs of a state to another state
875 : *
876 : * The comments for moveins() apply here as well. However, in current
877 : * usage, this is *only* called with brand-new target states, so that
878 : * only the "no need for de-duplication" code path is ever reached.
879 : * We keep the rest #ifdef'd out in case it's needed in the future.
880 : */
881 : static void
882 9513 : copyins(struct nfa *nfa,
883 : struct state *oldState,
884 : struct state *newState)
885 : {
886 : assert(oldState != newState);
887 : assert(newState->nins == 0); /* see comment above */
888 :
889 9513 : if (newState->nins == 0)
890 : {
891 : /* No need for de-duplication */
892 : struct arc *a;
893 :
894 130310 : for (a = oldState->ins; a != NULL; a = a->inchain)
895 120797 : createarc(nfa, a->type, a->co, a->from, newState);
896 : }
897 : #ifdef NOT_USED /* see comment above */
898 : else if (!BULK_ARC_OP_USE_SORT(oldState->nins, newState->nins))
899 : {
900 : /* With not too many arcs, just do them one at a time */
901 : struct arc *a;
902 :
903 : for (a = oldState->ins; a != NULL; a = a->inchain)
904 : cparc(nfa, a, a->from, newState);
905 : }
906 : else
907 : {
908 : /*
909 : * With many arcs, use a sort-merge approach. Note that createarc()
910 : * will put new arcs onto the front of newState's chain, so it does
911 : * not break our walk through the sorted part of the chain.
912 : */
913 : struct arc *oa;
914 : struct arc *na;
915 :
916 : /*
917 : * Because we bypass newarc() in this code path, we'd better include a
918 : * cancel check.
919 : */
920 : INTERRUPT(nfa->v->re);
921 :
922 : sortins(nfa, oldState);
923 : sortins(nfa, newState);
924 : if (NISERR())
925 : return; /* might have failed to sort */
926 : oa = oldState->ins;
927 : na = newState->ins;
928 : while (oa != NULL && na != NULL)
929 : {
930 : struct arc *a = oa;
931 :
932 : switch (sortins_cmp(&oa, &na))
933 : {
934 : case -1:
935 : /* newState does not have anything matching oa */
936 : oa = oa->inchain;
937 : createarc(nfa, a->type, a->co, a->from, newState);
938 : break;
939 : case 0:
940 : /* match, advance in both lists */
941 : oa = oa->inchain;
942 : na = na->inchain;
943 : break;
944 : case +1:
945 : /* advance only na; oa might have a match later */
946 : na = na->inchain;
947 : break;
948 : default:
949 : assert(NOTREACHED);
950 : }
951 : }
952 : while (oa != NULL)
953 : {
954 : /* newState does not have anything matching oa */
955 : struct arc *a = oa;
956 :
957 : oa = oa->inchain;
958 : createarc(nfa, a->type, a->co, a->from, newState);
959 : }
960 : }
961 : #endif /* NOT_USED */
962 9513 : }
963 :
964 : /*
965 : * mergeins - merge a list of inarcs into a state
966 : *
967 : * This is much like copyins, but the source arcs are listed in an array,
968 : * and are not guaranteed unique. It's okay to clobber the array contents.
969 : */
970 : static void
971 141292 : mergeins(struct nfa *nfa,
972 : struct state *s,
973 : struct arc **arcarray,
974 : int arccount)
975 : {
976 : struct arc *na;
977 : int i;
978 : int j;
979 :
980 141292 : if (arccount <= 0)
981 125981 : return;
982 :
983 : /*
984 : * Because we bypass newarc() in this code path, we'd better include a
985 : * cancel check.
986 : */
987 15311 : INTERRUPT(nfa->v->re);
988 :
989 : /* Sort existing inarcs as well as proposed new ones */
990 15311 : sortins(nfa, s);
991 15311 : if (NISERR())
992 0 : return; /* might have failed to sort */
993 :
994 15311 : qsort(arcarray, arccount, sizeof(struct arc *), sortins_cmp);
995 :
996 : /*
997 : * arcarray very likely includes dups, so we must eliminate them. (This
998 : * could be folded into the next loop, but it's not worth the trouble.)
999 : */
1000 15311 : j = 0;
1001 7515445 : for (i = 1; i < arccount; i++)
1002 : {
1003 7500134 : switch (sortins_cmp(&arcarray[j], &arcarray[i]))
1004 : {
1005 7499528 : case -1:
1006 : /* non-dup */
1007 7499528 : arcarray[++j] = arcarray[i];
1008 7499528 : break;
1009 606 : case 0:
1010 : /* dup */
1011 606 : break;
1012 7500134 : default:
1013 : /* trouble */
1014 : assert(NOTREACHED);
1015 : }
1016 : }
1017 15311 : arccount = j + 1;
1018 :
1019 : /*
1020 : * Now merge into s' inchain. Note that createarc() will put new arcs
1021 : * onto the front of s's chain, so it does not break our walk through the
1022 : * sorted part of the chain.
1023 : */
1024 15311 : i = 0;
1025 15311 : na = s->ins;
1026 7530546 : while (i < arccount && na != NULL)
1027 : {
1028 7515235 : struct arc *a = arcarray[i];
1029 :
1030 7515235 : switch (sortins_cmp(&a, &na))
1031 : {
1032 7493629 : case -1:
1033 : /* s does not have anything matching a */
1034 7493629 : createarc(nfa, a->type, a->co, a->from, s);
1035 7493629 : i++;
1036 7493629 : break;
1037 10 : case 0:
1038 : /* match, advance in both lists */
1039 10 : i++;
1040 10 : na = na->inchain;
1041 10 : break;
1042 21596 : case +1:
1043 : /* advance only na; array might have a match later */
1044 21596 : na = na->inchain;
1045 21596 : break;
1046 7515235 : default:
1047 : assert(NOTREACHED);
1048 : }
1049 : }
1050 36511 : while (i < arccount)
1051 : {
1052 : /* s does not have anything matching a */
1053 21200 : struct arc *a = arcarray[i];
1054 :
1055 21200 : createarc(nfa, a->type, a->co, a->from, s);
1056 21200 : i++;
1057 : }
1058 : }
1059 :
1060 : /*
1061 : * moveouts - move all out arcs of a state to another state
1062 : *
1063 : * See comments for moveins()
1064 : */
1065 : static void
1066 35406 : moveouts(struct nfa *nfa,
1067 : struct state *oldState,
1068 : struct state *newState)
1069 : {
1070 : assert(oldState != newState);
1071 :
1072 35406 : if (newState->nouts == 0)
1073 : {
1074 : /* No need for de-duplication */
1075 : struct arc *a;
1076 :
1077 28109 : while ((a = oldState->outs) != NULL)
1078 : {
1079 15503 : createarc(nfa, a->type, a->co, newState, a->to);
1080 15503 : freearc(nfa, a);
1081 : }
1082 : }
1083 22800 : else if (!BULK_ARC_OP_USE_SORT(oldState->nouts, newState->nouts))
1084 22792 : {
1085 : /* With not too many arcs, just do them one at a time */
1086 : struct arc *a;
1087 :
1088 54908 : while ((a = oldState->outs) != NULL)
1089 : {
1090 32116 : cparc(nfa, a, newState, a->to);
1091 32116 : freearc(nfa, a);
1092 : }
1093 : }
1094 : else
1095 : {
1096 : /*
1097 : * With many arcs, use a sort-merge approach. Note changearcsource()
1098 : * will put the arc onto the front of newState's chain, so it does not
1099 : * break our walk through the sorted part of the chain.
1100 : */
1101 : struct arc *oa;
1102 : struct arc *na;
1103 :
1104 : /*
1105 : * Because we bypass newarc() in this code path, we'd better include a
1106 : * cancel check.
1107 : */
1108 8 : INTERRUPT(nfa->v->re);
1109 :
1110 8 : sortouts(nfa, oldState);
1111 8 : sortouts(nfa, newState);
1112 8 : if (NISERR())
1113 0 : return; /* might have failed to sort */
1114 8 : oa = oldState->outs;
1115 8 : na = newState->outs;
1116 296 : while (oa != NULL && na != NULL)
1117 : {
1118 280 : struct arc *a = oa;
1119 :
1120 280 : switch (sortouts_cmp(&oa, &na))
1121 : {
1122 258 : case -1:
1123 : /* newState does not have anything matching oa */
1124 258 : oa = oa->outchain;
1125 :
1126 : /*
1127 : * Rather than doing createarc+freearc, we can just unlink
1128 : * and relink the existing arc struct.
1129 : */
1130 258 : changearcsource(a, newState);
1131 258 : break;
1132 14 : case 0:
1133 : /* match, advance in both lists */
1134 14 : oa = oa->outchain;
1135 14 : na = na->outchain;
1136 : /* ... and drop duplicate arc from oldState */
1137 14 : freearc(nfa, a);
1138 14 : break;
1139 8 : case +1:
1140 : /* advance only na; oa might have a match later */
1141 8 : na = na->outchain;
1142 8 : break;
1143 280 : default:
1144 : assert(NOTREACHED);
1145 : }
1146 : }
1147 44 : while (oa != NULL)
1148 : {
1149 : /* newState does not have anything matching oa */
1150 36 : struct arc *a = oa;
1151 :
1152 36 : oa = oa->outchain;
1153 36 : changearcsource(a, newState);
1154 : }
1155 : }
1156 :
1157 : assert(oldState->nouts == 0);
1158 : assert(oldState->outs == NULL);
1159 : }
1160 :
1161 : /*
1162 : * copyouts - copy out arcs of a state to another state
1163 : *
1164 : * See comments for copyins()
1165 : */
1166 : static void
1167 7210 : copyouts(struct nfa *nfa,
1168 : struct state *oldState,
1169 : struct state *newState)
1170 : {
1171 : assert(oldState != newState);
1172 : assert(newState->nouts == 0); /* see comment above */
1173 :
1174 7210 : if (newState->nouts == 0)
1175 : {
1176 : /* No need for de-duplication */
1177 : struct arc *a;
1178 :
1179 244269 : for (a = oldState->outs; a != NULL; a = a->outchain)
1180 237059 : createarc(nfa, a->type, a->co, newState, a->to);
1181 : }
1182 : #ifdef NOT_USED /* see comment above */
1183 : else if (!BULK_ARC_OP_USE_SORT(oldState->nouts, newState->nouts))
1184 : {
1185 : /* With not too many arcs, just do them one at a time */
1186 : struct arc *a;
1187 :
1188 : for (a = oldState->outs; a != NULL; a = a->outchain)
1189 : cparc(nfa, a, newState, a->to);
1190 : }
1191 : else
1192 : {
1193 : /*
1194 : * With many arcs, use a sort-merge approach. Note that createarc()
1195 : * will put new arcs onto the front of newState's chain, so it does
1196 : * not break our walk through the sorted part of the chain.
1197 : */
1198 : struct arc *oa;
1199 : struct arc *na;
1200 :
1201 : /*
1202 : * Because we bypass newarc() in this code path, we'd better include a
1203 : * cancel check.
1204 : */
1205 : INTERRUPT(nfa->v->re);
1206 :
1207 : sortouts(nfa, oldState);
1208 : sortouts(nfa, newState);
1209 : if (NISERR())
1210 : return; /* might have failed to sort */
1211 : oa = oldState->outs;
1212 : na = newState->outs;
1213 : while (oa != NULL && na != NULL)
1214 : {
1215 : struct arc *a = oa;
1216 :
1217 : switch (sortouts_cmp(&oa, &na))
1218 : {
1219 : case -1:
1220 : /* newState does not have anything matching oa */
1221 : oa = oa->outchain;
1222 : createarc(nfa, a->type, a->co, newState, a->to);
1223 : break;
1224 : case 0:
1225 : /* match, advance in both lists */
1226 : oa = oa->outchain;
1227 : na = na->outchain;
1228 : break;
1229 : case +1:
1230 : /* advance only na; oa might have a match later */
1231 : na = na->outchain;
1232 : break;
1233 : default:
1234 : assert(NOTREACHED);
1235 : }
1236 : }
1237 : while (oa != NULL)
1238 : {
1239 : /* newState does not have anything matching oa */
1240 : struct arc *a = oa;
1241 :
1242 : oa = oa->outchain;
1243 : createarc(nfa, a->type, a->co, newState, a->to);
1244 : }
1245 : }
1246 : #endif /* NOT_USED */
1247 7210 : }
1248 :
1249 : /*
1250 : * cloneouts - copy out arcs of a state to another state pair, modifying type
1251 : *
1252 : * This is only used to convert PLAIN arcs to AHEAD/BEHIND arcs, which share
1253 : * the same interpretation of "co". It wouldn't be sensible with LACONs.
1254 : */
1255 : static void
1256 175 : cloneouts(struct nfa *nfa,
1257 : struct state *old,
1258 : struct state *from,
1259 : struct state *to,
1260 : int type)
1261 : {
1262 : struct arc *a;
1263 :
1264 : assert(old != from);
1265 : assert(type == AHEAD || type == BEHIND);
1266 :
1267 653 : for (a = old->outs; a != NULL; a = a->outchain)
1268 : {
1269 : assert(a->type == PLAIN);
1270 478 : newarc(nfa, type, a->co, from, to);
1271 : }
1272 175 : }
1273 :
1274 : /*
1275 : * delsub - delete a sub-NFA, updating subre pointers if necessary
1276 : *
1277 : * This uses a recursive traversal of the sub-NFA, marking already-seen
1278 : * states using their tmp pointer.
1279 : */
1280 : static void
1281 5147 : delsub(struct nfa *nfa,
1282 : struct state *lp, /* the sub-NFA goes from here... */
1283 : struct state *rp) /* ...to here, *not* inclusive */
1284 : {
1285 : assert(lp != rp);
1286 :
1287 5147 : rp->tmp = rp; /* mark end */
1288 :
1289 5147 : deltraverse(nfa, lp, lp);
1290 5147 : if (NISERR())
1291 0 : return; /* asserts might not hold after failure */
1292 : assert(lp->nouts == 0 && rp->nins == 0); /* did the job */
1293 : assert(lp->no != FREESTATE && rp->no != FREESTATE); /* no more */
1294 :
1295 5147 : rp->tmp = NULL; /* unmark end */
1296 5147 : lp->tmp = NULL; /* and begin, marked by deltraverse */
1297 : }
1298 :
1299 : /*
1300 : * deltraverse - the recursive heart of delsub
1301 : * This routine's basic job is to destroy all out-arcs of the state.
1302 : */
1303 : static void
1304 15113 : deltraverse(struct nfa *nfa,
1305 : struct state *leftend,
1306 : struct state *s)
1307 : {
1308 : struct arc *a;
1309 : struct state *to;
1310 :
1311 : /* Since this is recursive, it could be driven to stack overflow */
1312 15113 : if (STACK_TOO_DEEP(nfa->v->re))
1313 : {
1314 0 : NERR(REG_ETOOBIG);
1315 0 : return;
1316 : }
1317 :
1318 15113 : if (s->nouts == 0)
1319 101 : return; /* nothing to do */
1320 15012 : if (s->tmp != NULL)
1321 5061 : return; /* already in progress */
1322 :
1323 9951 : s->tmp = s; /* mark as in progress */
1324 :
1325 19917 : while ((a = s->outs) != NULL)
1326 : {
1327 9966 : to = a->to;
1328 9966 : deltraverse(nfa, leftend, to);
1329 9966 : if (NISERR())
1330 0 : return; /* asserts might not hold after failure */
1331 : assert(to->nouts == 0 || to->tmp != NULL);
1332 9966 : freearc(nfa, a);
1333 9966 : if (to->nins == 0 && to->tmp == NULL)
1334 : {
1335 : assert(to->nouts == 0);
1336 4804 : freestate(nfa, to);
1337 : }
1338 : }
1339 :
1340 : assert(s->no != FREESTATE); /* we're still here */
1341 : assert(s == leftend || s->nins != 0); /* and still reachable */
1342 : assert(s->nouts == 0); /* but have no outarcs */
1343 :
1344 9951 : s->tmp = NULL; /* we're done here */
1345 : }
1346 :
1347 : /*
1348 : * dupnfa - duplicate sub-NFA
1349 : *
1350 : * Another recursive traversal, this time using tmp to point to duplicates
1351 : * as well as mark already-seen states. (You knew there was a reason why
1352 : * it's a state pointer, didn't you? :-))
1353 : */
1354 : static void
1355 7600 : dupnfa(struct nfa *nfa,
1356 : struct state *start, /* duplicate of subNFA starting here */
1357 : struct state *stop, /* and stopping here */
1358 : struct state *from, /* stringing duplicate from here */
1359 : struct state *to) /* to here */
1360 : {
1361 7600 : if (start == stop)
1362 : {
1363 0 : newarc(nfa, EMPTY, 0, from, to);
1364 0 : return;
1365 : }
1366 :
1367 7600 : stop->tmp = to;
1368 7600 : duptraverse(nfa, start, from);
1369 : /* done, except for clearing out the tmp pointers */
1370 :
1371 7600 : stop->tmp = NULL;
1372 7600 : cleartraverse(nfa, start);
1373 : }
1374 :
1375 : /*
1376 : * duptraverse - recursive heart of dupnfa
1377 : */
1378 : static void
1379 192901 : duptraverse(struct nfa *nfa,
1380 : struct state *s,
1381 : struct state *stmp) /* s's duplicate, or NULL */
1382 : {
1383 : struct arc *a;
1384 :
1385 : /* Since this is recursive, it could be driven to stack overflow */
1386 192901 : if (STACK_TOO_DEEP(nfa->v->re))
1387 : {
1388 0 : NERR(REG_ETOOBIG);
1389 0 : return;
1390 : }
1391 :
1392 192901 : if (s->tmp != NULL)
1393 59743 : return; /* already done */
1394 :
1395 133158 : s->tmp = (stmp == NULL) ? newstate(nfa) : stmp;
1396 133158 : if (s->tmp == NULL)
1397 : {
1398 : assert(NISERR());
1399 0 : return;
1400 : }
1401 :
1402 318459 : for (a = s->outs; a != NULL && !NISERR(); a = a->outchain)
1403 : {
1404 185301 : duptraverse(nfa, a->to, (struct state *) NULL);
1405 185301 : if (NISERR())
1406 0 : break;
1407 : assert(a->to->tmp != NULL);
1408 185301 : cparc(nfa, a, s->tmp, a->to->tmp);
1409 : }
1410 : }
1411 :
1412 : /*
1413 : * removeconstraints - remove any constraints in an NFA
1414 : *
1415 : * Constraint arcs are replaced by empty arcs, essentially treating all
1416 : * constraints as automatically satisfied.
1417 : */
1418 : static void
1419 101 : removeconstraints(struct nfa *nfa,
1420 : struct state *start, /* process subNFA starting here */
1421 : struct state *stop) /* and stopping here */
1422 : {
1423 101 : if (start == stop)
1424 0 : return;
1425 :
1426 101 : stop->tmp = stop;
1427 101 : removetraverse(nfa, start);
1428 : /* done, except for clearing out the tmp pointers */
1429 :
1430 101 : stop->tmp = NULL;
1431 101 : cleartraverse(nfa, start);
1432 : }
1433 :
1434 : /*
1435 : * removetraverse - recursive heart of removeconstraints
1436 : */
1437 : static void
1438 281 : removetraverse(struct nfa *nfa,
1439 : struct state *s)
1440 : {
1441 : struct arc *a;
1442 : struct arc *oa;
1443 :
1444 : /* Since this is recursive, it could be driven to stack overflow */
1445 281 : if (STACK_TOO_DEEP(nfa->v->re))
1446 : {
1447 0 : NERR(REG_ETOOBIG);
1448 0 : return;
1449 : }
1450 :
1451 281 : if (s->tmp != NULL)
1452 126 : return; /* already done */
1453 :
1454 155 : s->tmp = s;
1455 335 : for (a = s->outs; a != NULL && !NISERR(); a = oa)
1456 : {
1457 180 : removetraverse(nfa, a->to);
1458 180 : if (NISERR())
1459 0 : break;
1460 180 : oa = a->outchain;
1461 180 : switch (a->type)
1462 : {
1463 173 : case PLAIN:
1464 : case EMPTY:
1465 : case CANTMATCH:
1466 : /* nothing to do */
1467 173 : break;
1468 7 : case AHEAD:
1469 : case BEHIND:
1470 : case '^':
1471 : case '$':
1472 : case LACON:
1473 : /* replace it */
1474 7 : newarc(nfa, EMPTY, 0, s, a->to);
1475 7 : freearc(nfa, a);
1476 7 : break;
1477 0 : default:
1478 0 : NERR(REG_ASSERT);
1479 0 : break;
1480 : }
1481 : }
1482 : }
1483 :
1484 : /*
1485 : * cleartraverse - recursive cleanup for algorithms that leave tmp ptrs set
1486 : */
1487 : static void
1488 1096541 : cleartraverse(struct nfa *nfa,
1489 : struct state *s)
1490 : {
1491 : struct arc *a;
1492 :
1493 : /* Since this is recursive, it could be driven to stack overflow */
1494 1096541 : if (STACK_TOO_DEEP(nfa->v->re))
1495 : {
1496 0 : NERR(REG_ETOOBIG);
1497 0 : return;
1498 : }
1499 :
1500 1096541 : if (s->tmp == NULL)
1501 621913 : return;
1502 474628 : s->tmp = NULL;
1503 :
1504 1543357 : for (a = s->outs; a != NULL; a = a->outchain)
1505 1068729 : cleartraverse(nfa, a->to);
1506 : }
1507 :
1508 : /*
1509 : * single_color_transition - does getting from s1 to s2 cross one PLAIN arc?
1510 : *
1511 : * If traversing from s1 to s2 requires a single PLAIN match (possibly of any
1512 : * of a set of colors), return a state whose outarc list contains only PLAIN
1513 : * arcs of those color(s). Otherwise return NULL.
1514 : *
1515 : * This is used before optimizing the NFA, so there may be EMPTY arcs, which
1516 : * we should ignore; the possibility of an EMPTY is why the result state could
1517 : * be different from s1.
1518 : *
1519 : * It's worth troubling to handle multiple parallel PLAIN arcs here because a
1520 : * bracket construct such as [abc] might yield either one or several parallel
1521 : * PLAIN arcs depending on earlier atoms in the expression. We'd rather that
1522 : * that implementation detail not create user-visible performance differences.
1523 : */
1524 : static struct state *
1525 127 : single_color_transition(struct state *s1, struct state *s2)
1526 : {
1527 : struct arc *a;
1528 :
1529 : /* Ignore leading EMPTY arc, if any */
1530 127 : if (s1->nouts == 1 && s1->outs->type == EMPTY)
1531 127 : s1 = s1->outs->to;
1532 : /* Likewise for any trailing EMPTY arc */
1533 127 : if (s2->nins == 1 && s2->ins->type == EMPTY)
1534 127 : s2 = s2->ins->from;
1535 : /* Perhaps we could have a single-state loop in between, if so reject */
1536 127 : if (s1 == s2)
1537 0 : return NULL;
1538 : /* s1 must have at least one outarc... */
1539 127 : if (s1->outs == NULL)
1540 0 : return NULL;
1541 : /* ... and they must all be PLAIN arcs to s2 */
1542 218 : for (a = s1->outs; a != NULL; a = a->outchain)
1543 : {
1544 134 : if (a->type != PLAIN || a->to != s2)
1545 43 : return NULL;
1546 : }
1547 : /* OK, return s1 as the possessor of the relevant outarcs */
1548 84 : return s1;
1549 : }
1550 :
1551 : /*
1552 : * specialcolors - fill in special colors for an NFA
1553 : */
1554 : static void
1555 10060 : specialcolors(struct nfa *nfa)
1556 : {
1557 : /* false colors for BOS, BOL, EOS, EOL */
1558 10060 : if (nfa->parent == NULL)
1559 : {
1560 4057 : nfa->bos[0] = pseudocolor(nfa->cm);
1561 4057 : nfa->bos[1] = pseudocolor(nfa->cm);
1562 4057 : nfa->eos[0] = pseudocolor(nfa->cm);
1563 4057 : nfa->eos[1] = pseudocolor(nfa->cm);
1564 : }
1565 : else
1566 : {
1567 : assert(nfa->parent->bos[0] != COLORLESS);
1568 6003 : nfa->bos[0] = nfa->parent->bos[0];
1569 : assert(nfa->parent->bos[1] != COLORLESS);
1570 6003 : nfa->bos[1] = nfa->parent->bos[1];
1571 : assert(nfa->parent->eos[0] != COLORLESS);
1572 6003 : nfa->eos[0] = nfa->parent->eos[0];
1573 : assert(nfa->parent->eos[1] != COLORLESS);
1574 6003 : nfa->eos[1] = nfa->parent->eos[1];
1575 : }
1576 10060 : }
1577 :
1578 : /*
1579 : * optimize - optimize an NFA
1580 : *
1581 : * The main goal of this function is not so much "optimization" (though it
1582 : * does try to get rid of useless NFA states) as reducing the NFA to a form
1583 : * the regex executor can handle. The executor, and indeed the cNFA format
1584 : * that is its input, can only handle PLAIN and LACON arcs. The output of
1585 : * the regex parser also includes EMPTY (do-nothing) arcs, as well as
1586 : * ^, $, AHEAD, and BEHIND constraint arcs, which we must get rid of here.
1587 : * We first get rid of EMPTY arcs and then deal with the constraint arcs.
1588 : * The hardest part of either job is to get rid of circular loops of the
1589 : * target arc type. We would have to do that in any case, though, as such a
1590 : * loop would otherwise allow the executor to cycle through the loop endlessly
1591 : * without making any progress in the input string.
1592 : */
1593 : static long /* re_info bits */
1594 10057 : optimize(struct nfa *nfa,
1595 : FILE *f) /* for debug output; NULL none */
1596 : {
1597 : #ifdef REG_DEBUG
1598 : int verbose = (f != NULL) ? 1 : 0;
1599 :
1600 : if (verbose)
1601 : fprintf(f, "\ninitial cleanup:\n");
1602 : #endif
1603 : /* If we have any CANTMATCH arcs, drop them; but this is uncommon */
1604 10057 : if (nfa->flags & HASCANTMATCH)
1605 : {
1606 6 : removecantmatch(nfa);
1607 6 : nfa->flags &= ~HASCANTMATCH;
1608 : }
1609 10057 : cleanup(nfa); /* may simplify situation */
1610 : #ifdef REG_DEBUG
1611 : if (verbose)
1612 : dumpnfa(nfa, f);
1613 : if (verbose)
1614 : fprintf(f, "\nempties:\n");
1615 : #endif
1616 10057 : fixempties(nfa, f); /* get rid of EMPTY arcs */
1617 : #ifdef REG_DEBUG
1618 : if (verbose)
1619 : fprintf(f, "\nconstraints:\n");
1620 : #endif
1621 10057 : fixconstraintloops(nfa, f); /* get rid of constraint loops */
1622 10057 : pullback(nfa, f); /* pull back constraints backward */
1623 10057 : pushfwd(nfa, f); /* push fwd constraints forward */
1624 : #ifdef REG_DEBUG
1625 : if (verbose)
1626 : fprintf(f, "\nfinal cleanup:\n");
1627 : #endif
1628 10057 : cleanup(nfa); /* final tidying */
1629 : #ifdef REG_DEBUG
1630 : if (verbose)
1631 : dumpnfa(nfa, f);
1632 : #endif
1633 10057 : return analyze(nfa); /* and analysis */
1634 : }
1635 :
1636 : /*
1637 : * pullback - pull back constraints backward to eliminate them
1638 : */
1639 : static void
1640 10057 : pullback(struct nfa *nfa,
1641 : FILE *f) /* for debug output; NULL none */
1642 : {
1643 : struct state *s;
1644 : struct state *nexts;
1645 : struct arc *a;
1646 : struct arc *nexta;
1647 : struct state *intermediates;
1648 : int progress;
1649 :
1650 : /* find and pull until there are no more */
1651 : do
1652 : {
1653 15993 : progress = 0;
1654 246036 : for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
1655 : {
1656 230043 : nexts = s->next;
1657 230043 : intermediates = NULL;
1658 978990 : for (a = s->outs; a != NULL && !NISERR(); a = nexta)
1659 : {
1660 748947 : nexta = a->outchain;
1661 748947 : if (a->type == '^' || a->type == BEHIND)
1662 51507 : if (pull(nfa, a, &intermediates))
1663 19651 : progress = 1;
1664 : }
1665 : /* clear tmp fields of intermediate states created here */
1666 231273 : while (intermediates != NULL)
1667 : {
1668 1230 : struct state *ns = intermediates->tmp;
1669 :
1670 1230 : intermediates->tmp = NULL;
1671 1230 : intermediates = ns;
1672 : }
1673 : /* if s is now useless, get rid of it */
1674 230043 : if ((s->nins == 0 || s->nouts == 0) && !s->flag)
1675 17047 : dropstate(nfa, s);
1676 : }
1677 15993 : if (progress && f != NULL)
1678 0 : dumpnfa(nfa, f);
1679 15993 : } while (progress && !NISERR());
1680 10057 : if (NISERR())
1681 3 : return;
1682 :
1683 : /*
1684 : * Any ^ constraints we were able to pull to the start state can now be
1685 : * replaced by PLAIN arcs referencing the BOS or BOL colors. There should
1686 : * be no other ^ or BEHIND arcs left in the NFA, though we do not check
1687 : * that here (compact() will fail if so).
1688 : */
1689 37308 : for (a = nfa->pre->outs; a != NULL; a = nexta)
1690 : {
1691 27254 : nexta = a->outchain;
1692 27254 : if (a->type == '^')
1693 : {
1694 : assert(a->co == 0 || a->co == 1);
1695 19672 : newarc(nfa, PLAIN, nfa->bos[a->co], a->from, a->to);
1696 19672 : freearc(nfa, a);
1697 : }
1698 : }
1699 : }
1700 :
1701 : /*
1702 : * pull - pull a back constraint backward past its source state
1703 : *
1704 : * Returns 1 if successful (which it always is unless the source is the
1705 : * start state or we have an internal error), 0 if nothing happened.
1706 : *
1707 : * A significant property of this function is that it deletes no pre-existing
1708 : * states, and no outarcs of the constraint's from state other than the given
1709 : * constraint arc. This makes the loops in pullback() safe, at the cost that
1710 : * we may leave useless states behind. Therefore, we leave it to pullback()
1711 : * to delete such states.
1712 : *
1713 : * If the from state has multiple back-constraint outarcs, and/or multiple
1714 : * compatible constraint inarcs, we only need to create one new intermediate
1715 : * state per combination of predecessor and successor states. *intermediates
1716 : * points to a list of such intermediate states for this from state (chained
1717 : * through their tmp fields).
1718 : */
1719 : static int
1720 51507 : pull(struct nfa *nfa,
1721 : struct arc *con,
1722 : struct state **intermediates)
1723 : {
1724 51507 : struct state *from = con->from;
1725 51507 : struct state *to = con->to;
1726 : struct arc *a;
1727 : struct arc *nexta;
1728 : struct state *s;
1729 :
1730 : assert(from != to); /* should have gotten rid of this earlier */
1731 51507 : if (from->flag) /* can't pull back beyond start */
1732 31856 : return 0;
1733 19651 : if (from->nins == 0)
1734 : { /* unreachable */
1735 3652 : freearc(nfa, con);
1736 3652 : return 1;
1737 : }
1738 :
1739 : /*
1740 : * First, clone from state if necessary to avoid other outarcs. This may
1741 : * seem wasteful, but it simplifies the logic, and we'll get rid of the
1742 : * clone state again at the bottom.
1743 : */
1744 15999 : if (from->nouts > 1)
1745 : {
1746 9513 : s = newstate(nfa);
1747 9513 : if (NISERR())
1748 0 : return 0;
1749 9513 : copyins(nfa, from, s); /* duplicate inarcs */
1750 9513 : cparc(nfa, con, s, to); /* move constraint arc */
1751 9513 : freearc(nfa, con);
1752 9513 : if (NISERR())
1753 0 : return 0;
1754 9513 : from = s;
1755 9513 : con = from->outs;
1756 : }
1757 : assert(from->nouts == 1);
1758 :
1759 : /* propagate the constraint into the from state's inarcs */
1760 160286 : for (a = from->ins; a != NULL && !NISERR(); a = nexta)
1761 : {
1762 144287 : nexta = a->inchain;
1763 144287 : switch (combine(nfa, con, a))
1764 : {
1765 44462 : case INCOMPATIBLE: /* destroy the arc */
1766 44462 : freearc(nfa, a);
1767 44462 : break;
1768 8768 : case SATISFIED: /* no action needed */
1769 8768 : break;
1770 90167 : case COMPATIBLE: /* swap the two arcs, more or less */
1771 : /* need an intermediate state, but might have one already */
1772 101960 : for (s = *intermediates; s != NULL; s = s->tmp)
1773 : {
1774 : assert(s->nins > 0 && s->nouts > 0);
1775 100730 : if (s->ins->from == a->from && s->outs->to == to)
1776 88937 : break;
1777 : }
1778 90167 : if (s == NULL)
1779 : {
1780 1230 : s = newstate(nfa);
1781 1230 : if (NISERR())
1782 0 : return 0;
1783 1230 : s->tmp = *intermediates;
1784 1230 : *intermediates = s;
1785 : }
1786 90167 : cparc(nfa, con, a->from, s);
1787 90167 : cparc(nfa, a, s, to);
1788 90167 : freearc(nfa, a);
1789 90167 : break;
1790 890 : case REPLACEARC: /* replace arc's color */
1791 890 : newarc(nfa, a->type, con->co, a->from, to);
1792 890 : freearc(nfa, a);
1793 890 : break;
1794 0 : default:
1795 : assert(NOTREACHED);
1796 0 : break;
1797 : }
1798 : }
1799 :
1800 : /* remaining inarcs, if any, incorporate the constraint */
1801 15999 : moveins(nfa, from, to);
1802 15999 : freearc(nfa, con);
1803 : /* from state is now useless, but we leave it to pullback() to clean up */
1804 15999 : return 1;
1805 : }
1806 :
1807 : /*
1808 : * pushfwd - push forward constraints forward to eliminate them
1809 : */
1810 : static void
1811 10057 : pushfwd(struct nfa *nfa,
1812 : FILE *f) /* for debug output; NULL none */
1813 : {
1814 : struct state *s;
1815 : struct state *nexts;
1816 : struct arc *a;
1817 : struct arc *nexta;
1818 : struct state *intermediates;
1819 : int progress;
1820 :
1821 : /* find and push until there are no more */
1822 : do
1823 : {
1824 15070 : progress = 0;
1825 211625 : for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
1826 : {
1827 196555 : nexts = s->next;
1828 196555 : intermediates = NULL;
1829 863139 : for (a = s->ins; a != NULL && !NISERR(); a = nexta)
1830 : {
1831 666584 : nexta = a->inchain;
1832 666584 : if (a->type == '$' || a->type == AHEAD)
1833 37151 : if (push(nfa, a, &intermediates))
1834 11387 : progress = 1;
1835 : }
1836 : /* clear tmp fields of intermediate states created here */
1837 196557 : while (intermediates != NULL)
1838 : {
1839 2 : struct state *ns = intermediates->tmp;
1840 :
1841 2 : intermediates->tmp = NULL;
1842 2 : intermediates = ns;
1843 : }
1844 : /* if s is now useless, get rid of it */
1845 196555 : if ((s->nins == 0 || s->nouts == 0) && !s->flag)
1846 11667 : dropstate(nfa, s);
1847 : }
1848 15070 : if (progress && f != NULL)
1849 0 : dumpnfa(nfa, f);
1850 15070 : } while (progress && !NISERR());
1851 10057 : if (NISERR())
1852 3 : return;
1853 :
1854 : /*
1855 : * Any $ constraints we were able to push to the post state can now be
1856 : * replaced by PLAIN arcs referencing the EOS or EOL colors. There should
1857 : * be no other $ or AHEAD arcs left in the NFA, though we do not check
1858 : * that here (compact() will fail if so).
1859 : */
1860 31539 : for (a = nfa->post->ins; a != NULL; a = nexta)
1861 : {
1862 21485 : nexta = a->inchain;
1863 21485 : if (a->type == '$')
1864 : {
1865 : assert(a->co == 0 || a->co == 1);
1866 15350 : newarc(nfa, PLAIN, nfa->eos[a->co], a->from, a->to);
1867 15350 : freearc(nfa, a);
1868 : }
1869 : }
1870 : }
1871 :
1872 : /*
1873 : * push - push a forward constraint forward past its destination state
1874 : *
1875 : * Returns 1 if successful (which it always is unless the destination is the
1876 : * post state or we have an internal error), 0 if nothing happened.
1877 : *
1878 : * A significant property of this function is that it deletes no pre-existing
1879 : * states, and no inarcs of the constraint's to state other than the given
1880 : * constraint arc. This makes the loops in pushfwd() safe, at the cost that
1881 : * we may leave useless states behind. Therefore, we leave it to pushfwd()
1882 : * to delete such states.
1883 : *
1884 : * If the to state has multiple forward-constraint inarcs, and/or multiple
1885 : * compatible constraint outarcs, we only need to create one new intermediate
1886 : * state per combination of predecessor and successor states. *intermediates
1887 : * points to a list of such intermediate states for this to state (chained
1888 : * through their tmp fields).
1889 : */
1890 : static int
1891 37151 : push(struct nfa *nfa,
1892 : struct arc *con,
1893 : struct state **intermediates)
1894 : {
1895 37151 : struct state *from = con->from;
1896 37151 : struct state *to = con->to;
1897 : struct arc *a;
1898 : struct arc *nexta;
1899 : struct state *s;
1900 :
1901 : assert(to != from); /* should have gotten rid of this earlier */
1902 37151 : if (to->flag) /* can't push forward beyond end */
1903 25764 : return 0;
1904 11387 : if (to->nouts == 0)
1905 : { /* dead end */
1906 410 : freearc(nfa, con);
1907 410 : return 1;
1908 : }
1909 :
1910 : /*
1911 : * First, clone to state if necessary to avoid other inarcs. This may
1912 : * seem wasteful, but it simplifies the logic, and we'll get rid of the
1913 : * clone state again at the bottom.
1914 : */
1915 10977 : if (to->nins > 1)
1916 : {
1917 5723 : s = newstate(nfa);
1918 5723 : if (NISERR())
1919 0 : return 0;
1920 5723 : copyouts(nfa, to, s); /* duplicate outarcs */
1921 5723 : cparc(nfa, con, from, s); /* move constraint arc */
1922 5723 : freearc(nfa, con);
1923 5723 : if (NISERR())
1924 0 : return 0;
1925 5723 : to = s;
1926 5723 : con = to->ins;
1927 : }
1928 : assert(to->nins == 1);
1929 :
1930 : /* propagate the constraint into the to state's outarcs */
1931 66082 : for (a = to->outs; a != NULL && !NISERR(); a = nexta)
1932 : {
1933 55105 : nexta = a->outchain;
1934 55105 : switch (combine(nfa, con, a))
1935 : {
1936 46352 : case INCOMPATIBLE: /* destroy the arc */
1937 46352 : freearc(nfa, a);
1938 46352 : break;
1939 7428 : case SATISFIED: /* no action needed */
1940 7428 : break;
1941 8 : case COMPATIBLE: /* swap the two arcs, more or less */
1942 : /* need an intermediate state, but might have one already */
1943 8 : for (s = *intermediates; s != NULL; s = s->tmp)
1944 : {
1945 : assert(s->nins > 0 && s->nouts > 0);
1946 6 : if (s->ins->from == from && s->outs->to == a->to)
1947 6 : break;
1948 : }
1949 8 : if (s == NULL)
1950 : {
1951 2 : s = newstate(nfa);
1952 2 : if (NISERR())
1953 0 : return 0;
1954 2 : s->tmp = *intermediates;
1955 2 : *intermediates = s;
1956 : }
1957 8 : cparc(nfa, con, s, a->to);
1958 8 : cparc(nfa, a, from, s);
1959 8 : freearc(nfa, a);
1960 8 : break;
1961 1317 : case REPLACEARC: /* replace arc's color */
1962 1317 : newarc(nfa, a->type, con->co, from, a->to);
1963 1317 : freearc(nfa, a);
1964 1317 : break;
1965 0 : default:
1966 : assert(NOTREACHED);
1967 0 : break;
1968 : }
1969 : }
1970 :
1971 : /* remaining outarcs, if any, incorporate the constraint */
1972 10977 : moveouts(nfa, to, from);
1973 10977 : freearc(nfa, con);
1974 : /* to state is now useless, but we leave it to pushfwd() to clean up */
1975 10977 : return 1;
1976 : }
1977 :
1978 : /*
1979 : * combine - constraint lands on an arc, what happens?
1980 : *
1981 : * #def INCOMPATIBLE 1 // destroys arc
1982 : * #def SATISFIED 2 // constraint satisfied
1983 : * #def COMPATIBLE 3 // compatible but not satisfied yet
1984 : * #def REPLACEARC 4 // replace arc's color with constraint color
1985 : */
1986 : static int
1987 199392 : combine(struct nfa *nfa,
1988 : struct arc *con,
1989 : struct arc *a)
1990 : {
1991 : #define CA(ct,at) (((ct)<<CHAR_BIT) | (at))
1992 :
1993 199392 : switch (CA(con->type, a->type))
1994 : {
1995 45296 : case CA('^', PLAIN): /* newlines are handled separately */
1996 : case CA('$', PLAIN):
1997 45296 : return INCOMPATIBLE;
1998 : break;
1999 18658 : case CA(AHEAD, PLAIN): /* color constraints meet colors */
2000 : case CA(BEHIND, PLAIN):
2001 18658 : if (con->co == a->co)
2002 827 : return SATISFIED;
2003 17831 : if (con->co == RAINBOW)
2004 : {
2005 : /* con is satisfied unless arc's color is a pseudocolor */
2006 2 : if (!(nfa->cm->cd[a->co].flags & PSEUDO))
2007 2 : return SATISFIED;
2008 : }
2009 17829 : else if (a->co == RAINBOW)
2010 : {
2011 : /* con is incompatible if it's for a pseudocolor */
2012 : /* (this is hypothetical; we make no such constraints today) */
2013 2203 : if (nfa->cm->cd[con->co].flags & PSEUDO)
2014 0 : return INCOMPATIBLE;
2015 : /* otherwise, constraint constrains arc to be only its color */
2016 2203 : return REPLACEARC;
2017 : }
2018 15626 : return INCOMPATIBLE;
2019 : break;
2020 26407 : case CA('^', '^'): /* collision, similar constraints */
2021 : case CA('$', '$'):
2022 26407 : if (con->co == a->co) /* true duplication */
2023 14906 : return SATISFIED;
2024 11501 : return INCOMPATIBLE;
2025 : break;
2026 12310 : case CA(AHEAD, AHEAD): /* collision, similar constraints */
2027 : case CA(BEHIND, BEHIND):
2028 12310 : if (con->co == a->co) /* true duplication */
2029 459 : return SATISFIED;
2030 11851 : if (con->co == RAINBOW)
2031 : {
2032 : /* con is satisfied unless arc's color is a pseudocolor */
2033 2 : if (!(nfa->cm->cd[a->co].flags & PSEUDO))
2034 2 : return SATISFIED;
2035 : }
2036 11849 : else if (a->co == RAINBOW)
2037 : {
2038 : /* con is incompatible if it's for a pseudocolor */
2039 : /* (this is hypothetical; we make no such constraints today) */
2040 4 : if (nfa->cm->cd[con->co].flags & PSEUDO)
2041 0 : return INCOMPATIBLE;
2042 : /* otherwise, constraint constrains arc to be only its color */
2043 4 : return REPLACEARC;
2044 : }
2045 11845 : return INCOMPATIBLE;
2046 : break;
2047 6546 : case CA('^', BEHIND): /* collision, dissimilar constraints */
2048 : case CA(BEHIND, '^'):
2049 : case CA('$', AHEAD):
2050 : case CA(AHEAD, '$'):
2051 6546 : return INCOMPATIBLE;
2052 : break;
2053 90175 : case CA('^', '$'): /* constraints passing each other */
2054 : case CA('^', AHEAD):
2055 : case CA(BEHIND, '$'):
2056 : case CA(BEHIND, AHEAD):
2057 : case CA('$', '^'):
2058 : case CA('$', BEHIND):
2059 : case CA(AHEAD, '^'):
2060 : case CA(AHEAD, BEHIND):
2061 : case CA('^', LACON):
2062 : case CA(BEHIND, LACON):
2063 : case CA('$', LACON):
2064 : case CA(AHEAD, LACON):
2065 90175 : return COMPATIBLE;
2066 : break;
2067 : }
2068 : assert(NOTREACHED);
2069 0 : return INCOMPATIBLE; /* for benefit of blind compilers */
2070 : }
2071 :
2072 : /*
2073 : * fixempties - get rid of EMPTY arcs
2074 : */
2075 : static void
2076 10057 : fixempties(struct nfa *nfa,
2077 : FILE *f) /* for debug output; NULL none */
2078 : {
2079 : struct state *s;
2080 : struct state *s2;
2081 : struct state *nexts;
2082 : struct arc *a;
2083 : struct arc *nexta;
2084 : int totalinarcs;
2085 : struct arc **inarcsorig;
2086 : struct arc **arcarray;
2087 : int arccount;
2088 : int prevnins;
2089 : int nskip;
2090 :
2091 : /*
2092 : * First, get rid of any states whose sole out-arc is an EMPTY, since
2093 : * they're basically just aliases for their successor. The parsing
2094 : * algorithm creates enough of these that it's worth special-casing this.
2095 : */
2096 230260 : for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
2097 : {
2098 220203 : nexts = s->next;
2099 220203 : if (s->flag || s->nouts != 1)
2100 56762 : continue;
2101 163441 : a = s->outs;
2102 : assert(a != NULL && a->outchain == NULL);
2103 163441 : if (a->type != EMPTY)
2104 100814 : continue;
2105 62627 : if (s != a->to)
2106 62627 : moveins(nfa, s, a->to);
2107 62627 : dropstate(nfa, s);
2108 : }
2109 :
2110 : /*
2111 : * Similarly, get rid of any state with a single EMPTY in-arc, by folding
2112 : * it into its predecessor.
2113 : */
2114 167633 : for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
2115 : {
2116 157576 : nexts = s->next;
2117 : /* while we're at it, ensure tmp fields are clear for next step */
2118 : assert(s->tmp == NULL);
2119 157576 : if (s->flag || s->nins != 1)
2120 53928 : continue;
2121 103648 : a = s->ins;
2122 : assert(a != NULL && a->inchain == NULL);
2123 103648 : if (a->type != EMPTY)
2124 91825 : continue;
2125 11823 : if (s != a->from)
2126 11823 : moveouts(nfa, s, a->from);
2127 11823 : dropstate(nfa, s);
2128 : }
2129 :
2130 10057 : if (NISERR())
2131 0 : return;
2132 :
2133 : /*
2134 : * For each remaining NFA state, find all other states from which it is
2135 : * reachable by a chain of one or more EMPTY arcs. Then generate new arcs
2136 : * that eliminate the need for each such chain.
2137 : *
2138 : * We could replace a chain of EMPTY arcs that leads from a "from" state
2139 : * to a "to" state either by pushing non-EMPTY arcs forward (linking
2140 : * directly from "from"'s predecessors to "to") or by pulling them back
2141 : * (linking directly from "from" to "to"'s successors). We choose to
2142 : * always do the former; this choice is somewhat arbitrary, but the
2143 : * approach below requires that we uniformly do one or the other.
2144 : *
2145 : * Suppose we have a chain of N successive EMPTY arcs (where N can easily
2146 : * approach the size of the NFA). All of the intermediate states must
2147 : * have additional inarcs and outarcs, else they'd have been removed by
2148 : * the steps above. Assuming their inarcs are mostly not empties, we will
2149 : * add O(N^2) arcs to the NFA, since a non-EMPTY inarc leading to any one
2150 : * state in the chain must be duplicated to lead to all its successor
2151 : * states as well. So there is no hope of doing less than O(N^2) work;
2152 : * however, we should endeavor to keep the big-O cost from being even
2153 : * worse than that, which it can easily become without care. In
2154 : * particular, suppose we were to copy all S1's inarcs forward to S2, and
2155 : * then also to S3, and then later we consider pushing S2's inarcs forward
2156 : * to S3. If we include the arcs already copied from S1 in that, we'd be
2157 : * doing O(N^3) work. (The duplicate-arc elimination built into newarc()
2158 : * and its cohorts would get rid of the extra arcs, but not without cost.)
2159 : *
2160 : * We can avoid this cost by treating only arcs that existed at the start
2161 : * of this phase as candidates to be pushed forward. To identify those,
2162 : * we remember the first inarc each state had to start with. We rely on
2163 : * the fact that newarc() and friends put new arcs on the front of their
2164 : * to-states' inchains, and that this phase never deletes arcs, so that
2165 : * the original arcs must be the last arcs in their to-states' inchains.
2166 : *
2167 : * So the process here is that, for each state in the NFA, we gather up
2168 : * all non-EMPTY inarcs of states that can reach the target state via
2169 : * EMPTY arcs. We then sort, de-duplicate, and merge these arcs into the
2170 : * target state's inchain. (We can safely use sort-merge for this as long
2171 : * as we update each state's original-arcs pointer after we add arcs to
2172 : * it; the sort step of mergeins probably changed the order of the old
2173 : * arcs.)
2174 : *
2175 : * Another refinement worth making is that, because we only add non-EMPTY
2176 : * arcs during this phase, and all added arcs have the same from-state as
2177 : * the non-EMPTY arc they were cloned from, we know ahead of time that any
2178 : * states having only EMPTY outarcs will be useless for lack of outarcs
2179 : * after we drop the EMPTY arcs. (They cannot gain non-EMPTY outarcs if
2180 : * they had none to start with.) So we need not bother to update the
2181 : * inchains of such states at all.
2182 : */
2183 :
2184 : /* Remember the states' first original inarcs */
2185 : /* ... and while at it, count how many old inarcs there are altogether */
2186 10057 : inarcsorig = (struct arc **) MALLOC(nfa->nstates * sizeof(struct arc *));
2187 10057 : if (inarcsorig == NULL)
2188 : {
2189 0 : NERR(REG_ESPACE);
2190 0 : return;
2191 : }
2192 10057 : totalinarcs = 0;
2193 155810 : for (s = nfa->states; s != NULL; s = s->next)
2194 : {
2195 145753 : inarcsorig[s->no] = s->ins;
2196 145753 : totalinarcs += s->nins;
2197 : }
2198 :
2199 : /*
2200 : * Create a workspace for accumulating the inarcs to be added to the
2201 : * current target state. totalinarcs is probably a considerable
2202 : * overestimate of the space needed, but the NFA is unlikely to be large
2203 : * enough at this point to make it worth being smarter.
2204 : */
2205 10057 : arcarray = (struct arc **) MALLOC(totalinarcs * sizeof(struct arc *));
2206 10057 : if (arcarray == NULL)
2207 : {
2208 0 : NERR(REG_ESPACE);
2209 0 : FREE(inarcsorig);
2210 0 : return;
2211 : }
2212 :
2213 : /* And iterate over the target states */
2214 153329 : for (s = nfa->states; s != NULL && !NISERR(); s = s->next)
2215 : {
2216 : /* Ignore target states without non-EMPTY outarcs, per note above */
2217 143272 : if (!s->flag && !hasnonemptyout(s))
2218 1980 : continue;
2219 :
2220 : /* Find predecessor states and accumulate their original inarcs */
2221 141292 : arccount = 0;
2222 7634849 : for (s2 = emptyreachable(nfa, s, s, inarcsorig); s2 != s; s2 = nexts)
2223 : {
2224 : /* Add s2's original inarcs to arcarray[], but ignore empties */
2225 22501509 : for (a = inarcsorig[s2->no]; a != NULL; a = a->inchain)
2226 : {
2227 15007952 : if (a->type != EMPTY)
2228 7515445 : arcarray[arccount++] = a;
2229 : }
2230 :
2231 : /* Reset the tmp fields as we walk back */
2232 7493557 : nexts = s2->tmp;
2233 7493557 : s2->tmp = NULL;
2234 : }
2235 141292 : s->tmp = NULL;
2236 : assert(arccount <= totalinarcs);
2237 :
2238 : /* Remember how many original inarcs this state has */
2239 141292 : prevnins = s->nins;
2240 :
2241 : /* Add non-duplicate inarcs to target state */
2242 141292 : mergeins(nfa, s, arcarray, arccount);
2243 :
2244 : /* Now we must update the state's inarcsorig pointer */
2245 141292 : nskip = s->nins - prevnins;
2246 141292 : a = s->ins;
2247 7650412 : while (nskip-- > 0)
2248 7509120 : a = a->inchain;
2249 141292 : inarcsorig[s->no] = a;
2250 : }
2251 :
2252 10057 : FREE(arcarray);
2253 10057 : FREE(inarcsorig);
2254 :
2255 10057 : if (NISERR())
2256 3 : return;
2257 :
2258 : /*
2259 : * Now remove all the EMPTY arcs, since we don't need them anymore.
2260 : */
2261 146801 : for (s = nfa->states; s != NULL; s = s->next)
2262 : {
2263 769505 : for (a = s->outs; a != NULL; a = nexta)
2264 : {
2265 632758 : nexta = a->outchain;
2266 632758 : if (a->type == EMPTY)
2267 12741 : freearc(nfa, a);
2268 : }
2269 : }
2270 :
2271 : /*
2272 : * And remove any states that have become useless. (This cleanup is not
2273 : * very thorough, and would be even less so if we tried to combine it with
2274 : * the previous step; but cleanup() will take care of anything we miss.)
2275 : */
2276 146801 : for (s = nfa->states; s != NULL; s = nexts)
2277 : {
2278 136747 : nexts = s->next;
2279 136747 : if ((s->nins == 0 || s->nouts == 0) && !s->flag)
2280 1980 : dropstate(nfa, s);
2281 : }
2282 :
2283 10054 : if (f != NULL)
2284 0 : dumpnfa(nfa, f);
2285 : }
2286 :
2287 : /*
2288 : * emptyreachable - recursively find all states that can reach s by EMPTY arcs
2289 : *
2290 : * The return value is the last such state found. Its tmp field links back
2291 : * to the next-to-last such state, and so on back to s, so that all these
2292 : * states can be located without searching the whole NFA.
2293 : *
2294 : * Since this is only used in fixempties(), we pass in the inarcsorig[] array
2295 : * maintained by that function. This lets us skip over all new inarcs, which
2296 : * are certainly not EMPTY arcs.
2297 : *
2298 : * The maximum recursion depth here is equal to the length of the longest
2299 : * loop-free chain of EMPTY arcs, which is surely no more than the size of
2300 : * the NFA ... but that could still be enough to cause trouble.
2301 : */
2302 : static struct state *
2303 7634849 : emptyreachable(struct nfa *nfa,
2304 : struct state *s,
2305 : struct state *lastfound,
2306 : struct arc **inarcsorig)
2307 : {
2308 : struct arc *a;
2309 :
2310 : /* Since this is recursive, it could be driven to stack overflow */
2311 7634849 : if (STACK_TOO_DEEP(nfa->v->re))
2312 : {
2313 0 : NERR(REG_ETOOBIG);
2314 0 : return lastfound;
2315 : }
2316 :
2317 7634849 : s->tmp = lastfound;
2318 7634849 : lastfound = s;
2319 22868933 : for (a = inarcsorig[s->no]; a != NULL; a = a->inchain)
2320 : {
2321 15234084 : if (a->type == EMPTY && a->from->tmp == NULL)
2322 7493557 : lastfound = emptyreachable(nfa, a->from, lastfound, inarcsorig);
2323 : }
2324 7634849 : return lastfound;
2325 : }
2326 :
2327 : /*
2328 : * isconstraintarc - detect whether an arc is of a constraint type
2329 : */
2330 : static inline int
2331 1306239 : isconstraintarc(struct arc *a)
2332 : {
2333 1306239 : switch (a->type)
2334 : {
2335 168391 : case '^':
2336 : case '$':
2337 : case BEHIND:
2338 : case AHEAD:
2339 : case LACON:
2340 168391 : return 1;
2341 : }
2342 1137848 : return 0;
2343 : }
2344 :
2345 : /*
2346 : * hasconstraintout - does state have a constraint out arc?
2347 : */
2348 : static int
2349 12631 : hasconstraintout(struct state *s)
2350 : {
2351 : struct arc *a;
2352 :
2353 23960 : for (a = s->outs; a != NULL; a = a->outchain)
2354 : {
2355 19222 : if (isconstraintarc(a))
2356 7893 : return 1;
2357 : }
2358 4738 : return 0;
2359 : }
2360 :
2361 : /*
2362 : * fixconstraintloops - get rid of loops containing only constraint arcs
2363 : *
2364 : * A loop of states that contains only constraint arcs is useless, since
2365 : * passing around the loop represents no forward progress. Moreover, it
2366 : * would cause infinite looping in pullback/pushfwd, so we need to get rid
2367 : * of such loops before doing that.
2368 : */
2369 : static void
2370 10057 : fixconstraintloops(struct nfa *nfa,
2371 : FILE *f) /* for debug output; NULL none */
2372 : {
2373 : struct state *s;
2374 : struct state *nexts;
2375 : struct arc *a;
2376 : struct arc *nexta;
2377 : int hasconstraints;
2378 :
2379 : /*
2380 : * In the trivial case of a state that loops to itself, we can just drop
2381 : * the constraint arc altogether. This is worth special-casing because
2382 : * such loops are far more common than loops containing multiple states.
2383 : * While we're at it, note whether any constraint arcs survive.
2384 : */
2385 10057 : hasconstraints = 0;
2386 144824 : for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
2387 : {
2388 134767 : nexts = s->next;
2389 : /* while we're at it, ensure tmp fields are clear for next step */
2390 : assert(s->tmp == NULL);
2391 752805 : for (a = s->outs; a != NULL && !NISERR(); a = nexta)
2392 : {
2393 618038 : nexta = a->outchain;
2394 618038 : if (isconstraintarc(a))
2395 : {
2396 63097 : if (a->to == s)
2397 176 : freearc(nfa, a);
2398 : else
2399 62921 : hasconstraints = 1;
2400 : }
2401 : }
2402 : /* If we removed all the outarcs, the state is useless. */
2403 134767 : if (s->nouts == 0 && !s->flag)
2404 0 : dropstate(nfa, s);
2405 : }
2406 :
2407 : /* Nothing to do if no remaining constraint arcs */
2408 10057 : if (NISERR() || !hasconstraints)
2409 5 : return;
2410 :
2411 : /*
2412 : * Starting from each remaining NFA state, search outwards for a
2413 : * constraint loop. If we find a loop, break the loop, then start the
2414 : * search over. (We could possibly retain some state from the first scan,
2415 : * but it would complicate things greatly, and multi-state constraint
2416 : * loops are rare enough that it's not worth optimizing the case.)
2417 : */
2418 10052 : restart:
2419 152282 : for (s = nfa->states; s != NULL && !NISERR(); s = s->next)
2420 : {
2421 142230 : if (findconstraintloop(nfa, s))
2422 206 : goto restart;
2423 : }
2424 :
2425 10052 : if (NISERR())
2426 0 : return;
2427 :
2428 : /*
2429 : * Now remove any states that have become useless. (This cleanup is not
2430 : * very thorough, and would be even less so if we tried to combine it with
2431 : * the previous step; but cleanup() will take care of anything we miss.)
2432 : *
2433 : * Because findconstraintloop intentionally doesn't reset all tmp fields,
2434 : * we have to clear them after it's done. This is a convenient place to
2435 : * do that, too.
2436 : */
2437 145676 : for (s = nfa->states; s != NULL; s = nexts)
2438 : {
2439 135624 : nexts = s->next;
2440 135624 : s->tmp = NULL;
2441 135624 : if ((s->nins == 0 || s->nouts == 0) && !s->flag)
2442 213 : dropstate(nfa, s);
2443 : }
2444 :
2445 10052 : if (f != NULL)
2446 0 : dumpnfa(nfa, f);
2447 : }
2448 :
2449 : /*
2450 : * findconstraintloop - recursively find a loop of constraint arcs
2451 : *
2452 : * If we find a loop, break it by calling breakconstraintloop(), then
2453 : * return 1; otherwise return 0.
2454 : *
2455 : * State tmp fields are guaranteed all NULL on a success return, because
2456 : * breakconstraintloop does that. After a failure return, any state that
2457 : * is known not to be part of a loop is marked with s->tmp == s; this allows
2458 : * us not to have to re-prove that fact on later calls. (This convention is
2459 : * workable because we already eliminated single-state loops.)
2460 : *
2461 : * Note that the found loop doesn't necessarily include the first state we
2462 : * are called on. Any loop reachable from that state will do.
2463 : *
2464 : * The maximum recursion depth here is one more than the length of the longest
2465 : * loop-free chain of constraint arcs, which is surely no more than the size
2466 : * of the NFA ... but that could still be enough to cause trouble.
2467 : */
2468 : static int
2469 225215 : findconstraintloop(struct nfa *nfa, struct state *s)
2470 : {
2471 : struct arc *a;
2472 :
2473 : /* Since this is recursive, it could be driven to stack overflow */
2474 225215 : if (STACK_TOO_DEEP(nfa->v->re))
2475 : {
2476 0 : NERR(REG_ETOOBIG);
2477 0 : return 1; /* to exit as quickly as possible */
2478 : }
2479 :
2480 225215 : if (s->tmp != NULL)
2481 : {
2482 : /* Already proven uninteresting? */
2483 80615 : if (s->tmp == s)
2484 80409 : return 0;
2485 : /* Found a loop involving s */
2486 206 : breakconstraintloop(nfa, s);
2487 : /* The tmp fields have been cleaned up by breakconstraintloop */
2488 206 : return 1;
2489 : }
2490 797983 : for (a = s->outs; a != NULL; a = a->outchain)
2491 : {
2492 654042 : if (isconstraintarc(a))
2493 : {
2494 82985 : struct state *sto = a->to;
2495 :
2496 : assert(sto != s);
2497 82985 : s->tmp = sto;
2498 82985 : if (findconstraintloop(nfa, sto))
2499 659 : return 1;
2500 : }
2501 : }
2502 :
2503 : /*
2504 : * If we get here, no constraint loop exists leading out from s. Mark it
2505 : * with s->tmp == s so we need not rediscover that fact again later.
2506 : */
2507 143941 : s->tmp = s;
2508 143941 : return 0;
2509 : }
2510 :
2511 : /*
2512 : * breakconstraintloop - break a loop of constraint arcs
2513 : *
2514 : * sinitial is any one member state of the loop. Each loop member's tmp
2515 : * field links to its successor within the loop. (Note that this function
2516 : * will reset all the tmp fields to NULL.)
2517 : *
2518 : * We can break the loop by, for any one state S1 in the loop, cloning its
2519 : * loop successor state S2 (and possibly following states), and then moving
2520 : * all S1->S2 constraint arcs to point to the cloned S2. The cloned S2 should
2521 : * copy any non-constraint outarcs of S2. Constraint outarcs should be
2522 : * dropped if they point back to S1, else they need to be copied as arcs to
2523 : * similarly cloned states S3, S4, etc. In general, each cloned state copies
2524 : * non-constraint outarcs, drops constraint outarcs that would lead to itself
2525 : * or any earlier cloned state, and sends other constraint outarcs to newly
2526 : * cloned states. No cloned state will have any inarcs that aren't constraint
2527 : * arcs or do not lead from S1 or earlier-cloned states. It's okay to drop
2528 : * constraint back-arcs since they would not take us to any state we've not
2529 : * already been in; therefore, no new constraint loop is created. In this way
2530 : * we generate a modified NFA that can still represent every useful state
2531 : * sequence, but not sequences that represent state loops with no consumption
2532 : * of input data. Note that the set of cloned states will certainly include
2533 : * all of the loop member states other than S1, and it may also include
2534 : * non-loop states that are reachable from S2 via constraint arcs. This is
2535 : * important because there is no guarantee that findconstraintloop found a
2536 : * maximal loop (and searching for one would be NP-hard, so don't try).
2537 : * Frequently the "non-loop states" are actually part of a larger loop that
2538 : * we didn't notice, and indeed there may be several overlapping loops.
2539 : * This technique ensures convergence in such cases, while considering only
2540 : * the originally-found loop does not.
2541 : *
2542 : * If there is only one S1->S2 constraint arc, then that constraint is
2543 : * certainly satisfied when we enter any of the clone states. This means that
2544 : * in the common case where many of the constraint arcs are identically
2545 : * labeled, we can merge together clone states linked by a similarly-labeled
2546 : * constraint: if we can get to the first one we can certainly get to the
2547 : * second, so there's no need to distinguish. This greatly reduces the number
2548 : * of new states needed, so we preferentially break the given loop at a state
2549 : * pair where this is true.
2550 : *
2551 : * Furthermore, it's fairly common to find that a cloned successor state has
2552 : * no outarcs, especially if we're a bit aggressive about removing unnecessary
2553 : * outarcs. If that happens, then there is simply not any interesting state
2554 : * that can be reached through the predecessor's loop arcs, which means we can
2555 : * break the loop just by removing those loop arcs, with no new states added.
2556 : */
2557 : static void
2558 206 : breakconstraintloop(struct nfa *nfa, struct state *sinitial)
2559 : {
2560 : struct state *s;
2561 : struct state *shead;
2562 : struct state *stail;
2563 : struct state *sclone;
2564 : struct state *nexts;
2565 : struct arc *refarc;
2566 : struct arc *a;
2567 : struct arc *nexta;
2568 :
2569 : /*
2570 : * Start by identifying which loop step we want to break at.
2571 : * Preferentially this is one with only one constraint arc. (XXX are
2572 : * there any other secondary heuristics we want to use here?) Set refarc
2573 : * to point to the selected lone constraint arc, if there is one.
2574 : */
2575 206 : refarc = NULL;
2576 206 : s = sinitial;
2577 : do
2578 : {
2579 530 : nexts = s->tmp;
2580 : assert(nexts != s); /* should not see any one-element loops */
2581 530 : if (refarc == NULL)
2582 : {
2583 332 : int narcs = 0;
2584 :
2585 3800 : for (a = s->outs; a != NULL; a = a->outchain)
2586 : {
2587 3468 : if (a->to == nexts && isconstraintarc(a))
2588 : {
2589 1296 : refarc = a;
2590 1296 : narcs++;
2591 : }
2592 : }
2593 : assert(narcs > 0);
2594 332 : if (narcs > 1)
2595 186 : refarc = NULL; /* multiple constraint arcs here, no good */
2596 : }
2597 530 : s = nexts;
2598 530 : } while (s != sinitial);
2599 :
2600 206 : if (refarc)
2601 : {
2602 : /* break at the refarc */
2603 146 : shead = refarc->from;
2604 146 : stail = refarc->to;
2605 : assert(stail == shead->tmp);
2606 : }
2607 : else
2608 : {
2609 : /* for lack of a better idea, break after sinitial */
2610 60 : shead = sinitial;
2611 60 : stail = sinitial->tmp;
2612 : }
2613 :
2614 : /*
2615 : * Reset the tmp fields so that we can use them for local storage in
2616 : * clonesuccessorstates. (findconstraintloop won't mind, since it's just
2617 : * going to abandon its search anyway.)
2618 : */
2619 17361 : for (s = nfa->states; s != NULL; s = s->next)
2620 17155 : s->tmp = NULL;
2621 :
2622 : /*
2623 : * Recursively build clone state(s) as needed.
2624 : */
2625 206 : sclone = newstate(nfa);
2626 206 : if (sclone == NULL)
2627 : {
2628 : assert(NISERR());
2629 0 : return;
2630 : }
2631 :
2632 206 : clonesuccessorstates(nfa, stail, sclone, shead, refarc,
2633 : NULL, NULL, nfa->nstates);
2634 :
2635 206 : if (NISERR())
2636 0 : return;
2637 :
2638 : /*
2639 : * It's possible that sclone has no outarcs at all, in which case it's
2640 : * useless. (We don't try extremely hard to get rid of useless states
2641 : * here, but this is an easy and fairly common case.)
2642 : */
2643 206 : if (sclone->nouts == 0)
2644 : {
2645 49 : freestate(nfa, sclone);
2646 49 : sclone = NULL;
2647 : }
2648 :
2649 : /*
2650 : * Move shead's constraint-loop arcs to point to sclone, or just drop them
2651 : * if we discovered we don't need sclone.
2652 : */
2653 2256 : for (a = shead->outs; a != NULL; a = nexta)
2654 : {
2655 2050 : nexta = a->outchain;
2656 2050 : if (a->to == stail && isconstraintarc(a))
2657 : {
2658 489 : if (sclone)
2659 412 : cparc(nfa, a, shead, sclone);
2660 489 : freearc(nfa, a);
2661 489 : if (NISERR())
2662 0 : break;
2663 : }
2664 : }
2665 : }
2666 :
2667 : /*
2668 : * clonesuccessorstates - create a tree of constraint-arc successor states
2669 : *
2670 : * ssource is the state to be cloned, and sclone is the state to copy its
2671 : * outarcs into. sclone's inarcs, if any, should already be set up.
2672 : *
2673 : * spredecessor is the original predecessor state that we are trying to build
2674 : * successors for (it may not be the immediate predecessor of ssource).
2675 : * refarc, if not NULL, is the original constraint arc that is known to have
2676 : * been traversed out of spredecessor to reach the successor(s).
2677 : *
2678 : * For each cloned successor state, we transiently create a "donemap" that is
2679 : * a boolean array showing which source states we've already visited for this
2680 : * clone state. This prevents infinite recursion as well as useless repeat
2681 : * visits to the same state subtree (which can add up fast, since typical NFAs
2682 : * have multiple redundant arc pathways). Each donemap is a char array
2683 : * indexed by state number. The donemaps are all of the same size "nstates",
2684 : * which is nfa->nstates as of the start of the recursion. This is enough to
2685 : * have entries for all pre-existing states, but *not* entries for clone
2686 : * states created during the recursion. That's okay since we have no need to
2687 : * mark those.
2688 : *
2689 : * curdonemap is NULL when recursing to a new sclone state, or sclone's
2690 : * donemap when we are recursing without having created a new state (which we
2691 : * do when we decide we can merge a successor state into the current clone
2692 : * state). outerdonemap is NULL at the top level and otherwise the parent
2693 : * clone state's donemap.
2694 : *
2695 : * The successor states we create and fill here form a strict tree structure,
2696 : * with each state having exactly one predecessor, except that the toplevel
2697 : * state has no inarcs as yet (breakconstraintloop will add its inarcs from
2698 : * spredecessor after we're done). Thus, we can examine sclone's inarcs back
2699 : * to the root, plus refarc if any, to identify the set of constraints already
2700 : * known valid at the current point. This allows us to avoid generating extra
2701 : * successor states.
2702 : */
2703 : static void
2704 1811 : clonesuccessorstates(struct nfa *nfa,
2705 : struct state *ssource,
2706 : struct state *sclone,
2707 : struct state *spredecessor,
2708 : struct arc *refarc,
2709 : char *curdonemap,
2710 : char *outerdonemap,
2711 : int nstates)
2712 : {
2713 : char *donemap;
2714 : struct arc *a;
2715 :
2716 : /* Since this is recursive, it could be driven to stack overflow */
2717 1811 : if (STACK_TOO_DEEP(nfa->v->re))
2718 : {
2719 0 : NERR(REG_ETOOBIG);
2720 0 : return;
2721 : }
2722 :
2723 : /* If this state hasn't already got a donemap, create one */
2724 1811 : donemap = curdonemap;
2725 1811 : if (donemap == NULL)
2726 : {
2727 910 : donemap = (char *) MALLOC(nstates * sizeof(char));
2728 910 : if (donemap == NULL)
2729 : {
2730 0 : NERR(REG_ESPACE);
2731 0 : return;
2732 : }
2733 :
2734 910 : if (outerdonemap != NULL)
2735 : {
2736 : /*
2737 : * Not at outermost recursion level, so copy the outer level's
2738 : * donemap; this ensures that we see states in process of being
2739 : * visited at outer levels, or already merged into predecessor
2740 : * states, as ones we shouldn't traverse back to.
2741 : */
2742 704 : memcpy(donemap, outerdonemap, nstates * sizeof(char));
2743 : }
2744 : else
2745 : {
2746 : /* At outermost level, only spredecessor is off-limits */
2747 206 : memset(donemap, 0, nstates * sizeof(char));
2748 : assert(spredecessor->no < nstates);
2749 206 : donemap[spredecessor->no] = 1;
2750 : }
2751 : }
2752 :
2753 : /* Mark ssource as visited in the donemap */
2754 : assert(ssource->no < nstates);
2755 : assert(donemap[ssource->no] == 0);
2756 1811 : donemap[ssource->no] = 1;
2757 :
2758 : /*
2759 : * We proceed by first cloning all of ssource's outarcs, creating new
2760 : * clone states as needed but not doing more with them than that. Then in
2761 : * a second pass, recurse to process the child clone states. This allows
2762 : * us to have only one child clone state per reachable source state, even
2763 : * when there are multiple outarcs leading to the same state. Also, when
2764 : * we do visit a child state, its set of inarcs is known exactly, which
2765 : * makes it safe to apply the constraint-is-already-checked optimization.
2766 : * Also, this ensures that we've merged all the states we can into the
2767 : * current clone before we recurse to any children, thus possibly saving
2768 : * them from making extra images of those states.
2769 : *
2770 : * While this function runs, child clone states of the current state are
2771 : * marked by setting their tmp fields to point to the original state they
2772 : * were cloned from. This makes it possible to detect multiple outarcs
2773 : * leading to the same state, and also makes it easy to distinguish clone
2774 : * states from original states (which will have tmp == NULL).
2775 : */
2776 14963 : for (a = ssource->outs; a != NULL && !NISERR(); a = a->outchain)
2777 : {
2778 13152 : struct state *sto = a->to;
2779 :
2780 : /*
2781 : * We do not consider cloning successor states that have no constraint
2782 : * outarcs; just link to them as-is. They cannot be part of a
2783 : * constraint loop so there is no need to make copies. In particular,
2784 : * this rule keeps us from trying to clone the post state, which would
2785 : * be a bad idea.
2786 : */
2787 13152 : if (isconstraintarc(a) && hasconstraintout(sto))
2788 5485 : {
2789 : struct state *prevclone;
2790 : int canmerge;
2791 : struct arc *a2;
2792 :
2793 : /*
2794 : * Back-link constraint arcs must not be followed. Nor is there a
2795 : * need to revisit states previously merged into this clone.
2796 : */
2797 : assert(sto->no < nstates);
2798 7893 : if (donemap[sto->no] != 0)
2799 2408 : continue;
2800 :
2801 : /*
2802 : * Check whether we already have a child clone state for this
2803 : * source state.
2804 : */
2805 5485 : prevclone = NULL;
2806 18762 : for (a2 = sclone->outs; a2 != NULL; a2 = a2->outchain)
2807 : {
2808 17157 : if (a2->to->tmp == sto)
2809 : {
2810 3880 : prevclone = a2->to;
2811 3880 : break;
2812 : }
2813 : }
2814 :
2815 : /*
2816 : * If this arc is labeled the same as refarc, or the same as any
2817 : * arc we must have traversed to get to sclone, then no additional
2818 : * constraints need to be met to get to sto, so we should just
2819 : * merge its outarcs into sclone.
2820 : */
2821 5485 : if (refarc && a->type == refarc->type && a->co == refarc->co)
2822 901 : canmerge = 1;
2823 : else
2824 : {
2825 : struct state *s;
2826 :
2827 4584 : canmerge = 0;
2828 22946 : for (s = sclone; s->ins; s = s->ins->from)
2829 : {
2830 18362 : if (s->nins == 1 &&
2831 18 : a->type == s->ins->type && a->co == s->ins->co)
2832 : {
2833 0 : canmerge = 1;
2834 0 : break;
2835 : }
2836 : }
2837 : }
2838 :
2839 5485 : if (canmerge)
2840 : {
2841 : /*
2842 : * We can merge into sclone. If we previously made a child
2843 : * clone state, drop it; there's no need to visit it. (This
2844 : * can happen if ssource has multiple pathways to sto, and we
2845 : * only just now found one that is provably a no-op.)
2846 : */
2847 901 : if (prevclone)
2848 0 : dropstate(nfa, prevclone); /* kills our outarc, too */
2849 :
2850 : /* Recurse to merge sto's outarcs into sclone */
2851 901 : clonesuccessorstates(nfa,
2852 : sto,
2853 : sclone,
2854 : spredecessor,
2855 : refarc,
2856 : donemap,
2857 : outerdonemap,
2858 : nstates);
2859 : /* sto should now be marked as previously visited */
2860 : assert(NISERR() || donemap[sto->no] == 1);
2861 : }
2862 4584 : else if (prevclone)
2863 : {
2864 : /*
2865 : * We already have a clone state for this successor, so just
2866 : * make another arc to it.
2867 : */
2868 3880 : cparc(nfa, a, sclone, prevclone);
2869 : }
2870 : else
2871 : {
2872 : /*
2873 : * We need to create a new successor clone state.
2874 : */
2875 : struct state *stoclone;
2876 :
2877 704 : stoclone = newstate(nfa);
2878 704 : if (stoclone == NULL)
2879 : {
2880 : assert(NISERR());
2881 0 : break;
2882 : }
2883 : /* Mark it as to what it's a clone of */
2884 704 : stoclone->tmp = sto;
2885 : /* ... and add the outarc leading to it */
2886 704 : cparc(nfa, a, sclone, stoclone);
2887 : }
2888 : }
2889 : else
2890 : {
2891 : /*
2892 : * Non-constraint outarcs just get copied to sclone, as do outarcs
2893 : * leading to states with no constraint outarc.
2894 : */
2895 5259 : cparc(nfa, a, sclone, sto);
2896 : }
2897 : }
2898 :
2899 : /*
2900 : * If we are at outer level for this clone state, recurse to all its child
2901 : * clone states, clearing their tmp fields as we go. (If we're not
2902 : * outermost for sclone, leave this to be done by the outer call level.)
2903 : * Note that if we have multiple outarcs leading to the same clone state,
2904 : * it will only be recursed-to once.
2905 : */
2906 1811 : if (curdonemap == NULL)
2907 : {
2908 8083 : for (a = sclone->outs; a != NULL && !NISERR(); a = a->outchain)
2909 : {
2910 7173 : struct state *stoclone = a->to;
2911 7173 : struct state *sto = stoclone->tmp;
2912 :
2913 7173 : if (sto != NULL)
2914 : {
2915 704 : stoclone->tmp = NULL;
2916 704 : clonesuccessorstates(nfa,
2917 : sto,
2918 : stoclone,
2919 : spredecessor,
2920 : refarc,
2921 : NULL,
2922 : donemap,
2923 : nstates);
2924 : }
2925 : }
2926 :
2927 : /* Don't forget to free sclone's donemap when done with it */
2928 910 : FREE(donemap);
2929 : }
2930 : }
2931 :
2932 : /*
2933 : * removecantmatch - remove CANTMATCH arcs, which are no longer useful
2934 : * once we are done with the parsing phase. (We need them only to
2935 : * preserve connectedness of NFA subgraphs during parsing.)
2936 : */
2937 : static void
2938 6 : removecantmatch(struct nfa *nfa)
2939 : {
2940 : struct state *s;
2941 :
2942 46 : for (s = nfa->states; s != NULL; s = s->next)
2943 : {
2944 : struct arc *a;
2945 : struct arc *nexta;
2946 :
2947 101 : for (a = s->outs; a != NULL; a = nexta)
2948 : {
2949 61 : nexta = a->outchain;
2950 61 : if (a->type == CANTMATCH)
2951 : {
2952 4 : freearc(nfa, a);
2953 4 : if (NISERR())
2954 0 : return;
2955 : }
2956 : }
2957 : }
2958 : }
2959 :
2960 : /*
2961 : * cleanup - clean up NFA after optimizations
2962 : */
2963 : static void
2964 20114 : cleanup(struct nfa *nfa)
2965 : {
2966 : struct state *s;
2967 : struct state *nexts;
2968 : int n;
2969 :
2970 20114 : if (NISERR())
2971 3 : return;
2972 :
2973 : /* clear out unreachable or dead-end states */
2974 : /* use pre to mark reachable, then post to mark can-reach-post */
2975 20111 : markreachable(nfa, nfa->pre, (struct state *) NULL, nfa->pre);
2976 20111 : markcanreach(nfa, nfa->post, nfa->pre, nfa->post);
2977 364617 : for (s = nfa->states; s != NULL && !NISERR(); s = nexts)
2978 : {
2979 344506 : nexts = s->next;
2980 344506 : if (s->tmp != nfa->post && !s->flag)
2981 3140 : dropstate(nfa, s);
2982 : }
2983 : assert(NISERR() || nfa->post->nins == 0 || nfa->post->tmp == nfa->post);
2984 20111 : cleartraverse(nfa, nfa->pre);
2985 : assert(NISERR() || nfa->post->nins == 0 || nfa->post->tmp == NULL);
2986 : /* the nins==0 (final unreachable) case will be caught later */
2987 :
2988 : /* renumber surviving states */
2989 20111 : n = 0;
2990 361477 : for (s = nfa->states; s != NULL; s = s->next)
2991 341366 : s->no = n++;
2992 20111 : nfa->nstates = n;
2993 : }
2994 :
2995 : /*
2996 : * markreachable - recursive marking of reachable states
2997 : */
2998 : static void
2999 903493 : markreachable(struct nfa *nfa,
3000 : struct state *s,
3001 : struct state *okay, /* consider only states with this mark */
3002 : struct state *mark) /* the value to mark with */
3003 : {
3004 : struct arc *a;
3005 :
3006 : /* Since this is recursive, it could be driven to stack overflow */
3007 903493 : if (STACK_TOO_DEEP(nfa->v->re))
3008 : {
3009 0 : NERR(REG_ETOOBIG);
3010 0 : return;
3011 : }
3012 :
3013 903493 : if (s->tmp != okay)
3014 562132 : return;
3015 341361 : s->tmp = mark;
3016 :
3017 1224743 : for (a = s->outs; a != NULL; a = a->outchain)
3018 883382 : markreachable(nfa, a->to, okay, mark);
3019 : }
3020 :
3021 : /*
3022 : * markcanreach - recursive marking of states which can reach here
3023 : */
3024 : static void
3025 903939 : markcanreach(struct nfa *nfa,
3026 : struct state *s,
3027 : struct state *okay, /* consider only states with this mark */
3028 : struct state *mark) /* the value to mark with */
3029 : {
3030 : struct arc *a;
3031 :
3032 : /* Since this is recursive, it could be driven to stack overflow */
3033 903939 : if (STACK_TOO_DEEP(nfa->v->re))
3034 : {
3035 0 : NERR(REG_ETOOBIG);
3036 0 : return;
3037 : }
3038 :
3039 903939 : if (s->tmp != okay)
3040 562675 : return;
3041 341264 : s->tmp = mark;
3042 :
3043 1225092 : for (a = s->ins; a != NULL; a = a->inchain)
3044 883828 : markcanreach(nfa, a->from, okay, mark);
3045 : }
3046 :
3047 : /*
3048 : * analyze - ascertain potentially-useful facts about an optimized NFA
3049 : */
3050 : static long /* re_info bits to be ORed in */
3051 10057 : analyze(struct nfa *nfa)
3052 : {
3053 : struct arc *a;
3054 : struct arc *aa;
3055 :
3056 10057 : if (NISERR())
3057 3 : return 0;
3058 :
3059 : /* Detect whether NFA can't match anything */
3060 10054 : if (nfa->pre->outs == NULL)
3061 49 : return REG_UIMPOSSIBLE;
3062 :
3063 : /* Detect whether NFA matches all strings (possibly with length bounds) */
3064 10005 : checkmatchall(nfa);
3065 :
3066 : /* Detect whether NFA can possibly match a zero-length string */
3067 30010 : for (a = nfa->pre->outs; a != NULL; a = a->outchain)
3068 773502 : for (aa = a->to->outs; aa != NULL; aa = aa->outchain)
3069 753497 : if (aa->to == nfa->post)
3070 1095 : return REG_UEMPTYMATCH;
3071 8910 : return 0;
3072 : }
3073 :
3074 : /*
3075 : * checkmatchall - does the NFA represent no more than a string length test?
3076 : *
3077 : * If so, set nfa->minmatchall and nfa->maxmatchall correctly (they are -1
3078 : * to begin with) and set the MATCHALL bit in nfa->flags.
3079 : *
3080 : * To succeed, we require all arcs to be PLAIN RAINBOW arcs, except for those
3081 : * for pseudocolors (i.e., BOS/BOL/EOS/EOL). We must be able to reach the
3082 : * post state via RAINBOW arcs, and if there are any loops in the graph, they
3083 : * must be loop-to-self arcs, ensuring that each loop iteration consumes
3084 : * exactly one character. (Longer loops are problematic because they create
3085 : * non-consecutive possible match lengths; we have no good way to represent
3086 : * that situation for lengths beyond the DUPINF limit.)
3087 : *
3088 : * Pseudocolor arcs complicate things a little. We know that they can only
3089 : * appear as pre-state outarcs (for BOS/BOL) or post-state inarcs (for
3090 : * EOS/EOL). There, they must exactly replicate the parallel RAINBOW arcs,
3091 : * e.g. if the pre state has one RAINBOW outarc to state 2, it must have BOS
3092 : * and BOL outarcs to state 2, and no others. Missing or extra pseudocolor
3093 : * arcs can occur, meaning that the NFA involves some constraint on the
3094 : * adjacent characters, which makes it not a matchall NFA.
3095 : */
3096 : static void
3097 10005 : checkmatchall(struct nfa *nfa)
3098 : {
3099 : bool **haspaths;
3100 : struct state *s;
3101 : int i;
3102 :
3103 : /*
3104 : * If there are too many states, don't bother trying to detect matchall.
3105 : * This limit serves to bound the time and memory we could consume below.
3106 : * Note that even if the graph is all-RAINBOW, if there are significantly
3107 : * more than DUPINF states then it's likely that there are paths of length
3108 : * more than DUPINF, which would force us to fail anyhow. In practice,
3109 : * plausible ways of writing a matchall regex with maximum finite path
3110 : * length K tend not to have very many more than K states.
3111 : */
3112 10005 : if (nfa->nstates > DUPINF * 2)
3113 6 : return;
3114 :
3115 : /*
3116 : * First, scan all the states to verify that only RAINBOW arcs appear,
3117 : * plus pseudocolor arcs adjacent to the pre and post states. This lets
3118 : * us quickly eliminate most cases that aren't matchall NFAs.
3119 : */
3120 37139 : for (s = nfa->states; s != NULL; s = s->next)
3121 : {
3122 : struct arc *a;
3123 :
3124 102423 : for (a = s->outs; a != NULL; a = a->outchain)
3125 : {
3126 75283 : if (a->type != PLAIN)
3127 45 : return; /* any LACONs make it non-matchall */
3128 75238 : if (a->co != RAINBOW)
3129 : {
3130 32629 : if (nfa->cm->cd[a->co].flags & PSEUDO)
3131 : {
3132 : /*
3133 : * Pseudocolor arc: verify it's in a valid place (this
3134 : * seems quite unlikely to fail, but let's be sure).
3135 : */
3136 23459 : if (s == nfa->pre &&
3137 16997 : (a->co == nfa->bos[0] || a->co == nfa->bos[1]))
3138 : /* okay BOS/BOL arc */ ;
3139 6462 : else if (a->to == nfa->post &&
3140 6462 : (a->co == nfa->eos[0] || a->co == nfa->eos[1]))
3141 : /* okay EOS/EOL arc */ ;
3142 : else
3143 0 : return; /* unexpected pseudocolor arc */
3144 : /* We'll check these arcs some more below. */
3145 : }
3146 : else
3147 9170 : return; /* any other color makes it non-matchall */
3148 : }
3149 : }
3150 : /* Also, assert that the tmp fields are available for use. */
3151 : assert(s->tmp == NULL);
3152 : }
3153 :
3154 : /*
3155 : * The next cheapest check we can make is to verify that the BOS/BOL
3156 : * outarcs of the pre state reach the same states as its RAINBOW outarcs.
3157 : * If they don't, the NFA expresses some constraints on the character
3158 : * before the matched string, making it non-matchall. Likewise, the
3159 : * EOS/EOL inarcs of the post state must match its RAINBOW inarcs.
3160 : */
3161 784 : if (!check_out_colors_match(nfa->pre, RAINBOW, nfa->bos[0]) ||
3162 781 : !check_out_colors_match(nfa->pre, RAINBOW, nfa->bos[1]) ||
3163 613 : !check_in_colors_match(nfa->post, RAINBOW, nfa->eos[0]) ||
3164 609 : !check_in_colors_match(nfa->post, RAINBOW, nfa->eos[1]))
3165 283 : return;
3166 :
3167 : /*
3168 : * Initialize an array of path-length arrays, in which
3169 : * checkmatchall_recurse will return per-state results. This lets us
3170 : * memo-ize the recursive search and avoid exponential time consumption.
3171 : */
3172 501 : haspaths = (bool **) MALLOC(nfa->nstates * sizeof(bool *));
3173 501 : if (haspaths == NULL)
3174 0 : return; /* fail quietly */
3175 501 : memset(haspaths, 0, nfa->nstates * sizeof(bool *));
3176 :
3177 : /*
3178 : * Recursively search the graph for all-RAINBOW paths to the "post" state,
3179 : * starting at the "pre" state, and computing the lengths of the paths.
3180 : * (Given the preceding checks, there should be at least one such path.
3181 : * However we could get back a false result anyway, in case there are
3182 : * multi-state loops, paths exceeding DUPINF+1 length, or non-algorithmic
3183 : * failures such as ENOMEM.)
3184 : */
3185 501 : if (checkmatchall_recurse(nfa, nfa->pre, haspaths))
3186 : {
3187 : /* The useful result is the path length array for the pre state */
3188 489 : bool *haspath = haspaths[nfa->pre->no];
3189 : int minmatch,
3190 : maxmatch,
3191 : morematch;
3192 :
3193 : assert(haspath != NULL);
3194 :
3195 : /*
3196 : * haspath[] now represents the set of possible path lengths; but we
3197 : * want to reduce that to a min and max value, because it doesn't seem
3198 : * worth complicating regexec.c to deal with nonconsecutive possible
3199 : * match lengths. Find min and max of first run of lengths, then
3200 : * verify there are no nonconsecutive lengths.
3201 : */
3202 2004 : for (minmatch = 0; minmatch <= DUPINF + 1; minmatch++)
3203 : {
3204 2004 : if (haspath[minmatch])
3205 489 : break;
3206 : }
3207 : assert(minmatch <= DUPINF + 1); /* else checkmatchall_recurse lied */
3208 31533 : for (maxmatch = minmatch; maxmatch < DUPINF + 1; maxmatch++)
3209 : {
3210 31414 : if (!haspath[maxmatch + 1])
3211 370 : break;
3212 : }
3213 92079 : for (morematch = maxmatch + 1; morematch <= DUPINF + 1; morematch++)
3214 : {
3215 91596 : if (haspath[morematch])
3216 : {
3217 6 : haspath = NULL; /* fail, there are nonconsecutive lengths */
3218 6 : break;
3219 : }
3220 : }
3221 :
3222 489 : if (haspath != NULL)
3223 : {
3224 : /*
3225 : * Success, so record the info. Here we have a fine point: the
3226 : * path length from the pre state includes the pre-to-initial
3227 : * transition, so it's one more than the actually matched string
3228 : * length. (We avoided counting the final-to-post transition
3229 : * within checkmatchall_recurse, but not this one.) This is why
3230 : * checkmatchall_recurse allows one more level of path length than
3231 : * might seem necessary. This decrement also takes care of
3232 : * converting checkmatchall_recurse's definition of "infinity" as
3233 : * "DUPINF+1" to our normal representation as "DUPINF".
3234 : */
3235 : assert(minmatch > 0); /* else pre and post states were adjacent */
3236 483 : nfa->minmatchall = minmatch - 1;
3237 483 : nfa->maxmatchall = maxmatch - 1;
3238 483 : nfa->flags |= MATCHALL;
3239 : }
3240 : }
3241 :
3242 : /* Clean up */
3243 5233 : for (i = 0; i < nfa->nstates; i++)
3244 : {
3245 4732 : if (haspaths[i] != NULL)
3246 4231 : FREE(haspaths[i]);
3247 : }
3248 501 : FREE(haspaths);
3249 : }
3250 :
3251 : /*
3252 : * checkmatchall_recurse - recursive search for checkmatchall
3253 : *
3254 : * s is the state to be examined in this recursion level.
3255 : * haspaths[] is an array of per-state exit path length arrays.
3256 : *
3257 : * We return true if the search was performed successfully, false if
3258 : * we had to fail because of multi-state loops or other internal reasons.
3259 : * (Because "dead" states that can't reach the post state have been
3260 : * eliminated, and we already verified that only RAINBOW and matching
3261 : * pseudocolor arcs exist, every state should have RAINBOW path(s) to
3262 : * the post state. Hence we take a false result from recursive calls
3263 : * as meaning that we'd better fail altogether, not just that that
3264 : * particular state can't reach the post state.)
3265 : *
3266 : * On success, we store a malloc'd result array in haspaths[s->no],
3267 : * showing the possible path lengths from s to the post state.
3268 : * Each state's haspath[] array is of length DUPINF+2. The entries from
3269 : * k = 0 to DUPINF are true if there is an all-RAINBOW path of length k
3270 : * from this state to the string end. haspath[DUPINF+1] is true if all
3271 : * path lengths >= DUPINF+1 are possible. (Situations that cannot be
3272 : * represented under these rules cause failure.)
3273 : *
3274 : * checkmatchall is responsible for eventually freeing the haspath[] arrays.
3275 : */
3276 : static bool
3277 4231 : checkmatchall_recurse(struct nfa *nfa, struct state *s, bool **haspaths)
3278 : {
3279 4231 : bool result = false;
3280 4231 : bool foundloop = false;
3281 : bool *haspath;
3282 : struct arc *a;
3283 :
3284 : /*
3285 : * Since this is recursive, it could be driven to stack overflow. But we
3286 : * need not treat that as a hard failure; just deem the NFA non-matchall.
3287 : */
3288 4231 : if (STACK_TOO_DEEP(nfa->v->re))
3289 0 : return false;
3290 :
3291 : /* In case the search takes a long time, check for cancel */
3292 4231 : INTERRUPT(nfa->v->re);
3293 :
3294 : /* Create a haspath array for this state */
3295 4231 : haspath = (bool *) MALLOC((DUPINF + 2) * sizeof(bool));
3296 4231 : if (haspath == NULL)
3297 0 : return false; /* again, treat as non-matchall */
3298 4231 : memset(haspath, 0, (DUPINF + 2) * sizeof(bool));
3299 :
3300 : /* Mark this state as being visited */
3301 : assert(s->tmp == NULL);
3302 4231 : s->tmp = s;
3303 :
3304 41511 : for (a = s->outs; a != NULL; a = a->outchain)
3305 : {
3306 37328 : if (a->co != RAINBOW)
3307 3238 : continue; /* ignore pseudocolor arcs */
3308 34090 : if (a->to == nfa->post)
3309 : {
3310 : /* We found an all-RAINBOW path to the post state */
3311 495 : result = true;
3312 :
3313 : /*
3314 : * Mark this state as being zero steps away from the string end
3315 : * (the transition to the post state isn't counted).
3316 : */
3317 495 : haspath[0] = true;
3318 : }
3319 33595 : else if (a->to == s)
3320 : {
3321 : /* We found a cycle of length 1, which we'll deal with below. */
3322 122 : foundloop = true;
3323 : }
3324 33473 : else if (a->to->tmp != NULL)
3325 : {
3326 : /* It's busy, so we found a cycle of length > 1, so fail. */
3327 6 : result = false;
3328 6 : break;
3329 : }
3330 : else
3331 : {
3332 : /* Consider paths forward through this to-state. */
3333 : bool *nexthaspath;
3334 : int i;
3335 :
3336 : /* If to-state was not already visited, recurse */
3337 33467 : if (haspaths[a->to->no] == NULL)
3338 : {
3339 3730 : result = checkmatchall_recurse(nfa, a->to, haspaths);
3340 : /* Fail if any recursive path fails */
3341 3730 : if (!result)
3342 36 : break;
3343 : }
3344 : else
3345 : {
3346 : /* The previous visit must have found path(s) to the end */
3347 29737 : result = true;
3348 : }
3349 : assert(a->to->tmp == NULL);
3350 33431 : nexthaspath = haspaths[a->to->no];
3351 : assert(nexthaspath != NULL);
3352 :
3353 : /*
3354 : * Now, for every path of length i from a->to to the string end,
3355 : * there is a path of length i + 1 from s to the string end.
3356 : */
3357 33431 : if (nexthaspath[DUPINF] != nexthaspath[DUPINF + 1])
3358 : {
3359 : /*
3360 : * a->to has a path of length exactly DUPINF, but not longer;
3361 : * or it has paths of all lengths > DUPINF but not one of
3362 : * exactly that length. In either case, we cannot represent
3363 : * the possible path lengths from s correctly, so fail.
3364 : */
3365 6 : result = false;
3366 6 : break;
3367 : }
3368 : /* Merge knowledge of these path lengths into what we have */
3369 8590225 : for (i = 0; i < DUPINF; i++)
3370 8556800 : haspath[i + 1] |= nexthaspath[i];
3371 : /* Infinity + 1 is still infinity */
3372 33425 : haspath[DUPINF + 1] |= nexthaspath[DUPINF + 1];
3373 : }
3374 : }
3375 :
3376 4231 : if (result && foundloop)
3377 : {
3378 : /*
3379 : * If there is a length-1 loop at this state, then find the shortest
3380 : * known path length to the end. The loop means that every larger
3381 : * path length is possible, too. (It doesn't matter whether any of
3382 : * the longer lengths were already known possible.)
3383 : */
3384 : int i;
3385 :
3386 156 : for (i = 0; i <= DUPINF; i++)
3387 : {
3388 156 : if (haspath[i])
3389 122 : break;
3390 : }
3391 31442 : for (i++; i <= DUPINF + 1; i++)
3392 31320 : haspath[i] = true;
3393 : }
3394 :
3395 : /* Report out the completed path length map */
3396 : assert(s->no < nfa->nstates);
3397 : assert(haspaths[s->no] == NULL);
3398 4231 : haspaths[s->no] = haspath;
3399 :
3400 : /* Mark state no longer busy */
3401 4231 : s->tmp = NULL;
3402 :
3403 4231 : return result;
3404 : }
3405 :
3406 : /*
3407 : * check_out_colors_match - subroutine for checkmatchall
3408 : *
3409 : * Check whether the set of states reachable from s by arcs of color co1
3410 : * is equivalent to the set reachable by arcs of color co2.
3411 : * checkmatchall already verified that all of the NFA's arcs are PLAIN,
3412 : * so we need not examine arc types here.
3413 : */
3414 : static bool
3415 1565 : check_out_colors_match(struct state *s, color co1, color co2)
3416 : {
3417 1565 : bool result = true;
3418 : struct arc *a;
3419 :
3420 : /*
3421 : * To do this in linear time, we assume that the NFA contains no duplicate
3422 : * arcs. Run through the out-arcs, marking states reachable by arcs of
3423 : * color co1. Run through again, un-marking states reachable by arcs of
3424 : * color co2; if we see a not-marked state, we know this co2 arc is
3425 : * unmatched. Then run through again, checking for still-marked states,
3426 : * and in any case leaving all the tmp fields reset to NULL.
3427 : */
3428 9541 : for (a = s->outs; a != NULL; a = a->outchain)
3429 : {
3430 7976 : if (a->co == co1)
3431 : {
3432 : assert(a->to->tmp == NULL);
3433 2536 : a->to->tmp = a->to;
3434 : }
3435 : }
3436 9541 : for (a = s->outs; a != NULL; a = a->outchain)
3437 : {
3438 7976 : if (a->co == co2)
3439 : {
3440 2720 : if (a->to->tmp != NULL)
3441 2534 : a->to->tmp = NULL;
3442 : else
3443 186 : result = false; /* unmatched co2 arc */
3444 : }
3445 : }
3446 9541 : for (a = s->outs; a != NULL; a = a->outchain)
3447 : {
3448 7976 : if (a->co == co1)
3449 : {
3450 2536 : if (a->to->tmp != NULL)
3451 : {
3452 2 : result = false; /* unmatched co1 arc */
3453 2 : a->to->tmp = NULL;
3454 : }
3455 : }
3456 : }
3457 1565 : return result;
3458 : }
3459 :
3460 : /*
3461 : * check_in_colors_match - subroutine for checkmatchall
3462 : *
3463 : * Check whether the set of states that can reach s by arcs of color co1
3464 : * is equivalent to the set that can reach s by arcs of color co2.
3465 : * checkmatchall already verified that all of the NFA's arcs are PLAIN,
3466 : * so we need not examine arc types here.
3467 : */
3468 : static bool
3469 1222 : check_in_colors_match(struct state *s, color co1, color co2)
3470 : {
3471 1222 : bool result = true;
3472 : struct arc *a;
3473 :
3474 : /*
3475 : * Identical algorithm to check_out_colors_match, except examine the
3476 : * from-states of s' inarcs.
3477 : */
3478 4510 : for (a = s->ins; a != NULL; a = a->inchain)
3479 : {
3480 3288 : if (a->co == co1)
3481 : {
3482 : assert(a->from->tmp == NULL);
3483 1018 : a->from->tmp = a->from;
3484 : }
3485 : }
3486 4510 : for (a = s->ins; a != NULL; a = a->inchain)
3487 : {
3488 3288 : if (a->co == co2)
3489 : {
3490 1135 : if (a->from->tmp != NULL)
3491 1016 : a->from->tmp = NULL;
3492 : else
3493 119 : result = false; /* unmatched co2 arc */
3494 : }
3495 : }
3496 4510 : for (a = s->ins; a != NULL; a = a->inchain)
3497 : {
3498 3288 : if (a->co == co1)
3499 : {
3500 1018 : if (a->from->tmp != NULL)
3501 : {
3502 2 : result = false; /* unmatched co1 arc */
3503 2 : a->from->tmp = NULL;
3504 : }
3505 : }
3506 : }
3507 1222 : return result;
3508 : }
3509 :
3510 : /*
3511 : * compact - construct the compact representation of an NFA
3512 : */
3513 : static void
3514 10054 : compact(struct nfa *nfa,
3515 : struct cnfa *cnfa)
3516 : {
3517 : struct state *s;
3518 : struct arc *a;
3519 : size_t nstates;
3520 : size_t narcs;
3521 : struct carc *ca;
3522 : struct carc *first;
3523 :
3524 : assert(!NISERR());
3525 :
3526 10054 : nstates = 0;
3527 10054 : narcs = 0;
3528 132704 : for (s = nfa->states; s != NULL; s = s->next)
3529 : {
3530 122650 : nstates++;
3531 122650 : narcs += s->nouts + 1; /* need one extra for endmarker */
3532 : }
3533 :
3534 10054 : cnfa->stflags = (char *) MALLOC(nstates * sizeof(char));
3535 10054 : cnfa->states = (struct carc **) MALLOC(nstates * sizeof(struct carc *));
3536 10054 : cnfa->arcs = (struct carc *) MALLOC(narcs * sizeof(struct carc));
3537 10054 : if (cnfa->stflags == NULL || cnfa->states == NULL || cnfa->arcs == NULL)
3538 : {
3539 0 : if (cnfa->stflags != NULL)
3540 0 : FREE(cnfa->stflags);
3541 0 : if (cnfa->states != NULL)
3542 0 : FREE(cnfa->states);
3543 0 : if (cnfa->arcs != NULL)
3544 0 : FREE(cnfa->arcs);
3545 0 : NERR(REG_ESPACE);
3546 0 : return;
3547 : }
3548 10054 : cnfa->nstates = nstates;
3549 10054 : cnfa->pre = nfa->pre->no;
3550 10054 : cnfa->post = nfa->post->no;
3551 10054 : cnfa->bos[0] = nfa->bos[0];
3552 10054 : cnfa->bos[1] = nfa->bos[1];
3553 10054 : cnfa->eos[0] = nfa->eos[0];
3554 10054 : cnfa->eos[1] = nfa->eos[1];
3555 10054 : cnfa->ncolors = maxcolor(nfa->cm) + 1;
3556 10054 : cnfa->flags = nfa->flags;
3557 10054 : cnfa->minmatchall = nfa->minmatchall;
3558 10054 : cnfa->maxmatchall = nfa->maxmatchall;
3559 :
3560 10054 : ca = cnfa->arcs;
3561 132704 : for (s = nfa->states; s != NULL; s = s->next)
3562 : {
3563 : assert((size_t) s->no < nstates);
3564 122650 : cnfa->stflags[s->no] = 0;
3565 122650 : cnfa->states[s->no] = ca;
3566 122650 : first = ca;
3567 899462 : for (a = s->outs; a != NULL; a = a->outchain)
3568 776812 : switch (a->type)
3569 : {
3570 776713 : case PLAIN:
3571 776713 : ca->co = a->co;
3572 776713 : ca->to = a->to->no;
3573 776713 : ca++;
3574 776713 : break;
3575 99 : case LACON:
3576 : assert(s->no != cnfa->pre);
3577 : assert(a->co >= 0);
3578 99 : ca->co = (color) (cnfa->ncolors + a->co);
3579 99 : ca->to = a->to->no;
3580 99 : ca++;
3581 99 : cnfa->flags |= HASLACONS;
3582 99 : break;
3583 0 : default:
3584 0 : NERR(REG_ASSERT);
3585 0 : return;
3586 : }
3587 122650 : carcsort(first, ca - first);
3588 122650 : ca->co = COLORLESS;
3589 122650 : ca->to = 0;
3590 122650 : ca++;
3591 : }
3592 : assert(ca == &cnfa->arcs[narcs]);
3593 : assert(cnfa->nstates != 0);
3594 :
3595 : /* mark no-progress states */
3596 41565 : for (a = nfa->pre->outs; a != NULL; a = a->outchain)
3597 31511 : cnfa->stflags[a->to->no] = CNFA_NOPROGRESS;
3598 10054 : cnfa->stflags[nfa->pre->no] = CNFA_NOPROGRESS;
3599 : }
3600 :
3601 : /*
3602 : * carcsort - sort compacted-NFA arcs by color
3603 : */
3604 : static void
3605 122650 : carcsort(struct carc *first, size_t n)
3606 : {
3607 122650 : if (n > 1)
3608 23286 : qsort(first, n, sizeof(struct carc), carc_cmp);
3609 122650 : }
3610 :
3611 : static int
3612 7727270 : carc_cmp(const void *a, const void *b)
3613 : {
3614 7727270 : const struct carc *aa = (const struct carc *) a;
3615 7727270 : const struct carc *bb = (const struct carc *) b;
3616 :
3617 7727270 : if (aa->co < bb->co)
3618 69780 : return -1;
3619 7657490 : if (aa->co > bb->co)
3620 102176 : return +1;
3621 7555314 : if (aa->to < bb->to)
3622 5181713 : return -1;
3623 2373601 : if (aa->to > bb->to)
3624 2373601 : return +1;
3625 : /* This is unreached, since there should be no duplicate arcs now: */
3626 0 : return 0;
3627 : }
3628 :
3629 : /*
3630 : * freecnfa - free a compacted NFA
3631 : */
3632 : static void
3633 2148 : freecnfa(struct cnfa *cnfa)
3634 : {
3635 : assert(!NULLCNFA(*cnfa)); /* not empty already */
3636 2148 : FREE(cnfa->stflags);
3637 2148 : FREE(cnfa->states);
3638 2148 : FREE(cnfa->arcs);
3639 2148 : ZAPCNFA(*cnfa);
3640 2148 : }
3641 :
3642 : /*
3643 : * dumpnfa - dump an NFA in human-readable form
3644 : */
3645 : static void
3646 0 : dumpnfa(struct nfa *nfa,
3647 : FILE *f)
3648 : {
3649 : #ifdef REG_DEBUG
3650 : struct state *s;
3651 : int nstates = 0;
3652 : int narcs = 0;
3653 :
3654 : fprintf(f, "pre %d, post %d", nfa->pre->no, nfa->post->no);
3655 : if (nfa->bos[0] != COLORLESS)
3656 : fprintf(f, ", bos [%ld]", (long) nfa->bos[0]);
3657 : if (nfa->bos[1] != COLORLESS)
3658 : fprintf(f, ", bol [%ld]", (long) nfa->bos[1]);
3659 : if (nfa->eos[0] != COLORLESS)
3660 : fprintf(f, ", eos [%ld]", (long) nfa->eos[0]);
3661 : if (nfa->eos[1] != COLORLESS)
3662 : fprintf(f, ", eol [%ld]", (long) nfa->eos[1]);
3663 : if (nfa->flags & HASLACONS)
3664 : fprintf(f, ", haslacons");
3665 : if (nfa->flags & HASCANTMATCH)
3666 : fprintf(f, ", hascantmatch");
3667 : if (nfa->flags & MATCHALL)
3668 : {
3669 : fprintf(f, ", minmatchall %d", nfa->minmatchall);
3670 : if (nfa->maxmatchall == DUPINF)
3671 : fprintf(f, ", maxmatchall inf");
3672 : else
3673 : fprintf(f, ", maxmatchall %d", nfa->maxmatchall);
3674 : }
3675 : fprintf(f, "\n");
3676 : for (s = nfa->states; s != NULL; s = s->next)
3677 : {
3678 : dumpstate(s, f);
3679 : nstates++;
3680 : narcs += s->nouts;
3681 : }
3682 : fprintf(f, "total of %d states, %d arcs\n", nstates, narcs);
3683 : if (nfa->parent == NULL)
3684 : dumpcolors(nfa->cm, f);
3685 : fflush(f);
3686 : #endif
3687 0 : }
3688 :
3689 : #ifdef REG_DEBUG /* subordinates of dumpnfa */
3690 :
3691 : /*
3692 : * dumpstate - dump an NFA state in human-readable form
3693 : */
3694 : static void
3695 : dumpstate(struct state *s,
3696 : FILE *f)
3697 : {
3698 : struct arc *a;
3699 :
3700 : fprintf(f, "%d%s%c", s->no, (s->tmp != NULL) ? "T" : "",
3701 : (s->flag) ? s->flag : '.');
3702 : if (s->prev != NULL && s->prev->next != s)
3703 : fprintf(f, "\tstate chain bad\n");
3704 : if (s->nouts == 0)
3705 : fprintf(f, "\tno out arcs\n");
3706 : else
3707 : dumparcs(s, f);
3708 : for (a = s->ins; a != NULL; a = a->inchain)
3709 : {
3710 : if (a->to != s)
3711 : fprintf(f, "\tlink from %d to %d on %d's in-chain\n",
3712 : a->from->no, a->to->no, s->no);
3713 : }
3714 : fflush(f);
3715 : }
3716 :
3717 : /*
3718 : * dumparcs - dump out-arcs in human-readable form
3719 : */
3720 : static void
3721 : dumparcs(struct state *s,
3722 : FILE *f)
3723 : {
3724 : int pos;
3725 : struct arc *a;
3726 :
3727 : /* printing oldest arcs first is usually clearer */
3728 : a = s->outs;
3729 : assert(a != NULL);
3730 : while (a->outchain != NULL)
3731 : a = a->outchain;
3732 : pos = 1;
3733 : do
3734 : {
3735 : dumparc(a, s, f);
3736 : if (pos == 5)
3737 : {
3738 : fprintf(f, "\n");
3739 : pos = 1;
3740 : }
3741 : else
3742 : pos++;
3743 : a = a->outchainRev;
3744 : } while (a != NULL);
3745 : if (pos != 1)
3746 : fprintf(f, "\n");
3747 : }
3748 :
3749 : /*
3750 : * dumparc - dump one outarc in readable form, including prefixing tab
3751 : */
3752 : static void
3753 : dumparc(struct arc *a,
3754 : struct state *s,
3755 : FILE *f)
3756 : {
3757 : struct arc *aa;
3758 :
3759 : fprintf(f, "\t");
3760 : switch (a->type)
3761 : {
3762 : case PLAIN:
3763 : if (a->co == RAINBOW)
3764 : fprintf(f, "[*]");
3765 : else
3766 : fprintf(f, "[%ld]", (long) a->co);
3767 : break;
3768 : case AHEAD:
3769 : if (a->co == RAINBOW)
3770 : fprintf(f, ">*>");
3771 : else
3772 : fprintf(f, ">%ld>", (long) a->co);
3773 : break;
3774 : case BEHIND:
3775 : if (a->co == RAINBOW)
3776 : fprintf(f, "<*<");
3777 : else
3778 : fprintf(f, "<%ld<", (long) a->co);
3779 : break;
3780 : case LACON:
3781 : fprintf(f, ":%ld:", (long) a->co);
3782 : break;
3783 : case '^':
3784 : case '$':
3785 : fprintf(f, "%c%d", a->type, (int) a->co);
3786 : break;
3787 : case EMPTY:
3788 : break;
3789 : case CANTMATCH:
3790 : fprintf(f, "X");
3791 : break;
3792 : default:
3793 : fprintf(f, "0x%x/0%lo", a->type, (long) a->co);
3794 : break;
3795 : }
3796 : if (a->from != s)
3797 : fprintf(f, "?%d?", a->from->no);
3798 : for (aa = a->from->outs; aa != NULL; aa = aa->outchain)
3799 : if (aa == a)
3800 : break; /* NOTE BREAK OUT */
3801 : if (aa == NULL)
3802 : fprintf(f, "?!?"); /* missing from out-chain */
3803 : fprintf(f, "->");
3804 : if (a->to == NULL)
3805 : {
3806 : fprintf(f, "NULL");
3807 : return;
3808 : }
3809 : fprintf(f, "%d", a->to->no);
3810 : for (aa = a->to->ins; aa != NULL; aa = aa->inchain)
3811 : if (aa == a)
3812 : break; /* NOTE BREAK OUT */
3813 : if (aa == NULL)
3814 : fprintf(f, "?!?"); /* missing from in-chain */
3815 : }
3816 : #endif /* REG_DEBUG */
3817 :
3818 : /*
3819 : * dumpcnfa - dump a compacted NFA in human-readable form
3820 : */
3821 : #ifdef REG_DEBUG
3822 : static void
3823 : dumpcnfa(struct cnfa *cnfa,
3824 : FILE *f)
3825 : {
3826 : int st;
3827 :
3828 : fprintf(f, "pre %d, post %d", cnfa->pre, cnfa->post);
3829 : if (cnfa->bos[0] != COLORLESS)
3830 : fprintf(f, ", bos [%ld]", (long) cnfa->bos[0]);
3831 : if (cnfa->bos[1] != COLORLESS)
3832 : fprintf(f, ", bol [%ld]", (long) cnfa->bos[1]);
3833 : if (cnfa->eos[0] != COLORLESS)
3834 : fprintf(f, ", eos [%ld]", (long) cnfa->eos[0]);
3835 : if (cnfa->eos[1] != COLORLESS)
3836 : fprintf(f, ", eol [%ld]", (long) cnfa->eos[1]);
3837 : if (cnfa->flags & HASLACONS)
3838 : fprintf(f, ", haslacons");
3839 : if (cnfa->flags & MATCHALL)
3840 : {
3841 : fprintf(f, ", minmatchall %d", cnfa->minmatchall);
3842 : if (cnfa->maxmatchall == DUPINF)
3843 : fprintf(f, ", maxmatchall inf");
3844 : else
3845 : fprintf(f, ", maxmatchall %d", cnfa->maxmatchall);
3846 : }
3847 : fprintf(f, "\n");
3848 : for (st = 0; st < cnfa->nstates; st++)
3849 : dumpcstate(st, cnfa, f);
3850 : fflush(f);
3851 : }
3852 : #endif
3853 :
3854 : #ifdef REG_DEBUG /* subordinates of dumpcnfa */
3855 :
3856 : /*
3857 : * dumpcstate - dump a compacted-NFA state in human-readable form
3858 : */
3859 : static void
3860 : dumpcstate(int st,
3861 : struct cnfa *cnfa,
3862 : FILE *f)
3863 : {
3864 : struct carc *ca;
3865 : int pos;
3866 :
3867 : fprintf(f, "%d%s", st, (cnfa->stflags[st] & CNFA_NOPROGRESS) ? ":" : ".");
3868 : pos = 1;
3869 : for (ca = cnfa->states[st]; ca->co != COLORLESS; ca++)
3870 : {
3871 : if (ca->co == RAINBOW)
3872 : fprintf(f, "\t[*]->%d", ca->to);
3873 : else if (ca->co < cnfa->ncolors)
3874 : fprintf(f, "\t[%ld]->%d", (long) ca->co, ca->to);
3875 : else
3876 : fprintf(f, "\t:%ld:->%d", (long) (ca->co - cnfa->ncolors), ca->to);
3877 : if (pos == 5)
3878 : {
3879 : fprintf(f, "\n");
3880 : pos = 1;
3881 : }
3882 : else
3883 : pos++;
3884 : }
3885 : if (ca == cnfa->states[st] || pos != 1)
3886 : fprintf(f, "\n");
3887 : fflush(f);
3888 : }
3889 :
3890 : #endif /* REG_DEBUG */
|
