Commit | Line | Data |
a0d0e21e |
1 | /* regexec.c |
2 | */ |
3 | |
4 | /* |
5 | * "One Ring to rule them all, One Ring to find them..." |
6 | */ |
7 | |
a687059c |
8 | /* NOTE: this is derived from Henry Spencer's regexp code, and should not |
9 | * confused with the original package (see point 3 below). Thanks, Henry! |
10 | */ |
11 | |
12 | /* Additional note: this code is very heavily munged from Henry's version |
13 | * in places. In some spots I've traded clarity for efficiency, so don't |
14 | * blame Henry for some of the lack of readability. |
15 | */ |
16 | |
f0fcb552 |
17 | /*SUPPRESS 112*/ |
a687059c |
18 | /* |
19 | * regcomp and regexec -- regsub and regerror are not used in perl |
20 | * |
21 | * Copyright (c) 1986 by University of Toronto. |
22 | * Written by Henry Spencer. Not derived from licensed software. |
23 | * |
24 | * Permission is granted to anyone to use this software for any |
25 | * purpose on any computer system, and to redistribute it freely, |
26 | * subject to the following restrictions: |
27 | * |
28 | * 1. The author is not responsible for the consequences of use of |
29 | * this software, no matter how awful, even if they arise |
30 | * from defects in it. |
31 | * |
32 | * 2. The origin of this software must not be misrepresented, either |
33 | * by explicit claim or by omission. |
34 | * |
35 | * 3. Altered versions must be plainly marked as such, and must not |
36 | * be misrepresented as being the original software. |
37 | * |
38 | **** Alterations to Henry's code are... |
39 | **** |
a0d0e21e |
40 | **** Copyright (c) 1991-1994, Larry Wall |
a687059c |
41 | **** |
9ef589d8 |
42 | **** You may distribute under the terms of either the GNU General Public |
43 | **** License or the Artistic License, as specified in the README file. |
a687059c |
44 | * |
45 | * Beware that some of this code is subtly aware of the way operator |
46 | * precedence is structured in regular expressions. Serious changes in |
47 | * regular-expression syntax might require a total rethink. |
48 | */ |
49 | #include "EXTERN.h" |
50 | #include "perl.h" |
51 | #include "regcomp.h" |
52 | |
53 | #ifndef STATIC |
54 | #define STATIC static |
55 | #endif |
56 | |
57 | #ifdef DEBUGGING |
a0d0e21e |
58 | static I32 regnarrate = 0; |
59 | static char* regprogram = 0; |
a687059c |
60 | #endif |
61 | |
a0d0e21e |
62 | /* Current curly descriptor */ |
63 | typedef struct curcur CURCUR; |
64 | struct curcur { |
65 | int parenfloor; /* how far back to strip paren data */ |
66 | int cur; /* how many instances of scan we've matched */ |
67 | int min; /* the minimal number of scans to match */ |
68 | int max; /* the maximal number of scans to match */ |
69 | int minmod; /* whether to work our way up or down */ |
70 | char * scan; /* the thing to match */ |
71 | char * next; /* what has to match after it */ |
72 | char * lastloc; /* where we started matching this scan */ |
73 | CURCUR * oldcc; /* current curly before we started this one */ |
74 | }; |
75 | |
76 | static CURCUR* regcc; |
77 | |
78 | typedef I32 CHECKPOINT; |
79 | |
80 | CHECKPOINT regcppush _((I32 parenfloor)); |
81 | char * regcppop _((void)); |
82 | |
83 | CHECKPOINT |
84 | regcppush(parenfloor) |
85 | I32 parenfloor; |
86 | { |
87 | int retval = savestack_ix; |
88 | int i = (regsize - parenfloor) * 3; |
89 | int p; |
90 | |
91 | SSCHECK(i + 5); |
92 | for (p = regsize; p > parenfloor; p--) { |
93 | SSPUSHPTR(regendp[p]); |
94 | SSPUSHPTR(regstartp[p]); |
95 | SSPUSHINT(p); |
96 | } |
97 | SSPUSHINT(regsize); |
98 | SSPUSHINT(*reglastparen); |
99 | SSPUSHPTR(reginput); |
100 | SSPUSHINT(i + 3); |
101 | SSPUSHINT(SAVEt_REGCONTEXT); |
102 | return retval; |
103 | } |
104 | |
105 | char* |
106 | regcppop() |
107 | { |
108 | I32 i = SSPOPINT; |
109 | U32 paren = 0; |
110 | char *input; |
111 | char *tmps; |
112 | assert(i == SAVEt_REGCONTEXT); |
113 | i = SSPOPINT; |
114 | input = (char *) SSPOPPTR; |
115 | *reglastparen = SSPOPINT; |
116 | regsize = SSPOPINT; |
117 | for (i -= 3; i > 0; i -= 3) { |
118 | paren = (U32)SSPOPINT; |
119 | regstartp[paren] = (char *) SSPOPPTR; |
120 | tmps = (char*)SSPOPPTR; |
121 | if (paren <= *reglastparen) |
122 | regendp[paren] = tmps; |
123 | } |
124 | for (paren = *reglastparen + 1; paren <= regnpar; paren++) { |
125 | if (paren > regsize) |
126 | regstartp[paren] = Nullch; |
127 | regendp[paren] = Nullch; |
128 | } |
129 | return input; |
130 | } |
131 | |
132 | #define regcpblow(cp) leave_scope(cp) |
133 | |
a687059c |
134 | /* |
135 | * regexec and friends |
136 | */ |
137 | |
138 | /* |
a687059c |
139 | * Forwards. |
140 | */ |
a0d0e21e |
141 | |
142 | static I32 regmatch _((char *prog)); |
143 | static I32 regrepeat _((char *p, I32 max)); |
144 | static I32 regtry _((regexp *prog, char *startpos)); |
a687059c |
145 | |
146 | /* |
147 | - regexec - match a regexp against a string |
148 | */ |
79072805 |
149 | I32 |
a687059c |
150 | regexec(prog, stringarg, strend, strbeg, minend, screamer, safebase) |
151 | register regexp *prog; |
152 | char *stringarg; |
153 | register char *strend; /* pointer to null at end of string */ |
154 | char *strbeg; /* real beginning of string */ |
79072805 |
155 | I32 minend; /* end of match must be at least minend after stringarg */ |
156 | SV *screamer; |
157 | I32 safebase; /* no need to remember string in subbase */ |
a687059c |
158 | { |
a0d0e21e |
159 | register char *s; |
160 | register I32 i; |
161 | register char *c; |
162 | register char *startpos = stringarg; |
163 | register I32 tmp; |
164 | I32 minlen = 0; /* must match at least this many chars */ |
165 | I32 dontbother = 0; /* how many characters not to try at end */ |
166 | CURCUR cc; |
a687059c |
167 | |
a0d0e21e |
168 | cc.cur = 0; |
169 | regcc = &cc; |
170 | |
171 | #ifdef DEBUGGING |
172 | regnarrate = debug & 512; |
173 | regprogram = prog->program; |
174 | #endif |
175 | |
176 | /* Be paranoid... */ |
177 | if (prog == NULL || startpos == NULL) { |
178 | croak("NULL regexp parameter"); |
179 | return 0; |
180 | } |
181 | |
182 | if (startpos == strbeg) /* is ^ valid at stringarg? */ |
183 | regprev = '\n'; |
184 | else { |
185 | regprev = stringarg[-1]; |
186 | if (!multiline && regprev == '\n') |
187 | regprev = '\0'; /* force ^ to NOT match */ |
188 | } |
189 | regprecomp = prog->precomp; |
190 | regnpar = prog->nparens; |
191 | /* Check validity of program. */ |
192 | if (UCHARAT(prog->program) != MAGIC) { |
193 | FAIL("corrupted regexp program"); |
194 | } |
195 | |
196 | if (prog->do_folding) { |
197 | i = strend - startpos; |
198 | New(1101,c,i+1,char); |
199 | Copy(startpos, c, i+1, char); |
200 | startpos = c; |
201 | strend = startpos + i; |
202 | for (s = startpos; s < strend; s++) |
203 | if (isUPPER(*s)) |
204 | *s = toLOWER(*s); |
205 | } |
206 | |
207 | /* If there is a "must appear" string, look for it. */ |
208 | s = startpos; |
209 | if (prog->regmust != Nullsv && |
210 | (!(prog->reganch & ROPT_ANCH) |
211 | || (multiline && prog->regback >= 0)) ) |
212 | { |
213 | if (stringarg == strbeg && screamer) { |
214 | if (screamfirst[BmRARE(prog->regmust)] >= 0) |
215 | s = screaminstr(screamer,prog->regmust); |
216 | else |
217 | s = Nullch; |
0a12ae7d |
218 | } |
a0d0e21e |
219 | else |
220 | s = fbm_instr((unsigned char*)s, (unsigned char*)strend, |
221 | prog->regmust); |
222 | if (!s) { |
223 | ++BmUSEFUL(prog->regmust); /* hooray */ |
224 | goto phooey; /* not present */ |
a687059c |
225 | } |
a0d0e21e |
226 | else if (prog->regback >= 0) { |
227 | s -= prog->regback; |
228 | if (s < startpos) |
229 | s = startpos; |
230 | minlen = prog->regback + SvCUR(prog->regmust); |
a687059c |
231 | } |
a0d0e21e |
232 | else if (!prog->naughty && --BmUSEFUL(prog->regmust) < 0) { /* boo */ |
233 | SvREFCNT_dec(prog->regmust); |
234 | prog->regmust = Nullsv; /* disable regmust */ |
235 | s = startpos; |
236 | } |
237 | else { |
238 | s = startpos; |
239 | minlen = SvCUR(prog->regmust); |
a687059c |
240 | } |
a0d0e21e |
241 | } |
a687059c |
242 | |
a0d0e21e |
243 | /* Mark beginning of line for ^ . */ |
244 | regbol = startpos; |
a687059c |
245 | |
a0d0e21e |
246 | /* Mark end of line for $ (and such) */ |
247 | regeol = strend; |
a687059c |
248 | |
a0d0e21e |
249 | /* see how far we have to get to not match where we matched before */ |
250 | regtill = startpos+minend; |
a687059c |
251 | |
a0d0e21e |
252 | /* Simplest case: anchored match need be tried only once. */ |
253 | /* [unless multiline is set] */ |
254 | if (prog->reganch & ROPT_ANCH) { |
255 | if (regtry(prog, startpos)) |
256 | goto got_it; |
257 | else if (multiline || (prog->reganch & ROPT_IMPLICIT)) { |
258 | if (minlen) |
259 | dontbother = minlen - 1; |
260 | strend -= dontbother; |
261 | /* for multiline we only have to try after newlines */ |
262 | if (s > startpos) |
263 | s--; |
264 | while (s < strend) { |
265 | if (*s++ == '\n') { |
266 | if (s < strend && regtry(prog, s)) |
267 | goto got_it; |
268 | } |
35c8bce7 |
269 | } |
35c8bce7 |
270 | } |
a0d0e21e |
271 | goto phooey; |
272 | } |
35c8bce7 |
273 | |
a0d0e21e |
274 | /* Messy cases: unanchored match. */ |
275 | if (prog->regstart) { |
276 | if (prog->reganch & ROPT_SKIP) { /* we have /x+whatever/ */ |
277 | /* it must be a one character string */ |
278 | i = SvPVX(prog->regstart)[0]; |
279 | while (s < strend) { |
280 | if (*s == i) { |
281 | if (regtry(prog, s)) |
a687059c |
282 | goto got_it; |
a0d0e21e |
283 | s++; |
284 | while (s < strend && *s == i) |
285 | s++; |
a687059c |
286 | } |
a0d0e21e |
287 | s++; |
288 | } |
a687059c |
289 | } |
a0d0e21e |
290 | else if (SvPOK(prog->regstart) == 3) { |
291 | /* We know what string it must start with. */ |
292 | while ((s = fbm_instr((unsigned char*)s, |
293 | (unsigned char*)strend, prog->regstart)) != NULL) |
294 | { |
295 | if (regtry(prog, s)) |
296 | goto got_it; |
297 | s++; |
298 | } |
299 | } |
300 | else { |
301 | c = SvPVX(prog->regstart); |
302 | while ((s = ninstr(s, strend, c, c + SvCUR(prog->regstart))) != NULL) |
303 | { |
304 | if (regtry(prog, s)) |
305 | goto got_it; |
306 | s++; |
307 | } |
308 | } |
309 | goto phooey; |
310 | } |
311 | /*SUPPRESS 560*/ |
312 | if (c = prog->regstclass) { |
313 | I32 doevery = (prog->reganch & ROPT_SKIP) == 0; |
a687059c |
314 | |
a0d0e21e |
315 | if (minlen) |
316 | dontbother = minlen - 1; |
317 | strend -= dontbother; /* don't bother with what can't match */ |
318 | tmp = 1; |
319 | /* We know what class it must start with. */ |
320 | switch (OP(c)) { |
321 | case ANYOF: |
322 | c = OPERAND(c); |
323 | while (s < strend) { |
324 | i = UCHARAT(s); |
325 | if (!(c[i >> 3] & (1 << (i&7)))) { |
326 | if (tmp && regtry(prog, s)) |
327 | goto got_it; |
328 | else |
329 | tmp = doevery; |
a687059c |
330 | } |
a0d0e21e |
331 | else |
332 | tmp = 1; |
333 | s++; |
334 | } |
335 | break; |
336 | case BOUND: |
337 | if (minlen) |
338 | dontbother++,strend--; |
339 | if (s != startpos) { |
340 | i = s[-1]; |
341 | tmp = isALNUM(i); |
342 | } |
343 | else |
344 | tmp = isALNUM(regprev); /* assume not alphanumeric */ |
345 | while (s < strend) { |
346 | i = *s; |
347 | if (tmp != isALNUM(i)) { |
348 | tmp = !tmp; |
349 | if (regtry(prog, s)) |
350 | goto got_it; |
a687059c |
351 | } |
a0d0e21e |
352 | s++; |
353 | } |
354 | if ((minlen || tmp) && regtry(prog,s)) |
355 | goto got_it; |
356 | break; |
357 | case NBOUND: |
358 | if (minlen) |
359 | dontbother++,strend--; |
360 | if (s != startpos) { |
361 | i = s[-1]; |
362 | tmp = isALNUM(i); |
363 | } |
364 | else |
365 | tmp = isALNUM(regprev); /* assume not alphanumeric */ |
366 | while (s < strend) { |
367 | i = *s; |
368 | if (tmp != isALNUM(i)) |
369 | tmp = !tmp; |
370 | else if (regtry(prog, s)) |
371 | goto got_it; |
372 | s++; |
373 | } |
374 | if ((minlen || !tmp) && regtry(prog,s)) |
375 | goto got_it; |
376 | break; |
377 | case ALNUM: |
378 | while (s < strend) { |
379 | i = *s; |
380 | if (isALNUM(i)) { |
381 | if (tmp && regtry(prog, s)) |
382 | goto got_it; |
a687059c |
383 | else |
a0d0e21e |
384 | tmp = doevery; |
385 | } |
386 | else |
387 | tmp = 1; |
388 | s++; |
389 | } |
390 | break; |
391 | case NALNUM: |
392 | while (s < strend) { |
393 | i = *s; |
394 | if (!isALNUM(i)) { |
395 | if (tmp && regtry(prog, s)) |
396 | goto got_it; |
a687059c |
397 | else |
a0d0e21e |
398 | tmp = doevery; |
a687059c |
399 | } |
a0d0e21e |
400 | else |
401 | tmp = 1; |
402 | s++; |
403 | } |
404 | break; |
405 | case SPACE: |
406 | while (s < strend) { |
407 | if (isSPACE(*s)) { |
408 | if (tmp && regtry(prog, s)) |
409 | goto got_it; |
410 | else |
411 | tmp = doevery; |
2304df62 |
412 | } |
a0d0e21e |
413 | else |
414 | tmp = 1; |
415 | s++; |
416 | } |
417 | break; |
418 | case NSPACE: |
419 | while (s < strend) { |
420 | if (!isSPACE(*s)) { |
421 | if (tmp && regtry(prog, s)) |
422 | goto got_it; |
423 | else |
424 | tmp = doevery; |
a687059c |
425 | } |
a0d0e21e |
426 | else |
427 | tmp = 1; |
428 | s++; |
429 | } |
430 | break; |
431 | case DIGIT: |
432 | while (s < strend) { |
433 | if (isDIGIT(*s)) { |
434 | if (tmp && regtry(prog, s)) |
435 | goto got_it; |
436 | else |
437 | tmp = doevery; |
2b69d0c2 |
438 | } |
a0d0e21e |
439 | else |
440 | tmp = 1; |
441 | s++; |
442 | } |
443 | break; |
444 | case NDIGIT: |
445 | while (s < strend) { |
446 | if (!isDIGIT(*s)) { |
447 | if (tmp && regtry(prog, s)) |
448 | goto got_it; |
449 | else |
450 | tmp = doevery; |
a687059c |
451 | } |
a0d0e21e |
452 | else |
453 | tmp = 1; |
454 | s++; |
455 | } |
456 | break; |
a687059c |
457 | } |
a0d0e21e |
458 | } |
459 | else { |
460 | if (minlen) |
461 | dontbother = minlen - 1; |
462 | strend -= dontbother; |
463 | /* We don't know much -- general case. */ |
464 | do { |
465 | if (regtry(prog, s)) |
466 | goto got_it; |
467 | } while (s++ < strend); |
468 | } |
469 | |
470 | /* Failure. */ |
471 | goto phooey; |
a687059c |
472 | |
a0d0e21e |
473 | got_it: |
474 | prog->subbeg = strbeg; |
475 | prog->subend = strend; |
476 | if ((!safebase && (prog->nparens || sawampersand)) || prog->do_folding) { |
477 | strend += dontbother; /* uncheat */ |
478 | i = strend - startpos + (stringarg - strbeg); |
479 | if (safebase) { /* no need for $digit later */ |
480 | s = strbeg; |
481 | prog->subend = s+i; |
482 | } |
483 | else if (strbeg != prog->subbase) { |
484 | s = savepvn(strbeg,i); /* so $digit will work later */ |
485 | if (prog->subbase) |
486 | Safefree(prog->subbase); |
487 | prog->subbeg = prog->subbase = s; |
488 | prog->subend = s+i; |
489 | } |
490 | else { |
491 | prog->subbeg = s = prog->subbase; |
492 | prog->subend = s+i; |
493 | } |
494 | s += (stringarg - strbeg); |
495 | for (i = 0; i <= prog->nparens; i++) { |
496 | if (prog->endp[i]) { |
497 | prog->startp[i] = s + (prog->startp[i] - startpos); |
498 | prog->endp[i] = s + (prog->endp[i] - startpos); |
499 | } |
500 | } |
a687059c |
501 | if (prog->do_folding) |
a0d0e21e |
502 | Safefree(startpos); |
503 | } |
504 | return 1; |
505 | |
506 | phooey: |
507 | if (prog->do_folding) |
508 | Safefree(startpos); |
509 | return 0; |
a687059c |
510 | } |
511 | |
512 | /* |
513 | - regtry - try match at specific point |
514 | */ |
79072805 |
515 | static I32 /* 0 failure, 1 success */ |
a0d0e21e |
516 | regtry(prog, startpos) |
a687059c |
517 | regexp *prog; |
a0d0e21e |
518 | char *startpos; |
a687059c |
519 | { |
a0d0e21e |
520 | register I32 i; |
521 | register char **sp; |
522 | register char **ep; |
523 | |
524 | reginput = startpos; |
525 | regstartp = prog->startp; |
526 | regendp = prog->endp; |
527 | reglastparen = &prog->lastparen; |
528 | prog->lastparen = 0; |
529 | regsize = 0; |
530 | |
531 | sp = prog->startp; |
532 | ep = prog->endp; |
533 | if (prog->nparens) { |
534 | for (i = prog->nparens; i >= 0; i--) { |
535 | *sp++ = NULL; |
536 | *ep++ = NULL; |
a687059c |
537 | } |
a0d0e21e |
538 | } |
539 | if (regmatch(prog->program + 1) && reginput >= regtill) { |
540 | prog->startp[0] = startpos; |
541 | prog->endp[0] = reginput; |
542 | return 1; |
543 | } |
544 | else |
545 | return 0; |
a687059c |
546 | } |
547 | |
548 | /* |
549 | - regmatch - main matching routine |
550 | * |
551 | * Conceptually the strategy is simple: check to see whether the current |
552 | * node matches, call self recursively to see whether the rest matches, |
553 | * and then act accordingly. In practice we make some effort to avoid |
554 | * recursion, in particular by going through "ordinary" nodes (that don't |
555 | * need to know whether the rest of the match failed) by a loop instead of |
556 | * by recursion. |
557 | */ |
558 | /* [lwall] I've hoisted the register declarations to the outer block in order to |
559 | * maybe save a little bit of pushing and popping on the stack. It also takes |
560 | * advantage of machines that use a register save mask on subroutine entry. |
561 | */ |
79072805 |
562 | static I32 /* 0 failure, 1 success */ |
a687059c |
563 | regmatch(prog) |
564 | char *prog; |
565 | { |
a0d0e21e |
566 | register char *scan; /* Current node. */ |
567 | char *next; /* Next node. */ |
568 | register I32 nextchar; |
569 | register I32 n; /* no or next */ |
570 | register I32 ln; /* len or last */ |
571 | register char *s; /* operand or save */ |
572 | register char *locinput = reginput; |
573 | int minmod = 0; |
574 | |
575 | nextchar = *locinput; |
576 | scan = prog; |
577 | while (scan != NULL) { |
a687059c |
578 | #ifdef DEBUGGING |
a0d0e21e |
579 | if (regnarrate) |
580 | fprintf(stderr, "%2d%-8.8s\t<%.10s>\n", |
581 | scan - regprogram, regprop(scan), locinput); |
a687059c |
582 | #endif |
583 | |
584 | #ifdef REGALIGN |
a0d0e21e |
585 | next = scan + NEXT(scan); |
586 | if (next == scan) |
587 | next = NULL; |
a687059c |
588 | #else |
a0d0e21e |
589 | next = regnext(scan); |
a687059c |
590 | #endif |
591 | |
a0d0e21e |
592 | switch (OP(scan)) { |
593 | case BOL: |
594 | if (locinput == regbol |
595 | ? regprev == '\n' |
596 | : ((nextchar || locinput < regeol) && locinput[-1] == '\n') ) |
597 | { |
598 | /* regtill = regbol; */ |
599 | break; |
600 | } |
601 | return 0; |
602 | case MBOL: |
603 | if (locinput == regbol |
604 | ? regprev == '\n' |
605 | : ((nextchar || locinput < regeol) && locinput[-1] == '\n') ) |
606 | { |
607 | break; |
608 | } |
609 | return 0; |
610 | case SBOL: |
611 | if (locinput == regbol && regprev == '\n') |
612 | break; |
613 | return 0; |
614 | case GBOL: |
615 | if (locinput == regbol) |
616 | break; |
617 | return 0; |
618 | case EOL: |
619 | if (multiline) |
620 | goto meol; |
621 | else |
622 | goto seol; |
623 | case MEOL: |
624 | meol: |
625 | if ((nextchar || locinput < regeol) && nextchar != '\n') |
626 | return 0; |
627 | break; |
628 | case SEOL: |
629 | seol: |
630 | if ((nextchar || locinput < regeol) && nextchar != '\n') |
631 | return 0; |
632 | if (regeol - locinput > 1) |
633 | return 0; |
634 | break; |
635 | case SANY: |
636 | if (!nextchar && locinput >= regeol) |
637 | return 0; |
638 | nextchar = *++locinput; |
639 | break; |
640 | case ANY: |
641 | if (!nextchar && locinput >= regeol || nextchar == '\n') |
642 | return 0; |
643 | nextchar = *++locinput; |
644 | break; |
645 | case EXACTLY: |
646 | s = OPERAND(scan); |
647 | ln = *s++; |
648 | /* Inline the first character, for speed. */ |
649 | if (*s != nextchar) |
650 | return 0; |
651 | if (regeol - locinput < ln) |
652 | return 0; |
653 | if (ln > 1 && bcmp(s, locinput, ln) != 0) |
654 | return 0; |
655 | locinput += ln; |
656 | nextchar = *locinput; |
657 | break; |
658 | case ANYOF: |
659 | s = OPERAND(scan); |
660 | if (nextchar < 0) |
661 | nextchar = UCHARAT(locinput); |
662 | if (s[nextchar >> 3] & (1 << (nextchar&7))) |
663 | return 0; |
664 | if (!nextchar && locinput >= regeol) |
665 | return 0; |
666 | nextchar = *++locinput; |
667 | break; |
668 | case ALNUM: |
669 | if (!nextchar) |
670 | return 0; |
671 | if (!isALNUM(nextchar)) |
672 | return 0; |
673 | nextchar = *++locinput; |
674 | break; |
675 | case NALNUM: |
676 | if (!nextchar && locinput >= regeol) |
677 | return 0; |
678 | if (isALNUM(nextchar)) |
679 | return 0; |
680 | nextchar = *++locinput; |
681 | break; |
682 | case NBOUND: |
683 | case BOUND: |
684 | if (locinput == regbol) /* was last char in word? */ |
685 | ln = isALNUM(regprev); |
686 | else |
687 | ln = isALNUM(locinput[-1]); |
688 | n = isALNUM(nextchar); /* is next char in word? */ |
689 | if ((ln == n) == (OP(scan) == BOUND)) |
690 | return 0; |
691 | break; |
692 | case SPACE: |
693 | if (!nextchar && locinput >= regeol) |
694 | return 0; |
695 | if (!isSPACE(nextchar)) |
696 | return 0; |
697 | nextchar = *++locinput; |
698 | break; |
699 | case NSPACE: |
700 | if (!nextchar) |
701 | return 0; |
702 | if (isSPACE(nextchar)) |
703 | return 0; |
704 | nextchar = *++locinput; |
705 | break; |
706 | case DIGIT: |
707 | if (!isDIGIT(nextchar)) |
708 | return 0; |
709 | nextchar = *++locinput; |
710 | break; |
711 | case NDIGIT: |
712 | if (!nextchar && locinput >= regeol) |
713 | return 0; |
714 | if (isDIGIT(nextchar)) |
715 | return 0; |
716 | nextchar = *++locinput; |
717 | break; |
718 | case REF: |
719 | n = ARG1(scan); /* which paren pair */ |
720 | s = regstartp[n]; |
721 | if (!s) |
722 | return 0; |
723 | if (!regendp[n]) |
724 | return 0; |
725 | if (s == regendp[n]) |
726 | break; |
727 | /* Inline the first character, for speed. */ |
728 | if (*s != nextchar) |
729 | return 0; |
730 | ln = regendp[n] - s; |
731 | if (locinput + ln > regeol) |
732 | return 0; |
733 | if (ln > 1 && bcmp(s, locinput, ln) != 0) |
734 | return 0; |
735 | locinput += ln; |
736 | nextchar = *locinput; |
737 | break; |
738 | |
739 | case NOTHING: |
740 | break; |
741 | case BACK: |
742 | break; |
743 | case OPEN: |
744 | n = ARG1(scan); /* which paren pair */ |
745 | regstartp[n] = locinput; |
746 | if (n > regsize) |
747 | regsize = n; |
748 | break; |
749 | case CLOSE: |
750 | n = ARG1(scan); /* which paren pair */ |
751 | regendp[n] = locinput; |
752 | if (n > *reglastparen) |
753 | *reglastparen = n; |
754 | break; |
755 | case CURLYX: { |
756 | CURCUR cc; |
757 | CHECKPOINT cp = savestack_ix; |
758 | cc.oldcc = regcc; |
759 | regcc = &cc; |
760 | cc.parenfloor = *reglastparen; |
761 | cc.cur = -1; |
762 | cc.min = ARG1(scan); |
763 | cc.max = ARG2(scan); |
764 | cc.scan = NEXTOPER(scan) + 4; |
765 | cc.next = next; |
766 | cc.minmod = minmod; |
767 | cc.lastloc = 0; |
768 | reginput = locinput; |
769 | n = regmatch(PREVOPER(next)); /* start on the WHILEM */ |
770 | regcpblow(cp); |
771 | regcc = cc.oldcc; |
772 | return n; |
773 | } |
774 | /* NOT REACHED */ |
775 | case WHILEM: { |
776 | /* |
777 | * This is really hard to understand, because after we match |
778 | * what we're trying to match, we must make sure the rest of |
779 | * the RE is going to match for sure, and to do that we have |
780 | * to go back UP the parse tree by recursing ever deeper. And |
781 | * if it fails, we have to reset our parent's current state |
782 | * that we can try again after backing off. |
783 | */ |
784 | |
785 | CURCUR* cc = regcc; |
786 | n = cc->cur + 1; |
787 | reginput = locinput; |
788 | |
789 | /* If degenerate scan matches "", assume scan done. */ |
790 | |
791 | if (locinput == cc->lastloc) { |
792 | regcc = cc->oldcc; |
793 | ln = regcc->cur; |
794 | if (regmatch(cc->next)) |
795 | return TRUE; |
796 | regcc->cur = ln; |
797 | regcc = cc; |
798 | return FALSE; |
799 | } |
800 | |
801 | /* First just match a string of min scans. */ |
802 | |
803 | if (n < cc->min) { |
804 | cc->cur = n; |
805 | cc->lastloc = locinput; |
806 | return regmatch(cc->scan); |
807 | } |
808 | |
809 | /* Prefer next over scan for minimal matching. */ |
810 | |
811 | if (cc->minmod) { |
812 | regcc = cc->oldcc; |
813 | ln = regcc->cur; |
814 | if (regmatch(cc->next)) |
815 | return TRUE; /* All done. */ |
816 | regcc->cur = ln; |
817 | regcc = cc; |
818 | |
819 | if (n >= cc->max) /* Maximum greed exceeded? */ |
820 | return FALSE; |
a687059c |
821 | |
a0d0e21e |
822 | /* Try scanning more and see if it helps. */ |
823 | reginput = locinput; |
824 | cc->cur = n; |
825 | cc->lastloc = locinput; |
826 | return regmatch(cc->scan); |
827 | } |
828 | |
829 | /* Prefer scan over next for maximal matching. */ |
830 | |
831 | if (n < cc->max) { /* More greed allowed? */ |
832 | regcppush(cc->parenfloor); |
833 | cc->cur = n; |
834 | cc->lastloc = locinput; |
835 | if (regmatch(cc->scan)) |
836 | return TRUE; |
837 | regcppop(); /* Restore some previous $<digit>s? */ |
838 | reginput = locinput; |
839 | } |
840 | |
841 | /* Failed deeper matches of scan, so see if this one works. */ |
842 | regcc = cc->oldcc; |
843 | ln = regcc->cur; |
844 | if (regmatch(cc->next)) |
845 | return TRUE; |
846 | regcc->cur = ln; |
847 | regcc = cc; |
848 | return FALSE; |
849 | } |
850 | /* NOT REACHED */ |
851 | case BRANCH: { |
852 | if (OP(next) != BRANCH) /* No choice. */ |
853 | next = NEXTOPER(scan);/* Avoid recursion. */ |
854 | else { |
855 | do { |
856 | reginput = locinput; |
857 | if (regmatch(NEXTOPER(scan))) |
858 | return 1; |
a687059c |
859 | #ifdef REGALIGN |
a0d0e21e |
860 | /*SUPPRESS 560*/ |
861 | if (n = NEXT(scan)) |
862 | scan += n; |
863 | else |
864 | scan = NULL; |
a687059c |
865 | #else |
a0d0e21e |
866 | scan = regnext(scan); |
79072805 |
867 | #endif |
a0d0e21e |
868 | } while (scan != NULL && OP(scan) == BRANCH); |
869 | return 0; |
870 | /* NOTREACHED */ |
a687059c |
871 | } |
a0d0e21e |
872 | } |
873 | break; |
874 | case MINMOD: |
875 | minmod = 1; |
876 | break; |
877 | case CURLY: |
878 | ln = ARG1(scan); /* min to match */ |
879 | n = ARG2(scan); /* max to match */ |
880 | scan = NEXTOPER(scan) + 4; |
881 | goto repeat; |
882 | case STAR: |
883 | ln = 0; |
884 | n = 32767; |
885 | scan = NEXTOPER(scan); |
886 | goto repeat; |
887 | case PLUS: |
888 | /* |
889 | * Lookahead to avoid useless match attempts |
890 | * when we know what character comes next. |
891 | */ |
892 | ln = 1; |
893 | n = 32767; |
894 | scan = NEXTOPER(scan); |
895 | repeat: |
896 | if (OP(next) == EXACTLY) |
897 | nextchar = *(OPERAND(next)+1); |
898 | else |
899 | nextchar = -1000; |
900 | reginput = locinput; |
901 | if (minmod) { |
902 | minmod = 0; |
903 | if (ln && regrepeat(scan, ln) < ln) |
904 | return 0; |
905 | while (n >= ln) { |
906 | /* If it could work, try it. */ |
907 | if (nextchar == -1000 || *reginput == nextchar) |
908 | if (regmatch(next)) |
909 | return 1; |
910 | /* Couldn't or didn't -- back up. */ |
911 | if (regrepeat(scan, 1)) { |
912 | ln++; |
913 | reginput = locinput + ln; |
914 | } |
915 | else |
916 | return 0; |
917 | } |
918 | } |
919 | else { |
920 | n = regrepeat(scan, n); |
921 | if (ln < n && regkind[(U8)OP(next)] == EOL && |
922 | (!multiline || OP(next) == SEOL)) |
923 | ln = n; /* why back off? */ |
924 | while (n >= ln) { |
925 | /* If it could work, try it. */ |
926 | if (nextchar == -1000 || *reginput == nextchar) |
927 | if (regmatch(next)) |
928 | return 1; |
929 | /* Couldn't or didn't -- back up. */ |
930 | n--; |
931 | reginput = locinput + n; |
932 | } |
933 | } |
934 | return 0; |
935 | case SUCCEED: |
936 | case END: |
937 | reginput = locinput; /* put where regtry can find it */ |
938 | return 1; /* Success! */ |
939 | case IFMATCH: |
940 | reginput = locinput; |
941 | scan = NEXTOPER(scan); |
942 | if (!regmatch(scan)) |
943 | return 0; |
944 | break; |
945 | case UNLESSM: |
946 | reginput = locinput; |
947 | scan = NEXTOPER(scan); |
948 | if (regmatch(scan)) |
949 | return 0; |
950 | break; |
951 | default: |
952 | fprintf(stderr, "%x %d\n",(unsigned)scan,scan[1]); |
953 | FAIL("regexp memory corruption"); |
a687059c |
954 | } |
a0d0e21e |
955 | scan = next; |
956 | } |
a687059c |
957 | |
a0d0e21e |
958 | /* |
959 | * We get here only if there's trouble -- normally "case END" is |
960 | * the terminating point. |
961 | */ |
962 | FAIL("corrupted regexp pointers"); |
963 | /*NOTREACHED*/ |
964 | return 0; |
a687059c |
965 | } |
966 | |
967 | /* |
968 | - regrepeat - repeatedly match something simple, report how many |
969 | */ |
970 | /* |
971 | * [This routine now assumes that it will only match on things of length 1. |
972 | * That was true before, but now we assume scan - reginput is the count, |
973 | * rather than incrementing count on every character.] |
974 | */ |
79072805 |
975 | static I32 |
00bf170e |
976 | regrepeat(p, max) |
a687059c |
977 | char *p; |
79072805 |
978 | I32 max; |
a687059c |
979 | { |
a0d0e21e |
980 | register char *scan; |
981 | register char *opnd; |
982 | register I32 c; |
983 | register char *loceol = regeol; |
984 | |
985 | scan = reginput; |
986 | if (max != 32767 && max < loceol - scan) |
987 | loceol = scan + max; |
988 | opnd = OPERAND(p); |
989 | switch (OP(p)) { |
990 | case ANY: |
991 | while (scan < loceol && *scan != '\n') |
992 | scan++; |
993 | break; |
994 | case SANY: |
995 | scan = loceol; |
996 | break; |
997 | case EXACTLY: /* length of string is 1 */ |
998 | opnd++; |
999 | while (scan < loceol && *opnd == *scan) |
1000 | scan++; |
1001 | break; |
1002 | case ANYOF: |
1003 | c = UCHARAT(scan); |
1004 | while (scan < loceol && !(opnd[c >> 3] & (1 << (c & 7)))) { |
1005 | scan++; |
1006 | c = UCHARAT(scan); |
a687059c |
1007 | } |
a0d0e21e |
1008 | break; |
1009 | case ALNUM: |
1010 | while (scan < loceol && isALNUM(*scan)) |
1011 | scan++; |
1012 | break; |
1013 | case NALNUM: |
1014 | while (scan < loceol && !isALNUM(*scan)) |
1015 | scan++; |
1016 | break; |
1017 | case SPACE: |
1018 | while (scan < loceol && isSPACE(*scan)) |
1019 | scan++; |
1020 | break; |
1021 | case NSPACE: |
1022 | while (scan < loceol && !isSPACE(*scan)) |
1023 | scan++; |
1024 | break; |
1025 | case DIGIT: |
1026 | while (scan < loceol && isDIGIT(*scan)) |
1027 | scan++; |
1028 | break; |
1029 | case NDIGIT: |
1030 | while (scan < loceol && !isDIGIT(*scan)) |
1031 | scan++; |
1032 | break; |
1033 | default: /* Called on something of 0 width. */ |
1034 | break; /* So match right here or not at all. */ |
1035 | } |
a687059c |
1036 | |
a0d0e21e |
1037 | c = scan - reginput; |
1038 | reginput = scan; |
a687059c |
1039 | |
a0d0e21e |
1040 | return(c); |
a687059c |
1041 | } |
1042 | |
1043 | /* |
1044 | - regnext - dig the "next" pointer out of a node |
1045 | * |
1046 | * [Note, when REGALIGN is defined there are two places in regmatch() |
1047 | * that bypass this code for speed.] |
1048 | */ |
1049 | char * |
1050 | regnext(p) |
1051 | register char *p; |
1052 | { |
a0d0e21e |
1053 | register I32 offset; |
a687059c |
1054 | |
a0d0e21e |
1055 | if (p == ®dummy) |
1056 | return(NULL); |
a687059c |
1057 | |
a0d0e21e |
1058 | offset = NEXT(p); |
1059 | if (offset == 0) |
1060 | return(NULL); |
a687059c |
1061 | |
1062 | #ifdef REGALIGN |
a0d0e21e |
1063 | return(p+offset); |
a687059c |
1064 | #else |
a0d0e21e |
1065 | if (OP(p) == BACK) |
1066 | return(p-offset); |
1067 | else |
1068 | return(p+offset); |
a687059c |
1069 | #endif |
1070 | } |