Commit | Line | Data |
a687059c |
1 | /* NOTE: this is derived from Henry Spencer's regexp code, and should not |
2 | * confused with the original package (see point 3 below). Thanks, Henry! |
3 | */ |
4 | |
5 | /* Additional note: this code is very heavily munged from Henry's version |
6 | * in places. In some spots I've traded clarity for efficiency, so don't |
7 | * blame Henry for some of the lack of readability. |
8 | */ |
9 | |
ae986130 |
10 | /* $Header: regexec.c,v 3.0.1.1 89/11/11 04:52:04 lwall Locked $ |
a687059c |
11 | * |
12 | * $Log: regexec.c,v $ |
ae986130 |
13 | * Revision 3.0.1.1 89/11/11 04:52:04 lwall |
14 | * patch2: /\b$foo/ didn't work |
15 | * |
a687059c |
16 | * Revision 3.0 89/10/18 15:22:53 lwall |
17 | * 3.0 baseline |
18 | * |
19 | */ |
20 | |
21 | /* |
22 | * regcomp and regexec -- regsub and regerror are not used in perl |
23 | * |
24 | * Copyright (c) 1986 by University of Toronto. |
25 | * Written by Henry Spencer. Not derived from licensed software. |
26 | * |
27 | * Permission is granted to anyone to use this software for any |
28 | * purpose on any computer system, and to redistribute it freely, |
29 | * subject to the following restrictions: |
30 | * |
31 | * 1. The author is not responsible for the consequences of use of |
32 | * this software, no matter how awful, even if they arise |
33 | * from defects in it. |
34 | * |
35 | * 2. The origin of this software must not be misrepresented, either |
36 | * by explicit claim or by omission. |
37 | * |
38 | * 3. Altered versions must be plainly marked as such, and must not |
39 | * be misrepresented as being the original software. |
40 | * |
41 | **** Alterations to Henry's code are... |
42 | **** |
43 | **** Copyright (c) 1989, Larry Wall |
44 | **** |
45 | **** You may distribute under the terms of the GNU General Public License |
46 | **** as specified in the README file that comes with the perl 3.0 kit. |
47 | * |
48 | * Beware that some of this code is subtly aware of the way operator |
49 | * precedence is structured in regular expressions. Serious changes in |
50 | * regular-expression syntax might require a total rethink. |
51 | */ |
52 | #include "EXTERN.h" |
53 | #include "perl.h" |
54 | #include "regcomp.h" |
55 | |
56 | #ifndef STATIC |
57 | #define STATIC static |
58 | #endif |
59 | |
60 | #ifdef DEBUGGING |
61 | int regnarrate = 0; |
62 | #endif |
63 | |
64 | /* |
65 | * regexec and friends |
66 | */ |
67 | |
68 | /* |
69 | * Global work variables for regexec(). |
70 | */ |
71 | static char *regprecomp; |
72 | static char *reginput; /* String-input pointer. */ |
73 | static char *regbol; /* Beginning of input, for ^ check. */ |
74 | static char *regeol; /* End of input, for $ check. */ |
75 | static char **regstartp; /* Pointer to startp array. */ |
76 | static char **regendp; /* Ditto for endp. */ |
77 | static char *reglastparen; /* Similarly for lastparen. */ |
78 | static char *regtill; |
79 | |
80 | static char *regmystartp[10]; /* For remembering backreferences. */ |
81 | static char *regmyendp[10]; |
82 | |
83 | /* |
84 | * Forwards. |
85 | */ |
86 | STATIC int regtry(); |
87 | STATIC int regmatch(); |
88 | STATIC int regrepeat(); |
89 | |
90 | extern int multiline; |
91 | |
92 | /* |
93 | - regexec - match a regexp against a string |
94 | */ |
95 | int |
96 | regexec(prog, stringarg, strend, strbeg, minend, screamer, safebase) |
97 | register regexp *prog; |
98 | char *stringarg; |
99 | register char *strend; /* pointer to null at end of string */ |
100 | char *strbeg; /* real beginning of string */ |
101 | int minend; /* end of match must be at least minend after stringarg */ |
102 | STR *screamer; |
103 | int safebase; /* no need to remember string in subbase */ |
104 | { |
105 | register char *s; |
106 | register int i; |
107 | register char *c; |
108 | register char *string = stringarg; |
109 | register int tmp; |
110 | int minlen = 0; /* must match at least this many chars */ |
111 | int dontbother = 0; /* how many characters not to try at end */ |
112 | int beginning = (string == strbeg); /* is ^ valid at stringarg? */ |
113 | |
114 | /* Be paranoid... */ |
115 | if (prog == NULL || string == NULL) { |
116 | fatal("NULL regexp parameter"); |
117 | return(0); |
118 | } |
119 | |
120 | regprecomp = prog->precomp; |
121 | /* Check validity of program. */ |
122 | if (UCHARAT(prog->program) != MAGIC) { |
123 | FAIL("corrupted regexp program"); |
124 | } |
125 | |
126 | if (prog->do_folding) { |
127 | safebase = FALSE; |
128 | i = strend - string; |
129 | New(1101,c,i+1,char); |
130 | (void)bcopy(string, c, i+1); |
131 | string = c; |
132 | strend = string + i; |
133 | for (s = string; s < strend; s++) |
134 | if (isupper(*s)) |
135 | *s = tolower(*s); |
136 | } |
137 | |
138 | /* If there is a "must appear" string, look for it. */ |
139 | s = string; |
140 | if (prog->regmust != Nullstr) { |
141 | if (beginning && screamer) { |
142 | if (screamfirst[prog->regmust->str_rare] >= 0) |
143 | s = screaminstr(screamer,prog->regmust); |
144 | else |
145 | s = Nullch; |
146 | } |
147 | #ifndef lint |
148 | else |
149 | s = fbminstr((unsigned char*)s, (unsigned char*)strend, |
150 | prog->regmust); |
151 | #endif |
152 | if (!s) { |
153 | ++prog->regmust->str_u.str_useful; /* hooray */ |
154 | goto phooey; /* not present */ |
155 | } |
156 | else if (prog->regback >= 0) { |
157 | s -= prog->regback; |
158 | if (s < string) |
159 | s = string; |
160 | minlen = prog->regback + prog->regmust->str_cur; |
161 | } |
162 | else if (--prog->regmust->str_u.str_useful < 0) { /* boo */ |
163 | str_free(prog->regmust); |
164 | prog->regmust = Nullstr; /* disable regmust */ |
165 | s = string; |
166 | } |
167 | else { |
168 | s = string; |
169 | minlen = prog->regmust->str_cur; |
170 | } |
171 | } |
172 | |
173 | /* Mark beginning of line for ^ . */ |
174 | if (beginning) |
175 | regbol = string; |
176 | else |
177 | regbol = NULL; |
178 | |
179 | /* Mark end of line for $ (and such) */ |
180 | regeol = strend; |
181 | |
182 | /* see how far we have to get to not match where we matched before */ |
183 | regtill = string+minend; |
184 | |
185 | /* Simplest case: anchored match need be tried only once. */ |
186 | /* [unless multiline is set] */ |
187 | if (prog->reganch) { |
188 | if (regtry(prog, string)) |
189 | goto got_it; |
190 | else if (multiline) { |
191 | if (minlen) |
192 | dontbother = minlen - 1; |
193 | strend -= dontbother; |
194 | /* for multiline we only have to try after newlines */ |
195 | if (s > string) |
196 | s--; |
197 | for (; s < strend; s++) { |
198 | if (*s == '\n') { |
199 | if (++s < strend && regtry(prog, s)) |
200 | goto got_it; |
201 | } |
202 | } |
203 | } |
204 | goto phooey; |
205 | } |
206 | |
207 | /* Messy cases: unanchored match. */ |
208 | if (prog->regstart) { |
209 | /* We know what string it must start with. */ |
210 | if (prog->regstart->str_pok == 3) { |
211 | #ifndef lint |
212 | while ((s = fbminstr((unsigned char*)s, |
213 | (unsigned char*)strend, prog->regstart)) != NULL) |
214 | #else |
215 | while (s = Nullch) |
216 | #endif |
217 | { |
218 | if (regtry(prog, s)) |
219 | goto got_it; |
220 | s++; |
221 | } |
222 | } |
223 | else { |
224 | c = prog->regstart->str_ptr; |
225 | while ((s = ninstr(s, strend, |
226 | c, c + prog->regstart->str_cur )) != NULL) { |
227 | if (regtry(prog, s)) |
228 | goto got_it; |
229 | s++; |
230 | } |
231 | } |
232 | goto phooey; |
233 | } |
234 | if (c = prog->regstclass) { |
235 | if (minlen) |
236 | dontbother = minlen - 1; |
237 | strend -= dontbother; /* don't bother with what can't match */ |
238 | /* We know what class it must start with. */ |
239 | switch (OP(c)) { |
240 | case ANYOF: case ANYBUT: |
241 | c = OPERAND(c); |
242 | while (s < strend) { |
243 | i = *s; |
244 | if (!(c[i >> 3] & (1 << (i&7)))) |
245 | if (regtry(prog, s)) |
246 | goto got_it; |
247 | s++; |
248 | } |
249 | break; |
250 | case BOUND: |
251 | if (minlen) |
252 | dontbother++,strend--; |
253 | if (s != string) { |
254 | i = s[-1]; |
255 | tmp = (isalpha(i) || isdigit(i) || i == '_'); |
256 | } |
257 | else |
258 | tmp = 0; /* assume not alphanumeric */ |
259 | while (s < strend) { |
260 | i = *s; |
261 | if (tmp != (isalpha(i) || isdigit(i) || i == '_')) { |
262 | tmp = !tmp; |
263 | if (regtry(prog, s)) |
264 | goto got_it; |
265 | } |
266 | s++; |
267 | } |
ae986130 |
268 | if ((minlen || tmp) && regtry(prog,s)) |
a687059c |
269 | goto got_it; |
270 | break; |
271 | case NBOUND: |
272 | if (minlen) |
273 | dontbother++,strend--; |
274 | if (s != string) { |
275 | i = s[-1]; |
276 | tmp = (isalpha(i) || isdigit(i) || i == '_'); |
277 | } |
278 | else |
279 | tmp = 0; /* assume not alphanumeric */ |
280 | while (s < strend) { |
281 | i = *s; |
282 | if (tmp != (isalpha(i) || isdigit(i) || i == '_')) |
283 | tmp = !tmp; |
284 | else if (regtry(prog, s)) |
285 | goto got_it; |
286 | s++; |
287 | } |
ae986130 |
288 | if ((minlen || !tmp) && regtry(prog,s)) |
a687059c |
289 | goto got_it; |
290 | break; |
291 | case ALNUM: |
292 | while (s < strend) { |
293 | i = *s; |
294 | if (isalpha(i) || isdigit(i) || i == '_') |
295 | if (regtry(prog, s)) |
296 | goto got_it; |
297 | s++; |
298 | } |
299 | break; |
300 | case NALNUM: |
301 | while (s < strend) { |
302 | i = *s; |
303 | if (!isalpha(i) && !isdigit(i) && i != '_') |
304 | if (regtry(prog, s)) |
305 | goto got_it; |
306 | s++; |
307 | } |
308 | break; |
309 | case SPACE: |
310 | while (s < strend) { |
311 | if (isspace(*s)) |
312 | if (regtry(prog, s)) |
313 | goto got_it; |
314 | s++; |
315 | } |
316 | break; |
317 | case NSPACE: |
318 | while (s < strend) { |
319 | if (!isspace(*s)) |
320 | if (regtry(prog, s)) |
321 | goto got_it; |
322 | s++; |
323 | } |
324 | break; |
325 | case DIGIT: |
326 | while (s < strend) { |
327 | if (isdigit(*s)) |
328 | if (regtry(prog, s)) |
329 | goto got_it; |
330 | s++; |
331 | } |
332 | break; |
333 | case NDIGIT: |
334 | while (s < strend) { |
335 | if (!isdigit(*s)) |
336 | if (regtry(prog, s)) |
337 | goto got_it; |
338 | s++; |
339 | } |
340 | break; |
341 | } |
342 | } |
343 | else { |
344 | dontbother = minend; |
345 | strend -= dontbother; |
346 | /* We don't know much -- general case. */ |
347 | do { |
348 | if (regtry(prog, s)) |
349 | goto got_it; |
350 | } while (s++ < strend); |
351 | } |
352 | |
353 | /* Failure. */ |
354 | goto phooey; |
355 | |
356 | got_it: |
357 | if ((!safebase && (prog->nparens || sawampersand)) || prog->do_folding){ |
358 | strend += dontbother; /* uncheat */ |
359 | if (safebase) /* no need for $digit later */ |
360 | s = strbeg; |
361 | else if (strbeg != prog->subbase) { |
362 | i = strend - string + (stringarg - strbeg); |
363 | s = nsavestr(strbeg,i); /* so $digit will work later */ |
364 | if (prog->subbase) |
365 | Safefree(prog->subbase); |
366 | prog->subbase = s; |
367 | } |
368 | else |
369 | s = prog->subbase; |
370 | s += (stringarg - strbeg); |
371 | for (i = 0; i <= prog->nparens; i++) { |
372 | if (prog->endp[i]) { |
373 | prog->startp[i] = s + (prog->startp[i] - string); |
374 | prog->endp[i] = s + (prog->endp[i] - string); |
375 | } |
376 | } |
377 | if (prog->do_folding) |
378 | Safefree(string); |
379 | } |
380 | return(1); |
381 | |
382 | phooey: |
383 | if (prog->do_folding) |
384 | Safefree(string); |
385 | return(0); |
386 | } |
387 | |
388 | /* |
389 | - regtry - try match at specific point |
390 | */ |
391 | static int /* 0 failure, 1 success */ |
392 | regtry(prog, string) |
393 | regexp *prog; |
394 | char *string; |
395 | { |
396 | register int i; |
397 | register char **sp; |
398 | register char **ep; |
399 | |
400 | reginput = string; |
401 | regstartp = prog->startp; |
402 | regendp = prog->endp; |
403 | reglastparen = &prog->lastparen; |
404 | prog->lastparen = 0; |
405 | |
406 | sp = prog->startp; |
407 | ep = prog->endp; |
408 | if (prog->nparens) { |
409 | for (i = NSUBEXP; i > 0; i--) { |
410 | *sp++ = NULL; |
411 | *ep++ = NULL; |
412 | } |
413 | } |
414 | if (regmatch(prog->program + 1) && reginput >= regtill) { |
415 | prog->startp[0] = string; |
416 | prog->endp[0] = reginput; |
417 | return(1); |
418 | } else |
419 | return(0); |
420 | } |
421 | |
422 | /* |
423 | - regmatch - main matching routine |
424 | * |
425 | * Conceptually the strategy is simple: check to see whether the current |
426 | * node matches, call self recursively to see whether the rest matches, |
427 | * and then act accordingly. In practice we make some effort to avoid |
428 | * recursion, in particular by going through "ordinary" nodes (that don't |
429 | * need to know whether the rest of the match failed) by a loop instead of |
430 | * by recursion. |
431 | */ |
432 | /* [lwall] I've hoisted the register declarations to the outer block in order to |
433 | * maybe save a little bit of pushing and popping on the stack. It also takes |
434 | * advantage of machines that use a register save mask on subroutine entry. |
435 | */ |
436 | static int /* 0 failure, 1 success */ |
437 | regmatch(prog) |
438 | char *prog; |
439 | { |
440 | register char *scan; /* Current node. */ |
441 | char *next; /* Next node. */ |
442 | register int nextchar; |
443 | register int n; /* no or next */ |
444 | register int ln; /* len or last */ |
445 | register char *s; /* operand or save */ |
446 | register char *locinput = reginput; |
447 | |
448 | nextchar = *locinput; |
449 | scan = prog; |
450 | #ifdef DEBUGGING |
451 | if (scan != NULL && regnarrate) |
452 | fprintf(stderr, "%s(\n", regprop(scan)); |
453 | #endif |
454 | while (scan != NULL) { |
455 | #ifdef DEBUGGING |
456 | if (regnarrate) |
457 | fprintf(stderr, "%s...\n", regprop(scan)); |
458 | #endif |
459 | |
460 | #ifdef REGALIGN |
461 | next = scan + NEXT(scan); |
462 | if (next == scan) |
463 | next = NULL; |
464 | #else |
465 | next = regnext(scan); |
466 | #endif |
467 | |
468 | switch (OP(scan)) { |
469 | case BOL: |
470 | if (locinput == regbol || |
471 | ((nextchar || locinput < regeol) && |
472 | locinput[-1] == '\n') ) |
473 | { |
474 | regtill--; |
475 | break; |
476 | } |
477 | return(0); |
478 | case EOL: |
479 | if ((nextchar || locinput < regeol) && nextchar != '\n') |
480 | return(0); |
481 | regtill--; |
482 | break; |
483 | case ANY: |
484 | if ((nextchar == '\0' && locinput >= regeol) || |
485 | nextchar == '\n') |
486 | return(0); |
487 | nextchar = *++locinput; |
488 | break; |
489 | case EXACTLY: |
490 | s = OPERAND(scan); |
491 | ln = *s++; |
492 | /* Inline the first character, for speed. */ |
493 | if (*s != nextchar) |
494 | return(0); |
495 | if (locinput + ln > regeol) |
496 | return 0; |
497 | if (ln > 1 && bcmp(s, locinput, ln) != 0) |
498 | return(0); |
499 | locinput += ln; |
500 | nextchar = *locinput; |
501 | break; |
502 | case ANYOF: |
503 | case ANYBUT: |
504 | s = OPERAND(scan); |
505 | if (nextchar < 0) |
506 | nextchar = UCHARAT(locinput); |
507 | if (s[nextchar >> 3] & (1 << (nextchar&7))) |
508 | return(0); |
509 | nextchar = *++locinput; |
510 | if (!nextchar && locinput > regeol) |
511 | return 0; |
512 | break; |
513 | case ALNUM: |
514 | if (!nextchar) |
515 | return(0); |
516 | if (!isalpha(nextchar) && !isdigit(nextchar) && |
517 | nextchar != '_') |
518 | return(0); |
519 | nextchar = *++locinput; |
520 | break; |
521 | case NALNUM: |
522 | if (!nextchar && locinput >= regeol) |
523 | return(0); |
524 | if (isalpha(nextchar) || isdigit(nextchar) || |
525 | nextchar == '_') |
526 | return(0); |
527 | nextchar = *++locinput; |
528 | break; |
529 | case NBOUND: |
530 | case BOUND: |
531 | if (locinput == regbol) /* was last char in word? */ |
532 | ln = 0; |
533 | else |
534 | ln = (isalpha(locinput[-1]) || |
535 | isdigit(locinput[-1]) || |
536 | locinput[-1] == '_' ); |
537 | n = (isalpha(nextchar) || isdigit(nextchar) || |
538 | nextchar == '_' ); /* is next char in word? */ |
539 | if ((ln == n) == (OP(scan) == BOUND)) |
540 | return(0); |
541 | break; |
542 | case SPACE: |
543 | if (!nextchar && locinput >= regeol) |
544 | return(0); |
545 | if (!isspace(nextchar)) |
546 | return(0); |
547 | nextchar = *++locinput; |
548 | break; |
549 | case NSPACE: |
550 | if (!nextchar) |
551 | return(0); |
552 | if (isspace(nextchar)) |
553 | return(0); |
554 | nextchar = *++locinput; |
555 | break; |
556 | case DIGIT: |
557 | if (!isdigit(nextchar)) |
558 | return(0); |
559 | nextchar = *++locinput; |
560 | break; |
561 | case NDIGIT: |
562 | if (!nextchar && locinput >= regeol) |
563 | return(0); |
564 | if (isdigit(nextchar)) |
565 | return(0); |
566 | nextchar = *++locinput; |
567 | break; |
568 | case REF: |
569 | case REF+1: |
570 | case REF+2: |
571 | case REF+3: |
572 | case REF+4: |
573 | case REF+5: |
574 | case REF+6: |
575 | case REF+7: |
576 | case REF+8: |
577 | case REF+9: |
578 | n = OP(scan) - REF; |
579 | s = regmystartp[n]; |
580 | if (!s) |
581 | return(0); |
582 | if (!regmyendp[n]) |
583 | return(0); |
584 | if (s == regmyendp[n]) |
585 | break; |
586 | /* Inline the first character, for speed. */ |
587 | if (*s != nextchar) |
588 | return(0); |
589 | ln = regmyendp[n] - s; |
590 | if (locinput + ln > regeol) |
591 | return 0; |
592 | if (ln > 1 && bcmp(s, locinput, ln) != 0) |
593 | return(0); |
594 | locinput += ln; |
595 | nextchar = *locinput; |
596 | break; |
597 | |
598 | case NOTHING: |
599 | break; |
600 | case BACK: |
601 | break; |
602 | case OPEN+1: |
603 | case OPEN+2: |
604 | case OPEN+3: |
605 | case OPEN+4: |
606 | case OPEN+5: |
607 | case OPEN+6: |
608 | case OPEN+7: |
609 | case OPEN+8: |
610 | case OPEN+9: |
611 | n = OP(scan) - OPEN; |
612 | reginput = locinput; |
613 | |
614 | regmystartp[n] = locinput; /* for REF */ |
615 | if (regmatch(next)) { |
616 | /* |
617 | * Don't set startp if some later |
618 | * invocation of the same parentheses |
619 | * already has. |
620 | */ |
621 | if (regstartp[n] == NULL) |
622 | regstartp[n] = locinput; |
623 | return(1); |
624 | } else |
625 | return(0); |
626 | /* NOTREACHED */ |
627 | case CLOSE+1: |
628 | case CLOSE+2: |
629 | case CLOSE+3: |
630 | case CLOSE+4: |
631 | case CLOSE+5: |
632 | case CLOSE+6: |
633 | case CLOSE+7: |
634 | case CLOSE+8: |
635 | case CLOSE+9: { |
636 | n = OP(scan) - CLOSE; |
637 | reginput = locinput; |
638 | |
639 | regmyendp[n] = locinput; /* for REF */ |
640 | if (regmatch(next)) { |
641 | /* |
642 | * Don't set endp if some later |
643 | * invocation of the same parentheses |
644 | * already has. |
645 | */ |
646 | if (regendp[n] == NULL) { |
647 | regendp[n] = locinput; |
648 | if (n > *reglastparen) |
649 | *reglastparen = n; |
650 | } |
651 | return(1); |
652 | } else |
653 | return(0); |
654 | } |
655 | /*NOTREACHED*/ |
656 | case BRANCH: { |
657 | if (OP(next) != BRANCH) /* No choice. */ |
658 | next = NEXTOPER(scan); /* Avoid recursion. */ |
659 | else { |
660 | do { |
661 | reginput = locinput; |
662 | if (regmatch(NEXTOPER(scan))) |
663 | return(1); |
664 | #ifdef REGALIGN |
665 | if (n = NEXT(scan)) |
666 | scan += n; |
667 | else |
668 | scan = NULL; |
669 | #else |
670 | scan = regnext(scan); |
671 | #endif |
672 | } while (scan != NULL && OP(scan) == BRANCH); |
673 | return(0); |
674 | /* NOTREACHED */ |
675 | } |
676 | } |
677 | break; |
678 | case STAR: |
679 | case PLUS: |
680 | /* |
681 | * Lookahead to avoid useless match attempts |
682 | * when we know what character comes next. |
683 | */ |
684 | if (OP(next) == EXACTLY) |
685 | nextchar = *(OPERAND(next)+1); |
686 | else |
687 | nextchar = -1000; |
688 | ln = (OP(scan) == STAR) ? 0 : 1; |
689 | reginput = locinput; |
690 | n = regrepeat(NEXTOPER(scan)); |
691 | while (n >= ln) { |
692 | /* If it could work, try it. */ |
693 | if (nextchar == -1000 || *reginput == nextchar) |
694 | if (regmatch(next)) |
695 | return(1); |
696 | /* Couldn't or didn't -- back up. */ |
697 | n--; |
698 | reginput = locinput + n; |
699 | } |
700 | return(0); |
701 | case END: |
702 | reginput = locinput; /* put where regtry can find it */ |
703 | return(1); /* Success! */ |
704 | default: |
705 | printf("%x %d\n",scan,scan[1]); |
706 | FAIL("regexp memory corruption"); |
707 | } |
708 | |
709 | scan = next; |
710 | } |
711 | |
712 | /* |
713 | * We get here only if there's trouble -- normally "case END" is |
714 | * the terminating point. |
715 | */ |
716 | FAIL("corrupted regexp pointers"); |
717 | /*NOTREACHED*/ |
718 | #ifdef lint |
719 | return 0; |
720 | #endif |
721 | } |
722 | |
723 | /* |
724 | - regrepeat - repeatedly match something simple, report how many |
725 | */ |
726 | /* |
727 | * [This routine now assumes that it will only match on things of length 1. |
728 | * That was true before, but now we assume scan - reginput is the count, |
729 | * rather than incrementing count on every character.] |
730 | */ |
731 | static int |
732 | regrepeat(p) |
733 | char *p; |
734 | { |
735 | register char *scan; |
736 | register char *opnd; |
737 | register int c; |
738 | register char *loceol = regeol; |
739 | |
740 | scan = reginput; |
741 | opnd = OPERAND(p); |
742 | switch (OP(p)) { |
743 | case ANY: |
744 | while (scan < loceol && *scan != '\n') |
745 | scan++; |
746 | break; |
747 | case EXACTLY: /* length of string is 1 */ |
748 | opnd++; |
749 | while (scan < loceol && *opnd == *scan) |
750 | scan++; |
751 | break; |
752 | case ANYOF: |
753 | case ANYBUT: |
754 | c = UCHARAT(scan); |
755 | while (scan < loceol && !(opnd[c >> 3] & (1 << (c & 7)))) { |
756 | scan++; |
757 | c = UCHARAT(scan); |
758 | } |
759 | break; |
760 | case ALNUM: |
761 | while (isalpha(*scan) || isdigit(*scan) || *scan == '_') |
762 | scan++; |
763 | break; |
764 | case NALNUM: |
765 | while (scan < loceol && (!isalpha(*scan) && !isdigit(*scan) && |
766 | *scan != '_')) |
767 | scan++; |
768 | break; |
769 | case SPACE: |
770 | while (scan < loceol && isspace(*scan)) |
771 | scan++; |
772 | break; |
773 | case NSPACE: |
774 | while (scan < loceol && !isspace(*scan)) |
775 | scan++; |
776 | break; |
777 | case DIGIT: |
778 | while (isdigit(*scan)) |
779 | scan++; |
780 | break; |
781 | case NDIGIT: |
782 | while (scan < loceol && !isdigit(*scan)) |
783 | scan++; |
784 | break; |
785 | default: /* Oh dear. Called inappropriately. */ |
786 | FAIL("internal regexp foulup"); |
787 | /* NOTREACHED */ |
788 | } |
789 | |
790 | c = scan - reginput; |
791 | reginput = scan; |
792 | |
793 | return(c); |
794 | } |
795 | |
796 | /* |
797 | - regnext - dig the "next" pointer out of a node |
798 | * |
799 | * [Note, when REGALIGN is defined there are two places in regmatch() |
800 | * that bypass this code for speed.] |
801 | */ |
802 | char * |
803 | regnext(p) |
804 | register char *p; |
805 | { |
806 | register int offset; |
807 | |
808 | if (p == ®dummy) |
809 | return(NULL); |
810 | |
811 | offset = NEXT(p); |
812 | if (offset == 0) |
813 | return(NULL); |
814 | |
815 | #ifdef REGALIGN |
816 | return(p+offset); |
817 | #else |
818 | if (OP(p) == BACK) |
819 | return(p-offset); |
820 | else |
821 | return(p+offset); |
822 | #endif |
823 | } |