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 | |
34de22dd |
10 | /* $Header: regcomp.c,v 3.0.1.8 90/11/10 01:57:46 lwall Locked $ |
a687059c |
11 | * |
12 | * $Log: regcomp.c,v $ |
34de22dd |
13 | * Revision 3.0.1.8 90/11/10 01:57:46 lwall |
14 | * patch38: patterns with multiple constant strings occasionally malfed |
15 | * patch38: patterns like /foo.*foo/ sped up some |
16 | * |
e5d73d77 |
17 | * Revision 3.0.1.7 90/10/20 02:18:32 lwall |
18 | * patch37: /foo.*bar$/ wrongly optimized to do tail matching on "foo" |
19 | * |
0a12ae7d |
20 | * Revision 3.0.1.6 90/10/16 10:17:33 lwall |
21 | * patch29: patterns with multiple short literal strings sometimes failed |
22 | * |
6eb13c3b |
23 | * Revision 3.0.1.5 90/08/13 22:23:29 lwall |
24 | * patch28: /x{m}/ didn't work right |
25 | * |
00bf170e |
26 | * Revision 3.0.1.4 90/08/09 05:05:33 lwall |
27 | * patch19: sped up /x+y/ patterns greatly by not retrying on every x |
28 | * patch19: inhibited backoff on patterns anchored to the end like /\s+$/ |
29 | * patch19: sped up {m,n} on simple items |
30 | * patch19: optimized /.*whatever/ to /^.*whatever/ |
31 | * patch19: fixed character classes to allow backslashing hyphen |
32 | * |
79a0689e |
33 | * Revision 3.0.1.3 90/03/12 16:59:22 lwall |
34 | * patch13: pattern matches can now use \0 to mean \000 |
35 | * |
ac58e20f |
36 | * Revision 3.0.1.2 90/02/28 18:08:35 lwall |
37 | * patch9: /[\200-\377]/ didn't work on machines with signed chars |
38 | * |
ae986130 |
39 | * Revision 3.0.1.1 89/11/11 04:51:04 lwall |
40 | * patch2: /[\000]/ didn't work |
41 | * |
a687059c |
42 | * Revision 3.0 89/10/18 15:22:29 lwall |
43 | * 3.0 baseline |
44 | * |
45 | */ |
46 | |
47 | /* |
48 | * regcomp and regexec -- regsub and regerror are not used in perl |
49 | * |
50 | * Copyright (c) 1986 by University of Toronto. |
51 | * Written by Henry Spencer. Not derived from licensed software. |
52 | * |
53 | * Permission is granted to anyone to use this software for any |
54 | * purpose on any computer system, and to redistribute it freely, |
55 | * subject to the following restrictions: |
56 | * |
57 | * 1. The author is not responsible for the consequences of use of |
58 | * this software, no matter how awful, even if they arise |
59 | * from defects in it. |
60 | * |
61 | * 2. The origin of this software must not be misrepresented, either |
62 | * by explicit claim or by omission. |
63 | * |
64 | * 3. Altered versions must be plainly marked as such, and must not |
65 | * be misrepresented as being the original software. |
66 | * |
67 | * |
68 | **** Alterations to Henry's code are... |
69 | **** |
70 | **** Copyright (c) 1989, Larry Wall |
71 | **** |
72 | **** You may distribute under the terms of the GNU General Public License |
73 | **** as specified in the README file that comes with the perl 3.0 kit. |
74 | * |
75 | * Beware that some of this code is subtly aware of the way operator |
76 | * precedence is structured in regular expressions. Serious changes in |
77 | * regular-expression syntax might require a total rethink. |
78 | */ |
79 | #include "EXTERN.h" |
80 | #include "perl.h" |
81 | #include "INTERN.h" |
82 | #include "regcomp.h" |
83 | |
84 | #ifndef STATIC |
85 | #define STATIC static |
86 | #endif |
87 | |
88 | #define ISMULT1(c) ((c) == '*' || (c) == '+' || (c) == '?') |
89 | #define ISMULT2(s) ((*s) == '*' || (*s) == '+' || (*s) == '?' || \ |
90 | ((*s) == '{' && regcurly(s))) |
91 | #define META "^$.[()|?+*\\" |
92 | |
93 | /* |
94 | * Flags to be passed up and down. |
95 | */ |
96 | #define HASWIDTH 01 /* Known never to match null string. */ |
97 | #define SIMPLE 02 /* Simple enough to be STAR/PLUS operand. */ |
98 | #define SPSTART 04 /* Starts with * or +. */ |
99 | #define WORST 0 /* Worst case. */ |
100 | |
101 | /* |
102 | * Global work variables for regcomp(). |
103 | */ |
104 | static char *regprecomp; /* uncompiled string. */ |
105 | static char *regparse; /* Input-scan pointer. */ |
106 | static char *regxend; /* End of input for compile */ |
107 | static int regnpar; /* () count. */ |
108 | static char *regcode; /* Code-emit pointer; ®dummy = don't. */ |
109 | static long regsize; /* Code size. */ |
110 | static int regfold; |
111 | static int regsawbracket; /* Did we do {d,d} trick? */ |
112 | |
113 | /* |
114 | * Forward declarations for regcomp()'s friends. |
115 | */ |
116 | STATIC int regcurly(); |
117 | STATIC char *reg(); |
118 | STATIC char *regbranch(); |
119 | STATIC char *regpiece(); |
120 | STATIC char *regatom(); |
121 | STATIC char *regclass(); |
122 | STATIC char *regnode(); |
123 | STATIC void regc(); |
124 | STATIC void reginsert(); |
125 | STATIC void regtail(); |
126 | STATIC void regoptail(); |
127 | |
128 | /* |
129 | - regcomp - compile a regular expression into internal code |
130 | * |
131 | * We can't allocate space until we know how big the compiled form will be, |
132 | * but we can't compile it (and thus know how big it is) until we've got a |
133 | * place to put the code. So we cheat: we compile it twice, once with code |
134 | * generation turned off and size counting turned on, and once "for real". |
135 | * This also means that we don't allocate space until we are sure that the |
136 | * thing really will compile successfully, and we never have to move the |
137 | * code and thus invalidate pointers into it. (Note that it has to be in |
138 | * one piece because free() must be able to free it all.) [NB: not true in perl] |
139 | * |
140 | * Beware that the optimization-preparation code in here knows about some |
141 | * of the structure of the compiled regexp. [I'll say.] |
142 | */ |
143 | regexp * |
00bf170e |
144 | regcomp(exp,xend,fold) |
a687059c |
145 | char *exp; |
146 | char *xend; |
147 | int fold; |
a687059c |
148 | { |
149 | register regexp *r; |
150 | register char *scan; |
0a12ae7d |
151 | register STR *longish; |
152 | STR *longest; |
a687059c |
153 | register int len; |
154 | register char *first; |
155 | int flags; |
34de22dd |
156 | int backish; |
157 | int backest; |
a687059c |
158 | int curback; |
159 | extern char *safemalloc(); |
160 | extern char *savestr(); |
00bf170e |
161 | int sawplus = 0; |
a687059c |
162 | |
163 | if (exp == NULL) |
164 | fatal("NULL regexp argument"); |
165 | |
166 | /* First pass: determine size, legality. */ |
167 | regfold = fold; |
168 | regparse = exp; |
169 | regxend = xend; |
170 | regprecomp = nsavestr(exp,xend-exp); |
171 | regsawbracket = 0; |
172 | regnpar = 1; |
173 | regsize = 0L; |
174 | regcode = ®dummy; |
175 | regc(MAGIC); |
176 | if (reg(0, &flags) == NULL) { |
177 | Safefree(regprecomp); |
178 | return(NULL); |
179 | } |
180 | |
181 | /* Small enough for pointer-storage convention? */ |
182 | if (regsize >= 32767L) /* Probably could be 65535L. */ |
183 | FAIL("regexp too big"); |
184 | |
185 | /* Allocate space. */ |
186 | Newc(1001, r, sizeof(regexp) + (unsigned)regsize, char, regexp); |
187 | if (r == NULL) |
188 | FAIL("regexp out of space"); |
189 | |
190 | /* Second pass: emit code. */ |
191 | if (regsawbracket) |
192 | bcopy(regprecomp,exp,xend-exp); |
193 | r->precomp = regprecomp; |
194 | r->subbase = NULL; |
195 | regparse = exp; |
196 | regnpar = 1; |
197 | regcode = r->program; |
198 | regc(MAGIC); |
199 | if (reg(0, &flags) == NULL) |
200 | return(NULL); |
201 | |
202 | /* Dig out information for optimizations. */ |
203 | r->regstart = Nullstr; /* Worst-case defaults. */ |
204 | r->reganch = 0; |
205 | r->regmust = Nullstr; |
206 | r->regback = -1; |
207 | r->regstclass = Nullch; |
208 | scan = r->program+1; /* First BRANCH. */ |
209 | if (OP(regnext(scan)) == END) {/* Only one top-level choice. */ |
210 | scan = NEXTOPER(scan); |
211 | |
212 | first = scan; |
213 | while ((OP(first) > OPEN && OP(first) < CLOSE) || |
214 | (OP(first) == BRANCH && OP(regnext(first)) != BRANCH) || |
00bf170e |
215 | (OP(first) == PLUS) || |
216 | (OP(first) == CURLY && ARG1(first) > 0) ) { |
217 | if (OP(first) == CURLY) |
218 | first += 4; |
219 | else if (OP(first) == PLUS) |
220 | sawplus = 2; |
a687059c |
221 | first = NEXTOPER(first); |
00bf170e |
222 | } |
a687059c |
223 | |
224 | /* Starting-point info. */ |
225 | if (OP(first) == EXACTLY) { |
226 | r->regstart = |
227 | str_make(OPERAND(first)+1,*OPERAND(first)); |
228 | if (r->regstart->str_cur > !(sawstudy|fold)) |
229 | fbmcompile(r->regstart,fold); |
230 | } |
231 | else if ((exp = index(simple,OP(first))) && exp > simple) |
232 | r->regstclass = first; |
233 | else if (OP(first) == BOUND || OP(first) == NBOUND) |
234 | r->regstclass = first; |
00bf170e |
235 | else if (OP(first) == BOL || |
236 | (OP(first) == STAR && OP(NEXTOPER(first)) == ANY) ) |
237 | r->reganch = 1; /* kinda turn .* into ^.* */ |
238 | r->reganch |= sawplus; |
a687059c |
239 | |
240 | #ifdef DEBUGGING |
241 | if (debug & 512) |
242 | fprintf(stderr,"first %d next %d offset %d\n", |
243 | OP(first), OP(NEXTOPER(first)), first - scan); |
244 | #endif |
245 | /* |
246 | * If there's something expensive in the r.e., find the |
247 | * longest literal string that must appear and make it the |
248 | * regmust. Resolve ties in favor of later strings, since |
249 | * the regstart check works with the beginning of the r.e. |
250 | * and avoiding duplication strengthens checking. Not a |
251 | * strong reason, but sufficient in the absence of others. |
252 | * [Now we resolve ties in favor of the earlier string if |
253 | * it happens that curback has been invalidated, since the |
254 | * earlier string may buy us something the later one won't.] |
255 | */ |
0a12ae7d |
256 | longish = str_make("",0); |
a687059c |
257 | longest = str_make("",0); |
258 | len = 0; |
259 | curback = 0; |
34de22dd |
260 | backish = 0; |
261 | backest = 0; |
e5d73d77 |
262 | while (OP(scan) != END) { |
a687059c |
263 | if (OP(scan) == BRANCH) { |
264 | if (OP(regnext(scan)) == BRANCH) { |
265 | curback = -30000; |
266 | while (OP(scan) == BRANCH) |
267 | scan = regnext(scan); |
268 | } |
269 | else /* single branch is ok */ |
270 | scan = NEXTOPER(scan); |
271 | } |
272 | if (OP(scan) == EXACTLY) { |
273 | first = scan; |
274 | while (OP(regnext(scan)) >= CLOSE) |
275 | scan = regnext(scan); |
34de22dd |
276 | if (curback - backish == len) { |
0a12ae7d |
277 | str_ncat(longish, OPERAND(first)+1, |
a687059c |
278 | *OPERAND(first)); |
279 | len += *OPERAND(first); |
280 | curback += *OPERAND(first); |
281 | first = regnext(scan); |
282 | } |
283 | else if (*OPERAND(first) >= len + (curback >= 0)) { |
284 | len = *OPERAND(first); |
0a12ae7d |
285 | str_nset(longish, OPERAND(first)+1,len); |
34de22dd |
286 | backish = curback; |
a687059c |
287 | curback += len; |
288 | first = regnext(scan); |
289 | } |
290 | else |
291 | curback += *OPERAND(first); |
292 | } |
0a12ae7d |
293 | else if (index(varies,OP(scan))) { |
294 | curback = -30000; |
295 | len = 0; |
34de22dd |
296 | if (longish->str_cur > longest->str_cur) { |
0a12ae7d |
297 | str_sset(longest,longish); |
34de22dd |
298 | backest = backish; |
299 | } |
0a12ae7d |
300 | str_nset(longish,"",0); |
301 | } |
e5d73d77 |
302 | else if (index(simple,OP(scan))) { |
0a12ae7d |
303 | curback++; |
e5d73d77 |
304 | len = 0; |
34de22dd |
305 | if (longish->str_cur > longest->str_cur) { |
e5d73d77 |
306 | str_sset(longest,longish); |
34de22dd |
307 | backest = backish; |
308 | } |
e5d73d77 |
309 | str_nset(longish,"",0); |
310 | } |
a687059c |
311 | scan = regnext(scan); |
312 | } |
e5d73d77 |
313 | |
314 | /* Prefer earlier on tie, unless we can tail match latter */ |
315 | |
34de22dd |
316 | if (longish->str_cur + (OP(first) == EOL) > longest->str_cur) { |
0a12ae7d |
317 | str_sset(longest,longish); |
34de22dd |
318 | backest = backish; |
319 | } |
e5d73d77 |
320 | else |
321 | str_nset(longish,"",0); |
34de22dd |
322 | if (longest->str_cur |
323 | && |
324 | (!r->regstart |
325 | || |
326 | !fbminstr(r->regstart->str_ptr, |
327 | r->regstart->str_ptr + r->regstart->str_cur, |
328 | longest) |
329 | ) |
330 | ) |
331 | { |
a687059c |
332 | r->regmust = longest; |
34de22dd |
333 | if (backest < 0) |
334 | backest = -1; |
335 | r->regback = backest; |
0a12ae7d |
336 | if (longest->str_cur |
337 | > !(sawstudy || fold || OP(first) == EOL) ) |
a687059c |
338 | fbmcompile(r->regmust,fold); |
339 | r->regmust->str_u.str_useful = 100; |
e5d73d77 |
340 | if (OP(first) == EOL && longish->str_cur) |
a687059c |
341 | r->regmust->str_pok |= SP_TAIL; |
342 | } |
343 | else |
344 | str_free(longest); |
e5d73d77 |
345 | str_free(longish); |
a687059c |
346 | } |
347 | |
348 | r->do_folding = fold; |
349 | r->nparens = regnpar - 1; |
350 | #ifdef DEBUGGING |
351 | if (debug & 512) |
352 | regdump(r); |
353 | #endif |
354 | return(r); |
355 | } |
356 | |
357 | /* |
358 | - reg - regular expression, i.e. main body or parenthesized thing |
359 | * |
360 | * Caller must absorb opening parenthesis. |
361 | * |
362 | * Combining parenthesis handling with the base level of regular expression |
363 | * is a trifle forced, but the need to tie the tails of the branches to what |
364 | * follows makes it hard to avoid. |
365 | */ |
366 | static char * |
367 | reg(paren, flagp) |
368 | int paren; /* Parenthesized? */ |
369 | int *flagp; |
370 | { |
371 | register char *ret; |
372 | register char *br; |
373 | register char *ender; |
374 | register int parno; |
375 | int flags; |
376 | |
377 | *flagp = HASWIDTH; /* Tentatively. */ |
378 | |
379 | /* Make an OPEN node, if parenthesized. */ |
380 | if (paren) { |
381 | if (regnpar >= NSUBEXP) |
382 | FAIL("too many () in regexp"); |
383 | parno = regnpar; |
384 | regnpar++; |
385 | ret = regnode(OPEN+parno); |
386 | } else |
387 | ret = NULL; |
388 | |
389 | /* Pick up the branches, linking them together. */ |
390 | br = regbranch(&flags); |
391 | if (br == NULL) |
392 | return(NULL); |
393 | if (ret != NULL) |
394 | regtail(ret, br); /* OPEN -> first. */ |
395 | else |
396 | ret = br; |
397 | if (!(flags&HASWIDTH)) |
398 | *flagp &= ~HASWIDTH; |
399 | *flagp |= flags&SPSTART; |
400 | while (*regparse == '|') { |
401 | regparse++; |
402 | br = regbranch(&flags); |
403 | if (br == NULL) |
404 | return(NULL); |
405 | regtail(ret, br); /* BRANCH -> BRANCH. */ |
406 | if (!(flags&HASWIDTH)) |
407 | *flagp &= ~HASWIDTH; |
408 | *flagp |= flags&SPSTART; |
409 | } |
410 | |
411 | /* Make a closing node, and hook it on the end. */ |
412 | ender = regnode((paren) ? CLOSE+parno : END); |
413 | regtail(ret, ender); |
414 | |
415 | /* Hook the tails of the branches to the closing node. */ |
416 | for (br = ret; br != NULL; br = regnext(br)) |
417 | regoptail(br, ender); |
418 | |
419 | /* Check for proper termination. */ |
420 | if (paren && *regparse++ != ')') { |
421 | FAIL("unmatched () in regexp"); |
422 | } else if (!paren && regparse < regxend) { |
423 | if (*regparse == ')') { |
424 | FAIL("unmatched () in regexp"); |
425 | } else |
426 | FAIL("junk on end of regexp"); /* "Can't happen". */ |
427 | /* NOTREACHED */ |
428 | } |
429 | |
430 | return(ret); |
431 | } |
432 | |
433 | /* |
434 | - regbranch - one alternative of an | operator |
435 | * |
436 | * Implements the concatenation operator. |
437 | */ |
438 | static char * |
439 | regbranch(flagp) |
440 | int *flagp; |
441 | { |
442 | register char *ret; |
443 | register char *chain; |
444 | register char *latest; |
445 | int flags; |
446 | |
447 | *flagp = WORST; /* Tentatively. */ |
448 | |
449 | ret = regnode(BRANCH); |
450 | chain = NULL; |
451 | while (regparse < regxend && *regparse != '|' && *regparse != ')') { |
452 | latest = regpiece(&flags); |
453 | if (latest == NULL) |
454 | return(NULL); |
455 | *flagp |= flags&HASWIDTH; |
456 | if (chain == NULL) /* First piece. */ |
457 | *flagp |= flags&SPSTART; |
458 | else |
459 | regtail(chain, latest); |
460 | chain = latest; |
461 | } |
462 | if (chain == NULL) /* Loop ran zero times. */ |
463 | (void) regnode(NOTHING); |
464 | |
465 | return(ret); |
466 | } |
467 | |
468 | /* |
469 | - regpiece - something followed by possible [*+?] |
470 | * |
471 | * Note that the branching code sequences used for ? and the general cases |
472 | * of * and + are somewhat optimized: they use the same NOTHING node as |
473 | * both the endmarker for their branch list and the body of the last branch. |
474 | * It might seem that this node could be dispensed with entirely, but the |
475 | * endmarker role is not redundant. |
476 | */ |
477 | static char * |
478 | regpiece(flagp) |
479 | int *flagp; |
480 | { |
481 | register char *ret; |
482 | register char op; |
483 | register char *next; |
484 | int flags; |
485 | char *origparse = regparse; |
486 | int orignpar = regnpar; |
487 | char *max; |
488 | int iter; |
489 | char ch; |
490 | |
491 | ret = regatom(&flags); |
492 | if (ret == NULL) |
493 | return(NULL); |
494 | |
495 | op = *regparse; |
496 | |
497 | /* Here's a total kludge: if after the atom there's a {\d+,?\d*} |
498 | * then we decrement the first number by one and reset our |
499 | * parsing back to the beginning of the same atom. If the first number |
500 | * is down to 0, decrement the second number instead and fake up |
501 | * a ? after it. Given the way this compiler doesn't keep track |
502 | * of offsets on the first pass, this is the only way to replicate |
503 | * a piece of code. Sigh. |
504 | */ |
505 | if (op == '{' && regcurly(regparse)) { |
506 | next = regparse + 1; |
507 | max = Nullch; |
508 | while (isdigit(*next) || *next == ',') { |
509 | if (*next == ',') { |
510 | if (max) |
511 | break; |
512 | else |
513 | max = next; |
514 | } |
515 | next++; |
516 | } |
517 | if (*next == '}') { /* got one */ |
a687059c |
518 | if (!max) |
519 | max = next; |
520 | regparse++; |
521 | iter = atoi(regparse); |
00bf170e |
522 | if (flags&SIMPLE) { /* we can do it right after all */ |
523 | int tmp; |
524 | |
525 | reginsert(CURLY, ret); |
526 | if (*max == ',') |
527 | max++; |
6eb13c3b |
528 | else |
529 | max = regparse; |
00bf170e |
530 | tmp = atoi(max); |
531 | if (tmp && tmp < iter) |
532 | fatal("Can't do {n,m} with n > m"); |
533 | if (regcode != ®dummy) { |
534 | #ifdef REGALIGN |
535 | *(unsigned short *)(ret+3) = iter; |
536 | *(unsigned short *)(ret+5) = tmp; |
537 | #else |
538 | ret[3] = iter >> 8; ret[4] = iter & 0377; |
539 | ret[5] = tmp >> 8; ret[6] = tmp & 0377; |
540 | #endif |
541 | } |
542 | regparse = next; |
543 | goto nest_check; |
544 | } |
545 | regsawbracket++; /* remember we clobbered exp */ |
a687059c |
546 | if (iter > 0) { |
547 | ch = *max; |
548 | sprintf(regparse,"%.*d", max-regparse, iter - 1); |
549 | *max = ch; |
00bf170e |
550 | if (*max == ',' && max[1] != '}') { |
551 | if (atoi(max+1) <= 0) |
552 | fatal("Can't do {n,m} with n > m"); |
a687059c |
553 | ch = *next; |
554 | sprintf(max+1,"%.*d", next-(max+1), atoi(max+1) - 1); |
555 | *next = ch; |
556 | } |
00bf170e |
557 | if (iter != 1 || *max == ',') { |
a687059c |
558 | regparse = origparse; /* back up input pointer */ |
559 | regnpar = orignpar; /* don't make more parens */ |
560 | } |
561 | else { |
562 | regparse = next; |
563 | goto nest_check; |
564 | } |
565 | *flagp = flags; |
566 | return ret; |
567 | } |
568 | if (*max == ',') { |
569 | max++; |
570 | iter = atoi(max); |
571 | if (max == next) { /* any number more? */ |
572 | regparse = next; |
573 | op = '*'; /* fake up one with a star */ |
574 | } |
575 | else if (iter > 0) { |
576 | op = '?'; /* fake up optional atom */ |
577 | ch = *next; |
578 | sprintf(max,"%.*d", next-max, iter - 1); |
579 | *next = ch; |
580 | if (iter == 1) |
581 | regparse = next; |
582 | else { |
583 | regparse = origparse - 1; /* offset ++ below */ |
584 | regnpar = orignpar; |
585 | } |
586 | } |
587 | else |
588 | fatal("Can't do {n,0}"); |
589 | } |
590 | else |
591 | fatal("Can't do {0}"); |
592 | } |
593 | } |
594 | |
595 | if (!ISMULT1(op)) { |
596 | *flagp = flags; |
597 | return(ret); |
598 | } |
599 | |
600 | if (!(flags&HASWIDTH) && op != '?') |
601 | FAIL("regexp *+ operand could be empty"); |
602 | *flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH); |
603 | |
604 | if (op == '*' && (flags&SIMPLE)) |
605 | reginsert(STAR, ret); |
606 | else if (op == '*') { |
607 | /* Emit x* as (x&|), where & means "self". */ |
608 | reginsert(BRANCH, ret); /* Either x */ |
609 | regoptail(ret, regnode(BACK)); /* and loop */ |
610 | regoptail(ret, ret); /* back */ |
611 | regtail(ret, regnode(BRANCH)); /* or */ |
612 | regtail(ret, regnode(NOTHING)); /* null. */ |
613 | } else if (op == '+' && (flags&SIMPLE)) |
614 | reginsert(PLUS, ret); |
615 | else if (op == '+') { |
616 | /* Emit x+ as x(&|), where & means "self". */ |
617 | next = regnode(BRANCH); /* Either */ |
618 | regtail(ret, next); |
619 | regtail(regnode(BACK), ret); /* loop back */ |
620 | regtail(next, regnode(BRANCH)); /* or */ |
621 | regtail(ret, regnode(NOTHING)); /* null. */ |
622 | } else if (op == '?') { |
623 | /* Emit x? as (x|) */ |
624 | reginsert(BRANCH, ret); /* Either x */ |
625 | regtail(ret, regnode(BRANCH)); /* or */ |
626 | next = regnode(NOTHING); /* null. */ |
627 | regtail(ret, next); |
628 | regoptail(ret, next); |
629 | } |
630 | nest_check: |
631 | regparse++; |
632 | if (ISMULT2(regparse)) |
633 | FAIL("nested *?+ in regexp"); |
634 | |
635 | return(ret); |
636 | } |
637 | |
638 | /* |
639 | - regatom - the lowest level |
640 | * |
641 | * Optimization: gobbles an entire sequence of ordinary characters so that |
642 | * it can turn them into a single node, which is smaller to store and |
643 | * faster to run. Backslashed characters are exceptions, each becoming a |
644 | * separate node; the code is simpler that way and it's not worth fixing. |
645 | * |
646 | * [Yes, it is worth fixing, some scripts can run twice the speed.] |
647 | */ |
648 | static char * |
649 | regatom(flagp) |
650 | int *flagp; |
651 | { |
652 | register char *ret; |
653 | int flags; |
654 | |
655 | *flagp = WORST; /* Tentatively. */ |
656 | |
657 | switch (*regparse++) { |
658 | case '^': |
659 | ret = regnode(BOL); |
660 | break; |
661 | case '$': |
662 | ret = regnode(EOL); |
663 | break; |
664 | case '.': |
665 | ret = regnode(ANY); |
666 | *flagp |= HASWIDTH|SIMPLE; |
667 | break; |
668 | case '[': |
669 | ret = regclass(); |
670 | *flagp |= HASWIDTH|SIMPLE; |
671 | break; |
672 | case '(': |
673 | ret = reg(1, &flags); |
674 | if (ret == NULL) |
675 | return(NULL); |
676 | *flagp |= flags&(HASWIDTH|SPSTART); |
677 | break; |
678 | case '|': |
679 | case ')': |
680 | FAIL("internal urp in regexp"); /* Supposed to be caught earlier. */ |
681 | break; |
682 | case '?': |
683 | case '+': |
684 | case '*': |
685 | FAIL("?+* follows nothing in regexp"); |
686 | break; |
687 | case '\\': |
688 | switch (*regparse) { |
689 | case 'w': |
690 | ret = regnode(ALNUM); |
691 | *flagp |= HASWIDTH|SIMPLE; |
692 | regparse++; |
693 | break; |
694 | case 'W': |
695 | ret = regnode(NALNUM); |
696 | *flagp |= HASWIDTH|SIMPLE; |
697 | regparse++; |
698 | break; |
699 | case 'b': |
700 | ret = regnode(BOUND); |
701 | *flagp |= SIMPLE; |
702 | regparse++; |
703 | break; |
704 | case 'B': |
705 | ret = regnode(NBOUND); |
706 | *flagp |= SIMPLE; |
707 | regparse++; |
708 | break; |
709 | case 's': |
710 | ret = regnode(SPACE); |
711 | *flagp |= HASWIDTH|SIMPLE; |
712 | regparse++; |
713 | break; |
714 | case 'S': |
715 | ret = regnode(NSPACE); |
716 | *flagp |= HASWIDTH|SIMPLE; |
717 | regparse++; |
718 | break; |
719 | case 'd': |
720 | ret = regnode(DIGIT); |
721 | *flagp |= HASWIDTH|SIMPLE; |
722 | regparse++; |
723 | break; |
724 | case 'D': |
725 | ret = regnode(NDIGIT); |
726 | *flagp |= HASWIDTH|SIMPLE; |
727 | regparse++; |
728 | break; |
729 | case 'n': |
730 | case 'r': |
731 | case 't': |
732 | case 'f': |
733 | goto defchar; |
734 | case '0': case '1': case '2': case '3': case '4': |
735 | case '5': case '6': case '7': case '8': case '9': |
79a0689e |
736 | if (isdigit(regparse[1]) || *regparse == '0') |
a687059c |
737 | goto defchar; |
738 | else { |
739 | ret = regnode(REF + *regparse++ - '0'); |
740 | *flagp |= SIMPLE; |
741 | } |
742 | break; |
743 | case '\0': |
744 | if (regparse >= regxend) |
745 | FAIL("trailing \\ in regexp"); |
746 | /* FALL THROUGH */ |
747 | default: |
748 | goto defchar; |
749 | } |
750 | break; |
751 | default: { |
752 | register int len; |
753 | register char ender; |
754 | register char *p; |
755 | char *oldp; |
756 | int foo; |
757 | |
758 | defchar: |
759 | ret = regnode(EXACTLY); |
760 | regc(0); /* save spot for len */ |
761 | for (len=0, p=regparse-1; |
762 | len < 127 && p < regxend; |
763 | len++) |
764 | { |
765 | oldp = p; |
766 | switch (*p) { |
767 | case '^': |
768 | case '$': |
769 | case '.': |
770 | case '[': |
771 | case '(': |
772 | case ')': |
773 | case '|': |
774 | goto loopdone; |
775 | case '\\': |
776 | switch (*++p) { |
777 | case 'w': |
778 | case 'W': |
779 | case 'b': |
780 | case 'B': |
781 | case 's': |
782 | case 'S': |
783 | case 'd': |
784 | case 'D': |
785 | --p; |
786 | goto loopdone; |
787 | case 'n': |
788 | ender = '\n'; |
789 | p++; |
790 | break; |
791 | case 'r': |
792 | ender = '\r'; |
793 | p++; |
794 | break; |
795 | case 't': |
796 | ender = '\t'; |
797 | p++; |
798 | break; |
799 | case 'f': |
800 | ender = '\f'; |
801 | p++; |
802 | break; |
803 | case '0': case '1': case '2': case '3':case '4': |
804 | case '5': case '6': case '7': case '8':case '9': |
79a0689e |
805 | if (isdigit(p[1]) || *p == '0') { |
806 | foo = *p - '0'; |
807 | if (isdigit(p[1])) |
808 | foo = (foo<<3) + *++p - '0'; |
a687059c |
809 | if (isdigit(p[1])) |
810 | foo = (foo<<3) + *++p - '0'; |
811 | ender = foo; |
812 | p++; |
813 | } |
814 | else { |
815 | --p; |
816 | goto loopdone; |
817 | } |
818 | break; |
819 | case '\0': |
820 | if (p >= regxend) |
821 | FAIL("trailing \\ in regexp"); |
822 | /* FALL THROUGH */ |
823 | default: |
824 | ender = *p++; |
825 | break; |
826 | } |
827 | break; |
828 | default: |
829 | ender = *p++; |
830 | break; |
831 | } |
832 | if (regfold && isupper(ender)) |
833 | ender = tolower(ender); |
834 | if (ISMULT2(p)) { /* Back off on ?+*. */ |
835 | if (len) |
836 | p = oldp; |
837 | else { |
838 | len++; |
839 | regc(ender); |
840 | } |
841 | break; |
842 | } |
843 | regc(ender); |
844 | } |
845 | loopdone: |
846 | regparse = p; |
847 | if (len <= 0) |
848 | FAIL("internal disaster in regexp"); |
849 | *flagp |= HASWIDTH; |
850 | if (len == 1) |
851 | *flagp |= SIMPLE; |
852 | if (regcode != ®dummy) |
853 | *OPERAND(ret) = len; |
854 | regc('\0'); |
855 | } |
856 | break; |
857 | } |
858 | |
859 | return(ret); |
860 | } |
861 | |
862 | static void |
863 | regset(bits,def,c) |
864 | char *bits; |
865 | int def; |
866 | register int c; |
867 | { |
868 | if (regcode == ®dummy) |
869 | return; |
ac58e20f |
870 | c &= 255; |
a687059c |
871 | if (def) |
872 | bits[c >> 3] &= ~(1 << (c & 7)); |
873 | else |
874 | bits[c >> 3] |= (1 << (c & 7)); |
875 | } |
876 | |
877 | static char * |
878 | regclass() |
879 | { |
880 | register char *bits; |
881 | register int class; |
882 | register int lastclass; |
883 | register int range = 0; |
884 | register char *ret; |
885 | register int def; |
886 | |
00bf170e |
887 | ret = regnode(ANYOF); |
a687059c |
888 | if (*regparse == '^') { /* Complement of range. */ |
a687059c |
889 | regparse++; |
890 | def = 0; |
891 | } else { |
a687059c |
892 | def = 255; |
893 | } |
894 | bits = regcode; |
895 | for (class = 0; class < 32; class++) |
896 | regc(def); |
897 | if (*regparse == ']' || *regparse == '-') |
00bf170e |
898 | goto skipcond; /* allow 1st char to be ] or - */ |
a687059c |
899 | while (regparse < regxend && *regparse != ']') { |
00bf170e |
900 | skipcond: |
a687059c |
901 | class = UCHARAT(regparse++); |
902 | if (class == '\\') { |
903 | class = UCHARAT(regparse++); |
904 | switch (class) { |
905 | case 'w': |
906 | for (class = 'a'; class <= 'z'; class++) |
907 | regset(bits,def,class); |
908 | for (class = 'A'; class <= 'Z'; class++) |
909 | regset(bits,def,class); |
910 | for (class = '0'; class <= '9'; class++) |
911 | regset(bits,def,class); |
912 | regset(bits,def,'_'); |
913 | lastclass = 1234; |
914 | continue; |
915 | case 's': |
916 | regset(bits,def,' '); |
917 | regset(bits,def,'\t'); |
918 | regset(bits,def,'\r'); |
919 | regset(bits,def,'\f'); |
920 | regset(bits,def,'\n'); |
921 | lastclass = 1234; |
922 | continue; |
923 | case 'd': |
924 | for (class = '0'; class <= '9'; class++) |
925 | regset(bits,def,class); |
926 | lastclass = 1234; |
927 | continue; |
928 | case 'n': |
929 | class = '\n'; |
930 | break; |
931 | case 'r': |
932 | class = '\r'; |
933 | break; |
934 | case 't': |
935 | class = '\t'; |
936 | break; |
937 | case 'f': |
938 | class = '\f'; |
939 | break; |
940 | case 'b': |
941 | class = '\b'; |
942 | break; |
943 | case '0': case '1': case '2': case '3': case '4': |
944 | case '5': case '6': case '7': case '8': case '9': |
945 | class -= '0'; |
946 | if (isdigit(*regparse)) { |
947 | class <<= 3; |
948 | class += *regparse++ - '0'; |
949 | } |
950 | if (isdigit(*regparse)) { |
951 | class <<= 3; |
952 | class += *regparse++ - '0'; |
953 | } |
954 | break; |
955 | } |
956 | } |
a687059c |
957 | if (range) { |
958 | if (lastclass > class) |
959 | FAIL("invalid [] range in regexp"); |
00bf170e |
960 | range = 0; |
a687059c |
961 | } |
00bf170e |
962 | else { |
963 | lastclass = class; |
964 | if (*regparse == '-' && regparse+1 < regxend && |
965 | regparse[1] != ']') { |
966 | regparse++; |
967 | range = 1; |
968 | continue; /* do it next time */ |
969 | } |
970 | } |
971 | for ( ; lastclass <= class; lastclass++) { |
a687059c |
972 | regset(bits,def,lastclass); |
973 | if (regfold && isupper(lastclass)) |
974 | regset(bits,def,tolower(lastclass)); |
975 | } |
976 | lastclass = class; |
977 | } |
978 | if (*regparse != ']') |
979 | FAIL("unmatched [] in regexp"); |
a687059c |
980 | regparse++; |
981 | return ret; |
982 | } |
983 | |
984 | /* |
985 | - regnode - emit a node |
986 | */ |
987 | static char * /* Location. */ |
988 | regnode(op) |
989 | char op; |
990 | { |
991 | register char *ret; |
992 | register char *ptr; |
993 | |
994 | ret = regcode; |
995 | if (ret == ®dummy) { |
996 | #ifdef REGALIGN |
997 | if (!(regsize & 1)) |
998 | regsize++; |
999 | #endif |
1000 | regsize += 3; |
1001 | return(ret); |
1002 | } |
1003 | |
1004 | #ifdef REGALIGN |
1005 | #ifndef lint |
1006 | if (!((long)ret & 1)) |
1007 | *ret++ = 127; |
1008 | #endif |
1009 | #endif |
1010 | ptr = ret; |
1011 | *ptr++ = op; |
1012 | *ptr++ = '\0'; /* Null "next" pointer. */ |
1013 | *ptr++ = '\0'; |
1014 | regcode = ptr; |
1015 | |
1016 | return(ret); |
1017 | } |
1018 | |
1019 | /* |
1020 | - regc - emit (if appropriate) a byte of code |
1021 | */ |
1022 | static void |
1023 | regc(b) |
1024 | char b; |
1025 | { |
1026 | if (regcode != ®dummy) |
1027 | *regcode++ = b; |
1028 | else |
1029 | regsize++; |
1030 | } |
1031 | |
1032 | /* |
1033 | - reginsert - insert an operator in front of already-emitted operand |
1034 | * |
1035 | * Means relocating the operand. |
1036 | */ |
1037 | static void |
1038 | reginsert(op, opnd) |
1039 | char op; |
1040 | char *opnd; |
1041 | { |
1042 | register char *src; |
1043 | register char *dst; |
1044 | register char *place; |
00bf170e |
1045 | register offset = (op == CURLY ? 4 : 0); |
a687059c |
1046 | |
1047 | if (regcode == ®dummy) { |
1048 | #ifdef REGALIGN |
00bf170e |
1049 | regsize += 4 + offset; |
a687059c |
1050 | #else |
00bf170e |
1051 | regsize += 3 + offset; |
a687059c |
1052 | #endif |
1053 | return; |
1054 | } |
1055 | |
1056 | src = regcode; |
1057 | #ifdef REGALIGN |
00bf170e |
1058 | regcode += 4 + offset; |
a687059c |
1059 | #else |
00bf170e |
1060 | regcode += 3 + offset; |
a687059c |
1061 | #endif |
1062 | dst = regcode; |
1063 | while (src > opnd) |
1064 | *--dst = *--src; |
1065 | |
1066 | place = opnd; /* Op node, where operand used to be. */ |
1067 | *place++ = op; |
1068 | *place++ = '\0'; |
1069 | *place++ = '\0'; |
00bf170e |
1070 | while (offset-- > 0) |
1071 | *place++ = '\0'; |
a687059c |
1072 | } |
1073 | |
1074 | /* |
1075 | - regtail - set the next-pointer at the end of a node chain |
1076 | */ |
1077 | static void |
1078 | regtail(p, val) |
1079 | char *p; |
1080 | char *val; |
1081 | { |
1082 | register char *scan; |
1083 | register char *temp; |
1084 | register int offset; |
1085 | |
1086 | if (p == ®dummy) |
1087 | return; |
1088 | |
1089 | /* Find last node. */ |
1090 | scan = p; |
1091 | for (;;) { |
1092 | temp = regnext(scan); |
1093 | if (temp == NULL) |
1094 | break; |
1095 | scan = temp; |
1096 | } |
1097 | |
1098 | #ifdef REGALIGN |
1099 | offset = val - scan; |
1100 | #ifndef lint |
1101 | *(short*)(scan+1) = offset; |
1102 | #else |
1103 | offset = offset; |
1104 | #endif |
1105 | #else |
1106 | if (OP(scan) == BACK) |
1107 | offset = scan - val; |
1108 | else |
1109 | offset = val - scan; |
1110 | *(scan+1) = (offset>>8)&0377; |
1111 | *(scan+2) = offset&0377; |
1112 | #endif |
1113 | } |
1114 | |
1115 | /* |
1116 | - regoptail - regtail on operand of first argument; nop if operandless |
1117 | */ |
1118 | static void |
1119 | regoptail(p, val) |
1120 | char *p; |
1121 | char *val; |
1122 | { |
1123 | /* "Operandless" and "op != BRANCH" are synonymous in practice. */ |
1124 | if (p == NULL || p == ®dummy || OP(p) != BRANCH) |
1125 | return; |
1126 | regtail(NEXTOPER(p), val); |
1127 | } |
1128 | |
1129 | /* |
1130 | - regcurly - a little FSA that accepts {\d+,?\d*} |
1131 | */ |
1132 | STATIC int |
1133 | regcurly(s) |
1134 | register char *s; |
1135 | { |
1136 | if (*s++ != '{') |
1137 | return FALSE; |
1138 | if (!isdigit(*s)) |
1139 | return FALSE; |
1140 | while (isdigit(*s)) |
1141 | s++; |
1142 | if (*s == ',') |
1143 | s++; |
1144 | while (isdigit(*s)) |
1145 | s++; |
1146 | if (*s != '}') |
1147 | return FALSE; |
1148 | return TRUE; |
1149 | } |
1150 | |
1151 | #ifdef DEBUGGING |
1152 | |
1153 | /* |
1154 | - regdump - dump a regexp onto stderr in vaguely comprehensible form |
1155 | */ |
1156 | void |
1157 | regdump(r) |
1158 | regexp *r; |
1159 | { |
1160 | register char *s; |
1161 | register char op = EXACTLY; /* Arbitrary non-END op. */ |
1162 | register char *next; |
1163 | extern char *index(); |
1164 | |
1165 | |
1166 | s = r->program + 1; |
1167 | while (op != END) { /* While that wasn't END last time... */ |
1168 | #ifdef REGALIGN |
1169 | if (!((long)s & 1)) |
1170 | s++; |
1171 | #endif |
1172 | op = OP(s); |
1173 | fprintf(stderr,"%2d%s", s-r->program, regprop(s)); /* Where, what. */ |
0a12ae7d |
1174 | if (op == CURLY) |
1175 | s += 4; |
a687059c |
1176 | next = regnext(s); |
1177 | if (next == NULL) /* Next ptr. */ |
1178 | fprintf(stderr,"(0)"); |
1179 | else |
1180 | fprintf(stderr,"(%d)", (s-r->program)+(next-s)); |
1181 | s += 3; |
00bf170e |
1182 | if (op == ANYOF) { |
a687059c |
1183 | s += 32; |
1184 | } |
1185 | if (op == EXACTLY) { |
1186 | /* Literal string, where present. */ |
1187 | s++; |
1188 | while (*s != '\0') { |
1189 | (void)putchar(*s); |
1190 | s++; |
1191 | } |
1192 | s++; |
1193 | } |
1194 | (void)putchar('\n'); |
1195 | } |
1196 | |
1197 | /* Header fields of interest. */ |
1198 | if (r->regstart) |
1199 | fprintf(stderr,"start `%s' ", r->regstart->str_ptr); |
1200 | if (r->regstclass) |
1201 | fprintf(stderr,"stclass `%s' ", regprop(r->regstclass)); |
00bf170e |
1202 | if (r->reganch & 1) |
a687059c |
1203 | fprintf(stderr,"anchored "); |
00bf170e |
1204 | if (r->reganch & 2) |
1205 | fprintf(stderr,"plus "); |
a687059c |
1206 | if (r->regmust != NULL) |
1207 | fprintf(stderr,"must have \"%s\" back %d ", r->regmust->str_ptr, |
1208 | r->regback); |
1209 | fprintf(stderr,"\n"); |
1210 | } |
1211 | |
1212 | /* |
1213 | - regprop - printable representation of opcode |
1214 | */ |
1215 | char * |
1216 | regprop(op) |
1217 | char *op; |
1218 | { |
1219 | register char *p; |
1220 | |
1221 | (void) strcpy(buf, ":"); |
1222 | |
1223 | switch (OP(op)) { |
1224 | case BOL: |
1225 | p = "BOL"; |
1226 | break; |
1227 | case EOL: |
1228 | p = "EOL"; |
1229 | break; |
1230 | case ANY: |
1231 | p = "ANY"; |
1232 | break; |
1233 | case ANYOF: |
1234 | p = "ANYOF"; |
1235 | break; |
a687059c |
1236 | case BRANCH: |
1237 | p = "BRANCH"; |
1238 | break; |
1239 | case EXACTLY: |
1240 | p = "EXACTLY"; |
1241 | break; |
1242 | case NOTHING: |
1243 | p = "NOTHING"; |
1244 | break; |
1245 | case BACK: |
1246 | p = "BACK"; |
1247 | break; |
1248 | case END: |
1249 | p = "END"; |
1250 | break; |
1251 | case ALNUM: |
1252 | p = "ALNUM"; |
1253 | break; |
1254 | case NALNUM: |
1255 | p = "NALNUM"; |
1256 | break; |
1257 | case BOUND: |
1258 | p = "BOUND"; |
1259 | break; |
1260 | case NBOUND: |
1261 | p = "NBOUND"; |
1262 | break; |
1263 | case SPACE: |
1264 | p = "SPACE"; |
1265 | break; |
1266 | case NSPACE: |
1267 | p = "NSPACE"; |
1268 | break; |
1269 | case DIGIT: |
1270 | p = "DIGIT"; |
1271 | break; |
1272 | case NDIGIT: |
1273 | p = "NDIGIT"; |
1274 | break; |
00bf170e |
1275 | case CURLY: |
1276 | (void)sprintf(buf+strlen(buf), "CURLY {%d,%d}", |
1277 | ARG1(op),ARG2(op)); |
1278 | p = NULL; |
1279 | break; |
a687059c |
1280 | case REF: |
1281 | case REF+1: |
1282 | case REF+2: |
1283 | case REF+3: |
1284 | case REF+4: |
1285 | case REF+5: |
1286 | case REF+6: |
1287 | case REF+7: |
1288 | case REF+8: |
1289 | case REF+9: |
1290 | (void)sprintf(buf+strlen(buf), "REF%d", OP(op)-REF); |
1291 | p = NULL; |
1292 | break; |
1293 | case OPEN+1: |
1294 | case OPEN+2: |
1295 | case OPEN+3: |
1296 | case OPEN+4: |
1297 | case OPEN+5: |
1298 | case OPEN+6: |
1299 | case OPEN+7: |
1300 | case OPEN+8: |
1301 | case OPEN+9: |
1302 | (void)sprintf(buf+strlen(buf), "OPEN%d", OP(op)-OPEN); |
1303 | p = NULL; |
1304 | break; |
1305 | case CLOSE+1: |
1306 | case CLOSE+2: |
1307 | case CLOSE+3: |
1308 | case CLOSE+4: |
1309 | case CLOSE+5: |
1310 | case CLOSE+6: |
1311 | case CLOSE+7: |
1312 | case CLOSE+8: |
1313 | case CLOSE+9: |
1314 | (void)sprintf(buf+strlen(buf), "CLOSE%d", OP(op)-CLOSE); |
1315 | p = NULL; |
1316 | break; |
1317 | case STAR: |
1318 | p = "STAR"; |
1319 | break; |
1320 | case PLUS: |
1321 | p = "PLUS"; |
1322 | break; |
1323 | default: |
1324 | FAIL("corrupted regexp opcode"); |
1325 | } |
1326 | if (p != NULL) |
1327 | (void) strcat(buf, p); |
1328 | return(buf); |
1329 | } |
1330 | #endif /* DEBUGGING */ |
1331 | |
1332 | regfree(r) |
1333 | struct regexp *r; |
1334 | { |
1335 | if (r->precomp) |
1336 | Safefree(r->precomp); |
1337 | if (r->subbase) |
1338 | Safefree(r->subbase); |
1339 | if (r->regmust) |
1340 | str_free(r->regmust); |
1341 | if (r->regstart) |
1342 | str_free(r->regstart); |
1343 | Safefree(r); |
1344 | } |