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