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dd3b648e RP |
1 | /* Extended regular expression matching and search library. |
2 | Copyright (C) 1985, 1989 Free Software Foundation, Inc. | |
3 | ||
99a7de40 JG |
4 | This program is free software; you can redistribute it and/or modify |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 2 of the License, or | |
7 | (at your option) any later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program; if not, write to the Free Software | |
16 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
dd3b648e RP |
17 | |
18 | /* To test, compile with -Dtest. | |
19 | This Dtestable feature turns this into a self-contained program | |
20 | which reads a pattern, describes how it compiles, | |
21 | then reads a string and searches for it. */ | |
22 | ||
23 | #ifdef emacs | |
24 | ||
25 | /* The `emacs' switch turns on certain special matching commands | |
26 | that make sense only in emacs. */ | |
27 | ||
28 | #include "config.h" | |
29 | #include "lisp.h" | |
30 | #include "buffer.h" | |
31 | #include "syntax.h" | |
32 | ||
33 | #else /* not emacs */ | |
34 | ||
35 | #ifdef USG | |
36 | #ifndef BSTRING | |
37 | #define bcopy(s,d,n) memcpy((d),(s),(n)) | |
38 | #define bcmp(s1,s2,n) memcmp((s1),(s2),(n)) | |
39 | #define bzero(s,n) memset((s),0,(n)) | |
40 | #endif | |
41 | #endif | |
42 | ||
43 | /* Make alloca work the best possible way. */ | |
44 | #ifdef __GNUC__ | |
45 | #define alloca __builtin_alloca | |
46 | #else | |
47 | #ifdef sparc | |
48 | #include <alloca.h> | |
49 | #endif | |
50 | #endif | |
51 | ||
52 | /* | |
53 | * Define the syntax stuff, so we can do the \<...\> things. | |
54 | */ | |
55 | ||
56 | #ifndef Sword /* must be non-zero in some of the tests below... */ | |
57 | #define Sword 1 | |
58 | #endif | |
59 | ||
60 | #define SYNTAX(c) re_syntax_table[c] | |
61 | ||
62 | #ifdef SYNTAX_TABLE | |
63 | ||
64 | char *re_syntax_table; | |
65 | ||
66 | #else | |
67 | ||
68 | static char re_syntax_table[256]; | |
69 | ||
70 | static void | |
71 | init_syntax_once () | |
72 | { | |
73 | register int c; | |
74 | static int done = 0; | |
75 | ||
76 | if (done) | |
77 | return; | |
78 | ||
79 | bzero (re_syntax_table, sizeof re_syntax_table); | |
80 | ||
81 | for (c = 'a'; c <= 'z'; c++) | |
82 | re_syntax_table[c] = Sword; | |
83 | ||
84 | for (c = 'A'; c <= 'Z'; c++) | |
85 | re_syntax_table[c] = Sword; | |
86 | ||
87 | for (c = '0'; c <= '9'; c++) | |
88 | re_syntax_table[c] = Sword; | |
89 | ||
90 | done = 1; | |
91 | } | |
92 | ||
93 | #endif /* SYNTAX_TABLE */ | |
94 | #endif /* not emacs */ | |
95 | ||
96 | #include "regex.h" | |
97 | ||
98 | /* Number of failure points to allocate space for initially, | |
99 | when matching. If this number is exceeded, more space is allocated, | |
100 | so it is not a hard limit. */ | |
101 | ||
102 | #ifndef NFAILURES | |
103 | #define NFAILURES 80 | |
104 | #endif /* NFAILURES */ | |
105 | ||
106 | /* width of a byte in bits */ | |
107 | ||
108 | #define BYTEWIDTH 8 | |
109 | ||
110 | #ifndef SIGN_EXTEND_CHAR | |
111 | #define SIGN_EXTEND_CHAR(x) (x) | |
112 | #endif | |
113 | \f | |
114 | static int obscure_syntax = 0; | |
115 | ||
116 | /* Specify the precise syntax of regexp for compilation. | |
117 | This provides for compatibility for various utilities | |
118 | which historically have different, incompatible syntaxes. | |
119 | ||
120 | The argument SYNTAX is a bit-mask containing the two bits | |
121 | RE_NO_BK_PARENS and RE_NO_BK_VBAR. */ | |
122 | ||
123 | int | |
124 | re_set_syntax (syntax) | |
51b57ded | 125 | int syntax; |
dd3b648e RP |
126 | { |
127 | int ret; | |
128 | ||
129 | ret = obscure_syntax; | |
130 | obscure_syntax = syntax; | |
131 | return ret; | |
132 | } | |
133 | \f | |
134 | /* re_compile_pattern takes a regular-expression string | |
135 | and converts it into a buffer full of byte commands for matching. | |
136 | ||
137 | PATTERN is the address of the pattern string | |
138 | SIZE is the length of it. | |
139 | BUFP is a struct re_pattern_buffer * which points to the info | |
140 | on where to store the byte commands. | |
141 | This structure contains a char * which points to the | |
142 | actual space, which should have been obtained with malloc. | |
143 | re_compile_pattern may use realloc to grow the buffer space. | |
144 | ||
145 | The number of bytes of commands can be found out by looking in | |
146 | the struct re_pattern_buffer that bufp pointed to, | |
147 | after re_compile_pattern returns. | |
148 | */ | |
149 | ||
150 | #define PATPUSH(ch) (*b++ = (char) (ch)) | |
151 | ||
152 | #define PATFETCH(c) \ | |
153 | {if (p == pend) goto end_of_pattern; \ | |
154 | c = * (unsigned char *) p++; \ | |
155 | if (translate) c = translate[c]; } | |
156 | ||
157 | #define PATFETCH_RAW(c) \ | |
158 | {if (p == pend) goto end_of_pattern; \ | |
159 | c = * (unsigned char *) p++; } | |
160 | ||
161 | #define PATUNFETCH p-- | |
162 | ||
163 | #define EXTEND_BUFFER \ | |
164 | { char *old_buffer = bufp->buffer; \ | |
165 | if (bufp->allocated == (1<<16)) goto too_big; \ | |
166 | bufp->allocated *= 2; \ | |
167 | if (bufp->allocated > (1<<16)) bufp->allocated = (1<<16); \ | |
168 | if (!(bufp->buffer = (char *) realloc (bufp->buffer, bufp->allocated))) \ | |
169 | goto memory_exhausted; \ | |
170 | c = bufp->buffer - old_buffer; \ | |
171 | b += c; \ | |
172 | if (fixup_jump) \ | |
173 | fixup_jump += c; \ | |
174 | if (laststart) \ | |
175 | laststart += c; \ | |
176 | begalt += c; \ | |
177 | if (pending_exact) \ | |
178 | pending_exact += c; \ | |
179 | } | |
180 | ||
50e0dc41 | 181 | static void store_jump (), insert_jump (); |
dd3b648e RP |
182 | |
183 | char * | |
184 | re_compile_pattern (pattern, size, bufp) | |
185 | char *pattern; | |
186 | int size; | |
187 | struct re_pattern_buffer *bufp; | |
188 | { | |
189 | register char *b = bufp->buffer; | |
190 | register char *p = pattern; | |
191 | char *pend = pattern + size; | |
192 | register unsigned c, c1; | |
193 | char *p1; | |
194 | unsigned char *translate = (unsigned char *) bufp->translate; | |
195 | ||
196 | /* address of the count-byte of the most recently inserted "exactn" command. | |
197 | This makes it possible to tell whether a new exact-match character | |
198 | can be added to that command or requires a new "exactn" command. */ | |
199 | ||
200 | char *pending_exact = 0; | |
201 | ||
202 | /* address of the place where a forward-jump should go | |
203 | to the end of the containing expression. | |
204 | Each alternative of an "or", except the last, ends with a forward-jump | |
205 | of this sort. */ | |
206 | ||
207 | char *fixup_jump = 0; | |
208 | ||
209 | /* address of start of the most recently finished expression. | |
210 | This tells postfix * where to find the start of its operand. */ | |
211 | ||
212 | char *laststart = 0; | |
213 | ||
214 | /* In processing a repeat, 1 means zero matches is allowed */ | |
215 | ||
216 | char zero_times_ok; | |
217 | ||
218 | /* In processing a repeat, 1 means many matches is allowed */ | |
219 | ||
220 | char many_times_ok; | |
221 | ||
222 | /* address of beginning of regexp, or inside of last \( */ | |
223 | ||
224 | char *begalt = b; | |
225 | ||
226 | /* Stack of information saved by \( and restored by \). | |
227 | Four stack elements are pushed by each \(: | |
228 | First, the value of b. | |
229 | Second, the value of fixup_jump. | |
230 | Third, the value of regnum. | |
231 | Fourth, the value of begalt. */ | |
232 | ||
233 | int stackb[40]; | |
234 | int *stackp = stackb; | |
235 | int *stacke = stackb + 40; | |
236 | int *stackt; | |
237 | ||
238 | /* Counts \('s as they are encountered. Remembered for the matching \), | |
239 | where it becomes the "register number" to put in the stop_memory command */ | |
240 | ||
241 | int regnum = 1; | |
242 | ||
243 | bufp->fastmap_accurate = 0; | |
244 | ||
245 | #ifndef emacs | |
246 | #ifndef SYNTAX_TABLE | |
247 | /* | |
248 | * Initialize the syntax table. | |
249 | */ | |
250 | init_syntax_once(); | |
251 | #endif | |
252 | #endif | |
253 | ||
254 | if (bufp->allocated == 0) | |
255 | { | |
256 | bufp->allocated = 28; | |
257 | if (bufp->buffer) | |
258 | /* EXTEND_BUFFER loses when bufp->allocated is 0 */ | |
259 | bufp->buffer = (char *) realloc (bufp->buffer, 28); | |
260 | else | |
261 | /* Caller did not allocate a buffer. Do it for him */ | |
262 | bufp->buffer = (char *) malloc (28); | |
263 | if (!bufp->buffer) goto memory_exhausted; | |
264 | begalt = b = bufp->buffer; | |
265 | } | |
266 | ||
267 | while (p != pend) | |
268 | { | |
269 | if (b - bufp->buffer > bufp->allocated - 10) | |
270 | /* Note that EXTEND_BUFFER clobbers c */ | |
271 | EXTEND_BUFFER; | |
272 | ||
273 | PATFETCH (c); | |
274 | ||
275 | switch (c) | |
276 | { | |
277 | case '$': | |
278 | if (obscure_syntax & RE_TIGHT_VBAR) | |
279 | { | |
280 | if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS) && p != pend) | |
281 | goto normal_char; | |
282 | /* Make operand of last vbar end before this `$'. */ | |
283 | if (fixup_jump) | |
284 | store_jump (fixup_jump, jump, b); | |
285 | fixup_jump = 0; | |
286 | PATPUSH (endline); | |
287 | break; | |
288 | } | |
289 | ||
290 | /* $ means succeed if at end of line, but only in special contexts. | |
291 | If randomly in the middle of a pattern, it is a normal character. */ | |
292 | if (p == pend || *p == '\n' | |
293 | || (obscure_syntax & RE_CONTEXT_INDEP_OPS) | |
294 | || (obscure_syntax & RE_NO_BK_PARENS | |
295 | ? *p == ')' | |
296 | : *p == '\\' && p[1] == ')') | |
297 | || (obscure_syntax & RE_NO_BK_VBAR | |
298 | ? *p == '|' | |
299 | : *p == '\\' && p[1] == '|')) | |
300 | { | |
301 | PATPUSH (endline); | |
302 | break; | |
303 | } | |
304 | goto normal_char; | |
305 | ||
306 | case '^': | |
307 | /* ^ means succeed if at beg of line, but only if no preceding pattern. */ | |
308 | ||
309 | if (laststart && p[-2] != '\n' | |
310 | && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) | |
311 | goto normal_char; | |
312 | if (obscure_syntax & RE_TIGHT_VBAR) | |
313 | { | |
314 | if (p != pattern + 1 | |
315 | && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) | |
316 | goto normal_char; | |
317 | PATPUSH (begline); | |
318 | begalt = b; | |
319 | } | |
320 | else | |
321 | PATPUSH (begline); | |
322 | break; | |
323 | ||
324 | case '+': | |
325 | case '?': | |
326 | if (obscure_syntax & RE_BK_PLUS_QM) | |
327 | goto normal_char; | |
328 | handle_plus: | |
329 | case '*': | |
330 | /* If there is no previous pattern, char not special. */ | |
331 | if (!laststart && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) | |
332 | goto normal_char; | |
333 | /* If there is a sequence of repetition chars, | |
334 | collapse it down to equivalent to just one. */ | |
335 | zero_times_ok = 0; | |
336 | many_times_ok = 0; | |
337 | while (1) | |
338 | { | |
339 | zero_times_ok |= c != '+'; | |
340 | many_times_ok |= c != '?'; | |
341 | if (p == pend) | |
342 | break; | |
343 | PATFETCH (c); | |
344 | if (c == '*') | |
345 | ; | |
346 | else if (!(obscure_syntax & RE_BK_PLUS_QM) | |
347 | && (c == '+' || c == '?')) | |
348 | ; | |
349 | else if ((obscure_syntax & RE_BK_PLUS_QM) | |
350 | && c == '\\') | |
351 | { | |
352 | int c1; | |
353 | PATFETCH (c1); | |
354 | if (!(c1 == '+' || c1 == '?')) | |
355 | { | |
356 | PATUNFETCH; | |
357 | PATUNFETCH; | |
358 | break; | |
359 | } | |
360 | c = c1; | |
361 | } | |
362 | else | |
363 | { | |
364 | PATUNFETCH; | |
365 | break; | |
366 | } | |
367 | } | |
368 | ||
369 | /* Star, etc. applied to an empty pattern is equivalent | |
370 | to an empty pattern. */ | |
371 | if (!laststart) | |
372 | break; | |
373 | ||
374 | /* Now we know whether 0 matches is allowed, | |
375 | and whether 2 or more matches is allowed. */ | |
376 | if (many_times_ok) | |
377 | { | |
378 | /* If more than one repetition is allowed, | |
379 | put in a backward jump at the end. */ | |
380 | store_jump (b, maybe_finalize_jump, laststart - 3); | |
381 | b += 3; | |
382 | } | |
383 | insert_jump (on_failure_jump, laststart, b + 3, b); | |
384 | pending_exact = 0; | |
385 | b += 3; | |
386 | if (!zero_times_ok) | |
387 | { | |
388 | /* At least one repetition required: insert before the loop | |
389 | a skip over the initial on-failure-jump instruction */ | |
390 | insert_jump (dummy_failure_jump, laststart, laststart + 6, b); | |
391 | b += 3; | |
392 | } | |
393 | break; | |
394 | ||
395 | case '.': | |
396 | laststart = b; | |
397 | PATPUSH (anychar); | |
398 | break; | |
399 | ||
400 | case '[': | |
401 | while (b - bufp->buffer | |
402 | > bufp->allocated - 3 - (1 << BYTEWIDTH) / BYTEWIDTH) | |
403 | /* Note that EXTEND_BUFFER clobbers c */ | |
404 | EXTEND_BUFFER; | |
405 | ||
406 | laststart = b; | |
407 | if (*p == '^') | |
408 | PATPUSH (charset_not), p++; | |
409 | else | |
410 | PATPUSH (charset); | |
411 | p1 = p; | |
412 | ||
413 | PATPUSH ((1 << BYTEWIDTH) / BYTEWIDTH); | |
414 | /* Clear the whole map */ | |
415 | bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH); | |
416 | /* Read in characters and ranges, setting map bits */ | |
417 | while (1) | |
418 | { | |
419 | PATFETCH (c); | |
420 | if (c == ']' && p != p1 + 1) break; | |
421 | if (*p == '-' && p[1] != ']') | |
422 | { | |
423 | PATFETCH (c1); | |
424 | PATFETCH (c1); | |
425 | while (c <= c1) | |
426 | b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH), c++; | |
427 | } | |
428 | else | |
429 | { | |
430 | b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH); | |
431 | } | |
432 | } | |
433 | /* Discard any bitmap bytes that are all 0 at the end of the map. | |
434 | Decrement the map-length byte too. */ | |
435 | while ((int) b[-1] > 0 && b[b[-1] - 1] == 0) | |
436 | b[-1]--; | |
437 | b += b[-1]; | |
438 | break; | |
439 | ||
440 | case '(': | |
441 | if (! (obscure_syntax & RE_NO_BK_PARENS)) | |
442 | goto normal_char; | |
443 | else | |
444 | goto handle_open; | |
445 | ||
446 | case ')': | |
447 | if (! (obscure_syntax & RE_NO_BK_PARENS)) | |
448 | goto normal_char; | |
449 | else | |
450 | goto handle_close; | |
451 | ||
452 | case '\n': | |
453 | if (! (obscure_syntax & RE_NEWLINE_OR)) | |
454 | goto normal_char; | |
455 | else | |
456 | goto handle_bar; | |
457 | ||
458 | case '|': | |
459 | if (! (obscure_syntax & RE_NO_BK_VBAR)) | |
460 | goto normal_char; | |
461 | else | |
462 | goto handle_bar; | |
463 | ||
464 | case '\\': | |
465 | if (p == pend) goto invalid_pattern; | |
466 | PATFETCH_RAW (c); | |
467 | switch (c) | |
468 | { | |
469 | case '(': | |
470 | if (obscure_syntax & RE_NO_BK_PARENS) | |
471 | goto normal_backsl; | |
472 | handle_open: | |
473 | if (stackp == stacke) goto nesting_too_deep; | |
474 | if (regnum < RE_NREGS) | |
475 | { | |
476 | PATPUSH (start_memory); | |
477 | PATPUSH (regnum); | |
478 | } | |
479 | *stackp++ = b - bufp->buffer; | |
480 | *stackp++ = fixup_jump ? fixup_jump - bufp->buffer + 1 : 0; | |
481 | *stackp++ = regnum++; | |
482 | *stackp++ = begalt - bufp->buffer; | |
483 | fixup_jump = 0; | |
484 | laststart = 0; | |
485 | begalt = b; | |
486 | break; | |
487 | ||
488 | case ')': | |
489 | if (obscure_syntax & RE_NO_BK_PARENS) | |
490 | goto normal_backsl; | |
491 | handle_close: | |
492 | if (stackp == stackb) goto unmatched_close; | |
493 | begalt = *--stackp + bufp->buffer; | |
494 | if (fixup_jump) | |
495 | store_jump (fixup_jump, jump, b); | |
496 | if (stackp[-1] < RE_NREGS) | |
497 | { | |
498 | PATPUSH (stop_memory); | |
499 | PATPUSH (stackp[-1]); | |
500 | } | |
501 | stackp -= 2; | |
502 | fixup_jump = 0; | |
503 | if (*stackp) | |
504 | fixup_jump = *stackp + bufp->buffer - 1; | |
505 | laststart = *--stackp + bufp->buffer; | |
506 | break; | |
507 | ||
508 | case '|': | |
509 | if (obscure_syntax & RE_NO_BK_VBAR) | |
510 | goto normal_backsl; | |
511 | handle_bar: | |
512 | insert_jump (on_failure_jump, begalt, b + 6, b); | |
513 | pending_exact = 0; | |
514 | b += 3; | |
515 | if (fixup_jump) | |
516 | store_jump (fixup_jump, jump, b); | |
517 | fixup_jump = b; | |
518 | b += 3; | |
519 | laststart = 0; | |
520 | begalt = b; | |
521 | break; | |
522 | ||
523 | #ifdef emacs | |
524 | case '=': | |
525 | PATPUSH (at_dot); | |
526 | break; | |
527 | ||
528 | case 's': | |
529 | laststart = b; | |
530 | PATPUSH (syntaxspec); | |
531 | PATFETCH (c); | |
532 | PATPUSH (syntax_spec_code[c]); | |
533 | break; | |
534 | ||
535 | case 'S': | |
536 | laststart = b; | |
537 | PATPUSH (notsyntaxspec); | |
538 | PATFETCH (c); | |
539 | PATPUSH (syntax_spec_code[c]); | |
540 | break; | |
541 | #endif /* emacs */ | |
542 | ||
543 | case 'w': | |
544 | laststart = b; | |
545 | PATPUSH (wordchar); | |
546 | break; | |
547 | ||
548 | case 'W': | |
549 | laststart = b; | |
550 | PATPUSH (notwordchar); | |
551 | break; | |
552 | ||
553 | case '<': | |
554 | PATPUSH (wordbeg); | |
555 | break; | |
556 | ||
557 | case '>': | |
558 | PATPUSH (wordend); | |
559 | break; | |
560 | ||
561 | case 'b': | |
562 | PATPUSH (wordbound); | |
563 | break; | |
564 | ||
565 | case 'B': | |
566 | PATPUSH (notwordbound); | |
567 | break; | |
568 | ||
569 | case '`': | |
570 | PATPUSH (begbuf); | |
571 | break; | |
572 | ||
573 | case '\'': | |
574 | PATPUSH (endbuf); | |
575 | break; | |
576 | ||
577 | case '1': | |
578 | case '2': | |
579 | case '3': | |
580 | case '4': | |
581 | case '5': | |
582 | case '6': | |
583 | case '7': | |
584 | case '8': | |
585 | case '9': | |
586 | c1 = c - '0'; | |
587 | if (c1 >= regnum) | |
588 | goto normal_char; | |
589 | for (stackt = stackp - 2; stackt > stackb; stackt -= 4) | |
590 | if (*stackt == c1) | |
591 | goto normal_char; | |
592 | laststart = b; | |
593 | PATPUSH (duplicate); | |
594 | PATPUSH (c1); | |
595 | break; | |
596 | ||
597 | case '+': | |
598 | case '?': | |
599 | if (obscure_syntax & RE_BK_PLUS_QM) | |
600 | goto handle_plus; | |
601 | ||
602 | default: | |
603 | normal_backsl: | |
604 | /* You might think it would be useful for \ to mean | |
605 | not to translate; but if we don't translate it | |
606 | it will never match anything. */ | |
607 | if (translate) c = translate[c]; | |
608 | goto normal_char; | |
609 | } | |
610 | break; | |
611 | ||
612 | default: | |
613 | normal_char: | |
614 | if (!pending_exact || pending_exact + *pending_exact + 1 != b | |
615 | || *pending_exact == 0177 || *p == '*' || *p == '^' | |
616 | || ((obscure_syntax & RE_BK_PLUS_QM) | |
617 | ? *p == '\\' && (p[1] == '+' || p[1] == '?') | |
618 | : (*p == '+' || *p == '?'))) | |
619 | { | |
620 | laststart = b; | |
621 | PATPUSH (exactn); | |
622 | pending_exact = b; | |
623 | PATPUSH (0); | |
624 | } | |
625 | PATPUSH (c); | |
626 | (*pending_exact)++; | |
627 | } | |
628 | } | |
629 | ||
630 | if (fixup_jump) | |
631 | store_jump (fixup_jump, jump, b); | |
632 | ||
633 | if (stackp != stackb) goto unmatched_open; | |
634 | ||
635 | bufp->used = b - bufp->buffer; | |
636 | return 0; | |
637 | ||
638 | invalid_pattern: | |
639 | return "Invalid regular expression"; | |
640 | ||
641 | unmatched_open: | |
642 | return "Unmatched \\("; | |
643 | ||
644 | unmatched_close: | |
645 | return "Unmatched \\)"; | |
646 | ||
647 | end_of_pattern: | |
648 | return "Premature end of regular expression"; | |
649 | ||
650 | nesting_too_deep: | |
651 | return "Nesting too deep"; | |
652 | ||
653 | too_big: | |
654 | return "Regular expression too big"; | |
655 | ||
656 | memory_exhausted: | |
657 | return "Memory exhausted"; | |
658 | } | |
659 | ||
660 | /* Store where `from' points a jump operation to jump to where `to' points. | |
661 | `opcode' is the opcode to store. */ | |
662 | ||
50e0dc41 | 663 | static void |
dd3b648e RP |
664 | store_jump (from, opcode, to) |
665 | char *from, *to; | |
666 | char opcode; | |
667 | { | |
668 | from[0] = opcode; | |
669 | from[1] = (to - (from + 3)) & 0377; | |
670 | from[2] = (to - (from + 3)) >> 8; | |
671 | } | |
672 | ||
673 | /* Open up space at char FROM, and insert there a jump to TO. | |
674 | CURRENT_END gives te end of the storage no in use, | |
675 | so we know how much data to copy up. | |
676 | OP is the opcode of the jump to insert. | |
677 | ||
678 | If you call this function, you must zero out pending_exact. */ | |
679 | ||
50e0dc41 | 680 | static void |
dd3b648e RP |
681 | insert_jump (op, from, to, current_end) |
682 | char op; | |
683 | char *from, *to, *current_end; | |
684 | { | |
685 | register char *pto = current_end + 3; | |
686 | register char *pfrom = current_end; | |
687 | while (pfrom != from) | |
688 | *--pto = *--pfrom; | |
689 | store_jump (from, op, to); | |
690 | } | |
691 | \f | |
692 | /* Given a pattern, compute a fastmap from it. | |
693 | The fastmap records which of the (1 << BYTEWIDTH) possible characters | |
694 | can start a string that matches the pattern. | |
695 | This fastmap is used by re_search to skip quickly over totally implausible text. | |
696 | ||
697 | The caller must supply the address of a (1 << BYTEWIDTH)-byte data area | |
698 | as bufp->fastmap. | |
699 | The other components of bufp describe the pattern to be used. */ | |
700 | ||
701 | void | |
702 | re_compile_fastmap (bufp) | |
703 | struct re_pattern_buffer *bufp; | |
704 | { | |
705 | unsigned char *pattern = (unsigned char *) bufp->buffer; | |
706 | int size = bufp->used; | |
707 | register char *fastmap = bufp->fastmap; | |
708 | register unsigned char *p = pattern; | |
709 | register unsigned char *pend = pattern + size; | |
51b57ded | 710 | register int j; |
dd3b648e RP |
711 | unsigned char *translate = (unsigned char *) bufp->translate; |
712 | ||
713 | unsigned char *stackb[NFAILURES]; | |
714 | unsigned char **stackp = stackb; | |
715 | ||
716 | bzero (fastmap, (1 << BYTEWIDTH)); | |
717 | bufp->fastmap_accurate = 1; | |
718 | bufp->can_be_null = 0; | |
719 | ||
720 | while (p) | |
721 | { | |
722 | if (p == pend) | |
723 | { | |
724 | bufp->can_be_null = 1; | |
725 | break; | |
726 | } | |
727 | #ifdef SWITCH_ENUM_BUG | |
728 | switch ((int) ((enum regexpcode) *p++)) | |
729 | #else | |
730 | switch ((enum regexpcode) *p++) | |
731 | #endif | |
732 | { | |
733 | case exactn: | |
734 | if (translate) | |
735 | fastmap[translate[p[1]]] = 1; | |
736 | else | |
737 | fastmap[p[1]] = 1; | |
738 | break; | |
739 | ||
740 | case begline: | |
741 | case before_dot: | |
742 | case at_dot: | |
743 | case after_dot: | |
744 | case begbuf: | |
745 | case endbuf: | |
746 | case wordbound: | |
747 | case notwordbound: | |
748 | case wordbeg: | |
749 | case wordend: | |
750 | continue; | |
751 | ||
752 | case endline: | |
753 | if (translate) | |
754 | fastmap[translate['\n']] = 1; | |
755 | else | |
756 | fastmap['\n'] = 1; | |
757 | if (bufp->can_be_null != 1) | |
758 | bufp->can_be_null = 2; | |
759 | break; | |
760 | ||
761 | case finalize_jump: | |
762 | case maybe_finalize_jump: | |
763 | case jump: | |
764 | case dummy_failure_jump: | |
765 | bufp->can_be_null = 1; | |
766 | j = *p++ & 0377; | |
767 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; | |
768 | p += j + 1; /* The 1 compensates for missing ++ above */ | |
769 | if (j > 0) | |
770 | continue; | |
771 | /* Jump backward reached implies we just went through | |
772 | the body of a loop and matched nothing. | |
773 | Opcode jumped to should be an on_failure_jump. | |
774 | Just treat it like an ordinary jump. | |
775 | For a * loop, it has pushed its failure point already; | |
776 | if so, discard that as redundant. */ | |
777 | if ((enum regexpcode) *p != on_failure_jump) | |
778 | continue; | |
779 | p++; | |
780 | j = *p++ & 0377; | |
781 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; | |
782 | p += j + 1; /* The 1 compensates for missing ++ above */ | |
783 | if (stackp != stackb && *stackp == p) | |
784 | stackp--; | |
785 | continue; | |
786 | ||
787 | case on_failure_jump: | |
788 | j = *p++ & 0377; | |
789 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; | |
790 | p++; | |
791 | *++stackp = p + j; | |
792 | continue; | |
793 | ||
794 | case start_memory: | |
795 | case stop_memory: | |
796 | p++; | |
797 | continue; | |
798 | ||
799 | case duplicate: | |
800 | bufp->can_be_null = 1; | |
801 | fastmap['\n'] = 1; | |
802 | case anychar: | |
803 | for (j = 0; j < (1 << BYTEWIDTH); j++) | |
804 | if (j != '\n') | |
805 | fastmap[j] = 1; | |
806 | if (bufp->can_be_null) | |
807 | return; | |
808 | /* Don't return; check the alternative paths | |
809 | so we can set can_be_null if appropriate. */ | |
810 | break; | |
811 | ||
812 | case wordchar: | |
813 | for (j = 0; j < (1 << BYTEWIDTH); j++) | |
814 | if (SYNTAX (j) == Sword) | |
815 | fastmap[j] = 1; | |
816 | break; | |
817 | ||
818 | case notwordchar: | |
819 | for (j = 0; j < (1 << BYTEWIDTH); j++) | |
820 | if (SYNTAX (j) != Sword) | |
821 | fastmap[j] = 1; | |
822 | break; | |
823 | ||
824 | #ifdef emacs | |
825 | case syntaxspec: | |
826 | k = *p++; | |
827 | for (j = 0; j < (1 << BYTEWIDTH); j++) | |
828 | if (SYNTAX (j) == (enum syntaxcode) k) | |
829 | fastmap[j] = 1; | |
830 | break; | |
831 | ||
832 | case notsyntaxspec: | |
833 | k = *p++; | |
834 | for (j = 0; j < (1 << BYTEWIDTH); j++) | |
835 | if (SYNTAX (j) != (enum syntaxcode) k) | |
836 | fastmap[j] = 1; | |
837 | break; | |
838 | #endif /* emacs */ | |
839 | ||
840 | case charset: | |
841 | for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) | |
842 | if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))) | |
843 | { | |
844 | if (translate) | |
845 | fastmap[translate[j]] = 1; | |
846 | else | |
847 | fastmap[j] = 1; | |
848 | } | |
849 | break; | |
850 | ||
851 | case charset_not: | |
852 | /* Chars beyond end of map must be allowed */ | |
853 | for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++) | |
854 | if (translate) | |
855 | fastmap[translate[j]] = 1; | |
856 | else | |
857 | fastmap[j] = 1; | |
858 | ||
859 | for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) | |
860 | if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))) | |
861 | { | |
862 | if (translate) | |
863 | fastmap[translate[j]] = 1; | |
864 | else | |
865 | fastmap[j] = 1; | |
866 | } | |
867 | break; | |
868 | } | |
869 | ||
870 | /* Get here means we have successfully found the possible starting characters | |
871 | of one path of the pattern. We need not follow this path any farther. | |
872 | Instead, look at the next alternative remembered in the stack. */ | |
873 | if (stackp != stackb) | |
874 | p = *stackp--; | |
875 | else | |
876 | break; | |
877 | } | |
878 | } | |
879 | \f | |
880 | /* Like re_search_2, below, but only one string is specified. */ | |
881 | ||
882 | int | |
883 | re_search (pbufp, string, size, startpos, range, regs) | |
884 | struct re_pattern_buffer *pbufp; | |
885 | char *string; | |
886 | int size, startpos, range; | |
887 | struct re_registers *regs; | |
888 | { | |
889 | return re_search_2 (pbufp, 0, 0, string, size, startpos, range, regs, size); | |
890 | } | |
891 | ||
892 | /* Like re_match_2 but tries first a match starting at index STARTPOS, | |
893 | then at STARTPOS + 1, and so on. | |
894 | RANGE is the number of places to try before giving up. | |
895 | If RANGE is negative, the starting positions tried are | |
896 | STARTPOS, STARTPOS - 1, etc. | |
897 | It is up to the caller to make sure that range is not so large | |
898 | as to take the starting position outside of the input strings. | |
899 | ||
900 | The value returned is the position at which the match was found, | |
901 | or -1 if no match was found, | |
902 | or -2 if error (such as failure stack overflow). */ | |
903 | ||
904 | int | |
905 | re_search_2 (pbufp, string1, size1, string2, size2, startpos, range, regs, mstop) | |
906 | struct re_pattern_buffer *pbufp; | |
907 | char *string1, *string2; | |
908 | int size1, size2; | |
909 | int startpos; | |
910 | register int range; | |
911 | struct re_registers *regs; | |
912 | int mstop; | |
913 | { | |
914 | register char *fastmap = pbufp->fastmap; | |
915 | register unsigned char *translate = (unsigned char *) pbufp->translate; | |
916 | int total = size1 + size2; | |
917 | int val; | |
918 | ||
919 | /* Update the fastmap now if not correct already */ | |
920 | if (fastmap && !pbufp->fastmap_accurate) | |
921 | re_compile_fastmap (pbufp); | |
922 | ||
923 | /* Don't waste time in a long search for a pattern | |
924 | that says it is anchored. */ | |
925 | if (pbufp->used > 0 && (enum regexpcode) pbufp->buffer[0] == begbuf | |
926 | && range > 0) | |
927 | { | |
928 | if (startpos > 0) | |
929 | return -1; | |
930 | else | |
931 | range = 1; | |
932 | } | |
933 | ||
934 | while (1) | |
935 | { | |
936 | /* If a fastmap is supplied, skip quickly over characters | |
937 | that cannot possibly be the start of a match. | |
938 | Note, however, that if the pattern can possibly match | |
939 | the null string, we must test it at each starting point | |
940 | so that we take the first null string we get. */ | |
941 | ||
942 | if (fastmap && startpos < total && pbufp->can_be_null != 1) | |
943 | { | |
944 | if (range > 0) | |
945 | { | |
946 | register int lim = 0; | |
947 | register unsigned char *p; | |
948 | int irange = range; | |
949 | if (startpos < size1 && startpos + range >= size1) | |
950 | lim = range - (size1 - startpos); | |
951 | ||
952 | p = ((unsigned char *) | |
953 | &(startpos >= size1 ? string2 - size1 : string1)[startpos]); | |
954 | ||
955 | if (translate) | |
956 | { | |
957 | while (range > lim && !fastmap[translate[*p++]]) | |
958 | range--; | |
959 | } | |
960 | else | |
961 | { | |
962 | while (range > lim && !fastmap[*p++]) | |
963 | range--; | |
964 | } | |
965 | startpos += irange - range; | |
966 | } | |
967 | else | |
968 | { | |
969 | register unsigned char c; | |
970 | if (startpos >= size1) | |
971 | c = string2[startpos - size1]; | |
972 | else | |
973 | c = string1[startpos]; | |
974 | c &= 0xff; | |
975 | if (translate ? !fastmap[translate[c]] : !fastmap[c]) | |
976 | goto advance; | |
977 | } | |
978 | } | |
979 | ||
980 | if (range >= 0 && startpos == total | |
981 | && fastmap && pbufp->can_be_null == 0) | |
982 | return -1; | |
983 | ||
984 | val = re_match_2 (pbufp, string1, size1, string2, size2, startpos, regs, mstop); | |
985 | if (0 <= val) | |
986 | { | |
987 | if (val == -2) | |
988 | return -2; | |
989 | return startpos; | |
990 | } | |
991 | ||
992 | #ifdef C_ALLOCA | |
993 | alloca (0); | |
994 | #endif /* C_ALLOCA */ | |
995 | ||
996 | advance: | |
997 | if (!range) break; | |
998 | if (range > 0) range--, startpos++; else range++, startpos--; | |
999 | } | |
1000 | return -1; | |
1001 | } | |
1002 | \f | |
1003 | #ifndef emacs /* emacs never uses this */ | |
1004 | int | |
1005 | re_match (pbufp, string, size, pos, regs) | |
1006 | struct re_pattern_buffer *pbufp; | |
1007 | char *string; | |
1008 | int size, pos; | |
1009 | struct re_registers *regs; | |
1010 | { | |
1011 | return re_match_2 (pbufp, 0, 0, string, size, pos, regs, size); | |
1012 | } | |
1013 | #endif /* emacs */ | |
1014 | ||
1015 | /* Maximum size of failure stack. Beyond this, overflow is an error. */ | |
1016 | ||
1017 | int re_max_failures = 2000; | |
1018 | ||
1019 | static int bcmp_translate(); | |
1020 | /* Match the pattern described by PBUFP | |
1021 | against data which is the virtual concatenation of STRING1 and STRING2. | |
1022 | SIZE1 and SIZE2 are the sizes of the two data strings. | |
1023 | Start the match at position POS. | |
1024 | Do not consider matching past the position MSTOP. | |
1025 | ||
1026 | If pbufp->fastmap is nonzero, then it had better be up to date. | |
1027 | ||
1028 | The reason that the data to match are specified as two components | |
1029 | which are to be regarded as concatenated | |
1030 | is so this function can be used directly on the contents of an Emacs buffer. | |
1031 | ||
1032 | -1 is returned if there is no match. -2 is returned if there is | |
1033 | an error (such as match stack overflow). Otherwise the value is the length | |
1034 | of the substring which was matched. */ | |
1035 | ||
1036 | int | |
1037 | re_match_2 (pbufp, string1, size1, string2, size2, pos, regs, mstop) | |
1038 | struct re_pattern_buffer *pbufp; | |
1039 | unsigned char *string1, *string2; | |
1040 | int size1, size2; | |
1041 | int pos; | |
1042 | struct re_registers *regs; | |
1043 | int mstop; | |
1044 | { | |
1045 | register unsigned char *p = (unsigned char *) pbufp->buffer; | |
1046 | register unsigned char *pend = p + pbufp->used; | |
1047 | /* End of first string */ | |
1048 | unsigned char *end1; | |
1049 | /* End of second string */ | |
1050 | unsigned char *end2; | |
1051 | /* Pointer just past last char to consider matching */ | |
1052 | unsigned char *end_match_1, *end_match_2; | |
1053 | register unsigned char *d, *dend; | |
1054 | register int mcnt; | |
1055 | unsigned char *translate = (unsigned char *) pbufp->translate; | |
1056 | ||
1057 | /* Failure point stack. Each place that can handle a failure further down the line | |
1058 | pushes a failure point on this stack. It consists of two char *'s. | |
1059 | The first one pushed is where to resume scanning the pattern; | |
1060 | the second pushed is where to resume scanning the strings. | |
1061 | If the latter is zero, the failure point is a "dummy". | |
1062 | If a failure happens and the innermost failure point is dormant, | |
1063 | it discards that failure point and tries the next one. */ | |
1064 | ||
1065 | unsigned char *initial_stack[2 * NFAILURES]; | |
1066 | unsigned char **stackb = initial_stack; | |
1067 | unsigned char **stackp = stackb, **stacke = &stackb[2 * NFAILURES]; | |
1068 | ||
1069 | /* Information on the "contents" of registers. | |
1070 | These are pointers into the input strings; they record | |
1071 | just what was matched (on this attempt) by some part of the pattern. | |
1072 | The start_memory command stores the start of a register's contents | |
1073 | and the stop_memory command stores the end. | |
1074 | ||
1075 | At that point, regstart[regnum] points to the first character in the register, | |
1076 | regend[regnum] points to the first character beyond the end of the register, | |
1077 | regstart_seg1[regnum] is true iff regstart[regnum] points into string1, | |
1078 | and regend_seg1[regnum] is true iff regend[regnum] points into string1. */ | |
1079 | ||
1080 | unsigned char *regstart[RE_NREGS]; | |
1081 | unsigned char *regend[RE_NREGS]; | |
1082 | unsigned char regstart_seg1[RE_NREGS], regend_seg1[RE_NREGS]; | |
1083 | ||
1084 | /* Set up pointers to ends of strings. | |
1085 | Don't allow the second string to be empty unless both are empty. */ | |
1086 | if (!size2) | |
1087 | { | |
1088 | string2 = string1; | |
1089 | size2 = size1; | |
1090 | string1 = 0; | |
1091 | size1 = 0; | |
1092 | } | |
1093 | end1 = string1 + size1; | |
1094 | end2 = string2 + size2; | |
1095 | ||
1096 | /* Compute where to stop matching, within the two strings */ | |
1097 | if (mstop <= size1) | |
1098 | { | |
1099 | end_match_1 = string1 + mstop; | |
1100 | end_match_2 = string2; | |
1101 | } | |
1102 | else | |
1103 | { | |
1104 | end_match_1 = end1; | |
1105 | end_match_2 = string2 + mstop - size1; | |
1106 | } | |
1107 | ||
1108 | /* Initialize \) text positions to -1 | |
1109 | to mark ones that no \( or \) has been seen for. */ | |
1110 | ||
1111 | for (mcnt = 0; mcnt < sizeof (regend) / sizeof (*regend); mcnt++) | |
1112 | regend[mcnt] = (unsigned char *) -1; | |
1113 | ||
1114 | /* `p' scans through the pattern as `d' scans through the data. | |
1115 | `dend' is the end of the input string that `d' points within. | |
1116 | `d' is advanced into the following input string whenever necessary, | |
1117 | but this happens before fetching; | |
1118 | therefore, at the beginning of the loop, | |
1119 | `d' can be pointing at the end of a string, | |
1120 | but it cannot equal string2. */ | |
1121 | ||
1122 | if (pos <= size1) | |
1123 | d = string1 + pos, dend = end_match_1; | |
1124 | else | |
1125 | d = string2 + pos - size1, dend = end_match_2; | |
1126 | ||
1127 | /* Write PREFETCH; just before fetching a character with *d. */ | |
1128 | #define PREFETCH \ | |
1129 | while (d == dend) \ | |
1130 | { if (dend == end_match_2) goto fail; /* end of string2 => failure */ \ | |
1131 | d = string2; /* end of string1 => advance to string2. */ \ | |
1132 | dend = end_match_2; } | |
1133 | ||
1134 | /* This loop loops over pattern commands. | |
1135 | It exits by returning from the function if match is complete, | |
1136 | or it drops through if match fails at this starting point in the input data. */ | |
1137 | ||
1138 | while (1) | |
1139 | { | |
1140 | if (p == pend) | |
1141 | /* End of pattern means we have succeeded! */ | |
1142 | { | |
1143 | /* If caller wants register contents data back, convert it to indices */ | |
1144 | if (regs) | |
1145 | { | |
1146 | regs->start[0] = pos; | |
1147 | if (dend == end_match_1) | |
1148 | regs->end[0] = d - string1; | |
1149 | else | |
1150 | regs->end[0] = d - string2 + size1; | |
1151 | for (mcnt = 1; mcnt < RE_NREGS; mcnt++) | |
1152 | { | |
1153 | if (regend[mcnt] == (unsigned char *) -1) | |
1154 | { | |
1155 | regs->start[mcnt] = -1; | |
1156 | regs->end[mcnt] = -1; | |
1157 | continue; | |
1158 | } | |
1159 | if (regstart_seg1[mcnt]) | |
1160 | regs->start[mcnt] = regstart[mcnt] - string1; | |
1161 | else | |
1162 | regs->start[mcnt] = regstart[mcnt] - string2 + size1; | |
1163 | if (regend_seg1[mcnt]) | |
1164 | regs->end[mcnt] = regend[mcnt] - string1; | |
1165 | else | |
1166 | regs->end[mcnt] = regend[mcnt] - string2 + size1; | |
1167 | } | |
1168 | } | |
1169 | if (dend == end_match_1) | |
1170 | return (d - string1 - pos); | |
1171 | else | |
1172 | return d - string2 + size1 - pos; | |
1173 | } | |
1174 | ||
1175 | /* Otherwise match next pattern command */ | |
1176 | #ifdef SWITCH_ENUM_BUG | |
1177 | switch ((int) ((enum regexpcode) *p++)) | |
1178 | #else | |
1179 | switch ((enum regexpcode) *p++) | |
1180 | #endif | |
1181 | { | |
1182 | ||
1183 | /* \( is represented by a start_memory, \) by a stop_memory. | |
1184 | Both of those commands contain a "register number" argument. | |
1185 | The text matched within the \( and \) is recorded under that number. | |
1186 | Then, \<digit> turns into a `duplicate' command which | |
1187 | is followed by the numeric value of <digit> as the register number. */ | |
1188 | ||
1189 | case start_memory: | |
1190 | regstart[*p] = d; | |
1191 | regstart_seg1[*p++] = (dend == end_match_1); | |
1192 | break; | |
1193 | ||
1194 | case stop_memory: | |
1195 | regend[*p] = d; | |
1196 | regend_seg1[*p++] = (dend == end_match_1); | |
1197 | break; | |
1198 | ||
1199 | case duplicate: | |
1200 | { | |
1201 | int regno = *p++; /* Get which register to match against */ | |
1202 | register unsigned char *d2, *dend2; | |
1203 | ||
1204 | d2 = regstart[regno]; | |
1205 | dend2 = ((regstart_seg1[regno] == regend_seg1[regno]) | |
1206 | ? regend[regno] : end_match_1); | |
1207 | while (1) | |
1208 | { | |
1209 | /* Advance to next segment in register contents, if necessary */ | |
1210 | while (d2 == dend2) | |
1211 | { | |
1212 | if (dend2 == end_match_2) break; | |
1213 | if (dend2 == regend[regno]) break; | |
1214 | d2 = string2, dend2 = regend[regno]; /* end of string1 => advance to string2. */ | |
1215 | } | |
1216 | /* At end of register contents => success */ | |
1217 | if (d2 == dend2) break; | |
1218 | ||
1219 | /* Advance to next segment in data being matched, if necessary */ | |
1220 | PREFETCH; | |
1221 | ||
1222 | /* mcnt gets # consecutive chars to compare */ | |
1223 | mcnt = dend - d; | |
1224 | if (mcnt > dend2 - d2) | |
1225 | mcnt = dend2 - d2; | |
1226 | /* Compare that many; failure if mismatch, else skip them. */ | |
1227 | if (translate ? bcmp_translate (d, d2, mcnt, translate) : bcmp (d, d2, mcnt)) | |
1228 | goto fail; | |
1229 | d += mcnt, d2 += mcnt; | |
1230 | } | |
1231 | } | |
1232 | break; | |
1233 | ||
1234 | case anychar: | |
1235 | /* fetch a data character */ | |
1236 | PREFETCH; | |
1237 | /* Match anything but a newline. */ | |
1238 | if ((translate ? translate[*d++] : *d++) == '\n') | |
1239 | goto fail; | |
1240 | break; | |
1241 | ||
1242 | case charset: | |
1243 | case charset_not: | |
1244 | { | |
1245 | /* Nonzero for charset_not */ | |
1246 | int not = 0; | |
1247 | register int c; | |
1248 | if (*(p - 1) == (unsigned char) charset_not) | |
1249 | not = 1; | |
1250 | ||
1251 | /* fetch a data character */ | |
1252 | PREFETCH; | |
1253 | ||
1254 | if (translate) | |
1255 | c = translate [*d]; | |
1256 | else | |
1257 | c = *d; | |
1258 | ||
1259 | if (c < *p * BYTEWIDTH | |
1260 | && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) | |
1261 | not = !not; | |
1262 | ||
1263 | p += 1 + *p; | |
1264 | ||
1265 | if (!not) goto fail; | |
1266 | d++; | |
1267 | break; | |
1268 | } | |
1269 | ||
1270 | case begline: | |
1271 | if (d == string1 || d[-1] == '\n') | |
1272 | break; | |
1273 | goto fail; | |
1274 | ||
1275 | case endline: | |
1276 | if (d == end2 | |
1277 | || (d == end1 ? (size2 == 0 || *string2 == '\n') : *d == '\n')) | |
1278 | break; | |
1279 | goto fail; | |
1280 | ||
1281 | /* "or" constructs ("|") are handled by starting each alternative | |
1282 | with an on_failure_jump that points to the start of the next alternative. | |
1283 | Each alternative except the last ends with a jump to the joining point. | |
1284 | (Actually, each jump except for the last one really jumps | |
1285 | to the following jump, because tensioning the jumps is a hassle.) */ | |
1286 | ||
1287 | /* The start of a stupid repeat has an on_failure_jump that points | |
1288 | past the end of the repeat text. | |
1289 | This makes a failure point so that, on failure to match a repetition, | |
1290 | matching restarts past as many repetitions have been found | |
1291 | with no way to fail and look for another one. */ | |
1292 | ||
1293 | /* A smart repeat is similar but loops back to the on_failure_jump | |
1294 | so that each repetition makes another failure point. */ | |
1295 | ||
1296 | case on_failure_jump: | |
1297 | if (stackp == stacke) | |
1298 | { | |
1299 | unsigned char **stackx; | |
1300 | if (stacke - stackb > re_max_failures * 2) | |
1301 | return -2; | |
1302 | stackx = (unsigned char **) alloca (2 * (stacke - stackb) | |
1303 | * sizeof (char *)); | |
1304 | bcopy (stackb, stackx, (stacke - stackb) * sizeof (char *)); | |
1305 | stackp = stackx + (stackp - stackb); | |
1306 | stacke = stackx + 2 * (stacke - stackb); | |
1307 | stackb = stackx; | |
1308 | } | |
1309 | mcnt = *p++ & 0377; | |
1310 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; | |
1311 | p++; | |
1312 | *stackp++ = mcnt + p; | |
1313 | *stackp++ = d; | |
1314 | break; | |
1315 | ||
1316 | /* The end of a smart repeat has an maybe_finalize_jump back. | |
1317 | Change it either to a finalize_jump or an ordinary jump. */ | |
1318 | ||
1319 | case maybe_finalize_jump: | |
1320 | mcnt = *p++ & 0377; | |
1321 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; | |
1322 | p++; | |
1323 | { | |
1324 | register unsigned char *p2 = p; | |
1325 | /* Compare what follows with the begining of the repeat. | |
1326 | If we can establish that there is nothing that they would | |
1327 | both match, we can change to finalize_jump */ | |
1328 | while (p2 != pend | |
1329 | && (*p2 == (unsigned char) stop_memory | |
1330 | || *p2 == (unsigned char) start_memory)) | |
1331 | p2++; | |
1332 | if (p2 == pend) | |
1333 | p[-3] = (unsigned char) finalize_jump; | |
1334 | else if (*p2 == (unsigned char) exactn | |
1335 | || *p2 == (unsigned char) endline) | |
1336 | { | |
1337 | register int c = *p2 == (unsigned char) endline ? '\n' : p2[2]; | |
1338 | register unsigned char *p1 = p + mcnt; | |
1339 | /* p1[0] ... p1[2] are an on_failure_jump. | |
1340 | Examine what follows that */ | |
1341 | if (p1[3] == (unsigned char) exactn && p1[5] != c) | |
1342 | p[-3] = (unsigned char) finalize_jump; | |
1343 | else if (p1[3] == (unsigned char) charset | |
1344 | || p1[3] == (unsigned char) charset_not) | |
1345 | { | |
1346 | int not = p1[3] == (unsigned char) charset_not; | |
1347 | if (c < p1[4] * BYTEWIDTH | |
1348 | && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) | |
1349 | not = !not; | |
1350 | /* not is 1 if c would match */ | |
1351 | /* That means it is not safe to finalize */ | |
1352 | if (!not) | |
1353 | p[-3] = (unsigned char) finalize_jump; | |
1354 | } | |
1355 | } | |
1356 | } | |
1357 | p -= 2; | |
1358 | if (p[-1] != (unsigned char) finalize_jump) | |
1359 | { | |
1360 | p[-1] = (unsigned char) jump; | |
1361 | goto nofinalize; | |
1362 | } | |
1363 | ||
1364 | /* The end of a stupid repeat has a finalize-jump | |
1365 | back to the start, where another failure point will be made | |
1366 | which will point after all the repetitions found so far. */ | |
1367 | ||
1368 | case finalize_jump: | |
1369 | stackp -= 2; | |
1370 | ||
1371 | case jump: | |
1372 | nofinalize: | |
1373 | mcnt = *p++ & 0377; | |
1374 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; | |
1375 | p += mcnt + 1; /* The 1 compensates for missing ++ above */ | |
1376 | break; | |
1377 | ||
1378 | case dummy_failure_jump: | |
1379 | if (stackp == stacke) | |
1380 | { | |
1381 | unsigned char **stackx | |
1382 | = (unsigned char **) alloca (2 * (stacke - stackb) | |
1383 | * sizeof (char *)); | |
1384 | bcopy (stackb, stackx, (stacke - stackb) * sizeof (char *)); | |
1385 | stackp = stackx + (stackp - stackb); | |
1386 | stacke = stackx + 2 * (stacke - stackb); | |
1387 | stackb = stackx; | |
1388 | } | |
1389 | *stackp++ = 0; | |
1390 | *stackp++ = 0; | |
1391 | goto nofinalize; | |
1392 | ||
1393 | case wordbound: | |
1394 | if (d == string1 /* Points to first char */ | |
1395 | || d == end2 /* Points to end */ | |
1396 | || (d == end1 && size2 == 0)) /* Points to end */ | |
1397 | break; | |
1398 | if ((SYNTAX (d[-1]) == Sword) | |
1399 | != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) | |
1400 | break; | |
1401 | goto fail; | |
1402 | ||
1403 | case notwordbound: | |
1404 | if (d == string1 /* Points to first char */ | |
1405 | || d == end2 /* Points to end */ | |
1406 | || (d == end1 && size2 == 0)) /* Points to end */ | |
1407 | goto fail; | |
1408 | if ((SYNTAX (d[-1]) == Sword) | |
1409 | != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) | |
1410 | goto fail; | |
1411 | break; | |
1412 | ||
1413 | case wordbeg: | |
1414 | if (d == end2 /* Points to end */ | |
1415 | || (d == end1 && size2 == 0) /* Points to end */ | |
1416 | || SYNTAX (* (d == end1 ? string2 : d)) != Sword) /* Next char not a letter */ | |
1417 | goto fail; | |
1418 | if (d == string1 /* Points to first char */ | |
1419 | || SYNTAX (d[-1]) != Sword) /* prev char not letter */ | |
1420 | break; | |
1421 | goto fail; | |
1422 | ||
1423 | case wordend: | |
1424 | if (d == string1 /* Points to first char */ | |
1425 | || SYNTAX (d[-1]) != Sword) /* prev char not letter */ | |
1426 | goto fail; | |
1427 | if (d == end2 /* Points to end */ | |
1428 | || (d == end1 && size2 == 0) /* Points to end */ | |
1429 | || SYNTAX (d == end1 ? *string2 : *d) != Sword) /* Next char not a letter */ | |
1430 | break; | |
1431 | goto fail; | |
1432 | ||
1433 | #ifdef emacs | |
1434 | case before_dot: | |
1435 | if (((d - string2 <= (unsigned) size2) | |
1436 | ? d - bf_p2 : d - bf_p1) | |
1437 | <= point) | |
1438 | goto fail; | |
1439 | break; | |
1440 | ||
1441 | case at_dot: | |
1442 | if (((d - string2 <= (unsigned) size2) | |
1443 | ? d - bf_p2 : d - bf_p1) | |
1444 | == point) | |
1445 | goto fail; | |
1446 | break; | |
1447 | ||
1448 | case after_dot: | |
1449 | if (((d - string2 <= (unsigned) size2) | |
1450 | ? d - bf_p2 : d - bf_p1) | |
1451 | >= point) | |
1452 | goto fail; | |
1453 | break; | |
1454 | ||
1455 | case wordchar: | |
1456 | mcnt = (int) Sword; | |
1457 | goto matchsyntax; | |
1458 | ||
1459 | case syntaxspec: | |
1460 | mcnt = *p++; | |
1461 | matchsyntax: | |
1462 | PREFETCH; | |
1463 | if (SYNTAX (*d++) != (enum syntaxcode) mcnt) goto fail; | |
1464 | break; | |
1465 | ||
1466 | case notwordchar: | |
1467 | mcnt = (int) Sword; | |
1468 | goto matchnotsyntax; | |
1469 | ||
1470 | case notsyntaxspec: | |
1471 | mcnt = *p++; | |
1472 | matchnotsyntax: | |
1473 | PREFETCH; | |
1474 | if (SYNTAX (*d++) == (enum syntaxcode) mcnt) goto fail; | |
1475 | break; | |
1476 | #else | |
1477 | case wordchar: | |
1478 | PREFETCH; | |
1479 | if (SYNTAX (*d++) == 0) goto fail; | |
1480 | break; | |
1481 | ||
1482 | case notwordchar: | |
1483 | PREFETCH; | |
1484 | if (SYNTAX (*d++) != 0) goto fail; | |
1485 | break; | |
1486 | #endif /* not emacs */ | |
1487 | ||
1488 | case begbuf: | |
1489 | if (d == string1) /* Note, d cannot equal string2 */ | |
1490 | break; /* unless string1 == string2. */ | |
1491 | goto fail; | |
1492 | ||
1493 | case endbuf: | |
1494 | if (d == end2 || (d == end1 && size2 == 0)) | |
1495 | break; | |
1496 | goto fail; | |
1497 | ||
1498 | case exactn: | |
1499 | /* Match the next few pattern characters exactly. | |
1500 | mcnt is how many characters to match. */ | |
1501 | mcnt = *p++; | |
1502 | if (translate) | |
1503 | { | |
1504 | do | |
1505 | { | |
1506 | PREFETCH; | |
1507 | if (translate[*d++] != *p++) goto fail; | |
1508 | } | |
1509 | while (--mcnt); | |
1510 | } | |
1511 | else | |
1512 | { | |
1513 | do | |
1514 | { | |
1515 | PREFETCH; | |
1516 | if (*d++ != *p++) goto fail; | |
1517 | } | |
1518 | while (--mcnt); | |
1519 | } | |
1520 | break; | |
1521 | } | |
1522 | continue; /* Successfully matched one pattern command; keep matching */ | |
1523 | ||
1524 | /* Jump here if any matching operation fails. */ | |
1525 | fail: | |
1526 | if (stackp != stackb) | |
1527 | /* A restart point is known. Restart there and pop it. */ | |
1528 | { | |
1529 | if (!stackp[-2]) | |
1530 | { /* If innermost failure point is dormant, flush it and keep looking */ | |
1531 | stackp -= 2; | |
1532 | goto fail; | |
1533 | } | |
1534 | d = *--stackp; | |
1535 | p = *--stackp; | |
1536 | if (d >= string1 && d <= end1) | |
1537 | dend = end_match_1; | |
1538 | } | |
1539 | else break; /* Matching at this starting point really fails! */ | |
1540 | } | |
1541 | return -1; /* Failure to match */ | |
1542 | } | |
1543 | ||
1544 | static int | |
1545 | bcmp_translate (s1, s2, len, translate) | |
1546 | unsigned char *s1, *s2; | |
1547 | register int len; | |
1548 | unsigned char *translate; | |
1549 | { | |
1550 | register unsigned char *p1 = s1, *p2 = s2; | |
1551 | while (len) | |
1552 | { | |
1553 | if (translate [*p1++] != translate [*p2++]) return 1; | |
1554 | len--; | |
1555 | } | |
1556 | return 0; | |
1557 | } | |
1558 | \f | |
1559 | /* Entry points compatible with bsd4.2 regex library */ | |
1560 | ||
1561 | #ifndef emacs | |
1562 | ||
1563 | static struct re_pattern_buffer re_comp_buf; | |
1564 | ||
1565 | char * | |
1566 | re_comp (s) | |
1567 | char *s; | |
1568 | { | |
1569 | if (!s) | |
1570 | { | |
1571 | if (!re_comp_buf.buffer) | |
1572 | return "No previous regular expression"; | |
1573 | return 0; | |
1574 | } | |
1575 | ||
1576 | if (!re_comp_buf.buffer) | |
1577 | { | |
1578 | if (!(re_comp_buf.buffer = (char *) malloc (200))) | |
1579 | return "Memory exhausted"; | |
1580 | re_comp_buf.allocated = 200; | |
1581 | if (!(re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH))) | |
1582 | return "Memory exhausted"; | |
1583 | } | |
1584 | return re_compile_pattern (s, strlen (s), &re_comp_buf); | |
1585 | } | |
1586 | ||
1587 | int | |
1588 | re_exec (s) | |
1589 | char *s; | |
1590 | { | |
1591 | int len = strlen (s); | |
1592 | return 0 <= re_search (&re_comp_buf, s, len, 0, len, 0); | |
1593 | } | |
1594 | ||
1595 | #endif /* emacs */ | |
1596 | \f | |
1597 | #ifdef test | |
1598 | ||
1599 | #include <stdio.h> | |
1600 | ||
1601 | /* Indexed by a character, gives the upper case equivalent of the character */ | |
1602 | ||
1603 | static char upcase[0400] = | |
1604 | { 000, 001, 002, 003, 004, 005, 006, 007, | |
1605 | 010, 011, 012, 013, 014, 015, 016, 017, | |
1606 | 020, 021, 022, 023, 024, 025, 026, 027, | |
1607 | 030, 031, 032, 033, 034, 035, 036, 037, | |
1608 | 040, 041, 042, 043, 044, 045, 046, 047, | |
1609 | 050, 051, 052, 053, 054, 055, 056, 057, | |
1610 | 060, 061, 062, 063, 064, 065, 066, 067, | |
1611 | 070, 071, 072, 073, 074, 075, 076, 077, | |
1612 | 0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107, | |
1613 | 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, | |
1614 | 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, | |
1615 | 0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137, | |
1616 | 0140, 0101, 0102, 0103, 0104, 0105, 0106, 0107, | |
1617 | 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, | |
1618 | 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, | |
1619 | 0130, 0131, 0132, 0173, 0174, 0175, 0176, 0177, | |
1620 | 0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207, | |
1621 | 0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217, | |
1622 | 0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227, | |
1623 | 0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237, | |
1624 | 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247, | |
1625 | 0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257, | |
1626 | 0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267, | |
1627 | 0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277, | |
1628 | 0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307, | |
1629 | 0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317, | |
1630 | 0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327, | |
1631 | 0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337, | |
1632 | 0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347, | |
1633 | 0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357, | |
1634 | 0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367, | |
1635 | 0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377 | |
1636 | }; | |
1637 | ||
1638 | main (argc, argv) | |
1639 | int argc; | |
1640 | char **argv; | |
1641 | { | |
1642 | char pat[80]; | |
1643 | struct re_pattern_buffer buf; | |
1644 | int i; | |
1645 | char c; | |
1646 | char fastmap[(1 << BYTEWIDTH)]; | |
1647 | ||
1648 | /* Allow a command argument to specify the style of syntax. */ | |
1649 | if (argc > 1) | |
1650 | obscure_syntax = atoi (argv[1]); | |
1651 | ||
1652 | buf.allocated = 40; | |
1653 | buf.buffer = (char *) malloc (buf.allocated); | |
1654 | buf.fastmap = fastmap; | |
1655 | buf.translate = upcase; | |
1656 | ||
1657 | while (1) | |
1658 | { | |
1659 | gets (pat); | |
1660 | ||
1661 | if (*pat) | |
1662 | { | |
1663 | re_compile_pattern (pat, strlen(pat), &buf); | |
1664 | ||
1665 | for (i = 0; i < buf.used; i++) | |
1666 | printchar (buf.buffer[i]); | |
1667 | ||
1668 | putchar ('\n'); | |
1669 | ||
1670 | printf ("%d allocated, %d used.\n", buf.allocated, buf.used); | |
1671 | ||
1672 | re_compile_fastmap (&buf); | |
1673 | printf ("Allowed by fastmap: "); | |
1674 | for (i = 0; i < (1 << BYTEWIDTH); i++) | |
1675 | if (fastmap[i]) printchar (i); | |
1676 | putchar ('\n'); | |
1677 | } | |
1678 | ||
1679 | gets (pat); /* Now read the string to match against */ | |
1680 | ||
1681 | i = re_match (&buf, pat, strlen (pat), 0, 0); | |
1682 | printf ("Match value %d.\n", i); | |
1683 | } | |
1684 | } | |
1685 | ||
1686 | #ifdef NOTDEF | |
1687 | print_buf (bufp) | |
1688 | struct re_pattern_buffer *bufp; | |
1689 | { | |
1690 | int i; | |
1691 | ||
1692 | printf ("buf is :\n----------------\n"); | |
1693 | for (i = 0; i < bufp->used; i++) | |
1694 | printchar (bufp->buffer[i]); | |
1695 | ||
1696 | printf ("\n%d allocated, %d used.\n", bufp->allocated, bufp->used); | |
1697 | ||
1698 | printf ("Allowed by fastmap: "); | |
1699 | for (i = 0; i < (1 << BYTEWIDTH); i++) | |
1700 | if (bufp->fastmap[i]) | |
1701 | printchar (i); | |
1702 | printf ("\nAllowed by translate: "); | |
1703 | if (bufp->translate) | |
1704 | for (i = 0; i < (1 << BYTEWIDTH); i++) | |
1705 | if (bufp->translate[i]) | |
1706 | printchar (i); | |
1707 | printf ("\nfastmap is%s accurate\n", bufp->fastmap_accurate ? "" : "n't"); | |
1708 | printf ("can %s be null\n----------", bufp->can_be_null ? "" : "not"); | |
1709 | } | |
1710 | #endif | |
1711 | ||
1712 | printchar (c) | |
1713 | char c; | |
1714 | { | |
1715 | if (c < 041 || c >= 0177) | |
1716 | { | |
1717 | putchar ('\\'); | |
1718 | putchar (((c >> 6) & 3) + '0'); | |
1719 | putchar (((c >> 3) & 7) + '0'); | |
1720 | putchar ((c & 7) + '0'); | |
1721 | } | |
1722 | else | |
1723 | putchar (c); | |
1724 | } | |
1725 | ||
1726 | error (string) | |
1727 | char *string; | |
1728 | { | |
1729 | puts (string); | |
1730 | exit (1); | |
1731 | } | |
1732 | ||
1733 | #endif /* test */ |