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