4187119d |
1 | /* Extended regular expression matching and search library. |
2 | Copyright (C) 1985, 1989 Free Software Foundation, Inc. |
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3 | |
4187119d |
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 1, or (at your option) |
7 | any later version. |
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8 | |
4187119d |
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. |
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13 | |
4187119d |
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. |
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17 | |
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18 | |
4187119d |
19 | In other words, you are welcome to use, share and improve this program. |
20 | You are forbidden to forbid anyone else to use, share and improve |
21 | what you give them. Help stamp out software-hoarding! */ |
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22 | |
23 | |
24 | /* To test, compile with -Dtest. |
25 | This Dtestable feature turns this into a self-contained program |
26 | which reads a pattern, describes how it compiles, |
27 | then reads a string and searches for it. */ |
28 | |
29 | #ifdef emacs |
30 | |
31 | /* The `emacs' switch turns on certain special matching commands |
32 | that make sense only in emacs. */ |
33 | |
34 | #include "config.h" |
35 | #include "lisp.h" |
36 | #include "buffer.h" |
37 | #include "syntax.h" |
38 | |
39 | #else /* not emacs */ |
40 | |
41 | #ifdef USG |
4187119d |
42 | #ifndef BSTRING |
e91b87a3 |
43 | #define bcopy(s,d,n) memcpy((d),(s),(n)) |
44 | #define bcmp(s1,s2,n) memcmp((s1),(s2),(n)) |
45 | #define bzero(s,n) memset((s),0,(n)) |
46 | #endif |
4187119d |
47 | #endif |
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48 | |
49 | /* Make alloca work the best possible way. */ |
50 | #ifdef __GNUC__ |
51 | #define alloca __builtin_alloca |
52 | #else |
53 | #ifdef sparc |
54 | #include <alloca.h> |
55 | #endif |
56 | #endif |
57 | |
58 | /* |
59 | * Define the syntax stuff, so we can do the \<...\> things. |
60 | */ |
61 | |
62 | #ifndef Sword /* must be non-zero in some of the tests below... */ |
63 | #define Sword 1 |
64 | #endif |
65 | |
66 | #define SYNTAX(c) re_syntax_table[c] |
67 | |
68 | #ifdef SYNTAX_TABLE |
69 | |
70 | char *re_syntax_table; |
71 | |
72 | #else |
73 | |
74 | static char re_syntax_table[256]; |
75 | |
76 | static void |
77 | init_syntax_once () |
78 | { |
79 | register int c; |
80 | static int done = 0; |
81 | |
82 | if (done) |
83 | return; |
84 | |
85 | bzero (re_syntax_table, sizeof re_syntax_table); |
86 | |
87 | for (c = 'a'; c <= 'z'; c++) |
88 | re_syntax_table[c] = Sword; |
89 | |
90 | for (c = 'A'; c <= 'Z'; c++) |
91 | re_syntax_table[c] = Sword; |
92 | |
93 | for (c = '0'; c <= '9'; c++) |
94 | re_syntax_table[c] = Sword; |
95 | |
96 | done = 1; |
97 | } |
98 | |
99 | #endif /* SYNTAX_TABLE */ |
100 | #endif /* not emacs */ |
101 | |
102 | #include "regex.h" |
103 | |
104 | /* Number of failure points to allocate space for initially, |
105 | when matching. If this number is exceeded, more space is allocated, |
106 | so it is not a hard limit. */ |
107 | |
108 | #ifndef NFAILURES |
109 | #define NFAILURES 80 |
110 | #endif /* NFAILURES */ |
111 | |
112 | /* width of a byte in bits */ |
113 | |
114 | #define BYTEWIDTH 8 |
115 | |
116 | #ifndef SIGN_EXTEND_CHAR |
117 | #define SIGN_EXTEND_CHAR(x) (x) |
118 | #endif |
119 | \f |
120 | static int obscure_syntax = 0; |
121 | |
122 | /* Specify the precise syntax of regexp for compilation. |
123 | This provides for compatibility for various utilities |
124 | which historically have different, incompatible syntaxes. |
125 | |
126 | The argument SYNTAX is a bit-mask containing the two bits |
127 | RE_NO_BK_PARENS and RE_NO_BK_VBAR. */ |
128 | |
129 | int |
130 | re_set_syntax (syntax) |
131 | { |
132 | int ret; |
133 | |
134 | ret = obscure_syntax; |
135 | obscure_syntax = syntax; |
136 | return ret; |
137 | } |
138 | \f |
139 | /* re_compile_pattern takes a regular-expression string |
140 | and converts it into a buffer full of byte commands for matching. |
141 | |
142 | PATTERN is the address of the pattern string |
143 | SIZE is the length of it. |
144 | BUFP is a struct re_pattern_buffer * which points to the info |
145 | on where to store the byte commands. |
146 | This structure contains a char * which points to the |
147 | actual space, which should have been obtained with malloc. |
148 | re_compile_pattern may use realloc to grow the buffer space. |
149 | |
150 | The number of bytes of commands can be found out by looking in |
151 | the struct re_pattern_buffer that bufp pointed to, |
152 | after re_compile_pattern returns. |
153 | */ |
154 | |
155 | #define PATPUSH(ch) (*b++ = (char) (ch)) |
156 | |
157 | #define PATFETCH(c) \ |
158 | {if (p == pend) goto end_of_pattern; \ |
159 | c = * (unsigned char *) p++; \ |
160 | if (translate) c = translate[c]; } |
161 | |
162 | #define PATFETCH_RAW(c) \ |
163 | {if (p == pend) goto end_of_pattern; \ |
164 | c = * (unsigned char *) p++; } |
165 | |
166 | #define PATUNFETCH p-- |
167 | |
168 | #define EXTEND_BUFFER \ |
169 | { char *old_buffer = bufp->buffer; \ |
170 | if (bufp->allocated == (1<<16)) goto too_big; \ |
171 | bufp->allocated *= 2; \ |
172 | if (bufp->allocated > (1<<16)) bufp->allocated = (1<<16); \ |
173 | if (!(bufp->buffer = (char *) realloc (bufp->buffer, bufp->allocated))) \ |
174 | goto memory_exhausted; \ |
175 | c = bufp->buffer - old_buffer; \ |
176 | b += c; \ |
177 | if (fixup_jump) \ |
178 | fixup_jump += c; \ |
179 | if (laststart) \ |
180 | laststart += c; \ |
181 | begalt += c; \ |
182 | if (pending_exact) \ |
183 | pending_exact += c; \ |
184 | } |
185 | |
186 | static int store_jump (), insert_jump (); |
187 | |
188 | char * |
189 | re_compile_pattern (pattern, size, bufp) |
190 | char *pattern; |
191 | int size; |
192 | struct re_pattern_buffer *bufp; |
193 | { |
194 | register char *b = bufp->buffer; |
195 | register char *p = pattern; |
196 | char *pend = pattern + size; |
197 | register unsigned c, c1; |
198 | char *p1; |
199 | unsigned char *translate = (unsigned char *) bufp->translate; |
200 | |
201 | /* address of the count-byte of the most recently inserted "exactn" command. |
202 | This makes it possible to tell whether a new exact-match character |
203 | can be added to that command or requires a new "exactn" command. */ |
204 | |
205 | char *pending_exact = 0; |
206 | |
207 | /* address of the place where a forward-jump should go |
208 | to the end of the containing expression. |
209 | Each alternative of an "or", except the last, ends with a forward-jump |
210 | of this sort. */ |
211 | |
212 | char *fixup_jump = 0; |
213 | |
214 | /* address of start of the most recently finished expression. |
215 | This tells postfix * where to find the start of its operand. */ |
216 | |
217 | char *laststart = 0; |
218 | |
219 | /* In processing a repeat, 1 means zero matches is allowed */ |
220 | |
221 | char zero_times_ok; |
222 | |
223 | /* In processing a repeat, 1 means many matches is allowed */ |
224 | |
225 | char many_times_ok; |
226 | |
227 | /* address of beginning of regexp, or inside of last \( */ |
228 | |
229 | char *begalt = b; |
230 | |
231 | /* Stack of information saved by \( and restored by \). |
232 | Four stack elements are pushed by each \(: |
233 | First, the value of b. |
234 | Second, the value of fixup_jump. |
235 | Third, the value of regnum. |
236 | Fourth, the value of begalt. */ |
237 | |
238 | int stackb[40]; |
239 | int *stackp = stackb; |
240 | int *stacke = stackb + 40; |
241 | int *stackt; |
242 | |
243 | /* Counts \('s as they are encountered. Remembered for the matching \), |
244 | where it becomes the "register number" to put in the stop_memory command */ |
245 | |
246 | int regnum = 1; |
247 | |
248 | bufp->fastmap_accurate = 0; |
249 | |
250 | #ifndef emacs |
251 | #ifndef SYNTAX_TABLE |
252 | /* |
253 | * Initialize the syntax table. |
254 | */ |
255 | init_syntax_once(); |
256 | #endif |
257 | #endif |
258 | |
259 | if (bufp->allocated == 0) |
260 | { |
261 | bufp->allocated = 28; |
262 | if (bufp->buffer) |
263 | /* EXTEND_BUFFER loses when bufp->allocated is 0 */ |
264 | bufp->buffer = (char *) realloc (bufp->buffer, 28); |
265 | else |
266 | /* Caller did not allocate a buffer. Do it for him */ |
267 | bufp->buffer = (char *) malloc (28); |
268 | if (!bufp->buffer) goto memory_exhausted; |
269 | begalt = b = bufp->buffer; |
270 | } |
271 | |
272 | while (p != pend) |
273 | { |
274 | if (b - bufp->buffer > bufp->allocated - 10) |
275 | /* Note that EXTEND_BUFFER clobbers c */ |
276 | EXTEND_BUFFER; |
277 | |
278 | PATFETCH (c); |
279 | |
280 | switch (c) |
281 | { |
282 | case '$': |
283 | if (obscure_syntax & RE_TIGHT_VBAR) |
284 | { |
285 | if (! (obscure_syntax & RE_CONTEXT_INDEP_OPS) && p != pend) |
286 | goto normal_char; |
287 | /* Make operand of last vbar end before this `$'. */ |
288 | if (fixup_jump) |
289 | store_jump (fixup_jump, jump, b); |
290 | fixup_jump = 0; |
291 | PATPUSH (endline); |
292 | break; |
293 | } |
294 | |
295 | /* $ means succeed if at end of line, but only in special contexts. |
296 | If randomly in the middle of a pattern, it is a normal character. */ |
297 | if (p == pend || *p == '\n' |
298 | || (obscure_syntax & RE_CONTEXT_INDEP_OPS) |
299 | || (obscure_syntax & RE_NO_BK_PARENS |
300 | ? *p == ')' |
301 | : *p == '\\' && p[1] == ')') |
302 | || (obscure_syntax & RE_NO_BK_VBAR |
303 | ? *p == '|' |
304 | : *p == '\\' && p[1] == '|')) |
305 | { |
306 | PATPUSH (endline); |
307 | break; |
308 | } |
309 | goto normal_char; |
310 | |
311 | case '^': |
312 | /* ^ means succeed if at beg of line, but only if no preceding pattern. */ |
313 | |
314 | if (laststart && p[-2] != '\n' |
315 | && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) |
316 | goto normal_char; |
317 | if (obscure_syntax & RE_TIGHT_VBAR) |
318 | { |
319 | if (p != pattern + 1 |
320 | && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) |
321 | goto normal_char; |
322 | PATPUSH (begline); |
323 | begalt = b; |
324 | } |
325 | else |
326 | PATPUSH (begline); |
327 | break; |
328 | |
329 | case '+': |
330 | case '?': |
331 | if (obscure_syntax & RE_BK_PLUS_QM) |
332 | goto normal_char; |
333 | handle_plus: |
334 | case '*': |
335 | /* If there is no previous pattern, char not special. */ |
336 | if (!laststart && ! (obscure_syntax & RE_CONTEXT_INDEP_OPS)) |
337 | goto normal_char; |
338 | /* If there is a sequence of repetition chars, |
339 | collapse it down to equivalent to just one. */ |
340 | zero_times_ok = 0; |
341 | many_times_ok = 0; |
342 | while (1) |
343 | { |
344 | zero_times_ok |= c != '+'; |
345 | many_times_ok |= c != '?'; |
346 | if (p == pend) |
347 | break; |
348 | PATFETCH (c); |
349 | if (c == '*') |
350 | ; |
351 | else if (!(obscure_syntax & RE_BK_PLUS_QM) |
352 | && (c == '+' || c == '?')) |
353 | ; |
354 | else if ((obscure_syntax & RE_BK_PLUS_QM) |
355 | && c == '\\') |
356 | { |
357 | int c1; |
358 | PATFETCH (c1); |
359 | if (!(c1 == '+' || c1 == '?')) |
360 | { |
361 | PATUNFETCH; |
362 | PATUNFETCH; |
363 | break; |
364 | } |
365 | c = c1; |
366 | } |
367 | else |
368 | { |
369 | PATUNFETCH; |
370 | break; |
371 | } |
372 | } |
373 | |
374 | /* Star, etc. applied to an empty pattern is equivalent |
375 | to an empty pattern. */ |
376 | if (!laststart) |
377 | break; |
378 | |
379 | /* Now we know whether 0 matches is allowed, |
380 | and whether 2 or more matches is allowed. */ |
381 | if (many_times_ok) |
382 | { |
383 | /* If more than one repetition is allowed, |
384 | put in a backward jump at the end. */ |
385 | store_jump (b, maybe_finalize_jump, laststart - 3); |
386 | b += 3; |
387 | } |
388 | insert_jump (on_failure_jump, laststart, b + 3, b); |
389 | pending_exact = 0; |
390 | b += 3; |
391 | if (!zero_times_ok) |
392 | { |
393 | /* At least one repetition required: insert before the loop |
394 | a skip over the initial on-failure-jump instruction */ |
395 | insert_jump (dummy_failure_jump, laststart, laststart + 6, b); |
396 | b += 3; |
397 | } |
398 | break; |
399 | |
400 | case '.': |
401 | laststart = b; |
402 | PATPUSH (anychar); |
403 | break; |
404 | |
405 | case '[': |
406 | while (b - bufp->buffer |
407 | > bufp->allocated - 3 - (1 << BYTEWIDTH) / BYTEWIDTH) |
408 | /* Note that EXTEND_BUFFER clobbers c */ |
409 | EXTEND_BUFFER; |
410 | |
411 | laststart = b; |
412 | if (*p == '^') |
413 | PATPUSH (charset_not), p++; |
414 | else |
415 | PATPUSH (charset); |
416 | p1 = p; |
417 | |
418 | PATPUSH ((1 << BYTEWIDTH) / BYTEWIDTH); |
419 | /* Clear the whole map */ |
420 | bzero (b, (1 << BYTEWIDTH) / BYTEWIDTH); |
421 | /* Read in characters and ranges, setting map bits */ |
422 | while (1) |
423 | { |
424 | PATFETCH (c); |
425 | if (c == ']' && p != p1 + 1) break; |
426 | if (*p == '-' && p[1] != ']') |
427 | { |
428 | PATFETCH (c1); |
429 | PATFETCH (c1); |
430 | while (c <= c1) |
431 | b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH), c++; |
432 | } |
433 | else |
434 | { |
435 | b[c / BYTEWIDTH] |= 1 << (c % BYTEWIDTH); |
436 | } |
437 | } |
438 | /* Discard any bitmap bytes that are all 0 at the end of the map. |
439 | Decrement the map-length byte too. */ |
440 | while ((int) b[-1] > 0 && b[b[-1] - 1] == 0) |
441 | b[-1]--; |
442 | b += b[-1]; |
443 | break; |
444 | |
445 | case '(': |
446 | if (! (obscure_syntax & RE_NO_BK_PARENS)) |
447 | goto normal_char; |
448 | else |
449 | goto handle_open; |
450 | |
451 | case ')': |
452 | if (! (obscure_syntax & RE_NO_BK_PARENS)) |
453 | goto normal_char; |
454 | else |
455 | goto handle_close; |
456 | |
457 | case '\n': |
458 | if (! (obscure_syntax & RE_NEWLINE_OR)) |
459 | goto normal_char; |
460 | else |
461 | goto handle_bar; |
462 | |
463 | case '|': |
464 | if (! (obscure_syntax & RE_NO_BK_VBAR)) |
465 | goto normal_char; |
466 | else |
467 | goto handle_bar; |
468 | |
469 | case '\\': |
470 | if (p == pend) goto invalid_pattern; |
471 | PATFETCH_RAW (c); |
472 | switch (c) |
473 | { |
474 | case '(': |
475 | if (obscure_syntax & RE_NO_BK_PARENS) |
476 | goto normal_backsl; |
477 | handle_open: |
478 | if (stackp == stacke) goto nesting_too_deep; |
479 | if (regnum < RE_NREGS) |
480 | { |
481 | PATPUSH (start_memory); |
482 | PATPUSH (regnum); |
483 | } |
484 | *stackp++ = b - bufp->buffer; |
485 | *stackp++ = fixup_jump ? fixup_jump - bufp->buffer + 1 : 0; |
486 | *stackp++ = regnum++; |
487 | *stackp++ = begalt - bufp->buffer; |
488 | fixup_jump = 0; |
489 | laststart = 0; |
490 | begalt = b; |
491 | break; |
492 | |
493 | case ')': |
494 | if (obscure_syntax & RE_NO_BK_PARENS) |
495 | goto normal_backsl; |
496 | handle_close: |
497 | if (stackp == stackb) goto unmatched_close; |
498 | begalt = *--stackp + bufp->buffer; |
499 | if (fixup_jump) |
500 | store_jump (fixup_jump, jump, b); |
501 | if (stackp[-1] < RE_NREGS) |
502 | { |
503 | PATPUSH (stop_memory); |
504 | PATPUSH (stackp[-1]); |
505 | } |
506 | stackp -= 2; |
507 | fixup_jump = 0; |
508 | if (*stackp) |
509 | fixup_jump = *stackp + bufp->buffer - 1; |
510 | laststart = *--stackp + bufp->buffer; |
511 | break; |
512 | |
513 | case '|': |
514 | if (obscure_syntax & RE_NO_BK_VBAR) |
515 | goto normal_backsl; |
516 | handle_bar: |
517 | insert_jump (on_failure_jump, begalt, b + 6, b); |
518 | pending_exact = 0; |
519 | b += 3; |
520 | if (fixup_jump) |
521 | store_jump (fixup_jump, jump, b); |
522 | fixup_jump = b; |
523 | b += 3; |
524 | laststart = 0; |
525 | begalt = b; |
526 | break; |
527 | |
528 | #ifdef emacs |
529 | case '=': |
530 | PATPUSH (at_dot); |
531 | break; |
532 | |
533 | case 's': |
534 | laststart = b; |
535 | PATPUSH (syntaxspec); |
536 | PATFETCH (c); |
537 | PATPUSH (syntax_spec_code[c]); |
538 | break; |
539 | |
540 | case 'S': |
541 | laststart = b; |
542 | PATPUSH (notsyntaxspec); |
543 | PATFETCH (c); |
544 | PATPUSH (syntax_spec_code[c]); |
545 | break; |
546 | #endif /* emacs */ |
547 | |
548 | case 'w': |
549 | laststart = b; |
550 | PATPUSH (wordchar); |
551 | break; |
552 | |
553 | case 'W': |
554 | laststart = b; |
555 | PATPUSH (notwordchar); |
556 | break; |
557 | |
558 | case '<': |
559 | PATPUSH (wordbeg); |
560 | break; |
561 | |
562 | case '>': |
563 | PATPUSH (wordend); |
564 | break; |
565 | |
566 | case 'b': |
567 | PATPUSH (wordbound); |
568 | break; |
569 | |
570 | case 'B': |
571 | PATPUSH (notwordbound); |
572 | break; |
573 | |
574 | case '`': |
575 | PATPUSH (begbuf); |
576 | break; |
577 | |
578 | case '\'': |
579 | PATPUSH (endbuf); |
580 | break; |
581 | |
582 | case '1': |
583 | case '2': |
584 | case '3': |
585 | case '4': |
586 | case '5': |
587 | case '6': |
588 | case '7': |
589 | case '8': |
590 | case '9': |
591 | c1 = c - '0'; |
592 | if (c1 >= regnum) |
593 | goto normal_char; |
594 | for (stackt = stackp - 2; stackt > stackb; stackt -= 4) |
595 | if (*stackt == c1) |
596 | goto normal_char; |
597 | laststart = b; |
598 | PATPUSH (duplicate); |
599 | PATPUSH (c1); |
600 | break; |
601 | |
602 | case '+': |
603 | case '?': |
604 | if (obscure_syntax & RE_BK_PLUS_QM) |
605 | goto handle_plus; |
606 | |
607 | default: |
608 | normal_backsl: |
609 | /* You might think it would be useful for \ to mean |
610 | not to translate; but if we don't translate it |
611 | it will never match anything. */ |
612 | if (translate) c = translate[c]; |
613 | goto normal_char; |
614 | } |
615 | break; |
616 | |
617 | default: |
618 | normal_char: |
619 | if (!pending_exact || pending_exact + *pending_exact + 1 != b |
620 | || *pending_exact == 0177 || *p == '*' || *p == '^' |
621 | || ((obscure_syntax & RE_BK_PLUS_QM) |
622 | ? *p == '\\' && (p[1] == '+' || p[1] == '?') |
623 | : (*p == '+' || *p == '?'))) |
624 | { |
625 | laststart = b; |
626 | PATPUSH (exactn); |
627 | pending_exact = b; |
628 | PATPUSH (0); |
629 | } |
630 | PATPUSH (c); |
631 | (*pending_exact)++; |
632 | } |
633 | } |
634 | |
635 | if (fixup_jump) |
636 | store_jump (fixup_jump, jump, b); |
637 | |
638 | if (stackp != stackb) goto unmatched_open; |
639 | |
640 | bufp->used = b - bufp->buffer; |
641 | return 0; |
642 | |
643 | invalid_pattern: |
644 | return "Invalid regular expression"; |
645 | |
646 | unmatched_open: |
647 | return "Unmatched \\("; |
648 | |
649 | unmatched_close: |
650 | return "Unmatched \\)"; |
651 | |
652 | end_of_pattern: |
653 | return "Premature end of regular expression"; |
654 | |
655 | nesting_too_deep: |
656 | return "Nesting too deep"; |
657 | |
658 | too_big: |
659 | return "Regular expression too big"; |
660 | |
661 | memory_exhausted: |
662 | return "Memory exhausted"; |
663 | } |
664 | |
665 | /* Store where `from' points a jump operation to jump to where `to' points. |
666 | `opcode' is the opcode to store. */ |
667 | |
668 | static int |
669 | store_jump (from, opcode, to) |
670 | char *from, *to; |
671 | char opcode; |
672 | { |
673 | from[0] = opcode; |
674 | from[1] = (to - (from + 3)) & 0377; |
675 | from[2] = (to - (from + 3)) >> 8; |
676 | } |
677 | |
678 | /* Open up space at char FROM, and insert there a jump to TO. |
679 | CURRENT_END gives te end of the storage no in use, |
680 | so we know how much data to copy up. |
681 | OP is the opcode of the jump to insert. |
682 | |
683 | If you call this function, you must zero out pending_exact. */ |
684 | |
685 | static int |
686 | insert_jump (op, from, to, current_end) |
687 | char op; |
688 | char *from, *to, *current_end; |
689 | { |
690 | register char *pto = current_end + 3; |
691 | register char *pfrom = current_end; |
692 | while (pfrom != from) |
693 | *--pto = *--pfrom; |
694 | store_jump (from, op, to); |
695 | } |
696 | \f |
697 | /* Given a pattern, compute a fastmap from it. |
698 | The fastmap records which of the (1 << BYTEWIDTH) possible characters |
699 | can start a string that matches the pattern. |
700 | This fastmap is used by re_search to skip quickly over totally implausible text. |
701 | |
702 | The caller must supply the address of a (1 << BYTEWIDTH)-byte data area |
703 | as bufp->fastmap. |
704 | The other components of bufp describe the pattern to be used. */ |
705 | |
706 | void |
707 | re_compile_fastmap (bufp) |
708 | struct re_pattern_buffer *bufp; |
709 | { |
710 | unsigned char *pattern = (unsigned char *) bufp->buffer; |
711 | int size = bufp->used; |
712 | register char *fastmap = bufp->fastmap; |
713 | register unsigned char *p = pattern; |
714 | register unsigned char *pend = pattern + size; |
715 | register int j, k; |
716 | unsigned char *translate = (unsigned char *) bufp->translate; |
717 | |
718 | unsigned char *stackb[NFAILURES]; |
719 | unsigned char **stackp = stackb; |
720 | |
721 | bzero (fastmap, (1 << BYTEWIDTH)); |
722 | bufp->fastmap_accurate = 1; |
723 | bufp->can_be_null = 0; |
724 | |
725 | while (p) |
726 | { |
727 | if (p == pend) |
728 | { |
729 | bufp->can_be_null = 1; |
730 | break; |
731 | } |
732 | #ifdef SWITCH_ENUM_BUG |
733 | switch ((int) ((enum regexpcode) *p++)) |
734 | #else |
735 | switch ((enum regexpcode) *p++) |
736 | #endif |
737 | { |
738 | case exactn: |
739 | if (translate) |
740 | fastmap[translate[p[1]]] = 1; |
741 | else |
742 | fastmap[p[1]] = 1; |
743 | break; |
744 | |
745 | case begline: |
746 | case before_dot: |
747 | case at_dot: |
748 | case after_dot: |
749 | case begbuf: |
750 | case endbuf: |
751 | case wordbound: |
752 | case notwordbound: |
753 | case wordbeg: |
754 | case wordend: |
755 | continue; |
756 | |
757 | case endline: |
758 | if (translate) |
759 | fastmap[translate['\n']] = 1; |
760 | else |
761 | fastmap['\n'] = 1; |
762 | if (bufp->can_be_null != 1) |
763 | bufp->can_be_null = 2; |
764 | break; |
765 | |
766 | case finalize_jump: |
767 | case maybe_finalize_jump: |
768 | case jump: |
769 | case dummy_failure_jump: |
770 | bufp->can_be_null = 1; |
771 | j = *p++ & 0377; |
772 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
773 | p += j + 1; /* The 1 compensates for missing ++ above */ |
774 | if (j > 0) |
775 | continue; |
776 | /* Jump backward reached implies we just went through |
777 | the body of a loop and matched nothing. |
778 | Opcode jumped to should be an on_failure_jump. |
779 | Just treat it like an ordinary jump. |
780 | For a * loop, it has pushed its failure point already; |
781 | if so, discard that as redundant. */ |
782 | if ((enum regexpcode) *p != on_failure_jump) |
783 | continue; |
784 | p++; |
785 | j = *p++ & 0377; |
786 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
787 | p += j + 1; /* The 1 compensates for missing ++ above */ |
788 | if (stackp != stackb && *stackp == p) |
789 | stackp--; |
790 | continue; |
791 | |
792 | case on_failure_jump: |
793 | j = *p++ & 0377; |
794 | j += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
795 | p++; |
796 | *++stackp = p + j; |
797 | continue; |
798 | |
799 | case start_memory: |
800 | case stop_memory: |
801 | p++; |
802 | continue; |
803 | |
804 | case duplicate: |
805 | bufp->can_be_null = 1; |
806 | fastmap['\n'] = 1; |
807 | case anychar: |
808 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
809 | if (j != '\n') |
810 | fastmap[j] = 1; |
811 | if (bufp->can_be_null) |
812 | return; |
813 | /* Don't return; check the alternative paths |
814 | so we can set can_be_null if appropriate. */ |
815 | break; |
816 | |
817 | case wordchar: |
818 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
819 | if (SYNTAX (j) == Sword) |
820 | fastmap[j] = 1; |
821 | break; |
822 | |
823 | case notwordchar: |
824 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
825 | if (SYNTAX (j) != Sword) |
826 | fastmap[j] = 1; |
827 | break; |
828 | |
829 | #ifdef emacs |
830 | case syntaxspec: |
831 | k = *p++; |
832 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
833 | if (SYNTAX (j) == (enum syntaxcode) k) |
834 | fastmap[j] = 1; |
835 | break; |
836 | |
837 | case notsyntaxspec: |
838 | k = *p++; |
839 | for (j = 0; j < (1 << BYTEWIDTH); j++) |
840 | if (SYNTAX (j) != (enum syntaxcode) k) |
841 | fastmap[j] = 1; |
842 | break; |
843 | #endif /* emacs */ |
844 | |
845 | case charset: |
846 | for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) |
847 | if (p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH))) |
848 | { |
849 | if (translate) |
850 | fastmap[translate[j]] = 1; |
851 | else |
852 | fastmap[j] = 1; |
853 | } |
854 | break; |
855 | |
856 | case charset_not: |
857 | /* Chars beyond end of map must be allowed */ |
858 | for (j = *p * BYTEWIDTH; j < (1 << BYTEWIDTH); j++) |
859 | if (translate) |
860 | fastmap[translate[j]] = 1; |
861 | else |
862 | fastmap[j] = 1; |
863 | |
864 | for (j = *p++ * BYTEWIDTH - 1; j >= 0; j--) |
865 | if (!(p[j / BYTEWIDTH] & (1 << (j % BYTEWIDTH)))) |
866 | { |
867 | if (translate) |
868 | fastmap[translate[j]] = 1; |
869 | else |
870 | fastmap[j] = 1; |
871 | } |
872 | break; |
873 | } |
874 | |
875 | /* Get here means we have successfully found the possible starting characters |
876 | of one path of the pattern. We need not follow this path any farther. |
877 | Instead, look at the next alternative remembered in the stack. */ |
878 | if (stackp != stackb) |
879 | p = *stackp--; |
880 | else |
881 | break; |
882 | } |
883 | } |
884 | \f |
885 | /* Like re_search_2, below, but only one string is specified. */ |
886 | |
887 | int |
888 | re_search (pbufp, string, size, startpos, range, regs) |
889 | struct re_pattern_buffer *pbufp; |
890 | char *string; |
891 | int size, startpos, range; |
892 | struct re_registers *regs; |
893 | { |
894 | return re_search_2 (pbufp, 0, 0, string, size, startpos, range, regs, size); |
895 | } |
896 | |
897 | /* Like re_match_2 but tries first a match starting at index STARTPOS, |
898 | then at STARTPOS + 1, and so on. |
899 | RANGE is the number of places to try before giving up. |
900 | If RANGE is negative, the starting positions tried are |
901 | STARTPOS, STARTPOS - 1, etc. |
902 | It is up to the caller to make sure that range is not so large |
903 | as to take the starting position outside of the input strings. |
904 | |
905 | The value returned is the position at which the match was found, |
906 | or -1 if no match was found, |
907 | or -2 if error (such as failure stack overflow). */ |
908 | |
909 | int |
910 | re_search_2 (pbufp, string1, size1, string2, size2, startpos, range, regs, mstop) |
911 | struct re_pattern_buffer *pbufp; |
912 | char *string1, *string2; |
913 | int size1, size2; |
914 | int startpos; |
915 | register int range; |
916 | struct re_registers *regs; |
917 | int mstop; |
918 | { |
919 | register char *fastmap = pbufp->fastmap; |
920 | register unsigned char *translate = (unsigned char *) pbufp->translate; |
921 | int total = size1 + size2; |
922 | int val; |
923 | |
924 | /* Update the fastmap now if not correct already */ |
925 | if (fastmap && !pbufp->fastmap_accurate) |
926 | re_compile_fastmap (pbufp); |
927 | |
928 | /* Don't waste time in a long search for a pattern |
929 | that says it is anchored. */ |
930 | if (pbufp->used > 0 && (enum regexpcode) pbufp->buffer[0] == begbuf |
931 | && range > 0) |
932 | { |
933 | if (startpos > 0) |
934 | return -1; |
935 | else |
936 | range = 1; |
937 | } |
938 | |
939 | while (1) |
940 | { |
941 | /* If a fastmap is supplied, skip quickly over characters |
942 | that cannot possibly be the start of a match. |
943 | Note, however, that if the pattern can possibly match |
944 | the null string, we must test it at each starting point |
945 | so that we take the first null string we get. */ |
946 | |
947 | if (fastmap && startpos < total && pbufp->can_be_null != 1) |
948 | { |
949 | if (range > 0) |
950 | { |
951 | register int lim = 0; |
952 | register unsigned char *p; |
953 | int irange = range; |
954 | if (startpos < size1 && startpos + range >= size1) |
955 | lim = range - (size1 - startpos); |
956 | |
957 | p = ((unsigned char *) |
958 | &(startpos >= size1 ? string2 - size1 : string1)[startpos]); |
959 | |
960 | if (translate) |
961 | { |
962 | while (range > lim && !fastmap[translate[*p++]]) |
963 | range--; |
964 | } |
965 | else |
966 | { |
967 | while (range > lim && !fastmap[*p++]) |
968 | range--; |
969 | } |
970 | startpos += irange - range; |
971 | } |
972 | else |
973 | { |
974 | register unsigned char c; |
975 | if (startpos >= size1) |
976 | c = string2[startpos - size1]; |
977 | else |
978 | c = string1[startpos]; |
979 | c &= 0xff; |
980 | if (translate ? !fastmap[translate[c]] : !fastmap[c]) |
981 | goto advance; |
982 | } |
983 | } |
984 | |
985 | if (range >= 0 && startpos == total |
986 | && fastmap && pbufp->can_be_null == 0) |
987 | return -1; |
988 | |
989 | val = re_match_2 (pbufp, string1, size1, string2, size2, startpos, regs, mstop); |
990 | if (0 <= val) |
991 | { |
992 | if (val == -2) |
993 | return -2; |
994 | return startpos; |
995 | } |
996 | |
997 | #ifdef C_ALLOCA |
998 | alloca (0); |
999 | #endif /* C_ALLOCA */ |
1000 | |
1001 | advance: |
1002 | if (!range) break; |
1003 | if (range > 0) range--, startpos++; else range++, startpos--; |
1004 | } |
1005 | return -1; |
1006 | } |
1007 | \f |
1008 | #ifndef emacs /* emacs never uses this */ |
1009 | int |
1010 | re_match (pbufp, string, size, pos, regs) |
1011 | struct re_pattern_buffer *pbufp; |
1012 | char *string; |
1013 | int size, pos; |
1014 | struct re_registers *regs; |
1015 | { |
1016 | return re_match_2 (pbufp, 0, 0, string, size, pos, regs, size); |
1017 | } |
1018 | #endif /* emacs */ |
1019 | |
1020 | /* Maximum size of failure stack. Beyond this, overflow is an error. */ |
1021 | |
1022 | int re_max_failures = 2000; |
1023 | |
1024 | static int bcmp_translate(); |
1025 | /* Match the pattern described by PBUFP |
1026 | against data which is the virtual concatenation of STRING1 and STRING2. |
1027 | SIZE1 and SIZE2 are the sizes of the two data strings. |
1028 | Start the match at position POS. |
1029 | Do not consider matching past the position MSTOP. |
1030 | |
1031 | If pbufp->fastmap is nonzero, then it had better be up to date. |
1032 | |
1033 | The reason that the data to match are specified as two components |
1034 | which are to be regarded as concatenated |
1035 | is so this function can be used directly on the contents of an Emacs buffer. |
1036 | |
1037 | -1 is returned if there is no match. -2 is returned if there is |
1038 | an error (such as match stack overflow). Otherwise the value is the length |
1039 | of the substring which was matched. */ |
1040 | |
1041 | int |
1042 | re_match_2 (pbufp, string1, size1, string2, size2, pos, regs, mstop) |
1043 | struct re_pattern_buffer *pbufp; |
1044 | unsigned char *string1, *string2; |
1045 | int size1, size2; |
1046 | int pos; |
1047 | struct re_registers *regs; |
1048 | int mstop; |
1049 | { |
1050 | register unsigned char *p = (unsigned char *) pbufp->buffer; |
1051 | register unsigned char *pend = p + pbufp->used; |
1052 | /* End of first string */ |
1053 | unsigned char *end1; |
1054 | /* End of second string */ |
1055 | unsigned char *end2; |
1056 | /* Pointer just past last char to consider matching */ |
1057 | unsigned char *end_match_1, *end_match_2; |
1058 | register unsigned char *d, *dend; |
1059 | register int mcnt; |
1060 | unsigned char *translate = (unsigned char *) pbufp->translate; |
1061 | |
1062 | /* Failure point stack. Each place that can handle a failure further down the line |
1063 | pushes a failure point on this stack. It consists of two char *'s. |
1064 | The first one pushed is where to resume scanning the pattern; |
1065 | the second pushed is where to resume scanning the strings. |
1066 | If the latter is zero, the failure point is a "dummy". |
1067 | If a failure happens and the innermost failure point is dormant, |
1068 | it discards that failure point and tries the next one. */ |
1069 | |
1070 | unsigned char *initial_stack[2 * NFAILURES]; |
1071 | unsigned char **stackb = initial_stack; |
1072 | unsigned char **stackp = stackb, **stacke = &stackb[2 * NFAILURES]; |
1073 | |
1074 | /* Information on the "contents" of registers. |
1075 | These are pointers into the input strings; they record |
1076 | just what was matched (on this attempt) by some part of the pattern. |
1077 | The start_memory command stores the start of a register's contents |
1078 | and the stop_memory command stores the end. |
1079 | |
1080 | At that point, regstart[regnum] points to the first character in the register, |
1081 | regend[regnum] points to the first character beyond the end of the register, |
1082 | regstart_seg1[regnum] is true iff regstart[regnum] points into string1, |
1083 | and regend_seg1[regnum] is true iff regend[regnum] points into string1. */ |
1084 | |
1085 | unsigned char *regstart[RE_NREGS]; |
1086 | unsigned char *regend[RE_NREGS]; |
1087 | unsigned char regstart_seg1[RE_NREGS], regend_seg1[RE_NREGS]; |
1088 | |
1089 | /* Set up pointers to ends of strings. |
1090 | Don't allow the second string to be empty unless both are empty. */ |
1091 | if (!size2) |
1092 | { |
1093 | string2 = string1; |
1094 | size2 = size1; |
1095 | string1 = 0; |
1096 | size1 = 0; |
1097 | } |
1098 | end1 = string1 + size1; |
1099 | end2 = string2 + size2; |
1100 | |
1101 | /* Compute where to stop matching, within the two strings */ |
1102 | if (mstop <= size1) |
1103 | { |
1104 | end_match_1 = string1 + mstop; |
1105 | end_match_2 = string2; |
1106 | } |
1107 | else |
1108 | { |
1109 | end_match_1 = end1; |
1110 | end_match_2 = string2 + mstop - size1; |
1111 | } |
1112 | |
1113 | /* Initialize \) text positions to -1 |
1114 | to mark ones that no \( or \) has been seen for. */ |
1115 | |
1116 | for (mcnt = 0; mcnt < sizeof (regend) / sizeof (*regend); mcnt++) |
1117 | regend[mcnt] = (unsigned char *) -1; |
1118 | |
1119 | /* `p' scans through the pattern as `d' scans through the data. |
1120 | `dend' is the end of the input string that `d' points within. |
1121 | `d' is advanced into the following input string whenever necessary, |
1122 | but this happens before fetching; |
1123 | therefore, at the beginning of the loop, |
1124 | `d' can be pointing at the end of a string, |
1125 | but it cannot equal string2. */ |
1126 | |
1127 | if (pos <= size1) |
1128 | d = string1 + pos, dend = end_match_1; |
1129 | else |
1130 | d = string2 + pos - size1, dend = end_match_2; |
1131 | |
1132 | /* Write PREFETCH; just before fetching a character with *d. */ |
1133 | #define PREFETCH \ |
1134 | while (d == dend) \ |
1135 | { if (dend == end_match_2) goto fail; /* end of string2 => failure */ \ |
1136 | d = string2; /* end of string1 => advance to string2. */ \ |
1137 | dend = end_match_2; } |
1138 | |
1139 | /* This loop loops over pattern commands. |
1140 | It exits by returning from the function if match is complete, |
1141 | or it drops through if match fails at this starting point in the input data. */ |
1142 | |
1143 | while (1) |
1144 | { |
1145 | if (p == pend) |
1146 | /* End of pattern means we have succeeded! */ |
1147 | { |
1148 | /* If caller wants register contents data back, convert it to indices */ |
1149 | if (regs) |
1150 | { |
1151 | regs->start[0] = pos; |
1152 | if (dend == end_match_1) |
1153 | regs->end[0] = d - string1; |
1154 | else |
1155 | regs->end[0] = d - string2 + size1; |
1156 | for (mcnt = 1; mcnt < RE_NREGS; mcnt++) |
1157 | { |
1158 | if (regend[mcnt] == (unsigned char *) -1) |
1159 | { |
1160 | regs->start[mcnt] = -1; |
1161 | regs->end[mcnt] = -1; |
1162 | continue; |
1163 | } |
1164 | if (regstart_seg1[mcnt]) |
1165 | regs->start[mcnt] = regstart[mcnt] - string1; |
1166 | else |
1167 | regs->start[mcnt] = regstart[mcnt] - string2 + size1; |
1168 | if (regend_seg1[mcnt]) |
1169 | regs->end[mcnt] = regend[mcnt] - string1; |
1170 | else |
1171 | regs->end[mcnt] = regend[mcnt] - string2 + size1; |
1172 | } |
1173 | } |
1174 | if (dend == end_match_1) |
1175 | return (d - string1 - pos); |
1176 | else |
1177 | return d - string2 + size1 - pos; |
1178 | } |
1179 | |
1180 | /* Otherwise match next pattern command */ |
1181 | #ifdef SWITCH_ENUM_BUG |
1182 | switch ((int) ((enum regexpcode) *p++)) |
1183 | #else |
1184 | switch ((enum regexpcode) *p++) |
1185 | #endif |
1186 | { |
1187 | |
1188 | /* \( is represented by a start_memory, \) by a stop_memory. |
1189 | Both of those commands contain a "register number" argument. |
1190 | The text matched within the \( and \) is recorded under that number. |
1191 | Then, \<digit> turns into a `duplicate' command which |
1192 | is followed by the numeric value of <digit> as the register number. */ |
1193 | |
1194 | case start_memory: |
1195 | regstart[*p] = d; |
1196 | regstart_seg1[*p++] = (dend == end_match_1); |
1197 | break; |
1198 | |
1199 | case stop_memory: |
1200 | regend[*p] = d; |
1201 | regend_seg1[*p++] = (dend == end_match_1); |
1202 | break; |
1203 | |
1204 | case duplicate: |
1205 | { |
1206 | int regno = *p++; /* Get which register to match against */ |
1207 | register unsigned char *d2, *dend2; |
1208 | |
1209 | d2 = regstart[regno]; |
1210 | dend2 = ((regstart_seg1[regno] == regend_seg1[regno]) |
1211 | ? regend[regno] : end_match_1); |
1212 | while (1) |
1213 | { |
1214 | /* Advance to next segment in register contents, if necessary */ |
1215 | while (d2 == dend2) |
1216 | { |
1217 | if (dend2 == end_match_2) break; |
1218 | if (dend2 == regend[regno]) break; |
1219 | d2 = string2, dend2 = regend[regno]; /* end of string1 => advance to string2. */ |
1220 | } |
1221 | /* At end of register contents => success */ |
1222 | if (d2 == dend2) break; |
1223 | |
1224 | /* Advance to next segment in data being matched, if necessary */ |
1225 | PREFETCH; |
1226 | |
1227 | /* mcnt gets # consecutive chars to compare */ |
1228 | mcnt = dend - d; |
1229 | if (mcnt > dend2 - d2) |
1230 | mcnt = dend2 - d2; |
1231 | /* Compare that many; failure if mismatch, else skip them. */ |
1232 | if (translate ? bcmp_translate (d, d2, mcnt, translate) : bcmp (d, d2, mcnt)) |
1233 | goto fail; |
1234 | d += mcnt, d2 += mcnt; |
1235 | } |
1236 | } |
1237 | break; |
1238 | |
1239 | case anychar: |
1240 | /* fetch a data character */ |
1241 | PREFETCH; |
1242 | /* Match anything but a newline. */ |
1243 | if ((translate ? translate[*d++] : *d++) == '\n') |
1244 | goto fail; |
1245 | break; |
1246 | |
1247 | case charset: |
1248 | case charset_not: |
1249 | { |
1250 | /* Nonzero for charset_not */ |
1251 | int not = 0; |
1252 | register int c; |
1253 | if (*(p - 1) == (unsigned char) charset_not) |
1254 | not = 1; |
1255 | |
1256 | /* fetch a data character */ |
1257 | PREFETCH; |
1258 | |
1259 | if (translate) |
1260 | c = translate [*d]; |
1261 | else |
1262 | c = *d; |
1263 | |
1264 | if (c < *p * BYTEWIDTH |
1265 | && p[1 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) |
1266 | not = !not; |
1267 | |
1268 | p += 1 + *p; |
1269 | |
1270 | if (!not) goto fail; |
1271 | d++; |
1272 | break; |
1273 | } |
1274 | |
1275 | case begline: |
1276 | if (d == string1 || d[-1] == '\n') |
1277 | break; |
1278 | goto fail; |
1279 | |
1280 | case endline: |
1281 | if (d == end2 |
1282 | || (d == end1 ? (size2 == 0 || *string2 == '\n') : *d == '\n')) |
1283 | break; |
1284 | goto fail; |
1285 | |
1286 | /* "or" constructs ("|") are handled by starting each alternative |
1287 | with an on_failure_jump that points to the start of the next alternative. |
1288 | Each alternative except the last ends with a jump to the joining point. |
1289 | (Actually, each jump except for the last one really jumps |
1290 | to the following jump, because tensioning the jumps is a hassle.) */ |
1291 | |
1292 | /* The start of a stupid repeat has an on_failure_jump that points |
1293 | past the end of the repeat text. |
1294 | This makes a failure point so that, on failure to match a repetition, |
1295 | matching restarts past as many repetitions have been found |
1296 | with no way to fail and look for another one. */ |
1297 | |
1298 | /* A smart repeat is similar but loops back to the on_failure_jump |
1299 | so that each repetition makes another failure point. */ |
1300 | |
1301 | case on_failure_jump: |
1302 | if (stackp == stacke) |
1303 | { |
1304 | unsigned char **stackx; |
1305 | if (stacke - stackb > re_max_failures * 2) |
1306 | return -2; |
1307 | stackx = (unsigned char **) alloca (2 * (stacke - stackb) |
1308 | * sizeof (char *)); |
1309 | bcopy (stackb, stackx, (stacke - stackb) * sizeof (char *)); |
1310 | stackp = stackx + (stackp - stackb); |
1311 | stacke = stackx + 2 * (stacke - stackb); |
1312 | stackb = stackx; |
1313 | } |
1314 | mcnt = *p++ & 0377; |
1315 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
1316 | p++; |
1317 | *stackp++ = mcnt + p; |
1318 | *stackp++ = d; |
1319 | break; |
1320 | |
1321 | /* The end of a smart repeat has an maybe_finalize_jump back. |
1322 | Change it either to a finalize_jump or an ordinary jump. */ |
1323 | |
1324 | case maybe_finalize_jump: |
1325 | mcnt = *p++ & 0377; |
1326 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
1327 | p++; |
1328 | { |
1329 | register unsigned char *p2 = p; |
1330 | /* Compare what follows with the begining of the repeat. |
1331 | If we can establish that there is nothing that they would |
1332 | both match, we can change to finalize_jump */ |
1333 | while (p2 != pend |
1334 | && (*p2 == (unsigned char) stop_memory |
1335 | || *p2 == (unsigned char) start_memory)) |
1336 | p2++; |
1337 | if (p2 == pend) |
1338 | p[-3] = (unsigned char) finalize_jump; |
1339 | else if (*p2 == (unsigned char) exactn |
1340 | || *p2 == (unsigned char) endline) |
1341 | { |
1342 | register int c = *p2 == (unsigned char) endline ? '\n' : p2[2]; |
1343 | register unsigned char *p1 = p + mcnt; |
1344 | /* p1[0] ... p1[2] are an on_failure_jump. |
1345 | Examine what follows that */ |
1346 | if (p1[3] == (unsigned char) exactn && p1[5] != c) |
1347 | p[-3] = (unsigned char) finalize_jump; |
1348 | else if (p1[3] == (unsigned char) charset |
1349 | || p1[3] == (unsigned char) charset_not) |
1350 | { |
1351 | int not = p1[3] == (unsigned char) charset_not; |
1352 | if (c < p1[4] * BYTEWIDTH |
1353 | && p1[5 + c / BYTEWIDTH] & (1 << (c % BYTEWIDTH))) |
1354 | not = !not; |
1355 | /* not is 1 if c would match */ |
1356 | /* That means it is not safe to finalize */ |
1357 | if (!not) |
1358 | p[-3] = (unsigned char) finalize_jump; |
1359 | } |
1360 | } |
1361 | } |
1362 | p -= 2; |
1363 | if (p[-1] != (unsigned char) finalize_jump) |
1364 | { |
1365 | p[-1] = (unsigned char) jump; |
1366 | goto nofinalize; |
1367 | } |
1368 | |
1369 | /* The end of a stupid repeat has a finalize-jump |
1370 | back to the start, where another failure point will be made |
1371 | which will point after all the repetitions found so far. */ |
1372 | |
1373 | case finalize_jump: |
1374 | stackp -= 2; |
1375 | |
1376 | case jump: |
1377 | nofinalize: |
1378 | mcnt = *p++ & 0377; |
1379 | mcnt += SIGN_EXTEND_CHAR (*(char *)p) << 8; |
1380 | p += mcnt + 1; /* The 1 compensates for missing ++ above */ |
1381 | break; |
1382 | |
1383 | case dummy_failure_jump: |
1384 | if (stackp == stacke) |
1385 | { |
1386 | unsigned char **stackx |
1387 | = (unsigned char **) alloca (2 * (stacke - stackb) |
1388 | * sizeof (char *)); |
1389 | bcopy (stackb, stackx, (stacke - stackb) * sizeof (char *)); |
1390 | stackp = stackx + (stackp - stackb); |
1391 | stacke = stackx + 2 * (stacke - stackb); |
1392 | stackb = stackx; |
1393 | } |
1394 | *stackp++ = 0; |
1395 | *stackp++ = 0; |
1396 | goto nofinalize; |
1397 | |
1398 | case wordbound: |
1399 | if (d == string1 /* Points to first char */ |
1400 | || d == end2 /* Points to end */ |
1401 | || (d == end1 && size2 == 0)) /* Points to end */ |
1402 | break; |
1403 | if ((SYNTAX (d[-1]) == Sword) |
1404 | != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) |
1405 | break; |
1406 | goto fail; |
1407 | |
1408 | case notwordbound: |
1409 | if (d == string1 /* Points to first char */ |
1410 | || d == end2 /* Points to end */ |
1411 | || (d == end1 && size2 == 0)) /* Points to end */ |
1412 | goto fail; |
1413 | if ((SYNTAX (d[-1]) == Sword) |
1414 | != (SYNTAX (d == end1 ? *string2 : *d) == Sword)) |
1415 | goto fail; |
1416 | break; |
1417 | |
1418 | case wordbeg: |
1419 | if (d == end2 /* Points to end */ |
1420 | || (d == end1 && size2 == 0) /* Points to end */ |
1421 | || SYNTAX (* (d == end1 ? string2 : d)) != Sword) /* Next char not a letter */ |
1422 | goto fail; |
1423 | if (d == string1 /* Points to first char */ |
1424 | || SYNTAX (d[-1]) != Sword) /* prev char not letter */ |
1425 | break; |
1426 | goto fail; |
1427 | |
1428 | case wordend: |
1429 | if (d == string1 /* Points to first char */ |
1430 | || SYNTAX (d[-1]) != Sword) /* prev char not letter */ |
1431 | goto fail; |
1432 | if (d == end2 /* Points to end */ |
1433 | || (d == end1 && size2 == 0) /* Points to end */ |
1434 | || SYNTAX (d == end1 ? *string2 : *d) != Sword) /* Next char not a letter */ |
1435 | break; |
1436 | goto fail; |
1437 | |
1438 | #ifdef emacs |
1439 | case before_dot: |
1440 | if (((d - string2 <= (unsigned) size2) |
1441 | ? d - bf_p2 : d - bf_p1) |
1442 | <= point) |
1443 | goto fail; |
1444 | break; |
1445 | |
1446 | case at_dot: |
1447 | if (((d - string2 <= (unsigned) size2) |
1448 | ? d - bf_p2 : d - bf_p1) |
1449 | == point) |
1450 | goto fail; |
1451 | break; |
1452 | |
1453 | case after_dot: |
1454 | if (((d - string2 <= (unsigned) size2) |
1455 | ? d - bf_p2 : d - bf_p1) |
1456 | >= point) |
1457 | goto fail; |
1458 | break; |
1459 | |
1460 | case wordchar: |
1461 | mcnt = (int) Sword; |
1462 | goto matchsyntax; |
1463 | |
1464 | case syntaxspec: |
1465 | mcnt = *p++; |
1466 | matchsyntax: |
1467 | PREFETCH; |
1468 | if (SYNTAX (*d++) != (enum syntaxcode) mcnt) goto fail; |
1469 | break; |
1470 | |
1471 | case notwordchar: |
1472 | mcnt = (int) Sword; |
1473 | goto matchnotsyntax; |
1474 | |
1475 | case notsyntaxspec: |
1476 | mcnt = *p++; |
1477 | matchnotsyntax: |
1478 | PREFETCH; |
1479 | if (SYNTAX (*d++) == (enum syntaxcode) mcnt) goto fail; |
1480 | break; |
1481 | #else |
1482 | case wordchar: |
1483 | PREFETCH; |
1484 | if (SYNTAX (*d++) == 0) goto fail; |
1485 | break; |
1486 | |
1487 | case notwordchar: |
1488 | PREFETCH; |
1489 | if (SYNTAX (*d++) != 0) goto fail; |
1490 | break; |
1491 | #endif /* not emacs */ |
1492 | |
1493 | case begbuf: |
1494 | if (d == string1) /* Note, d cannot equal string2 */ |
1495 | break; /* unless string1 == string2. */ |
1496 | goto fail; |
1497 | |
1498 | case endbuf: |
1499 | if (d == end2 || (d == end1 && size2 == 0)) |
1500 | break; |
1501 | goto fail; |
1502 | |
1503 | case exactn: |
1504 | /* Match the next few pattern characters exactly. |
1505 | mcnt is how many characters to match. */ |
1506 | mcnt = *p++; |
1507 | if (translate) |
1508 | { |
1509 | do |
1510 | { |
1511 | PREFETCH; |
1512 | if (translate[*d++] != *p++) goto fail; |
1513 | } |
1514 | while (--mcnt); |
1515 | } |
1516 | else |
1517 | { |
1518 | do |
1519 | { |
1520 | PREFETCH; |
1521 | if (*d++ != *p++) goto fail; |
1522 | } |
1523 | while (--mcnt); |
1524 | } |
1525 | break; |
1526 | } |
1527 | continue; /* Successfully matched one pattern command; keep matching */ |
1528 | |
1529 | /* Jump here if any matching operation fails. */ |
1530 | fail: |
1531 | if (stackp != stackb) |
1532 | /* A restart point is known. Restart there and pop it. */ |
1533 | { |
1534 | if (!stackp[-2]) |
1535 | { /* If innermost failure point is dormant, flush it and keep looking */ |
1536 | stackp -= 2; |
1537 | goto fail; |
1538 | } |
1539 | d = *--stackp; |
1540 | p = *--stackp; |
1541 | if (d >= string1 && d <= end1) |
1542 | dend = end_match_1; |
1543 | } |
1544 | else break; /* Matching at this starting point really fails! */ |
1545 | } |
1546 | return -1; /* Failure to match */ |
1547 | } |
1548 | |
1549 | static int |
1550 | bcmp_translate (s1, s2, len, translate) |
1551 | unsigned char *s1, *s2; |
1552 | register int len; |
1553 | unsigned char *translate; |
1554 | { |
1555 | register unsigned char *p1 = s1, *p2 = s2; |
1556 | while (len) |
1557 | { |
1558 | if (translate [*p1++] != translate [*p2++]) return 1; |
1559 | len--; |
1560 | } |
1561 | return 0; |
1562 | } |
1563 | \f |
1564 | /* Entry points compatible with bsd4.2 regex library */ |
1565 | |
1566 | #ifndef emacs |
1567 | |
1568 | static struct re_pattern_buffer re_comp_buf; |
1569 | |
1570 | char * |
1571 | re_comp (s) |
1572 | char *s; |
1573 | { |
1574 | if (!s) |
1575 | { |
1576 | if (!re_comp_buf.buffer) |
1577 | return "No previous regular expression"; |
1578 | return 0; |
1579 | } |
1580 | |
1581 | if (!re_comp_buf.buffer) |
1582 | { |
1583 | if (!(re_comp_buf.buffer = (char *) malloc (200))) |
1584 | return "Memory exhausted"; |
1585 | re_comp_buf.allocated = 200; |
1586 | if (!(re_comp_buf.fastmap = (char *) malloc (1 << BYTEWIDTH))) |
1587 | return "Memory exhausted"; |
1588 | } |
1589 | return re_compile_pattern (s, strlen (s), &re_comp_buf); |
1590 | } |
1591 | |
1592 | int |
1593 | re_exec (s) |
1594 | char *s; |
1595 | { |
1596 | int len = strlen (s); |
1597 | return 0 <= re_search (&re_comp_buf, s, len, 0, len, 0); |
1598 | } |
1599 | |
1600 | #endif /* emacs */ |
1601 | \f |
1602 | #ifdef test |
1603 | |
1604 | #include <stdio.h> |
1605 | |
1606 | /* Indexed by a character, gives the upper case equivalent of the character */ |
1607 | |
1608 | static char upcase[0400] = |
1609 | { 000, 001, 002, 003, 004, 005, 006, 007, |
1610 | 010, 011, 012, 013, 014, 015, 016, 017, |
1611 | 020, 021, 022, 023, 024, 025, 026, 027, |
1612 | 030, 031, 032, 033, 034, 035, 036, 037, |
1613 | 040, 041, 042, 043, 044, 045, 046, 047, |
1614 | 050, 051, 052, 053, 054, 055, 056, 057, |
1615 | 060, 061, 062, 063, 064, 065, 066, 067, |
1616 | 070, 071, 072, 073, 074, 075, 076, 077, |
1617 | 0100, 0101, 0102, 0103, 0104, 0105, 0106, 0107, |
1618 | 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, |
1619 | 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, |
1620 | 0130, 0131, 0132, 0133, 0134, 0135, 0136, 0137, |
1621 | 0140, 0101, 0102, 0103, 0104, 0105, 0106, 0107, |
1622 | 0110, 0111, 0112, 0113, 0114, 0115, 0116, 0117, |
1623 | 0120, 0121, 0122, 0123, 0124, 0125, 0126, 0127, |
1624 | 0130, 0131, 0132, 0173, 0174, 0175, 0176, 0177, |
1625 | 0200, 0201, 0202, 0203, 0204, 0205, 0206, 0207, |
1626 | 0210, 0211, 0212, 0213, 0214, 0215, 0216, 0217, |
1627 | 0220, 0221, 0222, 0223, 0224, 0225, 0226, 0227, |
1628 | 0230, 0231, 0232, 0233, 0234, 0235, 0236, 0237, |
1629 | 0240, 0241, 0242, 0243, 0244, 0245, 0246, 0247, |
1630 | 0250, 0251, 0252, 0253, 0254, 0255, 0256, 0257, |
1631 | 0260, 0261, 0262, 0263, 0264, 0265, 0266, 0267, |
1632 | 0270, 0271, 0272, 0273, 0274, 0275, 0276, 0277, |
1633 | 0300, 0301, 0302, 0303, 0304, 0305, 0306, 0307, |
1634 | 0310, 0311, 0312, 0313, 0314, 0315, 0316, 0317, |
1635 | 0320, 0321, 0322, 0323, 0324, 0325, 0326, 0327, |
1636 | 0330, 0331, 0332, 0333, 0334, 0335, 0336, 0337, |
1637 | 0340, 0341, 0342, 0343, 0344, 0345, 0346, 0347, |
1638 | 0350, 0351, 0352, 0353, 0354, 0355, 0356, 0357, |
1639 | 0360, 0361, 0362, 0363, 0364, 0365, 0366, 0367, |
1640 | 0370, 0371, 0372, 0373, 0374, 0375, 0376, 0377 |
1641 | }; |
1642 | |
1643 | main (argc, argv) |
1644 | int argc; |
1645 | char **argv; |
1646 | { |
1647 | char pat[80]; |
1648 | struct re_pattern_buffer buf; |
1649 | int i; |
1650 | char c; |
1651 | char fastmap[(1 << BYTEWIDTH)]; |
1652 | |
1653 | /* Allow a command argument to specify the style of syntax. */ |
1654 | if (argc > 1) |
1655 | obscure_syntax = atoi (argv[1]); |
1656 | |
1657 | buf.allocated = 40; |
1658 | buf.buffer = (char *) malloc (buf.allocated); |
1659 | buf.fastmap = fastmap; |
1660 | buf.translate = upcase; |
1661 | |
1662 | while (1) |
1663 | { |
1664 | gets (pat); |
1665 | |
1666 | if (*pat) |
1667 | { |
1668 | re_compile_pattern (pat, strlen(pat), &buf); |
1669 | |
1670 | for (i = 0; i < buf.used; i++) |
1671 | printchar (buf.buffer[i]); |
1672 | |
1673 | putchar ('\n'); |
1674 | |
1675 | printf ("%d allocated, %d used.\n", buf.allocated, buf.used); |
1676 | |
1677 | re_compile_fastmap (&buf); |
1678 | printf ("Allowed by fastmap: "); |
1679 | for (i = 0; i < (1 << BYTEWIDTH); i++) |
1680 | if (fastmap[i]) printchar (i); |
1681 | putchar ('\n'); |
1682 | } |
1683 | |
1684 | gets (pat); /* Now read the string to match against */ |
1685 | |
1686 | i = re_match (&buf, pat, strlen (pat), 0, 0); |
1687 | printf ("Match value %d.\n", i); |
1688 | } |
1689 | } |
1690 | |
1691 | #ifdef NOTDEF |
1692 | print_buf (bufp) |
1693 | struct re_pattern_buffer *bufp; |
1694 | { |
1695 | int i; |
1696 | |
1697 | printf ("buf is :\n----------------\n"); |
1698 | for (i = 0; i < bufp->used; i++) |
1699 | printchar (bufp->buffer[i]); |
1700 | |
1701 | printf ("\n%d allocated, %d used.\n", bufp->allocated, bufp->used); |
1702 | |
1703 | printf ("Allowed by fastmap: "); |
1704 | for (i = 0; i < (1 << BYTEWIDTH); i++) |
1705 | if (bufp->fastmap[i]) |
1706 | printchar (i); |
1707 | printf ("\nAllowed by translate: "); |
1708 | if (bufp->translate) |
1709 | for (i = 0; i < (1 << BYTEWIDTH); i++) |
1710 | if (bufp->translate[i]) |
1711 | printchar (i); |
1712 | printf ("\nfastmap is%s accurate\n", bufp->fastmap_accurate ? "" : "n't"); |
1713 | printf ("can %s be null\n----------", bufp->can_be_null ? "" : "not"); |
1714 | } |
1715 | #endif |
1716 | |
1717 | printchar (c) |
1718 | char c; |
1719 | { |
1720 | if (c < 041 || c >= 0177) |
1721 | { |
1722 | putchar ('\\'); |
1723 | putchar (((c >> 6) & 3) + '0'); |
1724 | putchar (((c >> 3) & 7) + '0'); |
1725 | putchar ((c & 7) + '0'); |
1726 | } |
1727 | else |
1728 | putchar (c); |
1729 | } |
1730 | |
1731 | error (string) |
1732 | char *string; |
1733 | { |
1734 | puts (string); |
1735 | exit (1); |
1736 | } |
1737 | |
1738 | #endif /* test */ |