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Revision 1365 - (show annotations)
Sun Oct 6 18:33:56 2013 UTC (6 years ago) by ph10
File MIME type: text/plain
File size: 45794 byte(s)
Refactor named group handling for conditional tests.
1 /*************************************************
2 * Perl-Compatible Regular Expressions *
3 *************************************************/
4
5 /* PCRE is a library of functions to support regular expressions whose syntax
6 and semantics are as close as possible to those of the Perl 5 language.
7
8 Written by Philip Hazel
9 Copyright (c) 1997-2012 University of Cambridge
10
11 -----------------------------------------------------------------------------
12 Redistribution and use in source and binary forms, with or without
13 modification, are permitted provided that the following conditions are met:
14
15 * Redistributions of source code must retain the above copyright notice,
16 this list of conditions and the following disclaimer.
17
18 * Redistributions in binary form must reproduce the above copyright
19 notice, this list of conditions and the following disclaimer in the
20 documentation and/or other materials provided with the distribution.
21
22 * Neither the name of the University of Cambridge nor the names of its
23 contributors may be used to endorse or promote products derived from
24 this software without specific prior written permission.
25
26 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
27 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 POSSIBILITY OF SUCH DAMAGE.
37 -----------------------------------------------------------------------------
38 */
39
40
41 /* This module contains the external function pcre_study(), along with local
42 supporting functions. */
43
44
45 #ifdef HAVE_CONFIG_H
46 #include "config.h"
47 #endif
48
49 #include "pcre_internal.h"
50
51 #define SET_BIT(c) start_bits[c/8] |= (1 << (c&7))
52
53 /* Returns from set_start_bits() */
54
55 enum { SSB_FAIL, SSB_DONE, SSB_CONTINUE, SSB_UNKNOWN };
56
57
58
59 /*************************************************
60 * Find the minimum subject length for a group *
61 *************************************************/
62
63 /* Scan a parenthesized group and compute the minimum length of subject that
64 is needed to match it. This is a lower bound; it does not mean there is a
65 string of that length that matches. In UTF8 mode, the result is in characters
66 rather than bytes.
67
68 Arguments:
69 re compiled pattern block
70 code pointer to start of group (the bracket)
71 startcode pointer to start of the whole pattern's code
72 options the compiling options
73 int RECURSE depth
74
75 Returns: the minimum length
76 -1 if \C in UTF-8 mode or (*ACCEPT) was encountered
77 -2 internal error (missing capturing bracket)
78 -3 internal error (opcode not listed)
79 */
80
81 static int
82 find_minlength(const REAL_PCRE *re, const pcre_uchar *code,
83 const pcre_uchar *startcode, int options, int recurse_depth)
84 {
85 int length = -1;
86 /* PCRE_UTF16 has the same value as PCRE_UTF8. */
87 BOOL utf = (options & PCRE_UTF8) != 0;
88 BOOL had_recurse = FALSE;
89 register int branchlength = 0;
90 register pcre_uchar *cc = (pcre_uchar *)code + 1 + LINK_SIZE;
91
92 if (*code == OP_CBRA || *code == OP_SCBRA ||
93 *code == OP_CBRAPOS || *code == OP_SCBRAPOS) cc += IMM2_SIZE;
94
95 /* Scan along the opcodes for this branch. If we get to the end of the
96 branch, check the length against that of the other branches. */
97
98 for (;;)
99 {
100 int d, min;
101 pcre_uchar *cs, *ce;
102 register pcre_uchar op = *cc;
103
104 switch (op)
105 {
106 case OP_COND:
107 case OP_SCOND:
108
109 /* If there is only one branch in a condition, the implied branch has zero
110 length, so we don't add anything. This covers the DEFINE "condition"
111 automatically. */
112
113 cs = cc + GET(cc, 1);
114 if (*cs != OP_ALT)
115 {
116 cc = cs + 1 + LINK_SIZE;
117 break;
118 }
119
120 /* Otherwise we can fall through and treat it the same as any other
121 subpattern. */
122
123 case OP_CBRA:
124 case OP_SCBRA:
125 case OP_BRA:
126 case OP_SBRA:
127 case OP_CBRAPOS:
128 case OP_SCBRAPOS:
129 case OP_BRAPOS:
130 case OP_SBRAPOS:
131 case OP_ONCE:
132 case OP_ONCE_NC:
133 d = find_minlength(re, cc, startcode, options, recurse_depth);
134 if (d < 0) return d;
135 branchlength += d;
136 do cc += GET(cc, 1); while (*cc == OP_ALT);
137 cc += 1 + LINK_SIZE;
138 break;
139
140 /* ACCEPT makes things far too complicated; we have to give up. */
141
142 case OP_ACCEPT:
143 case OP_ASSERT_ACCEPT:
144 return -1;
145
146 /* Reached end of a branch; if it's a ket it is the end of a nested
147 call. If it's ALT it is an alternation in a nested call. If it is END it's
148 the end of the outer call. All can be handled by the same code. If an
149 ACCEPT was previously encountered, use the length that was in force at that
150 time, and pass back the shortest ACCEPT length. */
151
152 case OP_ALT:
153 case OP_KET:
154 case OP_KETRMAX:
155 case OP_KETRMIN:
156 case OP_KETRPOS:
157 case OP_END:
158 if (length < 0 || (!had_recurse && branchlength < length))
159 length = branchlength;
160 if (op != OP_ALT) return length;
161 cc += 1 + LINK_SIZE;
162 branchlength = 0;
163 had_recurse = FALSE;
164 break;
165
166 /* Skip over assertive subpatterns */
167
168 case OP_ASSERT:
169 case OP_ASSERT_NOT:
170 case OP_ASSERTBACK:
171 case OP_ASSERTBACK_NOT:
172 do cc += GET(cc, 1); while (*cc == OP_ALT);
173 /* Fall through */
174
175 /* Skip over things that don't match chars */
176
177 case OP_REVERSE:
178 case OP_CREF:
179 case OP_DNCREF:
180 case OP_RREF:
181 case OP_DNRREF:
182 case OP_DEF:
183 case OP_CALLOUT:
184 case OP_SOD:
185 case OP_SOM:
186 case OP_EOD:
187 case OP_EODN:
188 case OP_CIRC:
189 case OP_CIRCM:
190 case OP_DOLL:
191 case OP_DOLLM:
192 case OP_NOT_WORD_BOUNDARY:
193 case OP_WORD_BOUNDARY:
194 cc += PRIV(OP_lengths)[*cc];
195 break;
196
197 /* Skip over a subpattern that has a {0} or {0,x} quantifier */
198
199 case OP_BRAZERO:
200 case OP_BRAMINZERO:
201 case OP_BRAPOSZERO:
202 case OP_SKIPZERO:
203 cc += PRIV(OP_lengths)[*cc];
204 do cc += GET(cc, 1); while (*cc == OP_ALT);
205 cc += 1 + LINK_SIZE;
206 break;
207
208 /* Handle literal characters and + repetitions */
209
210 case OP_CHAR:
211 case OP_CHARI:
212 case OP_NOT:
213 case OP_NOTI:
214 case OP_PLUS:
215 case OP_PLUSI:
216 case OP_MINPLUS:
217 case OP_MINPLUSI:
218 case OP_POSPLUS:
219 case OP_POSPLUSI:
220 case OP_NOTPLUS:
221 case OP_NOTPLUSI:
222 case OP_NOTMINPLUS:
223 case OP_NOTMINPLUSI:
224 case OP_NOTPOSPLUS:
225 case OP_NOTPOSPLUSI:
226 branchlength++;
227 cc += 2;
228 #ifdef SUPPORT_UTF
229 if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
230 #endif
231 break;
232
233 case OP_TYPEPLUS:
234 case OP_TYPEMINPLUS:
235 case OP_TYPEPOSPLUS:
236 branchlength++;
237 cc += (cc[1] == OP_PROP || cc[1] == OP_NOTPROP)? 4 : 2;
238 break;
239
240 /* Handle exact repetitions. The count is already in characters, but we
241 need to skip over a multibyte character in UTF8 mode. */
242
243 case OP_EXACT:
244 case OP_EXACTI:
245 case OP_NOTEXACT:
246 case OP_NOTEXACTI:
247 branchlength += GET2(cc,1);
248 cc += 2 + IMM2_SIZE;
249 #ifdef SUPPORT_UTF
250 if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
251 #endif
252 break;
253
254 case OP_TYPEEXACT:
255 branchlength += GET2(cc,1);
256 cc += 2 + IMM2_SIZE + ((cc[1 + IMM2_SIZE] == OP_PROP
257 || cc[1 + IMM2_SIZE] == OP_NOTPROP)? 2 : 0);
258 break;
259
260 /* Handle single-char non-literal matchers */
261
262 case OP_PROP:
263 case OP_NOTPROP:
264 cc += 2;
265 /* Fall through */
266
267 case OP_NOT_DIGIT:
268 case OP_DIGIT:
269 case OP_NOT_WHITESPACE:
270 case OP_WHITESPACE:
271 case OP_NOT_WORDCHAR:
272 case OP_WORDCHAR:
273 case OP_ANY:
274 case OP_ALLANY:
275 case OP_EXTUNI:
276 case OP_HSPACE:
277 case OP_NOT_HSPACE:
278 case OP_VSPACE:
279 case OP_NOT_VSPACE:
280 branchlength++;
281 cc++;
282 break;
283
284 /* "Any newline" might match two characters, but it also might match just
285 one. */
286
287 case OP_ANYNL:
288 branchlength += 1;
289 cc++;
290 break;
291
292 /* The single-byte matcher means we can't proceed in UTF-8 mode. (In
293 non-UTF-8 mode \C will actually be turned into OP_ALLANY, so won't ever
294 appear, but leave the code, just in case.) */
295
296 case OP_ANYBYTE:
297 #ifdef SUPPORT_UTF
298 if (utf) return -1;
299 #endif
300 branchlength++;
301 cc++;
302 break;
303
304 /* For repeated character types, we have to test for \p and \P, which have
305 an extra two bytes of parameters. */
306
307 case OP_TYPESTAR:
308 case OP_TYPEMINSTAR:
309 case OP_TYPEQUERY:
310 case OP_TYPEMINQUERY:
311 case OP_TYPEPOSSTAR:
312 case OP_TYPEPOSQUERY:
313 if (cc[1] == OP_PROP || cc[1] == OP_NOTPROP) cc += 2;
314 cc += PRIV(OP_lengths)[op];
315 break;
316
317 case OP_TYPEUPTO:
318 case OP_TYPEMINUPTO:
319 case OP_TYPEPOSUPTO:
320 if (cc[1 + IMM2_SIZE] == OP_PROP
321 || cc[1 + IMM2_SIZE] == OP_NOTPROP) cc += 2;
322 cc += PRIV(OP_lengths)[op];
323 break;
324
325 /* Check a class for variable quantification */
326
327 case OP_CLASS:
328 case OP_NCLASS:
329 #if defined SUPPORT_UTF || defined COMPILE_PCRE16 || defined COMPILE_PCRE32
330 case OP_XCLASS:
331 /* The original code caused an unsigned overflow in 64 bit systems,
332 so now we use a conditional statement. */
333 if (op == OP_XCLASS)
334 cc += GET(cc, 1);
335 else
336 cc += PRIV(OP_lengths)[OP_CLASS];
337 #else
338 cc += PRIV(OP_lengths)[OP_CLASS];
339 #endif
340
341 switch (*cc)
342 {
343 case OP_CRPLUS:
344 case OP_CRMINPLUS:
345 branchlength++;
346 /* Fall through */
347
348 case OP_CRSTAR:
349 case OP_CRMINSTAR:
350 case OP_CRQUERY:
351 case OP_CRMINQUERY:
352 cc++;
353 break;
354
355 case OP_CRRANGE:
356 case OP_CRMINRANGE:
357 branchlength += GET2(cc,1);
358 cc += 1 + 2 * IMM2_SIZE;
359 break;
360
361 default:
362 branchlength++;
363 break;
364 }
365 break;
366
367 /* Backreferences and subroutine calls are treated in the same way: we find
368 the minimum length for the subpattern. A recursion, however, causes an
369 a flag to be set that causes the length of this branch to be ignored. The
370 logic is that a recursion can only make sense if there is another
371 alternation that stops the recursing. That will provide the minimum length
372 (when no recursion happens). A backreference within the group that it is
373 referencing behaves in the same way.
374
375 If PCRE_JAVASCRIPT_COMPAT is set, a backreference to an unset bracket
376 matches an empty string (by default it causes a matching failure), so in
377 that case we must set the minimum length to zero. */
378
379 case OP_DNREF: /* Duplicate named pattern back reference */
380 case OP_DNREFI:
381 if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
382 {
383 int count = GET2(cc, 1+IMM2_SIZE);
384 pcre_uchar *slot = (pcre_uchar *)re +
385 re->name_table_offset + GET2(cc, 1) * re->name_entry_size;
386 d = INT_MAX;
387 while (count-- > 0)
388 {
389 ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(slot, 0));
390 if (cs == NULL) return -2;
391 do ce += GET(ce, 1); while (*ce == OP_ALT);
392 if (cc > cs && cc < ce)
393 {
394 d = 0;
395 had_recurse = TRUE;
396 break;
397 }
398 else
399 {
400 int dd = find_minlength(re, cs, startcode, options, recurse_depth);
401 if (dd < d) d = dd;
402 }
403 slot += re->name_entry_size;
404 }
405 }
406 else d = 0;
407 cc += 1 + 2*IMM2_SIZE;
408 goto REPEAT_BACK_REFERENCE;
409
410 case OP_REF: /* Single back reference */
411 case OP_REFI:
412 if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
413 {
414 ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(cc, 1));
415 if (cs == NULL) return -2;
416 do ce += GET(ce, 1); while (*ce == OP_ALT);
417 if (cc > cs && cc < ce)
418 {
419 d = 0;
420 had_recurse = TRUE;
421 }
422 else
423 {
424 d = find_minlength(re, cs, startcode, options, recurse_depth);
425 }
426 }
427 else d = 0;
428 cc += 1 + IMM2_SIZE;
429
430 /* Handle repeated back references */
431
432 REPEAT_BACK_REFERENCE:
433 switch (*cc)
434 {
435 case OP_CRSTAR:
436 case OP_CRMINSTAR:
437 case OP_CRQUERY:
438 case OP_CRMINQUERY:
439 min = 0;
440 cc++;
441 break;
442
443 case OP_CRPLUS:
444 case OP_CRMINPLUS:
445 min = 1;
446 cc++;
447 break;
448
449 case OP_CRRANGE:
450 case OP_CRMINRANGE:
451 min = GET2(cc, 1);
452 cc += 1 + 2 * IMM2_SIZE;
453 break;
454
455 default:
456 min = 1;
457 break;
458 }
459
460 branchlength += min * d;
461 break;
462
463 /* We can easily detect direct recursion, but not mutual recursion. This is
464 caught by a recursion depth count. */
465
466 case OP_RECURSE:
467 cs = ce = (pcre_uchar *)startcode + GET(cc, 1);
468 do ce += GET(ce, 1); while (*ce == OP_ALT);
469 if ((cc > cs && cc < ce) || recurse_depth > 10)
470 had_recurse = TRUE;
471 else
472 {
473 branchlength += find_minlength(re, cs, startcode, options,
474 recurse_depth + 1);
475 }
476 cc += 1 + LINK_SIZE;
477 break;
478
479 /* Anything else does not or need not match a character. We can get the
480 item's length from the table, but for those that can match zero occurrences
481 of a character, we must take special action for UTF-8 characters. As it
482 happens, the "NOT" versions of these opcodes are used at present only for
483 ASCII characters, so they could be omitted from this list. However, in
484 future that may change, so we include them here so as not to leave a
485 gotcha for a future maintainer. */
486
487 case OP_UPTO:
488 case OP_UPTOI:
489 case OP_NOTUPTO:
490 case OP_NOTUPTOI:
491 case OP_MINUPTO:
492 case OP_MINUPTOI:
493 case OP_NOTMINUPTO:
494 case OP_NOTMINUPTOI:
495 case OP_POSUPTO:
496 case OP_POSUPTOI:
497 case OP_NOTPOSUPTO:
498 case OP_NOTPOSUPTOI:
499
500 case OP_STAR:
501 case OP_STARI:
502 case OP_NOTSTAR:
503 case OP_NOTSTARI:
504 case OP_MINSTAR:
505 case OP_MINSTARI:
506 case OP_NOTMINSTAR:
507 case OP_NOTMINSTARI:
508 case OP_POSSTAR:
509 case OP_POSSTARI:
510 case OP_NOTPOSSTAR:
511 case OP_NOTPOSSTARI:
512
513 case OP_QUERY:
514 case OP_QUERYI:
515 case OP_NOTQUERY:
516 case OP_NOTQUERYI:
517 case OP_MINQUERY:
518 case OP_MINQUERYI:
519 case OP_NOTMINQUERY:
520 case OP_NOTMINQUERYI:
521 case OP_POSQUERY:
522 case OP_POSQUERYI:
523 case OP_NOTPOSQUERY:
524 case OP_NOTPOSQUERYI:
525
526 cc += PRIV(OP_lengths)[op];
527 #ifdef SUPPORT_UTF
528 if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
529 #endif
530 break;
531
532 /* Skip these, but we need to add in the name length. */
533
534 case OP_MARK:
535 case OP_PRUNE_ARG:
536 case OP_SKIP_ARG:
537 case OP_THEN_ARG:
538 cc += PRIV(OP_lengths)[op] + cc[1];
539 break;
540
541 /* The remaining opcodes are just skipped over. */
542
543 case OP_CLOSE:
544 case OP_COMMIT:
545 case OP_FAIL:
546 case OP_PRUNE:
547 case OP_SET_SOM:
548 case OP_SKIP:
549 case OP_THEN:
550 cc += PRIV(OP_lengths)[op];
551 break;
552
553 /* This should not occur: we list all opcodes explicitly so that when
554 new ones get added they are properly considered. */
555
556 default:
557 return -3;
558 }
559 }
560 /* Control never gets here */
561 }
562
563
564
565 /*************************************************
566 * Set a bit and maybe its alternate case *
567 *************************************************/
568
569 /* Given a character, set its first byte's bit in the table, and also the
570 corresponding bit for the other version of a letter if we are caseless. In
571 UTF-8 mode, for characters greater than 127, we can only do the caseless thing
572 when Unicode property support is available.
573
574 Arguments:
575 start_bits points to the bit map
576 p points to the character
577 caseless the caseless flag
578 cd the block with char table pointers
579 utf TRUE for UTF-8 / UTF-16 / UTF-32 mode
580
581 Returns: pointer after the character
582 */
583
584 static const pcre_uchar *
585 set_table_bit(pcre_uint8 *start_bits, const pcre_uchar *p, BOOL caseless,
586 compile_data *cd, BOOL utf)
587 {
588 pcre_uint32 c = *p;
589
590 #ifdef COMPILE_PCRE8
591 SET_BIT(c);
592
593 #ifdef SUPPORT_UTF
594 if (utf && c > 127)
595 {
596 GETCHARINC(c, p);
597 #ifdef SUPPORT_UCP
598 if (caseless)
599 {
600 pcre_uchar buff[6];
601 c = UCD_OTHERCASE(c);
602 (void)PRIV(ord2utf)(c, buff);
603 SET_BIT(buff[0]);
604 }
605 #endif /* Not SUPPORT_UCP */
606 return p;
607 }
608 #else /* Not SUPPORT_UTF */
609 (void)(utf); /* Stops warning for unused parameter */
610 #endif /* SUPPORT_UTF */
611
612 /* Not UTF-8 mode, or character is less than 127. */
613
614 if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
615 return p + 1;
616 #endif /* COMPILE_PCRE8 */
617
618 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
619 if (c > 0xff)
620 {
621 c = 0xff;
622 caseless = FALSE;
623 }
624 SET_BIT(c);
625
626 #ifdef SUPPORT_UTF
627 if (utf && c > 127)
628 {
629 GETCHARINC(c, p);
630 #ifdef SUPPORT_UCP
631 if (caseless)
632 {
633 c = UCD_OTHERCASE(c);
634 if (c > 0xff)
635 c = 0xff;
636 SET_BIT(c);
637 }
638 #endif /* SUPPORT_UCP */
639 return p;
640 }
641 #else /* Not SUPPORT_UTF */
642 (void)(utf); /* Stops warning for unused parameter */
643 #endif /* SUPPORT_UTF */
644
645 if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
646 return p + 1;
647 #endif
648 }
649
650
651
652 /*************************************************
653 * Set bits for a positive character type *
654 *************************************************/
655
656 /* This function sets starting bits for a character type. In UTF-8 mode, we can
657 only do a direct setting for bytes less than 128, as otherwise there can be
658 confusion with bytes in the middle of UTF-8 characters. In a "traditional"
659 environment, the tables will only recognize ASCII characters anyway, but in at
660 least one Windows environment, some higher bytes bits were set in the tables.
661 So we deal with that case by considering the UTF-8 encoding.
662
663 Arguments:
664 start_bits the starting bitmap
665 cbit type the type of character wanted
666 table_limit 32 for non-UTF-8; 16 for UTF-8
667 cd the block with char table pointers
668
669 Returns: nothing
670 */
671
672 static void
673 set_type_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit,
674 compile_data *cd)
675 {
676 register pcre_uint32 c;
677 for (c = 0; c < table_limit; c++) start_bits[c] |= cd->cbits[c+cbit_type];
678 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
679 if (table_limit == 32) return;
680 for (c = 128; c < 256; c++)
681 {
682 if ((cd->cbits[c/8] & (1 << (c&7))) != 0)
683 {
684 pcre_uchar buff[6];
685 (void)PRIV(ord2utf)(c, buff);
686 SET_BIT(buff[0]);
687 }
688 }
689 #endif
690 }
691
692
693 /*************************************************
694 * Set bits for a negative character type *
695 *************************************************/
696
697 /* This function sets starting bits for a negative character type such as \D.
698 In UTF-8 mode, we can only do a direct setting for bytes less than 128, as
699 otherwise there can be confusion with bytes in the middle of UTF-8 characters.
700 Unlike in the positive case, where we can set appropriate starting bits for
701 specific high-valued UTF-8 characters, in this case we have to set the bits for
702 all high-valued characters. The lowest is 0xc2, but we overkill by starting at
703 0xc0 (192) for simplicity.
704
705 Arguments:
706 start_bits the starting bitmap
707 cbit type the type of character wanted
708 table_limit 32 for non-UTF-8; 16 for UTF-8
709 cd the block with char table pointers
710
711 Returns: nothing
712 */
713
714 static void
715 set_nottype_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit,
716 compile_data *cd)
717 {
718 register pcre_uint32 c;
719 for (c = 0; c < table_limit; c++) start_bits[c] |= ~cd->cbits[c+cbit_type];
720 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
721 if (table_limit != 32) for (c = 24; c < 32; c++) start_bits[c] = 0xff;
722 #endif
723 }
724
725
726
727 /*************************************************
728 * Create bitmap of starting bytes *
729 *************************************************/
730
731 /* This function scans a compiled unanchored expression recursively and
732 attempts to build a bitmap of the set of possible starting bytes. As time goes
733 by, we may be able to get more clever at doing this. The SSB_CONTINUE return is
734 useful for parenthesized groups in patterns such as (a*)b where the group
735 provides some optional starting bytes but scanning must continue at the outer
736 level to find at least one mandatory byte. At the outermost level, this
737 function fails unless the result is SSB_DONE.
738
739 Arguments:
740 code points to an expression
741 start_bits points to a 32-byte table, initialized to 0
742 utf TRUE if in UTF-8 / UTF-16 / UTF-32 mode
743 cd the block with char table pointers
744
745 Returns: SSB_FAIL => Failed to find any starting bytes
746 SSB_DONE => Found mandatory starting bytes
747 SSB_CONTINUE => Found optional starting bytes
748 SSB_UNKNOWN => Hit an unrecognized opcode
749 */
750
751 static int
752 set_start_bits(const pcre_uchar *code, pcre_uint8 *start_bits, BOOL utf,
753 compile_data *cd)
754 {
755 register pcre_uint32 c;
756 int yield = SSB_DONE;
757 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
758 int table_limit = utf? 16:32;
759 #else
760 int table_limit = 32;
761 #endif
762
763 #if 0
764 /* ========================================================================= */
765 /* The following comment and code was inserted in January 1999. In May 2006,
766 when it was observed to cause compiler warnings about unused values, I took it
767 out again. If anybody is still using OS/2, they will have to put it back
768 manually. */
769
770 /* This next statement and the later reference to dummy are here in order to
771 trick the optimizer of the IBM C compiler for OS/2 into generating correct
772 code. Apparently IBM isn't going to fix the problem, and we would rather not
773 disable optimization (in this module it actually makes a big difference, and
774 the pcre module can use all the optimization it can get). */
775
776 volatile int dummy;
777 /* ========================================================================= */
778 #endif
779
780 do
781 {
782 BOOL try_next = TRUE;
783 const pcre_uchar *tcode = code + 1 + LINK_SIZE;
784
785 if (*code == OP_CBRA || *code == OP_SCBRA ||
786 *code == OP_CBRAPOS || *code == OP_SCBRAPOS) tcode += IMM2_SIZE;
787
788 while (try_next) /* Loop for items in this branch */
789 {
790 int rc;
791
792 switch(*tcode)
793 {
794 /* If we reach something we don't understand, it means a new opcode has
795 been created that hasn't been added to this code. Hopefully this problem
796 will be discovered during testing. */
797
798 default:
799 return SSB_UNKNOWN;
800
801 /* Fail for a valid opcode that implies no starting bits. */
802
803 case OP_ACCEPT:
804 case OP_ASSERT_ACCEPT:
805 case OP_ALLANY:
806 case OP_ANY:
807 case OP_ANYBYTE:
808 case OP_CIRC:
809 case OP_CIRCM:
810 case OP_CLOSE:
811 case OP_COMMIT:
812 case OP_COND:
813 case OP_CREF:
814 case OP_DEF:
815 case OP_DNCREF:
816 case OP_DNREF:
817 case OP_DNREFI:
818 case OP_DNRREF:
819 case OP_DOLL:
820 case OP_DOLLM:
821 case OP_END:
822 case OP_EOD:
823 case OP_EODN:
824 case OP_EXTUNI:
825 case OP_FAIL:
826 case OP_MARK:
827 case OP_NOT:
828 case OP_NOTEXACT:
829 case OP_NOTEXACTI:
830 case OP_NOTI:
831 case OP_NOTMINPLUS:
832 case OP_NOTMINPLUSI:
833 case OP_NOTMINQUERY:
834 case OP_NOTMINQUERYI:
835 case OP_NOTMINSTAR:
836 case OP_NOTMINSTARI:
837 case OP_NOTMINUPTO:
838 case OP_NOTMINUPTOI:
839 case OP_NOTPLUS:
840 case OP_NOTPLUSI:
841 case OP_NOTPOSPLUS:
842 case OP_NOTPOSPLUSI:
843 case OP_NOTPOSQUERY:
844 case OP_NOTPOSQUERYI:
845 case OP_NOTPOSSTAR:
846 case OP_NOTPOSSTARI:
847 case OP_NOTPOSUPTO:
848 case OP_NOTPOSUPTOI:
849 case OP_NOTPROP:
850 case OP_NOTQUERY:
851 case OP_NOTQUERYI:
852 case OP_NOTSTAR:
853 case OP_NOTSTARI:
854 case OP_NOTUPTO:
855 case OP_NOTUPTOI:
856 case OP_NOT_HSPACE:
857 case OP_NOT_VSPACE:
858 case OP_PROP:
859 case OP_PRUNE:
860 case OP_PRUNE_ARG:
861 case OP_RECURSE:
862 case OP_REF:
863 case OP_REFI:
864 case OP_REVERSE:
865 case OP_RREF:
866 case OP_SCOND:
867 case OP_SET_SOM:
868 case OP_SKIP:
869 case OP_SKIP_ARG:
870 case OP_SOD:
871 case OP_SOM:
872 case OP_THEN:
873 case OP_THEN_ARG:
874 #if defined SUPPORT_UTF || !defined COMPILE_PCRE8
875 case OP_XCLASS:
876 #endif
877 return SSB_FAIL;
878
879 /* We can ignore word boundary tests. */
880
881 case OP_WORD_BOUNDARY:
882 case OP_NOT_WORD_BOUNDARY:
883 tcode++;
884 break;
885
886 /* If we hit a bracket or a positive lookahead assertion, recurse to set
887 bits from within the subpattern. If it can't find anything, we have to
888 give up. If it finds some mandatory character(s), we are done for this
889 branch. Otherwise, carry on scanning after the subpattern. */
890
891 case OP_BRA:
892 case OP_SBRA:
893 case OP_CBRA:
894 case OP_SCBRA:
895 case OP_BRAPOS:
896 case OP_SBRAPOS:
897 case OP_CBRAPOS:
898 case OP_SCBRAPOS:
899 case OP_ONCE:
900 case OP_ONCE_NC:
901 case OP_ASSERT:
902 rc = set_start_bits(tcode, start_bits, utf, cd);
903 if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
904 if (rc == SSB_DONE) try_next = FALSE; else
905 {
906 do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
907 tcode += 1 + LINK_SIZE;
908 }
909 break;
910
911 /* If we hit ALT or KET, it means we haven't found anything mandatory in
912 this branch, though we might have found something optional. For ALT, we
913 continue with the next alternative, but we have to arrange that the final
914 result from subpattern is SSB_CONTINUE rather than SSB_DONE. For KET,
915 return SSB_CONTINUE: if this is the top level, that indicates failure,
916 but after a nested subpattern, it causes scanning to continue. */
917
918 case OP_ALT:
919 yield = SSB_CONTINUE;
920 try_next = FALSE;
921 break;
922
923 case OP_KET:
924 case OP_KETRMAX:
925 case OP_KETRMIN:
926 case OP_KETRPOS:
927 return SSB_CONTINUE;
928
929 /* Skip over callout */
930
931 case OP_CALLOUT:
932 tcode += 2 + 2*LINK_SIZE;
933 break;
934
935 /* Skip over lookbehind and negative lookahead assertions */
936
937 case OP_ASSERT_NOT:
938 case OP_ASSERTBACK:
939 case OP_ASSERTBACK_NOT:
940 do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
941 tcode += 1 + LINK_SIZE;
942 break;
943
944 /* BRAZERO does the bracket, but carries on. */
945
946 case OP_BRAZERO:
947 case OP_BRAMINZERO:
948 case OP_BRAPOSZERO:
949 rc = set_start_bits(++tcode, start_bits, utf, cd);
950 if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
951 /* =========================================================================
952 See the comment at the head of this function concerning the next line,
953 which was an old fudge for the benefit of OS/2.
954 dummy = 1;
955 ========================================================================= */
956 do tcode += GET(tcode,1); while (*tcode == OP_ALT);
957 tcode += 1 + LINK_SIZE;
958 break;
959
960 /* SKIPZERO skips the bracket. */
961
962 case OP_SKIPZERO:
963 tcode++;
964 do tcode += GET(tcode,1); while (*tcode == OP_ALT);
965 tcode += 1 + LINK_SIZE;
966 break;
967
968 /* Single-char * or ? sets the bit and tries the next item */
969
970 case OP_STAR:
971 case OP_MINSTAR:
972 case OP_POSSTAR:
973 case OP_QUERY:
974 case OP_MINQUERY:
975 case OP_POSQUERY:
976 tcode = set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
977 break;
978
979 case OP_STARI:
980 case OP_MINSTARI:
981 case OP_POSSTARI:
982 case OP_QUERYI:
983 case OP_MINQUERYI:
984 case OP_POSQUERYI:
985 tcode = set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
986 break;
987
988 /* Single-char upto sets the bit and tries the next */
989
990 case OP_UPTO:
991 case OP_MINUPTO:
992 case OP_POSUPTO:
993 tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, FALSE, cd, utf);
994 break;
995
996 case OP_UPTOI:
997 case OP_MINUPTOI:
998 case OP_POSUPTOI:
999 tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, TRUE, cd, utf);
1000 break;
1001
1002 /* At least one single char sets the bit and stops */
1003
1004 case OP_EXACT:
1005 tcode += IMM2_SIZE;
1006 /* Fall through */
1007 case OP_CHAR:
1008 case OP_PLUS:
1009 case OP_MINPLUS:
1010 case OP_POSPLUS:
1011 (void)set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
1012 try_next = FALSE;
1013 break;
1014
1015 case OP_EXACTI:
1016 tcode += IMM2_SIZE;
1017 /* Fall through */
1018 case OP_CHARI:
1019 case OP_PLUSI:
1020 case OP_MINPLUSI:
1021 case OP_POSPLUSI:
1022 (void)set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
1023 try_next = FALSE;
1024 break;
1025
1026 /* Special spacing and line-terminating items. These recognize specific
1027 lists of characters. The difference between VSPACE and ANYNL is that the
1028 latter can match the two-character CRLF sequence, but that is not
1029 relevant for finding the first character, so their code here is
1030 identical. */
1031
1032 case OP_HSPACE:
1033 SET_BIT(CHAR_HT);
1034 SET_BIT(CHAR_SPACE);
1035 #ifdef SUPPORT_UTF
1036 if (utf)
1037 {
1038 #ifdef COMPILE_PCRE8
1039 SET_BIT(0xC2); /* For U+00A0 */
1040 SET_BIT(0xE1); /* For U+1680, U+180E */
1041 SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */
1042 SET_BIT(0xE3); /* For U+3000 */
1043 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1044 SET_BIT(0xA0);
1045 SET_BIT(0xFF); /* For characters > 255 */
1046 #endif /* COMPILE_PCRE[8|16|32] */
1047 }
1048 else
1049 #endif /* SUPPORT_UTF */
1050 {
1051 #ifndef EBCDIC
1052 SET_BIT(0xA0);
1053 #endif /* Not EBCDIC */
1054 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1055 SET_BIT(0xFF); /* For characters > 255 */
1056 #endif /* COMPILE_PCRE[16|32] */
1057 }
1058 try_next = FALSE;
1059 break;
1060
1061 case OP_ANYNL:
1062 case OP_VSPACE:
1063 SET_BIT(CHAR_LF);
1064 SET_BIT(CHAR_VT);
1065 SET_BIT(CHAR_FF);
1066 SET_BIT(CHAR_CR);
1067 #ifdef SUPPORT_UTF
1068 if (utf)
1069 {
1070 #ifdef COMPILE_PCRE8
1071 SET_BIT(0xC2); /* For U+0085 */
1072 SET_BIT(0xE2); /* For U+2028, U+2029 */
1073 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1074 SET_BIT(CHAR_NEL);
1075 SET_BIT(0xFF); /* For characters > 255 */
1076 #endif /* COMPILE_PCRE[8|16|32] */
1077 }
1078 else
1079 #endif /* SUPPORT_UTF */
1080 {
1081 SET_BIT(CHAR_NEL);
1082 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1083 SET_BIT(0xFF); /* For characters > 255 */
1084 #endif
1085 }
1086 try_next = FALSE;
1087 break;
1088
1089 /* Single character types set the bits and stop. Note that if PCRE_UCP
1090 is set, we do not see these op codes because \d etc are converted to
1091 properties. Therefore, these apply in the case when only characters less
1092 than 256 are recognized to match the types. */
1093
1094 case OP_NOT_DIGIT:
1095 set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
1096 try_next = FALSE;
1097 break;
1098
1099 case OP_DIGIT:
1100 set_type_bits(start_bits, cbit_digit, table_limit, cd);
1101 try_next = FALSE;
1102 break;
1103
1104 /* The cbit_space table has vertical tab as whitespace; we have to
1105 ensure it is set as not whitespace. Luckily, the code value is the same
1106 (0x0b) in ASCII and EBCDIC, so we can just adjust the appropriate bit. */
1107
1108 case OP_NOT_WHITESPACE:
1109 set_nottype_bits(start_bits, cbit_space, table_limit, cd);
1110 start_bits[1] |= 0x08;
1111 try_next = FALSE;
1112 break;
1113
1114 /* The cbit_space table has vertical tab as whitespace; we have to not
1115 set it from the table. Luckily, the code value is the same (0x0b) in
1116 ASCII and EBCDIC, so we can just adjust the appropriate bit. */
1117
1118 case OP_WHITESPACE:
1119 c = start_bits[1]; /* Save in case it was already set */
1120 set_type_bits(start_bits, cbit_space, table_limit, cd);
1121 start_bits[1] = (start_bits[1] & ~0x08) | c;
1122 try_next = FALSE;
1123 break;
1124
1125 case OP_NOT_WORDCHAR:
1126 set_nottype_bits(start_bits, cbit_word, table_limit, cd);
1127 try_next = FALSE;
1128 break;
1129
1130 case OP_WORDCHAR:
1131 set_type_bits(start_bits, cbit_word, table_limit, cd);
1132 try_next = FALSE;
1133 break;
1134
1135 /* One or more character type fudges the pointer and restarts, knowing
1136 it will hit a single character type and stop there. */
1137
1138 case OP_TYPEPLUS:
1139 case OP_TYPEMINPLUS:
1140 case OP_TYPEPOSPLUS:
1141 tcode++;
1142 break;
1143
1144 case OP_TYPEEXACT:
1145 tcode += 1 + IMM2_SIZE;
1146 break;
1147
1148 /* Zero or more repeats of character types set the bits and then
1149 try again. */
1150
1151 case OP_TYPEUPTO:
1152 case OP_TYPEMINUPTO:
1153 case OP_TYPEPOSUPTO:
1154 tcode += IMM2_SIZE; /* Fall through */
1155
1156 case OP_TYPESTAR:
1157 case OP_TYPEMINSTAR:
1158 case OP_TYPEPOSSTAR:
1159 case OP_TYPEQUERY:
1160 case OP_TYPEMINQUERY:
1161 case OP_TYPEPOSQUERY:
1162 switch(tcode[1])
1163 {
1164 default:
1165 case OP_ANY:
1166 case OP_ALLANY:
1167 return SSB_FAIL;
1168
1169 case OP_HSPACE:
1170 SET_BIT(CHAR_HT);
1171 SET_BIT(CHAR_SPACE);
1172 #ifdef SUPPORT_UTF
1173 if (utf)
1174 {
1175 #ifdef COMPILE_PCRE8
1176 SET_BIT(0xC2); /* For U+00A0 */
1177 SET_BIT(0xE1); /* For U+1680, U+180E */
1178 SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */
1179 SET_BIT(0xE3); /* For U+3000 */
1180 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1181 SET_BIT(0xA0);
1182 SET_BIT(0xFF); /* For characters > 255 */
1183 #endif /* COMPILE_PCRE[8|16|32] */
1184 }
1185 else
1186 #endif /* SUPPORT_UTF */
1187 #ifndef EBCDIC
1188 SET_BIT(0xA0);
1189 #endif /* Not EBCDIC */
1190 break;
1191
1192 case OP_ANYNL:
1193 case OP_VSPACE:
1194 SET_BIT(CHAR_LF);
1195 SET_BIT(CHAR_VT);
1196 SET_BIT(CHAR_FF);
1197 SET_BIT(CHAR_CR);
1198 #ifdef SUPPORT_UTF
1199 if (utf)
1200 {
1201 #ifdef COMPILE_PCRE8
1202 SET_BIT(0xC2); /* For U+0085 */
1203 SET_BIT(0xE2); /* For U+2028, U+2029 */
1204 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1205 SET_BIT(CHAR_NEL);
1206 SET_BIT(0xFF); /* For characters > 255 */
1207 #endif /* COMPILE_PCRE16 */
1208 }
1209 else
1210 #endif /* SUPPORT_UTF */
1211 SET_BIT(CHAR_NEL);
1212 break;
1213
1214 case OP_NOT_DIGIT:
1215 set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
1216 break;
1217
1218 case OP_DIGIT:
1219 set_type_bits(start_bits, cbit_digit, table_limit, cd);
1220 break;
1221
1222 /* The cbit_space table has vertical tab as whitespace; we no longer
1223 have to play fancy tricks because Perl added VT to its whitespace at
1224 release 5.18. PCRE added it at release 8.34. */
1225
1226 case OP_NOT_WHITESPACE:
1227 set_nottype_bits(start_bits, cbit_space, table_limit, cd);
1228 break;
1229
1230 case OP_WHITESPACE:
1231 set_type_bits(start_bits, cbit_space, table_limit, cd);
1232 break;
1233
1234 case OP_NOT_WORDCHAR:
1235 set_nottype_bits(start_bits, cbit_word, table_limit, cd);
1236 break;
1237
1238 case OP_WORDCHAR:
1239 set_type_bits(start_bits, cbit_word, table_limit, cd);
1240 break;
1241 }
1242
1243 tcode += 2;
1244 break;
1245
1246 /* Character class where all the information is in a bit map: set the
1247 bits and either carry on or not, according to the repeat count. If it was
1248 a negative class, and we are operating with UTF-8 characters, any byte
1249 with a value >= 0xc4 is a potentially valid starter because it starts a
1250 character with a value > 255. */
1251
1252 case OP_NCLASS:
1253 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
1254 if (utf)
1255 {
1256 start_bits[24] |= 0xf0; /* Bits for 0xc4 - 0xc8 */
1257 memset(start_bits+25, 0xff, 7); /* Bits for 0xc9 - 0xff */
1258 }
1259 #endif
1260 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1261 SET_BIT(0xFF); /* For characters > 255 */
1262 #endif
1263 /* Fall through */
1264
1265 case OP_CLASS:
1266 {
1267 pcre_uint8 *map;
1268 tcode++;
1269 map = (pcre_uint8 *)tcode;
1270
1271 /* In UTF-8 mode, the bits in a bit map correspond to character
1272 values, not to byte values. However, the bit map we are constructing is
1273 for byte values. So we have to do a conversion for characters whose
1274 value is > 127. In fact, there are only two possible starting bytes for
1275 characters in the range 128 - 255. */
1276
1277 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
1278 if (utf)
1279 {
1280 for (c = 0; c < 16; c++) start_bits[c] |= map[c];
1281 for (c = 128; c < 256; c++)
1282 {
1283 if ((map[c/8] && (1 << (c&7))) != 0)
1284 {
1285 int d = (c >> 6) | 0xc0; /* Set bit for this starter */
1286 start_bits[d/8] |= (1 << (d&7)); /* and then skip on to the */
1287 c = (c & 0xc0) + 0x40 - 1; /* next relevant character. */
1288 }
1289 }
1290 }
1291 else
1292 #endif
1293 {
1294 /* In non-UTF-8 mode, the two bit maps are completely compatible. */
1295 for (c = 0; c < 32; c++) start_bits[c] |= map[c];
1296 }
1297
1298 /* Advance past the bit map, and act on what follows. For a zero
1299 minimum repeat, continue; otherwise stop processing. */
1300
1301 tcode += 32 / sizeof(pcre_uchar);
1302 switch (*tcode)
1303 {
1304 case OP_CRSTAR:
1305 case OP_CRMINSTAR:
1306 case OP_CRQUERY:
1307 case OP_CRMINQUERY:
1308 tcode++;
1309 break;
1310
1311 case OP_CRRANGE:
1312 case OP_CRMINRANGE:
1313 if (GET2(tcode, 1) == 0) tcode += 1 + 2 * IMM2_SIZE;
1314 else try_next = FALSE;
1315 break;
1316
1317 default:
1318 try_next = FALSE;
1319 break;
1320 }
1321 }
1322 break; /* End of bitmap class handling */
1323
1324 } /* End of switch */
1325 } /* End of try_next loop */
1326
1327 code += GET(code, 1); /* Advance to next branch */
1328 }
1329 while (*code == OP_ALT);
1330 return yield;
1331 }
1332
1333
1334
1335
1336
1337 /*************************************************
1338 * Study a compiled expression *
1339 *************************************************/
1340
1341 /* This function is handed a compiled expression that it must study to produce
1342 information that will speed up the matching. It returns a pcre[16]_extra block
1343 which then gets handed back to pcre_exec().
1344
1345 Arguments:
1346 re points to the compiled expression
1347 options contains option bits
1348 errorptr points to where to place error messages;
1349 set NULL unless error
1350
1351 Returns: pointer to a pcre[16]_extra block, with study_data filled in and
1352 the appropriate flags set;
1353 NULL on error or if no optimization possible
1354 */
1355
1356 #if defined COMPILE_PCRE8
1357 PCRE_EXP_DEFN pcre_extra * PCRE_CALL_CONVENTION
1358 pcre_study(const pcre *external_re, int options, const char **errorptr)
1359 #elif defined COMPILE_PCRE16
1360 PCRE_EXP_DEFN pcre16_extra * PCRE_CALL_CONVENTION
1361 pcre16_study(const pcre16 *external_re, int options, const char **errorptr)
1362 #elif defined COMPILE_PCRE32
1363 PCRE_EXP_DEFN pcre32_extra * PCRE_CALL_CONVENTION
1364 pcre32_study(const pcre32 *external_re, int options, const char **errorptr)
1365 #endif
1366 {
1367 int min;
1368 BOOL bits_set = FALSE;
1369 pcre_uint8 start_bits[32];
1370 PUBL(extra) *extra = NULL;
1371 pcre_study_data *study;
1372 const pcre_uint8 *tables;
1373 pcre_uchar *code;
1374 compile_data compile_block;
1375 const REAL_PCRE *re = (const REAL_PCRE *)external_re;
1376
1377
1378 *errorptr = NULL;
1379
1380 if (re == NULL || re->magic_number != MAGIC_NUMBER)
1381 {
1382 *errorptr = "argument is not a compiled regular expression";
1383 return NULL;
1384 }
1385
1386 if ((re->flags & PCRE_MODE) == 0)
1387 {
1388 #if defined COMPILE_PCRE8
1389 *errorptr = "argument not compiled in 8 bit mode";
1390 #elif defined COMPILE_PCRE16
1391 *errorptr = "argument not compiled in 16 bit mode";
1392 #elif defined COMPILE_PCRE32
1393 *errorptr = "argument not compiled in 32 bit mode";
1394 #endif
1395 return NULL;
1396 }
1397
1398 if ((options & ~PUBLIC_STUDY_OPTIONS) != 0)
1399 {
1400 *errorptr = "unknown or incorrect option bit(s) set";
1401 return NULL;
1402 }
1403
1404 code = (pcre_uchar *)re + re->name_table_offset +
1405 (re->name_count * re->name_entry_size);
1406
1407 /* For an anchored pattern, or an unanchored pattern that has a first char, or
1408 a multiline pattern that matches only at "line starts", there is no point in
1409 seeking a list of starting bytes. */
1410
1411 if ((re->options & PCRE_ANCHORED) == 0 &&
1412 (re->flags & (PCRE_FIRSTSET|PCRE_STARTLINE)) == 0)
1413 {
1414 int rc;
1415
1416 /* Set the character tables in the block that is passed around */
1417
1418 tables = re->tables;
1419
1420 #if defined COMPILE_PCRE8
1421 if (tables == NULL)
1422 (void)pcre_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1423 (void *)(&tables));
1424 #elif defined COMPILE_PCRE16
1425 if (tables == NULL)
1426 (void)pcre16_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1427 (void *)(&tables));
1428 #elif defined COMPILE_PCRE32
1429 if (tables == NULL)
1430 (void)pcre32_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1431 (void *)(&tables));
1432 #endif
1433
1434 compile_block.lcc = tables + lcc_offset;
1435 compile_block.fcc = tables + fcc_offset;
1436 compile_block.cbits = tables + cbits_offset;
1437 compile_block.ctypes = tables + ctypes_offset;
1438
1439 /* See if we can find a fixed set of initial characters for the pattern. */
1440
1441 memset(start_bits, 0, 32 * sizeof(pcre_uint8));
1442 rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0,
1443 &compile_block);
1444 bits_set = rc == SSB_DONE;
1445 if (rc == SSB_UNKNOWN)
1446 {
1447 *errorptr = "internal error: opcode not recognized";
1448 return NULL;
1449 }
1450 }
1451
1452 /* Find the minimum length of subject string. */
1453
1454 switch(min = find_minlength(re, code, code, re->options, 0))
1455 {
1456 case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
1457 case -3: *errorptr = "internal error: opcode not recognized"; return NULL;
1458 default: break;
1459 }
1460
1461 /* If a set of starting bytes has been identified, or if the minimum length is
1462 greater than zero, or if JIT optimization has been requested, or if
1463 PCRE_STUDY_EXTRA_NEEDED is set, get a pcre[16]_extra block and a
1464 pcre_study_data block. The study data is put in the latter, which is pointed to
1465 by the former, which may also get additional data set later by the calling
1466 program. At the moment, the size of pcre_study_data is fixed. We nevertheless
1467 save it in a field for returning via the pcre_fullinfo() function so that if it
1468 becomes variable in the future, we don't have to change that code. */
1469
1470 if (bits_set || min > 0 || (options & (
1471 #ifdef SUPPORT_JIT
1472 PCRE_STUDY_JIT_COMPILE | PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE |
1473 PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE |
1474 #endif
1475 PCRE_STUDY_EXTRA_NEEDED)) != 0)
1476 {
1477 extra = (PUBL(extra) *)(PUBL(malloc))
1478 (sizeof(PUBL(extra)) + sizeof(pcre_study_data));
1479 if (extra == NULL)
1480 {
1481 *errorptr = "failed to get memory";
1482 return NULL;
1483 }
1484
1485 study = (pcre_study_data *)((char *)extra + sizeof(PUBL(extra)));
1486 extra->flags = PCRE_EXTRA_STUDY_DATA;
1487 extra->study_data = study;
1488
1489 study->size = sizeof(pcre_study_data);
1490 study->flags = 0;
1491
1492 /* Set the start bits always, to avoid unset memory errors if the
1493 study data is written to a file, but set the flag only if any of the bits
1494 are set, to save time looking when none are. */
1495
1496 if (bits_set)
1497 {
1498 study->flags |= PCRE_STUDY_MAPPED;
1499 memcpy(study->start_bits, start_bits, sizeof(start_bits));
1500 }
1501 else memset(study->start_bits, 0, 32 * sizeof(pcre_uint8));
1502
1503 #ifdef PCRE_DEBUG
1504 if (bits_set)
1505 {
1506 pcre_uint8 *ptr = start_bits;
1507 int i;
1508
1509 printf("Start bits:\n");
1510 for (i = 0; i < 32; i++)
1511 printf("%3d: %02x%s", i * 8, *ptr++, ((i + 1) & 0x7) != 0? " " : "\n");
1512 }
1513 #endif
1514
1515 /* Always set the minlength value in the block, because the JIT compiler
1516 makes use of it. However, don't set the bit unless the length is greater than
1517 zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time
1518 checking the zero case. */
1519
1520 if (min > 0)
1521 {
1522 study->flags |= PCRE_STUDY_MINLEN;
1523 study->minlength = min;
1524 }
1525 else study->minlength = 0;
1526
1527 /* If JIT support was compiled and requested, attempt the JIT compilation.
1528 If no starting bytes were found, and the minimum length is zero, and JIT
1529 compilation fails, abandon the extra block and return NULL, unless
1530 PCRE_STUDY_EXTRA_NEEDED is set. */
1531
1532 #ifdef SUPPORT_JIT
1533 extra->executable_jit = NULL;
1534 if ((options & PCRE_STUDY_JIT_COMPILE) != 0)
1535 PRIV(jit_compile)(re, extra, JIT_COMPILE);
1536 if ((options & PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE) != 0)
1537 PRIV(jit_compile)(re, extra, JIT_PARTIAL_SOFT_COMPILE);
1538 if ((options & PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE) != 0)
1539 PRIV(jit_compile)(re, extra, JIT_PARTIAL_HARD_COMPILE);
1540
1541 if (study->flags == 0 && (extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) == 0 &&
1542 (options & PCRE_STUDY_EXTRA_NEEDED) == 0)
1543 {
1544 #if defined COMPILE_PCRE8
1545 pcre_free_study(extra);
1546 #elif defined COMPILE_PCRE16
1547 pcre16_free_study(extra);
1548 #elif defined COMPILE_PCRE32
1549 pcre32_free_study(extra);
1550 #endif
1551 extra = NULL;
1552 }
1553 #endif
1554 }
1555
1556 return extra;
1557 }
1558
1559
1560 /*************************************************
1561 * Free the study data *
1562 *************************************************/
1563
1564 /* This function frees the memory that was obtained by pcre_study().
1565
1566 Argument: a pointer to the pcre[16]_extra block
1567 Returns: nothing
1568 */
1569
1570 #if defined COMPILE_PCRE8
1571 PCRE_EXP_DEFN void
1572 pcre_free_study(pcre_extra *extra)
1573 #elif defined COMPILE_PCRE16
1574 PCRE_EXP_DEFN void
1575 pcre16_free_study(pcre16_extra *extra)
1576 #elif defined COMPILE_PCRE32
1577 PCRE_EXP_DEFN void
1578 pcre32_free_study(pcre32_extra *extra)
1579 #endif
1580 {
1581 if (extra == NULL)
1582 return;
1583 #ifdef SUPPORT_JIT
1584 if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 &&
1585 extra->executable_jit != NULL)
1586 PRIV(jit_free)(extra->executable_jit);
1587 #endif
1588 PUBL(free)(extra);
1589 }
1590
1591 /* End of pcre_study.c */

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