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Revision 1032 - (show annotations)
Sat Sep 8 16:05:38 2012 UTC (7 years, 2 months ago) by ph10
File MIME type: text/plain
File size: 43045 byte(s)
Error occurred while calculating annotation data.
Get rid of compiler warnings for unused variables and a missing initializer 
when UTF support is not configured.
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 code pointer to start of group (the bracket)
70 startcode pointer to start of the whole pattern
71 options the compiling options
72 int RECURSE depth
73
74 Returns: the minimum length
75 -1 if \C in UTF-8 mode or (*ACCEPT) was encountered
76 -2 internal error (missing capturing bracket)
77 -3 internal error (opcode not listed)
78 */
79
80 static int
81 find_minlength(const pcre_uchar *code, const pcre_uchar *startcode, int options,
82 int recurse_depth)
83 {
84 int length = -1;
85 /* PCRE_UTF16 has the same value as PCRE_UTF8. */
86 BOOL utf = (options & PCRE_UTF8) != 0;
87 BOOL had_recurse = FALSE;
88 register int branchlength = 0;
89 register pcre_uchar *cc = (pcre_uchar *)code + 1 + LINK_SIZE;
90
91 if (*code == OP_CBRA || *code == OP_SCBRA ||
92 *code == OP_CBRAPOS || *code == OP_SCBRAPOS) cc += IMM2_SIZE;
93
94 /* Scan along the opcodes for this branch. If we get to the end of the
95 branch, check the length against that of the other branches. */
96
97 for (;;)
98 {
99 int d, min;
100 pcre_uchar *cs, *ce;
101 register int op = *cc;
102
103 switch (op)
104 {
105 case OP_COND:
106 case OP_SCOND:
107
108 /* If there is only one branch in a condition, the implied branch has zero
109 length, so we don't add anything. This covers the DEFINE "condition"
110 automatically. */
111
112 cs = cc + GET(cc, 1);
113 if (*cs != OP_ALT)
114 {
115 cc = cs + 1 + LINK_SIZE;
116 break;
117 }
118
119 /* Otherwise we can fall through and treat it the same as any other
120 subpattern. */
121
122 case OP_CBRA:
123 case OP_SCBRA:
124 case OP_BRA:
125 case OP_SBRA:
126 case OP_CBRAPOS:
127 case OP_SCBRAPOS:
128 case OP_BRAPOS:
129 case OP_SBRAPOS:
130 case OP_ONCE:
131 case OP_ONCE_NC:
132 d = find_minlength(cc, startcode, options, recurse_depth);
133 if (d < 0) return d;
134 branchlength += d;
135 do cc += GET(cc, 1); while (*cc == OP_ALT);
136 cc += 1 + LINK_SIZE;
137 break;
138
139 /* ACCEPT makes things far too complicated; we have to give up. */
140
141 case OP_ACCEPT:
142 case OP_ASSERT_ACCEPT:
143 return -1;
144
145 /* Reached end of a branch; if it's a ket it is the end of a nested
146 call. If it's ALT it is an alternation in a nested call. If it is END it's
147 the end of the outer call. All can be handled by the same code. If an
148 ACCEPT was previously encountered, use the length that was in force at that
149 time, and pass back the shortest ACCEPT length. */
150
151 case OP_ALT:
152 case OP_KET:
153 case OP_KETRMAX:
154 case OP_KETRMIN:
155 case OP_KETRPOS:
156 case OP_END:
157 if (length < 0 || (!had_recurse && branchlength < length))
158 length = branchlength;
159 if (op != OP_ALT) return length;
160 cc += 1 + LINK_SIZE;
161 branchlength = 0;
162 had_recurse = FALSE;
163 break;
164
165 /* Skip over assertive subpatterns */
166
167 case OP_ASSERT:
168 case OP_ASSERT_NOT:
169 case OP_ASSERTBACK:
170 case OP_ASSERTBACK_NOT:
171 do cc += GET(cc, 1); while (*cc == OP_ALT);
172 /* Fall through */
173
174 /* Skip over things that don't match chars */
175
176 case OP_REVERSE:
177 case OP_CREF:
178 case OP_NCREF:
179 case OP_RREF:
180 case OP_NRREF:
181 case OP_DEF:
182 case OP_CALLOUT:
183 case OP_SOD:
184 case OP_SOM:
185 case OP_EOD:
186 case OP_EODN:
187 case OP_CIRC:
188 case OP_CIRCM:
189 case OP_DOLL:
190 case OP_DOLLM:
191 case OP_NOT_WORD_BOUNDARY:
192 case OP_WORD_BOUNDARY:
193 cc += PRIV(OP_lengths)[*cc];
194 break;
195
196 /* Skip over a subpattern that has a {0} or {0,x} quantifier */
197
198 case OP_BRAZERO:
199 case OP_BRAMINZERO:
200 case OP_BRAPOSZERO:
201 case OP_SKIPZERO:
202 cc += PRIV(OP_lengths)[*cc];
203 do cc += GET(cc, 1); while (*cc == OP_ALT);
204 cc += 1 + LINK_SIZE;
205 break;
206
207 /* Handle literal characters and + repetitions */
208
209 case OP_CHAR:
210 case OP_CHARI:
211 case OP_NOT:
212 case OP_NOTI:
213 case OP_PLUS:
214 case OP_PLUSI:
215 case OP_MINPLUS:
216 case OP_MINPLUSI:
217 case OP_POSPLUS:
218 case OP_POSPLUSI:
219 case OP_NOTPLUS:
220 case OP_NOTPLUSI:
221 case OP_NOTMINPLUS:
222 case OP_NOTMINPLUSI:
223 case OP_NOTPOSPLUS:
224 case OP_NOTPOSPLUSI:
225 branchlength++;
226 cc += 2;
227 #ifdef SUPPORT_UTF
228 if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
229 #endif
230 break;
231
232 case OP_TYPEPLUS:
233 case OP_TYPEMINPLUS:
234 case OP_TYPEPOSPLUS:
235 branchlength++;
236 cc += (cc[1] == OP_PROP || cc[1] == OP_NOTPROP)? 4 : 2;
237 break;
238
239 /* Handle exact repetitions. The count is already in characters, but we
240 need to skip over a multibyte character in UTF8 mode. */
241
242 case OP_EXACT:
243 case OP_EXACTI:
244 case OP_NOTEXACT:
245 case OP_NOTEXACTI:
246 branchlength += GET2(cc,1);
247 cc += 2 + IMM2_SIZE;
248 #ifdef SUPPORT_UTF
249 if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
250 #endif
251 break;
252
253 case OP_TYPEEXACT:
254 branchlength += GET2(cc,1);
255 cc += 2 + IMM2_SIZE + ((cc[1 + IMM2_SIZE] == OP_PROP
256 || cc[1 + IMM2_SIZE] == OP_NOTPROP)? 2 : 0);
257 break;
258
259 /* Handle single-char non-literal matchers */
260
261 case OP_PROP:
262 case OP_NOTPROP:
263 cc += 2;
264 /* Fall through */
265
266 case OP_NOT_DIGIT:
267 case OP_DIGIT:
268 case OP_NOT_WHITESPACE:
269 case OP_WHITESPACE:
270 case OP_NOT_WORDCHAR:
271 case OP_WORDCHAR:
272 case OP_ANY:
273 case OP_ALLANY:
274 case OP_EXTUNI:
275 case OP_HSPACE:
276 case OP_NOT_HSPACE:
277 case OP_VSPACE:
278 case OP_NOT_VSPACE:
279 branchlength++;
280 cc++;
281 break;
282
283 /* "Any newline" might match two characters, but it also might match just
284 one. */
285
286 case OP_ANYNL:
287 branchlength += 1;
288 cc++;
289 break;
290
291 /* The single-byte matcher means we can't proceed in UTF-8 mode. (In
292 non-UTF-8 mode \C will actually be turned into OP_ALLANY, so won't ever
293 appear, but leave the code, just in case.) */
294
295 case OP_ANYBYTE:
296 #ifdef SUPPORT_UTF
297 if (utf) return -1;
298 #endif
299 branchlength++;
300 cc++;
301 break;
302
303 /* For repeated character types, we have to test for \p and \P, which have
304 an extra two bytes of parameters. */
305
306 case OP_TYPESTAR:
307 case OP_TYPEMINSTAR:
308 case OP_TYPEQUERY:
309 case OP_TYPEMINQUERY:
310 case OP_TYPEPOSSTAR:
311 case OP_TYPEPOSQUERY:
312 if (cc[1] == OP_PROP || cc[1] == OP_NOTPROP) cc += 2;
313 cc += PRIV(OP_lengths)[op];
314 break;
315
316 case OP_TYPEUPTO:
317 case OP_TYPEMINUPTO:
318 case OP_TYPEPOSUPTO:
319 if (cc[1 + IMM2_SIZE] == OP_PROP
320 || cc[1 + IMM2_SIZE] == OP_NOTPROP) cc += 2;
321 cc += PRIV(OP_lengths)[op];
322 break;
323
324 /* Check a class for variable quantification */
325
326 #if defined SUPPORT_UTF || !defined COMPILE_PCRE8
327 case OP_XCLASS:
328 cc += GET(cc, 1) - PRIV(OP_lengths)[OP_CLASS];
329 /* Fall through */
330 #endif
331
332 case OP_CLASS:
333 case OP_NCLASS:
334 cc += PRIV(OP_lengths)[OP_CLASS];
335
336 switch (*cc)
337 {
338 case OP_CRPLUS:
339 case OP_CRMINPLUS:
340 branchlength++;
341 /* Fall through */
342
343 case OP_CRSTAR:
344 case OP_CRMINSTAR:
345 case OP_CRQUERY:
346 case OP_CRMINQUERY:
347 cc++;
348 break;
349
350 case OP_CRRANGE:
351 case OP_CRMINRANGE:
352 branchlength += GET2(cc,1);
353 cc += 1 + 2 * IMM2_SIZE;
354 break;
355
356 default:
357 branchlength++;
358 break;
359 }
360 break;
361
362 /* Backreferences and subroutine calls are treated in the same way: we find
363 the minimum length for the subpattern. A recursion, however, causes an
364 a flag to be set that causes the length of this branch to be ignored. The
365 logic is that a recursion can only make sense if there is another
366 alternation that stops the recursing. That will provide the minimum length
367 (when no recursion happens). A backreference within the group that it is
368 referencing behaves in the same way.
369
370 If PCRE_JAVASCRIPT_COMPAT is set, a backreference to an unset bracket
371 matches an empty string (by default it causes a matching failure), so in
372 that case we must set the minimum length to zero. */
373
374 case OP_REF:
375 case OP_REFI:
376 if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
377 {
378 ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(cc, 1));
379 if (cs == NULL) return -2;
380 do ce += GET(ce, 1); while (*ce == OP_ALT);
381 if (cc > cs && cc < ce)
382 {
383 d = 0;
384 had_recurse = TRUE;
385 }
386 else
387 {
388 d = find_minlength(cs, startcode, options, recurse_depth);
389 }
390 }
391 else d = 0;
392 cc += 1 + IMM2_SIZE;
393
394 /* Handle repeated back references */
395
396 switch (*cc)
397 {
398 case OP_CRSTAR:
399 case OP_CRMINSTAR:
400 case OP_CRQUERY:
401 case OP_CRMINQUERY:
402 min = 0;
403 cc++;
404 break;
405
406 case OP_CRPLUS:
407 case OP_CRMINPLUS:
408 min = 1;
409 cc++;
410 break;
411
412 case OP_CRRANGE:
413 case OP_CRMINRANGE:
414 min = GET2(cc, 1);
415 cc += 1 + 2 * IMM2_SIZE;
416 break;
417
418 default:
419 min = 1;
420 break;
421 }
422
423 branchlength += min * d;
424 break;
425
426 /* We can easily detect direct recursion, but not mutual recursion. This is
427 caught by a recursion depth count. */
428
429 case OP_RECURSE:
430 cs = ce = (pcre_uchar *)startcode + GET(cc, 1);
431 do ce += GET(ce, 1); while (*ce == OP_ALT);
432 if ((cc > cs && cc < ce) || recurse_depth > 10)
433 had_recurse = TRUE;
434 else
435 {
436 branchlength += find_minlength(cs, startcode, options, recurse_depth + 1);
437 }
438 cc += 1 + LINK_SIZE;
439 break;
440
441 /* Anything else does not or need not match a character. We can get the
442 item's length from the table, but for those that can match zero occurrences
443 of a character, we must take special action for UTF-8 characters. As it
444 happens, the "NOT" versions of these opcodes are used at present only for
445 ASCII characters, so they could be omitted from this list. However, in
446 future that may change, so we include them here so as not to leave a
447 gotcha for a future maintainer. */
448
449 case OP_UPTO:
450 case OP_UPTOI:
451 case OP_NOTUPTO:
452 case OP_NOTUPTOI:
453 case OP_MINUPTO:
454 case OP_MINUPTOI:
455 case OP_NOTMINUPTO:
456 case OP_NOTMINUPTOI:
457 case OP_POSUPTO:
458 case OP_POSUPTOI:
459 case OP_NOTPOSUPTO:
460 case OP_NOTPOSUPTOI:
461
462 case OP_STAR:
463 case OP_STARI:
464 case OP_NOTSTAR:
465 case OP_NOTSTARI:
466 case OP_MINSTAR:
467 case OP_MINSTARI:
468 case OP_NOTMINSTAR:
469 case OP_NOTMINSTARI:
470 case OP_POSSTAR:
471 case OP_POSSTARI:
472 case OP_NOTPOSSTAR:
473 case OP_NOTPOSSTARI:
474
475 case OP_QUERY:
476 case OP_QUERYI:
477 case OP_NOTQUERY:
478 case OP_NOTQUERYI:
479 case OP_MINQUERY:
480 case OP_MINQUERYI:
481 case OP_NOTMINQUERY:
482 case OP_NOTMINQUERYI:
483 case OP_POSQUERY:
484 case OP_POSQUERYI:
485 case OP_NOTPOSQUERY:
486 case OP_NOTPOSQUERYI:
487
488 cc += PRIV(OP_lengths)[op];
489 #ifdef SUPPORT_UTF
490 if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
491 #endif
492 break;
493
494 /* Skip these, but we need to add in the name length. */
495
496 case OP_MARK:
497 case OP_PRUNE_ARG:
498 case OP_SKIP_ARG:
499 case OP_THEN_ARG:
500 cc += PRIV(OP_lengths)[op] + cc[1];
501 break;
502
503 /* The remaining opcodes are just skipped over. */
504
505 case OP_CLOSE:
506 case OP_COMMIT:
507 case OP_FAIL:
508 case OP_PRUNE:
509 case OP_SET_SOM:
510 case OP_SKIP:
511 case OP_THEN:
512 cc += PRIV(OP_lengths)[op];
513 break;
514
515 /* This should not occur: we list all opcodes explicitly so that when
516 new ones get added they are properly considered. */
517
518 default:
519 return -3;
520 }
521 }
522 /* Control never gets here */
523 }
524
525
526
527 /*************************************************
528 * Set a bit and maybe its alternate case *
529 *************************************************/
530
531 /* Given a character, set its first byte's bit in the table, and also the
532 corresponding bit for the other version of a letter if we are caseless. In
533 UTF-8 mode, for characters greater than 127, we can only do the caseless thing
534 when Unicode property support is available.
535
536 Arguments:
537 start_bits points to the bit map
538 p points to the character
539 caseless the caseless flag
540 cd the block with char table pointers
541 utf TRUE for UTF-8 / UTF-16 mode
542
543 Returns: pointer after the character
544 */
545
546 static const pcre_uchar *
547 set_table_bit(pcre_uint8 *start_bits, const pcre_uchar *p, BOOL caseless,
548 compile_data *cd, BOOL utf)
549 {
550 unsigned int c = *p;
551
552 #ifdef COMPILE_PCRE8
553 SET_BIT(c);
554
555 #ifdef SUPPORT_UTF
556 if (utf && c > 127)
557 {
558 GETCHARINC(c, p);
559 #ifdef SUPPORT_UCP
560 if (caseless)
561 {
562 pcre_uchar buff[6];
563 c = UCD_OTHERCASE(c);
564 (void)PRIV(ord2utf)(c, buff);
565 SET_BIT(buff[0]);
566 }
567 #endif /* Not SUPPORT_UCP */
568 return p;
569 }
570 #else /* Not SUPPORT_UTF */
571 (void)(utf); /* Stops warning for unused parameter */
572 #endif
573
574 /* Not UTF-8 mode, or character is less than 127. */
575
576 if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
577 return p + 1;
578 #endif
579
580 #ifdef COMPILE_PCRE16
581 if (c > 0xff)
582 {
583 c = 0xff;
584 caseless = FALSE;
585 }
586 SET_BIT(c);
587
588 #ifdef SUPPORT_UTF
589 if (utf && c > 127)
590 {
591 GETCHARINC(c, p);
592 #ifdef SUPPORT_UCP
593 if (caseless)
594 {
595 c = UCD_OTHERCASE(c);
596 if (c > 0xff)
597 c = 0xff;
598 SET_BIT(c);
599 }
600 #endif
601 return p;
602 }
603 #endif
604
605 if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
606 return p + 1;
607 #endif
608 }
609
610
611
612 /*************************************************
613 * Set bits for a positive character type *
614 *************************************************/
615
616 /* This function sets starting bits for a character type. In UTF-8 mode, we can
617 only do a direct setting for bytes less than 128, as otherwise there can be
618 confusion with bytes in the middle of UTF-8 characters. In a "traditional"
619 environment, the tables will only recognize ASCII characters anyway, but in at
620 least one Windows environment, some higher bytes bits were set in the tables.
621 So we deal with that case by considering the UTF-8 encoding.
622
623 Arguments:
624 start_bits the starting bitmap
625 cbit type the type of character wanted
626 table_limit 32 for non-UTF-8; 16 for UTF-8
627 cd the block with char table pointers
628
629 Returns: nothing
630 */
631
632 static void
633 set_type_bits(pcre_uint8 *start_bits, int cbit_type, int table_limit,
634 compile_data *cd)
635 {
636 register int c;
637 for (c = 0; c < table_limit; c++) start_bits[c] |= cd->cbits[c+cbit_type];
638 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
639 if (table_limit == 32) return;
640 for (c = 128; c < 256; c++)
641 {
642 if ((cd->cbits[c/8] & (1 << (c&7))) != 0)
643 {
644 pcre_uchar buff[6];
645 (void)PRIV(ord2utf)(c, buff);
646 SET_BIT(buff[0]);
647 }
648 }
649 #endif
650 }
651
652
653 /*************************************************
654 * Set bits for a negative character type *
655 *************************************************/
656
657 /* This function sets starting bits for a negative character type such as \D.
658 In UTF-8 mode, we can only do a direct setting for bytes less than 128, as
659 otherwise there can be confusion with bytes in the middle of UTF-8 characters.
660 Unlike in the positive case, where we can set appropriate starting bits for
661 specific high-valued UTF-8 characters, in this case we have to set the bits for
662 all high-valued characters. The lowest is 0xc2, but we overkill by starting at
663 0xc0 (192) for simplicity.
664
665 Arguments:
666 start_bits the starting bitmap
667 cbit type the type of character wanted
668 table_limit 32 for non-UTF-8; 16 for UTF-8
669 cd the block with char table pointers
670
671 Returns: nothing
672 */
673
674 static void
675 set_nottype_bits(pcre_uint8 *start_bits, int cbit_type, int table_limit,
676 compile_data *cd)
677 {
678 register int c;
679 for (c = 0; c < table_limit; c++) start_bits[c] |= ~cd->cbits[c+cbit_type];
680 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
681 if (table_limit != 32) for (c = 24; c < 32; c++) start_bits[c] = 0xff;
682 #endif
683 }
684
685
686
687 /*************************************************
688 * Create bitmap of starting bytes *
689 *************************************************/
690
691 /* This function scans a compiled unanchored expression recursively and
692 attempts to build a bitmap of the set of possible starting bytes. As time goes
693 by, we may be able to get more clever at doing this. The SSB_CONTINUE return is
694 useful for parenthesized groups in patterns such as (a*)b where the group
695 provides some optional starting bytes but scanning must continue at the outer
696 level to find at least one mandatory byte. At the outermost level, this
697 function fails unless the result is SSB_DONE.
698
699 Arguments:
700 code points to an expression
701 start_bits points to a 32-byte table, initialized to 0
702 utf TRUE if in UTF-8 / UTF-16 mode
703 cd the block with char table pointers
704
705 Returns: SSB_FAIL => Failed to find any starting bytes
706 SSB_DONE => Found mandatory starting bytes
707 SSB_CONTINUE => Found optional starting bytes
708 SSB_UNKNOWN => Hit an unrecognized opcode
709 */
710
711 static int
712 set_start_bits(const pcre_uchar *code, pcre_uint8 *start_bits, BOOL utf,
713 compile_data *cd)
714 {
715 register int c;
716 int yield = SSB_DONE;
717 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
718 int table_limit = utf? 16:32;
719 #else
720 int table_limit = 32;
721 #endif
722
723 #if 0
724 /* ========================================================================= */
725 /* The following comment and code was inserted in January 1999. In May 2006,
726 when it was observed to cause compiler warnings about unused values, I took it
727 out again. If anybody is still using OS/2, they will have to put it back
728 manually. */
729
730 /* This next statement and the later reference to dummy are here in order to
731 trick the optimizer of the IBM C compiler for OS/2 into generating correct
732 code. Apparently IBM isn't going to fix the problem, and we would rather not
733 disable optimization (in this module it actually makes a big difference, and
734 the pcre module can use all the optimization it can get). */
735
736 volatile int dummy;
737 /* ========================================================================= */
738 #endif
739
740 do
741 {
742 BOOL try_next = TRUE;
743 const pcre_uchar *tcode = code + 1 + LINK_SIZE;
744
745 if (*code == OP_CBRA || *code == OP_SCBRA ||
746 *code == OP_CBRAPOS || *code == OP_SCBRAPOS) tcode += IMM2_SIZE;
747
748 while (try_next) /* Loop for items in this branch */
749 {
750 int rc;
751
752 switch(*tcode)
753 {
754 /* If we reach something we don't understand, it means a new opcode has
755 been created that hasn't been added to this code. Hopefully this problem
756 will be discovered during testing. */
757
758 default:
759 return SSB_UNKNOWN;
760
761 /* Fail for a valid opcode that implies no starting bits. */
762
763 case OP_ACCEPT:
764 case OP_ASSERT_ACCEPT:
765 case OP_ALLANY:
766 case OP_ANY:
767 case OP_ANYBYTE:
768 case OP_CIRC:
769 case OP_CIRCM:
770 case OP_CLOSE:
771 case OP_COMMIT:
772 case OP_COND:
773 case OP_CREF:
774 case OP_DEF:
775 case OP_DOLL:
776 case OP_DOLLM:
777 case OP_END:
778 case OP_EOD:
779 case OP_EODN:
780 case OP_EXTUNI:
781 case OP_FAIL:
782 case OP_MARK:
783 case OP_NCREF:
784 case OP_NOT:
785 case OP_NOTEXACT:
786 case OP_NOTEXACTI:
787 case OP_NOTI:
788 case OP_NOTMINPLUS:
789 case OP_NOTMINPLUSI:
790 case OP_NOTMINQUERY:
791 case OP_NOTMINQUERYI:
792 case OP_NOTMINSTAR:
793 case OP_NOTMINSTARI:
794 case OP_NOTMINUPTO:
795 case OP_NOTMINUPTOI:
796 case OP_NOTPLUS:
797 case OP_NOTPLUSI:
798 case OP_NOTPOSPLUS:
799 case OP_NOTPOSPLUSI:
800 case OP_NOTPOSQUERY:
801 case OP_NOTPOSQUERYI:
802 case OP_NOTPOSSTAR:
803 case OP_NOTPOSSTARI:
804 case OP_NOTPOSUPTO:
805 case OP_NOTPOSUPTOI:
806 case OP_NOTPROP:
807 case OP_NOTQUERY:
808 case OP_NOTQUERYI:
809 case OP_NOTSTAR:
810 case OP_NOTSTARI:
811 case OP_NOTUPTO:
812 case OP_NOTUPTOI:
813 case OP_NOT_HSPACE:
814 case OP_NOT_VSPACE:
815 case OP_NRREF:
816 case OP_PROP:
817 case OP_PRUNE:
818 case OP_PRUNE_ARG:
819 case OP_RECURSE:
820 case OP_REF:
821 case OP_REFI:
822 case OP_REVERSE:
823 case OP_RREF:
824 case OP_SCOND:
825 case OP_SET_SOM:
826 case OP_SKIP:
827 case OP_SKIP_ARG:
828 case OP_SOD:
829 case OP_SOM:
830 case OP_THEN:
831 case OP_THEN_ARG:
832 #if defined SUPPORT_UTF || !defined COMPILE_PCRE8
833 case OP_XCLASS:
834 #endif
835 return SSB_FAIL;
836
837 /* We can ignore word boundary tests. */
838
839 case OP_WORD_BOUNDARY:
840 case OP_NOT_WORD_BOUNDARY:
841 tcode++;
842 break;
843
844 /* If we hit a bracket or a positive lookahead assertion, recurse to set
845 bits from within the subpattern. If it can't find anything, we have to
846 give up. If it finds some mandatory character(s), we are done for this
847 branch. Otherwise, carry on scanning after the subpattern. */
848
849 case OP_BRA:
850 case OP_SBRA:
851 case OP_CBRA:
852 case OP_SCBRA:
853 case OP_BRAPOS:
854 case OP_SBRAPOS:
855 case OP_CBRAPOS:
856 case OP_SCBRAPOS:
857 case OP_ONCE:
858 case OP_ONCE_NC:
859 case OP_ASSERT:
860 rc = set_start_bits(tcode, start_bits, utf, cd);
861 if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
862 if (rc == SSB_DONE) try_next = FALSE; else
863 {
864 do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
865 tcode += 1 + LINK_SIZE;
866 }
867 break;
868
869 /* If we hit ALT or KET, it means we haven't found anything mandatory in
870 this branch, though we might have found something optional. For ALT, we
871 continue with the next alternative, but we have to arrange that the final
872 result from subpattern is SSB_CONTINUE rather than SSB_DONE. For KET,
873 return SSB_CONTINUE: if this is the top level, that indicates failure,
874 but after a nested subpattern, it causes scanning to continue. */
875
876 case OP_ALT:
877 yield = SSB_CONTINUE;
878 try_next = FALSE;
879 break;
880
881 case OP_KET:
882 case OP_KETRMAX:
883 case OP_KETRMIN:
884 case OP_KETRPOS:
885 return SSB_CONTINUE;
886
887 /* Skip over callout */
888
889 case OP_CALLOUT:
890 tcode += 2 + 2*LINK_SIZE;
891 break;
892
893 /* Skip over lookbehind and negative lookahead assertions */
894
895 case OP_ASSERT_NOT:
896 case OP_ASSERTBACK:
897 case OP_ASSERTBACK_NOT:
898 do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
899 tcode += 1 + LINK_SIZE;
900 break;
901
902 /* BRAZERO does the bracket, but carries on. */
903
904 case OP_BRAZERO:
905 case OP_BRAMINZERO:
906 case OP_BRAPOSZERO:
907 rc = set_start_bits(++tcode, start_bits, utf, cd);
908 if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
909 /* =========================================================================
910 See the comment at the head of this function concerning the next line,
911 which was an old fudge for the benefit of OS/2.
912 dummy = 1;
913 ========================================================================= */
914 do tcode += GET(tcode,1); while (*tcode == OP_ALT);
915 tcode += 1 + LINK_SIZE;
916 break;
917
918 /* SKIPZERO skips the bracket. */
919
920 case OP_SKIPZERO:
921 tcode++;
922 do tcode += GET(tcode,1); while (*tcode == OP_ALT);
923 tcode += 1 + LINK_SIZE;
924 break;
925
926 /* Single-char * or ? sets the bit and tries the next item */
927
928 case OP_STAR:
929 case OP_MINSTAR:
930 case OP_POSSTAR:
931 case OP_QUERY:
932 case OP_MINQUERY:
933 case OP_POSQUERY:
934 tcode = set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
935 break;
936
937 case OP_STARI:
938 case OP_MINSTARI:
939 case OP_POSSTARI:
940 case OP_QUERYI:
941 case OP_MINQUERYI:
942 case OP_POSQUERYI:
943 tcode = set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
944 break;
945
946 /* Single-char upto sets the bit and tries the next */
947
948 case OP_UPTO:
949 case OP_MINUPTO:
950 case OP_POSUPTO:
951 tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, FALSE, cd, utf);
952 break;
953
954 case OP_UPTOI:
955 case OP_MINUPTOI:
956 case OP_POSUPTOI:
957 tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, TRUE, cd, utf);
958 break;
959
960 /* At least one single char sets the bit and stops */
961
962 case OP_EXACT:
963 tcode += IMM2_SIZE;
964 /* Fall through */
965 case OP_CHAR:
966 case OP_PLUS:
967 case OP_MINPLUS:
968 case OP_POSPLUS:
969 (void)set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
970 try_next = FALSE;
971 break;
972
973 case OP_EXACTI:
974 tcode += IMM2_SIZE;
975 /* Fall through */
976 case OP_CHARI:
977 case OP_PLUSI:
978 case OP_MINPLUSI:
979 case OP_POSPLUSI:
980 (void)set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
981 try_next = FALSE;
982 break;
983
984 /* Special spacing and line-terminating items. These recognize specific
985 lists of characters. The difference between VSPACE and ANYNL is that the
986 latter can match the two-character CRLF sequence, but that is not
987 relevant for finding the first character, so their code here is
988 identical. */
989
990 case OP_HSPACE:
991 SET_BIT(0x09);
992 SET_BIT(0x20);
993 #ifdef SUPPORT_UTF
994 if (utf)
995 {
996 #ifdef COMPILE_PCRE8
997 SET_BIT(0xC2); /* For U+00A0 */
998 SET_BIT(0xE1); /* For U+1680, U+180E */
999 SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */
1000 SET_BIT(0xE3); /* For U+3000 */
1001 #endif
1002 #ifdef COMPILE_PCRE16
1003 SET_BIT(0xA0);
1004 SET_BIT(0xFF); /* For characters > 255 */
1005 #endif
1006 }
1007 else
1008 #endif /* SUPPORT_UTF */
1009 {
1010 SET_BIT(0xA0);
1011 #ifdef COMPILE_PCRE16
1012 SET_BIT(0xFF); /* For characters > 255 */
1013 #endif
1014 }
1015 try_next = FALSE;
1016 break;
1017
1018 case OP_ANYNL:
1019 case OP_VSPACE:
1020 SET_BIT(0x0A);
1021 SET_BIT(0x0B);
1022 SET_BIT(0x0C);
1023 SET_BIT(0x0D);
1024 #ifdef SUPPORT_UTF
1025 if (utf)
1026 {
1027 #ifdef COMPILE_PCRE8
1028 SET_BIT(0xC2); /* For U+0085 */
1029 SET_BIT(0xE2); /* For U+2028, U+2029 */
1030 #endif
1031 #ifdef COMPILE_PCRE16
1032 SET_BIT(0x85);
1033 SET_BIT(0xFF); /* For characters > 255 */
1034 #endif
1035 }
1036 else
1037 #endif /* SUPPORT_UTF */
1038 {
1039 SET_BIT(0x85);
1040 #ifdef COMPILE_PCRE16
1041 SET_BIT(0xFF); /* For characters > 255 */
1042 #endif
1043 }
1044 try_next = FALSE;
1045 break;
1046
1047 /* Single character types set the bits and stop. Note that if PCRE_UCP
1048 is set, we do not see these op codes because \d etc are converted to
1049 properties. Therefore, these apply in the case when only characters less
1050 than 256 are recognized to match the types. */
1051
1052 case OP_NOT_DIGIT:
1053 set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
1054 try_next = FALSE;
1055 break;
1056
1057 case OP_DIGIT:
1058 set_type_bits(start_bits, cbit_digit, table_limit, cd);
1059 try_next = FALSE;
1060 break;
1061
1062 /* The cbit_space table has vertical tab as whitespace; we have to
1063 ensure it is set as not whitespace. */
1064
1065 case OP_NOT_WHITESPACE:
1066 set_nottype_bits(start_bits, cbit_space, table_limit, cd);
1067 start_bits[1] |= 0x08;
1068 try_next = FALSE;
1069 break;
1070
1071 /* The cbit_space table has vertical tab as whitespace; we have to
1072 not set it from the table. */
1073
1074 case OP_WHITESPACE:
1075 c = start_bits[1]; /* Save in case it was already set */
1076 set_type_bits(start_bits, cbit_space, table_limit, cd);
1077 start_bits[1] = (start_bits[1] & ~0x08) | c;
1078 try_next = FALSE;
1079 break;
1080
1081 case OP_NOT_WORDCHAR:
1082 set_nottype_bits(start_bits, cbit_word, table_limit, cd);
1083 try_next = FALSE;
1084 break;
1085
1086 case OP_WORDCHAR:
1087 set_type_bits(start_bits, cbit_word, table_limit, cd);
1088 try_next = FALSE;
1089 break;
1090
1091 /* One or more character type fudges the pointer and restarts, knowing
1092 it will hit a single character type and stop there. */
1093
1094 case OP_TYPEPLUS:
1095 case OP_TYPEMINPLUS:
1096 case OP_TYPEPOSPLUS:
1097 tcode++;
1098 break;
1099
1100 case OP_TYPEEXACT:
1101 tcode += 1 + IMM2_SIZE;
1102 break;
1103
1104 /* Zero or more repeats of character types set the bits and then
1105 try again. */
1106
1107 case OP_TYPEUPTO:
1108 case OP_TYPEMINUPTO:
1109 case OP_TYPEPOSUPTO:
1110 tcode += IMM2_SIZE; /* Fall through */
1111
1112 case OP_TYPESTAR:
1113 case OP_TYPEMINSTAR:
1114 case OP_TYPEPOSSTAR:
1115 case OP_TYPEQUERY:
1116 case OP_TYPEMINQUERY:
1117 case OP_TYPEPOSQUERY:
1118 switch(tcode[1])
1119 {
1120 default:
1121 case OP_ANY:
1122 case OP_ALLANY:
1123 return SSB_FAIL;
1124
1125 case OP_HSPACE:
1126 SET_BIT(0x09);
1127 SET_BIT(0x20);
1128 #ifdef SUPPORT_UTF
1129 if (utf)
1130 {
1131 #ifdef COMPILE_PCRE8
1132 SET_BIT(0xC2); /* For U+00A0 */
1133 SET_BIT(0xE1); /* For U+1680, U+180E */
1134 SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */
1135 SET_BIT(0xE3); /* For U+3000 */
1136 #endif
1137 #ifdef COMPILE_PCRE16
1138 SET_BIT(0xA0);
1139 SET_BIT(0xFF); /* For characters > 255 */
1140 #endif
1141 }
1142 else
1143 #endif /* SUPPORT_UTF */
1144 SET_BIT(0xA0);
1145 break;
1146
1147 case OP_ANYNL:
1148 case OP_VSPACE:
1149 SET_BIT(0x0A);
1150 SET_BIT(0x0B);
1151 SET_BIT(0x0C);
1152 SET_BIT(0x0D);
1153 #ifdef SUPPORT_UTF
1154 if (utf)
1155 {
1156 #ifdef COMPILE_PCRE8
1157 SET_BIT(0xC2); /* For U+0085 */
1158 SET_BIT(0xE2); /* For U+2028, U+2029 */
1159 #endif
1160 #ifdef COMPILE_PCRE16
1161 SET_BIT(0x85);
1162 SET_BIT(0xFF); /* For characters > 255 */
1163 #endif
1164 }
1165 else
1166 #endif /* SUPPORT_UTF */
1167 SET_BIT(0x85);
1168 break;
1169
1170 case OP_NOT_DIGIT:
1171 set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
1172 break;
1173
1174 case OP_DIGIT:
1175 set_type_bits(start_bits, cbit_digit, table_limit, cd);
1176 break;
1177
1178 /* The cbit_space table has vertical tab as whitespace; we have to
1179 ensure it gets set as not whitespace. */
1180
1181 case OP_NOT_WHITESPACE:
1182 set_nottype_bits(start_bits, cbit_space, table_limit, cd);
1183 start_bits[1] |= 0x08;
1184 break;
1185
1186 /* The cbit_space table has vertical tab as whitespace; we have to
1187 avoid setting it. */
1188
1189 case OP_WHITESPACE:
1190 c = start_bits[1]; /* Save in case it was already set */
1191 set_type_bits(start_bits, cbit_space, table_limit, cd);
1192 start_bits[1] = (start_bits[1] & ~0x08) | c;
1193 break;
1194
1195 case OP_NOT_WORDCHAR:
1196 set_nottype_bits(start_bits, cbit_word, table_limit, cd);
1197 break;
1198
1199 case OP_WORDCHAR:
1200 set_type_bits(start_bits, cbit_word, table_limit, cd);
1201 break;
1202 }
1203
1204 tcode += 2;
1205 break;
1206
1207 /* Character class where all the information is in a bit map: set the
1208 bits and either carry on or not, according to the repeat count. If it was
1209 a negative class, and we are operating with UTF-8 characters, any byte
1210 with a value >= 0xc4 is a potentially valid starter because it starts a
1211 character with a value > 255. */
1212
1213 case OP_NCLASS:
1214 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
1215 if (utf)
1216 {
1217 start_bits[24] |= 0xf0; /* Bits for 0xc4 - 0xc8 */
1218 memset(start_bits+25, 0xff, 7); /* Bits for 0xc9 - 0xff */
1219 }
1220 #endif
1221 #ifdef COMPILE_PCRE16
1222 SET_BIT(0xFF); /* For characters > 255 */
1223 #endif
1224 /* Fall through */
1225
1226 case OP_CLASS:
1227 {
1228 pcre_uint8 *map;
1229 tcode++;
1230 map = (pcre_uint8 *)tcode;
1231
1232 /* In UTF-8 mode, the bits in a bit map correspond to character
1233 values, not to byte values. However, the bit map we are constructing is
1234 for byte values. So we have to do a conversion for characters whose
1235 value is > 127. In fact, there are only two possible starting bytes for
1236 characters in the range 128 - 255. */
1237
1238 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
1239 if (utf)
1240 {
1241 for (c = 0; c < 16; c++) start_bits[c] |= map[c];
1242 for (c = 128; c < 256; c++)
1243 {
1244 if ((map[c/8] && (1 << (c&7))) != 0)
1245 {
1246 int d = (c >> 6) | 0xc0; /* Set bit for this starter */
1247 start_bits[d/8] |= (1 << (d&7)); /* and then skip on to the */
1248 c = (c & 0xc0) + 0x40 - 1; /* next relevant character. */
1249 }
1250 }
1251 }
1252 else
1253 #endif
1254 {
1255 /* In non-UTF-8 mode, the two bit maps are completely compatible. */
1256 for (c = 0; c < 32; c++) start_bits[c] |= map[c];
1257 }
1258
1259 /* Advance past the bit map, and act on what follows. For a zero
1260 minimum repeat, continue; otherwise stop processing. */
1261
1262 tcode += 32 / sizeof(pcre_uchar);
1263 switch (*tcode)
1264 {
1265 case OP_CRSTAR:
1266 case OP_CRMINSTAR:
1267 case OP_CRQUERY:
1268 case OP_CRMINQUERY:
1269 tcode++;
1270 break;
1271
1272 case OP_CRRANGE:
1273 case OP_CRMINRANGE:
1274 if (GET2(tcode, 1) == 0) tcode += 1 + 2 * IMM2_SIZE;
1275 else try_next = FALSE;
1276 break;
1277
1278 default:
1279 try_next = FALSE;
1280 break;
1281 }
1282 }
1283 break; /* End of bitmap class handling */
1284
1285 } /* End of switch */
1286 } /* End of try_next loop */
1287
1288 code += GET(code, 1); /* Advance to next branch */
1289 }
1290 while (*code == OP_ALT);
1291 return yield;
1292 }
1293
1294
1295
1296
1297
1298 /*************************************************
1299 * Study a compiled expression *
1300 *************************************************/
1301
1302 /* This function is handed a compiled expression that it must study to produce
1303 information that will speed up the matching. It returns a pcre[16]_extra block
1304 which then gets handed back to pcre_exec().
1305
1306 Arguments:
1307 re points to the compiled expression
1308 options contains option bits
1309 errorptr points to where to place error messages;
1310 set NULL unless error
1311
1312 Returns: pointer to a pcre[16]_extra block, with study_data filled in and
1313 the appropriate flags set;
1314 NULL on error or if no optimization possible
1315 */
1316
1317 #ifdef COMPILE_PCRE8
1318 PCRE_EXP_DEFN pcre_extra * PCRE_CALL_CONVENTION
1319 pcre_study(const pcre *external_re, int options, const char **errorptr)
1320 #else
1321 PCRE_EXP_DEFN pcre16_extra * PCRE_CALL_CONVENTION
1322 pcre16_study(const pcre16 *external_re, int options, const char **errorptr)
1323 #endif
1324 {
1325 int min;
1326 BOOL bits_set = FALSE;
1327 pcre_uint8 start_bits[32];
1328 PUBL(extra) *extra = NULL;
1329 pcre_study_data *study;
1330 const pcre_uint8 *tables;
1331 pcre_uchar *code;
1332 compile_data compile_block;
1333 const REAL_PCRE *re = (const REAL_PCRE *)external_re;
1334
1335 *errorptr = NULL;
1336
1337 if (re == NULL || re->magic_number != MAGIC_NUMBER)
1338 {
1339 *errorptr = "argument is not a compiled regular expression";
1340 return NULL;
1341 }
1342
1343 if ((re->flags & PCRE_MODE) == 0)
1344 {
1345 #ifdef COMPILE_PCRE8
1346 *errorptr = "argument is compiled in 16 bit mode";
1347 #else
1348 *errorptr = "argument is compiled in 8 bit mode";
1349 #endif
1350 return NULL;
1351 }
1352
1353 if ((options & ~PUBLIC_STUDY_OPTIONS) != 0)
1354 {
1355 *errorptr = "unknown or incorrect option bit(s) set";
1356 return NULL;
1357 }
1358
1359 code = (pcre_uchar *)re + re->name_table_offset +
1360 (re->name_count * re->name_entry_size);
1361
1362 /* For an anchored pattern, or an unanchored pattern that has a first char, or
1363 a multiline pattern that matches only at "line starts", there is no point in
1364 seeking a list of starting bytes. */
1365
1366 if ((re->options & PCRE_ANCHORED) == 0 &&
1367 (re->flags & (PCRE_FIRSTSET|PCRE_STARTLINE)) == 0)
1368 {
1369 int rc;
1370
1371 /* Set the character tables in the block that is passed around */
1372
1373 tables = re->tables;
1374
1375 #ifdef COMPILE_PCRE8
1376 if (tables == NULL)
1377 (void)pcre_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1378 (void *)(&tables));
1379 #else
1380 if (tables == NULL)
1381 (void)pcre16_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1382 (void *)(&tables));
1383 #endif
1384
1385 compile_block.lcc = tables + lcc_offset;
1386 compile_block.fcc = tables + fcc_offset;
1387 compile_block.cbits = tables + cbits_offset;
1388 compile_block.ctypes = tables + ctypes_offset;
1389
1390 /* See if we can find a fixed set of initial characters for the pattern. */
1391
1392 memset(start_bits, 0, 32 * sizeof(pcre_uint8));
1393 rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0,
1394 &compile_block);
1395 bits_set = rc == SSB_DONE;
1396 if (rc == SSB_UNKNOWN)
1397 {
1398 *errorptr = "internal error: opcode not recognized";
1399 return NULL;
1400 }
1401 }
1402
1403 /* Find the minimum length of subject string. */
1404
1405 switch(min = find_minlength(code, code, re->options, 0))
1406 {
1407 case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
1408 case -3: *errorptr = "internal error: opcode not recognized"; return NULL;
1409 default: break;
1410 }
1411
1412 /* If a set of starting bytes has been identified, or if the minimum length is
1413 greater than zero, or if JIT optimization has been requested, or if
1414 PCRE_STUDY_EXTRA_NEEDED is set, get a pcre[16]_extra block and a
1415 pcre_study_data block. The study data is put in the latter, which is pointed to
1416 by the former, which may also get additional data set later by the calling
1417 program. At the moment, the size of pcre_study_data is fixed. We nevertheless
1418 save it in a field for returning via the pcre_fullinfo() function so that if it
1419 becomes variable in the future, we don't have to change that code. */
1420
1421 if (bits_set || min > 0 || (options & (
1422 #ifdef SUPPORT_JIT
1423 PCRE_STUDY_JIT_COMPILE | PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE |
1424 PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE |
1425 #endif
1426 PCRE_STUDY_EXTRA_NEEDED)) != 0)
1427 {
1428 extra = (PUBL(extra) *)(PUBL(malloc))
1429 (sizeof(PUBL(extra)) + sizeof(pcre_study_data));
1430 if (extra == NULL)
1431 {
1432 *errorptr = "failed to get memory";
1433 return NULL;
1434 }
1435
1436 study = (pcre_study_data *)((char *)extra + sizeof(PUBL(extra)));
1437 extra->flags = PCRE_EXTRA_STUDY_DATA;
1438 extra->study_data = study;
1439
1440 study->size = sizeof(pcre_study_data);
1441 study->flags = 0;
1442
1443 /* Set the start bits always, to avoid unset memory errors if the
1444 study data is written to a file, but set the flag only if any of the bits
1445 are set, to save time looking when none are. */
1446
1447 if (bits_set)
1448 {
1449 study->flags |= PCRE_STUDY_MAPPED;
1450 memcpy(study->start_bits, start_bits, sizeof(start_bits));
1451 }
1452 else memset(study->start_bits, 0, 32 * sizeof(pcre_uint8));
1453
1454 #ifdef PCRE_DEBUG
1455 if (bits_set)
1456 {
1457 pcre_uint8 *ptr = start_bits;
1458 int i;
1459
1460 printf("Start bits:\n");
1461 for (i = 0; i < 32; i++)
1462 printf("%3d: %02x%s", i * 8, *ptr++, ((i + 1) & 0x7) != 0? " " : "\n");
1463 }
1464 #endif
1465
1466 /* Always set the minlength value in the block, because the JIT compiler
1467 makes use of it. However, don't set the bit unless the length is greater than
1468 zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time
1469 checking the zero case. */
1470
1471 if (min > 0)
1472 {
1473 study->flags |= PCRE_STUDY_MINLEN;
1474 study->minlength = min;
1475 }
1476 else study->minlength = 0;
1477
1478 /* If JIT support was compiled and requested, attempt the JIT compilation.
1479 If no starting bytes were found, and the minimum length is zero, and JIT
1480 compilation fails, abandon the extra block and return NULL, unless
1481 PCRE_STUDY_EXTRA_NEEDED is set. */
1482
1483 #ifdef SUPPORT_JIT
1484 extra->executable_jit = NULL;
1485 if ((options & PCRE_STUDY_JIT_COMPILE) != 0)
1486 PRIV(jit_compile)(re, extra, JIT_COMPILE);
1487 if ((options & PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE) != 0)
1488 PRIV(jit_compile)(re, extra, JIT_PARTIAL_SOFT_COMPILE);
1489 if ((options & PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE) != 0)
1490 PRIV(jit_compile)(re, extra, JIT_PARTIAL_HARD_COMPILE);
1491
1492 if (study->flags == 0 && (extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) == 0 &&
1493 (options & PCRE_STUDY_EXTRA_NEEDED) == 0)
1494 {
1495 #ifdef COMPILE_PCRE8
1496 pcre_free_study(extra);
1497 #endif
1498 #ifdef COMPILE_PCRE16
1499 pcre16_free_study(extra);
1500 #endif
1501 extra = NULL;
1502 }
1503 #endif
1504 }
1505
1506 return extra;
1507 }
1508
1509
1510 /*************************************************
1511 * Free the study data *
1512 *************************************************/
1513
1514 /* This function frees the memory that was obtained by pcre_study().
1515
1516 Argument: a pointer to the pcre[16]_extra block
1517 Returns: nothing
1518 */
1519
1520 #ifdef COMPILE_PCRE8
1521 PCRE_EXP_DEFN void
1522 pcre_free_study(pcre_extra *extra)
1523 #else
1524 PCRE_EXP_DEFN void
1525 pcre16_free_study(pcre16_extra *extra)
1526 #endif
1527 {
1528 if (extra == NULL)
1529 return;
1530 #ifdef SUPPORT_JIT
1531 if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 &&
1532 extra->executable_jit != NULL)
1533 PRIV(jit_free)(extra->executable_jit);
1534 #endif
1535 PUBL(free)(extra);
1536 }
1537
1538 /* End of pcre_study.c */

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