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Revision 1379 - (show annotations)
Mon Oct 14 13:54:07 2013 UTC (6 years, 1 month ago) by ph10
File MIME type: text/plain
File size: 46087 byte(s)
More auto-possessification additions, using possessive class repeats. These are 
not yet used for explicit possessification.
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 case OP_CRPOSPLUS:
346 branchlength++;
347 /* Fall through */
348
349 case OP_CRSTAR:
350 case OP_CRMINSTAR:
351 case OP_CRQUERY:
352 case OP_CRMINQUERY:
353 case OP_CRPOSSTAR:
354 case OP_CRPOSQUERY:
355 cc++;
356 break;
357
358 case OP_CRRANGE:
359 case OP_CRMINRANGE:
360 case OP_CRPOSRANGE:
361 branchlength += GET2(cc,1);
362 cc += 1 + 2 * IMM2_SIZE;
363 break;
364
365 default:
366 branchlength++;
367 break;
368 }
369 break;
370
371 /* Backreferences and subroutine calls are treated in the same way: we find
372 the minimum length for the subpattern. A recursion, however, causes an
373 a flag to be set that causes the length of this branch to be ignored. The
374 logic is that a recursion can only make sense if there is another
375 alternation that stops the recursing. That will provide the minimum length
376 (when no recursion happens). A backreference within the group that it is
377 referencing behaves in the same way.
378
379 If PCRE_JAVASCRIPT_COMPAT is set, a backreference to an unset bracket
380 matches an empty string (by default it causes a matching failure), so in
381 that case we must set the minimum length to zero. */
382
383 case OP_DNREF: /* Duplicate named pattern back reference */
384 case OP_DNREFI:
385 if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
386 {
387 int count = GET2(cc, 1+IMM2_SIZE);
388 pcre_uchar *slot = (pcre_uchar *)re +
389 re->name_table_offset + GET2(cc, 1) * re->name_entry_size;
390 d = INT_MAX;
391 while (count-- > 0)
392 {
393 ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(slot, 0));
394 if (cs == NULL) return -2;
395 do ce += GET(ce, 1); while (*ce == OP_ALT);
396 if (cc > cs && cc < ce)
397 {
398 d = 0;
399 had_recurse = TRUE;
400 break;
401 }
402 else
403 {
404 int dd = find_minlength(re, cs, startcode, options, recurse_depth);
405 if (dd < d) d = dd;
406 }
407 slot += re->name_entry_size;
408 }
409 }
410 else d = 0;
411 cc += 1 + 2*IMM2_SIZE;
412 goto REPEAT_BACK_REFERENCE;
413
414 case OP_REF: /* Single back reference */
415 case OP_REFI:
416 if ((options & PCRE_JAVASCRIPT_COMPAT) == 0)
417 {
418 ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(cc, 1));
419 if (cs == NULL) return -2;
420 do ce += GET(ce, 1); while (*ce == OP_ALT);
421 if (cc > cs && cc < ce)
422 {
423 d = 0;
424 had_recurse = TRUE;
425 }
426 else
427 {
428 d = find_minlength(re, cs, startcode, options, recurse_depth);
429 }
430 }
431 else d = 0;
432 cc += 1 + IMM2_SIZE;
433
434 /* Handle repeated back references */
435
436 REPEAT_BACK_REFERENCE:
437 switch (*cc)
438 {
439 case OP_CRSTAR:
440 case OP_CRMINSTAR:
441 case OP_CRQUERY:
442 case OP_CRMINQUERY:
443 case OP_CRPOSSTAR:
444 case OP_CRPOSQUERY:
445 min = 0;
446 cc++;
447 break;
448
449 case OP_CRPLUS:
450 case OP_CRMINPLUS:
451 case OP_CRPOSPLUS:
452 min = 1;
453 cc++;
454 break;
455
456 case OP_CRRANGE:
457 case OP_CRMINRANGE:
458 case OP_CRPOSRANGE:
459 min = GET2(cc, 1);
460 cc += 1 + 2 * IMM2_SIZE;
461 break;
462
463 default:
464 min = 1;
465 break;
466 }
467
468 branchlength += min * d;
469 break;
470
471 /* We can easily detect direct recursion, but not mutual recursion. This is
472 caught by a recursion depth count. */
473
474 case OP_RECURSE:
475 cs = ce = (pcre_uchar *)startcode + GET(cc, 1);
476 do ce += GET(ce, 1); while (*ce == OP_ALT);
477 if ((cc > cs && cc < ce) || recurse_depth > 10)
478 had_recurse = TRUE;
479 else
480 {
481 branchlength += find_minlength(re, cs, startcode, options,
482 recurse_depth + 1);
483 }
484 cc += 1 + LINK_SIZE;
485 break;
486
487 /* Anything else does not or need not match a character. We can get the
488 item's length from the table, but for those that can match zero occurrences
489 of a character, we must take special action for UTF-8 characters. As it
490 happens, the "NOT" versions of these opcodes are used at present only for
491 ASCII characters, so they could be omitted from this list. However, in
492 future that may change, so we include them here so as not to leave a
493 gotcha for a future maintainer. */
494
495 case OP_UPTO:
496 case OP_UPTOI:
497 case OP_NOTUPTO:
498 case OP_NOTUPTOI:
499 case OP_MINUPTO:
500 case OP_MINUPTOI:
501 case OP_NOTMINUPTO:
502 case OP_NOTMINUPTOI:
503 case OP_POSUPTO:
504 case OP_POSUPTOI:
505 case OP_NOTPOSUPTO:
506 case OP_NOTPOSUPTOI:
507
508 case OP_STAR:
509 case OP_STARI:
510 case OP_NOTSTAR:
511 case OP_NOTSTARI:
512 case OP_MINSTAR:
513 case OP_MINSTARI:
514 case OP_NOTMINSTAR:
515 case OP_NOTMINSTARI:
516 case OP_POSSTAR:
517 case OP_POSSTARI:
518 case OP_NOTPOSSTAR:
519 case OP_NOTPOSSTARI:
520
521 case OP_QUERY:
522 case OP_QUERYI:
523 case OP_NOTQUERY:
524 case OP_NOTQUERYI:
525 case OP_MINQUERY:
526 case OP_MINQUERYI:
527 case OP_NOTMINQUERY:
528 case OP_NOTMINQUERYI:
529 case OP_POSQUERY:
530 case OP_POSQUERYI:
531 case OP_NOTPOSQUERY:
532 case OP_NOTPOSQUERYI:
533
534 cc += PRIV(OP_lengths)[op];
535 #ifdef SUPPORT_UTF
536 if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]);
537 #endif
538 break;
539
540 /* Skip these, but we need to add in the name length. */
541
542 case OP_MARK:
543 case OP_PRUNE_ARG:
544 case OP_SKIP_ARG:
545 case OP_THEN_ARG:
546 cc += PRIV(OP_lengths)[op] + cc[1];
547 break;
548
549 /* The remaining opcodes are just skipped over. */
550
551 case OP_CLOSE:
552 case OP_COMMIT:
553 case OP_FAIL:
554 case OP_PRUNE:
555 case OP_SET_SOM:
556 case OP_SKIP:
557 case OP_THEN:
558 cc += PRIV(OP_lengths)[op];
559 break;
560
561 /* This should not occur: we list all opcodes explicitly so that when
562 new ones get added they are properly considered. */
563
564 default:
565 return -3;
566 }
567 }
568 /* Control never gets here */
569 }
570
571
572
573 /*************************************************
574 * Set a bit and maybe its alternate case *
575 *************************************************/
576
577 /* Given a character, set its first byte's bit in the table, and also the
578 corresponding bit for the other version of a letter if we are caseless. In
579 UTF-8 mode, for characters greater than 127, we can only do the caseless thing
580 when Unicode property support is available.
581
582 Arguments:
583 start_bits points to the bit map
584 p points to the character
585 caseless the caseless flag
586 cd the block with char table pointers
587 utf TRUE for UTF-8 / UTF-16 / UTF-32 mode
588
589 Returns: pointer after the character
590 */
591
592 static const pcre_uchar *
593 set_table_bit(pcre_uint8 *start_bits, const pcre_uchar *p, BOOL caseless,
594 compile_data *cd, BOOL utf)
595 {
596 pcre_uint32 c = *p;
597
598 #ifdef COMPILE_PCRE8
599 SET_BIT(c);
600
601 #ifdef SUPPORT_UTF
602 if (utf && c > 127)
603 {
604 GETCHARINC(c, p);
605 #ifdef SUPPORT_UCP
606 if (caseless)
607 {
608 pcre_uchar buff[6];
609 c = UCD_OTHERCASE(c);
610 (void)PRIV(ord2utf)(c, buff);
611 SET_BIT(buff[0]);
612 }
613 #endif /* Not SUPPORT_UCP */
614 return p;
615 }
616 #else /* Not SUPPORT_UTF */
617 (void)(utf); /* Stops warning for unused parameter */
618 #endif /* SUPPORT_UTF */
619
620 /* Not UTF-8 mode, or character is less than 127. */
621
622 if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
623 return p + 1;
624 #endif /* COMPILE_PCRE8 */
625
626 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
627 if (c > 0xff)
628 {
629 c = 0xff;
630 caseless = FALSE;
631 }
632 SET_BIT(c);
633
634 #ifdef SUPPORT_UTF
635 if (utf && c > 127)
636 {
637 GETCHARINC(c, p);
638 #ifdef SUPPORT_UCP
639 if (caseless)
640 {
641 c = UCD_OTHERCASE(c);
642 if (c > 0xff)
643 c = 0xff;
644 SET_BIT(c);
645 }
646 #endif /* SUPPORT_UCP */
647 return p;
648 }
649 #else /* Not SUPPORT_UTF */
650 (void)(utf); /* Stops warning for unused parameter */
651 #endif /* SUPPORT_UTF */
652
653 if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]);
654 return p + 1;
655 #endif
656 }
657
658
659
660 /*************************************************
661 * Set bits for a positive character type *
662 *************************************************/
663
664 /* This function sets starting bits for a character type. In UTF-8 mode, we can
665 only do a direct setting for bytes less than 128, as otherwise there can be
666 confusion with bytes in the middle of UTF-8 characters. In a "traditional"
667 environment, the tables will only recognize ASCII characters anyway, but in at
668 least one Windows environment, some higher bytes bits were set in the tables.
669 So we deal with that case by considering the UTF-8 encoding.
670
671 Arguments:
672 start_bits the starting bitmap
673 cbit type the type of character wanted
674 table_limit 32 for non-UTF-8; 16 for UTF-8
675 cd the block with char table pointers
676
677 Returns: nothing
678 */
679
680 static void
681 set_type_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit,
682 compile_data *cd)
683 {
684 register pcre_uint32 c;
685 for (c = 0; c < table_limit; c++) start_bits[c] |= cd->cbits[c+cbit_type];
686 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
687 if (table_limit == 32) return;
688 for (c = 128; c < 256; c++)
689 {
690 if ((cd->cbits[c/8] & (1 << (c&7))) != 0)
691 {
692 pcre_uchar buff[6];
693 (void)PRIV(ord2utf)(c, buff);
694 SET_BIT(buff[0]);
695 }
696 }
697 #endif
698 }
699
700
701 /*************************************************
702 * Set bits for a negative character type *
703 *************************************************/
704
705 /* This function sets starting bits for a negative character type such as \D.
706 In UTF-8 mode, we can only do a direct setting for bytes less than 128, as
707 otherwise there can be confusion with bytes in the middle of UTF-8 characters.
708 Unlike in the positive case, where we can set appropriate starting bits for
709 specific high-valued UTF-8 characters, in this case we have to set the bits for
710 all high-valued characters. The lowest is 0xc2, but we overkill by starting at
711 0xc0 (192) for simplicity.
712
713 Arguments:
714 start_bits the starting bitmap
715 cbit type the type of character wanted
716 table_limit 32 for non-UTF-8; 16 for UTF-8
717 cd the block with char table pointers
718
719 Returns: nothing
720 */
721
722 static void
723 set_nottype_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit,
724 compile_data *cd)
725 {
726 register pcre_uint32 c;
727 for (c = 0; c < table_limit; c++) start_bits[c] |= ~cd->cbits[c+cbit_type];
728 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
729 if (table_limit != 32) for (c = 24; c < 32; c++) start_bits[c] = 0xff;
730 #endif
731 }
732
733
734
735 /*************************************************
736 * Create bitmap of starting bytes *
737 *************************************************/
738
739 /* This function scans a compiled unanchored expression recursively and
740 attempts to build a bitmap of the set of possible starting bytes. As time goes
741 by, we may be able to get more clever at doing this. The SSB_CONTINUE return is
742 useful for parenthesized groups in patterns such as (a*)b where the group
743 provides some optional starting bytes but scanning must continue at the outer
744 level to find at least one mandatory byte. At the outermost level, this
745 function fails unless the result is SSB_DONE.
746
747 Arguments:
748 code points to an expression
749 start_bits points to a 32-byte table, initialized to 0
750 utf TRUE if in UTF-8 / UTF-16 / UTF-32 mode
751 cd the block with char table pointers
752
753 Returns: SSB_FAIL => Failed to find any starting bytes
754 SSB_DONE => Found mandatory starting bytes
755 SSB_CONTINUE => Found optional starting bytes
756 SSB_UNKNOWN => Hit an unrecognized opcode
757 */
758
759 static int
760 set_start_bits(const pcre_uchar *code, pcre_uint8 *start_bits, BOOL utf,
761 compile_data *cd)
762 {
763 register pcre_uint32 c;
764 int yield = SSB_DONE;
765 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
766 int table_limit = utf? 16:32;
767 #else
768 int table_limit = 32;
769 #endif
770
771 #if 0
772 /* ========================================================================= */
773 /* The following comment and code was inserted in January 1999. In May 2006,
774 when it was observed to cause compiler warnings about unused values, I took it
775 out again. If anybody is still using OS/2, they will have to put it back
776 manually. */
777
778 /* This next statement and the later reference to dummy are here in order to
779 trick the optimizer of the IBM C compiler for OS/2 into generating correct
780 code. Apparently IBM isn't going to fix the problem, and we would rather not
781 disable optimization (in this module it actually makes a big difference, and
782 the pcre module can use all the optimization it can get). */
783
784 volatile int dummy;
785 /* ========================================================================= */
786 #endif
787
788 do
789 {
790 BOOL try_next = TRUE;
791 const pcre_uchar *tcode = code + 1 + LINK_SIZE;
792
793 if (*code == OP_CBRA || *code == OP_SCBRA ||
794 *code == OP_CBRAPOS || *code == OP_SCBRAPOS) tcode += IMM2_SIZE;
795
796 while (try_next) /* Loop for items in this branch */
797 {
798 int rc;
799
800 switch(*tcode)
801 {
802 /* If we reach something we don't understand, it means a new opcode has
803 been created that hasn't been added to this code. Hopefully this problem
804 will be discovered during testing. */
805
806 default:
807 return SSB_UNKNOWN;
808
809 /* Fail for a valid opcode that implies no starting bits. */
810
811 case OP_ACCEPT:
812 case OP_ASSERT_ACCEPT:
813 case OP_ALLANY:
814 case OP_ANY:
815 case OP_ANYBYTE:
816 case OP_CIRC:
817 case OP_CIRCM:
818 case OP_CLOSE:
819 case OP_COMMIT:
820 case OP_COND:
821 case OP_CREF:
822 case OP_DEF:
823 case OP_DNCREF:
824 case OP_DNREF:
825 case OP_DNREFI:
826 case OP_DNRREF:
827 case OP_DOLL:
828 case OP_DOLLM:
829 case OP_END:
830 case OP_EOD:
831 case OP_EODN:
832 case OP_EXTUNI:
833 case OP_FAIL:
834 case OP_MARK:
835 case OP_NOT:
836 case OP_NOTEXACT:
837 case OP_NOTEXACTI:
838 case OP_NOTI:
839 case OP_NOTMINPLUS:
840 case OP_NOTMINPLUSI:
841 case OP_NOTMINQUERY:
842 case OP_NOTMINQUERYI:
843 case OP_NOTMINSTAR:
844 case OP_NOTMINSTARI:
845 case OP_NOTMINUPTO:
846 case OP_NOTMINUPTOI:
847 case OP_NOTPLUS:
848 case OP_NOTPLUSI:
849 case OP_NOTPOSPLUS:
850 case OP_NOTPOSPLUSI:
851 case OP_NOTPOSQUERY:
852 case OP_NOTPOSQUERYI:
853 case OP_NOTPOSSTAR:
854 case OP_NOTPOSSTARI:
855 case OP_NOTPOSUPTO:
856 case OP_NOTPOSUPTOI:
857 case OP_NOTPROP:
858 case OP_NOTQUERY:
859 case OP_NOTQUERYI:
860 case OP_NOTSTAR:
861 case OP_NOTSTARI:
862 case OP_NOTUPTO:
863 case OP_NOTUPTOI:
864 case OP_NOT_HSPACE:
865 case OP_NOT_VSPACE:
866 case OP_PROP:
867 case OP_PRUNE:
868 case OP_PRUNE_ARG:
869 case OP_RECURSE:
870 case OP_REF:
871 case OP_REFI:
872 case OP_REVERSE:
873 case OP_RREF:
874 case OP_SCOND:
875 case OP_SET_SOM:
876 case OP_SKIP:
877 case OP_SKIP_ARG:
878 case OP_SOD:
879 case OP_SOM:
880 case OP_THEN:
881 case OP_THEN_ARG:
882 #if defined SUPPORT_UTF || !defined COMPILE_PCRE8
883 case OP_XCLASS:
884 #endif
885 return SSB_FAIL;
886
887 /* We can ignore word boundary tests. */
888
889 case OP_WORD_BOUNDARY:
890 case OP_NOT_WORD_BOUNDARY:
891 tcode++;
892 break;
893
894 /* If we hit a bracket or a positive lookahead assertion, recurse to set
895 bits from within the subpattern. If it can't find anything, we have to
896 give up. If it finds some mandatory character(s), we are done for this
897 branch. Otherwise, carry on scanning after the subpattern. */
898
899 case OP_BRA:
900 case OP_SBRA:
901 case OP_CBRA:
902 case OP_SCBRA:
903 case OP_BRAPOS:
904 case OP_SBRAPOS:
905 case OP_CBRAPOS:
906 case OP_SCBRAPOS:
907 case OP_ONCE:
908 case OP_ONCE_NC:
909 case OP_ASSERT:
910 rc = set_start_bits(tcode, start_bits, utf, cd);
911 if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
912 if (rc == SSB_DONE) try_next = FALSE; else
913 {
914 do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
915 tcode += 1 + LINK_SIZE;
916 }
917 break;
918
919 /* If we hit ALT or KET, it means we haven't found anything mandatory in
920 this branch, though we might have found something optional. For ALT, we
921 continue with the next alternative, but we have to arrange that the final
922 result from subpattern is SSB_CONTINUE rather than SSB_DONE. For KET,
923 return SSB_CONTINUE: if this is the top level, that indicates failure,
924 but after a nested subpattern, it causes scanning to continue. */
925
926 case OP_ALT:
927 yield = SSB_CONTINUE;
928 try_next = FALSE;
929 break;
930
931 case OP_KET:
932 case OP_KETRMAX:
933 case OP_KETRMIN:
934 case OP_KETRPOS:
935 return SSB_CONTINUE;
936
937 /* Skip over callout */
938
939 case OP_CALLOUT:
940 tcode += 2 + 2*LINK_SIZE;
941 break;
942
943 /* Skip over lookbehind and negative lookahead assertions */
944
945 case OP_ASSERT_NOT:
946 case OP_ASSERTBACK:
947 case OP_ASSERTBACK_NOT:
948 do tcode += GET(tcode, 1); while (*tcode == OP_ALT);
949 tcode += 1 + LINK_SIZE;
950 break;
951
952 /* BRAZERO does the bracket, but carries on. */
953
954 case OP_BRAZERO:
955 case OP_BRAMINZERO:
956 case OP_BRAPOSZERO:
957 rc = set_start_bits(++tcode, start_bits, utf, cd);
958 if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc;
959 /* =========================================================================
960 See the comment at the head of this function concerning the next line,
961 which was an old fudge for the benefit of OS/2.
962 dummy = 1;
963 ========================================================================= */
964 do tcode += GET(tcode,1); while (*tcode == OP_ALT);
965 tcode += 1 + LINK_SIZE;
966 break;
967
968 /* SKIPZERO skips the bracket. */
969
970 case OP_SKIPZERO:
971 tcode++;
972 do tcode += GET(tcode,1); while (*tcode == OP_ALT);
973 tcode += 1 + LINK_SIZE;
974 break;
975
976 /* Single-char * or ? sets the bit and tries the next item */
977
978 case OP_STAR:
979 case OP_MINSTAR:
980 case OP_POSSTAR:
981 case OP_QUERY:
982 case OP_MINQUERY:
983 case OP_POSQUERY:
984 tcode = set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
985 break;
986
987 case OP_STARI:
988 case OP_MINSTARI:
989 case OP_POSSTARI:
990 case OP_QUERYI:
991 case OP_MINQUERYI:
992 case OP_POSQUERYI:
993 tcode = set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
994 break;
995
996 /* Single-char upto sets the bit and tries the next */
997
998 case OP_UPTO:
999 case OP_MINUPTO:
1000 case OP_POSUPTO:
1001 tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, FALSE, cd, utf);
1002 break;
1003
1004 case OP_UPTOI:
1005 case OP_MINUPTOI:
1006 case OP_POSUPTOI:
1007 tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, TRUE, cd, utf);
1008 break;
1009
1010 /* At least one single char sets the bit and stops */
1011
1012 case OP_EXACT:
1013 tcode += IMM2_SIZE;
1014 /* Fall through */
1015 case OP_CHAR:
1016 case OP_PLUS:
1017 case OP_MINPLUS:
1018 case OP_POSPLUS:
1019 (void)set_table_bit(start_bits, tcode + 1, FALSE, cd, utf);
1020 try_next = FALSE;
1021 break;
1022
1023 case OP_EXACTI:
1024 tcode += IMM2_SIZE;
1025 /* Fall through */
1026 case OP_CHARI:
1027 case OP_PLUSI:
1028 case OP_MINPLUSI:
1029 case OP_POSPLUSI:
1030 (void)set_table_bit(start_bits, tcode + 1, TRUE, cd, utf);
1031 try_next = FALSE;
1032 break;
1033
1034 /* Special spacing and line-terminating items. These recognize specific
1035 lists of characters. The difference between VSPACE and ANYNL is that the
1036 latter can match the two-character CRLF sequence, but that is not
1037 relevant for finding the first character, so their code here is
1038 identical. */
1039
1040 case OP_HSPACE:
1041 SET_BIT(CHAR_HT);
1042 SET_BIT(CHAR_SPACE);
1043 #ifdef SUPPORT_UTF
1044 if (utf)
1045 {
1046 #ifdef COMPILE_PCRE8
1047 SET_BIT(0xC2); /* For U+00A0 */
1048 SET_BIT(0xE1); /* For U+1680, U+180E */
1049 SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */
1050 SET_BIT(0xE3); /* For U+3000 */
1051 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1052 SET_BIT(0xA0);
1053 SET_BIT(0xFF); /* For characters > 255 */
1054 #endif /* COMPILE_PCRE[8|16|32] */
1055 }
1056 else
1057 #endif /* SUPPORT_UTF */
1058 {
1059 #ifndef EBCDIC
1060 SET_BIT(0xA0);
1061 #endif /* Not EBCDIC */
1062 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1063 SET_BIT(0xFF); /* For characters > 255 */
1064 #endif /* COMPILE_PCRE[16|32] */
1065 }
1066 try_next = FALSE;
1067 break;
1068
1069 case OP_ANYNL:
1070 case OP_VSPACE:
1071 SET_BIT(CHAR_LF);
1072 SET_BIT(CHAR_VT);
1073 SET_BIT(CHAR_FF);
1074 SET_BIT(CHAR_CR);
1075 #ifdef SUPPORT_UTF
1076 if (utf)
1077 {
1078 #ifdef COMPILE_PCRE8
1079 SET_BIT(0xC2); /* For U+0085 */
1080 SET_BIT(0xE2); /* For U+2028, U+2029 */
1081 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1082 SET_BIT(CHAR_NEL);
1083 SET_BIT(0xFF); /* For characters > 255 */
1084 #endif /* COMPILE_PCRE[8|16|32] */
1085 }
1086 else
1087 #endif /* SUPPORT_UTF */
1088 {
1089 SET_BIT(CHAR_NEL);
1090 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1091 SET_BIT(0xFF); /* For characters > 255 */
1092 #endif
1093 }
1094 try_next = FALSE;
1095 break;
1096
1097 /* Single character types set the bits and stop. Note that if PCRE_UCP
1098 is set, we do not see these op codes because \d etc are converted to
1099 properties. Therefore, these apply in the case when only characters less
1100 than 256 are recognized to match the types. */
1101
1102 case OP_NOT_DIGIT:
1103 set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
1104 try_next = FALSE;
1105 break;
1106
1107 case OP_DIGIT:
1108 set_type_bits(start_bits, cbit_digit, table_limit, cd);
1109 try_next = FALSE;
1110 break;
1111
1112 /* The cbit_space table has vertical tab as whitespace; we have to
1113 ensure it is set as not whitespace. Luckily, the code value is the same
1114 (0x0b) in ASCII and EBCDIC, so we can just adjust the appropriate bit. */
1115
1116 case OP_NOT_WHITESPACE:
1117 set_nottype_bits(start_bits, cbit_space, table_limit, cd);
1118 start_bits[1] |= 0x08;
1119 try_next = FALSE;
1120 break;
1121
1122 /* The cbit_space table has vertical tab as whitespace; we have to not
1123 set it from the table. Luckily, the code value is the same (0x0b) in
1124 ASCII and EBCDIC, so we can just adjust the appropriate bit. */
1125
1126 case OP_WHITESPACE:
1127 c = start_bits[1]; /* Save in case it was already set */
1128 set_type_bits(start_bits, cbit_space, table_limit, cd);
1129 start_bits[1] = (start_bits[1] & ~0x08) | c;
1130 try_next = FALSE;
1131 break;
1132
1133 case OP_NOT_WORDCHAR:
1134 set_nottype_bits(start_bits, cbit_word, table_limit, cd);
1135 try_next = FALSE;
1136 break;
1137
1138 case OP_WORDCHAR:
1139 set_type_bits(start_bits, cbit_word, table_limit, cd);
1140 try_next = FALSE;
1141 break;
1142
1143 /* One or more character type fudges the pointer and restarts, knowing
1144 it will hit a single character type and stop there. */
1145
1146 case OP_TYPEPLUS:
1147 case OP_TYPEMINPLUS:
1148 case OP_TYPEPOSPLUS:
1149 tcode++;
1150 break;
1151
1152 case OP_TYPEEXACT:
1153 tcode += 1 + IMM2_SIZE;
1154 break;
1155
1156 /* Zero or more repeats of character types set the bits and then
1157 try again. */
1158
1159 case OP_TYPEUPTO:
1160 case OP_TYPEMINUPTO:
1161 case OP_TYPEPOSUPTO:
1162 tcode += IMM2_SIZE; /* Fall through */
1163
1164 case OP_TYPESTAR:
1165 case OP_TYPEMINSTAR:
1166 case OP_TYPEPOSSTAR:
1167 case OP_TYPEQUERY:
1168 case OP_TYPEMINQUERY:
1169 case OP_TYPEPOSQUERY:
1170 switch(tcode[1])
1171 {
1172 default:
1173 case OP_ANY:
1174 case OP_ALLANY:
1175 return SSB_FAIL;
1176
1177 case OP_HSPACE:
1178 SET_BIT(CHAR_HT);
1179 SET_BIT(CHAR_SPACE);
1180 #ifdef SUPPORT_UTF
1181 if (utf)
1182 {
1183 #ifdef COMPILE_PCRE8
1184 SET_BIT(0xC2); /* For U+00A0 */
1185 SET_BIT(0xE1); /* For U+1680, U+180E */
1186 SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */
1187 SET_BIT(0xE3); /* For U+3000 */
1188 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1189 SET_BIT(0xA0);
1190 SET_BIT(0xFF); /* For characters > 255 */
1191 #endif /* COMPILE_PCRE[8|16|32] */
1192 }
1193 else
1194 #endif /* SUPPORT_UTF */
1195 #ifndef EBCDIC
1196 SET_BIT(0xA0);
1197 #endif /* Not EBCDIC */
1198 break;
1199
1200 case OP_ANYNL:
1201 case OP_VSPACE:
1202 SET_BIT(CHAR_LF);
1203 SET_BIT(CHAR_VT);
1204 SET_BIT(CHAR_FF);
1205 SET_BIT(CHAR_CR);
1206 #ifdef SUPPORT_UTF
1207 if (utf)
1208 {
1209 #ifdef COMPILE_PCRE8
1210 SET_BIT(0xC2); /* For U+0085 */
1211 SET_BIT(0xE2); /* For U+2028, U+2029 */
1212 #elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1213 SET_BIT(CHAR_NEL);
1214 SET_BIT(0xFF); /* For characters > 255 */
1215 #endif /* COMPILE_PCRE16 */
1216 }
1217 else
1218 #endif /* SUPPORT_UTF */
1219 SET_BIT(CHAR_NEL);
1220 break;
1221
1222 case OP_NOT_DIGIT:
1223 set_nottype_bits(start_bits, cbit_digit, table_limit, cd);
1224 break;
1225
1226 case OP_DIGIT:
1227 set_type_bits(start_bits, cbit_digit, table_limit, cd);
1228 break;
1229
1230 /* The cbit_space table has vertical tab as whitespace; we no longer
1231 have to play fancy tricks because Perl added VT to its whitespace at
1232 release 5.18. PCRE added it at release 8.34. */
1233
1234 case OP_NOT_WHITESPACE:
1235 set_nottype_bits(start_bits, cbit_space, table_limit, cd);
1236 break;
1237
1238 case OP_WHITESPACE:
1239 set_type_bits(start_bits, cbit_space, table_limit, cd);
1240 break;
1241
1242 case OP_NOT_WORDCHAR:
1243 set_nottype_bits(start_bits, cbit_word, table_limit, cd);
1244 break;
1245
1246 case OP_WORDCHAR:
1247 set_type_bits(start_bits, cbit_word, table_limit, cd);
1248 break;
1249 }
1250
1251 tcode += 2;
1252 break;
1253
1254 /* Character class where all the information is in a bit map: set the
1255 bits and either carry on or not, according to the repeat count. If it was
1256 a negative class, and we are operating with UTF-8 characters, any byte
1257 with a value >= 0xc4 is a potentially valid starter because it starts a
1258 character with a value > 255. */
1259
1260 case OP_NCLASS:
1261 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
1262 if (utf)
1263 {
1264 start_bits[24] |= 0xf0; /* Bits for 0xc4 - 0xc8 */
1265 memset(start_bits+25, 0xff, 7); /* Bits for 0xc9 - 0xff */
1266 }
1267 #endif
1268 #if defined COMPILE_PCRE16 || defined COMPILE_PCRE32
1269 SET_BIT(0xFF); /* For characters > 255 */
1270 #endif
1271 /* Fall through */
1272
1273 case OP_CLASS:
1274 {
1275 pcre_uint8 *map;
1276 tcode++;
1277 map = (pcre_uint8 *)tcode;
1278
1279 /* In UTF-8 mode, the bits in a bit map correspond to character
1280 values, not to byte values. However, the bit map we are constructing is
1281 for byte values. So we have to do a conversion for characters whose
1282 value is > 127. In fact, there are only two possible starting bytes for
1283 characters in the range 128 - 255. */
1284
1285 #if defined SUPPORT_UTF && defined COMPILE_PCRE8
1286 if (utf)
1287 {
1288 for (c = 0; c < 16; c++) start_bits[c] |= map[c];
1289 for (c = 128; c < 256; c++)
1290 {
1291 if ((map[c/8] && (1 << (c&7))) != 0)
1292 {
1293 int d = (c >> 6) | 0xc0; /* Set bit for this starter */
1294 start_bits[d/8] |= (1 << (d&7)); /* and then skip on to the */
1295 c = (c & 0xc0) + 0x40 - 1; /* next relevant character. */
1296 }
1297 }
1298 }
1299 else
1300 #endif
1301 {
1302 /* In non-UTF-8 mode, the two bit maps are completely compatible. */
1303 for (c = 0; c < 32; c++) start_bits[c] |= map[c];
1304 }
1305
1306 /* Advance past the bit map, and act on what follows. For a zero
1307 minimum repeat, continue; otherwise stop processing. */
1308
1309 tcode += 32 / sizeof(pcre_uchar);
1310 switch (*tcode)
1311 {
1312 case OP_CRSTAR:
1313 case OP_CRMINSTAR:
1314 case OP_CRQUERY:
1315 case OP_CRMINQUERY:
1316 case OP_CRPOSSTAR:
1317 case OP_CRPOSQUERY:
1318 tcode++;
1319 break;
1320
1321 case OP_CRRANGE:
1322 case OP_CRMINRANGE:
1323 case OP_CRPOSRANGE:
1324 if (GET2(tcode, 1) == 0) tcode += 1 + 2 * IMM2_SIZE;
1325 else try_next = FALSE;
1326 break;
1327
1328 default:
1329 try_next = FALSE;
1330 break;
1331 }
1332 }
1333 break; /* End of bitmap class handling */
1334
1335 } /* End of switch */
1336 } /* End of try_next loop */
1337
1338 code += GET(code, 1); /* Advance to next branch */
1339 }
1340 while (*code == OP_ALT);
1341 return yield;
1342 }
1343
1344
1345
1346
1347
1348 /*************************************************
1349 * Study a compiled expression *
1350 *************************************************/
1351
1352 /* This function is handed a compiled expression that it must study to produce
1353 information that will speed up the matching. It returns a pcre[16]_extra block
1354 which then gets handed back to pcre_exec().
1355
1356 Arguments:
1357 re points to the compiled expression
1358 options contains option bits
1359 errorptr points to where to place error messages;
1360 set NULL unless error
1361
1362 Returns: pointer to a pcre[16]_extra block, with study_data filled in and
1363 the appropriate flags set;
1364 NULL on error or if no optimization possible
1365 */
1366
1367 #if defined COMPILE_PCRE8
1368 PCRE_EXP_DEFN pcre_extra * PCRE_CALL_CONVENTION
1369 pcre_study(const pcre *external_re, int options, const char **errorptr)
1370 #elif defined COMPILE_PCRE16
1371 PCRE_EXP_DEFN pcre16_extra * PCRE_CALL_CONVENTION
1372 pcre16_study(const pcre16 *external_re, int options, const char **errorptr)
1373 #elif defined COMPILE_PCRE32
1374 PCRE_EXP_DEFN pcre32_extra * PCRE_CALL_CONVENTION
1375 pcre32_study(const pcre32 *external_re, int options, const char **errorptr)
1376 #endif
1377 {
1378 int min;
1379 BOOL bits_set = FALSE;
1380 pcre_uint8 start_bits[32];
1381 PUBL(extra) *extra = NULL;
1382 pcre_study_data *study;
1383 const pcre_uint8 *tables;
1384 pcre_uchar *code;
1385 compile_data compile_block;
1386 const REAL_PCRE *re = (const REAL_PCRE *)external_re;
1387
1388
1389 *errorptr = NULL;
1390
1391 if (re == NULL || re->magic_number != MAGIC_NUMBER)
1392 {
1393 *errorptr = "argument is not a compiled regular expression";
1394 return NULL;
1395 }
1396
1397 if ((re->flags & PCRE_MODE) == 0)
1398 {
1399 #if defined COMPILE_PCRE8
1400 *errorptr = "argument not compiled in 8 bit mode";
1401 #elif defined COMPILE_PCRE16
1402 *errorptr = "argument not compiled in 16 bit mode";
1403 #elif defined COMPILE_PCRE32
1404 *errorptr = "argument not compiled in 32 bit mode";
1405 #endif
1406 return NULL;
1407 }
1408
1409 if ((options & ~PUBLIC_STUDY_OPTIONS) != 0)
1410 {
1411 *errorptr = "unknown or incorrect option bit(s) set";
1412 return NULL;
1413 }
1414
1415 code = (pcre_uchar *)re + re->name_table_offset +
1416 (re->name_count * re->name_entry_size);
1417
1418 /* For an anchored pattern, or an unanchored pattern that has a first char, or
1419 a multiline pattern that matches only at "line starts", there is no point in
1420 seeking a list of starting bytes. */
1421
1422 if ((re->options & PCRE_ANCHORED) == 0 &&
1423 (re->flags & (PCRE_FIRSTSET|PCRE_STARTLINE)) == 0)
1424 {
1425 int rc;
1426
1427 /* Set the character tables in the block that is passed around */
1428
1429 tables = re->tables;
1430
1431 #if defined COMPILE_PCRE8
1432 if (tables == NULL)
1433 (void)pcre_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1434 (void *)(&tables));
1435 #elif defined COMPILE_PCRE16
1436 if (tables == NULL)
1437 (void)pcre16_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1438 (void *)(&tables));
1439 #elif defined COMPILE_PCRE32
1440 if (tables == NULL)
1441 (void)pcre32_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES,
1442 (void *)(&tables));
1443 #endif
1444
1445 compile_block.lcc = tables + lcc_offset;
1446 compile_block.fcc = tables + fcc_offset;
1447 compile_block.cbits = tables + cbits_offset;
1448 compile_block.ctypes = tables + ctypes_offset;
1449
1450 /* See if we can find a fixed set of initial characters for the pattern. */
1451
1452 memset(start_bits, 0, 32 * sizeof(pcre_uint8));
1453 rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0,
1454 &compile_block);
1455 bits_set = rc == SSB_DONE;
1456 if (rc == SSB_UNKNOWN)
1457 {
1458 *errorptr = "internal error: opcode not recognized";
1459 return NULL;
1460 }
1461 }
1462
1463 /* Find the minimum length of subject string. */
1464
1465 switch(min = find_minlength(re, code, code, re->options, 0))
1466 {
1467 case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
1468 case -3: *errorptr = "internal error: opcode not recognized"; return NULL;
1469 default: break;
1470 }
1471
1472 /* If a set of starting bytes has been identified, or if the minimum length is
1473 greater than zero, or if JIT optimization has been requested, or if
1474 PCRE_STUDY_EXTRA_NEEDED is set, get a pcre[16]_extra block and a
1475 pcre_study_data block. The study data is put in the latter, which is pointed to
1476 by the former, which may also get additional data set later by the calling
1477 program. At the moment, the size of pcre_study_data is fixed. We nevertheless
1478 save it in a field for returning via the pcre_fullinfo() function so that if it
1479 becomes variable in the future, we don't have to change that code. */
1480
1481 if (bits_set || min > 0 || (options & (
1482 #ifdef SUPPORT_JIT
1483 PCRE_STUDY_JIT_COMPILE | PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE |
1484 PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE |
1485 #endif
1486 PCRE_STUDY_EXTRA_NEEDED)) != 0)
1487 {
1488 extra = (PUBL(extra) *)(PUBL(malloc))
1489 (sizeof(PUBL(extra)) + sizeof(pcre_study_data));
1490 if (extra == NULL)
1491 {
1492 *errorptr = "failed to get memory";
1493 return NULL;
1494 }
1495
1496 study = (pcre_study_data *)((char *)extra + sizeof(PUBL(extra)));
1497 extra->flags = PCRE_EXTRA_STUDY_DATA;
1498 extra->study_data = study;
1499
1500 study->size = sizeof(pcre_study_data);
1501 study->flags = 0;
1502
1503 /* Set the start bits always, to avoid unset memory errors if the
1504 study data is written to a file, but set the flag only if any of the bits
1505 are set, to save time looking when none are. */
1506
1507 if (bits_set)
1508 {
1509 study->flags |= PCRE_STUDY_MAPPED;
1510 memcpy(study->start_bits, start_bits, sizeof(start_bits));
1511 }
1512 else memset(study->start_bits, 0, 32 * sizeof(pcre_uint8));
1513
1514 #ifdef PCRE_DEBUG
1515 if (bits_set)
1516 {
1517 pcre_uint8 *ptr = start_bits;
1518 int i;
1519
1520 printf("Start bits:\n");
1521 for (i = 0; i < 32; i++)
1522 printf("%3d: %02x%s", i * 8, *ptr++, ((i + 1) & 0x7) != 0? " " : "\n");
1523 }
1524 #endif
1525
1526 /* Always set the minlength value in the block, because the JIT compiler
1527 makes use of it. However, don't set the bit unless the length is greater than
1528 zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time
1529 checking the zero case. */
1530
1531 if (min > 0)
1532 {
1533 study->flags |= PCRE_STUDY_MINLEN;
1534 study->minlength = min;
1535 }
1536 else study->minlength = 0;
1537
1538 /* If JIT support was compiled and requested, attempt the JIT compilation.
1539 If no starting bytes were found, and the minimum length is zero, and JIT
1540 compilation fails, abandon the extra block and return NULL, unless
1541 PCRE_STUDY_EXTRA_NEEDED is set. */
1542
1543 #ifdef SUPPORT_JIT
1544 extra->executable_jit = NULL;
1545 if ((options & PCRE_STUDY_JIT_COMPILE) != 0)
1546 PRIV(jit_compile)(re, extra, JIT_COMPILE);
1547 if ((options & PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE) != 0)
1548 PRIV(jit_compile)(re, extra, JIT_PARTIAL_SOFT_COMPILE);
1549 if ((options & PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE) != 0)
1550 PRIV(jit_compile)(re, extra, JIT_PARTIAL_HARD_COMPILE);
1551
1552 if (study->flags == 0 && (extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) == 0 &&
1553 (options & PCRE_STUDY_EXTRA_NEEDED) == 0)
1554 {
1555 #if defined COMPILE_PCRE8
1556 pcre_free_study(extra);
1557 #elif defined COMPILE_PCRE16
1558 pcre16_free_study(extra);
1559 #elif defined COMPILE_PCRE32
1560 pcre32_free_study(extra);
1561 #endif
1562 extra = NULL;
1563 }
1564 #endif
1565 }
1566
1567 return extra;
1568 }
1569
1570
1571 /*************************************************
1572 * Free the study data *
1573 *************************************************/
1574
1575 /* This function frees the memory that was obtained by pcre_study().
1576
1577 Argument: a pointer to the pcre[16]_extra block
1578 Returns: nothing
1579 */
1580
1581 #if defined COMPILE_PCRE8
1582 PCRE_EXP_DEFN void
1583 pcre_free_study(pcre_extra *extra)
1584 #elif defined COMPILE_PCRE16
1585 PCRE_EXP_DEFN void
1586 pcre16_free_study(pcre16_extra *extra)
1587 #elif defined COMPILE_PCRE32
1588 PCRE_EXP_DEFN void
1589 pcre32_free_study(pcre32_extra *extra)
1590 #endif
1591 {
1592 if (extra == NULL)
1593 return;
1594 #ifdef SUPPORT_JIT
1595 if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 &&
1596 extra->executable_jit != NULL)
1597 PRIV(jit_free)(extra->executable_jit);
1598 #endif
1599 PUBL(free)(extra);
1600 }
1601
1602 /* End of pcre_study.c */

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