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Revision 1395 - (show annotations)
Sat Nov 9 16:54:52 2013 UTC (5 years, 11 months ago) by ph10
File size: 256601 byte(s)
Add (*NO_AUTO_POSSESS) and document interaction between auto-possessification 
and callouts.
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.34 xx-xxxx-201x
5 --------------------------
6
7 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
8 executable memory. Patch inspired by Carsten Klein.
9
10 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
11 this macro is never tested and has no effect, because the work to support
12 coverage involves only compiling and linking options and special targets in
13 the Makefile. The comment in config.h implied that defining the macro would
14 enable coverage support, which is totally false. There was also support for
15 setting this macro in the CMake files (my fault, I just copied it from
16 configure). SUPPORT_GCOV has now been removed.
17
18 3. Make a small performance improvement in strlen16() and strlen32() in
19 pcretest.
20
21 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
22 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
23 these cases). There was also one in pcretest.c.
24
25 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
26
27 6. In UTF mode, the code for checking whether a group could match an empty
28 string (which is used for indefinitely repeated groups to allow for
29 breaking an infinite loop) was broken when the group contained a repeated
30 negated single-character class with a character that occupied more than one
31 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
32 UTF-8 mode). The effect was undefined: the group might or might not be
33 deemed as matching an empty string, or the program might have crashed.
34
35 7. The code for checking whether a group could match an empty string was not
36 recognizing that \h, \H, \v, \V, and \R must match a character.
37
38 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
39 an empty string. If it can, pcretest shows this in its information output.
40
41 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
42 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
43 matched by pcre_exec() without using JIT:
44
45 (a) If the rest of the pattern did not match after a maximal run of
46 grapheme clusters, the code for backing up to try with fewer of them
47 did not always back up over a full grapheme when characters that do not
48 have the modifier quality were involved, e.g. Hangul syllables.
49
50 (b) If the match point in a subject started with modifier character, and
51 there was no match, the code could incorrectly back up beyond the match
52 point, and potentially beyond the first character in the subject,
53 leading to a segfault or an incorrect match result.
54
55 10. A conditional group with an assertion condition could lead to PCRE
56 recording an incorrect first data item for a match if no other first data
57 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
58 first data item, and therefore matched "ca" after "c" instead of at the
59 start.
60
61 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
62 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
63
64 12. The source of pcregrep now includes z/OS-specific code so that it can be
65 compiled for z/OS as part of the special z/OS distribution.
66
67 13. Added the -T and -TM options to pcretest.
68
69 14. The code in pcre_compile.c for creating the table of named capturing groups
70 has been refactored. Instead of creating the table dynamically during the
71 actual compiling pass, the information is remembered during the pre-compile
72 pass (on the stack unless there are more than 20 named groups, in which
73 case malloc() is used) and the whole table is created before the actual
74 compile happens. This has simplified the code (it is now nearly 150 lines
75 shorter) and prepared the way for better handling of references to groups
76 with duplicate names.
77
78 15. A back reference to a named subpattern when there is more than one of the
79 same name now checks them in the order in which they appear in the pattern.
80 The first one that is set is used for the reference. Previously only the
81 first one was inspected. This change makes PCRE more compatible with Perl.
82
83 16. Unicode character properties were updated from Unicode 6.3.0.
84
85 17. The compile-time code for auto-possessification has been refactored, based
86 on a patch by Zoltan Herczeg. It now happens after instead of during
87 compilation. The code is cleaner, and more cases are handled. The option
88 PCRE_NO_AUTO_POSSESSIFY is added for testing purposes, and the -O and /O
89 options in pcretest are provided to set it. It can also be set by
90 (*NO_AUTO_POSSESS) at the start of a pattern.
91
92 18. The character VT has been added to the set of characters that match \s and
93 are generally treated as white space, following this same change in Perl
94 5.18. There is now no difference between "Perl space" and "POSIX space".
95
96 19. The code for checking named groups as conditions, either for being set or
97 for being recursed, has been refactored (this is related to 14 and 15
98 above). Processing unduplicated named groups should now be as fast at
99 numerical groups, and processing duplicated groups should be faster than
100 before.
101
102 20. Two patches to the CMake build system, by Alexander Barkov:
103
104 (1) Replace the "source" command by "." in CMakeLists.txt because
105 "source" is a bash-ism.
106
107 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
108 without these the CMake build does not work on Solaris.
109
110 21. Perl has changed its handling of \8 and \9. If there is no previously
111 encountered capturing group of those numbers, they are treated as the
112 literal characters 8 and 9 instead of a binary zero followed by the
113 literals. PCRE now does the same.
114
115 22. Following Perl, added \o{} to specify codepoints in octal, making it
116 possible to specify values greater than 0777 and also making them
117 unambiguous.
118
119 23. Perl now gives an error for missing closing braces after \x{... instead of
120 treating the string as literal. PCRE now does the same.
121
122 24. RunTest used to grumble if an inappropriate test was selected explicitly,
123 but just skip it when running all tests. This make it awkward to run ranges
124 of tests when one of them was inappropriate. Now it just skips any
125 inappropriate tests, as it always did when running all tests.
126
127 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
128 character types such as \d or \w, too many callouts were inserted, and the
129 data that they returned was rubbish.
130
131 26. In UCP mode, \s was not matching two of the characters that Perl matches,
132 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
133 were matched by \h. The code has now been refactored so that the lists of
134 the horizontal and vertical whitespace characters used for \h and \v (which
135 are defined only in one place) are now also used for \s.
136
137 27. Add JIT support for the 64 bit TileGX architecture.
138 Patch by Jiong Wang (Tilera Corporation).
139
140 28. Possessive quantifiers for classes (both explicit and automatically
141 generated) now use special opcodes instead of wrapping in ONCE brackets.
142
143 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
144 (because it's meaningless), this was not happening when PCRE_CASELESS was
145 set. Not wrong, but inefficient.
146
147 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
148 properties for \w, \d, etc) is present in a test regex. Otherwise if the
149 test contains no characters greater than 255, Perl doesn't realise it
150 should be using Unicode semantics.
151
152 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
153 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
154 does in Unicode mode.
155
156 32. Added the "forbid" facility to pcretest so that putting tests into the
157 wrong test files can sometimes be quickly detected.
158
159 33. There is now a limit (default 250) on the depth of nesting of parentheses.
160 This limit is imposed to control the amount of system stack used at compile
161 time. It can be changed at build time by --with-parens-nest-limit=xxx or
162 the equivalent in CMake.
163
164 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
165 errors. Perl warns for these when in warning mode, but PCRE has no facility
166 for giving warnings.
167
168 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
169 However, this was not working for (?!) because it is optimized to (*FAIL),
170 for which PCRE does not allow quantifiers. The optimization is now disabled
171 when a quantifier follows (?!). I can't see any use for this, but it makes
172 things uniform.
173
174 36. Perl no longer allows group names to start with digits, so I have made this
175 change also in PCRE. It simplifies the code a bit.
176
177
178 Version 8.33 28-May-2013
179 ------------------------
180
181 1. Added 'U' to some constants that are compared to unsigned integers, to
182 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
183 variables that are added to signed variables, to ensure the result is
184 signed and can be negated.
185
186 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
187 CMake config files.
188
189 3. Revise the creation of config.h.generic so that all boolean macros are
190 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
191 overriding via -D on the command line possible.
192
193 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
194 to unsigned int is reported to make a quite noticeable speed difference in
195 a specific Windows environment. Testing on Linux did also appear to show
196 some benefit (and it is clearly not harmful). Also fixed the definition of
197 Xop which should be unsigned.
198
199 5. Related to (4), changing the definition of the intermediate variable cc
200 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
201 improvements.
202
203 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
204 unnecessary spaces.
205
206 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
207 and later.
208
209 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
210
211 9. Optimizing fast_forward_start_bits in JIT.
212
213 10. Adding support for callouts in JIT, and fixing some issues revealed
214 during this work. Namely:
215
216 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
217
218 (b) Minimum length was not checked before the matching is started.
219
220 11. The value of capture_last that is passed to callouts was incorrect in some
221 cases when there was a capture on one path that was subsequently abandoned
222 after a backtrack. Also, the capture_last value is now reset after a
223 recursion, since all captures are also reset in this case.
224
225 12. The interpreter no longer returns the "too many substrings" error in the
226 case when an overflowing capture is in a branch that is subsequently
227 abandoned after a backtrack.
228
229 13. In the pathological case when an offset vector of size 2 is used, pcretest
230 now prints out the matched string after a yield of 0 or 1.
231
232 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
233 Only supported by the JIT compiler at the moment.
234
235 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
236
237 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
238 offset of the starting point of the matching process, provided the offsets
239 vector is large enough.
240
241 17. The \A escape now records a lookbehind value of 1, though its execution
242 does not actually inspect the previous character. This is to ensure that,
243 in partial multi-segment matching, at least one character from the old
244 segment is retained when a new segment is processed. Otherwise, if there
245 are no lookbehinds in the pattern, \A might match incorrectly at the start
246 of a new segment.
247
248 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
249
250 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
251 gives some modest performance improvement in 8-bit mode.
252
253 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
254 be expressed in certain programming languages using Universal Character
255 Names.
256
257 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
258 which points out that "non characters" are not "characters that may not
259 appear in Unicode strings" but rather "characters that are reserved for
260 internal use and have only local meaning".
261
262 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
263 there was a conditional group that depended on an assertion, if the
264 assertion was false, the callout that immediately followed the alternation
265 in the condition was skipped when pcre_exec() was used for matching.
266
267 23. Allow an explicit callout to be inserted before an assertion that is the
268 condition for a conditional group, for compatibility with automatic
269 callouts, which always insert a callout at this point.
270
271 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
272 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
273
274 25. (*PRUNE) is now supported by the JIT compiler.
275
276 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
277
278 27. Fix the case where there are two or more SKIPs with arguments that may be
279 ignored.
280
281 28. (*SKIP) is now supported by the JIT compiler.
282
283 29. (*THEN) is now supported by the JIT compiler.
284
285 30. Update RunTest with additional test selector options.
286
287 31. The way PCRE handles backtracking verbs has been changed in two ways.
288
289 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
290 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
291 backtracking. In some cases this makes it more Perl-compatible, but Perl's
292 rather obscure rules do not always do the same thing.
293
294 (2) Previously, backtracking verbs were confined within assertions. This is
295 no longer the case for positive assertions, except for (*ACCEPT). Again,
296 this sometimes improves Perl compatibility, and sometimes does not.
297
298 32. A number of tests that were in test 2 because Perl did things differently
299 have been moved to test 1, because either Perl or PCRE has changed, and
300 these tests are now compatible.
301
302 32. Backtracking control verbs are now handled in the same way in JIT and
303 interpreter.
304
305 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
306 contained a forward subroutine reference caused a compile error.
307
308 34. Auto-detect and optimize limited repetitions in JIT.
309
310 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
311 blocking (*UTF) etc.
312
313 36. In the interpreter, maximizing pattern repetitions for characters and
314 character types now use tail recursion, which reduces stack usage.
315
316 37. The value of the max lookbehind was not correctly preserved if a compiled
317 and saved regex was reloaded on a host of different endianness.
318
319 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
320 of the compiled pattern block, expand the flags field from 16 to 32 bits
321 because it was almost full.
322
323 39. Try madvise first before posix_madvise.
324
325 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
326 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
327 original change locked out all matches of empty strings. This has been
328 changed so that one match of an empty string per line is recognized.
329 Subsequent searches on the same line (for colouring or for --only-matching,
330 for example) do not recognize empty strings.
331
332 41. Applied a user patch to fix a number of spelling mistakes in comments.
333
334 42. Data lines longer than 65536 caused pcretest to crash.
335
336 43. Clarified the data type for length and startoffset arguments for pcre_exec
337 and pcre_dfa_exec in the function-specific man pages, where they were
338 explicitly stated to be in bytes, never having been updated. I also added
339 some clarification to the pcreapi man page.
340
341 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
342 a segmentation fault.
343
344
345 Version 8.32 30-November-2012
346 -----------------------------
347
348 1. Improved JIT compiler optimizations for first character search and single
349 character iterators.
350
351 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
352 Patch by Daniel Richard G.
353
354 3. Single character iterator optimizations in the JIT compiler.
355
356 4. Improved JIT compiler optimizations for character ranges.
357
358 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
359 Reported by Giuseppe D'Angelo.
360
361 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
362 of a line, was being set incorrectly in cases where .* appeared inside
363 atomic brackets at the start of a pattern, or where there was a subsequent
364 *PRUNE or *SKIP.
365
366 7. Improved instruction cache flush for POWER/PowerPC.
367 Patch by Daniel Richard G.
368
369 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
370 grep:
371
372 (a) There is now no limit to the number of patterns to be matched.
373
374 (b) An error is given if a pattern is too long.
375
376 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
377 are now supported.
378
379 (d) --exclude-from and --include-from (multiple use) have been added.
380
381 (e) Exclusions and inclusions now apply to all files and directories, not
382 just to those obtained from scanning a directory recursively.
383
384 (f) Multiple uses of -f and --file-list are now supported.
385
386 (g) In a Windows environment, the default for -d has been changed from
387 "read" (the GNU grep default) to "skip", because otherwise the presence
388 of a directory in the file list provokes an error.
389
390 (h) The documentation has been revised and clarified in places.
391
392 9. Improve the matching speed of capturing brackets.
393
394 10. Changed the meaning of \X so that it now matches a Unicode extended
395 grapheme cluster.
396
397 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
398 out POSIX threads when JIT support is configured.
399
400 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
401
402 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
403 structure could go wrong in environments where size_t is not the same size
404 as int.
405
406 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
407 set.
408
409 15. The EBCDIC support had decayed; later updates to the code had included
410 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
411 general tidy up of EBCDIC-related issues, and the documentation was also
412 not quite right. There is now a test that can be run on ASCII systems to
413 check some of the EBCDIC-related things (but is it not a full test).
414
415 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
416 in a small tidy to the code.
417
418 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
419
420 18. If the --only-matching (-o) option in pcregrep is specified multiple
421 times, each one causes appropriate output. For example, -o1 -o2 outputs the
422 substrings matched by the 1st and 2nd capturing parentheses. A separating
423 string can be specified by --om-separator (default empty).
424
425 19. Improving the first n character searches.
426
427 20. Turn case lists for horizontal and vertical white space into macros so that
428 they are defined only once.
429
430 21. This set of changes together give more compatible Unicode case-folding
431 behaviour for characters that have more than one other case when UCP
432 support is available.
433
434 (a) The Unicode property table now has offsets into a new table of sets of
435 three or more characters that are case-equivalent. The MultiStage2.py
436 script that generates these tables (the pcre_ucd.c file) now scans
437 CaseFolding.txt instead of UnicodeData.txt for character case
438 information.
439
440 (b) The code for adding characters or ranges of characters to a character
441 class has been abstracted into a generalized function that also handles
442 case-independence. In UTF-mode with UCP support, this uses the new data
443 to handle characters with more than one other case.
444
445 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
446 whose other case is greater than 256 are now correctly matched
447 caselessly. Previously, the high codepoint matched the low one, but not
448 vice versa.
449
450 (d) The processing of \h, \H, \v, and \ in character classes now makes use
451 of the new class addition function, using character lists defined as
452 macros alongside the case definitions of 20 above.
453
454 (e) Caseless back references now work with characters that have more than
455 one other case.
456
457 (f) General caseless matching of characters with more than one other case
458 is supported.
459
460 22. Unicode character properties were updated from Unicode 6.2.0
461
462 23. Improved CMake support under Windows. Patch by Daniel Richard G.
463
464 24. Add support for 32-bit character strings, and UTF-32
465
466 25. Major JIT compiler update (code refactoring and bugfixing).
467 Experimental Sparc 32 support is added.
468
469 26. Applied a modified version of Daniel Richard G's patch to create
470 pcre.h.generic and config.h.generic by "make" instead of in the
471 PrepareRelease script.
472
473 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
474 pcre_compile.c when checking for a zero character.
475
476 28. Introducing a native interface for JIT. Through this interface, the compiled
477 machine code can be directly executed. The purpose of this interface is to
478 provide fast pattern matching, so several sanity checks are not performed.
479 However, feature tests are still performed. The new interface provides
480 1.4x speedup compared to the old one.
481
482 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
483 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
484 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
485
486 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
487 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
488 the "old" RFC 2279). Instead, it ended up passing a negative length to
489 pcre_exec().
490
491 31. Add support for GCC's visibility feature to hide internal functions.
492
493 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
494 "unknown -C option" after outputting 0 or 1.
495
496 33. There is now support for generating a code coverage report for the test
497 suite in environments where gcc is the compiler and lcov is installed. This
498 is mainly for the benefit of the developers.
499
500 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
501 unaddressable using valgrind annotations, allowing valgrind to detect
502 invalid memory accesses. This is mainly for the benefit of the developers.
503
504 25. (*UTF) can now be used to start a pattern in any of the three libraries.
505
506 26. Give configure error if --enable-cpp but no C++ compiler found.
507
508
509 Version 8.31 06-July-2012
510 -------------------------
511
512 1. Fixing a wrong JIT test case and some compiler warnings.
513
514 2. Removed a bashism from the RunTest script.
515
516 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
517 to unsigned type, result still unsigned" that was given by an MS compiler
518 on encountering the code "-sizeof(xxx)".
519
520 4. Partial matching support is added to the JIT compiler.
521
522 5. Fixed several bugs concerned with partial matching of items that consist
523 of more than one character:
524
525 (a) /^(..)\1/ did not partially match "aba" because checking references was
526 done on an "all or nothing" basis. This also applied to repeated
527 references.
528
529 (b) \R did not give a hard partial match if \r was found at the end of the
530 subject.
531
532 (c) \X did not give a hard partial match after matching one or more
533 characters at the end of the subject.
534
535 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
536 a partial match for the string "\r".
537
538 (e) When newline was set to CRLF, the metacharacter "." did not recognize
539 a partial match for a CR character at the end of the subject string.
540
541 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
542 running pcretest, the text "(JIT)" added to the output whenever JIT is
543 actually used to run the match.
544
545 7. Individual JIT compile options can be set in pcretest by following -s+[+]
546 or /S+[+] with a digit between 1 and 7.
547
548 8. OP_NOT now supports any UTF character not just single-byte ones.
549
550 9. (*MARK) control verb is now supported by the JIT compiler.
551
552 10. The command "./RunTest list" lists the available tests without actually
553 running any of them. (Because I keep forgetting what they all are.)
554
555 11. Add PCRE_INFO_MAXLOOKBEHIND.
556
557 12. Applied a (slightly modified) user-supplied patch that improves performance
558 when the heap is used for recursion (compiled with --disable-stack-for-
559 recursion). Instead of malloc and free for each heap frame each time a
560 logical recursion happens, frames are retained on a chain and re-used where
561 possible. This sometimes gives as much as 30% improvement.
562
563 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
564 call.
565
566 14. As documented, (*COMMIT) is now confined to within a positive assertion.
567
568 15. It is now possible to link pcretest with libedit as an alternative to
569 libreadline.
570
571 16. (*COMMIT) control verb is now supported by the JIT compiler.
572
573 17. The Unicode data tables have been updated to Unicode 6.1.0.
574
575 18. Added --file-list option to pcregrep.
576
577 19. Added binary file support to pcregrep, including the -a, --binary-files,
578 -I, and --text options.
579
580 20. The madvise function is renamed for posix_madvise for QNX compatibility
581 reasons. Fixed by Giuseppe D'Angelo.
582
583 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
584
585 22. Changed the option for creating symbolic links for 16-bit man pages from
586 -s to -sf so that re-installing does not cause issues.
587
588 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
589
590 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
591 matches in certain environments (the workspace was not being correctly
592 retained). Also added to pcre_dfa_exec() a simple plausibility check on
593 some of the workspace data at the beginning of a restart.
594
595 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
596 was not doing so when it should - probably a typo introduced by SVN 528
597 (change 8.10/14).
598
599 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
600 \w+ when the character tables indicated that \x{c4} was a word character.
601 There were several related cases, all because the tests for doing a table
602 lookup were testing for characters less than 127 instead of 255.
603
604 27. If a pattern contains capturing parentheses that are not used in a match,
605 their slots in the ovector are set to -1. For those that are higher than
606 any matched groups, this happens at the end of processing. In the case when
607 there were back references that the ovector was too small to contain
608 (causing temporary malloc'd memory to be used during matching), and the
609 highest capturing number was not used, memory off the end of the ovector
610 was incorrectly being set to -1. (It was using the size of the temporary
611 memory instead of the true size.)
612
613 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
614 ovector size, it uses memory at the end of the block that it has got.
615
616 29. Check for an overlong MARK name and give an error at compile time. The
617 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
618
619 30. JIT compiler update.
620
621 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
622 Rill for the patch.
623
624 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
625
626 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
627
628 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
629 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
630 was enabled.
631
632 35. Improve JIT code generation for greedy plus quantifier.
633
634 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
635 1 to "aa" instead of to an empty string. The bug affected repeated groups
636 that could potentially match an empty string.
637
638 37. Optimizing single character iterators in JIT.
639
640 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
641 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
642 codepoints that are too big for the mode are faulted, and in a UTF mode,
643 disallowed codepoints are also faulted.
644
645 39. If PCRE was compiled with UTF support, in three places in the DFA
646 matcher there was code that should only have been obeyed in UTF mode, but
647 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
648 processing when bytes with values greater than 127 were present. In 16-bit
649 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
650 both cases the values are those that cannot be the first data item in a UTF
651 character. The three items that might have provoked this were recursions,
652 possessively repeated groups, and atomic groups.
653
654 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
655 and pcregrep, because some OS require shared objects to be explicitly
656 passed to ld, causing the link step to fail if they are not.
657
658 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
659 mode, patterns that started with \h* or \R* might be incorrectly matched.
660
661
662 Version 8.30 04-February-2012
663 -----------------------------
664
665 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
666 name is defined in ctype.h.
667
668 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
669 only in quite long subpatterns.
670
671 3. Removed the function pcre_info(), which has been obsolete and deprecated
672 since it was replaced by pcre_fullinfo() in February 2000.
673
674 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
675 match a (*MARK), and the match failed at the start of the subject, a
676 reference to memory before the start of the subject could occur. This bug
677 was introduced by fix 17 of release 8.21.
678
679 5. A reference to an unset group with zero minimum repetition was giving
680 totally wrong answers (in non-JavaScript-compatibility mode). For example,
681 /(another)?(\1?)test/ matched against "hello world test". This bug was
682 introduced in release 8.13.
683
684 6. Add support for 16-bit character strings (a large amount of work involving
685 many changes and refactorings).
686
687 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
688 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
689 from a file.
690
691 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
692 rounding is not applied in this particular case).
693
694 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
695 if they appear, or are escaped, in patterns.
696
697 10. Get rid of a number of -Wunused-but-set-variable warnings.
698
699 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
700 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
701 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
702 also returns the mark "x". This bug applied to capturing parentheses,
703 non-capturing parentheses, and atomic parentheses. It also applied to some
704 assertions.
705
706 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
707 information out of configure.ac instead of relying on pcre.h.generic, which
708 is not stored in the repository.
709
710 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
711 -lreadline.
712
713 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
714
715 15. Applied Graycode's patch to put the top-level frame on the stack rather
716 than the heap when not using the stack for recursion. This gives a
717 performance improvement in many cases when recursion is not deep.
718
719 16. Experimental code added to "pcretest -C" to output the stack frame size.
720
721
722 Version 8.21 12-Dec-2011
723 ------------------------
724
725 1. Updating the JIT compiler.
726
727 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
728 are added as well.
729
730 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
731 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
732 calling _pcre_jit_exec. Some extra comments are added.
733
734 4. (*MARK) settings inside atomic groups that do not contain any capturing
735 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
736 was introduced by change 18 for 8.20.
737
738 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
739 ECMA-262 standard.
740
741 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
742 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
743 This bug was probably introduced by change 9 of 8.13.
744
745 7. While fixing 6 above, I noticed that a number of other items were being
746 incorrectly rejected as "not fixed length". This arose partly because newer
747 opcodes had not been added to the fixed-length checking code. I have (a)
748 corrected the bug and added tests for these items, and (b) arranged for an
749 error to occur if an unknown opcode is encountered while checking for fixed
750 length instead of just assuming "not fixed length". The items that were
751 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
752 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
753 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
754
755 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
756 being incorrectly compiled and would have given unpredicatble results.
757
758 9. A possessively repeated subpattern with minimum repeat count greater than
759 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
760 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
761 the first (A) could occur when it should not.
762
763 10. Add a cast and remove a redundant test from the code.
764
765 11. JIT should use pcre_malloc/pcre_free for allocation.
766
767 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
768 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
769 is anything other than /usr, -L is still shown).
770
771 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
772
773 14. Perl does not support \N without a following name in a [] class; PCRE now
774 also gives an error.
775
776 15. If a forward reference was repeated with an upper limit of around 2000,
777 it caused the error "internal error: overran compiling workspace". The
778 maximum number of forward references (including repeats) was limited by the
779 internal workspace, and dependent on the LINK_SIZE. The code has been
780 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
781 the default depends on LINK_SIZE. There is a new upper limit (for safety)
782 of around 200,000 forward references. While doing this, I also speeded up
783 the filling in of repeated forward references.
784
785 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
786 incorrectly expecting the subject to contain another "a" after the start.
787
788 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
789 in the match, the SKIP should be ignored. This was not happening; instead
790 the SKIP was being treated as NOMATCH. For patterns such as
791 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
792 tested.
793
794 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
795 now much more compatible with Perl, in particular in cases where the result
796 is a non-match for a non-anchored pattern. For example, if
797 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
798 "m", where previously it did not return a name. A side effect of this
799 change is that for partial matches, the last encountered mark name is
800 returned, as for non matches. A number of tests that were previously not
801 Perl-compatible have been moved into the Perl-compatible test files. The
802 refactoring has had the pleasing side effect of removing one argument from
803 the match() function, thus reducing its stack requirements.
804
805 19. If the /S+ option was used in pcretest to study a pattern using JIT,
806 subsequent uses of /S (without +) incorrectly behaved like /S+.
807
808 21. Retrieve executable code size support for the JIT compiler and fixing
809 some warnings.
810
811 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
812 not work when the shorter character appeared right at the end of the
813 subject string.
814
815 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
816 systems.
817
818 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
819 output it when the /M option is used in pcretest.
820
821 25. The CheckMan script was not being included in the distribution. Also, added
822 an explicit "perl" to run Perl scripts from the PrepareRelease script
823 because this is reportedly needed in Windows.
824
825 26. If study data was being save in a file and studying had not found a set of
826 "starts with" bytes for the pattern, the data written to the file (though
827 never used) was taken from uninitialized memory and so caused valgrind to
828 complain.
829
830 27. Updated RunTest.bat as provided by Sheri Pierce.
831
832 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
833
834 29. Computation of memory usage for the table of capturing group names was
835 giving an unnecessarily large value.
836
837
838 Version 8.20 21-Oct-2011
839 ------------------------
840
841 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
842 a POSIX class. After further experiments with Perl, which convinced me that
843 Perl has bugs and confusions, a closing square bracket is no longer allowed
844 in a POSIX name. This bug also affected patterns with classes that started
845 with full stops.
846
847 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
848 captured substring, but while checking the failing first alternative,
849 substring 1 is temporarily captured. If the output vector supplied to
850 pcre_exec() was not big enough for this capture, the yield of the function
851 was still zero ("insufficient space for captured substrings"). This cannot
852 be totally fixed without adding another stack variable, which seems a lot
853 of expense for a edge case. However, I have improved the situation in cases
854 such as /(a)(b)x|abc/ matched against "abc", where the return code
855 indicates that fewer than the maximum number of slots in the ovector have
856 been set.
857
858 3. Related to (2) above: when there are more back references in a pattern than
859 slots in the output vector, pcre_exec() uses temporary memory during
860 matching, and copies in the captures as far as possible afterwards. It was
861 using the entire output vector, but this conflicts with the specification
862 that only 2/3 is used for passing back captured substrings. Now it uses
863 only the first 2/3, for compatibility. This is, of course, another edge
864 case.
865
866 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
867 main code base, and can be used by building with --enable-jit. When this is
868 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
869 runtime --no-jit option is given.
870
871 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
872 ovector, the return from the function was zero, implying that there were
873 other matches that did not fit. The correct "exactly full" value is now
874 returned.
875
876 6. If a subpattern that was called recursively or as a subroutine contained
877 (*PRUNE) or any other control that caused it to give a non-standard return,
878 invalid errors such as "Error -26 (nested recursion at the same subject
879 position)" or even infinite loops could occur.
880
881 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
882 computing the minimum length on reaching *ACCEPT, and so ended up with the
883 wrong value of 1 rather than 0. Further investigation indicates that
884 computing a minimum subject length in the presence of *ACCEPT is difficult
885 (think back references, subroutine calls), and so I have changed the code
886 so that no minimum is registered for a pattern that contains *ACCEPT.
887
888 8. If (*THEN) was present in the first (true) branch of a conditional group,
889 it was not handled as intended. [But see 16 below.]
890
891 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
892 Sheri Pierce.
893
894 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
895 the first byte in a match must be "a".
896
897 11. Change 17 for 8.13 increased the recursion depth for patterns like
898 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
899 pattern contains any instances of (*THEN). If it does not, the old
900 optimizations are restored. It would be nice to do this on a per-group
901 basis, but at the moment that is not feasible.
902
903 12. In some environments, the output of pcretest -C is CRLF terminated. This
904 broke RunTest's code that checks for the link size. A single white space
905 character after the value is now allowed for.
906
907 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
908 For "fr", it uses the Windows-specific input and output files.
909
910 14. If (*THEN) appeared in a group that was called recursively or as a
911 subroutine, it did not work as intended. [But see next item.]
912
913 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
914 pattern fragments (but not containing any | characters). If A and B are
915 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
916 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
917 D. In other words, Perl considers parentheses that do not contain any |
918 characters to be part of a surrounding alternative, whereas PCRE was
919 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
920 differently. PCRE now behaves in the same way as Perl, except in the case
921 of subroutine/recursion calls such as (?1) which have in any case always
922 been different (but PCRE had them first :-).
923
924 16. Related to 15 above: Perl does not treat the | in a conditional group as
925 creating alternatives. Such a group is treated in the same way as an
926 ordinary group without any | characters when processing (*THEN). PCRE has
927 been changed to match Perl's behaviour.
928
929 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
930 RunGrepTest script failed.
931
932 18. Change 22 for version 13 caused atomic groups to use more stack. This is
933 inevitable for groups that contain captures, but it can lead to a lot of
934 stack use in large patterns. The old behaviour has been restored for atomic
935 groups that do not contain any capturing parentheses.
936
937 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
938 suppress the check for a minimum subject length at run time. (If it was
939 given to pcre_exec() or pcre_dfa_exec() it did work.)
940
941 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
942 fail to work when decoding hex characters in data strings in EBCDIC
943 environments.
944
945 21. It appears that in at least one Mac OS environment, the isxdigit() function
946 is implemented as a macro that evaluates to its argument more than once,
947 contravening the C 90 Standard (I haven't checked a later standard). There
948 was an instance in pcretest which caused it to go wrong when processing
949 \x{...} escapes in subject strings. The has been rewritten to avoid using
950 things like p++ in the argument of isxdigit().
951
952
953 Version 8.13 16-Aug-2011
954 ------------------------
955
956 1. The Unicode data tables have been updated to Unicode 6.0.0.
957
958 2. Two minor typos in pcre_internal.h have been fixed.
959
960 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
961 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
962 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
963
964 4. There were a number of related bugs in the code for matching backrefences
965 caselessly in UTF-8 mode when codes for the characters concerned were
966 different numbers of bytes. For example, U+023A and U+2C65 are an upper
967 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
968 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
969 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
970 2-byte code at the end of the subject (it thought there wasn't enough data
971 left).
972
973 5. Comprehensive information about what went wrong is now returned by
974 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
975 as the output vector has at least 2 elements. The offset of the start of
976 the failing character and a reason code are placed in the vector.
977
978 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
979 now returned is for the first byte of the failing character, instead of the
980 last byte inspected. This is an incompatible change, but I hope it is small
981 enough not to be a problem. It makes the returned offset consistent with
982 pcre_exec() and pcre_dfa_exec().
983
984 7. pcretest now gives a text phrase as well as the error number when
985 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
986 failure, the offset and reason code are output.
987
988 8. When \R was used with a maximizing quantifier it failed to skip backwards
989 over a \r\n pair if the subsequent match failed. Instead, it just skipped
990 back over a single character (\n). This seems wrong (because it treated the
991 two characters as a single entity when going forwards), conflicts with the
992 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
993 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
994 has been changed.
995
996 9. Some internal refactoring has changed the processing so that the handling
997 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
998 time (the PCRE_DOTALL option was changed this way some time ago: version
999 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1000 which was always a bit of a fudge. It also means that there is one less
1001 argument for the match() function, which reduces its stack requirements
1002 slightly. This change also fixes an incompatibility with Perl: the pattern
1003 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1004
1005 10. More internal refactoring has drastically reduced the number of recursive
1006 calls to match() for possessively repeated groups such as (abc)++ when
1007 using pcre_exec().
1008
1009 11. While implementing 10, a number of bugs in the handling of groups were
1010 discovered and fixed:
1011
1012 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1013 (a|)*(?1) gave a compile-time internal error.
1014 ((a|)+)+ did not notice that the outer group could match an empty string.
1015 (^a|^)+ was not marked as anchored.
1016 (.*a|.*)+ was not marked as matching at start or after a newline.
1017
1018 12. Yet more internal refactoring has removed another argument from the match()
1019 function. Special calls to this function are now indicated by setting a
1020 value in a variable in the "match data" data block.
1021
1022 13. Be more explicit in pcre_study() instead of relying on "default" for
1023 opcodes that mean there is no starting character; this means that when new
1024 ones are added and accidentally left out of pcre_study(), testing should
1025 pick them up.
1026
1027 14. The -s option of pcretest has been documented for ages as being an old
1028 synonym of -m (show memory usage). I have changed it to mean "force study
1029 for every regex", that is, assume /S for every regex. This is similar to -i
1030 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1031 using it. It makes it easier to run collections of tests with and without
1032 study enabled, and thereby test pcre_study() more easily. All the standard
1033 tests are now run with and without -s (but some patterns can be marked as
1034 "never study" - see 20 below).
1035
1036 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1037 restoration of the capturing data to the outer values was not happening
1038 correctly.
1039
1040 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1041 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1042 pattern had matched an empty string, and so incorrectly returned a no
1043 match.
1044
1045 17. There was optimizing code for the last branch of non-capturing parentheses,
1046 and also for the obeyed branch of a conditional subexpression, which used
1047 tail recursion to cut down on stack usage. Unfortunately, now that there is
1048 the possibility of (*THEN) occurring in these branches, tail recursion is
1049 no longer possible because the return has to be checked for (*THEN). These
1050 two optimizations have therefore been removed. [But see 8.20/11 above.]
1051
1052 18. If a pattern containing \R was studied, it was assumed that \R always
1053 matched two bytes, thus causing the minimum subject length to be
1054 incorrectly computed because \R can also match just one byte.
1055
1056 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1057 was incorrectly computed.
1058
1059 20. If /S is present twice on a test pattern in pcretest input, it now
1060 *disables* studying, thereby overriding the use of -s on the command line
1061 (see 14 above). This is necessary for one or two tests to keep the output
1062 identical in both cases.
1063
1064 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1065 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1066
1067 22. When an atomic group that contained a capturing parenthesis was
1068 successfully matched, but the branch in which it appeared failed, the
1069 capturing was not being forgotten if a higher numbered group was later
1070 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1071 group 1 to "a", when in fact it should be unset. This applied to multi-
1072 branched capturing and non-capturing groups, repeated or not, and also to
1073 positive assertions (capturing in negative assertions does not happen
1074 in PCRE) and also to nested atomic groups.
1075
1076 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1077 subject after a captured substring, to make it easier to tell which of a
1078 number of identical substrings has been captured.
1079
1080 24. The way atomic groups are processed by pcre_exec() has been changed so that
1081 if they are repeated, backtracking one repetition now resets captured
1082 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1083 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1084 "aaa". Previously, it would have been "a". As part of this code
1085 refactoring, the way recursive calls are handled has also been changed.
1086
1087 25. If an assertion condition captured any substrings, they were not passed
1088 back unless some other capturing happened later. For example, if
1089 (?(?=(a))a) was matched against "a", no capturing was returned.
1090
1091 26. When studying a pattern that contained subroutine calls or assertions,
1092 the code for finding the minimum length of a possible match was handling
1093 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1094 group 1 called group 2 while simultaneously a separate group 2 called group
1095 1). A stack overflow occurred in this case. I have fixed this by limiting
1096 the recursion depth to 10.
1097
1098 27. Updated RunTest.bat in the distribution to the version supplied by Tom
1099 Fortmann. This supports explicit test numbers on the command line, and has
1100 argument validation and error reporting.
1101
1102 28. An instance of \X with an unlimited repeat could fail if at any point the
1103 first character it looked at was a mark character.
1104
1105 29. Some minor code refactoring concerning Unicode properties and scripts
1106 should reduce the stack requirement of match() slightly.
1107
1108 30. Added the '=' option to pcretest to check the setting of unused capturing
1109 slots at the end of the pattern, which are documented as being -1, but are
1110 not included in the return count.
1111
1112 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1113 compiled something random. Now it gives a compile-time error (as does
1114 Perl).
1115
1116 32. A *MARK encountered during the processing of a positive assertion is now
1117 recorded and passed back (compatible with Perl).
1118
1119 33. If --only-matching or --colour was set on a pcregrep call whose pattern
1120 had alternative anchored branches, the search for a second match in a line
1121 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1122 matched the line "0102" twice. The same bug affected patterns that started
1123 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1124 twice.
1125
1126 34. Previously, PCRE did not allow quantification of assertions. However, Perl
1127 does, and because of capturing effects, quantifying parenthesized
1128 assertions may at times be useful. Quantifiers are now allowed for
1129 parenthesized assertions.
1130
1131 35. A minor code tidy in pcre_compile() when checking options for \R usage.
1132
1133 36. \g was being checked for fancy things in a character class, when it should
1134 just be a literal "g".
1135
1136 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1137 appearance of a nested POSIX class supersedes an apparent external class.
1138 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1139 unescaped square brackets may also appear as part of class names. For
1140 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1141 more like Perl. (But see 8.20/1 above.)
1142
1143 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1144 was because it thought it was \N{name}, which is not supported).
1145
1146 39. Add minix to OS list not supporting the -S option in pcretest.
1147
1148 40. PCRE tries to detect cases of infinite recursion at compile time, but it
1149 cannot analyze patterns in sufficient detail to catch mutual recursions
1150 such as ((?1))((?2)). There is now a runtime test that gives an error if a
1151 subgroup is called recursively as a subpattern for a second time at the
1152 same position in the subject string. In previous releases this might have
1153 been caught by the recursion limit, or it might have run out of stack.
1154
1155 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1156 happen only once. PCRE was, however incorrectly giving a compile time error
1157 "recursive call could loop indefinitely" because it cannot analyze the
1158 pattern in sufficient detail. The compile time test no longer happens when
1159 PCRE is compiling a conditional subpattern, but actual runaway loops are
1160 now caught at runtime (see 40 above).
1161
1162 42. It seems that Perl allows any characters other than a closing parenthesis
1163 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1164 has been changed to be the same.
1165
1166 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1167 as not to get warnings when autogen.sh is called. Also changed
1168 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1169
1170 44. To help people who use pcregrep to scan files containing exceedingly long
1171 lines, the following changes have been made:
1172
1173 (a) The default value of the buffer size parameter has been increased from
1174 8K to 20K. (The actual buffer used is three times this size.)
1175
1176 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1177 PCRE is built.
1178
1179 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1180 to be set at run time.
1181
1182 (d) Numerical values in pcregrep options can be followed by K or M, for
1183 example --buffer-size=50K.
1184
1185 (e) If a line being scanned overflows pcregrep's buffer, an error is now
1186 given and the return code is set to 2.
1187
1188 45. Add a pointer to the latest mark to the callout data block.
1189
1190 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1191 partial match of an empty string instead of no match. This was specific to
1192 the use of ".".
1193
1194 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1195 complete match instead of a partial match. This bug was dependent on both
1196 the PCRE_UTF8 and PCRE_DOTALL options being set.
1197
1198 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1199 starting byte set, because \b was not being ignored.
1200
1201
1202 Version 8.12 15-Jan-2011
1203 ------------------------
1204
1205 1. Fixed some typos in the markup of the man pages, and wrote a script that
1206 checks for such things as part of the documentation building process.
1207
1208 2. On a big-endian 64-bit system, pcregrep did not correctly process the
1209 --match-limit and --recursion-limit options (added for 8.11). In
1210 particular, this made one of the standard tests fail. (The integer value
1211 went into the wrong half of a long int.)
1212
1213 3. If the --colour option was given to pcregrep with -v (invert match), it
1214 did strange things, either producing crazy output, or crashing. It should,
1215 of course, ignore a request for colour when reporting lines that do not
1216 match.
1217
1218 4. Another pcregrep bug caused similar problems if --colour was specified with
1219 -M (multiline) and the pattern match finished with a line ending.
1220
1221 5. In pcregrep, when a pattern that ended with a literal newline sequence was
1222 matched in multiline mode, the following line was shown as part of the
1223 match. This seems wrong, so I have changed it.
1224
1225 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
1226 the check for further matches in the same line (so they could be coloured)
1227 to overrun the end of the current line. If another match was found, it was
1228 incorrectly shown (and then shown again when found in the next line).
1229
1230 7. If pcregrep was compiled under Windows, there was a reference to the
1231 function pcregrep_exit() before it was defined. I am assuming this was
1232 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1233 reported by a user. I've moved the definition above the reference.
1234
1235
1236 Version 8.11 10-Dec-2010
1237 ------------------------
1238
1239 1. (*THEN) was not working properly if there were untried alternatives prior
1240 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1241 backtracked to try for "b" instead of moving to the next alternative branch
1242 at the same level (in this case, to look for "c"). The Perl documentation
1243 is clear that when (*THEN) is backtracked onto, it goes to the "next
1244 alternative in the innermost enclosing group".
1245
1246 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1247 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
1248 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1249 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1250 (*THEN).
1251
1252 3. If \s appeared in a character class, it removed the VT character from
1253 the class, even if it had been included by some previous item, for example
1254 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1255 of \s, but is part of the POSIX "space" class.)
1256
1257 4. A partial match never returns an empty string (because you can always
1258 match an empty string at the end of the subject); however the checking for
1259 an empty string was starting at the "start of match" point. This has been
1260 changed to the "earliest inspected character" point, because the returned
1261 data for a partial match starts at this character. This means that, for
1262 example, /(?<=abc)def/ gives a partial match for the subject "abc"
1263 (previously it gave "no match").
1264
1265 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1266 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1267 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1268 has an implication that the given string is incomplete (because a partial
1269 match is preferred over a full match). For this reason, these items now
1270 give a partial match in this situation. [Aside: previously, the one case
1271 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1272 match rather than a full match, which was wrong by the old rules, but is
1273 now correct.]
1274
1275 6. There was a bug in the handling of #-introduced comments, recognized when
1276 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1277 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1278 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1279 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1280 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1281 places in pcre_compile().
1282
1283 7. Related to (6) above, when pcre_compile() was skipping #-introduced
1284 comments when looking ahead for named forward references to subpatterns,
1285 the only newline sequence it recognized was NL. It now handles newlines
1286 according to the set newline convention.
1287
1288 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1289 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1290 cater for a lack of strerror(). These oversights have been fixed.
1291
1292 9. Added --match-limit and --recursion-limit to pcregrep.
1293
1294 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1295
1296 11. When the -o option was used, pcregrep was setting a return code of 1, even
1297 when matches were found, and --line-buffered was not being honoured.
1298
1299 12. Added an optional parentheses number to the -o and --only-matching options
1300 of pcregrep.
1301
1302 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1303 can match an empty string. The code to do it in pcretest and pcredemo
1304 needed fixing:
1305
1306 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1307 only one byte after an empty string match just before CRLF (this case
1308 just got forgotten; "any" and "anycrlf" were OK).
1309
1310 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1311 mode when an empty string match preceded an ASCII character followed by
1312 a non-ASCII character. (The code for advancing by one character rather
1313 than one byte was nonsense.)
1314
1315 (c) The pcredemo.c sample program did not have any code at all to handle
1316 the cases when CRLF is a valid newline sequence.
1317
1318 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1319 as a starting offset was within the subject string. There is now a new
1320 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1321 negative or greater than the length of the string. In order to test this,
1322 pcretest is extended to allow the setting of negative starting offsets.
1323
1324 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1325 starting offset points to the beginning of a UTF-8 character was
1326 unnecessarily clumsy. I tidied it up.
1327
1328 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1329 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1330
1331 17. Nobody had reported that the --include_dir option, which was added in
1332 release 7.7 should have been called --include-dir (hyphen, not underscore)
1333 for compatibility with GNU grep. I have changed it to --include-dir, but
1334 left --include_dir as an undocumented synonym, and the same for
1335 --exclude-dir, though that is not available in GNU grep, at least as of
1336 release 2.5.4.
1337
1338 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1339 characters from a string of bytes) have been redefined so as not to use
1340 loops, in order to improve performance in some environments. At the same
1341 time, I abstracted some of the common code into auxiliary macros to save
1342 repetition (this should not affect the compiled code).
1343
1344 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1345 compile-time error is now given if \c is not followed by an ASCII
1346 character, that is, a byte less than 128. (In EBCDIC mode, the code is
1347 different, and any byte value is allowed.)
1348
1349 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1350 START_OPTIMIZE option, which is now allowed at compile time - but just
1351 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1352 to pcregrep and other applications that have no direct access to PCRE
1353 options. The new /Y option in pcretest sets this option when calling
1354 pcre_compile().
1355
1356 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1357 back references. Groups containing recursive back references were forced to
1358 be atomic by that change, but in the case of named groups, the amount of
1359 memory required was incorrectly computed, leading to "Failed: internal
1360 error: code overflow". This has been fixed.
1361
1362 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1363 pcretest.c, to avoid build problems in some Borland environments.
1364
1365
1366 Version 8.10 25-Jun-2010
1367 ------------------------
1368
1369 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1370 THEN.
1371
1372 2. (*ACCEPT) was not working when inside an atomic group.
1373
1374 3. Inside a character class, \B is treated as a literal by default, but
1375 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1376 causes the error). The code is unchanged, but I tidied the documentation.
1377
1378 4. Inside a character class, PCRE always treated \R and \X as literals,
1379 whereas Perl faults them if its -w option is set. I have changed PCRE so
1380 that it faults them when PCRE_EXTRA is set.
1381
1382 5. Added support for \N, which always matches any character other than
1383 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1384
1385 6. When compiling pcregrep with newer versions of gcc which may have
1386 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1387 declared with attribute warn_unused_result" were given. Just casting the
1388 result to (void) does not stop the warnings; a more elaborate fudge is
1389 needed. I've used a macro to implement this.
1390
1391 7. Minor change to pcretest.c to avoid a compiler warning.
1392
1393 8. Added four artifical Unicode properties to help with an option to make
1394 \s etc use properties (see next item). The new properties are: Xan
1395 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1396
1397 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1398 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1399 this option. Modified pcretest to add /W to test this facility. Added
1400 REG_UCP to make it available via the POSIX interface.
1401
1402 10. Added --line-buffered to pcregrep.
1403
1404 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1405 studied, and the match started with a letter with a code point greater than
1406 127 whose first byte was different to the first byte of the other case of
1407 the letter, the other case of this starting letter was not recognized
1408 (#976).
1409
1410 12. If a pattern that was studied started with a repeated Unicode property
1411 test, for example, \p{Nd}+, there was the theoretical possibility of
1412 setting up an incorrect bitmap of starting bytes, but fortunately it could
1413 not have actually happened in practice until change 8 above was made (it
1414 added property types that matched character-matching opcodes).
1415
1416 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1417 possible starting bytes for non-anchored patterns.
1418
1419 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1420 \R, and also a number of cases that involve Unicode properties, both
1421 explicit and implicit when PCRE_UCP is set.
1422
1423 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1424 input, it could crash or give wrong results if characters with values
1425 greater than 0xc0 were present in the subject string. (Detail: it assumed
1426 UTF-8 input when processing these items.)
1427
1428 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1429 size_t is 64-bit (#991).
1430
1431 17. Added a check for running out of memory when PCRE is compiled with
1432 --disable-stack-for-recursion (#990).
1433
1434 18. If the last data line in a file for pcretest does not have a newline on
1435 the end, a newline was missing in the output.
1436
1437 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1438 less than 128) in its various bitmaps. However, there is a facility for
1439 generating tables according to the current locale when PCRE is compiled. It
1440 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1441 characters, are recognized by isspace() and therefore were getting set in
1442 these tables, and indeed these tables seem to approximate to ISO 8859. This
1443 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1444 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1445 which of course cannot start UTF-8 characters. I have changed the code so
1446 that only real ASCII characters (less than 128) and the correct starting
1447 bytes for UTF-8 encodings are set for characters greater than 127 when in
1448 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1449 altogether.)
1450
1451 20. Added the /T option to pcretest so as to be able to run tests with non-
1452 standard character tables, thus making it possible to include the tests
1453 used for 19 above in the standard set of tests.
1454
1455 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1456 reference to a subpattern the other side of a comment that contains an
1457 opening parenthesis caused either an internal compiling error, or a
1458 reference to the wrong subpattern.
1459
1460
1461 Version 8.02 19-Mar-2010
1462 ------------------------
1463
1464 1. The Unicode data tables have been updated to Unicode 5.2.0.
1465
1466 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
1467 configured.
1468
1469 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
1470 original author of that file, following a query about its status.
1471
1472 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
1473 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1474
1475 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1476 quantifier applied to a forward-referencing subroutine call, could compile
1477 incorrect code or give the error "internal error: previously-checked
1478 referenced subpattern not found".
1479
1480 6. Both MS Visual Studio and Symbian OS have problems with initializing
1481 variables to point to external functions. For these systems, therefore,
1482 pcre_malloc etc. are now initialized to local functions that call the
1483 relevant global functions.
1484
1485 7. There were two entries missing in the vectors called coptable and poptable
1486 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1487 I've fixed the data, and added a kludgy way of testing at compile time that
1488 the lengths are correct (equal to the number of opcodes).
1489
1490 8. Following on from 7, I added a similar kludge to check the length of the
1491 eint vector in pcreposix.c.
1492
1493 9. Error texts for pcre_compile() are held as one long string to avoid too
1494 much relocation at load time. To find a text, the string is searched,
1495 counting zeros. There was no check for running off the end of the string,
1496 which could happen if a new error number was added without updating the
1497 string.
1498
1499 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1500
1501 11. \K was not working if it appeared in an atomic group or in a group that
1502 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1503 \K is "not well defined" if used in an assertion. PCRE now accepts it if
1504 the assertion is positive, but not if it is negative.
1505
1506 12. Change 11 fortuitously reduced the size of the stack frame used in the
1507 "match()" function of pcre_exec.c by one pointer. Forthcoming
1508 implementation of support for (*MARK) will need an extra pointer on the
1509 stack; I have reserved it now, so that the stack frame size does not
1510 decrease.
1511
1512 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1513 item in branch that calls a recursion is a subroutine call - as in the
1514 second branch in the above example - was incorrectly given the compile-
1515 time error "recursive call could loop indefinitely" because pcre_compile()
1516 was not correctly checking the subroutine for matching a non-empty string.
1517
1518 14. The checks for overrunning compiling workspace could trigger after an
1519 overrun had occurred. This is a "should never occur" error, but it can be
1520 triggered by pathological patterns such as hundreds of nested parentheses.
1521 The checks now trigger 100 bytes before the end of the workspace.
1522
1523 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1524
1525
1526 Version 8.01 19-Jan-2010
1527 ------------------------
1528
1529 1. If a pattern contained a conditional subpattern with only one branch (in
1530 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1531 computed the wrong minimum data length (which is of course zero for such
1532 subpatterns). This could cause incorrect "no match" results.
1533
1534 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1535 the pattern is reset in the first branch, pcre_compile() failed with
1536 "internal error: code overflow at offset...". This happened only when
1537 the reset was to the original external option setting. (An optimization
1538 abstracts leading options settings into an external setting, which was the
1539 cause of this.)
1540
1541 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1542 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1543 assertion pattern did not match (meaning that the assertion was true), it
1544 was incorrectly treated as false if the SKIP had been reached during the
1545 matching. This also applied to assertions used as conditions.
1546
1547 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
1548 assertion subpattern, including such a pattern used as a condition,
1549 unpredictable results occurred, instead of the error return
1550 PCRE_ERROR_DFA_UITEM.
1551
1552 5. The C++ GlobalReplace function was not working like Perl for the special
1553 situation when an empty string is matched. It now does the fancy magic
1554 stuff that is necessary.
1555
1556 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1557 removed. (These were left over from very, very early versions of PCRE.)
1558
1559 7. Some cosmetic changes to the code to make life easier when compiling it
1560 as part of something else:
1561
1562 (a) Change DEBUG to PCRE_DEBUG.
1563
1564 (b) In pcre_compile(), rename the member of the "branch_chain" structure
1565 called "current" as "current_branch", to prevent a collision with the
1566 Linux macro when compiled as a kernel module.
1567
1568 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1569 prevent a collision with the Linux macro when compiled as a kernel
1570 module.
1571
1572 8. In pcre_compile() there are some checks for integer overflows that used to
1573 cast potentially large values to (double). This has been changed to that
1574 when building, a check for int64_t is made, and if it is found, it is used
1575 instead, thus avoiding the use of floating point arithmetic. (There is no
1576 other use of FP in PCRE.) If int64_t is not found, the fallback is to
1577 double.
1578
1579 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
1580 2005 (difference between two addresses compared to an unsigned value).
1581
1582 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1583 custom one, because of the following reported problem in Windows:
1584
1585 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1586 under Win32.
1587 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1588 therefore missing the function definition.
1589 - The compiler thus generates a "C" signature for the test function.
1590 - The linker fails to find the "C" function.
1591 - PCRE fails to configure if asked to do so against libbz2.
1592
1593 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1594 messages were output:
1595
1596 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1597 rerunning libtoolize, to keep the correct libtool macros in-tree.
1598 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1599
1600 I have done both of these things.
1601
1602 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1603 most of the time, it *can* run out if it is given a pattern that contains a
1604 runaway infinite recursion. I updated the discussion in the pcrestack man
1605 page.
1606
1607 13. Now that we have gone to the x.xx style of version numbers, the minor
1608 version may start with zero. Using 08 or 09 is a bad idea because users
1609 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1610 interpreted as invalid octal numbers. I've updated the previous comment in
1611 configure.ac, and also added a check that gives an error if 08 or 09 are
1612 used.
1613
1614 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1615 causing partial matching to fail when the end of the subject matched \W
1616 in a UTF-8 pattern where \W was quantified with a minimum of 3.
1617
1618 15. There were some discrepancies between the declarations in pcre_internal.h
1619 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1620 their definitions. The declarations used "const uschar *" and the
1621 definitions used USPTR. Even though USPTR is normally defined as "const
1622 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1623 reported that: "This difference in casting confuses some C++ compilers, for
1624 example, SunCC recognizes above declarations as different functions and
1625 generates broken code for hbpcre." I have changed the declarations to use
1626 USPTR.
1627
1628 16. GNU libtool is named differently on some systems. The autogen.sh script now
1629 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1630 (FreeBSD).
1631
1632 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1633 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1634 comment: "Figure out how to create a longlong from a string: strtoll and
1635 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1636 instance, but it only takes 2 args instead of 3!"
1637
1638 18. A subtle bug concerned with back references has been fixed by a change of
1639 specification, with a corresponding code fix. A pattern such as
1640 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1641 refers, was giving matches when it shouldn't. For example, xa=xaaa would
1642 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1643 same bug. Such groups have to be quantified to be useful, or contained
1644 inside another quantified group. (If there's no repetition, the reference
1645 can never match.) The problem arises because, having left the group and
1646 moved on to the rest of the pattern, a later failure that backtracks into
1647 the group uses the captured value from the final iteration of the group
1648 rather than the correct earlier one. I have fixed this in PCRE by forcing
1649 any group that contains a reference to itself to be an atomic group; that
1650 is, there cannot be any backtracking into it once it has completed. This is
1651 similar to recursive and subroutine calls.
1652
1653
1654 Version 8.00 19-Oct-09
1655 ----------------------
1656
1657 1. The table for translating pcre_compile() error codes into POSIX error codes
1658 was out-of-date, and there was no check on the pcre_compile() error code
1659 being within the table. This could lead to an OK return being given in
1660 error.
1661
1662 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1663 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1664 in a Windows environment.
1665
1666 3. The pcregrep --count option prints the count for each file even when it is
1667 zero, as does GNU grep. However, pcregrep was also printing all files when
1668 --files-with-matches was added. Now, when both options are given, it prints
1669 counts only for those files that have at least one match. (GNU grep just
1670 prints the file name in this circumstance, but including the count seems
1671 more useful - otherwise, why use --count?) Also ensured that the
1672 combination -clh just lists non-zero counts, with no names.
1673
1674 4. The long form of the pcregrep -F option was incorrectly implemented as
1675 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1676 but it seems right to fix it, and I didn't think it was worth preserving
1677 the old behaviour.
1678
1679 5. The command line items --regex=pattern and --regexp=pattern were not
1680 recognized by pcregrep, which required --regex pattern or --regexp pattern
1681 (with a space rather than an '='). The man page documented the '=' forms,
1682 which are compatible with GNU grep; these now work.
1683
1684 6. No libpcreposix.pc file was created for pkg-config; there was just
1685 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1686
1687 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1688 when UCP support is not needed, by modifying the Python script that
1689 generates it from Unicode data files. This should not matter if the module
1690 is correctly used as a library, but I received one complaint about 50K of
1691 unwanted data. My guess is that the person linked everything into his
1692 program rather than using a library. Anyway, it does no harm.
1693
1694 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1695 was a minimum greater than 1 for a wide character in a possessive
1696 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1697 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1698 character. Chaos in the form of incorrect output or a compiling loop could
1699 result.
1700
1701 9. The restrictions on what a pattern can contain when partial matching is
1702 requested for pcre_exec() have been removed. All patterns can now be
1703 partially matched by this function. In addition, if there are at least two
1704 slots in the offset vector, the offset of the earliest inspected character
1705 for the match and the offset of the end of the subject are set in them when
1706 PCRE_ERROR_PARTIAL is returned.
1707
1708 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1709 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1710 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1711 and may be more useful for multi-segment matching.
1712
1713 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1714 used to be given if ever the end of the subject was reached; now it is
1715 given only if matching could not proceed because another character was
1716 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1717 string "Z", which now yields "no match" instead of "partial match". In the
1718 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1719 final character ended with (*FAIL).
1720
1721 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1722 if the pattern had a "must contain" character that was already found in the
1723 earlier partial match, unless partial matching was again requested. For
1724 example, with the pattern /dog.(body)?/, the "must contain" character is
1725 "g". If the first part-match was for the string "dog", restarting with
1726 "sbody" failed. This bug has been fixed.
1727
1728 13. The string returned by pcre_dfa_exec() after a partial match has been
1729 changed so that it starts at the first inspected character rather than the
1730 first character of the match. This makes a difference only if the pattern
1731 starts with a lookbehind assertion or \b or \B (\K is not supported by
1732 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1733 matching functions compatible, and I think it's the right thing to do.
1734
1735 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1736 so that the demonstration program is easily available in environments where
1737 PCRE has not been installed from source.
1738
1739 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1740 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1741 library.
1742
1743 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1744 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1745 is not the first non-POSIX option to be added. Clearly some people find
1746 these options useful.
1747
1748 17. If a caller to the POSIX matching function regexec() passes a non-zero
1749 value for nmatch with a NULL value for pmatch, the value of
1750 nmatch is forced to zero.
1751
1752 18. RunGrepTest did not have a test for the availability of the -u option of
1753 the diff command, as RunTest does. It now checks in the same way as
1754 RunTest, and also checks for the -b option.
1755
1756 19. If an odd number of negated classes containing just a single character
1757 interposed, within parentheses, between a forward reference to a named
1758 subpattern and the definition of the subpattern, compilation crashed with
1759 an internal error, complaining that it could not find the referenced
1760 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1761 [The bug was that it was starting one character too far in when skipping
1762 over the character class, thus treating the ] as data rather than
1763 terminating the class. This meant it could skip too much.]
1764
1765 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1766 /g option in pcretest when the pattern contains \K, which makes it possible
1767 to have an empty string match not at the start, even when the pattern is
1768 anchored. Updated pcretest and pcredemo to use this option.
1769
1770 21. If the maximum number of capturing subpatterns in a recursion was greater
1771 than the maximum at the outer level, the higher number was returned, but
1772 with unset values at the outer level. The correct (outer level) value is
1773 now given.
1774
1775 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1776 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1777 make it do so. The string so far is captured, making this feature
1778 compatible with Perl.
1779
1780 23. The tests have been re-organized, adding tests 11 and 12, to make it
1781 possible to check the Perl 5.10 features against Perl 5.10.
1782
1783 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1784 pattern matches a fixed length string. PCRE did not allow this; now it
1785 does. Neither allows recursion.
1786
1787 25. I finally figured out how to implement a request to provide the minimum
1788 length of subject string that was needed in order to match a given pattern.
1789 (It was back references and recursion that I had previously got hung up
1790 on.) This code has now been added to pcre_study(); it finds a lower bound
1791 to the length of subject needed. It is not necessarily the greatest lower
1792 bound, but using it to avoid searching strings that are too short does give
1793 some useful speed-ups. The value is available to calling programs via
1794 pcre_fullinfo().
1795
1796 26. While implementing 25, I discovered to my embarrassment that pcretest had
1797 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1798 study optimizations had never been tested with that matching function.
1799 Oops. What is worse, even when it was passed study data, there was a bug in
1800 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1801 were also very few tests of studied patterns with pcre_dfa_exec().
1802
1803 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1804 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1805 on the other side of the coin, they are no longer allowed to have different
1806 names, because these cannot be distinguished in PCRE, and this has caused
1807 confusion. (This is a difference from Perl.)
1808
1809 28. When duplicate subpattern names are present (necessarily with different
1810 numbers, as required by 27 above), and a test is made by name in a
1811 conditional pattern, either for a subpattern having been matched, or for
1812 recursion in such a pattern, all the associated numbered subpatterns are
1813 tested, and the overall condition is true if the condition is true for any
1814 one of them. This is the way Perl works, and is also more like the way
1815 testing by number works.
1816
1817
1818 Version 7.9 11-Apr-09
1819 ---------------------
1820
1821 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1822 (pcretest), all targets were linked against these libraries. This included
1823 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1824 libraries. This caused unwanted dependencies to be created. This problem
1825 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1826 pcretest is linked with readline.
1827
1828 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1829 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1830 moved outside it again, because FALSE and TRUE are already defined in AIX,
1831 but BOOL is not.
1832
1833 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1834 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1835
1836 4. The pcregrep documentation said spaces were inserted as well as colons (or
1837 hyphens) following file names and line numbers when outputting matching
1838 lines. This is not true; no spaces are inserted. I have also clarified the
1839 wording for the --colour (or --color) option.
1840
1841 5. In pcregrep, when --colour was used with -o, the list of matching strings
1842 was not coloured; this is different to GNU grep, so I have changed it to be
1843 the same.
1844
1845 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1846 each matching line was coloured. Now it goes on to look for further matches
1847 of any of the test patterns, which is the same behaviour as GNU grep.
1848
1849 7. A pattern that could match an empty string could cause pcregrep to loop; it
1850 doesn't make sense to accept an empty string match in pcregrep, so I have
1851 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1852 seems to be how GNU grep behaves. [But see later change 40 for release
1853 8.33.]
1854
1855 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1856 start or after a newline", because the conditional assertion was not being
1857 correctly handled. The rule now is that both the assertion and what follows
1858 in the first alternative must satisfy the test.
1859
1860 9. If auto-callout was enabled in a pattern with a conditional group whose
1861 condition was an assertion, PCRE could crash during matching, both with
1862 pcre_exec() and pcre_dfa_exec().
1863
1864 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1865 used for matching.
1866
1867 11. Unicode property support in character classes was not working for
1868 characters (bytes) greater than 127 when not in UTF-8 mode.
1869
1870 12. Added the -M command line option to pcretest.
1871
1872 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1873
1874 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1875
1876 16. Added comments and documentation about mis-use of no_arg in the C++
1877 wrapper.
1878
1879 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1880 from Martin Jerabek that uses macro names for all relevant character and
1881 string constants.
1882
1883 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1884 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1885 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1886 these, but not everybody uses configure.
1887
1888 19. A conditional group that had only one branch was not being correctly
1889 recognized as an item that could match an empty string. This meant that an
1890 enclosing group might also not be so recognized, causing infinite looping
1891 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1892 with the subject "ab", where knowledge that the repeated group can match
1893 nothing is needed in order to break the loop.
1894
1895 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1896 exec(), but without supplying a callout function, matching went wrong.
1897
1898 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1899 leak if the size of the offset vector was greater than 30. When the vector
1900 is smaller, the saved offsets during recursion go onto a local stack
1901 vector, but for larger vectors malloc() is used. It was failing to free
1902 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1903 error, in fact).
1904
1905 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1906 heapframe that is used only when UTF-8 support is enabled. This caused no
1907 problem, but was untidy.
1908
1909 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1910 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1911 included within another project.
1912
1913 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1914 slightly modified by me:
1915
1916 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1917 not building pcregrep.
1918
1919 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1920 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1921
1922 25. Forward references, both numeric and by name, in patterns that made use of
1923 duplicate group numbers, could behave incorrectly or give incorrect errors,
1924 because when scanning forward to find the reference group, PCRE was not
1925 taking into account the duplicate group numbers. A pattern such as
1926 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1927
1928 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1929 the feature of a custom pointer more persuasive (as requested by a user).
1930
1931 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1932 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1933 pre-defined.
1934
1935 28. Added support for (*UTF8) at the start of a pattern.
1936
1937 29. Arrange for flags added by the "release type" setting in CMake to be shown
1938 in the configuration summary.
1939
1940
1941 Version 7.8 05-Sep-08
1942 ---------------------
1943
1944 1. Replaced UCP searching code with optimized version as implemented for Ad
1945 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1946 stage table and inline lookup instead of a function, giving speed ups of 2
1947 to 5 times on some simple patterns that I tested. Permission was given to
1948 distribute the MultiStage2.py script that generates the tables (it's not in
1949 the tarball, but is in the Subversion repository).
1950
1951 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1952 scripts.
1953
1954 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1955 a group with a zero qualifier. The result of the study could be incorrect,
1956 or the function might crash, depending on the pattern.
1957
1958 4. Caseless matching was not working for non-ASCII characters in back
1959 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1960 It now works when Unicode Property Support is available.
1961
1962 5. In pcretest, an escape such as \x{de} in the data was always generating
1963 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1964 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1965 truncation.
1966
1967 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1968
1969 7. Added two (int) casts to pcregrep when printing the difference of two
1970 pointers, in case they are 64-bit values.
1971
1972 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1973 test 2 if it fails.
1974
1975 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1976 and a #define of that name to empty if it is not externally set. This is to
1977 allow users of MSVC to set it if necessary.
1978
1979 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1980 the convenience functions in the pcre_get.c source file.
1981
1982 11. An option change at the start of a pattern that had top-level alternatives
1983 could cause overwriting and/or a crash. This command provoked a crash in
1984 some environments:
1985
1986 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1987
1988 This potential security problem was recorded as CVE-2008-2371.
1989
1990 12. For a pattern where the match had to start at the beginning or immediately
1991 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1992 pcre_dfa_exec() could read past the end of the passed subject if there was
1993 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1994 pcretest so that it places the subject at the end of its malloc-ed buffer.
1995
1996 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1997 exec() might read past the end of the data buffer in UTF-8 mode.
1998
1999 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2000 the data contained the byte 0x85 as part of a UTF-8 character within its
2001 first line. This applied both to normal and DFA matching.
2002
2003 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2004 /^[^d]*?$/8 failed to match "abc".
2005
2006 16. Added a missing copyright notice to pcrecpp_internal.h.
2007
2008 17. Make it more clear in the documentation that values returned from
2009 pcre_exec() in ovector are byte offsets, not character counts.
2010
2011 18. Tidied a few places to stop certain compilers from issuing warnings.
2012
2013 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2014 supplied by Stefan Weber. I made a further small update for 7.8 because
2015 there is a change of source arrangements: the pcre_searchfuncs.c module is
2016 replaced by pcre_ucd.c.
2017
2018
2019 Version 7.7 07-May-08
2020 ---------------------
2021
2022 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2023 a string to a long long, pretend we don't even have a long long." This is
2024 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2025
2026 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2027 pre-7.6 versions, which defined a global no_arg variable instead of putting
2028 it in the RE class. (See also #8 below.)
2029
2030 3. Remove a line of dead code, identified by coverity and reported by Nuno
2031 Lopes.
2032
2033 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2034
2035 (1) The include/exclude patterns were being applied to the whole pathnames
2036 of files, instead of just to the final components.
2037
2038 (2) If there was more than one level of directory, the subdirectories were
2039 skipped unless they satisfied the include/exclude conditions. This is
2040 inconsistent with GNU grep (and could even be seen as contrary to the
2041 pcregrep specification - which I improved to make it absolutely clear).
2042 The action now is always to scan all levels of directory, and just
2043 apply the include/exclude patterns to regular files.
2044
2045 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2046 --exclude_dir in the tests to avoid scanning .svn directories.
2047
2048 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2049 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2050 doesn't support NULs in patterns.
2051
2052 7. Added some missing "const"s to declarations of static tables in
2053 pcre_compile.c and pcre_dfa_exec.c.
2054
2055 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2056 caused by fix #2 above. (Subsequently also a second patch to fix the
2057 first patch. And a third patch - this was a messy problem.)
2058
2059 9. Applied Craig's patch to remove the use of push_back().
2060
2061 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2062 matching function regexec().
2063
2064 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2065 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2066 references. PCRE supports relative numbers with this syntax (I don't think
2067 Oniguruma does).
2068
2069 12. Previously, a group with a zero repeat such as (...){0} was completely
2070 omitted from the compiled regex. However, this means that if the group
2071 was called as a subroutine from elsewhere in the pattern, things went wrong
2072 (an internal error was given). Such groups are now left in the compiled
2073 pattern, with a new opcode that causes them to be skipped at execution
2074 time.
2075
2076 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2077 to the way PCRE behaves:
2078
2079 (a) A lone ] character is dis-allowed (Perl treats it as data).
2080
2081 (b) A back reference to an unmatched subpattern matches an empty string
2082 (Perl fails the current match path).
2083
2084 (c) A data ] in a character class must be notated as \] because if the
2085 first data character in a class is ], it defines an empty class. (In
2086 Perl it is not possible to have an empty class.) The empty class []
2087 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2088 The negative empty class [^] matches any one character, independently
2089 of the DOTALL setting.
2090
2091 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2092 non-existent subpattern following a character class starting with ']' and
2093 containing () gave an internal compiling error instead of "reference to
2094 non-existent subpattern". Fortunately, when the pattern did exist, the
2095 compiled code was correct. (When scanning forwards to check for the
2096 existence of the subpattern, it was treating the data ']' as terminating
2097 the class, so got the count wrong. When actually compiling, the reference
2098 was subsequently set up correctly.)
2099
2100 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2101 it was being rejected as not supported by pcre_dfa_exec(), even though
2102 other assertions are supported. I have made pcre_dfa_exec() support
2103 (*FAIL).
2104
2105 16. The implementation of 13c above involved the invention of a new opcode,
2106 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2107 cannot be changed at match time, I realized I could make a small
2108 improvement to matching performance by compiling OP_ALLANY instead of
2109 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2110 on the OP_ANY path.
2111
2112 17. Compiling pcretest on Windows with readline support failed without the
2113 following two fixes: (1) Make the unistd.h include conditional on
2114 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2115
2116 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2117 ncurses library to be included for pcretest when ReadLine support is
2118 requested, but also to allow for it to be overridden. This patch came from
2119 Daniel Bergström.
2120
2121 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2122 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2123 any errors with the current Unicode tables. Thanks to Peter Kankowski for
2124 spotting this.
2125
2126
2127 Version 7.6 28-Jan-08
2128 ---------------------
2129
2130 1. A character class containing a very large number of characters with
2131 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2132 overflow.
2133
2134 2. Patch to cut out the "long long" test in pcrecpp_unittest when
2135 HAVE_LONG_LONG is not defined.
2136
2137 3. Applied Christian Ehrlicher's patch to update the CMake build files to
2138 bring them up to date and include new features. This patch includes:
2139
2140 - Fixed PH's badly added libz and libbz2 support.
2141 - Fixed a problem with static linking.
2142 - Added pcredemo. [But later removed - see 7 below.]
2143 - Fixed dftables problem and added an option.
2144 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2145 HAVE_LONG_LONG.
2146 - Added readline support for pcretest.
2147 - Added an listing of the option settings after cmake has run.
2148
2149 4. A user submitted a patch to Makefile that makes it easy to create
2150 "pcre.dll" under mingw when using Configure/Make. I added stuff to
2151 Makefile.am that cause it to include this special target, without
2152 affecting anything else. Note that the same mingw target plus all
2153 the other distribution libraries and programs are now supported
2154 when configuring with CMake (see 6 below) instead of with
2155 Configure/Make.
2156
2157 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2158 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2159 exported in the Windows port". It has not yet been confirmed that the patch
2160 solves the problem, but it does no harm.
2161
2162 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2163 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2164 with CMake, and also correct the comment about stack recursion.
2165
2166 7. Remove the automatic building of pcredemo from the ./configure system and
2167 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2168 of a program that users should build themselves after PCRE is installed, so
2169 building it automatically is not really right. What is more, it gave
2170 trouble in some build environments.
2171
2172 8. Further tidies to CMakeLists.txt from Sheri and Christian.
2173
2174
2175 Version 7.5 10-Jan-08
2176 ---------------------
2177
2178 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
2179 values in parens when parsing an RE using the C++ wrapper."
2180
2181 2. Negative specials like \S did not work in character classes in UTF-8 mode.
2182 Characters greater than 255 were excluded from the class instead of being
2183 included.
2184
2185 3. The same bug as (2) above applied to negated POSIX classes such as
2186 [:^space:].
2187
2188 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2189 defined or documented. It seems to have been a typo for PCRE_STATIC, so
2190 I have changed it.
2191
2192 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
2193 first named subpattern) and a construct such as (?&a) would reference the
2194 first named subpattern whose name started with "a" (in other words, the
2195 length check was missing). Both these problems are fixed. "Subpattern name
2196 expected" is now given for (?&) (a zero-length name), and this patch also
2197 makes it give the same error for \k'' (previously it complained that that
2198 was a reference to a non-existent subpattern).
2199
2200 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
2201 this is right because (?- can be followed by option settings as well as by
2202 digits. I have, however, made the messages clearer.
2203
2204 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2205 than the number used in the conditional) now cause a compile-time error.
2206 This is actually not compatible with Perl, which accepts such patterns, but
2207 treats the conditional as always being FALSE (as PCRE used to), but it
2208 seems to me that giving a diagnostic is better.
2209
2210 8. Change "alphameric" to the more common word "alphanumeric" in comments
2211 and messages.
2212
2213 9. Fix two occurrences of "backslash" in comments that should have been
2214 "backspace".
2215
2216 10. Remove two redundant lines of code that can never be obeyed (their function
2217 was moved elsewhere).
2218
2219 11. The program that makes PCRE's Unicode character property table had a bug
2220 which caused it to generate incorrect table entries for sequences of
2221 characters that have the same character type, but are in different scripts.
2222 It amalgamated them into a single range, with the script of the first of
2223 them. In other words, some characters were in the wrong script. There were
2224 thirteen such cases, affecting characters in the following ranges:
2225
2226 U+002b0 - U+002c1
2227 U+0060c - U+0060d
2228 U+0061e - U+00612
2229 U+0064b - U+0065e
2230 U+0074d - U+0076d
2231 U+01800 - U+01805
2232 U+01d00 - U+01d77
2233 U+01d9b - U+01dbf
2234 U+0200b - U+0200f
2235 U+030fc - U+030fe
2236 U+03260 - U+0327f
2237 U+0fb46 - U+0fbb1
2238 U+10450 - U+1049d
2239
2240 12. The -o option (show only the matching part of a line) for pcregrep was not
2241 compatible with GNU grep in that, if there was more than one match in a
2242 line, it showed only the first of them. It now behaves in the same way as
2243 GNU grep.
2244
2245 13. If the -o and -v options were combined for pcregrep, it printed a blank
2246 line for every non-matching line. GNU grep prints nothing, and pcregrep now
2247 does the same. The return code can be used to tell if there were any
2248 non-matching lines.
2249
2250 14. Added --file-offsets and --line-offsets to pcregrep.
2251
2252 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2253 infinitely looping recursion. The bug was that positive lookaheads were not
2254 being skipped when checking for a possible empty match (negative lookaheads
2255 and both kinds of lookbehind were skipped).
2256
2257 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2258 inclusion of <windows.h> to before rather than after the definition of
2259 INVALID_FILE_ATTRIBUTES (patch from David Byron).
2260
2261 17. Specifying a possessive quantifier with a specific limit for a Unicode
2262 character property caused pcre_compile() to compile bad code, which led at
2263 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2264 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2265 caused the error; without that there was no problem.
2266
2267 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2268
2269 19. Added --enable-pcretest-libreadline.
2270
2271 20. In pcrecpp.cc, the variable 'count' was incremented twice in
2272 RE::GlobalReplace(). As a result, the number of replacements returned was
2273 double what it should be. I removed one of the increments, but Craig sent a
2274 later patch that removed the other one (the right fix) and added unit tests
2275 that check the return values (which was not done before).
2276
2277 21. Several CMake things:
2278
2279 (1) Arranged that, when cmake is used on Unix, the libraries end up with
2280 the names libpcre and libpcreposix, not just pcre and pcreposix.
2281
2282 (2) The above change means that pcretest and pcregrep are now correctly
2283 linked with the newly-built libraries, not previously installed ones.
2284
2285 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2286
2287 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2288 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2289 UTF-8 newline character). The key issue is that the pattern starts .*;
2290 this means that the match must be either at the beginning, or after a
2291 newline. The bug was in the code for advancing after a failed match and
2292 checking that the new position followed a newline. It was not taking
2293 account of UTF-8 characters correctly.
2294
2295 23. PCRE was behaving differently from Perl in the way it recognized POSIX
2296 character classes. PCRE was not treating the sequence [:...:] as a
2297 character class unless the ... were all letters. Perl, however, seems to
2298 allow any characters between [: and :], though of course it rejects as
2299 unknown any "names" that contain non-letters, because all the known class
2300 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2301 for example, whereas PCRE did not - it did not recognize a POSIX character
2302 class. This seemed a bit dangerous, so the code has been changed to be
2303 closer to Perl. The behaviour is not identical to Perl, because PCRE will
2304 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2305 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2306 Perl does, and where it didn't before.
2307
2308 24. Rewrite so as to remove the single use of %n from pcregrep because in some
2309 Windows environments %n is disabled by default.
2310
2311
2312 Version 7.4 21-Sep-07
2313 ---------------------
2314
2315 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
2316 means that a class such as [\s] counted as "explicit reference to CR or
2317 LF". That isn't really right - the whole point of the change was to try to
2318 help when there was an actual mention of one of the two characters. So now
2319 the change happens only if \r or \n (or a literal CR or LF) character is
2320 encountered.
2321
2322 2. The 32-bit options word was also used for 6 internal flags, but the numbers
2323 of both had grown to the point where there were only 3 bits left.
2324 Fortunately, there was spare space in the data structure, and so I have
2325 moved the internal flags into a new 16-bit field to free up more option
2326 bits.
2327
2328 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2329 but did not set the internal JCHANGED flag - either of these is enough to
2330 control the way the "get" function works - but the PCRE_INFO_JCHANGED
2331 facility is supposed to tell if (?J) was ever used, so now (?J) at the
2332 start sets both bits.
2333
2334 4. Added options (at build time, compile time, exec time) to change \R from
2335 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2336
2337 5. doc/pcresyntax.html was missing from the distribution.
2338
2339 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2340 compatibility, even though it is no longer used.
2341
2342 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2343 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2344 windows.h file is present (where different names are used). [This was
2345 reversed later after testing - see 16 below.]
2346
2347 8. Changed all #include <config.h> to #include "config.h". There were also
2348 some further <pcre.h> cases that I changed to "pcre.h".
2349
2350 9. When pcregrep was used with the --colour option, it missed the line ending
2351 sequence off the lines that it output.
2352
2353 10. It was pointed out to me that arrays of string pointers cause lots of
2354 relocations when a shared library is dynamically loaded. A technique of
2355 using a single long string with a table of offsets can drastically reduce
2356 these. I have refactored PCRE in four places to do this. The result is
2357 dramatic:
2358
2359 Originally: 290
2360 After changing UCP table: 187
2361 After changing error message table: 43
2362 After changing table of "verbs" 36
2363 After changing table of Posix names 22
2364
2365 Thanks to the folks working on Gregex for glib for this insight.
2366
2367 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2368 unicode-properties was also set.
2369
2370 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2371
2372 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2373 checked only for CRLF.
2374
2375 14. Added casts to pcretest.c to avoid compiler warnings.
2376
2377 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2378
2379 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2380 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2381 entirely. This removes changes made in 7 above.
2382
2383 17. The CMake files have been updated, and there is now more information about
2384 building with CMake in the NON-UNIX-USE document.
2385
2386
2387 Version 7.3 28-Aug-07
2388 ---------------------
2389
2390 1. In the rejigging of the build system that eventually resulted in 7.1, the
2391 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2392 brackets there is not right, since it causes compilers to look for an
2393 installed pcre.h, not the version that is in the source that is being
2394 compiled (which of course may be different). I have changed it back to:
2395
2396 #include "pcre.h"
2397
2398 I have a vague recollection that the change was concerned with compiling in
2399 different directories, but in the new build system, that is taken care of
2400 by the VPATH setting the Makefile.
2401
2402 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2403 when the subject happened to end in the byte 0x85 (e.g. if the last
2404 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2405 characters but of course it shouldn't be taken as a newline when it is part
2406 of another character. The bug was that, for an unlimited repeat of . in
2407 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2408 characters when looking for a newline.
2409
2410 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2411
2412 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2413 in debug output.
2414
2415 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2416 long printing in the pcrecpp unittest when running under MinGW.
2417
2418 6. ESC_K was left out of the EBCDIC table.
2419
2420 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2421 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2422 limit also applies to "virtual nesting" when a pattern is recursive, and in
2423 this case 1000 isn't so big. I have been able to remove this limit at the
2424 expense of backing off one optimization in certain circumstances. Normally,
2425 when pcre_exec() would call its internal match() function recursively and
2426 immediately return the result unconditionally, it uses a "tail recursion"
2427 feature to save stack. However, when a subpattern that can match an empty
2428 string has an unlimited repetition quantifier, it no longer makes this
2429 optimization. That gives it a stack frame in which to save the data for
2430 checking that an empty string has been matched. Previously this was taken
2431 from the 1000-entry workspace that had been reserved. So now there is no
2432 explicit limit, but more stack is used.
2433
2434 8. Applied Daniel's patches to solve problems with the import/export magic
2435 syntax that is required for Windows, and which was going wrong for the
2436 pcreposix and pcrecpp parts of the library. These were overlooked when this
2437 problem was solved for the main library.
2438
2439 9. There were some crude static tests to avoid integer overflow when computing
2440 the size of patterns that contain repeated groups with explicit upper
2441 limits. As the maximum quantifier is 65535, the maximum group length was
2442 set at 30,000 so that the product of these two numbers did not overflow a
2443 32-bit integer. However, it turns out that people want to use groups that
2444 are longer than 30,000 bytes (though not repeat them that many times).
2445 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2446 made it possible to implement the integer overflow checks in a much more
2447 dynamic way, which I have now done. The artificial limitation on group
2448 length has been removed - we now have only the limit on the total length of
2449 the compiled pattern, which depends on the LINK_SIZE setting.
2450
2451 10. Fixed a bug in the documentation for get/copy named substring when
2452 duplicate names are permitted. If none of the named substrings are set, the
2453 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2454 empty string.
2455
2456 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2457 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2458 because the ] is interpreted as the first data character and the
2459 terminating ] is not found. PCRE has been made compatible with Perl in this
2460 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2461 cause memory overwriting.
2462
2463 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2464 string has been matched (to stop an infinite loop). It was not recognizing
2465 a conditional subpattern that could match an empty string if that
2466 subpattern was within another subpattern. For example, it looped when
2467 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
2468 condition was not nested. This bug has been fixed.
2469
2470 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2471 past the start of the subject in the presence of bytes with the top bit
2472 set, for example "\x8aBCD".
2473
2474 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2475 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2476
2477 14. Optimized (?!) to (*FAIL).
2478
2479 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2480 This restricts code points to be within the range 0 to 0x10FFFF, excluding
2481 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2482 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2483 does: it's just the validity check that is more restrictive.
2484
2485 16. Inserted checks for integer overflows during escape sequence (backslash)
2486 processing, and also fixed erroneous offset values for syntax errors during
2487 backslash processing.
2488
2489 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2490 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2491
2492 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2493 caused an overrun.
2494
2495 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2496 something other than just ASCII characters) inside a group that had an
2497 unlimited repeat caused a loop at compile time (while checking to see
2498 whether the group could match an empty string).
2499
2500 20. Debugging a pattern containing \p or \P could cause a crash. For example,
2501 [\P{Any}] did so. (Error in the code for printing property names.)
2502
2503 21. An orphan \E inside a character class could cause a crash.
2504
2505 22. A repeated capturing bracket such as (A)? could cause a wild memory
2506 reference during compilation.
2507
2508 23. There are several functions in pcre_compile() that scan along a compiled
2509 expression for various reasons (e.g. to see if it's fixed length for look
2510 behind). There were bugs in these functions when a repeated \p or \P was
2511 present in the pattern. These operators have additional parameters compared
2512 with \d, etc, and these were not being taken into account when moving along
2513 the compiled data. Specifically:
2514
2515 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2516 length.
2517
2518 (b) An item such as \pL+ within a repeated group could cause crashes or
2519 loops.
2520
2521 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2522 "reference to non-existent subpattern" error.
2523
2524 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2525
2526 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2527 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2528
2529 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2530
2531 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2532 character were causing crashes (broken optimization).
2533
2534 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2535 \p or \P) caused a compile-time loop.
2536
2537 28. More problems have arisen in unanchored patterns when CRLF is a valid line
2538 break. For example, the unstudied pattern [\r\n]A does not match the string
2539 "\r\nA" because change 7.0/46 below moves the current point on by two
2540 characters after failing to match at the start. However, the pattern \nA
2541 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2542 the same is true. There doesn't seem any very clean way out of this, but
2543 what I have chosen to do makes the common cases work: PCRE now takes note
2544 of whether there can be an explicit match for \r or \n anywhere in the
2545 pattern, and if so, 7.0/46 no longer applies. As part of this change,
2546 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2547 pattern has explicit CR or LF references.
2548
2549 29. Added (*CR) etc for changing newline setting at start of pattern.
2550
2551
2552 Version 7.2 19-Jun-07
2553 ---------------------
2554
2555 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2556 which is apparently normally available under Windows.
2557
2558 2. Re-jig the pcregrep tests with different newline settings in an attempt
2559 to make them independent of the local environment's newline setting.
2560
2561 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2562
2563 4. Some of the "internals" tests were previously cut out when the link size
2564 was not 2, because the output contained actual offsets. The recent new
2565 "Z" feature of pcretest means that these can be cut out, making the tests
2566 usable with all link sizes.
2567
2568 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2569 stack recursion. This gives a massive performance boost under BSD, but just
2570 a small improvement under Linux. However, it saves one field in the frame
2571 in all cases.
2572
2573 6. Added more features from the forthcoming Perl 5.10:
2574
2575 (a) (?-n) (where n is a string of digits) is a relative subroutine or
2576 recursion call. It refers to the nth most recently opened parentheses.
2577
2578 (b) (?+n) is also a relative subroutine call; it refers to the nth next
2579 to be opened parentheses.
2580
2581 (c) Conditions that refer to capturing parentheses can be specified
2582 relatively, for example, (?(-2)... or (?(+3)...
2583
2584 (d) \K resets the start of the current match so that everything before
2585 is not part of it.
2586
2587 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2588
2589 (f) \g{name} is another synonym - part of Perl 5.10's unification of
2590 reference syntax.
2591
2592 (g) (?| introduces a group in which the numbering of parentheses in each
2593 alternative starts with the same number.
2594
2595 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2596
2597 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2598 PCRE_INFO_JCHANGED.
2599
2600 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
2601 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2602 for detecting groups that can match an empty string.
2603
2604 9. A pattern with a very large number of alternatives (more than several
2605 hundred) was running out of internal workspace during the pre-compile
2606 phase, where pcre_compile() figures out how much memory will be needed. A
2607 bit of new cunning has reduced the workspace needed for groups with
2608 alternatives. The 1000-alternative test pattern now uses 12 bytes of
2609 workspace instead of running out of the 4096 that are available.
2610
2611 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2612
2613 11. Applied patch from Google to remove an optimization that didn't quite work.
2614 The report of the bug said:
2615
2616 pcrecpp::RE("a*").FullMatch("aaa") matches, while
2617 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2618 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2619
2620 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2621 it matched the wrong number of bytes.
2622
2623
2624 Version 7.1 24-Apr-07
2625 ---------------------
2626
2627 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2628 that is more "standard", making use of automake and other Autotools. There
2629 is some re-arrangement of the files and adjustment of comments consequent
2630 on this.
2631
2632 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2633 for recursive directory scanning broke on some systems because the files
2634 are not scanned in any specific order and on different systems the order
2635 was different. A call to "sort" has been inserted into RunGrepTest for the
2636 approprate test as a short-term fix. In the longer term there may be an
2637 alternative.
2638
2639 3. I had an email from Eric Raymond about problems translating some of PCRE's
2640 man pages to HTML (despite the fact that I distribute HTML pages, some
2641 people do their own conversions for various reasons). The problems
2642 concerned the use of low-level troff macros .br and .in. I have therefore
2643 removed all such uses from the man pages (some were redundant, some could
2644 be replaced by .nf/.fi pairs). The 132html script that I use to generate
2645 HTML has been updated to handle .nf/.fi and to complain if it encounters
2646 .br or .in.
2647
2648 4. Updated comments in configure.ac that get placed in config.h.in and also
2649 arranged for config.h to be included in the distribution, with the name
2650 config.h.generic, for the benefit of those who have to compile without
2651 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2652
2653 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2654 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2655 makevp.bat for the current PCRE, using the additional files
2656 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2657
2658 6. A Windows user reported a minor discrepancy with test 2, which turned out
2659 to be caused by a trailing space on an input line that had got lost in his
2660 copy. The trailing space was an accident, so I've just removed it.
2661
2662 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2663 that is needed.
2664
2665 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2666 as "const" (a) because they are and (b) because it helps the PHP
2667 maintainers who have recently made a script to detect big data structures
2668 in the php code that should be moved to the .rodata section. I remembered
2669 to update Builducptable as well, so it won't revert if ucptable.h is ever
2670 re-created.
2671
2672 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2673 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2674 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2675 support is not required. This saves 1.5-2K of code, which is important in
2676 some applications.
2677
2678 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2679 so as not to refer to the tables, even though these functions will never be
2680 called when UTF-8 support is disabled. Otherwise there are problems with a
2681 shared library.
2682
2683 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2684
2685 (a) It was defining its arguments as char * instead of void *.
2686
2687 (b) It was assuming that all moves were upwards in memory; this was true
2688 a long time ago when I wrote it, but is no longer the case.
2689
2690 The emulated memove() is provided for those environments that have neither
2691 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2692 is clearly not the case, as these two bugs were recently reported.
2693
2694 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2695 and Detrail to create the HTML documentation, the .txt form of the man
2696 pages, and it removes trailing spaces from listed files. It also creates
2697 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2698 case, it wraps all the #defines with #ifndefs. This script should be run
2699 before "make dist".
2700
2701 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2702 with Unicode property support.
2703
2704 (a) For a maximizing quantifier, if the two different cases of the
2705 character were of different lengths in their UTF-8 codings (there are
2706 some cases like this - I found 11), and the matching function had to
2707 back up over a mixture of the two cases, it incorrectly assumed they
2708 were both the same length.
2709
2710 (b) When PCRE was configured to use the heap rather than the stack for
2711 recursion during matching, it was not correctly preserving the data for
2712 the other case of a UTF-8 character when checking ahead for a match
2713 while processing a minimizing repeat. If the check also involved
2714 matching a wide character, but failed, corruption could cause an
2715 erroneous result when trying to check for a repeat of the original
2716 character.
2717
2718 13. Some tidying changes to the testing mechanism:
2719
2720 (a) The RunTest script now detects the internal link size and whether there
2721 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2722 values substituted by "configure". (The RunGrepTest script already did
2723 this for UTF-8.) The configure.ac script no longer substitutes the
2724 relevant variables.
2725
2726 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2727 with length and offset values. This means that the output is different
2728 for different internal link sizes. Test 2 is skipped for link sizes
2729 other than 2 because of this, bypassing the problem. Unfortunately,
2730 there was also a test in test 3 (the locale tests) that used /B and
2731 failed for link sizes other than 2. Rather than cut the whole test out,
2732 I have added a new /Z option to pcretest that replaces the length and
2733 offset values with spaces. This is now used to make test 3 independent
2734 of link size. (Test 2 will be tidied up later.)
2735
2736 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2737 segmentation fault instead of returning the appropriate error message.
2738
2739 15. In multiline mode when the newline sequence was set to "any", the pattern
2740 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2741 This doesn't seem right; it now treats the CRLF combination as the line
2742 ending, and so does not match in that case. It's only a pattern such as ^$
2743 that would hit this one: something like ^ABC$ would have failed after \r
2744 and then tried again after \r\n.
2745
2746 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2747 in an attempt to make files that differ only in their line terminators
2748 compare equal. This works on Linux.
2749
2750 17. Under certain error circumstances pcregrep might try to free random memory
2751 as it exited. This is now fixed, thanks to valgrind.
2752
2753 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2754 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2755 was because its rules for how to advance for /g after matching an empty
2756 string at the end of a line did not allow for this case. They now check for
2757 it specially.
2758
2759 20. pcretest is supposed to handle patterns and data of any length, by
2760 extending its buffers when necessary. It was getting this wrong when the
2761 buffer for a data line had to be extended.
2762
2763 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2764 CRLF as a newline sequence.
2765
2766 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2767 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2768 I have nevertheless tidied it up.
2769
2770 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2771
2772 24. Added a man page for pcre-config.
2773
2774
2775 Version 7.0 19-Dec-06
2776 ---------------------
2777
2778 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2779 moving to gcc 4.1.1.
2780
2781 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2782 sys/time.h, which is documented as needed for this function. It doesn't
2783 seem to matter on Linux, but it showed up on some releases of OS X.
2784
2785 3. It seems that there are systems where bytes whose values are greater than
2786 127 match isprint() in the "C" locale. The "C" locale should be the
2787 default when a C program starts up. In most systems, only ASCII printing
2788 characters match isprint(). This difference caused the output from pcretest
2789 to vary, making some of the tests fail. I have changed pcretest so that:
2790
2791 (a) When it is outputting text in the compiled version of a pattern, bytes
2792 other than 32-126 are always shown as hex escapes.
2793
2794 (b) When it is outputting text that is a matched part of a subject string,
2795 it does the same, unless a different locale has been set for the match
2796 (using the /L modifier). In this case, it uses isprint() to decide.
2797
2798 4. Fixed a major bug that caused incorrect computation of the amount of memory
2799 required for a compiled pattern when options that changed within the
2800 pattern affected the logic of the preliminary scan that determines the
2801 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2802 that the computed length was too small. The symptoms of this bug were
2803 either the PCRE error "internal error: code overflow" from pcre_compile(),
2804 or a glibc crash with a message such as "pcretest: free(): invalid next
2805 size (fast)". Examples of patterns that provoked this bug (shown in
2806 pcretest format) are:
2807
2808 /(?-x: )/x
2809 /(?x)(?-x: \s*#\s*)/
2810 /((?i)[\x{c0}])/8
2811 /(?i:[\x{c0}])/8
2812
2813 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2814 is now done differently.
2815
2816 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2817 wrapper classes; (b) implement a new function in the C++ scanner that is
2818 more efficient than the old way of doing things because it avoids levels of
2819 recursion in the regex matching; (c) add a paragraph to the documentation
2820 for the FullMatch() function.
2821
2822 6. The escape sequence \n was being treated as whatever was defined as
2823 "newline". Not only was this contrary to the documentation, which states
2824 that \n is character 10 (hex 0A), but it also went horribly wrong when
2825 "newline" was defined as CRLF. This has been fixed.
2826
2827 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2828 was being set to -1 for the "end of line" case (supposedly a value that no
2829 character can have). Though this value is never used (the check for end of
2830 line is "zero bytes in current character"), it caused compiler complaints.
2831 I've changed it to 0xffffffff.
2832
2833 8. In pcre_version.c, the version string was being built by a sequence of
2834 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2835 string (as it is for production releases) called a macro with an empty
2836 argument. The C standard says the result of this is undefined. The gcc
2837 compiler treats it as an empty string (which was what was wanted) but it is
2838 reported that Visual C gives an error. The source has been hacked around to
2839 avoid this problem.
2840
2841 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2842 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2843 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2844 of them did).
2845
2846 10. Originally, pcretest opened its input and output without "b"; then I was
2847 told that "b" was needed in some environments, so it was added for release
2848 5.0 to both the input and output. (It makes no difference on Unix-like
2849 systems.) Later I was told that it is wrong for the input on Windows. I've
2850 now abstracted the modes into two macros, to make it easier to fiddle with
2851 them, and removed "b" from the input mode under Windows.
2852
2853 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2854
2855 12. Added -help and --help to pcretest as an official way of being reminded
2856 of the options.
2857
2858 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2859 and pcrecpp.cc because they annoy compilers at high warning levels.
2860
2861 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2862
2863 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2864 scripts are not C programs :-) and which was not noticed because it works
2865 on Linux.
2866
2867 16. pcretest is supposed to handle any length of pattern and data line (as one
2868 line or as a continued sequence of lines) by extending its input buffer if
2869 necessary. This feature was broken for very long pattern lines, leading to
2870 a string of junk being passed to pcre_compile() if the pattern was longer
2871 than about 50K.
2872
2873 17. I have done a major re-factoring of the way pcre_compile() computes the
2874 amount of memory needed for a compiled pattern. Previously, there was code
2875 that made a preliminary scan of the pattern in order to do this. That was
2876 OK when PCRE was new, but as the facilities have expanded, it has become
2877 harder and harder to keep it in step with the real compile phase, and there
2878 have been a number of bugs (see for example, 4 above). I have now found a
2879 cunning way of running the real compile function in a "fake" mode that
2880 enables it to compute how much memory it would need, while actually only
2881 ever using a few hundred bytes of working memory and without too many
2882 tests of the mode. This should make future maintenance and development
2883 easier. A side effect of this work is that the limit of 200 on the nesting
2884 depth of parentheses has been removed (though this was never a serious
2885 limitation, I suspect). However, there is a downside: pcre_compile() now
2886 runs more slowly than before (30% or more, depending on the pattern). I
2887 hope this isn't a big issue. There is no effect on runtime performance.
2888
2889 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2890 newline (only possible for the last line of a file) and it was a
2891 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2892
2893 19. Added additional timing features to pcretest. (1) The -tm option now times
2894 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2895 separate command line item, by a number that specifies the number of
2896 repeats to use when timing. The default is 50000; this gives better
2897 precision, but takes uncomfortably long for very large patterns.
2898
2899 20. Extended pcre_study() to be more clever in cases where a branch of a
2900 subpattern has no definite first character. For example, (a*|b*)[cd] would
2901 previously give no result from pcre_study(). Now it recognizes that the
2902 first character must be a, b, c, or d.
2903
2904 21. There was an incorrect error "recursive call could loop indefinitely" if
2905 a subpattern (or the entire pattern) that was being tested for matching an
2906 empty string contained only one non-empty item after a nested subpattern.
2907 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2908 incorrectly, because the \d was being skipped in the check.
2909
2910 22. The pcretest program now has a new pattern option /B and a command line
2911 option -b, which is equivalent to adding /B to every pattern. This causes
2912 it to show the compiled bytecode, without the additional information that
2913 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2914 is the same as /B/I).
2915
2916 23. A new optimization is now able automatically to treat some sequences such
2917 as a*b as a*+b. More specifically, if something simple (such as a character
2918 or a simple class like \d) has an unlimited quantifier, and is followed by
2919 something that cannot possibly match the quantified thing, the quantifier
2920 is automatically "possessified".
2921
2922 24. A recursive reference to a subpattern whose number was greater than 39
2923 went wrong under certain circumstances in UTF-8 mode. This bug could also
2924 have affected the operation of pcre_study().
2925
2926 25. Realized that a little bit of performance could be had by replacing
2927 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2928
2929 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2930
2931 27. Possessive quantifiers such as a++ were previously implemented by turning
2932 them into atomic groups such as ($>a+). Now they have their own opcodes,
2933 which improves performance. This includes the automatically created ones
2934 from 23 above.
2935
2936 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2937 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2938 the first matched character to be a colon. This applied both to named and
2939 numbered groups.
2940
2941 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2942
2943 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2944 building PCRE on Windows easier, so I have included it in the distribution.
2945
2946 31. There is now a check in pcretest against a ridiculously large number being
2947 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2948 loop, the loop is abandoned.
2949
2950 32. Forward references to subpatterns in conditions such as (?(2)...) where
2951 subpattern 2 is defined later cause pcre_compile() to search forwards in
2952 the pattern for the relevant set of parentheses. This search went wrong
2953 when there were unescaped parentheses in a character class, parentheses
2954 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2955
2956 33. "Subroutine" calls and backreferences were previously restricted to
2957 referencing subpatterns earlier in the regex. This restriction has now
2958 been removed.
2959
2960 34. Added a number of extra features that are going to be in Perl 5.10. On the
2961 whole, these are just syntactic alternatives for features that PCRE had
2962 previously implemented using the Python syntax or my own invention. The
2963 other formats are all retained for compatibility.
2964
2965 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2966 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2967 also .NET compatible.
2968
2969 (b) A recursion or subroutine call to a named group can now be defined as
2970 (?&name) as well as (?P>name).
2971
2972 (c) A backreference to a named group can now be defined as \k<name> or
2973 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2974 5.10, are also .NET compatible.
2975
2976 (d) A conditional reference to a named group can now use the syntax
2977 (?(<name>) or (?('name') as well as (?(name).
2978
2979 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2980 groups (named and numbered) that are never evaluated inline, but can be
2981 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2982 is always false. There may be only one alternative in such a group.
2983
2984 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2985 as the simple (?(R). The condition is true only if the most recent
2986 recursion is that of the given number or name. It does not search out
2987 through the entire recursion stack.
2988
2989 (g) The escape \gN or \g{N} has been added, where N is a positive or
2990 negative number, specifying an absolute or relative reference.
2991
2992 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2993 some "unreachable code" warnings.
2994
2995 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2996 things, this adds five new scripts.
2997
2998 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2999 There were also incompatibilities regarding the handling of \Q..\E inside
3000 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3001 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3002
3003 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3004 matches an empty string, and forcibly breaks the loop. There were bugs in
3005 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3006 against aaaa the result was just "a" rather than "aaaa", for example. Two
3007 separate and independent bugs (that affected different cases) have been
3008 fixed.
3009
3010 39. Refactored the code to abolish the use of different opcodes for small
3011 capturing bracket numbers. This is a tidy that I avoided doing when I
3012 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3013 The new approach is not only tidier, it makes it possible to reduce the
3014 memory needed to fix the previous bug (38).
3015
3016 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3017 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3018 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3019 mode.
3020
3021 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3022 report.
3023
3024 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3025 copy construction and assignment in the C++ wrapper.
3026
3027 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3028 couple of bugs that could have given wrong results in the "--newline=crlf"
3029 case.
3030
3031 44. Added a number of casts and did some reorganization of signed/unsigned int
3032 variables following suggestions from Dair Grant. Also renamed the variable
3033 "this" as "item" because it is a C++ keyword.
3034
3035 45. Arranged for dftables to add
3036
3037 #include "pcre_internal.h"
3038
3039 to pcre_chartables.c because without it, gcc 4.x may remove the array
3040 definition from the final binary if PCRE is built into a static library and
3041 dead code stripping is activated.
3042
3043 46. For an unanchored pattern, if a match attempt fails at the start of a
3044 newline sequence, and the newline setting is CRLF or ANY, and the next two
3045 characters are CRLF, advance by two characters instead of one.
3046
3047
3048 Version 6.7 04-Jul-06
3049 ---------------------
3050
3051 1. In order to handle tests when input lines are enormously long, pcretest has
3052 been re-factored so that it automatically extends its buffers when
3053 necessary. The code is crude, but this _is_ just a test program. The
3054 default size has been increased from 32K to 50K.
3055
3056 2. The code in pcre_study() was using the value of the re argument before
3057 testing it for NULL. (Of course, in any sensible call of the function, it
3058 won't be NULL.)
3059
3060 3. The memmove() emulation function in pcre_internal.h, which is used on
3061 systems that lack both memmove() and bcopy() - that is, hardly ever -
3062 was missing a "static" storage class specifier.
3063
3064 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3065 containing an extended class (one that cannot be represented by a bitmap
3066 because it contains high-valued characters or Unicode property items, e.g.
3067 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3068 pattern, but PCRE should not loop if you do not (it no longer does).
3069 [Detail: two cases were found: (a) a repeated subpattern containing an
3070 extended class; (b) a recursive reference to a subpattern that followed a
3071 previous extended class. It wasn't skipping over the extended class
3072 correctly when UTF-8 mode was not set.]
3073
3074 5. A negated single-character class was not being recognized as fixed-length
3075 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3076 compile error "lookbehind assertion is not fixed length".
3077
3078 6. The RunPerlTest auxiliary script was showing an unexpected difference
3079 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3080 write a Perl script that can interpret lines of an input file either as
3081 byte characters or as UTF-8, which is what "perltest" was being required to
3082 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3083 can't do is switch easily at run time between having the "use utf8;" pragma
3084 or not. In the end, I fudged it by using the RunPerlTest script to insert
3085 "use utf8;" explicitly for the UTF-8 tests.
3086
3087 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3088 the end of the subject string, contrary to the documentation and to what
3089 Perl does. This was true of both matching functions. Now it matches only at
3090 the start of the subject and immediately after *internal* newlines.
3091
3092 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3093 a pointer to an int instead of a pointer to an unsigned long int. This
3094 caused problems on 64-bit systems.
3095
3096 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
3097 instance of the 'standard' template library not being so standard".
3098
3099 10. There was no check on the number of named subpatterns nor the maximum
3100 length of a subpattern name. The product of these values is used to compute
3101 the size of the memory block for a compiled pattern. By supplying a very
3102 long subpattern name and a large number of named subpatterns, the size
3103 computation could be caused to overflow. This is now prevented by limiting
3104 the length of names to 32 characters, and the number of named subpatterns
3105 to 10,000.
3106
3107 11. Subpatterns that are repeated with specific counts have to be replicated in
3108 the compiled pattern. The size of memory for this was computed from the
3109 length of the subpattern and the repeat count. The latter is limited to
3110 65535, but there was no limit on the former, meaning that integer overflow
3111 could in principle occur. The compiled length of a repeated subpattern is
3112 now limited to 30,000 bytes in order to prevent this.
3113
3114 12. Added the optional facility to have named substrings with the same name.
3115
3116 13. Added the ability to use a named substring as a condition, using the
3117 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
3118 are numbers (not recommended). Forward references are permitted.
3119
3120 14. Added forward references in named backreferences (if you see what I mean).
3121
3122 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
3123 pattern could run off the end of the subject. For example, the pattern
3124 "(?s)(.{1,5})"8 did this with the subject "ab".
3125
3126 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
3127 PCRE_CASELESS was set when matching characters that were quantified with ?
3128 or *.
3129
3130 17. A character class other than a single negated character that had a minimum
3131 but no maximum quantifier - for example [ab]{6,} - was not handled
3132 correctly by pce_dfa_exec(). It would match only one character.
3133
3134 18. A valid (though odd) pattern that looked like a POSIX character
3135 class but used an invalid character after [ (for example [[,abc,]]) caused
3136 pcre_compile() to give the error "Failed: internal error: code overflow" or
3137 in some cases to crash with a glibc free() error. This could even happen if
3138 the pattern terminated after [[ but there just happened to be a sequence of
3139 letters, a binary zero, and a closing ] in the memory that followed.
3140
3141 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
3142 over the years. Originally (before any Unicode support), just the bottom 8
3143 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
3144 output from "man perlunicode" includes this:
3145
3146 The regular expression compiler produces polymorphic opcodes. That
3147 is, the pattern adapts to the data and automatically switches to
3148 the Unicode character scheme when presented with Unicode data--or
3149 instead uses a traditional byte scheme when presented with byte
3150 data.
3151
3152 Sadly, a wide octal escape does not cause a switch, and in a string with
3153 no other multibyte characters, these octal escapes are treated as before.
3154 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
3155 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
3156 Unicode string.
3157
3158 I have not perpetrated such confusion in PCRE. Up till now, it took just
3159 the bottom 8 bits, as in old Perl. I have now made octal escapes with
3160 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
3161 translate to the appropriate multibyte character.
3162
3163 29. Applied some refactoring to reduce the number of warnings from Microsoft
3164 and Borland compilers. This has included removing the fudge introduced
3165 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
3166 a warning about an unused variable.
3167
3168 21. PCRE has not included VT (character 0x0b) in the set of whitespace
3169 characters since release 4.0, because Perl (from release 5.004) does not.
3170 [Or at least, is documented not to: some releases seem to be in conflict
3171 with the documentation.] However, when a pattern was studied with
3172 pcre_study() and all its branches started with \s, PCRE still included VT
3173 as a possible starting character. Of course, this did no harm; it just
3174 caused an unnecessary match attempt.
3175
3176 22. Removed a now-redundant internal flag bit that recorded the fact that case
3177 dependency changed within the pattern. This was once needed for "required
3178 byte" processing, but is no longer used. This recovers a now-scarce options
3179 bit. Also moved the least significant internal flag bit to the most-
3180 significant bit of the word, which was not previously used (hangover from
3181 the days when it was an int rather than a uint) to free up another bit for
3182 the future.
3183
3184 23. Added support for CRLF line endings as well as CR and LF. As well as the
3185 default being selectable at build time, it can now be changed at runtime
3186 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
3187 specify that it is scanning data with non-default line endings.
3188
3189 24. Changed the definition of CXXLINK to make it agree with the definition of
3190 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
3191
3192 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
3193 recursions. This makes a big different to stack usage for some patterns.
3194
3195 26. If a subpattern containing a named recursion or subroutine reference such
3196 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
3197 the space required for the compiled pattern went wrong and gave too small a
3198 value. Depending on the environment, this could lead to "Failed: internal
3199 error: code overflow at offset 49" or "glibc detected double free or
3200 corruption" errors.
3201
3202 27. Applied patches from Google (a) to support the new newline modes and (b) to
3203 advance over multibyte UTF-8 characters in GlobalReplace.
3204
3205 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
3206 difference for some implementation of PCRE in some Windows version.
3207
3208 29. Added some extra testing facilities to pcretest:
3209
3210 \q<number> in a data line sets the "match limit" value
3211 \Q<number> in a data line sets the "match recursion limt" value
3212 -S <number> sets the stack size, where <number> is in megabytes
3213
3214 The -S option isn't available for Windows.
3215
3216
3217 Version 6.6 06-Feb-06
3218 ---------------------
3219
3220 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
3221 in pcreposix.h. I have copied the definition from pcre.h.
3222
3223 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
3224 because pcre.h is no longer a built file.
3225
3226 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
3227 not normally included in the compiled code.
3228
3229
3230 Version 6.5 01-Feb-06
3231 ---------------------
3232
3233 1. When using the partial match feature with pcre_dfa_exec(), it was not
3234 anchoring the second and subsequent partial matches at the new starting
3235 point. This could lead to incorrect results. For example, with the pattern
3236 /1234/, partially matching against "123" and then "a4" gave a match.
3237
3238 2. Changes to pcregrep:
3239
3240 (a) All non-match returns from pcre_exec() were being treated as failures
3241 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
3242 error message is output. Some extra information is given for the
3243 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
3244 probably the only errors that are likely to be caused by users (by
3245 specifying a regex that has nested indefinite repeats, for instance).
3246 If there are more than 20 of these errors, pcregrep is abandoned.
3247
3248 (b) A binary zero was treated as data while matching, but terminated the
3249 output line if it was written out. This has been fixed: binary zeroes
3250 are now no different to any other data bytes.
3251
3252 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
3253 used to set a locale for matching. The --locale=xxxx long option has
3254 been added (no short equivalent) to specify a locale explicitly on the
3255 pcregrep command, overriding the environment variables.
3256
3257 (d) When -B was used with -n, some line numbers in the output were one less
3258 than they should have been.
3259
3260 (e) Added the -o (--only-matching) option.
3261
3262 (f) If -A or -C was used with -c (count only), some lines of context were
3263 accidentally printed for the final match.
3264
3265 (g) Added the -H (--with-filename) option.
3266
3267 (h) The combination of options -rh failed to suppress file names for files
3268 that were found from directory arguments.
3269
3270 (i) Added the -D (--devices) and -d (--directories) options.
3271
3272 (j) Added the -F (--fixed-strings) option.
3273
3274 (k) Allow "-" to be used as a file name for -f as well as for a data file.
3275
3276 (l) Added the --colo(u)r option.
3277
3278 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
3279 is not present by default.
3280
3281 3. A nasty bug was discovered in the handling of recursive patterns, that is,
3282 items such as (?R) or (?1), when the recursion could match a number of
3283 alternatives. If it matched one of the alternatives, but subsequently,
3284 outside the recursion, there was a failure, the code tried to back up into
3285 the recursion. However, because of the way PCRE is implemented, this is not
3286 possible, and the result was an incorrect result from the match.
3287
3288 In order to prevent this happening, the specification of recursion has
3289 been changed so that all such subpatterns are automatically treated as
3290 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
3291
3292 4. I had overlooked the fact that, in some locales, there are characters for
3293 which isalpha() is true but neither isupper() nor islower() are true. In
3294 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
3295 and ordfeminine) are like this. This affected the treatment of \w and \W
3296 when they appeared in character classes, but not when they appeared outside
3297 a character class. The bit map for "word" characters is now created
3298 separately from the results of isalnum() instead of just taking it from the
3299 upper, lower, and digit maps. (Plus the underscore character, of course.)
3300
3301 5. The above bug also affected the handling of POSIX character classes such as
3302 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
3303 permanent tables. Instead, the bit maps for such a class were previously
3304 created as the appropriate unions of the upper, lower, and digit bitmaps.
3305 Now they are created by subtraction from the [[:word:]] class, which has
3306 its own bitmap.
3307
3308 6. The [[:blank:]] character class matches horizontal, but not vertical space.
3309 It is created by subtracting the vertical space characters (\x09, \x0a,
3310 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
3311 subtraction was done in the overall bitmap for a character class, meaning
3312 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
3313 be recognized. This bug has been fixed.
3314
3315 7. Patches from the folks at Google:
3316
3317 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
3318 real life, but is still worth protecting against".
3319
3320 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
3321 regular expressions".
3322
3323 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
3324 have it.
3325
3326 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
3327 "configure" and the latter not, in order to fix a problem somebody had
3328 with compiling the Arg class on HP-UX.
3329
3330 (e) Improve the error-handling of the C++ wrapper a little bit.
3331
3332 (f) New tests for checking recursion limiting.
3333
3334 8. The pcre_memmove() function, which is used only if the environment does not
3335 have a standard memmove() function (and is therefore rarely compiled),
3336 contained two bugs: (a) use of int instead of size_t, and (b) it was not
3337 returning a result (though PCRE never actually uses the result).
3338
3339 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
3340 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
3341 returned instead of calling malloc() with an overflowing number that would
3342 most likely cause subsequent chaos.
3343
3344 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
3345
3346 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
3347 with this option is matched, the nmatch and pmatch options of regexec() are
3348 ignored.
3349
3350 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
3351 provided in case anyone wants to the the POSIX interface with UTF-8
3352 strings.
3353
3354 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
3355 C++ linking (needed for some HP-UX environments).
3356
3357 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
3358 (unused parameter) and in the pcre_printint() function (omitted "default"
3359 switch label when the default is to do nothing).
3360
3361 15. Added some code to make it possible, when PCRE is compiled as a C++
3362 library, to replace subject pointers for pcre_exec() with a smart pointer
3363 class, thus making it possible to process discontinuous strings.
3364
3365 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
3366 much the same function. They were added by different people who were trying
3367 to make PCRE easy to compile on non-Unix systems. It has been suggested
3368 that PCRE_EXPORT be abolished now that there is more automatic apparatus
3369 for compiling on Windows systems. I have therefore replaced it with
3370 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
3371 defaults to "extern" for C or "extern C" for C++, which works fine on
3372 Unix-like systems. It is now possible to override the value of PCRE_DATA_
3373 SCOPE with something explicit in config.h. In addition:
3374
3375 (a) pcreposix.h still had just "extern" instead of either of these macros;
3376 I have replaced it with PCRE_DATA_SCOPE.
3377
3378 (b) Functions such as _pcre_xclass(), which are internal to the library,
3379 but external in the C sense, all had PCRE_EXPORT in their definitions.
3380 This is apparently wrong for the Windows case, so I have removed it.
3381 (It makes no difference on Unix-like systems.)
3382
3383 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3384 of recursive calls to match(). This is different to MATCH_LIMIT because
3385 that limits the total number of calls to match(), not all of which increase
3386 the depth of recursion. Limiting the recursion depth limits the amount of
3387 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3388 when PCRE is compiled, and changed at run time. A patch from Google adds
3389 this functionality to the C++ interface.
3390
3391 18. Changes to the handling of Unicode character properties:
3392
3393 (a) Updated the table to Unicode 4.1.0.
3394
3395 (b) Recognize characters that are not in the table as "Cn" (undefined).
3396
3397 (c) I revised the way the table is implemented to a much improved format
3398 which includes recognition of ranges. It now supports the ranges that
3399 are defined in UnicodeData.txt, and it also amalgamates other
3400 characters into ranges. This has reduced the number of entries in the
3401 table from around 16,000 to around 3,000, thus reducing its size
3402 considerably. I realized I did not need to use a tree structure after
3403 all - a binary chop search is just as efficient. Having reduced the
3404 number of entries, I extended their size from 6 bytes to 8 bytes to
3405 allow for more data.
3406
3407 (d) Added support for Unicode script names via properties such as \p{Han}.
3408
3409 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3410 matching that character.
3411
3412 20. When matching a repeated Unicode property with a minimum greater than zero,
3413 (for example \pL{2,}), PCRE could look past the end of the subject if it
3414 reached it while seeking the minimum number of characters. This could
3415 happen only if some of the characters were more than one byte long, because
3416 there is a check for at least the minimum number of bytes.
3417
3418 21. Refactored the implementation of \p and \P so as to be more general, to
3419 allow for more different types of property in future. This has changed the
3420 compiled form incompatibly. Anybody with saved compiled patterns that use
3421 \p or \P will have to recompile them.
3422
3423 22. Added "Any" and "L&" to the supported property types.
3424
3425 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3426 but give a compile time error if the value is greater than 0xff.
3427
3428 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3429 accidentally not being installed or uninstalled.
3430
3431 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3432 made were to insert the current release number. This seemed silly, because
3433 it made things harder for people building PCRE on systems that don't run
3434 "configure". I have turned pcre.h into a distributed file, no longer built
3435 by "configure", with the version identification directly included. There is
3436 no longer a pcre.h.in file.
3437
3438 However, this change necessitated a change to the pcre-config script as
3439 well. It is built from pcre-config.in, and one of the substitutions was the
3440 release number. I have updated configure.ac so that ./configure now finds
3441 the release number by grepping pcre.h.
3442
3443 26. Added the ability to run the tests under valgrind.
3444
3445
3446 Version 6.4 05-Sep-05
3447 ---------------------
3448
3449 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3450 "--" to be printed when multiple files were scanned, even when none of the
3451 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3452 consider it to be a bug, and have restored the previous behaviour.
3453
3454 2. A couple of code tidies to get rid of compiler warnings.
3455
3456 3. The pcretest program used to cheat by referring to symbols in the library
3457 whose names begin with _pcre_. These are internal symbols that are not
3458 really supposed to be visible externally, and in some environments it is
3459 possible to suppress them. The cheating is now confined to including
3460 certain files from the library's source, which is a bit cleaner.
3461
3462 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
3463 file's purpose clearer.
3464
3465 5. Reorganized pcre_ucp_findchar().
3466
3467
3468 Version 6.3 15-Aug-05
3469 ---------------------
3470
3471 1. The file libpcre.pc.in did not have general read permission in the tarball.
3472
3473 2. There were some problems when building without C++ support:
3474
3475 (a) If C++ support was not built, "make install" and "make test" still
3476 tried to test it.
3477
3478 (b) There were problems when the value of CXX was explicitly set. Some
3479 changes have been made to try to fix these, and ...
3480
3481 (c) --disable-cpp can now be used to explicitly disable C++ support.
3482
3483 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
3484 backslash in a target when C++ was disabled. This confuses some
3485 versions of "make", apparently. Using an intermediate variable solves
3486 this. (Same for CPP_LOBJ.)
3487
3488 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
3489 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
3490 necessary on certain architectures.
3491
3492 4. Added a setting of -export-symbols-regex to the link command to remove
3493 those symbols that are exported in the C sense, but actually are local
3494 within the library, and not documented. Their names all begin with
3495 "_pcre_". This is not a perfect job, because (a) we have to except some
3496 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
3497 available (and never for static libraries). I have made a note to try to
3498 find a way round (a) in the future.
3499
3500
3501 Version 6.2 01-Aug-05
3502 ---------------------
3503
3504 1. There was no test for integer overflow of quantifier values. A construction
3505 such as {1111111111111111} would give undefined results. What is worse, if
3506 a minimum quantifier for a parenthesized subpattern overflowed and became
3507 negative, the calculation of the memory size went wrong. This could have
3508 led to memory overwriting.
3509
3510 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
3511
3512 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
3513 operating environments where this matters.
3514
3515 4. Applied Giuseppe Maxia's patch to add additional features for controlling
3516 PCRE options from within the C++ wrapper.
3517
3518 5. Named capturing subpatterns were not being correctly counted when a pattern
3519 was compiled. This caused two problems: (a) If there were more than 100
3520 such subpatterns, the calculation of the memory needed for the whole
3521 compiled pattern went wrong, leading to an overflow error. (b) Numerical
3522 back references of the form \12, where the number was greater than 9, were
3523 not recognized as back references, even though there were sufficient
3524 previous subpatterns.
3525
3526 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
3527 versions of gcc, e.g. 2.95.4.
3528
3529
3530 Version 6.1 21-Jun-05
3531 ---------------------
3532
3533 1. There was one reference to the variable "posix" in pcretest.c that was not
3534 surrounded by "#if !defined NOPOSIX".
3535
3536 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
3537 the cross-check on the old pcre_info() function, for the benefit of the
3538 cut-down version of PCRE that is currently imported into Exim.
3539
3540 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
3541 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
3542 patterns that start (?i) but I don't think that matters. The use of (?i) is
3543 just an example; this all applies to the other options as well.
3544
3545 4. Since libtool seems to echo the compile commands it is issuing, the output
3546 from "make" can be reduced a bit by putting "@" in front of each libtool
3547 compile command.
3548
3549 5. Patch from the folks at Google for configure.in to be a bit more thorough
3550 in checking for a suitable C++ installation before trying to compile the
3551 C++ stuff. This should fix a reported problem when a compiler was present,
3552 but no suitable headers.
3553
3554 6. The man pages all had just "PCRE" as their title. I have changed them to
3555 be the relevant file name. I have also arranged that these names are
3556 retained in the file doc/pcre.txt, which is a concatenation in text format
3557 of all the man pages except the little individual ones for each function.
3558
3559 7. The NON-UNIX-USE file had not been updated for the different set of source
3560 files that come with release 6. I also added a few comments about the C++
3561 wrapper.
3562
3563
3564 Version 6.0 07-Jun-05
3565 ---------------------
3566
3567 1. Some minor internal re-organization to help with my DFA experiments.
3568
3569 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3570 didn't matter for the library itself when fully configured, but did matter
3571 when compiling without UCP support, or within Exim, where the ucp files are
3572 not imported.
3573
3574 3. Refactoring of the library code to split up the various functions into
3575 different source modules. The addition of the new DFA matching code (see
3576 below) to a single monolithic source would have made it really too
3577 unwieldy, quite apart from causing all the code to be include in a
3578 statically linked application, when only some functions are used. This is
3579 relevant even without the DFA addition now that patterns can be compiled in
3580 one application and matched in another.
3581
3582 The downside of splitting up is that there have to be some external
3583 functions and data tables that are used internally in different modules of
3584 the library but which are not part of the API. These have all had their
3585 names changed to start with "_pcre_" so that they are unlikely to clash
3586 with other external names.
3587
3588 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3589 a different (DFA) algorithm. Although it is slower than the original
3590 function, it does have some advantages for certain types of matching
3591 problem.
3592
3593 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3594 including restarting after a partial match.
3595
3596 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3597 defined when compiling for Windows was sent to me. I have put it into the
3598 code, though I have no means of testing or verifying it.
3599
3600 7. Added the pcre_refcount() auxiliary function.
3601
3602 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3603 match before or at the first newline in the subject string. In pcretest,
3604 the /f option on a pattern can be used to set this.
3605
3606 9. A repeated \w when used in UTF-8 mode with characters greater than 256
3607 would behave wrongly. This has been present in PCRE since release 4.0.
3608
3609 10. A number of changes to the pcregrep command:
3610
3611 (a) Refactored how -x works; insert ^(...)$ instead of setting
3612 PCRE_ANCHORED and checking the length, in preparation for adding
3613 something similar for -w.
3614
3615 (b) Added the -w (match as a word) option.
3616
3617 (c) Refactored the way lines are read and buffered so as to have more
3618 than one at a time available.
3619
3620 (d) Implemented a pcregrep test script.
3621
3622 (e) Added the -M (multiline match) option. This allows patterns to match
3623 over several lines of the subject. The buffering ensures that at least
3624 8K, or the rest of the document (whichever is the shorter) is available
3625 for matching (and similarly the previous 8K for lookbehind assertions).
3626
3627 (f) Changed the --help output so that it now says
3628
3629 -w, --word-regex(p)
3630
3631 instead of two lines, one with "regex" and the other with "regexp"
3632 because that confused at least one person since the short forms are the
3633 same. (This required a bit of code, as the output is generated
3634 automatically from a table. It wasn't just a text change.)
3635
3636 (g) -- can be used to terminate pcregrep options if the next thing isn't an
3637 option but starts with a hyphen. Could be a pattern or a path name
3638 starting with a hyphen, for instance.
3639
3640 (h) "-" can be given as a file name to represent stdin.
3641
3642 (i) When file names are being printed, "(standard input)" is used for
3643 the standard input, for compatibility with GNU grep. Previously
3644 "<stdin>" was used.
3645
3646 (j) The option --label=xxx can be used to supply a name to be used for
3647 stdin when file names are being printed. There is no short form.
3648
3649 (k) Re-factored the options decoding logic because we are going to add
3650 two more options that take data. Such options can now be given in four
3651 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3652
3653 (l) Added the -A, -B, and -C options for requesting that lines of context
3654 around matches be printed.
3655
3656 (m) Added the -L option to print the names of files that do not contain
3657 any matching lines, that is, the complement of -l.
3658
3659 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3660 continue to scan other files.
3661
3662 (o) The -s option was incorrectly implemented. For compatibility with other
3663 greps, it now suppresses the error message for a non-existent or non-
3664 accessible file (but not the return code). There is a new option called
3665 -q that suppresses the output of matching lines, which was what -s was
3666 previously doing.
3667
3668 (p) Added --include and --exclude options to specify files for inclusion
3669 and exclusion when recursing.
3670
3671 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3672 Hopefully, it now does.
3673
3674 12. Missing cast in pcre_study().
3675
3676 13. Added an "uninstall" target to the makefile.
3677
3678 14. Replaced "extern" in the function prototypes in Makefile.in with
3679 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3680 world, but is set differently for Windows.
3681
3682 15. Added a second compiling function called pcre_compile2(). The only
3683 difference is that it has an extra argument, which is a pointer to an
3684 integer error code. When there is a compile-time failure, this is set
3685 non-zero, in addition to the error test pointer being set to point to an
3686 error message. The new argument may be NULL if no error number is required
3687 (but then you may as well call pcre_compile(), which is now just a
3688 wrapper). This facility is provided because some applications need a
3689 numeric error indication, but it has also enabled me to tidy up the way
3690 compile-time errors are handled in the POSIX wrapper.
3691
3692 16. Added VPATH=.libs to the makefile; this should help when building with one
3693 prefix path and installing with another. (Or so I'm told by someone who
3694 knows more about this stuff than I do.)
3695
3696 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3697 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3698 match everything, including newlines. This is not POSIX-compatible, but
3699 somebody wanted the feature. From pcretest it can be activated by using
3700 both the P and the s flags.
3701
3702 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3703
3704 19. libpcre.pc was being incorrectly installed as executable.
3705
3706 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3707 it now also looks for '\r' so that it will work unmodified on Windows.
3708
3709 21. Added Google's contributed C++ wrapper to the distribution.
3710
3711 22. Added some untidy missing memory free() calls in pcretest, to keep
3712 Electric Fence happy when testing.
3713
3714
3715
3716 Version 5.0 13-Sep-04
3717 ---------------------
3718
3719 1. Internal change: literal characters are no longer packed up into items
3720 containing multiple characters in a single byte-string. Each character
3721 is now matched using a separate opcode. However, there may be more than one
3722 byte in the character in UTF-8 mode.
3723
3724 2. The pcre_callout_block structure has two new fields: pattern_position and
3725 next_item_length. These contain the offset in the pattern to the next match
3726 item, and its length, respectively.
3727
3728 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3729 insertion of callouts before each pattern item. Added the /C option to
3730 pcretest to make use of this.
3731
3732 4. On the advice of a Windows user, the lines
3733
3734 #if defined(_WIN32) || defined(WIN32)
3735 _setmode( _fileno( stdout ), 0x8000 );
3736 #endif /* defined(_WIN32) || defined(WIN32) */
3737
3738 have been added to the source of pcretest. This apparently does useful
3739 magic in relation to line terminators.
3740
3741 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3742 for the benefit of those environments where the "b" makes a difference.
3743
3744 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3745 to know about it. I have put a hack into configure.in that adds in code
3746 to set GCC=yes if CC=icc. This seems to end up at a point in the
3747 generated configure script that is early enough to affect the setting of
3748 compiler options, which is what is needed, but I have no means of testing
3749 whether it really works. (The user who reported this had patched the
3750 generated configure script, which of course I cannot do.)
3751
3752 LATER: After change 22 below (new libtool files), the configure script
3753 seems to know about icc (and also ecc). Therefore, I have commented out
3754 this hack in configure.in.
3755
3756 7. Added support for pkg-config (2 patches were sent in).
3757
3758 8. Negated POSIX character classes that used a combination of internal tables
3759 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3760 [[:^ascii]]. Typically, they would match almost any characters. The other
3761 POSIX classes were not broken in this way.
3762
3763 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3764 to find the match, as PCRE was deluded into thinking that the match had to
3765 start at the start point or following a newline. The same bug applied to
3766 patterns with negative forward assertions or any backward assertions
3767 preceding ".*" at the start, unless the pattern required a fixed first
3768 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3769
3770 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3771 starting at the last subject character, bytes beyond the end of the subject
3772 string were read.
3773
3774 11. Renamed the variable "class" as "classbits" to make life easier for C++
3775 users. (Previously there was a macro definition, but it apparently wasn't
3776 enough.)
3777
3778 12. Added the new field "tables" to the extra data so that tables can be passed
3779 in at exec time, or the internal tables can be re-selected. This allows
3780 a compiled regex to be saved and re-used at a later time by a different
3781 program that might have everything at different addresses.
3782
3783 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3784 -R library as well as a -L library.
3785
3786 14. The debugging options of pcretest (-d on the command line or D on a
3787 pattern) showed incorrect output for anything following an extended class
3788 that contained multibyte characters and which was followed by a quantifier.
3789
3790 15. Added optional support for general category Unicode character properties
3791 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3792 support. It adds about 90K to the size of the library. The meanings of the
3793 inbuilt class escapes such as \d and \s have NOT been changed.
3794
3795 16. Updated pcredemo.c to include calls to free() to release the memory for the
3796 compiled pattern.
3797
3798 17. The generated file chartables.c was being created in the source directory
3799 instead of in the building directory. This caused the build to fail if the
3800 source directory was different from the building directory, and was
3801 read-only.
3802
3803 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3804 file. No doubt somebody will tell me if they don't make sense... Also added
3805 Dan Mooney's comments about building on OpenVMS.
3806
3807 19. Added support for partial matching via the PCRE_PARTIAL option for
3808 pcre_exec() and the \P data escape in pcretest.
3809
3810 20. Extended pcretest with 3 new pattern features:
3811
3812 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3813 write the compiled pattern to the file whose name is "rest-of-line".
3814 This is a straight binary dump of the data, with the saved pointer to
3815 the character tables forced to be NULL. The study data, if any, is
3816 written too. After writing, pcretest reads a new pattern.
3817
3818 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3819 compiled pattern from the given file. There must not be any
3820 occurrences of "<" in the file name (pretty unlikely); if there are,
3821 pcretest will instead treat the initial "<" as a pattern delimiter.
3822 After reading in the pattern, pcretest goes on to read data lines as
3823 usual.
3824
3825 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3826 and 16-bit fields in a compiled pattern, to simulate a pattern that
3827 was compiled on a host of opposite endianness.
3828
3829 21. The pcre-exec() function can now cope with patterns that were compiled on
3830 hosts of opposite endianness, with this restriction:
3831
3832 As for any compiled expression that is saved and used later, the tables
3833 pointer field cannot be preserved; the extra_data field in the arguments
3834 to pcre_exec() should be used to pass in a tables address if a value
3835 other than the default internal tables were used at compile time.
3836
3837 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3838 now diagnosed as an error. Previously, most of the time, a negative number
3839 would have been treated as zero, but if in addition "ovector" was passed as
3840 NULL, a crash could occur.
3841
3842 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3843 new versions from the libtool 1.5 distribution (the last one is a copy of
3844 a file called libtool.m4). This seems to have fixed the need to patch
3845 "configure" to support Darwin 1.3 (which I used to do). However, I still
3846 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3847 workstation).
3848
3849 24. Changed the PCRE licence to be the more standard "BSD" licence.
3850
3851
3852 Version 4.5 01-Dec-03
3853 ---------------------
3854
3855 1. There has been some re-arrangement of the code for the match() function so
3856 that it can be compiled in a version that does not call itself recursively.
3857 Instead, it keeps those local variables that need separate instances for
3858 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3859 needs to "recurse". Keeping track of where control must go is done by means
3860 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3861 hide most of the details from the main code, and operates only if
3862 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3863 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3864 operating.
3865
3866 To make it easier for callers to provide specially tailored get/free
3867 functions for this usage, two new functions, pcre_stack_malloc, and
3868 pcre_stack_free, are used. They are always called in strict stacking order,
3869 and the size of block requested is always the same.
3870
3871 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3872 PCRE has been compiled to use the stack or the heap for recursion. The
3873 -C option of pcretest uses this to show which version is compiled.
3874
3875 A new data escape \S, is added to pcretest; it causes the amounts of store
3876 obtained and freed by both kinds of malloc/free at match time to be added
3877 to the output.
3878
3879 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3880 what's available on my current Linux desktop machine.
3881
3882 3. When matching a UTF-8 string, the test for a valid string at the start has
3883 been extended. If start_offset is not zero, PCRE now checks that it points
3884 to a byte that is the start of a UTF-8 character. If not, it returns
3885 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3886 this is necessary because there may be backward assertions in the pattern.
3887 When matching the same subject several times, it may save resources to use
3888 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3889
3890 4. The code for checking the validity of UTF-8 strings has been tightened so
3891 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3892 containing "overlong sequences".
3893
3894 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3895 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3896 should have been "&", but it just so happened that all the cases this let
3897 through by mistake were picked up later in the function.
3898
3899 6. I had used a variable called "isblank" - this is a C99 function, causing
3900 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3901
3902 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3903 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3904 so the version is shown; (c) stop "make test" echoing "./RunTest".
3905
3906 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3907
3908 9. The prototype for memmove() for systems that don't have it was using
3909 size_t, but the inclusion of the header that defines size_t was later. I've
3910 moved the #includes for the C headers earlier to avoid this.
3911
3912 10. Added some adjustments to the code to make it easier to compiler on certain
3913 special systems:
3914
3915 (a) Some "const" qualifiers were missing.
3916 (b) Added the macro EXPORT before all exported functions; by default this
3917 is defined to be empty.
3918 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3919 that it reads its output file name as an argument instead of writing
3920 to the standard output and assuming this can be redirected.
3921
3922 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3923 class containing characters with values greater than 255, PCRE compilation
3924 went into a loop.
3925
3926 12. A recursive reference to a subpattern that was within another subpattern
3927 that had a minimum quantifier of zero caused PCRE to crash. For example,
3928 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3929 recursion. If the recursively-called subpattern itself had a zero repeat,
3930 that was OK.
3931
3932 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3933 buffer into which it was copied (for escape processing) was still set at
3934 1024, so long lines caused crashes.
3935
3936 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3937 "internal error: code overflow...". This applied to any character class
3938 that was followed by a possessive quantifier.
3939
3940 15. Modified the Makefile to add libpcre.la as a prerequisite for
3941 libpcreposix.la because I was told this is needed for a parallel build to
3942 work.
3943
3944 16. If a pattern that contained .* following optional items at the start was
3945 studied, the wrong optimizing data was generated, leading to matching
3946 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3947 matching string must start with a or b or c. The correct conclusion for
3948 this pattern is that a match can start with any character.
3949
3950
3951 Version 4.4 13-Aug-03
3952 ---------------------
3953
3954 1. In UTF-8 mode, a character class containing characters with values between
3955 127 and 255 was not handled correctly if the compiled pattern was studied.
3956 In fixing this, I have also improved the studying algorithm for such
3957 classes (slightly).
3958
3959 2. Three internal functions had redundant arguments passed to them. Removal
3960 might give a very teeny performance improvement.
3961
3962 3. Documentation bug: the value of the capture_top field in a callout is *one
3963 more than* the number of the hightest numbered captured substring.
3964
3965 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3966 in incorrectly linking with a previously installed version. They now link
3967 explicitly with libpcre.la.
3968
3969 5. configure.in no longer needs to recognize Cygwin specially.
3970
3971 6. A problem in pcre.in for Windows platforms is fixed.
3972
3973 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3974 pcretest, it used to include the size of the study block as part of its
3975 output. Unfortunately, the structure contains a field that has a different
3976 size on different hardware architectures. This meant that the tests that
3977 showed this size failed. As the block is currently always of a fixed size,
3978 this information isn't actually particularly useful in pcretest output, so
3979 I have just removed it.
3980
3981 8. Three pre-processor statements accidentally did not start in column 1.
3982 Sadly, there are *still* compilers around that complain, even though
3983 standard C has not required this for well over a decade. Sigh.
3984
3985 9. In pcretest, the code for checking callouts passed small integers in the
3986 callout_data field, which is a void * field. However, some picky compilers
3987 complained about the casts involved for this on 64-bit systems. Now
3988 pcretest passes the address of the small integer instead, which should get
3989 rid of the warnings.
3990
3991 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3992 both compile and run time, and gives an error if an invalid UTF-8 sequence
3993 is found. There is a option for disabling this check in cases where the
3994 string is known to be correct and/or the maximum performance is wanted.
3995
3996 11. In response to a bug report, I changed one line in Makefile.in from
3997
3998 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3999 to
4000 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4001
4002 to look similar to other lines, but I have no way of telling whether this
4003 is the right thing to do, as I do not use Windows. No doubt I'll get told
4004 if it's wrong...
4005
4006
4007 Version 4.3 21-May-03
4008 ---------------------
4009
4010 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4011 Makefile.
4012
4013 2. Some refactoring to improve the quality of the code:
4014
4015 (i) The utf8_table... variables are now declared "const".
4016
4017 (ii) The code for \cx, which used the "case flipping" table to upper case
4018 lower case letters, now just substracts 32. This is ASCII-specific,
4019 but the whole concept of \cx is ASCII-specific, so it seems
4020 reasonable.
4021
4022 (iii) PCRE was using its character types table to recognize decimal and
4023 hexadecimal digits in the pattern. This is silly, because it handles
4024 only 0-9, a-f, and A-F, but the character types table is locale-
4025 specific, which means strange things might happen. A private
4026 table is now used for this - though it costs 256 bytes, a table is
4027 much faster than multiple explicit tests. Of course, the standard
4028 character types table is still used for matching digits in subject
4029 strings against \d.
4030
4031 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4032 ending in _t are). So I've renamed it as ESC_tee.
4033
4034 3. The first argument for regexec() in the POSIX wrapper should have been
4035 defined as "const".
4036
4037 4. Changed pcretest to use malloc() for its buffers so that they can be
4038 Electric Fenced for debugging.
4039
4040 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4041 to read one or more bytes before the start of the subject string. Often this
4042 had no effect on PCRE's behaviour, but in some circumstances it could
4043 provoke a segmentation fault.
4044
4045 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4046 to try to read one or more bytes before the start of the subject string.
4047
4048 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4049 UTF-8 support could misbehave in various ways if the subject string
4050 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4051 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4052 back over UTF-8 characters.)
4053
4054
4055 Version 4.2 14-Apr-03
4056 ---------------------
4057
4058 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4059
4060 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4061 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4062 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4063 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4064 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4065 and BUILD_EXEEXT
4066 Note: automatic setting of the BUILD variables is not yet working
4067 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4068 compile-time but not at link-time
4069 [LINK]: use for linking executables only
4070 make different versions for Windows and non-Windows
4071 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4072 libraries
4073 [LINK_FOR_BUILD]: new variable
4074 [OBJEXT]: use throughout
4075 [EXEEXT]: use throughout
4076 <winshared>: new target
4077 <wininstall>: new target
4078 <dftables.o>: use native compiler
4079 <dftables>: use native linker
4080 <install>: handle Windows platform correctly
4081 <clean>: ditto
4082 <check>: ditto
4083 copy DLL to top builddir before testing
4084
4085 As part of these changes, -no-undefined was removed again. This was reported
4086 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4087 in any case.
4088
4089 3. Some tidies to get rid of compiler warnings:
4090
4091 . In the match_data structure, match_limit was an unsigned long int, whereas
4092 match_call_count was an int. I've made them both unsigned long ints.
4093
4094 . In pcretest the fact that a const uschar * doesn't automatically cast to
4095 a void * provoked a warning.
4096
4097 . Turning on some more compiler warnings threw up some "shadow" variables
4098 and a few more missing casts.
4099
4100 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
4101 option, a class that contained a single character with a value between 128
4102 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
4103
4104 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
4105 option, a class that contained several characters, but with at least one
4106 whose value was between 128 and 255 caused PCRE to crash.
4107
4108
4109 Version 4.1 12-Mar-03
4110 ---------------------
4111
4112 1. Compiling with gcc -pedantic found a couple of places where casts were
4113 needed, and a string in dftables.c that was longer than standard compilers are
4114 required to support.
4115
4116 2. Compiling with Sun's compiler found a few more places where the code could
4117 be tidied up in order to avoid warnings.
4118
4119 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
4120 first of these names is deprecated in the latest Autoconf in favour of the name
4121 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
4122 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
4123 analogy I have changed it to CFLAGS_FOR_BUILD.
4124
4125 4. Added -no-undefined to the linking command in the Makefile, because this is
4126 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
4127 linking step for the pcreposix library.
4128
4129 5. PCRE was failing to diagnose the case of two named groups with the same
4130 name.
4131
4132 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
4133 literal character that is needed in the subject for a match, and scans along to
4134 ensure that it is present before embarking on the full matching process. This
4135 saves time in cases of nested unlimited repeats that are never going to match.
4136 Problem: the scan can take a lot of time if the subject is very long (e.g.
4137 megabytes), thus penalizing straightforward matches. It is now done only if the
4138 amount of subject to be scanned is less than 1000 bytes.
4139
4140 7. A lesser problem with the same optimization is that it was recording the
4141 first character of an anchored pattern as "needed", thus provoking a search
4142 right along the subject, even when the first match of the pattern was going to
4143 fail. The "needed" character is now not set for anchored patterns, unless it
4144 follows something in the pattern that is of non-fixed length. Thus, it still
4145 fulfils its original purpose of finding quick non-matches in cases of nested
4146 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
4147
4148
4149 Version 4.0 17-Feb-03
4150 ---------------------
4151
4152 1. If a comment in an extended regex that started immediately after a meta-item
4153 extended to the end of string, PCRE compiled incorrect data. This could lead to
4154 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
4155
4156 2. Moved to autoconf 2.53 and libtool 1.4.2.
4157
4158 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
4159 the special perltest8 script is no longer needed - all the tests can be run
4160 from a single perltest script.
4161
4162 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
4163 by \s. It has now been removed in PCRE. This means it isn't recognized as
4164 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
4165 class [:space:] *does* include VT, thereby creating a mess.
4166
4167 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
4168 space and tab.
4169
4170 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
4171 its new features into the main test script, reducing the number of scripts.
4172
4173 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
4174 were backward compatible, and made the (?i) apply to the whole pattern, as if
4175 /i were given. Now it behaves more logically, and applies the option setting
4176 only to what follows. PCRE has been changed to follow suit. However, if it
4177 finds options settings right at the start of the pattern, it extracts them into
4178 the global options, as before. Thus, they show up in the info data.
4179
4180 8. Added support for the \Q...\E escape sequence. Characters in between are
4181 treated as literals. This is slightly different from Perl in that $ and @ are
4182 also handled as literals inside the quotes. In Perl, they will cause variable
4183 interpolation. Note the following examples:
4184
4185 Pattern PCRE matches Perl matches
4186
4187 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
4188 \Qabc\$xyz\E abc\$xyz abc\$xyz
4189 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
4190
4191 For compatibility with Perl, \Q...\E sequences are recognized inside character
4192 classes as well as outside them.
4193
4194 9. Re-organized 3 code statements in pcretest to avoid "overflow in
4195 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
4196 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
4197 signed/unsigned warnings.
4198
4199 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
4200 option for pcretest, so I've replaced it by a simple function that does just
4201 that job.
4202
4203 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
4204 "pcregrep -".
4205
4206 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
4207 Java package. This provides some syntactic sugar for simple cases of what my
4208 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
4209 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
4210 item, you can use this simplified notation. Note that only makes sense with
4211 greedy quantifiers. Consequently, the use of the possessive quantifier forces
4212 greediness, whatever the setting of the PCRE_UNGREEDY option.
4213
4214 13. A change of greediness default within a pattern was not taking effect at
4215 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
4216 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
4217 was abstracted outside.
4218
4219 14. PCRE now supports the \G assertion. It is true when the current matching
4220 position is at the start point of the match. This differs from \A when the
4221 starting offset is non-zero. Used with the /g option of pcretest (or similar
4222 code), it works in the same way as it does for Perl's /g option. If all
4223 alternatives of a regex begin with \G, the expression is anchored to the start
4224 match position, and the "anchored" flag is set in the compiled expression.
4225
4226 15. Some bugs concerning the handling of certain option changes within patterns
4227 have been fixed. These applied to options other than (?ims). For example,
4228 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
4229 been the other way round. Some of this was related to change 7 above.
4230
4231 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
4232 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
4233 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
4234 POSIX classes only within a class (e.g. /[[:alpha:]]/).
4235
4236 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
4237 mode. Unlike ".", it always matches newline, whatever the setting of
4238 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
4239 assertions. Perl allows it, but it doesn't (in general) work because it can't
4240 calculate the length of the lookbehind. At least, that's the case for Perl
4241 5.8.0 - I've been told they are going to document that it doesn't work in
4242 future.
4243
4244 18. Added an error diagnosis for escapes that PCRE does not support: these are
4245 \L, \l, \N, \P, \p, \U, \u, and \X.
4246
4247 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
4248 reading past the end of the pattern in cases such as /[abcd/.
4249
4250 20. PCRE was getting more memory than necessary for patterns with classes that
4251 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
4252
4253 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
4254 compiling PCRE for use with Virtual Pascal.
4255
4256 22. Small fix to the Makefile to make it work properly if the build is done
4257 outside the source tree.
4258
4259 23. Added a new extension: a condition to go with recursion. If a conditional
4260 subpattern starts with (?(R) the "true" branch is used if recursion has
4261 happened, whereas the "false" branch is used only at the top level.
4262
4263 24. When there was a very long string of literal characters (over 255 bytes
4264 without UTF support, over 250 bytes with UTF support), the computation of how
4265 much memory was required could be incorrect, leading to segfaults or other
4266 strange effects.
4267
4268 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
4269 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
4270 there was a subsequent back reference to those brackets. This meant that, for
4271 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
4272 possible to check for precisely this case. All we can do is abandon the
4273 optimization if .* occurs inside capturing brackets when there are any back
4274 references whatsoever. (See below for a better fix that came later.)
4275
4276 26. The handling of the optimization for finding the first character of a
4277 non-anchored pattern, and for finding a character that is required later in the
4278 match were failing in some cases. This didn't break the matching; it just
4279 failed to optimize when it could. The way this is done has been re-implemented.
4280
4281 27. Fixed typo in error message for invalid (?R item (it said "(?p").
4282
4283 28. Added a new feature that provides some of the functionality that Perl
4284 provides with (?{...}). The facility is termed a "callout". The way it is done
4285 in PCRE is for the caller to provide an optional function, by setting
4286 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
4287 global variable. By default it is unset, which disables all calling out. To get
4288 the function called, the regex must include (?C) at appropriate points. This
4289 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
4290 This provides a means of identifying different callout points. When PCRE
4291 reaches such a point in the regex, if pcre_callout has been set, the external
4292 function is called. It is provided with data in a structure called
4293 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
4294 matching continues; if it returns a non-zero value, the match at the current
4295 point fails. However, backtracking will occur if possible. [This was changed
4296 later and other features added - see item 49 below.]
4297
4298 29. pcretest is upgraded to test the callout functionality. It provides a
4299 callout function that displays information. By default, it shows the start of
4300 the match and the current position in the text. There are some new data escapes
4301 to vary what happens:
4302
4303 \C+ in addition, show current contents of captured substrings
4304 \C- do not supply a callout function
4305 \C!n return 1 when callout number n is reached
4306 \C!n!m return 1 when callout number n is reached for the mth time
4307
4308 30. If pcregrep was called with the -l option and just a single file name, it
4309 output "<stdin>" if a match was found, instead of the file name.
4310
4311 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
4312 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
4313 pcre_exec(). This saves a malloc/free per call. The default value of
4314 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
4315 when configuring.
4316
4317 32. The default maximum size of a compiled pattern is 64K. There have been a
4318 few cases of people hitting this limit. The code now uses macros to handle the
4319 storing of links as offsets within the compiled pattern. It defaults to 2-byte
4320 links, but this can be changed to 3 or 4 bytes by --with-link-size when
4321 configuring. Tests 2 and 5 work only with 2-byte links because they output
4322 debugging information about compiled patterns.
4323
4324 33. Internal code re-arrangements:
4325
4326 (a) Moved the debugging function for printing out a compiled regex into
4327 its own source file (printint.c) and used #include to pull it into
4328 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
4329 separate copies.
4330
4331 (b) Defined the list of op-code names for debugging as a macro in
4332 internal.h so that it is next to the definition of the opcodes.
4333
4334 (c) Defined a table of op-code lengths for simpler skipping along compiled
4335 code. This is again a macro in internal.h so that it is next to the
4336 definition of the opcodes.
4337
4338 34. Added support for recursive calls to individual subpatterns, along the
4339 lines of Robin Houston's patch (but implemented somewhat differently).
4340
4341 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
4342 allow it to read and process whole directories in Win32. This code was
4343 contributed by Lionel Fourquaux; it has not been tested by me.
4344
4345 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
4346 used to name a group. Names consist of alphanumerics and underscores, and must
4347 be unique. Back references use the syntax (?P=name) and recursive calls use
4348 (?P>name) which is a PCRE extension to the Python extension. Groups still have
4349 numbers. The function pcre_fullinfo() can be used after compilation to extract
4350 a name/number map. There are three relevant calls:
4351
4352 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
4353 PCRE_INFO_NAMECOUNT yields the number of entries
4354 PCRE_INFO_NAMETABLE yields a pointer to the map.
4355
4356 The map is a vector of fixed-size entries. The size of each entry depends on
4357 the length of the longest name used. The first two bytes of each entry are the
4358 group number, most significant byte first. There follows the corresponding
4359 name, zero terminated. The names are in alphabetical order.
4360
4361 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
4362 case instead of 255. Making it the same both with and without UTF-8 support
4363 means that the same test output works with both.
4364
4365 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
4366 calling malloc() with a zero argument.
4367
4368 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
4369 optimization. I've improved things by keeping a bitmap of backreferences with
4370 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
4371 fact referenced, the optimization can be applied. It is unlikely that a
4372 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
4373 the match to follow \n) will appear inside brackets with a number greater than
4374 31, but if it does, any back reference > 31 suppresses the optimization.
4375
4376 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
4377 of disabling numbered capturing parentheses. Any opening parenthesis that is
4378 not followed by ? behaves as if it were followed by ?: but named parentheses
4379 can still be used for capturing (and they will acquire numbers in the usual
4380 way).
4381
4382 41. Redesigned the return codes from the match() function into yes/no/error so
4383 that errors can be passed back from deep inside the nested calls. A malloc
4384 failure while inside a recursive subpattern call now causes the
4385 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4386
4387 42. It is now possible to set a limit on the number of times the match()
4388 function is called in a call to pcre_exec(). This facility makes it possible to
4389 limit the amount of recursion and backtracking, though not in a directly
4390 obvious way, because the match() function is used in a number of different
4391 circumstances. The count starts from zero for each position in the subject
4392 string (for non-anchored patterns). The default limit is, for compatibility, a
4393 large number, namely 10 000 000. You can change this in two ways:
4394
4395 (a) When configuring PCRE before making, you can use --with-match-limit=n
4396 to set a default value for the compiled library.
4397
4398 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4399 a different value is set. See 45 below.
4400
4401 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4402
4403 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4404 of things that can be changed at compile time. The first argument specifies
4405 what is wanted and the second points to where the information is to be placed.
4406 The current list of available information is:
4407
4408 PCRE_CONFIG_UTF8
4409
4410 The output is an integer that is set to one if UTF-8 support is available;
4411 otherwise it is set to zero.
4412
4413 PCRE_CONFIG_NEWLINE
4414
4415 The output is an integer that it set to the value of the code that is used for
4416 newline. It is either LF (10) or CR (13).
4417
4418 PCRE_CONFIG_LINK_SIZE
4419
4420 The output is an integer that contains the number of bytes used for internal
4421 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4422
4423 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4424
4425 The output is an integer that contains the threshold above which the POSIX
4426 interface uses malloc() for output vectors. See item 31 above.
4427
4428 PCRE_CONFIG_MATCH_LIMIT
4429
4430 The output is an unsigned integer that contains the default limit of the number
4431 of match() calls in a pcre_exec() execution. See 42 above.
4432
4433 44. pcretest has been upgraded by the addition of the -C option. This causes it
4434 to extract all the available output from the new pcre_config() function, and to
4435 output it. The program then exits immediately.
4436
4437 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4438 order to support additional features. One way would have been to define
4439 pcre_exec2() (for example) with extra arguments, but this would not have been
4440 extensible, and would also have required all calls to the original function to
4441 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4442 is used for passing in "extra" data from pcre_study().
4443
4444 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4445 contains the following fields:
4446
4447 flags a bitmap indicating which of the following fields are set
4448 study_data opaque data from pcre_study()
4449 match_limit a way of specifying a limit on match() calls for a specific
4450 call to pcre_exec()
4451 callout_data data for callouts (see 49 below)
4452
4453 The flag bits are also defined in pcre.h, and are
4454
4455 PCRE_EXTRA_STUDY_DATA
4456 PCRE_EXTRA_MATCH_LIMIT
4457 PCRE_EXTRA_CALLOUT_DATA
4458
4459 The pcre_study() function now returns one of these new pcre_extra blocks, with
4460 the actual study data pointed to by the study_data field, and the
4461 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
4462 before. That is, this change is entirely upwards-compatible and requires no
4463 change to existing code.
4464
4465 If you want to pass in additional data to pcre_exec(), you can either place it
4466 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
4467 block.
4468
4469 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
4470 data string contains the escape sequence \M, pcretest calls pcre_exec() several
4471 times with different match limits, until it finds the minimum value needed for
4472 pcre_exec() to complete. The value is then output. This can be instructive; for
4473 most simple matches the number is quite small, but for pathological cases it
4474 gets very large very quickly.
4475
4476 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
4477 returns the size of the data block pointed to by the study_data field in a
4478 pcre_extra block, that is, the value that was passed as the argument to
4479 pcre_malloc() when PCRE was getting memory in which to place the information
4480 created by pcre_study(). The fourth argument should point to a size_t variable.
4481 pcretest has been extended so that this information is shown after a successful
4482 pcre_study() call when information about the compiled regex is being displayed.
4483
4484 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
4485 because what follows is always an absolute path. (Later: it turns out that this
4486 is more than cosmetic for MinGW, because it doesn't like empty path
4487 components.)
4488
4489 49. Some changes have been made to the callout feature (see 28 above):
4490
4491 (i) A callout function now has three choices for what it returns:
4492
4493 0 => success, carry on matching
4494 > 0 => failure at this point, but backtrack if possible
4495 < 0 => serious error, return this value from pcre_exec()
4496
4497 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
4498 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
4499 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
4500 use by callout functions. It will never be used by PCRE itself.
4501
4502 (ii) The pcre_extra structure (see 45 above) has a void * field called
4503 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
4504 pcre_callout_block structure has a field of the same name. The contents of
4505 the field passed in the pcre_extra structure are passed to the callout
4506 function in the corresponding field in the callout block. This makes it
4507 easier to use the same callout-containing regex from multiple threads. For
4508 testing, the pcretest program has a new data escape
4509
4510 \C*n pass the number n (may be negative) as callout_data
4511
4512 If the callout function in pcretest receives a non-zero value as
4513 callout_data, it returns that value.
4514
4515 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
4516 there were some redundant $(CFLAGS) in commands that are now specified as
4517 $(LINK), which already includes $(CFLAGS).
4518
4519 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
4520 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
4521 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
4522 one-byte characters throughout. Note that case-insensitive matching applies
4523 only to characters whose values are less than 256. PCRE doesn't support the
4524 notion of cases for higher-valued characters.
4525
4526 (i) A character class whose characters are all within 0-255 is handled as
4527 a bit map, and the map is inverted for negative classes. Previously, a
4528 character > 255 always failed to match such a class; however it should
4529 match if the class was a negative one (e.g. [^ab]). This has been fixed.
4530
4531 (ii) A negated character class with a single character < 255 is coded as
4532 "not this character" (OP_NOT). This wasn't working properly when the test
4533 character was multibyte, either singly or repeated.
4534
4535 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
4536 mode, for example: \x{100}{2,3}.
4537
4538 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
4539 singly or repeated) now correctly test multibyte characters. However,
4540 PCRE doesn't recognize any characters with values greater than 255 as
4541 digits, spaces, or word characters. Such characters always match \D, \S,
4542 and \W, and never match \d, \s, or \w.
4543
4544 (v) Classes may now contain characters and character ranges with values
4545 greater than 255. For example: [ab\x{100}-\x{400}].
4546
4547 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
4548 PCRE in UTF-8 mode.
4549
4550 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
4551 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
4552 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
4553 value.)
4554
4555 53. The single man page has become too large. I have therefore split it up into
4556 a number of separate man pages. These also give rise to individual HTML pages;
4557 these are now put in a separate directory, and there is an index.html page that
4558 lists them all. Some hyperlinking between the pages has been installed.
4559
4560 54. Added convenience functions for handling named capturing parentheses.
4561
4562 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
4563 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
4564 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
4565 are faulted.
4566
4567 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
4568 calling configure. These values are used when compiling the dftables.c program
4569 which is run to generate the source of the default character tables. They
4570 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
4571 you will need to set these values.
4572
4573 57. Updated the building process for Windows DLL, as provided by Fred Cox.
4574
4575
4576 Version 3.9 02-Jan-02
4577 ---------------------
4578
4579 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
4580
4581 2. If --disable-static was given, the building process failed when trying to
4582 build pcretest and pcregrep. (For some reason it was using libtool to compile
4583 them, which is not right, as they aren't part of the library.)
4584
4585
4586 Version 3.8 18-Dec-01
4587 ---------------------
4588
4589 1. The experimental UTF-8 code was completely screwed up. It was packing the
4590 bytes in the wrong order. How dumb can you get?
4591
4592
4593 Version 3.7 29-Oct-01
4594 ---------------------
4595
4596 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
4597 This caused pcretest, when used on the test data, to segfault. Unfortunately,
4598 this didn't happen under Solaris 8, where I normally test things.
4599
4600 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
4601 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
4602 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
4603 this fix an hour or so after the initial 3.7 release.)
4604
4605
4606 Version 3.6 23-Oct-01
4607 ---------------------
4608
4609 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
4610 offsets passed as NULL with zero offset count.
4611
4612 2. The config.guess and config.sub files had not been updated when I moved to
4613 the latest autoconf.
4614
4615
4616 Version 3.5 15-Aug-01
4617 ---------------------
4618
4619 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
4620 had been forgotten.
4621
4622 2. By using declared but undefined structures, we can avoid using "void"
4623 definitions in pcre.h while keeping the internal definitions of the structures
4624 private.
4625
4626 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
4627 user point of view, this means that both static and shared libraries are built
4628 by default, but this can be individually controlled. More of the work of
4629 handling this static/shared cases is now inside libtool instead of PCRE's make
4630 file.
4631
4632 4. The pcretest utility is now installed along with pcregrep because it is
4633 useful for users (to test regexs) and by doing this, it automatically gets
4634 relinked by libtool. The documentation has been turned into a man page, so
4635 there are now .1, .txt, and .html versions in /doc.
4636
4637 5. Upgrades to pcregrep:
4638 (i) Added long-form option names like gnu grep.
4639 (ii) Added --help to list all options with an explanatory phrase.
4640 (iii) Added -r, --recursive to recurse into sub-directories.
4641 (iv) Added -f, --file to read patterns from a file.
4642
4643 6. pcre_exec() was referring to its "code" argument before testing that
4644 argument for NULL (and giving an error if it was NULL).
4645
4646 7. Upgraded Makefile.in to allow for compiling in a different directory from
4647 the source directory.
4648
4649 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
4650 options bits, the pointer it was passed was to an int instead of to an unsigned
4651 long int. This mattered only on 64-bit systems.
4652
4653 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
4654 generated) instead of pcre.in, which it its source. Also made the same change
4655 in several of the .c files.
4656
4657 10. A new release of gcc defines printf() as a macro, which broke pcretest
4658 because it had an ifdef in the middle of a string argument for printf(). Fixed
4659 by using separate calls to printf().
4660
4661 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4662 script, to force use of CR or LF instead of \n in the source. On non-Unix
4663 systems, the value can be set in config.h.
4664
4665 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4666 absolute limit. Changed the text of the error message to make this clear, and
4667 likewise updated the man page.
4668
4669 13. The limit of 99 on the number of capturing subpatterns has been removed.
4670 The new limit is 65535, which I hope will not be a "real" limit.
4671
4672
4673 Version 3.4 22-Aug-00
4674 ---------------------
4675
4676 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4677
4678 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4679
4680
4681 Version 3.3 01-Aug-00
4682 ---------------------
4683
4684 1. If an octal character was given, but the value was greater than \377, it
4685 was not getting masked to the least significant bits, as documented. This could
4686 lead to crashes in some systems.
4687
4688 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4689 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4690
4691 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4692 These just pass their arguments on to (pcre_free)(), but they are provided
4693 because some uses of PCRE bind it to non-C systems that can call its functions,
4694 but cannot call free() or pcre_free() directly.
4695
4696 4. Add "make test" as a synonym for "make check". Corrected some comments in
4697 the Makefile.
4698
4699 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4700 Makefile.
4701
4702 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4703 command called pgrep for grepping around the active processes.
4704
4705 7. Added the beginnings of support for UTF-8 character strings.
4706
4707 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4708 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4709 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4710 out for the ar command.)
4711
4712
4713 Version 3.2 12-May-00
4714 ---------------------
4715
4716 This is purely a bug fixing release.
4717
4718 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4719 of ZA. This was just one example of several cases that could provoke this bug,
4720 which was introduced by change 9 of version 2.00. The code for breaking
4721 infinite loops after an iteration that matches an empty string was't working
4722 correctly.
4723
4724 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4725 when matched against abbab (for example). After matching an empty string, it
4726 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4727 caused it to match further down the string than it should.
4728
4729 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4730 was there because it doesn't seem to be needed, and it causes trouble on some
4731 systems, as it is not a Standard C header. It has been removed.
4732
4733 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4734 were reported on the Macintosh. The changes were from
4735
4736 while ((c = *(++ptr)) != 0 && c != '\n');
4737 to
4738 while ((c = *(++ptr)) != 0 && c != '\n') ;
4739
4740 Totally extraordinary, but if that's what it takes...
4741
4742 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4743 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4744 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4745 assumes the way PCRE uses memmove() (always moving upwards).
4746
4747 6. PCRE is being used in one environment where strchr() is not available. There
4748 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4749 faster code anyway.
4750
4751
4752 Version 3.1 09-Feb-00
4753 ---------------------
4754
4755 The only change in this release is the fixing of some bugs in Makefile.in for
4756 the "install" target:
4757
4758 (1) It was failing to install pcreposix.h.
4759
4760 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4761
4762
4763 Version 3.0 01-Feb-00
4764 ---------------------
4765
4766 1. Add support for the /+ modifier to perltest (to output $` like it does in
4767 pcretest).
4768
4769 2. Add support for the /g modifier to perltest.
4770
4771 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4772 matches null strings.
4773
4774 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4775 pattern. Perl treats empty patterns specially - it reuses the most recent
4776 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4777 effect.
4778
4779 5. The POSIX interface was broken in that it was just handing over the POSIX
4780 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4781 required a bigger vector, with some working space on the end. This means that
4782 the POSIX wrapper now has to get and free some memory, and copy the results.
4783
4784 6. Added some simple autoconf support, placing the test data and the
4785 documentation in separate directories, re-organizing some of the
4786 information files, and making it build pcre-config (a GNU standard). Also added
4787 libtool support for building PCRE as a shared library, which is now the
4788 default.
4789
4790 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4791 09 are not valid octal constants. Single digits will be used for minor values
4792 less than 10.
4793
4794 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4795 existing programs that set these in the POSIX interface can use PCRE without
4796 modification.
4797
4798 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4799 return all that pcre_info() returns, plus additional data. The pcre_info()
4800 function is retained for compatibility, but is considered to be obsolete.
4801
4802 10. Added experimental recursion feature (?R) to handle one common case that
4803 Perl 5.6 will be able to do with (?p{...}).
4804
4805 11. Added support for POSIX character classes like [:alpha:], which Perl is
4806 adopting.
4807
4808
4809 Version 2.08 31-Aug-99
4810 ----------------------
4811
4812 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4813 trying to match at the startoffset position, but instead was moving forward to
4814 the next newline as if a previous match had failed.
4815
4816 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4817 and could get into a loop if a null string was matched other than at the start
4818 of the subject.
4819
4820 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4821 be distinguished at compile time, and for completeness also added PCRE_DATE.
4822
4823 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4824 in GnuWin32 environments.
4825
4826
4827 Version 2.07 29-Jul-99
4828 ----------------------
4829
4830 1. The documentation is now supplied in plain text form and HTML as well as in
4831 the form of man page sources.
4832
4833 2. C++ compilers don't like assigning (void *) values to other pointer types.
4834 In particular this affects malloc(). Although there is no problem in Standard
4835 C, I've put in casts to keep C++ compilers happy.
4836
4837 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4838 should be (const char *).
4839
4840 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4841 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4842 However, I haven't made this a standard facility. The documentation doesn't
4843 mention it, and the Makefile doesn't support it.
4844
4845 5. The Makefile now contains an "install" target, with editable destinations at
4846 the top of the file. The pcretest program is not installed.
4847
4848 6. pgrep -V now gives the PCRE version number and date.
4849
4850 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4851 causing the entire string to be ignored, instead of just the last character.
4852
4853 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4854 non-matching string, it can take a very, very long time, even for strings of
4855 quite modest length, because of the nested recursion. PCRE now does better in
4856 some of these cases. It does this by remembering the last required literal
4857 character in the pattern, and pre-searching the subject to ensure it is present
4858 before running the real match. In other words, it applies a heuristic to detect
4859 some types of certain failure quickly, and in the above example, if presented
4860 with a string that has no trailing " it gives "no match" very quickly.
4861
4862 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4863 other alternatives are tried instead.
4864
4865
4866 Version 2.06 09-Jun-99
4867 ----------------------
4868
4869 1. Change pcretest's output for amount of store used to show just the code
4870 space, because the remainder (the data block) varies in size between 32-bit and
4871 64-bit systems.
4872
4873 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4874 start matching at. This allows lookbehinds to work when searching for multiple
4875 occurrences in a string.
4876
4877 3. Added additional options to pcretest for testing multiple occurrences:
4878
4879 /+ outputs the rest of the string that follows a match
4880 /g loops for multiple occurrences, using the new startoffset argument
4881 /G loops for multiple occurrences by passing an incremented pointer
4882
4883 4. PCRE wasn't doing the "first character" optimization for patterns starting
4884 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4885 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4886 the letter 'x'. On long subject strings, this gives a significant speed-up.
4887
4888
4889 Version 2.05 21-Apr-99
4890 ----------------------
4891
4892 1. Changed the type of magic_number from int to long int so that it works
4893 properly on 16-bit systems.
4894
4895 2. Fixed a bug which caused patterns starting with .* not to work correctly
4896 when the subject string contained newline characters. PCRE was assuming
4897 anchoring for such patterns in all cases, which is not correct because .* will
4898 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4899 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4900 must be retried after every newline in the subject.
4901
4902
4903 Version 2.04 18-Feb-99
4904 ----------------------
4905
4906 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4907 computation of the store needed to hold the pattern was incorrect (too large).
4908 If such patterns were nested a few deep, this could multiply and become a real
4909 problem.
4910
4911 2. Added /M option to pcretest to show the memory requirement of a specific
4912 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4913
4914 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4915 compiled in such a way that the backtracking after subsequent failure was
4916 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4917 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4918
4919
4920 Version 2.03 02-Feb-99
4921 ----------------------
4922
4923 1. Fixed typo and small mistake in man page.
4924
4925 2. Added 4th condition (GPL supersedes if conflict) and created separate
4926 LICENCE file containing the conditions.
4927
4928 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4929 Perl, that is the internal \ allows the delimiter to be included in the
4930 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4931 the final delimiter, add \ to the end of the pattern (to test the error).
4932
4933 4. Added the convenience functions for extracting substrings after a successful
4934 match. Updated pcretest to make it able to test these functions.
4935
4936
4937 Version 2.02 14-Jan-99
4938 ----------------------
4939
4940 1. Initialized the working variables associated with each extraction so that
4941 their saving and restoring doesn't refer to uninitialized store.
4942
4943 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4944 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4945 fix the problem.
4946
4947 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4948 calls, and wasn't printing the correct value for compiling calls. Increased the
4949 default value of LOOPREPEAT, and the number of significant figures in the
4950 times.
4951
4952 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4953
4954 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4955 a building problem on Windows NT with a FAT file system.
4956
4957
4958 Version 2.01 21-Oct-98
4959 ----------------------
4960
4961 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4962 to character tables built by pcre_maketables() in the current locale. If NULL
4963 is passed, the default tables are used.
4964
4965
4966 Version 2.00 24-Sep-98
4967 ----------------------
4968
4969 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4970 it any more.
4971
4972 2. Allow quantification of (?>) groups, and make it work correctly.
4973
4974 3. The first character computation wasn't working for (?>) groups.
4975
4976 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4977 end of the subject) and add 5.005's \z, which really does match only at the
4978 very end of the subject.
4979
4980 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4981
4982 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4983 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4984 localized options. All options to pcre_study() were also removed.
4985
4986 7. Add other new features from 5.005:
4987
4988 $(?<= positive lookbehind
4989 $(?<! negative lookbehind
4990 (?imsx-imsx) added the unsetting capability
4991 such a setting is global if at outer level; local otherwise
4992 (?imsx-imsx:) non-capturing groups with option setting
4993 (?(cond)re|re) conditional pattern matching
4994
4995 A backreference to itself in a repeated group matches the previous
4996 captured string.
4997
4998 8. General tidying up of studying (both automatic and via "study")
4999 consequential on the addition of new assertions.
5000
5001 9. As in 5.005, unlimited repeated groups that could match an empty substring
5002 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5003 runtime if any iteration does actually match an empty substring.
5004
5005 10. Include the RunTest script in the distribution.
5006
5007 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5008 discrepancies, some of which were old and were also with respect to 5.004. They
5009 have now been fixed.
5010
5011
5012 Version 1.09 28-Apr-98
5013 ----------------------
5014
5015 1. A negated single character class followed by a quantifier with a minimum
5016 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5017 program crashes, or just wrong answers. This did not apply to negated classes
5018 containing more than one character, or to minima other than one.
5019
5020
5021 Version 1.08 27-Mar-98
5022 ----------------------
5023
5024 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5025
5026 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5027 latter must appear before anything that relies on it in the pattern.
5028
5029
5030 Version 1.07 16-Feb-98
5031 ----------------------
5032
5033 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5034 repeat of a potentially empty string).
5035
5036
5037 Version 1.06 23-Jan-98
5038 ----------------------
5039
5040 1. Added Markus Oberhumer's little patches for C++.
5041
5042 2. Literal strings longer than 255 characters were broken.
5043
5044
5045 Version 1.05 23-Dec-97
5046 ----------------------
5047
5048 1. Negated character classes containing more than one character were failing if
5049 PCRE_CASELESS was set at run time.
5050
5051
5052 Version 1.04 19-Dec-97
5053 ----------------------
5054
5055 1. Corrected the man page, where some "const" qualifiers had been omitted.
5056
5057 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5058 input syntax.
5059
5060 3. Fixed memory leak which occurred when a regex with back references was
5061 matched with an offsets vector that wasn't big enough. The temporary memory
5062 that is used in this case wasn't being freed if the match failed.
5063
5064 4. Tidied pcretest to ensure it frees memory that it gets.
5065
5066 5. Temporary memory was being obtained in the case where the passed offsets
5067 vector was exactly big enough.
5068
5069 6. Corrected definition of offsetof() from change 5 below.
5070
5071 7. I had screwed up change 6 below and broken the rules for the use of
5072 setjmp(). Now fixed.
5073
5074
5075 Version 1.03 18-Dec-97
5076 ----------------------
5077
5078 1. A erroneous regex with a missing opening parenthesis was correctly
5079 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5080 on some systems.
5081
5082 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5083 it was reported that one broken compiler failed on the former because "code" is
5084 also an independent variable.
5085
5086 3. The erroneous regex a[]b caused an array overrun reference.
5087
5088 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5089 fail on data ending with that character. (It was going on too far, and checking
5090 the next character, typically a binary zero.) This was specific to the
5091 optimized code for single-character negative classes.
5092
5093 5. Added a contributed patch from the TIN world which does the following:
5094
5095 + Add an undef for memmove, in case the the system defines a macro for it.
5096
5097 + Add a definition of offsetof(), in case there isn't one. (I don't know
5098 the reason behind this - offsetof() is part of the ANSI standard - but
5099 it does no harm).
5100
5101 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
5102 most of the places where whitespace preceded '#'. I have given up and
5103 allowed the remaining 2 cases to be at the margin.
5104
5105 + Rename some variables in pcre to eliminate shadowing. This seems very
5106 pedantic, but does no harm, of course.
5107
5108 6. Moved the call to setjmp() into its own function, to get rid of warnings
5109 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
5110
5111 7. Constructs such as \d{8,} were compiling into the equivalent of
5112 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
5113 outcome, but in this particular case used more store than had been allocated,
5114 which caused the bug to be discovered because it threw up an internal error.
5115
5116 8. The debugging code in both pcre and pcretest for outputting the compiled
5117 form of a regex was going wrong in the case of back references followed by
5118 curly-bracketed repeats.
5119
5120
5121 Version 1.02 12-Dec-97
5122 ----------------------
5123
5124 1. Typos in pcre.3 and comments in the source fixed.
5125
5126 2. Applied a contributed patch to get rid of places where it used to remove
5127 'const' from variables, and fixed some signed/unsigned and uninitialized
5128 variable warnings.
5129
5130 3. Added the "runtest" target to Makefile.
5131
5132 4. Set default compiler flag to -O2 rather than just -O.
5133
5134
5135 Version 1.01 19-Nov-97
5136 ----------------------
5137
5138 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
5139 like /([ab]*)*/, that is, for classes with more than one character in them.
5140
5141 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
5142 as /((?>a*))*/ (a PCRE_EXTRA facility).
5143
5144
5145 Version 1.00 18-Nov-97
5146 ----------------------
5147
5148 1. Added compile-time macros to support systems such as SunOS4 which don't have
5149 memmove() or strerror() but have other things that can be used instead.
5150
5151 2. Arranged that "make clean" removes the executables.
5152
5153
5154 Version 0.99 27-Oct-97
5155 ----------------------
5156
5157 1. Fixed bug in code for optimizing classes with only one character. It was
5158 initializing a 32-byte map regardless, which could cause it to run off the end
5159 of the memory it had got.
5160
5161 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
5162
5163
5164 Version 0.98 22-Oct-97
5165 ----------------------
5166
5167 1. Fixed bug in code for handling temporary memory usage when there are more
5168 back references than supplied space in the ovector. This could cause segfaults.
5169
5170
5171 Version 0.97 21-Oct-97
5172 ----------------------
5173
5174 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
5175
5176 2. Optimized negated single characters not to use a bit map.
5177
5178 3. Brought error texts together as macro definitions; clarified some of them;
5179 fixed one that was wrong - it said "range out of order" when it meant "invalid
5180 escape sequence".
5181
5182 4. Changed some char * arguments to const char *.
5183
5184 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
5185
5186 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
5187 pcretest.
5188
5189
5190 Version 0.96 16-Oct-97
5191 ----------------------
5192
5193 1. Added a simple "pgrep" utility to the distribution.
5194
5195 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
5196 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
5197 where "ddd" means "one or more decimal digits".
5198
5199 3. Fixed serious bug. If a pattern had a back reference, but the call to
5200 pcre_exec() didn't supply a large enough ovector to record the related
5201 identifying subpattern, the match always failed. PCRE now remembers the number
5202 of the largest back reference, and gets some temporary memory in which to save
5203 the offsets during matching if necessary, in order to ensure that
5204 backreferences always work.
5205
5206 4. Increased the compatibility with Perl in a number of ways:
5207
5208 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
5209 to request this handling. The option can be set at compile or exec time.
5210
5211 (b) $ matches before a terminating newline by default; an option
5212 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
5213 mode). The option can be set at compile or exec time.
5214
5215 (c) The handling of \ followed by a digit other than 0 is now supposed to be
5216 the same as Perl's. If the decimal number it represents is less than 10
5217 or there aren't that many previous left capturing parentheses, an octal
5218 escape is read. Inside a character class, it's always an octal escape,
5219 even if it is a single digit.
5220
5221 (d) An escaped but undefined alphabetic character is taken as a literal,
5222 unless PCRE_EXTRA is set. Currently this just reserves the remaining
5223 escapes.
5224
5225 (e) {0} is now permitted. (The previous item is removed from the compiled
5226 pattern).
5227
5228 5. Changed all the names of code files so that the basic parts are no longer
5229 than 10 characters, and abolished the teeny "globals.c" file.
5230
5231 6. Changed the handling of character classes; they are now done with a 32-byte
5232 bit map always.
5233
5234 7. Added the -d and /D options to pcretest to make it possible to look at the
5235 internals of compilation without having to recompile pcre.
5236
5237
5238 Version 0.95 23-Sep-97
5239 ----------------------
5240
5241 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
5242 \x20 at the start of a run of normal characters. These were being treated as
5243 real characters, instead of the source characters being re-checked.
5244
5245
5246 Version 0.94 18-Sep-97
5247 ----------------------
5248
5249 1. The functions are now thread-safe, with the caveat that the global variables
5250 containing pointers to malloc() and free() or alternative functions are the
5251 same for all threads.
5252
5253 2. Get pcre_study() to generate a bitmap of initial characters for non-
5254 anchored patterns when this is possible, and use it if passed to pcre_exec().
5255
5256
5257 Version 0.93 15-Sep-97
5258 ----------------------
5259
5260 1. /(b)|(:+)/ was computing an incorrect first character.
5261
5262 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
5263 but not actually doing anything yet.
5264
5265 3. Treat "-" characters in classes that cannot be part of ranges as literals,
5266 as Perl does (e.g. [-az] or [az-]).
5267
5268 4. Set the anchored flag if a branch starts with .* or .*? because that tests
5269 all possible positions.
5270
5271 5. Split up into different modules to avoid including unneeded functions in a
5272 compiled binary. However, compile and exec are still in one module. The "study"
5273 function is split off.
5274
5275 6. The character tables are now in a separate module whose source is generated
5276 by an auxiliary program - but can then be edited by hand if required. There are
5277 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
5278 toupper() in the code.
5279
5280 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
5281 make them global. Abolish the function for setting them, as the caller can now
5282 set them directly.
5283
5284
5285 Version 0.92 11-Sep-97
5286 ----------------------
5287
5288 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
5289 (e.g. /a{1,3}/) was broken (I mis-optimized it).
5290
5291 2. Caseless matching was not working in character classes if the characters in
5292 the pattern were in upper case.
5293
5294 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
5295
5296 4. Make PCRE_ANCHORED public and accept as a compile option.
5297
5298 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
5299 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
5300 pass them.
5301
5302 6. Give an error if bad option bits passed at compile or run time.
5303
5304 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
5305 pcretest to cause it to pass that flag.
5306
5307 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
5308 options, and the first character, if set.
5309
5310 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
5311
5312
5313 Version 0.91 10-Sep-97
5314 ----------------------
5315
5316 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
5317 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
5318
5319 2. PCRE was looping on encountering an indefinitely repeated back reference to
5320 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
5321 Perl does - treats the match as successful.
5322
5323 ****

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