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pcre32: docs: Add ChangeLog entry for pcre32
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.32
5 ------------
6
7 1. Improved JIT compiler optimizations for first character search and single
8 character iterators.
9
10 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
11 Patch by Daniel Richard G.
12
13 3. Single character iterator optimizations in the JIT compiler.
14
15 4. Improved JIT compiler optimizations for character ranges.
16
17 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
18 Reported by Giuseppe D'Angelo.
19
20 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
21 of a line, was being set incorrectly in cases where .* appeared inside
22 atomic brackets at the start of a pattern, or where there was a subsequent
23 *PRUNE or *SKIP.
24
25 7. Improved instruction cache flush for POWER/PowerPC.
26 Patch by Daniel Richard G.
27
28 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
29 grep:
30
31 (a) There is now no limit to the number of patterns to be matched.
32
33 (b) An error is given if a pattern is too long.
34
35 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
36 are now supported.
37
38 (d) --exclude-from and --include-from (multiple use) have been added.
39
40 (e) Exclusions and inclusions now apply to all files and directories, not
41 just to those obtained from scanning a directory recursively.
42
43 (f) Multiple uses of -f and --file-list are now supported.
44
45 (g) In a Windows environment, the default for -d has been changed from
46 "read" (the GNU grep default) to "skip", because otherwise the presence
47 of a directory in the file list provokes an error.
48
49 (h) The documentation has been revised and clarified in places.
50
51 9. Improve the matching speed of capturing brackets.
52
53 10. Changed the meaning of \X so that it now matches a Unicode extended
54 grapheme cluster.
55
56 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
57 out POSIX threads when JIT support is configured.
58
59 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
60
61 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
62 structure could go wrong in environments where size_t is not the same size
63 as int.
64
65 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
66 set.
67
68 15. The EBCDIC support had decayed; later updates to the code had included
69 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
70 general tidy up of EBCDIC-related issues, and the documentation was also
71 not quite right. There is now a test that can be run on ASCII systems to
72 check some of the EBCDIC-related things (but is it not a full test).
73
74 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
75 in a small tidy to the code.
76
77 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
78
79 18. If the --only-matching (-o) option in pcregrep is specified multiple
80 times, each one causes appropriate output. For example, -o1 -o2 outputs the
81 substrings matched by the 1st and 2nd capturing parentheses. A separating
82 string can be specified by --om-separator (default empty).
83
84 19. Improving the first n character searches.
85
86 20. Turn case lists for horizontal and vertical white space into macros so that
87 they are defined only once.
88
89 21. This set of changes together give more compatible Unicode case-folding
90 behaviour for characters that have more than one other case when UCP
91 support is available.
92
93 (a) The Unicode property table now has offsets into a new table of sets of
94 three or more characters that are case-equivalent. The MultiStage2.py
95 script that generates these tables (the pcre_ucd.c file) now scans
96 CaseFolding.txt instead of UnicodeData.txt for character case
97 information.
98
99 (b) The code for adding characters or ranges of characters to a character
100 class has been abstracted into a generalized function that also handles
101 case-independence. In UTF-mode with UCP support, this uses the new data
102 to handle characters with more than one other case.
103
104 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
105 whose other case is greater than 256 are now correctly matched
106 caselessly. Previously, the high codepoint matched the low one, but not
107 vice versa.
108
109 (d) The processing of \h, \H, \v, and \ in character classes now makes use
110 of the new class addition function, using character lists defined as
111 macros alongside the case definitions of 20 above.
112
113 (e) Caseless back references now work with characters that have more than
114 one other case.
115
116 (f) General caseless matching of characters with more than one other case
117 is supported.
118
119 22. Unicode character properties were updated from Unicode 6.2.0
120
121 23. Improved CMake support under Windows. Patch by Daniel Richard G.
122
123 24. Add support for 32-bit character strings, and UTF-32
124
125
126 Version 8.31 06-July-2012
127 -------------------------
128
129 1. Fixing a wrong JIT test case and some compiler warnings.
130
131 2. Removed a bashism from the RunTest script.
132
133 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
134 to unsigned type, result still unsigned" that was given by an MS compiler
135 on encountering the code "-sizeof(xxx)".
136
137 4. Partial matching support is added to the JIT compiler.
138
139 5. Fixed several bugs concerned with partial matching of items that consist
140 of more than one character:
141
142 (a) /^(..)\1/ did not partially match "aba" because checking references was
143 done on an "all or nothing" basis. This also applied to repeated
144 references.
145
146 (b) \R did not give a hard partial match if \r was found at the end of the
147 subject.
148
149 (c) \X did not give a hard partial match after matching one or more
150 characters at the end of the subject.
151
152 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
153 a partial match for the string "\r".
154
155 (e) When newline was set to CRLF, the metacharacter "." did not recognize
156 a partial match for a CR character at the end of the subject string.
157
158 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
159 running pcretest, the text "(JIT)" added to the output whenever JIT is
160 actually used to run the match.
161
162 7. Individual JIT compile options can be set in pcretest by following -s+[+]
163 or /S+[+] with a digit between 1 and 7.
164
165 8. OP_NOT now supports any UTF character not just single-byte ones.
166
167 9. (*MARK) control verb is now supported by the JIT compiler.
168
169 10. The command "./RunTest list" lists the available tests without actually
170 running any of them. (Because I keep forgetting what they all are.)
171
172 11. Add PCRE_INFO_MAXLOOKBEHIND.
173
174 12. Applied a (slightly modified) user-supplied patch that improves performance
175 when the heap is used for recursion (compiled with --disable-stack-for-
176 recursion). Instead of malloc and free for each heap frame each time a
177 logical recursion happens, frames are retained on a chain and re-used where
178 possible. This sometimes gives as much as 30% improvement.
179
180 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
181 call.
182
183 14. As documented, (*COMMIT) is now confined to within a positive assertion.
184
185 15. It is now possible to link pcretest with libedit as an alternative to
186 libreadline.
187
188 16. (*COMMIT) control verb is now supported by the JIT compiler.
189
190 17. The Unicode data tables have been updated to Unicode 6.1.0.
191
192 18. Added --file-list option to pcregrep.
193
194 19. Added binary file support to pcregrep, including the -a, --binary-files,
195 -I, and --text options.
196
197 20. The madvise function is renamed for posix_madvise for QNX compatibility
198 reasons. Fixed by Giuseppe D'Angelo.
199
200 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
201
202 22. Changed the option for creating symbolic links for 16-bit man pages from
203 -s to -sf so that re-installing does not cause issues.
204
205 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
206
207 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
208 matches in certain environments (the workspace was not being correctly
209 retained). Also added to pcre_dfa_exec() a simple plausibility check on
210 some of the workspace data at the beginning of a restart.
211
212 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
213 was not doing so when it should - probably a typo introduced by SVN 528
214 (change 8.10/14).
215
216 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
217 \w+ when the character tables indicated that \x{c4} was a word character.
218 There were several related cases, all because the tests for doing a table
219 lookup were testing for characters less than 127 instead of 255.
220
221 27. If a pattern contains capturing parentheses that are not used in a match,
222 their slots in the ovector are set to -1. For those that are higher than
223 any matched groups, this happens at the end of processing. In the case when
224 there were back references that the ovector was too small to contain
225 (causing temporary malloc'd memory to be used during matching), and the
226 highest capturing number was not used, memory off the end of the ovector
227 was incorrectly being set to -1. (It was using the size of the temporary
228 memory instead of the true size.)
229
230 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
231 ovector size, it uses memory at the end of the block that it has got.
232
233 29. Check for an overlong MARK name and give an error at compile time. The
234 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
235
236 30. JIT compiler update.
237
238 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
239 Rill for the patch.
240
241 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
242
243 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
244
245 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
246 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
247 was enabled.
248
249 35. Improve JIT code generation for greedy plus quantifier.
250
251 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
252 1 to "aa" instead of to an empty string. The bug affected repeated groups
253 that could potentially match an empty string.
254
255 37. Optimizing single character iterators in JIT.
256
257 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
258 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
259 codepoints that are too big for the mode are faulted, and in a UTF mode,
260 disallowed codepoints are also faulted.
261
262 39. If PCRE was compiled with UTF support, in three places in the DFA
263 matcher there was code that should only have been obeyed in UTF mode, but
264 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
265 processing when bytes with values greater than 127 were present. In 16-bit
266 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
267 both cases the values are those that cannot be the first data item in a UTF
268 character. The three items that might have provoked this were recursions,
269 possessively repeated groups, and atomic groups.
270
271 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
272 and pcregrep, because some OS require shared objects to be explicitly
273 passed to ld, causing the link step to fail if they are not.
274
275 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
276 mode, patterns that started with \h* or \R* might be incorrectly matched.
277
278
279 Version 8.30 04-February-2012
280 -----------------------------
281
282 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
283 name is defined in ctype.h.
284
285 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
286 only in quite long subpatterns.
287
288 3. Removed the function pcre_info(), which has been obsolete and deprecated
289 since it was replaced by pcre_fullinfo() in February 2000.
290
291 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
292 match a (*MARK), and the match failed at the start of the subject, a
293 reference to memory before the start of the subject could occur. This bug
294 was introduced by fix 17 of release 8.21.
295
296 5. A reference to an unset group with zero minimum repetition was giving
297 totally wrong answers (in non-JavaScript-compatibility mode). For example,
298 /(another)?(\1?)test/ matched against "hello world test". This bug was
299 introduced in release 8.13.
300
301 6. Add support for 16-bit character strings (a large amount of work involving
302 many changes and refactorings).
303
304 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
305 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
306 from a file.
307
308 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
309 rounding is not applied in this particular case).
310
311 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
312 if they appear, or are escaped, in patterns.
313
314 10. Get rid of a number of -Wunused-but-set-variable warnings.
315
316 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
317 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
318 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
319 also returns the mark "x". This bug applied to capturing parentheses,
320 non-capturing parentheses, and atomic parentheses. It also applied to some
321 assertions.
322
323 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
324 information out of configure.ac instead of relying on pcre.h.generic, which
325 is not stored in the repository.
326
327 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
328 -lreadline.
329
330 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
331
332 15. Applied Graycode's patch to put the top-level frame on the stack rather
333 than the heap when not using the stack for recursion. This gives a
334 performance improvement in many cases when recursion is not deep.
335
336 16. Experimental code added to "pcretest -C" to output the stack frame size.
337
338
339 Version 8.21 12-Dec-2011
340 ------------------------
341
342 1. Updating the JIT compiler.
343
344 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
345 are added as well.
346
347 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
348 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
349 calling _pcre_jit_exec. Some extra comments are added.
350
351 4. (*MARK) settings inside atomic groups that do not contain any capturing
352 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
353 was introduced by change 18 for 8.20.
354
355 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
356 ECMA-262 standard.
357
358 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
359 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
360 This bug was probably introduced by change 9 of 8.13.
361
362 7. While fixing 6 above, I noticed that a number of other items were being
363 incorrectly rejected as "not fixed length". This arose partly because newer
364 opcodes had not been added to the fixed-length checking code. I have (a)
365 corrected the bug and added tests for these items, and (b) arranged for an
366 error to occur if an unknown opcode is encountered while checking for fixed
367 length instead of just assuming "not fixed length". The items that were
368 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
369 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
370 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
371
372 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
373 being incorrectly compiled and would have given unpredicatble results.
374
375 9. A possessively repeated subpattern with minimum repeat count greater than
376 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
377 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
378 the first (A) could occur when it should not.
379
380 10. Add a cast and remove a redundant test from the code.
381
382 11. JIT should use pcre_malloc/pcre_free for allocation.
383
384 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
385 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
386 is anything other than /usr, -L is still shown).
387
388 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
389
390 14. Perl does not support \N without a following name in a [] class; PCRE now
391 also gives an error.
392
393 15. If a forward reference was repeated with an upper limit of around 2000,
394 it caused the error "internal error: overran compiling workspace". The
395 maximum number of forward references (including repeats) was limited by the
396 internal workspace, and dependent on the LINK_SIZE. The code has been
397 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
398 the default depends on LINK_SIZE. There is a new upper limit (for safety)
399 of around 200,000 forward references. While doing this, I also speeded up
400 the filling in of repeated forward references.
401
402 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
403 incorrectly expecting the subject to contain another "a" after the start.
404
405 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
406 in the match, the SKIP should be ignored. This was not happening; instead
407 the SKIP was being treated as NOMATCH. For patterns such as
408 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
409 tested.
410
411 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
412 now much more compatible with Perl, in particular in cases where the result
413 is a non-match for a non-anchored pattern. For example, if
414 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
415 "m", where previously it did not return a name. A side effect of this
416 change is that for partial matches, the last encountered mark name is
417 returned, as for non matches. A number of tests that were previously not
418 Perl-compatible have been moved into the Perl-compatible test files. The
419 refactoring has had the pleasing side effect of removing one argument from
420 the match() function, thus reducing its stack requirements.
421
422 19. If the /S+ option was used in pcretest to study a pattern using JIT,
423 subsequent uses of /S (without +) incorrectly behaved like /S+.
424
425 21. Retrieve executable code size support for the JIT compiler and fixing
426 some warnings.
427
428 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
429 not work when the shorter character appeared right at the end of the
430 subject string.
431
432 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
433 systems.
434
435 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
436 output it when the /M option is used in pcretest.
437
438 25. The CheckMan script was not being included in the distribution. Also, added
439 an explicit "perl" to run Perl scripts from the PrepareRelease script
440 because this is reportedly needed in Windows.
441
442 26. If study data was being save in a file and studying had not found a set of
443 "starts with" bytes for the pattern, the data written to the file (though
444 never used) was taken from uninitialized memory and so caused valgrind to
445 complain.
446
447 27. Updated RunTest.bat as provided by Sheri Pierce.
448
449 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
450
451 29. Computation of memory usage for the table of capturing group names was
452 giving an unnecessarily large value.
453
454
455 Version 8.20 21-Oct-2011
456 ------------------------
457
458 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
459 a POSIX class. After further experiments with Perl, which convinced me that
460 Perl has bugs and confusions, a closing square bracket is no longer allowed
461 in a POSIX name. This bug also affected patterns with classes that started
462 with full stops.
463
464 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
465 captured substring, but while checking the failing first alternative,
466 substring 1 is temporarily captured. If the output vector supplied to
467 pcre_exec() was not big enough for this capture, the yield of the function
468 was still zero ("insufficient space for captured substrings"). This cannot
469 be totally fixed without adding another stack variable, which seems a lot
470 of expense for a edge case. However, I have improved the situation in cases
471 such as /(a)(b)x|abc/ matched against "abc", where the return code
472 indicates that fewer than the maximum number of slots in the ovector have
473 been set.
474
475 3. Related to (2) above: when there are more back references in a pattern than
476 slots in the output vector, pcre_exec() uses temporary memory during
477 matching, and copies in the captures as far as possible afterwards. It was
478 using the entire output vector, but this conflicts with the specification
479 that only 2/3 is used for passing back captured substrings. Now it uses
480 only the first 2/3, for compatibility. This is, of course, another edge
481 case.
482
483 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
484 main code base, and can be used by building with --enable-jit. When this is
485 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
486 runtime --no-jit option is given.
487
488 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
489 ovector, the return from the function was zero, implying that there were
490 other matches that did not fit. The correct "exactly full" value is now
491 returned.
492
493 6. If a subpattern that was called recursively or as a subroutine contained
494 (*PRUNE) or any other control that caused it to give a non-standard return,
495 invalid errors such as "Error -26 (nested recursion at the same subject
496 position)" or even infinite loops could occur.
497
498 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
499 computing the minimum length on reaching *ACCEPT, and so ended up with the
500 wrong value of 1 rather than 0. Further investigation indicates that
501 computing a minimum subject length in the presence of *ACCEPT is difficult
502 (think back references, subroutine calls), and so I have changed the code
503 so that no minimum is registered for a pattern that contains *ACCEPT.
504
505 8. If (*THEN) was present in the first (true) branch of a conditional group,
506 it was not handled as intended. [But see 16 below.]
507
508 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
509 Sheri Pierce.
510
511 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
512 the first byte in a match must be "a".
513
514 11. Change 17 for 8.13 increased the recursion depth for patterns like
515 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
516 pattern contains any instances of (*THEN). If it does not, the old
517 optimizations are restored. It would be nice to do this on a per-group
518 basis, but at the moment that is not feasible.
519
520 12. In some environments, the output of pcretest -C is CRLF terminated. This
521 broke RunTest's code that checks for the link size. A single white space
522 character after the value is now allowed for.
523
524 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
525 For "fr", it uses the Windows-specific input and output files.
526
527 14. If (*THEN) appeared in a group that was called recursively or as a
528 subroutine, it did not work as intended. [But see next item.]
529
530 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
531 pattern fragments (but not containing any | characters). If A and B are
532 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
533 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
534 D. In other words, Perl considers parentheses that do not contain any |
535 characters to be part of a surrounding alternative, whereas PCRE was
536 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
537 differently. PCRE now behaves in the same way as Perl, except in the case
538 of subroutine/recursion calls such as (?1) which have in any case always
539 been different (but PCRE had them first :-).
540
541 16. Related to 15 above: Perl does not treat the | in a conditional group as
542 creating alternatives. Such a group is treated in the same way as an
543 ordinary group without any | characters when processing (*THEN). PCRE has
544 been changed to match Perl's behaviour.
545
546 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
547 RunGrepTest script failed.
548
549 18. Change 22 for version 13 caused atomic groups to use more stack. This is
550 inevitable for groups that contain captures, but it can lead to a lot of
551 stack use in large patterns. The old behaviour has been restored for atomic
552 groups that do not contain any capturing parentheses.
553
554 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
555 suppress the check for a minimum subject length at run time. (If it was
556 given to pcre_exec() or pcre_dfa_exec() it did work.)
557
558 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
559 fail to work when decoding hex characters in data strings in EBCDIC
560 environments.
561
562 21. It appears that in at least one Mac OS environment, the isxdigit() function
563 is implemented as a macro that evaluates to its argument more than once,
564 contravening the C 90 Standard (I haven't checked a later standard). There
565 was an instance in pcretest which caused it to go wrong when processing
566 \x{...} escapes in subject strings. The has been rewritten to avoid using
567 things like p++ in the argument of isxdigit().
568
569
570 Version 8.13 16-Aug-2011
571 ------------------------
572
573 1. The Unicode data tables have been updated to Unicode 6.0.0.
574
575 2. Two minor typos in pcre_internal.h have been fixed.
576
577 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
578 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
579 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
580
581 4. There were a number of related bugs in the code for matching backrefences
582 caselessly in UTF-8 mode when codes for the characters concerned were
583 different numbers of bytes. For example, U+023A and U+2C65 are an upper
584 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
585 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
586 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
587 2-byte code at the end of the subject (it thought there wasn't enough data
588 left).
589
590 5. Comprehensive information about what went wrong is now returned by
591 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
592 as the output vector has at least 2 elements. The offset of the start of
593 the failing character and a reason code are placed in the vector.
594
595 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
596 now returned is for the first byte of the failing character, instead of the
597 last byte inspected. This is an incompatible change, but I hope it is small
598 enough not to be a problem. It makes the returned offset consistent with
599 pcre_exec() and pcre_dfa_exec().
600
601 7. pcretest now gives a text phrase as well as the error number when
602 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
603 failure, the offset and reason code are output.
604
605 8. When \R was used with a maximizing quantifier it failed to skip backwards
606 over a \r\n pair if the subsequent match failed. Instead, it just skipped
607 back over a single character (\n). This seems wrong (because it treated the
608 two characters as a single entity when going forwards), conflicts with the
609 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
610 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
611 has been changed.
612
613 9. Some internal refactoring has changed the processing so that the handling
614 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
615 time (the PCRE_DOTALL option was changed this way some time ago: version
616 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
617 which was always a bit of a fudge. It also means that there is one less
618 argument for the match() function, which reduces its stack requirements
619 slightly. This change also fixes an incompatibility with Perl: the pattern
620 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
621
622 10. More internal refactoring has drastically reduced the number of recursive
623 calls to match() for possessively repeated groups such as (abc)++ when
624 using pcre_exec().
625
626 11. While implementing 10, a number of bugs in the handling of groups were
627 discovered and fixed:
628
629 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
630 (a|)*(?1) gave a compile-time internal error.
631 ((a|)+)+ did not notice that the outer group could match an empty string.
632 (^a|^)+ was not marked as anchored.
633 (.*a|.*)+ was not marked as matching at start or after a newline.
634
635 12. Yet more internal refactoring has removed another argument from the match()
636 function. Special calls to this function are now indicated by setting a
637 value in a variable in the "match data" data block.
638
639 13. Be more explicit in pcre_study() instead of relying on "default" for
640 opcodes that mean there is no starting character; this means that when new
641 ones are added and accidentally left out of pcre_study(), testing should
642 pick them up.
643
644 14. The -s option of pcretest has been documented for ages as being an old
645 synonym of -m (show memory usage). I have changed it to mean "force study
646 for every regex", that is, assume /S for every regex. This is similar to -i
647 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
648 using it. It makes it easier to run collections of tests with and without
649 study enabled, and thereby test pcre_study() more easily. All the standard
650 tests are now run with and without -s (but some patterns can be marked as
651 "never study" - see 20 below).
652
653 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
654 restoration of the capturing data to the outer values was not happening
655 correctly.
656
657 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
658 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
659 pattern had matched an empty string, and so incorrectly returned a no
660 match.
661
662 17. There was optimizing code for the last branch of non-capturing parentheses,
663 and also for the obeyed branch of a conditional subexpression, which used
664 tail recursion to cut down on stack usage. Unfortunately, now that there is
665 the possibility of (*THEN) occurring in these branches, tail recursion is
666 no longer possible because the return has to be checked for (*THEN). These
667 two optimizations have therefore been removed. [But see 8.20/11 above.]
668
669 18. If a pattern containing \R was studied, it was assumed that \R always
670 matched two bytes, thus causing the minimum subject length to be
671 incorrectly computed because \R can also match just one byte.
672
673 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
674 was incorrectly computed.
675
676 20. If /S is present twice on a test pattern in pcretest input, it now
677 *disables* studying, thereby overriding the use of -s on the command line
678 (see 14 above). This is necessary for one or two tests to keep the output
679 identical in both cases.
680
681 21. When (*ACCEPT) was used in an assertion that matched an empty string and
682 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
683
684 22. When an atomic group that contained a capturing parenthesis was
685 successfully matched, but the branch in which it appeared failed, the
686 capturing was not being forgotten if a higher numbered group was later
687 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
688 group 1 to "a", when in fact it should be unset. This applied to multi-
689 branched capturing and non-capturing groups, repeated or not, and also to
690 positive assertions (capturing in negative assertions does not happen
691 in PCRE) and also to nested atomic groups.
692
693 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
694 subject after a captured substring, to make it easier to tell which of a
695 number of identical substrings has been captured.
696
697 24. The way atomic groups are processed by pcre_exec() has been changed so that
698 if they are repeated, backtracking one repetition now resets captured
699 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
700 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
701 "aaa". Previously, it would have been "a". As part of this code
702 refactoring, the way recursive calls are handled has also been changed.
703
704 25. If an assertion condition captured any substrings, they were not passed
705 back unless some other capturing happened later. For example, if
706 (?(?=(a))a) was matched against "a", no capturing was returned.
707
708 26. When studying a pattern that contained subroutine calls or assertions,
709 the code for finding the minimum length of a possible match was handling
710 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
711 group 1 called group 2 while simultaneously a separate group 2 called group
712 1). A stack overflow occurred in this case. I have fixed this by limiting
713 the recursion depth to 10.
714
715 27. Updated RunTest.bat in the distribution to the version supplied by Tom
716 Fortmann. This supports explicit test numbers on the command line, and has
717 argument validation and error reporting.
718
719 28. An instance of \X with an unlimited repeat could fail if at any point the
720 first character it looked at was a mark character.
721
722 29. Some minor code refactoring concerning Unicode properties and scripts
723 should reduce the stack requirement of match() slightly.
724
725 30. Added the '=' option to pcretest to check the setting of unused capturing
726 slots at the end of the pattern, which are documented as being -1, but are
727 not included in the return count.
728
729 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
730 compiled something random. Now it gives a compile-time error (as does
731 Perl).
732
733 32. A *MARK encountered during the processing of a positive assertion is now
734 recorded and passed back (compatible with Perl).
735
736 33. If --only-matching or --colour was set on a pcregrep call whose pattern
737 had alternative anchored branches, the search for a second match in a line
738 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
739 matched the line "0102" twice. The same bug affected patterns that started
740 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
741 twice.
742
743 34. Previously, PCRE did not allow quantification of assertions. However, Perl
744 does, and because of capturing effects, quantifying parenthesized
745 assertions may at times be useful. Quantifiers are now allowed for
746 parenthesized assertions.
747
748 35. A minor code tidy in pcre_compile() when checking options for \R usage.
749
750 36. \g was being checked for fancy things in a character class, when it should
751 just be a literal "g".
752
753 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
754 appearance of a nested POSIX class supersedes an apparent external class.
755 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
756 unescaped square brackets may also appear as part of class names. For
757 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
758 more like Perl. (But see 8.20/1 above.)
759
760 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
761 was because it thought it was \N{name}, which is not supported).
762
763 39. Add minix to OS list not supporting the -S option in pcretest.
764
765 40. PCRE tries to detect cases of infinite recursion at compile time, but it
766 cannot analyze patterns in sufficient detail to catch mutual recursions
767 such as ((?1))((?2)). There is now a runtime test that gives an error if a
768 subgroup is called recursively as a subpattern for a second time at the
769 same position in the subject string. In previous releases this might have
770 been caught by the recursion limit, or it might have run out of stack.
771
772 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
773 happen only once. PCRE was, however incorrectly giving a compile time error
774 "recursive call could loop indefinitely" because it cannot analyze the
775 pattern in sufficient detail. The compile time test no longer happens when
776 PCRE is compiling a conditional subpattern, but actual runaway loops are
777 now caught at runtime (see 40 above).
778
779 42. It seems that Perl allows any characters other than a closing parenthesis
780 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
781 has been changed to be the same.
782
783 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
784 as not to get warnings when autogen.sh is called. Also changed
785 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
786
787 44. To help people who use pcregrep to scan files containing exceedingly long
788 lines, the following changes have been made:
789
790 (a) The default value of the buffer size parameter has been increased from
791 8K to 20K. (The actual buffer used is three times this size.)
792
793 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
794 PCRE is built.
795
796 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
797 to be set at run time.
798
799 (d) Numerical values in pcregrep options can be followed by K or M, for
800 example --buffer-size=50K.
801
802 (e) If a line being scanned overflows pcregrep's buffer, an error is now
803 given and the return code is set to 2.
804
805 45. Add a pointer to the latest mark to the callout data block.
806
807 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
808 partial match of an empty string instead of no match. This was specific to
809 the use of ".".
810
811 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
812 complete match instead of a partial match. This bug was dependent on both
813 the PCRE_UTF8 and PCRE_DOTALL options being set.
814
815 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
816 starting byte set, because \b was not being ignored.
817
818
819 Version 8.12 15-Jan-2011
820 ------------------------
821
822 1. Fixed some typos in the markup of the man pages, and wrote a script that
823 checks for such things as part of the documentation building process.
824
825 2. On a big-endian 64-bit system, pcregrep did not correctly process the
826 --match-limit and --recursion-limit options (added for 8.11). In
827 particular, this made one of the standard tests fail. (The integer value
828 went into the wrong half of a long int.)
829
830 3. If the --colour option was given to pcregrep with -v (invert match), it
831 did strange things, either producing crazy output, or crashing. It should,
832 of course, ignore a request for colour when reporting lines that do not
833 match.
834
835 4. Another pcregrep bug caused similar problems if --colour was specified with
836 -M (multiline) and the pattern match finished with a line ending.
837
838 5. In pcregrep, when a pattern that ended with a literal newline sequence was
839 matched in multiline mode, the following line was shown as part of the
840 match. This seems wrong, so I have changed it.
841
842 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
843 the check for further matches in the same line (so they could be coloured)
844 to overrun the end of the current line. If another match was found, it was
845 incorrectly shown (and then shown again when found in the next line).
846
847 7. If pcregrep was compiled under Windows, there was a reference to the
848 function pcregrep_exit() before it was defined. I am assuming this was
849 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
850 reported by a user. I've moved the definition above the reference.
851
852
853 Version 8.11 10-Dec-2010
854 ------------------------
855
856 1. (*THEN) was not working properly if there were untried alternatives prior
857 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
858 backtracked to try for "b" instead of moving to the next alternative branch
859 at the same level (in this case, to look for "c"). The Perl documentation
860 is clear that when (*THEN) is backtracked onto, it goes to the "next
861 alternative in the innermost enclosing group".
862
863 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
864 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
865 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
866 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
867 (*THEN).
868
869 3. If \s appeared in a character class, it removed the VT character from
870 the class, even if it had been included by some previous item, for example
871 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
872 of \s, but is part of the POSIX "space" class.)
873
874 4. A partial match never returns an empty string (because you can always
875 match an empty string at the end of the subject); however the checking for
876 an empty string was starting at the "start of match" point. This has been
877 changed to the "earliest inspected character" point, because the returned
878 data for a partial match starts at this character. This means that, for
879 example, /(?<=abc)def/ gives a partial match for the subject "abc"
880 (previously it gave "no match").
881
882 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
883 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
884 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
885 has an implication that the given string is incomplete (because a partial
886 match is preferred over a full match). For this reason, these items now
887 give a partial match in this situation. [Aside: previously, the one case
888 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
889 match rather than a full match, which was wrong by the old rules, but is
890 now correct.]
891
892 6. There was a bug in the handling of #-introduced comments, recognized when
893 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
894 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
895 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
896 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
897 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
898 places in pcre_compile().
899
900 7. Related to (6) above, when pcre_compile() was skipping #-introduced
901 comments when looking ahead for named forward references to subpatterns,
902 the only newline sequence it recognized was NL. It now handles newlines
903 according to the set newline convention.
904
905 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
906 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
907 cater for a lack of strerror(). These oversights have been fixed.
908
909 9. Added --match-limit and --recursion-limit to pcregrep.
910
911 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
912
913 11. When the -o option was used, pcregrep was setting a return code of 1, even
914 when matches were found, and --line-buffered was not being honoured.
915
916 12. Added an optional parentheses number to the -o and --only-matching options
917 of pcregrep.
918
919 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
920 can match an empty string. The code to do it in pcretest and pcredemo
921 needed fixing:
922
923 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
924 only one byte after an empty string match just before CRLF (this case
925 just got forgotten; "any" and "anycrlf" were OK).
926
927 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
928 mode when an empty string match preceded an ASCII character followed by
929 a non-ASCII character. (The code for advancing by one character rather
930 than one byte was nonsense.)
931
932 (c) The pcredemo.c sample program did not have any code at all to handle
933 the cases when CRLF is a valid newline sequence.
934
935 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
936 as a starting offset was within the subject string. There is now a new
937 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
938 negative or greater than the length of the string. In order to test this,
939 pcretest is extended to allow the setting of negative starting offsets.
940
941 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
942 starting offset points to the beginning of a UTF-8 character was
943 unnecessarily clumsy. I tidied it up.
944
945 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
946 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
947
948 17. Nobody had reported that the --include_dir option, which was added in
949 release 7.7 should have been called --include-dir (hyphen, not underscore)
950 for compatibility with GNU grep. I have changed it to --include-dir, but
951 left --include_dir as an undocumented synonym, and the same for
952 --exclude-dir, though that is not available in GNU grep, at least as of
953 release 2.5.4.
954
955 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
956 characters from a string of bytes) have been redefined so as not to use
957 loops, in order to improve performance in some environments. At the same
958 time, I abstracted some of the common code into auxiliary macros to save
959 repetition (this should not affect the compiled code).
960
961 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
962 compile-time error is now given if \c is not followed by an ASCII
963 character, that is, a byte less than 128. (In EBCDIC mode, the code is
964 different, and any byte value is allowed.)
965
966 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
967 START_OPTIMIZE option, which is now allowed at compile time - but just
968 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
969 to pcregrep and other applications that have no direct access to PCRE
970 options. The new /Y option in pcretest sets this option when calling
971 pcre_compile().
972
973 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
974 back references. Groups containing recursive back references were forced to
975 be atomic by that change, but in the case of named groups, the amount of
976 memory required was incorrectly computed, leading to "Failed: internal
977 error: code overflow". This has been fixed.
978
979 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
980 pcretest.c, to avoid build problems in some Borland environments.
981
982
983 Version 8.10 25-Jun-2010
984 ------------------------
985
986 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
987 THEN.
988
989 2. (*ACCEPT) was not working when inside an atomic group.
990
991 3. Inside a character class, \B is treated as a literal by default, but
992 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
993 causes the error). The code is unchanged, but I tidied the documentation.
994
995 4. Inside a character class, PCRE always treated \R and \X as literals,
996 whereas Perl faults them if its -w option is set. I have changed PCRE so
997 that it faults them when PCRE_EXTRA is set.
998
999 5. Added support for \N, which always matches any character other than
1000 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1001
1002 6. When compiling pcregrep with newer versions of gcc which may have
1003 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1004 declared with attribute warn_unused_result" were given. Just casting the
1005 result to (void) does not stop the warnings; a more elaborate fudge is
1006 needed. I've used a macro to implement this.
1007
1008 7. Minor change to pcretest.c to avoid a compiler warning.
1009
1010 8. Added four artifical Unicode properties to help with an option to make
1011 \s etc use properties (see next item). The new properties are: Xan
1012 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1013
1014 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1015 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1016 this option. Modified pcretest to add /W to test this facility. Added
1017 REG_UCP to make it available via the POSIX interface.
1018
1019 10. Added --line-buffered to pcregrep.
1020
1021 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1022 studied, and the match started with a letter with a code point greater than
1023 127 whose first byte was different to the first byte of the other case of
1024 the letter, the other case of this starting letter was not recognized
1025 (#976).
1026
1027 12. If a pattern that was studied started with a repeated Unicode property
1028 test, for example, \p{Nd}+, there was the theoretical possibility of
1029 setting up an incorrect bitmap of starting bytes, but fortunately it could
1030 not have actually happened in practice until change 8 above was made (it
1031 added property types that matched character-matching opcodes).
1032
1033 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1034 possible starting bytes for non-anchored patterns.
1035
1036 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1037 \R, and also a number of cases that involve Unicode properties, both
1038 explicit and implicit when PCRE_UCP is set.
1039
1040 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1041 input, it could crash or give wrong results if characters with values
1042 greater than 0xc0 were present in the subject string. (Detail: it assumed
1043 UTF-8 input when processing these items.)
1044
1045 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1046 size_t is 64-bit (#991).
1047
1048 17. Added a check for running out of memory when PCRE is compiled with
1049 --disable-stack-for-recursion (#990).
1050
1051 18. If the last data line in a file for pcretest does not have a newline on
1052 the end, a newline was missing in the output.
1053
1054 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1055 less than 128) in its various bitmaps. However, there is a facility for
1056 generating tables according to the current locale when PCRE is compiled. It
1057 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1058 characters, are recognized by isspace() and therefore were getting set in
1059 these tables, and indeed these tables seem to approximate to ISO 8859. This
1060 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1061 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1062 which of course cannot start UTF-8 characters. I have changed the code so
1063 that only real ASCII characters (less than 128) and the correct starting
1064 bytes for UTF-8 encodings are set for characters greater than 127 when in
1065 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1066 altogether.)
1067
1068 20. Added the /T option to pcretest so as to be able to run tests with non-
1069 standard character tables, thus making it possible to include the tests
1070 used for 19 above in the standard set of tests.
1071
1072 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1073 reference to a subpattern the other side of a comment that contains an
1074 opening parenthesis caused either an internal compiling error, or a
1075 reference to the wrong subpattern.
1076
1077
1078 Version 8.02 19-Mar-2010
1079 ------------------------
1080
1081 1. The Unicode data tables have been updated to Unicode 5.2.0.
1082
1083 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
1084 configured.
1085
1086 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
1087 original author of that file, following a query about its status.
1088
1089 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
1090 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1091
1092 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1093 quantifier applied to a forward-referencing subroutine call, could compile
1094 incorrect code or give the error "internal error: previously-checked
1095 referenced subpattern not found".
1096
1097 6. Both MS Visual Studio and Symbian OS have problems with initializing
1098 variables to point to external functions. For these systems, therefore,
1099 pcre_malloc etc. are now initialized to local functions that call the
1100 relevant global functions.
1101
1102 7. There were two entries missing in the vectors called coptable and poptable
1103 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1104 I've fixed the data, and added a kludgy way of testing at compile time that
1105 the lengths are correct (equal to the number of opcodes).
1106
1107 8. Following on from 7, I added a similar kludge to check the length of the
1108 eint vector in pcreposix.c.
1109
1110 9. Error texts for pcre_compile() are held as one long string to avoid too
1111 much relocation at load time. To find a text, the string is searched,
1112 counting zeros. There was no check for running off the end of the string,
1113 which could happen if a new error number was added without updating the
1114 string.
1115
1116 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1117
1118 11. \K was not working if it appeared in an atomic group or in a group that
1119 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1120 \K is "not well defined" if used in an assertion. PCRE now accepts it if
1121 the assertion is positive, but not if it is negative.
1122
1123 12. Change 11 fortuitously reduced the size of the stack frame used in the
1124 "match()" function of pcre_exec.c by one pointer. Forthcoming
1125 implementation of support for (*MARK) will need an extra pointer on the
1126 stack; I have reserved it now, so that the stack frame size does not
1127 decrease.
1128
1129 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1130 item in branch that calls a recursion is a subroutine call - as in the
1131 second branch in the above example - was incorrectly given the compile-
1132 time error "recursive call could loop indefinitely" because pcre_compile()
1133 was not correctly checking the subroutine for matching a non-empty string.
1134
1135 14. The checks for overrunning compiling workspace could trigger after an
1136 overrun had occurred. This is a "should never occur" error, but it can be
1137 triggered by pathological patterns such as hundreds of nested parentheses.
1138 The checks now trigger 100 bytes before the end of the workspace.
1139
1140 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1141
1142
1143 Version 8.01 19-Jan-2010
1144 ------------------------
1145
1146 1. If a pattern contained a conditional subpattern with only one branch (in
1147 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1148 computed the wrong minimum data length (which is of course zero for such
1149 subpatterns). This could cause incorrect "no match" results.
1150
1151 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1152 the pattern is reset in the first branch, pcre_compile() failed with
1153 "internal error: code overflow at offset...". This happened only when
1154 the reset was to the original external option setting. (An optimization
1155 abstracts leading options settings into an external setting, which was the
1156 cause of this.)
1157
1158 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1159 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1160 assertion pattern did not match (meaning that the assertion was true), it
1161 was incorrectly treated as false if the SKIP had been reached during the
1162 matching. This also applied to assertions used as conditions.
1163
1164 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
1165 assertion subpattern, including such a pattern used as a condition,
1166 unpredictable results occurred, instead of the error return
1167 PCRE_ERROR_DFA_UITEM.
1168
1169 5. The C++ GlobalReplace function was not working like Perl for the special
1170 situation when an empty string is matched. It now does the fancy magic
1171 stuff that is necessary.
1172
1173 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1174 removed. (These were left over from very, very early versions of PCRE.)
1175
1176 7. Some cosmetic changes to the code to make life easier when compiling it
1177 as part of something else:
1178
1179 (a) Change DEBUG to PCRE_DEBUG.
1180
1181 (b) In pcre_compile(), rename the member of the "branch_chain" structure
1182 called "current" as "current_branch", to prevent a collision with the
1183 Linux macro when compiled as a kernel module.
1184
1185 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1186 prevent a collision with the Linux macro when compiled as a kernel
1187 module.
1188
1189 8. In pcre_compile() there are some checks for integer overflows that used to
1190 cast potentially large values to (double). This has been changed to that
1191 when building, a check for int64_t is made, and if it is found, it is used
1192 instead, thus avoiding the use of floating point arithmetic. (There is no
1193 other use of FP in PCRE.) If int64_t is not found, the fallback is to
1194 double.
1195
1196 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
1197 2005 (difference between two addresses compared to an unsigned value).
1198
1199 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1200 custom one, because of the following reported problem in Windows:
1201
1202 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1203 under Win32.
1204 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1205 therefore missing the function definition.
1206 - The compiler thus generates a "C" signature for the test function.
1207 - The linker fails to find the "C" function.
1208 - PCRE fails to configure if asked to do so against libbz2.
1209
1210 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1211 messages were output:
1212
1213 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1214 rerunning libtoolize, to keep the correct libtool macros in-tree.
1215 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1216
1217 I have done both of these things.
1218
1219 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1220 most of the time, it *can* run out if it is given a pattern that contains a
1221 runaway infinite recursion. I updated the discussion in the pcrestack man
1222 page.
1223
1224 13. Now that we have gone to the x.xx style of version numbers, the minor
1225 version may start with zero. Using 08 or 09 is a bad idea because users
1226 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1227 interpreted as invalid octal numbers. I've updated the previous comment in
1228 configure.ac, and also added a check that gives an error if 08 or 09 are
1229 used.
1230
1231 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1232 causing partial matching to fail when the end of the subject matched \W
1233 in a UTF-8 pattern where \W was quantified with a minimum of 3.
1234
1235 15. There were some discrepancies between the declarations in pcre_internal.h
1236 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1237 their definitions. The declarations used "const uschar *" and the
1238 definitions used USPTR. Even though USPTR is normally defined as "const
1239 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1240 reported that: "This difference in casting confuses some C++ compilers, for
1241 example, SunCC recognizes above declarations as different functions and
1242 generates broken code for hbpcre." I have changed the declarations to use
1243 USPTR.
1244
1245 16. GNU libtool is named differently on some systems. The autogen.sh script now
1246 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1247 (FreeBSD).
1248
1249 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1250 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1251 comment: "Figure out how to create a longlong from a string: strtoll and
1252 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1253 instance, but it only takes 2 args instead of 3!"
1254
1255 18. A subtle bug concerned with back references has been fixed by a change of
1256 specification, with a corresponding code fix. A pattern such as
1257 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1258 refers, was giving matches when it shouldn't. For example, xa=xaaa would
1259 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1260 same bug. Such groups have to be quantified to be useful, or contained
1261 inside another quantified group. (If there's no repetition, the reference
1262 can never match.) The problem arises because, having left the group and
1263 moved on to the rest of the pattern, a later failure that backtracks into
1264 the group uses the captured value from the final iteration of the group
1265 rather than the correct earlier one. I have fixed this in PCRE by forcing
1266 any group that contains a reference to itself to be an atomic group; that
1267 is, there cannot be any backtracking into it once it has completed. This is
1268 similar to recursive and subroutine calls.
1269
1270
1271 Version 8.00 19-Oct-09
1272 ----------------------
1273
1274 1. The table for translating pcre_compile() error codes into POSIX error codes
1275 was out-of-date, and there was no check on the pcre_compile() error code
1276 being within the table. This could lead to an OK return being given in
1277 error.
1278
1279 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1280 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1281 in a Windows environment.
1282
1283 3. The pcregrep --count option prints the count for each file even when it is
1284 zero, as does GNU grep. However, pcregrep was also printing all files when
1285 --files-with-matches was added. Now, when both options are given, it prints
1286 counts only for those files that have at least one match. (GNU grep just
1287 prints the file name in this circumstance, but including the count seems
1288 more useful - otherwise, why use --count?) Also ensured that the
1289 combination -clh just lists non-zero counts, with no names.
1290
1291 4. The long form of the pcregrep -F option was incorrectly implemented as
1292 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1293 but it seems right to fix it, and I didn't think it was worth preserving
1294 the old behaviour.
1295
1296 5. The command line items --regex=pattern and --regexp=pattern were not
1297 recognized by pcregrep, which required --regex pattern or --regexp pattern
1298 (with a space rather than an '='). The man page documented the '=' forms,
1299 which are compatible with GNU grep; these now work.
1300
1301 6. No libpcreposix.pc file was created for pkg-config; there was just
1302 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1303
1304 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1305 when UCP support is not needed, by modifying the Python script that
1306 generates it from Unicode data files. This should not matter if the module
1307 is correctly used as a library, but I received one complaint about 50K of
1308 unwanted data. My guess is that the person linked everything into his
1309 program rather than using a library. Anyway, it does no harm.
1310
1311 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1312 was a minimum greater than 1 for a wide character in a possessive
1313 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1314 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1315 character. Chaos in the form of incorrect output or a compiling loop could
1316 result.
1317
1318 9. The restrictions on what a pattern can contain when partial matching is
1319 requested for pcre_exec() have been removed. All patterns can now be
1320 partially matched by this function. In addition, if there are at least two
1321 slots in the offset vector, the offset of the earliest inspected character
1322 for the match and the offset of the end of the subject are set in them when
1323 PCRE_ERROR_PARTIAL is returned.
1324
1325 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1326 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1327 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1328 and may be more useful for multi-segment matching.
1329
1330 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1331 used to be given if ever the end of the subject was reached; now it is
1332 given only if matching could not proceed because another character was
1333 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1334 string "Z", which now yields "no match" instead of "partial match". In the
1335 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1336 final character ended with (*FAIL).
1337
1338 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1339 if the pattern had a "must contain" character that was already found in the
1340 earlier partial match, unless partial matching was again requested. For
1341 example, with the pattern /dog.(body)?/, the "must contain" character is
1342 "g". If the first part-match was for the string "dog", restarting with
1343 "sbody" failed. This bug has been fixed.
1344
1345 13. The string returned by pcre_dfa_exec() after a partial match has been
1346 changed so that it starts at the first inspected character rather than the
1347 first character of the match. This makes a difference only if the pattern
1348 starts with a lookbehind assertion or \b or \B (\K is not supported by
1349 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1350 matching functions compatible, and I think it's the right thing to do.
1351
1352 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1353 so that the demonstration program is easily available in environments where
1354 PCRE has not been installed from source.
1355
1356 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1357 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1358 library.
1359
1360 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1361 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1362 is not the first non-POSIX option to be added. Clearly some people find
1363 these options useful.
1364
1365 17. If a caller to the POSIX matching function regexec() passes a non-zero
1366 value for nmatch with a NULL value for pmatch, the value of
1367 nmatch is forced to zero.
1368
1369 18. RunGrepTest did not have a test for the availability of the -u option of
1370 the diff command, as RunTest does. It now checks in the same way as
1371 RunTest, and also checks for the -b option.
1372
1373 19. If an odd number of negated classes containing just a single character
1374 interposed, within parentheses, between a forward reference to a named
1375 subpattern and the definition of the subpattern, compilation crashed with
1376 an internal error, complaining that it could not find the referenced
1377 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1378 [The bug was that it was starting one character too far in when skipping
1379 over the character class, thus treating the ] as data rather than
1380 terminating the class. This meant it could skip too much.]
1381
1382 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1383 /g option in pcretest when the pattern contains \K, which makes it possible
1384 to have an empty string match not at the start, even when the pattern is
1385 anchored. Updated pcretest and pcredemo to use this option.
1386
1387 21. If the maximum number of capturing subpatterns in a recursion was greater
1388 than the maximum at the outer level, the higher number was returned, but
1389 with unset values at the outer level. The correct (outer level) value is
1390 now given.
1391
1392 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1393 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1394 make it do so. The string so far is captured, making this feature
1395 compatible with Perl.
1396
1397 23. The tests have been re-organized, adding tests 11 and 12, to make it
1398 possible to check the Perl 5.10 features against Perl 5.10.
1399
1400 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1401 pattern matches a fixed length string. PCRE did not allow this; now it
1402 does. Neither allows recursion.
1403
1404 25. I finally figured out how to implement a request to provide the minimum
1405 length of subject string that was needed in order to match a given pattern.
1406 (It was back references and recursion that I had previously got hung up
1407 on.) This code has now been added to pcre_study(); it finds a lower bound
1408 to the length of subject needed. It is not necessarily the greatest lower
1409 bound, but using it to avoid searching strings that are too short does give
1410 some useful speed-ups. The value is available to calling programs via
1411 pcre_fullinfo().
1412
1413 26. While implementing 25, I discovered to my embarrassment that pcretest had
1414 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1415 study optimizations had never been tested with that matching function.
1416 Oops. What is worse, even when it was passed study data, there was a bug in
1417 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1418 were also very few tests of studied patterns with pcre_dfa_exec().
1419
1420 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1421 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1422 on the other side of the coin, they are no longer allowed to have different
1423 names, because these cannot be distinguished in PCRE, and this has caused
1424 confusion. (This is a difference from Perl.)
1425
1426 28. When duplicate subpattern names are present (necessarily with different
1427 numbers, as required by 27 above), and a test is made by name in a
1428 conditional pattern, either for a subpattern having been matched, or for
1429 recursion in such a pattern, all the associated numbered subpatterns are
1430 tested, and the overall condition is true if the condition is true for any
1431 one of them. This is the way Perl works, and is also more like the way
1432 testing by number works.
1433
1434
1435 Version 7.9 11-Apr-09
1436 ---------------------
1437
1438 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1439 (pcretest), all targets were linked against these libraries. This included
1440 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1441 libraries. This caused unwanted dependencies to be created. This problem
1442 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1443 pcretest is linked with readline.
1444
1445 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1446 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1447 moved outside it again, because FALSE and TRUE are already defined in AIX,
1448 but BOOL is not.
1449
1450 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1451 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1452
1453 4. The pcregrep documentation said spaces were inserted as well as colons (or
1454 hyphens) following file names and line numbers when outputting matching
1455 lines. This is not true; no spaces are inserted. I have also clarified the
1456 wording for the --colour (or --color) option.
1457
1458 5. In pcregrep, when --colour was used with -o, the list of matching strings
1459 was not coloured; this is different to GNU grep, so I have changed it to be
1460 the same.
1461
1462 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1463 each matching line was coloured. Now it goes on to look for further matches
1464 of any of the test patterns, which is the same behaviour as GNU grep.
1465
1466 7. A pattern that could match an empty string could cause pcregrep to loop; it
1467 doesn't make sense to accept an empty string match in pcregrep, so I have
1468 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1469 seems to be how GNU grep behaves.
1470
1471 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1472 start or after a newline", because the conditional assertion was not being
1473 correctly handled. The rule now is that both the assertion and what follows
1474 in the first alternative must satisfy the test.
1475
1476 9. If auto-callout was enabled in a pattern with a conditional group whose
1477 condition was an assertion, PCRE could crash during matching, both with
1478 pcre_exec() and pcre_dfa_exec().
1479
1480 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1481 used for matching.
1482
1483 11. Unicode property support in character classes was not working for
1484 characters (bytes) greater than 127 when not in UTF-8 mode.
1485
1486 12. Added the -M command line option to pcretest.
1487
1488 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1489
1490 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1491
1492 16. Added comments and documentation about mis-use of no_arg in the C++
1493 wrapper.
1494
1495 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1496 from Martin Jerabek that uses macro names for all relevant character and
1497 string constants.
1498
1499 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1500 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1501 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1502 these, but not everybody uses configure.
1503
1504 19. A conditional group that had only one branch was not being correctly
1505 recognized as an item that could match an empty string. This meant that an
1506 enclosing group might also not be so recognized, causing infinite looping
1507 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1508 with the subject "ab", where knowledge that the repeated group can match
1509 nothing is needed in order to break the loop.
1510
1511 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1512 exec(), but without supplying a callout function, matching went wrong.
1513
1514 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1515 leak if the size of the offset vector was greater than 30. When the vector
1516 is smaller, the saved offsets during recursion go onto a local stack
1517 vector, but for larger vectors malloc() is used. It was failing to free
1518 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1519 error, in fact).
1520
1521 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1522 heapframe that is used only when UTF-8 support is enabled. This caused no
1523 problem, but was untidy.
1524
1525 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1526 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1527 included within another project.
1528
1529 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1530 slightly modified by me:
1531
1532 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1533 not building pcregrep.
1534
1535 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1536 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1537
1538 25. Forward references, both numeric and by name, in patterns that made use of
1539 duplicate group numbers, could behave incorrectly or give incorrect errors,
1540 because when scanning forward to find the reference group, PCRE was not
1541 taking into account the duplicate group numbers. A pattern such as
1542 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1543
1544 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1545 the feature of a custom pointer more persuasive (as requested by a user).
1546
1547 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1548 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1549 pre-defined.
1550
1551 28. Added support for (*UTF8) at the start of a pattern.
1552
1553 29. Arrange for flags added by the "release type" setting in CMake to be shown
1554 in the configuration summary.
1555
1556
1557 Version 7.8 05-Sep-08
1558 ---------------------
1559
1560 1. Replaced UCP searching code with optimized version as implemented for Ad
1561 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1562 stage table and inline lookup instead of a function, giving speed ups of 2
1563 to 5 times on some simple patterns that I tested. Permission was given to
1564 distribute the MultiStage2.py script that generates the tables (it's not in
1565 the tarball, but is in the Subversion repository).
1566
1567 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1568 scripts.
1569
1570 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1571 a group with a zero qualifier. The result of the study could be incorrect,
1572 or the function might crash, depending on the pattern.
1573
1574 4. Caseless matching was not working for non-ASCII characters in back
1575 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1576 It now works when Unicode Property Support is available.
1577
1578 5. In pcretest, an escape such as \x{de} in the data was always generating
1579 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1580 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1581 truncation.
1582
1583 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1584
1585 7. Added two (int) casts to pcregrep when printing the difference of two
1586 pointers, in case they are 64-bit values.
1587
1588 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1589 test 2 if it fails.
1590
1591 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1592 and a #define of that name to empty if it is not externally set. This is to
1593 allow users of MSVC to set it if necessary.
1594
1595 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1596 the convenience functions in the pcre_get.c source file.
1597
1598 11. An option change at the start of a pattern that had top-level alternatives
1599 could cause overwriting and/or a crash. This command provoked a crash in
1600 some environments:
1601
1602 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1603
1604 This potential security problem was recorded as CVE-2008-2371.
1605
1606 12. For a pattern where the match had to start at the beginning or immediately
1607 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1608 pcre_dfa_exec() could read past the end of the passed subject if there was
1609 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1610 pcretest so that it places the subject at the end of its malloc-ed buffer.
1611
1612 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1613 exec() might read past the end of the data buffer in UTF-8 mode.
1614
1615 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1616 the data contained the byte 0x85 as part of a UTF-8 character within its
1617 first line. This applied both to normal and DFA matching.
1618
1619 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1620 /^[^d]*?$/8 failed to match "abc".
1621
1622 16. Added a missing copyright notice to pcrecpp_internal.h.
1623
1624 17. Make it more clear in the documentation that values returned from
1625 pcre_exec() in ovector are byte offsets, not character counts.
1626
1627 18. Tidied a few places to stop certain compilers from issuing warnings.
1628
1629 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1630 supplied by Stefan Weber. I made a further small update for 7.8 because
1631 there is a change of source arrangements: the pcre_searchfuncs.c module is
1632 replaced by pcre_ucd.c.
1633
1634
1635 Version 7.7 07-May-08
1636 ---------------------
1637
1638 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1639 a string to a long long, pretend we don't even have a long long." This is
1640 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1641
1642 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1643 pre-7.6 versions, which defined a global no_arg variable instead of putting
1644 it in the RE class. (See also #8 below.)
1645
1646 3. Remove a line of dead code, identified by coverity and reported by Nuno
1647 Lopes.
1648
1649 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1650
1651 (1) The include/exclude patterns were being applied to the whole pathnames
1652 of files, instead of just to the final components.
1653
1654 (2) If there was more than one level of directory, the subdirectories were
1655 skipped unless they satisfied the include/exclude conditions. This is
1656 inconsistent with GNU grep (and could even be seen as contrary to the
1657 pcregrep specification - which I improved to make it absolutely clear).
1658 The action now is always to scan all levels of directory, and just
1659 apply the include/exclude patterns to regular files.
1660
1661 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1662 --exclude_dir in the tests to avoid scanning .svn directories.
1663
1664 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1665 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1666 doesn't support NULs in patterns.
1667
1668 7. Added some missing "const"s to declarations of static tables in
1669 pcre_compile.c and pcre_dfa_exec.c.
1670
1671 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1672 caused by fix #2 above. (Subsequently also a second patch to fix the
1673 first patch. And a third patch - this was a messy problem.)
1674
1675 9. Applied Craig's patch to remove the use of push_back().
1676
1677 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1678 matching function regexec().
1679
1680 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1681 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1682 references. PCRE supports relative numbers with this syntax (I don't think
1683 Oniguruma does).
1684
1685 12. Previously, a group with a zero repeat such as (...){0} was completely
1686 omitted from the compiled regex. However, this means that if the group
1687 was called as a subroutine from elsewhere in the pattern, things went wrong
1688 (an internal error was given). Such groups are now left in the compiled
1689 pattern, with a new opcode that causes them to be skipped at execution
1690 time.
1691
1692 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1693 to the way PCRE behaves:
1694
1695 (a) A lone ] character is dis-allowed (Perl treats it as data).
1696
1697 (b) A back reference to an unmatched subpattern matches an empty string
1698 (Perl fails the current match path).
1699
1700 (c) A data ] in a character class must be notated as \] because if the
1701 first data character in a class is ], it defines an empty class. (In
1702 Perl it is not possible to have an empty class.) The empty class []
1703 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1704 The negative empty class [^] matches any one character, independently
1705 of the DOTALL setting.
1706
1707 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1708 non-existent subpattern following a character class starting with ']' and
1709 containing () gave an internal compiling error instead of "reference to
1710 non-existent subpattern". Fortunately, when the pattern did exist, the
1711 compiled code was correct. (When scanning forwards to check for the
1712 existencd of the subpattern, it was treating the data ']' as terminating
1713 the class, so got the count wrong. When actually compiling, the reference
1714 was subsequently set up correctly.)
1715
1716 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1717 it was being rejected as not supported by pcre_dfa_exec(), even though
1718 other assertions are supported. I have made pcre_dfa_exec() support
1719 (*FAIL).
1720
1721 16. The implementation of 13c above involved the invention of a new opcode,
1722 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1723 cannot be changed at match time, I realized I could make a small
1724 improvement to matching performance by compiling OP_ALLANY instead of
1725 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1726 on the OP_ANY path.
1727
1728 17. Compiling pcretest on Windows with readline support failed without the
1729 following two fixes: (1) Make the unistd.h include conditional on
1730 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1731
1732 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1733 ncurses library to be included for pcretest when ReadLine support is
1734 requested, but also to allow for it to be overridden. This patch came from
1735 Daniel Bergström.
1736
1737 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1738 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1739 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1740 spotting this.
1741
1742
1743 Version 7.6 28-Jan-08
1744 ---------------------
1745
1746 1. A character class containing a very large number of characters with
1747 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1748 overflow.
1749
1750 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1751 HAVE_LONG_LONG is not defined.
1752
1753 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1754 bring them up to date and include new features. This patch includes:
1755
1756 - Fixed PH's badly added libz and libbz2 support.
1757 - Fixed a problem with static linking.
1758 - Added pcredemo. [But later removed - see 7 below.]
1759 - Fixed dftables problem and added an option.
1760 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1761 HAVE_LONG_LONG.
1762 - Added readline support for pcretest.
1763 - Added an listing of the option settings after cmake has run.
1764
1765 4. A user submitted a patch to Makefile that makes it easy to create
1766 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1767 Makefile.am that cause it to include this special target, without
1768 affecting anything else. Note that the same mingw target plus all
1769 the other distribution libraries and programs are now supported
1770 when configuring with CMake (see 6 below) instead of with
1771 Configure/Make.
1772
1773 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1774 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1775 exported in the Windows port". It has not yet been confirmed that the patch
1776 solves the problem, but it does no harm.
1777
1778 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1779 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1780 with CMake, and also correct the comment about stack recursion.
1781
1782 7. Remove the automatic building of pcredemo from the ./configure system and
1783 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1784 of a program that users should build themselves after PCRE is installed, so
1785 building it automatically is not really right. What is more, it gave
1786 trouble in some build environments.
1787
1788 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1789
1790
1791 Version 7.5 10-Jan-08
1792 ---------------------
1793
1794 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1795 values in parens when parsing an RE using the C++ wrapper."
1796
1797 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1798 Characters greater than 255 were excluded from the class instead of being
1799 included.
1800
1801 3. The same bug as (2) above applied to negated POSIX classes such as
1802 [:^space:].
1803
1804 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1805 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1806 I have changed it.
1807
1808 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1809 first named subpattern) and a construct such as (?&a) would reference the
1810 first named subpattern whose name started with "a" (in other words, the
1811 length check was missing). Both these problems are fixed. "Subpattern name
1812 expected" is now given for (?&) (a zero-length name), and this patch also
1813 makes it give the same error for \k'' (previously it complained that that
1814 was a reference to a non-existent subpattern).
1815
1816 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1817 this is right because (?- can be followed by option settings as well as by
1818 digits. I have, however, made the messages clearer.
1819
1820 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1821 than the number used in the conditional) now cause a compile-time error.
1822 This is actually not compatible with Perl, which accepts such patterns, but
1823 treats the conditional as always being FALSE (as PCRE used to), but it
1824 seems to me that giving a diagnostic is better.
1825
1826 8. Change "alphameric" to the more common word "alphanumeric" in comments
1827 and messages.
1828
1829 9. Fix two occurrences of "backslash" in comments that should have been
1830 "backspace".
1831
1832 10. Remove two redundant lines of code that can never be obeyed (their function
1833 was moved elsewhere).
1834
1835 11. The program that makes PCRE's Unicode character property table had a bug
1836 which caused it to generate incorrect table entries for sequences of
1837 characters that have the same character type, but are in different scripts.
1838 It amalgamated them into a single range, with the script of the first of
1839 them. In other words, some characters were in the wrong script. There were
1840 thirteen such cases, affecting characters in the following ranges:
1841
1842 U+002b0 - U+002c1
1843 U+0060c - U+0060d
1844 U+0061e - U+00612
1845 U+0064b - U+0065e
1846 U+0074d - U+0076d
1847 U+01800 - U+01805
1848 U+01d00 - U+01d77
1849 U+01d9b - U+01dbf
1850 U+0200b - U+0200f
1851 U+030fc - U+030fe
1852 U+03260 - U+0327f
1853 U+0fb46 - U+0fbb1
1854 U+10450 - U+1049d
1855
1856 12. The -o option (show only the matching part of a line) for pcregrep was not
1857 compatible with GNU grep in that, if there was more than one match in a
1858 line, it showed only the first of them. It now behaves in the same way as
1859 GNU grep.
1860
1861 13. If the -o and -v options were combined for pcregrep, it printed a blank
1862 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1863 does the same. The return code can be used to tell if there were any
1864 non-matching lines.
1865
1866 14. Added --file-offsets and --line-offsets to pcregrep.
1867
1868 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1869 infinitely looping recursion. The bug was that positive lookaheads were not
1870 being skipped when checking for a possible empty match (negative lookaheads
1871 and both kinds of lookbehind were skipped).
1872
1873 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1874 inclusion of <windows.h> to before rather than after the definition of
1875 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1876
1877 17. Specifying a possessive quantifier with a specific limit for a Unicode
1878 character property caused pcre_compile() to compile bad code, which led at
1879 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1880 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1881 caused the error; without that there was no problem.
1882
1883 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1884
1885 19. Added --enable-pcretest-libreadline.
1886
1887 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1888 RE::GlobalReplace(). As a result, the number of replacements returned was
1889 double what it should be. I removed one of the increments, but Craig sent a
1890 later patch that removed the other one (the right fix) and added unit tests
1891 that check the return values (which was not done before).
1892
1893 21. Several CMake things:
1894
1895 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1896 the names libpcre and libpcreposix, not just pcre and pcreposix.
1897
1898 (2) The above change means that pcretest and pcregrep are now correctly
1899 linked with the newly-built libraries, not previously installed ones.
1900
1901 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1902
1903 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1904 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1905 UTF-8 newline character). The key issue is that the pattern starts .*;
1906 this means that the match must be either at the beginning, or after a
1907 newline. The bug was in the code for advancing after a failed match and
1908 checking that the new position followed a newline. It was not taking
1909 account of UTF-8 characters correctly.
1910
1911 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1912 character classes. PCRE was not treating the sequence [:...:] as a
1913 character class unless the ... were all letters. Perl, however, seems to
1914 allow any characters between [: and :], though of course it rejects as
1915 unknown any "names" that contain non-letters, because all the known class
1916 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1917 for example, whereas PCRE did not - it did not recognize a POSIX character
1918 class. This seemed a bit dangerous, so the code has been changed to be
1919 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1920 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1921 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1922 Perl does, and where it didn't before.
1923
1924 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1925 Windows environments %n is disabled by default.
1926
1927
1928 Version 7.4 21-Sep-07
1929 ---------------------
1930
1931 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1932 means that a class such as [\s] counted as "explicit reference to CR or
1933 LF". That isn't really right - the whole point of the change was to try to
1934 help when there was an actual mention of one of the two characters. So now
1935 the change happens only if \r or \n (or a literal CR or LF) character is
1936 encountered.
1937
1938 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1939 of both had grown to the point where there were only 3 bits left.
1940 Fortunately, there was spare space in the data structure, and so I have
1941 moved the internal flags into a new 16-bit field to free up more option
1942 bits.
1943
1944 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1945 but did not set the internal JCHANGED flag - either of these is enough to
1946 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1947 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1948 start sets both bits.
1949
1950 4. Added options (at build time, compile time, exec time) to change \R from
1951 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1952
1953 5. doc/pcresyntax.html was missing from the distribution.
1954
1955 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1956 compatibility, even though it is no longer used.
1957
1958 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1959 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1960 windows.h file is present (where different names are used). [This was
1961 reversed later after testing - see 16 below.]
1962
1963 8. Changed all #include <config.h> to #include "config.h". There were also
1964 some further <pcre.h> cases that I changed to "pcre.h".
1965
1966 9. When pcregrep was used with the --colour option, it missed the line ending
1967 sequence off the lines that it output.
1968
1969 10. It was pointed out to me that arrays of string pointers cause lots of
1970 relocations when a shared library is dynamically loaded. A technique of
1971 using a single long string with a table of offsets can drastically reduce
1972 these. I have refactored PCRE in four places to do this. The result is
1973 dramatic:
1974
1975 Originally: 290
1976 After changing UCP table: 187
1977 After changing error message table: 43
1978 After changing table of "verbs" 36
1979 After changing table of Posix names 22
1980
1981 Thanks to the folks working on Gregex for glib for this insight.
1982
1983 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1984 unicode-properties was also set.
1985
1986 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1987
1988 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1989 checked only for CRLF.
1990
1991 14. Added casts to pcretest.c to avoid compiler warnings.
1992
1993 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1994
1995 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1996 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1997 entirely. This removes changes made in 7 above.
1998
1999 17. The CMake files have been updated, and there is now more information about
2000 building with CMake in the NON-UNIX-USE document.
2001
2002
2003 Version 7.3 28-Aug-07
2004 ---------------------
2005
2006 1. In the rejigging of the build system that eventually resulted in 7.1, the
2007 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2008 brackets there is not right, since it causes compilers to look for an
2009 installed pcre.h, not the version that is in the source that is being
2010 compiled (which of course may be different). I have changed it back to:
2011
2012 #include "pcre.h"
2013
2014 I have a vague recollection that the change was concerned with compiling in
2015 different directories, but in the new build system, that is taken care of
2016 by the VPATH setting the Makefile.
2017
2018 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2019 when the subject happened to end in the byte 0x85 (e.g. if the last
2020 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2021 characters but of course it shouldn't be taken as a newline when it is part
2022 of another character. The bug was that, for an unlimited repeat of . in
2023 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2024 characters when looking for a newline.
2025
2026 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2027
2028 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2029 in debug output.
2030
2031 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2032 long printing in the pcrecpp unittest when running under MinGW.
2033
2034 6. ESC_K was left out of the EBCDIC table.
2035
2036 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2037 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2038 limit also applies to "virtual nesting" when a pattern is recursive, and in
2039 this case 1000 isn't so big. I have been able to remove this limit at the
2040 expense of backing off one optimization in certain circumstances. Normally,
2041 when pcre_exec() would call its internal match() function recursively and
2042 immediately return the result unconditionally, it uses a "tail recursion"
2043 feature to save stack. However, when a subpattern that can match an empty
2044 string has an unlimited repetition quantifier, it no longer makes this
2045 optimization. That gives it a stack frame in which to save the data for
2046 checking that an empty string has been matched. Previously this was taken
2047 from the 1000-entry workspace that had been reserved. So now there is no
2048 explicit limit, but more stack is used.
2049
2050 8. Applied Daniel's patches to solve problems with the import/export magic
2051 syntax that is required for Windows, and which was going wrong for the
2052 pcreposix and pcrecpp parts of the library. These were overlooked when this
2053 problem was solved for the main library.
2054
2055 9. There were some crude static tests to avoid integer overflow when computing
2056 the size of patterns that contain repeated groups with explicit upper
2057 limits. As the maximum quantifier is 65535, the maximum group length was
2058 set at 30,000 so that the product of these two numbers did not overflow a
2059 32-bit integer. However, it turns out that people want to use groups that
2060 are longer than 30,000 bytes (though not repeat them that many times).
2061 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2062 made it possible to implement the integer overflow checks in a much more
2063 dynamic way, which I have now done. The artificial limitation on group
2064 length has been removed - we now have only the limit on the total length of
2065 the compiled pattern, which depends on the LINK_SIZE setting.
2066
2067 10. Fixed a bug in the documentation for get/copy named substring when
2068 duplicate names are permitted. If none of the named substrings are set, the
2069 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2070 empty string.
2071
2072 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2073 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2074 because the ] is interpreted as the first data character and the
2075 terminating ] is not found. PCRE has been made compatible with Perl in this
2076 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2077 cause memory overwriting.
2078
2079 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2080 string has been matched (to stop an infinite loop). It was not recognizing
2081 a conditional subpattern that could match an empty string if that
2082 subpattern was within another subpattern. For example, it looped when
2083 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
2084 condition was not nested. This bug has been fixed.
2085
2086 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2087 past the start of the subject in the presence of bytes with the top bit
2088 set, for example "\x8aBCD".
2089
2090 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2091 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2092
2093 14. Optimized (?!) to (*FAIL).
2094
2095 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2096 This restricts code points to be within the range 0 to 0x10FFFF, excluding
2097 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2098 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2099 does: it's just the validity check that is more restrictive.
2100
2101 16. Inserted checks for integer overflows during escape sequence (backslash)
2102 processing, and also fixed erroneous offset values for syntax errors during
2103 backslash processing.
2104
2105 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2106 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2107
2108 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2109 caused an overrun.
2110
2111 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2112 something other than just ASCII characters) inside a group that had an
2113 unlimited repeat caused a loop at compile time (while checking to see
2114 whether the group could match an empty string).
2115
2116 20. Debugging a pattern containing \p or \P could cause a crash. For example,
2117 [\P{Any}] did so. (Error in the code for printing property names.)
2118
2119 21. An orphan \E inside a character class could cause a crash.
2120
2121 22. A repeated capturing bracket such as (A)? could cause a wild memory
2122 reference during compilation.
2123
2124 23. There are several functions in pcre_compile() that scan along a compiled
2125 expression for various reasons (e.g. to see if it's fixed length for look
2126 behind). There were bugs in these functions when a repeated \p or \P was
2127 present in the pattern. These operators have additional parameters compared
2128 with \d, etc, and these were not being taken into account when moving along
2129 the compiled data. Specifically:
2130
2131 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2132 length.
2133
2134 (b) An item such as \pL+ within a repeated group could cause crashes or
2135 loops.
2136
2137 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2138 "reference to non-existent subpattern" error.
2139
2140 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2141
2142 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2143 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2144
2145 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2146
2147 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2148 character were causing crashes (broken optimization).
2149
2150 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2151 \p or \P) caused a compile-time loop.
2152
2153 28. More problems have arisen in unanchored patterns when CRLF is a valid line
2154 break. For example, the unstudied pattern [\r\n]A does not match the string
2155 "\r\nA" because change 7.0/46 below moves the current point on by two
2156 characters after failing to match at the start. However, the pattern \nA
2157 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2158 the same is true. There doesn't seem any very clean way out of this, but
2159 what I have chosen to do makes the common cases work: PCRE now takes note
2160 of whether there can be an explicit match for \r or \n anywhere in the
2161 pattern, and if so, 7.0/46 no longer applies. As part of this change,
2162 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2163 pattern has explicit CR or LF references.
2164
2165 29. Added (*CR) etc for changing newline setting at start of pattern.
2166
2167
2168 Version 7.2 19-Jun-07
2169 ---------------------
2170
2171 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2172 which is apparently normally available under Windows.
2173
2174 2. Re-jig the pcregrep tests with different newline settings in an attempt
2175 to make them independent of the local environment's newline setting.
2176
2177 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2178
2179 4. Some of the "internals" tests were previously cut out when the link size
2180 was not 2, because the output contained actual offsets. The recent new
2181 "Z" feature of pcretest means that these can be cut out, making the tests
2182 usable with all link sizes.
2183
2184 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2185 stack recursion. This gives a massive performance boost under BSD, but just
2186 a small improvement under Linux. However, it saves one field in the frame
2187 in all cases.
2188
2189 6. Added more features from the forthcoming Perl 5.10:
2190
2191 (a) (?-n) (where n is a string of digits) is a relative subroutine or
2192 recursion call. It refers to the nth most recently opened parentheses.
2193
2194 (b) (?+n) is also a relative subroutine call; it refers to the nth next
2195 to be opened parentheses.
2196
2197 (c) Conditions that refer to capturing parentheses can be specified
2198 relatively, for example, (?(-2)... or (?(+3)...
2199
2200 (d) \K resets the start of the current match so that everything before
2201 is not part of it.
2202
2203 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2204
2205 (f) \g{name} is another synonym - part of Perl 5.10's unification of
2206 reference syntax.
2207
2208 (g) (?| introduces a group in which the numbering of parentheses in each
2209 alternative starts with the same number.
2210
2211 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2212
2213 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2214 PCRE_INFO_JCHANGED.
2215
2216 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
2217 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2218 for detecting groups that can match an empty string.
2219
2220 9. A pattern with a very large number of alternatives (more than several
2221 hundred) was running out of internal workspace during the pre-compile
2222 phase, where pcre_compile() figures out how much memory will be needed. A
2223 bit of new cunning has reduced the workspace needed for groups with
2224 alternatives. The 1000-alternative test pattern now uses 12 bytes of
2225 workspace instead of running out of the 4096 that are available.
2226
2227 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2228
2229 11. Applied patch from Google to remove an optimization that didn't quite work.
2230 The report of the bug said:
2231
2232 pcrecpp::RE("a*").FullMatch("aaa") matches, while
2233 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2234 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2235
2236 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2237 it matched the wrong number of bytes.
2238
2239
2240 Version 7.1 24-Apr-07
2241 ---------------------
2242
2243 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2244 that is more "standard", making use of automake and other Autotools. There
2245 is some re-arrangement of the files and adjustment of comments consequent
2246 on this.
2247
2248 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2249 for recursive directory scanning broke on some systems because the files
2250 are not scanned in any specific order and on different systems the order
2251 was different. A call to "sort" has been inserted into RunGrepTest for the
2252 approprate test as a short-term fix. In the longer term there may be an
2253 alternative.
2254
2255 3. I had an email from Eric Raymond about problems translating some of PCRE's
2256 man pages to HTML (despite the fact that I distribute HTML pages, some
2257 people do their own conversions for various reasons). The problems
2258 concerned the use of low-level troff macros .br and .in. I have therefore
2259 removed all such uses from the man pages (some were redundant, some could
2260 be replaced by .nf/.fi pairs). The 132html script that I use to generate
2261 HTML has been updated to handle .nf/.fi and to complain if it encounters
2262 .br or .in.
2263
2264 4. Updated comments in configure.ac that get placed in config.h.in and also
2265 arranged for config.h to be included in the distribution, with the name
2266 config.h.generic, for the benefit of those who have to compile without
2267 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2268
2269 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2270 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2271 makevp.bat for the current PCRE, using the additional files
2272 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2273
2274 6. A Windows user reported a minor discrepancy with test 2, which turned out
2275 to be caused by a trailing space on an input line that had got lost in his
2276 copy. The trailing space was an accident, so I've just removed it.
2277
2278 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2279 that is needed.
2280
2281 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2282 as "const" (a) because they are and (b) because it helps the PHP
2283 maintainers who have recently made a script to detect big data structures
2284 in the php code that should be moved to the .rodata section. I remembered
2285 to update Builducptable as well, so it won't revert if ucptable.h is ever
2286 re-created.
2287
2288 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2289 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2290 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2291 support is not required. This saves 1.5-2K of code, which is important in
2292 some applications.
2293
2294 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2295 so as not to refer to the tables, even though these functions will never be
2296 called when UTF-8 support is disabled. Otherwise there are problems with a
2297 shared library.
2298
2299 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2300
2301 (a) It was defining its arguments as char * instead of void *.
2302
2303 (b) It was assuming that all moves were upwards in memory; this was true
2304 a long time ago when I wrote it, but is no longer the case.
2305
2306 The emulated memove() is provided for those environments that have neither
2307 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2308 is clearly not the case, as these two bugs were recently reported.
2309
2310 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2311 and Detrail to create the HTML documentation, the .txt form of the man
2312 pages, and it removes trailing spaces from listed files. It also creates
2313 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2314 case, it wraps all the #defines with #ifndefs. This script should be run
2315 before "make dist".
2316
2317 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2318 with Unicode property support.
2319
2320 (a) For a maximizing quantifier, if the two different cases of the
2321 character were of different lengths in their UTF-8 codings (there are
2322 some cases like this - I found 11), and the matching function had to
2323 back up over a mixture of the two cases, it incorrectly assumed they
2324 were both the same length.
2325
2326 (b) When PCRE was configured to use the heap rather than the stack for
2327 recursion during matching, it was not correctly preserving the data for
2328 the other case of a UTF-8 character when checking ahead for a match
2329 while processing a minimizing repeat. If the check also involved
2330 matching a wide character, but failed, corruption could cause an
2331 erroneous result when trying to check for a repeat of the original
2332 character.
2333
2334 13. Some tidying changes to the testing mechanism:
2335
2336 (a) The RunTest script now detects the internal link size and whether there
2337 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2338 values substituted by "configure". (The RunGrepTest script already did
2339 this for UTF-8.) The configure.ac script no longer substitutes the
2340 relevant variables.
2341
2342 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2343 with length and offset values. This means that the output is different
2344 for different internal link sizes. Test 2 is skipped for link sizes
2345 other than 2 because of this, bypassing the problem. Unfortunately,
2346 there was also a test in test 3 (the locale tests) that used /B and
2347 failed for link sizes other than 2. Rather than cut the whole test out,
2348 I have added a new /Z option to pcretest that replaces the length and
2349 offset values with spaces. This is now used to make test 3 independent
2350 of link size. (Test 2 will be tidied up later.)
2351
2352 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2353 segmentation fault instead of returning the appropriate error message.
2354
2355 15. In multiline mode when the newline sequence was set to "any", the pattern
2356 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2357 This doesn't seem right; it now treats the CRLF combination as the line
2358 ending, and so does not match in that case. It's only a pattern such as ^$
2359 that would hit this one: something like ^ABC$ would have failed after \r
2360 and then tried again after \r\n.
2361
2362 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2363 in an attempt to make files that differ only in their line terminators
2364 compare equal. This works on Linux.
2365
2366 17. Under certain error circumstances pcregrep might try to free random memory
2367 as it exited. This is now fixed, thanks to valgrind.
2368
2369 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2370 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2371 was because its rules for how to advance for /g after matching an empty
2372 string at the end of a line did not allow for this case. They now check for
2373 it specially.
2374
2375 20. pcretest is supposed to handle patterns and data of any length, by
2376 extending its buffers when necessary. It was getting this wrong when the
2377 buffer for a data line had to be extended.
2378
2379 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2380 CRLF as a newline sequence.
2381
2382 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2383 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2384 I have nevertheless tidied it up.
2385
2386 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2387
2388 24. Added a man page for pcre-config.
2389
2390
2391 Version 7.0 19-Dec-06
2392 ---------------------
2393
2394 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2395 moving to gcc 4.1.1.
2396
2397 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2398 sys/time.h, which is documented as needed for this function. It doesn't
2399 seem to matter on Linux, but it showed up on some releases of OS X.
2400
2401 3. It seems that there are systems where bytes whose values are greater than
2402 127 match isprint() in the "C" locale. The "C" locale should be the
2403 default when a C program starts up. In most systems, only ASCII printing
2404 characters match isprint(). This difference caused the output from pcretest
2405 to vary, making some of the tests fail. I have changed pcretest so that:
2406
2407 (a) When it is outputting text in the compiled version of a pattern, bytes
2408 other than 32-126 are always shown as hex escapes.
2409
2410 (b) When it is outputting text that is a matched part of a subject string,
2411 it does the same, unless a different locale has been set for the match
2412 (using the /L modifier). In this case, it uses isprint() to decide.
2413
2414 4. Fixed a major bug that caused incorrect computation of the amount of memory
2415 required for a compiled pattern when options that changed within the
2416 pattern affected the logic of the preliminary scan that determines the
2417 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2418 that the computed length was too small. The symptoms of this bug were
2419 either the PCRE error "internal error: code overflow" from pcre_compile(),
2420 or a glibc crash with a message such as "pcretest: free(): invalid next
2421 size (fast)". Examples of patterns that provoked this bug (shown in
2422 pcretest format) are:
2423
2424 /(?-x: )/x
2425 /(?x)(?-x: \s*#\s*)/
2426 /((?i)[\x{c0}])/8
2427 /(?i:[\x{c0}])/8
2428
2429 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2430 is now done differently.
2431
2432 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2433 wrapper classes; (b) implement a new function in the C++ scanner that is
2434 more efficient than the old way of doing things because it avoids levels of
2435 recursion in the regex matching; (c) add a paragraph to the documentation
2436 for the FullMatch() function.
2437
2438 6. The escape sequence \n was being treated as whatever was defined as
2439 "newline". Not only was this contrary to the documentation, which states
2440 that \n is character 10 (hex 0A), but it also went horribly wrong when
2441 "newline" was defined as CRLF. This has been fixed.
2442
2443 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2444 was being set to -1 for the "end of line" case (supposedly a value that no
2445 character can have). Though this value is never used (the check for end of
2446 line is "zero bytes in current character"), it caused compiler complaints.
2447 I've changed it to 0xffffffff.
2448
2449 8. In pcre_version.c, the version string was being built by a sequence of
2450 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2451 string (as it is for production releases) called a macro with an empty
2452 argument. The C standard says the result of this is undefined. The gcc
2453 compiler treats it as an empty string (which was what was wanted) but it is
2454 reported that Visual C gives an error. The source has been hacked around to
2455 avoid this problem.
2456
2457 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2458 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2459 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2460 of them did).
2461
2462 10. Originally, pcretest opened its input and output without "b"; then I was
2463 told that "b" was needed in some environments, so it was added for release
2464 5.0 to both the input and output. (It makes no difference on Unix-like
2465 systems.) Later I was told that it is wrong for the input on Windows. I've
2466 now abstracted the modes into two macros, to make it easier to fiddle with
2467 them, and removed "b" from the input mode under Windows.
2468
2469 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2470
2471 12. Added -help and --help to pcretest as an official way of being reminded
2472 of the options.
2473
2474 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2475 and pcrecpp.cc because they annoy compilers at high warning levels.
2476
2477 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2478
2479 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2480 scripts are not C programs :-) and which was not noticed because it works
2481 on Linux.
2482
2483 16. pcretest is supposed to handle any length of pattern and data line (as one
2484 line or as a continued sequence of lines) by extending its input buffer if
2485 necessary. This feature was broken for very long pattern lines, leading to
2486 a string of junk being passed to pcre_compile() if the pattern was longer
2487 than about 50K.
2488
2489 17. I have done a major re-factoring of the way pcre_compile() computes the
2490 amount of memory needed for a compiled pattern. Previously, there was code
2491 that made a preliminary scan of the pattern in order to do this. That was
2492 OK when PCRE was new, but as the facilities have expanded, it has become
2493 harder and harder to keep it in step with the real compile phase, and there
2494 have been a number of bugs (see for example, 4 above). I have now found a
2495 cunning way of running the real compile function in a "fake" mode that
2496 enables it to compute how much memory it would need, while actually only
2497 ever using a few hundred bytes of working memory and without too many
2498 tests of the mode. This should make future maintenance and development
2499 easier. A side effect of this work is that the limit of 200 on the nesting
2500 depth of parentheses has been removed (though this was never a serious
2501 limitation, I suspect). However, there is a downside: pcre_compile() now
2502 runs more slowly than before (30% or more, depending on the pattern). I
2503 hope this isn't a big issue. There is no effect on runtime performance.
2504
2505 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2506 newline (only possible for the last line of a file) and it was a
2507 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2508
2509 19. Added additional timing features to pcretest. (1) The -tm option now times
2510 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2511 separate command line item, by a number that specifies the number of
2512 repeats to use when timing. The default is 50000; this gives better
2513 precision, but takes uncomfortably long for very large patterns.
2514
2515 20. Extended pcre_study() to be more clever in cases where a branch of a
2516 subpattern has no definite first character. For example, (a*|b*)[cd] would
2517 previously give no result from pcre_study(). Now it recognizes that the
2518 first character must be a, b, c, or d.
2519
2520 21. There was an incorrect error "recursive call could loop indefinitely" if
2521 a subpattern (or the entire pattern) that was being tested for matching an
2522 empty string contained only one non-empty item after a nested subpattern.
2523 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2524 incorrectly, because the \d was being skipped in the check.
2525
2526 22. The pcretest program now has a new pattern option /B and a command line
2527 option -b, which is equivalent to adding /B to every pattern. This causes
2528 it to show the compiled bytecode, without the additional information that
2529 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2530 is the same as /B/I).
2531
2532 23. A new optimization is now able automatically to treat some sequences such
2533 as a*b as a*+b. More specifically, if something simple (such as a character
2534 or a simple class like \d) has an unlimited quantifier, and is followed by
2535 something that cannot possibly match the quantified thing, the quantifier
2536 is automatically "possessified".
2537
2538 24. A recursive reference to a subpattern whose number was greater than 39
2539 went wrong under certain circumstances in UTF-8 mode. This bug could also
2540 have affected the operation of pcre_study().
2541
2542 25. Realized that a little bit of performance could be had by replacing
2543 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2544
2545 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2546
2547 27. Possessive quantifiers such as a++ were previously implemented by turning
2548 them into atomic groups such as ($>a+). Now they have their own opcodes,
2549 which improves performance. This includes the automatically created ones
2550 from 23 above.
2551
2552 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2553 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2554 the first matched character to be a colon. This applied both to named and
2555 numbered groups.
2556
2557 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2558
2559 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2560 building PCRE on Windows easier, so I have included it in the distribution.
2561
2562 31. There is now a check in pcretest against a ridiculously large number being
2563 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2564 loop, the loop is abandoned.
2565
2566 32. Forward references to subpatterns in conditions such as (?(2)...) where
2567 subpattern 2 is defined later cause pcre_compile() to search forwards in
2568 the pattern for the relevant set of parentheses. This search went wrong
2569 when there were unescaped parentheses in a character class, parentheses
2570 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2571
2572 33. "Subroutine" calls and backreferences were previously restricted to
2573 referencing subpatterns earlier in the regex. This restriction has now
2574 been removed.
2575
2576 34. Added a number of extra features that are going to be in Perl 5.10. On the
2577 whole, these are just syntactic alternatives for features that PCRE had
2578 previously implemented using the Python syntax or my own invention. The
2579 other formats are all retained for compatibility.
2580
2581 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2582 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2583 also .NET compatible.
2584
2585 (b) A recursion or subroutine call to a named group can now be defined as
2586 (?&name) as well as (?P>name).
2587
2588 (c) A backreference to a named group can now be defined as \k<name> or
2589 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2590 5.10, are also .NET compatible.
2591
2592 (d) A conditional reference to a named group can now use the syntax
2593 (?(<name>) or (?('name') as well as (?(name).
2594
2595 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2596 groups (named and numbered) that are never evaluated inline, but can be
2597 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2598 is always false. There may be only one alternative in such a group.
2599
2600 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2601 as the simple (?(R). The condition is true only if the most recent
2602 recursion is that of the given number or name. It does not search out
2603 through the entire recursion stack.
2604
2605 (g) The escape \gN or \g{N} has been added, where N is a positive or
2606 negative number, specifying an absolute or relative reference.
2607
2608 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2609 some "unreachable code" warnings.
2610
2611 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2612 things, this adds five new scripts.
2613
2614 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2615 There were also incompatibilities regarding the handling of \Q..\E inside
2616 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2617 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2618
2619 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2620 matches an empty string, and forcibly breaks the loop. There were bugs in
2621 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2622 against aaaa the result was just "a" rather than "aaaa", for example. Two
2623 separate and independent bugs (that affected different cases) have been
2624 fixed.
2625
2626 39. Refactored the code to abolish the use of different opcodes for small
2627 capturing bracket numbers. This is a tidy that I avoided doing when I
2628 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2629 The new approach is not only tidier, it makes it possible to reduce the
2630 memory needed to fix the previous bug (38).
2631
2632 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2633 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2634 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2635 mode.
2636
2637 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2638 report.
2639
2640 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2641 copy construction and assignment in the C++ wrapper.
2642
2643 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2644 couple of bugs that could have given wrong results in the "--newline=crlf"
2645 case.
2646
2647 44. Added a number of casts and did some reorganization of signed/unsigned int
2648 variables following suggestions from Dair Grant. Also renamed the variable
2649 "this" as "item" because it is a C++ keyword.
2650
2651 45. Arranged for dftables to add
2652
2653 #include "pcre_internal.h"
2654
2655 to pcre_chartables.c because without it, gcc 4.x may remove the array
2656 definition from the final binary if PCRE is built into a static library and
2657 dead code stripping is activated.
2658
2659 46. For an unanchored pattern, if a match attempt fails at the start of a
2660 newline sequence, and the newline setting is CRLF or ANY, and the next two
2661 characters are CRLF, advance by two characters instead of one.
2662
2663
2664 Version 6.7 04-Jul-06
2665 ---------------------
2666
2667 1. In order to handle tests when input lines are enormously long, pcretest has
2668 been re-factored so that it automatically extends its buffers when
2669 necessary. The code is crude, but this _is_ just a test program. The
2670 default size has been increased from 32K to 50K.
2671
2672 2. The code in pcre_study() was using the value of the re argument before
2673 testing it for NULL. (Of course, in any sensible call of the function, it
2674 won't be NULL.)
2675
2676 3. The memmove() emulation function in pcre_internal.h, which is used on
2677 systems that lack both memmove() and bcopy() - that is, hardly ever -
2678 was missing a "static" storage class specifier.
2679
2680 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2681 containing an extended class (one that cannot be represented by a bitmap
2682 because it contains high-valued characters or Unicode property items, e.g.
2683 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2684 pattern, but PCRE should not loop if you do not (it no longer does).
2685 [Detail: two cases were found: (a) a repeated subpattern containing an
2686 extended class; (b) a recursive reference to a subpattern that followed a
2687 previous extended class. It wasn't skipping over the extended class
2688 correctly when UTF-8 mode was not set.]
2689
2690 5. A negated single-character class was not being recognized as fixed-length
2691 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2692 compile error "lookbehind assertion is not fixed length".
2693
2694 6. The RunPerlTest auxiliary script was showing an unexpected difference
2695 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2696 write a Perl script that can interpret lines of an input file either as
2697 byte characters or as UTF-8, which is what "perltest" was being required to
2698 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2699 can't do is switch easily at run time between having the "use utf8;" pragma
2700 or not. In the end, I fudged it by using the RunPerlTest script to insert
2701 "use utf8;" explicitly for the UTF-8 tests.
2702
2703 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2704 the end of the subject string, contrary to the documentation and to what
2705 Perl does. This was true of both matching functions. Now it matches only at
2706 the start of the subject and immediately after *internal* newlines.
2707
2708 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2709 a pointer to an int instead of a pointer to an unsigned long int. This
2710 caused problems on 64-bit systems.
2711
2712 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2713 instance of the 'standard' template library not being so standard".
2714
2715 10. There was no check on the number of named subpatterns nor the maximum
2716 length of a subpattern name. The product of these values is used to compute
2717 the size of the memory block for a compiled pattern. By supplying a very
2718 long subpattern name and a large number of named subpatterns, the size
2719 computation could be caused to overflow. This is now prevented by limiting
2720 the length of names to 32 characters, and the number of named subpatterns
2721 to 10,000.
2722
2723 11. Subpatterns that are repeated with specific counts have to be replicated in
2724 the compiled pattern. The size of memory for this was computed from the
2725 length of the subpattern and the repeat count. The latter is limited to
2726 65535, but there was no limit on the former, meaning that integer overflow
2727 could in principle occur. The compiled length of a repeated subpattern is
2728 now limited to 30,000 bytes in order to prevent this.
2729
2730 12. Added the optional facility to have named substrings with the same name.
2731
2732 13. Added the ability to use a named substring as a condition, using the
2733 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2734 are numbers (not recommended). Forward references are permitted.
2735
2736 14. Added forward references in named backreferences (if you see what I mean).
2737
2738 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2739 pattern could run off the end of the subject. For example, the pattern
2740 "(?s)(.{1,5})"8 did this with the subject "ab".
2741
2742 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2743 PCRE_CASELESS was set when matching characters that were quantified with ?
2744 or *.
2745
2746 17. A character class other than a single negated character that had a minimum
2747 but no maximum quantifier - for example [ab]{6,} - was not handled
2748 correctly by pce_dfa_exec(). It would match only one character.
2749
2750 18. A valid (though odd) pattern that looked like a POSIX character
2751 class but used an invalid character after [ (for example [[,abc,]]) caused
2752 pcre_compile() to give the error "Failed: internal error: code overflow" or
2753 in some cases to crash with a glibc free() error. This could even happen if
2754 the pattern terminated after [[ but there just happened to be a sequence of
2755 letters, a binary zero, and a closing ] in the memory that followed.
2756
2757 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2758 over the years. Originally (before any Unicode support), just the bottom 8
2759 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2760 output from "man perlunicode" includes this:
2761
2762 The regular expression compiler produces polymorphic opcodes. That
2763 is, the pattern adapts to the data and automatically switches to
2764 the Unicode character scheme when presented with Unicode data--or
2765 instead uses a traditional byte scheme when presented with byte
2766 data.
2767
2768 Sadly, a wide octal escape does not cause a switch, and in a string with
2769 no other multibyte characters, these octal escapes are treated as before.
2770 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2771 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2772 Unicode string.
2773
2774 I have not perpetrated such confusion in PCRE. Up till now, it took just
2775 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2776 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2777 translate to the appropriate multibyte character.
2778
2779 29. Applied some refactoring to reduce the number of warnings from Microsoft
2780 and Borland compilers. This has included removing the fudge introduced
2781 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2782 a warning about an unused variable.
2783
2784 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2785 characters since release 4.0, because Perl (from release 5.004) does not.
2786 [Or at least, is documented not to: some releases seem to be in conflict
2787 with the documentation.] However, when a pattern was studied with
2788 pcre_study() and all its branches started with \s, PCRE still included VT
2789 as a possible starting character. Of course, this did no harm; it just
2790 caused an unnecessary match attempt.
2791
2792 22. Removed a now-redundant internal flag bit that recorded the fact that case
2793 dependency changed within the pattern. This was once needed for "required
2794 byte" processing, but is no longer used. This recovers a now-scarce options
2795 bit. Also moved the least significant internal flag bit to the most-
2796 significant bit of the word, which was not previously used (hangover from
2797 the days when it was an int rather than a uint) to free up another bit for
2798 the future.
2799
2800 23. Added support for CRLF line endings as well as CR and LF. As well as the
2801 default being selectable at build time, it can now be changed at runtime
2802 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2803 specify that it is scanning data with non-default line endings.
2804
2805 24. Changed the definition of CXXLINK to make it agree with the definition of
2806 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2807
2808 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2809 recursions. This makes a big different to stack usage for some patterns.
2810
2811 26. If a subpattern containing a named recursion or subroutine reference such
2812 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2813 the space required for the compiled pattern went wrong and gave too small a
2814 value. Depending on the environment, this could lead to "Failed: internal
2815 error: code overflow at offset 49" or "glibc detected double free or
2816 corruption" errors.
2817
2818 27. Applied patches from Google (a) to support the new newline modes and (b) to
2819 advance over multibyte UTF-8 characters in GlobalReplace.
2820
2821 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2822 difference for some implementation of PCRE in some Windows version.
2823
2824 29. Added some extra testing facilities to pcretest:
2825
2826 \q<number> in a data line sets the "match limit" value
2827 \Q<number> in a data line sets the "match recursion limt" value
2828 -S <number> sets the stack size, where <number> is in megabytes
2829
2830 The -S option isn't available for Windows.
2831
2832
2833 Version 6.6 06-Feb-06
2834 ---------------------
2835
2836 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2837 in pcreposix.h. I have copied the definition from pcre.h.
2838
2839 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2840 because pcre.h is no longer a built file.
2841
2842 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2843 not normally included in the compiled code.
2844
2845
2846 Version 6.5 01-Feb-06
2847 ---------------------
2848
2849 1. When using the partial match feature with pcre_dfa_exec(), it was not
2850 anchoring the second and subsequent partial matches at the new starting
2851 point. This could lead to incorrect results. For example, with the pattern
2852 /1234/, partially matching against "123" and then "a4" gave a match.
2853
2854 2. Changes to pcregrep:
2855
2856 (a) All non-match returns from pcre_exec() were being treated as failures
2857 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2858 error message is output. Some extra information is given for the
2859 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2860 probably the only errors that are likely to be caused by users (by
2861 specifying a regex that has nested indefinite repeats, for instance).
2862 If there are more than 20 of these errors, pcregrep is abandoned.
2863
2864 (b) A binary zero was treated as data while matching, but terminated the
2865 output line if it was written out. This has been fixed: binary zeroes
2866 are now no different to any other data bytes.
2867
2868 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2869 used to set a locale for matching. The --locale=xxxx long option has
2870 been added (no short equivalent) to specify a locale explicitly on the
2871 pcregrep command, overriding the environment variables.
2872
2873 (d) When -B was used with -n, some line numbers in the output were one less
2874 than they should have been.
2875
2876 (e) Added the -o (--only-matching) option.
2877
2878 (f) If -A or -C was used with -c (count only), some lines of context were
2879 accidentally printed for the final match.
2880
2881 (g) Added the -H (--with-filename) option.
2882
2883 (h) The combination of options -rh failed to suppress file names for files
2884 that were found from directory arguments.
2885
2886 (i) Added the -D (--devices) and -d (--directories) options.
2887
2888 (j) Added the -F (--fixed-strings) option.
2889
2890 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2891
2892 (l) Added the --colo(u)r option.
2893
2894 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2895 is not present by default.
2896
2897 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2898 items such as (?R) or (?1), when the recursion could match a number of
2899 alternatives. If it matched one of the alternatives, but subsequently,
2900 outside the recursion, there was a failure, the code tried to back up into
2901 the recursion. However, because of the way PCRE is implemented, this is not
2902 possible, and the result was an incorrect result from the match.
2903
2904 In order to prevent this happening, the specification of recursion has
2905 been changed so that all such subpatterns are automatically treated as
2906 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2907
2908 4. I had overlooked the fact that, in some locales, there are characters for
2909 which isalpha() is true but neither isupper() nor islower() are true. In
2910 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2911 and ordfeminine) are like this. This affected the treatment of \w and \W
2912 when they appeared in character classes, but not when they appeared outside
2913 a character class. The bit map for "word" characters is now created
2914 separately from the results of isalnum() instead of just taking it from the
2915 upper, lower, and digit maps. (Plus the underscore character, of course.)
2916
2917 5. The above bug also affected the handling of POSIX character classes such as
2918 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2919 permanent tables. Instead, the bit maps for such a class were previously
2920 created as the appropriate unions of the upper, lower, and digit bitmaps.
2921 Now they are created by subtraction from the [[:word:]] class, which has
2922 its own bitmap.
2923
2924 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2925 It is created by subtracting the vertical space characters (\x09, \x0a,
2926 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2927 subtraction was done in the overall bitmap for a character class, meaning
2928 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2929 be recognized. This bug has been fixed.
2930
2931 7. Patches from the folks at Google:
2932
2933 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2934 real life, but is still worth protecting against".
2935
2936 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2937 regular expressions".
2938
2939 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2940 have it.
2941
2942 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2943 "configure" and the latter not, in order to fix a problem somebody had
2944 with compiling the Arg class on HP-UX.
2945
2946 (e) Improve the error-handling of the C++ wrapper a little bit.
2947
2948 (f) New tests for checking recursion limiting.
2949
2950 8. The pcre_memmove() function, which is used only if the environment does not
2951 have a standard memmove() function (and is therefore rarely compiled),
2952 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2953 returning a result (though PCRE never actually uses the result).
2954
2955 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2956 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2957 returned instead of calling malloc() with an overflowing number that would
2958 most likely cause subsequent chaos.
2959
2960 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2961
2962 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2963 with this option is matched, the nmatch and pmatch options of regexec() are
2964 ignored.
2965
2966 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2967 provided in case anyone wants to the the POSIX interface with UTF-8
2968 strings.
2969
2970 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2971 C++ linking (needed for some HP-UX environments).
2972
2973 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2974 (unused parameter) and in the pcre_printint() function (omitted "default"
2975 switch label when the default is to do nothing).
2976
2977 15. Added some code to make it possible, when PCRE is compiled as a C++
2978 library, to replace subject pointers for pcre_exec() with a smart pointer
2979 class, thus making it possible to process discontinuous strings.
2980
2981 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2982 much the same function. They were added by different people who were trying
2983 to make PCRE easy to compile on non-Unix systems. It has been suggested
2984 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2985 for compiling on Windows systems. I have therefore replaced it with
2986 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2987 defaults to "extern" for C or "extern C" for C++, which works fine on
2988 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2989 SCOPE with something explicit in config.h. In addition:
2990
2991 (a) pcreposix.h still had just "extern" instead of either of these macros;
2992 I have replaced it with PCRE_DATA_SCOPE.
2993
2994 (b) Functions such as _pcre_xclass(), which are internal to the library,
2995 but external in the C sense, all had PCRE_EXPORT in their definitions.
2996 This is apparently wrong for the Windows case, so I have removed it.
2997 (It makes no difference on Unix-like systems.)
2998
2999 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3000 of recursive calls to match(). This is different to MATCH_LIMIT because
3001 that limits the total number of calls to match(), not all of which increase
3002 the depth of recursion. Limiting the recursion depth limits the amount of
3003 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3004 when PCRE is compiled, and changed at run time. A patch from Google adds
3005 this functionality to the C++ interface.
3006
3007 18. Changes to the handling of Unicode character properties:
3008
3009 (a) Updated the table to Unicode 4.1.0.
3010
3011 (b) Recognize characters that are not in the table as "Cn" (undefined).
3012
3013 (c) I revised the way the table is implemented to a much improved format
3014 which includes recognition of ranges. It now supports the ranges that
3015 are defined in UnicodeData.txt, and it also amalgamates other
3016 characters into ranges. This has reduced the number of entries in the
3017 table from around 16,000 to around 3,000, thus reducing its size
3018 considerably. I realized I did not need to use a tree structure after
3019 all - a binary chop search is just as efficient. Having reduced the
3020 number of entries, I extended their size from 6 bytes to 8 bytes to
3021 allow for more data.
3022
3023 (d) Added support for Unicode script names via properties such as \p{Han}.
3024
3025 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3026 matching that character.
3027
3028 20. When matching a repeated Unicode property with a minimum greater than zero,
3029 (for example \pL{2,}), PCRE could look past the end of the subject if it
3030 reached it while seeking the minimum number of characters. This could
3031 happen only if some of the characters were more than one byte long, because
3032 there is a check for at least the minimum number of bytes.
3033
3034 21. Refactored the implementation of \p and \P so as to be more general, to
3035 allow for more different types of property in future. This has changed the
3036 compiled form incompatibly. Anybody with saved compiled patterns that use
3037 \p or \P will have to recompile them.
3038
3039 22. Added "Any" and "L&" to the supported property types.
3040
3041 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3042 but give a compile time error if the value is greater than 0xff.
3043
3044 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3045 accidentally not being installed or uninstalled.
3046
3047 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3048 made were to insert the current release number. This seemed silly, because
3049 it made things harder for people building PCRE on systems that don't run
3050 "configure". I have turned pcre.h into a distributed file, no longer built
3051 by "configure", with the version identification directly included. There is
3052 no longer a pcre.h.in file.
3053
3054 However, this change necessitated a change to the pcre-config script as
3055 well. It is built from pcre-config.in, and one of the substitutions was the
3056 release number. I have updated configure.ac so that ./configure now finds
3057 the release number by grepping pcre.h.
3058
3059 26. Added the ability to run the tests under valgrind.
3060
3061
3062 Version 6.4 05-Sep-05
3063 ---------------------
3064
3065 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3066 "--" to be printed when multiple files were scanned, even when none of the
3067 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3068 consider it to be a bug, and have restored the previous behaviour.
3069
3070 2. A couple of code tidies to get rid of compiler warnings.
3071
3072 3. The pcretest program used to cheat by referring to symbols in the library
3073 whose names begin with _pcre_. These are internal symbols that are not
3074 really supposed to be visible externally, and in some environments it is
3075 possible to suppress them. The cheating is now confined to including
3076 certain files from the library's source, which is a bit cleaner.
3077
3078 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
3079 file's purpose clearer.
3080
3081 5. Reorganized pcre_ucp_findchar().
3082
3083
3084 Version 6.3 15-Aug-05
3085 ---------------------
3086
3087 1. The file libpcre.pc.in did not have general read permission in the tarball.
3088
3089 2. There were some problems when building without C++ support:
3090
3091 (a) If C++ support was not built, "make install" and "make test" still
3092 tried to test it.
3093
3094 (b) There were problems when the value of CXX was explicitly set. Some
3095 changes have been made to try to fix these, and ...
3096
3097 (c) --disable-cpp can now be used to explicitly disable C++ support.
3098
3099 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
3100 backslash in a target when C++ was disabled. This confuses some
3101 versions of "make", apparently. Using an intermediate variable solves
3102 this. (Same for CPP_LOBJ.)
3103
3104 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
3105 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
3106 necessary on certain architectures.
3107
3108 4. Added a setting of -export-symbols-regex to the link command to remove
3109 those symbols that are exported in the C sense, but actually are local
3110 within the library, and not documented. Their names all begin with
3111 "_pcre_". This is not a perfect job, because (a) we have to except some
3112 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
3113 available (and never for static libraries). I have made a note to try to
3114 find a way round (a) in the future.
3115
3116
3117 Version 6.2 01-Aug-05
3118 ---------------------
3119
3120 1. There was no test for integer overflow of quantifier values. A construction
3121 such as {1111111111111111} would give undefined results. What is worse, if
3122 a minimum quantifier for a parenthesized subpattern overflowed and became
3123 negative, the calculation of the memory size went wrong. This could have
3124 led to memory overwriting.
3125
3126 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
3127
3128 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
3129 operating environments where this matters.
3130
3131 4. Applied Giuseppe Maxia's patch to add additional features for controlling
3132 PCRE options from within the C++ wrapper.
3133
3134 5. Named capturing subpatterns were not being correctly counted when a pattern
3135 was compiled. This caused two problems: (a) If there were more than 100
3136 such subpatterns, the calculation of the memory needed for the whole
3137 compiled pattern went wrong, leading to an overflow error. (b) Numerical
3138 back references of the form \12, where the number was greater than 9, were
3139 not recognized as back references, even though there were sufficient
3140 previous subpatterns.
3141
3142 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
3143 versions of gcc, e.g. 2.95.4.
3144
3145
3146 Version 6.1 21-Jun-05
3147 ---------------------
3148
3149 1. There was one reference to the variable "posix" in pcretest.c that was not
3150 surrounded by "#if !defined NOPOSIX".
3151
3152 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
3153 the cross-check on the old pcre_info() function, for the benefit of the
3154 cut-down version of PCRE that is currently imported into Exim.
3155
3156 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
3157 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
3158 patterns that start (?i) but I don't think that matters. The use of (?i) is
3159 just an example; this all applies to the other options as well.
3160
3161 4. Since libtool seems to echo the compile commands it is issuing, the output
3162 from "make" can be reduced a bit by putting "@" in front of each libtool
3163 compile command.
3164
3165 5. Patch from the folks at Google for configure.in to be a bit more thorough
3166 in checking for a suitable C++ installation before trying to compile the
3167 C++ stuff. This should fix a reported problem when a compiler was present,
3168 but no suitable headers.
3169
3170 6. The man pages all had just "PCRE" as their title. I have changed them to
3171 be the relevant file name. I have also arranged that these names are
3172 retained in the file doc/pcre.txt, which is a concatenation in text format
3173 of all the man pages except the little individual ones for each function.
3174
3175 7. The NON-UNIX-USE file had not been updated for the different set of source
3176 files that come with release 6. I also added a few comments about the C++
3177 wrapper.
3178
3179
3180 Version 6.0 07-Jun-05
3181 ---------------------
3182
3183 1. Some minor internal re-organization to help with my DFA experiments.
3184
3185 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3186 didn't matter for the library itself when fully configured, but did matter
3187 when compiling without UCP support, or within Exim, where the ucp files are
3188 not imported.
3189
3190 3. Refactoring of the library code to split up the various functions into
3191 different source modules. The addition of the new DFA matching code (see
3192 below) to a single monolithic source would have made it really too
3193 unwieldy, quite apart from causing all the code to be include in a
3194 statically linked application, when only some functions are used. This is
3195 relevant even without the DFA addition now that patterns can be compiled in
3196 one application and matched in another.
3197
3198 The downside of splitting up is that there have to be some external
3199 functions and data tables that are used internally in different modules of
3200 the library but which are not part of the API. These have all had their
3201 names changed to start with "_pcre_" so that they are unlikely to clash
3202 with other external names.
3203
3204 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3205 a different (DFA) algorithm. Although it is slower than the original
3206 function, it does have some advantages for certain types of matching
3207 problem.
3208
3209 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3210 including restarting after a partial match.
3211
3212 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3213 defined when compiling for Windows was sent to me. I have put it into the
3214 code, though I have no means of testing or verifying it.
3215
3216 7. Added the pcre_refcount() auxiliary function.
3217
3218 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3219 match before or at the first newline in the subject string. In pcretest,
3220 the /f option on a pattern can be used to set this.
3221
3222 9. A repeated \w when used in UTF-8 mode with characters greater than 256
3223 would behave wrongly. This has been present in PCRE since release 4.0.
3224
3225 10. A number of changes to the pcregrep command:
3226
3227 (a) Refactored how -x works; insert ^(...)$ instead of setting
3228 PCRE_ANCHORED and checking the length, in preparation for adding
3229 something similar for -w.
3230
3231 (b) Added the -w (match as a word) option.
3232
3233 (c) Refactored the way lines are read and buffered so as to have more
3234 than one at a time available.
3235
3236 (d) Implemented a pcregrep test script.
3237
3238 (e) Added the -M (multiline match) option. This allows patterns to match
3239 over several lines of the subject. The buffering ensures that at least
3240 8K, or the rest of the document (whichever is the shorter) is available
3241 for matching (and similarly the previous 8K for lookbehind assertions).
3242
3243 (f) Changed the --help output so that it now says
3244
3245 -w, --word-regex(p)
3246
3247 instead of two lines, one with "regex" and the other with "regexp"
3248 because that confused at least one person since the short forms are the
3249 same. (This required a bit of code, as the output is generated
3250 automatically from a table. It wasn't just a text change.)
3251
3252 (g) -- can be used to terminate pcregrep options if the next thing isn't an
3253 option but starts with a hyphen. Could be a pattern or a path name
3254 starting with a hyphen, for instance.
3255
3256 (h) "-" can be given as a file name to represent stdin.
3257
3258 (i) When file names are being printed, "(standard input)" is used for
3259 the standard input, for compatibility with GNU grep. Previously
3260 "<stdin>" was used.
3261
3262 (j) The option --label=xxx can be used to supply a name to be used for
3263 stdin when file names are being printed. There is no short form.
3264
3265 (k) Re-factored the options decoding logic because we are going to add
3266 two more options that take data. Such options can now be given in four
3267 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3268
3269 (l) Added the -A, -B, and -C options for requesting that lines of context
3270 around matches be printed.
3271
3272 (m) Added the -L option to print the names of files that do not contain
3273 any matching lines, that is, the complement of -l.
3274
3275 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3276 continue to scan other files.
3277
3278 (o) The -s option was incorrectly implemented. For compatibility with other
3279 greps, it now suppresses the error message for a non-existent or non-
3280 accessible file (but not the return code). There is a new option called
3281 -q that suppresses the output of matching lines, which was what -s was
3282 previously doing.
3283
3284 (p) Added --include and --exclude options to specify files for inclusion
3285 and exclusion when recursing.
3286
3287 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3288 Hopefully, it now does.
3289
3290 12. Missing cast in pcre_study().
3291
3292 13. Added an "uninstall" target to the makefile.
3293
3294 14. Replaced "extern" in the function prototypes in Makefile.in with
3295 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3296 world, but is set differently for Windows.
3297
3298 15. Added a second compiling function called pcre_compile2(). The only
3299 difference is that it has an extra argument, which is a pointer to an
3300 integer error code. When there is a compile-time failure, this is set
3301 non-zero, in addition to the error test pointer being set to point to an
3302 error message. The new argument may be NULL if no error number is required
3303 (but then you may as well call pcre_compile(), which is now just a
3304 wrapper). This facility is provided because some applications need a
3305 numeric error indication, but it has also enabled me to tidy up the way
3306 compile-time errors are handled in the POSIX wrapper.
3307
3308 16. Added VPATH=.libs to the makefile; this should help when building with one
3309 prefix path and installing with another. (Or so I'm told by someone who
3310 knows more about this stuff than I do.)
3311
3312 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3313 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3314 match everything, including newlines. This is not POSIX-compatible, but
3315 somebody wanted the feature. From pcretest it can be activated by using
3316 both the P and the s flags.
3317
3318 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3319
3320 19. libpcre.pc was being incorrectly installed as executable.
3321
3322 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3323 it now also looks for '\r' so that it will work unmodified on Windows.
3324
3325 21. Added Google's contributed C++ wrapper to the distribution.
3326
3327 22. Added some untidy missing memory free() calls in pcretest, to keep
3328 Electric Fence happy when testing.
3329
3330
3331
3332 Version 5.0 13-Sep-04
3333 ---------------------
3334
3335 1. Internal change: literal characters are no longer packed up into items
3336 containing multiple characters in a single byte-string. Each character
3337 is now matched using a separate opcode. However, there may be more than one
3338 byte in the character in UTF-8 mode.
3339
3340 2. The pcre_callout_block structure has two new fields: pattern_position and
3341 next_item_length. These contain the offset in the pattern to the next match
3342 item, and its length, respectively.
3343
3344 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3345 insertion of callouts before each pattern item. Added the /C option to
3346 pcretest to make use of this.
3347
3348 4. On the advice of a Windows user, the lines
3349
3350 #if defined(_WIN32) || defined(WIN32)
3351 _setmode( _fileno( stdout ), 0x8000 );
3352 #endif /* defined(_WIN32) || defined(WIN32) */
3353
3354 have been added to the source of pcretest. This apparently does useful
3355 magic in relation to line terminators.
3356
3357 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3358 for the benefit of those environments where the "b" makes a difference.
3359
3360 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3361 to know about it. I have put a hack into configure.in that adds in code
3362 to set GCC=yes if CC=icc. This seems to end up at a point in the
3363 generated configure script that is early enough to affect the setting of
3364 compiler options, which is what is needed, but I have no means of testing
3365 whether it really works. (The user who reported this had patched the
3366 generated configure script, which of course I cannot do.)
3367
3368 LATER: After change 22 below (new libtool files), the configure script
3369 seems to know about icc (and also ecc). Therefore, I have commented out
3370 this hack in configure.in.
3371
3372 7. Added support for pkg-config (2 patches were sent in).
3373
3374 8. Negated POSIX character classes that used a combination of internal tables
3375 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3376 [[:^ascii]]. Typically, they would match almost any characters. The other
3377 POSIX classes were not broken in this way.
3378
3379 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3380 to find the match, as PCRE was deluded into thinking that the match had to
3381 start at the start point or following a newline. The same bug applied to
3382 patterns with negative forward assertions or any backward assertions
3383 preceding ".*" at the start, unless the pattern required a fixed first
3384 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3385
3386 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3387 starting at the last subject character, bytes beyond the end of the subject
3388 string were read.
3389
3390 11. Renamed the variable "class" as "classbits" to make life easier for C++
3391 users. (Previously there was a macro definition, but it apparently wasn't
3392 enough.)
3393
3394 12. Added the new field "tables" to the extra data so that tables can be passed
3395 in at exec time, or the internal tables can be re-selected. This allows
3396 a compiled regex to be saved and re-used at a later time by a different
3397 program that might have everything at different addresses.
3398
3399 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3400 -R library as well as a -L library.
3401
3402 14. The debugging options of pcretest (-d on the command line or D on a
3403 pattern) showed incorrect output for anything following an extended class
3404 that contained multibyte characters and which was followed by a quantifier.
3405
3406 15. Added optional support for general category Unicode character properties
3407 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3408 support. It adds about 90K to the size of the library. The meanings of the
3409 inbuilt class escapes such as \d and \s have NOT been changed.
3410
3411 16. Updated pcredemo.c to include calls to free() to release the memory for the
3412 compiled pattern.
3413
3414 17. The generated file chartables.c was being created in the source directory
3415 instead of in the building directory. This caused the build to fail if the
3416 source directory was different from the building directory, and was
3417 read-only.
3418
3419 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3420 file. No doubt somebody will tell me if they don't make sense... Also added
3421 Dan Mooney's comments about building on OpenVMS.
3422
3423 19. Added support for partial matching via the PCRE_PARTIAL option for
3424 pcre_exec() and the \P data escape in pcretest.
3425
3426 20. Extended pcretest with 3 new pattern features:
3427
3428 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3429 write the compiled pattern to the file whose name is "rest-of-line".
3430 This is a straight binary dump of the data, with the saved pointer to
3431 the character tables forced to be NULL. The study data, if any, is
3432 written too. After writing, pcretest reads a new pattern.
3433
3434 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3435 compiled pattern from the given file. There must not be any
3436 occurrences of "<" in the file name (pretty unlikely); if there are,
3437 pcretest will instead treat the initial "<" as a pattern delimiter.
3438 After reading in the pattern, pcretest goes on to read data lines as
3439 usual.
3440
3441 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3442 and 16-bit fields in a compiled pattern, to simulate a pattern that
3443 was compiled on a host of opposite endianness.
3444
3445 21. The pcre-exec() function can now cope with patterns that were compiled on
3446 hosts of opposite endianness, with this restriction:
3447
3448 As for any compiled expression that is saved and used later, the tables
3449 pointer field cannot be preserved; the extra_data field in the arguments
3450 to pcre_exec() should be used to pass in a tables address if a value
3451 other than the default internal tables were used at compile time.
3452
3453 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3454 now diagnosed as an error. Previously, most of the time, a negative number
3455 would have been treated as zero, but if in addition "ovector" was passed as
3456 NULL, a crash could occur.
3457
3458 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3459 new versions from the libtool 1.5 distribution (the last one is a copy of
3460 a file called libtool.m4). This seems to have fixed the need to patch
3461 "configure" to support Darwin 1.3 (which I used to do). However, I still
3462 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3463 workstation).
3464
3465 24. Changed the PCRE licence to be the more standard "BSD" licence.
3466
3467
3468 Version 4.5 01-Dec-03
3469 ---------------------
3470
3471 1. There has been some re-arrangement of the code for the match() function so
3472 that it can be compiled in a version that does not call itself recursively.
3473 Instead, it keeps those local variables that need separate instances for
3474 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3475 needs to "recurse". Keeping track of where control must go is done by means
3476 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3477 hide most of the details from the main code, and operates only if
3478 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3479 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3480 operating.
3481
3482 To make it easier for callers to provide specially tailored get/free
3483 functions for this usage, two new functions, pcre_stack_malloc, and
3484 pcre_stack_free, are used. They are always called in strict stacking order,
3485 and the size of block requested is always the same.
3486
3487 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3488 PCRE has been compiled to use the stack or the heap for recursion. The
3489 -C option of pcretest uses this to show which version is compiled.
3490
3491 A new data escape \S, is added to pcretest; it causes the amounts of store
3492 obtained and freed by both kinds of malloc/free at match time to be added
3493 to the output.
3494
3495 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3496 what's available on my current Linux desktop machine.
3497
3498 3. When matching a UTF-8 string, the test for a valid string at the start has
3499 been extended. If start_offset is not zero, PCRE now checks that it points
3500 to a byte that is the start of a UTF-8 character. If not, it returns
3501 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3502 this is necessary because there may be backward assertions in the pattern.
3503 When matching the same subject several times, it may save resources to use
3504 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3505
3506 4. The code for checking the validity of UTF-8 strings has been tightened so
3507 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3508 containing "overlong sequences".
3509
3510 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3511 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3512 should have been "&", but it just so happened that all the cases this let
3513 through by mistake were picked up later in the function.
3514
3515 6. I had used a variable called "isblank" - this is a C99 function, causing
3516 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3517
3518 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3519 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3520 so the version is shown; (c) stop "make test" echoing "./RunTest".
3521
3522 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3523
3524 9. The prototype for memmove() for systems that don't have it was using
3525 size_t, but the inclusion of the header that defines size_t was later. I've
3526 moved the #includes for the C headers earlier to avoid this.
3527
3528 10. Added some adjustments to the code to make it easier to compiler on certain
3529 special systems:
3530
3531 (a) Some "const" qualifiers were missing.
3532 (b) Added the macro EXPORT before all exported functions; by default this
3533 is defined to be empty.
3534 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3535 that it reads its output file name as an argument instead of writing
3536 to the standard output and assuming this can be redirected.
3537
3538 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3539 class containing characters with values greater than 255, PCRE compilation
3540 went into a loop.
3541
3542 12. A recursive reference to a subpattern that was within another subpattern
3543 that had a minimum quantifier of zero caused PCRE to crash. For example,
3544 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3545 recursion. If the recursively-called subpattern itself had a zero repeat,
3546 that was OK.
3547
3548 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3549 buffer into which it was copied (for escape processing) was still set at
3550 1024, so long lines caused crashes.
3551
3552 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3553 "internal error: code overflow...". This applied to any character class
3554 that was followed by a possessive quantifier.
3555
3556 15. Modified the Makefile to add libpcre.la as a prerequisite for
3557 libpcreposix.la because I was told this is needed for a parallel build to
3558 work.
3559
3560 16. If a pattern that contained .* following optional items at the start was
3561 studied, the wrong optimizing data was generated, leading to matching
3562 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3563 matching string must start with a or b or c. The correct conclusion for
3564 this pattern is that a match can start with any character.
3565
3566
3567 Version 4.4 13-Aug-03
3568 ---------------------
3569
3570 1. In UTF-8 mode, a character class containing characters with values between
3571 127 and 255 was not handled correctly if the compiled pattern was studied.
3572 In fixing this, I have also improved the studying algorithm for such
3573 classes (slightly).
3574
3575 2. Three internal functions had redundant arguments passed to them. Removal
3576 might give a very teeny performance improvement.
3577
3578 3. Documentation bug: the value of the capture_top field in a callout is *one
3579 more than* the number of the hightest numbered captured substring.
3580
3581 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3582 in incorrectly linking with a previously installed version. They now link
3583 explicitly with libpcre.la.
3584
3585 5. configure.in no longer needs to recognize Cygwin specially.
3586
3587 6. A problem in pcre.in for Windows platforms is fixed.
3588
3589 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3590 pcretest, it used to include the size of the study block as part of its
3591 output. Unfortunately, the structure contains a field that has a different
3592 size on different hardware architectures. This meant that the tests that
3593 showed this size failed. As the block is currently always of a fixed size,
3594 this information isn't actually particularly useful in pcretest output, so
3595 I have just removed it.
3596
3597 8. Three pre-processor statements accidentally did not start in column 1.
3598 Sadly, there are *still* compilers around that complain, even though
3599 standard C has not required this for well over a decade. Sigh.
3600
3601 9. In pcretest, the code for checking callouts passed small integers in the
3602 callout_data field, which is a void * field. However, some picky compilers
3603 complained about the casts involved for this on 64-bit systems. Now
3604 pcretest passes the address of the small integer instead, which should get
3605 rid of the warnings.
3606
3607 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3608 both compile and run time, and gives an error if an invalid UTF-8 sequence
3609 is found. There is a option for disabling this check in cases where the
3610 string is known to be correct and/or the maximum performance is wanted.
3611
3612 11. In response to a bug report, I changed one line in Makefile.in from
3613
3614 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3615 to
3616 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3617
3618 to look similar to other lines, but I have no way of telling whether this
3619 is the right thing to do, as I do not use Windows. No doubt I'll get told
3620 if it's wrong...
3621
3622
3623 Version 4.3 21-May-03
3624 ---------------------
3625
3626 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3627 Makefile.
3628
3629 2. Some refactoring to improve the quality of the code:
3630
3631 (i) The utf8_table... variables are now declared "const".
3632
3633 (ii) The code for \cx, which used the "case flipping" table to upper case
3634 lower case letters, now just substracts 32. This is ASCII-specific,
3635 but the whole concept of \cx is ASCII-specific, so it seems
3636 reasonable.
3637
3638 (iii) PCRE was using its character types table to recognize decimal and
3639 hexadecimal digits in the pattern. This is silly, because it handles
3640 only 0-9, a-f, and A-F, but the character types table is locale-
3641 specific, which means strange things might happen. A private
3642 table is now used for this - though it costs 256 bytes, a table is
3643 much faster than multiple explicit tests. Of course, the standard
3644 character types table is still used for matching digits in subject
3645 strings against \d.
3646
3647 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3648 ending in _t are). So I've renamed it as ESC_tee.
3649
3650 3. The first argument for regexec() in the POSIX wrapper should have been
3651 defined as "const".
3652
3653 4. Changed pcretest to use malloc() for its buffers so that they can be
3654 Electric Fenced for debugging.
3655
3656 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3657 to read one or more bytes before the start of the subject string. Often this
3658 had no effect on PCRE's behaviour, but in some circumstances it could
3659 provoke a segmentation fault.
3660
3661 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3662 to try to read one or more bytes before the start of the subject string.
3663
3664 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3665 UTF-8 support could misbehave in various ways if the subject string
3666 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3667 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3668 back over UTF-8 characters.)
3669
3670
3671 Version 4.2 14-Apr-03
3672 ---------------------
3673
3674 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3675
3676 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3677 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3678 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3679 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3680 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3681 and BUILD_EXEEXT
3682 Note: automatic setting of the BUILD variables is not yet working
3683 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3684 compile-time but not at link-time
3685 [LINK]: use for linking executables only
3686 make different versions for Windows and non-Windows
3687 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3688 libraries
3689 [LINK_FOR_BUILD]: new variable
3690 [OBJEXT]: use throughout
3691 [EXEEXT]: use throughout
3692 <winshared>: new target
3693 <wininstall>: new target
3694 <dftables.o>: use native compiler
3695 <dftables>: use native linker
3696 <install>: handle Windows platform correctly
3697 <clean>: ditto
3698 <check>: ditto
3699 copy DLL to top builddir before testing
3700
3701 As part of these changes, -no-undefined was removed again. This was reported
3702 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3703 in any case.
3704
3705 3. Some tidies to get rid of compiler warnings:
3706
3707 . In the match_data structure, match_limit was an unsigned long int, whereas
3708 match_call_count was an int. I've made them both unsigned long ints.
3709
3710 . In pcretest the fact that a const uschar * doesn't automatically cast to
3711 a void * provoked a warning.
3712
3713 . Turning on some more compiler warnings threw up some "shadow" variables
3714 and a few more missing casts.
3715
3716 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3717 option, a class that contained a single character with a value between 128
3718 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3719
3720 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3721 option, a class that contained several characters, but with at least one
3722 whose value was between 128 and 255 caused PCRE to crash.
3723
3724
3725 Version 4.1 12-Mar-03
3726 ---------------------
3727
3728 1. Compiling with gcc -pedantic found a couple of places where casts were
3729 needed, and a string in dftables.c that was longer than standard compilers are
3730 required to support.
3731
3732 2. Compiling with Sun's compiler found a few more places where the code could
3733 be tidied up in order to avoid warnings.
3734
3735 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3736 first of these names is deprecated in the latest Autoconf in favour of the name
3737 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3738 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3739 analogy I have changed it to CFLAGS_FOR_BUILD.
3740
3741 4. Added -no-undefined to the linking command in the Makefile, because this is
3742 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3743 linking step for the pcreposix library.
3744
3745 5. PCRE was failing to diagnose the case of two named groups with the same
3746 name.
3747
3748 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3749 literal character that is needed in the subject for a match, and scans along to
3750 ensure that it is present before embarking on the full matching process. This
3751 saves time in cases of nested unlimited repeats that are never going to match.
3752 Problem: the scan can take a lot of time if the subject is very long (e.g.
3753 megabytes), thus penalizing straightforward matches. It is now done only if the
3754 amount of subject to be scanned is less than 1000 bytes.
3755
3756 7. A lesser problem with the same optimization is that it was recording the
3757 first character of an anchored pattern as "needed", thus provoking a search
3758 right along the subject, even when the first match of the pattern was going to
3759 fail. The "needed" character is now not set for anchored patterns, unless it
3760 follows something in the pattern that is of non-fixed length. Thus, it still
3761 fulfils its original purpose of finding quick non-matches in cases of nested
3762 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3763
3764
3765 Version 4.0 17-Feb-03
3766 ---------------------
3767
3768 1. If a comment in an extended regex that started immediately after a meta-item
3769 extended to the end of string, PCRE compiled incorrect data. This could lead to
3770 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3771
3772 2. Moved to autoconf 2.53 and libtool 1.4.2.
3773
3774 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3775 the special perltest8 script is no longer needed - all the tests can be run
3776 from a single perltest script.
3777
3778 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3779 by \s. It has now been removed in PCRE. This means it isn't recognized as
3780 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3781 class [:space:] *does* include VT, thereby creating a mess.
3782
3783 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3784 space and tab.
3785
3786 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3787 its new features into the main test script, reducing the number of scripts.
3788
3789 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3790 were backward compatible, and made the (?i) apply to the whole pattern, as if
3791 /i were given. Now it behaves more logically, and applies the option setting
3792 only to what follows. PCRE has been changed to follow suit. However, if it
3793 finds options settings right at the start of the pattern, it extracts them into
3794 the global options, as before. Thus, they show up in the info data.
3795
3796 8. Added support for the \Q...\E escape sequence. Characters in between are
3797 treated as literals. This is slightly different from Perl in that $ and @ are
3798 also handled as literals inside the quotes. In Perl, they will cause variable
3799 interpolation. Note the following examples:
3800
3801 Pattern PCRE matches Perl matches
3802
3803 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3804 \Qabc\$xyz\E abc\$xyz abc\$xyz
3805 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3806
3807 For compatibility with Perl, \Q...\E sequences are recognized inside character
3808 classes as well as outside them.
3809
3810 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3811 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3812 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3813 signed/unsigned warnings.
3814
3815 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3816 option for pcretest, so I've replaced it by a simple function that does just
3817 that job.
3818
3819 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3820 "pcregrep -".
3821
3822 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3823 Java package. This provides some syntactic sugar for simple cases of what my
3824 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3825 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3826 item, you can use this simplified notation. Note that only makes sense with
3827 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3828 greediness, whatever the setting of the PCRE_UNGREEDY option.
3829
3830 13. A change of greediness default within a pattern was not taking effect at
3831 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3832 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3833 was abstracted outside.
3834
3835 14. PCRE now supports the \G assertion. It is true when the current matching
3836 position is at the start point of the match. This differs from \A when the
3837 starting offset is non-zero. Used with the /g option of pcretest (or similar
3838 code), it works in the same way as it does for Perl's /g option. If all
3839 alternatives of a regex begin with \G, the expression is anchored to the start
3840 match position, and the "anchored" flag is set in the compiled expression.
3841
3842 15. Some bugs concerning the handling of certain option changes within patterns
3843 have been fixed. These applied to options other than (?ims). For example,
3844 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3845 been the other way round. Some of this was related to change 7 above.
3846
3847 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3848 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3849 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3850 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3851
3852 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3853 mode. Unlike ".", it always matches newline, whatever the setting of
3854 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3855 assertions. Perl allows it, but it doesn't (in general) work because it can't
3856 calculate the length of the lookbehind. At least, that's the case for Perl
3857 5.8.0 - I've been told they are going to document that it doesn't work in
3858 future.
3859
3860 18. Added an error diagnosis for escapes that PCRE does not support: these are
3861 \L, \l, \N, \P, \p, \U, \u, and \X.
3862
3863 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3864 reading past the end of the pattern in cases such as /[abcd/.
3865
3866 20. PCRE was getting more memory than necessary for patterns with classes that
3867 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3868
3869 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3870 compiling PCRE for use with Virtual Pascal.
3871
3872 22. Small fix to the Makefile to make it work properly if the build is done
3873 outside the source tree.
3874
3875 23. Added a new extension: a condition to go with recursion. If a conditional
3876 subpattern starts with (?(R) the "true" branch is used if recursion has
3877 happened, whereas the "false" branch is used only at the top level.
3878
3879 24. When there was a very long string of literal characters (over 255 bytes
3880 without UTF support, over 250 bytes with UTF support), the computation of how
3881 much memory was required could be incorrect, leading to segfaults or other
3882 strange effects.
3883
3884 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3885 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3886 there was a subsequent back reference to those brackets. This meant that, for
3887 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3888 possible to check for precisely this case. All we can do is abandon the
3889 optimization if .* occurs inside capturing brackets when there are any back
3890 references whatsoever. (See below for a better fix that came later.)
3891
3892 26. The handling of the optimization for finding the first character of a
3893 non-anchored pattern, and for finding a character that is required later in the
3894 match were failing in some cases. This didn't break the matching; it just
3895 failed to optimize when it could. The way this is done has been re-implemented.
3896
3897 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3898
3899 28. Added a new feature that provides some of the functionality that Perl
3900 provides with (?{...}). The facility is termed a "callout". The way it is done
3901 in PCRE is for the caller to provide an optional function, by setting
3902 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3903 global variable. By default it is unset, which disables all calling out. To get
3904 the function called, the regex must include (?C) at appropriate points. This
3905 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3906 This provides a means of identifying different callout points. When PCRE
3907 reaches such a point in the regex, if pcre_callout has been set, the external
3908 function is called. It is provided with data in a structure called
3909 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3910 matching continues; if it returns a non-zero value, the match at the current
3911 point fails. However, backtracking will occur if possible. [This was changed
3912 later and other features added - see item 49 below.]
3913
3914 29. pcretest is upgraded to test the callout functionality. It provides a
3915 callout function that displays information. By default, it shows the start of
3916 the match and the current position in the text. There are some new data escapes
3917 to vary what happens:
3918
3919 \C+ in addition, show current contents of captured substrings
3920 \C- do not supply a callout function
3921 \C!n return 1 when callout number n is reached
3922 \C!n!m return 1 when callout number n is reached for the mth time
3923
3924 30. If pcregrep was called with the -l option and just a single file name, it
3925 output "<stdin>" if a match was found, instead of the file name.
3926
3927 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3928 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3929 pcre_exec(). This saves a malloc/free per call. The default value of
3930 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3931 when configuring.
3932
3933 32. The default maximum size of a compiled pattern is 64K. There have been a
3934 few cases of people hitting this limit. The code now uses macros to handle the
3935 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3936 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3937 configuring. Tests 2 and 5 work only with 2-byte links because they output
3938 debugging information about compiled patterns.
3939
3940 33. Internal code re-arrangements:
3941
3942 (a) Moved the debugging function for printing out a compiled regex into
3943 its own source file (printint.c) and used #include to pull it into
3944 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3945 separate copies.
3946
3947 (b) Defined the list of op-code names for debugging as a macro in
3948 internal.h so that it is next to the definition of the opcodes.
3949
3950 (c) Defined a table of op-code lengths for simpler skipping along compiled
3951 code. This is again a macro in internal.h so that it is next to the
3952 definition of the opcodes.
3953
3954 34. Added support for recursive calls to individual subpatterns, along the
3955 lines of Robin Houston's patch (but implemented somewhat differently).
3956
3957 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3958 allow it to read and process whole directories in Win32. This code was
3959 contributed by Lionel Fourquaux; it has not been tested by me.
3960
3961 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3962 used to name a group. Names consist of alphanumerics and underscores, and must
3963 be unique. Back references use the syntax (?P=name) and recursive calls use
3964 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3965 numbers. The function pcre_fullinfo() can be used after compilation to extract
3966 a name/number map. There are three relevant calls:
3967
3968 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3969 PCRE_INFO_NAMECOUNT yields the number of entries
3970 PCRE_INFO_NAMETABLE yields a pointer to the map.
3971
3972 The map is a vector of fixed-size entries. The size of each entry depends on
3973 the length of the longest name used. The first two bytes of each entry are the
3974 group number, most significant byte first. There follows the corresponding
3975 name, zero terminated. The names are in alphabetical order.
3976
3977 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3978 case instead of 255. Making it the same both with and without UTF-8 support
3979 means that the same test output works with both.
3980
3981 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3982 calling malloc() with a zero argument.
3983
3984 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3985 optimization. I've improved things by keeping a bitmap of backreferences with
3986 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3987 fact referenced, the optimization can be applied. It is unlikely that a
3988 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3989 the match to follow \n) will appear inside brackets with a number greater than
3990 31, but if it does, any back reference > 31 suppresses the optimization.
3991
3992 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3993 of disabling numbered capturing parentheses. Any opening parenthesis that is
3994 not followed by ? behaves as if it were followed by ?: but named parentheses
3995 can still be used for capturing (and they will acquire numbers in the usual
3996 way).
3997
3998 41. Redesigned the return codes from the match() function into yes/no/error so
3999 that errors can be passed back from deep inside the nested calls. A malloc
4000 failure while inside a recursive subpattern call now causes the
4001 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4002
4003 42. It is now possible to set a limit on the number of times the match()
4004 function is called in a call to pcre_exec(). This facility makes it possible to
4005 limit the amount of recursion and backtracking, though not in a directly
4006 obvious way, because the match() function is used in a number of different
4007 circumstances. The count starts from zero for each position in the subject
4008 string (for non-anchored patterns). The default limit is, for compatibility, a
4009 large number, namely 10 000 000. You can change this in two ways:
4010
4011 (a) When configuring PCRE before making, you can use --with-match-limit=n
4012 to set a default value for the compiled library.
4013
4014 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4015 a different value is set. See 45 below.
4016
4017 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4018
4019 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4020 of things that can be changed at compile time. The first argument specifies
4021 what is wanted and the second points to where the information is to be placed.
4022 The current list of available information is:
4023
4024 PCRE_CONFIG_UTF8
4025
4026 The output is an integer that is set to one if UTF-8 support is available;
4027 otherwise it is set to zero.
4028
4029 PCRE_CONFIG_NEWLINE
4030
4031 The output is an integer that it set to the value of the code that is used for
4032 newline. It is either LF (10) or CR (13).
4033
4034 PCRE_CONFIG_LINK_SIZE
4035
4036 The output is an integer that contains the number of bytes used for internal
4037 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4038
4039 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4040
4041 The output is an integer that contains the threshold above which the POSIX
4042 interface uses malloc() for output vectors. See item 31 above.
4043
4044 PCRE_CONFIG_MATCH_LIMIT
4045
4046 The output is an unsigned integer that contains the default limit of the number
4047 of match() calls in a pcre_exec() execution. See 42 above.
4048
4049 44. pcretest has been upgraded by the addition of the -C option. This causes it
4050 to extract all the available output from the new pcre_config() function, and to
4051 output it. The program then exits immediately.
4052
4053 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4054 order to support additional features. One way would have been to define
4055 pcre_exec2() (for example) with extra arguments, but this would not have been
4056 extensible, and would also have required all calls to the original function to
4057 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4058 is used for passing in "extra" data from pcre_study().
4059
4060 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4061 contains the following fields:
4062
4063 flags a bitmap indicating which of the following fields are set
4064 study_data opaque data from pcre_study()
4065 match_limit a way of specifying a limit on match() calls for a specific
4066 call to pcre_exec()
4067 callout_data data for callouts (see 49 below)
4068
4069 The flag bits are also defined in pcre.h, and are
4070
4071 PCRE_EXTRA_STUDY_DATA
4072 PCRE_EXTRA_MATCH_LIMIT
4073 PCRE_EXTRA_CALLOUT_DATA
4074
4075 The pcre_study() function now returns one of these new pcre_extra blocks, with
4076 the actual study data pointed to by the study_data field, and the
4077 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
4078 before. That is, this change is entirely upwards-compatible and requires no
4079 change to existing code.
4080
4081 If you want to pass in additional data to pcre_exec(), you can either place it
4082 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
4083 block.
4084
4085 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
4086 data string contains the escape sequence \M, pcretest calls pcre_exec() several
4087 times with different match limits, until it finds the minimum value needed for
4088 pcre_exec() to complete. The value is then output. This can be instructive; for
4089 most simple matches the number is quite small, but for pathological cases it
4090 gets very large very quickly.
4091
4092 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
4093 returns the size of the data block pointed to by the study_data field in a
4094 pcre_extra block, that is, the value that was passed as the argument to
4095 pcre_malloc() when PCRE was getting memory in which to place the information
4096 created by pcre_study(). The fourth argument should point to a size_t variable.
4097 pcretest has been extended so that this information is shown after a successful
4098 pcre_study() call when information about the compiled regex is being displayed.
4099
4100 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
4101 because what follows is always an absolute path. (Later: it turns out that this
4102 is more than cosmetic for MinGW, because it doesn't like empty path
4103 components.)
4104
4105 49. Some changes have been made to the callout feature (see 28 above):
4106
4107 (i) A callout function now has three choices for what it returns:
4108
4109 0 => success, carry on matching
4110 > 0 => failure at this point, but backtrack if possible
4111 < 0 => serious error, return this value from pcre_exec()
4112
4113 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
4114 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
4115 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
4116 use by callout functions. It will never be used by PCRE itself.
4117
4118 (ii) The pcre_extra structure (see 45 above) has a void * field called
4119 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
4120 pcre_callout_block structure has a field of the same name. The contents of
4121 the field passed in the pcre_extra structure are passed to the callout
4122 function in the corresponding field in the callout block. This makes it
4123 easier to use the same callout-containing regex from multiple threads. For
4124 testing, the pcretest program has a new data escape
4125
4126 \C*n pass the number n (may be negative) as callout_data
4127
4128 If the callout function in pcretest receives a non-zero value as
4129 callout_data, it returns that value.
4130
4131 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
4132 there were some redundant $(CFLAGS) in commands that are now specified as
4133 $(LINK), which already includes $(CFLAGS).
4134
4135 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
4136 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
4137 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
4138 one-byte characters throughout. Note that case-insensitive matching applies
4139 only to characters whose values are less than 256. PCRE doesn't support the
4140 notion of cases for higher-valued characters.
4141
4142 (i) A character class whose characters are all within 0-255 is handled as
4143 a bit map, and the map is inverted for negative classes. Previously, a
4144 character > 255 always failed to match such a class; however it should
4145 match if the class was a negative one (e.g. [^ab]). This has been fixed.
4146
4147 (ii) A negated character class with a single character < 255 is coded as
4148 "not this character" (OP_NOT). This wasn't working properly when the test
4149 character was multibyte, either singly or repeated.
4150
4151 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
4152 mode, for example: \x{100}{2,3}.
4153
4154 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
4155 singly or repeated) now correctly test multibyte characters. However,
4156 PCRE doesn't recognize any characters with values greater than 255 as
4157 digits, spaces, or word characters. Such characters always match \D, \S,
4158 and \W, and never match \d, \s, or \w.
4159
4160 (v) Classes may now contain characters and character ranges with values
4161 greater than 255. For example: [ab\x{100}-\x{400}].
4162
4163 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
4164 PCRE in UTF-8 mode.
4165
4166 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
4167 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
4168 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
4169 value.)
4170
4171 53. The single man page has become too large. I have therefore split it up into
4172 a number of separate man pages. These also give rise to individual HTML pages;
4173 these are now put in a separate directory, and there is an index.html page that
4174 lists them all. Some hyperlinking between the pages has been installed.
4175
4176 54. Added convenience functions for handling named capturing parentheses.
4177
4178 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
4179 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
4180 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
4181 are faulted.
4182
4183 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
4184 calling configure. These values are used when compiling the dftables.c program
4185 which is run to generate the source of the default character tables. They
4186 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
4187 you will need to set these values.
4188
4189 57. Updated the building process for Windows DLL, as provided by Fred Cox.
4190
4191
4192 Version 3.9 02-Jan-02
4193 ---------------------
4194
4195 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
4196
4197 2. If --disable-static was given, the building process failed when trying to
4198 build pcretest and pcregrep. (For some reason it was using libtool to compile
4199 them, which is not right, as they aren't part of the library.)
4200
4201
4202 Version 3.8 18-Dec-01
4203 ---------------------
4204
4205 1. The experimental UTF-8 code was completely screwed up. It was packing the
4206 bytes in the wrong order. How dumb can you get?
4207
4208
4209 Version 3.7 29-Oct-01
4210 ---------------------
4211
4212 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
4213 This caused pcretest, when used on the test data, to segfault. Unfortunately,
4214 this didn't happen under Solaris 8, where I normally test things.
4215
4216 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
4217 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
4218 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
4219 this fix an hour or so after the initial 3.7 release.)
4220
4221
4222 Version 3.6 23-Oct-01
4223 ---------------------
4224
4225 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
4226 offsets passed as NULL with zero offset count.
4227
4228 2. The config.guess and config.sub files had not been updated when I moved to
4229 the latest autoconf.
4230
4231
4232 Version 3.5 15-Aug-01
4233 ---------------------
4234
4235 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
4236 had been forgotten.
4237
4238 2. By using declared but undefined structures, we can avoid using "void"
4239 definitions in pcre.h while keeping the internal definitions of the structures
4240 private.
4241
4242 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
4243 user point of view, this means that both static and shared libraries are built
4244 by default, but this can be individually controlled. More of the work of
4245 handling this static/shared cases is now inside libtool instead of PCRE's make
4246 file.
4247
4248 4. The pcretest utility is now installed along with pcregrep because it is
4249 useful for users (to test regexs) and by doing this, it automatically gets
4250 relinked by libtool. The documentation has been turned into a man page, so
4251 there are now .1, .txt, and .html versions in /doc.
4252
4253 5. Upgrades to pcregrep:
4254 (i) Added long-form option names like gnu grep.
4255 (ii) Added --help to list all options with an explanatory phrase.
4256 (iii) Added -r, --recursive to recurse into sub-directories.
4257 (iv) Added -f, --file to read patterns from a file.
4258
4259 6. pcre_exec() was referring to its "code" argument before testing that
4260 argument for NULL (and giving an error if it was NULL).
4261
4262 7. Upgraded Makefile.in to allow for compiling in a different directory from
4263 the source directory.
4264
4265 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
4266 options bits, the pointer it was passed was to an int instead of to an unsigned
4267 long int. This mattered only on 64-bit systems.
4268
4269 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
4270 generated) instead of pcre.in, which it its source. Also made the same change
4271 in several of the .c files.
4272
4273 10. A new release of gcc defines printf() as a macro, which broke pcretest
4274 because it had an ifdef in the middle of a string argument for printf(). Fixed
4275 by using separate calls to printf().
4276
4277 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4278 script, to force use of CR or LF instead of \n in the source. On non-Unix
4279 systems, the value can be set in config.h.
4280
4281 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4282 absolute limit. Changed the text of the error message to make this clear, and
4283 likewise updated the man page.
4284
4285 13. The limit of 99 on the number of capturing subpatterns has been removed.
4286 The new limit is 65535, which I hope will not be a "real" limit.
4287
4288
4289 Version 3.4 22-Aug-00
4290 ---------------------
4291
4292 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4293
4294 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4295
4296
4297 Version 3.3 01-Aug-00
4298 ---------------------
4299
4300 1. If an octal character was given, but the value was greater than \377, it
4301 was not getting masked to the least significant bits, as documented. This could
4302 lead to crashes in some systems.
4303
4304 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4305 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4306
4307 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4308 These just pass their arguments on to (pcre_free)(), but they are provided
4309 because some uses of PCRE bind it to non-C systems that can call its functions,
4310 but cannot call free() or pcre_free() directly.
4311
4312 4. Add "make test" as a synonym for "make check". Corrected some comments in
4313 the Makefile.
4314
4315 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4316 Makefile.
4317
4318 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4319 command called pgrep for grepping around the active processes.
4320
4321 7. Added the beginnings of support for UTF-8 character strings.
4322
4323 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4324 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4325 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4326 out for the ar command.)
4327
4328
4329 Version 3.2 12-May-00
4330 ---------------------
4331
4332 This is purely a bug fixing release.
4333
4334 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4335 of ZA. This was just one example of several cases that could provoke this bug,
4336 which was introduced by change 9 of version 2.00. The code for breaking
4337 infinite loops after an iteration that matches an empty string was't working
4338 correctly.
4339
4340 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4341 when matched against abbab (for example). After matching an empty string, it
4342 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4343 caused it to match further down the string than it should.
4344
4345 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4346 was there because it doesn't seem to be needed, and it causes trouble on some
4347 systems, as it is not a Standard C header. It has been removed.
4348
4349 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4350 were reported on the Macintosh. The changes were from
4351
4352 while ((c = *(++ptr)) != 0 && c != '\n');
4353 to
4354 while ((c = *(++ptr)) != 0 && c != '\n') ;
4355
4356 Totally extraordinary, but if that's what it takes...
4357
4358 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4359 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4360 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4361 assumes the way PCRE uses memmove() (always moving upwards).
4362
4363 6. PCRE is being used in one environment where strchr() is not available. There
4364 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4365 faster code anyway.
4366
4367
4368 Version 3.1 09-Feb-00
4369 ---------------------
4370
4371 The only change in this release is the fixing of some bugs in Makefile.in for
4372 the "install" target:
4373
4374 (1) It was failing to install pcreposix.h.
4375
4376 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4377
4378
4379 Version 3.0 01-Feb-00
4380 ---------------------
4381
4382 1. Add support for the /+ modifier to perltest (to output $` like it does in
4383 pcretest).
4384
4385 2. Add support for the /g modifier to perltest.
4386
4387 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4388 matches null strings.
4389
4390 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4391 pattern. Perl treats empty patterns specially - it reuses the most recent
4392 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4393 effect.
4394
4395 5. The POSIX interface was broken in that it was just handing over the POSIX
4396 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4397 required a bigger vector, with some working space on the end. This means that
4398 the POSIX wrapper now has to get and free some memory, and copy the results.
4399
4400 6. Added some simple autoconf support, placing the test data and the
4401 documentation in separate directories, re-organizing some of the
4402 information files, and making it build pcre-config (a GNU standard). Also added
4403 libtool support for building PCRE as a shared library, which is now the
4404 default.
4405
4406 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4407 09 are not valid octal constants. Single digits will be used for minor values
4408 less than 10.
4409
4410 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4411 existing programs that set these in the POSIX interface can use PCRE without
4412 modification.
4413
4414 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4415 return all that pcre_info() returns, plus additional data. The pcre_info()
4416 function is retained for compatibility, but is considered to be obsolete.
4417
4418 10. Added experimental recursion feature (?R) to handle one common case that
4419 Perl 5.6 will be able to do with (?p{...}).
4420
4421 11. Added support for POSIX character classes like [:alpha:], which Perl is
4422 adopting.
4423
4424
4425 Version 2.08 31-Aug-99
4426 ----------------------
4427
4428 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4429 trying to match at the startoffset position, but instead was moving forward to
4430 the next newline as if a previous match had failed.
4431
4432 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4433 and could get into a loop if a null string was matched other than at the start
4434 of the subject.
4435
4436 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4437 be distinguished at compile time, and for completeness also added PCRE_DATE.
4438
4439 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4440 in GnuWin32 environments.
4441
4442
4443 Version 2.07 29-Jul-99
4444 ----------------------
4445
4446 1. The documentation is now supplied in plain text form and HTML as well as in
4447 the form of man page sources.
4448
4449 2. C++ compilers don't like assigning (void *) values to other pointer types.
4450 In particular this affects malloc(). Although there is no problem in Standard
4451 C, I've put in casts to keep C++ compilers happy.
4452
4453 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4454 should be (const char *).
4455
4456 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4457 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4458 However, I haven't made this a standard facility. The documentation doesn't
4459 mention it, and the Makefile doesn't support it.
4460
4461 5. The Makefile now contains an "install" target, with editable destinations at
4462 the top of the file. The pcretest program is not installed.
4463
4464 6. pgrep -V now gives the PCRE version number and date.
4465
4466 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4467 causing the entire string to be ignored, instead of just the last character.
4468
4469 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4470 non-matching string, it can take a very, very long time, even for strings of
4471 quite modest length, because of the nested recursion. PCRE now does better in
4472 some of these cases. It does this by remembering the last required literal
4473 character in the pattern, and pre-searching the subject to ensure it is present
4474 before running the real match. In other words, it applies a heuristic to detect
4475 some types of certain failure quickly, and in the above example, if presented
4476 with a string that has no trailing " it gives "no match" very quickly.
4477
4478 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4479 other alternatives are tried instead.
4480
4481
4482 Version 2.06 09-Jun-99
4483 ----------------------
4484
4485 1. Change pcretest's output for amount of store used to show just the code
4486 space, because the remainder (the data block) varies in size between 32-bit and
4487 64-bit systems.
4488
4489 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4490 start matching at. This allows lookbehinds to work when searching for multiple
4491 occurrences in a string.
4492
4493 3. Added additional options to pcretest for testing multiple occurrences:
4494
4495 /+ outputs the rest of the string that follows a match
4496 /g loops for multiple occurrences, using the new startoffset argument
4497 /G loops for multiple occurrences by passing an incremented pointer
4498
4499 4. PCRE wasn't doing the "first character" optimization for patterns starting
4500 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4501 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4502 the letter 'x'. On long subject strings, this gives a significant speed-up.
4503
4504
4505 Version 2.05 21-Apr-99
4506 ----------------------
4507
4508 1. Changed the type of magic_number from int to long int so that it works
4509 properly on 16-bit systems.
4510
4511 2. Fixed a bug which caused patterns starting with .* not to work correctly
4512 when the subject string contained newline characters. PCRE was assuming
4513 anchoring for such patterns in all cases, which is not correct because .* will
4514 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4515 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4516 must be retried after every newline in the subject.
4517
4518
4519 Version 2.04 18-Feb-99
4520 ----------------------
4521
4522 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4523 computation of the store needed to hold the pattern was incorrect (too large).
4524 If such patterns were nested a few deep, this could multiply and become a real
4525 problem.
4526
4527 2. Added /M option to pcretest to show the memory requirement of a specific
4528 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4529
4530 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4531 compiled in such a way that the backtracking after subsequent failure was
4532 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4533 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4534
4535
4536 Version 2.03 02-Feb-99
4537 ----------------------
4538
4539 1. Fixed typo and small mistake in man page.
4540
4541 2. Added 4th condition (GPL supersedes if conflict) and created separate
4542 LICENCE file containing the conditions.
4543
4544 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4545 Perl, that is the internal \ allows the delimiter to be included in the
4546 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4547 the final delimiter, add \ to the end of the pattern (to test the error).
4548
4549 4. Added the convenience functions for extracting substrings after a successful
4550 match. Updated pcretest to make it able to test these functions.
4551
4552
4553 Version 2.02 14-Jan-99
4554 ----------------------
4555
4556 1. Initialized the working variables associated with each extraction so that
4557 their saving and restoring doesn't refer to uninitialized store.
4558
4559 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4560 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4561 fix the problem.
4562
4563 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4564 calls, and wasn't printing the correct value for compiling calls. Increased the
4565 default value of LOOPREPEAT, and the number of significant figures in the
4566 times.
4567
4568 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4569
4570 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4571 a building problem on Windows NT with a FAT file system.
4572
4573
4574 Version 2.01 21-Oct-98
4575 ----------------------
4576
4577 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4578 to character tables built by pcre_maketables() in the current locale. If NULL
4579 is passed, the default tables are used.
4580
4581
4582 Version 2.00 24-Sep-98
4583 ----------------------
4584
4585 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4586 it any more.
4587
4588 2. Allow quantification of (?>) groups, and make it work correctly.
4589
4590 3. The first character computation wasn't working for (?>) groups.
4591
4592 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4593 end of the subject) and add 5.005's \z, which really does match only at the
4594 very end of the subject.
4595
4596 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4597
4598 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4599 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4600 localized options. All options to pcre_study() were also removed.
4601
4602 7. Add other new features from 5.005:
4603
4604 $(?<= positive lookbehind
4605 $(?<! negative lookbehind
4606 (?imsx-imsx) added the unsetting capability
4607 such a setting is global if at outer level; local otherwise
4608 (?imsx-imsx:) non-capturing groups with option setting
4609 (?(cond)re|re) conditional pattern matching
4610
4611 A backreference to itself in a repeated group matches the previous
4612 captured string.
4613
4614 8. General tidying up of studying (both automatic and via "study")
4615 consequential on the addition of new assertions.
4616
4617 9. As in 5.005, unlimited repeated groups that could match an empty substring
4618 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4619 runtime if any iteration does actually match an empty substring.
4620
4621 10. Include the RunTest script in the distribution.
4622
4623 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4624 discrepancies, some of which were old and were also with respect to 5.004. They
4625 have now been fixed.
4626
4627
4628 Version 1.09 28-Apr-98
4629 ----------------------
4630
4631 1. A negated single character class followed by a quantifier with a minimum
4632 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4633 program crashes, or just wrong answers. This did not apply to negated classes
4634 containing more than one character, or to minima other than one.
4635
4636
4637 Version 1.08 27-Mar-98
4638 ----------------------
4639
4640 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4641
4642 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4643 latter must appear before anything that relies on it in the pattern.
4644
4645
4646 Version 1.07 16-Feb-98
4647 ----------------------
4648
4649 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4650 repeat of a potentially empty string).
4651
4652
4653 Version 1.06 23-Jan-98
4654 ----------------------
4655
4656 1. Added Markus Oberhumer's little patches for C++.
4657
4658 2. Literal strings longer than 255 characters were broken.
4659
4660
4661 Version 1.05 23-Dec-97
4662 ----------------------
4663
4664 1. Negated character classes containing more than one character were failing if
4665 PCRE_CASELESS was set at run time.
4666
4667
4668 Version 1.04 19-Dec-97
4669 ----------------------
4670
4671 1. Corrected the man page, where some "const" qualifiers had been omitted.
4672
4673 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4674 input syntax.
4675
4676 3. Fixed memory leak which occurred when a regex with back references was
4677 matched with an offsets vector that wasn't big enough. The temporary memory
4678 that is used in this case wasn't being freed if the match failed.
4679
4680 4. Tidied pcretest to ensure it frees memory that it gets.
4681
4682 5. Temporary memory was being obtained in the case where the passed offsets
4683 vector was exactly big enough.
4684
4685 6. Corrected definition of offsetof() from change 5 below.
4686
4687 7. I had screwed up change 6 below and broken the rules for the use of
4688 setjmp(). Now fixed.
4689
4690
4691 Version 1.03 18-Dec-97
4692 ----------------------
4693
4694 1. A erroneous regex with a missing opening parenthesis was correctly
4695 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4696 on some systems.
4697
4698 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4699 it was reported that one broken compiler failed on the former because "code" is
4700 also an independent variable.
4701
4702 3. The erroneous regex a[]b caused an array overrun reference.
4703
4704 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4705 fail on data ending with that character. (It was going on too far, and checking
4706 the next character, typically a binary zero.) This was specific to the
4707 optimized code for single-character negative classes.
4708
4709 5. Added a contributed patch from the TIN world which does the following:
4710
4711 + Add an undef for memmove, in case the the system defines a macro for it.
4712
4713 + Add a definition of offsetof(), in case there isn't one. (I don't know
4714 the reason behind this - offsetof() is part of the ANSI standard - but
4715 it does no harm).
4716
4717 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4718 most of the places where whitespace preceded '#'. I have given up and
4719 allowed the remaining 2 cases to be at the margin.
4720
4721 + Rename some variables in pcre to eliminate shadowing. This seems very
4722 pedantic, but does no harm, of course.
4723
4724 6. Moved the call to setjmp() into its own function, to get rid of warnings
4725 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4726
4727 7. Constructs such as \d{8,} were compiling into the equivalent of
4728 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4729 outcome, but in this particular case used more store than had been allocated,
4730 which caused the bug to be discovered because it threw up an internal error.
4731
4732 8. The debugging code in both pcre and pcretest for outputting the compiled
4733 form of a regex was going wrong in the case of back references followed by
4734 curly-bracketed repeats.
4735
4736
4737 Version 1.02 12-Dec-97
4738 ----------------------
4739
4740 1. Typos in pcre.3 and comments in the source fixed.
4741
4742 2. Applied a contributed patch to get rid of places where it used to remove
4743 'const' from variables, and fixed some signed/unsigned and uninitialized
4744 variable warnings.
4745
4746 3. Added the "runtest" target to Makefile.
4747
4748 4. Set default compiler flag to -O2 rather than just -O.
4749
4750
4751 Version 1.01 19-Nov-97
4752 ----------------------
4753
4754 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4755 like /([ab]*)*/, that is, for classes with more than one character in them.
4756
4757 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4758 as /((?>a*))*/ (a PCRE_EXTRA facility).
4759
4760
4761 Version 1.00 18-Nov-97
4762 ----------------------
4763
4764 1. Added compile-time macros to support systems such as SunOS4 which don't have
4765 memmove() or strerror() but have other things that can be used instead.
4766
4767 2. Arranged that "make clean" removes the executables.
4768
4769
4770 Version 0.99 27-Oct-97
4771 ----------------------
4772
4773 1. Fixed bug in code for optimizing classes with only one character. It was
4774 initializing a 32-byte map regardless, which could cause it to run off the end
4775 of the memory it had got.
4776
4777 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4778
4779
4780 Version 0.98 22-Oct-97
4781 ----------------------
4782
4783 1. Fixed bug in code for handling temporary memory usage when there are more
4784 back references than supplied space in the ovector. This could cause segfaults.
4785
4786
4787 Version 0.97 21-Oct-97
4788 ----------------------
4789
4790 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4791
4792 2. Optimized negated single characters not to use a bit map.
4793
4794 3. Brought error texts together as macro definitions; clarified some of them;
4795 fixed one that was wrong - it said "range out of order" when it meant "invalid
4796 escape sequence".
4797
4798 4. Changed some char * arguments to const char *.
4799
4800 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4801
4802 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4803 pcretest.
4804
4805
4806 Version 0.96 16-Oct-97
4807 ----------------------
4808
4809 1. Added a simple "pgrep" utility to the distribution.
4810
4811 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4812 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4813 where "ddd" means "one or more decimal digits".
4814
4815 3. Fixed serious bug. If a pattern had a back reference, but the call to
4816 pcre_exec() didn't supply a large enough ovector to record the related
4817 identifying subpattern, the match always failed. PCRE now remembers the number
4818 of the largest back reference, and gets some temporary memory in which to save
4819 the offsets during matching if necessary, in order to ensure that
4820 backreferences always work.
4821
4822 4. Increased the compatibility with Perl in a number of ways:
4823
4824 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4825 to request this handling. The option can be set at compile or exec time.
4826
4827 (b) $ matches before a terminating newline by default; an option
4828 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4829 mode). The option can be set at compile or exec time.
4830
4831 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4832 the same as Perl's. If the decimal number it represents is less than 10
4833 or there aren't that many previous left capturing parentheses, an octal
4834 escape is read. Inside a character class, it's always an octal escape,
4835 even if it is a single digit.
4836
4837 (d) An escaped but undefined alphabetic character is taken as a literal,
4838 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4839 escapes.
4840
4841 (e) {0} is now permitted. (The previous item is removed from the compiled
4842 pattern).
4843
4844 5. Changed all the names of code files so that the basic parts are no longer
4845 than 10 characters, and abolished the teeny "globals.c" file.
4846
4847 6. Changed the handling of character classes; they are now done with a 32-byte
4848 bit map always.
4849
4850 7. Added the -d and /D options to pcretest to make it possible to look at the
4851 internals of compilation without having to recompile pcre.
4852
4853
4854 Version 0.95 23-Sep-97
4855 ----------------------
4856
4857 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4858 \x20 at the start of a run of normal characters. These were being treated as
4859 real characters, instead of the source characters being re-checked.
4860
4861
4862 Version 0.94 18-Sep-97
4863 ----------------------
4864
4865 1. The functions are now thread-safe, with the caveat that the global variables
4866 containing pointers to malloc() and free() or alternative functions are the
4867 same for all threads.
4868
4869 2. Get pcre_study() to generate a bitmap of initial characters for non-
4870 anchored patterns when this is possible, and use it if passed to pcre_exec().
4871
4872
4873 Version 0.93 15-Sep-97
4874 ----------------------
4875
4876 1. /(b)|(:+)/ was computing an incorrect first character.
4877
4878 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4879 but not actually doing anything yet.
4880
4881 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4882 as Perl does (e.g. [-az] or [az-]).
4883
4884 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4885 all possible positions.
4886
4887 5. Split up into different modules to avoid including unneeded functions in a
4888 compiled binary. However, compile and exec are still in one module. The "study"
4889 function is split off.
4890
4891 6. The character tables are now in a separate module whose source is generated
4892 by an auxiliary program - but can then be edited by hand if required. There are
4893 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4894 toupper() in the code.
4895
4896 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4897 make them global. Abolish the function for setting them, as the caller can now
4898 set them directly.
4899
4900
4901 Version 0.92 11-Sep-97
4902 ----------------------
4903
4904 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4905 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4906
4907 2. Caseless matching was not working in character classes if the characters in
4908 the pattern were in upper case.
4909
4910 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4911
4912 4. Make PCRE_ANCHORED public and accept as a compile option.
4913
4914 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4915 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4916 pass them.
4917
4918 6. Give an error if bad option bits passed at compile or run time.
4919
4920 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4921 pcretest to cause it to pass that flag.
4922
4923 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4924 options, and the first character, if set.
4925
4926 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4927
4928
4929 Version 0.91 10-Sep-97
4930 ----------------------
4931
4932 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4933 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4934
4935 2. PCRE was looping on encountering an indefinitely repeated back reference to
4936 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4937 Perl does - treats the match as successful.
4938
4939 ****

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