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Revision 1039 - (show annotations)
Thu Sep 13 16:39:03 2012 UTC (7 years, 2 months ago) by ph10
File size: 236036 byte(s)
Allow multiple -o in pcregrep, and add --om-separator.
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
85 Version 8.31 06-July-2012
86 -------------------------
87
88 1. Fixing a wrong JIT test case and some compiler warnings.
89
90 2. Removed a bashism from the RunTest script.
91
92 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
93 to unsigned type, result still unsigned" that was given by an MS compiler
94 on encountering the code "-sizeof(xxx)".
95
96 4. Partial matching support is added to the JIT compiler.
97
98 5. Fixed several bugs concerned with partial matching of items that consist
99 of more than one character:
100
101 (a) /^(..)\1/ did not partially match "aba" because checking references was
102 done on an "all or nothing" basis. This also applied to repeated
103 references.
104
105 (b) \R did not give a hard partial match if \r was found at the end of the
106 subject.
107
108 (c) \X did not give a hard partial match after matching one or more
109 characters at the end of the subject.
110
111 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
112 a partial match for the string "\r".
113
114 (e) When newline was set to CRLF, the metacharacter "." did not recognize
115 a partial match for a CR character at the end of the subject string.
116
117 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
118 running pcretest, the text "(JIT)" added to the output whenever JIT is
119 actually used to run the match.
120
121 7. Individual JIT compile options can be set in pcretest by following -s+[+]
122 or /S+[+] with a digit between 1 and 7.
123
124 8. OP_NOT now supports any UTF character not just single-byte ones.
125
126 9. (*MARK) control verb is now supported by the JIT compiler.
127
128 10. The command "./RunTest list" lists the available tests without actually
129 running any of them. (Because I keep forgetting what they all are.)
130
131 11. Add PCRE_INFO_MAXLOOKBEHIND.
132
133 12. Applied a (slightly modified) user-supplied patch that improves performance
134 when the heap is used for recursion (compiled with --disable-stack-for-
135 recursion). Instead of malloc and free for each heap frame each time a
136 logical recursion happens, frames are retained on a chain and re-used where
137 possible. This sometimes gives as much as 30% improvement.
138
139 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
140 call.
141
142 14. As documented, (*COMMIT) is now confined to within a positive assertion.
143
144 15. It is now possible to link pcretest with libedit as an alternative to
145 libreadline.
146
147 16. (*COMMIT) control verb is now supported by the JIT compiler.
148
149 17. The Unicode data tables have been updated to Unicode 6.1.0.
150
151 18. Added --file-list option to pcregrep.
152
153 19. Added binary file support to pcregrep, including the -a, --binary-files,
154 -I, and --text options.
155
156 20. The madvise function is renamed for posix_madvise for QNX compatibility
157 reasons. Fixed by Giuseppe D'Angelo.
158
159 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
160
161 22. Changed the option for creating symbolic links for 16-bit man pages from
162 -s to -sf so that re-installing does not cause issues.
163
164 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
165
166 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
167 matches in certain environments (the workspace was not being correctly
168 retained). Also added to pcre_dfa_exec() a simple plausibility check on
169 some of the workspace data at the beginning of a restart.
170
171 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
172 was not doing so when it should - probably a typo introduced by SVN 528
173 (change 8.10/14).
174
175 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
176 \w+ when the character tables indicated that \x{c4} was a word character.
177 There were several related cases, all because the tests for doing a table
178 lookup were testing for characters less than 127 instead of 255.
179
180 27. If a pattern contains capturing parentheses that are not used in a match,
181 their slots in the ovector are set to -1. For those that are higher than
182 any matched groups, this happens at the end of processing. In the case when
183 there were back references that the ovector was too small to contain
184 (causing temporary malloc'd memory to be used during matching), and the
185 highest capturing number was not used, memory off the end of the ovector
186 was incorrectly being set to -1. (It was using the size of the temporary
187 memory instead of the true size.)
188
189 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
190 ovector size, it uses memory at the end of the block that it has got.
191
192 29. Check for an overlong MARK name and give an error at compile time. The
193 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
194
195 30. JIT compiler update.
196
197 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
198 Rill for the patch.
199
200 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
201
202 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
203
204 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
205 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
206 was enabled.
207
208 35. Improve JIT code generation for greedy plus quantifier.
209
210 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
211 1 to "aa" instead of to an empty string. The bug affected repeated groups
212 that could potentially match an empty string.
213
214 37. Optimizing single character iterators in JIT.
215
216 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
217 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
218 codepoints that are too big for the mode are faulted, and in a UTF mode,
219 disallowed codepoints are also faulted.
220
221 39. If PCRE was compiled with UTF support, in three places in the DFA
222 matcher there was code that should only have been obeyed in UTF mode, but
223 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
224 processing when bytes with values greater than 127 were present. In 16-bit
225 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
226 both cases the values are those that cannot be the first data item in a UTF
227 character. The three items that might have provoked this were recursions,
228 possessively repeated groups, and atomic groups.
229
230 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
231 and pcregrep, because some OS require shared objects to be explicitly
232 passed to ld, causing the link step to fail if they are not.
233
234 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
235 mode, patterns that started with \h* or \R* might be incorrectly matched.
236
237
238 Version 8.30 04-February-2012
239 -----------------------------
240
241 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
242 name is defined in ctype.h.
243
244 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
245 only in quite long subpatterns.
246
247 3. Removed the function pcre_info(), which has been obsolete and deprecated
248 since it was replaced by pcre_fullinfo() in February 2000.
249
250 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
251 match a (*MARK), and the match failed at the start of the subject, a
252 reference to memory before the start of the subject could occur. This bug
253 was introduced by fix 17 of release 8.21.
254
255 5. A reference to an unset group with zero minimum repetition was giving
256 totally wrong answers (in non-JavaScript-compatibility mode). For example,
257 /(another)?(\1?)test/ matched against "hello world test". This bug was
258 introduced in release 8.13.
259
260 6. Add support for 16-bit character strings (a large amount of work involving
261 many changes and refactorings).
262
263 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
264 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
265 from a file.
266
267 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
268 rounding is not applied in this particular case).
269
270 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
271 if they appear, or are escaped, in patterns.
272
273 10. Get rid of a number of -Wunused-but-set-variable warnings.
274
275 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
276 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
277 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
278 also returns the mark "x". This bug applied to capturing parentheses,
279 non-capturing parentheses, and atomic parentheses. It also applied to some
280 assertions.
281
282 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
283 information out of configure.ac instead of relying on pcre.h.generic, which
284 is not stored in the repository.
285
286 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
287 -lreadline.
288
289 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
290
291 15. Applied Graycode's patch to put the top-level frame on the stack rather
292 than the heap when not using the stack for recursion. This gives a
293 performance improvement in many cases when recursion is not deep.
294
295 16. Experimental code added to "pcretest -C" to output the stack frame size.
296
297
298 Version 8.21 12-Dec-2011
299 ------------------------
300
301 1. Updating the JIT compiler.
302
303 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
304 are added as well.
305
306 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
307 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
308 calling _pcre_jit_exec. Some extra comments are added.
309
310 4. (*MARK) settings inside atomic groups that do not contain any capturing
311 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
312 was introduced by change 18 for 8.20.
313
314 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
315 ECMA-262 standard.
316
317 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
318 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
319 This bug was probably introduced by change 9 of 8.13.
320
321 7. While fixing 6 above, I noticed that a number of other items were being
322 incorrectly rejected as "not fixed length". This arose partly because newer
323 opcodes had not been added to the fixed-length checking code. I have (a)
324 corrected the bug and added tests for these items, and (b) arranged for an
325 error to occur if an unknown opcode is encountered while checking for fixed
326 length instead of just assuming "not fixed length". The items that were
327 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
328 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
329 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
330
331 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
332 being incorrectly compiled and would have given unpredicatble results.
333
334 9. A possessively repeated subpattern with minimum repeat count greater than
335 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
336 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
337 the first (A) could occur when it should not.
338
339 10. Add a cast and remove a redundant test from the code.
340
341 11. JIT should use pcre_malloc/pcre_free for allocation.
342
343 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
344 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
345 is anything other than /usr, -L is still shown).
346
347 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
348
349 14. Perl does not support \N without a following name in a [] class; PCRE now
350 also gives an error.
351
352 15. If a forward reference was repeated with an upper limit of around 2000,
353 it caused the error "internal error: overran compiling workspace". The
354 maximum number of forward references (including repeats) was limited by the
355 internal workspace, and dependent on the LINK_SIZE. The code has been
356 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
357 the default depends on LINK_SIZE. There is a new upper limit (for safety)
358 of around 200,000 forward references. While doing this, I also speeded up
359 the filling in of repeated forward references.
360
361 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
362 incorrectly expecting the subject to contain another "a" after the start.
363
364 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
365 in the match, the SKIP should be ignored. This was not happening; instead
366 the SKIP was being treated as NOMATCH. For patterns such as
367 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
368 tested.
369
370 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
371 now much more compatible with Perl, in particular in cases where the result
372 is a non-match for a non-anchored pattern. For example, if
373 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
374 "m", where previously it did not return a name. A side effect of this
375 change is that for partial matches, the last encountered mark name is
376 returned, as for non matches. A number of tests that were previously not
377 Perl-compatible have been moved into the Perl-compatible test files. The
378 refactoring has had the pleasing side effect of removing one argument from
379 the match() function, thus reducing its stack requirements.
380
381 19. If the /S+ option was used in pcretest to study a pattern using JIT,
382 subsequent uses of /S (without +) incorrectly behaved like /S+.
383
384 21. Retrieve executable code size support for the JIT compiler and fixing
385 some warnings.
386
387 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
388 not work when the shorter character appeared right at the end of the
389 subject string.
390
391 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
392 systems.
393
394 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
395 output it when the /M option is used in pcretest.
396
397 25. The CheckMan script was not being included in the distribution. Also, added
398 an explicit "perl" to run Perl scripts from the PrepareRelease script
399 because this is reportedly needed in Windows.
400
401 26. If study data was being save in a file and studying had not found a set of
402 "starts with" bytes for the pattern, the data written to the file (though
403 never used) was taken from uninitialized memory and so caused valgrind to
404 complain.
405
406 27. Updated RunTest.bat as provided by Sheri Pierce.
407
408 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
409
410 29. Computation of memory usage for the table of capturing group names was
411 giving an unnecessarily large value.
412
413
414 Version 8.20 21-Oct-2011
415 ------------------------
416
417 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
418 a POSIX class. After further experiments with Perl, which convinced me that
419 Perl has bugs and confusions, a closing square bracket is no longer allowed
420 in a POSIX name. This bug also affected patterns with classes that started
421 with full stops.
422
423 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
424 captured substring, but while checking the failing first alternative,
425 substring 1 is temporarily captured. If the output vector supplied to
426 pcre_exec() was not big enough for this capture, the yield of the function
427 was still zero ("insufficient space for captured substrings"). This cannot
428 be totally fixed without adding another stack variable, which seems a lot
429 of expense for a edge case. However, I have improved the situation in cases
430 such as /(a)(b)x|abc/ matched against "abc", where the return code
431 indicates that fewer than the maximum number of slots in the ovector have
432 been set.
433
434 3. Related to (2) above: when there are more back references in a pattern than
435 slots in the output vector, pcre_exec() uses temporary memory during
436 matching, and copies in the captures as far as possible afterwards. It was
437 using the entire output vector, but this conflicts with the specification
438 that only 2/3 is used for passing back captured substrings. Now it uses
439 only the first 2/3, for compatibility. This is, of course, another edge
440 case.
441
442 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
443 main code base, and can be used by building with --enable-jit. When this is
444 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
445 runtime --no-jit option is given.
446
447 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
448 ovector, the return from the function was zero, implying that there were
449 other matches that did not fit. The correct "exactly full" value is now
450 returned.
451
452 6. If a subpattern that was called recursively or as a subroutine contained
453 (*PRUNE) or any other control that caused it to give a non-standard return,
454 invalid errors such as "Error -26 (nested recursion at the same subject
455 position)" or even infinite loops could occur.
456
457 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
458 computing the minimum length on reaching *ACCEPT, and so ended up with the
459 wrong value of 1 rather than 0. Further investigation indicates that
460 computing a minimum subject length in the presence of *ACCEPT is difficult
461 (think back references, subroutine calls), and so I have changed the code
462 so that no minimum is registered for a pattern that contains *ACCEPT.
463
464 8. If (*THEN) was present in the first (true) branch of a conditional group,
465 it was not handled as intended. [But see 16 below.]
466
467 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
468 Sheri Pierce.
469
470 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
471 the first byte in a match must be "a".
472
473 11. Change 17 for 8.13 increased the recursion depth for patterns like
474 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
475 pattern contains any instances of (*THEN). If it does not, the old
476 optimizations are restored. It would be nice to do this on a per-group
477 basis, but at the moment that is not feasible.
478
479 12. In some environments, the output of pcretest -C is CRLF terminated. This
480 broke RunTest's code that checks for the link size. A single white space
481 character after the value is now allowed for.
482
483 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
484 For "fr", it uses the Windows-specific input and output files.
485
486 14. If (*THEN) appeared in a group that was called recursively or as a
487 subroutine, it did not work as intended. [But see next item.]
488
489 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
490 pattern fragments (but not containing any | characters). If A and B are
491 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
492 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
493 D. In other words, Perl considers parentheses that do not contain any |
494 characters to be part of a surrounding alternative, whereas PCRE was
495 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
496 differently. PCRE now behaves in the same way as Perl, except in the case
497 of subroutine/recursion calls such as (?1) which have in any case always
498 been different (but PCRE had them first :-).
499
500 16. Related to 15 above: Perl does not treat the | in a conditional group as
501 creating alternatives. Such a group is treated in the same way as an
502 ordinary group without any | characters when processing (*THEN). PCRE has
503 been changed to match Perl's behaviour.
504
505 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
506 RunGrepTest script failed.
507
508 18. Change 22 for version 13 caused atomic groups to use more stack. This is
509 inevitable for groups that contain captures, but it can lead to a lot of
510 stack use in large patterns. The old behaviour has been restored for atomic
511 groups that do not contain any capturing parentheses.
512
513 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
514 suppress the check for a minimum subject length at run time. (If it was
515 given to pcre_exec() or pcre_dfa_exec() it did work.)
516
517 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
518 fail to work when decoding hex characters in data strings in EBCDIC
519 environments.
520
521 21. It appears that in at least one Mac OS environment, the isxdigit() function
522 is implemented as a macro that evaluates to its argument more than once,
523 contravening the C 90 Standard (I haven't checked a later standard). There
524 was an instance in pcretest which caused it to go wrong when processing
525 \x{...} escapes in subject strings. The has been rewritten to avoid using
526 things like p++ in the argument of isxdigit().
527
528
529 Version 8.13 16-Aug-2011
530 ------------------------
531
532 1. The Unicode data tables have been updated to Unicode 6.0.0.
533
534 2. Two minor typos in pcre_internal.h have been fixed.
535
536 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
537 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
538 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
539
540 4. There were a number of related bugs in the code for matching backrefences
541 caselessly in UTF-8 mode when codes for the characters concerned were
542 different numbers of bytes. For example, U+023A and U+2C65 are an upper
543 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
544 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
545 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
546 2-byte code at the end of the subject (it thought there wasn't enough data
547 left).
548
549 5. Comprehensive information about what went wrong is now returned by
550 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
551 as the output vector has at least 2 elements. The offset of the start of
552 the failing character and a reason code are placed in the vector.
553
554 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
555 now returned is for the first byte of the failing character, instead of the
556 last byte inspected. This is an incompatible change, but I hope it is small
557 enough not to be a problem. It makes the returned offset consistent with
558 pcre_exec() and pcre_dfa_exec().
559
560 7. pcretest now gives a text phrase as well as the error number when
561 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
562 failure, the offset and reason code are output.
563
564 8. When \R was used with a maximizing quantifier it failed to skip backwards
565 over a \r\n pair if the subsequent match failed. Instead, it just skipped
566 back over a single character (\n). This seems wrong (because it treated the
567 two characters as a single entity when going forwards), conflicts with the
568 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
569 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
570 has been changed.
571
572 9. Some internal refactoring has changed the processing so that the handling
573 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
574 time (the PCRE_DOTALL option was changed this way some time ago: version
575 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
576 which was always a bit of a fudge. It also means that there is one less
577 argument for the match() function, which reduces its stack requirements
578 slightly. This change also fixes an incompatibility with Perl: the pattern
579 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
580
581 10. More internal refactoring has drastically reduced the number of recursive
582 calls to match() for possessively repeated groups such as (abc)++ when
583 using pcre_exec().
584
585 11. While implementing 10, a number of bugs in the handling of groups were
586 discovered and fixed:
587
588 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
589 (a|)*(?1) gave a compile-time internal error.
590 ((a|)+)+ did not notice that the outer group could match an empty string.
591 (^a|^)+ was not marked as anchored.
592 (.*a|.*)+ was not marked as matching at start or after a newline.
593
594 12. Yet more internal refactoring has removed another argument from the match()
595 function. Special calls to this function are now indicated by setting a
596 value in a variable in the "match data" data block.
597
598 13. Be more explicit in pcre_study() instead of relying on "default" for
599 opcodes that mean there is no starting character; this means that when new
600 ones are added and accidentally left out of pcre_study(), testing should
601 pick them up.
602
603 14. The -s option of pcretest has been documented for ages as being an old
604 synonym of -m (show memory usage). I have changed it to mean "force study
605 for every regex", that is, assume /S for every regex. This is similar to -i
606 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
607 using it. It makes it easier to run collections of tests with and without
608 study enabled, and thereby test pcre_study() more easily. All the standard
609 tests are now run with and without -s (but some patterns can be marked as
610 "never study" - see 20 below).
611
612 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
613 restoration of the capturing data to the outer values was not happening
614 correctly.
615
616 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
617 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
618 pattern had matched an empty string, and so incorrectly returned a no
619 match.
620
621 17. There was optimizing code for the last branch of non-capturing parentheses,
622 and also for the obeyed branch of a conditional subexpression, which used
623 tail recursion to cut down on stack usage. Unfortunately, now that there is
624 the possibility of (*THEN) occurring in these branches, tail recursion is
625 no longer possible because the return has to be checked for (*THEN). These
626 two optimizations have therefore been removed. [But see 8.20/11 above.]
627
628 18. If a pattern containing \R was studied, it was assumed that \R always
629 matched two bytes, thus causing the minimum subject length to be
630 incorrectly computed because \R can also match just one byte.
631
632 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
633 was incorrectly computed.
634
635 20. If /S is present twice on a test pattern in pcretest input, it now
636 *disables* studying, thereby overriding the use of -s on the command line
637 (see 14 above). This is necessary for one or two tests to keep the output
638 identical in both cases.
639
640 21. When (*ACCEPT) was used in an assertion that matched an empty string and
641 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
642
643 22. When an atomic group that contained a capturing parenthesis was
644 successfully matched, but the branch in which it appeared failed, the
645 capturing was not being forgotten if a higher numbered group was later
646 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
647 group 1 to "a", when in fact it should be unset. This applied to multi-
648 branched capturing and non-capturing groups, repeated or not, and also to
649 positive assertions (capturing in negative assertions does not happen
650 in PCRE) and also to nested atomic groups.
651
652 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
653 subject after a captured substring, to make it easier to tell which of a
654 number of identical substrings has been captured.
655
656 24. The way atomic groups are processed by pcre_exec() has been changed so that
657 if they are repeated, backtracking one repetition now resets captured
658 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
659 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
660 "aaa". Previously, it would have been "a". As part of this code
661 refactoring, the way recursive calls are handled has also been changed.
662
663 25. If an assertion condition captured any substrings, they were not passed
664 back unless some other capturing happened later. For example, if
665 (?(?=(a))a) was matched against "a", no capturing was returned.
666
667 26. When studying a pattern that contained subroutine calls or assertions,
668 the code for finding the minimum length of a possible match was handling
669 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
670 group 1 called group 2 while simultaneously a separate group 2 called group
671 1). A stack overflow occurred in this case. I have fixed this by limiting
672 the recursion depth to 10.
673
674 27. Updated RunTest.bat in the distribution to the version supplied by Tom
675 Fortmann. This supports explicit test numbers on the command line, and has
676 argument validation and error reporting.
677
678 28. An instance of \X with an unlimited repeat could fail if at any point the
679 first character it looked at was a mark character.
680
681 29. Some minor code refactoring concerning Unicode properties and scripts
682 should reduce the stack requirement of match() slightly.
683
684 30. Added the '=' option to pcretest to check the setting of unused capturing
685 slots at the end of the pattern, which are documented as being -1, but are
686 not included in the return count.
687
688 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
689 compiled something random. Now it gives a compile-time error (as does
690 Perl).
691
692 32. A *MARK encountered during the processing of a positive assertion is now
693 recorded and passed back (compatible with Perl).
694
695 33. If --only-matching or --colour was set on a pcregrep call whose pattern
696 had alternative anchored branches, the search for a second match in a line
697 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
698 matched the line "0102" twice. The same bug affected patterns that started
699 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
700 twice.
701
702 34. Previously, PCRE did not allow quantification of assertions. However, Perl
703 does, and because of capturing effects, quantifying parenthesized
704 assertions may at times be useful. Quantifiers are now allowed for
705 parenthesized assertions.
706
707 35. A minor code tidy in pcre_compile() when checking options for \R usage.
708
709 36. \g was being checked for fancy things in a character class, when it should
710 just be a literal "g".
711
712 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
713 appearance of a nested POSIX class supersedes an apparent external class.
714 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
715 unescaped square brackets may also appear as part of class names. For
716 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
717 more like Perl. (But see 8.20/1 above.)
718
719 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
720 was because it thought it was \N{name}, which is not supported).
721
722 39. Add minix to OS list not supporting the -S option in pcretest.
723
724 40. PCRE tries to detect cases of infinite recursion at compile time, but it
725 cannot analyze patterns in sufficient detail to catch mutual recursions
726 such as ((?1))((?2)). There is now a runtime test that gives an error if a
727 subgroup is called recursively as a subpattern for a second time at the
728 same position in the subject string. In previous releases this might have
729 been caught by the recursion limit, or it might have run out of stack.
730
731 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
732 happen only once. PCRE was, however incorrectly giving a compile time error
733 "recursive call could loop indefinitely" because it cannot analyze the
734 pattern in sufficient detail. The compile time test no longer happens when
735 PCRE is compiling a conditional subpattern, but actual runaway loops are
736 now caught at runtime (see 40 above).
737
738 42. It seems that Perl allows any characters other than a closing parenthesis
739 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
740 has been changed to be the same.
741
742 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
743 as not to get warnings when autogen.sh is called. Also changed
744 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
745
746 44. To help people who use pcregrep to scan files containing exceedingly long
747 lines, the following changes have been made:
748
749 (a) The default value of the buffer size parameter has been increased from
750 8K to 20K. (The actual buffer used is three times this size.)
751
752 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
753 PCRE is built.
754
755 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
756 to be set at run time.
757
758 (d) Numerical values in pcregrep options can be followed by K or M, for
759 example --buffer-size=50K.
760
761 (e) If a line being scanned overflows pcregrep's buffer, an error is now
762 given and the return code is set to 2.
763
764 45. Add a pointer to the latest mark to the callout data block.
765
766 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
767 partial match of an empty string instead of no match. This was specific to
768 the use of ".".
769
770 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
771 complete match instead of a partial match. This bug was dependent on both
772 the PCRE_UTF8 and PCRE_DOTALL options being set.
773
774 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
775 starting byte set, because \b was not being ignored.
776
777
778 Version 8.12 15-Jan-2011
779 ------------------------
780
781 1. Fixed some typos in the markup of the man pages, and wrote a script that
782 checks for such things as part of the documentation building process.
783
784 2. On a big-endian 64-bit system, pcregrep did not correctly process the
785 --match-limit and --recursion-limit options (added for 8.11). In
786 particular, this made one of the standard tests fail. (The integer value
787 went into the wrong half of a long int.)
788
789 3. If the --colour option was given to pcregrep with -v (invert match), it
790 did strange things, either producing crazy output, or crashing. It should,
791 of course, ignore a request for colour when reporting lines that do not
792 match.
793
794 4. Another pcregrep bug caused similar problems if --colour was specified with
795 -M (multiline) and the pattern match finished with a line ending.
796
797 5. In pcregrep, when a pattern that ended with a literal newline sequence was
798 matched in multiline mode, the following line was shown as part of the
799 match. This seems wrong, so I have changed it.
800
801 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
802 the check for further matches in the same line (so they could be coloured)
803 to overrun the end of the current line. If another match was found, it was
804 incorrectly shown (and then shown again when found in the next line).
805
806 7. If pcregrep was compiled under Windows, there was a reference to the
807 function pcregrep_exit() before it was defined. I am assuming this was
808 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
809 reported by a user. I've moved the definition above the reference.
810
811
812 Version 8.11 10-Dec-2010
813 ------------------------
814
815 1. (*THEN) was not working properly if there were untried alternatives prior
816 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
817 backtracked to try for "b" instead of moving to the next alternative branch
818 at the same level (in this case, to look for "c"). The Perl documentation
819 is clear that when (*THEN) is backtracked onto, it goes to the "next
820 alternative in the innermost enclosing group".
821
822 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
823 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
824 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
825 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
826 (*THEN).
827
828 3. If \s appeared in a character class, it removed the VT character from
829 the class, even if it had been included by some previous item, for example
830 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
831 of \s, but is part of the POSIX "space" class.)
832
833 4. A partial match never returns an empty string (because you can always
834 match an empty string at the end of the subject); however the checking for
835 an empty string was starting at the "start of match" point. This has been
836 changed to the "earliest inspected character" point, because the returned
837 data for a partial match starts at this character. This means that, for
838 example, /(?<=abc)def/ gives a partial match for the subject "abc"
839 (previously it gave "no match").
840
841 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
842 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
843 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
844 has an implication that the given string is incomplete (because a partial
845 match is preferred over a full match). For this reason, these items now
846 give a partial match in this situation. [Aside: previously, the one case
847 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
848 match rather than a full match, which was wrong by the old rules, but is
849 now correct.]
850
851 6. There was a bug in the handling of #-introduced comments, recognized when
852 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
853 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
854 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
855 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
856 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
857 places in pcre_compile().
858
859 7. Related to (6) above, when pcre_compile() was skipping #-introduced
860 comments when looking ahead for named forward references to subpatterns,
861 the only newline sequence it recognized was NL. It now handles newlines
862 according to the set newline convention.
863
864 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
865 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
866 cater for a lack of strerror(). These oversights have been fixed.
867
868 9. Added --match-limit and --recursion-limit to pcregrep.
869
870 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
871
872 11. When the -o option was used, pcregrep was setting a return code of 1, even
873 when matches were found, and --line-buffered was not being honoured.
874
875 12. Added an optional parentheses number to the -o and --only-matching options
876 of pcregrep.
877
878 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
879 can match an empty string. The code to do it in pcretest and pcredemo
880 needed fixing:
881
882 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
883 only one byte after an empty string match just before CRLF (this case
884 just got forgotten; "any" and "anycrlf" were OK).
885
886 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
887 mode when an empty string match preceded an ASCII character followed by
888 a non-ASCII character. (The code for advancing by one character rather
889 than one byte was nonsense.)
890
891 (c) The pcredemo.c sample program did not have any code at all to handle
892 the cases when CRLF is a valid newline sequence.
893
894 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
895 as a starting offset was within the subject string. There is now a new
896 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
897 negative or greater than the length of the string. In order to test this,
898 pcretest is extended to allow the setting of negative starting offsets.
899
900 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
901 starting offset points to the beginning of a UTF-8 character was
902 unnecessarily clumsy. I tidied it up.
903
904 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
905 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
906
907 17. Nobody had reported that the --include_dir option, which was added in
908 release 7.7 should have been called --include-dir (hyphen, not underscore)
909 for compatibility with GNU grep. I have changed it to --include-dir, but
910 left --include_dir as an undocumented synonym, and the same for
911 --exclude-dir, though that is not available in GNU grep, at least as of
912 release 2.5.4.
913
914 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
915 characters from a string of bytes) have been redefined so as not to use
916 loops, in order to improve performance in some environments. At the same
917 time, I abstracted some of the common code into auxiliary macros to save
918 repetition (this should not affect the compiled code).
919
920 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
921 compile-time error is now given if \c is not followed by an ASCII
922 character, that is, a byte less than 128. (In EBCDIC mode, the code is
923 different, and any byte value is allowed.)
924
925 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
926 START_OPTIMIZE option, which is now allowed at compile time - but just
927 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
928 to pcregrep and other applications that have no direct access to PCRE
929 options. The new /Y option in pcretest sets this option when calling
930 pcre_compile().
931
932 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
933 back references. Groups containing recursive back references were forced to
934 be atomic by that change, but in the case of named groups, the amount of
935 memory required was incorrectly computed, leading to "Failed: internal
936 error: code overflow". This has been fixed.
937
938 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
939 pcretest.c, to avoid build problems in some Borland environments.
940
941
942 Version 8.10 25-Jun-2010
943 ------------------------
944
945 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
946 THEN.
947
948 2. (*ACCEPT) was not working when inside an atomic group.
949
950 3. Inside a character class, \B is treated as a literal by default, but
951 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
952 causes the error). The code is unchanged, but I tidied the documentation.
953
954 4. Inside a character class, PCRE always treated \R and \X as literals,
955 whereas Perl faults them if its -w option is set. I have changed PCRE so
956 that it faults them when PCRE_EXTRA is set.
957
958 5. Added support for \N, which always matches any character other than
959 newline. (It is the same as "." when PCRE_DOTALL is not set.)
960
961 6. When compiling pcregrep with newer versions of gcc which may have
962 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
963 declared with attribute warn_unused_result" were given. Just casting the
964 result to (void) does not stop the warnings; a more elaborate fudge is
965 needed. I've used a macro to implement this.
966
967 7. Minor change to pcretest.c to avoid a compiler warning.
968
969 8. Added four artifical Unicode properties to help with an option to make
970 \s etc use properties (see next item). The new properties are: Xan
971 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
972
973 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
974 use Unicode properties. (*UCP) at the start of a pattern can be used to set
975 this option. Modified pcretest to add /W to test this facility. Added
976 REG_UCP to make it available via the POSIX interface.
977
978 10. Added --line-buffered to pcregrep.
979
980 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
981 studied, and the match started with a letter with a code point greater than
982 127 whose first byte was different to the first byte of the other case of
983 the letter, the other case of this starting letter was not recognized
984 (#976).
985
986 12. If a pattern that was studied started with a repeated Unicode property
987 test, for example, \p{Nd}+, there was the theoretical possibility of
988 setting up an incorrect bitmap of starting bytes, but fortunately it could
989 not have actually happened in practice until change 8 above was made (it
990 added property types that matched character-matching opcodes).
991
992 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
993 possible starting bytes for non-anchored patterns.
994
995 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
996 \R, and also a number of cases that involve Unicode properties, both
997 explicit and implicit when PCRE_UCP is set.
998
999 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1000 input, it could crash or give wrong results if characters with values
1001 greater than 0xc0 were present in the subject string. (Detail: it assumed
1002 UTF-8 input when processing these items.)
1003
1004 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1005 size_t is 64-bit (#991).
1006
1007 17. Added a check for running out of memory when PCRE is compiled with
1008 --disable-stack-for-recursion (#990).
1009
1010 18. If the last data line in a file for pcretest does not have a newline on
1011 the end, a newline was missing in the output.
1012
1013 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1014 less than 128) in its various bitmaps. However, there is a facility for
1015 generating tables according to the current locale when PCRE is compiled. It
1016 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1017 characters, are recognized by isspace() and therefore were getting set in
1018 these tables, and indeed these tables seem to approximate to ISO 8859. This
1019 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1020 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1021 which of course cannot start UTF-8 characters. I have changed the code so
1022 that only real ASCII characters (less than 128) and the correct starting
1023 bytes for UTF-8 encodings are set for characters greater than 127 when in
1024 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1025 altogether.)
1026
1027 20. Added the /T option to pcretest so as to be able to run tests with non-
1028 standard character tables, thus making it possible to include the tests
1029 used for 19 above in the standard set of tests.
1030
1031 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1032 reference to a subpattern the other side of a comment that contains an
1033 opening parenthesis caused either an internal compiling error, or a
1034 reference to the wrong subpattern.
1035
1036
1037 Version 8.02 19-Mar-2010
1038 ------------------------
1039
1040 1. The Unicode data tables have been updated to Unicode 5.2.0.
1041
1042 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
1043 configured.
1044
1045 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
1046 original author of that file, following a query about its status.
1047
1048 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
1049 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1050
1051 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1052 quantifier applied to a forward-referencing subroutine call, could compile
1053 incorrect code or give the error "internal error: previously-checked
1054 referenced subpattern not found".
1055
1056 6. Both MS Visual Studio and Symbian OS have problems with initializing
1057 variables to point to external functions. For these systems, therefore,
1058 pcre_malloc etc. are now initialized to local functions that call the
1059 relevant global functions.
1060
1061 7. There were two entries missing in the vectors called coptable and poptable
1062 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1063 I've fixed the data, and added a kludgy way of testing at compile time that
1064 the lengths are correct (equal to the number of opcodes).
1065
1066 8. Following on from 7, I added a similar kludge to check the length of the
1067 eint vector in pcreposix.c.
1068
1069 9. Error texts for pcre_compile() are held as one long string to avoid too
1070 much relocation at load time. To find a text, the string is searched,
1071 counting zeros. There was no check for running off the end of the string,
1072 which could happen if a new error number was added without updating the
1073 string.
1074
1075 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1076
1077 11. \K was not working if it appeared in an atomic group or in a group that
1078 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1079 \K is "not well defined" if used in an assertion. PCRE now accepts it if
1080 the assertion is positive, but not if it is negative.
1081
1082 12. Change 11 fortuitously reduced the size of the stack frame used in the
1083 "match()" function of pcre_exec.c by one pointer. Forthcoming
1084 implementation of support for (*MARK) will need an extra pointer on the
1085 stack; I have reserved it now, so that the stack frame size does not
1086 decrease.
1087
1088 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1089 item in branch that calls a recursion is a subroutine call - as in the
1090 second branch in the above example - was incorrectly given the compile-
1091 time error "recursive call could loop indefinitely" because pcre_compile()
1092 was not correctly checking the subroutine for matching a non-empty string.
1093
1094 14. The checks for overrunning compiling workspace could trigger after an
1095 overrun had occurred. This is a "should never occur" error, but it can be
1096 triggered by pathological patterns such as hundreds of nested parentheses.
1097 The checks now trigger 100 bytes before the end of the workspace.
1098
1099 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1100
1101
1102 Version 8.01 19-Jan-2010
1103 ------------------------
1104
1105 1. If a pattern contained a conditional subpattern with only one branch (in
1106 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1107 computed the wrong minimum data length (which is of course zero for such
1108 subpatterns). This could cause incorrect "no match" results.
1109
1110 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1111 the pattern is reset in the first branch, pcre_compile() failed with
1112 "internal error: code overflow at offset...". This happened only when
1113 the reset was to the original external option setting. (An optimization
1114 abstracts leading options settings into an external setting, which was the
1115 cause of this.)
1116
1117 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1118 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1119 assertion pattern did not match (meaning that the assertion was true), it
1120 was incorrectly treated as false if the SKIP had been reached during the
1121 matching. This also applied to assertions used as conditions.
1122
1123 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
1124 assertion subpattern, including such a pattern used as a condition,
1125 unpredictable results occurred, instead of the error return
1126 PCRE_ERROR_DFA_UITEM.
1127
1128 5. The C++ GlobalReplace function was not working like Perl for the special
1129 situation when an empty string is matched. It now does the fancy magic
1130 stuff that is necessary.
1131
1132 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1133 removed. (These were left over from very, very early versions of PCRE.)
1134
1135 7. Some cosmetic changes to the code to make life easier when compiling it
1136 as part of something else:
1137
1138 (a) Change DEBUG to PCRE_DEBUG.
1139
1140 (b) In pcre_compile(), rename the member of the "branch_chain" structure
1141 called "current" as "current_branch", to prevent a collision with the
1142 Linux macro when compiled as a kernel module.
1143
1144 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1145 prevent a collision with the Linux macro when compiled as a kernel
1146 module.
1147
1148 8. In pcre_compile() there are some checks for integer overflows that used to
1149 cast potentially large values to (double). This has been changed to that
1150 when building, a check for int64_t is made, and if it is found, it is used
1151 instead, thus avoiding the use of floating point arithmetic. (There is no
1152 other use of FP in PCRE.) If int64_t is not found, the fallback is to
1153 double.
1154
1155 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
1156 2005 (difference between two addresses compared to an unsigned value).
1157
1158 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1159 custom one, because of the following reported problem in Windows:
1160
1161 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1162 under Win32.
1163 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1164 therefore missing the function definition.
1165 - The compiler thus generates a "C" signature for the test function.
1166 - The linker fails to find the "C" function.
1167 - PCRE fails to configure if asked to do so against libbz2.
1168
1169 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1170 messages were output:
1171
1172 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1173 rerunning libtoolize, to keep the correct libtool macros in-tree.
1174 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1175
1176 I have done both of these things.
1177
1178 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1179 most of the time, it *can* run out if it is given a pattern that contains a
1180 runaway infinite recursion. I updated the discussion in the pcrestack man
1181 page.
1182
1183 13. Now that we have gone to the x.xx style of version numbers, the minor
1184 version may start with zero. Using 08 or 09 is a bad idea because users
1185 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1186 interpreted as invalid octal numbers. I've updated the previous comment in
1187 configure.ac, and also added a check that gives an error if 08 or 09 are
1188 used.
1189
1190 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1191 causing partial matching to fail when the end of the subject matched \W
1192 in a UTF-8 pattern where \W was quantified with a minimum of 3.
1193
1194 15. There were some discrepancies between the declarations in pcre_internal.h
1195 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1196 their definitions. The declarations used "const uschar *" and the
1197 definitions used USPTR. Even though USPTR is normally defined as "const
1198 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1199 reported that: "This difference in casting confuses some C++ compilers, for
1200 example, SunCC recognizes above declarations as different functions and
1201 generates broken code for hbpcre." I have changed the declarations to use
1202 USPTR.
1203
1204 16. GNU libtool is named differently on some systems. The autogen.sh script now
1205 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1206 (FreeBSD).
1207
1208 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1209 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1210 comment: "Figure out how to create a longlong from a string: strtoll and
1211 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1212 instance, but it only takes 2 args instead of 3!"
1213
1214 18. A subtle bug concerned with back references has been fixed by a change of
1215 specification, with a corresponding code fix. A pattern such as
1216 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1217 refers, was giving matches when it shouldn't. For example, xa=xaaa would
1218 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1219 same bug. Such groups have to be quantified to be useful, or contained
1220 inside another quantified group. (If there's no repetition, the reference
1221 can never match.) The problem arises because, having left the group and
1222 moved on to the rest of the pattern, a later failure that backtracks into
1223 the group uses the captured value from the final iteration of the group
1224 rather than the correct earlier one. I have fixed this in PCRE by forcing
1225 any group that contains a reference to itself to be an atomic group; that
1226 is, there cannot be any backtracking into it once it has completed. This is
1227 similar to recursive and subroutine calls.
1228
1229
1230 Version 8.00 19-Oct-09
1231 ----------------------
1232
1233 1. The table for translating pcre_compile() error codes into POSIX error codes
1234 was out-of-date, and there was no check on the pcre_compile() error code
1235 being within the table. This could lead to an OK return being given in
1236 error.
1237
1238 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1239 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1240 in a Windows environment.
1241
1242 3. The pcregrep --count option prints the count for each file even when it is
1243 zero, as does GNU grep. However, pcregrep was also printing all files when
1244 --files-with-matches was added. Now, when both options are given, it prints
1245 counts only for those files that have at least one match. (GNU grep just
1246 prints the file name in this circumstance, but including the count seems
1247 more useful - otherwise, why use --count?) Also ensured that the
1248 combination -clh just lists non-zero counts, with no names.
1249
1250 4. The long form of the pcregrep -F option was incorrectly implemented as
1251 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1252 but it seems right to fix it, and I didn't think it was worth preserving
1253 the old behaviour.
1254
1255 5. The command line items --regex=pattern and --regexp=pattern were not
1256 recognized by pcregrep, which required --regex pattern or --regexp pattern
1257 (with a space rather than an '='). The man page documented the '=' forms,
1258 which are compatible with GNU grep; these now work.
1259
1260 6. No libpcreposix.pc file was created for pkg-config; there was just
1261 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1262
1263 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1264 when UCP support is not needed, by modifying the Python script that
1265 generates it from Unicode data files. This should not matter if the module
1266 is correctly used as a library, but I received one complaint about 50K of
1267 unwanted data. My guess is that the person linked everything into his
1268 program rather than using a library. Anyway, it does no harm.
1269
1270 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1271 was a minimum greater than 1 for a wide character in a possessive
1272 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1273 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1274 character. Chaos in the form of incorrect output or a compiling loop could
1275 result.
1276
1277 9. The restrictions on what a pattern can contain when partial matching is
1278 requested for pcre_exec() have been removed. All patterns can now be
1279 partially matched by this function. In addition, if there are at least two
1280 slots in the offset vector, the offset of the earliest inspected character
1281 for the match and the offset of the end of the subject are set in them when
1282 PCRE_ERROR_PARTIAL is returned.
1283
1284 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1285 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1286 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1287 and may be more useful for multi-segment matching.
1288
1289 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1290 used to be given if ever the end of the subject was reached; now it is
1291 given only if matching could not proceed because another character was
1292 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1293 string "Z", which now yields "no match" instead of "partial match". In the
1294 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1295 final character ended with (*FAIL).
1296
1297 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1298 if the pattern had a "must contain" character that was already found in the
1299 earlier partial match, unless partial matching was again requested. For
1300 example, with the pattern /dog.(body)?/, the "must contain" character is
1301 "g". If the first part-match was for the string "dog", restarting with
1302 "sbody" failed. This bug has been fixed.
1303
1304 13. The string returned by pcre_dfa_exec() after a partial match has been
1305 changed so that it starts at the first inspected character rather than the
1306 first character of the match. This makes a difference only if the pattern
1307 starts with a lookbehind assertion or \b or \B (\K is not supported by
1308 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1309 matching functions compatible, and I think it's the right thing to do.
1310
1311 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1312 so that the demonstration program is easily available in environments where
1313 PCRE has not been installed from source.
1314
1315 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1316 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1317 library.
1318
1319 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1320 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1321 is not the first non-POSIX option to be added. Clearly some people find
1322 these options useful.
1323
1324 17. If a caller to the POSIX matching function regexec() passes a non-zero
1325 value for nmatch with a NULL value for pmatch, the value of
1326 nmatch is forced to zero.
1327
1328 18. RunGrepTest did not have a test for the availability of the -u option of
1329 the diff command, as RunTest does. It now checks in the same way as
1330 RunTest, and also checks for the -b option.
1331
1332 19. If an odd number of negated classes containing just a single character
1333 interposed, within parentheses, between a forward reference to a named
1334 subpattern and the definition of the subpattern, compilation crashed with
1335 an internal error, complaining that it could not find the referenced
1336 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1337 [The bug was that it was starting one character too far in when skipping
1338 over the character class, thus treating the ] as data rather than
1339 terminating the class. This meant it could skip too much.]
1340
1341 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1342 /g option in pcretest when the pattern contains \K, which makes it possible
1343 to have an empty string match not at the start, even when the pattern is
1344 anchored. Updated pcretest and pcredemo to use this option.
1345
1346 21. If the maximum number of capturing subpatterns in a recursion was greater
1347 than the maximum at the outer level, the higher number was returned, but
1348 with unset values at the outer level. The correct (outer level) value is
1349 now given.
1350
1351 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1352 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1353 make it do so. The string so far is captured, making this feature
1354 compatible with Perl.
1355
1356 23. The tests have been re-organized, adding tests 11 and 12, to make it
1357 possible to check the Perl 5.10 features against Perl 5.10.
1358
1359 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1360 pattern matches a fixed length string. PCRE did not allow this; now it
1361 does. Neither allows recursion.
1362
1363 25. I finally figured out how to implement a request to provide the minimum
1364 length of subject string that was needed in order to match a given pattern.
1365 (It was back references and recursion that I had previously got hung up
1366 on.) This code has now been added to pcre_study(); it finds a lower bound
1367 to the length of subject needed. It is not necessarily the greatest lower
1368 bound, but using it to avoid searching strings that are too short does give
1369 some useful speed-ups. The value is available to calling programs via
1370 pcre_fullinfo().
1371
1372 26. While implementing 25, I discovered to my embarrassment that pcretest had
1373 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1374 study optimizations had never been tested with that matching function.
1375 Oops. What is worse, even when it was passed study data, there was a bug in
1376 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1377 were also very few tests of studied patterns with pcre_dfa_exec().
1378
1379 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1380 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1381 on the other side of the coin, they are no longer allowed to have different
1382 names, because these cannot be distinguished in PCRE, and this has caused
1383 confusion. (This is a difference from Perl.)
1384
1385 28. When duplicate subpattern names are present (necessarily with different
1386 numbers, as required by 27 above), and a test is made by name in a
1387 conditional pattern, either for a subpattern having been matched, or for
1388 recursion in such a pattern, all the associated numbered subpatterns are
1389 tested, and the overall condition is true if the condition is true for any
1390 one of them. This is the way Perl works, and is also more like the way
1391 testing by number works.
1392
1393
1394 Version 7.9 11-Apr-09
1395 ---------------------
1396
1397 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1398 (pcretest), all targets were linked against these libraries. This included
1399 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1400 libraries. This caused unwanted dependencies to be created. This problem
1401 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1402 pcretest is linked with readline.
1403
1404 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1405 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1406 moved outside it again, because FALSE and TRUE are already defined in AIX,
1407 but BOOL is not.
1408
1409 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1410 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1411
1412 4. The pcregrep documentation said spaces were inserted as well as colons (or
1413 hyphens) following file names and line numbers when outputting matching
1414 lines. This is not true; no spaces are inserted. I have also clarified the
1415 wording for the --colour (or --color) option.
1416
1417 5. In pcregrep, when --colour was used with -o, the list of matching strings
1418 was not coloured; this is different to GNU grep, so I have changed it to be
1419 the same.
1420
1421 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1422 each matching line was coloured. Now it goes on to look for further matches
1423 of any of the test patterns, which is the same behaviour as GNU grep.
1424
1425 7. A pattern that could match an empty string could cause pcregrep to loop; it
1426 doesn't make sense to accept an empty string match in pcregrep, so I have
1427 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1428 seems to be how GNU grep behaves.
1429
1430 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1431 start or after a newline", because the conditional assertion was not being
1432 correctly handled. The rule now is that both the assertion and what follows
1433 in the first alternative must satisfy the test.
1434
1435 9. If auto-callout was enabled in a pattern with a conditional group whose
1436 condition was an assertion, PCRE could crash during matching, both with
1437 pcre_exec() and pcre_dfa_exec().
1438
1439 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1440 used for matching.
1441
1442 11. Unicode property support in character classes was not working for
1443 characters (bytes) greater than 127 when not in UTF-8 mode.
1444
1445 12. Added the -M command line option to pcretest.
1446
1447 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1448
1449 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1450
1451 16. Added comments and documentation about mis-use of no_arg in the C++
1452 wrapper.
1453
1454 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1455 from Martin Jerabek that uses macro names for all relevant character and
1456 string constants.
1457
1458 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1459 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1460 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1461 these, but not everybody uses configure.
1462
1463 19. A conditional group that had only one branch was not being correctly
1464 recognized as an item that could match an empty string. This meant that an
1465 enclosing group might also not be so recognized, causing infinite looping
1466 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1467 with the subject "ab", where knowledge that the repeated group can match
1468 nothing is needed in order to break the loop.
1469
1470 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1471 exec(), but without supplying a callout function, matching went wrong.
1472
1473 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1474 leak if the size of the offset vector was greater than 30. When the vector
1475 is smaller, the saved offsets during recursion go onto a local stack
1476 vector, but for larger vectors malloc() is used. It was failing to free
1477 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1478 error, in fact).
1479
1480 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1481 heapframe that is used only when UTF-8 support is enabled. This caused no
1482 problem, but was untidy.
1483
1484 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1485 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1486 included within another project.
1487
1488 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1489 slightly modified by me:
1490
1491 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1492 not building pcregrep.
1493
1494 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1495 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1496
1497 25. Forward references, both numeric and by name, in patterns that made use of
1498 duplicate group numbers, could behave incorrectly or give incorrect errors,
1499 because when scanning forward to find the reference group, PCRE was not
1500 taking into account the duplicate group numbers. A pattern such as
1501 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1502
1503 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1504 the feature of a custom pointer more persuasive (as requested by a user).
1505
1506 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1507 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1508 pre-defined.
1509
1510 28. Added support for (*UTF8) at the start of a pattern.
1511
1512 29. Arrange for flags added by the "release type" setting in CMake to be shown
1513 in the configuration summary.
1514
1515
1516 Version 7.8 05-Sep-08
1517 ---------------------
1518
1519 1. Replaced UCP searching code with optimized version as implemented for Ad
1520 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1521 stage table and inline lookup instead of a function, giving speed ups of 2
1522 to 5 times on some simple patterns that I tested. Permission was given to
1523 distribute the MultiStage2.py script that generates the tables (it's not in
1524 the tarball, but is in the Subversion repository).
1525
1526 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1527 scripts.
1528
1529 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1530 a group with a zero qualifier. The result of the study could be incorrect,
1531 or the function might crash, depending on the pattern.
1532
1533 4. Caseless matching was not working for non-ASCII characters in back
1534 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1535 It now works when Unicode Property Support is available.
1536
1537 5. In pcretest, an escape such as \x{de} in the data was always generating
1538 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1539 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1540 truncation.
1541
1542 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1543
1544 7. Added two (int) casts to pcregrep when printing the difference of two
1545 pointers, in case they are 64-bit values.
1546
1547 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1548 test 2 if it fails.
1549
1550 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1551 and a #define of that name to empty if it is not externally set. This is to
1552 allow users of MSVC to set it if necessary.
1553
1554 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1555 the convenience functions in the pcre_get.c source file.
1556
1557 11. An option change at the start of a pattern that had top-level alternatives
1558 could cause overwriting and/or a crash. This command provoked a crash in
1559 some environments:
1560
1561 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1562
1563 This potential security problem was recorded as CVE-2008-2371.
1564
1565 12. For a pattern where the match had to start at the beginning or immediately
1566 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1567 pcre_dfa_exec() could read past the end of the passed subject if there was
1568 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1569 pcretest so that it places the subject at the end of its malloc-ed buffer.
1570
1571 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1572 exec() might read past the end of the data buffer in UTF-8 mode.
1573
1574 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1575 the data contained the byte 0x85 as part of a UTF-8 character within its
1576 first line. This applied both to normal and DFA matching.
1577
1578 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1579 /^[^d]*?$/8 failed to match "abc".
1580
1581 16. Added a missing copyright notice to pcrecpp_internal.h.
1582
1583 17. Make it more clear in the documentation that values returned from
1584 pcre_exec() in ovector are byte offsets, not character counts.
1585
1586 18. Tidied a few places to stop certain compilers from issuing warnings.
1587
1588 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1589 supplied by Stefan Weber. I made a further small update for 7.8 because
1590 there is a change of source arrangements: the pcre_searchfuncs.c module is
1591 replaced by pcre_ucd.c.
1592
1593
1594 Version 7.7 07-May-08
1595 ---------------------
1596
1597 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1598 a string to a long long, pretend we don't even have a long long." This is
1599 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1600
1601 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1602 pre-7.6 versions, which defined a global no_arg variable instead of putting
1603 it in the RE class. (See also #8 below.)
1604
1605 3. Remove a line of dead code, identified by coverity and reported by Nuno
1606 Lopes.
1607
1608 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1609
1610 (1) The include/exclude patterns were being applied to the whole pathnames
1611 of files, instead of just to the final components.
1612
1613 (2) If there was more than one level of directory, the subdirectories were
1614 skipped unless they satisfied the include/exclude conditions. This is
1615 inconsistent with GNU grep (and could even be seen as contrary to the
1616 pcregrep specification - which I improved to make it absolutely clear).
1617 The action now is always to scan all levels of directory, and just
1618 apply the include/exclude patterns to regular files.
1619
1620 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1621 --exclude_dir in the tests to avoid scanning .svn directories.
1622
1623 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1624 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1625 doesn't support NULs in patterns.
1626
1627 7. Added some missing "const"s to declarations of static tables in
1628 pcre_compile.c and pcre_dfa_exec.c.
1629
1630 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1631 caused by fix #2 above. (Subsequently also a second patch to fix the
1632 first patch. And a third patch - this was a messy problem.)
1633
1634 9. Applied Craig's patch to remove the use of push_back().
1635
1636 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1637 matching function regexec().
1638
1639 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1640 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1641 references. PCRE supports relative numbers with this syntax (I don't think
1642 Oniguruma does).
1643
1644 12. Previously, a group with a zero repeat such as (...){0} was completely
1645 omitted from the compiled regex. However, this means that if the group
1646 was called as a subroutine from elsewhere in the pattern, things went wrong
1647 (an internal error was given). Such groups are now left in the compiled
1648 pattern, with a new opcode that causes them to be skipped at execution
1649 time.
1650
1651 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1652 to the way PCRE behaves:
1653
1654 (a) A lone ] character is dis-allowed (Perl treats it as data).
1655
1656 (b) A back reference to an unmatched subpattern matches an empty string
1657 (Perl fails the current match path).
1658
1659 (c) A data ] in a character class must be notated as \] because if the
1660 first data character in a class is ], it defines an empty class. (In
1661 Perl it is not possible to have an empty class.) The empty class []
1662 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1663 The negative empty class [^] matches any one character, independently
1664 of the DOTALL setting.
1665
1666 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1667 non-existent subpattern following a character class starting with ']' and
1668 containing () gave an internal compiling error instead of "reference to
1669 non-existent subpattern". Fortunately, when the pattern did exist, the
1670 compiled code was correct. (When scanning forwards to check for the
1671 existencd of the subpattern, it was treating the data ']' as terminating
1672 the class, so got the count wrong. When actually compiling, the reference
1673 was subsequently set up correctly.)
1674
1675 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1676 it was being rejected as not supported by pcre_dfa_exec(), even though
1677 other assertions are supported. I have made pcre_dfa_exec() support
1678 (*FAIL).
1679
1680 16. The implementation of 13c above involved the invention of a new opcode,
1681 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1682 cannot be changed at match time, I realized I could make a small
1683 improvement to matching performance by compiling OP_ALLANY instead of
1684 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1685 on the OP_ANY path.
1686
1687 17. Compiling pcretest on Windows with readline support failed without the
1688 following two fixes: (1) Make the unistd.h include conditional on
1689 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1690
1691 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1692 ncurses library to be included for pcretest when ReadLine support is
1693 requested, but also to allow for it to be overridden. This patch came from
1694 Daniel Bergström.
1695
1696 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1697 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1698 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1699 spotting this.
1700
1701
1702 Version 7.6 28-Jan-08
1703 ---------------------
1704
1705 1. A character class containing a very large number of characters with
1706 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1707 overflow.
1708
1709 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1710 HAVE_LONG_LONG is not defined.
1711
1712 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1713 bring them up to date and include new features. This patch includes:
1714
1715 - Fixed PH's badly added libz and libbz2 support.
1716 - Fixed a problem with static linking.
1717 - Added pcredemo. [But later removed - see 7 below.]
1718 - Fixed dftables problem and added an option.
1719 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1720 HAVE_LONG_LONG.
1721 - Added readline support for pcretest.
1722 - Added an listing of the option settings after cmake has run.
1723
1724 4. A user submitted a patch to Makefile that makes it easy to create
1725 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1726 Makefile.am that cause it to include this special target, without
1727 affecting anything else. Note that the same mingw target plus all
1728 the other distribution libraries and programs are now supported
1729 when configuring with CMake (see 6 below) instead of with
1730 Configure/Make.
1731
1732 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1733 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1734 exported in the Windows port". It has not yet been confirmed that the patch
1735 solves the problem, but it does no harm.
1736
1737 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1738 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1739 with CMake, and also correct the comment about stack recursion.
1740
1741 7. Remove the automatic building of pcredemo from the ./configure system and
1742 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1743 of a program that users should build themselves after PCRE is installed, so
1744 building it automatically is not really right. What is more, it gave
1745 trouble in some build environments.
1746
1747 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1748
1749
1750 Version 7.5 10-Jan-08
1751 ---------------------
1752
1753 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1754 values in parens when parsing an RE using the C++ wrapper."
1755
1756 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1757 Characters greater than 255 were excluded from the class instead of being
1758 included.
1759
1760 3. The same bug as (2) above applied to negated POSIX classes such as
1761 [:^space:].
1762
1763 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1764 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1765 I have changed it.
1766
1767 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1768 first named subpattern) and a construct such as (?&a) would reference the
1769 first named subpattern whose name started with "a" (in other words, the
1770 length check was missing). Both these problems are fixed. "Subpattern name
1771 expected" is now given for (?&) (a zero-length name), and this patch also
1772 makes it give the same error for \k'' (previously it complained that that
1773 was a reference to a non-existent subpattern).
1774
1775 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1776 this is right because (?- can be followed by option settings as well as by
1777 digits. I have, however, made the messages clearer.
1778
1779 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1780 than the number used in the conditional) now cause a compile-time error.
1781 This is actually not compatible with Perl, which accepts such patterns, but
1782 treats the conditional as always being FALSE (as PCRE used to), but it
1783 seems to me that giving a diagnostic is better.
1784
1785 8. Change "alphameric" to the more common word "alphanumeric" in comments
1786 and messages.
1787
1788 9. Fix two occurrences of "backslash" in comments that should have been
1789 "backspace".
1790
1791 10. Remove two redundant lines of code that can never be obeyed (their function
1792 was moved elsewhere).
1793
1794 11. The program that makes PCRE's Unicode character property table had a bug
1795 which caused it to generate incorrect table entries for sequences of
1796 characters that have the same character type, but are in different scripts.
1797 It amalgamated them into a single range, with the script of the first of
1798 them. In other words, some characters were in the wrong script. There were
1799 thirteen such cases, affecting characters in the following ranges:
1800
1801 U+002b0 - U+002c1
1802 U+0060c - U+0060d
1803 U+0061e - U+00612
1804 U+0064b - U+0065e
1805 U+0074d - U+0076d
1806 U+01800 - U+01805
1807 U+01d00 - U+01d77
1808 U+01d9b - U+01dbf
1809 U+0200b - U+0200f
1810 U+030fc - U+030fe
1811 U+03260 - U+0327f
1812 U+0fb46 - U+0fbb1
1813 U+10450 - U+1049d
1814
1815 12. The -o option (show only the matching part of a line) for pcregrep was not
1816 compatible with GNU grep in that, if there was more than one match in a
1817 line, it showed only the first of them. It now behaves in the same way as
1818 GNU grep.
1819
1820 13. If the -o and -v options were combined for pcregrep, it printed a blank
1821 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1822 does the same. The return code can be used to tell if there were any
1823 non-matching lines.
1824
1825 14. Added --file-offsets and --line-offsets to pcregrep.
1826
1827 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1828 infinitely looping recursion. The bug was that positive lookaheads were not
1829 being skipped when checking for a possible empty match (negative lookaheads
1830 and both kinds of lookbehind were skipped).
1831
1832 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1833 inclusion of <windows.h> to before rather than after the definition of
1834 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1835
1836 17. Specifying a possessive quantifier with a specific limit for a Unicode
1837 character property caused pcre_compile() to compile bad code, which led at
1838 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1839 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1840 caused the error; without that there was no problem.
1841
1842 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1843
1844 19. Added --enable-pcretest-libreadline.
1845
1846 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1847 RE::GlobalReplace(). As a result, the number of replacements returned was
1848 double what it should be. I removed one of the increments, but Craig sent a
1849 later patch that removed the other one (the right fix) and added unit tests
1850 that check the return values (which was not done before).
1851
1852 21. Several CMake things:
1853
1854 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1855 the names libpcre and libpcreposix, not just pcre and pcreposix.
1856
1857 (2) The above change means that pcretest and pcregrep are now correctly
1858 linked with the newly-built libraries, not previously installed ones.
1859
1860 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1861
1862 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1863 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1864 UTF-8 newline character). The key issue is that the pattern starts .*;
1865 this means that the match must be either at the beginning, or after a
1866 newline. The bug was in the code for advancing after a failed match and
1867 checking that the new position followed a newline. It was not taking
1868 account of UTF-8 characters correctly.
1869
1870 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1871 character classes. PCRE was not treating the sequence [:...:] as a
1872 character class unless the ... were all letters. Perl, however, seems to
1873 allow any characters between [: and :], though of course it rejects as
1874 unknown any "names" that contain non-letters, because all the known class
1875 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1876 for example, whereas PCRE did not - it did not recognize a POSIX character
1877 class. This seemed a bit dangerous, so the code has been changed to be
1878 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1879 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1880 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1881 Perl does, and where it didn't before.
1882
1883 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1884 Windows environments %n is disabled by default.
1885
1886
1887 Version 7.4 21-Sep-07
1888 ---------------------
1889
1890 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1891 means that a class such as [\s] counted as "explicit reference to CR or
1892 LF". That isn't really right - the whole point of the change was to try to
1893 help when there was an actual mention of one of the two characters. So now
1894 the change happens only if \r or \n (or a literal CR or LF) character is
1895 encountered.
1896
1897 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1898 of both had grown to the point where there were only 3 bits left.
1899 Fortunately, there was spare space in the data structure, and so I have
1900 moved the internal flags into a new 16-bit field to free up more option
1901 bits.
1902
1903 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1904 but did not set the internal JCHANGED flag - either of these is enough to
1905 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1906 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1907 start sets both bits.
1908
1909 4. Added options (at build time, compile time, exec time) to change \R from
1910 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1911
1912 5. doc/pcresyntax.html was missing from the distribution.
1913
1914 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1915 compatibility, even though it is no longer used.
1916
1917 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1918 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1919 windows.h file is present (where different names are used). [This was
1920 reversed later after testing - see 16 below.]
1921
1922 8. Changed all #include <config.h> to #include "config.h". There were also
1923 some further <pcre.h> cases that I changed to "pcre.h".
1924
1925 9. When pcregrep was used with the --colour option, it missed the line ending
1926 sequence off the lines that it output.
1927
1928 10. It was pointed out to me that arrays of string pointers cause lots of
1929 relocations when a shared library is dynamically loaded. A technique of
1930 using a single long string with a table of offsets can drastically reduce
1931 these. I have refactored PCRE in four places to do this. The result is
1932 dramatic:
1933
1934 Originally: 290
1935 After changing UCP table: 187
1936 After changing error message table: 43
1937 After changing table of "verbs" 36
1938 After changing table of Posix names 22
1939
1940 Thanks to the folks working on Gregex for glib for this insight.
1941
1942 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1943 unicode-properties was also set.
1944
1945 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1946
1947 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1948 checked only for CRLF.
1949
1950 14. Added casts to pcretest.c to avoid compiler warnings.
1951
1952 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1953
1954 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1955 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1956 entirely. This removes changes made in 7 above.
1957
1958 17. The CMake files have been updated, and there is now more information about
1959 building with CMake in the NON-UNIX-USE document.
1960
1961
1962 Version 7.3 28-Aug-07
1963 ---------------------
1964
1965 1. In the rejigging of the build system that eventually resulted in 7.1, the
1966 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1967 brackets there is not right, since it causes compilers to look for an
1968 installed pcre.h, not the version that is in the source that is being
1969 compiled (which of course may be different). I have changed it back to:
1970
1971 #include "pcre.h"
1972
1973 I have a vague recollection that the change was concerned with compiling in
1974 different directories, but in the new build system, that is taken care of
1975 by the VPATH setting the Makefile.
1976
1977 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1978 when the subject happened to end in the byte 0x85 (e.g. if the last
1979 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1980 characters but of course it shouldn't be taken as a newline when it is part
1981 of another character. The bug was that, for an unlimited repeat of . in
1982 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1983 characters when looking for a newline.
1984
1985 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1986
1987 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1988 in debug output.
1989
1990 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1991 long printing in the pcrecpp unittest when running under MinGW.
1992
1993 6. ESC_K was left out of the EBCDIC table.
1994
1995 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1996 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1997 limit also applies to "virtual nesting" when a pattern is recursive, and in
1998 this case 1000 isn't so big. I have been able to remove this limit at the
1999 expense of backing off one optimization in certain circumstances. Normally,
2000 when pcre_exec() would call its internal match() function recursively and
2001 immediately return the result unconditionally, it uses a "tail recursion"
2002 feature to save stack. However, when a subpattern that can match an empty
2003 string has an unlimited repetition quantifier, it no longer makes this
2004 optimization. That gives it a stack frame in which to save the data for
2005 checking that an empty string has been matched. Previously this was taken
2006 from the 1000-entry workspace that had been reserved. So now there is no
2007 explicit limit, but more stack is used.
2008
2009 8. Applied Daniel's patches to solve problems with the import/export magic
2010 syntax that is required for Windows, and which was going wrong for the
2011 pcreposix and pcrecpp parts of the library. These were overlooked when this
2012 problem was solved for the main library.
2013
2014 9. There were some crude static tests to avoid integer overflow when computing
2015 the size of patterns that contain repeated groups with explicit upper
2016 limits. As the maximum quantifier is 65535, the maximum group length was
2017 set at 30,000 so that the product of these two numbers did not overflow a
2018 32-bit integer. However, it turns out that people want to use groups that
2019 are longer than 30,000 bytes (though not repeat them that many times).
2020 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2021 made it possible to implement the integer overflow checks in a much more
2022 dynamic way, which I have now done. The artificial limitation on group
2023 length has been removed - we now have only the limit on the total length of
2024 the compiled pattern, which depends on the LINK_SIZE setting.
2025
2026 10. Fixed a bug in the documentation for get/copy named substring when
2027 duplicate names are permitted. If none of the named substrings are set, the
2028 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2029 empty string.
2030
2031 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2032 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2033 because the ] is interpreted as the first data character and the
2034 terminating ] is not found. PCRE has been made compatible with Perl in this
2035 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2036 cause memory overwriting.
2037
2038 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2039 string has been matched (to stop an infinite loop). It was not recognizing
2040 a conditional subpattern that could match an empty string if that
2041 subpattern was within another subpattern. For example, it looped when
2042 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
2043 condition was not nested. This bug has been fixed.
2044
2045 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2046 past the start of the subject in the presence of bytes with the top bit
2047 set, for example "\x8aBCD".
2048
2049 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2050 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2051
2052 14. Optimized (?!) to (*FAIL).
2053
2054 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2055 This restricts code points to be within the range 0 to 0x10FFFF, excluding
2056 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2057 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2058 does: it's just the validity check that is more restrictive.
2059
2060 16. Inserted checks for integer overflows during escape sequence (backslash)
2061 processing, and also fixed erroneous offset values for syntax errors during
2062 backslash processing.
2063
2064 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2065 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2066
2067 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2068 caused an overrun.
2069
2070 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2071 something other than just ASCII characters) inside a group that had an
2072 unlimited repeat caused a loop at compile time (while checking to see
2073 whether the group could match an empty string).
2074
2075 20. Debugging a pattern containing \p or \P could cause a crash. For example,
2076 [\P{Any}] did so. (Error in the code for printing property names.)
2077
2078 21. An orphan \E inside a character class could cause a crash.
2079
2080 22. A repeated capturing bracket such as (A)? could cause a wild memory
2081 reference during compilation.
2082
2083 23. There are several functions in pcre_compile() that scan along a compiled
2084 expression for various reasons (e.g. to see if it's fixed length for look
2085 behind). There were bugs in these functions when a repeated \p or \P was
2086 present in the pattern. These operators have additional parameters compared
2087 with \d, etc, and these were not being taken into account when moving along
2088 the compiled data. Specifically:
2089
2090 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2091 length.
2092
2093 (b) An item such as \pL+ within a repeated group could cause crashes or
2094 loops.
2095
2096 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2097 "reference to non-existent subpattern" error.
2098
2099 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2100
2101 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2102 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2103
2104 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2105
2106 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2107 character were causing crashes (broken optimization).
2108
2109 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2110 \p or \P) caused a compile-time loop.
2111
2112 28. More problems have arisen in unanchored patterns when CRLF is a valid line
2113 break. For example, the unstudied pattern [\r\n]A does not match the string
2114 "\r\nA" because change 7.0/46 below moves the current point on by two
2115 characters after failing to match at the start. However, the pattern \nA
2116 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2117 the same is true. There doesn't seem any very clean way out of this, but
2118 what I have chosen to do makes the common cases work: PCRE now takes note
2119 of whether there can be an explicit match for \r or \n anywhere in the
2120 pattern, and if so, 7.0/46 no longer applies. As part of this change,
2121 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2122 pattern has explicit CR or LF references.
2123
2124 29. Added (*CR) etc for changing newline setting at start of pattern.
2125
2126
2127 Version 7.2 19-Jun-07
2128 ---------------------
2129
2130 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2131 which is apparently normally available under Windows.
2132
2133 2. Re-jig the pcregrep tests with different newline settings in an attempt
2134 to make them independent of the local environment's newline setting.
2135
2136 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2137
2138 4. Some of the "internals" tests were previously cut out when the link size
2139 was not 2, because the output contained actual offsets. The recent new
2140 "Z" feature of pcretest means that these can be cut out, making the tests
2141 usable with all link sizes.
2142
2143 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2144 stack recursion. This gives a massive performance boost under BSD, but just
2145 a small improvement under Linux. However, it saves one field in the frame
2146 in all cases.
2147
2148 6. Added more features from the forthcoming Perl 5.10:
2149
2150 (a) (?-n) (where n is a string of digits) is a relative subroutine or
2151 recursion call. It refers to the nth most recently opened parentheses.
2152
2153 (b) (?+n) is also a relative subroutine call; it refers to the nth next
2154 to be opened parentheses.
2155
2156 (c) Conditions that refer to capturing parentheses can be specified
2157 relatively, for example, (?(-2)... or (?(+3)...
2158
2159 (d) \K resets the start of the current match so that everything before
2160 is not part of it.
2161
2162 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2163
2164 (f) \g{name} is another synonym - part of Perl 5.10's unification of
2165 reference syntax.
2166
2167 (g) (?| introduces a group in which the numbering of parentheses in each
2168 alternative starts with the same number.
2169
2170 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2171
2172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2173 PCRE_INFO_JCHANGED.
2174
2175 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
2176 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2177 for detecting groups that can match an empty string.
2178
2179 9. A pattern with a very large number of alternatives (more than several
2180 hundred) was running out of internal workspace during the pre-compile
2181 phase, where pcre_compile() figures out how much memory will be needed. A
2182 bit of new cunning has reduced the workspace needed for groups with
2183 alternatives. The 1000-alternative test pattern now uses 12 bytes of
2184 workspace instead of running out of the 4096 that are available.
2185
2186 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2187
2188 11. Applied patch from Google to remove an optimization that didn't quite work.
2189 The report of the bug said:
2190
2191 pcrecpp::RE("a*").FullMatch("aaa") matches, while
2192 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2193 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2194
2195 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2196 it matched the wrong number of bytes.
2197
2198
2199 Version 7.1 24-Apr-07
2200 ---------------------
2201
2202 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2203 that is more "standard", making use of automake and other Autotools. There
2204 is some re-arrangement of the files and adjustment of comments consequent
2205 on this.
2206
2207 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2208 for recursive directory scanning broke on some systems because the files
2209 are not scanned in any specific order and on different systems the order
2210 was different. A call to "sort" has been inserted into RunGrepTest for the
2211 approprate test as a short-term fix. In the longer term there may be an
2212 alternative.
2213
2214 3. I had an email from Eric Raymond about problems translating some of PCRE's
2215 man pages to HTML (despite the fact that I distribute HTML pages, some
2216 people do their own conversions for various reasons). The problems
2217 concerned the use of low-level troff macros .br and .in. I have therefore
2218 removed all such uses from the man pages (some were redundant, some could
2219 be replaced by .nf/.fi pairs). The 132html script that I use to generate
2220 HTML has been updated to handle .nf/.fi and to complain if it encounters
2221 .br or .in.
2222
2223 4. Updated comments in configure.ac that get placed in config.h.in and also
2224 arranged for config.h to be included in the distribution, with the name
2225 config.h.generic, for the benefit of those who have to compile without
2226 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2227
2228 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2229 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2230 makevp.bat for the current PCRE, using the additional files
2231 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2232
2233 6. A Windows user reported a minor discrepancy with test 2, which turned out
2234 to be caused by a trailing space on an input line that had got lost in his
2235 copy. The trailing space was an accident, so I've just removed it.
2236
2237 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2238 that is needed.
2239
2240 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2241 as "const" (a) because they are and (b) because it helps the PHP
2242 maintainers who have recently made a script to detect big data structures
2243 in the php code that should be moved to the .rodata section. I remembered
2244 to update Builducptable as well, so it won't revert if ucptable.h is ever
2245 re-created.
2246
2247 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2248 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2249 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2250 support is not required. This saves 1.5-2K of code, which is important in
2251 some applications.
2252
2253 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2254 so as not to refer to the tables, even though these functions will never be
2255 called when UTF-8 support is disabled. Otherwise there are problems with a
2256 shared library.
2257
2258 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2259
2260 (a) It was defining its arguments as char * instead of void *.
2261
2262 (b) It was assuming that all moves were upwards in memory; this was true
2263 a long time ago when I wrote it, but is no longer the case.
2264
2265 The emulated memove() is provided for those environments that have neither
2266 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2267 is clearly not the case, as these two bugs were recently reported.
2268
2269 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2270 and Detrail to create the HTML documentation, the .txt form of the man
2271 pages, and it removes trailing spaces from listed files. It also creates
2272 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2273 case, it wraps all the #defines with #ifndefs. This script should be run
2274 before "make dist".
2275
2276 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2277 with Unicode property support.
2278
2279 (a) For a maximizing quantifier, if the two different cases of the
2280 character were of different lengths in their UTF-8 codings (there are
2281 some cases like this - I found 11), and the matching function had to
2282 back up over a mixture of the two cases, it incorrectly assumed they
2283 were both the same length.
2284
2285 (b) When PCRE was configured to use the heap rather than the stack for
2286 recursion during matching, it was not correctly preserving the data for
2287 the other case of a UTF-8 character when checking ahead for a match
2288 while processing a minimizing repeat. If the check also involved
2289 matching a wide character, but failed, corruption could cause an
2290 erroneous result when trying to check for a repeat of the original
2291 character.
2292
2293 13. Some tidying changes to the testing mechanism:
2294
2295 (a) The RunTest script now detects the internal link size and whether there
2296 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2297 values substituted by "configure". (The RunGrepTest script already did
2298 this for UTF-8.) The configure.ac script no longer substitutes the
2299 relevant variables.
2300
2301 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2302 with length and offset values. This means that the output is different
2303 for different internal link sizes. Test 2 is skipped for link sizes
2304 other than 2 because of this, bypassing the problem. Unfortunately,
2305 there was also a test in test 3 (the locale tests) that used /B and
2306 failed for link sizes other than 2. Rather than cut the whole test out,
2307 I have added a new /Z option to pcretest that replaces the length and
2308 offset values with spaces. This is now used to make test 3 independent
2309 of link size. (Test 2 will be tidied up later.)
2310
2311 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2312 segmentation fault instead of returning the appropriate error message.
2313
2314 15. In multiline mode when the newline sequence was set to "any", the pattern
2315 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2316 This doesn't seem right; it now treats the CRLF combination as the line
2317 ending, and so does not match in that case. It's only a pattern such as ^$
2318 that would hit this one: something like ^ABC$ would have failed after \r
2319 and then tried again after \r\n.
2320
2321 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2322 in an attempt to make files that differ only in their line terminators
2323 compare equal. This works on Linux.
2324
2325 17. Under certain error circumstances pcregrep might try to free random memory
2326 as it exited. This is now fixed, thanks to valgrind.
2327
2328 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2329 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2330 was because its rules for how to advance for /g after matching an empty
2331 string at the end of a line did not allow for this case. They now check for
2332 it specially.
2333
2334 20. pcretest is supposed to handle patterns and data of any length, by
2335 extending its buffers when necessary. It was getting this wrong when the
2336 buffer for a data line had to be extended.
2337
2338 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2339 CRLF as a newline sequence.
2340
2341 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2342 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2343 I have nevertheless tidied it up.
2344
2345 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2346
2347 24. Added a man page for pcre-config.
2348
2349
2350 Version 7.0 19-Dec-06
2351 ---------------------
2352
2353 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2354 moving to gcc 4.1.1.
2355
2356 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2357 sys/time.h, which is documented as needed for this function. It doesn't
2358 seem to matter on Linux, but it showed up on some releases of OS X.
2359
2360 3. It seems that there are systems where bytes whose values are greater than
2361 127 match isprint() in the "C" locale. The "C" locale should be the
2362 default when a C program starts up. In most systems, only ASCII printing
2363 characters match isprint(). This difference caused the output from pcretest
2364 to vary, making some of the tests fail. I have changed pcretest so that:
2365
2366 (a) When it is outputting text in the compiled version of a pattern, bytes
2367 other than 32-126 are always shown as hex escapes.
2368
2369 (b) When it is outputting text that is a matched part of a subject string,
2370 it does the same, unless a different locale has been set for the match
2371 (using the /L modifier). In this case, it uses isprint() to decide.
2372
2373 4. Fixed a major bug that caused incorrect computation of the amount of memory
2374 required for a compiled pattern when options that changed within the
2375 pattern affected the logic of the preliminary scan that determines the
2376 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2377 that the computed length was too small. The symptoms of this bug were
2378 either the PCRE error "internal error: code overflow" from pcre_compile(),
2379 or a glibc crash with a message such as "pcretest: free(): invalid next
2380 size (fast)". Examples of patterns that provoked this bug (shown in
2381 pcretest format) are:
2382
2383 /(?-x: )/x
2384 /(?x)(?-x: \s*#\s*)/
2385 /((?i)[\x{c0}])/8
2386 /(?i:[\x{c0}])/8
2387
2388 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2389 is now done differently.
2390
2391 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2392 wrapper classes; (b) implement a new function in the C++ scanner that is
2393 more efficient than the old way of doing things because it avoids levels of
2394 recursion in the regex matching; (c) add a paragraph to the documentation
2395 for the FullMatch() function.
2396
2397 6. The escape sequence \n was being treated as whatever was defined as
2398 "newline". Not only was this contrary to the documentation, which states
2399 that \n is character 10 (hex 0A), but it also went horribly wrong when
2400 "newline" was defined as CRLF. This has been fixed.
2401
2402 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2403 was being set to -1 for the "end of line" case (supposedly a value that no
2404 character can have). Though this value is never used (the check for end of
2405 line is "zero bytes in current character"), it caused compiler complaints.
2406 I've changed it to 0xffffffff.
2407
2408 8. In pcre_version.c, the version string was being built by a sequence of
2409 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2410 string (as it is for production releases) called a macro with an empty
2411 argument. The C standard says the result of this is undefined. The gcc
2412 compiler treats it as an empty string (which was what was wanted) but it is
2413 reported that Visual C gives an error. The source has been hacked around to
2414 avoid this problem.
2415
2416 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2417 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2418 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2419 of them did).
2420
2421 10. Originally, pcretest opened its input and output without "b"; then I was
2422 told that "b" was needed in some environments, so it was added for release
2423 5.0 to both the input and output. (It makes no difference on Unix-like
2424 systems.) Later I was told that it is wrong for the input on Windows. I've
2425 now abstracted the modes into two macros, to make it easier to fiddle with
2426 them, and removed "b" from the input mode under Windows.
2427
2428 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2429
2430 12. Added -help and --help to pcretest as an official way of being reminded
2431 of the options.
2432
2433 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2434 and pcrecpp.cc because they annoy compilers at high warning levels.
2435
2436 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2437
2438 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2439 scripts are not C programs :-) and which was not noticed because it works
2440 on Linux.
2441
2442 16. pcretest is supposed to handle any length of pattern and data line (as one
2443 line or as a continued sequence of lines) by extending its input buffer if
2444 necessary. This feature was broken for very long pattern lines, leading to
2445 a string of junk being passed to pcre_compile() if the pattern was longer
2446 than about 50K.
2447
2448 17. I have done a major re-factoring of the way pcre_compile() computes the
2449 amount of memory needed for a compiled pattern. Previously, there was code
2450 that made a preliminary scan of the pattern in order to do this. That was
2451 OK when PCRE was new, but as the facilities have expanded, it has become
2452 harder and harder to keep it in step with the real compile phase, and there
2453 have been a number of bugs (see for example, 4 above). I have now found a
2454 cunning way of running the real compile function in a "fake" mode that
2455 enables it to compute how much memory it would need, while actually only
2456 ever using a few hundred bytes of working memory and without too many
2457 tests of the mode. This should make future maintenance and development
2458 easier. A side effect of this work is that the limit of 200 on the nesting
2459 depth of parentheses has been removed (though this was never a serious
2460 limitation, I suspect). However, there is a downside: pcre_compile() now
2461 runs more slowly than before (30% or more, depending on the pattern). I
2462 hope this isn't a big issue. There is no effect on runtime performance.
2463
2464 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2465 newline (only possible for the last line of a file) and it was a
2466 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2467
2468 19. Added additional timing features to pcretest. (1) The -tm option now times
2469 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2470 separate command line item, by a number that specifies the number of
2471 repeats to use when timing. The default is 50000; this gives better
2472 precision, but takes uncomfortably long for very large patterns.
2473
2474 20. Extended pcre_study() to be more clever in cases where a branch of a
2475 subpattern has no definite first character. For example, (a*|b*)[cd] would
2476 previously give no result from pcre_study(). Now it recognizes that the
2477 first character must be a, b, c, or d.
2478
2479 21. There was an incorrect error "recursive call could loop indefinitely" if
2480 a subpattern (or the entire pattern) that was being tested for matching an
2481 empty string contained only one non-empty item after a nested subpattern.
2482 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2483 incorrectly, because the \d was being skipped in the check.
2484
2485 22. The pcretest program now has a new pattern option /B and a command line
2486 option -b, which is equivalent to adding /B to every pattern. This causes
2487 it to show the compiled bytecode, without the additional information that
2488 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2489 is the same as /B/I).
2490
2491 23. A new optimization is now able automatically to treat some sequences such
2492 as a*b as a*+b. More specifically, if something simple (such as a character
2493 or a simple class like \d) has an unlimited quantifier, and is followed by
2494 something that cannot possibly match the quantified thing, the quantifier
2495 is automatically "possessified".
2496
2497 24. A recursive reference to a subpattern whose number was greater than 39
2498 went wrong under certain circumstances in UTF-8 mode. This bug could also
2499 have affected the operation of pcre_study().
2500
2501 25. Realized that a little bit of performance could be had by replacing
2502 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2503
2504 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2505
2506 27. Possessive quantifiers such as a++ were previously implemented by turning
2507 them into atomic groups such as ($>a+). Now they have their own opcodes,
2508 which improves performance. This includes the automatically created ones
2509 from 23 above.
2510
2511 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2512 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2513 the first matched character to be a colon. This applied both to named and
2514 numbered groups.
2515
2516 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2517
2518 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2519 building PCRE on Windows easier, so I have included it in the distribution.
2520
2521 31. There is now a check in pcretest against a ridiculously large number being
2522 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2523 loop, the loop is abandoned.
2524
2525 32. Forward references to subpatterns in conditions such as (?(2)...) where
2526 subpattern 2 is defined later cause pcre_compile() to search forwards in
2527 the pattern for the relevant set of parentheses. This search went wrong
2528 when there were unescaped parentheses in a character class, parentheses
2529 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2530
2531 33. "Subroutine" calls and backreferences were previously restricted to
2532 referencing subpatterns earlier in the regex. This restriction has now
2533 been removed.
2534
2535 34. Added a number of extra features that are going to be in Perl 5.10. On the
2536 whole, these are just syntactic alternatives for features that PCRE had
2537 previously implemented using the Python syntax or my own invention. The
2538 other formats are all retained for compatibility.
2539
2540 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2541 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2542 also .NET compatible.
2543
2544 (b) A recursion or subroutine call to a named group can now be defined as
2545 (?&name) as well as (?P>name).
2546
2547 (c) A backreference to a named group can now be defined as \k<name> or
2548 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2549 5.10, are also .NET compatible.
2550
2551 (d) A conditional reference to a named group can now use the syntax
2552 (?(<name>) or (?('name') as well as (?(name).
2553
2554 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2555 groups (named and numbered) that are never evaluated inline, but can be
2556 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2557 is always false. There may be only one alternative in such a group.
2558
2559 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2560 as the simple (?(R). The condition is true only if the most recent
2561 recursion is that of the given number or name. It does not search out
2562 through the entire recursion stack.
2563
2564 (g) The escape \gN or \g{N} has been added, where N is a positive or
2565 negative number, specifying an absolute or relative reference.
2566
2567 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2568 some "unreachable code" warnings.
2569
2570 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2571 things, this adds five new scripts.
2572
2573 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2574 There were also incompatibilities regarding the handling of \Q..\E inside
2575 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2576 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2577
2578 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2579 matches an empty string, and forcibly breaks the loop. There were bugs in
2580 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2581 against aaaa the result was just "a" rather than "aaaa", for example. Two
2582 separate and independent bugs (that affected different cases) have been
2583 fixed.
2584
2585 39. Refactored the code to abolish the use of different opcodes for small
2586 capturing bracket numbers. This is a tidy that I avoided doing when I
2587 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2588 The new approach is not only tidier, it makes it possible to reduce the
2589 memory needed to fix the previous bug (38).
2590
2591 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2592 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2593 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2594 mode.
2595
2596 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2597 report.
2598
2599 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2600 copy construction and assignment in the C++ wrapper.
2601
2602 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2603 couple of bugs that could have given wrong results in the "--newline=crlf"
2604 case.
2605
2606 44. Added a number of casts and did some reorganization of signed/unsigned int
2607 variables following suggestions from Dair Grant. Also renamed the variable
2608 "this" as "item" because it is a C++ keyword.
2609
2610 45. Arranged for dftables to add
2611
2612 #include "pcre_internal.h"
2613
2614 to pcre_chartables.c because without it, gcc 4.x may remove the array
2615 definition from the final binary if PCRE is built into a static library and
2616 dead code stripping is activated.
2617
2618 46. For an unanchored pattern, if a match attempt fails at the start of a
2619 newline sequence, and the newline setting is CRLF or ANY, and the next two
2620 characters are CRLF, advance by two characters instead of one.
2621
2622
2623 Version 6.7 04-Jul-06
2624 ---------------------
2625
2626 1. In order to handle tests when input lines are enormously long, pcretest has
2627 been re-factored so that it automatically extends its buffers when
2628 necessary. The code is crude, but this _is_ just a test program. The
2629 default size has been increased from 32K to 50K.
2630
2631 2. The code in pcre_study() was using the value of the re argument before
2632 testing it for NULL. (Of course, in any sensible call of the function, it
2633 won't be NULL.)
2634
2635 3. The memmove() emulation function in pcre_internal.h, which is used on
2636 systems that lack both memmove() and bcopy() - that is, hardly ever -
2637 was missing a "static" storage class specifier.
2638
2639 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2640 containing an extended class (one that cannot be represented by a bitmap
2641 because it contains high-valued characters or Unicode property items, e.g.
2642 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2643 pattern, but PCRE should not loop if you do not (it no longer does).
2644 [Detail: two cases were found: (a) a repeated subpattern containing an
2645 extended class; (b) a recursive reference to a subpattern that followed a
2646 previous extended class. It wasn't skipping over the extended class
2647 correctly when UTF-8 mode was not set.]
2648
2649 5. A negated single-character class was not being recognized as fixed-length
2650 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2651 compile error "lookbehind assertion is not fixed length".
2652
2653 6. The RunPerlTest auxiliary script was showing an unexpected difference
2654 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2655 write a Perl script that can interpret lines of an input file either as
2656 byte characters or as UTF-8, which is what "perltest" was being required to
2657 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2658 can't do is switch easily at run time between having the "use utf8;" pragma
2659 or not. In the end, I fudged it by using the RunPerlTest script to insert
2660 "use utf8;" explicitly for the UTF-8 tests.
2661
2662 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2663 the end of the subject string, contrary to the documentation and to what
2664 Perl does. This was true of both matching functions. Now it matches only at
2665 the start of the subject and immediately after *internal* newlines.
2666
2667 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2668 a pointer to an int instead of a pointer to an unsigned long int. This
2669 caused problems on 64-bit systems.
2670
2671 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2672 instance of the 'standard' template library not being so standard".
2673
2674 10. There was no check on the number of named subpatterns nor the maximum
2675 length of a subpattern name. The product of these values is used to compute
2676 the size of the memory block for a compiled pattern. By supplying a very
2677 long subpattern name and a large number of named subpatterns, the size
2678 computation could be caused to overflow. This is now prevented by limiting
2679 the length of names to 32 characters, and the number of named subpatterns
2680 to 10,000.
2681
2682 11. Subpatterns that are repeated with specific counts have to be replicated in
2683 the compiled pattern. The size of memory for this was computed from the
2684 length of the subpattern and the repeat count. The latter is limited to
2685 65535, but there was no limit on the former, meaning that integer overflow
2686 could in principle occur. The compiled length of a repeated subpattern is
2687 now limited to 30,000 bytes in order to prevent this.
2688
2689 12. Added the optional facility to have named substrings with the same name.
2690
2691 13. Added the ability to use a named substring as a condition, using the
2692 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2693 are numbers (not recommended). Forward references are permitted.
2694
2695 14. Added forward references in named backreferences (if you see what I mean).
2696
2697 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2698 pattern could run off the end of the subject. For example, the pattern
2699 "(?s)(.{1,5})"8 did this with the subject "ab".
2700
2701 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2702 PCRE_CASELESS was set when matching characters that were quantified with ?
2703 or *.
2704
2705 17. A character class other than a single negated character that had a minimum
2706 but no maximum quantifier - for example [ab]{6,} - was not handled
2707 correctly by pce_dfa_exec(). It would match only one character.
2708
2709 18. A valid (though odd) pattern that looked like a POSIX character
2710 class but used an invalid character after [ (for example [[,abc,]]) caused
2711 pcre_compile() to give the error "Failed: internal error: code overflow" or
2712 in some cases to crash with a glibc free() error. This could even happen if
2713 the pattern terminated after [[ but there just happened to be a sequence of
2714 letters, a binary zero, and a closing ] in the memory that followed.
2715
2716 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2717 over the years. Originally (before any Unicode support), just the bottom 8
2718 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2719 output from "man perlunicode" includes this:
2720
2721 The regular expression compiler produces polymorphic opcodes. That
2722 is, the pattern adapts to the data and automatically switches to
2723 the Unicode character scheme when presented with Unicode data--or
2724 instead uses a traditional byte scheme when presented with byte
2725 data.
2726
2727 Sadly, a wide octal escape does not cause a switch, and in a string with
2728 no other multibyte characters, these octal escapes are treated as before.
2729 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2730 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2731 Unicode string.
2732
2733 I have not perpetrated such confusion in PCRE. Up till now, it took just
2734 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2735 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2736 translate to the appropriate multibyte character.
2737
2738 29. Applied some refactoring to reduce the number of warnings from Microsoft
2739 and Borland compilers. This has included removing the fudge introduced
2740 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2741 a warning about an unused variable.
2742
2743 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2744 characters since release 4.0, because Perl (from release 5.004) does not.
2745 [Or at least, is documented not to: some releases seem to be in conflict
2746 with the documentation.] However, when a pattern was studied with
2747 pcre_study() and all its branches started with \s, PCRE still included VT
2748 as a possible starting character. Of course, this did no harm; it just
2749 caused an unnecessary match attempt.
2750
2751 22. Removed a now-redundant internal flag bit that recorded the fact that case
2752 dependency changed within the pattern. This was once needed for "required
2753 byte" processing, but is no longer used. This recovers a now-scarce options
2754 bit. Also moved the least significant internal flag bit to the most-
2755 significant bit of the word, which was not previously used (hangover from
2756 the days when it was an int rather than a uint) to free up another bit for
2757 the future.
2758
2759 23. Added support for CRLF line endings as well as CR and LF. As well as the
2760 default being selectable at build time, it can now be changed at runtime
2761 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2762 specify that it is scanning data with non-default line endings.
2763
2764 24. Changed the definition of CXXLINK to make it agree with the definition of
2765 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2766
2767 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2768 recursions. This makes a big different to stack usage for some patterns.
2769
2770 26. If a subpattern containing a named recursion or subroutine reference such
2771 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2772 the space required for the compiled pattern went wrong and gave too small a
2773 value. Depending on the environment, this could lead to "Failed: internal
2774 error: code overflow at offset 49" or "glibc detected double free or
2775 corruption" errors.
2776
2777 27. Applied patches from Google (a) to support the new newline modes and (b) to
2778 advance over multibyte UTF-8 characters in GlobalReplace.
2779
2780 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2781 difference for some implementation of PCRE in some Windows version.
2782
2783 29. Added some extra testing facilities to pcretest:
2784
2785 \q<number> in a data line sets the "match limit" value
2786 \Q<number> in a data line sets the "match recursion limt" value
2787 -S <number> sets the stack size, where <number> is in megabytes
2788
2789 The -S option isn't available for Windows.
2790
2791
2792 Version 6.6 06-Feb-06
2793 ---------------------
2794
2795 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2796 in pcreposix.h. I have copied the definition from pcre.h.
2797
2798 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2799 because pcre.h is no longer a built file.
2800
2801 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2802 not normally included in the compiled code.
2803
2804
2805 Version 6.5 01-Feb-06
2806 ---------------------
2807
2808 1. When using the partial match feature with pcre_dfa_exec(), it was not
2809 anchoring the second and subsequent partial matches at the new starting
2810 point. This could lead to incorrect results. For example, with the pattern
2811 /1234/, partially matching against "123" and then "a4" gave a match.
2812
2813 2. Changes to pcregrep:
2814
2815 (a) All non-match returns from pcre_exec() were being treated as failures
2816 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2817 error message is output. Some extra information is given for the
2818 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2819 probably the only errors that are likely to be caused by users (by
2820 specifying a regex that has nested indefinite repeats, for instance).
2821 If there are more than 20 of these errors, pcregrep is abandoned.
2822
2823 (b) A binary zero was treated as data while matching, but terminated the
2824 output line if it was written out. This has been fixed: binary zeroes
2825 are now no different to any other data bytes.
2826
2827 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2828 used to set a locale for matching. The --locale=xxxx long option has
2829 been added (no short equivalent) to specify a locale explicitly on the
2830 pcregrep command, overriding the environment variables.
2831
2832 (d) When -B was used with -n, some line numbers in the output were one less
2833 than they should have been.
2834
2835 (e) Added the -o (--only-matching) option.
2836
2837 (f) If -A or -C was used with -c (count only), some lines of context were
2838 accidentally printed for the final match.
2839
2840 (g) Added the -H (--with-filename) option.
2841
2842 (h) The combination of options -rh failed to suppress file names for files
2843 that were found from directory arguments.
2844
2845 (i) Added the -D (--devices) and -d (--directories) options.
2846
2847 (j) Added the -F (--fixed-strings) option.
2848
2849 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2850
2851 (l) Added the --colo(u)r option.
2852
2853 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2854 is not present by default.
2855
2856 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2857 items such as (?R) or (?1), when the recursion could match a number of
2858 alternatives. If it matched one of the alternatives, but subsequently,
2859 outside the recursion, there was a failure, the code tried to back up into
2860 the recursion. However, because of the way PCRE is implemented, this is not
2861 possible, and the result was an incorrect result from the match.
2862
2863 In order to prevent this happening, the specification of recursion has
2864 been changed so that all such subpatterns are automatically treated as
2865 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2866
2867 4. I had overlooked the fact that, in some locales, there are characters for
2868 which isalpha() is true but neither isupper() nor islower() are true. In
2869 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2870 and ordfeminine) are like this. This affected the treatment of \w and \W
2871 when they appeared in character classes, but not when they appeared outside
2872 a character class. The bit map for "word" characters is now created
2873 separately from the results of isalnum() instead of just taking it from the
2874 upper, lower, and digit maps. (Plus the underscore character, of course.)
2875
2876 5. The above bug also affected the handling of POSIX character classes such as
2877 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2878 permanent tables. Instead, the bit maps for such a class were previously
2879 created as the appropriate unions of the upper, lower, and digit bitmaps.
2880 Now they are created by subtraction from the [[:word:]] class, which has
2881 its own bitmap.
2882
2883 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2884 It is created by subtracting the vertical space characters (\x09, \x0a,
2885 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2886 subtraction was done in the overall bitmap for a character class, meaning
2887 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2888 be recognized. This bug has been fixed.
2889
2890 7. Patches from the folks at Google:
2891
2892 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2893 real life, but is still worth protecting against".
2894
2895 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2896 regular expressions".
2897
2898 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2899 have it.
2900
2901 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2902 "configure" and the latter not, in order to fix a problem somebody had
2903 with compiling the Arg class on HP-UX.
2904
2905 (e) Improve the error-handling of the C++ wrapper a little bit.
2906
2907 (f) New tests for checking recursion limiting.
2908
2909 8. The pcre_memmove() function, which is used only if the environment does not
2910 have a standard memmove() function (and is therefore rarely compiled),
2911 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2912 returning a result (though PCRE never actually uses the result).
2913
2914 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2915 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2916 returned instead of calling malloc() with an overflowing number that would
2917 most likely cause subsequent chaos.
2918
2919 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2920
2921 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2922 with this option is matched, the nmatch and pmatch options of regexec() are
2923 ignored.
2924
2925 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2926 provided in case anyone wants to the the POSIX interface with UTF-8
2927 strings.
2928
2929 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2930 C++ linking (needed for some HP-UX environments).
2931
2932 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2933 (unused parameter) and in the pcre_printint() function (omitted "default"
2934 switch label when the default is to do nothing).
2935
2936 15. Added some code to make it possible, when PCRE is compiled as a C++
2937 library, to replace subject pointers for pcre_exec() with a smart pointer
2938 class, thus making it possible to process discontinuous strings.
2939
2940 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2941 much the same function. They were added by different people who were trying
2942 to make PCRE easy to compile on non-Unix systems. It has been suggested
2943 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2944 for compiling on Windows systems. I have therefore replaced it with
2945 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2946 defaults to "extern" for C or "extern C" for C++, which works fine on
2947 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2948 SCOPE with something explicit in config.h. In addition:
2949
2950 (a) pcreposix.h still had just "extern" instead of either of these macros;
2951 I have replaced it with PCRE_DATA_SCOPE.
2952
2953 (b) Functions such as _pcre_xclass(), which are internal to the library,
2954 but external in the C sense, all had PCRE_EXPORT in their definitions.
2955 This is apparently wrong for the Windows case, so I have removed it.
2956 (It makes no difference on Unix-like systems.)
2957
2958 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2959 of recursive calls to match(). This is different to MATCH_LIMIT because
2960 that limits the total number of calls to match(), not all of which increase
2961 the depth of recursion. Limiting the recursion depth limits the amount of
2962 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2963 when PCRE is compiled, and changed at run time. A patch from Google adds
2964 this functionality to the C++ interface.
2965
2966 18. Changes to the handling of Unicode character properties:
2967
2968 (a) Updated the table to Unicode 4.1.0.
2969
2970 (b) Recognize characters that are not in the table as "Cn" (undefined).
2971
2972 (c) I revised the way the table is implemented to a much improved format
2973 which includes recognition of ranges. It now supports the ranges that
2974 are defined in UnicodeData.txt, and it also amalgamates other
2975 characters into ranges. This has reduced the number of entries in the
2976 table from around 16,000 to around 3,000, thus reducing its size
2977 considerably. I realized I did not need to use a tree structure after
2978 all - a binary chop search is just as efficient. Having reduced the
2979 number of entries, I extended their size from 6 bytes to 8 bytes to
2980 allow for more data.
2981
2982 (d) Added support for Unicode script names via properties such as \p{Han}.
2983
2984 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2985 matching that character.
2986
2987 20. When matching a repeated Unicode property with a minimum greater than zero,
2988 (for example \pL{2,}), PCRE could look past the end of the subject if it
2989 reached it while seeking the minimum number of characters. This could
2990 happen only if some of the characters were more than one byte long, because
2991 there is a check for at least the minimum number of bytes.
2992
2993 21. Refactored the implementation of \p and \P so as to be more general, to
2994 allow for more different types of property in future. This has changed the
2995 compiled form incompatibly. Anybody with saved compiled patterns that use
2996 \p or \P will have to recompile them.
2997
2998 22. Added "Any" and "L&" to the supported property types.
2999
3000 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3001 but give a compile time error if the value is greater than 0xff.
3002
3003 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3004 accidentally not being installed or uninstalled.
3005
3006 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3007 made were to insert the current release number. This seemed silly, because
3008 it made things harder for people building PCRE on systems that don't run
3009 "configure". I have turned pcre.h into a distributed file, no longer built
3010 by "configure", with the version identification directly included. There is
3011 no longer a pcre.h.in file.
3012
3013 However, this change necessitated a change to the pcre-config script as
3014 well. It is built from pcre-config.in, and one of the substitutions was the
3015 release number. I have updated configure.ac so that ./configure now finds
3016 the release number by grepping pcre.h.
3017
3018 26. Added the ability to run the tests under valgrind.
3019
3020
3021 Version 6.4 05-Sep-05
3022 ---------------------
3023
3024 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3025 "--" to be printed when multiple files were scanned, even when none of the
3026 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3027 consider it to be a bug, and have restored the previous behaviour.
3028
3029 2. A couple of code tidies to get rid of compiler warnings.
3030
3031 3. The pcretest program used to cheat by referring to symbols in the library
3032 whose names begin with _pcre_. These are internal symbols that are not
3033 really supposed to be visible externally, and in some environments it is
3034 possible to suppress them. The cheating is now confined to including
3035 certain files from the library's source, which is a bit cleaner.
3036
3037 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
3038 file's purpose clearer.
3039
3040 5. Reorganized pcre_ucp_findchar().
3041
3042
3043 Version 6.3 15-Aug-05
3044 ---------------------
3045
3046 1. The file libpcre.pc.in did not have general read permission in the tarball.
3047
3048 2. There were some problems when building without C++ support:
3049
3050 (a) If C++ support was not built, "make install" and "make test" still
3051 tried to test it.
3052
3053 (b) There were problems when the value of CXX was explicitly set. Some
3054 changes have been made to try to fix these, and ...
3055
3056 (c) --disable-cpp can now be used to explicitly disable C++ support.
3057
3058 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
3059 backslash in a target when C++ was disabled. This confuses some
3060 versions of "make", apparently. Using an intermediate variable solves
3061 this. (Same for CPP_LOBJ.)
3062
3063 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
3064 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
3065 necessary on certain architectures.
3066
3067 4. Added a setting of -export-symbols-regex to the link command to remove
3068 those symbols that are exported in the C sense, but actually are local
3069 within the library, and not documented. Their names all begin with
3070 "_pcre_". This is not a perfect job, because (a) we have to except some
3071 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
3072 available (and never for static libraries). I have made a note to try to
3073 find a way round (a) in the future.
3074
3075
3076 Version 6.2 01-Aug-05
3077 ---------------------
3078
3079 1. There was no test for integer overflow of quantifier values. A construction
3080 such as {1111111111111111} would give undefined results. What is worse, if
3081 a minimum quantifier for a parenthesized subpattern overflowed and became
3082 negative, the calculation of the memory size went wrong. This could have
3083 led to memory overwriting.
3084
3085 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
3086
3087 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
3088 operating environments where this matters.
3089
3090 4. Applied Giuseppe Maxia's patch to add additional features for controlling
3091 PCRE options from within the C++ wrapper.
3092
3093 5. Named capturing subpatterns were not being correctly counted when a pattern
3094 was compiled. This caused two problems: (a) If there were more than 100
3095 such subpatterns, the calculation of the memory needed for the whole
3096 compiled pattern went wrong, leading to an overflow error. (b) Numerical
3097 back references of the form \12, where the number was greater than 9, were
3098 not recognized as back references, even though there were sufficient
3099 previous subpatterns.
3100
3101 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
3102 versions of gcc, e.g. 2.95.4.
3103
3104
3105 Version 6.1 21-Jun-05
3106 ---------------------
3107
3108 1. There was one reference to the variable "posix" in pcretest.c that was not
3109 surrounded by "#if !defined NOPOSIX".
3110
3111 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
3112 the cross-check on the old pcre_info() function, for the benefit of the
3113 cut-down version of PCRE that is currently imported into Exim.
3114
3115 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
3116 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
3117 patterns that start (?i) but I don't think that matters. The use of (?i) is
3118 just an example; this all applies to the other options as well.
3119
3120 4. Since libtool seems to echo the compile commands it is issuing, the output
3121 from "make" can be reduced a bit by putting "@" in front of each libtool
3122 compile command.
3123
3124 5. Patch from the folks at Google for configure.in to be a bit more thorough
3125 in checking for a suitable C++ installation before trying to compile the
3126 C++ stuff. This should fix a reported problem when a compiler was present,
3127 but no suitable headers.
3128
3129 6. The man pages all had just "PCRE" as their title. I have changed them to
3130 be the relevant file name. I have also arranged that these names are
3131 retained in the file doc/pcre.txt, which is a concatenation in text format
3132 of all the man pages except the little individual ones for each function.
3133
3134 7. The NON-UNIX-USE file had not been updated for the different set of source
3135 files that come with release 6. I also added a few comments about the C++
3136 wrapper.
3137
3138
3139 Version 6.0 07-Jun-05
3140 ---------------------
3141
3142 1. Some minor internal re-organization to help with my DFA experiments.
3143
3144 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3145 didn't matter for the library itself when fully configured, but did matter
3146 when compiling without UCP support, or within Exim, where the ucp files are
3147 not imported.
3148
3149 3. Refactoring of the library code to split up the various functions into
3150 different source modules. The addition of the new DFA matching code (see
3151 below) to a single monolithic source would have made it really too
3152 unwieldy, quite apart from causing all the code to be include in a
3153 statically linked application, when only some functions are used. This is
3154 relevant even without the DFA addition now that patterns can be compiled in
3155 one application and matched in another.
3156
3157 The downside of splitting up is that there have to be some external
3158 functions and data tables that are used internally in different modules of
3159 the library but which are not part of the API. These have all had their
3160 names changed to start with "_pcre_" so that they are unlikely to clash
3161 with other external names.
3162
3163 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3164 a different (DFA) algorithm. Although it is slower than the original
3165 function, it does have some advantages for certain types of matching
3166 problem.
3167
3168 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3169 including restarting after a partial match.
3170
3171 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3172 defined when compiling for Windows was sent to me. I have put it into the
3173 code, though I have no means of testing or verifying it.
3174
3175 7. Added the pcre_refcount() auxiliary function.
3176
3177 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3178 match before or at the first newline in the subject string. In pcretest,
3179 the /f option on a pattern can be used to set this.
3180
3181 9. A repeated \w when used in UTF-8 mode with characters greater than 256
3182 would behave wrongly. This has been present in PCRE since release 4.0.
3183
3184 10. A number of changes to the pcregrep command:
3185
3186 (a) Refactored how -x works; insert ^(...)$ instead of setting
3187 PCRE_ANCHORED and checking the length, in preparation for adding
3188 something similar for -w.
3189
3190 (b) Added the -w (match as a word) option.
3191
3192 (c) Refactored the way lines are read and buffered so as to have more
3193 than one at a time available.
3194
3195 (d) Implemented a pcregrep test script.
3196
3197 (e) Added the -M (multiline match) option. This allows patterns to match
3198 over several lines of the subject. The buffering ensures that at least
3199 8K, or the rest of the document (whichever is the shorter) is available
3200 for matching (and similarly the previous 8K for lookbehind assertions).
3201
3202 (f) Changed the --help output so that it now says
3203
3204 -w, --word-regex(p)
3205
3206 instead of two lines, one with "regex" and the other with "regexp"
3207 because that confused at least one person since the short forms are the
3208 same. (This required a bit of code, as the output is generated
3209 automatically from a table. It wasn't just a text change.)
3210
3211 (g) -- can be used to terminate pcregrep options if the next thing isn't an
3212 option but starts with a hyphen. Could be a pattern or a path name
3213 starting with a hyphen, for instance.
3214
3215 (h) "-" can be given as a file name to represent stdin.
3216
3217 (i) When file names are being printed, "(standard input)" is used for
3218 the standard input, for compatibility with GNU grep. Previously
3219 "<stdin>" was used.
3220
3221 (j) The option --label=xxx can be used to supply a name to be used for
3222 stdin when file names are being printed. There is no short form.
3223
3224 (k) Re-factored the options decoding logic because we are going to add
3225 two more options that take data. Such options can now be given in four
3226 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3227
3228 (l) Added the -A, -B, and -C options for requesting that lines of context
3229 around matches be printed.
3230
3231 (m) Added the -L option to print the names of files that do not contain
3232 any matching lines, that is, the complement of -l.
3233
3234 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3235 continue to scan other files.
3236
3237 (o) The -s option was incorrectly implemented. For compatibility with other
3238 greps, it now suppresses the error message for a non-existent or non-
3239 accessible file (but not the return code). There is a new option called
3240 -q that suppresses the output of matching lines, which was what -s was
3241 previously doing.
3242
3243 (p) Added --include and --exclude options to specify files for inclusion
3244 and exclusion when recursing.
3245
3246 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3247 Hopefully, it now does.
3248
3249 12. Missing cast in pcre_study().
3250
3251 13. Added an "uninstall" target to the makefile.
3252
3253 14. Replaced "extern" in the function prototypes in Makefile.in with
3254 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3255 world, but is set differently for Windows.
3256
3257 15. Added a second compiling function called pcre_compile2(). The only
3258 difference is that it has an extra argument, which is a pointer to an
3259 integer error code. When there is a compile-time failure, this is set
3260 non-zero, in addition to the error test pointer being set to point to an
3261 error message. The new argument may be NULL if no error number is required
3262 (but then you may as well call pcre_compile(), which is now just a
3263 wrapper). This facility is provided because some applications need a
3264 numeric error indication, but it has also enabled me to tidy up the way
3265 compile-time errors are handled in the POSIX wrapper.
3266
3267 16. Added VPATH=.libs to the makefile; this should help when building with one
3268 prefix path and installing with another. (Or so I'm told by someone who
3269 knows more about this stuff than I do.)
3270
3271 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3272 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3273 match everything, including newlines. This is not POSIX-compatible, but
3274 somebody wanted the feature. From pcretest it can be activated by using
3275 both the P and the s flags.
3276
3277 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3278
3279 19. libpcre.pc was being incorrectly installed as executable.
3280
3281 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3282 it now also looks for '\r' so that it will work unmodified on Windows.
3283
3284 21. Added Google's contributed C++ wrapper to the distribution.
3285
3286 22. Added some untidy missing memory free() calls in pcretest, to keep
3287 Electric Fence happy when testing.
3288
3289
3290
3291 Version 5.0 13-Sep-04
3292 ---------------------
3293
3294 1. Internal change: literal characters are no longer packed up into items
3295 containing multiple characters in a single byte-string. Each character
3296 is now matched using a separate opcode. However, there may be more than one
3297 byte in the character in UTF-8 mode.
3298
3299 2. The pcre_callout_block structure has two new fields: pattern_position and
3300 next_item_length. These contain the offset in the pattern to the next match
3301 item, and its length, respectively.
3302
3303 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3304 insertion of callouts before each pattern item. Added the /C option to
3305 pcretest to make use of this.
3306
3307 4. On the advice of a Windows user, the lines
3308
3309 #if defined(_WIN32) || defined(WIN32)
3310 _setmode( _fileno( stdout ), 0x8000 );
3311 #endif /* defined(_WIN32) || defined(WIN32) */
3312
3313 have been added to the source of pcretest. This apparently does useful
3314 magic in relation to line terminators.
3315
3316 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3317 for the benefit of those environments where the "b" makes a difference.
3318
3319 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3320 to know about it. I have put a hack into configure.in that adds in code
3321 to set GCC=yes if CC=icc. This seems to end up at a point in the
3322 generated configure script that is early enough to affect the setting of
3323 compiler options, which is what is needed, but I have no means of testing
3324 whether it really works. (The user who reported this had patched the
3325 generated configure script, which of course I cannot do.)
3326
3327 LATER: After change 22 below (new libtool files), the configure script
3328 seems to know about icc (and also ecc). Therefore, I have commented out
3329 this hack in configure.in.
3330
3331 7. Added support for pkg-config (2 patches were sent in).
3332
3333 8. Negated POSIX character classes that used a combination of internal tables
3334 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3335 [[:^ascii]]. Typically, they would match almost any characters. The other
3336 POSIX classes were not broken in this way.
3337
3338 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3339 to find the match, as PCRE was deluded into thinking that the match had to
3340 start at the start point or following a newline. The same bug applied to
3341 patterns with negative forward assertions or any backward assertions
3342 preceding ".*" at the start, unless the pattern required a fixed first
3343 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3344
3345 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3346 starting at the last subject character, bytes beyond the end of the subject
3347 string were read.
3348
3349 11. Renamed the variable "class" as "classbits" to make life easier for C++
3350 users. (Previously there was a macro definition, but it apparently wasn't
3351 enough.)
3352
3353 12. Added the new field "tables" to the extra data so that tables can be passed
3354 in at exec time, or the internal tables can be re-selected. This allows
3355 a compiled regex to be saved and re-used at a later time by a different
3356 program that might have everything at different addresses.
3357
3358 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3359 -R library as well as a -L library.
3360
3361 14. The debugging options of pcretest (-d on the command line or D on a
3362 pattern) showed incorrect output for anything following an extended class
3363 that contained multibyte characters and which was followed by a quantifier.
3364
3365 15. Added optional support for general category Unicode character properties
3366 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3367 support. It adds about 90K to the size of the library. The meanings of the
3368 inbuilt class escapes such as \d and \s have NOT been changed.
3369
3370 16. Updated pcredemo.c to include calls to free() to release the memory for the
3371 compiled pattern.
3372
3373 17. The generated file chartables.c was being created in the source directory
3374 instead of in the building directory. This caused the build to fail if the
3375 source directory was different from the building directory, and was
3376 read-only.
3377
3378 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3379 file. No doubt somebody will tell me if they don't make sense... Also added
3380 Dan Mooney's comments about building on OpenVMS.
3381
3382 19. Added support for partial matching via the PCRE_PARTIAL option for
3383 pcre_exec() and the \P data escape in pcretest.
3384
3385 20. Extended pcretest with 3 new pattern features:
3386
3387 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3388 write the compiled pattern to the file whose name is "rest-of-line".
3389 This is a straight binary dump of the data, with the saved pointer to
3390 the character tables forced to be NULL. The study data, if any, is
3391 written too. After writing, pcretest reads a new pattern.
3392
3393 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3394 compiled pattern from the given file. There must not be any
3395 occurrences of "<" in the file name (pretty unlikely); if there are,
3396 pcretest will instead treat the initial "<" as a pattern delimiter.
3397 After reading in the pattern, pcretest goes on to read data lines as
3398 usual.
3399
3400 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3401 and 16-bit fields in a compiled pattern, to simulate a pattern that
3402 was compiled on a host of opposite endianness.
3403
3404 21. The pcre-exec() function can now cope with patterns that were compiled on
3405 hosts of opposite endianness, with this restriction:
3406
3407 As for any compiled expression that is saved and used later, the tables
3408 pointer field cannot be preserved; the extra_data field in the arguments
3409 to pcre_exec() should be used to pass in a tables address if a value
3410 other than the default internal tables were used at compile time.
3411
3412 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3413 now diagnosed as an error. Previously, most of the time, a negative number
3414 would have been treated as zero, but if in addition "ovector" was passed as
3415 NULL, a crash could occur.
3416
3417 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3418 new versions from the libtool 1.5 distribution (the last one is a copy of
3419 a file called libtool.m4). This seems to have fixed the need to patch
3420 "configure" to support Darwin 1.3 (which I used to do). However, I still
3421 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3422 workstation).
3423
3424 24. Changed the PCRE licence to be the more standard "BSD" licence.
3425
3426
3427 Version 4.5 01-Dec-03
3428 ---------------------
3429
3430 1. There has been some re-arrangement of the code for the match() function so
3431 that it can be compiled in a version that does not call itself recursively.
3432 Instead, it keeps those local variables that need separate instances for
3433 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3434 needs to "recurse". Keeping track of where control must go is done by means
3435 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3436 hide most of the details from the main code, and operates only if
3437 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3438 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3439 operating.
3440
3441 To make it easier for callers to provide specially tailored get/free
3442 functions for this usage, two new functions, pcre_stack_malloc, and
3443 pcre_stack_free, are used. They are always called in strict stacking order,
3444 and the size of block requested is always the same.
3445
3446 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3447 PCRE has been compiled to use the stack or the heap for recursion. The
3448 -C option of pcretest uses this to show which version is compiled.
3449
3450 A new data escape \S, is added to pcretest; it causes the amounts of store
3451 obtained and freed by both kinds of malloc/free at match time to be added
3452 to the output.
3453
3454 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3455 what's available on my current Linux desktop machine.
3456
3457 3. When matching a UTF-8 string, the test for a valid string at the start has
3458 been extended. If start_offset is not zero, PCRE now checks that it points
3459 to a byte that is the start of a UTF-8 character. If not, it returns
3460 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3461 this is necessary because there may be backward assertions in the pattern.
3462 When matching the same subject several times, it may save resources to use
3463 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3464
3465 4. The code for checking the validity of UTF-8 strings has been tightened so
3466 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3467 containing "overlong sequences".
3468
3469 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3470 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3471 should have been "&", but it just so happened that all the cases this let
3472 through by mistake were picked up later in the function.
3473
3474 6. I had used a variable called "isblank" - this is a C99 function, causing
3475 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3476
3477 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3478 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3479 so the version is shown; (c) stop "make test" echoing "./RunTest".
3480
3481 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3482
3483 9. The prototype for memmove() for systems that don't have it was using
3484 size_t, but the inclusion of the header that defines size_t was later. I've
3485 moved the #includes for the C headers earlier to avoid this.
3486
3487 10. Added some adjustments to the code to make it easier to compiler on certain
3488 special systems:
3489
3490 (a) Some "const" qualifiers were missing.
3491 (b) Added the macro EXPORT before all exported functions; by default this
3492 is defined to be empty.
3493 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3494 that it reads its output file name as an argument instead of writing
3495 to the standard output and assuming this can be redirected.
3496
3497 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3498 class containing characters with values greater than 255, PCRE compilation
3499 went into a loop.
3500
3501 12. A recursive reference to a subpattern that was within another subpattern
3502 that had a minimum quantifier of zero caused PCRE to crash. For example,
3503 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3504 recursion. If the recursively-called subpattern itself had a zero repeat,
3505 that was OK.
3506
3507 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3508 buffer into which it was copied (for escape processing) was still set at
3509 1024, so long lines caused crashes.
3510
3511 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3512 "internal error: code overflow...". This applied to any character class
3513 that was followed by a possessive quantifier.
3514
3515 15. Modified the Makefile to add libpcre.la as a prerequisite for
3516 libpcreposix.la because I was told this is needed for a parallel build to
3517 work.
3518
3519 16. If a pattern that contained .* following optional items at the start was
3520 studied, the wrong optimizing data was generated, leading to matching
3521 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3522 matching string must start with a or b or c. The correct conclusion for
3523 this pattern is that a match can start with any character.
3524
3525
3526 Version 4.4 13-Aug-03
3527 ---------------------
3528
3529 1. In UTF-8 mode, a character class containing characters with values between
3530 127 and 255 was not handled correctly if the compiled pattern was studied.
3531 In fixing this, I have also improved the studying algorithm for such
3532 classes (slightly).
3533
3534 2. Three internal functions had redundant arguments passed to them. Removal
3535 might give a very teeny performance improvement.
3536
3537 3. Documentation bug: the value of the capture_top field in a callout is *one
3538 more than* the number of the hightest numbered captured substring.
3539
3540 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3541 in incorrectly linking with a previously installed version. They now link
3542 explicitly with libpcre.la.
3543
3544 5. configure.in no longer needs to recognize Cygwin specially.
3545
3546 6. A problem in pcre.in for Windows platforms is fixed.
3547
3548 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3549 pcretest, it used to include the size of the study block as part of its
3550 output. Unfortunately, the structure contains a field that has a different
3551 size on different hardware architectures. This meant that the tests that
3552 showed this size failed. As the block is currently always of a fixed size,
3553 this information isn't actually particularly useful in pcretest output, so
3554 I have just removed it.
3555
3556 8. Three pre-processor statements accidentally did not start in column 1.
3557 Sadly, there are *still* compilers around that complain, even though
3558 standard C has not required this for well over a decade. Sigh.
3559
3560 9. In pcretest, the code for checking callouts passed small integers in the
3561 callout_data field, which is a void * field. However, some picky compilers
3562 complained about the casts involved for this on 64-bit systems. Now
3563 pcretest passes the address of the small integer instead, which should get
3564 rid of the warnings.
3565
3566 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3567 both compile and run time, and gives an error if an invalid UTF-8 sequence
3568 is found. There is a option for disabling this check in cases where the
3569 string is known to be correct and/or the maximum performance is wanted.
3570
3571 11. In response to a bug report, I changed one line in Makefile.in from
3572
3573 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3574 to
3575 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3576
3577 to look similar to other lines, but I have no way of telling whether this
3578 is the right thing to do, as I do not use Windows. No doubt I'll get told
3579 if it's wrong...
3580
3581
3582 Version 4.3 21-May-03
3583 ---------------------
3584
3585 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3586 Makefile.
3587
3588 2. Some refactoring to improve the quality of the code:
3589
3590 (i) The utf8_table... variables are now declared "const".
3591
3592 (ii) The code for \cx, which used the "case flipping" table to upper case
3593 lower case letters, now just substracts 32. This is ASCII-specific,
3594 but the whole concept of \cx is ASCII-specific, so it seems
3595 reasonable.
3596
3597 (iii) PCRE was using its character types table to recognize decimal and
3598 hexadecimal digits in the pattern. This is silly, because it handles
3599 only 0-9, a-f, and A-F, but the character types table is locale-
3600 specific, which means strange things might happen. A private
3601 table is now used for this - though it costs 256 bytes, a table is
3602 much faster than multiple explicit tests. Of course, the standard
3603 character types table is still used for matching digits in subject
3604 strings against \d.
3605
3606 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3607 ending in _t are). So I've renamed it as ESC_tee.
3608
3609 3. The first argument for regexec() in the POSIX wrapper should have been
3610 defined as "const".
3611
3612 4. Changed pcretest to use malloc() for its buffers so that they can be
3613 Electric Fenced for debugging.
3614
3615 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3616 to read one or more bytes before the start of the subject string. Often this
3617 had no effect on PCRE's behaviour, but in some circumstances it could
3618 provoke a segmentation fault.
3619
3620 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3621 to try to read one or more bytes before the start of the subject string.
3622
3623 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3624 UTF-8 support could misbehave in various ways if the subject string
3625 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3626 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3627 back over UTF-8 characters.)
3628
3629
3630 Version 4.2 14-Apr-03
3631 ---------------------
3632
3633 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3634
3635 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3636 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3637 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3638 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3639 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3640 and BUILD_EXEEXT
3641 Note: automatic setting of the BUILD variables is not yet working
3642 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3643 compile-time but not at link-time
3644 [LINK]: use for linking executables only
3645 make different versions for Windows and non-Windows
3646 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3647 libraries
3648 [LINK_FOR_BUILD]: new variable
3649 [OBJEXT]: use throughout
3650 [EXEEXT]: use throughout
3651 <winshared>: new target
3652 <wininstall>: new target
3653 <dftables.o>: use native compiler
3654 <dftables>: use native linker
3655 <install>: handle Windows platform correctly
3656 <clean>: ditto
3657 <check>: ditto
3658 copy DLL to top builddir before testing
3659
3660 As part of these changes, -no-undefined was removed again. This was reported
3661 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3662 in any case.
3663
3664 3. Some tidies to get rid of compiler warnings:
3665
3666 . In the match_data structure, match_limit was an unsigned long int, whereas
3667 match_call_count was an int. I've made them both unsigned long ints.
3668
3669 . In pcretest the fact that a const uschar * doesn't automatically cast to
3670 a void * provoked a warning.
3671
3672 . Turning on some more compiler warnings threw up some "shadow" variables
3673 and a few more missing casts.
3674
3675 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3676 option, a class that contained a single character with a value between 128
3677 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3678
3679 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3680 option, a class that contained several characters, but with at least one
3681 whose value was between 128 and 255 caused PCRE to crash.
3682
3683
3684 Version 4.1 12-Mar-03
3685 ---------------------
3686
3687 1. Compiling with gcc -pedantic found a couple of places where casts were
3688 needed, and a string in dftables.c that was longer than standard compilers are
3689 required to support.
3690
3691 2. Compiling with Sun's compiler found a few more places where the code could
3692 be tidied up in order to avoid warnings.
3693
3694 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3695 first of these names is deprecated in the latest Autoconf in favour of the name
3696 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3697 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3698 analogy I have changed it to CFLAGS_FOR_BUILD.
3699
3700 4. Added -no-undefined to the linking command in the Makefile, because this is
3701 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3702 linking step for the pcreposix library.
3703
3704 5. PCRE was failing to diagnose the case of two named groups with the same
3705 name.
3706
3707 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3708 literal character that is needed in the subject for a match, and scans along to
3709 ensure that it is present before embarking on the full matching process. This
3710 saves time in cases of nested unlimited repeats that are never going to match.
3711 Problem: the scan can take a lot of time if the subject is very long (e.g.
3712 megabytes), thus penalizing straightforward matches. It is now done only if the
3713 amount of subject to be scanned is less than 1000 bytes.
3714
3715 7. A lesser problem with the same optimization is that it was recording the
3716 first character of an anchored pattern as "needed", thus provoking a search
3717 right along the subject, even when the first match of the pattern was going to
3718 fail. The "needed" character is now not set for anchored patterns, unless it
3719 follows something in the pattern that is of non-fixed length. Thus, it still
3720 fulfils its original purpose of finding quick non-matches in cases of nested
3721 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3722
3723
3724 Version 4.0 17-Feb-03
3725 ---------------------
3726
3727 1. If a comment in an extended regex that started immediately after a meta-item
3728 extended to the end of string, PCRE compiled incorrect data. This could lead to
3729 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3730
3731 2. Moved to autoconf 2.53 and libtool 1.4.2.
3732
3733 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3734 the special perltest8 script is no longer needed - all the tests can be run
3735 from a single perltest script.
3736
3737 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3738 by \s. It has now been removed in PCRE. This means it isn't recognized as
3739 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3740 class [:space:] *does* include VT, thereby creating a mess.
3741
3742 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3743 space and tab.
3744
3745 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3746 its new features into the main test script, reducing the number of scripts.
3747
3748 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3749 were backward compatible, and made the (?i) apply to the whole pattern, as if
3750 /i were given. Now it behaves more logically, and applies the option setting
3751 only to what follows. PCRE has been changed to follow suit. However, if it
3752 finds options settings right at the start of the pattern, it extracts them into
3753 the global options, as before. Thus, they show up in the info data.
3754
3755 8. Added support for the \Q...\E escape sequence. Characters in between are
3756 treated as literals. This is slightly different from Perl in that $ and @ are
3757 also handled as literals inside the quotes. In Perl, they will cause variable
3758 interpolation. Note the following examples:
3759
3760 Pattern PCRE matches Perl matches
3761
3762 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3763 \Qabc\$xyz\E abc\$xyz abc\$xyz
3764 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3765
3766 For compatibility with Perl, \Q...\E sequences are recognized inside character
3767 classes as well as outside them.
3768
3769 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3770 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3771 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3772 signed/unsigned warnings.
3773
3774 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3775 option for pcretest, so I've replaced it by a simple function that does just
3776 that job.
3777
3778 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3779 "pcregrep -".
3780
3781 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3782 Java package. This provides some syntactic sugar for simple cases of what my
3783 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3784 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3785 item, you can use this simplified notation. Note that only makes sense with
3786 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3787 greediness, whatever the setting of the PCRE_UNGREEDY option.
3788
3789 13. A change of greediness default within a pattern was not taking effect at
3790 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3791 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3792 was abstracted outside.
3793
3794 14. PCRE now supports the \G assertion. It is true when the current matching
3795 position is at the start point of the match. This differs from \A when the
3796 starting offset is non-zero. Used with the /g option of pcretest (or similar
3797 code), it works in the same way as it does for Perl's /g option. If all
3798 alternatives of a regex begin with \G, the expression is anchored to the start
3799 match position, and the "anchored" flag is set in the compiled expression.
3800
3801 15. Some bugs concerning the handling of certain option changes within patterns
3802 have been fixed. These applied to options other than (?ims). For example,
3803 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3804 been the other way round. Some of this was related to change 7 above.
3805
3806 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3807 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3808 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3809 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3810
3811 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3812 mode. Unlike ".", it always matches newline, whatever the setting of
3813 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3814 assertions. Perl allows it, but it doesn't (in general) work because it can't
3815 calculate the length of the lookbehind. At least, that's the case for Perl
3816 5.8.0 - I've been told they are going to document that it doesn't work in
3817 future.
3818
3819 18. Added an error diagnosis for escapes that PCRE does not support: these are
3820 \L, \l, \N, \P, \p, \U, \u, and \X.
3821
3822 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3823 reading past the end of the pattern in cases such as /[abcd/.
3824
3825 20. PCRE was getting more memory than necessary for patterns with classes that
3826 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3827
3828 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3829 compiling PCRE for use with Virtual Pascal.
3830
3831 22. Small fix to the Makefile to make it work properly if the build is done
3832 outside the source tree.
3833
3834 23. Added a new extension: a condition to go with recursion. If a conditional
3835 subpattern starts with (?(R) the "true" branch is used if recursion has
3836 happened, whereas the "false" branch is used only at the top level.
3837
3838 24. When there was a very long string of literal characters (over 255 bytes
3839 without UTF support, over 250 bytes with UTF support), the computation of how
3840 much memory was required could be incorrect, leading to segfaults or other
3841 strange effects.
3842
3843 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3844 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3845 there was a subsequent back reference to those brackets. This meant that, for
3846 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3847 possible to check for precisely this case. All we can do is abandon the
3848 optimization if .* occurs inside capturing brackets when there are any back
3849 references whatsoever. (See below for a better fix that came later.)
3850
3851 26. The handling of the optimization for finding the first character of a
3852 non-anchored pattern, and for finding a character that is required later in the
3853 match were failing in some cases. This didn't break the matching; it just
3854 failed to optimize when it could. The way this is done has been re-implemented.
3855
3856 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3857
3858 28. Added a new feature that provides some of the functionality that Perl
3859 provides with (?{...}). The facility is termed a "callout". The way it is done
3860 in PCRE is for the caller to provide an optional function, by setting
3861 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3862 global variable. By default it is unset, which disables all calling out. To get
3863 the function called, the regex must include (?C) at appropriate points. This
3864 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3865 This provides a means of identifying different callout points. When PCRE
3866 reaches such a point in the regex, if pcre_callout has been set, the external
3867 function is called. It is provided with data in a structure called
3868 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3869 matching continues; if it returns a non-zero value, the match at the current
3870 point fails. However, backtracking will occur if possible. [This was changed
3871 later and other features added - see item 49 below.]
3872
3873 29. pcretest is upgraded to test the callout functionality. It provides a
3874 callout function that displays information. By default, it shows the start of
3875 the match and the current position in the text. There are some new data escapes
3876 to vary what happens:
3877
3878 \C+ in addition, show current contents of captured substrings
3879 \C- do not supply a callout function
3880 \C!n return 1 when callout number n is reached
3881 \C!n!m return 1 when callout number n is reached for the mth time
3882
3883 30. If pcregrep was called with the -l option and just a single file name, it
3884 output "<stdin>" if a match was found, instead of the file name.
3885
3886 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3887 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3888 pcre_exec(). This saves a malloc/free per call. The default value of
3889 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3890 when configuring.
3891
3892 32. The default maximum size of a compiled pattern is 64K. There have been a
3893 few cases of people hitting this limit. The code now uses macros to handle the
3894 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3895 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3896 configuring. Tests 2 and 5 work only with 2-byte links because they output
3897 debugging information about compiled patterns.
3898
3899 33. Internal code re-arrangements:
3900
3901 (a) Moved the debugging function for printing out a compiled regex into
3902 its own source file (printint.c) and used #include to pull it into
3903 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3904 separate copies.
3905
3906 (b) Defined the list of op-code names for debugging as a macro in
3907 internal.h so that it is next to the definition of the opcodes.
3908
3909 (c) Defined a table of op-code lengths for simpler skipping along compiled
3910 code. This is again a macro in internal.h so that it is next to the
3911 definition of the opcodes.
3912
3913 34. Added support for recursive calls to individual subpatterns, along the
3914 lines of Robin Houston's patch (but implemented somewhat differently).
3915
3916 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3917 allow it to read and process whole directories in Win32. This code was
3918 contributed by Lionel Fourquaux; it has not been tested by me.
3919
3920 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3921 used to name a group. Names consist of alphanumerics and underscores, and must
3922 be unique. Back references use the syntax (?P=name) and recursive calls use
3923 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3924 numbers. The function pcre_fullinfo() can be used after compilation to extract
3925 a name/number map. There are three relevant calls:
3926
3927 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3928 PCRE_INFO_NAMECOUNT yields the number of entries
3929 PCRE_INFO_NAMETABLE yields a pointer to the map.
3930
3931 The map is a vector of fixed-size entries. The size of each entry depends on
3932 the length of the longest name used. The first two bytes of each entry are the
3933 group number, most significant byte first. There follows the corresponding
3934 name, zero terminated. The names are in alphabetical order.
3935
3936 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3937 case instead of 255. Making it the same both with and without UTF-8 support
3938 means that the same test output works with both.
3939
3940 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3941 calling malloc() with a zero argument.
3942
3943 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3944 optimization. I've improved things by keeping a bitmap of backreferences with
3945 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3946 fact referenced, the optimization can be applied. It is unlikely that a
3947 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3948 the match to follow \n) will appear inside brackets with a number greater than
3949 31, but if it does, any back reference > 31 suppresses the optimization.
3950
3951 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3952 of disabling numbered capturing parentheses. Any opening parenthesis that is
3953 not followed by ? behaves as if it were followed by ?: but named parentheses
3954 can still be used for capturing (and they will acquire numbers in the usual
3955 way).
3956
3957 41. Redesigned the return codes from the match() function into yes/no/error so
3958 that errors can be passed back from deep inside the nested calls. A malloc
3959 failure while inside a recursive subpattern call now causes the
3960 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3961
3962 42. It is now possible to set a limit on the number of times the match()
3963 function is called in a call to pcre_exec(). This facility makes it possible to
3964 limit the amount of recursion and backtracking, though not in a directly
3965 obvious way, because the match() function is used in a number of different
3966 circumstances. The count starts from zero for each position in the subject
3967 string (for non-anchored patterns). The default limit is, for compatibility, a
3968 large number, namely 10 000 000. You can change this in two ways:
3969
3970 (a) When configuring PCRE before making, you can use --with-match-limit=n
3971 to set a default value for the compiled library.
3972
3973 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3974 a different value is set. See 45 below.
3975
3976 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3977
3978 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3979 of things that can be changed at compile time. The first argument specifies
3980 what is wanted and the second points to where the information is to be placed.
3981 The current list of available information is:
3982
3983 PCRE_CONFIG_UTF8
3984
3985 The output is an integer that is set to one if UTF-8 support is available;
3986 otherwise it is set to zero.
3987
3988 PCRE_CONFIG_NEWLINE
3989
3990 The output is an integer that it set to the value of the code that is used for
3991 newline. It is either LF (10) or CR (13).
3992
3993 PCRE_CONFIG_LINK_SIZE
3994
3995 The output is an integer that contains the number of bytes used for internal
3996 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3997
3998 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3999
4000 The output is an integer that contains the threshold above which the POSIX
4001 interface uses malloc() for output vectors. See item 31 above.
4002
4003 PCRE_CONFIG_MATCH_LIMIT
4004
4005 The output is an unsigned integer that contains the default limit of the number
4006 of match() calls in a pcre_exec() execution. See 42 above.
4007
4008 44. pcretest has been upgraded by the addition of the -C option. This causes it
4009 to extract all the available output from the new pcre_config() function, and to
4010 output it. The program then exits immediately.
4011
4012 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4013 order to support additional features. One way would have been to define
4014 pcre_exec2() (for example) with extra arguments, but this would not have been
4015 extensible, and would also have required all calls to the original function to
4016 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4017 is used for passing in "extra" data from pcre_study().
4018
4019 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4020 contains the following fields:
4021
4022 flags a bitmap indicating which of the following fields are set
4023 study_data opaque data from pcre_study()
4024 match_limit a way of specifying a limit on match() calls for a specific
4025 call to pcre_exec()
4026 callout_data data for callouts (see 49 below)
4027
4028 The flag bits are also defined in pcre.h, and are
4029
4030 PCRE_EXTRA_STUDY_DATA
4031 PCRE_EXTRA_MATCH_LIMIT
4032 PCRE_EXTRA_CALLOUT_DATA
4033
4034 The pcre_study() function now returns one of these new pcre_extra blocks, with
4035 the actual study data pointed to by the study_data field, and the
4036 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
4037 before. That is, this change is entirely upwards-compatible and requires no
4038 change to existing code.
4039
4040 If you want to pass in additional data to pcre_exec(), you can either place it
4041 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
4042 block.
4043
4044 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
4045 data string contains the escape sequence \M, pcretest calls pcre_exec() several
4046 times with different match limits, until it finds the minimum value needed for
4047 pcre_exec() to complete. The value is then output. This can be instructive; for
4048 most simple matches the number is quite small, but for pathological cases it
4049 gets very large very quickly.
4050
4051 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
4052 returns the size of the data block pointed to by the study_data field in a
4053 pcre_extra block, that is, the value that was passed as the argument to
4054 pcre_malloc() when PCRE was getting memory in which to place the information
4055 created by pcre_study(). The fourth argument should point to a size_t variable.
4056 pcretest has been extended so that this information is shown after a successful
4057 pcre_study() call when information about the compiled regex is being displayed.
4058
4059 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
4060 because what follows is always an absolute path. (Later: it turns out that this
4061 is more than cosmetic for MinGW, because it doesn't like empty path
4062 components.)
4063
4064 49. Some changes have been made to the callout feature (see 28 above):
4065
4066 (i) A callout function now has three choices for what it returns:
4067
4068 0 => success, carry on matching
4069 > 0 => failure at this point, but backtrack if possible
4070 < 0 => serious error, return this value from pcre_exec()
4071
4072 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
4073 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
4074 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
4075 use by callout functions. It will never be used by PCRE itself.
4076
4077 (ii) The pcre_extra structure (see 45 above) has a void * field called
4078 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
4079 pcre_callout_block structure has a field of the same name. The contents of
4080 the field passed in the pcre_extra structure are passed to the callout
4081 function in the corresponding field in the callout block. This makes it
4082 easier to use the same callout-containing regex from multiple threads. For
4083 testing, the pcretest program has a new data escape
4084
4085 \C*n pass the number n (may be negative) as callout_data
4086
4087 If the callout function in pcretest receives a non-zero value as
4088 callout_data, it returns that value.
4089
4090 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
4091 there were some redundant $(CFLAGS) in commands that are now specified as
4092 $(LINK), which already includes $(CFLAGS).
4093
4094 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
4095 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
4096 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
4097 one-byte characters throughout. Note that case-insensitive matching applies
4098 only to characters whose values are less than 256. PCRE doesn't support the
4099 notion of cases for higher-valued characters.
4100
4101 (i) A character class whose characters are all within 0-255 is handled as
4102 a bit map, and the map is inverted for negative classes. Previously, a
4103 character > 255 always failed to match such a class; however it should
4104 match if the class was a negative one (e.g. [^ab]). This has been fixed.
4105
4106 (ii) A negated character class with a single character < 255 is coded as
4107 "not this character" (OP_NOT). This wasn't working properly when the test
4108 character was multibyte, either singly or repeated.
4109
4110 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
4111 mode, for example: \x{100}{2,3}.
4112
4113 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
4114 singly or repeated) now correctly test multibyte characters. However,
4115 PCRE doesn't recognize any characters with values greater than 255 as
4116 digits, spaces, or word characters. Such characters always match \D, \S,
4117 and \W, and never match \d, \s, or \w.
4118
4119 (v) Classes may now contain characters and character ranges with values
4120 greater than 255. For example: [ab\x{100}-\x{400}].
4121
4122 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
4123 PCRE in UTF-8 mode.
4124
4125 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
4126 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
4127 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
4128 value.)
4129
4130 53. The single man page has become too large. I have therefore split it up into
4131 a number of separate man pages. These also give rise to individual HTML pages;
4132 these are now put in a separate directory, and there is an index.html page that
4133 lists them all. Some hyperlinking between the pages has been installed.
4134
4135 54. Added convenience functions for handling named capturing parentheses.
4136
4137 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
4138 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
4139 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
4140 are faulted.
4141
4142 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
4143 calling configure. These values are used when compiling the dftables.c program
4144 which is run to generate the source of the default character tables. They
4145 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
4146 you will need to set these values.
4147
4148 57. Updated the building process for Windows DLL, as provided by Fred Cox.
4149
4150
4151 Version 3.9 02-Jan-02
4152 ---------------------
4153
4154 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
4155
4156 2. If --disable-static was given, the building process failed when trying to
4157 build pcretest and pcregrep. (For some reason it was using libtool to compile
4158 them, which is not right, as they aren't part of the library.)
4159
4160
4161 Version 3.8 18-Dec-01
4162 ---------------------
4163
4164 1. The experimental UTF-8 code was completely screwed up. It was packing the
4165 bytes in the wrong order. How dumb can you get?
4166
4167
4168 Version 3.7 29-Oct-01
4169 ---------------------
4170
4171 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
4172 This caused pcretest, when used on the test data, to segfault. Unfortunately,
4173 this didn't happen under Solaris 8, where I normally test things.
4174
4175 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
4176 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
4177 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
4178 this fix an hour or so after the initial 3.7 release.)
4179
4180
4181 Version 3.6 23-Oct-01
4182 ---------------------
4183
4184 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
4185 offsets passed as NULL with zero offset count.
4186
4187 2. The config.guess and config.sub files had not been updated when I moved to
4188 the latest autoconf.
4189
4190
4191 Version 3.5 15-Aug-01
4192 ---------------------
4193
4194 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
4195 had been forgotten.
4196
4197 2. By using declared but undefined structures, we can avoid using "void"
4198 definitions in pcre.h while keeping the internal definitions of the structures
4199 private.
4200
4201 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
4202 user point of view, this means that both static and shared libraries are built
4203 by default, but this can be individually controlled. More of the work of
4204 handling this static/shared cases is now inside libtool instead of PCRE's make
4205 file.
4206
4207 4. The pcretest utility is now installed along with pcregrep because it is
4208 useful for users (to test regexs) and by doing this, it automatically gets
4209 relinked by libtool. The documentation has been turned into a man page, so
4210 there are now .1, .txt, and .html versions in /doc.
4211
4212 5. Upgrades to pcregrep:
4213 (i) Added long-form option names like gnu grep.
4214 (ii) Added --help to list all options with an explanatory phrase.
4215 (iii) Added -r, --recursive to recurse into sub-directories.
4216 (iv) Added -f, --file to read patterns from a file.
4217
4218 6. pcre_exec() was referring to its "code" argument before testing that
4219 argument for NULL (and giving an error if it was NULL).
4220
4221 7. Upgraded Makefile.in to allow for compiling in a different directory from
4222 the source directory.
4223
4224 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
4225 options bits, the pointer it was passed was to an int instead of to an unsigned
4226 long int. This mattered only on 64-bit systems.
4227
4228 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
4229 generated) instead of pcre.in, which it its source. Also made the same change
4230 in several of the .c files.
4231
4232 10. A new release of gcc defines printf() as a macro, which broke pcretest
4233 because it had an ifdef in the middle of a string argument for printf(). Fixed
4234 by using separate calls to printf().
4235
4236 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4237 script, to force use of CR or LF instead of \n in the source. On non-Unix
4238 systems, the value can be set in config.h.
4239
4240 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4241 absolute limit. Changed the text of the error message to make this clear, and
4242 likewise updated the man page.
4243
4244 13. The limit of 99 on the number of capturing subpatterns has been removed.
4245 The new limit is 65535, which I hope will not be a "real" limit.
4246
4247
4248 Version 3.4 22-Aug-00
4249 ---------------------
4250
4251 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4252
4253 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4254
4255
4256 Version 3.3 01-Aug-00
4257 ---------------------
4258
4259 1. If an octal character was given, but the value was greater than \377, it
4260 was not getting masked to the least significant bits, as documented. This could
4261 lead to crashes in some systems.
4262
4263 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4264 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4265
4266 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4267 These just pass their arguments on to (pcre_free)(), but they are provided
4268 because some uses of PCRE bind it to non-C systems that can call its functions,
4269 but cannot call free() or pcre_free() directly.
4270
4271 4. Add "make test" as a synonym for "make check". Corrected some comments in
4272 the Makefile.
4273
4274 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4275 Makefile.
4276
4277 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4278 command called pgrep for grepping around the active processes.
4279
4280 7. Added the beginnings of support for UTF-8 character strings.
4281
4282 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4283 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4284 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4285 out for the ar command.)
4286
4287
4288 Version 3.2 12-May-00
4289 ---------------------
4290
4291 This is purely a bug fixing release.
4292
4293 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4294 of ZA. This was just one example of several cases that could provoke this bug,
4295 which was introduced by change 9 of version 2.00. The code for breaking
4296 infinite loops after an iteration that matches an empty string was't working
4297 correctly.
4298
4299 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4300 when matched against abbab (for example). After matching an empty string, it
4301 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4302 caused it to match further down the string than it should.
4303
4304 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4305 was there because it doesn't seem to be needed, and it causes trouble on some
4306 systems, as it is not a Standard C header. It has been removed.
4307
4308 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4309 were reported on the Macintosh. The changes were from
4310
4311 while ((c = *(++ptr)) != 0 && c != '\n');
4312 to
4313 while ((c = *(++ptr)) != 0 && c != '\n') ;
4314
4315 Totally extraordinary, but if that's what it takes...
4316
4317 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4318 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4319 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4320 assumes the way PCRE uses memmove() (always moving upwards).
4321
4322 6. PCRE is being used in one environment where strchr() is not available. There
4323 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4324 faster code anyway.
4325
4326
4327 Version 3.1 09-Feb-00
4328 ---------------------
4329
4330 The only change in this release is the fixing of some bugs in Makefile.in for
4331 the "install" target:
4332
4333 (1) It was failing to install pcreposix.h.
4334
4335 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4336
4337
4338 Version 3.0 01-Feb-00
4339 ---------------------
4340
4341 1. Add support for the /+ modifier to perltest (to output $` like it does in
4342 pcretest).
4343
4344 2. Add support for the /g modifier to perltest.
4345
4346 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4347 matches null strings.
4348
4349 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4350 pattern. Perl treats empty patterns specially - it reuses the most recent
4351 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4352 effect.
4353
4354 5. The POSIX interface was broken in that it was just handing over the POSIX
4355 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4356 required a bigger vector, with some working space on the end. This means that
4357 the POSIX wrapper now has to get and free some memory, and copy the results.
4358
4359 6. Added some simple autoconf support, placing the test data and the
4360 documentation in separate directories, re-organizing some of the
4361 information files, and making it build pcre-config (a GNU standard). Also added
4362 libtool support for building PCRE as a shared library, which is now the
4363 default.
4364
4365 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4366 09 are not valid octal constants. Single digits will be used for minor values
4367 less than 10.
4368
4369 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4370 existing programs that set these in the POSIX interface can use PCRE without
4371 modification.
4372
4373 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4374 return all that pcre_info() returns, plus additional data. The pcre_info()
4375 function is retained for compatibility, but is considered to be obsolete.
4376
4377 10. Added experimental recursion feature (?R) to handle one common case that
4378 Perl 5.6 will be able to do with (?p{...}).
4379
4380 11. Added support for POSIX character classes like [:alpha:], which Perl is
4381 adopting.
4382
4383
4384 Version 2.08 31-Aug-99
4385 ----------------------
4386
4387 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4388 trying to match at the startoffset position, but instead was moving forward to
4389 the next newline as if a previous match had failed.
4390
4391 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4392 and could get into a loop if a null string was matched other than at the start
4393 of the subject.
4394
4395 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4396 be distinguished at compile time, and for completeness also added PCRE_DATE.
4397
4398 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4399 in GnuWin32 environments.
4400
4401
4402 Version 2.07 29-Jul-99
4403 ----------------------
4404
4405 1. The documentation is now supplied in plain text form and HTML as well as in
4406 the form of man page sources.
4407
4408 2. C++ compilers don't like assigning (void *) values to other pointer types.
4409 In particular this affects malloc(). Although there is no problem in Standard
4410 C, I've put in casts to keep C++ compilers happy.
4411
4412 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4413 should be (const char *).
4414
4415 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4416 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4417 However, I haven't made this a standard facility. The documentation doesn't
4418 mention it, and the Makefile doesn't support it.
4419
4420 5. The Makefile now contains an "install" target, with editable destinations at
4421 the top of the file. The pcretest program is not installed.
4422
4423 6. pgrep -V now gives the PCRE version number and date.
4424
4425 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4426 causing the entire string to be ignored, instead of just the last character.
4427
4428 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4429 non-matching string, it can take a very, very long time, even for strings of
4430 quite modest length, because of the nested recursion. PCRE now does better in
4431 some of these cases. It does this by remembering the last required literal
4432 character in the pattern, and pre-searching the subject to ensure it is present
4433 before running the real match. In other words, it applies a heuristic to detect
4434 some types of certain failure quickly, and in the above example, if presented
4435 with a string that has no trailing " it gives "no match" very quickly.
4436
4437 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4438 other alternatives are tried instead.
4439
4440
4441 Version 2.06 09-Jun-99
4442 ----------------------
4443
4444 1. Change pcretest's output for amount of store used to show just the code
4445 space, because the remainder (the data block) varies in size between 32-bit and
4446 64-bit systems.
4447
4448 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4449 start matching at. This allows lookbehinds to work when searching for multiple
4450 occurrences in a string.
4451
4452 3. Added additional options to pcretest for testing multiple occurrences:
4453
4454 /+ outputs the rest of the string that follows a match
4455 /g loops for multiple occurrences, using the new startoffset argument
4456 /G loops for multiple occurrences by passing an incremented pointer
4457
4458 4. PCRE wasn't doing the "first character" optimization for patterns starting
4459 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4460 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4461 the letter 'x'. On long subject strings, this gives a significant speed-up.
4462
4463
4464 Version 2.05 21-Apr-99
4465 ----------------------
4466
4467 1. Changed the type of magic_number from int to long int so that it works
4468 properly on 16-bit systems.
4469
4470 2. Fixed a bug which caused patterns starting with .* not to work correctly
4471 when the subject string contained newline characters. PCRE was assuming
4472 anchoring for such patterns in all cases, which is not correct because .* will
4473 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4474 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4475 must be retried after every newline in the subject.
4476
4477
4478 Version 2.04 18-Feb-99
4479 ----------------------
4480
4481 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4482 computation of the store needed to hold the pattern was incorrect (too large).
4483 If such patterns were nested a few deep, this could multiply and become a real
4484 problem.
4485
4486 2. Added /M option to pcretest to show the memory requirement of a specific
4487 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4488
4489 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4490 compiled in such a way that the backtracking after subsequent failure was
4491 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4492 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4493
4494
4495 Version 2.03 02-Feb-99
4496 ----------------------
4497
4498 1. Fixed typo and small mistake in man page.
4499
4500 2. Added 4th condition (GPL supersedes if conflict) and created separate
4501 LICENCE file containing the conditions.
4502
4503 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4504 Perl, that is the internal \ allows the delimiter to be included in the
4505 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4506 the final delimiter, add \ to the end of the pattern (to test the error).
4507
4508 4. Added the convenience functions for extracting substrings after a successful
4509 match. Updated pcretest to make it able to test these functions.
4510
4511
4512 Version 2.02 14-Jan-99
4513 ----------------------
4514
4515 1. Initialized the working variables associated with each extraction so that
4516 their saving and restoring doesn't refer to uninitialized store.
4517
4518 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4519 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4520 fix the problem.
4521
4522 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4523 calls, and wasn't printing the correct value for compiling calls. Increased the
4524 default value of LOOPREPEAT, and the number of significant figures in the
4525 times.
4526
4527 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4528
4529 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4530 a building problem on Windows NT with a FAT file system.
4531
4532
4533 Version 2.01 21-Oct-98
4534 ----------------------
4535
4536 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4537 to character tables built by pcre_maketables() in the current locale. If NULL
4538 is passed, the default tables are used.
4539
4540
4541 Version 2.00 24-Sep-98
4542 ----------------------
4543
4544 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4545 it any more.
4546
4547 2. Allow quantification of (?>) groups, and make it work correctly.
4548
4549 3. The first character computation wasn't working for (?>) groups.
4550
4551 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4552 end of the subject) and add 5.005's \z, which really does match only at the
4553 very end of the subject.
4554
4555 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4556
4557 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4558 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4559 localized options. All options to pcre_study() were also removed.
4560
4561 7. Add other new features from 5.005:
4562
4563 $(?<= positive lookbehind
4564 $(?<! negative lookbehind
4565 (?imsx-imsx) added the unsetting capability
4566 such a setting is global if at outer level; local otherwise
4567 (?imsx-imsx:) non-capturing groups with option setting
4568 (?(cond)re|re) conditional pattern matching
4569
4570 A backreference to itself in a repeated group matches the previous
4571 captured string.
4572
4573 8. General tidying up of studying (both automatic and via "study")
4574 consequential on the addition of new assertions.
4575
4576 9. As in 5.005, unlimited repeated groups that could match an empty substring
4577 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4578 runtime if any iteration does actually match an empty substring.
4579
4580 10. Include the RunTest script in the distribution.
4581
4582 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4583 discrepancies, some of which were old and were also with respect to 5.004. They
4584 have now been fixed.
4585
4586
4587 Version 1.09 28-Apr-98
4588 ----------------------
4589
4590 1. A negated single character class followed by a quantifier with a minimum
4591 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4592 program crashes, or just wrong answers. This did not apply to negated classes
4593 containing more than one character, or to minima other than one.
4594
4595
4596 Version 1.08 27-Mar-98
4597 ----------------------
4598
4599 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4600
4601 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4602 latter must appear before anything that relies on it in the pattern.
4603
4604
4605 Version 1.07 16-Feb-98
4606 ----------------------
4607
4608 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4609 repeat of a potentially empty string).
4610
4611
4612 Version 1.06 23-Jan-98
4613 ----------------------
4614
4615 1. Added Markus Oberhumer's little patches for C++.
4616
4617 2. Literal strings longer than 255 characters were broken.
4618
4619
4620 Version 1.05 23-Dec-97
4621 ----------------------
4622
4623 1. Negated character classes containing more than one character were failing if
4624 PCRE_CASELESS was set at run time.
4625
4626
4627 Version 1.04 19-Dec-97
4628 ----------------------
4629
4630 1. Corrected the man page, where some "const" qualifiers had been omitted.
4631
4632 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4633 input syntax.
4634
4635 3. Fixed memory leak which occurred when a regex with back references was
4636 matched with an offsets vector that wasn't big enough. The temporary memory
4637 that is used in this case wasn't being freed if the match failed.
4638
4639 4. Tidied pcretest to ensure it frees memory that it gets.
4640
4641 5. Temporary memory was being obtained in the case where the passed offsets
4642 vector was exactly big enough.
4643
4644 6. Corrected definition of offsetof() from change 5 below.
4645
4646 7. I had screwed up change 6 below and broken the rules for the use of
4647 setjmp(). Now fixed.
4648
4649
4650 Version 1.03 18-Dec-97
4651 ----------------------
4652
4653 1. A erroneous regex with a missing opening parenthesis was correctly
4654 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4655 on some systems.
4656
4657 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4658 it was reported that one broken compiler failed on the former because "code" is
4659 also an independent variable.
4660
4661 3. The erroneous regex a[]b caused an array overrun reference.
4662
4663 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4664 fail on data ending with that character. (It was going on too far, and checking
4665 the next character, typically a binary zero.) This was specific to the
4666 optimized code for single-character negative classes.
4667
4668 5. Added a contributed patch from the TIN world which does the following:
4669
4670 + Add an undef for memmove, in case the the system defines a macro for it.
4671
4672 + Add a definition of offsetof(), in case there isn't one. (I don't know
4673 the reason behind this - offsetof() is part of the ANSI standard - but
4674 it does no harm).
4675
4676 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4677 most of the places where whitespace preceded '#'. I have given up and
4678 allowed the remaining 2 cases to be at the margin.
4679
4680 + Rename some variables in pcre to eliminate shadowing. This seems very
4681 pedantic, but does no harm, of course.
4682
4683 6. Moved the call to setjmp() into its own function, to get rid of warnings
4684 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4685
4686 7. Constructs such as \d{8,} were compiling into the equivalent of
4687 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4688 outcome, but in this particular case used more store than had been allocated,
4689 which caused the bug to be discovered because it threw up an internal error.
4690
4691 8. The debugging code in both pcre and pcretest for outputting the compiled
4692 form of a regex was going wrong in the case of back references followed by
4693 curly-bracketed repeats.
4694
4695
4696 Version 1.02 12-Dec-97
4697 ----------------------
4698
4699 1. Typos in pcre.3 and comments in the source fixed.
4700
4701 2. Applied a contributed patch to get rid of places where it used to remove
4702 'const' from variables, and fixed some signed/unsigned and uninitialized
4703 variable warnings.
4704
4705 3. Added the "runtest" target to Makefile.
4706
4707 4. Set default compiler flag to -O2 rather than just -O.
4708
4709
4710 Version 1.01 19-Nov-97
4711 ----------------------
4712
4713 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4714 like /([ab]*)*/, that is, for classes with more than one character in them.
4715
4716 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4717 as /((?>a*))*/ (a PCRE_EXTRA facility).
4718
4719
4720 Version 1.00 18-Nov-97
4721 ----------------------
4722
4723 1. Added compile-time macros to support systems such as SunOS4 which don't have
4724 memmove() or strerror() but have other things that can be used instead.
4725
4726 2. Arranged that "make clean" removes the executables.
4727
4728
4729 Version 0.99 27-Oct-97
4730 ----------------------
4731
4732 1. Fixed bug in code for optimizing classes with only one character. It was
4733 initializing a 32-byte map regardless, which could cause it to run off the end
4734 of the memory it had got.
4735
4736 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4737
4738
4739 Version 0.98 22-Oct-97
4740 ----------------------
4741
4742 1. Fixed bug in code for handling temporary memory usage when there are more
4743 back references than supplied space in the ovector. This could cause segfaults.
4744
4745
4746 Version 0.97 21-Oct-97
4747 ----------------------
4748
4749 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4750
4751 2. Optimized negated single characters not to use a bit map.
4752
4753 3. Brought error texts together as macro definitions; clarified some of them;
4754 fixed one that was wrong - it said "range out of order" when it meant "invalid
4755 escape sequence".
4756
4757 4. Changed some char * arguments to const char *.
4758
4759 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4760
4761 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4762 pcretest.
4763
4764
4765 Version 0.96 16-Oct-97
4766 ----------------------
4767
4768 1. Added a simple "pgrep" utility to the distribution.
4769
4770 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4771 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4772 where "ddd" means "one or more decimal digits".
4773
4774 3. Fixed serious bug. If a pattern had a back reference, but the call to
4775 pcre_exec() didn't supply a large enough ovector to record the related
4776 identifying subpattern, the match always failed. PCRE now remembers the number
4777 of the largest back reference, and gets some temporary memory in which to save
4778 the offsets during matching if necessary, in order to ensure that
4779 backreferences always work.
4780
4781 4. Increased the compatibility with Perl in a number of ways:
4782
4783 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4784 to request this handling. The option can be set at compile or exec time.
4785
4786 (b) $ matches before a terminating newline by default; an option
4787 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4788 mode). The option can be set at compile or exec time.
4789
4790 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4791 the same as Perl's. If the decimal number it represents is less than 10
4792 or there aren't that many previous left capturing parentheses, an octal
4793 escape is read. Inside a character class, it's always an octal escape,
4794 even if it is a single digit.
4795
4796 (d) An escaped but undefined alphabetic character is taken as a literal,
4797 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4798 escapes.
4799
4800 (e) {0} is now permitted. (The previous item is removed from the compiled
4801 pattern).
4802
4803 5. Changed all the names of code files so that the basic parts are no longer
4804 than 10 characters, and abolished the teeny "globals.c" file.
4805
4806 6. Changed the handling of character classes; they are now done with a 32-byte
4807 bit map always.
4808
4809 7. Added the -d and /D options to pcretest to make it possible to look at the
4810 internals of compilation without having to recompile pcre.
4811
4812
4813 Version 0.95 23-Sep-97
4814 ----------------------
4815
4816 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4817 \x20 at the start of a run of normal characters. These were being treated as
4818 real characters, instead of the source characters being re-checked.
4819
4820
4821 Version 0.94 18-Sep-97
4822 ----------------------
4823
4824 1. The functions are now thread-safe, with the caveat that the global variables
4825 containing pointers to malloc() and free() or alternative functions are the
4826 same for all threads.
4827
4828 2. Get pcre_study() to generate a bitmap of initial characters for non-
4829 anchored patterns when this is possible, and use it if passed to pcre_exec().
4830
4831
4832 Version 0.93 15-Sep-97
4833 ----------------------
4834
4835 1. /(b)|(:+)/ was computing an incorrect first character.
4836
4837 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4838 but not actually doing anything yet.
4839
4840 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4841 as Perl does (e.g. [-az] or [az-]).
4842
4843 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4844 all possible positions.
4845
4846 5. Split up into different modules to avoid including unneeded functions in a
4847 compiled binary. However, compile and exec are still in one module. The "study"
4848 function is split off.
4849
4850 6. The character tables are now in a separate module whose source is generated
4851 by an auxiliary program - but can then be edited by hand if required. There are
4852 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4853 toupper() in the code.
4854
4855 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4856 make them global. Abolish the function for setting them, as the caller can now
4857 set them directly.
4858
4859
4860 Version 0.92 11-Sep-97
4861 ----------------------
4862
4863 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4864 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4865
4866 2. Caseless matching was not working in character classes if the characters in
4867 the pattern were in upper case.
4868
4869 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4870
4871 4. Make PCRE_ANCHORED public and accept as a compile option.
4872
4873 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4874 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4875 pass them.
4876
4877 6. Give an error if bad option bits passed at compile or run time.
4878
4879 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4880 pcretest to cause it to pass that flag.
4881
4882 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4883 options, and the first character, if set.
4884
4885 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4886
4887
4888 Version 0.91 10-Sep-97
4889 ----------------------
4890
4891 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4892 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4893
4894 2. PCRE was looping on encountering an indefinitely repeated back reference to
4895 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4896 Perl does - treats the match as successful.
4897
4898 ****

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