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Revision 964 - (show annotations) (download)
Fri May 4 13:03:39 2012 UTC (2 years, 4 months ago) by ph10
File size: 230740 byte(s)
Check for overlong name in (*MARK) etc.

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

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