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Revision 963 - (show annotations)
Sat Apr 21 18:06:31 2012 UTC (7 years, 7 months ago) by ph10
File size: 230586 byte(s)
Fix ovector overrun when backreferences need temporary memory and the highest 
block is not used.
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
112 Version 8.30 04-February-2012
113 -----------------------------
114
115 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
116 name is defined in ctype.h.
117
118 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
119 only in quite long subpatterns.
120
121 3. Removed the function pcre_info(), which has been obsolete and deprecated
122 since it was replaced by pcre_fullinfo() in February 2000.
123
124 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
125 match a (*MARK), and the match failed at the start of the subject, a
126 reference to memory before the start of the subject could occur. This bug
127 was introduced by fix 17 of release 8.21.
128
129 5. A reference to an unset group with zero minimum repetition was giving
130 totally wrong answers (in non-JavaScript-compatibility mode). For example,
131 /(another)?(\1?)test/ matched against "hello world test". This bug was
132 introduced in release 8.13.
133
134 6. Add support for 16-bit character strings (a large amount of work involving
135 many changes and refactorings).
136
137 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
138 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
139 from a file.
140
141 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
142 rounding is not applied in this particular case).
143
144 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
145 if they appear, or are escaped, in patterns.
146
147 10. Get rid of a number of -Wunused-but-set-variable warnings.
148
149 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
150 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
151 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
152 also returns the mark "x". This bug applied to capturing parentheses,
153 non-capturing parentheses, and atomic parentheses. It also applied to some
154 assertions.
155
156 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
157 information out of configure.ac instead of relying on pcre.h.generic, which
158 is not stored in the repository.
159
160 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
161 -lreadline.
162
163 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
164
165 15. Applied Graycode's patch to put the top-level frame on the stack rather
166 than the heap when not using the stack for recursion. This gives a
167 performance improvement in many cases when recursion is not deep.
168
169 16. Experimental code added to "pcretest -C" to output the stack frame size.
170
171
172 Version 8.21 12-Dec-2011
173 ------------------------
174
175 1. Updating the JIT compiler.
176
177 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
178 are added as well.
179
180 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
181 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
182 calling _pcre_jit_exec. Some extra comments are added.
183
184 4. (*MARK) settings inside atomic groups that do not contain any capturing
185 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
186 was introduced by change 18 for 8.20.
187
188 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
189 ECMA-262 standard.
190
191 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
192 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
193 This bug was probably introduced by change 9 of 8.13.
194
195 7. While fixing 6 above, I noticed that a number of other items were being
196 incorrectly rejected as "not fixed length". This arose partly because newer
197 opcodes had not been added to the fixed-length checking code. I have (a)
198 corrected the bug and added tests for these items, and (b) arranged for an
199 error to occur if an unknown opcode is encountered while checking for fixed
200 length instead of just assuming "not fixed length". The items that were
201 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
202 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
203 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
204
205 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
206 being incorrectly compiled and would have given unpredicatble results.
207
208 9. A possessively repeated subpattern with minimum repeat count greater than
209 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
210 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
211 the first (A) could occur when it should not.
212
213 10. Add a cast and remove a redundant test from the code.
214
215 11. JIT should use pcre_malloc/pcre_free for allocation.
216
217 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
218 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
219 is anything other than /usr, -L is still shown).
220
221 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
222
223 14. Perl does not support \N without a following name in a [] class; PCRE now
224 also gives an error.
225
226 15. If a forward reference was repeated with an upper limit of around 2000,
227 it caused the error "internal error: overran compiling workspace". The
228 maximum number of forward references (including repeats) was limited by the
229 internal workspace, and dependent on the LINK_SIZE. The code has been
230 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
231 the default depends on LINK_SIZE. There is a new upper limit (for safety)
232 of around 200,000 forward references. While doing this, I also speeded up
233 the filling in of repeated forward references.
234
235 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
236 incorrectly expecting the subject to contain another "a" after the start.
237
238 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
239 in the match, the SKIP should be ignored. This was not happening; instead
240 the SKIP was being treated as NOMATCH. For patterns such as
241 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
242 tested.
243
244 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
245 now much more compatible with Perl, in particular in cases where the result
246 is a non-match for a non-anchored pattern. For example, if
247 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
248 "m", where previously it did not return a name. A side effect of this
249 change is that for partial matches, the last encountered mark name is
250 returned, as for non matches. A number of tests that were previously not
251 Perl-compatible have been moved into the Perl-compatible test files. The
252 refactoring has had the pleasing side effect of removing one argument from
253 the match() function, thus reducing its stack requirements.
254
255 19. If the /S+ option was used in pcretest to study a pattern using JIT,
256 subsequent uses of /S (without +) incorrectly behaved like /S+.
257
258 21. Retrieve executable code size support for the JIT compiler and fixing
259 some warnings.
260
261 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
262 not work when the shorter character appeared right at the end of the
263 subject string.
264
265 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
266 systems.
267
268 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
269 output it when the /M option is used in pcretest.
270
271 25. The CheckMan script was not being included in the distribution. Also, added
272 an explicit "perl" to run Perl scripts from the PrepareRelease script
273 because this is reportedly needed in Windows.
274
275 26. If study data was being save in a file and studying had not found a set of
276 "starts with" bytes for the pattern, the data written to the file (though
277 never used) was taken from uninitialized memory and so caused valgrind to
278 complain.
279
280 27. Updated RunTest.bat as provided by Sheri Pierce.
281
282 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
283
284 29. Computation of memory usage for the table of capturing group names was
285 giving an unnecessarily large value.
286
287
288 Version 8.20 21-Oct-2011
289 ------------------------
290
291 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
292 a POSIX class. After further experiments with Perl, which convinced me that
293 Perl has bugs and confusions, a closing square bracket is no longer allowed
294 in a POSIX name. This bug also affected patterns with classes that started
295 with full stops.
296
297 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
298 captured substring, but while checking the failing first alternative,
299 substring 1 is temporarily captured. If the output vector supplied to
300 pcre_exec() was not big enough for this capture, the yield of the function
301 was still zero ("insufficient space for captured substrings"). This cannot
302 be totally fixed without adding another stack variable, which seems a lot
303 of expense for a edge case. However, I have improved the situation in cases
304 such as /(a)(b)x|abc/ matched against "abc", where the return code
305 indicates that fewer than the maximum number of slots in the ovector have
306 been set.
307
308 3. Related to (2) above: when there are more back references in a pattern than
309 slots in the output vector, pcre_exec() uses temporary memory during
310 matching, and copies in the captures as far as possible afterwards. It was
311 using the entire output vector, but this conflicts with the specification
312 that only 2/3 is used for passing back captured substrings. Now it uses
313 only the first 2/3, for compatibility. This is, of course, another edge
314 case.
315
316 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
317 main code base, and can be used by building with --enable-jit. When this is
318 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
319 runtime --no-jit option is given.
320
321 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
322 ovector, the return from the function was zero, implying that there were
323 other matches that did not fit. The correct "exactly full" value is now
324 returned.
325
326 6. If a subpattern that was called recursively or as a subroutine contained
327 (*PRUNE) or any other control that caused it to give a non-standard return,
328 invalid errors such as "Error -26 (nested recursion at the same subject
329 position)" or even infinite loops could occur.
330
331 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
332 computing the minimum length on reaching *ACCEPT, and so ended up with the
333 wrong value of 1 rather than 0. Further investigation indicates that
334 computing a minimum subject length in the presence of *ACCEPT is difficult
335 (think back references, subroutine calls), and so I have changed the code
336 so that no minimum is registered for a pattern that contains *ACCEPT.
337
338 8. If (*THEN) was present in the first (true) branch of a conditional group,
339 it was not handled as intended. [But see 16 below.]
340
341 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
342 Sheri Pierce.
343
344 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
345 the first byte in a match must be "a".
346
347 11. Change 17 for 8.13 increased the recursion depth for patterns like
348 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
349 pattern contains any instances of (*THEN). If it does not, the old
350 optimizations are restored. It would be nice to do this on a per-group
351 basis, but at the moment that is not feasible.
352
353 12. In some environments, the output of pcretest -C is CRLF terminated. This
354 broke RunTest's code that checks for the link size. A single white space
355 character after the value is now allowed for.
356
357 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
358 For "fr", it uses the Windows-specific input and output files.
359
360 14. If (*THEN) appeared in a group that was called recursively or as a
361 subroutine, it did not work as intended. [But see next item.]
362
363 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
364 pattern fragments (but not containing any | characters). If A and B are
365 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
366 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
367 D. In other words, Perl considers parentheses that do not contain any |
368 characters to be part of a surrounding alternative, whereas PCRE was
369 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
370 differently. PCRE now behaves in the same way as Perl, except in the case
371 of subroutine/recursion calls such as (?1) which have in any case always
372 been different (but PCRE had them first :-).
373
374 16. Related to 15 above: Perl does not treat the | in a conditional group as
375 creating alternatives. Such a group is treated in the same way as an
376 ordinary group without any | characters when processing (*THEN). PCRE has
377 been changed to match Perl's behaviour.
378
379 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
380 RunGrepTest script failed.
381
382 18. Change 22 for version 13 caused atomic groups to use more stack. This is
383 inevitable for groups that contain captures, but it can lead to a lot of
384 stack use in large patterns. The old behaviour has been restored for atomic
385 groups that do not contain any capturing parentheses.
386
387 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
388 suppress the check for a minimum subject length at run time. (If it was
389 given to pcre_exec() or pcre_dfa_exec() it did work.)
390
391 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
392 fail to work when decoding hex characters in data strings in EBCDIC
393 environments.
394
395 21. It appears that in at least one Mac OS environment, the isxdigit() function
396 is implemented as a macro that evaluates to its argument more than once,
397 contravening the C 90 Standard (I haven't checked a later standard). There
398 was an instance in pcretest which caused it to go wrong when processing
399 \x{...} escapes in subject strings. The has been rewritten to avoid using
400 things like p++ in the argument of isxdigit().
401
402
403 Version 8.13 16-Aug-2011
404 ------------------------
405
406 1. The Unicode data tables have been updated to Unicode 6.0.0.
407
408 2. Two minor typos in pcre_internal.h have been fixed.
409
410 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
411 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
412 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
413
414 4. There were a number of related bugs in the code for matching backrefences
415 caselessly in UTF-8 mode when codes for the characters concerned were
416 different numbers of bytes. For example, U+023A and U+2C65 are an upper
417 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
418 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
419 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
420 2-byte code at the end of the subject (it thought there wasn't enough data
421 left).
422
423 5. Comprehensive information about what went wrong is now returned by
424 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
425 as the output vector has at least 2 elements. The offset of the start of
426 the failing character and a reason code are placed in the vector.
427
428 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
429 now returned is for the first byte of the failing character, instead of the
430 last byte inspected. This is an incompatible change, but I hope it is small
431 enough not to be a problem. It makes the returned offset consistent with
432 pcre_exec() and pcre_dfa_exec().
433
434 7. pcretest now gives a text phrase as well as the error number when
435 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
436 failure, the offset and reason code are output.
437
438 8. When \R was used with a maximizing quantifier it failed to skip backwards
439 over a \r\n pair if the subsequent match failed. Instead, it just skipped
440 back over a single character (\n). This seems wrong (because it treated the
441 two characters as a single entity when going forwards), conflicts with the
442 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
443 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
444 has been changed.
445
446 9. Some internal refactoring has changed the processing so that the handling
447 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
448 time (the PCRE_DOTALL option was changed this way some time ago: version
449 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
450 which was always a bit of a fudge. It also means that there is one less
451 argument for the match() function, which reduces its stack requirements
452 slightly. This change also fixes an incompatibility with Perl: the pattern
453 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
454
455 10. More internal refactoring has drastically reduced the number of recursive
456 calls to match() for possessively repeated groups such as (abc)++ when
457 using pcre_exec().
458
459 11. While implementing 10, a number of bugs in the handling of groups were
460 discovered and fixed:
461
462 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
463 (a|)*(?1) gave a compile-time internal error.
464 ((a|)+)+ did not notice that the outer group could match an empty string.
465 (^a|^)+ was not marked as anchored.
466 (.*a|.*)+ was not marked as matching at start or after a newline.
467
468 12. Yet more internal refactoring has removed another argument from the match()
469 function. Special calls to this function are now indicated by setting a
470 value in a variable in the "match data" data block.
471
472 13. Be more explicit in pcre_study() instead of relying on "default" for
473 opcodes that mean there is no starting character; this means that when new
474 ones are added and accidentally left out of pcre_study(), testing should
475 pick them up.
476
477 14. The -s option of pcretest has been documented for ages as being an old
478 synonym of -m (show memory usage). I have changed it to mean "force study
479 for every regex", that is, assume /S for every regex. This is similar to -i
480 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
481 using it. It makes it easier to run collections of tests with and without
482 study enabled, and thereby test pcre_study() more easily. All the standard
483 tests are now run with and without -s (but some patterns can be marked as
484 "never study" - see 20 below).
485
486 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
487 restoration of the capturing data to the outer values was not happening
488 correctly.
489
490 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
491 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
492 pattern had matched an empty string, and so incorrectly returned a no
493 match.
494
495 17. There was optimizing code for the last branch of non-capturing parentheses,
496 and also for the obeyed branch of a conditional subexpression, which used
497 tail recursion to cut down on stack usage. Unfortunately, now that there is
498 the possibility of (*THEN) occurring in these branches, tail recursion is
499 no longer possible because the return has to be checked for (*THEN). These
500 two optimizations have therefore been removed. [But see 8.20/11 above.]
501
502 18. If a pattern containing \R was studied, it was assumed that \R always
503 matched two bytes, thus causing the minimum subject length to be
504 incorrectly computed because \R can also match just one byte.
505
506 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
507 was incorrectly computed.
508
509 20. If /S is present twice on a test pattern in pcretest input, it now
510 *disables* studying, thereby overriding the use of -s on the command line
511 (see 14 above). This is necessary for one or two tests to keep the output
512 identical in both cases.
513
514 21. When (*ACCEPT) was used in an assertion that matched an empty string and
515 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
516
517 22. When an atomic group that contained a capturing parenthesis was
518 successfully matched, but the branch in which it appeared failed, the
519 capturing was not being forgotten if a higher numbered group was later
520 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
521 group 1 to "a", when in fact it should be unset. This applied to multi-
522 branched capturing and non-capturing groups, repeated or not, and also to
523 positive assertions (capturing in negative assertions does not happen
524 in PCRE) and also to nested atomic groups.
525
526 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
527 subject after a captured substring, to make it easier to tell which of a
528 number of identical substrings has been captured.
529
530 24. The way atomic groups are processed by pcre_exec() has been changed so that
531 if they are repeated, backtracking one repetition now resets captured
532 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
533 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
534 "aaa". Previously, it would have been "a". As part of this code
535 refactoring, the way recursive calls are handled has also been changed.
536
537 25. If an assertion condition captured any substrings, they were not passed
538 back unless some other capturing happened later. For example, if
539 (?(?=(a))a) was matched against "a", no capturing was returned.
540
541 26. When studying a pattern that contained subroutine calls or assertions,
542 the code for finding the minimum length of a possible match was handling
543 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
544 group 1 called group 2 while simultaneously a separate group 2 called group
545 1). A stack overflow occurred in this case. I have fixed this by limiting
546 the recursion depth to 10.
547
548 27. Updated RunTest.bat in the distribution to the version supplied by Tom
549 Fortmann. This supports explicit test numbers on the command line, and has
550 argument validation and error reporting.
551
552 28. An instance of \X with an unlimited repeat could fail if at any point the
553 first character it looked at was a mark character.
554
555 29. Some minor code refactoring concerning Unicode properties and scripts
556 should reduce the stack requirement of match() slightly.
557
558 30. Added the '=' option to pcretest to check the setting of unused capturing
559 slots at the end of the pattern, which are documented as being -1, but are
560 not included in the return count.
561
562 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
563 compiled something random. Now it gives a compile-time error (as does
564 Perl).
565
566 32. A *MARK encountered during the processing of a positive assertion is now
567 recorded and passed back (compatible with Perl).
568
569 33. If --only-matching or --colour was set on a pcregrep call whose pattern
570 had alternative anchored branches, the search for a second match in a line
571 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
572 matched the line "0102" twice. The same bug affected patterns that started
573 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
574 twice.
575
576 34. Previously, PCRE did not allow quantification of assertions. However, Perl
577 does, and because of capturing effects, quantifying parenthesized
578 assertions may at times be useful. Quantifiers are now allowed for
579 parenthesized assertions.
580
581 35. A minor code tidy in pcre_compile() when checking options for \R usage.
582
583 36. \g was being checked for fancy things in a character class, when it should
584 just be a literal "g".
585
586 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
587 appearance of a nested POSIX class supersedes an apparent external class.
588 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
589 unescaped square brackets may also appear as part of class names. For
590 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
591 more like Perl. (But see 8.20/1 above.)
592
593 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
594 was because it thought it was \N{name}, which is not supported).
595
596 39. Add minix to OS list not supporting the -S option in pcretest.
597
598 40. PCRE tries to detect cases of infinite recursion at compile time, but it
599 cannot analyze patterns in sufficient detail to catch mutual recursions
600 such as ((?1))((?2)). There is now a runtime test that gives an error if a
601 subgroup is called recursively as a subpattern for a second time at the
602 same position in the subject string. In previous releases this might have
603 been caught by the recursion limit, or it might have run out of stack.
604
605 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
606 happen only once. PCRE was, however incorrectly giving a compile time error
607 "recursive call could loop indefinitely" because it cannot analyze the
608 pattern in sufficient detail. The compile time test no longer happens when
609 PCRE is compiling a conditional subpattern, but actual runaway loops are
610 now caught at runtime (see 40 above).
611
612 42. It seems that Perl allows any characters other than a closing parenthesis
613 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
614 has been changed to be the same.
615
616 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
617 as not to get warnings when autogen.sh is called. Also changed
618 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
619
620 44. To help people who use pcregrep to scan files containing exceedingly long
621 lines, the following changes have been made:
622
623 (a) The default value of the buffer size parameter has been increased from
624 8K to 20K. (The actual buffer used is three times this size.)
625
626 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
627 PCRE is built.
628
629 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
630 to be set at run time.
631
632 (d) Numerical values in pcregrep options can be followed by K or M, for
633 example --buffer-size=50K.
634
635 (e) If a line being scanned overflows pcregrep's buffer, an error is now
636 given and the return code is set to 2.
637
638 45. Add a pointer to the latest mark to the callout data block.
639
640 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
641 partial match of an empty string instead of no match. This was specific to
642 the use of ".".
643
644 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
645 complete match instead of a partial match. This bug was dependent on both
646 the PCRE_UTF8 and PCRE_DOTALL options being set.
647
648 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
649 starting byte set, because \b was not being ignored.
650
651
652 Version 8.12 15-Jan-2011
653 ------------------------
654
655 1. Fixed some typos in the markup of the man pages, and wrote a script that
656 checks for such things as part of the documentation building process.
657
658 2. On a big-endian 64-bit system, pcregrep did not correctly process the
659 --match-limit and --recursion-limit options (added for 8.11). In
660 particular, this made one of the standard tests fail. (The integer value
661 went into the wrong half of a long int.)
662
663 3. If the --colour option was given to pcregrep with -v (invert match), it
664 did strange things, either producing crazy output, or crashing. It should,
665 of course, ignore a request for colour when reporting lines that do not
666 match.
667
668 4. Another pcregrep bug caused similar problems if --colour was specified with
669 -M (multiline) and the pattern match finished with a line ending.
670
671 5. In pcregrep, when a pattern that ended with a literal newline sequence was
672 matched in multiline mode, the following line was shown as part of the
673 match. This seems wrong, so I have changed it.
674
675 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
676 the check for further matches in the same line (so they could be coloured)
677 to overrun the end of the current line. If another match was found, it was
678 incorrectly shown (and then shown again when found in the next line).
679
680 7. If pcregrep was compiled under Windows, there was a reference to the
681 function pcregrep_exit() before it was defined. I am assuming this was
682 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
683 reported by a user. I've moved the definition above the reference.
684
685
686 Version 8.11 10-Dec-2010
687 ------------------------
688
689 1. (*THEN) was not working properly if there were untried alternatives prior
690 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
691 backtracked to try for "b" instead of moving to the next alternative branch
692 at the same level (in this case, to look for "c"). The Perl documentation
693 is clear that when (*THEN) is backtracked onto, it goes to the "next
694 alternative in the innermost enclosing group".
695
696 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
697 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
698 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
699 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
700 (*THEN).
701
702 3. If \s appeared in a character class, it removed the VT character from
703 the class, even if it had been included by some previous item, for example
704 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
705 of \s, but is part of the POSIX "space" class.)
706
707 4. A partial match never returns an empty string (because you can always
708 match an empty string at the end of the subject); however the checking for
709 an empty string was starting at the "start of match" point. This has been
710 changed to the "earliest inspected character" point, because the returned
711 data for a partial match starts at this character. This means that, for
712 example, /(?<=abc)def/ gives a partial match for the subject "abc"
713 (previously it gave "no match").
714
715 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
716 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
717 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
718 has an implication that the given string is incomplete (because a partial
719 match is preferred over a full match). For this reason, these items now
720 give a partial match in this situation. [Aside: previously, the one case
721 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
722 match rather than a full match, which was wrong by the old rules, but is
723 now correct.]
724
725 6. There was a bug in the handling of #-introduced comments, recognized when
726 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
727 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
728 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
729 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
730 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
731 places in pcre_compile().
732
733 7. Related to (6) above, when pcre_compile() was skipping #-introduced
734 comments when looking ahead for named forward references to subpatterns,
735 the only newline sequence it recognized was NL. It now handles newlines
736 according to the set newline convention.
737
738 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
739 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
740 cater for a lack of strerror(). These oversights have been fixed.
741
742 9. Added --match-limit and --recursion-limit to pcregrep.
743
744 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
745
746 11. When the -o option was used, pcregrep was setting a return code of 1, even
747 when matches were found, and --line-buffered was not being honoured.
748
749 12. Added an optional parentheses number to the -o and --only-matching options
750 of pcregrep.
751
752 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
753 can match an empty string. The code to do it in pcretest and pcredemo
754 needed fixing:
755
756 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
757 only one byte after an empty string match just before CRLF (this case
758 just got forgotten; "any" and "anycrlf" were OK).
759
760 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
761 mode when an empty string match preceded an ASCII character followed by
762 a non-ASCII character. (The code for advancing by one character rather
763 than one byte was nonsense.)
764
765 (c) The pcredemo.c sample program did not have any code at all to handle
766 the cases when CRLF is a valid newline sequence.
767
768 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
769 as a starting offset was within the subject string. There is now a new
770 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
771 negative or greater than the length of the string. In order to test this,
772 pcretest is extended to allow the setting of negative starting offsets.
773
774 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
775 starting offset points to the beginning of a UTF-8 character was
776 unnecessarily clumsy. I tidied it up.
777
778 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
779 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
780
781 17. Nobody had reported that the --include_dir option, which was added in
782 release 7.7 should have been called --include-dir (hyphen, not underscore)
783 for compatibility with GNU grep. I have changed it to --include-dir, but
784 left --include_dir as an undocumented synonym, and the same for
785 --exclude-dir, though that is not available in GNU grep, at least as of
786 release 2.5.4.
787
788 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
789 characters from a string of bytes) have been redefined so as not to use
790 loops, in order to improve performance in some environments. At the same
791 time, I abstracted some of the common code into auxiliary macros to save
792 repetition (this should not affect the compiled code).
793
794 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
795 compile-time error is now given if \c is not followed by an ASCII
796 character, that is, a byte less than 128. (In EBCDIC mode, the code is
797 different, and any byte value is allowed.)
798
799 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
800 START_OPTIMIZE option, which is now allowed at compile time - but just
801 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
802 to pcregrep and other applications that have no direct access to PCRE
803 options. The new /Y option in pcretest sets this option when calling
804 pcre_compile().
805
806 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
807 back references. Groups containing recursive back references were forced to
808 be atomic by that change, but in the case of named groups, the amount of
809 memory required was incorrectly computed, leading to "Failed: internal
810 error: code overflow". This has been fixed.
811
812 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
813 pcretest.c, to avoid build problems in some Borland environments.
814
815
816 Version 8.10 25-Jun-2010
817 ------------------------
818
819 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
820 THEN.
821
822 2. (*ACCEPT) was not working when inside an atomic group.
823
824 3. Inside a character class, \B is treated as a literal by default, but
825 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
826 causes the error). The code is unchanged, but I tidied the documentation.
827
828 4. Inside a character class, PCRE always treated \R and \X as literals,
829 whereas Perl faults them if its -w option is set. I have changed PCRE so
830 that it faults them when PCRE_EXTRA is set.
831
832 5. Added support for \N, which always matches any character other than
833 newline. (It is the same as "." when PCRE_DOTALL is not set.)
834
835 6. When compiling pcregrep with newer versions of gcc which may have
836 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
837 declared with attribute warn_unused_result" were given. Just casting the
838 result to (void) does not stop the warnings; a more elaborate fudge is
839 needed. I've used a macro to implement this.
840
841 7. Minor change to pcretest.c to avoid a compiler warning.
842
843 8. Added four artifical Unicode properties to help with an option to make
844 \s etc use properties (see next item). The new properties are: Xan
845 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
846
847 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
848 use Unicode properties. (*UCP) at the start of a pattern can be used to set
849 this option. Modified pcretest to add /W to test this facility. Added
850 REG_UCP to make it available via the POSIX interface.
851
852 10. Added --line-buffered to pcregrep.
853
854 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
855 studied, and the match started with a letter with a code point greater than
856 127 whose first byte was different to the first byte of the other case of
857 the letter, the other case of this starting letter was not recognized
858 (#976).
859
860 12. If a pattern that was studied started with a repeated Unicode property
861 test, for example, \p{Nd}+, there was the theoretical possibility of
862 setting up an incorrect bitmap of starting bytes, but fortunately it could
863 not have actually happened in practice until change 8 above was made (it
864 added property types that matched character-matching opcodes).
865
866 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
867 possible starting bytes for non-anchored patterns.
868
869 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
870 \R, and also a number of cases that involve Unicode properties, both
871 explicit and implicit when PCRE_UCP is set.
872
873 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
874 input, it could crash or give wrong results if characters with values
875 greater than 0xc0 were present in the subject string. (Detail: it assumed
876 UTF-8 input when processing these items.)
877
878 16. Added a lot of (int) casts to avoid compiler warnings in systems where
879 size_t is 64-bit (#991).
880
881 17. Added a check for running out of memory when PCRE is compiled with
882 --disable-stack-for-recursion (#990).
883
884 18. If the last data line in a file for pcretest does not have a newline on
885 the end, a newline was missing in the output.
886
887 19. The default pcre_chartables.c file recognizes only ASCII characters (values
888 less than 128) in its various bitmaps. However, there is a facility for
889 generating tables according to the current locale when PCRE is compiled. It
890 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
891 characters, are recognized by isspace() and therefore were getting set in
892 these tables, and indeed these tables seem to approximate to ISO 8859. This
893 caused a problem in UTF-8 mode when pcre_study() was used to create a list
894 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
895 which of course cannot start UTF-8 characters. I have changed the code so
896 that only real ASCII characters (less than 128) and the correct starting
897 bytes for UTF-8 encodings are set for characters greater than 127 when in
898 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
899 altogether.)
900
901 20. Added the /T option to pcretest so as to be able to run tests with non-
902 standard character tables, thus making it possible to include the tests
903 used for 19 above in the standard set of tests.
904
905 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
906 reference to a subpattern the other side of a comment that contains an
907 opening parenthesis caused either an internal compiling error, or a
908 reference to the wrong subpattern.
909
910
911 Version 8.02 19-Mar-2010
912 ------------------------
913
914 1. The Unicode data tables have been updated to Unicode 5.2.0.
915
916 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
917 configured.
918
919 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
920 original author of that file, following a query about its status.
921
922 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
923 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
924
925 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
926 quantifier applied to a forward-referencing subroutine call, could compile
927 incorrect code or give the error "internal error: previously-checked
928 referenced subpattern not found".
929
930 6. Both MS Visual Studio and Symbian OS have problems with initializing
931 variables to point to external functions. For these systems, therefore,
932 pcre_malloc etc. are now initialized to local functions that call the
933 relevant global functions.
934
935 7. There were two entries missing in the vectors called coptable and poptable
936 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
937 I've fixed the data, and added a kludgy way of testing at compile time that
938 the lengths are correct (equal to the number of opcodes).
939
940 8. Following on from 7, I added a similar kludge to check the length of the
941 eint vector in pcreposix.c.
942
943 9. Error texts for pcre_compile() are held as one long string to avoid too
944 much relocation at load time. To find a text, the string is searched,
945 counting zeros. There was no check for running off the end of the string,
946 which could happen if a new error number was added without updating the
947 string.
948
949 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
950
951 11. \K was not working if it appeared in an atomic group or in a group that
952 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
953 \K is "not well defined" if used in an assertion. PCRE now accepts it if
954 the assertion is positive, but not if it is negative.
955
956 12. Change 11 fortuitously reduced the size of the stack frame used in the
957 "match()" function of pcre_exec.c by one pointer. Forthcoming
958 implementation of support for (*MARK) will need an extra pointer on the
959 stack; I have reserved it now, so that the stack frame size does not
960 decrease.
961
962 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
963 item in branch that calls a recursion is a subroutine call - as in the
964 second branch in the above example - was incorrectly given the compile-
965 time error "recursive call could loop indefinitely" because pcre_compile()
966 was not correctly checking the subroutine for matching a non-empty string.
967
968 14. The checks for overrunning compiling workspace could trigger after an
969 overrun had occurred. This is a "should never occur" error, but it can be
970 triggered by pathological patterns such as hundreds of nested parentheses.
971 The checks now trigger 100 bytes before the end of the workspace.
972
973 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
974
975
976 Version 8.01 19-Jan-2010
977 ------------------------
978
979 1. If a pattern contained a conditional subpattern with only one branch (in
980 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
981 computed the wrong minimum data length (which is of course zero for such
982 subpatterns). This could cause incorrect "no match" results.
983
984 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
985 the pattern is reset in the first branch, pcre_compile() failed with
986 "internal error: code overflow at offset...". This happened only when
987 the reset was to the original external option setting. (An optimization
988 abstracts leading options settings into an external setting, which was the
989 cause of this.)
990
991 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
992 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
993 assertion pattern did not match (meaning that the assertion was true), it
994 was incorrectly treated as false if the SKIP had been reached during the
995 matching. This also applied to assertions used as conditions.
996
997 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
998 assertion subpattern, including such a pattern used as a condition,
999 unpredictable results occurred, instead of the error return
1000 PCRE_ERROR_DFA_UITEM.
1001
1002 5. The C++ GlobalReplace function was not working like Perl for the special
1003 situation when an empty string is matched. It now does the fancy magic
1004 stuff that is necessary.
1005
1006 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1007 removed. (These were left over from very, very early versions of PCRE.)
1008
1009 7. Some cosmetic changes to the code to make life easier when compiling it
1010 as part of something else:
1011
1012 (a) Change DEBUG to PCRE_DEBUG.
1013
1014 (b) In pcre_compile(), rename the member of the "branch_chain" structure
1015 called "current" as "current_branch", to prevent a collision with the
1016 Linux macro when compiled as a kernel module.
1017
1018 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1019 prevent a collision with the Linux macro when compiled as a kernel
1020 module.
1021
1022 8. In pcre_compile() there are some checks for integer overflows that used to
1023 cast potentially large values to (double). This has been changed to that
1024 when building, a check for int64_t is made, and if it is found, it is used
1025 instead, thus avoiding the use of floating point arithmetic. (There is no
1026 other use of FP in PCRE.) If int64_t is not found, the fallback is to
1027 double.
1028
1029 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
1030 2005 (difference between two addresses compared to an unsigned value).
1031
1032 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1033 custom one, because of the following reported problem in Windows:
1034
1035 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1036 under Win32.
1037 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1038 therefore missing the function definition.
1039 - The compiler thus generates a "C" signature for the test function.
1040 - The linker fails to find the "C" function.
1041 - PCRE fails to configure if asked to do so against libbz2.
1042
1043 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1044 messages were output:
1045
1046 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1047 rerunning libtoolize, to keep the correct libtool macros in-tree.
1048 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1049
1050 I have done both of these things.
1051
1052 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1053 most of the time, it *can* run out if it is given a pattern that contains a
1054 runaway infinite recursion. I updated the discussion in the pcrestack man
1055 page.
1056
1057 13. Now that we have gone to the x.xx style of version numbers, the minor
1058 version may start with zero. Using 08 or 09 is a bad idea because users
1059 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1060 interpreted as invalid octal numbers. I've updated the previous comment in
1061 configure.ac, and also added a check that gives an error if 08 or 09 are
1062 used.
1063
1064 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1065 causing partial matching to fail when the end of the subject matched \W
1066 in a UTF-8 pattern where \W was quantified with a minimum of 3.
1067
1068 15. There were some discrepancies between the declarations in pcre_internal.h
1069 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1070 their definitions. The declarations used "const uschar *" and the
1071 definitions used USPTR. Even though USPTR is normally defined as "const
1072 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1073 reported that: "This difference in casting confuses some C++ compilers, for
1074 example, SunCC recognizes above declarations as different functions and
1075 generates broken code for hbpcre." I have changed the declarations to use
1076 USPTR.
1077
1078 16. GNU libtool is named differently on some systems. The autogen.sh script now
1079 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1080 (FreeBSD).
1081
1082 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1083 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1084 comment: "Figure out how to create a longlong from a string: strtoll and
1085 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1086 instance, but it only takes 2 args instead of 3!"
1087
1088 18. A subtle bug concerned with back references has been fixed by a change of
1089 specification, with a corresponding code fix. A pattern such as
1090 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1091 refers, was giving matches when it shouldn't. For example, xa=xaaa would
1092 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1093 same bug. Such groups have to be quantified to be useful, or contained
1094 inside another quantified group. (If there's no repetition, the reference
1095 can never match.) The problem arises because, having left the group and
1096 moved on to the rest of the pattern, a later failure that backtracks into
1097 the group uses the captured value from the final iteration of the group
1098 rather than the correct earlier one. I have fixed this in PCRE by forcing
1099 any group that contains a reference to itself to be an atomic group; that
1100 is, there cannot be any backtracking into it once it has completed. This is
1101 similar to recursive and subroutine calls.
1102
1103
1104 Version 8.00 19-Oct-09
1105 ----------------------
1106
1107 1. The table for translating pcre_compile() error codes into POSIX error codes
1108 was out-of-date, and there was no check on the pcre_compile() error code
1109 being within the table. This could lead to an OK return being given in
1110 error.
1111
1112 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1113 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1114 in a Windows environment.
1115
1116 3. The pcregrep --count option prints the count for each file even when it is
1117 zero, as does GNU grep. However, pcregrep was also printing all files when
1118 --files-with-matches was added. Now, when both options are given, it prints
1119 counts only for those files that have at least one match. (GNU grep just
1120 prints the file name in this circumstance, but including the count seems
1121 more useful - otherwise, why use --count?) Also ensured that the
1122 combination -clh just lists non-zero counts, with no names.
1123
1124 4. The long form of the pcregrep -F option was incorrectly implemented as
1125 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1126 but it seems right to fix it, and I didn't think it was worth preserving
1127 the old behaviour.
1128
1129 5. The command line items --regex=pattern and --regexp=pattern were not
1130 recognized by pcregrep, which required --regex pattern or --regexp pattern
1131 (with a space rather than an '='). The man page documented the '=' forms,
1132 which are compatible with GNU grep; these now work.
1133
1134 6. No libpcreposix.pc file was created for pkg-config; there was just
1135 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1136
1137 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1138 when UCP support is not needed, by modifying the Python script that
1139 generates it from Unicode data files. This should not matter if the module
1140 is correctly used as a library, but I received one complaint about 50K of
1141 unwanted data. My guess is that the person linked everything into his
1142 program rather than using a library. Anyway, it does no harm.
1143
1144 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1145 was a minimum greater than 1 for a wide character in a possessive
1146 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1147 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1148 character. Chaos in the form of incorrect output or a compiling loop could
1149 result.
1150
1151 9. The restrictions on what a pattern can contain when partial matching is
1152 requested for pcre_exec() have been removed. All patterns can now be
1153 partially matched by this function. In addition, if there are at least two
1154 slots in the offset vector, the offset of the earliest inspected character
1155 for the match and the offset of the end of the subject are set in them when
1156 PCRE_ERROR_PARTIAL is returned.
1157
1158 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1159 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1160 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1161 and may be more useful for multi-segment matching.
1162
1163 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1164 used to be given if ever the end of the subject was reached; now it is
1165 given only if matching could not proceed because another character was
1166 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1167 string "Z", which now yields "no match" instead of "partial match". In the
1168 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1169 final character ended with (*FAIL).
1170
1171 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1172 if the pattern had a "must contain" character that was already found in the
1173 earlier partial match, unless partial matching was again requested. For
1174 example, with the pattern /dog.(body)?/, the "must contain" character is
1175 "g". If the first part-match was for the string "dog", restarting with
1176 "sbody" failed. This bug has been fixed.
1177
1178 13. The string returned by pcre_dfa_exec() after a partial match has been
1179 changed so that it starts at the first inspected character rather than the
1180 first character of the match. This makes a difference only if the pattern
1181 starts with a lookbehind assertion or \b or \B (\K is not supported by
1182 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1183 matching functions compatible, and I think it's the right thing to do.
1184
1185 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1186 so that the demonstration program is easily available in environments where
1187 PCRE has not been installed from source.
1188
1189 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1190 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1191 library.
1192
1193 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1194 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1195 is not the first non-POSIX option to be added. Clearly some people find
1196 these options useful.
1197
1198 17. If a caller to the POSIX matching function regexec() passes a non-zero
1199 value for nmatch with a NULL value for pmatch, the value of
1200 nmatch is forced to zero.
1201
1202 18. RunGrepTest did not have a test for the availability of the -u option of
1203 the diff command, as RunTest does. It now checks in the same way as
1204 RunTest, and also checks for the -b option.
1205
1206 19. If an odd number of negated classes containing just a single character
1207 interposed, within parentheses, between a forward reference to a named
1208 subpattern and the definition of the subpattern, compilation crashed with
1209 an internal error, complaining that it could not find the referenced
1210 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1211 [The bug was that it was starting one character too far in when skipping
1212 over the character class, thus treating the ] as data rather than
1213 terminating the class. This meant it could skip too much.]
1214
1215 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1216 /g option in pcretest when the pattern contains \K, which makes it possible
1217 to have an empty string match not at the start, even when the pattern is
1218 anchored. Updated pcretest and pcredemo to use this option.
1219
1220 21. If the maximum number of capturing subpatterns in a recursion was greater
1221 than the maximum at the outer level, the higher number was returned, but
1222 with unset values at the outer level. The correct (outer level) value is
1223 now given.
1224
1225 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1226 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1227 make it do so. The string so far is captured, making this feature
1228 compatible with Perl.
1229
1230 23. The tests have been re-organized, adding tests 11 and 12, to make it
1231 possible to check the Perl 5.10 features against Perl 5.10.
1232
1233 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1234 pattern matches a fixed length string. PCRE did not allow this; now it
1235 does. Neither allows recursion.
1236
1237 25. I finally figured out how to implement a request to provide the minimum
1238 length of subject string that was needed in order to match a given pattern.
1239 (It was back references and recursion that I had previously got hung up
1240 on.) This code has now been added to pcre_study(); it finds a lower bound
1241 to the length of subject needed. It is not necessarily the greatest lower
1242 bound, but using it to avoid searching strings that are too short does give
1243 some useful speed-ups. The value is available to calling programs via
1244 pcre_fullinfo().
1245
1246 26. While implementing 25, I discovered to my embarrassment that pcretest had
1247 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1248 study optimizations had never been tested with that matching function.
1249 Oops. What is worse, even when it was passed study data, there was a bug in
1250 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1251 were also very few tests of studied patterns with pcre_dfa_exec().
1252
1253 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1254 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1255 on the other side of the coin, they are no longer allowed to have different
1256 names, because these cannot be distinguished in PCRE, and this has caused
1257 confusion. (This is a difference from Perl.)
1258
1259 28. When duplicate subpattern names are present (necessarily with different
1260 numbers, as required by 27 above), and a test is made by name in a
1261 conditional pattern, either for a subpattern having been matched, or for
1262 recursion in such a pattern, all the associated numbered subpatterns are
1263 tested, and the overall condition is true if the condition is true for any
1264 one of them. This is the way Perl works, and is also more like the way
1265 testing by number works.
1266
1267
1268 Version 7.9 11-Apr-09
1269 ---------------------
1270
1271 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1272 (pcretest), all targets were linked against these libraries. This included
1273 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1274 libraries. This caused unwanted dependencies to be created. This problem
1275 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1276 pcretest is linked with readline.
1277
1278 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1279 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1280 moved outside it again, because FALSE and TRUE are already defined in AIX,
1281 but BOOL is not.
1282
1283 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1284 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1285
1286 4. The pcregrep documentation said spaces were inserted as well as colons (or
1287 hyphens) following file names and line numbers when outputting matching
1288 lines. This is not true; no spaces are inserted. I have also clarified the
1289 wording for the --colour (or --color) option.
1290
1291 5. In pcregrep, when --colour was used with -o, the list of matching strings
1292 was not coloured; this is different to GNU grep, so I have changed it to be
1293 the same.
1294
1295 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1296 each matching line was coloured. Now it goes on to look for further matches
1297 of any of the test patterns, which is the same behaviour as GNU grep.
1298
1299 7. A pattern that could match an empty string could cause pcregrep to loop; it
1300 doesn't make sense to accept an empty string match in pcregrep, so I have
1301 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1302 seems to be how GNU grep behaves.
1303
1304 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1305 start or after a newline", because the conditional assertion was not being
1306 correctly handled. The rule now is that both the assertion and what follows
1307 in the first alternative must satisfy the test.
1308
1309 9. If auto-callout was enabled in a pattern with a conditional group whose
1310 condition was an assertion, PCRE could crash during matching, both with
1311 pcre_exec() and pcre_dfa_exec().
1312
1313 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1314 used for matching.
1315
1316 11. Unicode property support in character classes was not working for
1317 characters (bytes) greater than 127 when not in UTF-8 mode.
1318
1319 12. Added the -M command line option to pcretest.
1320
1321 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1322
1323 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1324
1325 16. Added comments and documentation about mis-use of no_arg in the C++
1326 wrapper.
1327
1328 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1329 from Martin Jerabek that uses macro names for all relevant character and
1330 string constants.
1331
1332 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1333 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1334 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1335 these, but not everybody uses configure.
1336
1337 19. A conditional group that had only one branch was not being correctly
1338 recognized as an item that could match an empty string. This meant that an
1339 enclosing group might also not be so recognized, causing infinite looping
1340 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1341 with the subject "ab", where knowledge that the repeated group can match
1342 nothing is needed in order to break the loop.
1343
1344 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1345 exec(), but without supplying a callout function, matching went wrong.
1346
1347 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1348 leak if the size of the offset vector was greater than 30. When the vector
1349 is smaller, the saved offsets during recursion go onto a local stack
1350 vector, but for larger vectors malloc() is used. It was failing to free
1351 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1352 error, in fact).
1353
1354 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1355 heapframe that is used only when UTF-8 support is enabled. This caused no
1356 problem, but was untidy.
1357
1358 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1359 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1360 included within another project.
1361
1362 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1363 slightly modified by me:
1364
1365 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1366 not building pcregrep.
1367
1368 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1369 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1370
1371 25. Forward references, both numeric and by name, in patterns that made use of
1372 duplicate group numbers, could behave incorrectly or give incorrect errors,
1373 because when scanning forward to find the reference group, PCRE was not
1374 taking into account the duplicate group numbers. A pattern such as
1375 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1376
1377 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1378 the feature of a custom pointer more persuasive (as requested by a user).
1379
1380 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1381 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1382 pre-defined.
1383
1384 28. Added support for (*UTF8) at the start of a pattern.
1385
1386 29. Arrange for flags added by the "release type" setting in CMake to be shown
1387 in the configuration summary.
1388
1389
1390 Version 7.8 05-Sep-08
1391 ---------------------
1392
1393 1. Replaced UCP searching code with optimized version as implemented for Ad
1394 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1395 stage table and inline lookup instead of a function, giving speed ups of 2
1396 to 5 times on some simple patterns that I tested. Permission was given to
1397 distribute the MultiStage2.py script that generates the tables (it's not in
1398 the tarball, but is in the Subversion repository).
1399
1400 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1401 scripts.
1402
1403 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1404 a group with a zero qualifier. The result of the study could be incorrect,
1405 or the function might crash, depending on the pattern.
1406
1407 4. Caseless matching was not working for non-ASCII characters in back
1408 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1409 It now works when Unicode Property Support is available.
1410
1411 5. In pcretest, an escape such as \x{de} in the data was always generating
1412 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1413 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1414 truncation.
1415
1416 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1417
1418 7. Added two (int) casts to pcregrep when printing the difference of two
1419 pointers, in case they are 64-bit values.
1420
1421 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1422 test 2 if it fails.
1423
1424 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1425 and a #define of that name to empty if it is not externally set. This is to
1426 allow users of MSVC to set it if necessary.
1427
1428 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1429 the convenience functions in the pcre_get.c source file.
1430
1431 11. An option change at the start of a pattern that had top-level alternatives
1432 could cause overwriting and/or a crash. This command provoked a crash in
1433 some environments:
1434
1435 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1436
1437 This potential security problem was recorded as CVE-2008-2371.
1438
1439 12. For a pattern where the match had to start at the beginning or immediately
1440 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1441 pcre_dfa_exec() could read past the end of the passed subject if there was
1442 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1443 pcretest so that it places the subject at the end of its malloc-ed buffer.
1444
1445 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1446 exec() might read past the end of the data buffer in UTF-8 mode.
1447
1448 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1449 the data contained the byte 0x85 as part of a UTF-8 character within its
1450 first line. This applied both to normal and DFA matching.
1451
1452 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1453 /^[^d]*?$/8 failed to match "abc".
1454
1455 16. Added a missing copyright notice to pcrecpp_internal.h.
1456
1457 17. Make it more clear in the documentation that values returned from
1458 pcre_exec() in ovector are byte offsets, not character counts.
1459
1460 18. Tidied a few places to stop certain compilers from issuing warnings.
1461
1462 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1463 supplied by Stefan Weber. I made a further small update for 7.8 because
1464 there is a change of source arrangements: the pcre_searchfuncs.c module is
1465 replaced by pcre_ucd.c.
1466
1467
1468 Version 7.7 07-May-08
1469 ---------------------
1470
1471 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1472 a string to a long long, pretend we don't even have a long long." This is
1473 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1474
1475 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1476 pre-7.6 versions, which defined a global no_arg variable instead of putting
1477 it in the RE class. (See also #8 below.)
1478
1479 3. Remove a line of dead code, identified by coverity and reported by Nuno
1480 Lopes.
1481
1482 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1483
1484 (1) The include/exclude patterns were being applied to the whole pathnames
1485 of files, instead of just to the final components.
1486
1487 (2) If there was more than one level of directory, the subdirectories were
1488 skipped unless they satisfied the include/exclude conditions. This is
1489 inconsistent with GNU grep (and could even be seen as contrary to the
1490 pcregrep specification - which I improved to make it absolutely clear).
1491 The action now is always to scan all levels of directory, and just
1492 apply the include/exclude patterns to regular files.
1493
1494 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1495 --exclude_dir in the tests to avoid scanning .svn directories.
1496
1497 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1498 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1499 doesn't support NULs in patterns.
1500
1501 7. Added some missing "const"s to declarations of static tables in
1502 pcre_compile.c and pcre_dfa_exec.c.
1503
1504 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1505 caused by fix #2 above. (Subsequently also a second patch to fix the
1506 first patch. And a third patch - this was a messy problem.)
1507
1508 9. Applied Craig's patch to remove the use of push_back().
1509
1510 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1511 matching function regexec().
1512
1513 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1514 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1515 references. PCRE supports relative numbers with this syntax (I don't think
1516 Oniguruma does).
1517
1518 12. Previously, a group with a zero repeat such as (...){0} was completely
1519 omitted from the compiled regex. However, this means that if the group
1520 was called as a subroutine from elsewhere in the pattern, things went wrong
1521 (an internal error was given). Such groups are now left in the compiled
1522 pattern, with a new opcode that causes them to be skipped at execution
1523 time.
1524
1525 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1526 to the way PCRE behaves:
1527
1528 (a) A lone ] character is dis-allowed (Perl treats it as data).
1529
1530 (b) A back reference to an unmatched subpattern matches an empty string
1531 (Perl fails the current match path).
1532
1533 (c) A data ] in a character class must be notated as \] because if the
1534 first data character in a class is ], it defines an empty class. (In
1535 Perl it is not possible to have an empty class.) The empty class []
1536 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1537 The negative empty class [^] matches any one character, independently
1538 of the DOTALL setting.
1539
1540 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1541 non-existent subpattern following a character class starting with ']' and
1542 containing () gave an internal compiling error instead of "reference to
1543 non-existent subpattern". Fortunately, when the pattern did exist, the
1544 compiled code was correct. (When scanning forwards to check for the
1545 existencd of the subpattern, it was treating the data ']' as terminating
1546 the class, so got the count wrong. When actually compiling, the reference
1547 was subsequently set up correctly.)
1548
1549 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1550 it was being rejected as not supported by pcre_dfa_exec(), even though
1551 other assertions are supported. I have made pcre_dfa_exec() support
1552 (*FAIL).
1553
1554 16. The implementation of 13c above involved the invention of a new opcode,
1555 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1556 cannot be changed at match time, I realized I could make a small
1557 improvement to matching performance by compiling OP_ALLANY instead of
1558 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1559 on the OP_ANY path.
1560
1561 17. Compiling pcretest on Windows with readline support failed without the
1562 following two fixes: (1) Make the unistd.h include conditional on
1563 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1564
1565 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1566 ncurses library to be included for pcretest when ReadLine support is
1567 requested, but also to allow for it to be overridden. This patch came from
1568 Daniel Bergström.
1569
1570 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1571 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1572 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1573 spotting this.
1574
1575
1576 Version 7.6 28-Jan-08
1577 ---------------------
1578
1579 1. A character class containing a very large number of characters with
1580 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1581 overflow.
1582
1583 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1584 HAVE_LONG_LONG is not defined.
1585
1586 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1587 bring them up to date and include new features. This patch includes:
1588
1589 - Fixed PH's badly added libz and libbz2 support.
1590 - Fixed a problem with static linking.
1591 - Added pcredemo. [But later removed - see 7 below.]
1592 - Fixed dftables problem and added an option.
1593 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1594 HAVE_LONG_LONG.
1595 - Added readline support for pcretest.
1596 - Added an listing of the option settings after cmake has run.
1597
1598 4. A user submitted a patch to Makefile that makes it easy to create
1599 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1600 Makefile.am that cause it to include this special target, without
1601 affecting anything else. Note that the same mingw target plus all
1602 the other distribution libraries and programs are now supported
1603 when configuring with CMake (see 6 below) instead of with
1604 Configure/Make.
1605
1606 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1607 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1608 exported in the Windows port". It has not yet been confirmed that the patch
1609 solves the problem, but it does no harm.
1610
1611 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1612 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1613 with CMake, and also correct the comment about stack recursion.
1614
1615 7. Remove the automatic building of pcredemo from the ./configure system and
1616 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1617 of a program that users should build themselves after PCRE is installed, so
1618 building it automatically is not really right. What is more, it gave
1619 trouble in some build environments.
1620
1621 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1622
1623
1624 Version 7.5 10-Jan-08
1625 ---------------------
1626
1627 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1628 values in parens when parsing an RE using the C++ wrapper."
1629
1630 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1631 Characters greater than 255 were excluded from the class instead of being
1632 included.
1633
1634 3. The same bug as (2) above applied to negated POSIX classes such as
1635 [:^space:].
1636
1637 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1638 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1639 I have changed it.
1640
1641 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1642 first named subpattern) and a construct such as (?&a) would reference the
1643 first named subpattern whose name started with "a" (in other words, the
1644 length check was missing). Both these problems are fixed. "Subpattern name
1645 expected" is now given for (?&) (a zero-length name), and this patch also
1646 makes it give the same error for \k'' (previously it complained that that
1647 was a reference to a non-existent subpattern).
1648
1649 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1650 this is right because (?- can be followed by option settings as well as by
1651 digits. I have, however, made the messages clearer.
1652
1653 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1654 than the number used in the conditional) now cause a compile-time error.
1655 This is actually not compatible with Perl, which accepts such patterns, but
1656 treats the conditional as always being FALSE (as PCRE used to), but it
1657 seems to me that giving a diagnostic is better.
1658
1659 8. Change "alphameric" to the more common word "alphanumeric" in comments
1660 and messages.
1661
1662 9. Fix two occurrences of "backslash" in comments that should have been
1663 "backspace".
1664
1665 10. Remove two redundant lines of code that can never be obeyed (their function
1666 was moved elsewhere).
1667
1668 11. The program that makes PCRE's Unicode character property table had a bug
1669 which caused it to generate incorrect table entries for sequences of
1670 characters that have the same character type, but are in different scripts.
1671 It amalgamated them into a single range, with the script of the first of
1672 them. In other words, some characters were in the wrong script. There were
1673 thirteen such cases, affecting characters in the following ranges:
1674
1675 U+002b0 - U+002c1
1676 U+0060c - U+0060d
1677 U+0061e - U+00612
1678 U+0064b - U+0065e
1679 U+0074d - U+0076d
1680 U+01800 - U+01805
1681 U+01d00 - U+01d77
1682 U+01d9b - U+01dbf
1683 U+0200b - U+0200f
1684 U+030fc - U+030fe
1685 U+03260 - U+0327f
1686 U+0fb46 - U+0fbb1
1687 U+10450 - U+1049d
1688
1689 12. The -o option (show only the matching part of a line) for pcregrep was not
1690 compatible with GNU grep in that, if there was more than one match in a
1691 line, it showed only the first of them. It now behaves in the same way as
1692 GNU grep.
1693
1694 13. If the -o and -v options were combined for pcregrep, it printed a blank
1695 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1696 does the same. The return code can be used to tell if there were any
1697 non-matching lines.
1698
1699 14. Added --file-offsets and --line-offsets to pcregrep.
1700
1701 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1702 infinitely looping recursion. The bug was that positive lookaheads were not
1703 being skipped when checking for a possible empty match (negative lookaheads
1704 and both kinds of lookbehind were skipped).
1705
1706 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1707 inclusion of <windows.h> to before rather than after the definition of
1708 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1709
1710 17. Specifying a possessive quantifier with a specific limit for a Unicode
1711 character property caused pcre_compile() to compile bad code, which led at
1712 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1713 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1714 caused the error; without that there was no problem.
1715
1716 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1717
1718 19. Added --enable-pcretest-libreadline.
1719
1720 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1721 RE::GlobalReplace(). As a result, the number of replacements returned was
1722 double what it should be. I removed one of the increments, but Craig sent a
1723 later patch that removed the other one (the right fix) and added unit tests
1724 that check the return values (which was not done before).
1725
1726 21. Several CMake things:
1727
1728 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1729 the names libpcre and libpcreposix, not just pcre and pcreposix.
1730
1731 (2) The above change means that pcretest and pcregrep are now correctly
1732 linked with the newly-built libraries, not previously installed ones.
1733
1734 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1735
1736 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1737 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1738 UTF-8 newline character). The key issue is that the pattern starts .*;
1739 this means that the match must be either at the beginning, or after a
1740 newline. The bug was in the code for advancing after a failed match and
1741 checking that the new position followed a newline. It was not taking
1742 account of UTF-8 characters correctly.
1743
1744 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1745 character classes. PCRE was not treating the sequence [:...:] as a
1746 character class unless the ... were all letters. Perl, however, seems to
1747 allow any characters between [: and :], though of course it rejects as
1748 unknown any "names" that contain non-letters, because all the known class
1749 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1750 for example, whereas PCRE did not - it did not recognize a POSIX character
1751 class. This seemed a bit dangerous, so the code has been changed to be
1752 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1753 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1754 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1755 Perl does, and where it didn't before.
1756
1757 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1758 Windows environments %n is disabled by default.
1759
1760
1761 Version 7.4 21-Sep-07
1762 ---------------------
1763
1764 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1765 means that a class such as [\s] counted as "explicit reference to CR or
1766 LF". That isn't really right - the whole point of the change was to try to
1767 help when there was an actual mention of one of the two characters. So now
1768 the change happens only if \r or \n (or a literal CR or LF) character is
1769 encountered.
1770
1771 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1772 of both had grown to the point where there were only 3 bits left.
1773 Fortunately, there was spare space in the data structure, and so I have
1774 moved the internal flags into a new 16-bit field to free up more option
1775 bits.
1776
1777 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1778 but did not set the internal JCHANGED flag - either of these is enough to
1779 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1780 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1781 start sets both bits.
1782
1783 4. Added options (at build time, compile time, exec time) to change \R from
1784 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1785
1786 5. doc/pcresyntax.html was missing from the distribution.
1787
1788 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1789 compatibility, even though it is no longer used.
1790
1791 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1792 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1793 windows.h file is present (where different names are used). [This was
1794 reversed later after testing - see 16 below.]
1795
1796 8. Changed all #include <config.h> to #include "config.h". There were also
1797 some further <pcre.h> cases that I changed to "pcre.h".
1798
1799 9. When pcregrep was used with the --colour option, it missed the line ending
1800 sequence off the lines that it output.
1801
1802 10. It was pointed out to me that arrays of string pointers cause lots of
1803 relocations when a shared library is dynamically loaded. A technique of
1804 using a single long string with a table of offsets can drastically reduce
1805 these. I have refactored PCRE in four places to do this. The result is
1806 dramatic:
1807
1808 Originally: 290
1809 After changing UCP table: 187
1810 After changing error message table: 43
1811 After changing table of "verbs" 36
1812 After changing table of Posix names 22
1813
1814 Thanks to the folks working on Gregex for glib for this insight.
1815
1816 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1817 unicode-properties was also set.
1818
1819 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1820
1821 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1822 checked only for CRLF.
1823
1824 14. Added casts to pcretest.c to avoid compiler warnings.
1825
1826 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1827
1828 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1829 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1830 entirely. This removes changes made in 7 above.
1831
1832 17. The CMake files have been updated, and there is now more information about
1833 building with CMake in the NON-UNIX-USE document.
1834
1835
1836 Version 7.3 28-Aug-07
1837 ---------------------
1838
1839 1. In the rejigging of the build system that eventually resulted in 7.1, the
1840 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1841 brackets there is not right, since it causes compilers to look for an
1842 installed pcre.h, not the version that is in the source that is being
1843 compiled (which of course may be different). I have changed it back to:
1844
1845 #include "pcre.h"
1846
1847 I have a vague recollection that the change was concerned with compiling in
1848 different directories, but in the new build system, that is taken care of
1849 by the VPATH setting the Makefile.
1850
1851 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1852 when the subject happened to end in the byte 0x85 (e.g. if the last
1853 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1854 characters but of course it shouldn't be taken as a newline when it is part
1855 of another character. The bug was that, for an unlimited repeat of . in
1856 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1857 characters when looking for a newline.
1858
1859 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1860
1861 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1862 in debug output.
1863
1864 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1865 long printing in the pcrecpp unittest when running under MinGW.
1866
1867 6. ESC_K was left out of the EBCDIC table.
1868
1869 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1870 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1871 limit also applies to "virtual nesting" when a pattern is recursive, and in
1872 this case 1000 isn't so big. I have been able to remove this limit at the
1873 expense of backing off one optimization in certain circumstances. Normally,
1874 when pcre_exec() would call its internal match() function recursively and
1875 immediately return the result unconditionally, it uses a "tail recursion"
1876 feature to save stack. However, when a subpattern that can match an empty
1877 string has an unlimited repetition quantifier, it no longer makes this
1878 optimization. That gives it a stack frame in which to save the data for
1879 checking that an empty string has been matched. Previously this was taken
1880 from the 1000-entry workspace that had been reserved. So now there is no
1881 explicit limit, but more stack is used.
1882
1883 8. Applied Daniel's patches to solve problems with the import/export magic
1884 syntax that is required for Windows, and which was going wrong for the
1885 pcreposix and pcrecpp parts of the library. These were overlooked when this
1886 problem was solved for the main library.
1887
1888 9. There were some crude static tests to avoid integer overflow when computing
1889 the size of patterns that contain repeated groups with explicit upper
1890 limits. As the maximum quantifier is 65535, the maximum group length was
1891 set at 30,000 so that the product of these two numbers did not overflow a
1892 32-bit integer. However, it turns out that people want to use groups that
1893 are longer than 30,000 bytes (though not repeat them that many times).
1894 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1895 made it possible to implement the integer overflow checks in a much more
1896 dynamic way, which I have now done. The artificial limitation on group
1897 length has been removed - we now have only the limit on the total length of
1898 the compiled pattern, which depends on the LINK_SIZE setting.
1899
1900 10. Fixed a bug in the documentation for get/copy named substring when
1901 duplicate names are permitted. If none of the named substrings are set, the
1902 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1903 empty string.
1904
1905 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1906 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1907 because the ] is interpreted as the first data character and the
1908 terminating ] is not found. PCRE has been made compatible with Perl in this
1909 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1910 cause memory overwriting.
1911
1912 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1913 string has been matched (to stop an infinite loop). It was not recognizing
1914 a conditional subpattern that could match an empty string if that
1915 subpattern was within another subpattern. For example, it looped when
1916 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1917 condition was not nested. This bug has been fixed.
1918
1919 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1920 past the start of the subject in the presence of bytes with the top bit
1921 set, for example "\x8aBCD".
1922
1923 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1924 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1925
1926 14. Optimized (?!) to (*FAIL).
1927
1928 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1929 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1930 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1931 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1932 does: it's just the validity check that is more restrictive.
1933
1934 16. Inserted checks for integer overflows during escape sequence (backslash)
1935 processing, and also fixed erroneous offset values for syntax errors during
1936 backslash processing.
1937
1938 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1939 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1940
1941 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1942 caused an overrun.
1943
1944 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1945 something other than just ASCII characters) inside a group that had an
1946 unlimited repeat caused a loop at compile time (while checking to see
1947 whether the group could match an empty string).
1948
1949 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1950 [\P{Any}] did so. (Error in the code for printing property names.)
1951
1952 21. An orphan \E inside a character class could cause a crash.
1953
1954 22. A repeated capturing bracket such as (A)? could cause a wild memory
1955 reference during compilation.
1956
1957 23. There are several functions in pcre_compile() that scan along a compiled
1958 expression for various reasons (e.g. to see if it's fixed length for look
1959 behind). There were bugs in these functions when a repeated \p or \P was
1960 present in the pattern. These operators have additional parameters compared
1961 with \d, etc, and these were not being taken into account when moving along
1962 the compiled data. Specifically:
1963
1964 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1965 length.
1966
1967 (b) An item such as \pL+ within a repeated group could cause crashes or
1968 loops.
1969
1970 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1971 "reference to non-existent subpattern" error.
1972
1973 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1974
1975 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1976 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1977
1978 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1979
1980 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1981 character were causing crashes (broken optimization).
1982
1983 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1984 \p or \P) caused a compile-time loop.
1985
1986 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1987 break. For example, the unstudied pattern [\r\n]A does not match the string
1988 "\r\nA" because change 7.0/46 below moves the current point on by two
1989 characters after failing to match at the start. However, the pattern \nA
1990 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1991 the same is true. There doesn't seem any very clean way out of this, but
1992 what I have chosen to do makes the common cases work: PCRE now takes note
1993 of whether there can be an explicit match for \r or \n anywhere in the
1994 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1995 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1996 pattern has explicit CR or LF references.
1997
1998 29. Added (*CR) etc for changing newline setting at start of pattern.
1999
2000
2001 Version 7.2 19-Jun-07
2002 ---------------------
2003
2004 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2005 which is apparently normally available under Windows.
2006
2007 2. Re-jig the pcregrep tests with different newline settings in an attempt
2008 to make them independent of the local environment's newline setting.
2009
2010 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2011
2012 4. Some of the "internals" tests were previously cut out when the link size
2013 was not 2, because the output contained actual offsets. The recent new
2014 "Z" feature of pcretest means that these can be cut out, making the tests
2015 usable with all link sizes.
2016
2017 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2018 stack recursion. This gives a massive performance boost under BSD, but just
2019 a small improvement under Linux. However, it saves one field in the frame
2020 in all cases.
2021
2022 6. Added more features from the forthcoming Perl 5.10:
2023
2024 (a) (?-n) (where n is a string of digits) is a relative subroutine or
2025 recursion call. It refers to the nth most recently opened parentheses.
2026
2027 (b) (?+n) is also a relative subroutine call; it refers to the nth next
2028 to be opened parentheses.
2029
2030 (c) Conditions that refer to capturing parentheses can be specified
2031 relatively, for example, (?(-2)... or (?(+3)...
2032
2033 (d) \K resets the start of the current match so that everything before
2034 is not part of it.
2035
2036 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2037
2038 (f) \g{name} is another synonym - part of Perl 5.10's unification of
2039 reference syntax.
2040
2041 (g) (?| introduces a group in which the numbering of parentheses in each
2042 alternative starts with the same number.
2043
2044 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2045
2046 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2047 PCRE_INFO_JCHANGED.
2048
2049 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
2050 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2051 for detecting groups that can match an empty string.
2052
2053 9. A pattern with a very large number of alternatives (more than several
2054 hundred) was running out of internal workspace during the pre-compile
2055 phase, where pcre_compile() figures out how much memory will be needed. A
2056 bit of new cunning has reduced the workspace needed for groups with
2057 alternatives. The 1000-alternative test pattern now uses 12 bytes of
2058 workspace instead of running out of the 4096 that are available.
2059
2060 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2061
2062 11. Applied patch from Google to remove an optimization that didn't quite work.
2063 The report of the bug said:
2064
2065 pcrecpp::RE("a*").FullMatch("aaa") matches, while
2066 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2067 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2068
2069 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2070 it matched the wrong number of bytes.
2071
2072
2073 Version 7.1 24-Apr-07
2074 ---------------------
2075
2076 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2077 that is more "standard", making use of automake and other Autotools. There
2078 is some re-arrangement of the files and adjustment of comments consequent
2079 on this.
2080
2081 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2082 for recursive directory scanning broke on some systems because the files
2083 are not scanned in any specific order and on different systems the order
2084 was different. A call to "sort" has been inserted into RunGrepTest for the
2085 approprate test as a short-term fix. In the longer term there may be an
2086 alternative.
2087
2088 3. I had an email from Eric Raymond about problems translating some of PCRE's
2089 man pages to HTML (despite the fact that I distribute HTML pages, some
2090 people do their own conversions for various reasons). The problems
2091 concerned the use of low-level troff macros .br and .in. I have therefore
2092 removed all such uses from the man pages (some were redundant, some could
2093 be replaced by .nf/.fi pairs). The 132html script that I use to generate
2094 HTML has been updated to handle .nf/.fi and to complain if it encounters
2095 .br or .in.
2096
2097 4. Updated comments in configure.ac that get placed in config.h.in and also
2098 arranged for config.h to be included in the distribution, with the name
2099 config.h.generic, for the benefit of those who have to compile without
2100 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2101
2102 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2103 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2104 makevp.bat for the current PCRE, using the additional files
2105 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2106
2107 6. A Windows user reported a minor discrepancy with test 2, which turned out
2108 to be caused by a trailing space on an input line that had got lost in his
2109 copy. The trailing space was an accident, so I've just removed it.
2110
2111 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2112 that is needed.
2113
2114 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2115 as "const" (a) because they are and (b) because it helps the PHP
2116 maintainers who have recently made a script to detect big data structures
2117 in the php code that should be moved to the .rodata section. I remembered
2118 to update Builducptable as well, so it won't revert if ucptable.h is ever
2119 re-created.
2120
2121 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2122 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2123 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2124 support is not required. This saves 1.5-2K of code, which is important in
2125 some applications.
2126
2127 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2128 so as not to refer to the tables, even though these functions will never be
2129 called when UTF-8 support is disabled. Otherwise there are problems with a
2130 shared library.
2131
2132 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2133
2134 (a) It was defining its arguments as char * instead of void *.
2135
2136 (b) It was assuming that all moves were upwards in memory; this was true
2137 a long time ago when I wrote it, but is no longer the case.
2138
2139 The emulated memove() is provided for those environments that have neither
2140 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2141 is clearly not the case, as these two bugs were recently reported.
2142
2143 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2144 and Detrail to create the HTML documentation, the .txt form of the man
2145 pages, and it removes trailing spaces from listed files. It also creates
2146 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2147 case, it wraps all the #defines with #ifndefs. This script should be run
2148 before "make dist".
2149
2150 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2151 with Unicode property support.
2152
2153 (a) For a maximizing quantifier, if the two different cases of the
2154 character were of different lengths in their UTF-8 codings (there are
2155 some cases like this - I found 11), and the matching function had to
2156 back up over a mixture of the two cases, it incorrectly assumed they
2157 were both the same length.
2158
2159 (b) When PCRE was configured to use the heap rather than the stack for
2160 recursion during matching, it was not correctly preserving the data for
2161 the other case of a UTF-8 character when checking ahead for a match
2162 while processing a minimizing repeat. If the check also involved
2163 matching a wide character, but failed, corruption could cause an
2164 erroneous result when trying to check for a repeat of the original
2165 character.
2166
2167 13. Some tidying changes to the testing mechanism:
2168
2169 (a) The RunTest script now detects the internal link size and whether there
2170 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2171 values substituted by "configure". (The RunGrepTest script already did
2172 this for UTF-8.) The configure.ac script no longer substitutes the
2173 relevant variables.
2174
2175 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2176 with length and offset values. This means that the output is different
2177 for different internal link sizes. Test 2 is skipped for link sizes
2178 other than 2 because of this, bypassing the problem. Unfortunately,
2179 there was also a test in test 3 (the locale tests) that used /B and
2180 failed for link sizes other than 2. Rather than cut the whole test out,
2181 I have added a new /Z option to pcretest that replaces the length and
2182 offset values with spaces. This is now used to make test 3 independent
2183 of link size. (Test 2 will be tidied up later.)
2184
2185 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2186 segmentation fault instead of returning the appropriate error message.
2187
2188 15. In multiline mode when the newline sequence was set to "any", the pattern
2189 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2190 This doesn't seem right; it now treats the CRLF combination as the line
2191 ending, and so does not match in that case. It's only a pattern such as ^$
2192 that would hit this one: something like ^ABC$ would have failed after \r
2193 and then tried again after \r\n.
2194
2195 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2196 in an attempt to make files that differ only in their line terminators
2197 compare equal. This works on Linux.
2198
2199 17. Under certain error circumstances pcregrep might try to free random memory
2200 as it exited. This is now fixed, thanks to valgrind.
2201
2202 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2203 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2204 was because its rules for how to advance for /g after matching an empty
2205 string at the end of a line did not allow for this case. They now check for
2206 it specially.
2207
2208 20. pcretest is supposed to handle patterns and data of any length, by
2209 extending its buffers when necessary. It was getting this wrong when the
2210 buffer for a data line had to be extended.
2211
2212 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2213 CRLF as a newline sequence.
2214
2215 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2216 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2217 I have nevertheless tidied it up.
2218
2219 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2220
2221 24. Added a man page for pcre-config.
2222
2223
2224 Version 7.0 19-Dec-06
2225 ---------------------
2226
2227 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2228 moving to gcc 4.1.1.
2229
2230 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2231 sys/time.h, which is documented as needed for this function. It doesn't
2232 seem to matter on Linux, but it showed up on some releases of OS X.
2233
2234 3. It seems that there are systems where bytes whose values are greater than
2235 127 match isprint() in the "C" locale. The "C" locale should be the
2236 default when a C program starts up. In most systems, only ASCII printing
2237 characters match isprint(). This difference caused the output from pcretest
2238 to vary, making some of the tests fail. I have changed pcretest so that:
2239
2240 (a) When it is outputting text in the compiled version of a pattern, bytes
2241 other than 32-126 are always shown as hex escapes.
2242
2243 (b) When it is outputting text that is a matched part of a subject string,
2244 it does the same, unless a different locale has been set for the match
2245 (using the /L modifier). In this case, it uses isprint() to decide.
2246
2247 4. Fixed a major bug that caused incorrect computation of the amount of memory
2248 required for a compiled pattern when options that changed within the
2249 pattern affected the logic of the preliminary scan that determines the
2250 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2251 that the computed length was too small. The symptoms of this bug were
2252 either the PCRE error "internal error: code overflow" from pcre_compile(),
2253 or a glibc crash with a message such as "pcretest: free(): invalid next
2254 size (fast)". Examples of patterns that provoked this bug (shown in
2255 pcretest format) are:
2256
2257 /(?-x: )/x
2258 /(?x)(?-x: \s*#\s*)/
2259 /((?i)[\x{c0}])/8
2260 /(?i:[\x{c0}])/8
2261
2262 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2263 is now done differently.
2264
2265 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2266 wrapper classes; (b) implement a new function in the C++ scanner that is
2267 more efficient than the old way of doing things because it avoids levels of
2268 recursion in the regex matching; (c) add a paragraph to the documentation
2269 for the FullMatch() function.
2270
2271 6. The escape sequence \n was being treated as whatever was defined as
2272 "newline". Not only was this contrary to the documentation, which states
2273 that \n is character 10 (hex 0A), but it also went horribly wrong when
2274 "newline" was defined as CRLF. This has been fixed.
2275
2276 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2277 was being set to -1 for the "end of line" case (supposedly a value that no
2278 character can have). Though this value is never used (the check for end of
2279 line is "zero bytes in current character"), it caused compiler complaints.
2280 I've changed it to 0xffffffff.
2281
2282 8. In pcre_version.c, the version string was being built by a sequence of
2283 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2284 string (as it is for production releases) called a macro with an empty
2285 argument. The C standard says the result of this is undefined. The gcc
2286 compiler treats it as an empty string (which was what was wanted) but it is
2287 reported that Visual C gives an error. The source has been hacked around to
2288 avoid this problem.
2289
2290 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2291 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2292 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2293 of them did).
2294
2295 10. Originally, pcretest opened its input and output without "b"; then I was
2296 told that "b" was needed in some environments, so it was added for release
2297 5.0 to both the input and output. (It makes no difference on Unix-like
2298 systems.) Later I was told that it is wrong for the input on Windows. I've
2299 now abstracted the modes into two macros, to make it easier to fiddle with
2300 them, and removed "b" from the input mode under Windows.
2301
2302 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2303
2304 12. Added -help and --help to pcretest as an official way of being reminded
2305 of the options.
2306
2307 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2308 and pcrecpp.cc because they annoy compilers at high warning levels.
2309
2310 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2311
2312 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2313 scripts are not C programs :-) and which was not noticed because it works
2314 on Linux.
2315
2316 16. pcretest is supposed to handle any length of pattern and data line (as one
2317 line or as a continued sequence of lines) by extending its input buffer if
2318 necessary. This feature was broken for very long pattern lines, leading to
2319 a string of junk being passed to pcre_compile() if the pattern was longer
2320 than about 50K.
2321
2322 17. I have done a major re-factoring of the way pcre_compile() computes the
2323 amount of memory needed for a compiled pattern. Previously, there was code
2324 that made a preliminary scan of the pattern in order to do this. That was
2325 OK when PCRE was new, but as the facilities have expanded, it has become
2326 harder and harder to keep it in step with the real compile phase, and there
2327 have been a number of bugs (see for example, 4 above). I have now found a
2328 cunning way of running the real compile function in a "fake" mode that
2329 enables it to compute how much memory it would need, while actually only
2330 ever using a few hundred bytes of working memory and without too many
2331 tests of the mode. This should make future maintenance and development
2332 easier. A side effect of this work is that the limit of 200 on the nesting
2333 depth of parentheses has been removed (though this was never a serious
2334 limitation, I suspect). However, there is a downside: pcre_compile() now
2335 runs more slowly than before (30% or more, depending on the pattern). I
2336 hope this isn't a big issue. There is no effect on runtime performance.
2337
2338 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2339 newline (only possible for the last line of a file) and it was a
2340 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2341
2342 19. Added additional timing features to pcretest. (1) The -tm option now times
2343 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2344 separate command line item, by a number that specifies the number of
2345 repeats to use when timing. The default is 50000; this gives better
2346 precision, but takes uncomfortably long for very large patterns.
2347
2348 20. Extended pcre_study() to be more clever in cases where a branch of a
2349 subpattern has no definite first character. For example, (a*|b*)[cd] would
2350 previously give no result from pcre_study(). Now it recognizes that the
2351 first character must be a, b, c, or d.
2352
2353 21. There was an incorrect error "recursive call could loop indefinitely" if
2354 a subpattern (or the entire pattern) that was being tested for matching an
2355 empty string contained only one non-empty item after a nested subpattern.
2356 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2357 incorrectly, because the \d was being skipped in the check.
2358
2359 22. The pcretest program now has a new pattern option /B and a command line
2360 option -b, which is equivalent to adding /B to every pattern. This causes
2361 it to show the compiled bytecode, without the additional information that
2362 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2363 is the same as /B/I).
2364
2365 23. A new optimization is now able automatically to treat some sequences such
2366 as a*b as a*+b. More specifically, if something simple (such as a character
2367 or a simple class like \d) has an unlimited quantifier, and is followed by
2368 something that cannot possibly match the quantified thing, the quantifier
2369 is automatically "possessified".
2370
2371 24. A recursive reference to a subpattern whose number was greater than 39
2372 went wrong under certain circumstances in UTF-8 mode. This bug could also
2373 have affected the operation of pcre_study().
2374
2375 25. Realized that a little bit of performance could be had by replacing
2376 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2377
2378 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2379
2380 27. Possessive quantifiers such as a++ were previously implemented by turning
2381 them into atomic groups such as ($>a+). Now they have their own opcodes,
2382 which improves performance. This includes the automatically created ones
2383 from 23 above.
2384
2385 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2386 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2387 the first matched character to be a colon. This applied both to named and
2388 numbered groups.
2389
2390 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2391
2392 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2393 building PCRE on Windows easier, so I have included it in the distribution.
2394
2395 31. There is now a check in pcretest against a ridiculously large number being
2396 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2397 loop, the loop is abandoned.
2398
2399 32. Forward references to subpatterns in conditions such as (?(2)...) where
2400 subpattern 2 is defined later cause pcre_compile() to search forwards in
2401 the pattern for the relevant set of parentheses. This search went wrong
2402 when there were unescaped parentheses in a character class, parentheses
2403 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2404
2405 33. "Subroutine" calls and backreferences were previously restricted to
2406 referencing subpatterns earlier in the regex. This restriction has now
2407 been removed.
2408
2409 34. Added a number of extra features that are going to be in Perl 5.10. On the
2410 whole, these are just syntactic alternatives for features that PCRE had
2411 previously implemented using the Python syntax or my own invention. The
2412 other formats are all retained for compatibility.
2413
2414 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2415 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2416 also .NET compatible.
2417
2418 (b) A recursion or subroutine call to a named group can now be defined as
2419 (?&name) as well as (?P>name).
2420
2421 (c) A backreference to a named group can now be defined as \k<name> or
2422 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2423 5.10, are also .NET compatible.
2424
2425 (d) A conditional reference to a named group can now use the syntax
2426 (?(<name>) or (?('name') as well as (?(name).
2427
2428 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2429 groups (named and numbered) that are never evaluated inline, but can be
2430 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2431 is always false. There may be only one alternative in such a group.
2432
2433 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2434 as the simple (?(R). The condition is true only if the most recent
2435 recursion is that of the given number or name. It does not search out
2436 through the entire recursion stack.
2437
2438 (g) The escape \gN or \g{N} has been added, where N is a positive or
2439 negative number, specifying an absolute or relative reference.
2440
2441 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2442 some "unreachable code" warnings.
2443
2444 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2445 things, this adds five new scripts.
2446
2447 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2448 There were also incompatibilities regarding the handling of \Q..\E inside
2449 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2450 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2451
2452 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2453 matches an empty string, and forcibly breaks the loop. There were bugs in
2454 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2455 against aaaa the result was just "a" rather than "aaaa", for example. Two
2456 separate and independent bugs (that affected different cases) have been
2457 fixed.
2458
2459 39. Refactored the code to abolish the use of different opcodes for small
2460 capturing bracket numbers. This is a tidy that I avoided doing when I
2461 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2462 The new approach is not only tidier, it makes it possible to reduce the
2463 memory needed to fix the previous bug (38).
2464
2465 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2466 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2467 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2468 mode.
2469
2470 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2471 report.
2472
2473 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2474 copy construction and assignment in the C++ wrapper.
2475
2476 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2477 couple of bugs that could have given wrong results in the "--newline=crlf"
2478 case.
2479
2480 44. Added a number of casts and did some reorganization of signed/unsigned int
2481 variables following suggestions from Dair Grant. Also renamed the variable
2482 "this" as "item" because it is a C++ keyword.
2483
2484 45. Arranged for dftables to add
2485
2486 #include "pcre_internal.h"
2487
2488 to pcre_chartables.c because without it, gcc 4.x may remove the array
2489 definition from the final binary if PCRE is built into a static library and
2490 dead code stripping is activated.
2491
2492 46. For an unanchored pattern, if a match attempt fails at the start of a
2493 newline sequence, and the newline setting is CRLF or ANY, and the next two
2494 characters are CRLF, advance by two characters instead of one.
2495
2496
2497 Version 6.7 04-Jul-06
2498 ---------------------
2499
2500 1. In order to handle tests when input lines are enormously long, pcretest has
2501 been re-factored so that it automatically extends its buffers when
2502 necessary. The code is crude, but this _is_ just a test program. The
2503 default size has been increased from 32K to 50K.
2504
2505 2. The code in pcre_study() was using the value of the re argument before
2506 testing it for NULL. (Of course, in any sensible call of the function, it
2507 won't be NULL.)
2508
2509 3. The memmove() emulation function in pcre_internal.h, which is used on
2510 systems that lack both memmove() and bcopy() - that is, hardly ever -
2511 was missing a "static" storage class specifier.
2512
2513 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2514 containing an extended class (one that cannot be represented by a bitmap
2515 because it contains high-valued characters or Unicode property items, e.g.
2516 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2517 pattern, but PCRE should not loop if you do not (it no longer does).
2518 [Detail: two cases were found: (a) a repeated subpattern containing an
2519 extended class; (b) a recursive reference to a subpattern that followed a
2520 previous extended class. It wasn't skipping over the extended class
2521 correctly when UTF-8 mode was not set.]
2522
2523 5. A negated single-character class was not being recognized as fixed-length
2524 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2525 compile error "lookbehind assertion is not fixed length".
2526
2527 6. The RunPerlTest auxiliary script was showing an unexpected difference
2528 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2529 write a Perl script that can interpret lines of an input file either as
2530 byte characters or as UTF-8, which is what "perltest" was being required to
2531 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2532 can't do is switch easily at run time between having the "use utf8;" pragma
2533 or not. In the end, I fudged it by using the RunPerlTest script to insert
2534 "use utf8;" explicitly for the UTF-8 tests.
2535
2536 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2537 the end of the subject string, contrary to the documentation and to what
2538 Perl does. This was true of both matching functions. Now it matches only at
2539 the start of the subject and immediately after *internal* newlines.
2540
2541 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2542 a pointer to an int instead of a pointer to an unsigned long int. This
2543 caused problems on 64-bit systems.
2544
2545 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2546 instance of the 'standard' template library not being so standard".
2547
2548 10. There was no check on the number of named subpatterns nor the maximum
2549 length of a subpattern name. The product of these values is used to compute
2550 the size of the memory block for a compiled pattern. By supplying a very
2551 long subpattern name and a large number of named subpatterns, the size
2552 computation could be caused to overflow. This is now prevented by limiting
2553 the length of names to 32 characters, and the number of named subpatterns
2554 to 10,000.
2555
2556 11. Subpatterns that are repeated with specific counts have to be replicated in
2557 the compiled pattern. The size of memory for this was computed from the
2558 length of the subpattern and the repeat count. The latter is limited to
2559 65535, but there was no limit on the former, meaning that integer overflow
2560 could in principle occur. The compiled length of a repeated subpattern is
2561 now limited to 30,000 bytes in order to prevent this.
2562
2563 12. Added the optional facility to have named substrings with the same name.
2564
2565 13. Added the ability to use a named substring as a condition, using the
2566 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2567 are numbers (not recommended). Forward references are permitted.
2568
2569 14. Added forward references in named backreferences (if you see what I mean).
2570
2571 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2572 pattern could run off the end of the subject. For example, the pattern
2573 "(?s)(.{1,5})"8 did this with the subject "ab".
2574
2575 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2576 PCRE_CASELESS was set when matching characters that were quantified with ?
2577 or *.
2578
2579 17. A character class other than a single negated character that had a minimum
2580 but no maximum quantifier - for example [ab]{6,} - was not handled
2581 correctly by pce_dfa_exec(). It would match only one character.
2582
2583 18. A valid (though odd) pattern that looked like a POSIX character
2584 class but used an invalid character after [ (for example [[,abc,]]) caused
2585 pcre_compile() to give the error "Failed: internal error: code overflow" or
2586 in some cases to crash with a glibc free() error. This could even happen if
2587 the pattern terminated after [[ but there just happened to be a sequence of
2588 letters, a binary zero, and a closing ] in the memory that followed.
2589
2590 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2591 over the years. Originally (before any Unicode support), just the bottom 8
2592 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2593 output from "man perlunicode" includes this:
2594
2595 The regular expression compiler produces polymorphic opcodes. That
2596 is, the pattern adapts to the data and automatically switches to
2597 the Unicode character scheme when presented with Unicode data--or
2598 instead uses a traditional byte scheme when presented with byte
2599 data.
2600
2601 Sadly, a wide octal escape does not cause a switch, and in a string with
2602 no other multibyte characters, these octal escapes are treated as before.
2603 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2604 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2605 Unicode string.
2606
2607 I have not perpetrated such confusion in PCRE. Up till now, it took just
2608 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2609 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2610 translate to the appropriate multibyte character.
2611
2612 29. Applied some refactoring to reduce the number of warnings from Microsoft
2613 and Borland compilers. This has included removing the fudge introduced
2614 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2615 a warning about an unused variable.
2616
2617 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2618 characters since release 4.0, because Perl (from release 5.004) does not.
2619 [Or at least, is documented not to: some releases seem to be in conflict
2620 with the documentation.] However, when a pattern was studied with
2621 pcre_study() and all its branches started with \s, PCRE still included VT
2622 as a possible starting character. Of course, this did no harm; it just
2623 caused an unnecessary match attempt.
2624
2625 22. Removed a now-redundant internal flag bit that recorded the fact that case
2626 dependency changed within the pattern. This was once needed for "required
2627 byte" processing, but is no longer used. This recovers a now-scarce options
2628 bit. Also moved the least significant internal flag bit to the most-
2629 significant bit of the word, which was not previously used (hangover from
2630 the days when it was an int rather than a uint) to free up another bit for
2631 the future.
2632
2633 23. Added support for CRLF line endings as well as CR and LF. As well as the
2634 default being selectable at build time, it can now be changed at runtime
2635 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2636 specify that it is scanning data with non-default line endings.
2637
2638 24. Changed the definition of CXXLINK to make it agree with the definition of
2639 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2640
2641 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2642 recursions. This makes a big different to stack usage for some patterns.
2643
2644 26. If a subpattern containing a named recursion or subroutine reference such
2645 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2646 the space required for the compiled pattern went wrong and gave too small a
2647 value. Depending on the environment, this could lead to "Failed: internal
2648 error: code overflow at offset 49" or "glibc detected double free or
2649 corruption" errors.
2650
2651 27. Applied patches from Google (a) to support the new newline modes and (b) to
2652 advance over multibyte UTF-8 characters in GlobalReplace.
2653
2654 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2655 difference for some implementation of PCRE in some Windows version.
2656
2657 29. Added some extra testing facilities to pcretest:
2658
2659 \q<number> in a data line sets the "match limit" value
2660 \Q<number> in a data line sets the "match recursion limt" value
2661 -S <number> sets the stack size, where <number> is in megabytes
2662
2663 The -S option isn't available for Windows.
2664
2665
2666 Version 6.6 06-Feb-06
2667 ---------------------
2668
2669 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2670 in pcreposix.h. I have copied the definition from pcre.h.
2671
2672 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2673 because pcre.h is no longer a built file.
2674
2675 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2676 not normally included in the compiled code.
2677
2678
2679 Version 6.5 01-Feb-06
2680 ---------------------
2681
2682 1. When using the partial match feature with pcre_dfa_exec(), it was not
2683 anchoring the second and subsequent partial matches at the new starting
2684 point. This could lead to incorrect results. For example, with the pattern
2685 /1234/, partially matching against "123" and then "a4" gave a match.
2686
2687 2. Changes to pcregrep:
2688
2689 (a) All non-match returns from pcre_exec() were being treated as failures
2690 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2691 error message is output. Some extra information is given for the
2692 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2693 probably the only errors that are likely to be caused by users (by
2694 specifying a regex that has nested indefinite repeats, for instance).
2695 If there are more than 20 of these errors, pcregrep is abandoned.
2696
2697 (b) A binary zero was treated as data while matching, but terminated the
2698 output line if it was written out. This has been fixed: binary zeroes
2699 are now no different to any other data bytes.
2700
2701 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2702 used to set a locale for matching. The --locale=xxxx long option has
2703 been added (no short equivalent) to specify a locale explicitly on the
2704 pcregrep command, overriding the environment variables.
2705
2706 (d) When -B was used with -n, some line numbers in the output were one less
2707 than they should have been.
2708
2709 (e) Added the -o (--only-matching) option.
2710
2711 (f) If -A or -C was used with -c (count only), some lines of context were
2712 accidentally printed for the final match.
2713
2714 (g) Added the -H (--with-filename) option.
2715
2716 (h) The combination of options -rh failed to suppress file names for files
2717 that were found from directory arguments.
2718
2719 (i) Added the -D (--devices) and -d (--directories) options.
2720
2721 (j) Added the -F (--fixed-strings) option.
2722
2723 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2724
2725 (l) Added the --colo(u)r option.
2726
2727 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2728 is not present by default.
2729
2730 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2731 items such as (?R) or (?1), when the recursion could match a number of
2732 alternatives. If it matched one of the alternatives, but subsequently,
2733 outside the recursion, there was a failure, the code tried to back up into
2734 the recursion. However, because of the way PCRE is implemented, this is not
2735 possible, and the result was an incorrect result from the match.
2736
2737 In order to prevent this happening, the specification of recursion has
2738 been changed so that all such subpatterns are automatically treated as
2739 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2740
2741 4. I had overlooked the fact that, in some locales, there are characters for
2742 which isalpha() is true but neither isupper() nor islower() are true. In
2743 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2744 and ordfeminine) are like this. This affected the treatment of \w and \W
2745 when they appeared in character classes, but not when they appeared outside
2746 a character class. The bit map for "word" characters is now created
2747 separately from the results of isalnum() instead of just taking it from the
2748 upper, lower, and digit maps. (Plus the underscore character, of course.)
2749
2750 5. The above bug also affected the handling of POSIX character classes such as
2751 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2752 permanent tables. Instead, the bit maps for such a class were previously
2753 created as the appropriate unions of the upper, lower, and digit bitmaps.
2754 Now they are created by subtraction from the [[:word:]] class, which has
2755 its own bitmap.
2756
2757 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2758 It is created by subtracting the vertical space characters (\x09, \x0a,
2759 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2760 subtraction was done in the overall bitmap for a character class, meaning
2761 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2762 be recognized. This bug has been fixed.
2763
2764 7. Patches from the folks at Google:
2765
2766 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2767 real life, but is still worth protecting against".
2768
2769 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2770 regular expressions".
2771
2772 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2773 have it.
2774
2775 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2776 "configure" and the latter not, in order to fix a problem somebody had
2777 with compiling the Arg class on HP-UX.
2778
2779 (e) Improve the error-handling of the C++ wrapper a little bit.
2780
2781 (f) New tests for checking recursion limiting.
2782
2783 8. The pcre_memmove() function, which is used only if the environment does not
2784 have a standard memmove() function (and is therefore rarely compiled),
2785 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2786 returning a result (though PCRE never actually uses the result).
2787
2788 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2789 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2790 returned instead of calling malloc() with an overflowing number that would
2791 most likely cause subsequent chaos.
2792
2793 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2794
2795 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2796 with this option is matched, the nmatch and pmatch options of regexec() are
2797 ignored.
2798
2799 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2800 provided in case anyone wants to the the POSIX interface with UTF-8
2801 strings.
2802
2803 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2804 C++ linking (needed for some HP-UX environments).
2805
2806 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2807 (unused parameter) and in the pcre_printint() function (omitted "default"
2808 switch label when the default is to do nothing).
2809
2810 15. Added some code to make it possible, when PCRE is compiled as a C++
2811 library, to replace subject pointers for pcre_exec() with a smart pointer
2812 class, thus making it possible to process discontinuous strings.
2813
2814 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2815 much the same function. They were added by different people who were trying
2816 to make PCRE easy to compile on non-Unix systems. It has been suggested
2817 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2818 for compiling on Windows systems. I have therefore replaced it with
2819 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2820 defaults to "extern" for C or "extern C" for C++, which works fine on
2821 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2822 SCOPE with something explicit in config.h. In addition:
2823
2824 (a) pcreposix.h still had just "extern" instead of either of these macros;
2825 I have replaced it with PCRE_DATA_SCOPE.
2826
2827 (b) Functions such as _pcre_xclass(), which are internal to the library,
2828 but external in the C sense, all had PCRE_EXPORT in their definitions.
2829 This is apparently wrong for the Windows case, so I have removed it.
2830 (It makes no difference on Unix-like systems.)
2831
2832 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2833 of recursive calls to match(). This is different to MATCH_LIMIT because
2834 that limits the total number of calls to match(), not all of which increase
2835 the depth of recursion. Limiting the recursion depth limits the amount of
2836 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2837 when PCRE is compiled, and changed at run time. A patch from Google adds
2838 this functionality to the C++ interface.
2839
2840 18. Changes to the handling of Unicode character properties:
2841
2842 (a) Updated the table to Unicode 4.1.0.
2843
2844 (b) Recognize characters that are not in the table as "Cn" (undefined).
2845
2846 (c) I revised the way the table is implemented to a much improved format
2847 which includes recognition of ranges. It now supports the ranges that
2848 are defined in UnicodeData.txt, and it also amalgamates other
2849 characters into ranges. This has reduced the number of entries in the
2850 table from around 16,000 to around 3,000, thus reducing its size
2851 considerably. I realized I did not need to use a tree structure after
2852 all - a binary chop search is just as efficient. Having reduced the
2853 number of entries, I extended their size from 6 bytes to 8 bytes to
2854 allow for more data.
2855
2856 (d) Added support for Unicode script names via properties such as \p{Han}.
2857
2858 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2859 matching that character.
2860
2861 20. When matching a repeated Unicode property with a minimum greater than zero,
2862 (for example \pL{2,}), PCRE could look past the end of the subject if it
2863 reached it while seeking the minimum number of characters. This could
2864 happen only if some of the characters were more than one byte long, because
2865 there is a check for at least the minimum number of bytes.
2866
2867 21. Refactored the implementation of \p and \P so as to be more general, to
2868 allow for more different types of property in future. This has changed the
2869 compiled form incompatibly. Anybody with saved compiled patterns that use
2870 \p or \P will have to recompile them.
2871
2872 22. Added "Any" and "L&" to the supported property types.
2873
2874 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2875 but give a compile time error if the value is greater than 0xff.
2876
2877 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2878 accidentally not being installed or uninstalled.
2879
2880 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2881 made were to insert the current release number. This seemed silly, because
2882 it made things harder for people building PCRE on systems that don't run
2883 "configure". I have turned pcre.h into a distributed file, no longer built
2884 by "configure", with the version identification directly included. There is
2885 no longer a pcre.h.in file.
2886
2887 However, this change necessitated a change to the pcre-config script as
2888 well. It is built from pcre-config.in, and one of the substitutions was the
2889 release number. I have updated configure.ac so that ./configure now finds
2890 the release number by grepping pcre.h.
2891
2892 26. Added the ability to run the tests under valgrind.
2893
2894
2895 Version 6.4 05-Sep-05
2896 ---------------------
2897
2898 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2899 "--" to be printed when multiple files were scanned, even when none of the
2900 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2901 consider it to be a bug, and have restored the previous behaviour.
2902
2903 2. A couple of code tidies to get rid of compiler warnings.
2904
2905 3. The pcretest program used to cheat by referring to symbols in the library
2906 whose names begin with _pcre_. These are internal symbols that are not
2907 really supposed to be visible externally, and in some environments it is
2908 possible to suppress them. The cheating is now confined to including
2909 certain files from the library's source, which is a bit cleaner.
2910
2911 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2912 file's purpose clearer.
2913
2914 5. Reorganized pcre_ucp_findchar().
2915
2916
2917 Version 6.3 15-Aug-05
2918 ---------------------
2919
2920 1. The file libpcre.pc.in did not have general read permission in the tarball.
2921
2922 2. There were some problems when building without C++ support:
2923
2924 (a) If C++ support was not built, "make install" and "make test" still
2925 tried to test it.
2926
2927 (b) There were problems when the value of CXX was explicitly set. Some
2928 changes have been made to try to fix these, and ...
2929
2930 (c) --disable-cpp can now be used to explicitly disable C++ support.
2931
2932 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2933 backslash in a target when C++ was disabled. This confuses some
2934 versions of "make", apparently. Using an intermediate variable solves
2935 this. (Same for CPP_LOBJ.)
2936
2937 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2938 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2939 necessary on certain architectures.
2940
2941 4. Added a setting of -export-symbols-regex to the link command to remove
2942 those symbols that are exported in the C sense, but actually are local
2943 within the library, and not documented. Their names all begin with
2944 "_pcre_". This is not a perfect job, because (a) we have to except some
2945 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2946 available (and never for static libraries). I have made a note to try to
2947 find a way round (a) in the future.
2948
2949
2950 Version 6.2 01-Aug-05
2951 ---------------------
2952
2953 1. There was no test for integer overflow of quantifier values. A construction
2954 such as {1111111111111111} would give undefined results. What is worse, if
2955 a minimum quantifier for a parenthesized subpattern overflowed and became
2956 negative, the calculation of the memory size went wrong. This could have
2957 led to memory overwriting.
2958
2959 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2960
2961 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2962 operating environments where this matters.
2963
2964 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2965 PCRE options from within the C++ wrapper.
2966
2967 5. Named capturing subpatterns were not being correctly counted when a pattern
2968 was compiled. This caused two problems: (a) If there were more than 100
2969 such subpatterns, the calculation of the memory needed for the whole
2970 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2971 back references of the form \12, where the number was greater than 9, were
2972 not recognized as back references, even though there were sufficient
2973 previous subpatterns.
2974
2975 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2976 versions of gcc, e.g. 2.95.4.
2977
2978
2979 Version 6.1 21-Jun-05
2980 ---------------------
2981
2982 1. There was one reference to the variable "posix" in pcretest.c that was not
2983 surrounded by "#if !defined NOPOSIX".
2984
2985 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2986 the cross-check on the old pcre_info() function, for the benefit of the
2987 cut-down version of PCRE that is currently imported into Exim.
2988
2989 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2990 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2991 patterns that start (?i) but I don't think that matters. The use of (?i) is
2992 just an example; this all applies to the other options as well.
2993
2994 4. Since libtool seems to echo the compile commands it is issuing, the output
2995 from "make" can be reduced a bit by putting "@" in front of each libtool
2996 compile command.
2997
2998 5. Patch from the folks at Google for configure.in to be a bit more thorough
2999 in checking for a suitable C++ installation before trying to compile the
3000 C++ stuff. This should fix a reported problem when a compiler was present,
3001 but no suitable headers.
3002
3003 6. The man pages all had just "PCRE" as their title. I have changed them to
3004 be the relevant file name. I have also arranged that these names are
3005 retained in the file doc/pcre.txt, which is a concatenation in text format
3006 of all the man pages except the little individual ones for each function.
3007
3008 7. The NON-UNIX-USE file had not been updated for the different set of source
3009 files that come with release 6. I also added a few comments about the C++
3010 wrapper.
3011
3012
3013 Version 6.0 07-Jun-05
3014 ---------------------
3015
3016 1. Some minor internal re-organization to help with my DFA experiments.
3017
3018 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3019 didn't matter for the library itself when fully configured, but did matter
3020 when compiling without UCP support, or within Exim, where the ucp files are
3021 not imported.
3022
3023 3. Refactoring of the library code to split up the various functions into
3024 different source modules. The addition of the new DFA matching code (see
3025 below) to a single monolithic source would have made it really too
3026 unwieldy, quite apart from causing all the code to be include in a
3027 statically linked application, when only some functions are used. This is
3028 relevant even without the DFA addition now that patterns can be compiled in
3029 one application and matched in another.
3030
3031 The downside of splitting up is that there have to be some external
3032 functions and data tables that are used internally in different modules of
3033 the library but which are not part of the API. These have all had their
3034 names changed to start with "_pcre_" so that they are unlikely to clash
3035 with other external names.
3036
3037 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3038 a different (DFA) algorithm. Although it is slower than the original
3039 function, it does have some advantages for certain types of matching
3040 problem.
3041
3042 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3043 including restarting after a partial match.
3044
3045 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3046 defined when compiling for Windows was sent to me. I have put it into the
3047 code, though I have no means of testing or verifying it.
3048
3049 7. Added the pcre_refcount() auxiliary function.
3050
3051 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3052 match before or at the first newline in the subject string. In pcretest,
3053 the /f option on a pattern can be used to set this.
3054
3055 9. A repeated \w when used in UTF-8 mode with characters greater than 256
3056 would behave wrongly. This has been present in PCRE since release 4.0.
3057
3058 10. A number of changes to the pcregrep command:
3059
3060 (a) Refactored how -x works; insert ^(...)$ instead of setting
3061 PCRE_ANCHORED and checking the length, in preparation for adding
3062 something similar for -w.
3063
3064 (b) Added the -w (match as a word) option.
3065
3066 (c) Refactored the way lines are read and buffered so as to have more
3067 than one at a time available.
3068
3069 (d) Implemented a pcregrep test script.
3070
3071 (e) Added the -M (multiline match) option. This allows patterns to match
3072 over several lines of the subject. The buffering ensures that at least
3073 8K, or the rest of the document (whichever is the shorter) is available
3074 for matching (and similarly the previous 8K for lookbehind assertions).
3075
3076 (f) Changed the --help output so that it now says
3077
3078 -w, --word-regex(p)
3079
3080 instead of two lines, one with "regex" and the other with "regexp"
3081 because that confused at least one person since the short forms are the
3082 same. (This required a bit of code, as the output is generated
3083 automatically from a table. It wasn't just a text change.)
3084
3085 (g) -- can be used to terminate pcregrep options if the next thing isn't an
3086 option but starts with a hyphen. Could be a pattern or a path name
3087 starting with a hyphen, for instance.
3088
3089 (h) "-" can be given as a file name to represent stdin.
3090
3091 (i) When file names are being printed, "(standard input)" is used for
3092 the standard input, for compatibility with GNU grep. Previously
3093 "<stdin>" was used.
3094
3095 (j) The option --label=xxx can be used to supply a name to be used for
3096 stdin when file names are being printed. There is no short form.
3097
3098 (k) Re-factored the options decoding logic because we are going to add
3099 two more options that take data. Such options can now be given in four
3100 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3101
3102 (l) Added the -A, -B, and -C options for requesting that lines of context
3103 around matches be printed.
3104
3105 (m) Added the -L option to print the names of files that do not contain
3106 any matching lines, that is, the complement of -l.
3107
3108 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3109 continue to scan other files.
3110
3111 (o) The -s option was incorrectly implemented. For compatibility with other
3112 greps, it now suppresses the error message for a non-existent or non-
3113 accessible file (but not the return code). There is a new option called
3114 -q that suppresses the output of matching lines, which was what -s was
3115 previously doing.
3116
3117 (p) Added --include and --exclude options to specify files for inclusion
3118 and exclusion when recursing.
3119
3120 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3121 Hopefully, it now does.
3122
3123 12. Missing cast in pcre_study().
3124
3125 13. Added an "uninstall" target to the makefile.
3126
3127 14. Replaced "extern" in the function prototypes in Makefile.in with
3128 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3129 world, but is set differently for Windows.
3130
3131 15. Added a second compiling function called pcre_compile2(). The only
3132 difference is that it has an extra argument, which is a pointer to an
3133 integer error code. When there is a compile-time failure, this is set
3134 non-zero, in addition to the error test pointer being set to point to an
3135 error message. The new argument may be NULL if no error number is required
3136 (but then you may as well call pcre_compile(), which is now just a
3137 wrapper). This facility is provided because some applications need a
3138 numeric error indication, but it has also enabled me to tidy up the way
3139 compile-time errors are handled in the POSIX wrapper.
3140
3141 16. Added VPATH=.libs to the makefile; this should help when building with one
3142 prefix path and installing with another. (Or so I'm told by someone who
3143 knows more about this stuff than I do.)
3144
3145 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3146 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3147 match everything, including newlines. This is not POSIX-compatible, but
3148 somebody wanted the feature. From pcretest it can be activated by using
3149 both the P and the s flags.
3150
3151 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3152
3153 19. libpcre.pc was being incorrectly installed as executable.
3154
3155 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3156 it now also looks for '\r' so that it will work unmodified on Windows.
3157
3158 21. Added Google's contributed C++ wrapper to the distribution.
3159
3160 22. Added some untidy missing memory free() calls in pcretest, to keep
3161 Electric Fence happy when testing.
3162
3163
3164
3165 Version 5.0 13-Sep-04
3166 ---------------------
3167
3168 1. Internal change: literal characters are no longer packed up into items
3169 containing multiple characters in a single byte-string. Each character
3170 is now matched using a separate opcode. However, there may be more than one
3171 byte in the character in UTF-8 mode.
3172
3173 2. The pcre_callout_block structure has two new fields: pattern_position and
3174 next_item_length. These contain the offset in the pattern to the next match
3175 item, and its length, respectively.
3176
3177 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3178 insertion of callouts before each pattern item. Added the /C option to
3179 pcretest to make use of this.
3180
3181 4. On the advice of a Windows user, the lines
3182
3183 #if defined(_WIN32) || defined(WIN32)
3184 _setmode( _fileno( stdout ), 0x8000 );
3185 #endif /* defined(_WIN32) || defined(WIN32) */
3186
3187 have been added to the source of pcretest. This apparently does useful
3188 magic in relation to line terminators.
3189
3190 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3191 for the benefit of those environments where the "b" makes a difference.
3192
3193 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3194 to know about it. I have put a hack into configure.in that adds in code
3195 to set GCC=yes if CC=icc. This seems to end up at a point in the
3196 generated configure script that is early enough to affect the setting of
3197 compiler options, which is what is needed, but I have no means of testing
3198 whether it really works. (The user who reported this had patched the
3199 generated configure script, which of course I cannot do.)
3200
3201 LATER: After change 22 below (new libtool files), the configure script
3202 seems to know about icc (and also ecc). Therefore, I have commented out
3203 this hack in configure.in.
3204
3205 7. Added support for pkg-config (2 patches were sent in).
3206
3207 8. Negated POSIX character classes that used a combination of internal tables
3208 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3209 [[:^ascii]]. Typically, they would match almost any characters. The other
3210 POSIX classes were not broken in this way.
3211
3212 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3213 to find the match, as PCRE was deluded into thinking that the match had to
3214 start at the start point or following a newline. The same bug applied to
3215 patterns with negative forward assertions or any backward assertions
3216 preceding ".*" at the start, unless the pattern required a fixed first
3217 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3218
3219 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3220 starting at the last subject character, bytes beyond the end of the subject
3221 string were read.
3222
3223 11. Renamed the variable "class" as "classbits" to make life easier for C++
3224 users. (Previously there was a macro definition, but it apparently wasn't
3225 enough.)
3226
3227 12. Added the new field "tables" to the extra data so that tables can be passed
3228 in at exec time, or the internal tables can be re-selected. This allows
3229 a compiled regex to be saved and re-used at a later time by a different
3230 program that might have everything at different addresses.
3231
3232 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3233 -R library as well as a -L library.
3234
3235 14. The debugging options of pcretest (-d on the command line or D on a
3236 pattern) showed incorrect output for anything following an extended class
3237 that contained multibyte characters and which was followed by a quantifier.
3238
3239 15. Added optional support for general category Unicode character properties
3240 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3241 support. It adds about 90K to the size of the library. The meanings of the
3242 inbuilt class escapes such as \d and \s have NOT been changed.
3243
3244 16. Updated pcredemo.c to include calls to free() to release the memory for the
3245 compiled pattern.
3246
3247 17. The generated file chartables.c was being created in the source directory
3248 instead of in the building directory. This caused the build to fail if the
3249 source directory was different from the building directory, and was
3250 read-only.
3251
3252 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3253 file. No doubt somebody will tell me if they don't make sense... Also added
3254 Dan Mooney's comments about building on OpenVMS.
3255
3256 19. Added support for partial matching via the PCRE_PARTIAL option for
3257 pcre_exec() and the \P data escape in pcretest.
3258
3259 20. Extended pcretest with 3 new pattern features:
3260
3261 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3262 write the compiled pattern to the file whose name is "rest-of-line".
3263 This is a straight binary dump of the data, with the saved pointer to
3264 the character tables forced to be NULL. The study data, if any, is
3265 written too. After writing, pcretest reads a new pattern.
3266
3267 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3268 compiled pattern from the given file. There must not be any
3269 occurrences of "<" in the file name (pretty unlikely); if there are,
3270 pcretest will instead treat the initial "<" as a pattern delimiter.
3271 After reading in the pattern, pcretest goes on to read data lines as
3272 usual.
3273
3274 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3275 and 16-bit fields in a compiled pattern, to simulate a pattern that
3276 was compiled on a host of opposite endianness.
3277
3278 21. The pcre-exec() function can now cope with patterns that were compiled on
3279 hosts of opposite endianness, with this restriction:
3280
3281 As for any compiled expression that is saved and used later, the tables
3282 pointer field cannot be preserved; the extra_data field in the arguments
3283 to pcre_exec() should be used to pass in a tables address if a value
3284 other than the default internal tables were used at compile time.
3285
3286 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3287 now diagnosed as an error. Previously, most of the time, a negative number
3288 would have been treated as zero, but if in addition "ovector" was passed as
3289 NULL, a crash could occur.
3290
3291 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3292 new versions from the libtool 1.5 distribution (the last one is a copy of
3293 a file called libtool.m4). This seems to have fixed the need to patch
3294 "configure" to support Darwin 1.3 (which I used to do). However, I still
3295 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3296 workstation).
3297
3298 24. Changed the PCRE licence to be the more standard "BSD" licence.
3299
3300
3301 Version 4.5 01-Dec-03
3302 ---------------------
3303
3304 1. There has been some re-arrangement of the code for the match() function so
3305 that it can be compiled in a version that does not call itself recursively.
3306 Instead, it keeps those local variables that need separate instances for
3307 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3308 needs to "recurse". Keeping track of where control must go is done by means
3309 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3310 hide most of the details from the main code, and operates only if
3311 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3312 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3313 operating.
3314
3315 To make it easier for callers to provide specially tailored get/free
3316 functions for this usage, two new functions, pcre_stack_malloc, and
3317 pcre_stack_free, are used. They are always called in strict stacking order,
3318 and the size of block requested is always the same.
3319
3320 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3321 PCRE has been compiled to use the stack or the heap for recursion. The
3322 -C option of pcretest uses this to show which version is compiled.
3323
3324 A new data escape \S, is added to pcretest; it causes the amounts of store
3325 obtained and freed by both kinds of malloc/free at match time to be added
3326 to the output.
3327
3328 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3329 what's available on my current Linux desktop machine.
3330
3331 3. When matching a UTF-8 string, the test for a valid string at the start has
3332 been extended. If start_offset is not zero, PCRE now checks that it points
3333 to a byte that is the start of a UTF-8 character. If not, it returns
3334 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3335 this is necessary because there may be backward assertions in the pattern.
3336 When matching the same subject several times, it may save resources to use
3337 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3338
3339 4. The code for checking the validity of UTF-8 strings has been tightened so
3340 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3341 containing "overlong sequences".
3342
3343 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3344 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3345 should have been "&", but it just so happened that all the cases this let
3346 through by mistake were picked up later in the function.
3347
3348 6. I had used a variable called "isblank" - this is a C99 function, causing
3349 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3350
3351 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3352 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3353 so the version is shown; (c) stop "make test" echoing "./RunTest".
3354
3355 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3356
3357 9. The prototype for memmove() for systems that don't have it was using
3358 size_t, but the inclusion of the header that defines size_t was later. I've
3359 moved the #includes for the C headers earlier to avoid this.
3360
3361 10. Added some adjustments to the code to make it easier to compiler on certain
3362 special systems:
3363
3364 (a) Some "const" qualifiers were missing.
3365 (b) Added the macro EXPORT before all exported functions; by default this
3366 is defined to be empty.
3367 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3368 that it reads its output file name as an argument instead of writing
3369 to the standard output and assuming this can be redirected.
3370
3371 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3372 class containing characters with values greater than 255, PCRE compilation
3373 went into a loop.
3374
3375 12. A recursive reference to a subpattern that was within another subpattern
3376 that had a minimum quantifier of zero caused PCRE to crash. For example,
3377 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3378 recursion. If the recursively-called subpattern itself had a zero repeat,
3379 that was OK.
3380
3381 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3382 buffer into which it was copied (for escape processing) was still set at
3383 1024, so long lines caused crashes.
3384
3385 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3386 "internal error: code overflow...". This applied to any character class
3387 that was followed by a possessive quantifier.
3388
3389 15. Modified the Makefile to add libpcre.la as a prerequisite for
3390 libpcreposix.la because I was told this is needed for a parallel build to
3391 work.
3392
3393 16. If a pattern that contained .* following optional items at the start was
3394 studied, the wrong optimizing data was generated, leading to matching
3395 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3396 matching string must start with a or b or c. The correct conclusion for
3397 this pattern is that a match can start with any character.
3398
3399
3400 Version 4.4 13-Aug-03
3401 ---------------------
3402
3403 1. In UTF-8 mode, a character class containing characters with values between
3404 127 and 255 was not handled correctly if the compiled pattern was studied.
3405 In fixing this, I have also improved the studying algorithm for such
3406 classes (slightly).
3407
3408 2. Three internal functions had redundant arguments passed to them. Removal
3409 might give a very teeny performance improvement.
3410
3411 3. Documentation bug: the value of the capture_top field in a callout is *one
3412 more than* the number of the hightest numbered captured substring.
3413
3414 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3415 in incorrectly linking with a previously installed version. They now link
3416 explicitly with libpcre.la.
3417
3418 5. configure.in no longer needs to recognize Cygwin specially.
3419
3420 6. A problem in pcre.in for Windows platforms is fixed.
3421
3422 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3423 pcretest, it used to include the size of the study block as part of its
3424 output. Unfortunately, the structure contains a field that has a different
3425 size on different hardware architectures. This meant that the tests that
3426 showed this size failed. As the block is currently always of a fixed size,
3427 this information isn't actually particularly useful in pcretest output, so
3428 I have just removed it.
3429
3430 8. Three pre-processor statements accidentally did not start in column 1.
3431 Sadly, there are *still* compilers around that complain, even though
3432 standard C has not required this for well over a decade. Sigh.
3433
3434 9. In pcretest, the code for checking callouts passed small integers in the
3435 callout_data field, which is a void * field. However, some picky compilers
3436 complained about the casts involved for this on 64-bit systems. Now
3437 pcretest passes the address of the small integer instead, which should get
3438 rid of the warnings.
3439
3440 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3441 both compile and run time, and gives an error if an invalid UTF-8 sequence
3442 is found. There is a option for disabling this check in cases where the
3443 string is known to be correct and/or the maximum performance is wanted.
3444
3445 11. In response to a bug report, I changed one line in Makefile.in from
3446
3447 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3448 to
3449 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3450
3451 to look similar to other lines, but I have no way of telling whether this
3452 is the right thing to do, as I do not use Windows. No doubt I'll get told
3453 if it's wrong...
3454
3455
3456 Version 4.3 21-May-03
3457 ---------------------
3458
3459 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3460 Makefile.
3461
3462 2. Some refactoring to improve the quality of the code:
3463
3464 (i) The utf8_table... variables are now declared "const".
3465
3466 (ii) The code for \cx, which used the "case flipping" table to upper case
3467 lower case letters, now just substracts 32. This is ASCII-specific,
3468 but the whole concept of \cx is ASCII-specific, so it seems
3469 reasonable.
3470
3471 (iii) PCRE was using its character types table to recognize decimal and
3472 hexadecimal digits in the pattern. This is silly, because it handles
3473 only 0-9, a-f, and A-F, but the character types table is locale-
3474 specific, which means strange things might happen. A private
3475 table is now used for this - though it costs 256 bytes, a table is
3476 much faster than multiple explicit tests. Of course, the standard
3477 character types table is still used for matching digits in subject
3478 strings against \d.
3479
3480 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3481 ending in _t are). So I've renamed it as ESC_tee.
3482
3483 3. The first argument for regexec() in the POSIX wrapper should have been
3484 defined as "const".
3485
3486 4. Changed pcretest to use malloc() for its buffers so that they can be
3487 Electric Fenced for debugging.
3488
3489 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3490 to read one or more bytes before the start of the subject string. Often this
3491 had no effect on PCRE's behaviour, but in some circumstances it could
3492 provoke a segmentation fault.
3493
3494 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3495 to try to read one or more bytes before the start of the subject string.
3496
3497 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3498 UTF-8 support could misbehave in various ways if the subject string
3499 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3500 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3501 back over UTF-8 characters.)
3502
3503
3504 Version 4.2 14-Apr-03
3505 ---------------------
3506
3507 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3508
3509 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3510 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3511 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3512 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3513 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3514 and BUILD_EXEEXT
3515 Note: automatic setting of the BUILD variables is not yet working
3516 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3517 compile-time but not at link-time
3518 [LINK]: use for linking executables only
3519 make different versions for Windows and non-Windows
3520 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3521 libraries
3522 [LINK_FOR_BUILD]: new variable
3523 [OBJEXT]: use throughout
3524 [EXEEXT]: use throughout
3525 <winshared>: new target
3526 <wininstall>: new target
3527 <dftables.o>: use native compiler
3528 <dftables>: use native linker
3529 <install>: handle Windows platform correctly
3530 <clean>: ditto
3531 <check>: ditto
3532 copy DLL to top builddir before testing
3533
3534 As part of these changes, -no-undefined was removed again. This was reported
3535 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3536 in any case.
3537
3538 3. Some tidies to get rid of compiler warnings:
3539
3540 . In the match_data structure, match_limit was an unsigned long int, whereas
3541 match_call_count was an int. I've made them both unsigned long ints.
3542
3543 . In pcretest the fact that a const uschar * doesn't automatically cast to
3544 a void * provoked a warning.
3545
3546 . Turning on some more compiler warnings threw up some "shadow" variables
3547 and a few more missing casts.
3548
3549 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3550 option, a class that contained a single character with a value between 128
3551 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3552
3553 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3554 option, a class that contained several characters, but with at least one
3555 whose value was between 128 and 255 caused PCRE to crash.
3556
3557
3558 Version 4.1 12-Mar-03
3559 ---------------------
3560
3561 1. Compiling with gcc -pedantic found a couple of places where casts were
3562 needed, and a string in dftables.c that was longer than standard compilers are
3563 required to support.
3564
3565 2. Compiling with Sun's compiler found a few more places where the code could
3566 be tidied up in order to avoid warnings.
3567
3568 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3569 first of these names is deprecated in the latest Autoconf in favour of the name
3570 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3571 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3572 analogy I have changed it to CFLAGS_FOR_BUILD.
3573
3574 4. Added -no-undefined to the linking command in the Makefile, because this is
3575 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3576 linking step for the pcreposix library.
3577
3578 5. PCRE was failing to diagnose the case of two named groups with the same
3579 name.
3580
3581 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3582 literal character that is needed in the subject for a match, and scans along to
3583 ensure that it is present before embarking on the full matching process. This
3584 saves time in cases of nested unlimited repeats that are never going to match.
3585 Problem: the scan can take a lot of time if the subject is very long (e.g.
3586 megabytes), thus penalizing straightforward matches. It is now done only if the
3587 amount of subject to be scanned is less than 1000 bytes.
3588
3589 7. A lesser problem with the same optimization is that it was recording the
3590 first character of an anchored pattern as "needed", thus provoking a search
3591 right along the subject, even when the first match of the pattern was going to
3592 fail. The "needed" character is now not set for anchored patterns, unless it
3593 follows something in the pattern that is of non-fixed length. Thus, it still
3594 fulfils its original purpose of finding quick non-matches in cases of nested
3595 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3596
3597
3598 Version 4.0 17-Feb-03
3599 ---------------------
3600
3601 1. If a comment in an extended regex that started immediately after a meta-item
3602 extended to the end of string, PCRE compiled incorrect data. This could lead to
3603 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3604
3605 2. Moved to autoconf 2.53 and libtool 1.4.2.
3606
3607 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3608 the special perltest8 script is no longer needed - all the tests can be run
3609 from a single perltest script.
3610
3611 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3612 by \s. It has now been removed in PCRE. This means it isn't recognized as
3613 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3614 class [:space:] *does* include VT, thereby creating a mess.
3615
3616 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3617 space and tab.
3618
3619 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3620 its new features into the main test script, reducing the number of scripts.
3621
3622 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3623 were backward compatible, and made the (?i) apply to the whole pattern, as if
3624 /i were given. Now it behaves more logically, and applies the option setting
3625 only to what follows. PCRE has been changed to follow suit. However, if it
3626 finds options settings right at the start of the pattern, it extracts them into
3627 the global options, as before. Thus, they show up in the info data.
3628
3629 8. Added support for the \Q...\E escape sequence. Characters in between are
3630 treated as literals. This is slightly different from Perl in that $ and @ are
3631 also handled as literals inside the quotes. In Perl, they will cause variable
3632 interpolation. Note the following examples:
3633
3634 Pattern PCRE matches Perl matches
3635
3636 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3637 \Qabc\$xyz\E abc\$xyz abc\$xyz
3638 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3639
3640 For compatibility with Perl, \Q...\E sequences are recognized inside character
3641 classes as well as outside them.
3642
3643 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3644 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3645 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3646 signed/unsigned warnings.
3647
3648 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3649 option for pcretest, so I've replaced it by a simple function that does just
3650 that job.
3651
3652 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3653 "pcregrep -".
3654
3655 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3656 Java package. This provides some syntactic sugar for simple cases of what my
3657 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3658 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3659 item, you can use this simplified notation. Note that only makes sense with
3660 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3661 greediness, whatever the setting of the PCRE_UNGREEDY option.
3662
3663 13. A change of greediness default within a pattern was not taking effect at
3664 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3665 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3666 was abstracted outside.
3667
3668 14. PCRE now supports the \G assertion. It is true when the current matching
3669 position is at the start point of the match. This differs from \A when the
3670 starting offset is non-zero. Used with the /g option of pcretest (or similar
3671 code), it works in the same way as it does for Perl's /g option. If all
3672 alternatives of a regex begin with \G, the expression is anchored to the start
3673 match position, and the "anchored" flag is set in the compiled expression.
3674
3675 15. Some bugs concerning the handling of certain option changes within patterns
3676 have been fixed. These applied to options other than (?ims). For example,
3677 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3678 been the other way round. Some of this was related to change 7 above.
3679
3680 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3681 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3682 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3683 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3684
3685 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3686 mode. Unlike ".", it always matches newline, whatever the setting of
3687 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3688 assertions. Perl allows it, but it doesn't (in general) work because it can't
3689 calculate the length of the lookbehind. At least, that's the case for Perl
3690 5.8.0 - I've been told they are going to document that it doesn't work in
3691 future.
3692
3693 18. Added an error diagnosis for escapes that PCRE does not support: these are
3694 \L, \l, \N, \P, \p, \U, \u, and \X.
3695
3696 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3697 reading past the end of the pattern in cases such as /[abcd/.
3698
3699 20. PCRE was getting more memory than necessary for patterns with classes that
3700 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3701
3702 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3703 compiling PCRE for use with Virtual Pascal.
3704
3705 22. Small fix to the Makefile to make it work properly if the build is done
3706 outside the source tree.
3707
3708 23. Added a new extension: a condition to go with recursion. If a conditional
3709 subpattern starts with (?(R) the "true" branch is used if recursion has
3710 happened, whereas the "false" branch is used only at the top level.
3711
3712 24. When there was a very long string of literal characters (over 255 bytes
3713 without UTF support, over 250 bytes with UTF support), the computation of how
3714 much memory was required could be incorrect, leading to segfaults or other
3715 strange effects.
3716
3717 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3718 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3719 there was a subsequent back reference to those brackets. This meant that, for
3720 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3721 possible to check for precisely this case. All we can do is abandon the
3722 optimization if .* occurs inside capturing brackets when there are any back
3723 references whatsoever. (See below for a better fix that came later.)
3724
3725 26. The handling of the optimization for finding the first character of a
3726 non-anchored pattern, and for finding a character that is required later in the
3727 match were failing in some cases. This didn't break the matching; it just
3728 failed to optimize when it could. The way this is done has been re-implemented.
3729
3730 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3731
3732 28. Added a new feature that provides some of the functionality that Perl
3733 provides with (?{...}). The facility is termed a "callout". The way it is done
3734 in PCRE is for the caller to provide an optional function, by setting
3735 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3736 global variable. By default it is unset, which disables all calling out. To get
3737 the function called, the regex must include (?C) at appropriate points. This
3738 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3739 This provides a means of identifying different callout points. When PCRE
3740 reaches such a point in the regex, if pcre_callout has been set, the external
3741 function is called. It is provided with data in a structure called
3742 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3743 matching continues; if it returns a non-zero value, the match at the current
3744 point fails. However, backtracking will occur if possible. [This was changed
3745 later and other features added - see item 49 below.]
3746
3747 29. pcretest is upgraded to test the callout functionality. It provides a
3748 callout function that displays information. By default, it shows the start of
3749 the match and the current position in the text. There are some new data escapes
3750 to vary what happens:
3751
3752 \C+ in addition, show current contents of captured substrings
3753 \C- do not supply a callout function
3754 \C!n return 1 when callout number n is reached
3755 \C!n!m return 1 when callout number n is reached for the mth time
3756
3757 30. If pcregrep was called with the -l option and just a single file name, it
3758 output "<stdin>" if a match was found, instead of the file name.
3759
3760 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3761 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3762 pcre_exec(). This saves a malloc/free per call. The default value of
3763 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3764 when configuring.
3765
3766 32. The default maximum size of a compiled pattern is 64K. There have been a
3767 few cases of people hitting this limit. The code now uses macros to handle the
3768 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3769 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3770 configuring. Tests 2 and 5 work only with 2-byte links because they output
3771 debugging information about compiled patterns.
3772
3773 33. Internal code re-arrangements:
3774
3775 (a) Moved the debugging function for printing out a compiled regex into
3776 its own source file (printint.c) and used #include to pull it into
3777 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3778 separate copies.
3779
3780 (b) Defined the list of op-code names for debugging as a macro in
3781 internal.h so that it is next to the definition of the opcodes.
3782
3783 (c) Defined a table of op-code lengths for simpler skipping along compiled
3784 code. This is again a macro in internal.h so that it is next to the
3785 definition of the opcodes.
3786
3787 34. Added support for recursive calls to individual subpatterns, along the
3788 lines of Robin Houston's patch (but implemented somewhat differently).
3789
3790 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3791 allow it to read and process whole directories in Win32. This code was
3792 contributed by Lionel Fourquaux; it has not been tested by me.
3793
3794 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3795 used to name a group. Names consist of alphanumerics and underscores, and must
3796 be unique. Back references use the syntax (?P=name) and recursive calls use
3797 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3798 numbers. The function pcre_fullinfo() can be used after compilation to extract
3799 a name/number map. There are three relevant calls:
3800
3801 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3802 PCRE_INFO_NAMECOUNT yields the number of entries
3803 PCRE_INFO_NAMETABLE yields a pointer to the map.
3804
3805 The map is a vector of fixed-size entries. The size of each entry depends on
3806 the length of the longest name used. The first two bytes of each entry are the
3807 group number, most significant byte first. There follows the corresponding
3808 name, zero terminated. The names are in alphabetical order.
3809
3810 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3811 case instead of 255. Making it the same both with and without UTF-8 support
3812 means that the same test output works with both.
3813
3814 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3815 calling malloc() with a zero argument.
3816
3817 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3818 optimization. I've improved things by keeping a bitmap of backreferences with
3819 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3820 fact referenced, the optimization can be applied. It is unlikely that a
3821 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3822 the match to follow \n) will appear inside brackets with a number greater than
3823 31, but if it does, any back reference > 31 suppresses the optimization.
3824
3825 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3826 of disabling numbered capturing parentheses. Any opening parenthesis that is
3827 not followed by ? behaves as if it were followed by ?: but named parentheses
3828 can still be used for capturing (and they will acquire numbers in the usual
3829 way).
3830
3831 41. Redesigned the return codes from the match() function into yes/no/error so
3832 that errors can be passed back from deep inside the nested calls. A malloc
3833 failure while inside a recursive subpattern call now causes the
3834 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3835
3836 42. It is now possible to set a limit on the number of times the match()
3837 function is called in a call to pcre_exec(). This facility makes it possible to
3838 limit the amount of recursion and backtracking, though not in a directly
3839 obvious way, because the match() function is used in a number of different
3840 circumstances. The count starts from zero for each position in the subject
3841 string (for non-anchored patterns). The default limit is, for compatibility, a
3842 large number, namely 10 000 000. You can change this in two ways:
3843
3844 (a) When configuring PCRE before making, you can use --with-match-limit=n
3845 to set a default value for the compiled library.
3846
3847 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3848 a different value is set. See 45 below.
3849
3850 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3851
3852 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3853 of things that can be changed at compile time. The first argument specifies
3854 what is wanted and the second points to where the information is to be placed.
3855 The current list of available information is:
3856
3857 PCRE_CONFIG_UTF8
3858
3859 The output is an integer that is set to one if UTF-8 support is available;
3860 otherwise it is set to zero.
3861
3862 PCRE_CONFIG_NEWLINE
3863
3864 The output is an integer that it set to the value of the code that is used for
3865 newline. It is either LF (10) or CR (13).
3866
3867 PCRE_CONFIG_LINK_SIZE
3868
3869 The output is an integer that contains the number of bytes used for internal
3870 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3871
3872 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3873
3874 The output is an integer that contains the threshold above which the POSIX
3875 interface uses malloc() for output vectors. See item 31 above.
3876
3877 PCRE_CONFIG_MATCH_LIMIT
3878
3879 The output is an unsigned integer that contains the default limit of the number
3880 of match() calls in a pcre_exec() execution. See 42 above.
3881
3882 44. pcretest has been upgraded by the addition of the -C option. This causes it
3883 to extract all the available output from the new pcre_config() function, and to
3884 output it. The program then exits immediately.
3885
3886 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3887 order to support additional features. One way would have been to define
3888 pcre_exec2() (for example) with extra arguments, but this would not have been
3889 extensible, and would also have required all calls to the original function to
3890 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3891 is used for passing in "extra" data from pcre_study().
3892
3893 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3894 contains the following fields:
3895
3896 flags a bitmap indicating which of the following fields are set
3897 study_data opaque data from pcre_study()
3898 match_limit a way of specifying a limit on match() calls for a specific
3899 call to pcre_exec()
3900 callout_data data for callouts (see 49 below)
3901
3902 The flag bits are also defined in pcre.h, and are
3903
3904 PCRE_EXTRA_STUDY_DATA
3905 PCRE_EXTRA_MATCH_LIMIT
3906 PCRE_EXTRA_CALLOUT_DATA
3907
3908 The pcre_study() function now returns one of these new pcre_extra blocks, with
3909 the actual study data pointed to by the study_data field, and the
3910 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3911 before. That is, this change is entirely upwards-compatible and requires no
3912 change to existing code.
3913
3914 If you want to pass in additional data to pcre_exec(), you can either place it
3915 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3916 block.
3917
3918 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3919 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3920 times with different match limits, until it finds the minimum value needed for
3921 pcre_exec() to complete. The value is then output. This can be instructive; for
3922 most simple matches the number is quite small, but for pathological cases it
3923 gets very large very quickly.
3924
3925 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3926 returns the size of the data block pointed to by the study_data field in a
3927 pcre_extra block, that is, the value that was passed as the argument to
3928 pcre_malloc() when PCRE was getting memory in which to place the information
3929 created by pcre_study(). The fourth argument should point to a size_t variable.
3930 pcretest has been extended so that this information is shown after a successful
3931 pcre_study() call when information about the compiled regex is being displayed.
3932
3933 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3934 because what follows is always an absolute path. (Later: it turns out that this
3935 is more than cosmetic for MinGW, because it doesn't like empty path
3936 components.)
3937
3938 49. Some changes have been made to the callout feature (see 28 above):
3939
3940 (i) A callout function now has three choices for what it returns:
3941
3942 0 => success, carry on matching
3943 > 0 => failure at this point, but backtrack if possible
3944 < 0 => serious error, return this value from pcre_exec()
3945
3946 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3947 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3948 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3949 use by callout functions. It will never be used by PCRE itself.
3950
3951 (ii) The pcre_extra structure (see 45 above) has a void * field called
3952 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3953 pcre_callout_block structure has a field of the same name. The contents of
3954 the field passed in the pcre_extra structure are passed to the callout
3955 function in the corresponding field in the callout block. This makes it
3956 easier to use the same callout-containing regex from multiple threads. For
3957 testing, the pcretest program has a new data escape
3958
3959 \C*n pass the number n (may be negative) as callout_data
3960
3961 If the callout function in pcretest receives a non-zero value as
3962 callout_data, it returns that value.
3963
3964 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3965 there were some redundant $(CFLAGS) in commands that are now specified as
3966 $(LINK), which already includes $(CFLAGS).
3967
3968 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3969 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3970 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3971 one-byte characters throughout. Note that case-insensitive matching applies
3972 only to characters whose values are less than 256. PCRE doesn't support the
3973 notion of cases for higher-valued characters.
3974
3975 (i) A character class whose characters are all within 0-255 is handled as
3976 a bit map, and the map is inverted for negative classes. Previously, a
3977 character > 255 always failed to match such a class; however it should
3978 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3979
3980 (ii) A negated character class with a single character < 255 is coded as
3981 "not this character" (OP_NOT). This wasn't working properly when the test
3982 character was multibyte, either singly or repeated.
3983
3984 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3985 mode, for example: \x{100}{2,3}.
3986
3987 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3988 singly or repeated) now correctly test multibyte characters. However,
3989 PCRE doesn't recognize any characters with values greater than 255 as
3990 digits, spaces, or word characters. Such characters always match \D, \S,
3991 and \W, and never match \d, \s, or \w.
3992
3993 (v) Classes may now contain characters and character ranges with values
3994 greater than 255. For example: [ab\x{100}-\x{400}].
3995
3996 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3997 PCRE in UTF-8 mode.
3998
3999 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
4000 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
4001 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
4002 value.)
4003
4004 53. The single man page has become too large. I have therefore split it up into
4005 a number of separate man pages. These also give rise to individual HTML pages;
4006 these are now put in a separate directory, and there is an index.html page that
4007 lists them all. Some hyperlinking between the pages has been installed.
4008
4009 54. Added convenience functions for handling named capturing parentheses.
4010
4011 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
4012 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
4013 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
4014 are faulted.
4015
4016 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
4017 calling configure. These values are used when compiling the dftables.c program
4018 which is run to generate the source of the default character tables. They
4019 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
4020 you will need to set these values.
4021
4022 57. Updated the building process for Windows DLL, as provided by Fred Cox.
4023
4024
4025 Version 3.9 02-Jan-02
4026 ---------------------
4027
4028 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
4029
4030 2. If --disable-static was given, the building process failed when trying to
4031 build pcretest and pcregrep. (For some reason it was using libtool to compile
4032 them, which is not right, as they aren't part of the library.)
4033
4034
4035 Version 3.8 18-Dec-01
4036 ---------------------
4037
4038 1. The experimental UTF-8 code was completely screwed up. It was packing the
4039 bytes in the wrong order. How dumb can you get?
4040
4041
4042 Version 3.7 29-Oct-01
4043 ---------------------
4044
4045 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
4046 This caused pcretest, when used on the test data, to segfault. Unfortunately,
4047 this didn't happen under Solaris 8, where I normally test things.
4048
4049 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
4050 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
4051 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
4052 this fix an hour or so after the initial 3.7 release.)
4053
4054
4055 Version 3.6 23-Oct-01
4056 ---------------------
4057
4058 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
4059 offsets passed as NULL with zero offset count.
4060
4061 2. The config.guess and config.sub files had not been updated when I moved to
4062 the latest autoconf.
4063
4064
4065 Version 3.5 15-Aug-01
4066 ---------------------
4067
4068 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
4069 had been forgotten.
4070
4071 2. By using declared but undefined structures, we can avoid using "void"
4072 definitions in pcre.h while keeping the internal definitions of the structures
4073 private.
4074
4075 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
4076 user point of view, this means that both static and shared libraries are built
4077 by default, but this can be individually controlled. More of the work of
4078 handling this static/shared cases is now inside libtool instead of PCRE's make
4079 file.
4080
4081 4. The pcretest utility is now installed along with pcregrep because it is
4082 useful for users (to test regexs) and by doing this, it automatically gets
4083 relinked by libtool. The documentation has been turned into a man page, so
4084 there are now .1, .txt, and .html versions in /doc.
4085
4086 5. Upgrades to pcregrep:
4087 (i) Added long-form option names like gnu grep.
4088 (ii) Added --help to list all options with an explanatory phrase.
4089 (iii) Added -r, --recursive to recurse into sub-directories.
4090 (iv) Added -f, --file to read patterns from a file.
4091
4092 6. pcre_exec() was referring to its "code" argument before testing that
4093 argument for NULL (and giving an error if it was NULL).
4094
4095 7. Upgraded Makefile.in to allow for compiling in a different directory from
4096 the source directory.
4097
4098 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
4099 options bits, the pointer it was passed was to an int instead of to an unsigned
4100 long int. This mattered only on 64-bit systems.
4101
4102 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
4103 generated) instead of pcre.in, which it its source. Also made the same change
4104 in several of the .c files.
4105
4106 10. A new release of gcc defines printf() as a macro, which broke pcretest
4107 because it had an ifdef in the middle of a string argument for printf(). Fixed
4108 by using separate calls to printf().
4109
4110 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4111 script, to force use of CR or LF instead of \n in the source. On non-Unix
4112 systems, the value can be set in config.h.
4113
4114 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4115 absolute limit. Changed the text of the error message to make this clear, and
4116 likewise updated the man page.
4117
4118 13. The limit of 99 on the number of capturing subpatterns has been removed.
4119 The new limit is 65535, which I hope will not be a "real" limit.
4120
4121
4122 Version 3.4 22-Aug-00
4123 ---------------------
4124
4125 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4126
4127 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4128
4129
4130 Version 3.3 01-Aug-00
4131 ---------------------
4132
4133 1. If an octal character was given, but the value was greater than \377, it
4134 was not getting masked to the least significant bits, as documented. This could
4135 lead to crashes in some systems.
4136
4137 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4138 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4139
4140 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4141 These just pass their arguments on to (pcre_free)(), but they are provided
4142 because some uses of PCRE bind it to non-C systems that can call its functions,
4143 but cannot call free() or pcre_free() directly.
4144
4145 4. Add "make test" as a synonym for "make check". Corrected some comments in
4146 the Makefile.
4147
4148 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4149 Makefile.
4150
4151 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4152 command called pgrep for grepping around the active processes.
4153
4154 7. Added the beginnings of support for UTF-8 character strings.
4155
4156 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4157 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4158 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4159 out for the ar command.)
4160
4161
4162 Version 3.2 12-May-00
4163 ---------------------
4164
4165 This is purely a bug fixing release.
4166
4167 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4168 of ZA. This was just one example of several cases that could provoke this bug,
4169 which was introduced by change 9 of version 2.00. The code for breaking
4170 infinite loops after an iteration that matches an empty string was't working
4171 correctly.
4172
4173 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4174 when matched against abbab (for example). After matching an empty string, it
4175 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4176 caused it to match further down the string than it should.
4177
4178 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4179 was there because it doesn't seem to be needed, and it causes trouble on some
4180 systems, as it is not a Standard C header. It has been removed.
4181
4182 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4183 were reported on the Macintosh. The changes were from
4184
4185 while ((c = *(++ptr)) != 0 && c != '\n');
4186 to
4187 while ((c = *(++ptr)) != 0 && c != '\n') ;
4188
4189 Totally extraordinary, but if that's what it takes...
4190
4191 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4192 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4193 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4194 assumes the way PCRE uses memmove() (always moving upwards).
4195
4196 6. PCRE is being used in one environment where strchr() is not available. There
4197 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4198 faster code anyway.
4199
4200
4201 Version 3.1 09-Feb-00
4202 ---------------------
4203
4204 The only change in this release is the fixing of some bugs in Makefile.in for
4205 the "install" target:
4206
4207 (1) It was failing to install pcreposix.h.
4208
4209 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4210
4211
4212 Version 3.0 01-Feb-00
4213 ---------------------
4214
4215 1. Add support for the /+ modifier to perltest (to output $` like it does in
4216 pcretest).
4217
4218 2. Add support for the /g modifier to perltest.
4219
4220 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4221 matches null strings.
4222
4223 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4224 pattern. Perl treats empty patterns specially - it reuses the most recent
4225 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4226 effect.
4227
4228 5. The POSIX interface was broken in that it was just handing over the POSIX
4229 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4230 required a bigger vector, with some working space on the end. This means that
4231 the POSIX wrapper now has to get and free some memory, and copy the results.
4232
4233 6. Added some simple autoconf support, placing the test data and the
4234 documentation in separate directories, re-organizing some of the
4235 information files, and making it build pcre-config (a GNU standard). Also added
4236 libtool support for building PCRE as a shared library, which is now the
4237 default.
4238
4239 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4240 09 are not valid octal constants. Single digits will be used for minor values
4241 less than 10.
4242
4243 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4244 existing programs that set these in the POSIX interface can use PCRE without
4245 modification.
4246
4247 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4248 return all that pcre_info() returns, plus additional data. The pcre_info()
4249 function is retained for compatibility, but is considered to be obsolete.
4250
4251 10. Added experimental recursion feature (?R) to handle one common case that
4252 Perl 5.6 will be able to do with (?p{...}).
4253
4254 11. Added support for POSIX character classes like [:alpha:], which Perl is
4255 adopting.
4256
4257
4258 Version 2.08 31-Aug-99
4259 ----------------------
4260
4261 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4262 trying to match at the startoffset position, but instead was moving forward to
4263 the next newline as if a previous match had failed.
4264
4265 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4266 and could get into a loop if a null string was matched other than at the start
4267 of the subject.
4268
4269 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4270 be distinguished at compile time, and for completeness also added PCRE_DATE.
4271
4272 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4273 in GnuWin32 environments.
4274
4275
4276 Version 2.07 29-Jul-99
4277 ----------------------
4278
4279 1. The documentation is now supplied in plain text form and HTML as well as in
4280 the form of man page sources.
4281
4282 2. C++ compilers don't like assigning (void *) values to other pointer types.
4283 In particular this affects malloc(). Although there is no problem in Standard
4284 C, I've put in casts to keep C++ compilers happy.
4285
4286 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4287 should be (const char *).
4288
4289 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4290 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4291 However, I haven't made this a standard facility. The documentation doesn't
4292 mention it, and the Makefile doesn't support it.
4293
4294 5. The Makefile now contains an "install" target, with editable destinations at
4295 the top of the file. The pcretest program is not installed.
4296
4297 6. pgrep -V now gives the PCRE version number and date.
4298
4299 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4300 causing the entire string to be ignored, instead of just the last character.
4301
4302 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4303 non-matching string, it can take a very, very long time, even for strings of
4304 quite modest length, because of the nested recursion. PCRE now does better in
4305 some of these cases. It does this by remembering the last required literal
4306 character in the pattern, and pre-searching the subject to ensure it is present
4307 before running the real match. In other words, it applies a heuristic to detect
4308 some types of certain failure quickly, and in the above example, if presented
4309 with a string that has no trailing " it gives "no match" very quickly.
4310
4311 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4312 other alternatives are tried instead.
4313
4314
4315 Version 2.06 09-Jun-99
4316 ----------------------
4317
4318 1. Change pcretest's output for amount of store used to show just the code
4319 space, because the remainder (the data block) varies in size between 32-bit and
4320 64-bit systems.
4321
4322 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4323 start matching at. This allows lookbehinds to work when searching for multiple
4324 occurrences in a string.
4325
4326 3. Added additional options to pcretest for testing multiple occurrences:
4327
4328 /+ outputs the rest of the string that follows a match
4329 /g loops for multiple occurrences, using the new startoffset argument
4330 /G loops for multiple occurrences by passing an incremented pointer
4331
4332 4. PCRE wasn't doing the "first character" optimization for patterns starting
4333 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4334 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4335 the letter 'x'. On long subject strings, this gives a significant speed-up.
4336
4337
4338 Version 2.05 21-Apr-99
4339 ----------------------
4340
4341 1. Changed the type of magic_number from int to long int so that it works
4342 properly on 16-bit systems.
4343
4344 2. Fixed a bug which caused patterns starting with .* not to work correctly
4345 when the subject string contained newline characters. PCRE was assuming
4346 anchoring for such patterns in all cases, which is not correct because .* will
4347 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4348 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4349 must be retried after every newline in the subject.
4350
4351
4352 Version 2.04 18-Feb-99
4353 ----------------------
4354
4355 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4356 computation of the store needed to hold the pattern was incorrect (too large).
4357 If such patterns were nested a few deep, this could multiply and become a real
4358 problem.
4359
4360 2. Added /M option to pcretest to show the memory requirement of a specific
4361 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4362
4363 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4364 compiled in such a way that the backtracking after subsequent failure was
4365 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4366 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4367
4368
4369 Version 2.03 02-Feb-99
4370 ----------------------
4371
4372 1. Fixed typo and small mistake in man page.
4373
4374 2. Added 4th condition (GPL supersedes if conflict) and created separate
4375 LICENCE file containing the conditions.
4376
4377 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4378 Perl, that is the internal \ allows the delimiter to be included in the
4379 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4380 the final delimiter, add \ to the end of the pattern (to test the error).
4381
4382 4. Added the convenience functions for extracting substrings after a successful
4383 match. Updated pcretest to make it able to test these functions.
4384
4385
4386 Version 2.02 14-Jan-99
4387 ----------------------
4388
4389 1. Initialized the working variables associated with each extraction so that
4390 their saving and restoring doesn't refer to uninitialized store.
4391
4392 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4393 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4394 fix the problem.
4395
4396 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4397 calls, and wasn't printing the correct value for compiling calls. Increased the
4398 default value of LOOPREPEAT, and the number of significant figures in the
4399 times.
4400
4401 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4402
4403 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4404 a building problem on Windows NT with a FAT file system.
4405
4406
4407 Version 2.01 21-Oct-98
4408 ----------------------
4409
4410 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4411 to character tables built by pcre_maketables() in the current locale. If NULL
4412 is passed, the default tables are used.
4413
4414
4415 Version 2.00 24-Sep-98
4416 ----------------------
4417
4418 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4419 it any more.
4420
4421 2. Allow quantification of (?>) groups, and make it work correctly.
4422
4423 3. The first character computation wasn't working for (?>) groups.
4424
4425 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4426 end of the subject) and add 5.005's \z, which really does match only at the
4427 very end of the subject.
4428
4429 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4430
4431 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4432 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4433 localized options. All options to pcre_study() were also removed.
4434
4435 7. Add other new features from 5.005:
4436
4437 $(?<= positive lookbehind
4438 $(?<! negative lookbehind
4439 (?imsx-imsx) added the unsetting capability
4440 such a setting is global if at outer level; local otherwise
4441 (?imsx-imsx:) non-capturing groups with option setting
4442 (?(cond)re|re) conditional pattern matching
4443
4444 A backreference to itself in a repeated group matches the previous
4445 captured string.
4446
4447 8. General tidying up of studying (both automatic and via "study")
4448 consequential on the addition of new assertions.
4449
4450 9. As in 5.005, unlimited repeated groups that could match an empty substring
4451 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4452 runtime if any iteration does actually match an empty substring.
4453
4454 10. Include the RunTest script in the distribution.
4455
4456 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4457 discrepancies, some of which were old and were also with respect to 5.004. They
4458 have now been fixed.
4459
4460
4461 Version 1.09 28-Apr-98
4462 ----------------------
4463
4464 1. A negated single character class followed by a quantifier with a minimum
4465 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4466 program crashes, or just wrong answers. This did not apply to negated classes
4467 containing more than one character, or to minima other than one.
4468
4469
4470 Version 1.08 27-Mar-98
4471 ----------------------
4472
4473 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4474
4475 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4476 latter must appear before anything that relies on it in the pattern.
4477
4478
4479 Version 1.07 16-Feb-98
4480 ----------------------
4481
4482 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4483 repeat of a potentially empty string).
4484
4485
4486 Version 1.06 23-Jan-98
4487 ----------------------
4488
4489 1. Added Markus Oberhumer's little patches for C++.
4490
4491 2. Literal strings longer than 255 characters were broken.
4492
4493
4494 Version 1.05 23-Dec-97
4495 ----------------------
4496
4497 1. Negated character classes containing more than one character were failing if
4498 PCRE_CASELESS was set at run time.
4499
4500
4501 Version 1.04 19-Dec-97
4502 ----------------------
4503
4504 1. Corrected the man page, where some "const" qualifiers had been omitted.
4505
4506 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4507 input syntax.
4508
4509 3. Fixed memory leak which occurred when a regex with back references was
4510 matched with an offsets vector that wasn't big enough. The temporary memory
4511 that is used in this case wasn't being freed if the match failed.
4512
4513 4. Tidied pcretest to ensure it frees memory that it gets.
4514
4515 5. Temporary memory was being obtained in the case where the passed offsets
4516 vector was exactly big enough.
4517
4518 6. Corrected definition of offsetof() from change 5 below.
4519
4520 7. I had screwed up change 6 below and broken the rules for the use of
4521 setjmp(). Now fixed.
4522
4523
4524 Version 1.03 18-Dec-97
4525 ----------------------
4526
4527 1. A erroneous regex with a missing opening parenthesis was correctly
4528 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4529 on some systems.
4530
4531 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4532 it was reported that one broken compiler failed on the former because "code" is
4533 also an independent variable.
4534
4535 3. The erroneous regex a[]b caused an array overrun reference.
4536
4537 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4538 fail on data ending with that character. (It was going on too far, and checking
4539 the next character, typically a binary zero.) This was specific to the
4540 optimized code for single-character negative classes.
4541
4542 5. Added a contributed patch from the TIN world which does the following:
4543
4544 + Add an undef for memmove, in case the the system defines a macro for it.
4545
4546 + Add a definition of offsetof(), in case there isn't one. (I don't know
4547 the reason behind this - offsetof() is part of the ANSI standard - but
4548 it does no harm).
4549
4550 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4551 most of the places where whitespace preceded '#'. I have given up and
4552 allowed the remaining 2 cases to be at the margin.
4553
4554 + Rename some variables in pcre to eliminate shadowing. This seems very
4555 pedantic, but does no harm, of course.
4556
4557 6. Moved the call to setjmp() into its own function, to get rid of warnings
4558 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4559
4560 7. Constructs such as \d{8,} were compiling into the equivalent of
4561 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4562 outcome, but in this particular case used more store than had been allocated,
4563 which caused the bug to be discovered because it threw up an internal error.
4564
4565 8. The debugging code in both pcre and pcretest for outputting the compiled
4566 form of a regex was going wrong in the case of back references followed by
4567 curly-bracketed repeats.
4568
4569
4570 Version 1.02 12-Dec-97
4571 ----------------------
4572
4573 1. Typos in pcre.3 and comments in the source fixed.
4574
4575 2. Applied a contributed patch to get rid of places where it used to remove
4576 'const' from variables, and fixed some signed/unsigned and uninitialized
4577 variable warnings.
4578
4579 3. Added the "runtest" target to Makefile.
4580
4581 4. Set default compiler flag to -O2 rather than just -O.
4582
4583
4584 Version 1.01 19-Nov-97
4585 ----------------------
4586
4587 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4588 like /([ab]*)*/, that is, for classes with more than one character in them.
4589
4590 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4591 as /((?>a*))*/ (a PCRE_EXTRA facility).
4592
4593
4594 Version 1.00 18-Nov-97
4595 ----------------------
4596
4597 1. Added compile-time macros to support systems such as SunOS4 which don't have
4598 memmove() or strerror() but have other things that can be used instead.
4599
4600 2. Arranged that "make clean" removes the executables.
4601
4602
4603 Version 0.99 27-Oct-97
4604 ----------------------
4605
4606 1. Fixed bug in code for optimizing classes with only one character. It was
4607 initializing a 32-byte map regardless, which could cause it to run off the end
4608 of the memory it had got.
4609
4610 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4611
4612
4613 Version 0.98 22-Oct-97
4614 ----------------------
4615
4616 1. Fixed bug in code for handling temporary memory usage when there are more
4617 back references than supplied space in the ovector. This could cause segfaults.
4618
4619
4620 Version 0.97 21-Oct-97
4621 ----------------------
4622
4623 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4624
4625 2. Optimized negated single characters not to use a bit map.
4626
4627 3. Brought error texts together as macro definitions; clarified some of them;
4628 fixed one that was wrong - it said "range out of order" when it meant "invalid
4629 escape sequence".
4630
4631 4. Changed some char * arguments to const char *.
4632
4633 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4634
4635 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4636 pcretest.
4637
4638
4639 Version 0.96 16-Oct-97
4640 ----------------------
4641
4642 1. Added a simple "pgrep" utility to the distribution.
4643
4644 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4645 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4646 where "ddd" means "one or more decimal digits".
4647
4648 3. Fixed serious bug. If a pattern had a back reference, but the call to
4649 pcre_exec() didn't supply a large enough ovector to record the related
4650 identifying subpattern, the match always failed. PCRE now remembers the number
4651 of the largest back reference, and gets some temporary memory in which to save
4652 the offsets during matching if necessary, in order to ensure that
4653 backreferences always work.
4654
4655 4. Increased the compatibility with Perl in a number of ways:
4656
4657 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4658 to request this handling. The option can be set at compile or exec time.
4659
4660 (b) $ matches before a terminating newline by default; an option
4661 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4662 mode). The option can be set at compile or exec time.
4663
4664 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4665 the same as Perl's. If the decimal number it represents is less than 10
4666 or there aren't that many previous left capturing parentheses, an octal
4667 escape is read. Inside a character class, it's always an octal escape,
4668 even if it is a single digit.
4669
4670 (d) An escaped but undefined alphabetic character is taken as a literal,
4671 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4672 escapes.
4673
4674 (e) {0} is now permitted. (The previous item is removed from the compiled
4675 pattern).
4676
4677 5. Changed all the names of code files so that the basic parts are no longer
4678 than 10 characters, and abolished the teeny "globals.c" file.
4679
4680 6. Changed the handling of character classes; they are now done with a 32-byte
4681 bit map always.
4682
4683 7. Added the -d and /D options to pcretest to make it possible to look at the
4684 internals of compilation without having to recompile pcre.
4685
4686
4687 Version 0.95 23-Sep-97
4688 ----------------------
4689
4690 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4691 \x20 at the start of a run of normal characters. These were being treated as
4692 real characters, instead of the source characters being re-checked.
4693
4694
4695 Version 0.94 18-Sep-97
4696 ----------------------
4697
4698 1. The functions are now thread-safe, with the caveat that the global variables
4699 containing pointers to malloc() and free() or alternative functions are the
4700 same for all threads.
4701
4702 2. Get pcre_study() to generate a bitmap of initial characters for non-
4703 anchored patterns when this is possible, and use it if passed to pcre_exec().
4704
4705
4706 Version 0.93 15-Sep-97
4707 ----------------------
4708
4709 1. /(b)|(:+)/ was computing an incorrect first character.
4710
4711 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4712 but not actually doing anything yet.
4713
4714 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4715 as Perl does (e.g. [-az] or [az-]).
4716
4717 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4718 all possible positions.
4719
4720 5. Split up into different modules to avoid including unneeded functions in a
4721 compiled binary. However, compile and exec are still in one module. The "study"
4722 function is split off.
4723
4724 6. The character tables are now in a separate module whose source is generated
4725 by an auxiliary program - but can then be edited by hand if required. There are
4726 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4727 toupper() in the code.
4728
4729 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4730 make them global. Abolish the function for setting them, as the caller can now
4731 set them directly.
4732
4733
4734 Version 0.92 11-Sep-97
4735 ----------------------
4736
4737 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4738 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4739
4740 2. Caseless matching was not working in character classes if the characters in
4741 the pattern were in upper case.
4742
4743 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4744
4745 4. Make PCRE_ANCHORED public and accept as a compile option.
4746
4747 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4748 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4749 pass them.
4750
4751 6. Give an error if bad option bits passed at compile or run time.
4752
4753 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4754 pcretest to cause it to pass that flag.
4755
4756 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4757 options, and the first character, if set.
4758
4759 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4760
4761
4762 Version 0.91 10-Sep-97
4763 ----------------------
4764
4765 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4766 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4767
4768 2. PCRE was looping on encountering an indefinitely repeated back reference to
4769 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4770 Perl does - treats the match as successful.
4771
4772 ****

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