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Revision 980 - (show annotations)
Mon Jun 18 16:47:14 2012 UTC (7 years, 5 months ago) by ph10
File size: 232610 byte(s)
Error occurred while calculating annotation data.
Add libpcre.la to link commands for pcretest and pcregrep because this is 
required in some OS for shared objects.
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.31 02-June-2012
5 -------------------------
6
7 1. Fixing a wrong JIT test case and some compiler warnings.
8
9 2. Removed a bashism from the RunTest script.
10
11 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
12 to unsigned type, result still unsigned" that was given by an MS compiler
13 on encountering the code "-sizeof(xxx)".
14
15 4. Partial matching support is added to the JIT compiler.
16
17 5. Fixed several bugs concerned with partial matching of items that consist
18 of more than one character:
19
20 (a) /^(..)\1/ did not partially match "aba" because checking references was
21 done on an "all or nothing" basis. This also applied to repeated
22 references.
23
24 (b) \R did not give a hard partial match if \r was found at the end of the
25 subject.
26
27 (c) \X did not give a hard partial match after matching one or more
28 characters at the end of the subject.
29
30 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
31 a partial match for the string "\r".
32
33 (e) When newline was set to CRLF, the metacharacter "." did not recognize
34 a partial match for a CR character at the end of the subject string.
35
36 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
37 running pcretest, the text "(JIT)" added to the output whenever JIT is
38 actually used to run the match.
39
40 7. Individual JIT compile options can be set in pcretest by following -s+[+]
41 or /S+[+] with a digit between 1 and 7.
42
43 8. OP_NOT now supports any UTF character not just single-byte ones.
44
45 9. (*MARK) control verb is now supported by the JIT compiler.
46
47 10. The command "./RunTest list" lists the available tests without actually
48 running any of them. (Because I keep forgetting what they all are.)
49
50 11. Add PCRE_INFO_MAXLOOKBEHIND.
51
52 12. Applied a (slightly modified) user-supplied patch that improves performance
53 when the heap is used for recursion (compiled with --disable-stack-for-
54 recursion). Instead of malloc and free for each heap frame each time a
55 logical recursion happens, frames are retained on a chain and re-used where
56 possible. This sometimes gives as much as 30% improvement.
57
58 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
59 call.
60
61 14. As documented, (*COMMIT) is now confined to within a positive assertion.
62
63 15. It is now possible to link pcretest with libedit as an alternative to
64 libreadline.
65
66 16. (*COMMIT) control verb is now supported by the JIT compiler.
67
68 17. The Unicode data tables have been updated to Unicode 6.1.0.
69
70 18. Added --file-list option to pcregrep.
71
72 19. Added binary file support to pcregrep, including the -a, --binary-files,
73 -I, and --text options.
74
75 20. The madvise function is renamed for posix_madvise for QNX compatibility
76 reasons. Fixed by Giuseppe D'Angelo.
77
78 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
79
80 22. Changed the option for creating symbolic links for 16-bit man pages from
81 -s to -sf so that re-installing does not cause issues.
82
83 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
84
85 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
86 matches in certain environments (the workspace was not being correctly
87 retained). Also added to pcre_dfa_exec() a simple plausibility check on
88 some of the workspace data at the beginning of a restart.
89
90 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
91 was not doing so when it should - probably a typo introduced by SVN 528
92 (change 8.10/14).
93
94 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
95 \w+ when the character tables indicated that \x{c4} was a word character.
96 There were several related cases, all because the tests for doing a table
97 lookup were testing for characters less than 127 instead of 255.
98
99 27. If a pattern contains capturing parentheses that are not used in a match,
100 their slots in the ovector are set to -1. For those that are higher than
101 any matched groups, this happens at the end of processing. In the case when
102 there were back references that the ovector was too small to contain
103 (causing temporary malloc'd memory to be used during matching), and the
104 highest capturing number was not used, memory off the end of the ovector
105 was incorrectly being set to -1. (It was using the size of the temporary
106 memory instead of the true size.)
107
108 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
109 ovector size, it uses memory at the end of the block that it has got.
110
111 29. Check for an overlong MARK name and give an error at compile time. The
112 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
113
114 30. JIT compiler update.
115
116 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
117 Rill for the patch.
118
119 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
120
121 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
122
123 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
124 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
125 was enabled.
126
127 35. Improve JIT code generation for greedy plus quantifier.
128
129 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
130 1 to "aa" instead of to an empty string. The bug affected repeated groups
131 that could potentially match an empty string.
132
133 37. Optimizing single character iterators in JIT.
134
135 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
136 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
137 codepoints that are too big for the mode are faulted, and in a UTF mode,
138 disallowed codepoints are also faulted.
139
140 39. If PCRE was compiled with UTF support, in three places in the DFA
141 matcher there was code that should only have been obeyed in UTF mode, but
142 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
143 processing when bytes with values greater than 127 were present. In 16-bit
144 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
145 both cases the values are those that cannot be the first data item in a UTF
146 character. The three items that might have provoked this were recursions,
147 possessively repeated groups, and atomic groups.
148
149 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
150 and pcregrep, because some OS require shared objects to be explicitly
151 passed to ld, causing the link step to fail if they are not.
152
153
154 Version 8.30 04-February-2012
155 -----------------------------
156
157 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
158 name is defined in ctype.h.
159
160 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
161 only in quite long subpatterns.
162
163 3. Removed the function pcre_info(), which has been obsolete and deprecated
164 since it was replaced by pcre_fullinfo() in February 2000.
165
166 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
167 match a (*MARK), and the match failed at the start of the subject, a
168 reference to memory before the start of the subject could occur. This bug
169 was introduced by fix 17 of release 8.21.
170
171 5. A reference to an unset group with zero minimum repetition was giving
172 totally wrong answers (in non-JavaScript-compatibility mode). For example,
173 /(another)?(\1?)test/ matched against "hello world test". This bug was
174 introduced in release 8.13.
175
176 6. Add support for 16-bit character strings (a large amount of work involving
177 many changes and refactorings).
178
179 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
180 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
181 from a file.
182
183 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
184 rounding is not applied in this particular case).
185
186 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
187 if they appear, or are escaped, in patterns.
188
189 10. Get rid of a number of -Wunused-but-set-variable warnings.
190
191 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
192 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
193 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
194 also returns the mark "x". This bug applied to capturing parentheses,
195 non-capturing parentheses, and atomic parentheses. It also applied to some
196 assertions.
197
198 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
199 information out of configure.ac instead of relying on pcre.h.generic, which
200 is not stored in the repository.
201
202 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
203 -lreadline.
204
205 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
206
207 15. Applied Graycode's patch to put the top-level frame on the stack rather
208 than the heap when not using the stack for recursion. This gives a
209 performance improvement in many cases when recursion is not deep.
210
211 16. Experimental code added to "pcretest -C" to output the stack frame size.
212
213
214 Version 8.21 12-Dec-2011
215 ------------------------
216
217 1. Updating the JIT compiler.
218
219 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
220 are added as well.
221
222 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
223 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
224 calling _pcre_jit_exec. Some extra comments are added.
225
226 4. (*MARK) settings inside atomic groups that do not contain any capturing
227 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
228 was introduced by change 18 for 8.20.
229
230 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
231 ECMA-262 standard.
232
233 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
234 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
235 This bug was probably introduced by change 9 of 8.13.
236
237 7. While fixing 6 above, I noticed that a number of other items were being
238 incorrectly rejected as "not fixed length". This arose partly because newer
239 opcodes had not been added to the fixed-length checking code. I have (a)
240 corrected the bug and added tests for these items, and (b) arranged for an
241 error to occur if an unknown opcode is encountered while checking for fixed
242 length instead of just assuming "not fixed length". The items that were
243 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
244 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
245 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
246
247 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
248 being incorrectly compiled and would have given unpredicatble results.
249
250 9. A possessively repeated subpattern with minimum repeat count greater than
251 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
252 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
253 the first (A) could occur when it should not.
254
255 10. Add a cast and remove a redundant test from the code.
256
257 11. JIT should use pcre_malloc/pcre_free for allocation.
258
259 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
260 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
261 is anything other than /usr, -L is still shown).
262
263 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
264
265 14. Perl does not support \N without a following name in a [] class; PCRE now
266 also gives an error.
267
268 15. If a forward reference was repeated with an upper limit of around 2000,
269 it caused the error "internal error: overran compiling workspace". The
270 maximum number of forward references (including repeats) was limited by the
271 internal workspace, and dependent on the LINK_SIZE. The code has been
272 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
273 the default depends on LINK_SIZE. There is a new upper limit (for safety)
274 of around 200,000 forward references. While doing this, I also speeded up
275 the filling in of repeated forward references.
276
277 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
278 incorrectly expecting the subject to contain another "a" after the start.
279
280 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
281 in the match, the SKIP should be ignored. This was not happening; instead
282 the SKIP was being treated as NOMATCH. For patterns such as
283 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
284 tested.
285
286 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
287 now much more compatible with Perl, in particular in cases where the result
288 is a non-match for a non-anchored pattern. For example, if
289 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
290 "m", where previously it did not return a name. A side effect of this
291 change is that for partial matches, the last encountered mark name is
292 returned, as for non matches. A number of tests that were previously not
293 Perl-compatible have been moved into the Perl-compatible test files. The
294 refactoring has had the pleasing side effect of removing one argument from
295 the match() function, thus reducing its stack requirements.
296
297 19. If the /S+ option was used in pcretest to study a pattern using JIT,
298 subsequent uses of /S (without +) incorrectly behaved like /S+.
299
300 21. Retrieve executable code size support for the JIT compiler and fixing
301 some warnings.
302
303 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
304 not work when the shorter character appeared right at the end of the
305 subject string.
306
307 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
308 systems.
309
310 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
311 output it when the /M option is used in pcretest.
312
313 25. The CheckMan script was not being included in the distribution. Also, added
314 an explicit "perl" to run Perl scripts from the PrepareRelease script
315 because this is reportedly needed in Windows.
316
317 26. If study data was being save in a file and studying had not found a set of
318 "starts with" bytes for the pattern, the data written to the file (though
319 never used) was taken from uninitialized memory and so caused valgrind to
320 complain.
321
322 27. Updated RunTest.bat as provided by Sheri Pierce.
323
324 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
325
326 29. Computation of memory usage for the table of capturing group names was
327 giving an unnecessarily large value.
328
329
330 Version 8.20 21-Oct-2011
331 ------------------------
332
333 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
334 a POSIX class. After further experiments with Perl, which convinced me that
335 Perl has bugs and confusions, a closing square bracket is no longer allowed
336 in a POSIX name. This bug also affected patterns with classes that started
337 with full stops.
338
339 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
340 captured substring, but while checking the failing first alternative,
341 substring 1 is temporarily captured. If the output vector supplied to
342 pcre_exec() was not big enough for this capture, the yield of the function
343 was still zero ("insufficient space for captured substrings"). This cannot
344 be totally fixed without adding another stack variable, which seems a lot
345 of expense for a edge case. However, I have improved the situation in cases
346 such as /(a)(b)x|abc/ matched against "abc", where the return code
347 indicates that fewer than the maximum number of slots in the ovector have
348 been set.
349
350 3. Related to (2) above: when there are more back references in a pattern than
351 slots in the output vector, pcre_exec() uses temporary memory during
352 matching, and copies in the captures as far as possible afterwards. It was
353 using the entire output vector, but this conflicts with the specification
354 that only 2/3 is used for passing back captured substrings. Now it uses
355 only the first 2/3, for compatibility. This is, of course, another edge
356 case.
357
358 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
359 main code base, and can be used by building with --enable-jit. When this is
360 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
361 runtime --no-jit option is given.
362
363 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
364 ovector, the return from the function was zero, implying that there were
365 other matches that did not fit. The correct "exactly full" value is now
366 returned.
367
368 6. If a subpattern that was called recursively or as a subroutine contained
369 (*PRUNE) or any other control that caused it to give a non-standard return,
370 invalid errors such as "Error -26 (nested recursion at the same subject
371 position)" or even infinite loops could occur.
372
373 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
374 computing the minimum length on reaching *ACCEPT, and so ended up with the
375 wrong value of 1 rather than 0. Further investigation indicates that
376 computing a minimum subject length in the presence of *ACCEPT is difficult
377 (think back references, subroutine calls), and so I have changed the code
378 so that no minimum is registered for a pattern that contains *ACCEPT.
379
380 8. If (*THEN) was present in the first (true) branch of a conditional group,
381 it was not handled as intended. [But see 16 below.]
382
383 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
384 Sheri Pierce.
385
386 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
387 the first byte in a match must be "a".
388
389 11. Change 17 for 8.13 increased the recursion depth for patterns like
390 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
391 pattern contains any instances of (*THEN). If it does not, the old
392 optimizations are restored. It would be nice to do this on a per-group
393 basis, but at the moment that is not feasible.
394
395 12. In some environments, the output of pcretest -C is CRLF terminated. This
396 broke RunTest's code that checks for the link size. A single white space
397 character after the value is now allowed for.
398
399 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
400 For "fr", it uses the Windows-specific input and output files.
401
402 14. If (*THEN) appeared in a group that was called recursively or as a
403 subroutine, it did not work as intended. [But see next item.]
404
405 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
406 pattern fragments (but not containing any | characters). If A and B are
407 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
408 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
409 D. In other words, Perl considers parentheses that do not contain any |
410 characters to be part of a surrounding alternative, whereas PCRE was
411 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
412 differently. PCRE now behaves in the same way as Perl, except in the case
413 of subroutine/recursion calls such as (?1) which have in any case always
414 been different (but PCRE had them first :-).
415
416 16. Related to 15 above: Perl does not treat the | in a conditional group as
417 creating alternatives. Such a group is treated in the same way as an
418 ordinary group without any | characters when processing (*THEN). PCRE has
419 been changed to match Perl's behaviour.
420
421 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
422 RunGrepTest script failed.
423
424 18. Change 22 for version 13 caused atomic groups to use more stack. This is
425 inevitable for groups that contain captures, but it can lead to a lot of
426 stack use in large patterns. The old behaviour has been restored for atomic
427 groups that do not contain any capturing parentheses.
428
429 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
430 suppress the check for a minimum subject length at run time. (If it was
431 given to pcre_exec() or pcre_dfa_exec() it did work.)
432
433 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
434 fail to work when decoding hex characters in data strings in EBCDIC
435 environments.
436
437 21. It appears that in at least one Mac OS environment, the isxdigit() function
438 is implemented as a macro that evaluates to its argument more than once,
439 contravening the C 90 Standard (I haven't checked a later standard). There
440 was an instance in pcretest which caused it to go wrong when processing
441 \x{...} escapes in subject strings. The has been rewritten to avoid using
442 things like p++ in the argument of isxdigit().
443
444
445 Version 8.13 16-Aug-2011
446 ------------------------
447
448 1. The Unicode data tables have been updated to Unicode 6.0.0.
449
450 2. Two minor typos in pcre_internal.h have been fixed.
451
452 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
453 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
454 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
455
456 4. There were a number of related bugs in the code for matching backrefences
457 caselessly in UTF-8 mode when codes for the characters concerned were
458 different numbers of bytes. For example, U+023A and U+2C65 are an upper
459 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
460 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
461 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
462 2-byte code at the end of the subject (it thought there wasn't enough data
463 left).
464
465 5. Comprehensive information about what went wrong is now returned by
466 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
467 as the output vector has at least 2 elements. The offset of the start of
468 the failing character and a reason code are placed in the vector.
469
470 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
471 now returned is for the first byte of the failing character, instead of the
472 last byte inspected. This is an incompatible change, but I hope it is small
473 enough not to be a problem. It makes the returned offset consistent with
474 pcre_exec() and pcre_dfa_exec().
475
476 7. pcretest now gives a text phrase as well as the error number when
477 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
478 failure, the offset and reason code are output.
479
480 8. When \R was used with a maximizing quantifier it failed to skip backwards
481 over a \r\n pair if the subsequent match failed. Instead, it just skipped
482 back over a single character (\n). This seems wrong (because it treated the
483 two characters as a single entity when going forwards), conflicts with the
484 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
485 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
486 has been changed.
487
488 9. Some internal refactoring has changed the processing so that the handling
489 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
490 time (the PCRE_DOTALL option was changed this way some time ago: version
491 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
492 which was always a bit of a fudge. It also means that there is one less
493 argument for the match() function, which reduces its stack requirements
494 slightly. This change also fixes an incompatibility with Perl: the pattern
495 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
496
497 10. More internal refactoring has drastically reduced the number of recursive
498 calls to match() for possessively repeated groups such as (abc)++ when
499 using pcre_exec().
500
501 11. While implementing 10, a number of bugs in the handling of groups were
502 discovered and fixed:
503
504 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
505 (a|)*(?1) gave a compile-time internal error.
506 ((a|)+)+ did not notice that the outer group could match an empty string.
507 (^a|^)+ was not marked as anchored.
508 (.*a|.*)+ was not marked as matching at start or after a newline.
509
510 12. Yet more internal refactoring has removed another argument from the match()
511 function. Special calls to this function are now indicated by setting a
512 value in a variable in the "match data" data block.
513
514 13. Be more explicit in pcre_study() instead of relying on "default" for
515 opcodes that mean there is no starting character; this means that when new
516 ones are added and accidentally left out of pcre_study(), testing should
517 pick them up.
518
519 14. The -s option of pcretest has been documented for ages as being an old
520 synonym of -m (show memory usage). I have changed it to mean "force study
521 for every regex", that is, assume /S for every regex. This is similar to -i
522 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
523 using it. It makes it easier to run collections of tests with and without
524 study enabled, and thereby test pcre_study() more easily. All the standard
525 tests are now run with and without -s (but some patterns can be marked as
526 "never study" - see 20 below).
527
528 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
529 restoration of the capturing data to the outer values was not happening
530 correctly.
531
532 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
533 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
534 pattern had matched an empty string, and so incorrectly returned a no
535 match.
536
537 17. There was optimizing code for the last branch of non-capturing parentheses,
538 and also for the obeyed branch of a conditional subexpression, which used
539 tail recursion to cut down on stack usage. Unfortunately, now that there is
540 the possibility of (*THEN) occurring in these branches, tail recursion is
541 no longer possible because the return has to be checked for (*THEN). These
542 two optimizations have therefore been removed. [But see 8.20/11 above.]
543
544 18. If a pattern containing \R was studied, it was assumed that \R always
545 matched two bytes, thus causing the minimum subject length to be
546 incorrectly computed because \R can also match just one byte.
547
548 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
549 was incorrectly computed.
550
551 20. If /S is present twice on a test pattern in pcretest input, it now
552 *disables* studying, thereby overriding the use of -s on the command line
553 (see 14 above). This is necessary for one or two tests to keep the output
554 identical in both cases.
555
556 21. When (*ACCEPT) was used in an assertion that matched an empty string and
557 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
558
559 22. When an atomic group that contained a capturing parenthesis was
560 successfully matched, but the branch in which it appeared failed, the
561 capturing was not being forgotten if a higher numbered group was later
562 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
563 group 1 to "a", when in fact it should be unset. This applied to multi-
564 branched capturing and non-capturing groups, repeated or not, and also to
565 positive assertions (capturing in negative assertions does not happen
566 in PCRE) and also to nested atomic groups.
567
568 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
569 subject after a captured substring, to make it easier to tell which of a
570 number of identical substrings has been captured.
571
572 24. The way atomic groups are processed by pcre_exec() has been changed so that
573 if they are repeated, backtracking one repetition now resets captured
574 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
575 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
576 "aaa". Previously, it would have been "a". As part of this code
577 refactoring, the way recursive calls are handled has also been changed.
578
579 25. If an assertion condition captured any substrings, they were not passed
580 back unless some other capturing happened later. For example, if
581 (?(?=(a))a) was matched against "a", no capturing was returned.
582
583 26. When studying a pattern that contained subroutine calls or assertions,
584 the code for finding the minimum length of a possible match was handling
585 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
586 group 1 called group 2 while simultaneously a separate group 2 called group
587 1). A stack overflow occurred in this case. I have fixed this by limiting
588 the recursion depth to 10.
589
590 27. Updated RunTest.bat in the distribution to the version supplied by Tom
591 Fortmann. This supports explicit test numbers on the command line, and has
592 argument validation and error reporting.
593
594 28. An instance of \X with an unlimited repeat could fail if at any point the
595 first character it looked at was a mark character.
596
597 29. Some minor code refactoring concerning Unicode properties and scripts
598 should reduce the stack requirement of match() slightly.
599
600 30. Added the '=' option to pcretest to check the setting of unused capturing
601 slots at the end of the pattern, which are documented as being -1, but are
602 not included in the return count.
603
604 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
605 compiled something random. Now it gives a compile-time error (as does
606 Perl).
607
608 32. A *MARK encountered during the processing of a positive assertion is now
609 recorded and passed back (compatible with Perl).
610
611 33. If --only-matching or --colour was set on a pcregrep call whose pattern
612 had alternative anchored branches, the search for a second match in a line
613 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
614 matched the line "0102" twice. The same bug affected patterns that started
615 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
616 twice.
617
618 34. Previously, PCRE did not allow quantification of assertions. However, Perl
619 does, and because of capturing effects, quantifying parenthesized
620 assertions may at times be useful. Quantifiers are now allowed for
621 parenthesized assertions.
622
623 35. A minor code tidy in pcre_compile() when checking options for \R usage.
624
625 36. \g was being checked for fancy things in a character class, when it should
626 just be a literal "g".
627
628 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
629 appearance of a nested POSIX class supersedes an apparent external class.
630 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
631 unescaped square brackets may also appear as part of class names. For
632 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
633 more like Perl. (But see 8.20/1 above.)
634
635 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
636 was because it thought it was \N{name}, which is not supported).
637
638 39. Add minix to OS list not supporting the -S option in pcretest.
639
640 40. PCRE tries to detect cases of infinite recursion at compile time, but it
641 cannot analyze patterns in sufficient detail to catch mutual recursions
642 such as ((?1))((?2)). There is now a runtime test that gives an error if a
643 subgroup is called recursively as a subpattern for a second time at the
644 same position in the subject string. In previous releases this might have
645 been caught by the recursion limit, or it might have run out of stack.
646
647 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
648 happen only once. PCRE was, however incorrectly giving a compile time error
649 "recursive call could loop indefinitely" because it cannot analyze the
650 pattern in sufficient detail. The compile time test no longer happens when
651 PCRE is compiling a conditional subpattern, but actual runaway loops are
652 now caught at runtime (see 40 above).
653
654 42. It seems that Perl allows any characters other than a closing parenthesis
655 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
656 has been changed to be the same.
657
658 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
659 as not to get warnings when autogen.sh is called. Also changed
660 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
661
662 44. To help people who use pcregrep to scan files containing exceedingly long
663 lines, the following changes have been made:
664
665 (a) The default value of the buffer size parameter has been increased from
666 8K to 20K. (The actual buffer used is three times this size.)
667
668 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
669 PCRE is built.
670
671 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
672 to be set at run time.
673
674 (d) Numerical values in pcregrep options can be followed by K or M, for
675 example --buffer-size=50K.
676
677 (e) If a line being scanned overflows pcregrep's buffer, an error is now
678 given and the return code is set to 2.
679
680 45. Add a pointer to the latest mark to the callout data block.
681
682 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
683 partial match of an empty string instead of no match. This was specific to
684 the use of ".".
685
686 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
687 complete match instead of a partial match. This bug was dependent on both
688 the PCRE_UTF8 and PCRE_DOTALL options being set.
689
690 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
691 starting byte set, because \b was not being ignored.
692
693
694 Version 8.12 15-Jan-2011
695 ------------------------
696
697 1. Fixed some typos in the markup of the man pages, and wrote a script that
698 checks for such things as part of the documentation building process.
699
700 2. On a big-endian 64-bit system, pcregrep did not correctly process the
701 --match-limit and --recursion-limit options (added for 8.11). In
702 particular, this made one of the standard tests fail. (The integer value
703 went into the wrong half of a long int.)
704
705 3. If the --colour option was given to pcregrep with -v (invert match), it
706 did strange things, either producing crazy output, or crashing. It should,
707 of course, ignore a request for colour when reporting lines that do not
708 match.
709
710 4. Another pcregrep bug caused similar problems if --colour was specified with
711 -M (multiline) and the pattern match finished with a line ending.
712
713 5. In pcregrep, when a pattern that ended with a literal newline sequence was
714 matched in multiline mode, the following line was shown as part of the
715 match. This seems wrong, so I have changed it.
716
717 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
718 the check for further matches in the same line (so they could be coloured)
719 to overrun the end of the current line. If another match was found, it was
720 incorrectly shown (and then shown again when found in the next line).
721
722 7. If pcregrep was compiled under Windows, there was a reference to the
723 function pcregrep_exit() before it was defined. I am assuming this was
724 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
725 reported by a user. I've moved the definition above the reference.
726
727
728 Version 8.11 10-Dec-2010
729 ------------------------
730
731 1. (*THEN) was not working properly if there were untried alternatives prior
732 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
733 backtracked to try for "b" instead of moving to the next alternative branch
734 at the same level (in this case, to look for "c"). The Perl documentation
735 is clear that when (*THEN) is backtracked onto, it goes to the "next
736 alternative in the innermost enclosing group".
737
738 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
739 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
740 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
741 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
742 (*THEN).
743
744 3. If \s appeared in a character class, it removed the VT character from
745 the class, even if it had been included by some previous item, for example
746 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
747 of \s, but is part of the POSIX "space" class.)
748
749 4. A partial match never returns an empty string (because you can always
750 match an empty string at the end of the subject); however the checking for
751 an empty string was starting at the "start of match" point. This has been
752 changed to the "earliest inspected character" point, because the returned
753 data for a partial match starts at this character. This means that, for
754 example, /(?<=abc)def/ gives a partial match for the subject "abc"
755 (previously it gave "no match").
756
757 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
758 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
759 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
760 has an implication that the given string is incomplete (because a partial
761 match is preferred over a full match). For this reason, these items now
762 give a partial match in this situation. [Aside: previously, the one case
763 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
764 match rather than a full match, which was wrong by the old rules, but is
765 now correct.]
766
767 6. There was a bug in the handling of #-introduced comments, recognized when
768 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
769 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
770 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
771 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
772 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
773 places in pcre_compile().
774
775 7. Related to (6) above, when pcre_compile() was skipping #-introduced
776 comments when looking ahead for named forward references to subpatterns,
777 the only newline sequence it recognized was NL. It now handles newlines
778 according to the set newline convention.
779
780 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
781 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
782 cater for a lack of strerror(). These oversights have been fixed.
783
784 9. Added --match-limit and --recursion-limit to pcregrep.
785
786 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
787
788 11. When the -o option was used, pcregrep was setting a return code of 1, even
789 when matches were found, and --line-buffered was not being honoured.
790
791 12. Added an optional parentheses number to the -o and --only-matching options
792 of pcregrep.
793
794 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
795 can match an empty string. The code to do it in pcretest and pcredemo
796 needed fixing:
797
798 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
799 only one byte after an empty string match just before CRLF (this case
800 just got forgotten; "any" and "anycrlf" were OK).
801
802 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
803 mode when an empty string match preceded an ASCII character followed by
804 a non-ASCII character. (The code for advancing by one character rather
805 than one byte was nonsense.)
806
807 (c) The pcredemo.c sample program did not have any code at all to handle
808 the cases when CRLF is a valid newline sequence.
809
810 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
811 as a starting offset was within the subject string. There is now a new
812 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
813 negative or greater than the length of the string. In order to test this,
814 pcretest is extended to allow the setting of negative starting offsets.
815
816 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
817 starting offset points to the beginning of a UTF-8 character was
818 unnecessarily clumsy. I tidied it up.
819
820 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
821 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
822
823 17. Nobody had reported that the --include_dir option, which was added in
824 release 7.7 should have been called --include-dir (hyphen, not underscore)
825 for compatibility with GNU grep. I have changed it to --include-dir, but
826 left --include_dir as an undocumented synonym, and the same for
827 --exclude-dir, though that is not available in GNU grep, at least as of
828 release 2.5.4.
829
830 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
831 characters from a string of bytes) have been redefined so as not to use
832 loops, in order to improve performance in some environments. At the same
833 time, I abstracted some of the common code into auxiliary macros to save
834 repetition (this should not affect the compiled code).
835
836 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
837 compile-time error is now given if \c is not followed by an ASCII
838 character, that is, a byte less than 128. (In EBCDIC mode, the code is
839 different, and any byte value is allowed.)
840
841 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
842 START_OPTIMIZE option, which is now allowed at compile time - but just
843 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
844 to pcregrep and other applications that have no direct access to PCRE
845 options. The new /Y option in pcretest sets this option when calling
846 pcre_compile().
847
848 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
849 back references. Groups containing recursive back references were forced to
850 be atomic by that change, but in the case of named groups, the amount of
851 memory required was incorrectly computed, leading to "Failed: internal
852 error: code overflow". This has been fixed.
853
854 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
855 pcretest.c, to avoid build problems in some Borland environments.
856
857
858 Version 8.10 25-Jun-2010
859 ------------------------
860
861 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
862 THEN.
863
864 2. (*ACCEPT) was not working when inside an atomic group.
865
866 3. Inside a character class, \B is treated as a literal by default, but
867 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
868 causes the error). The code is unchanged, but I tidied the documentation.
869
870 4. Inside a character class, PCRE always treated \R and \X as literals,
871 whereas Perl faults them if its -w option is set. I have changed PCRE so
872 that it faults them when PCRE_EXTRA is set.
873
874 5. Added support for \N, which always matches any character other than
875 newline. (It is the same as "." when PCRE_DOTALL is not set.)
876
877 6. When compiling pcregrep with newer versions of gcc which may have
878 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
879 declared with attribute warn_unused_result" were given. Just casting the
880 result to (void) does not stop the warnings; a more elaborate fudge is
881 needed. I've used a macro to implement this.
882
883 7. Minor change to pcretest.c to avoid a compiler warning.
884
885 8. Added four artifical Unicode properties to help with an option to make
886 \s etc use properties (see next item). The new properties are: Xan
887 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
888
889 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
890 use Unicode properties. (*UCP) at the start of a pattern can be used to set
891 this option. Modified pcretest to add /W to test this facility. Added
892 REG_UCP to make it available via the POSIX interface.
893
894 10. Added --line-buffered to pcregrep.
895
896 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
897 studied, and the match started with a letter with a code point greater than
898 127 whose first byte was different to the first byte of the other case of
899 the letter, the other case of this starting letter was not recognized
900 (#976).
901
902 12. If a pattern that was studied started with a repeated Unicode property
903 test, for example, \p{Nd}+, there was the theoretical possibility of
904 setting up an incorrect bitmap of starting bytes, but fortunately it could
905 not have actually happened in practice until change 8 above was made (it
906 added property types that matched character-matching opcodes).
907
908 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
909 possible starting bytes for non-anchored patterns.
910
911 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
912 \R, and also a number of cases that involve Unicode properties, both
913 explicit and implicit when PCRE_UCP is set.
914
915 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
916 input, it could crash or give wrong results if characters with values
917 greater than 0xc0 were present in the subject string. (Detail: it assumed
918 UTF-8 input when processing these items.)
919
920 16. Added a lot of (int) casts to avoid compiler warnings in systems where
921 size_t is 64-bit (#991).
922
923 17. Added a check for running out of memory when PCRE is compiled with
924 --disable-stack-for-recursion (#990).
925
926 18. If the last data line in a file for pcretest does not have a newline on
927 the end, a newline was missing in the output.
928
929 19. The default pcre_chartables.c file recognizes only ASCII characters (values
930 less than 128) in its various bitmaps. However, there is a facility for
931 generating tables according to the current locale when PCRE is compiled. It
932 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
933 characters, are recognized by isspace() and therefore were getting set in
934 these tables, and indeed these tables seem to approximate to ISO 8859. This
935 caused a problem in UTF-8 mode when pcre_study() was used to create a list
936 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
937 which of course cannot start UTF-8 characters. I have changed the code so
938 that only real ASCII characters (less than 128) and the correct starting
939 bytes for UTF-8 encodings are set for characters greater than 127 when in
940 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
941 altogether.)
942
943 20. Added the /T option to pcretest so as to be able to run tests with non-
944 standard character tables, thus making it possible to include the tests
945 used for 19 above in the standard set of tests.
946
947 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
948 reference to a subpattern the other side of a comment that contains an
949 opening parenthesis caused either an internal compiling error, or a
950 reference to the wrong subpattern.
951
952
953 Version 8.02 19-Mar-2010
954 ------------------------
955
956 1. The Unicode data tables have been updated to Unicode 5.2.0.
957
958 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
959 configured.
960
961 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
962 original author of that file, following a query about its status.
963
964 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
965 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
966
967 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
968 quantifier applied to a forward-referencing subroutine call, could compile
969 incorrect code or give the error "internal error: previously-checked
970 referenced subpattern not found".
971
972 6. Both MS Visual Studio and Symbian OS have problems with initializing
973 variables to point to external functions. For these systems, therefore,
974 pcre_malloc etc. are now initialized to local functions that call the
975 relevant global functions.
976
977 7. There were two entries missing in the vectors called coptable and poptable
978 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
979 I've fixed the data, and added a kludgy way of testing at compile time that
980 the lengths are correct (equal to the number of opcodes).
981
982 8. Following on from 7, I added a similar kludge to check the length of the
983 eint vector in pcreposix.c.
984
985 9. Error texts for pcre_compile() are held as one long string to avoid too
986 much relocation at load time. To find a text, the string is searched,
987 counting zeros. There was no check for running off the end of the string,
988 which could happen if a new error number was added without updating the
989 string.
990
991 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
992
993 11. \K was not working if it appeared in an atomic group or in a group that
994 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
995 \K is "not well defined" if used in an assertion. PCRE now accepts it if
996 the assertion is positive, but not if it is negative.
997
998 12. Change 11 fortuitously reduced the size of the stack frame used in the
999 "match()" function of pcre_exec.c by one pointer. Forthcoming
1000 implementation of support for (*MARK) will need an extra pointer on the
1001 stack; I have reserved it now, so that the stack frame size does not
1002 decrease.
1003
1004 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1005 item in branch that calls a recursion is a subroutine call - as in the
1006 second branch in the above example - was incorrectly given the compile-
1007 time error "recursive call could loop indefinitely" because pcre_compile()
1008 was not correctly checking the subroutine for matching a non-empty string.
1009
1010 14. The checks for overrunning compiling workspace could trigger after an
1011 overrun had occurred. This is a "should never occur" error, but it can be
1012 triggered by pathological patterns such as hundreds of nested parentheses.
1013 The checks now trigger 100 bytes before the end of the workspace.
1014
1015 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1016
1017
1018 Version 8.01 19-Jan-2010
1019 ------------------------
1020
1021 1. If a pattern contained a conditional subpattern with only one branch (in
1022 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1023 computed the wrong minimum data length (which is of course zero for such
1024 subpatterns). This could cause incorrect "no match" results.
1025
1026 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1027 the pattern is reset in the first branch, pcre_compile() failed with
1028 "internal error: code overflow at offset...". This happened only when
1029 the reset was to the original external option setting. (An optimization
1030 abstracts leading options settings into an external setting, which was the
1031 cause of this.)
1032
1033 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1034 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1035 assertion pattern did not match (meaning that the assertion was true), it
1036 was incorrectly treated as false if the SKIP had been reached during the
1037 matching. This also applied to assertions used as conditions.
1038
1039 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
1040 assertion subpattern, including such a pattern used as a condition,
1041 unpredictable results occurred, instead of the error return
1042 PCRE_ERROR_DFA_UITEM.
1043
1044 5. The C++ GlobalReplace function was not working like Perl for the special
1045 situation when an empty string is matched. It now does the fancy magic
1046 stuff that is necessary.
1047
1048 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1049 removed. (These were left over from very, very early versions of PCRE.)
1050
1051 7. Some cosmetic changes to the code to make life easier when compiling it
1052 as part of something else:
1053
1054 (a) Change DEBUG to PCRE_DEBUG.
1055
1056 (b) In pcre_compile(), rename the member of the "branch_chain" structure
1057 called "current" as "current_branch", to prevent a collision with the
1058 Linux macro when compiled as a kernel module.
1059
1060 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1061 prevent a collision with the Linux macro when compiled as a kernel
1062 module.
1063
1064 8. In pcre_compile() there are some checks for integer overflows that used to
1065 cast potentially large values to (double). This has been changed to that
1066 when building, a check for int64_t is made, and if it is found, it is used
1067 instead, thus avoiding the use of floating point arithmetic. (There is no
1068 other use of FP in PCRE.) If int64_t is not found, the fallback is to
1069 double.
1070
1071 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
1072 2005 (difference between two addresses compared to an unsigned value).
1073
1074 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1075 custom one, because of the following reported problem in Windows:
1076
1077 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1078 under Win32.
1079 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1080 therefore missing the function definition.
1081 - The compiler thus generates a "C" signature for the test function.
1082 - The linker fails to find the "C" function.
1083 - PCRE fails to configure if asked to do so against libbz2.
1084
1085 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1086 messages were output:
1087
1088 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1089 rerunning libtoolize, to keep the correct libtool macros in-tree.
1090 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1091
1092 I have done both of these things.
1093
1094 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1095 most of the time, it *can* run out if it is given a pattern that contains a
1096 runaway infinite recursion. I updated the discussion in the pcrestack man
1097 page.
1098
1099 13. Now that we have gone to the x.xx style of version numbers, the minor
1100 version may start with zero. Using 08 or 09 is a bad idea because users
1101 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1102 interpreted as invalid octal numbers. I've updated the previous comment in
1103 configure.ac, and also added a check that gives an error if 08 or 09 are
1104 used.
1105
1106 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1107 causing partial matching to fail when the end of the subject matched \W
1108 in a UTF-8 pattern where \W was quantified with a minimum of 3.
1109
1110 15. There were some discrepancies between the declarations in pcre_internal.h
1111 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1112 their definitions. The declarations used "const uschar *" and the
1113 definitions used USPTR. Even though USPTR is normally defined as "const
1114 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1115 reported that: "This difference in casting confuses some C++ compilers, for
1116 example, SunCC recognizes above declarations as different functions and
1117 generates broken code for hbpcre." I have changed the declarations to use
1118 USPTR.
1119
1120 16. GNU libtool is named differently on some systems. The autogen.sh script now
1121 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1122 (FreeBSD).
1123
1124 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1125 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1126 comment: "Figure out how to create a longlong from a string: strtoll and
1127 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1128 instance, but it only takes 2 args instead of 3!"
1129
1130 18. A subtle bug concerned with back references has been fixed by a change of
1131 specification, with a corresponding code fix. A pattern such as
1132 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1133 refers, was giving matches when it shouldn't. For example, xa=xaaa would
1134 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1135 same bug. Such groups have to be quantified to be useful, or contained
1136 inside another quantified group. (If there's no repetition, the reference
1137 can never match.) The problem arises because, having left the group and
1138 moved on to the rest of the pattern, a later failure that backtracks into
1139 the group uses the captured value from the final iteration of the group
1140 rather than the correct earlier one. I have fixed this in PCRE by forcing
1141 any group that contains a reference to itself to be an atomic group; that
1142 is, there cannot be any backtracking into it once it has completed. This is
1143 similar to recursive and subroutine calls.
1144
1145
1146 Version 8.00 19-Oct-09
1147 ----------------------
1148
1149 1. The table for translating pcre_compile() error codes into POSIX error codes
1150 was out-of-date, and there was no check on the pcre_compile() error code
1151 being within the table. This could lead to an OK return being given in
1152 error.
1153
1154 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1155 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1156 in a Windows environment.
1157
1158 3. The pcregrep --count option prints the count for each file even when it is
1159 zero, as does GNU grep. However, pcregrep was also printing all files when
1160 --files-with-matches was added. Now, when both options are given, it prints
1161 counts only for those files that have at least one match. (GNU grep just
1162 prints the file name in this circumstance, but including the count seems
1163 more useful - otherwise, why use --count?) Also ensured that the
1164 combination -clh just lists non-zero counts, with no names.
1165
1166 4. The long form of the pcregrep -F option was incorrectly implemented as
1167 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1168 but it seems right to fix it, and I didn't think it was worth preserving
1169 the old behaviour.
1170
1171 5. The command line items --regex=pattern and --regexp=pattern were not
1172 recognized by pcregrep, which required --regex pattern or --regexp pattern
1173 (with a space rather than an '='). The man page documented the '=' forms,
1174 which are compatible with GNU grep; these now work.
1175
1176 6. No libpcreposix.pc file was created for pkg-config; there was just
1177 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1178
1179 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1180 when UCP support is not needed, by modifying the Python script that
1181 generates it from Unicode data files. This should not matter if the module
1182 is correctly used as a library, but I received one complaint about 50K of
1183 unwanted data. My guess is that the person linked everything into his
1184 program rather than using a library. Anyway, it does no harm.
1185
1186 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1187 was a minimum greater than 1 for a wide character in a possessive
1188 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1189 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1190 character. Chaos in the form of incorrect output or a compiling loop could
1191 result.
1192
1193 9. The restrictions on what a pattern can contain when partial matching is
1194 requested for pcre_exec() have been removed. All patterns can now be
1195 partially matched by this function. In addition, if there are at least two
1196 slots in the offset vector, the offset of the earliest inspected character
1197 for the match and the offset of the end of the subject are set in them when
1198 PCRE_ERROR_PARTIAL is returned.
1199
1200 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1201 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1202 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1203 and may be more useful for multi-segment matching.
1204
1205 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1206 used to be given if ever the end of the subject was reached; now it is
1207 given only if matching could not proceed because another character was
1208 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1209 string "Z", which now yields "no match" instead of "partial match". In the
1210 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1211 final character ended with (*FAIL).
1212
1213 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1214 if the pattern had a "must contain" character that was already found in the
1215 earlier partial match, unless partial matching was again requested. For
1216 example, with the pattern /dog.(body)?/, the "must contain" character is
1217 "g". If the first part-match was for the string "dog", restarting with
1218 "sbody" failed. This bug has been fixed.
1219
1220 13. The string returned by pcre_dfa_exec() after a partial match has been
1221 changed so that it starts at the first inspected character rather than the
1222 first character of the match. This makes a difference only if the pattern
1223 starts with a lookbehind assertion or \b or \B (\K is not supported by
1224 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1225 matching functions compatible, and I think it's the right thing to do.
1226
1227 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1228 so that the demonstration program is easily available in environments where
1229 PCRE has not been installed from source.
1230
1231 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1232 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1233 library.
1234
1235 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1236 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1237 is not the first non-POSIX option to be added. Clearly some people find
1238 these options useful.
1239
1240 17. If a caller to the POSIX matching function regexec() passes a non-zero
1241 value for nmatch with a NULL value for pmatch, the value of
1242 nmatch is forced to zero.
1243
1244 18. RunGrepTest did not have a test for the availability of the -u option of
1245 the diff command, as RunTest does. It now checks in the same way as
1246 RunTest, and also checks for the -b option.
1247
1248 19. If an odd number of negated classes containing just a single character
1249 interposed, within parentheses, between a forward reference to a named
1250 subpattern and the definition of the subpattern, compilation crashed with
1251 an internal error, complaining that it could not find the referenced
1252 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1253 [The bug was that it was starting one character too far in when skipping
1254 over the character class, thus treating the ] as data rather than
1255 terminating the class. This meant it could skip too much.]
1256
1257 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1258 /g option in pcretest when the pattern contains \K, which makes it possible
1259 to have an empty string match not at the start, even when the pattern is
1260 anchored. Updated pcretest and pcredemo to use this option.
1261
1262 21. If the maximum number of capturing subpatterns in a recursion was greater
1263 than the maximum at the outer level, the higher number was returned, but
1264 with unset values at the outer level. The correct (outer level) value is
1265 now given.
1266
1267 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1268 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1269 make it do so. The string so far is captured, making this feature
1270 compatible with Perl.
1271
1272 23. The tests have been re-organized, adding tests 11 and 12, to make it
1273 possible to check the Perl 5.10 features against Perl 5.10.
1274
1275 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1276 pattern matches a fixed length string. PCRE did not allow this; now it
1277 does. Neither allows recursion.
1278
1279 25. I finally figured out how to implement a request to provide the minimum
1280 length of subject string that was needed in order to match a given pattern.
1281 (It was back references and recursion that I had previously got hung up
1282 on.) This code has now been added to pcre_study(); it finds a lower bound
1283 to the length of subject needed. It is not necessarily the greatest lower
1284 bound, but using it to avoid searching strings that are too short does give
1285 some useful speed-ups. The value is available to calling programs via
1286 pcre_fullinfo().
1287
1288 26. While implementing 25, I discovered to my embarrassment that pcretest had
1289 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1290 study optimizations had never been tested with that matching function.
1291 Oops. What is worse, even when it was passed study data, there was a bug in
1292 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1293 were also very few tests of studied patterns with pcre_dfa_exec().
1294
1295 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1296 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1297 on the other side of the coin, they are no longer allowed to have different
1298 names, because these cannot be distinguished in PCRE, and this has caused
1299 confusion. (This is a difference from Perl.)
1300
1301 28. When duplicate subpattern names are present (necessarily with different
1302 numbers, as required by 27 above), and a test is made by name in a
1303 conditional pattern, either for a subpattern having been matched, or for
1304 recursion in such a pattern, all the associated numbered subpatterns are
1305 tested, and the overall condition is true if the condition is true for any
1306 one of them. This is the way Perl works, and is also more like the way
1307 testing by number works.
1308
1309
1310 Version 7.9 11-Apr-09
1311 ---------------------
1312
1313 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1314 (pcretest), all targets were linked against these libraries. This included
1315 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1316 libraries. This caused unwanted dependencies to be created. This problem
1317 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1318 pcretest is linked with readline.
1319
1320 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1321 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1322 moved outside it again, because FALSE and TRUE are already defined in AIX,
1323 but BOOL is not.
1324
1325 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1326 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1327
1328 4. The pcregrep documentation said spaces were inserted as well as colons (or
1329 hyphens) following file names and line numbers when outputting matching
1330 lines. This is not true; no spaces are inserted. I have also clarified the
1331 wording for the --colour (or --color) option.
1332
1333 5. In pcregrep, when --colour was used with -o, the list of matching strings
1334 was not coloured; this is different to GNU grep, so I have changed it to be
1335 the same.
1336
1337 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1338 each matching line was coloured. Now it goes on to look for further matches
1339 of any of the test patterns, which is the same behaviour as GNU grep.
1340
1341 7. A pattern that could match an empty string could cause pcregrep to loop; it
1342 doesn't make sense to accept an empty string match in pcregrep, so I have
1343 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1344 seems to be how GNU grep behaves.
1345
1346 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1347 start or after a newline", because the conditional assertion was not being
1348 correctly handled. The rule now is that both the assertion and what follows
1349 in the first alternative must satisfy the test.
1350
1351 9. If auto-callout was enabled in a pattern with a conditional group whose
1352 condition was an assertion, PCRE could crash during matching, both with
1353 pcre_exec() and pcre_dfa_exec().
1354
1355 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1356 used for matching.
1357
1358 11. Unicode property support in character classes was not working for
1359 characters (bytes) greater than 127 when not in UTF-8 mode.
1360
1361 12. Added the -M command line option to pcretest.
1362
1363 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1364
1365 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1366
1367 16. Added comments and documentation about mis-use of no_arg in the C++
1368 wrapper.
1369
1370 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1371 from Martin Jerabek that uses macro names for all relevant character and
1372 string constants.
1373
1374 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1375 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1376 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1377 these, but not everybody uses configure.
1378
1379 19. A conditional group that had only one branch was not being correctly
1380 recognized as an item that could match an empty string. This meant that an
1381 enclosing group might also not be so recognized, causing infinite looping
1382 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1383 with the subject "ab", where knowledge that the repeated group can match
1384 nothing is needed in order to break the loop.
1385
1386 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1387 exec(), but without supplying a callout function, matching went wrong.
1388
1389 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1390 leak if the size of the offset vector was greater than 30. When the vector
1391 is smaller, the saved offsets during recursion go onto a local stack
1392 vector, but for larger vectors malloc() is used. It was failing to free
1393 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1394 error, in fact).
1395
1396 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1397 heapframe that is used only when UTF-8 support is enabled. This caused no
1398 problem, but was untidy.
1399
1400 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1401 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1402 included within another project.
1403
1404 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1405 slightly modified by me:
1406
1407 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1408 not building pcregrep.
1409
1410 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1412
1413 25. Forward references, both numeric and by name, in patterns that made use of
1414 duplicate group numbers, could behave incorrectly or give incorrect errors,
1415 because when scanning forward to find the reference group, PCRE was not
1416 taking into account the duplicate group numbers. A pattern such as
1417 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1418
1419 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1420 the feature of a custom pointer more persuasive (as requested by a user).
1421
1422 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1423 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1424 pre-defined.
1425
1426 28. Added support for (*UTF8) at the start of a pattern.
1427
1428 29. Arrange for flags added by the "release type" setting in CMake to be shown
1429 in the configuration summary.
1430
1431
1432 Version 7.8 05-Sep-08
1433 ---------------------
1434
1435 1. Replaced UCP searching code with optimized version as implemented for Ad
1436 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1437 stage table and inline lookup instead of a function, giving speed ups of 2
1438 to 5 times on some simple patterns that I tested. Permission was given to
1439 distribute the MultiStage2.py script that generates the tables (it's not in
1440 the tarball, but is in the Subversion repository).
1441
1442 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1443 scripts.
1444
1445 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1446 a group with a zero qualifier. The result of the study could be incorrect,
1447 or the function might crash, depending on the pattern.
1448
1449 4. Caseless matching was not working for non-ASCII characters in back
1450 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1451 It now works when Unicode Property Support is available.
1452
1453 5. In pcretest, an escape such as \x{de} in the data was always generating
1454 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1455 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1456 truncation.
1457
1458 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1459
1460 7. Added two (int) casts to pcregrep when printing the difference of two
1461 pointers, in case they are 64-bit values.
1462
1463 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1464 test 2 if it fails.
1465
1466 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1467 and a #define of that name to empty if it is not externally set. This is to
1468 allow users of MSVC to set it if necessary.
1469
1470 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1471 the convenience functions in the pcre_get.c source file.
1472
1473 11. An option change at the start of a pattern that had top-level alternatives
1474 could cause overwriting and/or a crash. This command provoked a crash in
1475 some environments:
1476
1477 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1478
1479 This potential security problem was recorded as CVE-2008-2371.
1480
1481 12. For a pattern where the match had to start at the beginning or immediately
1482 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1483 pcre_dfa_exec() could read past the end of the passed subject if there was
1484 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1485 pcretest so that it places the subject at the end of its malloc-ed buffer.
1486
1487 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1488 exec() might read past the end of the data buffer in UTF-8 mode.
1489
1490 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1491 the data contained the byte 0x85 as part of a UTF-8 character within its
1492 first line. This applied both to normal and DFA matching.
1493
1494 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1495 /^[^d]*?$/8 failed to match "abc".
1496
1497 16. Added a missing copyright notice to pcrecpp_internal.h.
1498
1499 17. Make it more clear in the documentation that values returned from
1500 pcre_exec() in ovector are byte offsets, not character counts.
1501
1502 18. Tidied a few places to stop certain compilers from issuing warnings.
1503
1504 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1505 supplied by Stefan Weber. I made a further small update for 7.8 because
1506 there is a change of source arrangements: the pcre_searchfuncs.c module is
1507 replaced by pcre_ucd.c.
1508
1509
1510 Version 7.7 07-May-08
1511 ---------------------
1512
1513 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1514 a string to a long long, pretend we don't even have a long long." This is
1515 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1516
1517 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1518 pre-7.6 versions, which defined a global no_arg variable instead of putting
1519 it in the RE class. (See also #8 below.)
1520
1521 3. Remove a line of dead code, identified by coverity and reported by Nuno
1522 Lopes.
1523
1524 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1525
1526 (1) The include/exclude patterns were being applied to the whole pathnames
1527 of files, instead of just to the final components.
1528
1529 (2) If there was more than one level of directory, the subdirectories were
1530 skipped unless they satisfied the include/exclude conditions. This is
1531 inconsistent with GNU grep (and could even be seen as contrary to the
1532 pcregrep specification - which I improved to make it absolutely clear).
1533 The action now is always to scan all levels of directory, and just
1534 apply the include/exclude patterns to regular files.
1535
1536 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1537 --exclude_dir in the tests to avoid scanning .svn directories.
1538
1539 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1540 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1541 doesn't support NULs in patterns.
1542
1543 7. Added some missing "const"s to declarations of static tables in
1544 pcre_compile.c and pcre_dfa_exec.c.
1545
1546 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1547 caused by fix #2 above. (Subsequently also a second patch to fix the
1548 first patch. And a third patch - this was a messy problem.)
1549
1550 9. Applied Craig's patch to remove the use of push_back().
1551
1552 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1553 matching function regexec().
1554
1555 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1556 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1557 references. PCRE supports relative numbers with this syntax (I don't think
1558 Oniguruma does).
1559
1560 12. Previously, a group with a zero repeat such as (...){0} was completely
1561 omitted from the compiled regex. However, this means that if the group
1562 was called as a subroutine from elsewhere in the pattern, things went wrong
1563 (an internal error was given). Such groups are now left in the compiled
1564 pattern, with a new opcode that causes them to be skipped at execution
1565 time.
1566
1567 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1568 to the way PCRE behaves:
1569
1570 (a) A lone ] character is dis-allowed (Perl treats it as data).
1571
1572 (b) A back reference to an unmatched subpattern matches an empty string
1573 (Perl fails the current match path).
1574
1575 (c) A data ] in a character class must be notated as \] because if the
1576 first data character in a class is ], it defines an empty class. (In
1577 Perl it is not possible to have an empty class.) The empty class []
1578 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1579 The negative empty class [^] matches any one character, independently
1580 of the DOTALL setting.
1581
1582 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1583 non-existent subpattern following a character class starting with ']' and
1584 containing () gave an internal compiling error instead of "reference to
1585 non-existent subpattern". Fortunately, when the pattern did exist, the
1586 compiled code was correct. (When scanning forwards to check for the
1587 existencd of the subpattern, it was treating the data ']' as terminating
1588 the class, so got the count wrong. When actually compiling, the reference
1589 was subsequently set up correctly.)
1590
1591 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1592 it was being rejected as not supported by pcre_dfa_exec(), even though
1593 other assertions are supported. I have made pcre_dfa_exec() support
1594 (*FAIL).
1595
1596 16. The implementation of 13c above involved the invention of a new opcode,
1597 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1598 cannot be changed at match time, I realized I could make a small
1599 improvement to matching performance by compiling OP_ALLANY instead of
1600 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1601 on the OP_ANY path.
1602
1603 17. Compiling pcretest on Windows with readline support failed without the
1604 following two fixes: (1) Make the unistd.h include conditional on
1605 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1606
1607 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1608 ncurses library to be included for pcretest when ReadLine support is
1609 requested, but also to allow for it to be overridden. This patch came from
1610 Daniel Bergström.
1611
1612 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1613 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1614 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1615 spotting this.
1616
1617
1618 Version 7.6 28-Jan-08
1619 ---------------------
1620
1621 1. A character class containing a very large number of characters with
1622 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1623 overflow.
1624
1625 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1626 HAVE_LONG_LONG is not defined.
1627
1628 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1629 bring them up to date and include new features. This patch includes:
1630
1631 - Fixed PH's badly added libz and libbz2 support.
1632 - Fixed a problem with static linking.
1633 - Added pcredemo. [But later removed - see 7 below.]
1634 - Fixed dftables problem and added an option.
1635 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1636 HAVE_LONG_LONG.
1637 - Added readline support for pcretest.
1638 - Added an listing of the option settings after cmake has run.
1639
1640 4. A user submitted a patch to Makefile that makes it easy to create
1641 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1642 Makefile.am that cause it to include this special target, without
1643 affecting anything else. Note that the same mingw target plus all
1644 the other distribution libraries and programs are now supported
1645 when configuring with CMake (see 6 below) instead of with
1646 Configure/Make.
1647
1648 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1649 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1650 exported in the Windows port". It has not yet been confirmed that the patch
1651 solves the problem, but it does no harm.
1652
1653 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1654 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1655 with CMake, and also correct the comment about stack recursion.
1656
1657 7. Remove the automatic building of pcredemo from the ./configure system and
1658 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1659 of a program that users should build themselves after PCRE is installed, so
1660 building it automatically is not really right. What is more, it gave
1661 trouble in some build environments.
1662
1663 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1664
1665
1666 Version 7.5 10-Jan-08
1667 ---------------------
1668
1669 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1670 values in parens when parsing an RE using the C++ wrapper."
1671
1672 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1673 Characters greater than 255 were excluded from the class instead of being
1674 included.
1675
1676 3. The same bug as (2) above applied to negated POSIX classes such as
1677 [:^space:].
1678
1679 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1680 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1681 I have changed it.
1682
1683 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1684 first named subpattern) and a construct such as (?&a) would reference the
1685 first named subpattern whose name started with "a" (in other words, the
1686 length check was missing). Both these problems are fixed. "Subpattern name
1687 expected" is now given for (?&) (a zero-length name), and this patch also
1688 makes it give the same error for \k'' (previously it complained that that
1689 was a reference to a non-existent subpattern).
1690
1691 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1692 this is right because (?- can be followed by option settings as well as by
1693 digits. I have, however, made the messages clearer.
1694
1695 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1696 than the number used in the conditional) now cause a compile-time error.
1697 This is actually not compatible with Perl, which accepts such patterns, but
1698 treats the conditional as always being FALSE (as PCRE used to), but it
1699 seems to me that giving a diagnostic is better.
1700
1701 8. Change "alphameric" to the more common word "alphanumeric" in comments
1702 and messages.
1703
1704 9. Fix two occurrences of "backslash" in comments that should have been
1705 "backspace".
1706
1707 10. Remove two redundant lines of code that can never be obeyed (their function
1708 was moved elsewhere).
1709
1710 11. The program that makes PCRE's Unicode character property table had a bug
1711 which caused it to generate incorrect table entries for sequences of
1712 characters that have the same character type, but are in different scripts.
1713 It amalgamated them into a single range, with the script of the first of
1714 them. In other words, some characters were in the wrong script. There were
1715 thirteen such cases, affecting characters in the following ranges:
1716
1717 U+002b0 - U+002c1
1718 U+0060c - U+0060d
1719 U+0061e - U+00612
1720 U+0064b - U+0065e
1721 U+0074d - U+0076d
1722 U+01800 - U+01805
1723 U+01d00 - U+01d77
1724 U+01d9b - U+01dbf
1725 U+0200b - U+0200f
1726 U+030fc - U+030fe
1727 U+03260 - U+0327f
1728 U+0fb46 - U+0fbb1
1729 U+10450 - U+1049d
1730
1731 12. The -o option (show only the matching part of a line) for pcregrep was not
1732 compatible with GNU grep in that, if there was more than one match in a
1733 line, it showed only the first of them. It now behaves in the same way as
1734 GNU grep.
1735
1736 13. If the -o and -v options were combined for pcregrep, it printed a blank
1737 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1738 does the same. The return code can be used to tell if there were any
1739 non-matching lines.
1740
1741 14. Added --file-offsets and --line-offsets to pcregrep.
1742
1743 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1744 infinitely looping recursion. The bug was that positive lookaheads were not
1745 being skipped when checking for a possible empty match (negative lookaheads
1746 and both kinds of lookbehind were skipped).
1747
1748 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1749 inclusion of <windows.h> to before rather than after the definition of
1750 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1751
1752 17. Specifying a possessive quantifier with a specific limit for a Unicode
1753 character property caused pcre_compile() to compile bad code, which led at
1754 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1755 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1756 caused the error; without that there was no problem.
1757
1758 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1759
1760 19. Added --enable-pcretest-libreadline.
1761
1762 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1763 RE::GlobalReplace(). As a result, the number of replacements returned was
1764 double what it should be. I removed one of the increments, but Craig sent a
1765 later patch that removed the other one (the right fix) and added unit tests
1766 that check the return values (which was not done before).
1767
1768 21. Several CMake things:
1769
1770 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1771 the names libpcre and libpcreposix, not just pcre and pcreposix.
1772
1773 (2) The above change means that pcretest and pcregrep are now correctly
1774 linked with the newly-built libraries, not previously installed ones.
1775
1776 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1777
1778 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1779 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1780 UTF-8 newline character). The key issue is that the pattern starts .*;
1781 this means that the match must be either at the beginning, or after a
1782 newline. The bug was in the code for advancing after a failed match and
1783 checking that the new position followed a newline. It was not taking
1784 account of UTF-8 characters correctly.
1785
1786 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1787 character classes. PCRE was not treating the sequence [:...:] as a
1788 character class unless the ... were all letters. Perl, however, seems to
1789 allow any characters between [: and :], though of course it rejects as
1790 unknown any "names" that contain non-letters, because all the known class
1791 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1792 for example, whereas PCRE did not - it did not recognize a POSIX character
1793 class. This seemed a bit dangerous, so the code has been changed to be
1794 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1795 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1796 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1797 Perl does, and where it didn't before.
1798
1799 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1800 Windows environments %n is disabled by default.
1801
1802
1803 Version 7.4 21-Sep-07
1804 ---------------------
1805
1806 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1807 means that a class such as [\s] counted as "explicit reference to CR or
1808 LF". That isn't really right - the whole point of the change was to try to
1809 help when there was an actual mention of one of the two characters. So now
1810 the change happens only if \r or \n (or a literal CR or LF) character is
1811 encountered.
1812
1813 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1814 of both had grown to the point where there were only 3 bits left.
1815 Fortunately, there was spare space in the data structure, and so I have
1816 moved the internal flags into a new 16-bit field to free up more option
1817 bits.
1818
1819 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1820 but did not set the internal JCHANGED flag - either of these is enough to
1821 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1822 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1823 start sets both bits.
1824
1825 4. Added options (at build time, compile time, exec time) to change \R from
1826 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1827
1828 5. doc/pcresyntax.html was missing from the distribution.
1829
1830 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1831 compatibility, even though it is no longer used.
1832
1833 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1834 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1835 windows.h file is present (where different names are used). [This was
1836 reversed later after testing - see 16 below.]
1837
1838 8. Changed all #include <config.h> to #include "config.h". There were also
1839 some further <pcre.h> cases that I changed to "pcre.h".
1840
1841 9. When pcregrep was used with the --colour option, it missed the line ending
1842 sequence off the lines that it output.
1843
1844 10. It was pointed out to me that arrays of string pointers cause lots of
1845 relocations when a shared library is dynamically loaded. A technique of
1846 using a single long string with a table of offsets can drastically reduce
1847 these. I have refactored PCRE in four places to do this. The result is
1848 dramatic:
1849
1850 Originally: 290
1851 After changing UCP table: 187
1852 After changing error message table: 43
1853 After changing table of "verbs" 36
1854 After changing table of Posix names 22
1855
1856 Thanks to the folks working on Gregex for glib for this insight.
1857
1858 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1859 unicode-properties was also set.
1860
1861 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1862
1863 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1864 checked only for CRLF.
1865
1866 14. Added casts to pcretest.c to avoid compiler warnings.
1867
1868 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1869
1870 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1871 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1872 entirely. This removes changes made in 7 above.
1873
1874 17. The CMake files have been updated, and there is now more information about
1875 building with CMake in the NON-UNIX-USE document.
1876
1877
1878 Version 7.3 28-Aug-07
1879 ---------------------
1880
1881 1. In the rejigging of the build system that eventually resulted in 7.1, the
1882 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1883 brackets there is not right, since it causes compilers to look for an
1884 installed pcre.h, not the version that is in the source that is being
1885 compiled (which of course may be different). I have changed it back to:
1886
1887 #include "pcre.h"
1888
1889 I have a vague recollection that the change was concerned with compiling in
1890 different directories, but in the new build system, that is taken care of
1891 by the VPATH setting the Makefile.
1892
1893 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1894 when the subject happened to end in the byte 0x85 (e.g. if the last
1895 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1896 characters but of course it shouldn't be taken as a newline when it is part
1897 of another character. The bug was that, for an unlimited repeat of . in
1898 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1899 characters when looking for a newline.
1900
1901 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1902
1903 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1904 in debug output.
1905
1906 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1907 long printing in the pcrecpp unittest when running under MinGW.
1908
1909 6. ESC_K was left out of the EBCDIC table.
1910
1911 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1912 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1913 limit also applies to "virtual nesting" when a pattern is recursive, and in
1914 this case 1000 isn't so big. I have been able to remove this limit at the
1915 expense of backing off one optimization in certain circumstances. Normally,
1916 when pcre_exec() would call its internal match() function recursively and
1917 immediately return the result unconditionally, it uses a "tail recursion"
1918 feature to save stack. However, when a subpattern that can match an empty
1919 string has an unlimited repetition quantifier, it no longer makes this
1920 optimization. That gives it a stack frame in which to save the data for
1921 checking that an empty string has been matched. Previously this was taken
1922 from the 1000-entry workspace that had been reserved. So now there is no
1923 explicit limit, but more stack is used.
1924
1925 8. Applied Daniel's patches to solve problems with the import/export magic
1926 syntax that is required for Windows, and which was going wrong for the
1927 pcreposix and pcrecpp parts of the library. These were overlooked when this
1928 problem was solved for the main library.
1929
1930 9. There were some crude static tests to avoid integer overflow when computing
1931 the size of patterns that contain repeated groups with explicit upper
1932 limits. As the maximum quantifier is 65535, the maximum group length was
1933 set at 30,000 so that the product of these two numbers did not overflow a
1934 32-bit integer. However, it turns out that people want to use groups that
1935 are longer than 30,000 bytes (though not repeat them that many times).
1936 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1937 made it possible to implement the integer overflow checks in a much more
1938 dynamic way, which I have now done. The artificial limitation on group
1939 length has been removed - we now have only the limit on the total length of
1940 the compiled pattern, which depends on the LINK_SIZE setting.
1941
1942 10. Fixed a bug in the documentation for get/copy named substring when
1943 duplicate names are permitted. If none of the named substrings are set, the
1944 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1945 empty string.
1946
1947 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1948 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1949 because the ] is interpreted as the first data character and the
1950 terminating ] is not found. PCRE has been made compatible with Perl in this
1951 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1952 cause memory overwriting.
1953
1954 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1955 string has been matched (to stop an infinite loop). It was not recognizing
1956 a conditional subpattern that could match an empty string if that
1957 subpattern was within another subpattern. For example, it looped when
1958 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1959 condition was not nested. This bug has been fixed.
1960
1961 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1962 past the start of the subject in the presence of bytes with the top bit
1963 set, for example "\x8aBCD".
1964
1965 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1966 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1967
1968 14. Optimized (?!) to (*FAIL).
1969
1970 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1971 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1972 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1973 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1974 does: it's just the validity check that is more restrictive.
1975
1976 16. Inserted checks for integer overflows during escape sequence (backslash)
1977 processing, and also fixed erroneous offset values for syntax errors during
1978 backslash processing.
1979
1980 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1981 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1982
1983 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1984 caused an overrun.
1985
1986 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1987 something other than just ASCII characters) inside a group that had an
1988 unlimited repeat caused a loop at compile time (while checking to see
1989 whether the group could match an empty string).
1990
1991 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1992 [\P{Any}] did so. (Error in the code for printing property names.)
1993
1994 21. An orphan \E inside a character class could cause a crash.
1995
1996 22. A repeated capturing bracket such as (A)? could cause a wild memory
1997 reference during compilation.
1998
1999 23. There are several functions in pcre_compile() that scan along a compiled
2000 expression for various reasons (e.g. to see if it's fixed length for look
2001 behind). There were bugs in these functions when a repeated \p or \P was
2002 present in the pattern. These operators have additional parameters compared
2003 with \d, etc, and these were not being taken into account when moving along
2004 the compiled data. Specifically:
2005
2006 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2007 length.
2008
2009 (b) An item such as \pL+ within a repeated group could cause crashes or
2010 loops.
2011
2012 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2013 "reference to non-existent subpattern" error.
2014
2015 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2016
2017 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2018 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2019
2020 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2021
2022 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2023 character were causing crashes (broken optimization).
2024
2025 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2026 \p or \P) caused a compile-time loop.
2027
2028 28. More problems have arisen in unanchored patterns when CRLF is a valid line
2029 break. For example, the unstudied pattern [\r\n]A does not match the string
2030 "\r\nA" because change 7.0/46 below moves the current point on by two
2031 characters after failing to match at the start. However, the pattern \nA
2032 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2033 the same is true. There doesn't seem any very clean way out of this, but
2034 what I have chosen to do makes the common cases work: PCRE now takes note
2035 of whether there can be an explicit match for \r or \n anywhere in the
2036 pattern, and if so, 7.0/46 no longer applies. As part of this change,
2037 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2038 pattern has explicit CR or LF references.
2039
2040 29. Added (*CR) etc for changing newline setting at start of pattern.
2041
2042
2043 Version 7.2 19-Jun-07
2044 ---------------------
2045
2046 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2047 which is apparently normally available under Windows.
2048
2049 2. Re-jig the pcregrep tests with different newline settings in an attempt
2050 to make them independent of the local environment's newline setting.
2051
2052 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2053
2054 4. Some of the "internals" tests were previously cut out when the link size
2055 was not 2, because the output contained actual offsets. The recent new
2056 "Z" feature of pcretest means that these can be cut out, making the tests
2057 usable with all link sizes.
2058
2059 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2060 stack recursion. This gives a massive performance boost under BSD, but just
2061 a small improvement under Linux. However, it saves one field in the frame
2062 in all cases.
2063
2064 6. Added more features from the forthcoming Perl 5.10:
2065
2066 (a) (?-n) (where n is a string of digits) is a relative subroutine or
2067 recursion call. It refers to the nth most recently opened parentheses.
2068
2069 (b) (?+n) is also a relative subroutine call; it refers to the nth next
2070 to be opened parentheses.
2071
2072 (c) Conditions that refer to capturing parentheses can be specified
2073 relatively, for example, (?(-2)... or (?(+3)...
2074
2075 (d) \K resets the start of the current match so that everything before
2076 is not part of it.
2077
2078 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2079
2080 (f) \g{name} is another synonym - part of Perl 5.10's unification of
2081 reference syntax.
2082
2083 (g) (?| introduces a group in which the numbering of parentheses in each
2084 alternative starts with the same number.
2085
2086 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2087
2088 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2089 PCRE_INFO_JCHANGED.
2090
2091 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
2092 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2093 for detecting groups that can match an empty string.
2094
2095 9. A pattern with a very large number of alternatives (more than several
2096 hundred) was running out of internal workspace during the pre-compile
2097 phase, where pcre_compile() figures out how much memory will be needed. A
2098 bit of new cunning has reduced the workspace needed for groups with
2099 alternatives. The 1000-alternative test pattern now uses 12 bytes of
2100 workspace instead of running out of the 4096 that are available.
2101
2102 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2103
2104 11. Applied patch from Google to remove an optimization that didn't quite work.
2105 The report of the bug said:
2106
2107 pcrecpp::RE("a*").FullMatch("aaa") matches, while
2108 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2109 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2110
2111 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2112 it matched the wrong number of bytes.
2113
2114
2115 Version 7.1 24-Apr-07
2116 ---------------------
2117
2118 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2119 that is more "standard", making use of automake and other Autotools. There
2120 is some re-arrangement of the files and adjustment of comments consequent
2121 on this.
2122
2123 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2124 for recursive directory scanning broke on some systems because the files
2125 are not scanned in any specific order and on different systems the order
2126 was different. A call to "sort" has been inserted into RunGrepTest for the
2127 approprate test as a short-term fix. In the longer term there may be an
2128 alternative.
2129
2130 3. I had an email from Eric Raymond about problems translating some of PCRE's
2131 man pages to HTML (despite the fact that I distribute HTML pages, some
2132 people do their own conversions for various reasons). The problems
2133 concerned the use of low-level troff macros .br and .in. I have therefore
2134 removed all such uses from the man pages (some were redundant, some could
2135 be replaced by .nf/.fi pairs). The 132html script that I use to generate
2136 HTML has been updated to handle .nf/.fi and to complain if it encounters
2137 .br or .in.
2138
2139 4. Updated comments in configure.ac that get placed in config.h.in and also
2140 arranged for config.h to be included in the distribution, with the name
2141 config.h.generic, for the benefit of those who have to compile without
2142 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2143
2144 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2145 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2146 makevp.bat for the current PCRE, using the additional files
2147 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2148
2149 6. A Windows user reported a minor discrepancy with test 2, which turned out
2150 to be caused by a trailing space on an input line that had got lost in his
2151 copy. The trailing space was an accident, so I've just removed it.
2152
2153 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2154 that is needed.
2155
2156 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2157 as "const" (a) because they are and (b) because it helps the PHP
2158 maintainers who have recently made a script to detect big data structures
2159 in the php code that should be moved to the .rodata section. I remembered
2160 to update Builducptable as well, so it won't revert if ucptable.h is ever
2161 re-created.
2162
2163 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2164 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2165 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2166 support is not required. This saves 1.5-2K of code, which is important in
2167 some applications.
2168
2169 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2170 so as not to refer to the tables, even though these functions will never be
2171 called when UTF-8 support is disabled. Otherwise there are problems with a
2172 shared library.
2173
2174 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2175
2176 (a) It was defining its arguments as char * instead of void *.
2177
2178 (b) It was assuming that all moves were upwards in memory; this was true
2179 a long time ago when I wrote it, but is no longer the case.
2180
2181 The emulated memove() is provided for those environments that have neither
2182 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2183 is clearly not the case, as these two bugs were recently reported.
2184
2185 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2186 and Detrail to create the HTML documentation, the .txt form of the man
2187 pages, and it removes trailing spaces from listed files. It also creates
2188 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2189 case, it wraps all the #defines with #ifndefs. This script should be run
2190 before "make dist".
2191
2192 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2193 with Unicode property support.
2194
2195 (a) For a maximizing quantifier, if the two different cases of the
2196 character were of different lengths in their UTF-8 codings (there are
2197 some cases like this - I found 11), and the matching function had to
2198 back up over a mixture of the two cases, it incorrectly assumed they
2199 were both the same length.
2200
2201 (b) When PCRE was configured to use the heap rather than the stack for
2202 recursion during matching, it was not correctly preserving the data for
2203 the other case of a UTF-8 character when checking ahead for a match
2204 while processing a minimizing repeat. If the check also involved
2205 matching a wide character, but failed, corruption could cause an
2206 erroneous result when trying to check for a repeat of the original
2207 character.
2208
2209 13. Some tidying changes to the testing mechanism:
2210
2211 (a) The RunTest script now detects the internal link size and whether there
2212 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2213 values substituted by "configure". (The RunGrepTest script already did
2214 this for UTF-8.) The configure.ac script no longer substitutes the
2215 relevant variables.
2216
2217 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2218 with length and offset values. This means that the output is different
2219 for different internal link sizes. Test 2 is skipped for link sizes
2220 other than 2 because of this, bypassing the problem. Unfortunately,
2221 there was also a test in test 3 (the locale tests) that used /B and
2222 failed for link sizes other than 2. Rather than cut the whole test out,
2223 I have added a new /Z option to pcretest that replaces the length and
2224 offset values with spaces. This is now used to make test 3 independent
2225 of link size. (Test 2 will be tidied up later.)
2226
2227 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2228 segmentation fault instead of returning the appropriate error message.
2229
2230 15. In multiline mode when the newline sequence was set to "any", the pattern
2231 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2232 This doesn't seem right; it now treats the CRLF combination as the line
2233 ending, and so does not match in that case. It's only a pattern such as ^$
2234 that would hit this one: something like ^ABC$ would have failed after \r
2235 and then tried again after \r\n.
2236
2237 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2238 in an attempt to make files that differ only in their line terminators
2239 compare equal. This works on Linux.
2240
2241 17. Under certain error circumstances pcregrep might try to free random memory
2242 as it exited. This is now fixed, thanks to valgrind.
2243
2244 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2245 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2246 was because its rules for how to advance for /g after matching an empty
2247 string at the end of a line did not allow for this case. They now check for
2248 it specially.
2249
2250 20. pcretest is supposed to handle patterns and data of any length, by
2251 extending its buffers when necessary. It was getting this wrong when the
2252 buffer for a data line had to be extended.
2253
2254 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2255 CRLF as a newline sequence.
2256
2257 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2258 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2259 I have nevertheless tidied it up.
2260
2261 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2262
2263 24. Added a man page for pcre-config.
2264
2265
2266 Version 7.0 19-Dec-06
2267 ---------------------
2268
2269 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2270 moving to gcc 4.1.1.
2271
2272 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2273 sys/time.h, which is documented as needed for this function. It doesn't
2274 seem to matter on Linux, but it showed up on some releases of OS X.
2275
2276 3. It seems that there are systems where bytes whose values are greater than
2277 127 match isprint() in the "C" locale. The "C" locale should be the
2278 default when a C program starts up. In most systems, only ASCII printing
2279 characters match isprint(). This difference caused the output from pcretest
2280 to vary, making some of the tests fail. I have changed pcretest so that:
2281
2282 (a) When it is outputting text in the compiled version of a pattern, bytes
2283 other than 32-126 are always shown as hex escapes.
2284
2285 (b) When it is outputting text that is a matched part of a subject string,
2286 it does the same, unless a different locale has been set for the match
2287 (using the /L modifier). In this case, it uses isprint() to decide.
2288
2289 4. Fixed a major bug that caused incorrect computation of the amount of memory
2290 required for a compiled pattern when options that changed within the
2291 pattern affected the logic of the preliminary scan that determines the
2292 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2293 that the computed length was too small. The symptoms of this bug were
2294 either the PCRE error "internal error: code overflow" from pcre_compile(),
2295 or a glibc crash with a message such as "pcretest: free(): invalid next
2296 size (fast)". Examples of patterns that provoked this bug (shown in
2297 pcretest format) are:
2298
2299 /(?-x: )/x
2300 /(?x)(?-x: \s*#\s*)/
2301 /((?i)[\x{c0}])/8
2302 /(?i:[\x{c0}])/8
2303
2304 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2305 is now done differently.
2306
2307 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2308 wrapper classes; (b) implement a new function in the C++ scanner that is
2309 more efficient than the old way of doing things because it avoids levels of
2310 recursion in the regex matching; (c) add a paragraph to the documentation
2311 for the FullMatch() function.
2312
2313 6. The escape sequence \n was being treated as whatever was defined as
2314 "newline". Not only was this contrary to the documentation, which states
2315 that \n is character 10 (hex 0A), but it also went horribly wrong when
2316 "newline" was defined as CRLF. This has been fixed.
2317
2318 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2319 was being set to -1 for the "end of line" case (supposedly a value that no
2320 character can have). Though this value is never used (the check for end of
2321 line is "zero bytes in current character"), it caused compiler complaints.
2322 I've changed it to 0xffffffff.
2323
2324 8. In pcre_version.c, the version string was being built by a sequence of
2325 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2326 string (as it is for production releases) called a macro with an empty
2327 argument. The C standard says the result of this is undefined. The gcc
2328 compiler treats it as an empty string (which was what was wanted) but it is
2329 reported that Visual C gives an error. The source has been hacked around to
2330 avoid this problem.
2331
2332 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2333 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2334 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2335 of them did).
2336
2337 10. Originally, pcretest opened its input and output without "b"; then I was
2338 told that "b" was needed in some environments, so it was added for release
2339 5.0 to both the input and output. (It makes no difference on Unix-like
2340 systems.) Later I was told that it is wrong for the input on Windows. I've
2341 now abstracted the modes into two macros, to make it easier to fiddle with
2342 them, and removed "b" from the input mode under Windows.
2343
2344 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2345
2346 12. Added -help and --help to pcretest as an official way of being reminded
2347 of the options.
2348
2349 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2350 and pcrecpp.cc because they annoy compilers at high warning levels.
2351
2352 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2353
2354 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2355 scripts are not C programs :-) and which was not noticed because it works
2356 on Linux.
2357
2358 16. pcretest is supposed to handle any length of pattern and data line (as one
2359 line or as a continued sequence of lines) by extending its input buffer if
2360 necessary. This feature was broken for very long pattern lines, leading to
2361 a string of junk being passed to pcre_compile() if the pattern was longer
2362 than about 50K.
2363
2364 17. I have done a major re-factoring of the way pcre_compile() computes the
2365 amount of memory needed for a compiled pattern. Previously, there was code
2366 that made a preliminary scan of the pattern in order to do this. That was
2367 OK when PCRE was new, but as the facilities have expanded, it has become
2368 harder and harder to keep it in step with the real compile phase, and there
2369 have been a number of bugs (see for example, 4 above). I have now found a
2370 cunning way of running the real compile function in a "fake" mode that
2371 enables it to compute how much memory it would need, while actually only
2372 ever using a few hundred bytes of working memory and without too many
2373 tests of the mode. This should make future maintenance and development
2374 easier. A side effect of this work is that the limit of 200 on the nesting
2375 depth of parentheses has been removed (though this was never a serious
2376 limitation, I suspect). However, there is a downside: pcre_compile() now
2377 runs more slowly than before (30% or more, depending on the pattern). I
2378 hope this isn't a big issue. There is no effect on runtime performance.
2379
2380 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2381 newline (only possible for the last line of a file) and it was a
2382 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2383
2384 19. Added additional timing features to pcretest. (1) The -tm option now times
2385 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2386 separate command line item, by a number that specifies the number of
2387 repeats to use when timing. The default is 50000; this gives better
2388 precision, but takes uncomfortably long for very large patterns.
2389
2390 20. Extended pcre_study() to be more clever in cases where a branch of a
2391 subpattern has no definite first character. For example, (a*|b*)[cd] would
2392 previously give no result from pcre_study(). Now it recognizes that the
2393 first character must be a, b, c, or d.
2394
2395 21. There was an incorrect error "recursive call could loop indefinitely" if
2396 a subpattern (or the entire pattern) that was being tested for matching an
2397 empty string contained only one non-empty item after a nested subpattern.
2398 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2399 incorrectly, because the \d was being skipped in the check.
2400
2401 22. The pcretest program now has a new pattern option /B and a command line
2402 option -b, which is equivalent to adding /B to every pattern. This causes
2403 it to show the compiled bytecode, without the additional information that
2404 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2405 is the same as /B/I).
2406
2407 23. A new optimization is now able automatically to treat some sequences such
2408 as a*b as a*+b. More specifically, if something simple (such as a character
2409 or a simple class like \d) has an unlimited quantifier, and is followed by
2410 something that cannot possibly match the quantified thing, the quantifier
2411 is automatically "possessified".
2412
2413 24. A recursive reference to a subpattern whose number was greater than 39
2414 went wrong under certain circumstances in UTF-8 mode. This bug could also
2415 have affected the operation of pcre_study().
2416
2417 25. Realized that a little bit of performance could be had by replacing
2418 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2419
2420 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2421
2422 27. Possessive quantifiers such as a++ were previously implemented by turning
2423 them into atomic groups such as ($>a+). Now they have their own opcodes,
2424 which improves performance. This includes the automatically created ones
2425 from 23 above.
2426
2427 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2428 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2429 the first matched character to be a colon. This applied both to named and
2430 numbered groups.
2431
2432 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2433
2434 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2435 building PCRE on Windows easier, so I have included it in the distribution.
2436
2437 31. There is now a check in pcretest against a ridiculously large number being
2438 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2439 loop, the loop is abandoned.
2440
2441 32. Forward references to subpatterns in conditions such as (?(2)...) where
2442 subpattern 2 is defined later cause pcre_compile() to search forwards in
2443 the pattern for the relevant set of parentheses. This search went wrong
2444 when there were unescaped parentheses in a character class, parentheses
2445 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2446
2447 33. "Subroutine" calls and backreferences were previously restricted to
2448 referencing subpatterns earlier in the regex. This restriction has now
2449 been removed.
2450
2451 34. Added a number of extra features that are going to be in Perl 5.10. On the
2452 whole, these are just syntactic alternatives for features that PCRE had
2453 previously implemented using the Python syntax or my own invention. The
2454 other formats are all retained for compatibility.
2455
2456 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2457 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2458 also .NET compatible.
2459
2460 (b) A recursion or subroutine call to a named group can now be defined as
2461 (?&name) as well as (?P>name).
2462
2463 (c) A backreference to a named group can now be defined as \k<name> or
2464 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2465 5.10, are also .NET compatible.
2466
2467 (d) A conditional reference to a named group can now use the syntax
2468 (?(<name>) or (?('name') as well as (?(name).
2469
2470 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2471 groups (named and numbered) that are never evaluated inline, but can be
2472 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2473 is always false. There may be only one alternative in such a group.
2474
2475 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2476 as the simple (?(R). The condition is true only if the most recent
2477 recursion is that of the given number or name. It does not search out
2478 through the entire recursion stack.
2479
2480 (g) The escape \gN or \g{N} has been added, where N is a positive or
2481 negative number, specifying an absolute or relative reference.
2482
2483 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2484 some "unreachable code" warnings.
2485
2486 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2487 things, this adds five new scripts.
2488
2489 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2490 There were also incompatibilities regarding the handling of \Q..\E inside
2491 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2492 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2493
2494 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2495 matches an empty string, and forcibly breaks the loop. There were bugs in
2496 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2497 against aaaa the result was just "a" rather than "aaaa", for example. Two
2498 separate and independent bugs (that affected different cases) have been
2499 fixed.
2500
2501 39. Refactored the code to abolish the use of different opcodes for small
2502 capturing bracket numbers. This is a tidy that I avoided doing when I
2503 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2504 The new approach is not only tidier, it makes it possible to reduce the
2505 memory needed to fix the previous bug (38).
2506
2507 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2508 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2509 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2510 mode.
2511
2512 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2513 report.
2514
2515 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2516 copy construction and assignment in the C++ wrapper.
2517
2518 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2519 couple of bugs that could have given wrong results in the "--newline=crlf"
2520 case.
2521
2522 44. Added a number of casts and did some reorganization of signed/unsigned int
2523 variables following suggestions from Dair Grant. Also renamed the variable
2524 "this" as "item" because it is a C++ keyword.
2525
2526 45. Arranged for dftables to add
2527
2528 #include "pcre_internal.h"
2529
2530 to pcre_chartables.c because without it, gcc 4.x may remove the array
2531 definition from the final binary if PCRE is built into a static library and
2532 dead code stripping is activated.
2533
2534 46. For an unanchored pattern, if a match attempt fails at the start of a
2535 newline sequence, and the newline setting is CRLF or ANY, and the next two
2536 characters are CRLF, advance by two characters instead of one.
2537
2538
2539 Version 6.7 04-Jul-06
2540 ---------------------
2541
2542 1. In order to handle tests when input lines are enormously long, pcretest has
2543 been re-factored so that it automatically extends its buffers when
2544 necessary. The code is crude, but this _is_ just a test program. The
2545 default size has been increased from 32K to 50K.
2546
2547 2. The code in pcre_study() was using the value of the re argument before
2548 testing it for NULL. (Of course, in any sensible call of the function, it
2549 won't be NULL.)
2550
2551 3. The memmove() emulation function in pcre_internal.h, which is used on
2552 systems that lack both memmove() and bcopy() - that is, hardly ever -
2553 was missing a "static" storage class specifier.
2554
2555 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2556 containing an extended class (one that cannot be represented by a bitmap
2557 because it contains high-valued characters or Unicode property items, e.g.
2558 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2559 pattern, but PCRE should not loop if you do not (it no longer does).
2560 [Detail: two cases were found: (a) a repeated subpattern containing an
2561 extended class; (b) a recursive reference to a subpattern that followed a
2562 previous extended class. It wasn't skipping over the extended class
2563 correctly when UTF-8 mode was not set.]
2564
2565 5. A negated single-character class was not being recognized as fixed-length
2566 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2567 compile error "lookbehind assertion is not fixed length".
2568
2569 6. The RunPerlTest auxiliary script was showing an unexpected difference
2570 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2571 write a Perl script that can interpret lines of an input file either as
2572 byte characters or as UTF-8, which is what "perltest" was being required to
2573 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2574 can't do is switch easily at run time between having the "use utf8;" pragma
2575 or not. In the end, I fudged it by using the RunPerlTest script to insert
2576 "use utf8;" explicitly for the UTF-8 tests.
2577
2578 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2579 the end of the subject string, contrary to the documentation and to what
2580 Perl does. This was true of both matching functions. Now it matches only at
2581 the start of the subject and immediately after *internal* newlines.
2582
2583 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2584 a pointer to an int instead of a pointer to an unsigned long int. This
2585 caused problems on 64-bit systems.
2586
2587 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2588 instance of the 'standard' template library not being so standard".
2589
2590 10. There was no check on the number of named subpatterns nor the maximum
2591 length of a subpattern name. The product of these values is used to compute
2592 the size of the memory block for a compiled pattern. By supplying a very
2593 long subpattern name and a large number of named subpatterns, the size
2594 computation could be caused to overflow. This is now prevented by limiting
2595 the length of names to 32 characters, and the number of named subpatterns
2596 to 10,000.
2597
2598 11. Subpatterns that are repeated with specific counts have to be replicated in
2599 the compiled pattern. The size of memory for this was computed from the
2600 length of the subpattern and the repeat count. The latter is limited to
2601 65535, but there was no limit on the former, meaning that integer overflow
2602 could in principle occur. The compiled length of a repeated subpattern is
2603 now limited to 30,000 bytes in order to prevent this.
2604
2605 12. Added the optional facility to have named substrings with the same name.
2606
2607 13. Added the ability to use a named substring as a condition, using the
2608 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2609 are numbers (not recommended). Forward references are permitted.
2610
2611 14. Added forward references in named backreferences (if you see what I mean).
2612
2613 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2614 pattern could run off the end of the subject. For example, the pattern
2615 "(?s)(.{1,5})"8 did this with the subject "ab".
2616
2617 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2618 PCRE_CASELESS was set when matching characters that were quantified with ?
2619 or *.
2620
2621 17. A character class other than a single negated character that had a minimum
2622 but no maximum quantifier - for example [ab]{6,} - was not handled
2623 correctly by pce_dfa_exec(). It would match only one character.
2624
2625 18. A valid (though odd) pattern that looked like a POSIX character
2626 class but used an invalid character after [ (for example [[,abc,]]) caused
2627 pcre_compile() to give the error "Failed: internal error: code overflow" or
2628 in some cases to crash with a glibc free() error. This could even happen if
2629 the pattern terminated after [[ but there just happened to be a sequence of
2630 letters, a binary zero, and a closing ] in the memory that followed.
2631
2632 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2633 over the years. Originally (before any Unicode support), just the bottom 8
2634 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2635 output from "man perlunicode" includes this:
2636
2637 The regular expression compiler produces polymorphic opcodes. That
2638 is, the pattern adapts to the data and automatically switches to
2639 the Unicode character scheme when presented with Unicode data--or
2640 instead uses a traditional byte scheme when presented with byte
2641 data.
2642
2643 Sadly, a wide octal escape does not cause a switch, and in a string with
2644 no other multibyte characters, these octal escapes are treated as before.
2645 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2646 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2647 Unicode string.
2648
2649 I have not perpetrated such confusion in PCRE. Up till now, it took just
2650 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2651 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2652 translate to the appropriate multibyte character.
2653
2654 29. Applied some refactoring to reduce the number of warnings from Microsoft
2655 and Borland compilers. This has included removing the fudge introduced
2656 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2657 a warning about an unused variable.
2658
2659 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2660 characters since release 4.0, because Perl (from release 5.004) does not.
2661 [Or at least, is documented not to: some releases seem to be in conflict
2662 with the documentation.] However, when a pattern was studied with
2663 pcre_study() and all its branches started with \s, PCRE still included VT
2664 as a possible starting character. Of course, this did no harm; it just
2665 caused an unnecessary match attempt.
2666
2667 22. Removed a now-redundant internal flag bit that recorded the fact that case
2668 dependency changed within the pattern. This was once needed for "required
2669 byte" processing, but is no longer used. This recovers a now-scarce options
2670 bit. Also moved the least significant internal flag bit to the most-
2671 significant bit of the word, which was not previously used (hangover from
2672 the days when it was an int rather than a uint) to free up another bit for
2673 the future.
2674
2675 23. Added support for CRLF line endings as well as CR and LF. As well as the
2676 default being selectable at build time, it can now be changed at runtime
2677 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2678 specify that it is scanning data with non-default line endings.
2679
2680 24. Changed the definition of CXXLINK to make it agree with the definition of
2681 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2682
2683 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2684 recursions. This makes a big different to stack usage for some patterns.
2685
2686 26. If a subpattern containing a named recursion or subroutine reference such
2687 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2688 the space required for the compiled pattern went wrong and gave too small a
2689 value. Depending on the environment, this could lead to "Failed: internal
2690 error: code overflow at offset 49" or "glibc detected double free or
2691 corruption" errors.
2692
2693 27. Applied patches from Google (a) to support the new newline modes and (b) to
2694 advance over multibyte UTF-8 characters in GlobalReplace.
2695
2696 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2697 difference for some implementation of PCRE in some Windows version.
2698
2699 29. Added some extra testing facilities to pcretest:
2700
2701 \q<number> in a data line sets the "match limit" value
2702 \Q<number> in a data line sets the "match recursion limt" value
2703 -S <number> sets the stack size, where <number> is in megabytes
2704
2705 The -S option isn't available for Windows.
2706
2707
2708 Version 6.6 06-Feb-06
2709 ---------------------
2710
2711 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2712 in pcreposix.h. I have copied the definition from pcre.h.
2713
2714 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2715 because pcre.h is no longer a built file.
2716
2717 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2718 not normally included in the compiled code.
2719
2720
2721 Version 6.5 01-Feb-06
2722 ---------------------
2723
2724 1. When using the partial match feature with pcre_dfa_exec(), it was not
2725 anchoring the second and subsequent partial matches at the new starting
2726 point. This could lead to incorrect results. For example, with the pattern
2727 /1234/, partially matching against "123" and then "a4" gave a match.
2728
2729 2. Changes to pcregrep:
2730
2731 (a) All non-match returns from pcre_exec() were being treated as failures
2732 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2733 error message is output. Some extra information is given for the
2734 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2735 probably the only errors that are likely to be caused by users (by
2736 specifying a regex that has nested indefinite repeats, for instance).
2737 If there are more than 20 of these errors, pcregrep is abandoned.
2738
2739 (b) A binary zero was treated as data while matching, but terminated the
2740 output line if it was written out. This has been fixed: binary zeroes
2741 are now no different to any other data bytes.
2742
2743 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2744 used to set a locale for matching. The --locale=xxxx long option has
2745 been added (no short equivalent) to specify a locale explicitly on the
2746 pcregrep command, overriding the environment variables.
2747
2748 (d) When -B was used with -n, some line numbers in the output were one less
2749 than they should have been.
2750
2751 (e) Added the -o (--only-matching) option.
2752
2753 (f) If -A or -C was used with -c (count only), some lines of context were
2754 accidentally printed for the final match.
2755
2756 (g) Added the -H (--with-filename) option.
2757
2758 (h) The combination of options -rh failed to suppress file names for files
2759 that were found from directory arguments.
2760
2761 (i) Added the -D (--devices) and -d (--directories) options.
2762
2763 (j) Added the -F (--fixed-strings) option.
2764
2765 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2766
2767 (l) Added the --colo(u)r option.
2768
2769 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2770 is not present by default.
2771
2772 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2773 items such as (?R) or (?1), when the recursion could match a number of
2774 alternatives. If it matched one of the alternatives, but subsequently,
2775 outside the recursion, there was a failure, the code tried to back up into
2776 the recursion. However, because of the way PCRE is implemented, this is not
2777 possible, and the result was an incorrect result from the match.
2778
2779 In order to prevent this happening, the specification of recursion has
2780 been changed so that all such subpatterns are automatically treated as
2781 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2782
2783 4. I had overlooked the fact that, in some locales, there are characters for
2784 which isalpha() is true but neither isupper() nor islower() are true. In
2785 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2786 and ordfeminine) are like this. This affected the treatment of \w and \W
2787 when they appeared in character classes, but not when they appeared outside
2788 a character class. The bit map for "word" characters is now created
2789 separately from the results of isalnum() instead of just taking it from the
2790 upper, lower, and digit maps. (Plus the underscore character, of course.)
2791
2792 5. The above bug also affected the handling of POSIX character classes such as
2793 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2794 permanent tables. Instead, the bit maps for such a class were previously
2795 created as the appropriate unions of the upper, lower, and digit bitmaps.
2796 Now they are created by subtraction from the [[:word:]] class, which has
2797 its own bitmap.
2798
2799 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2800 It is created by subtracting the vertical space characters (\x09, \x0a,
2801 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2802 subtraction was done in the overall bitmap for a character class, meaning
2803 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2804 be recognized. This bug has been fixed.
2805
2806 7. Patches from the folks at Google:
2807
2808 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2809 real life, but is still worth protecting against".
2810
2811 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2812 regular expressions".
2813
2814 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2815 have it.
2816
2817 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2818 "configure" and the latter not, in order to fix a problem somebody had
2819 with compiling the Arg class on HP-UX.
2820
2821 (e) Improve the error-handling of the C++ wrapper a little bit.
2822
2823 (f) New tests for checking recursion limiting.
2824
2825 8. The pcre_memmove() function, which is used only if the environment does not
2826 have a standard memmove() function (and is therefore rarely compiled),
2827 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2828 returning a result (though PCRE never actually uses the result).
2829
2830 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2831 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2832 returned instead of calling malloc() with an overflowing number that would
2833 most likely cause subsequent chaos.
2834
2835 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2836
2837 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2838 with this option is matched, the nmatch and pmatch options of regexec() are
2839 ignored.
2840
2841 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2842 provided in case anyone wants to the the POSIX interface with UTF-8
2843 strings.
2844
2845 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2846 C++ linking (needed for some HP-UX environments).
2847
2848 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2849 (unused parameter) and in the pcre_printint() function (omitted "default"
2850 switch label when the default is to do nothing).
2851
2852 15. Added some code to make it possible, when PCRE is compiled as a C++
2853 library, to replace subject pointers for pcre_exec() with a smart pointer
2854 class, thus making it possible to process discontinuous strings.
2855
2856 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2857 much the same function. They were added by different people who were trying
2858 to make PCRE easy to compile on non-Unix systems. It has been suggested
2859 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2860 for compiling on Windows systems. I have therefore replaced it with
2861 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2862 defaults to "extern" for C or "extern C" for C++, which works fine on
2863 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2864 SCOPE with something explicit in config.h. In addition:
2865
2866 (a) pcreposix.h still had just "extern" instead of either of these macros;
2867 I have replaced it with PCRE_DATA_SCOPE.
2868
2869 (b) Functions such as _pcre_xclass(), which are internal to the library,
2870 but external in the C sense, all had PCRE_EXPORT in their definitions.
2871 This is apparently wrong for the Windows case, so I have removed it.
2872 (It makes no difference on Unix-like systems.)
2873
2874 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2875 of recursive calls to match(). This is different to MATCH_LIMIT because
2876 that limits the total number of calls to match(), not all of which increase
2877 the depth of recursion. Limiting the recursion depth limits the amount of
2878 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2879 when PCRE is compiled, and changed at run time. A patch from Google adds
2880 this functionality to the C++ interface.
2881
2882 18. Changes to the handling of Unicode character properties:
2883
2884 (a) Updated the table to Unicode 4.1.0.
2885
2886 (b) Recognize characters that are not in the table as "Cn" (undefined).
2887
2888 (c) I revised the way the table is implemented to a much improved format
2889 which includes recognition of ranges. It now supports the ranges that
2890 are defined in UnicodeData.txt, and it also amalgamates other
2891 characters into ranges. This has reduced the number of entries in the
2892 table from around 16,000 to around 3,000, thus reducing its size
2893 considerably. I realized I did not need to use a tree structure after
2894 all - a binary chop search is just as efficient. Having reduced the
2895 number of entries, I extended their size from 6 bytes to 8 bytes to
2896 allow for more data.
2897
2898 (d) Added support for Unicode script names via properties such as \p{Han}.
2899
2900 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2901 matching that character.
2902
2903 20. When matching a repeated Unicode property with a minimum greater than zero,
2904 (for example \pL{2,}), PCRE could look past the end of the subject if it
2905 reached it while seeking the minimum number of characters. This could
2906 happen only if some of the characters were more than one byte long, because
2907 there is a check for at least the minimum number of bytes.
2908
2909 21. Refactored the implementation of \p and \P so as to be more general, to
2910 allow for more different types of property in future. This has changed the
2911 compiled form incompatibly. Anybody with saved compiled patterns that use
2912 \p or \P will have to recompile them.
2913
2914 22. Added "Any" and "L&" to the supported property types.
2915
2916 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2917 but give a compile time error if the value is greater than 0xff.
2918
2919 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2920 accidentally not being installed or uninstalled.
2921
2922 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2923 made were to insert the current release number. This seemed silly, because
2924 it made things harder for people building PCRE on systems that don't run
2925 "configure". I have turned pcre.h into a distributed file, no longer built
2926 by "configure", with the version identification directly included. There is
2927 no longer a pcre.h.in file.
2928
2929 However, this change necessitated a change to the pcre-config script as
2930 well. It is built from pcre-config.in, and one of the substitutions was the
2931 release number. I have updated configure.ac so that ./configure now finds
2932 the release number by grepping pcre.h.
2933
2934 26. Added the ability to run the tests under valgrind.
2935
2936
2937 Version 6.4 05-Sep-05
2938 ---------------------
2939
2940 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2941 "--" to be printed when multiple files were scanned, even when none of the
2942 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2943 consider it to be a bug, and have restored the previous behaviour.
2944
2945 2. A couple of code tidies to get rid of compiler warnings.
2946
2947 3. The pcretest program used to cheat by referring to symbols in the library
2948 whose names begin with _pcre_. These are internal symbols that are not
2949 really supposed to be visible externally, and in some environments it is
2950 possible to suppress them. The cheating is now confined to including
2951 certain files from the library's source, which is a bit cleaner.
2952
2953 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2954 file's purpose clearer.
2955
2956 5. Reorganized pcre_ucp_findchar().
2957
2958
2959 Version 6.3 15-Aug-05
2960 ---------------------
2961
2962 1. The file libpcre.pc.in did not have general read permission in the tarball.
2963
2964 2. There were some problems when building without C++ support:
2965
2966 (a) If C++ support was not built, "make install" and "make test" still
2967 tried to test it.
2968
2969 (b) There were problems when the value of CXX was explicitly set. Some
2970 changes have been made to try to fix these, and ...
2971
2972 (c) --disable-cpp can now be used to explicitly disable C++ support.
2973
2974 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2975 backslash in a target when C++ was disabled. This confuses some
2976 versions of "make", apparently. Using an intermediate variable solves
2977 this. (Same for CPP_LOBJ.)
2978
2979 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2980 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2981 necessary on certain architectures.
2982
2983 4. Added a setting of -export-symbols-regex to the link command to remove
2984 those symbols that are exported in the C sense, but actually are local
2985 within the library, and not documented. Their names all begin with
2986 "_pcre_". This is not a perfect job, because (a) we have to except some
2987 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2988 available (and never for static libraries). I have made a note to try to
2989 find a way round (a) in the future.
2990
2991
2992 Version 6.2 01-Aug-05
2993 ---------------------
2994
2995 1. There was no test for integer overflow of quantifier values. A construction
2996 such as {1111111111111111} would give undefined results. What is worse, if
2997 a minimum quantifier for a parenthesized subpattern overflowed and became
2998 negative, the calculation of the memory size went wrong. This could have
2999 led to memory overwriting.
3000
3001 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
3002
3003 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
3004 operating environments where this matters.
3005
3006 4. Applied Giuseppe Maxia's patch to add additional features for controlling
3007 PCRE options from within the C++ wrapper.
3008
3009 5. Named capturing subpatterns were not being correctly counted when a pattern
3010 was compiled. This caused two problems: (a) If there were more than 100
3011 such subpatterns, the calculation of the memory needed for the whole
3012 compiled pattern went wrong, leading to an overflow error. (b) Numerical
3013 back references of the form \12, where the number was greater than 9, were
3014 not recognized as back references, even though there were sufficient
3015 previous subpatterns.
3016
3017 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
3018 versions of gcc, e.g. 2.95.4.
3019
3020
3021 Version 6.1 21-Jun-05
3022 ---------------------
3023
3024 1. There was one reference to the variable "posix" in pcretest.c that was not
3025 surrounded by "#if !defined NOPOSIX".
3026
3027 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
3028 the cross-check on the old pcre_info() function, for the benefit of the
3029 cut-down version of PCRE that is currently imported into Exim.
3030
3031 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
3032 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
3033 patterns that start (?i) but I don't think that matters. The use of (?i) is
3034 just an example; this all applies to the other options as well.
3035
3036 4. Since libtool seems to echo the compile commands it is issuing, the output
3037 from "make" can be reduced a bit by putting "@" in front of each libtool
3038 compile command.
3039
3040 5. Patch from the folks at Google for configure.in to be a bit more thorough
3041 in checking for a suitable C++ installation before trying to compile the
3042 C++ stuff. This should fix a reported problem when a compiler was present,
3043 but no suitable headers.
3044
3045 6. The man pages all had just "PCRE" as their title. I have changed them to
3046 be the relevant file name. I have also arranged that these names are
3047 retained in the file doc/pcre.txt, which is a concatenation in text format
3048 of all the man pages except the little individual ones for each function.
3049
3050 7. The NON-UNIX-USE file had not been updated for the different set of source
3051 files that come with release 6. I also added a few comments about the C++
3052 wrapper.
3053
3054
3055 Version 6.0 07-Jun-05
3056 ---------------------
3057
3058 1. Some minor internal re-organization to help with my DFA experiments.
3059
3060 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3061 didn't matter for the library itself when fully configured, but did matter
3062 when compiling without UCP support, or within Exim, where the ucp files are
3063 not imported.
3064
3065 3. Refactoring of the library code to split up the various functions into
3066 different source modules. The addition of the new DFA matching code (see
3067 below) to a single monolithic source would have made it really too
3068 unwieldy, quite apart from causing all the code to be include in a
3069 statically linked application, when only some functions are used. This is
3070 relevant even without the DFA addition now that patterns can be compiled in
3071 one application and matched in another.
3072
3073 The downside of splitting up is that there have to be some external
3074 functions and data tables that are used internally in different modules of
3075 the library but which are not part of the API. These have all had their
3076 names changed to start with "_pcre_" so that they are unlikely to clash
3077 with other external names.
3078
3079 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3080 a different (DFA) algorithm. Although it is slower than the original
3081 function, it does have some advantages for certain types of matching
3082 problem.
3083
3084 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3085 including restarting after a partial match.
3086
3087 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3088 defined when compiling for Windows was sent to me. I have put it into the
3089 code, though I have no means of testing or verifying it.
3090
3091 7. Added the pcre_refcount() auxiliary function.
3092
3093 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3094 match before or at the first newline in the subject string. In pcretest,
3095 the /f option on a pattern can be used to set this.
3096
3097 9. A repeated \w when used in UTF-8 mode with characters greater than 256
3098 would behave wrongly. This has been present in PCRE since release 4.0.
3099
3100 10. A number of changes to the pcregrep command:
3101
3102 (a) Refactored how -x works; insert ^(...)$ instead of setting
3103 PCRE_ANCHORED and checking the length, in preparation for adding
3104 something similar for -w.
3105
3106 (b) Added the -w (match as a word) option.
3107
3108 (c) Refactored the way lines are read and buffered so as to have more
3109 than one at a time available.
3110
3111 (d) Implemented a pcregrep test script.
3112
3113 (e) Added the -M (multiline match) option. This allows patterns to match
3114 over several lines of the subject. The buffering ensures that at least
3115 8K, or the rest of the document (whichever is the shorter) is available
3116 for matching (and similarly the previous 8K for lookbehind assertions).
3117
3118 (f) Changed the --help output so that it now says
3119
3120 -w, --word-regex(p)
3121
3122 instead of two lines, one with "regex" and the other with "regexp"
3123 because that confused at least one person since the short forms are the
3124 same. (This required a bit of code, as the output is generated
3125 automatically from a table. It wasn't just a text change.)
3126
3127 (g) -- can be used to terminate pcregrep options if the next thing isn't an
3128 option but starts with a hyphen. Could be a pattern or a path name
3129 starting with a hyphen, for instance.
3130
3131 (h) "-" can be given as a file name to represent stdin.
3132
3133 (i) When file names are being printed, "(standard input)" is used for
3134 the standard input, for compatibility with GNU grep. Previously
3135 "<stdin>" was used.
3136
3137 (j) The option --label=xxx can be used to supply a name to be used for
3138 stdin when file names are being printed. There is no short form.
3139
3140 (k) Re-factored the options decoding logic because we are going to add
3141 two more options that take data. Such options can now be given in four
3142 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3143
3144 (l) Added the -A, -B, and -C options for requesting that lines of context
3145 around matches be printed.
3146
3147 (m) Added the -L option to print the names of files that do not contain
3148 any matching lines, that is, the complement of -l.
3149
3150 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3151 continue to scan other files.
3152
3153 (o) The -s option was incorrectly implemented. For compatibility with other
3154 greps, it now suppresses the error message for a non-existent or non-
3155 accessible file (but not the return code). There is a new option called
3156 -q that suppresses the output of matching lines, which was what -s was
3157 previously doing.
3158
3159 (p) Added --include and --exclude options to specify files for inclusion
3160 and exclusion when recursing.
3161
3162 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3163 Hopefully, it now does.
3164
3165 12. Missing cast in pcre_study().
3166
3167 13. Added an "uninstall" target to the makefile.
3168
3169 14. Replaced "extern" in the function prototypes in Makefile.in with
3170 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3171 world, but is set differently for Windows.
3172
3173 15. Added a second compiling function called pcre_compile2(). The only
3174 difference is that it has an extra argument, which is a pointer to an
3175 integer error code. When there is a compile-time failure, this is set
3176 non-zero, in addition to the error test pointer being set to point to an
3177 error message. The new argument may be NULL if no error number is required
3178 (but then you may as well call pcre_compile(), which is now just a
3179 wrapper). This facility is provided because some applications need a
3180 numeric error indication, but it has also enabled me to tidy up the way
3181 compile-time errors are handled in the POSIX wrapper.
3182
3183 16. Added VPATH=.libs to the makefile; this should help when building with one
3184 prefix path and installing with another. (Or so I'm told by someone who
3185 knows more about this stuff than I do.)
3186
3187 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3188 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3189 match everything, including newlines. This is not POSIX-compatible, but
3190 somebody wanted the feature. From pcretest it can be activated by using
3191 both the P and the s flags.
3192
3193 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3194
3195 19. libpcre.pc was being incorrectly installed as executable.
3196
3197 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3198 it now also looks for '\r' so that it will work unmodified on Windows.
3199
3200 21. Added Google's contributed C++ wrapper to the distribution.
3201
3202 22. Added some untidy missing memory free() calls in pcretest, to keep
3203 Electric Fence happy when testing.
3204
3205
3206
3207 Version 5.0 13-Sep-04
3208 ---------------------
3209
3210 1. Internal change: literal characters are no longer packed up into items
3211 containing multiple characters in a single byte-string. Each character
3212 is now matched using a separate opcode. However, there may be more than one
3213 byte in the character in UTF-8 mode.
3214
3215 2. The pcre_callout_block structure has two new fields: pattern_position and
3216 next_item_length. These contain the offset in the pattern to the next match
3217 item, and its length, respectively.
3218
3219 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3220 insertion of callouts before each pattern item. Added the /C option to
3221 pcretest to make use of this.
3222
3223 4. On the advice of a Windows user, the lines
3224
3225 #if defined(_WIN32) || defined(WIN32)
3226 _setmode( _fileno( stdout ), 0x8000 );
3227 #endif /* defined(_WIN32) || defined(WIN32) */
3228
3229 have been added to the source of pcretest. This apparently does useful
3230 magic in relation to line terminators.
3231
3232 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3233 for the benefit of those environments where the "b" makes a difference.
3234
3235 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3236 to know about it. I have put a hack into configure.in that adds in code
3237 to set GCC=yes if CC=icc. This seems to end up at a point in the
3238 generated configure script that is early enough to affect the setting of
3239 compiler options, which is what is needed, but I have no means of testing
3240 whether it really works. (The user who reported this had patched the
3241 generated configure script, which of course I cannot do.)
3242
3243 LATER: After change 22 below (new libtool files), the configure script
3244 seems to know about icc (and also ecc). Therefore, I have commented out
3245 this hack in configure.in.
3246
3247 7. Added support for pkg-config (2 patches were sent in).
3248
3249 8. Negated POSIX character classes that used a combination of internal tables
3250 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3251 [[:^ascii]]. Typically, they would match almost any characters. The other
3252 POSIX classes were not broken in this way.
3253
3254 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3255 to find the match, as PCRE was deluded into thinking that the match had to
3256 start at the start point or following a newline. The same bug applied to
3257 patterns with negative forward assertions or any backward assertions
3258 preceding ".*" at the start, unless the pattern required a fixed first
3259 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3260
3261 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3262 starting at the last subject character, bytes beyond the end of the subject
3263 string were read.
3264
3265 11. Renamed the variable "class" as "classbits" to make life easier for C++
3266 users. (Previously there was a macro definition, but it apparently wasn't
3267 enough.)
3268
3269 12. Added the new field "tables" to the extra data so that tables can be passed
3270 in at exec time, or the internal tables can be re-selected. This allows
3271 a compiled regex to be saved and re-used at a later time by a different
3272 program that might have everything at different addresses.
3273
3274 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3275 -R library as well as a -L library.
3276
3277 14. The debugging options of pcretest (-d on the command line or D on a
3278 pattern) showed incorrect output for anything following an extended class
3279 that contained multibyte characters and which was followed by a quantifier.
3280
3281 15. Added optional support for general category Unicode character properties
3282 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3283 support. It adds about 90K to the size of the library. The meanings of the
3284 inbuilt class escapes such as \d and \s have NOT been changed.
3285
3286 16. Updated pcredemo.c to include calls to free() to release the memory for the
3287 compiled pattern.
3288
3289 17. The generated file chartables.c was being created in the source directory
3290 instead of in the building directory. This caused the build to fail if the
3291 source directory was different from the building directory, and was
3292 read-only.
3293
3294 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3295 file. No doubt somebody will tell me if they don't make sense... Also added
3296 Dan Mooney's comments about building on OpenVMS.
3297
3298 19. Added support for partial matching via the PCRE_PARTIAL option for
3299 pcre_exec() and the \P data escape in pcretest.
3300
3301 20. Extended pcretest with 3 new pattern features:
3302
3303 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3304 write the compiled pattern to the file whose name is "rest-of-line".
3305 This is a straight binary dump of the data, with the saved pointer to
3306 the character tables forced to be NULL. The study data, if any, is
3307 written too. After writing, pcretest reads a new pattern.
3308
3309 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3310 compiled pattern from the given file. There must not be any
3311 occurrences of "<" in the file name (pretty unlikely); if there are,
3312 pcretest will instead treat the initial "<" as a pattern delimiter.
3313 After reading in the pattern, pcretest goes on to read data lines as
3314 usual.
3315
3316 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3317 and 16-bit fields in a compiled pattern, to simulate a pattern that
3318 was compiled on a host of opposite endianness.
3319
3320 21. The pcre-exec() function can now cope with patterns that were compiled on
3321 hosts of opposite endianness, with this restriction:
3322
3323 As for any compiled expression that is saved and used later, the tables
3324 pointer field cannot be preserved; the extra_data field in the arguments
3325 to pcre_exec() should be used to pass in a tables address if a value
3326 other than the default internal tables were used at compile time.
3327
3328 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3329 now diagnosed as an error. Previously, most of the time, a negative number
3330 would have been treated as zero, but if in addition "ovector" was passed as
3331 NULL, a crash could occur.
3332
3333 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3334 new versions from the libtool 1.5 distribution (the last one is a copy of
3335 a file called libtool.m4). This seems to have fixed the need to patch
3336 "configure" to support Darwin 1.3 (which I used to do). However, I still
3337 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3338 workstation).
3339
3340 24. Changed the PCRE licence to be the more standard "BSD" licence.
3341
3342
3343 Version 4.5 01-Dec-03
3344 ---------------------
3345
3346 1. There has been some re-arrangement of the code for the match() function so
3347 that it can be compiled in a version that does not call itself recursively.
3348 Instead, it keeps those local variables that need separate instances for
3349 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3350 needs to "recurse". Keeping track of where control must go is done by means
3351 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3352 hide most of the details from the main code, and operates only if
3353 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3354 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3355 operating.
3356
3357 To make it easier for callers to provide specially tailored get/free
3358 functions for this usage, two new functions, pcre_stack_malloc, and
3359 pcre_stack_free, are used. They are always called in strict stacking order,
3360 and the size of block requested is always the same.
3361
3362 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3363 PCRE has been compiled to use the stack or the heap for recursion. The
3364 -C option of pcretest uses this to show which version is compiled.
3365
3366 A new data escape \S, is added to pcretest; it causes the amounts of store
3367 obtained and freed by both kinds of malloc/free at match time to be added
3368 to the output.
3369
3370 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3371 what's available on my current Linux desktop machine.
3372
3373 3. When matching a UTF-8 string, the test for a valid string at the start has
3374 been extended. If start_offset is not zero, PCRE now checks that it points
3375 to a byte that is the start of a UTF-8 character. If not, it returns
3376 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3377 this is necessary because there may be backward assertions in the pattern.
3378 When matching the same subject several times, it may save resources to use
3379 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3380
3381 4. The code for checking the validity of UTF-8 strings has been tightened so
3382 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3383 containing "overlong sequences".
3384
3385 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3386 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3387 should have been "&", but it just so happened that all the cases this let
3388 through by mistake were picked up later in the function.
3389
3390 6. I had used a variable called "isblank" - this is a C99 function, causing
3391 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3392
3393 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3394 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3395 so the version is shown; (c) stop "make test" echoing "./RunTest".
3396
3397 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3398
3399 9. The prototype for memmove() for systems that don't have it was using
3400 size_t, but the inclusion of the header that defines size_t was later. I've
3401 moved the #includes for the C headers earlier to avoid this.
3402
3403 10. Added some adjustments to the code to make it easier to compiler on certain
3404 special systems:
3405
3406 (a) Some "const" qualifiers were missing.
3407 (b) Added the macro EXPORT before all exported functions; by default this
3408 is defined to be empty.
3409 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3410 that it reads its output file name as an argument instead of writing
3411 to the standard output and assuming this can be redirected.
3412
3413 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3414 class containing characters with values greater than 255, PCRE compilation
3415 went into a loop.
3416
3417 12. A recursive reference to a subpattern that was within another subpattern
3418 that had a minimum quantifier of zero caused PCRE to crash. For example,
3419 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3420 recursion. If the recursively-called subpattern itself had a zero repeat,
3421 that was OK.
3422
3423 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3424 buffer into which it was copied (for escape processing) was still set at
3425 1024, so long lines caused crashes.
3426
3427 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3428 "internal error: code overflow...". This applied to any character class
3429 that was followed by a possessive quantifier.
3430
3431 15. Modified the Makefile to add libpcre.la as a prerequisite for
3432 libpcreposix.la because I was told this is needed for a parallel build to
3433 work.
3434
3435 16. If a pattern that contained .* following optional items at the start was
3436 studied, the wrong optimizing data was generated, leading to matching
3437 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3438 matching string must start with a or b or c. The correct conclusion for
3439 this pattern is that a match can start with any character.
3440
3441
3442 Version 4.4 13-Aug-03
3443 ---------------------
3444
3445 1. In UTF-8 mode, a character class containing characters with values between
3446 127 and 255 was not handled correctly if the compiled pattern was studied.
3447 In fixing this, I have also improved the studying algorithm for such
3448 classes (slightly).
3449
3450 2. Three internal functions had redundant arguments passed to them. Removal
3451 might give a very teeny performance improvement.
3452
3453 3. Documentation bug: the value of the capture_top field in a callout is *one
3454 more than* the number of the hightest numbered captured substring.
3455
3456 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3457 in incorrectly linking with a previously installed version. They now link
3458 explicitly with libpcre.la.
3459
3460 5. configure.in no longer needs to recognize Cygwin specially.
3461
3462 6. A problem in pcre.in for Windows platforms is fixed.
3463
3464 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3465 pcretest, it used to include the size of the study block as part of its
3466 output. Unfortunately, the structure contains a field that has a different
3467 size on different hardware architectures. This meant that the tests that
3468 showed this size failed. As the block is currently always of a fixed size,
3469 this information isn't actually particularly useful in pcretest output, so
3470 I have just removed it.
3471
3472 8. Three pre-processor statements accidentally did not start in column 1.
3473 Sadly, there are *still* compilers around that complain, even though
3474 standard C has not required this for well over a decade. Sigh.
3475
3476 9. In pcretest, the code for checking callouts passed small integers in the
3477 callout_data field, which is a void * field. However, some picky compilers
3478 complained about the casts involved for this on 64-bit systems. Now
3479 pcretest passes the address of the small integer instead, which should get
3480 rid of the warnings.
3481
3482 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3483 both compile and run time, and gives an error if an invalid UTF-8 sequence
3484 is found. There is a option for disabling this check in cases where the
3485 string is known to be correct and/or the maximum performance is wanted.
3486
3487 11. In response to a bug report, I changed one line in Makefile.in from
3488
3489 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3490 to
3491 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3492
3493 to look similar to other lines, but I have no way of telling whether this
3494 is the right thing to do, as I do not use Windows. No doubt I'll get told
3495 if it's wrong...
3496
3497
3498 Version 4.3 21-May-03
3499 ---------------------
3500
3501 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3502 Makefile.
3503
3504 2. Some refactoring to improve the quality of the code:
3505
3506 (i) The utf8_table... variables are now declared "const".
3507
3508 (ii) The code for \cx, which used the "case flipping" table to upper case
3509 lower case letters, now just substracts 32. This is ASCII-specific,
3510 but the whole concept of \cx is ASCII-specific, so it seems
3511 reasonable.
3512
3513 (iii) PCRE was using its character types table to recognize decimal and
3514 hexadecimal digits in the pattern. This is silly, because it handles
3515 only 0-9, a-f, and A-F, but the character types table is locale-
3516 specific, which means strange things might happen. A private
3517 table is now used for this - though it costs 256 bytes, a table is
3518 much faster than multiple explicit tests. Of course, the standard
3519 character types table is still used for matching digits in subject
3520 strings against \d.
3521
3522 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3523 ending in _t are). So I've renamed it as ESC_tee.
3524
3525 3. The first argument for regexec() in the POSIX wrapper should have been
3526 defined as "const".
3527
3528 4. Changed pcretest to use malloc() for its buffers so that they can be
3529 Electric Fenced for debugging.
3530
3531 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3532 to read one or more bytes before the start of the subject string. Often this
3533 had no effect on PCRE's behaviour, but in some circumstances it could
3534 provoke a segmentation fault.
3535
3536 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3537 to try to read one or more bytes before the start of the subject string.
3538
3539 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3540 UTF-8 support could misbehave in various ways if the subject string
3541 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3542 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3543 back over UTF-8 characters.)
3544
3545
3546 Version 4.2 14-Apr-03
3547 ---------------------
3548
3549 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3550
3551 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3552 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3553 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3554 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3555 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3556 and BUILD_EXEEXT
3557 Note: automatic setting of the BUILD variables is not yet working
3558 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3559 compile-time but not at link-time
3560 [LINK]: use for linking executables only
3561 make different versions for Windows and non-Windows
3562 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3563 libraries
3564 [LINK_FOR_BUILD]: new variable
3565 [OBJEXT]: use throughout
3566 [EXEEXT]: use throughout
3567 <winshared>: new target
3568 <wininstall>: new target
3569 <dftables.o>: use native compiler
3570 <dftables>: use native linker
3571 <install>: handle Windows platform correctly
3572 <clean>: ditto
3573 <check>: ditto
3574 copy DLL to top builddir before testing
3575
3576 As part of these changes, -no-undefined was removed again. This was reported
3577 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3578 in any case.
3579
3580 3. Some tidies to get rid of compiler warnings:
3581
3582 . In the match_data structure, match_limit was an unsigned long int, whereas
3583 match_call_count was an int. I've made them both unsigned long ints.
3584
3585 . In pcretest the fact that a const uschar * doesn't automatically cast to
3586 a void * provoked a warning.
3587
3588 . Turning on some more compiler warnings threw up some "shadow" variables
3589 and a few more missing casts.
3590
3591 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3592 option, a class that contained a single character with a value between 128
3593 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3594
3595 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3596 option, a class that contained several characters, but with at least one
3597 whose value was between 128 and 255 caused PCRE to crash.
3598
3599
3600 Version 4.1 12-Mar-03
3601 ---------------------
3602
3603 1. Compiling with gcc -pedantic found a couple of places where casts were
3604 needed, and a string in dftables.c that was longer than standard compilers are
3605 required to support.
3606
3607 2. Compiling with Sun's compiler found a few more places where the code could
3608 be tidied up in order to avoid warnings.
3609
3610 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3611 first of these names is deprecated in the latest Autoconf in favour of the name
3612 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3613 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3614 analogy I have changed it to CFLAGS_FOR_BUILD.
3615
3616 4. Added -no-undefined to the linking command in the Makefile, because this is
3617 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3618 linking step for the pcreposix library.
3619
3620 5. PCRE was failing to diagnose the case of two named groups with the same
3621 name.
3622
3623 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3624 literal character that is needed in the subject for a match, and scans along to
3625 ensure that it is present before embarking on the full matching process. This
3626 saves time in cases of nested unlimited repeats that are never going to match.
3627 Problem: the scan can take a lot of time if the subject is very long (e.g.
3628 megabytes), thus penalizing straightforward matches. It is now done only if the
3629 amount of subject to be scanned is less than 1000 bytes.
3630
3631 7. A lesser problem with the same optimization is that it was recording the
3632 first character of an anchored pattern as "needed", thus provoking a search
3633 right along the subject, even when the first match of the pattern was going to
3634 fail. The "needed" character is now not set for anchored patterns, unless it
3635 follows something in the pattern that is of non-fixed length. Thus, it still
3636 fulfils its original purpose of finding quick non-matches in cases of nested
3637 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3638
3639
3640 Version 4.0 17-Feb-03
3641 ---------------------
3642
3643 1. If a comment in an extended regex that started immediately after a meta-item
3644 extended to the end of string, PCRE compiled incorrect data. This could lead to
3645 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3646
3647 2. Moved to autoconf 2.53 and libtool 1.4.2.
3648
3649 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3650 the special perltest8 script is no longer needed - all the tests can be run
3651 from a single perltest script.
3652
3653 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3654 by \s. It has now been removed in PCRE. This means it isn't recognized as
3655 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3656 class [:space:] *does* include VT, thereby creating a mess.
3657
3658 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3659 space and tab.
3660
3661 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3662 its new features into the main test script, reducing the number of scripts.
3663
3664 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3665 were backward compatible, and made the (?i) apply to the whole pattern, as if
3666 /i were given. Now it behaves more logically, and applies the option setting
3667 only to what follows. PCRE has been changed to follow suit. However, if it
3668 finds options settings right at the start of the pattern, it extracts them into
3669 the global options, as before. Thus, they show up in the info data.
3670
3671 8. Added support for the \Q...\E escape sequence. Characters in between are
3672 treated as literals. This is slightly different from Perl in that $ and @ are
3673 also handled as literals inside the quotes. In Perl, they will cause variable
3674 interpolation. Note the following examples:
3675
3676 Pattern PCRE matches Perl matches
3677
3678 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3679 \Qabc\$xyz\E abc\$xyz abc\$xyz
3680 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3681
3682 For compatibility with Perl, \Q...\E sequences are recognized inside character
3683 classes as well as outside them.
3684
3685 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3686 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3687 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3688 signed/unsigned warnings.
3689
3690 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3691 option for pcretest, so I've replaced it by a simple function that does just
3692 that job.
3693
3694 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3695 "pcregrep -".
3696
3697 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3698 Java package. This provides some syntactic sugar for simple cases of what my
3699 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3700 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3701 item, you can use this simplified notation. Note that only makes sense with
3702 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3703 greediness, whatever the setting of the PCRE_UNGREEDY option.
3704
3705 13. A change of greediness default within a pattern was not taking effect at
3706 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3707 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3708 was abstracted outside.
3709
3710 14. PCRE now supports the \G assertion. It is true when the current matching
3711 position is at the start point of the match. This differs from \A when the
3712 starting offset is non-zero. Used with the /g option of pcretest (or similar
3713 code), it works in the same way as it does for Perl's /g option. If all
3714 alternatives of a regex begin with \G, the expression is anchored to the start
3715 match position, and the "anchored" flag is set in the compiled expression.
3716
3717 15. Some bugs concerning the handling of certain option changes within patterns
3718 have been fixed. These applied to options other than (?ims). For example,
3719 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3720 been the other way round. Some of this was related to change 7 above.
3721
3722 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3723 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3724 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3725 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3726
3727 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3728 mode. Unlike ".", it always matches newline, whatever the setting of
3729 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3730 assertions. Perl allows it, but it doesn't (in general) work because it can't
3731 calculate the length of the lookbehind. At least, that's the case for Perl
3732 5.8.0 - I've been told they are going to document that it doesn't work in
3733 future.
3734
3735 18. Added an error diagnosis for escapes that PCRE does not support: these are
3736 \L, \l, \N, \P, \p, \U, \u, and \X.
3737
3738 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3739 reading past the end of the pattern in cases such as /[abcd/.
3740
3741 20. PCRE was getting more memory than necessary for patterns with classes that
3742 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3743
3744 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3745 compiling PCRE for use with Virtual Pascal.
3746
3747 22. Small fix to the Makefile to make it work properly if the build is done
3748 outside the source tree.
3749
3750 23. Added a new extension: a condition to go with recursion. If a conditional
3751 subpattern starts with (?(R) the "true" branch is used if recursion has
3752 happened, whereas the "false" branch is used only at the top level.
3753
3754 24. When there was a very long string of literal characters (over 255 bytes
3755 without UTF support, over 250 bytes with UTF support), the computation of how
3756 much memory was required could be incorrect, leading to segfaults or other
3757 strange effects.
3758
3759 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3760 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3761 there was a subsequent back reference to those brackets. This meant that, for
3762 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3763 possible to check for precisely this case. All we can do is abandon the
3764 optimization if .* occurs inside capturing brackets when there are any back
3765 references whatsoever. (See below for a better fix that came later.)
3766
3767 26. The handling of the optimization for finding the first character of a
3768 non-anchored pattern, and for finding a character that is required later in the
3769 match were failing in some cases. This didn't break the matching; it just
3770 failed to optimize when it could. The way this is done has been re-implemented.
3771
3772 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3773
3774 28. Added a new feature that provides some of the functionality that Perl
3775 provides with (?{...}). The facility is termed a "callout". The way it is done
3776 in PCRE is for the caller to provide an optional function, by setting
3777 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3778 global variable. By default it is unset, which disables all calling out. To get
3779 the function called, the regex must include (?C) at appropriate points. This
3780 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3781 This provides a means of identifying different callout points. When PCRE
3782 reaches such a point in the regex, if pcre_callout has been set, the external
3783 function is called. It is provided with data in a structure called
3784 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3785 matching continues; if it returns a non-zero value, the match at the current
3786 point fails. However, backtracking will occur if possible. [This was changed
3787 later and other features added - see item 49 below.]
3788
3789 29. pcretest is upgraded to test the callout functionality. It provides a
3790 callout function that displays information. By default, it shows the start of
3791 the match and the current position in the text. There are some new data escapes
3792 to vary what happens:
3793
3794 \C+ in addition, show current contents of captured substrings
3795 \C- do not supply a callout function
3796 \C!n return 1 when callout number n is reached
3797 \C!n!m return 1 when callout number n is reached for the mth time
3798
3799 30. If pcregrep was called with the -l option and just a single file name, it
3800 output "<stdin>" if a match was found, instead of the file name.
3801
3802 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3803 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3804 pcre_exec(). This saves a malloc/free per call. The default value of
3805 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3806 when configuring.
3807
3808 32. The default maximum size of a compiled pattern is 64K. There have been a
3809 few cases of people hitting this limit. The code now uses macros to handle the
3810 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3811 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3812 configuring. Tests 2 and 5 work only with 2-byte links because they output
3813 debugging information about compiled patterns.
3814
3815 33. Internal code re-arrangements:
3816
3817 (a) Moved the debugging function for printing out a compiled regex into
3818 its own source file (printint.c) and used #include to pull it into
3819 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3820 separate copies.
3821
3822 (b) Defined the list of op-code names for debugging as a macro in
3823 internal.h so that it is next to the definition of the opcodes.
3824
3825 (c) Defined a table of op-code lengths for simpler skipping along compiled
3826 code. This is again a macro in internal.h so that it is next to the
3827 definition of the opcodes.
3828
3829 34. Added support for recursive calls to individual subpatterns, along the
3830 lines of Robin Houston's patch (but implemented somewhat differently).
3831
3832 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3833 allow it to read and process whole directories in Win32. This code was
3834 contributed by Lionel Fourquaux; it has not been tested by me.
3835
3836 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3837 used to name a group. Names consist of alphanumerics and underscores, and must
3838 be unique. Back references use the syntax (?P=name) and recursive calls use
3839 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3840 numbers. The function pcre_fullinfo() can be used after compilation to extract
3841 a name/number map. There are three relevant calls:
3842
3843 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3844 PCRE_INFO_NAMECOUNT yields the number of entries
3845 PCRE_INFO_NAMETABLE yields a pointer to the map.
3846
3847 The map is a vector of fixed-size entries. The size of each entry depends on
3848 the length of the longest name used. The first two bytes of each entry are the
3849 group number, most significant byte first. There follows the corresponding
3850 name, zero terminated. The names are in alphabetical order.
3851
3852 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3853 case instead of 255. Making it the same both with and without UTF-8 support
3854 means that the same test output works with both.
3855
3856 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3857 calling malloc() with a zero argument.
3858
3859 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3860 optimization. I've improved things by keeping a bitmap of backreferences with
3861 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3862 fact referenced, the optimization can be applied. It is unlikely that a
3863 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3864 the match to follow \n) will appear inside brackets with a number greater than
3865 31, but if it does, any back reference > 31 suppresses the optimization.
3866
3867 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3868 of disabling numbered capturing parentheses. Any opening parenthesis that is
3869 not followed by ? behaves as if it were followed by ?: but named parentheses
3870 can still be used for capturing (and they will acquire numbers in the usual
3871 way).
3872
3873 41. Redesigned the return codes from the match() function into yes/no/error so
3874 that errors can be passed back from deep inside the nested calls. A malloc
3875 failure while inside a recursive subpattern call now causes the
3876 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3877
3878 42. It is now possible to set a limit on the number of times the match()
3879 function is called in a call to pcre_exec(). This facility makes it possible to
3880 limit the amount of recursion and backtracking, though not in a directly
3881 obvious way, because the match() function is used in a number of different
3882 circumstances. The count starts from zero for each position in the subject
3883 string (for non-anchored patterns). The default limit is, for compatibility, a
3884 large number, namely 10 000 000. You can change this in two ways:
3885
3886 (a) When configuring PCRE before making, you can use --with-match-limit=n
3887 to set a default value for the compiled library.
3888
3889 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3890 a different value is set. See 45 below.
3891
3892 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3893
3894 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3895 of things that can be changed at compile time. The first argument specifies
3896 what is wanted and the second points to where the information is to be placed.
3897 The current list of available information is:
3898
3899 PCRE_CONFIG_UTF8
3900
3901 The output is an integer that is set to one if UTF-8 support is available;
3902 otherwise it is set to zero.
3903
3904 PCRE_CONFIG_NEWLINE
3905
3906 The output is an integer that it set to the value of the code that is used for
3907 newline. It is either LF (10) or CR (13).
3908
3909 PCRE_CONFIG_LINK_SIZE
3910
3911 The output is an integer that contains the number of bytes used for internal
3912 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3913
3914 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3915
3916 The output is an integer that contains the threshold above which the POSIX
3917 interface uses malloc() for output vectors. See item 31 above.
3918
3919 PCRE_CONFIG_MATCH_LIMIT
3920
3921 The output is an unsigned integer that contains the default limit of the number
3922 of match() calls in a pcre_exec() execution. See 42 above.
3923
3924 44. pcretest has been upgraded by the addition of the -C option. This causes it
3925 to extract all the available output from the new pcre_config() function, and to
3926 output it. The program then exits immediately.
3927
3928 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3929 order to support additional features. One way would have been to define
3930 pcre_exec2() (for example) with extra arguments, but this would not have been
3931 extensible, and would also have required all calls to the original function to
3932 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3933 is used for passing in "extra" data from pcre_study().
3934
3935 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3936 contains the following fields:
3937
3938 flags a bitmap indicating which of the following fields are set
3939 study_data opaque data from pcre_study()
3940 match_limit a way of specifying a limit on match() calls for a specific
3941 call to pcre_exec()
3942 callout_data data for callouts (see 49 below)
3943
3944 The flag bits are also defined in pcre.h, and are
3945
3946 PCRE_EXTRA_STUDY_DATA
3947 PCRE_EXTRA_MATCH_LIMIT
3948 PCRE_EXTRA_CALLOUT_DATA
3949
3950 The pcre_study() function now returns one of these new pcre_extra blocks, with
3951 the actual study data pointed to by the study_data field, and the
3952 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3953 before. That is, this change is entirely upwards-compatible and requires no
3954 change to existing code.
3955
3956 If you want to pass in additional data to pcre_exec(), you can either place it
3957 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3958 block.
3959
3960 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3961 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3962 times with different match limits, until it finds the minimum value needed for
3963 pcre_exec() to complete. The value is then output. This can be instructive; for
3964 most simple matches the number is quite small, but for pathological cases it
3965 gets very large very quickly.
3966
3967 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3968 returns the size of the data block pointed to by the study_data field in a
3969 pcre_extra block, that is, the value that was passed as the argument to
3970 pcre_malloc() when PCRE was getting memory in which to place the information
3971 created by pcre_study(). The fourth argument should point to a size_t variable.
3972 pcretest has been extended so that this information is shown after a successful
3973 pcre_study() call when information about the compiled regex is being displayed.
3974
3975 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3976 because what follows is always an absolute path. (Later: it turns out that this
3977 is more than cosmetic for MinGW, because it doesn't like empty path
3978 components.)
3979
3980 49. Some changes have been made to the callout feature (see 28 above):
3981
3982 (i) A callout function now has three choices for what it returns:
3983
3984 0 => success, carry on matching
3985 > 0 => failure at this point, but backtrack if possible
3986 < 0 => serious error, return this value from pcre_exec()
3987
3988 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3989 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3990 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3991 use by callout functions. It will never be used by PCRE itself.
3992
3993 (ii) The pcre_extra structure (see 45 above) has a void * field called
3994 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3995 pcre_callout_block structure has a field of the same name. The contents of
3996 the field passed in the pcre_extra structure are passed to the callout
3997 function in the corresponding field in the callout block. This makes it
3998 easier to use the same callout-containing regex from multiple threads. For
3999 testing, the pcretest program has a new data escape
4000
4001 \C*n pass the number n (may be negative) as callout_data
4002
4003 If the callout function in pcretest receives a non-zero value as
4004 callout_data, it returns that value.
4005
4006 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
4007 there were some redundant $(CFLAGS) in commands that are now specified as
4008 $(LINK), which already includes $(CFLAGS).
4009
4010 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
4011 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
4012 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
4013 one-byte characters throughout. Note that case-insensitive matching applies
4014 only to characters whose values are less than 256. PCRE doesn't support the
4015 notion of cases for higher-valued characters.
4016
4017 (i) A character class whose characters are all within 0-255 is handled as
4018 a bit map, and the map is inverted for negative classes. Previously, a
4019 character > 255 always failed to match such a class; however it should
4020 match if the class was a negative one (e.g. [^ab]). This has been fixed.
4021
4022 (ii) A negated character class with a single character < 255 is coded as
4023 "not this character" (OP_NOT). This wasn't working properly when the test
4024 character was multibyte, either singly or repeated.
4025
4026 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
4027 mode, for example: \x{100}{2,3}.
4028
4029 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
4030 singly or repeated) now correctly test multibyte characters. However,
4031 PCRE doesn't recognize any characters with values greater than 255 as
4032 digits, spaces, or word characters. Such characters always match \D, \S,
4033 and \W, and never match \d, \s, or \w.
4034
4035 (v) Classes may now contain characters and character ranges with values
4036 greater than 255. For example: [ab\x{100}-\x{400}].
4037
4038 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
4039 PCRE in UTF-8 mode.
4040
4041 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
4042 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
4043 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
4044 value.)
4045
4046 53. The single man page has become too large. I have therefore split it up into
4047 a number of separate man pages. These also give rise to individual HTML pages;
4048 these are now put in a separate directory, and there is an index.html page that
4049 lists them all. Some hyperlinking between the pages has been installed.
4050
4051 54. Added convenience functions for handling named capturing parentheses.
4052
4053 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
4054 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
4055 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
4056 are faulted.
4057
4058 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
4059 calling configure. These values are used when compiling the dftables.c program
4060 which is run to generate the source of the default character tables. They
4061 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
4062 you will need to set these values.
4063
4064 57. Updated the building process for Windows DLL, as provided by Fred Cox.
4065
4066
4067 Version 3.9 02-Jan-02
4068 ---------------------
4069
4070 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
4071
4072 2. If --disable-static was given, the building process failed when trying to
4073 build pcretest and pcregrep. (For some reason it was using libtool to compile
4074 them, which is not right, as they aren't part of the library.)
4075
4076
4077 Version 3.8 18-Dec-01
4078 ---------------------
4079
4080 1. The experimental UTF-8 code was completely screwed up. It was packing the
4081 bytes in the wrong order. How dumb can you get?
4082
4083
4084 Version 3.7 29-Oct-01
4085 ---------------------
4086
4087 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
4088 This caused pcretest, when used on the test data, to segfault. Unfortunately,
4089 this didn't happen under Solaris 8, where I normally test things.
4090
4091 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
4092 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
4093 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
4094 this fix an hour or so after the initial 3.7 release.)
4095
4096
4097 Version 3.6 23-Oct-01
4098 ---------------------
4099
4100 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
4101 offsets passed as NULL with zero offset count.
4102
4103 2. The config.guess and config.sub files had not been updated when I moved to
4104 the latest autoconf.
4105
4106
4107 Version 3.5 15-Aug-01
4108 ---------------------
4109
4110 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
4111 had been forgotten.
4112
4113 2. By using declared but undefined structures, we can avoid using "void"
4114 definitions in pcre.h while keeping the internal definitions of the structures
4115 private.
4116
4117 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
4118 user point of view, this means that both static and shared libraries are built
4119 by default, but this can be individually controlled. More of the work of
4120 handling this static/shared cases is now inside libtool instead of PCRE's make
4121 file.
4122
4123 4. The pcretest utility is now installed along with pcregrep because it is
4124 useful for users (to test regexs) and by doing this, it automatically gets
4125 relinked by libtool. The documentation has been turned into a man page, so
4126 there are now .1, .txt, and .html versions in /doc.
4127
4128 5. Upgrades to pcregrep:
4129 (i) Added long-form option names like gnu grep.
4130 (ii) Added --help to list all options with an explanatory phrase.
4131 (iii) Added -r, --recursive to recurse into sub-directories.
4132 (iv) Added -f, --file to read patterns from a file.
4133
4134 6. pcre_exec() was referring to its "code" argument before testing that
4135 argument for NULL (and giving an error if it was NULL).
4136
4137 7. Upgraded Makefile.in to allow for compiling in a different directory from
4138 the source directory.
4139
4140 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
4141 options bits, the pointer it was passed was to an int instead of to an unsigned
4142 long int. This mattered only on 64-bit systems.
4143
4144 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
4145 generated) instead of pcre.in, which it its source. Also made the same change
4146 in several of the .c files.
4147
4148 10. A new release of gcc defines printf() as a macro, which broke pcretest
4149 because it had an ifdef in the middle of a string argument for printf(). Fixed
4150 by using separate calls to printf().
4151
4152 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4153 script, to force use of CR or LF instead of \n in the source. On non-Unix
4154 systems, the value can be set in config.h.
4155
4156 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4157 absolute limit. Changed the text of the error message to make this clear, and
4158 likewise updated the man page.
4159
4160 13. The limit of 99 on the number of capturing subpatterns has been removed.
4161 The new limit is 65535, which I hope will not be a "real" limit.
4162
4163
4164 Version 3.4 22-Aug-00
4165 ---------------------
4166
4167 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4168
4169 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4170
4171
4172 Version 3.3 01-Aug-00
4173 ---------------------
4174
4175 1. If an octal character was given, but the value was greater than \377, it
4176 was not getting masked to the least significant bits, as documented. This could
4177 lead to crashes in some systems.
4178
4179 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4180 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4181
4182 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4183 These just pass their arguments on to (pcre_free)(), but they are provided
4184 because some uses of PCRE bind it to non-C systems that can call its functions,
4185 but cannot call free() or pcre_free() directly.
4186
4187 4. Add "make test" as a synonym for "make check". Corrected some comments in
4188 the Makefile.
4189
4190 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4191 Makefile.
4192
4193 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4194 command called pgrep for grepping around the active processes.
4195
4196 7. Added the beginnings of support for UTF-8 character strings.
4197
4198 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4199 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4200 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4201 out for the ar command.)
4202
4203
4204 Version 3.2 12-May-00
4205 ---------------------
4206
4207 This is purely a bug fixing release.
4208
4209 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4210 of ZA. This was just one example of several cases that could provoke this bug,
4211 which was introduced by change 9 of version 2.00. The code for breaking
4212 infinite loops after an iteration that matches an empty string was't working
4213 correctly.
4214
4215 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4216 when matched against abbab (for example). After matching an empty string, it
4217 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4218 caused it to match further down the string than it should.
4219
4220 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4221 was there because it doesn't seem to be needed, and it causes trouble on some
4222 systems, as it is not a Standard C header. It has been removed.
4223
4224 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4225 were reported on the Macintosh. The changes were from
4226
4227 while ((c = *(++ptr)) != 0 && c != '\n');
4228 to
4229 while ((c = *(++ptr)) != 0 && c != '\n') ;
4230
4231 Totally extraordinary, but if that's what it takes...
4232
4233 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4234 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4235 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4236 assumes the way PCRE uses memmove() (always moving upwards).
4237
4238 6. PCRE is being used in one environment where strchr() is not available. There
4239 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4240 faster code anyway.
4241
4242
4243 Version 3.1 09-Feb-00
4244 ---------------------
4245
4246 The only change in this release is the fixing of some bugs in Makefile.in for
4247 the "install" target:
4248
4249 (1) It was failing to install pcreposix.h.
4250
4251 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4252
4253
4254 Version 3.0 01-Feb-00
4255 ---------------------
4256
4257 1. Add support for the /+ modifier to perltest (to output $` like it does in
4258 pcretest).
4259
4260 2. Add support for the /g modifier to perltest.
4261
4262 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4263 matches null strings.
4264
4265 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4266 pattern. Perl treats empty patterns specially - it reuses the most recent
4267 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4268 effect.
4269
4270 5. The POSIX interface was broken in that it was just handing over the POSIX
4271 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4272 required a bigger vector, with some working space on the end. This means that
4273 the POSIX wrapper now has to get and free some memory, and copy the results.
4274
4275 6. Added some simple autoconf support, placing the test data and the
4276 documentation in separate directories, re-organizing some of the
4277 information files, and making it build pcre-config (a GNU standard). Also added
4278 libtool support for building PCRE as a shared library, which is now the
4279 default.
4280
4281 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4282 09 are not valid octal constants. Single digits will be used for minor values
4283 less than 10.
4284
4285 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4286 existing programs that set these in the POSIX interface can use PCRE without
4287 modification.
4288
4289 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4290 return all that pcre_info() returns, plus additional data. The pcre_info()
4291 function is retained for compatibility, but is considered to be obsolete.
4292
4293 10. Added experimental recursion feature (?R) to handle one common case that
4294 Perl 5.6 will be able to do with (?p{...}).
4295
4296 11. Added support for POSIX character classes like [:alpha:], which Perl is
4297 adopting.
4298
4299
4300 Version 2.08 31-Aug-99
4301 ----------------------
4302
4303 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4304 trying to match at the startoffset position, but instead was moving forward to
4305 the next newline as if a previous match had failed.
4306
4307 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4308 and could get into a loop if a null string was matched other than at the start
4309 of the subject.
4310
4311 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4312 be distinguished at compile time, and for completeness also added PCRE_DATE.
4313
4314 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4315 in GnuWin32 environments.
4316
4317
4318 Version 2.07 29-Jul-99
4319 ----------------------
4320
4321 1. The documentation is now supplied in plain text form and HTML as well as in
4322 the form of man page sources.
4323
4324 2. C++ compilers don't like assigning (void *) values to other pointer types.
4325 In particular this affects malloc(). Although there is no problem in Standard
4326 C, I've put in casts to keep C++ compilers happy.
4327
4328 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4329 should be (const char *).
4330
4331 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4332 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4333 However, I haven't made this a standard facility. The documentation doesn't
4334 mention it, and the Makefile doesn't support it.
4335
4336 5. The Makefile now contains an "install" target, with editable destinations at
4337 the top of the file. The pcretest program is not installed.
4338
4339 6. pgrep -V now gives the PCRE version number and date.
4340
4341 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4342 causing the entire string to be ignored, instead of just the last character.
4343
4344 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4345 non-matching string, it can take a very, very long time, even for strings of
4346 quite modest length, because of the nested recursion. PCRE now does better in
4347 some of these cases. It does this by remembering the last required literal
4348 character in the pattern, and pre-searching the subject to ensure it is present
4349 before running the real match. In other words, it applies a heuristic to detect
4350 some types of certain failure quickly, and in the above example, if presented
4351 with a string that has no trailing " it gives "no match" very quickly.
4352
4353 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4354 other alternatives are tried instead.
4355
4356
4357 Version 2.06 09-Jun-99
4358 ----------------------
4359
4360 1. Change pcretest's output for amount of store used to show just the code
4361 space, because the remainder (the data block) varies in size between 32-bit and
4362 64-bit systems.
4363
4364 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4365 start matching at. This allows lookbehinds to work when searching for multiple
4366 occurrences in a string.
4367
4368 3. Added additional options to pcretest for testing multiple occurrences:
4369
4370 /+ outputs the rest of the string that follows a match
4371 /g loops for multiple occurrences, using the new startoffset argument
4372 /G loops for multiple occurrences by passing an incremented pointer
4373
4374 4. PCRE wasn't doing the "first character" optimization for patterns starting
4375 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4376 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4377 the letter 'x'. On long subject strings, this gives a significant speed-up.
4378
4379
4380 Version 2.05 21-Apr-99
4381 ----------------------
4382
4383 1. Changed the type of magic_number from int to long int so that it works
4384 properly on 16-bit systems.
4385
4386 2. Fixed a bug which caused patterns starting with .* not to work correctly
4387 when the subject string contained newline characters. PCRE was assuming
4388 anchoring for such patterns in all cases, which is not correct because .* will
4389 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4390 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4391 must be retried after every newline in the subject.
4392
4393
4394 Version 2.04 18-Feb-99
4395 ----------------------
4396
4397 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4398 computation of the store needed to hold the pattern was incorrect (too large).
4399 If such patterns were nested a few deep, this could multiply and become a real
4400 problem.
4401
4402 2. Added /M option to pcretest to show the memory requirement of a specific
4403 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4404
4405 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4406 compiled in such a way that the backtracking after subsequent failure was
4407 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4408 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4409
4410
4411 Version 2.03 02-Feb-99
4412 ----------------------
4413
4414 1. Fixed typo and small mistake in man page.
4415
4416 2. Added 4th condition (GPL supersedes if conflict) and created separate
4417 LICENCE file containing the conditions.
4418
4419 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4420 Perl, that is the internal \ allows the delimiter to be included in the
4421 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4422 the final delimiter, add \ to the end of the pattern (to test the error).
4423
4424 4. Added the convenience functions for extracting substrings after a successful
4425 match. Updated pcretest to make it able to test these functions.
4426
4427
4428 Version 2.02 14-Jan-99
4429 ----------------------
4430
4431 1. Initialized the working variables associated with each extraction so that
4432 their saving and restoring doesn't refer to uninitialized store.
4433
4434 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4435 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4436 fix the problem.
4437
4438 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4439 calls, and wasn't printing the correct value for compiling calls. Increased the
4440 default value of LOOPREPEAT, and the number of significant figures in the
4441 times.
4442
4443 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4444
4445 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4446 a building problem on Windows NT with a FAT file system.
4447
4448
4449 Version 2.01 21-Oct-98
4450 ----------------------
4451
4452 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4453 to character tables built by pcre_maketables() in the current locale. If NULL
4454 is passed, the default tables are used.
4455
4456
4457 Version 2.00 24-Sep-98
4458 ----------------------
4459
4460 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4461 it any more.
4462
4463 2. Allow quantification of (?>) groups, and make it work correctly.
4464
4465 3. The first character computation wasn't working for (?>) groups.
4466
4467 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4468 end of the subject) and add 5.005's \z, which really does match only at the
4469 very end of the subject.
4470
4471 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4472
4473 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4474 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4475 localized options. All options to pcre_study() were also removed.
4476
4477 7. Add other new features from 5.005:
4478
4479 $(?<= positive lookbehind
4480 $(?<! negative lookbehind
4481 (?imsx-imsx) added the unsetting capability
4482 such a setting is global if at outer level; local otherwise
4483 (?imsx-imsx:) non-capturing groups with option setting
4484 (?(cond)re|re) conditional pattern matching
4485
4486 A backreference to itself in a repeated group matches the previous
4487 captured string.
4488
4489 8. General tidying up of studying (both automatic and via "study")
4490 consequential on the addition of new assertions.
4491
4492 9. As in 5.005, unlimited repeated groups that could match an empty substring
4493 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4494 runtime if any iteration does actually match an empty substring.
4495
4496 10. Include the RunTest script in the distribution.
4497
4498 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4499 discrepancies, some of which were old and were also with respect to 5.004. They
4500 have now been fixed.
4501
4502
4503 Version 1.09 28-Apr-98
4504 ----------------------
4505
4506 1. A negated single character class followed by a quantifier with a minimum
4507 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4508 program crashes, or just wrong answers. This did not apply to negated classes
4509 containing more than one character, or to minima other than one.
4510
4511
4512 Version 1.08 27-Mar-98
4513 ----------------------
4514
4515 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4516
4517 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4518 latter must appear before anything that relies on it in the pattern.
4519
4520
4521 Version 1.07 16-Feb-98
4522 ----------------------
4523
4524 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4525 repeat of a potentially empty string).
4526
4527
4528 Version 1.06 23-Jan-98
4529 ----------------------
4530
4531 1. Added Markus Oberhumer's little patches for C++.
4532
4533 2. Literal strings longer than 255 characters were broken.
4534
4535
4536 Version 1.05 23-Dec-97
4537 ----------------------
4538
4539 1. Negated character classes containing more than one character were failing if
4540 PCRE_CASELESS was set at run time.
4541
4542
4543 Version 1.04 19-Dec-97
4544 ----------------------
4545
4546 1. Corrected the man page, where some "const" qualifiers had been omitted.
4547
4548 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4549 input syntax.
4550
4551 3. Fixed memory leak which occurred when a regex with back references was
4552 matched with an offsets vector that wasn't big enough. The temporary memory
4553 that is used in this case wasn't being freed if the match failed.
4554
4555 4. Tidied pcretest to ensure it frees memory that it gets.
4556
4557 5. Temporary memory was being obtained in the case where the passed offsets
4558 vector was exactly big enough.
4559
4560 6. Corrected definition of offsetof() from change 5 below.
4561
4562 7. I had screwed up change 6 below and broken the rules for the use of
4563 setjmp(). Now fixed.
4564
4565
4566 Version 1.03 18-Dec-97
4567 ----------------------
4568
4569 1. A erroneous regex with a missing opening parenthesis was correctly
4570 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4571 on some systems.
4572
4573 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4574 it was reported that one broken compiler failed on the former because "code" is
4575 also an independent variable.
4576
4577 3. The erroneous regex a[]b caused an array overrun reference.
4578
4579 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4580 fail on data ending with that character. (It was going on too far, and checking
4581 the next character, typically a binary zero.) This was specific to the
4582 optimized code for single-character negative classes.
4583
4584 5. Added a contributed patch from the TIN world which does the following:
4585
4586 + Add an undef for memmove, in case the the system defines a macro for it.
4587
4588 + Add a definition of offsetof(), in case there isn't one. (I don't know
4589 the reason behind this - offsetof() is part of the ANSI standard - but
4590 it does no harm).
4591
4592 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4593 most of the places where whitespace preceded '#'. I have given up and
4594 allowed the remaining 2 cases to be at the margin.
4595
4596 + Rename some variables in pcre to eliminate shadowing. This seems very
4597 pedantic, but does no harm, of course.
4598
4599 6. Moved the call to setjmp() into its own function, to get rid of warnings
4600 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4601
4602 7. Constructs such as \d{8,} were compiling into the equivalent of
4603 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4604 outcome, but in this particular case used more store than had been allocated,
4605 which caused the bug to be discovered because it threw up an internal error.
4606
4607 8. The debugging code in both pcre and pcretest for outputting the compiled
4608 form of a regex was going wrong in the case of back references followed by
4609 curly-bracketed repeats.
4610
4611
4612 Version 1.02 12-Dec-97
4613 ----------------------
4614
4615 1. Typos in pcre.3 and comments in the source fixed.
4616
4617 2. Applied a contributed patch to get rid of places where it used to remove
4618 'const' from variables, and fixed some signed/unsigned and uninitialized
4619 variable warnings.
4620
4621 3. Added the "runtest" target to Makefile.
4622
4623 4. Set default compiler flag to -O2 rather than just -O.
4624
4625
4626 Version 1.01 19-Nov-97
4627 ----------------------
4628
4629 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4630 like /([ab]*)*/, that is, for classes with more than one character in them.
4631
4632 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4633 as /((?>a*))*/ (a PCRE_EXTRA facility).
4634
4635
4636 Version 1.00 18-Nov-97
4637 ----------------------
4638
4639 1. Added compile-time macros to support systems such as SunOS4 which don't have
4640 memmove() or strerror() but have other things that can be used instead.
4641
4642 2. Arranged that "make clean" removes the executables.
4643
4644
4645 Version 0.99 27-Oct-97
4646 ----------------------
4647
4648 1. Fixed bug in code for optimizing classes with only one character. It was
4649 initializing a 32-byte map regardless, which could cause it to run off the end
4650 of the memory it had got.
4651
4652 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4653
4654
4655 Version 0.98 22-Oct-97
4656 ----------------------
4657
4658 1. Fixed bug in code for handling temporary memory usage when there are more
4659 back references than supplied space in the ovector. This could cause segfaults.
4660
4661
4662 Version 0.97 21-Oct-97
4663 ----------------------
4664
4665 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4666
4667 2. Optimized negated single characters not to use a bit map.
4668
4669 3. Brought error texts together as macro definitions; clarified some of them;
4670 fixed one that was wrong - it said "range out of order" when it meant "invalid
4671 escape sequence".
4672
4673 4. Changed some char * arguments to const char *.
4674
4675 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4676
4677 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4678 pcretest.
4679
4680
4681 Version 0.96 16-Oct-97
4682 ----------------------
4683
4684 1. Added a simple "pgrep" utility to the distribution.
4685
4686 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4687 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4688 where "ddd" means "one or more decimal digits".
4689
4690 3. Fixed serious bug. If a pattern had a back reference, but the call to
4691 pcre_exec() didn't supply a large enough ovector to record the related
4692 identifying subpattern, the match always failed. PCRE now remembers the number
4693 of the largest back reference, and gets some temporary memory in which to save
4694 the offsets during matching if necessary, in order to ensure that
4695 backreferences always work.
4696
4697 4. Increased the compatibility with Perl in a number of ways:
4698
4699 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4700 to request this handling. The option can be set at compile or exec time.
4701
4702 (b) $ matches before a terminating newline by default; an option
4703 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4704 mode). The option can be set at compile or exec time.
4705
4706 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4707 the same as Perl's. If the decimal number it represents is less than 10
4708 or there aren't that many previous left capturing parentheses, an octal
4709 escape is read. Inside a character class, it's always an octal escape,
4710 even if it is a single digit.
4711
4712 (d) An escaped but undefined alphabetic character is taken as a literal,
4713 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4714 escapes.
4715
4716 (e) {0} is now permitted. (The previous item is removed from the compiled
4717 pattern).
4718
4719 5. Changed all the names of code files so that the basic parts are no longer
4720 than 10 characters, and abolished the teeny "globals.c" file.
4721
4722 6. Changed the handling of character classes; they are now done with a 32-byte
4723 bit map always.
4724
4725 7. Added the -d and /D options to pcretest to make it possible to look at the
4726 internals of compilation without having to recompile pcre.
4727
4728
4729 Version 0.95 23-Sep-97
4730 ----------------------
4731
4732 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4733 \x20 at the start of a run of normal characters. These were being treated as
4734 real characters, instead of the source characters being re-checked.
4735
4736
4737 Version 0.94 18-Sep-97
4738 ----------------------
4739
4740 1. The functions are now thread-safe, with the caveat that the global variables
4741 containing pointers to malloc() and free() or alternative functions are the
4742 same for all threads.
4743
4744 2. Get pcre_study() to generate a bitmap of initial characters for non-
4745 anchored patterns when this is possible, and use it if passed to pcre_exec().
4746
4747
4748 Version 0.93 15-Sep-97
4749 ----------------------
4750
4751 1. /(b)|(:+)/ was computing an incorrect first character.
4752
4753 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4754 but not actually doing anything yet.
4755
4756 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4757 as Perl does (e.g. [-az] or [az-]).
4758
4759 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4760 all possible positions.
4761
4762 5. Split up into different modules to avoid including unneeded functions in a
4763 compiled binary. However, compile and exec are still in one module. The "study"
4764 function is split off.
4765
4766 6. The character tables are now in a separate module whose source is generated
4767 by an auxiliary program - but can then be edited by hand if required. There are
4768 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4769 toupper() in the code.
4770
4771 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4772 make them global. Abolish the function for setting them, as the caller can now
4773 set them directly.
4774
4775
4776 Version 0.92 11-Sep-97
4777 ----------------------
4778
4779 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4780 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4781
4782 2. Caseless matching was not working in character classes if the characters in
4783 the pattern were in upper case.
4784
4785 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4786
4787 4. Make PCRE_ANCHORED public and accept as a compile option.
4788
4789 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4790 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4791 pass them.
4792
4793 6. Give an error if bad option bits passed at compile or run time.
4794
4795 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4796 pcretest to cause it to pass that flag.
4797
4798 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4799 options, and the first character, if set.
4800
4801 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4802
4803
4804 Version 0.91 10-Sep-97
4805 ----------------------
4806
4807 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4808 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4809
4810 2. PCRE was looping on encountering an indefinitely repeated back reference to
4811 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4812 Perl does - treats the match as successful.
4813
4814 ****

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