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Revision 997 - (show annotations)
Fri Jul 27 11:31:03 2012 UTC (7 years, 3 months ago) by zherczeg
File size: 233591 byte(s)
Improved instruction cache flush for POWER/PowerPC
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.32
5 ------------
6
7 1. Improved JIT compiler optimizations for first character search and single
8 character iterators.
9
10 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
11 Patch by Daniel Richard G.
12
13 3. Single character iterator optimizations in the JIT compiler.
14
15 4. Improved JIT compiler optimizations for character ranges.
16
17 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
18 Reported by Giuseppe D'Angelo.
19
20 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
21 of a line, was being set incorrectly in cases where .* appeared inside
22 atomic brackets at the start of a pattern, or where there was a subsequent
23 *PRUNE or *SKIP.
24
25 7. Improved instruction cache flush for POWER/PowerPC.
26 Patch by Daniel Richard G.
27
28
29 Version 8.31 06-July-2012
30 -------------------------
31
32 1. Fixing a wrong JIT test case and some compiler warnings.
33
34 2. Removed a bashism from the RunTest script.
35
36 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
37 to unsigned type, result still unsigned" that was given by an MS compiler
38 on encountering the code "-sizeof(xxx)".
39
40 4. Partial matching support is added to the JIT compiler.
41
42 5. Fixed several bugs concerned with partial matching of items that consist
43 of more than one character:
44
45 (a) /^(..)\1/ did not partially match "aba" because checking references was
46 done on an "all or nothing" basis. This also applied to repeated
47 references.
48
49 (b) \R did not give a hard partial match if \r was found at the end of the
50 subject.
51
52 (c) \X did not give a hard partial match after matching one or more
53 characters at the end of the subject.
54
55 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
56 a partial match for the string "\r".
57
58 (e) When newline was set to CRLF, the metacharacter "." did not recognize
59 a partial match for a CR character at the end of the subject string.
60
61 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
62 running pcretest, the text "(JIT)" added to the output whenever JIT is
63 actually used to run the match.
64
65 7. Individual JIT compile options can be set in pcretest by following -s+[+]
66 or /S+[+] with a digit between 1 and 7.
67
68 8. OP_NOT now supports any UTF character not just single-byte ones.
69
70 9. (*MARK) control verb is now supported by the JIT compiler.
71
72 10. The command "./RunTest list" lists the available tests without actually
73 running any of them. (Because I keep forgetting what they all are.)
74
75 11. Add PCRE_INFO_MAXLOOKBEHIND.
76
77 12. Applied a (slightly modified) user-supplied patch that improves performance
78 when the heap is used for recursion (compiled with --disable-stack-for-
79 recursion). Instead of malloc and free for each heap frame each time a
80 logical recursion happens, frames are retained on a chain and re-used where
81 possible. This sometimes gives as much as 30% improvement.
82
83 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
84 call.
85
86 14. As documented, (*COMMIT) is now confined to within a positive assertion.
87
88 15. It is now possible to link pcretest with libedit as an alternative to
89 libreadline.
90
91 16. (*COMMIT) control verb is now supported by the JIT compiler.
92
93 17. The Unicode data tables have been updated to Unicode 6.1.0.
94
95 18. Added --file-list option to pcregrep.
96
97 19. Added binary file support to pcregrep, including the -a, --binary-files,
98 -I, and --text options.
99
100 20. The madvise function is renamed for posix_madvise for QNX compatibility
101 reasons. Fixed by Giuseppe D'Angelo.
102
103 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
104
105 22. Changed the option for creating symbolic links for 16-bit man pages from
106 -s to -sf so that re-installing does not cause issues.
107
108 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
109
110 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
111 matches in certain environments (the workspace was not being correctly
112 retained). Also added to pcre_dfa_exec() a simple plausibility check on
113 some of the workspace data at the beginning of a restart.
114
115 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
116 was not doing so when it should - probably a typo introduced by SVN 528
117 (change 8.10/14).
118
119 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
120 \w+ when the character tables indicated that \x{c4} was a word character.
121 There were several related cases, all because the tests for doing a table
122 lookup were testing for characters less than 127 instead of 255.
123
124 27. If a pattern contains capturing parentheses that are not used in a match,
125 their slots in the ovector are set to -1. For those that are higher than
126 any matched groups, this happens at the end of processing. In the case when
127 there were back references that the ovector was too small to contain
128 (causing temporary malloc'd memory to be used during matching), and the
129 highest capturing number was not used, memory off the end of the ovector
130 was incorrectly being set to -1. (It was using the size of the temporary
131 memory instead of the true size.)
132
133 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
134 ovector size, it uses memory at the end of the block that it has got.
135
136 29. Check for an overlong MARK name and give an error at compile time. The
137 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
138
139 30. JIT compiler update.
140
141 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
142 Rill for the patch.
143
144 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
145
146 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
147
148 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
149 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
150 was enabled.
151
152 35. Improve JIT code generation for greedy plus quantifier.
153
154 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
155 1 to "aa" instead of to an empty string. The bug affected repeated groups
156 that could potentially match an empty string.
157
158 37. Optimizing single character iterators in JIT.
159
160 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
161 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
162 codepoints that are too big for the mode are faulted, and in a UTF mode,
163 disallowed codepoints are also faulted.
164
165 39. If PCRE was compiled with UTF support, in three places in the DFA
166 matcher there was code that should only have been obeyed in UTF mode, but
167 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
168 processing when bytes with values greater than 127 were present. In 16-bit
169 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
170 both cases the values are those that cannot be the first data item in a UTF
171 character. The three items that might have provoked this were recursions,
172 possessively repeated groups, and atomic groups.
173
174 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
175 and pcregrep, because some OS require shared objects to be explicitly
176 passed to ld, causing the link step to fail if they are not.
177
178 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
179 mode, patterns that started with \h* or \R* might be incorrectly matched.
180
181
182 Version 8.30 04-February-2012
183 -----------------------------
184
185 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
186 name is defined in ctype.h.
187
188 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
189 only in quite long subpatterns.
190
191 3. Removed the function pcre_info(), which has been obsolete and deprecated
192 since it was replaced by pcre_fullinfo() in February 2000.
193
194 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
195 match a (*MARK), and the match failed at the start of the subject, a
196 reference to memory before the start of the subject could occur. This bug
197 was introduced by fix 17 of release 8.21.
198
199 5. A reference to an unset group with zero minimum repetition was giving
200 totally wrong answers (in non-JavaScript-compatibility mode). For example,
201 /(another)?(\1?)test/ matched against "hello world test". This bug was
202 introduced in release 8.13.
203
204 6. Add support for 16-bit character strings (a large amount of work involving
205 many changes and refactorings).
206
207 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
208 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
209 from a file.
210
211 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
212 rounding is not applied in this particular case).
213
214 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
215 if they appear, or are escaped, in patterns.
216
217 10. Get rid of a number of -Wunused-but-set-variable warnings.
218
219 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
220 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
221 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
222 also returns the mark "x". This bug applied to capturing parentheses,
223 non-capturing parentheses, and atomic parentheses. It also applied to some
224 assertions.
225
226 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
227 information out of configure.ac instead of relying on pcre.h.generic, which
228 is not stored in the repository.
229
230 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
231 -lreadline.
232
233 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
234
235 15. Applied Graycode's patch to put the top-level frame on the stack rather
236 than the heap when not using the stack for recursion. This gives a
237 performance improvement in many cases when recursion is not deep.
238
239 16. Experimental code added to "pcretest -C" to output the stack frame size.
240
241
242 Version 8.21 12-Dec-2011
243 ------------------------
244
245 1. Updating the JIT compiler.
246
247 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
248 are added as well.
249
250 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
251 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
252 calling _pcre_jit_exec. Some extra comments are added.
253
254 4. (*MARK) settings inside atomic groups that do not contain any capturing
255 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
256 was introduced by change 18 for 8.20.
257
258 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
259 ECMA-262 standard.
260
261 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
262 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
263 This bug was probably introduced by change 9 of 8.13.
264
265 7. While fixing 6 above, I noticed that a number of other items were being
266 incorrectly rejected as "not fixed length". This arose partly because newer
267 opcodes had not been added to the fixed-length checking code. I have (a)
268 corrected the bug and added tests for these items, and (b) arranged for an
269 error to occur if an unknown opcode is encountered while checking for fixed
270 length instead of just assuming "not fixed length". The items that were
271 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
272 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
273 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
274
275 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
276 being incorrectly compiled and would have given unpredicatble results.
277
278 9. A possessively repeated subpattern with minimum repeat count greater than
279 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
280 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
281 the first (A) could occur when it should not.
282
283 10. Add a cast and remove a redundant test from the code.
284
285 11. JIT should use pcre_malloc/pcre_free for allocation.
286
287 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
288 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
289 is anything other than /usr, -L is still shown).
290
291 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
292
293 14. Perl does not support \N without a following name in a [] class; PCRE now
294 also gives an error.
295
296 15. If a forward reference was repeated with an upper limit of around 2000,
297 it caused the error "internal error: overran compiling workspace". The
298 maximum number of forward references (including repeats) was limited by the
299 internal workspace, and dependent on the LINK_SIZE. The code has been
300 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
301 the default depends on LINK_SIZE. There is a new upper limit (for safety)
302 of around 200,000 forward references. While doing this, I also speeded up
303 the filling in of repeated forward references.
304
305 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
306 incorrectly expecting the subject to contain another "a" after the start.
307
308 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
309 in the match, the SKIP should be ignored. This was not happening; instead
310 the SKIP was being treated as NOMATCH. For patterns such as
311 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
312 tested.
313
314 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
315 now much more compatible with Perl, in particular in cases where the result
316 is a non-match for a non-anchored pattern. For example, if
317 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
318 "m", where previously it did not return a name. A side effect of this
319 change is that for partial matches, the last encountered mark name is
320 returned, as for non matches. A number of tests that were previously not
321 Perl-compatible have been moved into the Perl-compatible test files. The
322 refactoring has had the pleasing side effect of removing one argument from
323 the match() function, thus reducing its stack requirements.
324
325 19. If the /S+ option was used in pcretest to study a pattern using JIT,
326 subsequent uses of /S (without +) incorrectly behaved like /S+.
327
328 21. Retrieve executable code size support for the JIT compiler and fixing
329 some warnings.
330
331 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
332 not work when the shorter character appeared right at the end of the
333 subject string.
334
335 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
336 systems.
337
338 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
339 output it when the /M option is used in pcretest.
340
341 25. The CheckMan script was not being included in the distribution. Also, added
342 an explicit "perl" to run Perl scripts from the PrepareRelease script
343 because this is reportedly needed in Windows.
344
345 26. If study data was being save in a file and studying had not found a set of
346 "starts with" bytes for the pattern, the data written to the file (though
347 never used) was taken from uninitialized memory and so caused valgrind to
348 complain.
349
350 27. Updated RunTest.bat as provided by Sheri Pierce.
351
352 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
353
354 29. Computation of memory usage for the table of capturing group names was
355 giving an unnecessarily large value.
356
357
358 Version 8.20 21-Oct-2011
359 ------------------------
360
361 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
362 a POSIX class. After further experiments with Perl, which convinced me that
363 Perl has bugs and confusions, a closing square bracket is no longer allowed
364 in a POSIX name. This bug also affected patterns with classes that started
365 with full stops.
366
367 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
368 captured substring, but while checking the failing first alternative,
369 substring 1 is temporarily captured. If the output vector supplied to
370 pcre_exec() was not big enough for this capture, the yield of the function
371 was still zero ("insufficient space for captured substrings"). This cannot
372 be totally fixed without adding another stack variable, which seems a lot
373 of expense for a edge case. However, I have improved the situation in cases
374 such as /(a)(b)x|abc/ matched against "abc", where the return code
375 indicates that fewer than the maximum number of slots in the ovector have
376 been set.
377
378 3. Related to (2) above: when there are more back references in a pattern than
379 slots in the output vector, pcre_exec() uses temporary memory during
380 matching, and copies in the captures as far as possible afterwards. It was
381 using the entire output vector, but this conflicts with the specification
382 that only 2/3 is used for passing back captured substrings. Now it uses
383 only the first 2/3, for compatibility. This is, of course, another edge
384 case.
385
386 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
387 main code base, and can be used by building with --enable-jit. When this is
388 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
389 runtime --no-jit option is given.
390
391 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
392 ovector, the return from the function was zero, implying that there were
393 other matches that did not fit. The correct "exactly full" value is now
394 returned.
395
396 6. If a subpattern that was called recursively or as a subroutine contained
397 (*PRUNE) or any other control that caused it to give a non-standard return,
398 invalid errors such as "Error -26 (nested recursion at the same subject
399 position)" or even infinite loops could occur.
400
401 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
402 computing the minimum length on reaching *ACCEPT, and so ended up with the
403 wrong value of 1 rather than 0. Further investigation indicates that
404 computing a minimum subject length in the presence of *ACCEPT is difficult
405 (think back references, subroutine calls), and so I have changed the code
406 so that no minimum is registered for a pattern that contains *ACCEPT.
407
408 8. If (*THEN) was present in the first (true) branch of a conditional group,
409 it was not handled as intended. [But see 16 below.]
410
411 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
412 Sheri Pierce.
413
414 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
415 the first byte in a match must be "a".
416
417 11. Change 17 for 8.13 increased the recursion depth for patterns like
418 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
419 pattern contains any instances of (*THEN). If it does not, the old
420 optimizations are restored. It would be nice to do this on a per-group
421 basis, but at the moment that is not feasible.
422
423 12. In some environments, the output of pcretest -C is CRLF terminated. This
424 broke RunTest's code that checks for the link size. A single white space
425 character after the value is now allowed for.
426
427 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
428 For "fr", it uses the Windows-specific input and output files.
429
430 14. If (*THEN) appeared in a group that was called recursively or as a
431 subroutine, it did not work as intended. [But see next item.]
432
433 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
434 pattern fragments (but not containing any | characters). If A and B are
435 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
436 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
437 D. In other words, Perl considers parentheses that do not contain any |
438 characters to be part of a surrounding alternative, whereas PCRE was
439 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
440 differently. PCRE now behaves in the same way as Perl, except in the case
441 of subroutine/recursion calls such as (?1) which have in any case always
442 been different (but PCRE had them first :-).
443
444 16. Related to 15 above: Perl does not treat the | in a conditional group as
445 creating alternatives. Such a group is treated in the same way as an
446 ordinary group without any | characters when processing (*THEN). PCRE has
447 been changed to match Perl's behaviour.
448
449 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
450 RunGrepTest script failed.
451
452 18. Change 22 for version 13 caused atomic groups to use more stack. This is
453 inevitable for groups that contain captures, but it can lead to a lot of
454 stack use in large patterns. The old behaviour has been restored for atomic
455 groups that do not contain any capturing parentheses.
456
457 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
458 suppress the check for a minimum subject length at run time. (If it was
459 given to pcre_exec() or pcre_dfa_exec() it did work.)
460
461 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
462 fail to work when decoding hex characters in data strings in EBCDIC
463 environments.
464
465 21. It appears that in at least one Mac OS environment, the isxdigit() function
466 is implemented as a macro that evaluates to its argument more than once,
467 contravening the C 90 Standard (I haven't checked a later standard). There
468 was an instance in pcretest which caused it to go wrong when processing
469 \x{...} escapes in subject strings. The has been rewritten to avoid using
470 things like p++ in the argument of isxdigit().
471
472
473 Version 8.13 16-Aug-2011
474 ------------------------
475
476 1. The Unicode data tables have been updated to Unicode 6.0.0.
477
478 2. Two minor typos in pcre_internal.h have been fixed.
479
480 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
481 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
482 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
483
484 4. There were a number of related bugs in the code for matching backrefences
485 caselessly in UTF-8 mode when codes for the characters concerned were
486 different numbers of bytes. For example, U+023A and U+2C65 are an upper
487 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
488 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
489 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
490 2-byte code at the end of the subject (it thought there wasn't enough data
491 left).
492
493 5. Comprehensive information about what went wrong is now returned by
494 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
495 as the output vector has at least 2 elements. The offset of the start of
496 the failing character and a reason code are placed in the vector.
497
498 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
499 now returned is for the first byte of the failing character, instead of the
500 last byte inspected. This is an incompatible change, but I hope it is small
501 enough not to be a problem. It makes the returned offset consistent with
502 pcre_exec() and pcre_dfa_exec().
503
504 7. pcretest now gives a text phrase as well as the error number when
505 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
506 failure, the offset and reason code are output.
507
508 8. When \R was used with a maximizing quantifier it failed to skip backwards
509 over a \r\n pair if the subsequent match failed. Instead, it just skipped
510 back over a single character (\n). This seems wrong (because it treated the
511 two characters as a single entity when going forwards), conflicts with the
512 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
513 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
514 has been changed.
515
516 9. Some internal refactoring has changed the processing so that the handling
517 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
518 time (the PCRE_DOTALL option was changed this way some time ago: version
519 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
520 which was always a bit of a fudge. It also means that there is one less
521 argument for the match() function, which reduces its stack requirements
522 slightly. This change also fixes an incompatibility with Perl: the pattern
523 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
524
525 10. More internal refactoring has drastically reduced the number of recursive
526 calls to match() for possessively repeated groups such as (abc)++ when
527 using pcre_exec().
528
529 11. While implementing 10, a number of bugs in the handling of groups were
530 discovered and fixed:
531
532 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
533 (a|)*(?1) gave a compile-time internal error.
534 ((a|)+)+ did not notice that the outer group could match an empty string.
535 (^a|^)+ was not marked as anchored.
536 (.*a|.*)+ was not marked as matching at start or after a newline.
537
538 12. Yet more internal refactoring has removed another argument from the match()
539 function. Special calls to this function are now indicated by setting a
540 value in a variable in the "match data" data block.
541
542 13. Be more explicit in pcre_study() instead of relying on "default" for
543 opcodes that mean there is no starting character; this means that when new
544 ones are added and accidentally left out of pcre_study(), testing should
545 pick them up.
546
547 14. The -s option of pcretest has been documented for ages as being an old
548 synonym of -m (show memory usage). I have changed it to mean "force study
549 for every regex", that is, assume /S for every regex. This is similar to -i
550 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
551 using it. It makes it easier to run collections of tests with and without
552 study enabled, and thereby test pcre_study() more easily. All the standard
553 tests are now run with and without -s (but some patterns can be marked as
554 "never study" - see 20 below).
555
556 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
557 restoration of the capturing data to the outer values was not happening
558 correctly.
559
560 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
561 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
562 pattern had matched an empty string, and so incorrectly returned a no
563 match.
564
565 17. There was optimizing code for the last branch of non-capturing parentheses,
566 and also for the obeyed branch of a conditional subexpression, which used
567 tail recursion to cut down on stack usage. Unfortunately, now that there is
568 the possibility of (*THEN) occurring in these branches, tail recursion is
569 no longer possible because the return has to be checked for (*THEN). These
570 two optimizations have therefore been removed. [But see 8.20/11 above.]
571
572 18. If a pattern containing \R was studied, it was assumed that \R always
573 matched two bytes, thus causing the minimum subject length to be
574 incorrectly computed because \R can also match just one byte.
575
576 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
577 was incorrectly computed.
578
579 20. If /S is present twice on a test pattern in pcretest input, it now
580 *disables* studying, thereby overriding the use of -s on the command line
581 (see 14 above). This is necessary for one or two tests to keep the output
582 identical in both cases.
583
584 21. When (*ACCEPT) was used in an assertion that matched an empty string and
585 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
586
587 22. When an atomic group that contained a capturing parenthesis was
588 successfully matched, but the branch in which it appeared failed, the
589 capturing was not being forgotten if a higher numbered group was later
590 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
591 group 1 to "a", when in fact it should be unset. This applied to multi-
592 branched capturing and non-capturing groups, repeated or not, and also to
593 positive assertions (capturing in negative assertions does not happen
594 in PCRE) and also to nested atomic groups.
595
596 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
597 subject after a captured substring, to make it easier to tell which of a
598 number of identical substrings has been captured.
599
600 24. The way atomic groups are processed by pcre_exec() has been changed so that
601 if they are repeated, backtracking one repetition now resets captured
602 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
603 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
604 "aaa". Previously, it would have been "a". As part of this code
605 refactoring, the way recursive calls are handled has also been changed.
606
607 25. If an assertion condition captured any substrings, they were not passed
608 back unless some other capturing happened later. For example, if
609 (?(?=(a))a) was matched against "a", no capturing was returned.
610
611 26. When studying a pattern that contained subroutine calls or assertions,
612 the code for finding the minimum length of a possible match was handling
613 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
614 group 1 called group 2 while simultaneously a separate group 2 called group
615 1). A stack overflow occurred in this case. I have fixed this by limiting
616 the recursion depth to 10.
617
618 27. Updated RunTest.bat in the distribution to the version supplied by Tom
619 Fortmann. This supports explicit test numbers on the command line, and has
620 argument validation and error reporting.
621
622 28. An instance of \X with an unlimited repeat could fail if at any point the
623 first character it looked at was a mark character.
624
625 29. Some minor code refactoring concerning Unicode properties and scripts
626 should reduce the stack requirement of match() slightly.
627
628 30. Added the '=' option to pcretest to check the setting of unused capturing
629 slots at the end of the pattern, which are documented as being -1, but are
630 not included in the return count.
631
632 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
633 compiled something random. Now it gives a compile-time error (as does
634 Perl).
635
636 32. A *MARK encountered during the processing of a positive assertion is now
637 recorded and passed back (compatible with Perl).
638
639 33. If --only-matching or --colour was set on a pcregrep call whose pattern
640 had alternative anchored branches, the search for a second match in a line
641 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
642 matched the line "0102" twice. The same bug affected patterns that started
643 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
644 twice.
645
646 34. Previously, PCRE did not allow quantification of assertions. However, Perl
647 does, and because of capturing effects, quantifying parenthesized
648 assertions may at times be useful. Quantifiers are now allowed for
649 parenthesized assertions.
650
651 35. A minor code tidy in pcre_compile() when checking options for \R usage.
652
653 36. \g was being checked for fancy things in a character class, when it should
654 just be a literal "g".
655
656 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
657 appearance of a nested POSIX class supersedes an apparent external class.
658 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
659 unescaped square brackets may also appear as part of class names. For
660 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
661 more like Perl. (But see 8.20/1 above.)
662
663 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
664 was because it thought it was \N{name}, which is not supported).
665
666 39. Add minix to OS list not supporting the -S option in pcretest.
667
668 40. PCRE tries to detect cases of infinite recursion at compile time, but it
669 cannot analyze patterns in sufficient detail to catch mutual recursions
670 such as ((?1))((?2)). There is now a runtime test that gives an error if a
671 subgroup is called recursively as a subpattern for a second time at the
672 same position in the subject string. In previous releases this might have
673 been caught by the recursion limit, or it might have run out of stack.
674
675 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
676 happen only once. PCRE was, however incorrectly giving a compile time error
677 "recursive call could loop indefinitely" because it cannot analyze the
678 pattern in sufficient detail. The compile time test no longer happens when
679 PCRE is compiling a conditional subpattern, but actual runaway loops are
680 now caught at runtime (see 40 above).
681
682 42. It seems that Perl allows any characters other than a closing parenthesis
683 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
684 has been changed to be the same.
685
686 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
687 as not to get warnings when autogen.sh is called. Also changed
688 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
689
690 44. To help people who use pcregrep to scan files containing exceedingly long
691 lines, the following changes have been made:
692
693 (a) The default value of the buffer size parameter has been increased from
694 8K to 20K. (The actual buffer used is three times this size.)
695
696 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
697 PCRE is built.
698
699 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
700 to be set at run time.
701
702 (d) Numerical values in pcregrep options can be followed by K or M, for
703 example --buffer-size=50K.
704
705 (e) If a line being scanned overflows pcregrep's buffer, an error is now
706 given and the return code is set to 2.
707
708 45. Add a pointer to the latest mark to the callout data block.
709
710 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
711 partial match of an empty string instead of no match. This was specific to
712 the use of ".".
713
714 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
715 complete match instead of a partial match. This bug was dependent on both
716 the PCRE_UTF8 and PCRE_DOTALL options being set.
717
718 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
719 starting byte set, because \b was not being ignored.
720
721
722 Version 8.12 15-Jan-2011
723 ------------------------
724
725 1. Fixed some typos in the markup of the man pages, and wrote a script that
726 checks for such things as part of the documentation building process.
727
728 2. On a big-endian 64-bit system, pcregrep did not correctly process the
729 --match-limit and --recursion-limit options (added for 8.11). In
730 particular, this made one of the standard tests fail. (The integer value
731 went into the wrong half of a long int.)
732
733 3. If the --colour option was given to pcregrep with -v (invert match), it
734 did strange things, either producing crazy output, or crashing. It should,
735 of course, ignore a request for colour when reporting lines that do not
736 match.
737
738 4. Another pcregrep bug caused similar problems if --colour was specified with
739 -M (multiline) and the pattern match finished with a line ending.
740
741 5. In pcregrep, when a pattern that ended with a literal newline sequence was
742 matched in multiline mode, the following line was shown as part of the
743 match. This seems wrong, so I have changed it.
744
745 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
746 the check for further matches in the same line (so they could be coloured)
747 to overrun the end of the current line. If another match was found, it was
748 incorrectly shown (and then shown again when found in the next line).
749
750 7. If pcregrep was compiled under Windows, there was a reference to the
751 function pcregrep_exit() before it was defined. I am assuming this was
752 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
753 reported by a user. I've moved the definition above the reference.
754
755
756 Version 8.11 10-Dec-2010
757 ------------------------
758
759 1. (*THEN) was not working properly if there were untried alternatives prior
760 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
761 backtracked to try for "b" instead of moving to the next alternative branch
762 at the same level (in this case, to look for "c"). The Perl documentation
763 is clear that when (*THEN) is backtracked onto, it goes to the "next
764 alternative in the innermost enclosing group".
765
766 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
767 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
768 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
769 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
770 (*THEN).
771
772 3. If \s appeared in a character class, it removed the VT character from
773 the class, even if it had been included by some previous item, for example
774 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
775 of \s, but is part of the POSIX "space" class.)
776
777 4. A partial match never returns an empty string (because you can always
778 match an empty string at the end of the subject); however the checking for
779 an empty string was starting at the "start of match" point. This has been
780 changed to the "earliest inspected character" point, because the returned
781 data for a partial match starts at this character. This means that, for
782 example, /(?<=abc)def/ gives a partial match for the subject "abc"
783 (previously it gave "no match").
784
785 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
786 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
787 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
788 has an implication that the given string is incomplete (because a partial
789 match is preferred over a full match). For this reason, these items now
790 give a partial match in this situation. [Aside: previously, the one case
791 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
792 match rather than a full match, which was wrong by the old rules, but is
793 now correct.]
794
795 6. There was a bug in the handling of #-introduced comments, recognized when
796 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
797 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
798 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
799 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
800 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
801 places in pcre_compile().
802
803 7. Related to (6) above, when pcre_compile() was skipping #-introduced
804 comments when looking ahead for named forward references to subpatterns,
805 the only newline sequence it recognized was NL. It now handles newlines
806 according to the set newline convention.
807
808 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
809 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
810 cater for a lack of strerror(). These oversights have been fixed.
811
812 9. Added --match-limit and --recursion-limit to pcregrep.
813
814 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
815
816 11. When the -o option was used, pcregrep was setting a return code of 1, even
817 when matches were found, and --line-buffered was not being honoured.
818
819 12. Added an optional parentheses number to the -o and --only-matching options
820 of pcregrep.
821
822 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
823 can match an empty string. The code to do it in pcretest and pcredemo
824 needed fixing:
825
826 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
827 only one byte after an empty string match just before CRLF (this case
828 just got forgotten; "any" and "anycrlf" were OK).
829
830 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
831 mode when an empty string match preceded an ASCII character followed by
832 a non-ASCII character. (The code for advancing by one character rather
833 than one byte was nonsense.)
834
835 (c) The pcredemo.c sample program did not have any code at all to handle
836 the cases when CRLF is a valid newline sequence.
837
838 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
839 as a starting offset was within the subject string. There is now a new
840 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
841 negative or greater than the length of the string. In order to test this,
842 pcretest is extended to allow the setting of negative starting offsets.
843
844 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
845 starting offset points to the beginning of a UTF-8 character was
846 unnecessarily clumsy. I tidied it up.
847
848 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
849 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
850
851 17. Nobody had reported that the --include_dir option, which was added in
852 release 7.7 should have been called --include-dir (hyphen, not underscore)
853 for compatibility with GNU grep. I have changed it to --include-dir, but
854 left --include_dir as an undocumented synonym, and the same for
855 --exclude-dir, though that is not available in GNU grep, at least as of
856 release 2.5.4.
857
858 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
859 characters from a string of bytes) have been redefined so as not to use
860 loops, in order to improve performance in some environments. At the same
861 time, I abstracted some of the common code into auxiliary macros to save
862 repetition (this should not affect the compiled code).
863
864 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
865 compile-time error is now given if \c is not followed by an ASCII
866 character, that is, a byte less than 128. (In EBCDIC mode, the code is
867 different, and any byte value is allowed.)
868
869 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
870 START_OPTIMIZE option, which is now allowed at compile time - but just
871 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
872 to pcregrep and other applications that have no direct access to PCRE
873 options. The new /Y option in pcretest sets this option when calling
874 pcre_compile().
875
876 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
877 back references. Groups containing recursive back references were forced to
878 be atomic by that change, but in the case of named groups, the amount of
879 memory required was incorrectly computed, leading to "Failed: internal
880 error: code overflow". This has been fixed.
881
882 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
883 pcretest.c, to avoid build problems in some Borland environments.
884
885
886 Version 8.10 25-Jun-2010
887 ------------------------
888
889 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
890 THEN.
891
892 2. (*ACCEPT) was not working when inside an atomic group.
893
894 3. Inside a character class, \B is treated as a literal by default, but
895 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
896 causes the error). The code is unchanged, but I tidied the documentation.
897
898 4. Inside a character class, PCRE always treated \R and \X as literals,
899 whereas Perl faults them if its -w option is set. I have changed PCRE so
900 that it faults them when PCRE_EXTRA is set.
901
902 5. Added support for \N, which always matches any character other than
903 newline. (It is the same as "." when PCRE_DOTALL is not set.)
904
905 6. When compiling pcregrep with newer versions of gcc which may have
906 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
907 declared with attribute warn_unused_result" were given. Just casting the
908 result to (void) does not stop the warnings; a more elaborate fudge is
909 needed. I've used a macro to implement this.
910
911 7. Minor change to pcretest.c to avoid a compiler warning.
912
913 8. Added four artifical Unicode properties to help with an option to make
914 \s etc use properties (see next item). The new properties are: Xan
915 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
916
917 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
918 use Unicode properties. (*UCP) at the start of a pattern can be used to set
919 this option. Modified pcretest to add /W to test this facility. Added
920 REG_UCP to make it available via the POSIX interface.
921
922 10. Added --line-buffered to pcregrep.
923
924 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
925 studied, and the match started with a letter with a code point greater than
926 127 whose first byte was different to the first byte of the other case of
927 the letter, the other case of this starting letter was not recognized
928 (#976).
929
930 12. If a pattern that was studied started with a repeated Unicode property
931 test, for example, \p{Nd}+, there was the theoretical possibility of
932 setting up an incorrect bitmap of starting bytes, but fortunately it could
933 not have actually happened in practice until change 8 above was made (it
934 added property types that matched character-matching opcodes).
935
936 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
937 possible starting bytes for non-anchored patterns.
938
939 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
940 \R, and also a number of cases that involve Unicode properties, both
941 explicit and implicit when PCRE_UCP is set.
942
943 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
944 input, it could crash or give wrong results if characters with values
945 greater than 0xc0 were present in the subject string. (Detail: it assumed
946 UTF-8 input when processing these items.)
947
948 16. Added a lot of (int) casts to avoid compiler warnings in systems where
949 size_t is 64-bit (#991).
950
951 17. Added a check for running out of memory when PCRE is compiled with
952 --disable-stack-for-recursion (#990).
953
954 18. If the last data line in a file for pcretest does not have a newline on
955 the end, a newline was missing in the output.
956
957 19. The default pcre_chartables.c file recognizes only ASCII characters (values
958 less than 128) in its various bitmaps. However, there is a facility for
959 generating tables according to the current locale when PCRE is compiled. It
960 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
961 characters, are recognized by isspace() and therefore were getting set in
962 these tables, and indeed these tables seem to approximate to ISO 8859. This
963 caused a problem in UTF-8 mode when pcre_study() was used to create a list
964 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
965 which of course cannot start UTF-8 characters. I have changed the code so
966 that only real ASCII characters (less than 128) and the correct starting
967 bytes for UTF-8 encodings are set for characters greater than 127 when in
968 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
969 altogether.)
970
971 20. Added the /T option to pcretest so as to be able to run tests with non-
972 standard character tables, thus making it possible to include the tests
973 used for 19 above in the standard set of tests.
974
975 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
976 reference to a subpattern the other side of a comment that contains an
977 opening parenthesis caused either an internal compiling error, or a
978 reference to the wrong subpattern.
979
980
981 Version 8.02 19-Mar-2010
982 ------------------------
983
984 1. The Unicode data tables have been updated to Unicode 5.2.0.
985
986 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
987 configured.
988
989 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
990 original author of that file, following a query about its status.
991
992 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
993 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
994
995 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
996 quantifier applied to a forward-referencing subroutine call, could compile
997 incorrect code or give the error "internal error: previously-checked
998 referenced subpattern not found".
999
1000 6. Both MS Visual Studio and Symbian OS have problems with initializing
1001 variables to point to external functions. For these systems, therefore,
1002 pcre_malloc etc. are now initialized to local functions that call the
1003 relevant global functions.
1004
1005 7. There were two entries missing in the vectors called coptable and poptable
1006 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1007 I've fixed the data, and added a kludgy way of testing at compile time that
1008 the lengths are correct (equal to the number of opcodes).
1009
1010 8. Following on from 7, I added a similar kludge to check the length of the
1011 eint vector in pcreposix.c.
1012
1013 9. Error texts for pcre_compile() are held as one long string to avoid too
1014 much relocation at load time. To find a text, the string is searched,
1015 counting zeros. There was no check for running off the end of the string,
1016 which could happen if a new error number was added without updating the
1017 string.
1018
1019 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1020
1021 11. \K was not working if it appeared in an atomic group or in a group that
1022 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1023 \K is "not well defined" if used in an assertion. PCRE now accepts it if
1024 the assertion is positive, but not if it is negative.
1025
1026 12. Change 11 fortuitously reduced the size of the stack frame used in the
1027 "match()" function of pcre_exec.c by one pointer. Forthcoming
1028 implementation of support for (*MARK) will need an extra pointer on the
1029 stack; I have reserved it now, so that the stack frame size does not
1030 decrease.
1031
1032 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1033 item in branch that calls a recursion is a subroutine call - as in the
1034 second branch in the above example - was incorrectly given the compile-
1035 time error "recursive call could loop indefinitely" because pcre_compile()
1036 was not correctly checking the subroutine for matching a non-empty string.
1037
1038 14. The checks for overrunning compiling workspace could trigger after an
1039 overrun had occurred. This is a "should never occur" error, but it can be
1040 triggered by pathological patterns such as hundreds of nested parentheses.
1041 The checks now trigger 100 bytes before the end of the workspace.
1042
1043 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1044
1045
1046 Version 8.01 19-Jan-2010
1047 ------------------------
1048
1049 1. If a pattern contained a conditional subpattern with only one branch (in
1050 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1051 computed the wrong minimum data length (which is of course zero for such
1052 subpatterns). This could cause incorrect "no match" results.
1053
1054 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1055 the pattern is reset in the first branch, pcre_compile() failed with
1056 "internal error: code overflow at offset...". This happened only when
1057 the reset was to the original external option setting. (An optimization
1058 abstracts leading options settings into an external setting, which was the
1059 cause of this.)
1060
1061 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1062 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1063 assertion pattern did not match (meaning that the assertion was true), it
1064 was incorrectly treated as false if the SKIP had been reached during the
1065 matching. This also applied to assertions used as conditions.
1066
1067 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
1068 assertion subpattern, including such a pattern used as a condition,
1069 unpredictable results occurred, instead of the error return
1070 PCRE_ERROR_DFA_UITEM.
1071
1072 5. The C++ GlobalReplace function was not working like Perl for the special
1073 situation when an empty string is matched. It now does the fancy magic
1074 stuff that is necessary.
1075
1076 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1077 removed. (These were left over from very, very early versions of PCRE.)
1078
1079 7. Some cosmetic changes to the code to make life easier when compiling it
1080 as part of something else:
1081
1082 (a) Change DEBUG to PCRE_DEBUG.
1083
1084 (b) In pcre_compile(), rename the member of the "branch_chain" structure
1085 called "current" as "current_branch", to prevent a collision with the
1086 Linux macro when compiled as a kernel module.
1087
1088 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1089 prevent a collision with the Linux macro when compiled as a kernel
1090 module.
1091
1092 8. In pcre_compile() there are some checks for integer overflows that used to
1093 cast potentially large values to (double). This has been changed to that
1094 when building, a check for int64_t is made, and if it is found, it is used
1095 instead, thus avoiding the use of floating point arithmetic. (There is no
1096 other use of FP in PCRE.) If int64_t is not found, the fallback is to
1097 double.
1098
1099 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
1100 2005 (difference between two addresses compared to an unsigned value).
1101
1102 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1103 custom one, because of the following reported problem in Windows:
1104
1105 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1106 under Win32.
1107 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1108 therefore missing the function definition.
1109 - The compiler thus generates a "C" signature for the test function.
1110 - The linker fails to find the "C" function.
1111 - PCRE fails to configure if asked to do so against libbz2.
1112
1113 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1114 messages were output:
1115
1116 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1117 rerunning libtoolize, to keep the correct libtool macros in-tree.
1118 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1119
1120 I have done both of these things.
1121
1122 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1123 most of the time, it *can* run out if it is given a pattern that contains a
1124 runaway infinite recursion. I updated the discussion in the pcrestack man
1125 page.
1126
1127 13. Now that we have gone to the x.xx style of version numbers, the minor
1128 version may start with zero. Using 08 or 09 is a bad idea because users
1129 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1130 interpreted as invalid octal numbers. I've updated the previous comment in
1131 configure.ac, and also added a check that gives an error if 08 or 09 are
1132 used.
1133
1134 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1135 causing partial matching to fail when the end of the subject matched \W
1136 in a UTF-8 pattern where \W was quantified with a minimum of 3.
1137
1138 15. There were some discrepancies between the declarations in pcre_internal.h
1139 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1140 their definitions. The declarations used "const uschar *" and the
1141 definitions used USPTR. Even though USPTR is normally defined as "const
1142 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1143 reported that: "This difference in casting confuses some C++ compilers, for
1144 example, SunCC recognizes above declarations as different functions and
1145 generates broken code for hbpcre." I have changed the declarations to use
1146 USPTR.
1147
1148 16. GNU libtool is named differently on some systems. The autogen.sh script now
1149 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1150 (FreeBSD).
1151
1152 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1153 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1154 comment: "Figure out how to create a longlong from a string: strtoll and
1155 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1156 instance, but it only takes 2 args instead of 3!"
1157
1158 18. A subtle bug concerned with back references has been fixed by a change of
1159 specification, with a corresponding code fix. A pattern such as
1160 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1161 refers, was giving matches when it shouldn't. For example, xa=xaaa would
1162 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1163 same bug. Such groups have to be quantified to be useful, or contained
1164 inside another quantified group. (If there's no repetition, the reference
1165 can never match.) The problem arises because, having left the group and
1166 moved on to the rest of the pattern, a later failure that backtracks into
1167 the group uses the captured value from the final iteration of the group
1168 rather than the correct earlier one. I have fixed this in PCRE by forcing
1169 any group that contains a reference to itself to be an atomic group; that
1170 is, there cannot be any backtracking into it once it has completed. This is
1171 similar to recursive and subroutine calls.
1172
1173
1174 Version 8.00 19-Oct-09
1175 ----------------------
1176
1177 1. The table for translating pcre_compile() error codes into POSIX error codes
1178 was out-of-date, and there was no check on the pcre_compile() error code
1179 being within the table. This could lead to an OK return being given in
1180 error.
1181
1182 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1183 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1184 in a Windows environment.
1185
1186 3. The pcregrep --count option prints the count for each file even when it is
1187 zero, as does GNU grep. However, pcregrep was also printing all files when
1188 --files-with-matches was added. Now, when both options are given, it prints
1189 counts only for those files that have at least one match. (GNU grep just
1190 prints the file name in this circumstance, but including the count seems
1191 more useful - otherwise, why use --count?) Also ensured that the
1192 combination -clh just lists non-zero counts, with no names.
1193
1194 4. The long form of the pcregrep -F option was incorrectly implemented as
1195 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1196 but it seems right to fix it, and I didn't think it was worth preserving
1197 the old behaviour.
1198
1199 5. The command line items --regex=pattern and --regexp=pattern were not
1200 recognized by pcregrep, which required --regex pattern or --regexp pattern
1201 (with a space rather than an '='). The man page documented the '=' forms,
1202 which are compatible with GNU grep; these now work.
1203
1204 6. No libpcreposix.pc file was created for pkg-config; there was just
1205 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1206
1207 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1208 when UCP support is not needed, by modifying the Python script that
1209 generates it from Unicode data files. This should not matter if the module
1210 is correctly used as a library, but I received one complaint about 50K of
1211 unwanted data. My guess is that the person linked everything into his
1212 program rather than using a library. Anyway, it does no harm.
1213
1214 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1215 was a minimum greater than 1 for a wide character in a possessive
1216 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1217 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1218 character. Chaos in the form of incorrect output or a compiling loop could
1219 result.
1220
1221 9. The restrictions on what a pattern can contain when partial matching is
1222 requested for pcre_exec() have been removed. All patterns can now be
1223 partially matched by this function. In addition, if there are at least two
1224 slots in the offset vector, the offset of the earliest inspected character
1225 for the match and the offset of the end of the subject are set in them when
1226 PCRE_ERROR_PARTIAL is returned.
1227
1228 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1229 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1230 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1231 and may be more useful for multi-segment matching.
1232
1233 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1234 used to be given if ever the end of the subject was reached; now it is
1235 given only if matching could not proceed because another character was
1236 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1237 string "Z", which now yields "no match" instead of "partial match". In the
1238 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1239 final character ended with (*FAIL).
1240
1241 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1242 if the pattern had a "must contain" character that was already found in the
1243 earlier partial match, unless partial matching was again requested. For
1244 example, with the pattern /dog.(body)?/, the "must contain" character is
1245 "g". If the first part-match was for the string "dog", restarting with
1246 "sbody" failed. This bug has been fixed.
1247
1248 13. The string returned by pcre_dfa_exec() after a partial match has been
1249 changed so that it starts at the first inspected character rather than the
1250 first character of the match. This makes a difference only if the pattern
1251 starts with a lookbehind assertion or \b or \B (\K is not supported by
1252 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1253 matching functions compatible, and I think it's the right thing to do.
1254
1255 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1256 so that the demonstration program is easily available in environments where
1257 PCRE has not been installed from source.
1258
1259 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1260 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1261 library.
1262
1263 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1264 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1265 is not the first non-POSIX option to be added. Clearly some people find
1266 these options useful.
1267
1268 17. If a caller to the POSIX matching function regexec() passes a non-zero
1269 value for nmatch with a NULL value for pmatch, the value of
1270 nmatch is forced to zero.
1271
1272 18. RunGrepTest did not have a test for the availability of the -u option of
1273 the diff command, as RunTest does. It now checks in the same way as
1274 RunTest, and also checks for the -b option.
1275
1276 19. If an odd number of negated classes containing just a single character
1277 interposed, within parentheses, between a forward reference to a named
1278 subpattern and the definition of the subpattern, compilation crashed with
1279 an internal error, complaining that it could not find the referenced
1280 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1281 [The bug was that it was starting one character too far in when skipping
1282 over the character class, thus treating the ] as data rather than
1283 terminating the class. This meant it could skip too much.]
1284
1285 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1286 /g option in pcretest when the pattern contains \K, which makes it possible
1287 to have an empty string match not at the start, even when the pattern is
1288 anchored. Updated pcretest and pcredemo to use this option.
1289
1290 21. If the maximum number of capturing subpatterns in a recursion was greater
1291 than the maximum at the outer level, the higher number was returned, but
1292 with unset values at the outer level. The correct (outer level) value is
1293 now given.
1294
1295 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1296 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1297 make it do so. The string so far is captured, making this feature
1298 compatible with Perl.
1299
1300 23. The tests have been re-organized, adding tests 11 and 12, to make it
1301 possible to check the Perl 5.10 features against Perl 5.10.
1302
1303 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1304 pattern matches a fixed length string. PCRE did not allow this; now it
1305 does. Neither allows recursion.
1306
1307 25. I finally figured out how to implement a request to provide the minimum
1308 length of subject string that was needed in order to match a given pattern.
1309 (It was back references and recursion that I had previously got hung up
1310 on.) This code has now been added to pcre_study(); it finds a lower bound
1311 to the length of subject needed. It is not necessarily the greatest lower
1312 bound, but using it to avoid searching strings that are too short does give
1313 some useful speed-ups. The value is available to calling programs via
1314 pcre_fullinfo().
1315
1316 26. While implementing 25, I discovered to my embarrassment that pcretest had
1317 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1318 study optimizations had never been tested with that matching function.
1319 Oops. What is worse, even when it was passed study data, there was a bug in
1320 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1321 were also very few tests of studied patterns with pcre_dfa_exec().
1322
1323 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1324 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1325 on the other side of the coin, they are no longer allowed to have different
1326 names, because these cannot be distinguished in PCRE, and this has caused
1327 confusion. (This is a difference from Perl.)
1328
1329 28. When duplicate subpattern names are present (necessarily with different
1330 numbers, as required by 27 above), and a test is made by name in a
1331 conditional pattern, either for a subpattern having been matched, or for
1332 recursion in such a pattern, all the associated numbered subpatterns are
1333 tested, and the overall condition is true if the condition is true for any
1334 one of them. This is the way Perl works, and is also more like the way
1335 testing by number works.
1336
1337
1338 Version 7.9 11-Apr-09
1339 ---------------------
1340
1341 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1342 (pcretest), all targets were linked against these libraries. This included
1343 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1344 libraries. This caused unwanted dependencies to be created. This problem
1345 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1346 pcretest is linked with readline.
1347
1348 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1349 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1350 moved outside it again, because FALSE and TRUE are already defined in AIX,
1351 but BOOL is not.
1352
1353 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1354 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1355
1356 4. The pcregrep documentation said spaces were inserted as well as colons (or
1357 hyphens) following file names and line numbers when outputting matching
1358 lines. This is not true; no spaces are inserted. I have also clarified the
1359 wording for the --colour (or --color) option.
1360
1361 5. In pcregrep, when --colour was used with -o, the list of matching strings
1362 was not coloured; this is different to GNU grep, so I have changed it to be
1363 the same.
1364
1365 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1366 each matching line was coloured. Now it goes on to look for further matches
1367 of any of the test patterns, which is the same behaviour as GNU grep.
1368
1369 7. A pattern that could match an empty string could cause pcregrep to loop; it
1370 doesn't make sense to accept an empty string match in pcregrep, so I have
1371 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1372 seems to be how GNU grep behaves.
1373
1374 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1375 start or after a newline", because the conditional assertion was not being
1376 correctly handled. The rule now is that both the assertion and what follows
1377 in the first alternative must satisfy the test.
1378
1379 9. If auto-callout was enabled in a pattern with a conditional group whose
1380 condition was an assertion, PCRE could crash during matching, both with
1381 pcre_exec() and pcre_dfa_exec().
1382
1383 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1384 used for matching.
1385
1386 11. Unicode property support in character classes was not working for
1387 characters (bytes) greater than 127 when not in UTF-8 mode.
1388
1389 12. Added the -M command line option to pcretest.
1390
1391 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1392
1393 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1394
1395 16. Added comments and documentation about mis-use of no_arg in the C++
1396 wrapper.
1397
1398 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1399 from Martin Jerabek that uses macro names for all relevant character and
1400 string constants.
1401
1402 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1403 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1404 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1405 these, but not everybody uses configure.
1406
1407 19. A conditional group that had only one branch was not being correctly
1408 recognized as an item that could match an empty string. This meant that an
1409 enclosing group might also not be so recognized, causing infinite looping
1410 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1411 with the subject "ab", where knowledge that the repeated group can match
1412 nothing is needed in order to break the loop.
1413
1414 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1415 exec(), but without supplying a callout function, matching went wrong.
1416
1417 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1418 leak if the size of the offset vector was greater than 30. When the vector
1419 is smaller, the saved offsets during recursion go onto a local stack
1420 vector, but for larger vectors malloc() is used. It was failing to free
1421 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1422 error, in fact).
1423
1424 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1425 heapframe that is used only when UTF-8 support is enabled. This caused no
1426 problem, but was untidy.
1427
1428 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1429 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1430 included within another project.
1431
1432 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1433 slightly modified by me:
1434
1435 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1436 not building pcregrep.
1437
1438 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1439 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1440
1441 25. Forward references, both numeric and by name, in patterns that made use of
1442 duplicate group numbers, could behave incorrectly or give incorrect errors,
1443 because when scanning forward to find the reference group, PCRE was not
1444 taking into account the duplicate group numbers. A pattern such as
1445 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1446
1447 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1448 the feature of a custom pointer more persuasive (as requested by a user).
1449
1450 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1451 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1452 pre-defined.
1453
1454 28. Added support for (*UTF8) at the start of a pattern.
1455
1456 29. Arrange for flags added by the "release type" setting in CMake to be shown
1457 in the configuration summary.
1458
1459
1460 Version 7.8 05-Sep-08
1461 ---------------------
1462
1463 1. Replaced UCP searching code with optimized version as implemented for Ad
1464 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1465 stage table and inline lookup instead of a function, giving speed ups of 2
1466 to 5 times on some simple patterns that I tested. Permission was given to
1467 distribute the MultiStage2.py script that generates the tables (it's not in
1468 the tarball, but is in the Subversion repository).
1469
1470 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1471 scripts.
1472
1473 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1474 a group with a zero qualifier. The result of the study could be incorrect,
1475 or the function might crash, depending on the pattern.
1476
1477 4. Caseless matching was not working for non-ASCII characters in back
1478 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1479 It now works when Unicode Property Support is available.
1480
1481 5. In pcretest, an escape such as \x{de} in the data was always generating
1482 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1483 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1484 truncation.
1485
1486 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1487
1488 7. Added two (int) casts to pcregrep when printing the difference of two
1489 pointers, in case they are 64-bit values.
1490
1491 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1492 test 2 if it fails.
1493
1494 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1495 and a #define of that name to empty if it is not externally set. This is to
1496 allow users of MSVC to set it if necessary.
1497
1498 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1499 the convenience functions in the pcre_get.c source file.
1500
1501 11. An option change at the start of a pattern that had top-level alternatives
1502 could cause overwriting and/or a crash. This command provoked a crash in
1503 some environments:
1504
1505 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1506
1507 This potential security problem was recorded as CVE-2008-2371.
1508
1509 12. For a pattern where the match had to start at the beginning or immediately
1510 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1511 pcre_dfa_exec() could read past the end of the passed subject if there was
1512 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1513 pcretest so that it places the subject at the end of its malloc-ed buffer.
1514
1515 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1516 exec() might read past the end of the data buffer in UTF-8 mode.
1517
1518 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1519 the data contained the byte 0x85 as part of a UTF-8 character within its
1520 first line. This applied both to normal and DFA matching.
1521
1522 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1523 /^[^d]*?$/8 failed to match "abc".
1524
1525 16. Added a missing copyright notice to pcrecpp_internal.h.
1526
1527 17. Make it more clear in the documentation that values returned from
1528 pcre_exec() in ovector are byte offsets, not character counts.
1529
1530 18. Tidied a few places to stop certain compilers from issuing warnings.
1531
1532 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1533 supplied by Stefan Weber. I made a further small update for 7.8 because
1534 there is a change of source arrangements: the pcre_searchfuncs.c module is
1535 replaced by pcre_ucd.c.
1536
1537
1538 Version 7.7 07-May-08
1539 ---------------------
1540
1541 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1542 a string to a long long, pretend we don't even have a long long." This is
1543 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1544
1545 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1546 pre-7.6 versions, which defined a global no_arg variable instead of putting
1547 it in the RE class. (See also #8 below.)
1548
1549 3. Remove a line of dead code, identified by coverity and reported by Nuno
1550 Lopes.
1551
1552 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1553
1554 (1) The include/exclude patterns were being applied to the whole pathnames
1555 of files, instead of just to the final components.
1556
1557 (2) If there was more than one level of directory, the subdirectories were
1558 skipped unless they satisfied the include/exclude conditions. This is
1559 inconsistent with GNU grep (and could even be seen as contrary to the
1560 pcregrep specification - which I improved to make it absolutely clear).
1561 The action now is always to scan all levels of directory, and just
1562 apply the include/exclude patterns to regular files.
1563
1564 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1565 --exclude_dir in the tests to avoid scanning .svn directories.
1566
1567 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1568 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1569 doesn't support NULs in patterns.
1570
1571 7. Added some missing "const"s to declarations of static tables in
1572 pcre_compile.c and pcre_dfa_exec.c.
1573
1574 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1575 caused by fix #2 above. (Subsequently also a second patch to fix the
1576 first patch. And a third patch - this was a messy problem.)
1577
1578 9. Applied Craig's patch to remove the use of push_back().
1579
1580 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1581 matching function regexec().
1582
1583 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1584 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1585 references. PCRE supports relative numbers with this syntax (I don't think
1586 Oniguruma does).
1587
1588 12. Previously, a group with a zero repeat such as (...){0} was completely
1589 omitted from the compiled regex. However, this means that if the group
1590 was called as a subroutine from elsewhere in the pattern, things went wrong
1591 (an internal error was given). Such groups are now left in the compiled
1592 pattern, with a new opcode that causes them to be skipped at execution
1593 time.
1594
1595 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1596 to the way PCRE behaves:
1597
1598 (a) A lone ] character is dis-allowed (Perl treats it as data).
1599
1600 (b) A back reference to an unmatched subpattern matches an empty string
1601 (Perl fails the current match path).
1602
1603 (c) A data ] in a character class must be notated as \] because if the
1604 first data character in a class is ], it defines an empty class. (In
1605 Perl it is not possible to have an empty class.) The empty class []
1606 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1607 The negative empty class [^] matches any one character, independently
1608 of the DOTALL setting.
1609
1610 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1611 non-existent subpattern following a character class starting with ']' and
1612 containing () gave an internal compiling error instead of "reference to
1613 non-existent subpattern". Fortunately, when the pattern did exist, the
1614 compiled code was correct. (When scanning forwards to check for the
1615 existencd of the subpattern, it was treating the data ']' as terminating
1616 the class, so got the count wrong. When actually compiling, the reference
1617 was subsequently set up correctly.)
1618
1619 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1620 it was being rejected as not supported by pcre_dfa_exec(), even though
1621 other assertions are supported. I have made pcre_dfa_exec() support
1622 (*FAIL).
1623
1624 16. The implementation of 13c above involved the invention of a new opcode,
1625 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1626 cannot be changed at match time, I realized I could make a small
1627 improvement to matching performance by compiling OP_ALLANY instead of
1628 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1629 on the OP_ANY path.
1630
1631 17. Compiling pcretest on Windows with readline support failed without the
1632 following two fixes: (1) Make the unistd.h include conditional on
1633 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1634
1635 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1636 ncurses library to be included for pcretest when ReadLine support is
1637 requested, but also to allow for it to be overridden. This patch came from
1638 Daniel Bergström.
1639
1640 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1641 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1642 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1643 spotting this.
1644
1645
1646 Version 7.6 28-Jan-08
1647 ---------------------
1648
1649 1. A character class containing a very large number of characters with
1650 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1651 overflow.
1652
1653 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1654 HAVE_LONG_LONG is not defined.
1655
1656 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1657 bring them up to date and include new features. This patch includes:
1658
1659 - Fixed PH's badly added libz and libbz2 support.
1660 - Fixed a problem with static linking.
1661 - Added pcredemo. [But later removed - see 7 below.]
1662 - Fixed dftables problem and added an option.
1663 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1664 HAVE_LONG_LONG.
1665 - Added readline support for pcretest.
1666 - Added an listing of the option settings after cmake has run.
1667
1668 4. A user submitted a patch to Makefile that makes it easy to create
1669 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1670 Makefile.am that cause it to include this special target, without
1671 affecting anything else. Note that the same mingw target plus all
1672 the other distribution libraries and programs are now supported
1673 when configuring with CMake (see 6 below) instead of with
1674 Configure/Make.
1675
1676 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1677 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1678 exported in the Windows port". It has not yet been confirmed that the patch
1679 solves the problem, but it does no harm.
1680
1681 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1682 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1683 with CMake, and also correct the comment about stack recursion.
1684
1685 7. Remove the automatic building of pcredemo from the ./configure system and
1686 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1687 of a program that users should build themselves after PCRE is installed, so
1688 building it automatically is not really right. What is more, it gave
1689 trouble in some build environments.
1690
1691 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1692
1693
1694 Version 7.5 10-Jan-08
1695 ---------------------
1696
1697 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1698 values in parens when parsing an RE using the C++ wrapper."
1699
1700 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1701 Characters greater than 255 were excluded from the class instead of being
1702 included.
1703
1704 3. The same bug as (2) above applied to negated POSIX classes such as
1705 [:^space:].
1706
1707 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1708 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1709 I have changed it.
1710
1711 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1712 first named subpattern) and a construct such as (?&a) would reference the
1713 first named subpattern whose name started with "a" (in other words, the
1714 length check was missing). Both these problems are fixed. "Subpattern name
1715 expected" is now given for (?&) (a zero-length name), and this patch also
1716 makes it give the same error for \k'' (previously it complained that that
1717 was a reference to a non-existent subpattern).
1718
1719 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1720 this is right because (?- can be followed by option settings as well as by
1721 digits. I have, however, made the messages clearer.
1722
1723 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1724 than the number used in the conditional) now cause a compile-time error.
1725 This is actually not compatible with Perl, which accepts such patterns, but
1726 treats the conditional as always being FALSE (as PCRE used to), but it
1727 seems to me that giving a diagnostic is better.
1728
1729 8. Change "alphameric" to the more common word "alphanumeric" in comments
1730 and messages.
1731
1732 9. Fix two occurrences of "backslash" in comments that should have been
1733 "backspace".
1734
1735 10. Remove two redundant lines of code that can never be obeyed (their function
1736 was moved elsewhere).
1737
1738 11. The program that makes PCRE's Unicode character property table had a bug
1739 which caused it to generate incorrect table entries for sequences of
1740 characters that have the same character type, but are in different scripts.
1741 It amalgamated them into a single range, with the script of the first of
1742 them. In other words, some characters were in the wrong script. There were
1743 thirteen such cases, affecting characters in the following ranges:
1744
1745 U+002b0 - U+002c1
1746 U+0060c - U+0060d
1747 U+0061e - U+00612
1748 U+0064b - U+0065e
1749 U+0074d - U+0076d
1750 U+01800 - U+01805
1751 U+01d00 - U+01d77
1752 U+01d9b - U+01dbf
1753 U+0200b - U+0200f
1754 U+030fc - U+030fe
1755 U+03260 - U+0327f
1756 U+0fb46 - U+0fbb1
1757 U+10450 - U+1049d
1758
1759 12. The -o option (show only the matching part of a line) for pcregrep was not
1760 compatible with GNU grep in that, if there was more than one match in a
1761 line, it showed only the first of them. It now behaves in the same way as
1762 GNU grep.
1763
1764 13. If the -o and -v options were combined for pcregrep, it printed a blank
1765 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1766 does the same. The return code can be used to tell if there were any
1767 non-matching lines.
1768
1769 14. Added --file-offsets and --line-offsets to pcregrep.
1770
1771 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1772 infinitely looping recursion. The bug was that positive lookaheads were not
1773 being skipped when checking for a possible empty match (negative lookaheads
1774 and both kinds of lookbehind were skipped).
1775
1776 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1777 inclusion of <windows.h> to before rather than after the definition of
1778 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1779
1780 17. Specifying a possessive quantifier with a specific limit for a Unicode
1781 character property caused pcre_compile() to compile bad code, which led at
1782 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1783 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1784 caused the error; without that there was no problem.
1785
1786 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1787
1788 19. Added --enable-pcretest-libreadline.
1789
1790 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1791 RE::GlobalReplace(). As a result, the number of replacements returned was
1792 double what it should be. I removed one of the increments, but Craig sent a
1793 later patch that removed the other one (the right fix) and added unit tests
1794 that check the return values (which was not done before).
1795
1796 21. Several CMake things:
1797
1798 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1799 the names libpcre and libpcreposix, not just pcre and pcreposix.
1800
1801 (2) The above change means that pcretest and pcregrep are now correctly
1802 linked with the newly-built libraries, not previously installed ones.
1803
1804 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1805
1806 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1807 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1808 UTF-8 newline character). The key issue is that the pattern starts .*;
1809 this means that the match must be either at the beginning, or after a
1810 newline. The bug was in the code for advancing after a failed match and
1811 checking that the new position followed a newline. It was not taking
1812 account of UTF-8 characters correctly.
1813
1814 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1815 character classes. PCRE was not treating the sequence [:...:] as a
1816 character class unless the ... were all letters. Perl, however, seems to
1817 allow any characters between [: and :], though of course it rejects as
1818 unknown any "names" that contain non-letters, because all the known class
1819 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1820 for example, whereas PCRE did not - it did not recognize a POSIX character
1821 class. This seemed a bit dangerous, so the code has been changed to be
1822 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1823 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1824 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1825 Perl does, and where it didn't before.
1826
1827 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1828 Windows environments %n is disabled by default.
1829
1830
1831 Version 7.4 21-Sep-07
1832 ---------------------
1833
1834 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1835 means that a class such as [\s] counted as "explicit reference to CR or
1836 LF". That isn't really right - the whole point of the change was to try to
1837 help when there was an actual mention of one of the two characters. So now
1838 the change happens only if \r or \n (or a literal CR or LF) character is
1839 encountered.
1840
1841 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1842 of both had grown to the point where there were only 3 bits left.
1843 Fortunately, there was spare space in the data structure, and so I have
1844 moved the internal flags into a new 16-bit field to free up more option
1845 bits.
1846
1847 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1848 but did not set the internal JCHANGED flag - either of these is enough to
1849 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1850 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1851 start sets both bits.
1852
1853 4. Added options (at build time, compile time, exec time) to change \R from
1854 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1855
1856 5. doc/pcresyntax.html was missing from the distribution.
1857
1858 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1859 compatibility, even though it is no longer used.
1860
1861 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1862 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1863 windows.h file is present (where different names are used). [This was
1864 reversed later after testing - see 16 below.]
1865
1866 8. Changed all #include <config.h> to #include "config.h". There were also
1867 some further <pcre.h> cases that I changed to "pcre.h".
1868
1869 9. When pcregrep was used with the --colour option, it missed the line ending
1870 sequence off the lines that it output.
1871
1872 10. It was pointed out to me that arrays of string pointers cause lots of
1873 relocations when a shared library is dynamically loaded. A technique of
1874 using a single long string with a table of offsets can drastically reduce
1875 these. I have refactored PCRE in four places to do this. The result is
1876 dramatic:
1877
1878 Originally: 290
1879 After changing UCP table: 187
1880 After changing error message table: 43
1881 After changing table of "verbs" 36
1882 After changing table of Posix names 22
1883
1884 Thanks to the folks working on Gregex for glib for this insight.
1885
1886 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1887 unicode-properties was also set.
1888
1889 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1890
1891 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1892 checked only for CRLF.
1893
1894 14. Added casts to pcretest.c to avoid compiler warnings.
1895
1896 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1897
1898 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1899 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1900 entirely. This removes changes made in 7 above.
1901
1902 17. The CMake files have been updated, and there is now more information about
1903 building with CMake in the NON-UNIX-USE document.
1904
1905
1906 Version 7.3 28-Aug-07
1907 ---------------------
1908
1909 1. In the rejigging of the build system that eventually resulted in 7.1, the
1910 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1911 brackets there is not right, since it causes compilers to look for an
1912 installed pcre.h, not the version that is in the source that is being
1913 compiled (which of course may be different). I have changed it back to:
1914
1915 #include "pcre.h"
1916
1917 I have a vague recollection that the change was concerned with compiling in
1918 different directories, but in the new build system, that is taken care of
1919 by the VPATH setting the Makefile.
1920
1921 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1922 when the subject happened to end in the byte 0x85 (e.g. if the last
1923 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1924 characters but of course it shouldn't be taken as a newline when it is part
1925 of another character. The bug was that, for an unlimited repeat of . in
1926 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1927 characters when looking for a newline.
1928
1929 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1930
1931 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1932 in debug output.
1933
1934 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1935 long printing in the pcrecpp unittest when running under MinGW.
1936
1937 6. ESC_K was left out of the EBCDIC table.
1938
1939 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1940 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1941 limit also applies to "virtual nesting" when a pattern is recursive, and in
1942 this case 1000 isn't so big. I have been able to remove this limit at the
1943 expense of backing off one optimization in certain circumstances. Normally,
1944 when pcre_exec() would call its internal match() function recursively and
1945 immediately return the result unconditionally, it uses a "tail recursion"
1946 feature to save stack. However, when a subpattern that can match an empty
1947 string has an unlimited repetition quantifier, it no longer makes this
1948 optimization. That gives it a stack frame in which to save the data for
1949 checking that an empty string has been matched. Previously this was taken
1950 from the 1000-entry workspace that had been reserved. So now there is no
1951 explicit limit, but more stack is used.
1952
1953 8. Applied Daniel's patches to solve problems with the import/export magic
1954 syntax that is required for Windows, and which was going wrong for the
1955 pcreposix and pcrecpp parts of the library. These were overlooked when this
1956 problem was solved for the main library.
1957
1958 9. There were some crude static tests to avoid integer overflow when computing
1959 the size of patterns that contain repeated groups with explicit upper
1960 limits. As the maximum quantifier is 65535, the maximum group length was
1961 set at 30,000 so that the product of these two numbers did not overflow a
1962 32-bit integer. However, it turns out that people want to use groups that
1963 are longer than 30,000 bytes (though not repeat them that many times).
1964 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1965 made it possible to implement the integer overflow checks in a much more
1966 dynamic way, which I have now done. The artificial limitation on group
1967 length has been removed - we now have only the limit on the total length of
1968 the compiled pattern, which depends on the LINK_SIZE setting.
1969
1970 10. Fixed a bug in the documentation for get/copy named substring when
1971 duplicate names are permitted. If none of the named substrings are set, the
1972 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1973 empty string.
1974
1975 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1976 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1977 because the ] is interpreted as the first data character and the
1978 terminating ] is not found. PCRE has been made compatible with Perl in this
1979 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1980 cause memory overwriting.
1981
1982 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1983 string has been matched (to stop an infinite loop). It was not recognizing
1984 a conditional subpattern that could match an empty string if that
1985 subpattern was within another subpattern. For example, it looped when
1986 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1987 condition was not nested. This bug has been fixed.
1988
1989 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1990 past the start of the subject in the presence of bytes with the top bit
1991 set, for example "\x8aBCD".
1992
1993 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1994 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1995
1996 14. Optimized (?!) to (*FAIL).
1997
1998 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1999 This restricts code points to be within the range 0 to 0x10FFFF, excluding
2000 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2001 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2002 does: it's just the validity check that is more restrictive.
2003
2004 16. Inserted checks for integer overflows during escape sequence (backslash)
2005 processing, and also fixed erroneous offset values for syntax errors during
2006 backslash processing.
2007
2008 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2009 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2010
2011 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2012 caused an overrun.
2013
2014 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2015 something other than just ASCII characters) inside a group that had an
2016 unlimited repeat caused a loop at compile time (while checking to see
2017 whether the group could match an empty string).
2018
2019 20. Debugging a pattern containing \p or \P could cause a crash. For example,
2020 [\P{Any}] did so. (Error in the code for printing property names.)
2021
2022 21. An orphan \E inside a character class could cause a crash.
2023
2024 22. A repeated capturing bracket such as (A)? could cause a wild memory
2025 reference during compilation.
2026
2027 23. There are several functions in pcre_compile() that scan along a compiled
2028 expression for various reasons (e.g. to see if it's fixed length for look
2029 behind). There were bugs in these functions when a repeated \p or \P was
2030 present in the pattern. These operators have additional parameters compared
2031 with \d, etc, and these were not being taken into account when moving along
2032 the compiled data. Specifically:
2033
2034 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2035 length.
2036
2037 (b) An item such as \pL+ within a repeated group could cause crashes or
2038 loops.
2039
2040 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2041 "reference to non-existent subpattern" error.
2042
2043 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2044
2045 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2046 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2047
2048 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2049
2050 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2051 character were causing crashes (broken optimization).
2052
2053 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2054 \p or \P) caused a compile-time loop.
2055
2056 28. More problems have arisen in unanchored patterns when CRLF is a valid line
2057 break. For example, the unstudied pattern [\r\n]A does not match the string
2058 "\r\nA" because change 7.0/46 below moves the current point on by two
2059 characters after failing to match at the start. However, the pattern \nA
2060 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2061 the same is true. There doesn't seem any very clean way out of this, but
2062 what I have chosen to do makes the common cases work: PCRE now takes note
2063 of whether there can be an explicit match for \r or \n anywhere in the
2064 pattern, and if so, 7.0/46 no longer applies. As part of this change,
2065 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2066 pattern has explicit CR or LF references.
2067
2068 29. Added (*CR) etc for changing newline setting at start of pattern.
2069
2070
2071 Version 7.2 19-Jun-07
2072 ---------------------
2073
2074 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2075 which is apparently normally available under Windows.
2076
2077 2. Re-jig the pcregrep tests with different newline settings in an attempt
2078 to make them independent of the local environment's newline setting.
2079
2080 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2081
2082 4. Some of the "internals" tests were previously cut out when the link size
2083 was not 2, because the output contained actual offsets. The recent new
2084 "Z" feature of pcretest means that these can be cut out, making the tests
2085 usable with all link sizes.
2086
2087 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2088 stack recursion. This gives a massive performance boost under BSD, but just
2089 a small improvement under Linux. However, it saves one field in the frame
2090 in all cases.
2091
2092 6. Added more features from the forthcoming Perl 5.10:
2093
2094 (a) (?-n) (where n is a string of digits) is a relative subroutine or
2095 recursion call. It refers to the nth most recently opened parentheses.
2096
2097 (b) (?+n) is also a relative subroutine call; it refers to the nth next
2098 to be opened parentheses.
2099
2100 (c) Conditions that refer to capturing parentheses can be specified
2101 relatively, for example, (?(-2)... or (?(+3)...
2102
2103 (d) \K resets the start of the current match so that everything before
2104 is not part of it.
2105
2106 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2107
2108 (f) \g{name} is another synonym - part of Perl 5.10's unification of
2109 reference syntax.
2110
2111 (g) (?| introduces a group in which the numbering of parentheses in each
2112 alternative starts with the same number.
2113
2114 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2115
2116 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2117 PCRE_INFO_JCHANGED.
2118
2119 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
2120 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2121 for detecting groups that can match an empty string.
2122
2123 9. A pattern with a very large number of alternatives (more than several
2124 hundred) was running out of internal workspace during the pre-compile
2125 phase, where pcre_compile() figures out how much memory will be needed. A
2126 bit of new cunning has reduced the workspace needed for groups with
2127 alternatives. The 1000-alternative test pattern now uses 12 bytes of
2128 workspace instead of running out of the 4096 that are available.
2129
2130 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2131
2132 11. Applied patch from Google to remove an optimization that didn't quite work.
2133 The report of the bug said:
2134
2135 pcrecpp::RE("a*").FullMatch("aaa") matches, while
2136 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2137 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2138
2139 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2140 it matched the wrong number of bytes.
2141
2142
2143 Version 7.1 24-Apr-07
2144 ---------------------
2145
2146 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2147 that is more "standard", making use of automake and other Autotools. There
2148 is some re-arrangement of the files and adjustment of comments consequent
2149 on this.
2150
2151 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2152 for recursive directory scanning broke on some systems because the files
2153 are not scanned in any specific order and on different systems the order
2154 was different. A call to "sort" has been inserted into RunGrepTest for the
2155 approprate test as a short-term fix. In the longer term there may be an
2156 alternative.
2157
2158 3. I had an email from Eric Raymond about problems translating some of PCRE's
2159 man pages to HTML (despite the fact that I distribute HTML pages, some
2160 people do their own conversions for various reasons). The problems
2161 concerned the use of low-level troff macros .br and .in. I have therefore
2162 removed all such uses from the man pages (some were redundant, some could
2163 be replaced by .nf/.fi pairs). The 132html script that I use to generate
2164 HTML has been updated to handle .nf/.fi and to complain if it encounters
2165 .br or .in.
2166
2167 4. Updated comments in configure.ac that get placed in config.h.in and also
2168 arranged for config.h to be included in the distribution, with the name
2169 config.h.generic, for the benefit of those who have to compile without
2170 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2171
2172 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2173 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2174 makevp.bat for the current PCRE, using the additional files
2175 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2176
2177 6. A Windows user reported a minor discrepancy with test 2, which turned out
2178 to be caused by a trailing space on an input line that had got lost in his
2179 copy. The trailing space was an accident, so I've just removed it.
2180
2181 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2182 that is needed.
2183
2184 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2185 as "const" (a) because they are and (b) because it helps the PHP
2186 maintainers who have recently made a script to detect big data structures
2187 in the php code that should be moved to the .rodata section. I remembered
2188 to update Builducptable as well, so it won't revert if ucptable.h is ever
2189 re-created.
2190
2191 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2192 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2193 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2194 support is not required. This saves 1.5-2K of code, which is important in
2195 some applications.
2196
2197 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2198 so as not to refer to the tables, even though these functions will never be
2199 called when UTF-8 support is disabled. Otherwise there are problems with a
2200 shared library.
2201
2202 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2203
2204 (a) It was defining its arguments as char * instead of void *.
2205
2206 (b) It was assuming that all moves were upwards in memory; this was true
2207 a long time ago when I wrote it, but is no longer the case.
2208
2209 The emulated memove() is provided for those environments that have neither
2210 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2211 is clearly not the case, as these two bugs were recently reported.
2212
2213 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2214 and Detrail to create the HTML documentation, the .txt form of the man
2215 pages, and it removes trailing spaces from listed files. It also creates
2216 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2217 case, it wraps all the #defines with #ifndefs. This script should be run
2218 before "make dist".
2219
2220 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2221 with Unicode property support.
2222
2223 (a) For a maximizing quantifier, if the two different cases of the
2224 character were of different lengths in their UTF-8 codings (there are
2225 some cases like this - I found 11), and the matching function had to
2226 back up over a mixture of the two cases, it incorrectly assumed they
2227 were both the same length.
2228
2229 (b) When PCRE was configured to use the heap rather than the stack for
2230 recursion during matching, it was not correctly preserving the data for
2231 the other case of a UTF-8 character when checking ahead for a match
2232 while processing a minimizing repeat. If the check also involved
2233 matching a wide character, but failed, corruption could cause an
2234 erroneous result when trying to check for a repeat of the original
2235 character.
2236
2237 13. Some tidying changes to the testing mechanism:
2238
2239 (a) The RunTest script now detects the internal link size and whether there
2240 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2241 values substituted by "configure". (The RunGrepTest script already did
2242 this for UTF-8.) The configure.ac script no longer substitutes the
2243 relevant variables.
2244
2245 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2246 with length and offset values. This means that the output is different
2247 for different internal link sizes. Test 2 is skipped for link sizes
2248 other than 2 because of this, bypassing the problem. Unfortunately,
2249 there was also a test in test 3 (the locale tests) that used /B and
2250 failed for link sizes other than 2. Rather than cut the whole test out,
2251 I have added a new /Z option to pcretest that replaces the length and
2252 offset values with spaces. This is now used to make test 3 independent
2253 of link size. (Test 2 will be tidied up later.)
2254
2255 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2256 segmentation fault instead of returning the appropriate error message.
2257
2258 15. In multiline mode when the newline sequence was set to "any", the pattern
2259 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2260 This doesn't seem right; it now treats the CRLF combination as the line
2261 ending, and so does not match in that case. It's only a pattern such as ^$
2262 that would hit this one: something like ^ABC$ would have failed after \r
2263 and then tried again after \r\n.
2264
2265 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2266 in an attempt to make files that differ only in their line terminators
2267 compare equal. This works on Linux.
2268
2269 17. Under certain error circumstances pcregrep might try to free random memory
2270 as it exited. This is now fixed, thanks to valgrind.
2271
2272 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2273 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2274 was because its rules for how to advance for /g after matching an empty
2275 string at the end of a line did not allow for this case. They now check for
2276 it specially.
2277
2278 20. pcretest is supposed to handle patterns and data of any length, by
2279 extending its buffers when necessary. It was getting this wrong when the
2280 buffer for a data line had to be extended.
2281
2282 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2283 CRLF as a newline sequence.
2284
2285 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2286 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2287 I have nevertheless tidied it up.
2288
2289 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2290
2291 24. Added a man page for pcre-config.
2292
2293
2294 Version 7.0 19-Dec-06
2295 ---------------------
2296
2297 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2298 moving to gcc 4.1.1.
2299
2300 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2301 sys/time.h, which is documented as needed for this function. It doesn't
2302 seem to matter on Linux, but it showed up on some releases of OS X.
2303
2304 3. It seems that there are systems where bytes whose values are greater than
2305 127 match isprint() in the "C" locale. The "C" locale should be the
2306 default when a C program starts up. In most systems, only ASCII printing
2307 characters match isprint(). This difference caused the output from pcretest
2308 to vary, making some of the tests fail. I have changed pcretest so that:
2309
2310 (a) When it is outputting text in the compiled version of a pattern, bytes
2311 other than 32-126 are always shown as hex escapes.
2312
2313 (b) When it is outputting text that is a matched part of a subject string,
2314 it does the same, unless a different locale has been set for the match
2315 (using the /L modifier). In this case, it uses isprint() to decide.
2316
2317 4. Fixed a major bug that caused incorrect computation of the amount of memory
2318 required for a compiled pattern when options that changed within the
2319 pattern affected the logic of the preliminary scan that determines the
2320 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2321 that the computed length was too small. The symptoms of this bug were
2322 either the PCRE error "internal error: code overflow" from pcre_compile(),
2323 or a glibc crash with a message such as "pcretest: free(): invalid next
2324 size (fast)". Examples of patterns that provoked this bug (shown in
2325 pcretest format) are:
2326
2327 /(?-x: )/x
2328 /(?x)(?-x: \s*#\s*)/
2329 /((?i)[\x{c0}])/8
2330 /(?i:[\x{c0}])/8
2331
2332 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2333 is now done differently.
2334
2335 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2336 wrapper classes; (b) implement a new function in the C++ scanner that is
2337 more efficient than the old way of doing things because it avoids levels of
2338 recursion in the regex matching; (c) add a paragraph to the documentation
2339 for the FullMatch() function.
2340
2341 6. The escape sequence \n was being treated as whatever was defined as
2342 "newline". Not only was this contrary to the documentation, which states
2343 that \n is character 10 (hex 0A), but it also went horribly wrong when
2344 "newline" was defined as CRLF. This has been fixed.
2345
2346 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2347 was being set to -1 for the "end of line" case (supposedly a value that no
2348 character can have). Though this value is never used (the check for end of
2349 line is "zero bytes in current character"), it caused compiler complaints.
2350 I've changed it to 0xffffffff.
2351
2352 8. In pcre_version.c, the version string was being built by a sequence of
2353 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2354 string (as it is for production releases) called a macro with an empty
2355 argument. The C standard says the result of this is undefined. The gcc
2356 compiler treats it as an empty string (which was what was wanted) but it is
2357 reported that Visual C gives an error. The source has been hacked around to
2358 avoid this problem.
2359
2360 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2361 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2362 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2363 of them did).
2364
2365 10. Originally, pcretest opened its input and output without "b"; then I was
2366 told that "b" was needed in some environments, so it was added for release
2367 5.0 to both the input and output. (It makes no difference on Unix-like
2368 systems.) Later I was told that it is wrong for the input on Windows. I've
2369 now abstracted the modes into two macros, to make it easier to fiddle with
2370 them, and removed "b" from the input mode under Windows.
2371
2372 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2373
2374 12. Added -help and --help to pcretest as an official way of being reminded
2375 of the options.
2376
2377 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2378 and pcrecpp.cc because they annoy compilers at high warning levels.
2379
2380 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2381
2382 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2383 scripts are not C programs :-) and which was not noticed because it works
2384 on Linux.
2385
2386 16. pcretest is supposed to handle any length of pattern and data line (as one
2387 line or as a continued sequence of lines) by extending its input buffer if
2388 necessary. This feature was broken for very long pattern lines, leading to
2389 a string of junk being passed to pcre_compile() if the pattern was longer
2390 than about 50K.
2391
2392 17. I have done a major re-factoring of the way pcre_compile() computes the
2393 amount of memory needed for a compiled pattern. Previously, there was code
2394 that made a preliminary scan of the pattern in order to do this. That was
2395 OK when PCRE was new, but as the facilities have expanded, it has become
2396 harder and harder to keep it in step with the real compile phase, and there
2397 have been a number of bugs (see for example, 4 above). I have now found a
2398 cunning way of running the real compile function in a "fake" mode that
2399 enables it to compute how much memory it would need, while actually only
2400 ever using a few hundred bytes of working memory and without too many
2401 tests of the mode. This should make future maintenance and development
2402 easier. A side effect of this work is that the limit of 200 on the nesting
2403 depth of parentheses has been removed (though this was never a serious
2404 limitation, I suspect). However, there is a downside: pcre_compile() now
2405 runs more slowly than before (30% or more, depending on the pattern). I
2406 hope this isn't a big issue. There is no effect on runtime performance.
2407
2408 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2409 newline (only possible for the last line of a file) and it was a
2410 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2411
2412 19. Added additional timing features to pcretest. (1) The -tm option now times
2413 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2414 separate command line item, by a number that specifies the number of
2415 repeats to use when timing. The default is 50000; this gives better
2416 precision, but takes uncomfortably long for very large patterns.
2417
2418 20. Extended pcre_study() to be more clever in cases where a branch of a
2419 subpattern has no definite first character. For example, (a*|b*)[cd] would
2420 previously give no result from pcre_study(). Now it recognizes that the
2421 first character must be a, b, c, or d.
2422
2423 21. There was an incorrect error "recursive call could loop indefinitely" if
2424 a subpattern (or the entire pattern) that was being tested for matching an
2425 empty string contained only one non-empty item after a nested subpattern.
2426 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2427 incorrectly, because the \d was being skipped in the check.
2428
2429 22. The pcretest program now has a new pattern option /B and a command line
2430 option -b, which is equivalent to adding /B to every pattern. This causes
2431 it to show the compiled bytecode, without the additional information that
2432 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2433 is the same as /B/I).
2434
2435 23. A new optimization is now able automatically to treat some sequences such
2436 as a*b as a*+b. More specifically, if something simple (such as a character
2437 or a simple class like \d) has an unlimited quantifier, and is followed by
2438 something that cannot possibly match the quantified thing, the quantifier
2439 is automatically "possessified".
2440
2441 24. A recursive reference to a subpattern whose number was greater than 39
2442 went wrong under certain circumstances in UTF-8 mode. This bug could also
2443 have affected the operation of pcre_study().
2444
2445 25. Realized that a little bit of performance could be had by replacing
2446 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2447
2448 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2449
2450 27. Possessive quantifiers such as a++ were previously implemented by turning
2451 them into atomic groups such as ($>a+). Now they have their own opcodes,
2452 which improves performance. This includes the automatically created ones
2453 from 23 above.
2454
2455 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2456 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2457 the first matched character to be a colon. This applied both to named and
2458 numbered groups.
2459
2460 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2461
2462 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2463 building PCRE on Windows easier, so I have included it in the distribution.
2464
2465 31. There is now a check in pcretest against a ridiculously large number being
2466 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2467 loop, the loop is abandoned.
2468
2469 32. Forward references to subpatterns in conditions such as (?(2)...) where
2470 subpattern 2 is defined later cause pcre_compile() to search forwards in
2471 the pattern for the relevant set of parentheses. This search went wrong
2472 when there were unescaped parentheses in a character class, parentheses
2473 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2474
2475 33. "Subroutine" calls and backreferences were previously restricted to
2476 referencing subpatterns earlier in the regex. This restriction has now
2477 been removed.
2478
2479 34. Added a number of extra features that are going to be in Perl 5.10. On the
2480 whole, these are just syntactic alternatives for features that PCRE had
2481 previously implemented using the Python syntax or my own invention. The
2482 other formats are all retained for compatibility.
2483
2484 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2485 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2486 also .NET compatible.
2487
2488 (b) A recursion or subroutine call to a named group can now be defined as
2489 (?&name) as well as (?P>name).
2490
2491 (c) A backreference to a named group can now be defined as \k<name> or
2492 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2493 5.10, are also .NET compatible.
2494
2495 (d) A conditional reference to a named group can now use the syntax
2496 (?(<name>) or (?('name') as well as (?(name).
2497
2498 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2499 groups (named and numbered) that are never evaluated inline, but can be
2500 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2501 is always false. There may be only one alternative in such a group.
2502
2503 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2504 as the simple (?(R). The condition is true only if the most recent
2505 recursion is that of the given number or name. It does not search out
2506 through the entire recursion stack.
2507
2508 (g) The escape \gN or \g{N} has been added, where N is a positive or
2509 negative number, specifying an absolute or relative reference.
2510
2511 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2512 some "unreachable code" warnings.
2513
2514 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2515 things, this adds five new scripts.
2516
2517 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2518 There were also incompatibilities regarding the handling of \Q..\E inside
2519 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2520 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2521
2522 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2523 matches an empty string, and forcibly breaks the loop. There were bugs in
2524 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2525 against aaaa the result was just "a" rather than "aaaa", for example. Two
2526 separate and independent bugs (that affected different cases) have been
2527 fixed.
2528
2529 39. Refactored the code to abolish the use of different opcodes for small
2530 capturing bracket numbers. This is a tidy that I avoided doing when I
2531 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2532 The new approach is not only tidier, it makes it possible to reduce the
2533 memory needed to fix the previous bug (38).
2534
2535 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2536 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2537 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2538 mode.
2539
2540 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2541 report.
2542
2543 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2544 copy construction and assignment in the C++ wrapper.
2545
2546 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2547 couple of bugs that could have given wrong results in the "--newline=crlf"
2548 case.
2549
2550 44. Added a number of casts and did some reorganization of signed/unsigned int
2551 variables following suggestions from Dair Grant. Also renamed the variable
2552 "this" as "item" because it is a C++ keyword.
2553
2554 45. Arranged for dftables to add
2555
2556 #include "pcre_internal.h"
2557
2558 to pcre_chartables.c because without it, gcc 4.x may remove the array
2559 definition from the final binary if PCRE is built into a static library and
2560 dead code stripping is activated.
2561
2562 46. For an unanchored pattern, if a match attempt fails at the start of a
2563 newline sequence, and the newline setting is CRLF or ANY, and the next two
2564 characters are CRLF, advance by two characters instead of one.
2565
2566
2567 Version 6.7 04-Jul-06
2568 ---------------------
2569
2570 1. In order to handle tests when input lines are enormously long, pcretest has
2571 been re-factored so that it automatically extends its buffers when
2572 necessary. The code is crude, but this _is_ just a test program. The
2573 default size has been increased from 32K to 50K.
2574
2575 2. The code in pcre_study() was using the value of the re argument before
2576 testing it for NULL. (Of course, in any sensible call of the function, it
2577 won't be NULL.)
2578
2579 3. The memmove() emulation function in pcre_internal.h, which is used on
2580 systems that lack both memmove() and bcopy() - that is, hardly ever -
2581 was missing a "static" storage class specifier.
2582
2583 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2584 containing an extended class (one that cannot be represented by a bitmap
2585 because it contains high-valued characters or Unicode property items, e.g.
2586 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2587 pattern, but PCRE should not loop if you do not (it no longer does).
2588 [Detail: two cases were found: (a) a repeated subpattern containing an
2589 extended class; (b) a recursive reference to a subpattern that followed a
2590 previous extended class. It wasn't skipping over the extended class
2591 correctly when UTF-8 mode was not set.]
2592
2593 5. A negated single-character class was not being recognized as fixed-length
2594 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2595 compile error "lookbehind assertion is not fixed length".
2596
2597 6. The RunPerlTest auxiliary script was showing an unexpected difference
2598 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2599 write a Perl script that can interpret lines of an input file either as
2600 byte characters or as UTF-8, which is what "perltest" was being required to
2601 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2602 can't do is switch easily at run time between having the "use utf8;" pragma
2603 or not. In the end, I fudged it by using the RunPerlTest script to insert
2604 "use utf8;" explicitly for the UTF-8 tests.
2605
2606 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2607 the end of the subject string, contrary to the documentation and to what
2608 Perl does. This was true of both matching functions. Now it matches only at
2609 the start of the subject and immediately after *internal* newlines.
2610
2611 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2612 a pointer to an int instead of a pointer to an unsigned long int. This
2613 caused problems on 64-bit systems.
2614
2615 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2616 instance of the 'standard' template library not being so standard".
2617
2618 10. There was no check on the number of named subpatterns nor the maximum
2619 length of a subpattern name. The product of these values is used to compute
2620 the size of the memory block for a compiled pattern. By supplying a very
2621 long subpattern name and a large number of named subpatterns, the size
2622 computation could be caused to overflow. This is now prevented by limiting
2623 the length of names to 32 characters, and the number of named subpatterns
2624 to 10,000.
2625
2626 11. Subpatterns that are repeated with specific counts have to be replicated in
2627 the compiled pattern. The size of memory for this was computed from the
2628 length of the subpattern and the repeat count. The latter is limited to
2629 65535, but there was no limit on the former, meaning that integer overflow
2630 could in principle occur. The compiled length of a repeated subpattern is
2631 now limited to 30,000 bytes in order to prevent this.
2632
2633 12. Added the optional facility to have named substrings with the same name.
2634
2635 13. Added the ability to use a named substring as a condition, using the
2636 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2637 are numbers (not recommended). Forward references are permitted.
2638
2639 14. Added forward references in named backreferences (if you see what I mean).
2640
2641 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2642 pattern could run off the end of the subject. For example, the pattern
2643 "(?s)(.{1,5})"8 did this with the subject "ab".
2644
2645 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2646 PCRE_CASELESS was set when matching characters that were quantified with ?
2647 or *.
2648
2649 17. A character class other than a single negated character that had a minimum
2650 but no maximum quantifier - for example [ab]{6,} - was not handled
2651 correctly by pce_dfa_exec(). It would match only one character.
2652
2653 18. A valid (though odd) pattern that looked like a POSIX character
2654 class but used an invalid character after [ (for example [[,abc,]]) caused
2655 pcre_compile() to give the error "Failed: internal error: code overflow" or
2656 in some cases to crash with a glibc free() error. This could even happen if
2657 the pattern terminated after [[ but there just happened to be a sequence of
2658 letters, a binary zero, and a closing ] in the memory that followed.
2659
2660 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2661 over the years. Originally (before any Unicode support), just the bottom 8
2662 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2663 output from "man perlunicode" includes this:
2664
2665 The regular expression compiler produces polymorphic opcodes. That
2666 is, the pattern adapts to the data and automatically switches to
2667 the Unicode character scheme when presented with Unicode data--or
2668 instead uses a traditional byte scheme when presented with byte
2669 data.
2670
2671 Sadly, a wide octal escape does not cause a switch, and in a string with
2672 no other multibyte characters, these octal escapes are treated as before.
2673 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2674 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2675 Unicode string.
2676
2677 I have not perpetrated such confusion in PCRE. Up till now, it took just
2678 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2679 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2680 translate to the appropriate multibyte character.
2681
2682 29. Applied some refactoring to reduce the number of warnings from Microsoft
2683 and Borland compilers. This has included removing the fudge introduced
2684 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2685 a warning about an unused variable.
2686
2687 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2688 characters since release 4.0, because Perl (from release 5.004) does not.
2689 [Or at least, is documented not to: some releases seem to be in conflict
2690 with the documentation.] However, when a pattern was studied with
2691 pcre_study() and all its branches started with \s, PCRE still included VT
2692 as a possible starting character. Of course, this did no harm; it just
2693 caused an unnecessary match attempt.
2694
2695 22. Removed a now-redundant internal flag bit that recorded the fact that case
2696 dependency changed within the pattern. This was once needed for "required
2697 byte" processing, but is no longer used. This recovers a now-scarce options
2698 bit. Also moved the least significant internal flag bit to the most-
2699 significant bit of the word, which was not previously used (hangover from
2700 the days when it was an int rather than a uint) to free up another bit for
2701 the future.
2702
2703 23. Added support for CRLF line endings as well as CR and LF. As well as the
2704 default being selectable at build time, it can now be changed at runtime
2705 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2706 specify that it is scanning data with non-default line endings.
2707
2708 24. Changed the definition of CXXLINK to make it agree with the definition of
2709 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2710
2711 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2712 recursions. This makes a big different to stack usage for some patterns.
2713
2714 26. If a subpattern containing a named recursion or subroutine reference such
2715 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2716 the space required for the compiled pattern went wrong and gave too small a
2717 value. Depending on the environment, this could lead to "Failed: internal
2718 error: code overflow at offset 49" or "glibc detected double free or
2719 corruption" errors.
2720
2721 27. Applied patches from Google (a) to support the new newline modes and (b) to
2722 advance over multibyte UTF-8 characters in GlobalReplace.
2723
2724 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2725 difference for some implementation of PCRE in some Windows version.
2726
2727 29. Added some extra testing facilities to pcretest:
2728
2729 \q<number> in a data line sets the "match limit" value
2730 \Q<number> in a data line sets the "match recursion limt" value
2731 -S <number> sets the stack size, where <number> is in megabytes
2732
2733 The -S option isn't available for Windows.
2734
2735
2736 Version 6.6 06-Feb-06
2737 ---------------------
2738
2739 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2740 in pcreposix.h. I have copied the definition from pcre.h.
2741
2742 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2743 because pcre.h is no longer a built file.
2744
2745 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2746 not normally included in the compiled code.
2747
2748
2749 Version 6.5 01-Feb-06
2750 ---------------------
2751
2752 1. When using the partial match feature with pcre_dfa_exec(), it was not
2753 anchoring the second and subsequent partial matches at the new starting
2754 point. This could lead to incorrect results. For example, with the pattern
2755 /1234/, partially matching against "123" and then "a4" gave a match.
2756
2757 2. Changes to pcregrep:
2758
2759 (a) All non-match returns from pcre_exec() were being treated as failures
2760 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2761 error message is output. Some extra information is given for the
2762 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2763 probably the only errors that are likely to be caused by users (by
2764 specifying a regex that has nested indefinite repeats, for instance).
2765 If there are more than 20 of these errors, pcregrep is abandoned.
2766
2767 (b) A binary zero was treated as data while matching, but terminated the
2768 output line if it was written out. This has been fixed: binary zeroes
2769 are now no different to any other data bytes.
2770
2771 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2772 used to set a locale for matching. The --locale=xxxx long option has
2773 been added (no short equivalent) to specify a locale explicitly on the
2774 pcregrep command, overriding the environment variables.
2775
2776 (d) When -B was used with -n, some line numbers in the output were one less
2777 than they should have been.
2778
2779 (e) Added the -o (--only-matching) option.
2780
2781 (f) If -A or -C was used with -c (count only), some lines of context were
2782 accidentally printed for the final match.
2783
2784 (g) Added the -H (--with-filename) option.
2785
2786 (h) The combination of options -rh failed to suppress file names for files
2787 that were found from directory arguments.
2788
2789 (i) Added the -D (--devices) and -d (--directories) options.
2790
2791 (j) Added the -F (--fixed-strings) option.
2792
2793 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2794
2795 (l) Added the --colo(u)r option.
2796
2797 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2798 is not present by default.
2799
2800 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2801 items such as (?R) or (?1), when the recursion could match a number of
2802 alternatives. If it matched one of the alternatives, but subsequently,
2803 outside the recursion, there was a failure, the code tried to back up into
2804 the recursion. However, because of the way PCRE is implemented, this is not
2805 possible, and the result was an incorrect result from the match.
2806
2807 In order to prevent this happening, the specification of recursion has
2808 been changed so that all such subpatterns are automatically treated as
2809 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2810
2811 4. I had overlooked the fact that, in some locales, there are characters for
2812 which isalpha() is true but neither isupper() nor islower() are true. In
2813 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2814 and ordfeminine) are like this. This affected the treatment of \w and \W
2815 when they appeared in character classes, but not when they appeared outside
2816 a character class. The bit map for "word" characters is now created
2817 separately from the results of isalnum() instead of just taking it from the
2818 upper, lower, and digit maps. (Plus the underscore character, of course.)
2819
2820 5. The above bug also affected the handling of POSIX character classes such as
2821 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2822 permanent tables. Instead, the bit maps for such a class were previously
2823 created as the appropriate unions of the upper, lower, and digit bitmaps.
2824 Now they are created by subtraction from the [[:word:]] class, which has
2825 its own bitmap.
2826
2827 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2828 It is created by subtracting the vertical space characters (\x09, \x0a,
2829 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2830 subtraction was done in the overall bitmap for a character class, meaning
2831 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2832 be recognized. This bug has been fixed.
2833
2834 7. Patches from the folks at Google:
2835
2836 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2837 real life, but is still worth protecting against".
2838
2839 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2840 regular expressions".
2841
2842 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2843 have it.
2844
2845 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2846 "configure" and the latter not, in order to fix a problem somebody had
2847 with compiling the Arg class on HP-UX.
2848
2849 (e) Improve the error-handling of the C++ wrapper a little bit.
2850
2851 (f) New tests for checking recursion limiting.
2852
2853 8. The pcre_memmove() function, which is used only if the environment does not
2854 have a standard memmove() function (and is therefore rarely compiled),
2855 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2856 returning a result (though PCRE never actually uses the result).
2857
2858 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2859 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2860 returned instead of calling malloc() with an overflowing number that would
2861 most likely cause subsequent chaos.
2862
2863 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2864
2865 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2866 with this option is matched, the nmatch and pmatch options of regexec() are
2867 ignored.
2868
2869 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2870 provided in case anyone wants to the the POSIX interface with UTF-8
2871 strings.
2872
2873 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2874 C++ linking (needed for some HP-UX environments).
2875
2876 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2877 (unused parameter) and in the pcre_printint() function (omitted "default"
2878 switch label when the default is to do nothing).
2879
2880 15. Added some code to make it possible, when PCRE is compiled as a C++
2881 library, to replace subject pointers for pcre_exec() with a smart pointer
2882 class, thus making it possible to process discontinuous strings.
2883
2884 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2885 much the same function. They were added by different people who were trying
2886 to make PCRE easy to compile on non-Unix systems. It has been suggested
2887 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2888 for compiling on Windows systems. I have therefore replaced it with
2889 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2890 defaults to "extern" for C or "extern C" for C++, which works fine on
2891 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2892 SCOPE with something explicit in config.h. In addition:
2893
2894 (a) pcreposix.h still had just "extern" instead of either of these macros;
2895 I have replaced it with PCRE_DATA_SCOPE.
2896
2897 (b) Functions such as _pcre_xclass(), which are internal to the library,
2898 but external in the C sense, all had PCRE_EXPORT in their definitions.
2899 This is apparently wrong for the Windows case, so I have removed it.
2900 (It makes no difference on Unix-like systems.)
2901
2902 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2903 of recursive calls to match(). This is different to MATCH_LIMIT because
2904 that limits the total number of calls to match(), not all of which increase
2905 the depth of recursion. Limiting the recursion depth limits the amount of
2906 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2907 when PCRE is compiled, and changed at run time. A patch from Google adds
2908 this functionality to the C++ interface.
2909
2910 18. Changes to the handling of Unicode character properties:
2911
2912 (a) Updated the table to Unicode 4.1.0.
2913
2914 (b) Recognize characters that are not in the table as "Cn" (undefined).
2915
2916 (c) I revised the way the table is implemented to a much improved format
2917 which includes recognition of ranges. It now supports the ranges that
2918 are defined in UnicodeData.txt, and it also amalgamates other
2919 characters into ranges. This has reduced the number of entries in the
2920 table from around 16,000 to around 3,000, thus reducing its size
2921 considerably. I realized I did not need to use a tree structure after
2922 all - a binary chop search is just as efficient. Having reduced the
2923 number of entries, I extended their size from 6 bytes to 8 bytes to
2924 allow for more data.
2925
2926 (d) Added support for Unicode script names via properties such as \p{Han}.
2927
2928 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2929 matching that character.
2930
2931 20. When matching a repeated Unicode property with a minimum greater than zero,
2932 (for example \pL{2,}), PCRE could look past the end of the subject if it
2933 reached it while seeking the minimum number of characters. This could
2934 happen only if some of the characters were more than one byte long, because
2935 there is a check for at least the minimum number of bytes.
2936
2937 21. Refactored the implementation of \p and \P so as to be more general, to
2938 allow for more different types of property in future. This has changed the
2939 compiled form incompatibly. Anybody with saved compiled patterns that use
2940 \p or \P will have to recompile them.
2941
2942 22. Added "Any" and "L&" to the supported property types.
2943
2944 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2945 but give a compile time error if the value is greater than 0xff.
2946
2947 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2948 accidentally not being installed or uninstalled.
2949
2950 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2951 made were to insert the current release number. This seemed silly, because
2952 it made things harder for people building PCRE on systems that don't run
2953 "configure". I have turned pcre.h into a distributed file, no longer built
2954 by "configure", with the version identification directly included. There is
2955 no longer a pcre.h.in file.
2956
2957 However, this change necessitated a change to the pcre-config script as
2958 well. It is built from pcre-config.in, and one of the substitutions was the
2959 release number. I have updated configure.ac so that ./configure now finds
2960 the release number by grepping pcre.h.
2961
2962 26. Added the ability to run the tests under valgrind.
2963
2964
2965 Version 6.4 05-Sep-05
2966 ---------------------
2967
2968 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2969 "--" to be printed when multiple files were scanned, even when none of the
2970 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2971 consider it to be a bug, and have restored the previous behaviour.
2972
2973 2. A couple of code tidies to get rid of compiler warnings.
2974
2975 3. The pcretest program used to cheat by referring to symbols in the library
2976 whose names begin with _pcre_. These are internal symbols that are not
2977 really supposed to be visible externally, and in some environments it is
2978 possible to suppress them. The cheating is now confined to including
2979 certain files from the library's source, which is a bit cleaner.
2980
2981 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2982 file's purpose clearer.
2983
2984 5. Reorganized pcre_ucp_findchar().
2985
2986
2987 Version 6.3 15-Aug-05
2988 ---------------------
2989
2990 1. The file libpcre.pc.in did not have general read permission in the tarball.
2991
2992 2. There were some problems when building without C++ support:
2993
2994 (a) If C++ support was not built, "make install" and "make test" still
2995 tried to test it.
2996
2997 (b) There were problems when the value of CXX was explicitly set. Some
2998 changes have been made to try to fix these, and ...
2999
3000 (c) --disable-cpp can now be used to explicitly disable C++ support.
3001
3002 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
3003 backslash in a target when C++ was disabled. This confuses some
3004 versions of "make", apparently. Using an intermediate variable solves
3005 this. (Same for CPP_LOBJ.)
3006
3007 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
3008 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
3009 necessary on certain architectures.
3010
3011 4. Added a setting of -export-symbols-regex to the link command to remove
3012 those symbols that are exported in the C sense, but actually are local
3013 within the library, and not documented. Their names all begin with
3014 "_pcre_". This is not a perfect job, because (a) we have to except some
3015 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
3016 available (and never for static libraries). I have made a note to try to
3017 find a way round (a) in the future.
3018
3019
3020 Version 6.2 01-Aug-05
3021 ---------------------
3022
3023 1. There was no test for integer overflow of quantifier values. A construction
3024 such as {1111111111111111} would give undefined results. What is worse, if
3025 a minimum quantifier for a parenthesized subpattern overflowed and became
3026 negative, the calculation of the memory size went wrong. This could have
3027 led to memory overwriting.
3028
3029 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
3030
3031 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
3032 operating environments where this matters.
3033
3034 4. Applied Giuseppe Maxia's patch to add additional features for controlling
3035 PCRE options from within the C++ wrapper.
3036
3037 5. Named capturing subpatterns were not being correctly counted when a pattern
3038 was compiled. This caused two problems: (a) If there were more than 100
3039 such subpatterns, the calculation of the memory needed for the whole
3040 compiled pattern went wrong, leading to an overflow error. (b) Numerical
3041 back references of the form \12, where the number was greater than 9, were
3042 not recognized as back references, even though there were sufficient
3043 previous subpatterns.
3044
3045 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
3046 versions of gcc, e.g. 2.95.4.
3047
3048
3049 Version 6.1 21-Jun-05
3050 ---------------------
3051
3052 1. There was one reference to the variable "posix" in pcretest.c that was not
3053 surrounded by "#if !defined NOPOSIX".
3054
3055 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
3056 the cross-check on the old pcre_info() function, for the benefit of the
3057 cut-down version of PCRE that is currently imported into Exim.
3058
3059 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
3060 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
3061 patterns that start (?i) but I don't think that matters. The use of (?i) is
3062 just an example; this all applies to the other options as well.
3063
3064 4. Since libtool seems to echo the compile commands it is issuing, the output
3065 from "make" can be reduced a bit by putting "@" in front of each libtool
3066 compile command.
3067
3068 5. Patch from the folks at Google for configure.in to be a bit more thorough
3069 in checking for a suitable C++ installation before trying to compile the
3070 C++ stuff. This should fix a reported problem when a compiler was present,
3071 but no suitable headers.
3072
3073 6. The man pages all had just "PCRE" as their title. I have changed them to
3074 be the relevant file name. I have also arranged that these names are
3075 retained in the file doc/pcre.txt, which is a concatenation in text format
3076 of all the man pages except the little individual ones for each function.
3077
3078 7. The NON-UNIX-USE file had not been updated for the different set of source
3079 files that come with release 6. I also added a few comments about the C++
3080 wrapper.
3081
3082
3083 Version 6.0 07-Jun-05
3084 ---------------------
3085
3086 1. Some minor internal re-organization to help with my DFA experiments.
3087
3088 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3089 didn't matter for the library itself when fully configured, but did matter
3090 when compiling without UCP support, or within Exim, where the ucp files are
3091 not imported.
3092
3093 3. Refactoring of the library code to split up the various functions into
3094 different source modules. The addition of the new DFA matching code (see
3095 below) to a single monolithic source would have made it really too
3096 unwieldy, quite apart from causing all the code to be include in a
3097 statically linked application, when only some functions are used. This is
3098 relevant even without the DFA addition now that patterns can be compiled in
3099 one application and matched in another.
3100
3101 The downside of splitting up is that there have to be some external
3102 functions and data tables that are used internally in different modules of
3103 the library but which are not part of the API. These have all had their
3104 names changed to start with "_pcre_" so that they are unlikely to clash
3105 with other external names.
3106
3107 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3108 a different (DFA) algorithm. Although it is slower than the original
3109 function, it does have some advantages for certain types of matching
3110 problem.
3111
3112 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3113 including restarting after a partial match.
3114
3115 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3116 defined when compiling for Windows was sent to me. I have put it into the
3117 code, though I have no means of testing or verifying it.
3118
3119 7. Added the pcre_refcount() auxiliary function.
3120
3121 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3122 match before or at the first newline in the subject string. In pcretest,
3123 the /f option on a pattern can be used to set this.
3124
3125 9. A repeated \w when used in UTF-8 mode with characters greater than 256
3126 would behave wrongly. This has been present in PCRE since release 4.0.
3127
3128 10. A number of changes to the pcregrep command:
3129
3130 (a) Refactored how -x works; insert ^(...)$ instead of setting
3131 PCRE_ANCHORED and checking the length, in preparation for adding
3132 something similar for -w.
3133
3134 (b) Added the -w (match as a word) option.
3135
3136 (c) Refactored the way lines are read and buffered so as to have more
3137 than one at a time available.
3138
3139 (d) Implemented a pcregrep test script.
3140
3141 (e) Added the -M (multiline match) option. This allows patterns to match
3142 over several lines of the subject. The buffering ensures that at least
3143 8K, or the rest of the document (whichever is the shorter) is available
3144 for matching (and similarly the previous 8K for lookbehind assertions).
3145
3146 (f) Changed the --help output so that it now says
3147
3148 -w, --word-regex(p)
3149
3150 instead of two lines, one with "regex" and the other with "regexp"
3151 because that confused at least one person since the short forms are the
3152 same. (This required a bit of code, as the output is generated
3153 automatically from a table. It wasn't just a text change.)
3154
3155 (g) -- can be used to terminate pcregrep options if the next thing isn't an
3156 option but starts with a hyphen. Could be a pattern or a path name
3157 starting with a hyphen, for instance.
3158
3159 (h) "-" can be given as a file name to represent stdin.
3160
3161 (i) When file names are being printed, "(standard input)" is used for
3162 the standard input, for compatibility with GNU grep. Previously
3163 "<stdin>" was used.
3164
3165 (j) The option --label=xxx can be used to supply a name to be used for
3166 stdin when file names are being printed. There is no short form.
3167
3168 (k) Re-factored the options decoding logic because we are going to add
3169 two more options that take data. Such options can now be given in four
3170 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3171
3172 (l) Added the -A, -B, and -C options for requesting that lines of context
3173 around matches be printed.
3174
3175 (m) Added the -L option to print the names of files that do not contain
3176 any matching lines, that is, the complement of -l.
3177
3178 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3179 continue to scan other files.
3180
3181 (o) The -s option was incorrectly implemented. For compatibility with other
3182 greps, it now suppresses the error message for a non-existent or non-
3183 accessible file (but not the return code). There is a new option called
3184 -q that suppresses the output of matching lines, which was what -s was
3185 previously doing.
3186
3187 (p) Added --include and --exclude options to specify files for inclusion
3188 and exclusion when recursing.
3189
3190 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3191 Hopefully, it now does.
3192
3193 12. Missing cast in pcre_study().
3194
3195 13. Added an "uninstall" target to the makefile.
3196
3197 14. Replaced "extern" in the function prototypes in Makefile.in with
3198 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3199 world, but is set differently for Windows.
3200
3201 15. Added a second compiling function called pcre_compile2(). The only
3202 difference is that it has an extra argument, which is a pointer to an
3203 integer error code. When there is a compile-time failure, this is set
3204 non-zero, in addition to the error test pointer being set to point to an
3205 error message. The new argument may be NULL if no error number is required
3206 (but then you may as well call pcre_compile(), which is now just a
3207 wrapper). This facility is provided because some applications need a
3208 numeric error indication, but it has also enabled me to tidy up the way
3209 compile-time errors are handled in the POSIX wrapper.
3210
3211 16. Added VPATH=.libs to the makefile; this should help when building with one
3212 prefix path and installing with another. (Or so I'm told by someone who
3213 knows more about this stuff than I do.)
3214
3215 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3216 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3217 match everything, including newlines. This is not POSIX-compatible, but
3218 somebody wanted the feature. From pcretest it can be activated by using
3219 both the P and the s flags.
3220
3221 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3222
3223 19. libpcre.pc was being incorrectly installed as executable.
3224
3225 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3226 it now also looks for '\r' so that it will work unmodified on Windows.
3227
3228 21. Added Google's contributed C++ wrapper to the distribution.
3229
3230 22. Added some untidy missing memory free() calls in pcretest, to keep
3231 Electric Fence happy when testing.
3232
3233
3234
3235 Version 5.0 13-Sep-04
3236 ---------------------
3237
3238 1. Internal change: literal characters are no longer packed up into items
3239 containing multiple characters in a single byte-string. Each character
3240 is now matched using a separate opcode. However, there may be more than one
3241 byte in the character in UTF-8 mode.
3242
3243 2. The pcre_callout_block structure has two new fields: pattern_position and
3244 next_item_length. These contain the offset in the pattern to the next match
3245 item, and its length, respectively.
3246
3247 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3248 insertion of callouts before each pattern item. Added the /C option to
3249 pcretest to make use of this.
3250
3251 4. On the advice of a Windows user, the lines
3252
3253 #if defined(_WIN32) || defined(WIN32)
3254 _setmode( _fileno( stdout ), 0x8000 );
3255 #endif /* defined(_WIN32) || defined(WIN32) */
3256
3257 have been added to the source of pcretest. This apparently does useful
3258 magic in relation to line terminators.
3259
3260 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3261 for the benefit of those environments where the "b" makes a difference.
3262
3263 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3264 to know about it. I have put a hack into configure.in that adds in code
3265 to set GCC=yes if CC=icc. This seems to end up at a point in the
3266 generated configure script that is early enough to affect the setting of
3267 compiler options, which is what is needed, but I have no means of testing
3268 whether it really works. (The user who reported this had patched the
3269 generated configure script, which of course I cannot do.)
3270
3271 LATER: After change 22 below (new libtool files), the configure script
3272 seems to know about icc (and also ecc). Therefore, I have commented out
3273 this hack in configure.in.
3274
3275 7. Added support for pkg-config (2 patches were sent in).
3276
3277 8. Negated POSIX character classes that used a combination of internal tables
3278 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3279 [[:^ascii]]. Typically, they would match almost any characters. The other
3280 POSIX classes were not broken in this way.
3281
3282 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3283 to find the match, as PCRE was deluded into thinking that the match had to
3284 start at the start point or following a newline. The same bug applied to
3285 patterns with negative forward assertions or any backward assertions
3286 preceding ".*" at the start, unless the pattern required a fixed first
3287 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3288
3289 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3290 starting at the last subject character, bytes beyond the end of the subject
3291 string were read.
3292
3293 11. Renamed the variable "class" as "classbits" to make life easier for C++
3294 users. (Previously there was a macro definition, but it apparently wasn't
3295 enough.)
3296
3297 12. Added the new field "tables" to the extra data so that tables can be passed
3298 in at exec time, or the internal tables can be re-selected. This allows
3299 a compiled regex to be saved and re-used at a later time by a different
3300 program that might have everything at different addresses.
3301
3302 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3303 -R library as well as a -L library.
3304
3305 14. The debugging options of pcretest (-d on the command line or D on a
3306 pattern) showed incorrect output for anything following an extended class
3307 that contained multibyte characters and which was followed by a quantifier.
3308
3309 15. Added optional support for general category Unicode character properties
3310 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3311 support. It adds about 90K to the size of the library. The meanings of the
3312 inbuilt class escapes such as \d and \s have NOT been changed.
3313
3314 16. Updated pcredemo.c to include calls to free() to release the memory for the
3315 compiled pattern.
3316
3317 17. The generated file chartables.c was being created in the source directory
3318 instead of in the building directory. This caused the build to fail if the
3319 source directory was different from the building directory, and was
3320 read-only.
3321
3322 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3323 file. No doubt somebody will tell me if they don't make sense... Also added
3324 Dan Mooney's comments about building on OpenVMS.
3325
3326 19. Added support for partial matching via the PCRE_PARTIAL option for
3327 pcre_exec() and the \P data escape in pcretest.
3328
3329 20. Extended pcretest with 3 new pattern features:
3330
3331 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3332 write the compiled pattern to the file whose name is "rest-of-line".
3333 This is a straight binary dump of the data, with the saved pointer to
3334 the character tables forced to be NULL. The study data, if any, is
3335 written too. After writing, pcretest reads a new pattern.
3336
3337 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3338 compiled pattern from the given file. There must not be any
3339 occurrences of "<" in the file name (pretty unlikely); if there are,
3340 pcretest will instead treat the initial "<" as a pattern delimiter.
3341 After reading in the pattern, pcretest goes on to read data lines as
3342 usual.
3343
3344 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3345 and 16-bit fields in a compiled pattern, to simulate a pattern that
3346 was compiled on a host of opposite endianness.
3347
3348 21. The pcre-exec() function can now cope with patterns that were compiled on
3349 hosts of opposite endianness, with this restriction:
3350
3351 As for any compiled expression that is saved and used later, the tables
3352 pointer field cannot be preserved; the extra_data field in the arguments
3353 to pcre_exec() should be used to pass in a tables address if a value
3354 other than the default internal tables were used at compile time.
3355
3356 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3357 now diagnosed as an error. Previously, most of the time, a negative number
3358 would have been treated as zero, but if in addition "ovector" was passed as
3359 NULL, a crash could occur.
3360
3361 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3362 new versions from the libtool 1.5 distribution (the last one is a copy of
3363 a file called libtool.m4). This seems to have fixed the need to patch
3364 "configure" to support Darwin 1.3 (which I used to do). However, I still
3365 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3366 workstation).
3367
3368 24. Changed the PCRE licence to be the more standard "BSD" licence.
3369
3370
3371 Version 4.5 01-Dec-03
3372 ---------------------
3373
3374 1. There has been some re-arrangement of the code for the match() function so
3375 that it can be compiled in a version that does not call itself recursively.
3376 Instead, it keeps those local variables that need separate instances for
3377 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3378 needs to "recurse". Keeping track of where control must go is done by means
3379 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3380 hide most of the details from the main code, and operates only if
3381 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3382 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3383 operating.
3384
3385 To make it easier for callers to provide specially tailored get/free
3386 functions for this usage, two new functions, pcre_stack_malloc, and
3387 pcre_stack_free, are used. They are always called in strict stacking order,
3388 and the size of block requested is always the same.
3389
3390 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3391 PCRE has been compiled to use the stack or the heap for recursion. The
3392 -C option of pcretest uses this to show which version is compiled.
3393
3394 A new data escape \S, is added to pcretest; it causes the amounts of store
3395 obtained and freed by both kinds of malloc/free at match time to be added
3396 to the output.
3397
3398 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3399 what's available on my current Linux desktop machine.
3400
3401 3. When matching a UTF-8 string, the test for a valid string at the start has
3402 been extended. If start_offset is not zero, PCRE now checks that it points
3403 to a byte that is the start of a UTF-8 character. If not, it returns
3404 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3405 this is necessary because there may be backward assertions in the pattern.
3406 When matching the same subject several times, it may save resources to use
3407 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3408
3409 4. The code for checking the validity of UTF-8 strings has been tightened so
3410 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3411 containing "overlong sequences".
3412
3413 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3414 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3415 should have been "&", but it just so happened that all the cases this let
3416 through by mistake were picked up later in the function.
3417
3418 6. I had used a variable called "isblank" - this is a C99 function, causing
3419 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3420
3421 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3422 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3423 so the version is shown; (c) stop "make test" echoing "./RunTest".
3424
3425 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3426
3427 9. The prototype for memmove() for systems that don't have it was using
3428 size_t, but the inclusion of the header that defines size_t was later. I've
3429 moved the #includes for the C headers earlier to avoid this.
3430
3431 10. Added some adjustments to the code to make it easier to compiler on certain
3432 special systems:
3433
3434 (a) Some "const" qualifiers were missing.
3435 (b) Added the macro EXPORT before all exported functions; by default this
3436 is defined to be empty.
3437 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3438 that it reads its output file name as an argument instead of writing
3439 to the standard output and assuming this can be redirected.
3440
3441 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3442 class containing characters with values greater than 255, PCRE compilation
3443 went into a loop.
3444
3445 12. A recursive reference to a subpattern that was within another subpattern
3446 that had a minimum quantifier of zero caused PCRE to crash. For example,
3447 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3448 recursion. If the recursively-called subpattern itself had a zero repeat,
3449 that was OK.
3450
3451 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3452 buffer into which it was copied (for escape processing) was still set at
3453 1024, so long lines caused crashes.
3454
3455 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3456 "internal error: code overflow...". This applied to any character class
3457 that was followed by a possessive quantifier.
3458
3459 15. Modified the Makefile to add libpcre.la as a prerequisite for
3460 libpcreposix.la because I was told this is needed for a parallel build to
3461 work.
3462
3463 16. If a pattern that contained .* following optional items at the start was
3464 studied, the wrong optimizing data was generated, leading to matching
3465 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3466 matching string must start with a or b or c. The correct conclusion for
3467 this pattern is that a match can start with any character.
3468
3469
3470 Version 4.4 13-Aug-03
3471 ---------------------
3472
3473 1. In UTF-8 mode, a character class containing characters with values between
3474 127 and 255 was not handled correctly if the compiled pattern was studied.
3475 In fixing this, I have also improved the studying algorithm for such
3476 classes (slightly).
3477
3478 2. Three internal functions had redundant arguments passed to them. Removal
3479 might give a very teeny performance improvement.
3480
3481 3. Documentation bug: the value of the capture_top field in a callout is *one
3482 more than* the number of the hightest numbered captured substring.
3483
3484 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3485 in incorrectly linking with a previously installed version. They now link
3486 explicitly with libpcre.la.
3487
3488 5. configure.in no longer needs to recognize Cygwin specially.
3489
3490 6. A problem in pcre.in for Windows platforms is fixed.
3491
3492 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3493 pcretest, it used to include the size of the study block as part of its
3494 output. Unfortunately, the structure contains a field that has a different
3495 size on different hardware architectures. This meant that the tests that
3496 showed this size failed. As the block is currently always of a fixed size,
3497 this information isn't actually particularly useful in pcretest output, so
3498 I have just removed it.
3499
3500 8. Three pre-processor statements accidentally did not start in column 1.
3501 Sadly, there are *still* compilers around that complain, even though
3502 standard C has not required this for well over a decade. Sigh.
3503
3504 9. In pcretest, the code for checking callouts passed small integers in the
3505 callout_data field, which is a void * field. However, some picky compilers
3506 complained about the casts involved for this on 64-bit systems. Now
3507 pcretest passes the address of the small integer instead, which should get
3508 rid of the warnings.
3509
3510 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3511 both compile and run time, and gives an error if an invalid UTF-8 sequence
3512 is found. There is a option for disabling this check in cases where the
3513 string is known to be correct and/or the maximum performance is wanted.
3514
3515 11. In response to a bug report, I changed one line in Makefile.in from
3516
3517 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3518 to
3519 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3520
3521 to look similar to other lines, but I have no way of telling whether this
3522 is the right thing to do, as I do not use Windows. No doubt I'll get told
3523 if it's wrong...
3524
3525
3526 Version 4.3 21-May-03
3527 ---------------------
3528
3529 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3530 Makefile.
3531
3532 2. Some refactoring to improve the quality of the code:
3533
3534 (i) The utf8_table... variables are now declared "const".
3535
3536 (ii) The code for \cx, which used the "case flipping" table to upper case
3537 lower case letters, now just substracts 32. This is ASCII-specific,
3538 but the whole concept of \cx is ASCII-specific, so it seems
3539 reasonable.
3540
3541 (iii) PCRE was using its character types table to recognize decimal and
3542 hexadecimal digits in the pattern. This is silly, because it handles
3543 only 0-9, a-f, and A-F, but the character types table is locale-
3544 specific, which means strange things might happen. A private
3545 table is now used for this - though it costs 256 bytes, a table is
3546 much faster than multiple explicit tests. Of course, the standard
3547 character types table is still used for matching digits in subject
3548 strings against \d.
3549
3550 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3551 ending in _t are). So I've renamed it as ESC_tee.
3552
3553 3. The first argument for regexec() in the POSIX wrapper should have been
3554 defined as "const".
3555
3556 4. Changed pcretest to use malloc() for its buffers so that they can be
3557 Electric Fenced for debugging.
3558
3559 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3560 to read one or more bytes before the start of the subject string. Often this
3561 had no effect on PCRE's behaviour, but in some circumstances it could
3562 provoke a segmentation fault.
3563
3564 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3565 to try to read one or more bytes before the start of the subject string.
3566
3567 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3568 UTF-8 support could misbehave in various ways if the subject string
3569 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3570 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3571 back over UTF-8 characters.)
3572
3573
3574 Version 4.2 14-Apr-03
3575 ---------------------
3576
3577 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3578
3579 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3580 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3581 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3582 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3583 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3584 and BUILD_EXEEXT
3585 Note: automatic setting of the BUILD variables is not yet working
3586 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3587 compile-time but not at link-time
3588 [LINK]: use for linking executables only
3589 make different versions for Windows and non-Windows
3590 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3591 libraries
3592 [LINK_FOR_BUILD]: new variable
3593 [OBJEXT]: use throughout
3594 [EXEEXT]: use throughout
3595 <winshared>: new target
3596 <wininstall>: new target
3597 <dftables.o>: use native compiler
3598 <dftables>: use native linker
3599 <install>: handle Windows platform correctly
3600 <clean>: ditto
3601 <check>: ditto
3602 copy DLL to top builddir before testing
3603
3604 As part of these changes, -no-undefined was removed again. This was reported
3605 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3606 in any case.
3607
3608 3. Some tidies to get rid of compiler warnings:
3609
3610 . In the match_data structure, match_limit was an unsigned long int, whereas
3611 match_call_count was an int. I've made them both unsigned long ints.
3612
3613 . In pcretest the fact that a const uschar * doesn't automatically cast to
3614 a void * provoked a warning.
3615
3616 . Turning on some more compiler warnings threw up some "shadow" variables
3617 and a few more missing casts.
3618
3619 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3620 option, a class that contained a single character with a value between 128
3621 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3622
3623 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3624 option, a class that contained several characters, but with at least one
3625 whose value was between 128 and 255 caused PCRE to crash.
3626
3627
3628 Version 4.1 12-Mar-03
3629 ---------------------
3630
3631 1. Compiling with gcc -pedantic found a couple of places where casts were
3632 needed, and a string in dftables.c that was longer than standard compilers are
3633 required to support.
3634
3635 2. Compiling with Sun's compiler found a few more places where the code could
3636 be tidied up in order to avoid warnings.
3637
3638 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3639 first of these names is deprecated in the latest Autoconf in favour of the name
3640 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3641 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3642 analogy I have changed it to CFLAGS_FOR_BUILD.
3643
3644 4. Added -no-undefined to the linking command in the Makefile, because this is
3645 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3646 linking step for the pcreposix library.
3647
3648 5. PCRE was failing to diagnose the case of two named groups with the same
3649 name.
3650
3651 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3652 literal character that is needed in the subject for a match, and scans along to
3653 ensure that it is present before embarking on the full matching process. This
3654 saves time in cases of nested unlimited repeats that are never going to match.
3655 Problem: the scan can take a lot of time if the subject is very long (e.g.
3656 megabytes), thus penalizing straightforward matches. It is now done only if the
3657 amount of subject to be scanned is less than 1000 bytes.
3658
3659 7. A lesser problem with the same optimization is that it was recording the
3660 first character of an anchored pattern as "needed", thus provoking a search
3661 right along the subject, even when the first match of the pattern was going to
3662 fail. The "needed" character is now not set for anchored patterns, unless it
3663 follows something in the pattern that is of non-fixed length. Thus, it still
3664 fulfils its original purpose of finding quick non-matches in cases of nested
3665 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3666
3667
3668 Version 4.0 17-Feb-03
3669 ---------------------
3670
3671 1. If a comment in an extended regex that started immediately after a meta-item
3672 extended to the end of string, PCRE compiled incorrect data. This could lead to
3673 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3674
3675 2. Moved to autoconf 2.53 and libtool 1.4.2.
3676
3677 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3678 the special perltest8 script is no longer needed - all the tests can be run
3679 from a single perltest script.
3680
3681 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3682 by \s. It has now been removed in PCRE. This means it isn't recognized as
3683 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3684 class [:space:] *does* include VT, thereby creating a mess.
3685
3686 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3687 space and tab.
3688
3689 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3690 its new features into the main test script, reducing the number of scripts.
3691
3692 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3693 were backward compatible, and made the (?i) apply to the whole pattern, as if
3694 /i were given. Now it behaves more logically, and applies the option setting
3695 only to what follows. PCRE has been changed to follow suit. However, if it
3696 finds options settings right at the start of the pattern, it extracts them into
3697 the global options, as before. Thus, they show up in the info data.
3698
3699 8. Added support for the \Q...\E escape sequence. Characters in between are
3700 treated as literals. This is slightly different from Perl in that $ and @ are
3701 also handled as literals inside the quotes. In Perl, they will cause variable
3702 interpolation. Note the following examples:
3703
3704 Pattern PCRE matches Perl matches
3705
3706 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3707 \Qabc\$xyz\E abc\$xyz abc\$xyz
3708 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3709
3710 For compatibility with Perl, \Q...\E sequences are recognized inside character
3711 classes as well as outside them.
3712
3713 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3714 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3715 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3716 signed/unsigned warnings.
3717
3718 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3719 option for pcretest, so I've replaced it by a simple function that does just
3720 that job.
3721
3722 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3723 "pcregrep -".
3724
3725 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3726 Java package. This provides some syntactic sugar for simple cases of what my
3727 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3728 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3729 item, you can use this simplified notation. Note that only makes sense with
3730 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3731 greediness, whatever the setting of the PCRE_UNGREEDY option.
3732
3733 13. A change of greediness default within a pattern was not taking effect at
3734 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3735 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3736 was abstracted outside.
3737
3738 14. PCRE now supports the \G assertion. It is true when the current matching
3739 position is at the start point of the match. This differs from \A when the
3740 starting offset is non-zero. Used with the /g option of pcretest (or similar
3741 code), it works in the same way as it does for Perl's /g option. If all
3742 alternatives of a regex begin with \G, the expression is anchored to the start
3743 match position, and the "anchored" flag is set in the compiled expression.
3744
3745 15. Some bugs concerning the handling of certain option changes within patterns
3746 have been fixed. These applied to options other than (?ims). For example,
3747 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3748 been the other way round. Some of this was related to change 7 above.
3749
3750 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3751 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3752 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3753 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3754
3755 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3756 mode. Unlike ".", it always matches newline, whatever the setting of
3757 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3758 assertions. Perl allows it, but it doesn't (in general) work because it can't
3759 calculate the length of the lookbehind. At least, that's the case for Perl
3760 5.8.0 - I've been told they are going to document that it doesn't work in
3761 future.
3762
3763 18. Added an error diagnosis for escapes that PCRE does not support: these are
3764 \L, \l, \N, \P, \p, \U, \u, and \X.
3765
3766 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3767 reading past the end of the pattern in cases such as /[abcd/.
3768
3769 20. PCRE was getting more memory than necessary for patterns with classes that
3770 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3771
3772 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3773 compiling PCRE for use with Virtual Pascal.
3774
3775 22. Small fix to the Makefile to make it work properly if the build is done
3776 outside the source tree.
3777
3778 23. Added a new extension: a condition to go with recursion. If a conditional
3779 subpattern starts with (?(R) the "true" branch is used if recursion has
3780 happened, whereas the "false" branch is used only at the top level.
3781
3782 24. When there was a very long string of literal characters (over 255 bytes
3783 without UTF support, over 250 bytes with UTF support), the computation of how
3784 much memory was required could be incorrect, leading to segfaults or other
3785 strange effects.
3786
3787 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3788 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3789 there was a subsequent back reference to those brackets. This meant that, for
3790 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3791 possible to check for precisely this case. All we can do is abandon the
3792 optimization if .* occurs inside capturing brackets when there are any back
3793 references whatsoever. (See below for a better fix that came later.)
3794
3795 26. The handling of the optimization for finding the first character of a
3796 non-anchored pattern, and for finding a character that is required later in the
3797 match were failing in some cases. This didn't break the matching; it just
3798 failed to optimize when it could. The way this is done has been re-implemented.
3799
3800 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3801
3802 28. Added a new feature that provides some of the functionality that Perl
3803 provides with (?{...}). The facility is termed a "callout". The way it is done
3804 in PCRE is for the caller to provide an optional function, by setting
3805 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3806 global variable. By default it is unset, which disables all calling out. To get
3807 the function called, the regex must include (?C) at appropriate points. This
3808 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3809 This provides a means of identifying different callout points. When PCRE
3810 reaches such a point in the regex, if pcre_callout has been set, the external
3811 function is called. It is provided with data in a structure called
3812 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3813 matching continues; if it returns a non-zero value, the match at the current
3814 point fails. However, backtracking will occur if possible. [This was changed
3815 later and other features added - see item 49 below.]
3816
3817 29. pcretest is upgraded to test the callout functionality. It provides a
3818 callout function that displays information. By default, it shows the start of
3819 the match and the current position in the text. There are some new data escapes
3820 to vary what happens:
3821
3822 \C+ in addition, show current contents of captured substrings
3823 \C- do not supply a callout function
3824 \C!n return 1 when callout number n is reached
3825 \C!n!m return 1 when callout number n is reached for the mth time
3826
3827 30. If pcregrep was called with the -l option and just a single file name, it
3828 output "<stdin>" if a match was found, instead of the file name.
3829
3830 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3831 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3832 pcre_exec(). This saves a malloc/free per call. The default value of
3833 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3834 when configuring.
3835
3836 32. The default maximum size of a compiled pattern is 64K. There have been a
3837 few cases of people hitting this limit. The code now uses macros to handle the
3838 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3839 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3840 configuring. Tests 2 and 5 work only with 2-byte links because they output
3841 debugging information about compiled patterns.
3842
3843 33. Internal code re-arrangements:
3844
3845 (a) Moved the debugging function for printing out a compiled regex into
3846 its own source file (printint.c) and used #include to pull it into
3847 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3848 separate copies.
3849
3850 (b) Defined the list of op-code names for debugging as a macro in
3851 internal.h so that it is next to the definition of the opcodes.
3852
3853 (c) Defined a table of op-code lengths for simpler skipping along compiled
3854 code. This is again a macro in internal.h so that it is next to the
3855 definition of the opcodes.
3856
3857 34. Added support for recursive calls to individual subpatterns, along the
3858 lines of Robin Houston's patch (but implemented somewhat differently).
3859
3860 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3861 allow it to read and process whole directories in Win32. This code was
3862 contributed by Lionel Fourquaux; it has not been tested by me.
3863
3864 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3865 used to name a group. Names consist of alphanumerics and underscores, and must
3866 be unique. Back references use the syntax (?P=name) and recursive calls use
3867 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3868 numbers. The function pcre_fullinfo() can be used after compilation to extract
3869 a name/number map. There are three relevant calls:
3870
3871 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3872 PCRE_INFO_NAMECOUNT yields the number of entries
3873 PCRE_INFO_NAMETABLE yields a pointer to the map.
3874
3875 The map is a vector of fixed-size entries. The size of each entry depends on
3876 the length of the longest name used. The first two bytes of each entry are the
3877 group number, most significant byte first. There follows the corresponding
3878 name, zero terminated. The names are in alphabetical order.
3879
3880 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3881 case instead of 255. Making it the same both with and without UTF-8 support
3882 means that the same test output works with both.
3883
3884 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3885 calling malloc() with a zero argument.
3886
3887 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3888 optimization. I've improved things by keeping a bitmap of backreferences with
3889 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3890 fact referenced, the optimization can be applied. It is unlikely that a
3891 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3892 the match to follow \n) will appear inside brackets with a number greater than
3893 31, but if it does, any back reference > 31 suppresses the optimization.
3894
3895 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3896 of disabling numbered capturing parentheses. Any opening parenthesis that is
3897 not followed by ? behaves as if it were followed by ?: but named parentheses
3898 can still be used for capturing (and they will acquire numbers in the usual
3899 way).
3900
3901 41. Redesigned the return codes from the match() function into yes/no/error so
3902 that errors can be passed back from deep inside the nested calls. A malloc
3903 failure while inside a recursive subpattern call now causes the
3904 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3905
3906 42. It is now possible to set a limit on the number of times the match()
3907 function is called in a call to pcre_exec(). This facility makes it possible to
3908 limit the amount of recursion and backtracking, though not in a directly
3909 obvious way, because the match() function is used in a number of different
3910 circumstances. The count starts from zero for each position in the subject
3911 string (for non-anchored patterns). The default limit is, for compatibility, a
3912 large number, namely 10 000 000. You can change this in two ways:
3913
3914 (a) When configuring PCRE before making, you can use --with-match-limit=n
3915 to set a default value for the compiled library.
3916
3917 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3918 a different value is set. See 45 below.
3919
3920 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3921
3922 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3923 of things that can be changed at compile time. The first argument specifies
3924 what is wanted and the second points to where the information is to be placed.
3925 The current list of available information is:
3926
3927 PCRE_CONFIG_UTF8
3928
3929 The output is an integer that is set to one if UTF-8 support is available;
3930 otherwise it is set to zero.
3931
3932 PCRE_CONFIG_NEWLINE
3933
3934 The output is an integer that it set to the value of the code that is used for
3935 newline. It is either LF (10) or CR (13).
3936
3937 PCRE_CONFIG_LINK_SIZE
3938
3939 The output is an integer that contains the number of bytes used for internal
3940 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3941
3942 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3943
3944 The output is an integer that contains the threshold above which the POSIX
3945 interface uses malloc() for output vectors. See item 31 above.
3946
3947 PCRE_CONFIG_MATCH_LIMIT
3948
3949 The output is an unsigned integer that contains the default limit of the number
3950 of match() calls in a pcre_exec() execution. See 42 above.
3951
3952 44. pcretest has been upgraded by the addition of the -C option. This causes it
3953 to extract all the available output from the new pcre_config() function, and to
3954 output it. The program then exits immediately.
3955
3956 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3957 order to support additional features. One way would have been to define
3958 pcre_exec2() (for example) with extra arguments, but this would not have been
3959 extensible, and would also have required all calls to the original function to
3960 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3961 is used for passing in "extra" data from pcre_study().
3962
3963 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3964 contains the following fields:
3965
3966 flags a bitmap indicating which of the following fields are set
3967 study_data opaque data from pcre_study()
3968 match_limit a way of specifying a limit on match() calls for a specific
3969 call to pcre_exec()
3970 callout_data data for callouts (see 49 below)
3971
3972 The flag bits are also defined in pcre.h, and are
3973
3974 PCRE_EXTRA_STUDY_DATA
3975 PCRE_EXTRA_MATCH_LIMIT
3976 PCRE_EXTRA_CALLOUT_DATA
3977
3978 The pcre_study() function now returns one of these new pcre_extra blocks, with
3979 the actual study data pointed to by the study_data field, and the
3980 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3981 before. That is, this change is entirely upwards-compatible and requires no
3982 change to existing code.
3983
3984 If you want to pass in additional data to pcre_exec(), you can either place it
3985 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3986 block.
3987
3988 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3989 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3990 times with different match limits, until it finds the minimum value needed for
3991 pcre_exec() to complete. The value is then output. This can be instructive; for
3992 most simple matches the number is quite small, but for pathological cases it
3993 gets very large very quickly.
3994
3995 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3996 returns the size of the data block pointed to by the study_data field in a
3997 pcre_extra block, that is, the value that was passed as the argument to
3998 pcre_malloc() when PCRE was getting memory in which to place the information
3999 created by pcre_study(). The fourth argument should point to a size_t variable.
4000 pcretest has been extended so that this information is shown after a successful
4001 pcre_study() call when information about the compiled regex is being displayed.
4002
4003 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
4004 because what follows is always an absolute path. (Later: it turns out that this
4005 is more than cosmetic for MinGW, because it doesn't like empty path
4006 components.)
4007
4008 49. Some changes have been made to the callout feature (see 28 above):
4009
4010 (i) A callout function now has three choices for what it returns:
4011
4012 0 => success, carry on matching
4013 > 0 => failure at this point, but backtrack if possible
4014 < 0 => serious error, return this value from pcre_exec()
4015
4016 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
4017 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
4018 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
4019 use by callout functions. It will never be used by PCRE itself.
4020
4021 (ii) The pcre_extra structure (see 45 above) has a void * field called
4022 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
4023 pcre_callout_block structure has a field of the same name. The contents of
4024 the field passed in the pcre_extra structure are passed to the callout
4025 function in the corresponding field in the callout block. This makes it
4026 easier to use the same callout-containing regex from multiple threads. For
4027 testing, the pcretest program has a new data escape
4028
4029 \C*n pass the number n (may be negative) as callout_data
4030
4031 If the callout function in pcretest receives a non-zero value as
4032 callout_data, it returns that value.
4033
4034 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
4035 there were some redundant $(CFLAGS) in commands that are now specified as
4036 $(LINK), which already includes $(CFLAGS).
4037
4038 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
4039 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
4040 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
4041 one-byte characters throughout. Note that case-insensitive matching applies
4042 only to characters whose values are less than 256. PCRE doesn't support the
4043 notion of cases for higher-valued characters.
4044
4045 (i) A character class whose characters are all within 0-255 is handled as
4046 a bit map, and the map is inverted for negative classes. Previously, a
4047 character > 255 always failed to match such a class; however it should
4048 match if the class was a negative one (e.g. [^ab]). This has been fixed.
4049
4050 (ii) A negated character class with a single character < 255 is coded as
4051 "not this character" (OP_NOT). This wasn't working properly when the test
4052 character was multibyte, either singly or repeated.
4053
4054 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
4055 mode, for example: \x{100}{2,3}.
4056
4057 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
4058 singly or repeated) now correctly test multibyte characters. However,
4059 PCRE doesn't recognize any characters with values greater than 255 as
4060 digits, spaces, or word characters. Such characters always match \D, \S,
4061 and \W, and never match \d, \s, or \w.
4062
4063 (v) Classes may now contain characters and character ranges with values
4064 greater than 255. For example: [ab\x{100}-\x{400}].
4065
4066 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
4067 PCRE in UTF-8 mode.
4068
4069 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
4070 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
4071 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
4072 value.)
4073
4074 53. The single man page has become too large. I have therefore split it up into
4075 a number of separate man pages. These also give rise to individual HTML pages;
4076 these are now put in a separate directory, and there is an index.html page that
4077 lists them all. Some hyperlinking between the pages has been installed.
4078
4079 54. Added convenience functions for handling named capturing parentheses.
4080
4081 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
4082 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
4083 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
4084 are faulted.
4085
4086 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
4087 calling configure. These values are used when compiling the dftables.c program
4088 which is run to generate the source of the default character tables. They
4089 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
4090 you will need to set these values.
4091
4092 57. Updated the building process for Windows DLL, as provided by Fred Cox.
4093
4094
4095 Version 3.9 02-Jan-02
4096 ---------------------
4097
4098 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
4099
4100 2. If --disable-static was given, the building process failed when trying to
4101 build pcretest and pcregrep. (For some reason it was using libtool to compile
4102 them, which is not right, as they aren't part of the library.)
4103
4104
4105 Version 3.8 18-Dec-01
4106 ---------------------
4107
4108 1. The experimental UTF-8 code was completely screwed up. It was packing the
4109 bytes in the wrong order. How dumb can you get?
4110
4111
4112 Version 3.7 29-Oct-01
4113 ---------------------
4114
4115 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
4116 This caused pcretest, when used on the test data, to segfault. Unfortunately,
4117 this didn't happen under Solaris 8, where I normally test things.
4118
4119 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
4120 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
4121 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
4122 this fix an hour or so after the initial 3.7 release.)
4123
4124
4125 Version 3.6 23-Oct-01
4126 ---------------------
4127
4128 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
4129 offsets passed as NULL with zero offset count.
4130
4131 2. The config.guess and config.sub files had not been updated when I moved to
4132 the latest autoconf.
4133
4134
4135 Version 3.5 15-Aug-01
4136 ---------------------
4137
4138 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
4139 had been forgotten.
4140
4141 2. By using declared but undefined structures, we can avoid using "void"
4142 definitions in pcre.h while keeping the internal definitions of the structures
4143 private.
4144
4145 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
4146 user point of view, this means that both static and shared libraries are built
4147 by default, but this can be individually controlled. More of the work of
4148 handling this static/shared cases is now inside libtool instead of PCRE's make
4149 file.
4150
4151 4. The pcretest utility is now installed along with pcregrep because it is
4152 useful for users (to test regexs) and by doing this, it automatically gets
4153 relinked by libtool. The documentation has been turned into a man page, so
4154 there are now .1, .txt, and .html versions in /doc.
4155
4156 5. Upgrades to pcregrep:
4157 (i) Added long-form option names like gnu grep.
4158 (ii) Added --help to list all options with an explanatory phrase.
4159 (iii) Added -r, --recursive to recurse into sub-directories.
4160 (iv) Added -f, --file to read patterns from a file.
4161
4162 6. pcre_exec() was referring to its "code" argument before testing that
4163 argument for NULL (and giving an error if it was NULL).
4164
4165 7. Upgraded Makefile.in to allow for compiling in a different directory from
4166 the source directory.
4167
4168 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
4169 options bits, the pointer it was passed was to an int instead of to an unsigned
4170 long int. This mattered only on 64-bit systems.
4171
4172 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
4173 generated) instead of pcre.in, which it its source. Also made the same change
4174 in several of the .c files.
4175
4176 10. A new release of gcc defines printf() as a macro, which broke pcretest
4177 because it had an ifdef in the middle of a string argument for printf(). Fixed
4178 by using separate calls to printf().
4179
4180 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4181 script, to force use of CR or LF instead of \n in the source. On non-Unix
4182 systems, the value can be set in config.h.
4183
4184 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4185 absolute limit. Changed the text of the error message to make this clear, and
4186 likewise updated the man page.
4187
4188 13. The limit of 99 on the number of capturing subpatterns has been removed.
4189 The new limit is 65535, which I hope will not be a "real" limit.
4190
4191
4192 Version 3.4 22-Aug-00
4193 ---------------------
4194
4195 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4196
4197 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4198
4199
4200 Version 3.3 01-Aug-00
4201 ---------------------
4202
4203 1. If an octal character was given, but the value was greater than \377, it
4204 was not getting masked to the least significant bits, as documented. This could
4205 lead to crashes in some systems.
4206
4207 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4208 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4209
4210 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4211 These just pass their arguments on to (pcre_free)(), but they are provided
4212 because some uses of PCRE bind it to non-C systems that can call its functions,
4213 but cannot call free() or pcre_free() directly.
4214
4215 4. Add "make test" as a synonym for "make check". Corrected some comments in
4216 the Makefile.
4217
4218 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4219 Makefile.
4220
4221 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4222 command called pgrep for grepping around the active processes.
4223
4224 7. Added the beginnings of support for UTF-8 character strings.
4225
4226 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4227 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4228 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4229 out for the ar command.)
4230
4231
4232 Version 3.2 12-May-00
4233 ---------------------
4234
4235 This is purely a bug fixing release.
4236
4237 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4238 of ZA. This was just one example of several cases that could provoke this bug,
4239 which was introduced by change 9 of version 2.00. The code for breaking
4240 infinite loops after an iteration that matches an empty string was't working
4241 correctly.
4242
4243 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4244 when matched against abbab (for example). After matching an empty string, it
4245 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4246 caused it to match further down the string than it should.
4247
4248 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4249 was there because it doesn't seem to be needed, and it causes trouble on some
4250 systems, as it is not a Standard C header. It has been removed.
4251
4252 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4253 were reported on the Macintosh. The changes were from
4254
4255 while ((c = *(++ptr)) != 0 && c != '\n');
4256 to
4257 while ((c = *(++ptr)) != 0 && c != '\n') ;
4258
4259 Totally extraordinary, but if that's what it takes...
4260
4261 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4262 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4263 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4264 assumes the way PCRE uses memmove() (always moving upwards).
4265
4266 6. PCRE is being used in one environment where strchr() is not available. There
4267 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4268 faster code anyway.
4269
4270
4271 Version 3.1 09-Feb-00
4272 ---------------------
4273
4274 The only change in this release is the fixing of some bugs in Makefile.in for
4275 the "install" target:
4276
4277 (1) It was failing to install pcreposix.h.
4278
4279 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4280
4281
4282 Version 3.0 01-Feb-00
4283 ---------------------
4284
4285 1. Add support for the /+ modifier to perltest (to output $` like it does in
4286 pcretest).
4287
4288 2. Add support for the /g modifier to perltest.
4289
4290 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4291 matches null strings.
4292
4293 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4294 pattern. Perl treats empty patterns specially - it reuses the most recent
4295 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4296 effect.
4297
4298 5. The POSIX interface was broken in that it was just handing over the POSIX
4299 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4300 required a bigger vector, with some working space on the end. This means that
4301 the POSIX wrapper now has to get and free some memory, and copy the results.
4302
4303 6. Added some simple autoconf support, placing the test data and the
4304 documentation in separate directories, re-organizing some of the
4305 information files, and making it build pcre-config (a GNU standard). Also added
4306 libtool support for building PCRE as a shared library, which is now the
4307 default.
4308
4309 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4310 09 are not valid octal constants. Single digits will be used for minor values
4311 less than 10.
4312
4313 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4314 existing programs that set these in the POSIX interface can use PCRE without
4315 modification.
4316
4317 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4318 return all that pcre_info() returns, plus additional data. The pcre_info()
4319 function is retained for compatibility, but is considered to be obsolete.
4320
4321 10. Added experimental recursion feature (?R) to handle one common case that
4322 Perl 5.6 will be able to do with (?p{...}).
4323
4324 11. Added support for POSIX character classes like [:alpha:], which Perl is
4325 adopting.
4326
4327
4328 Version 2.08 31-Aug-99
4329 ----------------------
4330
4331 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4332 trying to match at the startoffset position, but instead was moving forward to
4333 the next newline as if a previous match had failed.
4334
4335 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4336 and could get into a loop if a null string was matched other than at the start
4337 of the subject.
4338
4339 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4340 be distinguished at compile time, and for completeness also added PCRE_DATE.
4341
4342 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4343 in GnuWin32 environments.
4344
4345
4346 Version 2.07 29-Jul-99
4347 ----------------------
4348
4349 1. The documentation is now supplied in plain text form and HTML as well as in
4350 the form of man page sources.
4351
4352 2. C++ compilers don't like assigning (void *) values to other pointer types.
4353 In particular this affects malloc(). Although there is no problem in Standard
4354 C, I've put in casts to keep C++ compilers happy.
4355
4356 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4357 should be (const char *).
4358
4359 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4360 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4361 However, I haven't made this a standard facility. The documentation doesn't
4362 mention it, and the Makefile doesn't support it.
4363
4364 5. The Makefile now contains an "install" target, with editable destinations at
4365 the top of the file. The pcretest program is not installed.
4366
4367 6. pgrep -V now gives the PCRE version number and date.
4368
4369 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4370 causing the entire string to be ignored, instead of just the last character.
4371
4372 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4373 non-matching string, it can take a very, very long time, even for strings of
4374 quite modest length, because of the nested recursion. PCRE now does better in
4375 some of these cases. It does this by remembering the last required literal
4376 character in the pattern, and pre-searching the subject to ensure it is present
4377 before running the real match. In other words, it applies a heuristic to detect
4378 some types of certain failure quickly, and in the above example, if presented
4379 with a string that has no trailing " it gives "no match" very quickly.
4380
4381 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4382 other alternatives are tried instead.
4383
4384
4385 Version 2.06 09-Jun-99
4386 ----------------------
4387
4388 1. Change pcretest's output for amount of store used to show just the code
4389 space, because the remainder (the data block) varies in size between 32-bit and
4390 64-bit systems.
4391
4392 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4393 start matching at. This allows lookbehinds to work when searching for multiple
4394 occurrences in a string.
4395
4396 3. Added additional options to pcretest for testing multiple occurrences:
4397
4398 /+ outputs the rest of the string that follows a match
4399 /g loops for multiple occurrences, using the new startoffset argument
4400 /G loops for multiple occurrences by passing an incremented pointer
4401
4402 4. PCRE wasn't doing the "first character" optimization for patterns starting
4403 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4404 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4405 the letter 'x'. On long subject strings, this gives a significant speed-up.
4406
4407
4408 Version 2.05 21-Apr-99
4409 ----------------------
4410
4411 1. Changed the type of magic_number from int to long int so that it works
4412 properly on 16-bit systems.
4413
4414 2. Fixed a bug which caused patterns starting with .* not to work correctly
4415 when the subject string contained newline characters. PCRE was assuming
4416 anchoring for such patterns in all cases, which is not correct because .* will
4417 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4418 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4419 must be retried after every newline in the subject.
4420
4421
4422 Version 2.04 18-Feb-99
4423 ----------------------
4424
4425 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4426 computation of the store needed to hold the pattern was incorrect (too large).
4427 If such patterns were nested a few deep, this could multiply and become a real
4428 problem.
4429
4430 2. Added /M option to pcretest to show the memory requirement of a specific
4431 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4432
4433 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4434 compiled in such a way that the backtracking after subsequent failure was
4435 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4436 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4437
4438
4439 Version 2.03 02-Feb-99
4440 ----------------------
4441
4442 1. Fixed typo and small mistake in man page.
4443
4444 2. Added 4th condition (GPL supersedes if conflict) and created separate
4445 LICENCE file containing the conditions.
4446
4447 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4448 Perl, that is the internal \ allows the delimiter to be included in the
4449 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4450 the final delimiter, add \ to the end of the pattern (to test the error).
4451
4452 4. Added the convenience functions for extracting substrings after a successful
4453 match. Updated pcretest to make it able to test these functions.
4454
4455
4456 Version 2.02 14-Jan-99
4457 ----------------------
4458
4459 1. Initialized the working variables associated with each extraction so that
4460 their saving and restoring doesn't refer to uninitialized store.
4461
4462 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4463 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4464 fix the problem.
4465
4466 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4467 calls, and wasn't printing the correct value for compiling calls. Increased the
4468 default value of LOOPREPEAT, and the number of significant figures in the
4469 times.
4470
4471 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4472
4473 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4474 a building problem on Windows NT with a FAT file system.
4475
4476
4477 Version 2.01 21-Oct-98
4478 ----------------------
4479
4480 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4481 to character tables built by pcre_maketables() in the current locale. If NULL
4482 is passed, the default tables are used.
4483
4484
4485 Version 2.00 24-Sep-98
4486 ----------------------
4487
4488 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4489 it any more.
4490
4491 2. Allow quantification of (?>) groups, and make it work correctly.
4492
4493 3. The first character computation wasn't working for (?>) groups.
4494
4495 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4496 end of the subject) and add 5.005's \z, which really does match only at the
4497 very end of the subject.
4498
4499 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4500
4501 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4502 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4503 localized options. All options to pcre_study() were also removed.
4504
4505 7. Add other new features from 5.005:
4506
4507 $(?<= positive lookbehind
4508 $(?<! negative lookbehind
4509 (?imsx-imsx) added the unsetting capability
4510 such a setting is global if at outer level; local otherwise
4511 (?imsx-imsx:) non-capturing groups with option setting
4512 (?(cond)re|re) conditional pattern matching
4513
4514 A backreference to itself in a repeated group matches the previous
4515 captured string.
4516
4517 8. General tidying up of studying (both automatic and via "study")
4518 consequential on the addition of new assertions.
4519
4520 9. As in 5.005, unlimited repeated groups that could match an empty substring
4521 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4522 runtime if any iteration does actually match an empty substring.
4523
4524 10. Include the RunTest script in the distribution.
4525
4526 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4527 discrepancies, some of which were old and were also with respect to 5.004. They
4528 have now been fixed.
4529
4530
4531 Version 1.09 28-Apr-98
4532 ----------------------
4533
4534 1. A negated single character class followed by a quantifier with a minimum
4535 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4536 program crashes, or just wrong answers. This did not apply to negated classes
4537 containing more than one character, or to minima other than one.
4538
4539
4540 Version 1.08 27-Mar-98
4541 ----------------------
4542
4543 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4544
4545 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4546 latter must appear before anything that relies on it in the pattern.
4547
4548
4549 Version 1.07 16-Feb-98
4550 ----------------------
4551
4552 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4553 repeat of a potentially empty string).
4554
4555
4556 Version 1.06 23-Jan-98
4557 ----------------------
4558
4559 1. Added Markus Oberhumer's little patches for C++.
4560
4561 2. Literal strings longer than 255 characters were broken.
4562
4563
4564 Version 1.05 23-Dec-97
4565 ----------------------
4566
4567 1. Negated character classes containing more than one character were failing if
4568 PCRE_CASELESS was set at run time.
4569
4570
4571 Version 1.04 19-Dec-97
4572 ----------------------
4573
4574 1. Corrected the man page, where some "const" qualifiers had been omitted.
4575
4576 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4577 input syntax.
4578
4579 3. Fixed memory leak which occurred when a regex with back references was
4580 matched with an offsets vector that wasn't big enough. The temporary memory
4581 that is used in this case wasn't being freed if the match failed.
4582
4583 4. Tidied pcretest to ensure it frees memory that it gets.
4584
4585 5. Temporary memory was being obtained in the case where the passed offsets
4586 vector was exactly big enough.
4587
4588 6. Corrected definition of offsetof() from change 5 below.
4589
4590 7. I had screwed up change 6 below and broken the rules for the use of
4591 setjmp(). Now fixed.
4592
4593
4594 Version 1.03 18-Dec-97
4595 ----------------------
4596
4597 1. A erroneous regex with a missing opening parenthesis was correctly
4598 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4599 on some systems.
4600
4601 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4602 it was reported that one broken compiler failed on the former because "code" is
4603 also an independent variable.
4604
4605 3. The erroneous regex a[]b caused an array overrun reference.
4606
4607 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4608 fail on data ending with that character. (It was going on too far, and checking
4609 the next character, typically a binary zero.) This was specific to the
4610 optimized code for single-character negative classes.
4611
4612 5. Added a contributed patch from the TIN world which does the following:
4613
4614 + Add an undef for memmove, in case the the system defines a macro for it.
4615
4616 + Add a definition of offsetof(), in case there isn't one. (I don't know
4617 the reason behind this - offsetof() is part of the ANSI standard - but
4618 it does no harm).
4619
4620 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4621 most of the places where whitespace preceded '#'. I have given up and
4622 allowed the remaining 2 cases to be at the margin.
4623
4624 + Rename some variables in pcre to eliminate shadowing. This seems very
4625 pedantic, but does no harm, of course.
4626
4627 6. Moved the call to setjmp() into its own function, to get rid of warnings
4628 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4629
4630 7. Constructs such as \d{8,} were compiling into the equivalent of
4631 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4632 outcome, but in this particular case used more store than had been allocated,
4633 which caused the bug to be discovered because it threw up an internal error.
4634
4635 8. The debugging code in both pcre and pcretest for outputting the compiled
4636 form of a regex was going wrong in the case of back references followed by
4637 curly-bracketed repeats.
4638
4639
4640 Version 1.02 12-Dec-97
4641 ----------------------
4642
4643 1. Typos in pcre.3 and comments in the source fixed.
4644
4645 2. Applied a contributed patch to get rid of places where it used to remove
4646 'const' from variables, and fixed some signed/unsigned and uninitialized
4647 variable warnings.
4648
4649 3. Added the "runtest" target to Makefile.
4650
4651 4. Set default compiler flag to -O2 rather than just -O.
4652
4653
4654 Version 1.01 19-Nov-97
4655 ----------------------
4656
4657 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4658 like /([ab]*)*/, that is, for classes with more than one character in them.
4659
4660 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4661 as /((?>a*))*/ (a PCRE_EXTRA facility).
4662
4663
4664 Version 1.00 18-Nov-97
4665 ----------------------
4666
4667 1. Added compile-time macros to support systems such as SunOS4 which don't have
4668 memmove() or strerror() but have other things that can be used instead.
4669
4670 2. Arranged that "make clean" removes the executables.
4671
4672
4673 Version 0.99 27-Oct-97
4674 ----------------------
4675
4676 1. Fixed bug in code for optimizing classes with only one character. It was
4677 initializing a 32-byte map regardless, which could cause it to run off the end
4678 of the memory it had got.
4679
4680 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4681
4682
4683 Version 0.98 22-Oct-97
4684 ----------------------
4685
4686 1. Fixed bug in code for handling temporary memory usage when there are more
4687 back references than supplied space in the ovector. This could cause segfaults.
4688
4689
4690 Version 0.97 21-Oct-97
4691 ----------------------
4692
4693 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4694
4695 2. Optimized negated single characters not to use a bit map.
4696
4697 3. Brought error texts together as macro definitions; clarified some of them;
4698 fixed one that was wrong - it said "range out of order" when it meant "invalid
4699 escape sequence".
4700
4701 4. Changed some char * arguments to const char *.
4702
4703 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4704
4705 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4706 pcretest.
4707
4708
4709 Version 0.96 16-Oct-97
4710 ----------------------
4711
4712 1. Added a simple "pgrep" utility to the distribution.
4713
4714 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4715 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4716 where "ddd" means "one or more decimal digits".
4717
4718 3. Fixed serious bug. If a pattern had a back reference, but the call to
4719 pcre_exec() didn't supply a large enough ovector to record the related
4720 identifying subpattern, the match always failed. PCRE now remembers the number
4721 of the largest back reference, and gets some temporary memory in which to save
4722 the offsets during matching if necessary, in order to ensure that
4723 backreferences always work.
4724
4725 4. Increased the compatibility with Perl in a number of ways:
4726
4727 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4728 to request this handling. The option can be set at compile or exec time.
4729
4730 (b) $ matches before a terminating newline by default; an option
4731 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4732 mode). The option can be set at compile or exec time.
4733
4734 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4735 the same as Perl's. If the decimal number it represents is less than 10
4736 or there aren't that many previous left capturing parentheses, an octal
4737 escape is read. Inside a character class, it's always an octal escape,
4738 even if it is a single digit.
4739
4740 (d) An escaped but undefined alphabetic character is taken as a literal,
4741 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4742 escapes.
4743
4744 (e) {0} is now permitted. (The previous item is removed from the compiled
4745 pattern).
4746
4747 5. Changed all the names of code files so that the basic parts are no longer
4748 than 10 characters, and abolished the teeny "globals.c" file.
4749
4750 6. Changed the handling of character classes; they are now done with a 32-byte
4751 bit map always.
4752
4753 7. Added the -d and /D options to pcretest to make it possible to look at the
4754 internals of compilation without having to recompile pcre.
4755
4756
4757 Version 0.95 23-Sep-97
4758 ----------------------
4759
4760 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4761 \x20 at the start of a run of normal characters. These were being treated as
4762 real characters, instead of the source characters being re-checked.
4763
4764
4765 Version 0.94 18-Sep-97
4766 ----------------------
4767
4768 1. The functions are now thread-safe, with the caveat that the global variables
4769 containing pointers to malloc() and free() or alternative functions are the
4770 same for all threads.
4771
4772 2. Get pcre_study() to generate a bitmap of initial characters for non-
4773 anchored patterns when this is possible, and use it if passed to pcre_exec().
4774
4775
4776 Version 0.93 15-Sep-97
4777 ----------------------
4778
4779 1. /(b)|(:+)/ was computing an incorrect first character.
4780
4781 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4782 but not actually doing anything yet.
4783
4784 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4785 as Perl does (e.g. [-az] or [az-]).
4786
4787 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4788 all possible positions.
4789
4790 5. Split up into different modules to avoid including unneeded functions in a
4791 compiled binary. However, compile and exec are still in one module. The "study"
4792 function is split off.
4793
4794 6. The character tables are now in a separate module whose source is generated
4795 by an auxiliary program - but can then be edited by hand if required. There are
4796 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4797 toupper() in the code.
4798
4799 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4800 make them global. Abolish the function for setting them, as the caller can now
4801 set them directly.
4802
4803
4804 Version 0.92 11-Sep-97
4805 ----------------------
4806
4807 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4808 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4809
4810 2. Caseless matching was not working in character classes if the characters in
4811 the pattern were in upper case.
4812
4813 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4814
4815 4. Make PCRE_ANCHORED public and accept as a compile option.
4816
4817 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4818 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4819 pass them.
4820
4821 6. Give an error if bad option bits passed at compile or run time.
4822
4823 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4824 pcretest to cause it to pass that flag.
4825
4826 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4827 options, and the first character, if set.
4828
4829 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4830
4831
4832 Version 0.91 10-Sep-97
4833 ----------------------
4834
4835 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4836 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4837
4838 2. PCRE was looping on encountering an indefinitely repeated back reference to
4839 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4840 Perl does - treats the match as successful.
4841
4842 ****

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