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Revision 1464 - (show annotations)
Fri Mar 14 11:45:56 2014 UTC (5 years, 7 months ago) by zherczeg
File size: 263855 byte(s)
Error occurred while calculating annotation data.
Disable incorrect error messages reported by the JIT test program.
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.35-RC1 04-March-2014
5 ------------------------------
6
7 1. A new flag is set, when property checks are present in an XCLASS.
8 When this flag is not set, PCRE can perform certain optimizations
9 such as studying these XCLASS-es.
10
11 2. The auto-possessification of character sets were improved: a normal
12 and an extended character set can be compared now. Furthermore
13 the JIT compiler optimizes more character set checks.
14
15 3. Got rid of some compiler warnings for potentially uninitialized variables
16 that show up only when compiled with -O2.
17
18 4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
19 of a match later then the end of the match. The pcretest program was not
20 handling the case sensibly - it was outputting from the start to the next
21 binary zero. It now reports this situation in a message, and outputs the
22 text from the end to the start.
23
24 5. Fast forward search is improved in JIT. Instead of the first three
25 characters, any three characters with fixed position can be searched.
26 Search order: first, last, middle.
27
28 6. Improve character range checks in JIT. Characters are read by an inprecise
29 function now, which returns with an unknown value if the character code is
30 above a certain treshold (e.g: 256). The only limitation is that the value
31 must be bigger than the treshold as well. This function is useful, when
32 the characters above the treshold are handled in the same way.
33
34 7. The macros whose names start with RAWUCHAR are placeholders for a future
35 mode in which only the bottom 21 bits of 32-bit data items are used. To
36 make this more memorable for those maintaining the code, the names have
37 been changed to start with UCHAR21, and an extensive comment has been added
38 to their definition.
39
40 8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
41 to the export list in Makefile.am (they were accidentally omitted from the
42 8.34 tarball).
43
44 9. The informational output from pcretest used the phrase "starting byte set"
45 which is inappropriate for the 16-bit and 32-bit libraries. As the output
46 for "first char" and "need char" really means "non-UTF-char", I've changed
47 "byte" to "char", and slightly reworded the output. The documentation about
48 these values has also been (I hope) clarified.
49
50 10. Another JIT related optimization: use table jumps for selecting the correct
51 backtracking path, when more than four alternatives are present inside a
52 bracket.
53
54 11. Empty match is not possible, when the minimum length is greater than zero,
55 and there is no \K in the pattern. JIT should avoid empty match checks in
56 such cases.
57
58 12. In a caseless character class with UCP support, when a character with more
59 than one alternative case was not the first character of a range, not all
60 the alternative cases were added to the class. For example, s and \x{17f}
61 are both alternative cases for S: the class [RST] was handled correctly,
62 but [R-T] was not.
63
64 13. The configure.ac file always checked for pthread support when JIT was
65 enabled. This is not used in Windows, so I have put this test inside a
66 check for the presence of windows.h (which was already tested for).
67
68 14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
69 The algorithm provides a way to skip certain starting offsets, and usually
70 faster than linear prefix searches.
71
72 15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
73 as for 'fr_FR' and 'french'. For some reason, however, it then used the
74 Windows-specific input and output files, which have 'french' screwed in.
75 So this could never have worked. One of the problems with locales is that
76 they aren't always the same. I have now updated RunTest so that it checks
77 the output of the locale test (test 3) against three different output
78 files, and it allows the test to pass if any one of them matches. With luck
79 this should make the test pass on some versions of Solaris where it was
80 failing. Because of the uncertainty, the script did not used to stop if
81 test 3 failed; it now does. If further versions of a French locale ever
82 come to light, they can now easily be added.
83
84 16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
85 there was a message during ./configure, but it did not stop. This now
86 provokes an error. The invalid example in README has been corrected.
87 If a value less than the minimum is given, the minimum value has always
88 been used, but now a warning is given.
89
90 17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
91 was a bug in the test system, which is now fixed. Also, the list of various
92 configurations that are tested for each release did not have one with both
93 16/32 bits and --enable-bar-anycrlf. It now does.
94
95 18. pcretest was missing "-C bsr" for displaying the \R default setting.
96
97 19. Little endian PowerPC systems are supported now by the JIT compiler.
98
99 20. The fast forward newline mechanism could enter to an infinite loop on
100 certain invalid UTF-8 input. Although we don't support these cases
101 this issue can be fixed by a performance optimization.
102
103 21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
104 not take account if existing stack usage. There is now a new global
105 variable called pcre_stack_guard that can be set to point to an external
106 function to check stack availability. It is called at the start of
107 processing every parenthesized group.
108
109 22. A typo in the code meant that in ungreedy mode the max/min qualifier
110 behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
111 not match "ab".
112
113 23. When UTF was disabled, the JIT program reported some incorrect compile
114 errors. These messages are silenced now.
115
116
117 Version 8.34 15-December-2013
118 -----------------------------
119
120 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
121 executable memory. Patch inspired by Carsten Klein.
122
123 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
124 this macro is never tested and has no effect, because the work to support
125 coverage involves only compiling and linking options and special targets in
126 the Makefile. The comment in config.h implied that defining the macro would
127 enable coverage support, which is totally false. There was also support for
128 setting this macro in the CMake files (my fault, I just copied it from
129 configure). SUPPORT_GCOV has now been removed.
130
131 3. Make a small performance improvement in strlen16() and strlen32() in
132 pcretest.
133
134 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
135 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
136 these cases). There was also one in pcretest.c.
137
138 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
139
140 6. In UTF mode, the code for checking whether a group could match an empty
141 string (which is used for indefinitely repeated groups to allow for
142 breaking an infinite loop) was broken when the group contained a repeated
143 negated single-character class with a character that occupied more than one
144 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
145 UTF-8 mode). The effect was undefined: the group might or might not be
146 deemed as matching an empty string, or the program might have crashed.
147
148 7. The code for checking whether a group could match an empty string was not
149 recognizing that \h, \H, \v, \V, and \R must match a character.
150
151 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
152 an empty string. If it can, pcretest shows this in its information output.
153
154 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
155 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
156 matched by pcre_exec() without using JIT:
157
158 (a) If the rest of the pattern did not match after a maximal run of
159 grapheme clusters, the code for backing up to try with fewer of them
160 did not always back up over a full grapheme when characters that do not
161 have the modifier quality were involved, e.g. Hangul syllables.
162
163 (b) If the match point in a subject started with modifier character, and
164 there was no match, the code could incorrectly back up beyond the match
165 point, and potentially beyond the first character in the subject,
166 leading to a segfault or an incorrect match result.
167
168 10. A conditional group with an assertion condition could lead to PCRE
169 recording an incorrect first data item for a match if no other first data
170 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
171 first data item, and therefore matched "ca" after "c" instead of at the
172 start.
173
174 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
175 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
176
177 12. The source of pcregrep now includes z/OS-specific code so that it can be
178 compiled for z/OS as part of the special z/OS distribution.
179
180 13. Added the -T and -TM options to pcretest.
181
182 14. The code in pcre_compile.c for creating the table of named capturing groups
183 has been refactored. Instead of creating the table dynamically during the
184 actual compiling pass, the information is remembered during the pre-compile
185 pass (on the stack unless there are more than 20 named groups, in which
186 case malloc() is used) and the whole table is created before the actual
187 compile happens. This has simplified the code (it is now nearly 150 lines
188 shorter) and prepared the way for better handling of references to groups
189 with duplicate names.
190
191 15. A back reference to a named subpattern when there is more than one of the
192 same name now checks them in the order in which they appear in the pattern.
193 The first one that is set is used for the reference. Previously only the
194 first one was inspected. This change makes PCRE more compatible with Perl.
195
196 16. Unicode character properties were updated from Unicode 6.3.0.
197
198 17. The compile-time code for auto-possessification has been refactored, based
199 on a patch by Zoltan Herczeg. It now happens after instead of during
200 compilation. The code is cleaner, and more cases are handled. The option
201 PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
202 options in pcretest are provided to set it. It can also be set by
203 (*NO_AUTO_POSSESS) at the start of a pattern.
204
205 18. The character VT has been added to the default ("C" locale) set of
206 characters that match \s and are generally treated as white space,
207 following this same change in Perl 5.18. There is now no difference between
208 "Perl space" and "POSIX space". Whether VT is treated as white space in
209 other locales depends on the locale.
210
211 19. The code for checking named groups as conditions, either for being set or
212 for being recursed, has been refactored (this is related to 14 and 15
213 above). Processing unduplicated named groups should now be as fast at
214 numerical groups, and processing duplicated groups should be faster than
215 before.
216
217 20. Two patches to the CMake build system, by Alexander Barkov:
218
219 (1) Replace the "source" command by "." in CMakeLists.txt because
220 "source" is a bash-ism.
221
222 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
223 without these the CMake build does not work on Solaris.
224
225 21. Perl has changed its handling of \8 and \9. If there is no previously
226 encountered capturing group of those numbers, they are treated as the
227 literal characters 8 and 9 instead of a binary zero followed by the
228 literals. PCRE now does the same.
229
230 22. Following Perl, added \o{} to specify codepoints in octal, making it
231 possible to specify values greater than 0777 and also making them
232 unambiguous.
233
234 23. Perl now gives an error for missing closing braces after \x{... instead of
235 treating the string as literal. PCRE now does the same.
236
237 24. RunTest used to grumble if an inappropriate test was selected explicitly,
238 but just skip it when running all tests. This make it awkward to run ranges
239 of tests when one of them was inappropriate. Now it just skips any
240 inappropriate tests, as it always did when running all tests.
241
242 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
243 character types such as \d or \w, too many callouts were inserted, and the
244 data that they returned was rubbish.
245
246 26. In UCP mode, \s was not matching two of the characters that Perl matches,
247 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
248 were matched by \h. The code has now been refactored so that the lists of
249 the horizontal and vertical whitespace characters used for \h and \v (which
250 are defined only in one place) are now also used for \s.
251
252 27. Add JIT support for the 64 bit TileGX architecture.
253 Patch by Jiong Wang (Tilera Corporation).
254
255 28. Possessive quantifiers for classes (both explicit and automatically
256 generated) now use special opcodes instead of wrapping in ONCE brackets.
257
258 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
259 (because it's meaningless), this was not happening when PCRE_CASELESS was
260 set. Not wrong, but inefficient.
261
262 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
263 properties for \w, \d, etc) is present in a test regex. Otherwise if the
264 test contains no characters greater than 255, Perl doesn't realise it
265 should be using Unicode semantics.
266
267 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
268 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
269 does in Unicode mode.
270
271 32. Added the "forbid" facility to pcretest so that putting tests into the
272 wrong test files can sometimes be quickly detected.
273
274 33. There is now a limit (default 250) on the depth of nesting of parentheses.
275 This limit is imposed to control the amount of system stack used at compile
276 time. It can be changed at build time by --with-parens-nest-limit=xxx or
277 the equivalent in CMake.
278
279 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
280 errors. Perl warns for these when in warning mode, but PCRE has no facility
281 for giving warnings.
282
283 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
284 However, this was not working for (?!) because it is optimized to (*FAIL),
285 for which PCRE does not allow quantifiers. The optimization is now disabled
286 when a quantifier follows (?!). I can't see any use for this, but it makes
287 things uniform.
288
289 36. Perl no longer allows group names to start with digits, so I have made this
290 change also in PCRE. It simplifies the code a bit.
291
292 37. In extended mode, Perl ignores spaces before a + that indicates a
293 possessive quantifier. PCRE allowed a space before the quantifier, but not
294 before the possessive +. It now does.
295
296 38. The use of \K (reset reported match start) within a repeated possessive
297 group such as (a\Kb)*+ was not working.
298
299 40. Document that the same character tables must be used at compile time and
300 run time, and that the facility to pass tables to pcre_exec() and
301 pcre_dfa_exec() is for use only with saved/restored patterns.
302
303 41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
304 features for Builds with MSVC:
305
306 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
307 builds). The .rc files can be used to set FileDescription and many other
308 attributes.
309
310 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
311 This allows higher-level build scripts which want .pdb files to avoid
312 hard-coding the exact files needed."
313
314 42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
315 mean "start of word" and "end of word", respectively, as a transition aid.
316
317 43. A minimizing repeat of a class containing codepoints greater than 255 in
318 non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
319 compiled to use the heap for recursion.
320
321 44. Got rid of some compiler warnings for unused variables when UTF but not UCP
322 is configured.
323
324
325 Version 8.33 28-May-2013
326 ------------------------
327
328 1. Added 'U' to some constants that are compared to unsigned integers, to
329 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
330 variables that are added to signed variables, to ensure the result is
331 signed and can be negated.
332
333 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
334 CMake config files.
335
336 3. Revise the creation of config.h.generic so that all boolean macros are
337 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
338 overriding via -D on the command line possible.
339
340 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
341 to unsigned int is reported to make a quite noticeable speed difference in
342 a specific Windows environment. Testing on Linux did also appear to show
343 some benefit (and it is clearly not harmful). Also fixed the definition of
344 Xop which should be unsigned.
345
346 5. Related to (4), changing the definition of the intermediate variable cc
347 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
348 improvements.
349
350 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
351 unnecessary spaces.
352
353 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
354 and later.
355
356 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
357
358 9. Optimizing fast_forward_start_bits in JIT.
359
360 10. Adding support for callouts in JIT, and fixing some issues revealed
361 during this work. Namely:
362
363 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
364
365 (b) Minimum length was not checked before the matching is started.
366
367 11. The value of capture_last that is passed to callouts was incorrect in some
368 cases when there was a capture on one path that was subsequently abandoned
369 after a backtrack. Also, the capture_last value is now reset after a
370 recursion, since all captures are also reset in this case.
371
372 12. The interpreter no longer returns the "too many substrings" error in the
373 case when an overflowing capture is in a branch that is subsequently
374 abandoned after a backtrack.
375
376 13. In the pathological case when an offset vector of size 2 is used, pcretest
377 now prints out the matched string after a yield of 0 or 1.
378
379 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
380 Only supported by the JIT compiler at the moment.
381
382 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
383
384 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
385 offset of the starting point of the matching process, provided the offsets
386 vector is large enough.
387
388 17. The \A escape now records a lookbehind value of 1, though its execution
389 does not actually inspect the previous character. This is to ensure that,
390 in partial multi-segment matching, at least one character from the old
391 segment is retained when a new segment is processed. Otherwise, if there
392 are no lookbehinds in the pattern, \A might match incorrectly at the start
393 of a new segment.
394
395 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
396
397 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
398 gives some modest performance improvement in 8-bit mode.
399
400 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
401 be expressed in certain programming languages using Universal Character
402 Names.
403
404 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
405 which points out that "non characters" are not "characters that may not
406 appear in Unicode strings" but rather "characters that are reserved for
407 internal use and have only local meaning".
408
409 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
410 there was a conditional group that depended on an assertion, if the
411 assertion was false, the callout that immediately followed the alternation
412 in the condition was skipped when pcre_exec() was used for matching.
413
414 23. Allow an explicit callout to be inserted before an assertion that is the
415 condition for a conditional group, for compatibility with automatic
416 callouts, which always insert a callout at this point.
417
418 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
419 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
420
421 25. (*PRUNE) is now supported by the JIT compiler.
422
423 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
424
425 27. Fix the case where there are two or more SKIPs with arguments that may be
426 ignored.
427
428 28. (*SKIP) is now supported by the JIT compiler.
429
430 29. (*THEN) is now supported by the JIT compiler.
431
432 30. Update RunTest with additional test selector options.
433
434 31. The way PCRE handles backtracking verbs has been changed in two ways.
435
436 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
437 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
438 backtracking. In some cases this makes it more Perl-compatible, but Perl's
439 rather obscure rules do not always do the same thing.
440
441 (2) Previously, backtracking verbs were confined within assertions. This is
442 no longer the case for positive assertions, except for (*ACCEPT). Again,
443 this sometimes improves Perl compatibility, and sometimes does not.
444
445 32. A number of tests that were in test 2 because Perl did things differently
446 have been moved to test 1, because either Perl or PCRE has changed, and
447 these tests are now compatible.
448
449 32. Backtracking control verbs are now handled in the same way in JIT and
450 interpreter.
451
452 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
453 contained a forward subroutine reference caused a compile error.
454
455 34. Auto-detect and optimize limited repetitions in JIT.
456
457 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
458 blocking (*UTF) etc.
459
460 36. In the interpreter, maximizing pattern repetitions for characters and
461 character types now use tail recursion, which reduces stack usage.
462
463 37. The value of the max lookbehind was not correctly preserved if a compiled
464 and saved regex was reloaded on a host of different endianness.
465
466 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
467 of the compiled pattern block, expand the flags field from 16 to 32 bits
468 because it was almost full.
469
470 39. Try madvise first before posix_madvise.
471
472 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
473 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
474 original change locked out all matches of empty strings. This has been
475 changed so that one match of an empty string per line is recognized.
476 Subsequent searches on the same line (for colouring or for --only-matching,
477 for example) do not recognize empty strings.
478
479 41. Applied a user patch to fix a number of spelling mistakes in comments.
480
481 42. Data lines longer than 65536 caused pcretest to crash.
482
483 43. Clarified the data type for length and startoffset arguments for pcre_exec
484 and pcre_dfa_exec in the function-specific man pages, where they were
485 explicitly stated to be in bytes, never having been updated. I also added
486 some clarification to the pcreapi man page.
487
488 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
489 a segmentation fault.
490
491
492 Version 8.32 30-November-2012
493 -----------------------------
494
495 1. Improved JIT compiler optimizations for first character search and single
496 character iterators.
497
498 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
499 Patch by Daniel Richard G.
500
501 3. Single character iterator optimizations in the JIT compiler.
502
503 4. Improved JIT compiler optimizations for character ranges.
504
505 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
506 Reported by Giuseppe D'Angelo.
507
508 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
509 of a line, was being set incorrectly in cases where .* appeared inside
510 atomic brackets at the start of a pattern, or where there was a subsequent
511 *PRUNE or *SKIP.
512
513 7. Improved instruction cache flush for POWER/PowerPC.
514 Patch by Daniel Richard G.
515
516 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
517 grep:
518
519 (a) There is now no limit to the number of patterns to be matched.
520
521 (b) An error is given if a pattern is too long.
522
523 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
524 are now supported.
525
526 (d) --exclude-from and --include-from (multiple use) have been added.
527
528 (e) Exclusions and inclusions now apply to all files and directories, not
529 just to those obtained from scanning a directory recursively.
530
531 (f) Multiple uses of -f and --file-list are now supported.
532
533 (g) In a Windows environment, the default for -d has been changed from
534 "read" (the GNU grep default) to "skip", because otherwise the presence
535 of a directory in the file list provokes an error.
536
537 (h) The documentation has been revised and clarified in places.
538
539 9. Improve the matching speed of capturing brackets.
540
541 10. Changed the meaning of \X so that it now matches a Unicode extended
542 grapheme cluster.
543
544 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
545 out POSIX threads when JIT support is configured.
546
547 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
548
549 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
550 structure could go wrong in environments where size_t is not the same size
551 as int.
552
553 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
554 set.
555
556 15. The EBCDIC support had decayed; later updates to the code had included
557 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
558 general tidy up of EBCDIC-related issues, and the documentation was also
559 not quite right. There is now a test that can be run on ASCII systems to
560 check some of the EBCDIC-related things (but is it not a full test).
561
562 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
563 in a small tidy to the code.
564
565 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
566
567 18. If the --only-matching (-o) option in pcregrep is specified multiple
568 times, each one causes appropriate output. For example, -o1 -o2 outputs the
569 substrings matched by the 1st and 2nd capturing parentheses. A separating
570 string can be specified by --om-separator (default empty).
571
572 19. Improving the first n character searches.
573
574 20. Turn case lists for horizontal and vertical white space into macros so that
575 they are defined only once.
576
577 21. This set of changes together give more compatible Unicode case-folding
578 behaviour for characters that have more than one other case when UCP
579 support is available.
580
581 (a) The Unicode property table now has offsets into a new table of sets of
582 three or more characters that are case-equivalent. The MultiStage2.py
583 script that generates these tables (the pcre_ucd.c file) now scans
584 CaseFolding.txt instead of UnicodeData.txt for character case
585 information.
586
587 (b) The code for adding characters or ranges of characters to a character
588 class has been abstracted into a generalized function that also handles
589 case-independence. In UTF-mode with UCP support, this uses the new data
590 to handle characters with more than one other case.
591
592 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
593 whose other case is greater than 256 are now correctly matched
594 caselessly. Previously, the high codepoint matched the low one, but not
595 vice versa.
596
597 (d) The processing of \h, \H, \v, and \ in character classes now makes use
598 of the new class addition function, using character lists defined as
599 macros alongside the case definitions of 20 above.
600
601 (e) Caseless back references now work with characters that have more than
602 one other case.
603
604 (f) General caseless matching of characters with more than one other case
605 is supported.
606
607 22. Unicode character properties were updated from Unicode 6.2.0
608
609 23. Improved CMake support under Windows. Patch by Daniel Richard G.
610
611 24. Add support for 32-bit character strings, and UTF-32
612
613 25. Major JIT compiler update (code refactoring and bugfixing).
614 Experimental Sparc 32 support is added.
615
616 26. Applied a modified version of Daniel Richard G's patch to create
617 pcre.h.generic and config.h.generic by "make" instead of in the
618 PrepareRelease script.
619
620 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
621 pcre_compile.c when checking for a zero character.
622
623 28. Introducing a native interface for JIT. Through this interface, the compiled
624 machine code can be directly executed. The purpose of this interface is to
625 provide fast pattern matching, so several sanity checks are not performed.
626 However, feature tests are still performed. The new interface provides
627 1.4x speedup compared to the old one.
628
629 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
630 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
631 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
632
633 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
634 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
635 the "old" RFC 2279). Instead, it ended up passing a negative length to
636 pcre_exec().
637
638 31. Add support for GCC's visibility feature to hide internal functions.
639
640 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
641 "unknown -C option" after outputting 0 or 1.
642
643 33. There is now support for generating a code coverage report for the test
644 suite in environments where gcc is the compiler and lcov is installed. This
645 is mainly for the benefit of the developers.
646
647 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
648 unaddressable using valgrind annotations, allowing valgrind to detect
649 invalid memory accesses. This is mainly for the benefit of the developers.
650
651 25. (*UTF) can now be used to start a pattern in any of the three libraries.
652
653 26. Give configure error if --enable-cpp but no C++ compiler found.
654
655
656 Version 8.31 06-July-2012
657 -------------------------
658
659 1. Fixing a wrong JIT test case and some compiler warnings.
660
661 2. Removed a bashism from the RunTest script.
662
663 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
664 to unsigned type, result still unsigned" that was given by an MS compiler
665 on encountering the code "-sizeof(xxx)".
666
667 4. Partial matching support is added to the JIT compiler.
668
669 5. Fixed several bugs concerned with partial matching of items that consist
670 of more than one character:
671
672 (a) /^(..)\1/ did not partially match "aba" because checking references was
673 done on an "all or nothing" basis. This also applied to repeated
674 references.
675
676 (b) \R did not give a hard partial match if \r was found at the end of the
677 subject.
678
679 (c) \X did not give a hard partial match after matching one or more
680 characters at the end of the subject.
681
682 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
683 a partial match for the string "\r".
684
685 (e) When newline was set to CRLF, the metacharacter "." did not recognize
686 a partial match for a CR character at the end of the subject string.
687
688 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
689 running pcretest, the text "(JIT)" added to the output whenever JIT is
690 actually used to run the match.
691
692 7. Individual JIT compile options can be set in pcretest by following -s+[+]
693 or /S+[+] with a digit between 1 and 7.
694
695 8. OP_NOT now supports any UTF character not just single-byte ones.
696
697 9. (*MARK) control verb is now supported by the JIT compiler.
698
699 10. The command "./RunTest list" lists the available tests without actually
700 running any of them. (Because I keep forgetting what they all are.)
701
702 11. Add PCRE_INFO_MAXLOOKBEHIND.
703
704 12. Applied a (slightly modified) user-supplied patch that improves performance
705 when the heap is used for recursion (compiled with --disable-stack-for-
706 recursion). Instead of malloc and free for each heap frame each time a
707 logical recursion happens, frames are retained on a chain and re-used where
708 possible. This sometimes gives as much as 30% improvement.
709
710 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
711 call.
712
713 14. As documented, (*COMMIT) is now confined to within a positive assertion.
714
715 15. It is now possible to link pcretest with libedit as an alternative to
716 libreadline.
717
718 16. (*COMMIT) control verb is now supported by the JIT compiler.
719
720 17. The Unicode data tables have been updated to Unicode 6.1.0.
721
722 18. Added --file-list option to pcregrep.
723
724 19. Added binary file support to pcregrep, including the -a, --binary-files,
725 -I, and --text options.
726
727 20. The madvise function is renamed for posix_madvise for QNX compatibility
728 reasons. Fixed by Giuseppe D'Angelo.
729
730 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
731
732 22. Changed the option for creating symbolic links for 16-bit man pages from
733 -s to -sf so that re-installing does not cause issues.
734
735 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
736
737 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
738 matches in certain environments (the workspace was not being correctly
739 retained). Also added to pcre_dfa_exec() a simple plausibility check on
740 some of the workspace data at the beginning of a restart.
741
742 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
743 was not doing so when it should - probably a typo introduced by SVN 528
744 (change 8.10/14).
745
746 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
747 \w+ when the character tables indicated that \x{c4} was a word character.
748 There were several related cases, all because the tests for doing a table
749 lookup were testing for characters less than 127 instead of 255.
750
751 27. If a pattern contains capturing parentheses that are not used in a match,
752 their slots in the ovector are set to -1. For those that are higher than
753 any matched groups, this happens at the end of processing. In the case when
754 there were back references that the ovector was too small to contain
755 (causing temporary malloc'd memory to be used during matching), and the
756 highest capturing number was not used, memory off the end of the ovector
757 was incorrectly being set to -1. (It was using the size of the temporary
758 memory instead of the true size.)
759
760 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
761 ovector size, it uses memory at the end of the block that it has got.
762
763 29. Check for an overlong MARK name and give an error at compile time. The
764 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
765
766 30. JIT compiler update.
767
768 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
769 Rill for the patch.
770
771 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
772
773 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
774
775 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
776 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
777 was enabled.
778
779 35. Improve JIT code generation for greedy plus quantifier.
780
781 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
782 1 to "aa" instead of to an empty string. The bug affected repeated groups
783 that could potentially match an empty string.
784
785 37. Optimizing single character iterators in JIT.
786
787 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
788 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
789 codepoints that are too big for the mode are faulted, and in a UTF mode,
790 disallowed codepoints are also faulted.
791
792 39. If PCRE was compiled with UTF support, in three places in the DFA
793 matcher there was code that should only have been obeyed in UTF mode, but
794 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
795 processing when bytes with values greater than 127 were present. In 16-bit
796 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
797 both cases the values are those that cannot be the first data item in a UTF
798 character. The three items that might have provoked this were recursions,
799 possessively repeated groups, and atomic groups.
800
801 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
802 and pcregrep, because some OS require shared objects to be explicitly
803 passed to ld, causing the link step to fail if they are not.
804
805 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
806 mode, patterns that started with \h* or \R* might be incorrectly matched.
807
808
809 Version 8.30 04-February-2012
810 -----------------------------
811
812 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
813 name is defined in ctype.h.
814
815 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
816 only in quite long subpatterns.
817
818 3. Removed the function pcre_info(), which has been obsolete and deprecated
819 since it was replaced by pcre_fullinfo() in February 2000.
820
821 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
822 match a (*MARK), and the match failed at the start of the subject, a
823 reference to memory before the start of the subject could occur. This bug
824 was introduced by fix 17 of release 8.21.
825
826 5. A reference to an unset group with zero minimum repetition was giving
827 totally wrong answers (in non-JavaScript-compatibility mode). For example,
828 /(another)?(\1?)test/ matched against "hello world test". This bug was
829 introduced in release 8.13.
830
831 6. Add support for 16-bit character strings (a large amount of work involving
832 many changes and refactorings).
833
834 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
835 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
836 from a file.
837
838 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
839 rounding is not applied in this particular case).
840
841 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
842 if they appear, or are escaped, in patterns.
843
844 10. Get rid of a number of -Wunused-but-set-variable warnings.
845
846 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
847 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
848 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
849 also returns the mark "x". This bug applied to capturing parentheses,
850 non-capturing parentheses, and atomic parentheses. It also applied to some
851 assertions.
852
853 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
854 information out of configure.ac instead of relying on pcre.h.generic, which
855 is not stored in the repository.
856
857 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
858 -lreadline.
859
860 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
861
862 15. Applied Graycode's patch to put the top-level frame on the stack rather
863 than the heap when not using the stack for recursion. This gives a
864 performance improvement in many cases when recursion is not deep.
865
866 16. Experimental code added to "pcretest -C" to output the stack frame size.
867
868
869 Version 8.21 12-Dec-2011
870 ------------------------
871
872 1. Updating the JIT compiler.
873
874 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
875 are added as well.
876
877 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
878 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
879 calling _pcre_jit_exec. Some extra comments are added.
880
881 4. (*MARK) settings inside atomic groups that do not contain any capturing
882 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
883 was introduced by change 18 for 8.20.
884
885 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
886 ECMA-262 standard.
887
888 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
889 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
890 This bug was probably introduced by change 9 of 8.13.
891
892 7. While fixing 6 above, I noticed that a number of other items were being
893 incorrectly rejected as "not fixed length". This arose partly because newer
894 opcodes had not been added to the fixed-length checking code. I have (a)
895 corrected the bug and added tests for these items, and (b) arranged for an
896 error to occur if an unknown opcode is encountered while checking for fixed
897 length instead of just assuming "not fixed length". The items that were
898 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
899 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
900 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
901
902 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
903 being incorrectly compiled and would have given unpredicatble results.
904
905 9. A possessively repeated subpattern with minimum repeat count greater than
906 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
907 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
908 the first (A) could occur when it should not.
909
910 10. Add a cast and remove a redundant test from the code.
911
912 11. JIT should use pcre_malloc/pcre_free for allocation.
913
914 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
915 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
916 is anything other than /usr, -L is still shown).
917
918 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
919
920 14. Perl does not support \N without a following name in a [] class; PCRE now
921 also gives an error.
922
923 15. If a forward reference was repeated with an upper limit of around 2000,
924 it caused the error "internal error: overran compiling workspace". The
925 maximum number of forward references (including repeats) was limited by the
926 internal workspace, and dependent on the LINK_SIZE. The code has been
927 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
928 the default depends on LINK_SIZE. There is a new upper limit (for safety)
929 of around 200,000 forward references. While doing this, I also speeded up
930 the filling in of repeated forward references.
931
932 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
933 incorrectly expecting the subject to contain another "a" after the start.
934
935 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
936 in the match, the SKIP should be ignored. This was not happening; instead
937 the SKIP was being treated as NOMATCH. For patterns such as
938 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
939 tested.
940
941 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
942 now much more compatible with Perl, in particular in cases where the result
943 is a non-match for a non-anchored pattern. For example, if
944 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
945 "m", where previously it did not return a name. A side effect of this
946 change is that for partial matches, the last encountered mark name is
947 returned, as for non matches. A number of tests that were previously not
948 Perl-compatible have been moved into the Perl-compatible test files. The
949 refactoring has had the pleasing side effect of removing one argument from
950 the match() function, thus reducing its stack requirements.
951
952 19. If the /S+ option was used in pcretest to study a pattern using JIT,
953 subsequent uses of /S (without +) incorrectly behaved like /S+.
954
955 21. Retrieve executable code size support for the JIT compiler and fixing
956 some warnings.
957
958 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
959 not work when the shorter character appeared right at the end of the
960 subject string.
961
962 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
963 systems.
964
965 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
966 output it when the /M option is used in pcretest.
967
968 25. The CheckMan script was not being included in the distribution. Also, added
969 an explicit "perl" to run Perl scripts from the PrepareRelease script
970 because this is reportedly needed in Windows.
971
972 26. If study data was being save in a file and studying had not found a set of
973 "starts with" bytes for the pattern, the data written to the file (though
974 never used) was taken from uninitialized memory and so caused valgrind to
975 complain.
976
977 27. Updated RunTest.bat as provided by Sheri Pierce.
978
979 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
980
981 29. Computation of memory usage for the table of capturing group names was
982 giving an unnecessarily large value.
983
984
985 Version 8.20 21-Oct-2011
986 ------------------------
987
988 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
989 a POSIX class. After further experiments with Perl, which convinced me that
990 Perl has bugs and confusions, a closing square bracket is no longer allowed
991 in a POSIX name. This bug also affected patterns with classes that started
992 with full stops.
993
994 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
995 captured substring, but while checking the failing first alternative,
996 substring 1 is temporarily captured. If the output vector supplied to
997 pcre_exec() was not big enough for this capture, the yield of the function
998 was still zero ("insufficient space for captured substrings"). This cannot
999 be totally fixed without adding another stack variable, which seems a lot
1000 of expense for a edge case. However, I have improved the situation in cases
1001 such as /(a)(b)x|abc/ matched against "abc", where the return code
1002 indicates that fewer than the maximum number of slots in the ovector have
1003 been set.
1004
1005 3. Related to (2) above: when there are more back references in a pattern than
1006 slots in the output vector, pcre_exec() uses temporary memory during
1007 matching, and copies in the captures as far as possible afterwards. It was
1008 using the entire output vector, but this conflicts with the specification
1009 that only 2/3 is used for passing back captured substrings. Now it uses
1010 only the first 2/3, for compatibility. This is, of course, another edge
1011 case.
1012
1013 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
1014 main code base, and can be used by building with --enable-jit. When this is
1015 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1016 runtime --no-jit option is given.
1017
1018 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
1019 ovector, the return from the function was zero, implying that there were
1020 other matches that did not fit. The correct "exactly full" value is now
1021 returned.
1022
1023 6. If a subpattern that was called recursively or as a subroutine contained
1024 (*PRUNE) or any other control that caused it to give a non-standard return,
1025 invalid errors such as "Error -26 (nested recursion at the same subject
1026 position)" or even infinite loops could occur.
1027
1028 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1029 computing the minimum length on reaching *ACCEPT, and so ended up with the
1030 wrong value of 1 rather than 0. Further investigation indicates that
1031 computing a minimum subject length in the presence of *ACCEPT is difficult
1032 (think back references, subroutine calls), and so I have changed the code
1033 so that no minimum is registered for a pattern that contains *ACCEPT.
1034
1035 8. If (*THEN) was present in the first (true) branch of a conditional group,
1036 it was not handled as intended. [But see 16 below.]
1037
1038 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1039 Sheri Pierce.
1040
1041 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1042 the first byte in a match must be "a".
1043
1044 11. Change 17 for 8.13 increased the recursion depth for patterns like
1045 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1046 pattern contains any instances of (*THEN). If it does not, the old
1047 optimizations are restored. It would be nice to do this on a per-group
1048 basis, but at the moment that is not feasible.
1049
1050 12. In some environments, the output of pcretest -C is CRLF terminated. This
1051 broke RunTest's code that checks for the link size. A single white space
1052 character after the value is now allowed for.
1053
1054 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1055 For "fr", it uses the Windows-specific input and output files.
1056
1057 14. If (*THEN) appeared in a group that was called recursively or as a
1058 subroutine, it did not work as intended. [But see next item.]
1059
1060 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1061 pattern fragments (but not containing any | characters). If A and B are
1062 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1063 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1064 D. In other words, Perl considers parentheses that do not contain any |
1065 characters to be part of a surrounding alternative, whereas PCRE was
1066 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1067 differently. PCRE now behaves in the same way as Perl, except in the case
1068 of subroutine/recursion calls such as (?1) which have in any case always
1069 been different (but PCRE had them first :-).
1070
1071 16. Related to 15 above: Perl does not treat the | in a conditional group as
1072 creating alternatives. Such a group is treated in the same way as an
1073 ordinary group without any | characters when processing (*THEN). PCRE has
1074 been changed to match Perl's behaviour.
1075
1076 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1077 RunGrepTest script failed.
1078
1079 18. Change 22 for version 13 caused atomic groups to use more stack. This is
1080 inevitable for groups that contain captures, but it can lead to a lot of
1081 stack use in large patterns. The old behaviour has been restored for atomic
1082 groups that do not contain any capturing parentheses.
1083
1084 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1085 suppress the check for a minimum subject length at run time. (If it was
1086 given to pcre_exec() or pcre_dfa_exec() it did work.)
1087
1088 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1089 fail to work when decoding hex characters in data strings in EBCDIC
1090 environments.
1091
1092 21. It appears that in at least one Mac OS environment, the isxdigit() function
1093 is implemented as a macro that evaluates to its argument more than once,
1094 contravening the C 90 Standard (I haven't checked a later standard). There
1095 was an instance in pcretest which caused it to go wrong when processing
1096 \x{...} escapes in subject strings. The has been rewritten to avoid using
1097 things like p++ in the argument of isxdigit().
1098
1099
1100 Version 8.13 16-Aug-2011
1101 ------------------------
1102
1103 1. The Unicode data tables have been updated to Unicode 6.0.0.
1104
1105 2. Two minor typos in pcre_internal.h have been fixed.
1106
1107 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1108 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1109 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1110
1111 4. There were a number of related bugs in the code for matching backrefences
1112 caselessly in UTF-8 mode when codes for the characters concerned were
1113 different numbers of bytes. For example, U+023A and U+2C65 are an upper
1114 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1115 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1116 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1117 2-byte code at the end of the subject (it thought there wasn't enough data
1118 left).
1119
1120 5. Comprehensive information about what went wrong is now returned by
1121 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1122 as the output vector has at least 2 elements. The offset of the start of
1123 the failing character and a reason code are placed in the vector.
1124
1125 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
1126 now returned is for the first byte of the failing character, instead of the
1127 last byte inspected. This is an incompatible change, but I hope it is small
1128 enough not to be a problem. It makes the returned offset consistent with
1129 pcre_exec() and pcre_dfa_exec().
1130
1131 7. pcretest now gives a text phrase as well as the error number when
1132 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1133 failure, the offset and reason code are output.
1134
1135 8. When \R was used with a maximizing quantifier it failed to skip backwards
1136 over a \r\n pair if the subsequent match failed. Instead, it just skipped
1137 back over a single character (\n). This seems wrong (because it treated the
1138 two characters as a single entity when going forwards), conflicts with the
1139 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1140 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1141 has been changed.
1142
1143 9. Some internal refactoring has changed the processing so that the handling
1144 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1145 time (the PCRE_DOTALL option was changed this way some time ago: version
1146 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1147 which was always a bit of a fudge. It also means that there is one less
1148 argument for the match() function, which reduces its stack requirements
1149 slightly. This change also fixes an incompatibility with Perl: the pattern
1150 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1151
1152 10. More internal refactoring has drastically reduced the number of recursive
1153 calls to match() for possessively repeated groups such as (abc)++ when
1154 using pcre_exec().
1155
1156 11. While implementing 10, a number of bugs in the handling of groups were
1157 discovered and fixed:
1158
1159 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1160 (a|)*(?1) gave a compile-time internal error.
1161 ((a|)+)+ did not notice that the outer group could match an empty string.
1162 (^a|^)+ was not marked as anchored.
1163 (.*a|.*)+ was not marked as matching at start or after a newline.
1164
1165 12. Yet more internal refactoring has removed another argument from the match()
1166 function. Special calls to this function are now indicated by setting a
1167 value in a variable in the "match data" data block.
1168
1169 13. Be more explicit in pcre_study() instead of relying on "default" for
1170 opcodes that mean there is no starting character; this means that when new
1171 ones are added and accidentally left out of pcre_study(), testing should
1172 pick them up.
1173
1174 14. The -s option of pcretest has been documented for ages as being an old
1175 synonym of -m (show memory usage). I have changed it to mean "force study
1176 for every regex", that is, assume /S for every regex. This is similar to -i
1177 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1178 using it. It makes it easier to run collections of tests with and without
1179 study enabled, and thereby test pcre_study() more easily. All the standard
1180 tests are now run with and without -s (but some patterns can be marked as
1181 "never study" - see 20 below).
1182
1183 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1184 restoration of the capturing data to the outer values was not happening
1185 correctly.
1186
1187 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1188 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1189 pattern had matched an empty string, and so incorrectly returned a no
1190 match.
1191
1192 17. There was optimizing code for the last branch of non-capturing parentheses,
1193 and also for the obeyed branch of a conditional subexpression, which used
1194 tail recursion to cut down on stack usage. Unfortunately, now that there is
1195 the possibility of (*THEN) occurring in these branches, tail recursion is
1196 no longer possible because the return has to be checked for (*THEN). These
1197 two optimizations have therefore been removed. [But see 8.20/11 above.]
1198
1199 18. If a pattern containing \R was studied, it was assumed that \R always
1200 matched two bytes, thus causing the minimum subject length to be
1201 incorrectly computed because \R can also match just one byte.
1202
1203 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1204 was incorrectly computed.
1205
1206 20. If /S is present twice on a test pattern in pcretest input, it now
1207 *disables* studying, thereby overriding the use of -s on the command line
1208 (see 14 above). This is necessary for one or two tests to keep the output
1209 identical in both cases.
1210
1211 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1212 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1213
1214 22. When an atomic group that contained a capturing parenthesis was
1215 successfully matched, but the branch in which it appeared failed, the
1216 capturing was not being forgotten if a higher numbered group was later
1217 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1218 group 1 to "a", when in fact it should be unset. This applied to multi-
1219 branched capturing and non-capturing groups, repeated or not, and also to
1220 positive assertions (capturing in negative assertions does not happen
1221 in PCRE) and also to nested atomic groups.
1222
1223 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1224 subject after a captured substring, to make it easier to tell which of a
1225 number of identical substrings has been captured.
1226
1227 24. The way atomic groups are processed by pcre_exec() has been changed so that
1228 if they are repeated, backtracking one repetition now resets captured
1229 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1230 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1231 "aaa". Previously, it would have been "a". As part of this code
1232 refactoring, the way recursive calls are handled has also been changed.
1233
1234 25. If an assertion condition captured any substrings, they were not passed
1235 back unless some other capturing happened later. For example, if
1236 (?(?=(a))a) was matched against "a", no capturing was returned.
1237
1238 26. When studying a pattern that contained subroutine calls or assertions,
1239 the code for finding the minimum length of a possible match was handling
1240 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1241 group 1 called group 2 while simultaneously a separate group 2 called group
1242 1). A stack overflow occurred in this case. I have fixed this by limiting
1243 the recursion depth to 10.
1244
1245 27. Updated RunTest.bat in the distribution to the version supplied by Tom
1246 Fortmann. This supports explicit test numbers on the command line, and has
1247 argument validation and error reporting.
1248
1249 28. An instance of \X with an unlimited repeat could fail if at any point the
1250 first character it looked at was a mark character.
1251
1252 29. Some minor code refactoring concerning Unicode properties and scripts
1253 should reduce the stack requirement of match() slightly.
1254
1255 30. Added the '=' option to pcretest to check the setting of unused capturing
1256 slots at the end of the pattern, which are documented as being -1, but are
1257 not included in the return count.
1258
1259 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1260 compiled something random. Now it gives a compile-time error (as does
1261 Perl).
1262
1263 32. A *MARK encountered during the processing of a positive assertion is now
1264 recorded and passed back (compatible with Perl).
1265
1266 33. If --only-matching or --colour was set on a pcregrep call whose pattern
1267 had alternative anchored branches, the search for a second match in a line
1268 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1269 matched the line "0102" twice. The same bug affected patterns that started
1270 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1271 twice.
1272
1273 34. Previously, PCRE did not allow quantification of assertions. However, Perl
1274 does, and because of capturing effects, quantifying parenthesized
1275 assertions may at times be useful. Quantifiers are now allowed for
1276 parenthesized assertions.
1277
1278 35. A minor code tidy in pcre_compile() when checking options for \R usage.
1279
1280 36. \g was being checked for fancy things in a character class, when it should
1281 just be a literal "g".
1282
1283 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1284 appearance of a nested POSIX class supersedes an apparent external class.
1285 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1286 unescaped square brackets may also appear as part of class names. For
1287 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1288 more like Perl. (But see 8.20/1 above.)
1289
1290 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1291 was because it thought it was \N{name}, which is not supported).
1292
1293 39. Add minix to OS list not supporting the -S option in pcretest.
1294
1295 40. PCRE tries to detect cases of infinite recursion at compile time, but it
1296 cannot analyze patterns in sufficient detail to catch mutual recursions
1297 such as ((?1))((?2)). There is now a runtime test that gives an error if a
1298 subgroup is called recursively as a subpattern for a second time at the
1299 same position in the subject string. In previous releases this might have
1300 been caught by the recursion limit, or it might have run out of stack.
1301
1302 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1303 happen only once. PCRE was, however incorrectly giving a compile time error
1304 "recursive call could loop indefinitely" because it cannot analyze the
1305 pattern in sufficient detail. The compile time test no longer happens when
1306 PCRE is compiling a conditional subpattern, but actual runaway loops are
1307 now caught at runtime (see 40 above).
1308
1309 42. It seems that Perl allows any characters other than a closing parenthesis
1310 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1311 has been changed to be the same.
1312
1313 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1314 as not to get warnings when autogen.sh is called. Also changed
1315 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1316
1317 44. To help people who use pcregrep to scan files containing exceedingly long
1318 lines, the following changes have been made:
1319
1320 (a) The default value of the buffer size parameter has been increased from
1321 8K to 20K. (The actual buffer used is three times this size.)
1322
1323 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1324 PCRE is built.
1325
1326 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1327 to be set at run time.
1328
1329 (d) Numerical values in pcregrep options can be followed by K or M, for
1330 example --buffer-size=50K.
1331
1332 (e) If a line being scanned overflows pcregrep's buffer, an error is now
1333 given and the return code is set to 2.
1334
1335 45. Add a pointer to the latest mark to the callout data block.
1336
1337 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1338 partial match of an empty string instead of no match. This was specific to
1339 the use of ".".
1340
1341 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1342 complete match instead of a partial match. This bug was dependent on both
1343 the PCRE_UTF8 and PCRE_DOTALL options being set.
1344
1345 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1346 starting byte set, because \b was not being ignored.
1347
1348
1349 Version 8.12 15-Jan-2011
1350 ------------------------
1351
1352 1. Fixed some typos in the markup of the man pages, and wrote a script that
1353 checks for such things as part of the documentation building process.
1354
1355 2. On a big-endian 64-bit system, pcregrep did not correctly process the
1356 --match-limit and --recursion-limit options (added for 8.11). In
1357 particular, this made one of the standard tests fail. (The integer value
1358 went into the wrong half of a long int.)
1359
1360 3. If the --colour option was given to pcregrep with -v (invert match), it
1361 did strange things, either producing crazy output, or crashing. It should,
1362 of course, ignore a request for colour when reporting lines that do not
1363 match.
1364
1365 4. Another pcregrep bug caused similar problems if --colour was specified with
1366 -M (multiline) and the pattern match finished with a line ending.
1367
1368 5. In pcregrep, when a pattern that ended with a literal newline sequence was
1369 matched in multiline mode, the following line was shown as part of the
1370 match. This seems wrong, so I have changed it.
1371
1372 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
1373 the check for further matches in the same line (so they could be coloured)
1374 to overrun the end of the current line. If another match was found, it was
1375 incorrectly shown (and then shown again when found in the next line).
1376
1377 7. If pcregrep was compiled under Windows, there was a reference to the
1378 function pcregrep_exit() before it was defined. I am assuming this was
1379 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1380 reported by a user. I've moved the definition above the reference.
1381
1382
1383 Version 8.11 10-Dec-2010
1384 ------------------------
1385
1386 1. (*THEN) was not working properly if there were untried alternatives prior
1387 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1388 backtracked to try for "b" instead of moving to the next alternative branch
1389 at the same level (in this case, to look for "c"). The Perl documentation
1390 is clear that when (*THEN) is backtracked onto, it goes to the "next
1391 alternative in the innermost enclosing group".
1392
1393 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1394 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
1395 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1396 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1397 (*THEN).
1398
1399 3. If \s appeared in a character class, it removed the VT character from
1400 the class, even if it had been included by some previous item, for example
1401 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1402 of \s, but is part of the POSIX "space" class.)
1403
1404 4. A partial match never returns an empty string (because you can always
1405 match an empty string at the end of the subject); however the checking for
1406 an empty string was starting at the "start of match" point. This has been
1407 changed to the "earliest inspected character" point, because the returned
1408 data for a partial match starts at this character. This means that, for
1409 example, /(?<=abc)def/ gives a partial match for the subject "abc"
1410 (previously it gave "no match").
1411
1412 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1413 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1414 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1415 has an implication that the given string is incomplete (because a partial
1416 match is preferred over a full match). For this reason, these items now
1417 give a partial match in this situation. [Aside: previously, the one case
1418 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1419 match rather than a full match, which was wrong by the old rules, but is
1420 now correct.]
1421
1422 6. There was a bug in the handling of #-introduced comments, recognized when
1423 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1424 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1425 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1426 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1427 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1428 places in pcre_compile().
1429
1430 7. Related to (6) above, when pcre_compile() was skipping #-introduced
1431 comments when looking ahead for named forward references to subpatterns,
1432 the only newline sequence it recognized was NL. It now handles newlines
1433 according to the set newline convention.
1434
1435 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1436 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1437 cater for a lack of strerror(). These oversights have been fixed.
1438
1439 9. Added --match-limit and --recursion-limit to pcregrep.
1440
1441 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1442
1443 11. When the -o option was used, pcregrep was setting a return code of 1, even
1444 when matches were found, and --line-buffered was not being honoured.
1445
1446 12. Added an optional parentheses number to the -o and --only-matching options
1447 of pcregrep.
1448
1449 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1450 can match an empty string. The code to do it in pcretest and pcredemo
1451 needed fixing:
1452
1453 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1454 only one byte after an empty string match just before CRLF (this case
1455 just got forgotten; "any" and "anycrlf" were OK).
1456
1457 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1458 mode when an empty string match preceded an ASCII character followed by
1459 a non-ASCII character. (The code for advancing by one character rather
1460 than one byte was nonsense.)
1461
1462 (c) The pcredemo.c sample program did not have any code at all to handle
1463 the cases when CRLF is a valid newline sequence.
1464
1465 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1466 as a starting offset was within the subject string. There is now a new
1467 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1468 negative or greater than the length of the string. In order to test this,
1469 pcretest is extended to allow the setting of negative starting offsets.
1470
1471 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1472 starting offset points to the beginning of a UTF-8 character was
1473 unnecessarily clumsy. I tidied it up.
1474
1475 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1476 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1477
1478 17. Nobody had reported that the --include_dir option, which was added in
1479 release 7.7 should have been called --include-dir (hyphen, not underscore)
1480 for compatibility with GNU grep. I have changed it to --include-dir, but
1481 left --include_dir as an undocumented synonym, and the same for
1482 --exclude-dir, though that is not available in GNU grep, at least as of
1483 release 2.5.4.
1484
1485 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1486 characters from a string of bytes) have been redefined so as not to use
1487 loops, in order to improve performance in some environments. At the same
1488 time, I abstracted some of the common code into auxiliary macros to save
1489 repetition (this should not affect the compiled code).
1490
1491 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1492 compile-time error is now given if \c is not followed by an ASCII
1493 character, that is, a byte less than 128. (In EBCDIC mode, the code is
1494 different, and any byte value is allowed.)
1495
1496 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1497 START_OPTIMIZE option, which is now allowed at compile time - but just
1498 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1499 to pcregrep and other applications that have no direct access to PCRE
1500 options. The new /Y option in pcretest sets this option when calling
1501 pcre_compile().
1502
1503 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1504 back references. Groups containing recursive back references were forced to
1505 be atomic by that change, but in the case of named groups, the amount of
1506 memory required was incorrectly computed, leading to "Failed: internal
1507 error: code overflow". This has been fixed.
1508
1509 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1510 pcretest.c, to avoid build problems in some Borland environments.
1511
1512
1513 Version 8.10 25-Jun-2010
1514 ------------------------
1515
1516 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1517 THEN.
1518
1519 2. (*ACCEPT) was not working when inside an atomic group.
1520
1521 3. Inside a character class, \B is treated as a literal by default, but
1522 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1523 causes the error). The code is unchanged, but I tidied the documentation.
1524
1525 4. Inside a character class, PCRE always treated \R and \X as literals,
1526 whereas Perl faults them if its -w option is set. I have changed PCRE so
1527 that it faults them when PCRE_EXTRA is set.
1528
1529 5. Added support for \N, which always matches any character other than
1530 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1531
1532 6. When compiling pcregrep with newer versions of gcc which may have
1533 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1534 declared with attribute warn_unused_result" were given. Just casting the
1535 result to (void) does not stop the warnings; a more elaborate fudge is
1536 needed. I've used a macro to implement this.
1537
1538 7. Minor change to pcretest.c to avoid a compiler warning.
1539
1540 8. Added four artifical Unicode properties to help with an option to make
1541 \s etc use properties (see next item). The new properties are: Xan
1542 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1543
1544 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1545 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1546 this option. Modified pcretest to add /W to test this facility. Added
1547 REG_UCP to make it available via the POSIX interface.
1548
1549 10. Added --line-buffered to pcregrep.
1550
1551 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1552 studied, and the match started with a letter with a code point greater than
1553 127 whose first byte was different to the first byte of the other case of
1554 the letter, the other case of this starting letter was not recognized
1555 (#976).
1556
1557 12. If a pattern that was studied started with a repeated Unicode property
1558 test, for example, \p{Nd}+, there was the theoretical possibility of
1559 setting up an incorrect bitmap of starting bytes, but fortunately it could
1560 not have actually happened in practice until change 8 above was made (it
1561 added property types that matched character-matching opcodes).
1562
1563 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1564 possible starting bytes for non-anchored patterns.
1565
1566 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1567 \R, and also a number of cases that involve Unicode properties, both
1568 explicit and implicit when PCRE_UCP is set.
1569
1570 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1571 input, it could crash or give wrong results if characters with values
1572 greater than 0xc0 were present in the subject string. (Detail: it assumed
1573 UTF-8 input when processing these items.)
1574
1575 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1576 size_t is 64-bit (#991).
1577
1578 17. Added a check for running out of memory when PCRE is compiled with
1579 --disable-stack-for-recursion (#990).
1580
1581 18. If the last data line in a file for pcretest does not have a newline on
1582 the end, a newline was missing in the output.
1583
1584 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1585 less than 128) in its various bitmaps. However, there is a facility for
1586 generating tables according to the current locale when PCRE is compiled. It
1587 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1588 characters, are recognized by isspace() and therefore were getting set in
1589 these tables, and indeed these tables seem to approximate to ISO 8859. This
1590 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1591 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1592 which of course cannot start UTF-8 characters. I have changed the code so
1593 that only real ASCII characters (less than 128) and the correct starting
1594 bytes for UTF-8 encodings are set for characters greater than 127 when in
1595 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1596 altogether.)
1597
1598 20. Added the /T option to pcretest so as to be able to run tests with non-
1599 standard character tables, thus making it possible to include the tests
1600 used for 19 above in the standard set of tests.
1601
1602 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1603 reference to a subpattern the other side of a comment that contains an
1604 opening parenthesis caused either an internal compiling error, or a
1605 reference to the wrong subpattern.
1606
1607
1608 Version 8.02 19-Mar-2010
1609 ------------------------
1610
1611 1. The Unicode data tables have been updated to Unicode 5.2.0.
1612
1613 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
1614 configured.
1615
1616 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
1617 original author of that file, following a query about its status.
1618
1619 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
1620 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1621
1622 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1623 quantifier applied to a forward-referencing subroutine call, could compile
1624 incorrect code or give the error "internal error: previously-checked
1625 referenced subpattern not found".
1626
1627 6. Both MS Visual Studio and Symbian OS have problems with initializing
1628 variables to point to external functions. For these systems, therefore,
1629 pcre_malloc etc. are now initialized to local functions that call the
1630 relevant global functions.
1631
1632 7. There were two entries missing in the vectors called coptable and poptable
1633 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1634 I've fixed the data, and added a kludgy way of testing at compile time that
1635 the lengths are correct (equal to the number of opcodes).
1636
1637 8. Following on from 7, I added a similar kludge to check the length of the
1638 eint vector in pcreposix.c.
1639
1640 9. Error texts for pcre_compile() are held as one long string to avoid too
1641 much relocation at load time. To find a text, the string is searched,
1642 counting zeros. There was no check for running off the end of the string,
1643 which could happen if a new error number was added without updating the
1644 string.
1645
1646 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1647
1648 11. \K was not working if it appeared in an atomic group or in a group that
1649 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
1650 \K is "not well defined" if used in an assertion. PCRE now accepts it if
1651 the assertion is positive, but not if it is negative.
1652
1653 12. Change 11 fortuitously reduced the size of the stack frame used in the
1654 "match()" function of pcre_exec.c by one pointer. Forthcoming
1655 implementation of support for (*MARK) will need an extra pointer on the
1656 stack; I have reserved it now, so that the stack frame size does not
1657 decrease.
1658
1659 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
1660 item in branch that calls a recursion is a subroutine call - as in the
1661 second branch in the above example - was incorrectly given the compile-
1662 time error "recursive call could loop indefinitely" because pcre_compile()
1663 was not correctly checking the subroutine for matching a non-empty string.
1664
1665 14. The checks for overrunning compiling workspace could trigger after an
1666 overrun had occurred. This is a "should never occur" error, but it can be
1667 triggered by pathological patterns such as hundreds of nested parentheses.
1668 The checks now trigger 100 bytes before the end of the workspace.
1669
1670 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
1671
1672
1673 Version 8.01 19-Jan-2010
1674 ------------------------
1675
1676 1. If a pattern contained a conditional subpattern with only one branch (in
1677 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
1678 computed the wrong minimum data length (which is of course zero for such
1679 subpatterns). This could cause incorrect "no match" results.
1680
1681 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
1682 the pattern is reset in the first branch, pcre_compile() failed with
1683 "internal error: code overflow at offset...". This happened only when
1684 the reset was to the original external option setting. (An optimization
1685 abstracts leading options settings into an external setting, which was the
1686 cause of this.)
1687
1688 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
1689 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
1690 assertion pattern did not match (meaning that the assertion was true), it
1691 was incorrectly treated as false if the SKIP had been reached during the
1692 matching. This also applied to assertions used as conditions.
1693
1694 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
1695 assertion subpattern, including such a pattern used as a condition,
1696 unpredictable results occurred, instead of the error return
1697 PCRE_ERROR_DFA_UITEM.
1698
1699 5. The C++ GlobalReplace function was not working like Perl for the special
1700 situation when an empty string is matched. It now does the fancy magic
1701 stuff that is necessary.
1702
1703 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
1704 removed. (These were left over from very, very early versions of PCRE.)
1705
1706 7. Some cosmetic changes to the code to make life easier when compiling it
1707 as part of something else:
1708
1709 (a) Change DEBUG to PCRE_DEBUG.
1710
1711 (b) In pcre_compile(), rename the member of the "branch_chain" structure
1712 called "current" as "current_branch", to prevent a collision with the
1713 Linux macro when compiled as a kernel module.
1714
1715 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
1716 prevent a collision with the Linux macro when compiled as a kernel
1717 module.
1718
1719 8. In pcre_compile() there are some checks for integer overflows that used to
1720 cast potentially large values to (double). This has been changed to that
1721 when building, a check for int64_t is made, and if it is found, it is used
1722 instead, thus avoiding the use of floating point arithmetic. (There is no
1723 other use of FP in PCRE.) If int64_t is not found, the fallback is to
1724 double.
1725
1726 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
1727 2005 (difference between two addresses compared to an unsigned value).
1728
1729 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
1730 custom one, because of the following reported problem in Windows:
1731
1732 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
1733 under Win32.
1734 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
1735 therefore missing the function definition.
1736 - The compiler thus generates a "C" signature for the test function.
1737 - The linker fails to find the "C" function.
1738 - PCRE fails to configure if asked to do so against libbz2.
1739
1740 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
1741 messages were output:
1742
1743 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
1744 rerunning libtoolize, to keep the correct libtool macros in-tree.
1745 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
1746
1747 I have done both of these things.
1748
1749 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
1750 most of the time, it *can* run out if it is given a pattern that contains a
1751 runaway infinite recursion. I updated the discussion in the pcrestack man
1752 page.
1753
1754 13. Now that we have gone to the x.xx style of version numbers, the minor
1755 version may start with zero. Using 08 or 09 is a bad idea because users
1756 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
1757 interpreted as invalid octal numbers. I've updated the previous comment in
1758 configure.ac, and also added a check that gives an error if 08 or 09 are
1759 used.
1760
1761 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
1762 causing partial matching to fail when the end of the subject matched \W
1763 in a UTF-8 pattern where \W was quantified with a minimum of 3.
1764
1765 15. There were some discrepancies between the declarations in pcre_internal.h
1766 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
1767 their definitions. The declarations used "const uschar *" and the
1768 definitions used USPTR. Even though USPTR is normally defined as "const
1769 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
1770 reported that: "This difference in casting confuses some C++ compilers, for
1771 example, SunCC recognizes above declarations as different functions and
1772 generates broken code for hbpcre." I have changed the declarations to use
1773 USPTR.
1774
1775 16. GNU libtool is named differently on some systems. The autogen.sh script now
1776 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
1777 (FreeBSD).
1778
1779 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
1780 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
1781 comment: "Figure out how to create a longlong from a string: strtoll and
1782 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
1783 instance, but it only takes 2 args instead of 3!"
1784
1785 18. A subtle bug concerned with back references has been fixed by a change of
1786 specification, with a corresponding code fix. A pattern such as
1787 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
1788 refers, was giving matches when it shouldn't. For example, xa=xaaa would
1789 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
1790 same bug. Such groups have to be quantified to be useful, or contained
1791 inside another quantified group. (If there's no repetition, the reference
1792 can never match.) The problem arises because, having left the group and
1793 moved on to the rest of the pattern, a later failure that backtracks into
1794 the group uses the captured value from the final iteration of the group
1795 rather than the correct earlier one. I have fixed this in PCRE by forcing
1796 any group that contains a reference to itself to be an atomic group; that
1797 is, there cannot be any backtracking into it once it has completed. This is
1798 similar to recursive and subroutine calls.
1799
1800
1801 Version 8.00 19-Oct-09
1802 ----------------------
1803
1804 1. The table for translating pcre_compile() error codes into POSIX error codes
1805 was out-of-date, and there was no check on the pcre_compile() error code
1806 being within the table. This could lead to an OK return being given in
1807 error.
1808
1809 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1810 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1811 in a Windows environment.
1812
1813 3. The pcregrep --count option prints the count for each file even when it is
1814 zero, as does GNU grep. However, pcregrep was also printing all files when
1815 --files-with-matches was added. Now, when both options are given, it prints
1816 counts only for those files that have at least one match. (GNU grep just
1817 prints the file name in this circumstance, but including the count seems
1818 more useful - otherwise, why use --count?) Also ensured that the
1819 combination -clh just lists non-zero counts, with no names.
1820
1821 4. The long form of the pcregrep -F option was incorrectly implemented as
1822 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1823 but it seems right to fix it, and I didn't think it was worth preserving
1824 the old behaviour.
1825
1826 5. The command line items --regex=pattern and --regexp=pattern were not
1827 recognized by pcregrep, which required --regex pattern or --regexp pattern
1828 (with a space rather than an '='). The man page documented the '=' forms,
1829 which are compatible with GNU grep; these now work.
1830
1831 6. No libpcreposix.pc file was created for pkg-config; there was just
1832 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1833
1834 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1835 when UCP support is not needed, by modifying the Python script that
1836 generates it from Unicode data files. This should not matter if the module
1837 is correctly used as a library, but I received one complaint about 50K of
1838 unwanted data. My guess is that the person linked everything into his
1839 program rather than using a library. Anyway, it does no harm.
1840
1841 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1842 was a minimum greater than 1 for a wide character in a possessive
1843 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1844 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1845 character. Chaos in the form of incorrect output or a compiling loop could
1846 result.
1847
1848 9. The restrictions on what a pattern can contain when partial matching is
1849 requested for pcre_exec() have been removed. All patterns can now be
1850 partially matched by this function. In addition, if there are at least two
1851 slots in the offset vector, the offset of the earliest inspected character
1852 for the match and the offset of the end of the subject are set in them when
1853 PCRE_ERROR_PARTIAL is returned.
1854
1855 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1856 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1857 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1858 and may be more useful for multi-segment matching.
1859
1860 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1861 used to be given if ever the end of the subject was reached; now it is
1862 given only if matching could not proceed because another character was
1863 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1864 string "Z", which now yields "no match" instead of "partial match". In the
1865 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1866 final character ended with (*FAIL).
1867
1868 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1869 if the pattern had a "must contain" character that was already found in the
1870 earlier partial match, unless partial matching was again requested. For
1871 example, with the pattern /dog.(body)?/, the "must contain" character is
1872 "g". If the first part-match was for the string "dog", restarting with
1873 "sbody" failed. This bug has been fixed.
1874
1875 13. The string returned by pcre_dfa_exec() after a partial match has been
1876 changed so that it starts at the first inspected character rather than the
1877 first character of the match. This makes a difference only if the pattern
1878 starts with a lookbehind assertion or \b or \B (\K is not supported by
1879 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1880 matching functions compatible, and I think it's the right thing to do.
1881
1882 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1883 so that the demonstration program is easily available in environments where
1884 PCRE has not been installed from source.
1885
1886 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1887 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1888 library.
1889
1890 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1891 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1892 is not the first non-POSIX option to be added. Clearly some people find
1893 these options useful.
1894
1895 17. If a caller to the POSIX matching function regexec() passes a non-zero
1896 value for nmatch with a NULL value for pmatch, the value of
1897 nmatch is forced to zero.
1898
1899 18. RunGrepTest did not have a test for the availability of the -u option of
1900 the diff command, as RunTest does. It now checks in the same way as
1901 RunTest, and also checks for the -b option.
1902
1903 19. If an odd number of negated classes containing just a single character
1904 interposed, within parentheses, between a forward reference to a named
1905 subpattern and the definition of the subpattern, compilation crashed with
1906 an internal error, complaining that it could not find the referenced
1907 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1908 [The bug was that it was starting one character too far in when skipping
1909 over the character class, thus treating the ] as data rather than
1910 terminating the class. This meant it could skip too much.]
1911
1912 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1913 /g option in pcretest when the pattern contains \K, which makes it possible
1914 to have an empty string match not at the start, even when the pattern is
1915 anchored. Updated pcretest and pcredemo to use this option.
1916
1917 21. If the maximum number of capturing subpatterns in a recursion was greater
1918 than the maximum at the outer level, the higher number was returned, but
1919 with unset values at the outer level. The correct (outer level) value is
1920 now given.
1921
1922 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1923 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1924 make it do so. The string so far is captured, making this feature
1925 compatible with Perl.
1926
1927 23. The tests have been re-organized, adding tests 11 and 12, to make it
1928 possible to check the Perl 5.10 features against Perl 5.10.
1929
1930 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1931 pattern matches a fixed length string. PCRE did not allow this; now it
1932 does. Neither allows recursion.
1933
1934 25. I finally figured out how to implement a request to provide the minimum
1935 length of subject string that was needed in order to match a given pattern.
1936 (It was back references and recursion that I had previously got hung up
1937 on.) This code has now been added to pcre_study(); it finds a lower bound
1938 to the length of subject needed. It is not necessarily the greatest lower
1939 bound, but using it to avoid searching strings that are too short does give
1940 some useful speed-ups. The value is available to calling programs via
1941 pcre_fullinfo().
1942
1943 26. While implementing 25, I discovered to my embarrassment that pcretest had
1944 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1945 study optimizations had never been tested with that matching function.
1946 Oops. What is worse, even when it was passed study data, there was a bug in
1947 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1948 were also very few tests of studied patterns with pcre_dfa_exec().
1949
1950 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1951 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1952 on the other side of the coin, they are no longer allowed to have different
1953 names, because these cannot be distinguished in PCRE, and this has caused
1954 confusion. (This is a difference from Perl.)
1955
1956 28. When duplicate subpattern names are present (necessarily with different
1957 numbers, as required by 27 above), and a test is made by name in a
1958 conditional pattern, either for a subpattern having been matched, or for
1959 recursion in such a pattern, all the associated numbered subpatterns are
1960 tested, and the overall condition is true if the condition is true for any
1961 one of them. This is the way Perl works, and is also more like the way
1962 testing by number works.
1963
1964
1965 Version 7.9 11-Apr-09
1966 ---------------------
1967
1968 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1969 (pcretest), all targets were linked against these libraries. This included
1970 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1971 libraries. This caused unwanted dependencies to be created. This problem
1972 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1973 pcretest is linked with readline.
1974
1975 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1976 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1977 moved outside it again, because FALSE and TRUE are already defined in AIX,
1978 but BOOL is not.
1979
1980 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1981 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1982
1983 4. The pcregrep documentation said spaces were inserted as well as colons (or
1984 hyphens) following file names and line numbers when outputting matching
1985 lines. This is not true; no spaces are inserted. I have also clarified the
1986 wording for the --colour (or --color) option.
1987
1988 5. In pcregrep, when --colour was used with -o, the list of matching strings
1989 was not coloured; this is different to GNU grep, so I have changed it to be
1990 the same.
1991
1992 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1993 each matching line was coloured. Now it goes on to look for further matches
1994 of any of the test patterns, which is the same behaviour as GNU grep.
1995
1996 7. A pattern that could match an empty string could cause pcregrep to loop; it
1997 doesn't make sense to accept an empty string match in pcregrep, so I have
1998 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1999 seems to be how GNU grep behaves. [But see later change 40 for release
2000 8.33.]
2001
2002 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2003 start or after a newline", because the conditional assertion was not being
2004 correctly handled. The rule now is that both the assertion and what follows
2005 in the first alternative must satisfy the test.
2006
2007 9. If auto-callout was enabled in a pattern with a conditional group whose
2008 condition was an assertion, PCRE could crash during matching, both with
2009 pcre_exec() and pcre_dfa_exec().
2010
2011 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
2012 used for matching.
2013
2014 11. Unicode property support in character classes was not working for
2015 characters (bytes) greater than 127 when not in UTF-8 mode.
2016
2017 12. Added the -M command line option to pcretest.
2018
2019 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
2020
2021 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
2022
2023 16. Added comments and documentation about mis-use of no_arg in the C++
2024 wrapper.
2025
2026 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
2027 from Martin Jerabek that uses macro names for all relevant character and
2028 string constants.
2029
2030 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
2031 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
2032 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
2033 these, but not everybody uses configure.
2034
2035 19. A conditional group that had only one branch was not being correctly
2036 recognized as an item that could match an empty string. This meant that an
2037 enclosing group might also not be so recognized, causing infinite looping
2038 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
2039 with the subject "ab", where knowledge that the repeated group can match
2040 nothing is needed in order to break the loop.
2041
2042 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
2043 exec(), but without supplying a callout function, matching went wrong.
2044
2045 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
2046 leak if the size of the offset vector was greater than 30. When the vector
2047 is smaller, the saved offsets during recursion go onto a local stack
2048 vector, but for larger vectors malloc() is used. It was failing to free
2049 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
2050 error, in fact).
2051
2052 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
2053 heapframe that is used only when UTF-8 support is enabled. This caused no
2054 problem, but was untidy.
2055
2056 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
2057 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
2058 included within another project.
2059
2060 24. Steven Van Ingelgem's patches to add more options to the CMake support,
2061 slightly modified by me:
2062
2063 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
2064 not building pcregrep.
2065
2066 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
2067 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
2068
2069 25. Forward references, both numeric and by name, in patterns that made use of
2070 duplicate group numbers, could behave incorrectly or give incorrect errors,
2071 because when scanning forward to find the reference group, PCRE was not
2072 taking into account the duplicate group numbers. A pattern such as
2073 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
2074
2075 26. Changed a few more instances of "const unsigned char *" to USPTR, making
2076 the feature of a custom pointer more persuasive (as requested by a user).
2077
2078 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
2079 pcretest.c, inside #ifndefs, because it seems they are sometimes already
2080 pre-defined.
2081
2082 28. Added support for (*UTF8) at the start of a pattern.
2083
2084 29. Arrange for flags added by the "release type" setting in CMake to be shown
2085 in the configuration summary.
2086
2087
2088 Version 7.8 05-Sep-08
2089 ---------------------
2090
2091 1. Replaced UCP searching code with optimized version as implemented for Ad
2092 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
2093 stage table and inline lookup instead of a function, giving speed ups of 2
2094 to 5 times on some simple patterns that I tested. Permission was given to
2095 distribute the MultiStage2.py script that generates the tables (it's not in
2096 the tarball, but is in the Subversion repository).
2097
2098 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
2099 scripts.
2100
2101 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
2102 a group with a zero qualifier. The result of the study could be incorrect,
2103 or the function might crash, depending on the pattern.
2104
2105 4. Caseless matching was not working for non-ASCII characters in back
2106 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2107 It now works when Unicode Property Support is available.
2108
2109 5. In pcretest, an escape such as \x{de} in the data was always generating
2110 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2111 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2112 truncation.
2113
2114 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2115
2116 7. Added two (int) casts to pcregrep when printing the difference of two
2117 pointers, in case they are 64-bit values.
2118
2119 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
2120 test 2 if it fails.
2121
2122 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2123 and a #define of that name to empty if it is not externally set. This is to
2124 allow users of MSVC to set it if necessary.
2125
2126 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2127 the convenience functions in the pcre_get.c source file.
2128
2129 11. An option change at the start of a pattern that had top-level alternatives
2130 could cause overwriting and/or a crash. This command provoked a crash in
2131 some environments:
2132
2133 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2134
2135 This potential security problem was recorded as CVE-2008-2371.
2136
2137 12. For a pattern where the match had to start at the beginning or immediately
2138 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2139 pcre_dfa_exec() could read past the end of the passed subject if there was
2140 no match. To help with detecting such bugs (e.g. with valgrind), I modified
2141 pcretest so that it places the subject at the end of its malloc-ed buffer.
2142
2143 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2144 exec() might read past the end of the data buffer in UTF-8 mode.
2145
2146 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2147 the data contained the byte 0x85 as part of a UTF-8 character within its
2148 first line. This applied both to normal and DFA matching.
2149
2150 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2151 /^[^d]*?$/8 failed to match "abc".
2152
2153 16. Added a missing copyright notice to pcrecpp_internal.h.
2154
2155 17. Make it more clear in the documentation that values returned from
2156 pcre_exec() in ovector are byte offsets, not character counts.
2157
2158 18. Tidied a few places to stop certain compilers from issuing warnings.
2159
2160 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2161 supplied by Stefan Weber. I made a further small update for 7.8 because
2162 there is a change of source arrangements: the pcre_searchfuncs.c module is
2163 replaced by pcre_ucd.c.
2164
2165
2166 Version 7.7 07-May-08
2167 ---------------------
2168
2169 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2170 a string to a long long, pretend we don't even have a long long." This is
2171 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2172
2173 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2174 pre-7.6 versions, which defined a global no_arg variable instead of putting
2175 it in the RE class. (See also #8 below.)
2176
2177 3. Remove a line of dead code, identified by coverity and reported by Nuno
2178 Lopes.
2179
2180 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2181
2182 (1) The include/exclude patterns were being applied to the whole pathnames
2183 of files, instead of just to the final components.
2184
2185 (2) If there was more than one level of directory, the subdirectories were
2186 skipped unless they satisfied the include/exclude conditions. This is
2187 inconsistent with GNU grep (and could even be seen as contrary to the
2188 pcregrep specification - which I improved to make it absolutely clear).
2189 The action now is always to scan all levels of directory, and just
2190 apply the include/exclude patterns to regular files.
2191
2192 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2193 --exclude_dir in the tests to avoid scanning .svn directories.
2194
2195 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2196 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2197 doesn't support NULs in patterns.
2198
2199 7. Added some missing "const"s to declarations of static tables in
2200 pcre_compile.c and pcre_dfa_exec.c.
2201
2202 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2203 caused by fix #2 above. (Subsequently also a second patch to fix the
2204 first patch. And a third patch - this was a messy problem.)
2205
2206 9. Applied Craig's patch to remove the use of push_back().
2207
2208 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2209 matching function regexec().
2210
2211 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2212 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2213 references. PCRE supports relative numbers with this syntax (I don't think
2214 Oniguruma does).
2215
2216 12. Previously, a group with a zero repeat such as (...){0} was completely
2217 omitted from the compiled regex. However, this means that if the group
2218 was called as a subroutine from elsewhere in the pattern, things went wrong
2219 (an internal error was given). Such groups are now left in the compiled
2220 pattern, with a new opcode that causes them to be skipped at execution
2221 time.
2222
2223 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2224 to the way PCRE behaves:
2225
2226 (a) A lone ] character is dis-allowed (Perl treats it as data).
2227
2228 (b) A back reference to an unmatched subpattern matches an empty string
2229 (Perl fails the current match path).
2230
2231 (c) A data ] in a character class must be notated as \] because if the
2232 first data character in a class is ], it defines an empty class. (In
2233 Perl it is not possible to have an empty class.) The empty class []
2234 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2235 The negative empty class [^] matches any one character, independently
2236 of the DOTALL setting.
2237
2238 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2239 non-existent subpattern following a character class starting with ']' and
2240 containing () gave an internal compiling error instead of "reference to
2241 non-existent subpattern". Fortunately, when the pattern did exist, the
2242 compiled code was correct. (When scanning forwards to check for the
2243 existence of the subpattern, it was treating the data ']' as terminating
2244 the class, so got the count wrong. When actually compiling, the reference
2245 was subsequently set up correctly.)
2246
2247 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2248 it was being rejected as not supported by pcre_dfa_exec(), even though
2249 other assertions are supported. I have made pcre_dfa_exec() support
2250 (*FAIL).
2251
2252 16. The implementation of 13c above involved the invention of a new opcode,
2253 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2254 cannot be changed at match time, I realized I could make a small
2255 improvement to matching performance by compiling OP_ALLANY instead of
2256 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2257 on the OP_ANY path.
2258
2259 17. Compiling pcretest on Windows with readline support failed without the
2260 following two fixes: (1) Make the unistd.h include conditional on
2261 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2262
2263 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2264 ncurses library to be included for pcretest when ReadLine support is
2265 requested, but also to allow for it to be overridden. This patch came from
2266 Daniel Bergström.
2267
2268 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2269 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2270 any errors with the current Unicode tables. Thanks to Peter Kankowski for
2271 spotting this.
2272
2273
2274 Version 7.6 28-Jan-08
2275 ---------------------
2276
2277 1. A character class containing a very large number of characters with
2278 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2279 overflow.
2280
2281 2. Patch to cut out the "long long" test in pcrecpp_unittest when
2282 HAVE_LONG_LONG is not defined.
2283
2284 3. Applied Christian Ehrlicher's patch to update the CMake build files to
2285 bring them up to date and include new features. This patch includes:
2286
2287 - Fixed PH's badly added libz and libbz2 support.
2288 - Fixed a problem with static linking.
2289 - Added pcredemo. [But later removed - see 7 below.]
2290 - Fixed dftables problem and added an option.
2291 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2292 HAVE_LONG_LONG.
2293 - Added readline support for pcretest.
2294 - Added an listing of the option settings after cmake has run.
2295
2296 4. A user submitted a patch to Makefile that makes it easy to create
2297 "pcre.dll" under mingw when using Configure/Make. I added stuff to
2298 Makefile.am that cause it to include this special target, without
2299 affecting anything else. Note that the same mingw target plus all
2300 the other distribution libraries and programs are now supported
2301 when configuring with CMake (see 6 below) instead of with
2302 Configure/Make.
2303
2304 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2305 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2306 exported in the Windows port". It has not yet been confirmed that the patch
2307 solves the problem, but it does no harm.
2308
2309 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2310 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2311 with CMake, and also correct the comment about stack recursion.
2312
2313 7. Remove the automatic building of pcredemo from the ./configure system and
2314 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2315 of a program that users should build themselves after PCRE is installed, so
2316 building it automatically is not really right. What is more, it gave
2317 trouble in some build environments.
2318
2319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
2320
2321
2322 Version 7.5 10-Jan-08
2323 ---------------------
2324
2325 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
2326 values in parens when parsing an RE using the C++ wrapper."
2327
2328 2. Negative specials like \S did not work in character classes in UTF-8 mode.
2329 Characters greater than 255 were excluded from the class instead of being
2330 included.
2331
2332 3. The same bug as (2) above applied to negated POSIX classes such as
2333 [:^space:].
2334
2335 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2336 defined or documented. It seems to have been a typo for PCRE_STATIC, so
2337 I have changed it.
2338
2339 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
2340 first named subpattern) and a construct such as (?&a) would reference the
2341 first named subpattern whose name started with "a" (in other words, the
2342 length check was missing). Both these problems are fixed. "Subpattern name
2343 expected" is now given for (?&) (a zero-length name), and this patch also
2344 makes it give the same error for \k'' (previously it complained that that
2345 was a reference to a non-existent subpattern).
2346
2347 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
2348 this is right because (?- can be followed by option settings as well as by
2349 digits. I have, however, made the messages clearer.
2350
2351 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2352 than the number used in the conditional) now cause a compile-time error.
2353 This is actually not compatible with Perl, which accepts such patterns, but
2354 treats the conditional as always being FALSE (as PCRE used to), but it
2355 seems to me that giving a diagnostic is better.
2356
2357 8. Change "alphameric" to the more common word "alphanumeric" in comments
2358 and messages.
2359
2360 9. Fix two occurrences of "backslash" in comments that should have been
2361 "backspace".
2362
2363 10. Remove two redundant lines of code that can never be obeyed (their function
2364 was moved elsewhere).
2365
2366 11. The program that makes PCRE's Unicode character property table had a bug
2367 which caused it to generate incorrect table entries for sequences of
2368 characters that have the same character type, but are in different scripts.
2369 It amalgamated them into a single range, with the script of the first of
2370 them. In other words, some characters were in the wrong script. There were
2371 thirteen such cases, affecting characters in the following ranges:
2372
2373 U+002b0 - U+002c1
2374 U+0060c - U+0060d
2375 U+0061e - U+00612
2376 U+0064b - U+0065e
2377 U+0074d - U+0076d
2378 U+01800 - U+01805
2379 U+01d00 - U+01d77
2380 U+01d9b - U+01dbf
2381 U+0200b - U+0200f
2382 U+030fc - U+030fe
2383 U+03260 - U+0327f
2384 U+0fb46 - U+0fbb1
2385 U+10450 - U+1049d
2386
2387 12. The -o option (show only the matching part of a line) for pcregrep was not
2388 compatible with GNU grep in that, if there was more than one match in a
2389 line, it showed only the first of them. It now behaves in the same way as
2390 GNU grep.
2391
2392 13. If the -o and -v options were combined for pcregrep, it printed a blank
2393 line for every non-matching line. GNU grep prints nothing, and pcregrep now
2394 does the same. The return code can be used to tell if there were any
2395 non-matching lines.
2396
2397 14. Added --file-offsets and --line-offsets to pcregrep.
2398
2399 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2400 infinitely looping recursion. The bug was that positive lookaheads were not
2401 being skipped when checking for a possible empty match (negative lookaheads
2402 and both kinds of lookbehind were skipped).
2403
2404 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2405 inclusion of <windows.h> to before rather than after the definition of
2406 INVALID_FILE_ATTRIBUTES (patch from David Byron).
2407
2408 17. Specifying a possessive quantifier with a specific limit for a Unicode
2409 character property caused pcre_compile() to compile bad code, which led at
2410 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2411 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2412 caused the error; without that there was no problem.
2413
2414 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2415
2416 19. Added --enable-pcretest-libreadline.
2417
2418 20. In pcrecpp.cc, the variable 'count' was incremented twice in
2419 RE::GlobalReplace(). As a result, the number of replacements returned was
2420 double what it should be. I removed one of the increments, but Craig sent a
2421 later patch that removed the other one (the right fix) and added unit tests
2422 that check the return values (which was not done before).
2423
2424 21. Several CMake things:
2425
2426 (1) Arranged that, when cmake is used on Unix, the libraries end up with
2427 the names libpcre and libpcreposix, not just pcre and pcreposix.
2428
2429 (2) The above change means that pcretest and pcregrep are now correctly
2430 linked with the newly-built libraries, not previously installed ones.
2431
2432 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2433
2434 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2435 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2436 UTF-8 newline character). The key issue is that the pattern starts .*;
2437 this means that the match must be either at the beginning, or after a
2438 newline. The bug was in the code for advancing after a failed match and
2439 checking that the new position followed a newline. It was not taking
2440 account of UTF-8 characters correctly.
2441
2442 23. PCRE was behaving differently from Perl in the way it recognized POSIX
2443 character classes. PCRE was not treating the sequence [:...:] as a
2444 character class unless the ... were all letters. Perl, however, seems to
2445 allow any characters between [: and :], though of course it rejects as
2446 unknown any "names" that contain non-letters, because all the known class
2447 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2448 for example, whereas PCRE did not - it did not recognize a POSIX character
2449 class. This seemed a bit dangerous, so the code has been changed to be
2450 closer to Perl. The behaviour is not identical to Perl, because PCRE will
2451 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2452 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2453 Perl does, and where it didn't before.
2454
2455 24. Rewrite so as to remove the single use of %n from pcregrep because in some
2456 Windows environments %n is disabled by default.
2457
2458
2459 Version 7.4 21-Sep-07
2460 ---------------------
2461
2462 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
2463 means that a class such as [\s] counted as "explicit reference to CR or
2464 LF". That isn't really right - the whole point of the change was to try to
2465 help when there was an actual mention of one of the two characters. So now
2466 the change happens only if \r or \n (or a literal CR or LF) character is
2467 encountered.
2468
2469 2. The 32-bit options word was also used for 6 internal flags, but the numbers
2470 of both had grown to the point where there were only 3 bits left.
2471 Fortunately, there was spare space in the data structure, and so I have
2472 moved the internal flags into a new 16-bit field to free up more option
2473 bits.
2474
2475 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2476 but did not set the internal JCHANGED flag - either of these is enough to
2477 control the way the "get" function works - but the PCRE_INFO_JCHANGED
2478 facility is supposed to tell if (?J) was ever used, so now (?J) at the
2479 start sets both bits.
2480
2481 4. Added options (at build time, compile time, exec time) to change \R from
2482 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2483
2484 5. doc/pcresyntax.html was missing from the distribution.
2485
2486 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2487 compatibility, even though it is no longer used.
2488
2489 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2490 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2491 windows.h file is present (where different names are used). [This was
2492 reversed later after testing - see 16 below.]
2493
2494 8. Changed all #include <config.h> to #include "config.h". There were also
2495 some further <pcre.h> cases that I changed to "pcre.h".
2496
2497 9. When pcregrep was used with the --colour option, it missed the line ending
2498 sequence off the lines that it output.
2499
2500 10. It was pointed out to me that arrays of string pointers cause lots of
2501 relocations when a shared library is dynamically loaded. A technique of
2502 using a single long string with a table of offsets can drastically reduce
2503 these. I have refactored PCRE in four places to do this. The result is
2504 dramatic:
2505
2506 Originally: 290
2507 After changing UCP table: 187
2508 After changing error message table: 43
2509 After changing table of "verbs" 36
2510 After changing table of Posix names 22
2511
2512 Thanks to the folks working on Gregex for glib for this insight.
2513
2514 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2515 unicode-properties was also set.
2516
2517 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2518
2519 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2520 checked only for CRLF.
2521
2522 14. Added casts to pcretest.c to avoid compiler warnings.
2523
2524 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2525
2526 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2527 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2528 entirely. This removes changes made in 7 above.
2529
2530 17. The CMake files have been updated, and there is now more information about
2531 building with CMake in the NON-UNIX-USE document.
2532
2533
2534 Version 7.3 28-Aug-07
2535 ---------------------
2536
2537 1. In the rejigging of the build system that eventually resulted in 7.1, the
2538 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2539 brackets there is not right, since it causes compilers to look for an
2540 installed pcre.h, not the version that is in the source that is being
2541 compiled (which of course may be different). I have changed it back to:
2542
2543 #include "pcre.h"
2544
2545 I have a vague recollection that the change was concerned with compiling in
2546 different directories, but in the new build system, that is taken care of
2547 by the VPATH setting the Makefile.
2548
2549 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2550 when the subject happened to end in the byte 0x85 (e.g. if the last
2551 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2552 characters but of course it shouldn't be taken as a newline when it is part
2553 of another character. The bug was that, for an unlimited repeat of . in
2554 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2555 characters when looking for a newline.
2556
2557 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2558
2559 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2560 in debug output.
2561
2562 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2563 long printing in the pcrecpp unittest when running under MinGW.
2564
2565 6. ESC_K was left out of the EBCDIC table.
2566
2567 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2568 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2569 limit also applies to "virtual nesting" when a pattern is recursive, and in
2570 this case 1000 isn't so big. I have been able to remove this limit at the
2571 expense of backing off one optimization in certain circumstances. Normally,
2572 when pcre_exec() would call its internal match() function recursively and
2573 immediately return the result unconditionally, it uses a "tail recursion"
2574 feature to save stack. However, when a subpattern that can match an empty
2575 string has an unlimited repetition quantifier, it no longer makes this
2576 optimization. That gives it a stack frame in which to save the data for
2577 checking that an empty string has been matched. Previously this was taken
2578 from the 1000-entry workspace that had been reserved. So now there is no
2579 explicit limit, but more stack is used.
2580
2581 8. Applied Daniel's patches to solve problems with the import/export magic
2582 syntax that is required for Windows, and which was going wrong for the
2583 pcreposix and pcrecpp parts of the library. These were overlooked when this
2584 problem was solved for the main library.
2585
2586 9. There were some crude static tests to avoid integer overflow when computing
2587 the size of patterns that contain repeated groups with explicit upper
2588 limits. As the maximum quantifier is 65535, the maximum group length was
2589 set at 30,000 so that the product of these two numbers did not overflow a
2590 32-bit integer. However, it turns out that people want to use groups that
2591 are longer than 30,000 bytes (though not repeat them that many times).
2592 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2593 made it possible to implement the integer overflow checks in a much more
2594 dynamic way, which I have now done. The artificial limitation on group
2595 length has been removed - we now have only the limit on the total length of
2596 the compiled pattern, which depends on the LINK_SIZE setting.
2597
2598 10. Fixed a bug in the documentation for get/copy named substring when
2599 duplicate names are permitted. If none of the named substrings are set, the
2600 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2601 empty string.
2602
2603 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2604 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2605 because the ] is interpreted as the first data character and the
2606 terminating ] is not found. PCRE has been made compatible with Perl in this
2607 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2608 cause memory overwriting.
2609
2610 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2611 string has been matched (to stop an infinite loop). It was not recognizing
2612 a conditional subpattern that could match an empty string if that
2613 subpattern was within another subpattern. For example, it looped when
2614 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
2615 condition was not nested. This bug has been fixed.
2616
2617 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2618 past the start of the subject in the presence of bytes with the top bit
2619 set, for example "\x8aBCD".
2620
2621 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2622 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2623
2624 14. Optimized (?!) to (*FAIL).
2625
2626 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2627 This restricts code points to be within the range 0 to 0x10FFFF, excluding
2628 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2629 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2630 does: it's just the validity check that is more restrictive.
2631
2632 16. Inserted checks for integer overflows during escape sequence (backslash)
2633 processing, and also fixed erroneous offset values for syntax errors during
2634 backslash processing.
2635
2636 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2637 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2638
2639 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2640 caused an overrun.
2641
2642 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2643 something other than just ASCII characters) inside a group that had an
2644 unlimited repeat caused a loop at compile time (while checking to see
2645 whether the group could match an empty string).
2646
2647 20. Debugging a pattern containing \p or \P could cause a crash. For example,
2648 [\P{Any}] did so. (Error in the code for printing property names.)
2649
2650 21. An orphan \E inside a character class could cause a crash.
2651
2652 22. A repeated capturing bracket such as (A)? could cause a wild memory
2653 reference during compilation.
2654
2655 23. There are several functions in pcre_compile() that scan along a compiled
2656 expression for various reasons (e.g. to see if it's fixed length for look
2657 behind). There were bugs in these functions when a repeated \p or \P was
2658 present in the pattern. These operators have additional parameters compared
2659 with \d, etc, and these were not being taken into account when moving along
2660 the compiled data. Specifically:
2661
2662 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
2663 length.
2664
2665 (b) An item such as \pL+ within a repeated group could cause crashes or
2666 loops.
2667
2668 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
2669 "reference to non-existent subpattern" error.
2670
2671 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
2672
2673 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
2674 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
2675
2676 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
2677
2678 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
2679 character were causing crashes (broken optimization).
2680
2681 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
2682 \p or \P) caused a compile-time loop.
2683
2684 28. More problems have arisen in unanchored patterns when CRLF is a valid line
2685 break. For example, the unstudied pattern [\r\n]A does not match the string
2686 "\r\nA" because change 7.0/46 below moves the current point on by two
2687 characters after failing to match at the start. However, the pattern \nA
2688 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
2689 the same is true. There doesn't seem any very clean way out of this, but
2690 what I have chosen to do makes the common cases work: PCRE now takes note
2691 of whether there can be an explicit match for \r or \n anywhere in the
2692 pattern, and if so, 7.0/46 no longer applies. As part of this change,
2693 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
2694 pattern has explicit CR or LF references.
2695
2696 29. Added (*CR) etc for changing newline setting at start of pattern.
2697
2698
2699 Version 7.2 19-Jun-07
2700 ---------------------
2701
2702 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
2703 which is apparently normally available under Windows.
2704
2705 2. Re-jig the pcregrep tests with different newline settings in an attempt
2706 to make them independent of the local environment's newline setting.
2707
2708 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
2709
2710 4. Some of the "internals" tests were previously cut out when the link size
2711 was not 2, because the output contained actual offsets. The recent new
2712 "Z" feature of pcretest means that these can be cut out, making the tests
2713 usable with all link sizes.
2714
2715 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
2716 stack recursion. This gives a massive performance boost under BSD, but just
2717 a small improvement under Linux. However, it saves one field in the frame
2718 in all cases.
2719
2720 6. Added more features from the forthcoming Perl 5.10:
2721
2722 (a) (?-n) (where n is a string of digits) is a relative subroutine or
2723 recursion call. It refers to the nth most recently opened parentheses.
2724
2725 (b) (?+n) is also a relative subroutine call; it refers to the nth next
2726 to be opened parentheses.
2727
2728 (c) Conditions that refer to capturing parentheses can be specified
2729 relatively, for example, (?(-2)... or (?(+3)...
2730
2731 (d) \K resets the start of the current match so that everything before
2732 is not part of it.
2733
2734 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
2735
2736 (f) \g{name} is another synonym - part of Perl 5.10's unification of
2737 reference syntax.
2738
2739 (g) (?| introduces a group in which the numbering of parentheses in each
2740 alternative starts with the same number.
2741
2742 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
2743
2744 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
2745 PCRE_INFO_JCHANGED.
2746
2747 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
2748 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
2749 for detecting groups that can match an empty string.
2750
2751 9. A pattern with a very large number of alternatives (more than several
2752 hundred) was running out of internal workspace during the pre-compile
2753 phase, where pcre_compile() figures out how much memory will be needed. A
2754 bit of new cunning has reduced the workspace needed for groups with
2755 alternatives. The 1000-alternative test pattern now uses 12 bytes of
2756 workspace instead of running out of the 4096 that are available.
2757
2758 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
2759
2760 11. Applied patch from Google to remove an optimization that didn't quite work.
2761 The report of the bug said:
2762
2763 pcrecpp::RE("a*").FullMatch("aaa") matches, while
2764 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
2765 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
2766
2767 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
2768 it matched the wrong number of bytes.
2769
2770
2771 Version 7.1 24-Apr-07
2772 ---------------------
2773
2774 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
2775 that is more "standard", making use of automake and other Autotools. There
2776 is some re-arrangement of the files and adjustment of comments consequent
2777 on this.
2778
2779 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
2780 for recursive directory scanning broke on some systems because the files
2781 are not scanned in any specific order and on different systems the order
2782 was different. A call to "sort" has been inserted into RunGrepTest for the
2783 approprate test as a short-term fix. In the longer term there may be an
2784 alternative.
2785
2786 3. I had an email from Eric Raymond about problems translating some of PCRE's
2787 man pages to HTML (despite the fact that I distribute HTML pages, some
2788 people do their own conversions for various reasons). The problems
2789 concerned the use of low-level troff macros .br and .in. I have therefore
2790 removed all such uses from the man pages (some were redundant, some could
2791 be replaced by .nf/.fi pairs). The 132html script that I use to generate
2792 HTML has been updated to handle .nf/.fi and to complain if it encounters
2793 .br or .in.
2794
2795 4. Updated comments in configure.ac that get placed in config.h.in and also
2796 arranged for config.h to be included in the distribution, with the name
2797 config.h.generic, for the benefit of those who have to compile without
2798 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
2799
2800 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
2801 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
2802 makevp.bat for the current PCRE, using the additional files
2803 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
2804
2805 6. A Windows user reported a minor discrepancy with test 2, which turned out
2806 to be caused by a trailing space on an input line that had got lost in his
2807 copy. The trailing space was an accident, so I've just removed it.
2808
2809 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2810 that is needed.
2811
2812 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2813 as "const" (a) because they are and (b) because it helps the PHP
2814 maintainers who have recently made a script to detect big data structures
2815 in the php code that should be moved to the .rodata section. I remembered
2816 to update Builducptable as well, so it won't revert if ucptable.h is ever
2817 re-created.
2818
2819 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2820 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2821 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2822 support is not required. This saves 1.5-2K of code, which is important in
2823 some applications.
2824
2825 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2826 so as not to refer to the tables, even though these functions will never be
2827 called when UTF-8 support is disabled. Otherwise there are problems with a
2828 shared library.
2829
2830 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2831
2832 (a) It was defining its arguments as char * instead of void *.
2833
2834 (b) It was assuming that all moves were upwards in memory; this was true
2835 a long time ago when I wrote it, but is no longer the case.
2836
2837 The emulated memove() is provided for those environments that have neither
2838 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2839 is clearly not the case, as these two bugs were recently reported.
2840
2841 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2842 and Detrail to create the HTML documentation, the .txt form of the man
2843 pages, and it removes trailing spaces from listed files. It also creates
2844 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2845 case, it wraps all the #defines with #ifndefs. This script should be run
2846 before "make dist".
2847
2848 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2849 with Unicode property support.
2850
2851 (a) For a maximizing quantifier, if the two different cases of the
2852 character were of different lengths in their UTF-8 codings (there are
2853 some cases like this - I found 11), and the matching function had to
2854 back up over a mixture of the two cases, it incorrectly assumed they
2855 were both the same length.
2856
2857 (b) When PCRE was configured to use the heap rather than the stack for
2858 recursion during matching, it was not correctly preserving the data for
2859 the other case of a UTF-8 character when checking ahead for a match
2860 while processing a minimizing repeat. If the check also involved
2861 matching a wide character, but failed, corruption could cause an
2862 erroneous result when trying to check for a repeat of the original
2863 character.
2864
2865 13. Some tidying changes to the testing mechanism:
2866
2867 (a) The RunTest script now detects the internal link size and whether there
2868 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2869 values substituted by "configure". (The RunGrepTest script already did
2870 this for UTF-8.) The configure.ac script no longer substitutes the
2871 relevant variables.
2872
2873 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2874 with length and offset values. This means that the output is different
2875 for different internal link sizes. Test 2 is skipped for link sizes
2876 other than 2 because of this, bypassing the problem. Unfortunately,
2877 there was also a test in test 3 (the locale tests) that used /B and
2878 failed for link sizes other than 2. Rather than cut the whole test out,
2879 I have added a new /Z option to pcretest that replaces the length and
2880 offset values with spaces. This is now used to make test 3 independent
2881 of link size. (Test 2 will be tidied up later.)
2882
2883 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2884 segmentation fault instead of returning the appropriate error message.
2885
2886 15. In multiline mode when the newline sequence was set to "any", the pattern
2887 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2888 This doesn't seem right; it now treats the CRLF combination as the line
2889 ending, and so does not match in that case. It's only a pattern such as ^$
2890 that would hit this one: something like ^ABC$ would have failed after \r
2891 and then tried again after \r\n.
2892
2893 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2894 in an attempt to make files that differ only in their line terminators
2895 compare equal. This works on Linux.
2896
2897 17. Under certain error circumstances pcregrep might try to free random memory
2898 as it exited. This is now fixed, thanks to valgrind.
2899
2900 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2901 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2902 was because its rules for how to advance for /g after matching an empty
2903 string at the end of a line did not allow for this case. They now check for
2904 it specially.
2905
2906 20. pcretest is supposed to handle patterns and data of any length, by
2907 extending its buffers when necessary. It was getting this wrong when the
2908 buffer for a data line had to be extended.
2909
2910 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2911 CRLF as a newline sequence.
2912
2913 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2914 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2915 I have nevertheless tidied it up.
2916
2917 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2918
2919 24. Added a man page for pcre-config.
2920
2921
2922 Version 7.0 19-Dec-06
2923 ---------------------
2924
2925 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2926 moving to gcc 4.1.1.
2927
2928 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2929 sys/time.h, which is documented as needed for this function. It doesn't
2930 seem to matter on Linux, but it showed up on some releases of OS X.
2931
2932 3. It seems that there are systems where bytes whose values are greater than
2933 127 match isprint() in the "C" locale. The "C" locale should be the
2934 default when a C program starts up. In most systems, only ASCII printing
2935 characters match isprint(). This difference caused the output from pcretest
2936 to vary, making some of the tests fail. I have changed pcretest so that:
2937
2938 (a) When it is outputting text in the compiled version of a pattern, bytes
2939 other than 32-126 are always shown as hex escapes.
2940
2941 (b) When it is outputting text that is a matched part of a subject string,
2942 it does the same, unless a different locale has been set for the match
2943 (using the /L modifier). In this case, it uses isprint() to decide.
2944
2945 4. Fixed a major bug that caused incorrect computation of the amount of memory
2946 required for a compiled pattern when options that changed within the
2947 pattern affected the logic of the preliminary scan that determines the
2948 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2949 that the computed length was too small. The symptoms of this bug were
2950 either the PCRE error "internal error: code overflow" from pcre_compile(),
2951 or a glibc crash with a message such as "pcretest: free(): invalid next
2952 size (fast)". Examples of patterns that provoked this bug (shown in
2953 pcretest format) are:
2954
2955 /(?-x: )/x
2956 /(?x)(?-x: \s*#\s*)/
2957 /((?i)[\x{c0}])/8
2958 /(?i:[\x{c0}])/8
2959
2960 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2961 is now done differently.
2962
2963 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2964 wrapper classes; (b) implement a new function in the C++ scanner that is
2965 more efficient than the old way of doing things because it avoids levels of
2966 recursion in the regex matching; (c) add a paragraph to the documentation
2967 for the FullMatch() function.
2968
2969 6. The escape sequence \n was being treated as whatever was defined as
2970 "newline". Not only was this contrary to the documentation, which states
2971 that \n is character 10 (hex 0A), but it also went horribly wrong when
2972 "newline" was defined as CRLF. This has been fixed.
2973
2974 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2975 was being set to -1 for the "end of line" case (supposedly a value that no
2976 character can have). Though this value is never used (the check for end of
2977 line is "zero bytes in current character"), it caused compiler complaints.
2978 I've changed it to 0xffffffff.
2979
2980 8. In pcre_version.c, the version string was being built by a sequence of
2981 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2982 string (as it is for production releases) called a macro with an empty
2983 argument. The C standard says the result of this is undefined. The gcc
2984 compiler treats it as an empty string (which was what was wanted) but it is
2985 reported that Visual C gives an error. The source has been hacked around to
2986 avoid this problem.
2987
2988 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2989 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2990 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2991 of them did).
2992
2993 10. Originally, pcretest opened its input and output without "b"; then I was
2994 told that "b" was needed in some environments, so it was added for release
2995 5.0 to both the input and output. (It makes no difference on Unix-like
2996 systems.) Later I was told that it is wrong for the input on Windows. I've
2997 now abstracted the modes into two macros, to make it easier to fiddle with
2998 them, and removed "b" from the input mode under Windows.
2999
3000 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
3001
3002 12. Added -help and --help to pcretest as an official way of being reminded
3003 of the options.
3004
3005 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
3006 and pcrecpp.cc because they annoy compilers at high warning levels.
3007
3008 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
3009
3010 15. Fixed an occurrence of == in configure.ac that should have been = (shell
3011 scripts are not C programs :-) and which was not noticed because it works
3012 on Linux.
3013
3014 16. pcretest is supposed to handle any length of pattern and data line (as one
3015 line or as a continued sequence of lines) by extending its input buffer if
3016 necessary. This feature was broken for very long pattern lines, leading to
3017 a string of junk being passed to pcre_compile() if the pattern was longer
3018 than about 50K.
3019
3020 17. I have done a major re-factoring of the way pcre_compile() computes the
3021 amount of memory needed for a compiled pattern. Previously, there was code
3022 that made a preliminary scan of the pattern in order to do this. That was
3023 OK when PCRE was new, but as the facilities have expanded, it has become
3024 harder and harder to keep it in step with the real compile phase, and there
3025 have been a number of bugs (see for example, 4 above). I have now found a
3026 cunning way of running the real compile function in a "fake" mode that
3027 enables it to compute how much memory it would need, while actually only
3028 ever using a few hundred bytes of working memory and without too many
3029 tests of the mode. This should make future maintenance and development
3030 easier. A side effect of this work is that the limit of 200 on the nesting
3031 depth of parentheses has been removed (though this was never a serious
3032 limitation, I suspect). However, there is a downside: pcre_compile() now
3033 runs more slowly than before (30% or more, depending on the pattern). I
3034 hope this isn't a big issue. There is no effect on runtime performance.
3035
3036 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
3037 newline (only possible for the last line of a file) and it was a
3038 pattern that set a locale (followed by /Lsomething), pcretest crashed.
3039
3040 19. Added additional timing features to pcretest. (1) The -tm option now times
3041 matching only, not compiling. (2) Both -t and -tm can be followed, as a
3042 separate command line item, by a number that specifies the number of
3043 repeats to use when timing. The default is 50000; this gives better
3044 precision, but takes uncomfortably long for very large patterns.
3045
3046 20. Extended pcre_study() to be more clever in cases where a branch of a
3047 subpattern has no definite first character. For example, (a*|b*)[cd] would
3048 previously give no result from pcre_study(). Now it recognizes that the
3049 first character must be a, b, c, or d.
3050
3051 21. There was an incorrect error "recursive call could loop indefinitely" if
3052 a subpattern (or the entire pattern) that was being tested for matching an
3053 empty string contained only one non-empty item after a nested subpattern.
3054 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
3055 incorrectly, because the \d was being skipped in the check.
3056
3057 22. The pcretest program now has a new pattern option /B and a command line
3058 option -b, which is equivalent to adding /B to every pattern. This causes
3059 it to show the compiled bytecode, without the additional information that
3060 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
3061 is the same as /B/I).
3062
3063 23. A new optimization is now able automatically to treat some sequences such
3064 as a*b as a*+b. More specifically, if something simple (such as a character
3065 or a simple class like \d) has an unlimited quantifier, and is followed by
3066 something that cannot possibly match the quantified thing, the quantifier
3067 is automatically "possessified".
3068
3069 24. A recursive reference to a subpattern whose number was greater than 39
3070 went wrong under certain circumstances in UTF-8 mode. This bug could also
3071 have affected the operation of pcre_study().
3072
3073 25. Realized that a little bit of performance could be had by replacing
3074 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
3075
3076 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
3077
3078 27. Possessive quantifiers such as a++ were previously implemented by turning
3079 them into atomic groups such as ($>a+). Now they have their own opcodes,
3080 which improves performance. This includes the automatically created ones
3081 from 23 above.
3082
3083 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
3084 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
3085 the first matched character to be a colon. This applied both to named and
3086 numbered groups.
3087
3088 29. The ucpinternal.h header file was missing its idempotency #ifdef.
3089
3090 30. I was sent a "project" file called libpcre.a.dev which I understand makes
3091 building PCRE on Windows easier, so I have included it in the distribution.
3092
3093 31. There is now a check in pcretest against a ridiculously large number being
3094 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
3095 loop, the loop is abandoned.
3096
3097 32. Forward references to subpatterns in conditions such as (?(2)...) where
3098 subpattern 2 is defined later cause pcre_compile() to search forwards in
3099 the pattern for the relevant set of parentheses. This search went wrong
3100 when there were unescaped parentheses in a character class, parentheses
3101 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
3102
3103 33. "Subroutine" calls and backreferences were previously restricted to
3104 referencing subpatterns earlier in the regex. This restriction has now
3105 been removed.
3106
3107 34. Added a number of extra features that are going to be in Perl 5.10. On the
3108 whole, these are just syntactic alternatives for features that PCRE had
3109 previously implemented using the Python syntax or my own invention. The
3110 other formats are all retained for compatibility.
3111
3112 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
3113 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
3114 also .NET compatible.
3115
3116 (b) A recursion or subroutine call to a named group can now be defined as
3117 (?&name) as well as (?P>name).
3118
3119 (c) A backreference to a named group can now be defined as \k<name> or
3120 \k'name' as well as (?P=name). The new forms, as well as being in Perl
3121 5.10, are also .NET compatible.
3122
3123 (d) A conditional reference to a named group can now use the syntax
3124 (?(<name>) or (?('name') as well as (?(name).
3125
3126 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
3127 groups (named and numbered) that are never evaluated inline, but can be
3128 called as "subroutines" from elsewhere. In effect, the DEFINE condition
3129 is always false. There may be only one alternative in such a group.
3130
3131 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
3132 as the simple (?(R). The condition is true only if the most recent
3133 recursion is that of the given number or name. It does not search out
3134 through the entire recursion stack.
3135
3136 (g) The escape \gN or \g{N} has been added, where N is a positive or
3137 negative number, specifying an absolute or relative reference.
3138
3139 35. Tidied to get rid of some further signed/unsigned compiler warnings and
3140 some "unreachable code" warnings.
3141
3142 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
3143 things, this adds five new scripts.
3144
3145 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
3146 There were also incompatibilities regarding the handling of \Q..\E inside
3147 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3148 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3149
3150 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3151 matches an empty string, and forcibly breaks the loop. There were bugs in
3152 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3153 against aaaa the result was just "a" rather than "aaaa", for example. Two
3154 separate and independent bugs (that affected different cases) have been
3155 fixed.
3156
3157 39. Refactored the code to abolish the use of different opcodes for small
3158 capturing bracket numbers. This is a tidy that I avoided doing when I
3159 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3160 The new approach is not only tidier, it makes it possible to reduce the
3161 memory needed to fix the previous bug (38).
3162
3163 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3164 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3165 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3166 mode.
3167
3168 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3169 report.
3170
3171 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3172 copy construction and assignment in the C++ wrapper.
3173
3174 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3175 couple of bugs that could have given wrong results in the "--newline=crlf"
3176 case.
3177
3178 44. Added a number of casts and did some reorganization of signed/unsigned int
3179 variables following suggestions from Dair Grant. Also renamed the variable
3180 "this" as "item" because it is a C++ keyword.
3181
3182 45. Arranged for dftables to add
3183
3184 #include "pcre_internal.h"
3185
3186 to pcre_chartables.c because without it, gcc 4.x may remove the array
3187 definition from the final binary if PCRE is built into a static library and
3188 dead code stripping is activated.
3189
3190 46. For an unanchored pattern, if a match attempt fails at the start of a
3191 newline sequence, and the newline setting is CRLF or ANY, and the next two
3192 characters are CRLF, advance by two characters instead of one.
3193
3194
3195 Version 6.7 04-Jul-06
3196 ---------------------
3197
3198 1. In order to handle tests when input lines are enormously long, pcretest has
3199 been re-factored so that it automatically extends its buffers when
3200 necessary. The code is crude, but this _is_ just a test program. The
3201 default size has been increased from 32K to 50K.
3202
3203 2. The code in pcre_study() was using the value of the re argument before
3204 testing it for NULL. (Of course, in any sensible call of the function, it
3205 won't be NULL.)
3206
3207 3. The memmove() emulation function in pcre_internal.h, which is used on
3208 systems that lack both memmove() and bcopy() - that is, hardly ever -
3209 was missing a "static" storage class specifier.
3210
3211 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3212 containing an extended class (one that cannot be represented by a bitmap
3213 because it contains high-valued characters or Unicode property items, e.g.
3214 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3215 pattern, but PCRE should not loop if you do not (it no longer does).
3216 [Detail: two cases were found: (a) a repeated subpattern containing an
3217 extended class; (b) a recursive reference to a subpattern that followed a
3218 previous extended class. It wasn't skipping over the extended class
3219 correctly when UTF-8 mode was not set.]
3220
3221 5. A negated single-character class was not being recognized as fixed-length
3222 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3223 compile error "lookbehind assertion is not fixed length".
3224
3225 6. The RunPerlTest auxiliary script was showing an unexpected difference
3226 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3227 write a Perl script that can interpret lines of an input file either as
3228 byte characters or as UTF-8, which is what "perltest" was being required to
3229 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3230 can't do is switch easily at run time between having the "use utf8;" pragma
3231 or not. In the end, I fudged it by using the RunPerlTest script to insert
3232 "use utf8;" explicitly for the UTF-8 tests.
3233
3234 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3235 the end of the subject string, contrary to the documentation and to what
3236 Perl does. This was true of both matching functions. Now it matches only at
3237 the start of the subject and immediately after *internal* newlines.
3238
3239 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3240 a pointer to an int instead of a pointer to an unsigned long int. This
3241 caused problems on 64-bit systems.
3242
3243 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
3244 instance of the 'standard' template library not being so standard".
3245
3246 10. There was no check on the number of named subpatterns nor the maximum
3247 length of a subpattern name. The product of these values is used to compute
3248 the size of the memory block for a compiled pattern. By supplying a very
3249 long subpattern name and a large number of named subpatterns, the size
3250 computation could be caused to overflow. This is now prevented by limiting
3251 the length of names to 32 characters, and the number of named subpatterns
3252 to 10,000.
3253
3254 11. Subpatterns that are repeated with specific counts have to be replicated in
3255 the compiled pattern. The size of memory for this was computed from the
3256 length of the subpattern and the repeat count. The latter is limited to
3257 65535, but there was no limit on the former, meaning that integer overflow
3258 could in principle occur. The compiled length of a repeated subpattern is
3259 now limited to 30,000 bytes in order to prevent this.
3260
3261 12. Added the optional facility to have named substrings with the same name.
3262
3263 13. Added the ability to use a named substring as a condition, using the
3264 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
3265 are numbers (not recommended). Forward references are permitted.
3266
3267 14. Added forward references in named backreferences (if you see what I mean).
3268
3269 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
3270 pattern could run off the end of the subject. For example, the pattern
3271 "(?s)(.{1,5})"8 did this with the subject "ab".
3272
3273 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
3274 PCRE_CASELESS was set when matching characters that were quantified with ?
3275 or *.
3276
3277 17. A character class other than a single negated character that had a minimum
3278 but no maximum quantifier - for example [ab]{6,} - was not handled
3279 correctly by pce_dfa_exec(). It would match only one character.
3280
3281 18. A valid (though odd) pattern that looked like a POSIX character
3282 class but used an invalid character after [ (for example [[,abc,]]) caused
3283 pcre_compile() to give the error "Failed: internal error: code overflow" or
3284 in some cases to crash with a glibc free() error. This could even happen if
3285 the pattern terminated after [[ but there just happened to be a sequence of
3286 letters, a binary zero, and a closing ] in the memory that followed.
3287
3288 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
3289 over the years. Originally (before any Unicode support), just the bottom 8
3290 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
3291 output from "man perlunicode" includes this:
3292
3293 The regular expression compiler produces polymorphic opcodes. That
3294 is, the pattern adapts to the data and automatically switches to
3295 the Unicode character scheme when presented with Unicode data--or
3296 instead uses a traditional byte scheme when presented with byte
3297 data.
3298
3299 Sadly, a wide octal escape does not cause a switch, and in a string with
3300 no other multibyte characters, these octal escapes are treated as before.
3301 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
3302 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
3303 Unicode string.
3304
3305 I have not perpetrated such confusion in PCRE. Up till now, it took just
3306 the bottom 8 bits, as in old Perl. I have now made octal escapes with
3307 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
3308 translate to the appropriate multibyte character.
3309
3310 29. Applied some refactoring to reduce the number of warnings from Microsoft
3311 and Borland compilers. This has included removing the fudge introduced
3312 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
3313 a warning about an unused variable.
3314
3315 21. PCRE has not included VT (character 0x0b) in the set of whitespace
3316 characters since release 4.0, because Perl (from release 5.004) does not.
3317 [Or at least, is documented not to: some releases seem to be in conflict
3318 with the documentation.] However, when a pattern was studied with
3319 pcre_study() and all its branches started with \s, PCRE still included VT
3320 as a possible starting character. Of course, this did no harm; it just
3321 caused an unnecessary match attempt.
3322
3323 22. Removed a now-redundant internal flag bit that recorded the fact that case
3324 dependency changed within the pattern. This was once needed for "required
3325 byte" processing, but is no longer used. This recovers a now-scarce options
3326 bit. Also moved the least significant internal flag bit to the most-
3327 significant bit of the word, which was not previously used (hangover from
3328 the days when it was an int rather than a uint) to free up another bit for
3329 the future.
3330
3331 23. Added support for CRLF line endings as well as CR and LF. As well as the
3332 default being selectable at build time, it can now be changed at runtime
3333 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
3334 specify that it is scanning data with non-default line endings.
3335
3336 24. Changed the definition of CXXLINK to make it agree with the definition of
3337 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
3338
3339 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
3340 recursions. This makes a big different to stack usage for some patterns.
3341
3342 26. If a subpattern containing a named recursion or subroutine reference such
3343 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
3344 the space required for the compiled pattern went wrong and gave too small a
3345 value. Depending on the environment, this could lead to "Failed: internal
3346 error: code overflow at offset 49" or "glibc detected double free or
3347 corruption" errors.
3348
3349 27. Applied patches from Google (a) to support the new newline modes and (b) to
3350 advance over multibyte UTF-8 characters in GlobalReplace.
3351
3352 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
3353 difference for some implementation of PCRE in some Windows version.
3354
3355 29. Added some extra testing facilities to pcretest:
3356
3357 \q<number> in a data line sets the "match limit" value
3358 \Q<number> in a data line sets the "match recursion limt" value
3359 -S <number> sets the stack size, where <number> is in megabytes
3360
3361 The -S option isn't available for Windows.
3362
3363
3364 Version 6.6 06-Feb-06
3365 ---------------------
3366
3367 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
3368 in pcreposix.h. I have copied the definition from pcre.h.
3369
3370 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
3371 because pcre.h is no longer a built file.
3372
3373 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
3374 not normally included in the compiled code.
3375
3376
3377 Version 6.5 01-Feb-06
3378 ---------------------
3379
3380 1. When using the partial match feature with pcre_dfa_exec(), it was not
3381 anchoring the second and subsequent partial matches at the new starting
3382 point. This could lead to incorrect results. For example, with the pattern
3383 /1234/, partially matching against "123" and then "a4" gave a match.
3384
3385 2. Changes to pcregrep:
3386
3387 (a) All non-match returns from pcre_exec() were being treated as failures
3388 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
3389 error message is output. Some extra information is given for the
3390 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
3391 probably the only errors that are likely to be caused by users (by
3392 specifying a regex that has nested indefinite repeats, for instance).
3393 If there are more than 20 of these errors, pcregrep is abandoned.
3394
3395 (b) A binary zero was treated as data while matching, but terminated the
3396 output line if it was written out. This has been fixed: binary zeroes
3397 are now no different to any other data bytes.
3398
3399 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
3400 used to set a locale for matching. The --locale=xxxx long option has
3401 been added (no short equivalent) to specify a locale explicitly on the
3402 pcregrep command, overriding the environment variables.
3403
3404 (d) When -B was used with -n, some line numbers in the output were one less
3405 than they should have been.
3406
3407 (e) Added the -o (--only-matching) option.
3408
3409 (f) If -A or -C was used with -c (count only), some lines of context were
3410 accidentally printed for the final match.
3411
3412 (g) Added the -H (--with-filename) option.
3413
3414 (h) The combination of options -rh failed to suppress file names for files
3415 that were found from directory arguments.
3416
3417 (i) Added the -D (--devices) and -d (--directories) options.
3418
3419 (j) Added the -F (--fixed-strings) option.
3420
3421 (k) Allow "-" to be used as a file name for -f as well as for a data file.
3422
3423 (l) Added the --colo(u)r option.
3424
3425 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
3426 is not present by default.
3427
3428 3. A nasty bug was discovered in the handling of recursive patterns, that is,
3429 items such as (?R) or (?1), when the recursion could match a number of
3430 alternatives. If it matched one of the alternatives, but subsequently,
3431 outside the recursion, there was a failure, the code tried to back up into
3432 the recursion. However, because of the way PCRE is implemented, this is not
3433 possible, and the result was an incorrect result from the match.
3434
3435 In order to prevent this happening, the specification of recursion has
3436 been changed so that all such subpatterns are automatically treated as
3437 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
3438
3439 4. I had overlooked the fact that, in some locales, there are characters for
3440 which isalpha() is true but neither isupper() nor islower() are true. In
3441 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
3442 and ordfeminine) are like this. This affected the treatment of \w and \W
3443 when they appeared in character classes, but not when they appeared outside
3444 a character class. The bit map for "word" characters is now created
3445 separately from the results of isalnum() instead of just taking it from the
3446 upper, lower, and digit maps. (Plus the underscore character, of course.)
3447
3448 5. The above bug also affected the handling of POSIX character classes such as
3449 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
3450 permanent tables. Instead, the bit maps for such a class were previously
3451 created as the appropriate unions of the upper, lower, and digit bitmaps.
3452 Now they are created by subtraction from the [[:word:]] class, which has
3453 its own bitmap.
3454
3455 6. The [[:blank:]] character class matches horizontal, but not vertical space.
3456 It is created by subtracting the vertical space characters (\x09, \x0a,
3457 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
3458 subtraction was done in the overall bitmap for a character class, meaning
3459 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
3460 be recognized. This bug has been fixed.
3461
3462 7. Patches from the folks at Google:
3463
3464 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
3465 real life, but is still worth protecting against".
3466
3467 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
3468 regular expressions".
3469
3470 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
3471 have it.
3472
3473 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
3474 "configure" and the latter not, in order to fix a problem somebody had
3475 with compiling the Arg class on HP-UX.
3476
3477 (e) Improve the error-handling of the C++ wrapper a little bit.
3478
3479 (f) New tests for checking recursion limiting.
3480
3481 8. The pcre_memmove() function, which is used only if the environment does not
3482 have a standard memmove() function (and is therefore rarely compiled),
3483 contained two bugs: (a) use of int instead of size_t, and (b) it was not
3484 returning a result (though PCRE never actually uses the result).
3485
3486 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
3487 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
3488 returned instead of calling malloc() with an overflowing number that would
3489 most likely cause subsequent chaos.
3490
3491 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
3492
3493 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
3494 with this option is matched, the nmatch and pmatch options of regexec() are
3495 ignored.
3496
3497 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
3498 provided in case anyone wants to the the POSIX interface with UTF-8
3499 strings.
3500
3501 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
3502 C++ linking (needed for some HP-UX environments).
3503
3504 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
3505 (unused parameter) and in the pcre_printint() function (omitted "default"
3506 switch label when the default is to do nothing).
3507
3508 15. Added some code to make it possible, when PCRE is compiled as a C++
3509 library, to replace subject pointers for pcre_exec() with a smart pointer
3510 class, thus making it possible to process discontinuous strings.
3511
3512 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
3513 much the same function. They were added by different people who were trying
3514 to make PCRE easy to compile on non-Unix systems. It has been suggested
3515 that PCRE_EXPORT be abolished now that there is more automatic apparatus
3516 for compiling on Windows systems. I have therefore replaced it with
3517 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
3518 defaults to "extern" for C or "extern C" for C++, which works fine on
3519 Unix-like systems. It is now possible to override the value of PCRE_DATA_
3520 SCOPE with something explicit in config.h. In addition:
3521
3522 (a) pcreposix.h still had just "extern" instead of either of these macros;
3523 I have replaced it with PCRE_DATA_SCOPE.
3524
3525 (b) Functions such as _pcre_xclass(), which are internal to the library,
3526 but external in the C sense, all had PCRE_EXPORT in their definitions.
3527 This is apparently wrong for the Windows case, so I have removed it.
3528 (It makes no difference on Unix-like systems.)
3529
3530 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3531 of recursive calls to match(). This is different to MATCH_LIMIT because
3532 that limits the total number of calls to match(), not all of which increase
3533 the depth of recursion. Limiting the recursion depth limits the amount of
3534 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3535 when PCRE is compiled, and changed at run time. A patch from Google adds
3536 this functionality to the C++ interface.
3537
3538 18. Changes to the handling of Unicode character properties:
3539
3540 (a) Updated the table to Unicode 4.1.0.
3541
3542 (b) Recognize characters that are not in the table as "Cn" (undefined).
3543
3544 (c) I revised the way the table is implemented to a much improved format
3545 which includes recognition of ranges. It now supports the ranges that
3546 are defined in UnicodeData.txt, and it also amalgamates other
3547 characters into ranges. This has reduced the number of entries in the
3548 table from around 16,000 to around 3,000, thus reducing its size
3549 considerably. I realized I did not need to use a tree structure after
3550 all - a binary chop search is just as efficient. Having reduced the
3551 number of entries, I extended their size from 6 bytes to 8 bytes to
3552 allow for more data.
3553
3554 (d) Added support for Unicode script names via properties such as \p{Han}.
3555
3556 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3557 matching that character.
3558
3559 20. When matching a repeated Unicode property with a minimum greater than zero,
3560 (for example \pL{2,}), PCRE could look past the end of the subject if it
3561 reached it while seeking the minimum number of characters. This could
3562 happen only if some of the characters were more than one byte long, because
3563 there is a check for at least the minimum number of bytes.
3564
3565 21. Refactored the implementation of \p and \P so as to be more general, to
3566 allow for more different types of property in future. This has changed the
3567 compiled form incompatibly. Anybody with saved compiled patterns that use
3568 \p or \P will have to recompile them.
3569
3570 22. Added "Any" and "L&" to the supported property types.
3571
3572 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3573 but give a compile time error if the value is greater than 0xff.
3574
3575 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3576 accidentally not being installed or uninstalled.
3577
3578 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3579 made were to insert the current release number. This seemed silly, because
3580 it made things harder for people building PCRE on systems that don't run
3581 "configure". I have turned pcre.h into a distributed file, no longer built
3582 by "configure", with the version identification directly included. There is
3583 no longer a pcre.h.in file.
3584
3585 However, this change necessitated a change to the pcre-config script as
3586 well. It is built from pcre-config.in, and one of the substitutions was the
3587 release number. I have updated configure.ac so that ./configure now finds
3588 the release number by grepping pcre.h.
3589
3590 26. Added the ability to run the tests under valgrind.
3591
3592
3593 Version 6.4 05-Sep-05
3594 ---------------------
3595
3596 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3597 "--" to be printed when multiple files were scanned, even when none of the
3598 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3599 consider it to be a bug, and have restored the previous behaviour.
3600
3601 2. A couple of code tidies to get rid of compiler warnings.
3602
3603 3. The pcretest program used to cheat by referring to symbols in the library
3604 whose names begin with _pcre_. These are internal symbols that are not
3605 really supposed to be visible externally, and in some environments it is
3606 possible to suppress them. The cheating is now confined to including
3607 certain files from the library's source, which is a bit cleaner.
3608
3609 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
3610 file's purpose clearer.
3611
3612 5. Reorganized pcre_ucp_findchar().
3613
3614
3615 Version 6.3 15-Aug-05
3616 ---------------------
3617
3618 1. The file libpcre.pc.in did not have general read permission in the tarball.
3619
3620 2. There were some problems when building without C++ support:
3621
3622 (a) If C++ support was not built, "make install" and "make test" still
3623 tried to test it.
3624
3625 (b) There were problems when the value of CXX was explicitly set. Some
3626 changes have been made to try to fix these, and ...
3627
3628 (c) --disable-cpp can now be used to explicitly disable C++ support.
3629
3630 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
3631 backslash in a target when C++ was disabled. This confuses some
3632 versions of "make", apparently. Using an intermediate variable solves
3633 this. (Same for CPP_LOBJ.)
3634
3635 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
3636 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
3637 necessary on certain architectures.
3638
3639 4. Added a setting of -export-symbols-regex to the link command to remove
3640 those symbols that are exported in the C sense, but actually are local
3641 within the library, and not documented. Their names all begin with
3642 "_pcre_". This is not a perfect job, because (a) we have to except some
3643 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
3644 available (and never for static libraries). I have made a note to try to
3645 find a way round (a) in the future.
3646
3647
3648 Version 6.2 01-Aug-05
3649 ---------------------
3650
3651 1. There was no test for integer overflow of quantifier values. A construction
3652 such as {1111111111111111} would give undefined results. What is worse, if
3653 a minimum quantifier for a parenthesized subpattern overflowed and became
3654 negative, the calculation of the memory size went wrong. This could have
3655 led to memory overwriting.
3656
3657 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
3658
3659 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
3660 operating environments where this matters.
3661
3662 4. Applied Giuseppe Maxia's patch to add additional features for controlling
3663 PCRE options from within the C++ wrapper.
3664
3665 5. Named capturing subpatterns were not being correctly counted when a pattern
3666 was compiled. This caused two problems: (a) If there were more than 100
3667 such subpatterns, the calculation of the memory needed for the whole
3668 compiled pattern went wrong, leading to an overflow error. (b) Numerical
3669 back references of the form \12, where the number was greater than 9, were
3670 not recognized as back references, even though there were sufficient
3671 previous subpatterns.
3672
3673 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
3674 versions of gcc, e.g. 2.95.4.
3675
3676
3677 Version 6.1 21-Jun-05
3678 ---------------------
3679
3680 1. There was one reference to the variable "posix" in pcretest.c that was not
3681 surrounded by "#if !defined NOPOSIX".
3682
3683 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
3684 the cross-check on the old pcre_info() function, for the benefit of the
3685 cut-down version of PCRE that is currently imported into Exim.
3686
3687 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
3688 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
3689 patterns that start (?i) but I don't think that matters. The use of (?i) is
3690 just an example; this all applies to the other options as well.
3691
3692 4. Since libtool seems to echo the compile commands it is issuing, the output
3693 from "make" can be reduced a bit by putting "@" in front of each libtool
3694 compile command.
3695
3696 5. Patch from the folks at Google for configure.in to be a bit more thorough
3697 in checking for a suitable C++ installation before trying to compile the
3698 C++ stuff. This should fix a reported problem when a compiler was present,
3699 but no suitable headers.
3700
3701 6. The man pages all had just "PCRE" as their title. I have changed them to
3702 be the relevant file name. I have also arranged that these names are
3703 retained in the file doc/pcre.txt, which is a concatenation in text format
3704 of all the man pages except the little individual ones for each function.
3705
3706 7. The NON-UNIX-USE file had not been updated for the different set of source
3707 files that come with release 6. I also added a few comments about the C++
3708 wrapper.
3709
3710
3711 Version 6.0 07-Jun-05
3712 ---------------------
3713
3714 1. Some minor internal re-organization to help with my DFA experiments.
3715
3716 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
3717 didn't matter for the library itself when fully configured, but did matter
3718 when compiling without UCP support, or within Exim, where the ucp files are
3719 not imported.
3720
3721 3. Refactoring of the library code to split up the various functions into
3722 different source modules. The addition of the new DFA matching code (see
3723 below) to a single monolithic source would have made it really too
3724 unwieldy, quite apart from causing all the code to be include in a
3725 statically linked application, when only some functions are used. This is
3726 relevant even without the DFA addition now that patterns can be compiled in
3727 one application and matched in another.
3728
3729 The downside of splitting up is that there have to be some external
3730 functions and data tables that are used internally in different modules of
3731 the library but which are not part of the API. These have all had their
3732 names changed to start with "_pcre_" so that they are unlikely to clash
3733 with other external names.
3734
3735 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
3736 a different (DFA) algorithm. Although it is slower than the original
3737 function, it does have some advantages for certain types of matching
3738 problem.
3739
3740 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
3741 including restarting after a partial match.
3742
3743 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
3744 defined when compiling for Windows was sent to me. I have put it into the
3745 code, though I have no means of testing or verifying it.
3746
3747 7. Added the pcre_refcount() auxiliary function.
3748
3749 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
3750 match before or at the first newline in the subject string. In pcretest,
3751 the /f option on a pattern can be used to set this.
3752
3753 9. A repeated \w when used in UTF-8 mode with characters greater than 256
3754 would behave wrongly. This has been present in PCRE since release 4.0.
3755
3756 10. A number of changes to the pcregrep command:
3757
3758 (a) Refactored how -x works; insert ^(...)$ instead of setting
3759 PCRE_ANCHORED and checking the length, in preparation for adding
3760 something similar for -w.
3761
3762 (b) Added the -w (match as a word) option.
3763
3764 (c) Refactored the way lines are read and buffered so as to have more
3765 than one at a time available.
3766
3767 (d) Implemented a pcregrep test script.
3768
3769 (e) Added the -M (multiline match) option. This allows patterns to match
3770 over several lines of the subject. The buffering ensures that at least
3771 8K, or the rest of the document (whichever is the shorter) is available
3772 for matching (and similarly the previous 8K for lookbehind assertions).
3773
3774 (f) Changed the --help output so that it now says
3775
3776 -w, --word-regex(p)
3777
3778 instead of two lines, one with "regex" and the other with "regexp"
3779 because that confused at least one person since the short forms are the
3780 same. (This required a bit of code, as the output is generated
3781 automatically from a table. It wasn't just a text change.)
3782
3783 (g) -- can be used to terminate pcregrep options if the next thing isn't an
3784 option but starts with a hyphen. Could be a pattern or a path name
3785 starting with a hyphen, for instance.
3786
3787 (h) "-" can be given as a file name to represent stdin.
3788
3789 (i) When file names are being printed, "(standard input)" is used for
3790 the standard input, for compatibility with GNU grep. Previously
3791 "<stdin>" was used.
3792
3793 (j) The option --label=xxx can be used to supply a name to be used for
3794 stdin when file names are being printed. There is no short form.
3795
3796 (k) Re-factored the options decoding logic because we are going to add
3797 two more options that take data. Such options can now be given in four
3798 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
3799
3800 (l) Added the -A, -B, and -C options for requesting that lines of context
3801 around matches be printed.
3802
3803 (m) Added the -L option to print the names of files that do not contain
3804 any matching lines, that is, the complement of -l.
3805
3806 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3807 continue to scan other files.
3808
3809 (o) The -s option was incorrectly implemented. For compatibility with other
3810 greps, it now suppresses the error message for a non-existent or non-
3811 accessible file (but not the return code). There is a new option called
3812 -q that suppresses the output of matching lines, which was what -s was
3813 previously doing.
3814
3815 (p) Added --include and --exclude options to specify files for inclusion
3816 and exclusion when recursing.
3817
3818 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3819 Hopefully, it now does.
3820
3821 12. Missing cast in pcre_study().
3822
3823 13. Added an "uninstall" target to the makefile.
3824
3825 14. Replaced "extern" in the function prototypes in Makefile.in with
3826 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3827 world, but is set differently for Windows.
3828
3829 15. Added a second compiling function called pcre_compile2(). The only
3830 difference is that it has an extra argument, which is a pointer to an
3831 integer error code. When there is a compile-time failure, this is set
3832 non-zero, in addition to the error test pointer being set to point to an
3833 error message. The new argument may be NULL if no error number is required
3834 (but then you may as well call pcre_compile(), which is now just a
3835 wrapper). This facility is provided because some applications need a
3836 numeric error indication, but it has also enabled me to tidy up the way
3837 compile-time errors are handled in the POSIX wrapper.
3838
3839 16. Added VPATH=.libs to the makefile; this should help when building with one
3840 prefix path and installing with another. (Or so I'm told by someone who
3841 knows more about this stuff than I do.)
3842
3843 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3844 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3845 match everything, including newlines. This is not POSIX-compatible, but
3846 somebody wanted the feature. From pcretest it can be activated by using
3847 both the P and the s flags.
3848
3849 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3850
3851 19. libpcre.pc was being incorrectly installed as executable.
3852
3853 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3854 it now also looks for '\r' so that it will work unmodified on Windows.
3855
3856 21. Added Google's contributed C++ wrapper to the distribution.
3857
3858 22. Added some untidy missing memory free() calls in pcretest, to keep
3859 Electric Fence happy when testing.
3860
3861
3862
3863 Version 5.0 13-Sep-04
3864 ---------------------
3865
3866 1. Internal change: literal characters are no longer packed up into items
3867 containing multiple characters in a single byte-string. Each character
3868 is now matched using a separate opcode. However, there may be more than one
3869 byte in the character in UTF-8 mode.
3870
3871 2. The pcre_callout_block structure has two new fields: pattern_position and
3872 next_item_length. These contain the offset in the pattern to the next match
3873 item, and its length, respectively.
3874
3875 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3876 insertion of callouts before each pattern item. Added the /C option to
3877 pcretest to make use of this.
3878
3879 4. On the advice of a Windows user, the lines
3880
3881 #if defined(_WIN32) || defined(WIN32)
3882 _setmode( _fileno( stdout ), 0x8000 );
3883 #endif /* defined(_WIN32) || defined(WIN32) */
3884
3885 have been added to the source of pcretest. This apparently does useful
3886 magic in relation to line terminators.
3887
3888 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3889 for the benefit of those environments where the "b" makes a difference.
3890
3891 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3892 to know about it. I have put a hack into configure.in that adds in code
3893 to set GCC=yes if CC=icc. This seems to end up at a point in the
3894 generated configure script that is early enough to affect the setting of
3895 compiler options, which is what is needed, but I have no means of testing
3896 whether it really works. (The user who reported this had patched the
3897 generated configure script, which of course I cannot do.)
3898
3899 LATER: After change 22 below (new libtool files), the configure script
3900 seems to know about icc (and also ecc). Therefore, I have commented out
3901 this hack in configure.in.
3902
3903 7. Added support for pkg-config (2 patches were sent in).
3904
3905 8. Negated POSIX character classes that used a combination of internal tables
3906 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3907 [[:^ascii]]. Typically, they would match almost any characters. The other
3908 POSIX classes were not broken in this way.
3909
3910 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3911 to find the match, as PCRE was deluded into thinking that the match had to
3912 start at the start point or following a newline. The same bug applied to
3913 patterns with negative forward assertions or any backward assertions
3914 preceding ".*" at the start, unless the pattern required a fixed first
3915 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3916
3917 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3918 starting at the last subject character, bytes beyond the end of the subject
3919 string were read.
3920
3921 11. Renamed the variable "class" as "classbits" to make life easier for C++
3922 users. (Previously there was a macro definition, but it apparently wasn't
3923 enough.)
3924
3925 12. Added the new field "tables" to the extra data so that tables can be passed
3926 in at exec time, or the internal tables can be re-selected. This allows
3927 a compiled regex to be saved and re-used at a later time by a different
3928 program that might have everything at different addresses.
3929
3930 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3931 -R library as well as a -L library.
3932
3933 14. The debugging options of pcretest (-d on the command line or D on a
3934 pattern) showed incorrect output for anything following an extended class
3935 that contained multibyte characters and which was followed by a quantifier.
3936
3937 15. Added optional support for general category Unicode character properties
3938 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3939 support. It adds about 90K to the size of the library. The meanings of the
3940 inbuilt class escapes such as \d and \s have NOT been changed.
3941
3942 16. Updated pcredemo.c to include calls to free() to release the memory for the
3943 compiled pattern.
3944
3945 17. The generated file chartables.c was being created in the source directory
3946 instead of in the building directory. This caused the build to fail if the
3947 source directory was different from the building directory, and was
3948 read-only.
3949
3950 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3951 file. No doubt somebody will tell me if they don't make sense... Also added
3952 Dan Mooney's comments about building on OpenVMS.
3953
3954 19. Added support for partial matching via the PCRE_PARTIAL option for
3955 pcre_exec() and the \P data escape in pcretest.
3956
3957 20. Extended pcretest with 3 new pattern features:
3958
3959 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3960 write the compiled pattern to the file whose name is "rest-of-line".
3961 This is a straight binary dump of the data, with the saved pointer to
3962 the character tables forced to be NULL. The study data, if any, is
3963 written too. After writing, pcretest reads a new pattern.
3964
3965 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3966 compiled pattern from the given file. There must not be any
3967 occurrences of "<" in the file name (pretty unlikely); if there are,
3968 pcretest will instead treat the initial "<" as a pattern delimiter.
3969 After reading in the pattern, pcretest goes on to read data lines as
3970 usual.
3971
3972 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3973 and 16-bit fields in a compiled pattern, to simulate a pattern that
3974 was compiled on a host of opposite endianness.
3975
3976 21. The pcre-exec() function can now cope with patterns that were compiled on
3977 hosts of opposite endianness, with this restriction:
3978
3979 As for any compiled expression that is saved and used later, the tables
3980 pointer field cannot be preserved; the extra_data field in the arguments
3981 to pcre_exec() should be used to pass in a tables address if a value
3982 other than the default internal tables were used at compile time.
3983
3984 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3985 now diagnosed as an error. Previously, most of the time, a negative number
3986 would have been treated as zero, but if in addition "ovector" was passed as
3987 NULL, a crash could occur.
3988
3989 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3990 new versions from the libtool 1.5 distribution (the last one is a copy of
3991 a file called libtool.m4). This seems to have fixed the need to patch
3992 "configure" to support Darwin 1.3 (which I used to do). However, I still
3993 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3994 workstation).
3995
3996 24. Changed the PCRE licence to be the more standard "BSD" licence.
3997
3998
3999 Version 4.5 01-Dec-03
4000 ---------------------
4001
4002 1. There has been some re-arrangement of the code for the match() function so
4003 that it can be compiled in a version that does not call itself recursively.
4004 Instead, it keeps those local variables that need separate instances for
4005 each "recursion" in a frame on the heap, and gets/frees frames whenever it
4006 needs to "recurse". Keeping track of where control must go is done by means
4007 of setjmp/longjmp. The whole thing is implemented by a set of macros that
4008 hide most of the details from the main code, and operates only if
4009 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
4010 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
4011 operating.
4012
4013 To make it easier for callers to provide specially tailored get/free
4014 functions for this usage, two new functions, pcre_stack_malloc, and
4015 pcre_stack_free, are used. They are always called in strict stacking order,
4016 and the size of block requested is always the same.
4017
4018 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
4019 PCRE has been compiled to use the stack or the heap for recursion. The
4020 -C option of pcretest uses this to show which version is compiled.
4021
4022 A new data escape \S, is added to pcretest; it causes the amounts of store
4023 obtained and freed by both kinds of malloc/free at match time to be added
4024 to the output.
4025
4026 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
4027 what's available on my current Linux desktop machine.
4028
4029 3. When matching a UTF-8 string, the test for a valid string at the start has
4030 been extended. If start_offset is not zero, PCRE now checks that it points
4031 to a byte that is the start of a UTF-8 character. If not, it returns
4032 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
4033 this is necessary because there may be backward assertions in the pattern.
4034 When matching the same subject several times, it may save resources to use
4035 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4036
4037 4. The code for checking the validity of UTF-8 strings has been tightened so
4038 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
4039 containing "overlong sequences".
4040
4041 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
4042 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
4043 should have been "&", but it just so happened that all the cases this let
4044 through by mistake were picked up later in the function.
4045
4046 6. I had used a variable called "isblank" - this is a C99 function, causing
4047 some compilers to warn. To avoid this, I renamed it (as "blankclass").
4048
4049 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
4050 prompting; (b) run "./pcretest /dev/null" at the start of the test script
4051 so the version is shown; (c) stop "make test" echoing "./RunTest".
4052
4053 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
4054
4055 9. The prototype for memmove() for systems that don't have it was using
4056 size_t, but the inclusion of the header that defines size_t was later. I've
4057 moved the #includes for the C headers earlier to avoid this.
4058
4059 10. Added some adjustments to the code to make it easier to compiler on certain
4060 special systems:
4061
4062 (a) Some "const" qualifiers were missing.
4063 (b) Added the macro EXPORT before all exported functions; by default this
4064 is defined to be empty.
4065 (c) Changed the dftables auxiliary program (that builds chartables.c) so
4066 that it reads its output file name as an argument instead of writing
4067 to the standard output and assuming this can be redirected.
4068
4069 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
4070 class containing characters with values greater than 255, PCRE compilation
4071 went into a loop.
4072
4073 12. A recursive reference to a subpattern that was within another subpattern
4074 that had a minimum quantifier of zero caused PCRE to crash. For example,
4075 (x(y(?2))z)? provoked this bug with a subject that got as far as the
4076 recursion. If the recursively-called subpattern itself had a zero repeat,
4077 that was OK.
4078
4079 13. In pcretest, the buffer for reading a data line was set at 30K, but the
4080 buffer into which it was copied (for escape processing) was still set at
4081 1024, so long lines caused crashes.
4082
4083 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
4084 "internal error: code overflow...". This applied to any character class
4085 that was followed by a possessive quantifier.
4086
4087 15. Modified the Makefile to add libpcre.la as a prerequisite for
4088 libpcreposix.la because I was told this is needed for a parallel build to
4089 work.
4090
4091 16. If a pattern that contained .* following optional items at the start was
4092 studied, the wrong optimizing data was generated, leading to matching
4093 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
4094 matching string must start with a or b or c. The correct conclusion for
4095 this pattern is that a match can start with any character.
4096
4097
4098 Version 4.4 13-Aug-03
4099 ---------------------
4100
4101 1. In UTF-8 mode, a character class containing characters with values between
4102 127 and 255 was not handled correctly if the compiled pattern was studied.
4103 In fixing this, I have also improved the studying algorithm for such
4104 classes (slightly).
4105
4106 2. Three internal functions had redundant arguments passed to them. Removal
4107 might give a very teeny performance improvement.
4108
4109 3. Documentation bug: the value of the capture_top field in a callout is *one
4110 more than* the number of the hightest numbered captured substring.
4111
4112 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
4113 in incorrectly linking with a previously installed version. They now link
4114 explicitly with libpcre.la.
4115
4116 5. configure.in no longer needs to recognize Cygwin specially.
4117
4118 6. A problem in pcre.in for Windows platforms is fixed.
4119
4120 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
4121 pcretest, it used to include the size of the study block as part of its
4122 output. Unfortunately, the structure contains a field that has a different
4123 size on different hardware architectures. This meant that the tests that
4124 showed this size failed. As the block is currently always of a fixed size,
4125 this information isn't actually particularly useful in pcretest output, so
4126 I have just removed it.
4127
4128 8. Three pre-processor statements accidentally did not start in column 1.
4129 Sadly, there are *still* compilers around that complain, even though
4130 standard C has not required this for well over a decade. Sigh.
4131
4132 9. In pcretest, the code for checking callouts passed small integers in the
4133 callout_data field, which is a void * field. However, some picky compilers
4134 complained about the casts involved for this on 64-bit systems. Now
4135 pcretest passes the address of the small integer instead, which should get
4136 rid of the warnings.
4137
4138 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
4139 both compile and run time, and gives an error if an invalid UTF-8 sequence
4140 is found. There is a option for disabling this check in cases where the
4141 string is known to be correct and/or the maximum performance is wanted.
4142
4143 11. In response to a bug report, I changed one line in Makefile.in from
4144
4145 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
4146 to
4147 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4148
4149 to look similar to other lines, but I have no way of telling whether this
4150 is the right thing to do, as I do not use Windows. No doubt I'll get told
4151 if it's wrong...
4152
4153
4154 Version 4.3 21-May-03
4155 ---------------------
4156
4157 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4158 Makefile.
4159
4160 2. Some refactoring to improve the quality of the code:
4161
4162 (i) The utf8_table... variables are now declared "const".
4163
4164 (ii) The code for \cx, which used the "case flipping" table to upper case
4165 lower case letters, now just substracts 32. This is ASCII-specific,
4166 but the whole concept of \cx is ASCII-specific, so it seems
4167 reasonable.
4168
4169 (iii) PCRE was using its character types table to recognize decimal and
4170 hexadecimal digits in the pattern. This is silly, because it handles
4171 only 0-9, a-f, and A-F, but the character types table is locale-
4172 specific, which means strange things might happen. A private
4173 table is now used for this - though it costs 256 bytes, a table is
4174 much faster than multiple explicit tests. Of course, the standard
4175 character types table is still used for matching digits in subject
4176 strings against \d.
4177
4178 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4179 ending in _t are). So I've renamed it as ESC_tee.
4180
4181 3. The first argument for regexec() in the POSIX wrapper should have been
4182 defined as "const".
4183
4184 4. Changed pcretest to use malloc() for its buffers so that they can be
4185 Electric Fenced for debugging.
4186
4187 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4188 to read one or more bytes before the start of the subject string. Often this
4189 had no effect on PCRE's behaviour, but in some circumstances it could
4190 provoke a segmentation fault.
4191
4192 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4193 to try to read one or more bytes before the start of the subject string.
4194
4195 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4196 UTF-8 support could misbehave in various ways if the subject string
4197 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4198 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4199 back over UTF-8 characters.)
4200
4201
4202 Version 4.2 14-Apr-03
4203 ---------------------
4204
4205 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4206
4207 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4208 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4209 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4210 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4211 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4212 and BUILD_EXEEXT
4213 Note: automatic setting of the BUILD variables is not yet working
4214 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4215 compile-time but not at link-time
4216 [LINK]: use for linking executables only
4217 make different versions for Windows and non-Windows
4218 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4219 libraries
4220 [LINK_FOR_BUILD]: new variable
4221 [OBJEXT]: use throughout
4222 [EXEEXT]: use throughout
4223 <winshared>: new target
4224 <wininstall>: new target
4225 <dftables.o>: use native compiler
4226 <dftables>: use native linker
4227 <install>: handle Windows platform correctly
4228 <clean>: ditto
4229 <check>: ditto
4230 copy DLL to top builddir before testing
4231
4232 As part of these changes, -no-undefined was removed again. This was reported
4233 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4234 in any case.
4235
4236 3. Some tidies to get rid of compiler warnings:
4237
4238 . In the match_data structure, match_limit was an unsigned long int, whereas
4239 match_call_count was an int. I've made them both unsigned long ints.
4240
4241 . In pcretest the fact that a const uschar * doesn't automatically cast to
4242 a void * provoked a warning.
4243
4244 . Turning on some more compiler warnings threw up some "shadow" variables
4245 and a few more missing casts.
4246
4247 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
4248 option, a class that contained a single character with a value between 128
4249 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
4250
4251 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
4252 option, a class that contained several characters, but with at least one
4253 whose value was between 128 and 255 caused PCRE to crash.
4254
4255
4256 Version 4.1 12-Mar-03
4257 ---------------------
4258
4259 1. Compiling with gcc -pedantic found a couple of places where casts were
4260 needed, and a string in dftables.c that was longer than standard compilers are
4261 required to support.
4262
4263 2. Compiling with Sun's compiler found a few more places where the code could
4264 be tidied up in order to avoid warnings.
4265
4266 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
4267 first of these names is deprecated in the latest Autoconf in favour of the name
4268 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
4269 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
4270 analogy I have changed it to CFLAGS_FOR_BUILD.
4271
4272 4. Added -no-undefined to the linking command in the Makefile, because this is
4273 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
4274 linking step for the pcreposix library.
4275
4276 5. PCRE was failing to diagnose the case of two named groups with the same
4277 name.
4278
4279 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
4280 literal character that is needed in the subject for a match, and scans along to
4281 ensure that it is present before embarking on the full matching process. This
4282 saves time in cases of nested unlimited repeats that are never going to match.
4283 Problem: the scan can take a lot of time if the subject is very long (e.g.
4284 megabytes), thus penalizing straightforward matches. It is now done only if the
4285 amount of subject to be scanned is less than 1000 bytes.
4286
4287 7. A lesser problem with the same optimization is that it was recording the
4288 first character of an anchored pattern as "needed", thus provoking a search
4289 right along the subject, even when the first match of the pattern was going to
4290 fail. The "needed" character is now not set for anchored patterns, unless it
4291 follows something in the pattern that is of non-fixed length. Thus, it still
4292 fulfils its original purpose of finding quick non-matches in cases of nested
4293 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
4294
4295
4296 Version 4.0 17-Feb-03
4297 ---------------------
4298
4299 1. If a comment in an extended regex that started immediately after a meta-item
4300 extended to the end of string, PCRE compiled incorrect data. This could lead to
4301 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
4302
4303 2. Moved to autoconf 2.53 and libtool 1.4.2.
4304
4305 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
4306 the special perltest8 script is no longer needed - all the tests can be run
4307 from a single perltest script.
4308
4309 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
4310 by \s. It has now been removed in PCRE. This means it isn't recognized as
4311 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
4312 class [:space:] *does* include VT, thereby creating a mess.
4313
4314 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
4315 space and tab.
4316
4317 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
4318 its new features into the main test script, reducing the number of scripts.
4319
4320 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
4321 were backward compatible, and made the (?i) apply to the whole pattern, as if
4322 /i were given. Now it behaves more logically, and applies the option setting
4323 only to what follows. PCRE has been changed to follow suit. However, if it
4324 finds options settings right at the start of the pattern, it extracts them into
4325 the global options, as before. Thus, they show up in the info data.
4326
4327 8. Added support for the \Q...\E escape sequence. Characters in between are
4328 treated as literals. This is slightly different from Perl in that $ and @ are
4329 also handled as literals inside the quotes. In Perl, they will cause variable
4330 interpolation. Note the following examples:
4331
4332 Pattern PCRE matches Perl matches
4333
4334 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
4335 \Qabc\$xyz\E abc\$xyz abc\$xyz
4336 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
4337
4338 For compatibility with Perl, \Q...\E sequences are recognized inside character
4339 classes as well as outside them.
4340
4341 9. Re-organized 3 code statements in pcretest to avoid "overflow in
4342 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
4343 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
4344 signed/unsigned warnings.
4345
4346 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
4347 option for pcretest, so I've replaced it by a simple function that does just
4348 that job.
4349
4350 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
4351 "pcregrep -".
4352
4353 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
4354 Java package. This provides some syntactic sugar for simple cases of what my
4355 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
4356 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
4357 item, you can use this simplified notation. Note that only makes sense with
4358 greedy quantifiers. Consequently, the use of the possessive quantifier forces
4359 greediness, whatever the setting of the PCRE_UNGREEDY option.
4360
4361 13. A change of greediness default within a pattern was not taking effect at
4362 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
4363 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
4364 was abstracted outside.
4365
4366 14. PCRE now supports the \G assertion. It is true when the current matching
4367 position is at the start point of the match. This differs from \A when the
4368 starting offset is non-zero. Used with the /g option of pcretest (or similar
4369 code), it works in the same way as it does for Perl's /g option. If all
4370 alternatives of a regex begin with \G, the expression is anchored to the start
4371 match position, and the "anchored" flag is set in the compiled expression.
4372
4373 15. Some bugs concerning the handling of certain option changes within patterns
4374 have been fixed. These applied to options other than (?ims). For example,
4375 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
4376 been the other way round. Some of this was related to change 7 above.
4377
4378 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
4379 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
4380 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
4381 POSIX classes only within a class (e.g. /[[:alpha:]]/).
4382
4383 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
4384 mode. Unlike ".", it always matches newline, whatever the setting of
4385 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
4386 assertions. Perl allows it, but it doesn't (in general) work because it can't
4387 calculate the length of the lookbehind. At least, that's the case for Perl
4388 5.8.0 - I've been told they are going to document that it doesn't work in
4389 future.
4390
4391 18. Added an error diagnosis for escapes that PCRE does not support: these are
4392 \L, \l, \N, \P, \p, \U, \u, and \X.
4393
4394 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
4395 reading past the end of the pattern in cases such as /[abcd/.
4396
4397 20. PCRE was getting more memory than necessary for patterns with classes that
4398 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
4399
4400 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
4401 compiling PCRE for use with Virtual Pascal.
4402
4403 22. Small fix to the Makefile to make it work properly if the build is done
4404 outside the source tree.
4405
4406 23. Added a new extension: a condition to go with recursion. If a conditional
4407 subpattern starts with (?(R) the "true" branch is used if recursion has
4408 happened, whereas the "false" branch is used only at the top level.
4409
4410 24. When there was a very long string of literal characters (over 255 bytes
4411 without UTF support, over 250 bytes with UTF support), the computation of how
4412 much memory was required could be incorrect, leading to segfaults or other
4413 strange effects.
4414
4415 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
4416 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
4417 there was a subsequent back reference to those brackets. This meant that, for
4418 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
4419 possible to check for precisely this case. All we can do is abandon the
4420 optimization if .* occurs inside capturing brackets when there are any back
4421 references whatsoever. (See below for a better fix that came later.)
4422
4423 26. The handling of the optimization for finding the first character of a
4424 non-anchored pattern, and for finding a character that is required later in the
4425 match were failing in some cases. This didn't break the matching; it just
4426 failed to optimize when it could. The way this is done has been re-implemented.
4427
4428 27. Fixed typo in error message for invalid (?R item (it said "(?p").
4429
4430 28. Added a new feature that provides some of the functionality that Perl
4431 provides with (?{...}). The facility is termed a "callout". The way it is done
4432 in PCRE is for the caller to provide an optional function, by setting
4433 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
4434 global variable. By default it is unset, which disables all calling out. To get
4435 the function called, the regex must include (?C) at appropriate points. This
4436 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
4437 This provides a means of identifying different callout points. When PCRE
4438 reaches such a point in the regex, if pcre_callout has been set, the external
4439 function is called. It is provided with data in a structure called
4440 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
4441 matching continues; if it returns a non-zero value, the match at the current
4442 point fails. However, backtracking will occur if possible. [This was changed
4443 later and other features added - see item 49 below.]
4444
4445 29. pcretest is upgraded to test the callout functionality. It provides a
4446 callout function that displays information. By default, it shows the start of
4447 the match and the current position in the text. There are some new data escapes
4448 to vary what happens:
4449
4450 \C+ in addition, show current contents of captured substrings
4451 \C- do not supply a callout function
4452 \C!n return 1 when callout number n is reached
4453 \C!n!m return 1 when callout number n is reached for the mth time
4454
4455 30. If pcregrep was called with the -l option and just a single file name, it
4456 output "<stdin>" if a match was found, instead of the file name.
4457
4458 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
4459 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
4460 pcre_exec(). This saves a malloc/free per call. The default value of
4461 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
4462 when configuring.
4463
4464 32. The default maximum size of a compiled pattern is 64K. There have been a
4465 few cases of people hitting this limit. The code now uses macros to handle the
4466 storing of links as offsets within the compiled pattern. It defaults to 2-byte
4467 links, but this can be changed to 3 or 4 bytes by --with-link-size when
4468 configuring. Tests 2 and 5 work only with 2-byte links because they output
4469 debugging information about compiled patterns.
4470
4471 33. Internal code re-arrangements:
4472
4473 (a) Moved the debugging function for printing out a compiled regex into
4474 its own source file (printint.c) and used #include to pull it into
4475 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
4476 separate copies.
4477
4478 (b) Defined the list of op-code names for debugging as a macro in
4479 internal.h so that it is next to the definition of the opcodes.
4480
4481 (c) Defined a table of op-code lengths for simpler skipping along compiled
4482 code. This is again a macro in internal.h so that it is next to the
4483 definition of the opcodes.
4484
4485 34. Added support for recursive calls to individual subpatterns, along the
4486 lines of Robin Houston's patch (but implemented somewhat differently).
4487
4488 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
4489 allow it to read and process whole directories in Win32. This code was
4490 contributed by Lionel Fourquaux; it has not been tested by me.
4491
4492 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
4493 used to name a group. Names consist of alphanumerics and underscores, and must
4494 be unique. Back references use the syntax (?P=name) and recursive calls use
4495 (?P>name) which is a PCRE extension to the Python extension. Groups still have
4496 numbers. The function pcre_fullinfo() can be used after compilation to extract
4497 a name/number map. There are three relevant calls:
4498
4499 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
4500 PCRE_INFO_NAMECOUNT yields the number of entries
4501 PCRE_INFO_NAMETABLE yields a pointer to the map.
4502
4503 The map is a vector of fixed-size entries. The size of each entry depends on
4504 the length of the longest name used. The first two bytes of each entry are the
4505 group number, most significant byte first. There follows the corresponding
4506 name, zero terminated. The names are in alphabetical order.
4507
4508 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
4509 case instead of 255. Making it the same both with and without UTF-8 support
4510 means that the same test output works with both.
4511
4512 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
4513 calling malloc() with a zero argument.
4514
4515 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
4516 optimization. I've improved things by keeping a bitmap of backreferences with
4517 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
4518 fact referenced, the optimization can be applied. It is unlikely that a
4519 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
4520 the match to follow \n) will appear inside brackets with a number greater than
4521 31, but if it does, any back reference > 31 suppresses the optimization.
4522
4523 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
4524 of disabling numbered capturing parentheses. Any opening parenthesis that is
4525 not followed by ? behaves as if it were followed by ?: but named parentheses
4526 can still be used for capturing (and they will acquire numbers in the usual
4527 way).
4528
4529 41. Redesigned the return codes from the match() function into yes/no/error so
4530 that errors can be passed back from deep inside the nested calls. A malloc
4531 failure while inside a recursive subpattern call now causes the
4532 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4533
4534 42. It is now possible to set a limit on the number of times the match()
4535 function is called in a call to pcre_exec(). This facility makes it possible to
4536 limit the amount of recursion and backtracking, though not in a directly
4537 obvious way, because the match() function is used in a number of different
4538 circumstances. The count starts from zero for each position in the subject
4539 string (for non-anchored patterns). The default limit is, for compatibility, a
4540 large number, namely 10 000 000. You can change this in two ways:
4541
4542 (a) When configuring PCRE before making, you can use --with-match-limit=n
4543 to set a default value for the compiled library.
4544
4545 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4546 a different value is set. See 45 below.
4547
4548 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4549
4550 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4551 of things that can be changed at compile time. The first argument specifies
4552 what is wanted and the second points to where the information is to be placed.
4553 The current list of available information is:
4554
4555 PCRE_CONFIG_UTF8
4556
4557 The output is an integer that is set to one if UTF-8 support is available;
4558 otherwise it is set to zero.
4559
4560 PCRE_CONFIG_NEWLINE
4561
4562 The output is an integer that it set to the value of the code that is used for
4563 newline. It is either LF (10) or CR (13).
4564
4565 PCRE_CONFIG_LINK_SIZE
4566
4567 The output is an integer that contains the number of bytes used for internal
4568 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4569
4570 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4571
4572 The output is an integer that contains the threshold above which the POSIX
4573 interface uses malloc() for output vectors. See item 31 above.
4574
4575 PCRE_CONFIG_MATCH_LIMIT
4576
4577 The output is an unsigned integer that contains the default limit of the number
4578 of match() calls in a pcre_exec() execution. See 42 above.
4579
4580 44. pcretest has been upgraded by the addition of the -C option. This causes it
4581 to extract all the available output from the new pcre_config() function, and to
4582 output it. The program then exits immediately.
4583
4584 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4585 order to support additional features. One way would have been to define
4586 pcre_exec2() (for example) with extra arguments, but this would not have been
4587 extensible, and would also have required all calls to the original function to
4588 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4589 is used for passing in "extra" data from pcre_study().
4590
4591 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4592 contains the following fields:
4593
4594 flags a bitmap indicating which of the following fields are set
4595 study_data opaque data from pcre_study()
4596 match_limit a way of specifying a limit on match() calls for a specific
4597 call to pcre_exec()
4598 callout_data data for callouts (see 49 below)
4599
4600 The flag bits are also defined in pcre.h, and are
4601
4602 PCRE_EXTRA_STUDY_DATA
4603 PCRE_EXTRA_MATCH_LIMIT
4604 PCRE_EXTRA_CALLOUT_DATA
4605
4606 The pcre_study() function now returns one of these new pcre_extra blocks, with
4607 the actual study data pointed to by the study_data field, and the
4608 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
4609 before. That is, this change is entirely upwards-compatible and requires no
4610 change to existing code.
4611
4612 If you want to pass in additional data to pcre_exec(), you can either place it
4613 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
4614 block.
4615
4616 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
4617 data string contains the escape sequence \M, pcretest calls pcre_exec() several
4618 times with different match limits, until it finds the minimum value needed for
4619 pcre_exec() to complete. The value is then output. This can be instructive; for
4620 most simple matches the number is quite small, but for pathological cases it
4621 gets very large very quickly.
4622
4623 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
4624 returns the size of the data block pointed to by the study_data field in a
4625 pcre_extra block, that is, the value that was passed as the argument to
4626 pcre_malloc() when PCRE was getting memory in which to place the information
4627 created by pcre_study(). The fourth argument should point to a size_t variable.
4628 pcretest has been extended so that this information is shown after a successful
4629 pcre_study() call when information about the compiled regex is being displayed.
4630
4631 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
4632 because what follows is always an absolute path. (Later: it turns out that this
4633 is more than cosmetic for MinGW, because it doesn't like empty path
4634 components.)
4635
4636 49. Some changes have been made to the callout feature (see 28 above):
4637
4638 (i) A callout function now has three choices for what it returns:
4639
4640 0 => success, carry on matching
4641 > 0 => failure at this point, but backtrack if possible
4642 < 0 => serious error, return this value from pcre_exec()
4643
4644 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
4645 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
4646 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
4647 use by callout functions. It will never be used by PCRE itself.
4648
4649 (ii) The pcre_extra structure (see 45 above) has a void * field called
4650 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
4651 pcre_callout_block structure has a field of the same name. The contents of
4652 the field passed in the pcre_extra structure are passed to the callout
4653 function in the corresponding field in the callout block. This makes it
4654 easier to use the same callout-containing regex from multiple threads. For
4655 testing, the pcretest program has a new data escape
4656
4657 \C*n pass the number n (may be negative) as callout_data
4658
4659 If the callout function in pcretest receives a non-zero value as
4660 callout_data, it returns that value.
4661
4662 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
4663 there were some redundant $(CFLAGS) in commands that are now specified as
4664 $(LINK), which already includes $(CFLAGS).
4665
4666 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
4667 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
4668 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
4669 one-byte characters throughout. Note that case-insensitive matching applies
4670 only to characters whose values are less than 256. PCRE doesn't support the
4671 notion of cases for higher-valued characters.
4672
4673 (i) A character class whose characters are all within 0-255 is handled as
4674 a bit map, and the map is inverted for negative classes. Previously, a
4675 character > 255 always failed to match such a class; however it should
4676 match if the class was a negative one (e.g. [^ab]). This has been fixed.
4677
4678 (ii) A negated character class with a single character < 255 is coded as
4679 "not this character" (OP_NOT). This wasn't working properly when the test
4680 character was multibyte, either singly or repeated.
4681
4682 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
4683 mode, for example: \x{100}{2,3}.
4684
4685 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
4686 singly or repeated) now correctly test multibyte characters. However,
4687 PCRE doesn't recognize any characters with values greater than 255 as
4688 digits, spaces, or word characters. Such characters always match \D, \S,
4689 and \W, and never match \d, \s, or \w.
4690
4691 (v) Classes may now contain characters and character ranges with values
4692 greater than 255. For example: [ab\x{100}-\x{400}].
4693
4694 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
4695 PCRE in UTF-8 mode.
4696
4697 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
4698 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
4699 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
4700 value.)
4701
4702 53. The single man page has become too large. I have therefore split it up into
4703 a number of separate man pages. These also give rise to individual HTML pages;
4704 these are now put in a separate directory, and there is an index.html page that
4705 lists them all. Some hyperlinking between the pages has been installed.
4706
4707 54. Added convenience functions for handling named capturing parentheses.
4708
4709 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
4710 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
4711 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
4712 are faulted.
4713
4714 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
4715 calling configure. These values are used when compiling the dftables.c program
4716 which is run to generate the source of the default character tables. They
4717 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
4718 you will need to set these values.
4719
4720 57. Updated the building process for Windows DLL, as provided by Fred Cox.
4721
4722
4723 Version 3.9 02-Jan-02
4724 ---------------------
4725
4726 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
4727
4728 2. If --disable-static was given, the building process failed when trying to
4729 build pcretest and pcregrep. (For some reason it was using libtool to compile
4730 them, which is not right, as they aren't part of the library.)
4731
4732
4733 Version 3.8 18-Dec-01
4734 ---------------------
4735
4736 1. The experimental UTF-8 code was completely screwed up. It was packing the
4737 bytes in the wrong order. How dumb can you get?
4738
4739
4740 Version 3.7 29-Oct-01
4741 ---------------------
4742
4743 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
4744 This caused pcretest, when used on the test data, to segfault. Unfortunately,
4745 this didn't happen under Solaris 8, where I normally test things.
4746
4747 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
4748 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
4749 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
4750 this fix an hour or so after the initial 3.7 release.)
4751
4752
4753 Version 3.6 23-Oct-01
4754 ---------------------
4755
4756 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
4757 offsets passed as NULL with zero offset count.
4758
4759 2. The config.guess and config.sub files had not been updated when I moved to
4760 the latest autoconf.
4761
4762
4763 Version 3.5 15-Aug-01
4764 ---------------------
4765
4766 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
4767 had been forgotten.
4768
4769 2. By using declared but undefined structures, we can avoid using "void"
4770 definitions in pcre.h while keeping the internal definitions of the structures
4771 private.
4772
4773 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
4774 user point of view, this means that both static and shared libraries are built
4775 by default, but this can be individually controlled. More of the work of
4776 handling this static/shared cases is now inside libtool instead of PCRE's make
4777 file.
4778
4779 4. The pcretest utility is now installed along with pcregrep because it is
4780 useful for users (to test regexs) and by doing this, it automatically gets
4781 relinked by libtool. The documentation has been turned into a man page, so
4782 there are now .1, .txt, and .html versions in /doc.
4783
4784 5. Upgrades to pcregrep:
4785 (i) Added long-form option names like gnu grep.
4786 (ii) Added --help to list all options with an explanatory phrase.
4787 (iii) Added -r, --recursive to recurse into sub-directories.
4788 (iv) Added -f, --file to read patterns from a file.
4789
4790 6. pcre_exec() was referring to its "code" argument before testing that
4791 argument for NULL (and giving an error if it was NULL).
4792
4793 7. Upgraded Makefile.in to allow for compiling in a different directory from
4794 the source directory.
4795
4796 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
4797 options bits, the pointer it was passed was to an int instead of to an unsigned
4798 long int. This mattered only on 64-bit systems.
4799
4800 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
4801 generated) instead of pcre.in, which it its source. Also made the same change
4802 in several of the .c files.
4803
4804 10. A new release of gcc defines printf() as a macro, which broke pcretest
4805 because it had an ifdef in the middle of a string argument for printf(). Fixed
4806 by using separate calls to printf().
4807
4808 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4809 script, to force use of CR or LF instead of \n in the source. On non-Unix
4810 systems, the value can be set in config.h.
4811
4812 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4813 absolute limit. Changed the text of the error message to make this clear, and
4814 likewise updated the man page.
4815
4816 13. The limit of 99 on the number of capturing subpatterns has been removed.
4817 The new limit is 65535, which I hope will not be a "real" limit.
4818
4819
4820 Version 3.4 22-Aug-00
4821 ---------------------
4822
4823 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4824
4825 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4826
4827
4828 Version 3.3 01-Aug-00
4829 ---------------------
4830
4831 1. If an octal character was given, but the value was greater than \377, it
4832 was not getting masked to the least significant bits, as documented. This could
4833 lead to crashes in some systems.
4834
4835 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4836 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4837
4838 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4839 These just pass their arguments on to (pcre_free)(), but they are provided
4840 because some uses of PCRE bind it to non-C systems that can call its functions,
4841 but cannot call free() or pcre_free() directly.
4842
4843 4. Add "make test" as a synonym for "make check". Corrected some comments in
4844 the Makefile.
4845
4846 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4847 Makefile.
4848
4849 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4850 command called pgrep for grepping around the active processes.
4851
4852 7. Added the beginnings of support for UTF-8 character strings.
4853
4854 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4855 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4856 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4857 out for the ar command.)
4858
4859
4860 Version 3.2 12-May-00
4861 ---------------------
4862
4863 This is purely a bug fixing release.
4864
4865 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4866 of ZA. This was just one example of several cases that could provoke this bug,
4867 which was introduced by change 9 of version 2.00. The code for breaking
4868 infinite loops after an iteration that matches an empty string was't working
4869 correctly.
4870
4871 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4872 when matched against abbab (for example). After matching an empty string, it
4873 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4874 caused it to match further down the string than it should.
4875
4876 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4877 was there because it doesn't seem to be needed, and it causes trouble on some
4878 systems, as it is not a Standard C header. It has been removed.
4879
4880 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4881 were reported on the Macintosh. The changes were from
4882
4883 while ((c = *(++ptr)) != 0 && c != '\n');
4884 to
4885 while ((c = *(++ptr)) != 0 && c != '\n') ;
4886
4887 Totally extraordinary, but if that's what it takes...
4888
4889 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4890 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4891 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4892 assumes the way PCRE uses memmove() (always moving upwards).
4893
4894 6. PCRE is being used in one environment where strchr() is not available. There
4895 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4896 faster code anyway.
4897
4898
4899 Version 3.1 09-Feb-00
4900 ---------------------
4901
4902 The only change in this release is the fixing of some bugs in Makefile.in for
4903 the "install" target:
4904
4905 (1) It was failing to install pcreposix.h.
4906
4907 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4908
4909
4910 Version 3.0 01-Feb-00
4911 ---------------------
4912
4913 1. Add support for the /+ modifier to perltest (to output $` like it does in
4914 pcretest).
4915
4916 2. Add support for the /g modifier to perltest.
4917
4918 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4919 matches null strings.
4920
4921 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4922 pattern. Perl treats empty patterns specially - it reuses the most recent
4923 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4924 effect.
4925
4926 5. The POSIX interface was broken in that it was just handing over the POSIX
4927 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4928 required a bigger vector, with some working space on the end. This means that
4929 the POSIX wrapper now has to get and free some memory, and copy the results.
4930
4931 6. Added some simple autoconf support, placing the test data and the
4932 documentation in separate directories, re-organizing some of the
4933 information files, and making it build pcre-config (a GNU standard). Also added
4934 libtool support for building PCRE as a shared library, which is now the
4935 default.
4936
4937 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4938 09 are not valid octal constants. Single digits will be used for minor values
4939 less than 10.
4940
4941 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4942 existing programs that set these in the POSIX interface can use PCRE without
4943 modification.
4944
4945 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4946 return all that pcre_info() returns, plus additional data. The pcre_info()
4947 function is retained for compatibility, but is considered to be obsolete.
4948
4949 10. Added experimental recursion feature (?R) to handle one common case that
4950 Perl 5.6 will be able to do with (?p{...}).
4951
4952 11. Added support for POSIX character classes like [:alpha:], which Perl is
4953 adopting.
4954
4955
4956 Version 2.08 31-Aug-99
4957 ----------------------
4958
4959 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4960 trying to match at the startoffset position, but instead was moving forward to
4961 the next newline as if a previous match had failed.
4962
4963 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4964 and could get into a loop if a null string was matched other than at the start
4965 of the subject.
4966
4967 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4968 be distinguished at compile time, and for completeness also added PCRE_DATE.
4969
4970 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4971 in GnuWin32 environments.
4972
4973
4974 Version 2.07 29-Jul-99
4975 ----------------------
4976
4977 1. The documentation is now supplied in plain text form and HTML as well as in
4978 the form of man page sources.
4979
4980 2. C++ compilers don't like assigning (void *) values to other pointer types.
4981 In particular this affects malloc(). Although there is no problem in Standard
4982 C, I've put in casts to keep C++ compilers happy.
4983
4984 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4985 should be (const char *).
4986
4987 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4988 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4989 However, I haven't made this a standard facility. The documentation doesn't
4990 mention it, and the Makefile doesn't support it.
4991
4992 5. The Makefile now contains an "install" target, with editable destinations at
4993 the top of the file. The pcretest program is not installed.
4994
4995 6. pgrep -V now gives the PCRE version number and date.
4996
4997 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4998 causing the entire string to be ignored, instead of just the last character.
4999
5000 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
5001 non-matching string, it can take a very, very long time, even for strings of
5002 quite modest length, because of the nested recursion. PCRE now does better in
5003 some of these cases. It does this by remembering the last required literal
5004 character in the pattern, and pre-searching the subject to ensure it is present
5005 before running the real match. In other words, it applies a heuristic to detect
5006 some types of certain failure quickly, and in the above example, if presented
5007 with a string that has no trailing " it gives "no match" very quickly.
5008
5009 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
5010 other alternatives are tried instead.
5011
5012
5013 Version 2.06 09-Jun-99
5014 ----------------------
5015
5016 1. Change pcretest's output for amount of store used to show just the code
5017 space, because the remainder (the data block) varies in size between 32-bit and
5018 64-bit systems.
5019
5020 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
5021 start matching at. This allows lookbehinds to work when searching for multiple
5022 occurrences in a string.
5023
5024 3. Added additional options to pcretest for testing multiple occurrences:
5025
5026 /+ outputs the rest of the string that follows a match
5027 /g loops for multiple occurrences, using the new startoffset argument
5028 /G loops for multiple occurrences by passing an incremented pointer
5029
5030 4. PCRE wasn't doing the "first character" optimization for patterns starting
5031 with \b or \B, though it was doing it for other lookbehind assertions. That is,
5032 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
5033 the letter 'x'. On long subject strings, this gives a significant speed-up.
5034
5035
5036 Version 2.05 21-Apr-99
5037 ----------------------
5038
5039 1. Changed the type of magic_number from int to long int so that it works
5040 properly on 16-bit systems.
5041
5042 2. Fixed a bug which caused patterns starting with .* not to work correctly
5043 when the subject string contained newline characters. PCRE was assuming
5044 anchoring for such patterns in all cases, which is not correct because .* will
5045 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
5046 DOTALL is set at top level; otherwise it knows that patterns starting with .*
5047 must be retried after every newline in the subject.
5048
5049
5050 Version 2.04 18-Feb-99
5051 ----------------------
5052
5053 1. For parenthesized subpatterns with repeats whose minimum was zero, the
5054 computation of the store needed to hold the pattern was incorrect (too large).
5055 If such patterns were nested a few deep, this could multiply and become a real
5056 problem.
5057
5058 2. Added /M option to pcretest to show the memory requirement of a specific
5059 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
5060
5061 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
5062 compiled in such a way that the backtracking after subsequent failure was
5063 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
5064 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
5065
5066
5067 Version 2.03 02-Feb-99
5068 ----------------------
5069
5070 1. Fixed typo and small mistake in man page.
5071
5072 2. Added 4th condition (GPL supersedes if conflict) and created separate
5073 LICENCE file containing the conditions.
5074
5075 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
5076 Perl, that is the internal \ allows the delimiter to be included in the
5077 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
5078 the final delimiter, add \ to the end of the pattern (to test the error).
5079
5080 4. Added the convenience functions for extracting substrings after a successful
5081 match. Updated pcretest to make it able to test these functions.
5082
5083
5084 Version 2.02 14-Jan-99
5085 ----------------------
5086
5087 1. Initialized the working variables associated with each extraction so that
5088 their saving and restoring doesn't refer to uninitialized store.
5089
5090 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
5091 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
5092 fix the problem.
5093
5094 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
5095 calls, and wasn't printing the correct value for compiling calls. Increased the
5096 default value of LOOPREPEAT, and the number of significant figures in the
5097 times.
5098
5099 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
5100
5101 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
5102 a building problem on Windows NT with a FAT file system.
5103
5104
5105 Version 2.01 21-Oct-98
5106 ----------------------
5107
5108 1. Changed the API for pcre_compile() to allow for the provision of a pointer
5109 to character tables built by pcre_maketables() in the current locale. If NULL
5110 is passed, the default tables are used.
5111
5112
5113 Version 2.00 24-Sep-98
5114 ----------------------
5115
5116 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
5117 it any more.
5118
5119 2. Allow quantification of (?>) groups, and make it work correctly.
5120
5121 3. The first character computation wasn't working for (?>) groups.
5122
5123 4. Correct the implementation of \Z (it is permitted to match on the \n at the
5124 end of the subject) and add 5.005's \z, which really does match only at the
5125 very end of the subject.
5126
5127 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
5128
5129 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
5130 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
5131 localized options. All options to pcre_study() were also removed.
5132
5133 7. Add other new features from 5.005:
5134
5135 $(?<= positive lookbehind
5136 $(?<! negative lookbehind
5137 (?imsx-imsx) added the unsetting capability
5138 such a setting is global if at outer level; local otherwise
5139 (?imsx-imsx:) non-capturing groups with option setting
5140 (?(cond)re|re) conditional pattern matching
5141
5142 A backreference to itself in a repeated group matches the previous
5143 captured string.
5144
5145 8. General tidying up of studying (both automatic and via "study")
5146 consequential on the addition of new assertions.
5147
5148 9. As in 5.005, unlimited repeated groups that could match an empty substring
5149 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5150 runtime if any iteration does actually match an empty substring.
5151
5152 10. Include the RunTest script in the distribution.
5153
5154 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5155 discrepancies, some of which were old and were also with respect to 5.004. They
5156 have now been fixed.
5157
5158
5159 Version 1.09 28-Apr-98
5160 ----------------------
5161
5162 1. A negated single character class followed by a quantifier with a minimum
5163 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5164 program crashes, or just wrong answers. This did not apply to negated classes
5165 containing more than one character, or to minima other than one.
5166
5167
5168 Version 1.08 27-Mar-98
5169 ----------------------
5170
5171 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5172
5173 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5174 latter must appear before anything that relies on it in the pattern.
5175
5176
5177 Version 1.07 16-Feb-98
5178 ----------------------
5179
5180 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5181 repeat of a potentially empty string).
5182
5183
5184 Version 1.06 23-Jan-98
5185 ----------------------
5186
5187 1. Added Markus Oberhumer's little patches for C++.
5188
5189 2. Literal strings longer than 255 characters were broken.
5190
5191
5192 Version 1.05 23-Dec-97
5193 ----------------------
5194
5195 1. Negated character classes containing more than one character were failing if
5196 PCRE_CASELESS was set at run time.
5197
5198
5199 Version 1.04 19-Dec-97
5200 ----------------------
5201
5202 1. Corrected the man page, where some "const" qualifiers had been omitted.
5203
5204 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5205 input syntax.
5206
5207 3. Fixed memory leak which occurred when a regex with back references was
5208 matched with an offsets vector that wasn't big enough. The temporary memory
5209 that is used in this case wasn't being freed if the match failed.
5210
5211 4. Tidied pcretest to ensure it frees memory that it gets.
5212
5213 5. Temporary memory was being obtained in the case where the passed offsets
5214 vector was exactly big enough.
5215
5216 6. Corrected definition of offsetof() from change 5 below.
5217
5218 7. I had screwed up change 6 below and broken the rules for the use of
5219 setjmp(). Now fixed.
5220
5221
5222 Version 1.03 18-Dec-97
5223 ----------------------
5224
5225 1. A erroneous regex with a missing opening parenthesis was correctly
5226 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5227 on some systems.
5228
5229 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5230 it was reported that one broken compiler failed on the former because "code" is
5231 also an independent variable.
5232
5233 3. The erroneous regex a[]b caused an array overrun reference.
5234
5235 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5236 fail on data ending with that character. (It was going on too far, and checking
5237 the next character, typically a binary zero.) This was specific to the
5238 optimized code for single-character negative classes.
5239
5240 5. Added a contributed patch from the TIN world which does the following:
5241
5242 + Add an undef for memmove, in case the the system defines a macro for it.
5243
5244 + Add a definition of offsetof(), in case there isn't one. (I don't know
5245 the reason behind this - offsetof() is part of the ANSI standard - but
5246 it does no harm).
5247
5248 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
5249 most of the places where whitespace preceded '#'. I have given up and
5250 allowed the remaining 2 cases to be at the margin.
5251
5252 + Rename some variables in pcre to eliminate shadowing. This seems very
5253 pedantic, but does no harm, of course.
5254
5255 6. Moved the call to setjmp() into its own function, to get rid of warnings
5256 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
5257
5258 7. Constructs such as \d{8,} were compiling into the equivalent of
5259 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
5260 outcome, but in this particular case used more store than had been allocated,
5261 which caused the bug to be discovered because it threw up an internal error.
5262
5263 8. The debugging code in both pcre and pcretest for outputting the compiled
5264 form of a regex was going wrong in the case of back references followed by
5265 curly-bracketed repeats.
5266
5267
5268 Version 1.02 12-Dec-97
5269 ----------------------
5270
5271 1. Typos in pcre.3 and comments in the source fixed.
5272
5273 2. Applied a contributed patch to get rid of places where it used to remove
5274 'const' from variables, and fixed some signed/unsigned and uninitialized
5275 variable warnings.
5276
5277 3. Added the "runtest" target to Makefile.
5278
5279 4. Set default compiler flag to -O2 rather than just -O.
5280
5281
5282 Version 1.01 19-Nov-97
5283 ----------------------
5284
5285 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
5286 like /([ab]*)*/, that is, for classes with more than one character in them.
5287
5288 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
5289 as /((?>a*))*/ (a PCRE_EXTRA facility).
5290
5291
5292 Version 1.00 18-Nov-97
5293 ----------------------
5294
5295 1. Added compile-time macros to support systems such as SunOS4 which don't have
5296 memmove() or strerror() but have other things that can be used instead.
5297
5298 2. Arranged that "make clean" removes the executables.
5299
5300
5301 Version 0.99 27-Oct-97
5302 ----------------------
5303
5304 1. Fixed bug in code for optimizing classes with only one character. It was
5305 initializing a 32-byte map regardless, which could cause it to run off the end
5306 of the memory it had got.
5307
5308 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
5309
5310
5311 Version 0.98 22-Oct-97
5312 ----------------------
5313
5314 1. Fixed bug in code for handling temporary memory usage when there are more
5315 back references than supplied space in the ovector. This could cause segfaults.
5316
5317
5318 Version 0.97 21-Oct-97
5319 ----------------------
5320
5321 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
5322
5323 2. Optimized negated single characters not to use a bit map.
5324
5325 3. Brought error texts together as macro definitions; clarified some of them;
5326 fixed one that was wrong - it said "range out of order" when it meant "invalid
5327 escape sequence".
5328
5329 4. Changed some char * arguments to const char *.
5330
5331 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
5332
5333 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
5334 pcretest.
5335
5336
5337 Version 0.96 16-Oct-97
5338 ----------------------
5339
5340 1. Added a simple "pgrep" utility to the distribution.
5341
5342 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
5343 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
5344 where "ddd" means "one or more decimal digits".
5345
5346 3. Fixed serious bug. If a pattern had a back reference, but the call to
5347 pcre_exec() didn't supply a large enough ovector to record the related
5348 identifying subpattern, the match always failed. PCRE now remembers the number
5349 of the largest back reference, and gets some temporary memory in which to save
5350 the offsets during matching if necessary, in order to ensure that
5351 backreferences always work.
5352
5353 4. Increased the compatibility with Perl in a number of ways:
5354
5355 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
5356 to request this handling. The option can be set at compile or exec time.
5357
5358 (b) $ matches before a terminating newline by default; an option
5359 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
5360 mode). The option can be set at compile or exec time.
5361
5362 (c) The handling of \ followed by a digit other than 0 is now supposed to be
5363 the same as Perl's. If the decimal number it represents is less than 10
5364 or there aren't that many previous left capturing parentheses, an octal
5365 escape is read. Inside a character class, it's always an octal escape,
5366 even if it is a single digit.
5367
5368 (d) An escaped but undefined alphabetic character is taken as a literal,
5369 unless PCRE_EXTRA is set. Currently this just reserves the remaining
5370 escapes.
5371
5372 (e) {0} is now permitted. (The previous item is removed from the compiled
5373 pattern).
5374
5375 5. Changed all the names of code files so that the basic parts are no longer
5376 than 10 characters, and abolished the teeny "globals.c" file.
5377
5378 6. Changed the handling of character classes; they are now done with a 32-byte
5379 bit map always.
5380
5381 7. Added the -d and /D options to pcretest to make it possible to look at the
5382 internals of compilation without having to recompile pcre.
5383
5384
5385 Version 0.95 23-Sep-97
5386 ----------------------
5387
5388 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
5389 \x20 at the start of a run of normal characters. These were being treated as
5390 real characters, instead of the source characters being re-checked.
5391
5392
5393 Version 0.94 18-Sep-97
5394 ----------------------
5395
5396 1. The functions are now thread-safe, with the caveat that the global variables
5397 containing pointers to malloc() and free() or alternative functions are the
5398 same for all threads.
5399
5400 2. Get pcre_study() to generate a bitmap of initial characters for non-
5401 anchored patterns when this is possible, and use it if passed to pcre_exec().
5402
5403
5404 Version 0.93 15-Sep-97
5405 ----------------------
5406
5407 1. /(b)|(:+)/ was computing an incorrect first character.
5408
5409 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
5410 but not actually doing anything yet.
5411
5412 3. Treat "-" characters in classes that cannot be part of ranges as literals,
5413 as Perl does (e.g. [-az] or [az-]).
5414
5415 4. Set the anchored flag if a branch starts with .* or .*? because that tests
5416 all possible positions.
5417
5418 5. Split up into different modules to avoid including unneeded functions in a
5419 compiled binary. However, compile and exec are still in one module. The "study"
5420 function is split off.
5421
5422 6. The character tables are now in a separate module whose source is generated
5423 by an auxiliary program - but can then be edited by hand if required. There are
5424 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
5425 toupper() in the code.
5426
5427 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
5428 make them global. Abolish the function for setting them, as the caller can now
5429 set them directly.
5430
5431
5432 Version 0.92 11-Sep-97
5433 ----------------------
5434
5435 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
5436 (e.g. /a{1,3}/) was broken (I mis-optimized it).
5437
5438 2. Caseless matching was not working in character classes if the characters in
5439 the pattern were in upper case.
5440
5441 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
5442
5443 4. Make PCRE_ANCHORED public and accept as a compile option.
5444
5445 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
5446 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
5447 pass them.
5448
5449 6. Give an error if bad option bits passed at compile or run time.
5450
5451 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
5452 pcretest to cause it to pass that flag.
5453
5454 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
5455 options, and the first character, if set.
5456
5457 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
5458
5459
5460 Version 0.91 10-Sep-97
5461 ----------------------
5462
5463 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
5464 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
5465
5466 2. PCRE was looping on encountering an indefinitely repeated back reference to
5467 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
5468 Perl does - treats the match as successful.
5469
5470 ****

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