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JIT should return with error when the compiled pattern requires more stack space than the maximum.
1 ChangeLog for PCRE
2 ------------------
3
4 Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
5 development is happening in the PCRE2 10.xx series.
6
7 Version 8.38 xx-xxx-xxxx
8 ------------------------
9
10 1. If a group that contained a recursive back reference also contained a
11 forward reference subroutine call followed by a non-forward-reference
12 subroutine call, for example /.((?2)(?R)\1)()/, pcre2_compile() failed to
13 compile correct code, leading to undefined behaviour or an internally
14 detected error. This bug was discovered by the LLVM fuzzer.
15
16 2. Quantification of certain items (e.g. atomic back references) could cause
17 incorrect code to be compiled when recursive forward references were
18 involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
19 This bug was discovered by the LLVM fuzzer.
20
21 3. A repeated conditional group whose condition was a reference by name caused
22 a buffer overflow if there was more than one group with the given name.
23 This bug was discovered by the LLVM fuzzer.
24
25 4. A recursive back reference by name within a group that had the same name as
26 another group caused a buffer overflow. For example:
27 /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
28
29 5. A forward reference by name to a group whose number is the same as the
30 current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
31 a buffer overflow at compile time. This bug was discovered by the LLVM
32 fuzzer.
33
34 6. A lookbehind assertion within a set of mutually recursive subpatterns could
35 provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
36
37 7. Another buffer overflow bug involved duplicate named groups with a
38 reference between their definition, with a group that reset capture
39 numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
40 fixed by always allowing for more memory, even if not needed. (A proper fix
41 is implemented in PCRE2, but it involves more refactoring.)
42
43 8. There was no check for integer overflow in subroutine calls such as (?123).
44
45 9. The table entry for \l in EBCDIC environments was incorrect, leading to its
46 being treated as a literal 'l' instead of causing an error.
47
48 10. There was a buffer overflow if pcre_exec() was called with an ovector of
49 size 1. This bug was found by american fuzzy lop.
50
51 11. If a non-capturing group containing a conditional group that could match
52 an empty string was repeated, it was not identified as matching an empty
53 string itself. For example: /^(?:(?(1)x|)+)+$()/.
54
55 12. In an EBCDIC environment, pcretest was mishandling the escape sequences
56 \a and \e in test subject lines.
57
58 13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
59 instead of the EBCDIC value.
60
61 14. The handling of \c in an EBCDIC environment has been revised so that it is
62 now compatible with the specification in Perl's perlebcdic page.
63
64 15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
65 ASCII/Unicode. This has now been added to the list of characters that are
66 recognized as white space in EBCDIC.
67
68 16. When PCRE was compiled without UCP support, the use of \p and \P gave an
69 error (correctly) when used outside a class, but did not give an error
70 within a class.
71
72 17. \h within a class was incorrectly compiled in EBCDIC environments.
73
74 18. A pattern with an unmatched closing parenthesis that contained a backward
75 assertion which itself contained a forward reference caused buffer
76 overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
77
78 19. JIT should return with error when the compiled pattern requires more stack
79 space than the maximum.
80
81
82 Version 8.37 28-April-2015
83 --------------------------
84
85 1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
86 for those parentheses to be closed with whatever has been captured so far.
87 However, it was failing to mark any other groups between the hightest
88 capture so far and the currrent group as "unset". Thus, the ovector for
89 those groups contained whatever was previously there. An example is the
90 pattern /(x)|((*ACCEPT))/ when matched against "abcd".
91
92 2. If an assertion condition was quantified with a minimum of zero (an odd
93 thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
94
95 3. If a pattern in pcretest input had the P (POSIX) modifier followed by an
96 unrecognized modifier, a crash could occur.
97
98 4. An attempt to do global matching in pcretest with a zero-length ovector
99 caused a crash.
100
101 5. Fixed a memory leak during matching that could occur for a subpattern
102 subroutine call (recursive or otherwise) if the number of captured groups
103 that had to be saved was greater than ten.
104
105 6. Catch a bad opcode during auto-possessification after compiling a bad UTF
106 string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
107 UTF with NO_UTF_CHECK is documented as having an undefined outcome.
108
109 7. A UTF pattern containing a "not" match of a non-ASCII character and a
110 subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
111
112 8. When a pattern is compiled, it remembers the highest back reference so that
113 when matching, if the ovector is too small, extra memory can be obtained to
114 use instead. A conditional subpattern whose condition is a check on a
115 capture having happened, such as, for example in the pattern
116 /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
117 setting the highest backreference number. This mattered only if pcre_exec()
118 was called with an ovector that was too small to hold the capture, and there
119 was no other kind of back reference (a situation which is probably quite
120 rare). The effect of the bug was that the condition was always treated as
121 FALSE when the capture could not be consulted, leading to a incorrect
122 behaviour by pcre_exec(). This bug has been fixed.
123
124 9. A reference to a duplicated named group (either a back reference or a test
125 for being set in a conditional) that occurred in a part of the pattern where
126 PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
127 to be incorrectly calculated, leading to overwriting.
128
129 10. A mutually recursive set of back references such as (\2)(\1) caused a
130 segfault at study time (while trying to find the minimum matching length).
131 The infinite loop is now broken (with the minimum length unset, that is,
132 zero).
133
134 11. If an assertion that was used as a condition was quantified with a minimum
135 of zero, matching went wrong. In particular, if the whole group had
136 unlimited repetition and could match an empty string, a segfault was
137 likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
138 assertions to be quantified, but not if they are being used as conditions,
139 so the above pattern is faulted by Perl. PCRE has now been changed so that
140 it also rejects such patterns.
141
142 12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
143 failed to allow the zero-repeat case if pcre2_exec() was called with an
144 ovector too small to capture the group.
145
146 13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
147 Red Hat Product Security:
148
149 (a) A crash if /K and /F were both set with the option to save the compiled
150 pattern.
151
152 (b) Another crash if the option to print captured substrings in a callout
153 was combined with setting a null ovector, for example \O\C+ as a subject
154 string.
155
156 14. A pattern such as "((?2){0,1999}())?", which has a group containing a
157 forward reference repeated a large (but limited) number of times within a
158 repeated outer group that has a zero minimum quantifier, caused incorrect
159 code to be compiled, leading to the error "internal error:
160 previously-checked referenced subpattern not found" when an incorrect
161 memory address was read. This bug was reported as "heap overflow",
162 discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
163 CVE-2015-2325.
164
165 23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
166 call within a group that also contained a recursive back reference caused
167 incorrect code to be compiled. This bug was reported as "heap overflow",
168 discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
169 number CVE-2015-2326.
170
171 24. Computing the size of the JIT read-only data in advance has been a source
172 of various issues, and new ones are still appear unfortunately. To fix
173 existing and future issues, size computation is eliminated from the code,
174 and replaced by on-demand memory allocation.
175
176 25. A pattern such as /(?i)[A-`]/, where characters in the other case are
177 adjacent to the end of the range, and the range contained characters with
178 more than one other case, caused incorrect behaviour when compiled in UTF
179 mode. In that example, the range a-j was left out of the class.
180
181 26. Fix JIT compilation of conditional blocks, which assertion
182 is converted to (*FAIL). E.g: /(?(?!))/.
183
184 27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
185 discovered by the LLVM fuzzer.
186
187 28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
188 when this assertion was used as a condition, for example (?(?!)a|b). In
189 pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
190 error about an unsupported item.
191
192 29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
193 possessification code could take exponential time to complete. A recursion
194 depth limit of 1000 has been imposed to limit the resources used by this
195 optimization.
196
197 30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
198 such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
199 because \S ensures they are all in the class. The code for doing this was
200 interacting badly with the code for computing the amount of space needed to
201 compile the pattern, leading to a buffer overflow. This bug was discovered
202 by the LLVM fuzzer.
203
204 31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
205 other kinds of group caused stack overflow at compile time. This bug was
206 discovered by the LLVM fuzzer.
207
208 32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
209 between a subroutine call and its quantifier was incorrectly compiled,
210 leading to buffer overflow or other errors. This bug was discovered by the
211 LLVM fuzzer.
212
213 33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
214 assertion after (?(. The code was failing to check the character after
215 (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
216 was discovered by the LLVM fuzzer.
217
218 34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
219 a fixed maximum following a group that contains a subroutine reference was
220 incorrectly compiled and could trigger buffer overflow. This bug was
221 discovered by the LLVM fuzzer.
222
223 35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
224 caused a stack overflow instead of the diagnosis of a non-fixed length
225 lookbehind assertion. This bug was discovered by the LLVM fuzzer.
226
227 36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
228 (e.g. /(?<=\Ka)/) could make pcregrep loop.
229
230 37. There was a similar problem to 36 in pcretest for global matches.
231
232 38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
233 and a subsequent item in the pattern caused a non-match, backtracking over
234 the repeated \X did not stop, but carried on past the start of the subject,
235 causing reference to random memory and/or a segfault. There were also some
236 other cases where backtracking after \C could crash. This set of bugs was
237 discovered by the LLVM fuzzer.
238
239 39. The function for finding the minimum length of a matching string could take
240 a very long time if mutual recursion was present many times in a pattern,
241 for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
242 method has been implemented. This infelicity was discovered by the LLVM
243 fuzzer.
244
245 40. Static linking against the PCRE library using the pkg-config module was
246 failing on missing pthread symbols.
247
248
249 Version 8.36 26-September-2014
250 ------------------------------
251
252 1. Got rid of some compiler warnings in the C++ modules that were shown up by
253 -Wmissing-field-initializers and -Wunused-parameter.
254
255 2. The tests for quantifiers being too big (greater than 65535) were being
256 applied after reading the number, and stupidly assuming that integer
257 overflow would give a negative number. The tests are now applied as the
258 numbers are read.
259
260 3. Tidy code in pcre_exec.c where two branches that used to be different are
261 now the same.
262
263 4. The JIT compiler did not generate match limit checks for certain
264 bracketed expressions with quantifiers. This may lead to exponential
265 backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
266 issue should be resolved now.
267
268 5. Fixed an issue, which occures when nested alternatives are optimized
269 with table jumps.
270
271 6. Inserted two casts and changed some ints to size_t in the light of some
272 reported 64-bit compiler warnings (Bugzilla 1477).
273
274 7. Fixed a bug concerned with zero-minimum possessive groups that could match
275 an empty string, which sometimes were behaving incorrectly in the
276 interpreter (though correctly in the JIT matcher). This pcretest input is
277 an example:
278
279 '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
280 NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
281
282 the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
283 JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
284 for an empty string was breaking the inner loop and carrying on at a lower
285 level, when possessive repeated groups should always return to a higher
286 level as they have no backtrack points in them. The empty string test now
287 occurs at the outer level.
288
289 8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
290 ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
291
292 9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
293 doesn't).
294
295 10. Change 8.34/15 introduced a bug that caused the amount of memory needed
296 to hold a pattern to be incorrectly computed (too small) when there were
297 named back references to duplicated names. This could cause "internal
298 error: code overflow" or "double free or corruption" or other memory
299 handling errors.
300
301 11. When named subpatterns had the same prefixes, back references could be
302 confused. For example, in this pattern:
303
304 /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
305
306 the reference to 'Name' was incorrectly treated as a reference to a
307 duplicate name.
308
309 12. A pattern such as /^s?c/mi8 where the optional character has more than
310 one "other case" was incorrectly compiled such that it would only try to
311 match starting at "c".
312
313 13. When a pattern starting with \s was studied, VT was not included in the
314 list of possible starting characters; this should have been part of the
315 8.34/18 patch.
316
317 14. If a character class started [\Qx]... where x is any character, the class
318 was incorrectly terminated at the ].
319
320 15. If a pattern that started with a caseless match for a character with more
321 than one "other case" was studied, PCRE did not set up the starting code
322 unit bit map for the list of possible characters. Now it does. This is an
323 optimization improvement, not a bug fix.
324
325 16. The Unicode data tables have been updated to Unicode 7.0.0.
326
327 17. Fixed a number of memory leaks in pcregrep.
328
329 18. Avoid a compiler warning (from some compilers) for a function call with
330 a cast that removes "const" from an lvalue by using an intermediate
331 variable (to which the compiler does not object).
332
333 19. Incorrect code was compiled if a group that contained an internal recursive
334 back reference was optional (had quantifier with a minimum of zero). This
335 example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
336 caused segmentation faults because of stack overflows at compile time.
337
338 20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
339 group that is quantified with an indefinite repeat, caused a compile-time
340 loop which used up all the system stack and provoked a segmentation fault.
341 This was not the same bug as 19 above.
342
343 21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
344 Patch by Mike Frysinger.
345
346
347 Version 8.35 04-April-2014
348 --------------------------
349
350 1. A new flag is set, when property checks are present in an XCLASS.
351 When this flag is not set, PCRE can perform certain optimizations
352 such as studying these XCLASS-es.
353
354 2. The auto-possessification of character sets were improved: a normal
355 and an extended character set can be compared now. Furthermore
356 the JIT compiler optimizes more character set checks.
357
358 3. Got rid of some compiler warnings for potentially uninitialized variables
359 that show up only when compiled with -O2.
360
361 4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
362 of a match later then the end of the match. The pcretest program was not
363 handling the case sensibly - it was outputting from the start to the next
364 binary zero. It now reports this situation in a message, and outputs the
365 text from the end to the start.
366
367 5. Fast forward search is improved in JIT. Instead of the first three
368 characters, any three characters with fixed position can be searched.
369 Search order: first, last, middle.
370
371 6. Improve character range checks in JIT. Characters are read by an inprecise
372 function now, which returns with an unknown value if the character code is
373 above a certain threshold (e.g: 256). The only limitation is that the value
374 must be bigger than the threshold as well. This function is useful when
375 the characters above the threshold are handled in the same way.
376
377 7. The macros whose names start with RAWUCHAR are placeholders for a future
378 mode in which only the bottom 21 bits of 32-bit data items are used. To
379 make this more memorable for those maintaining the code, the names have
380 been changed to start with UCHAR21, and an extensive comment has been added
381 to their definition.
382
383 8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
384 to the export list in Makefile.am (they were accidentally omitted from the
385 8.34 tarball).
386
387 9. The informational output from pcretest used the phrase "starting byte set"
388 which is inappropriate for the 16-bit and 32-bit libraries. As the output
389 for "first char" and "need char" really means "non-UTF-char", I've changed
390 "byte" to "char", and slightly reworded the output. The documentation about
391 these values has also been (I hope) clarified.
392
393 10. Another JIT related optimization: use table jumps for selecting the correct
394 backtracking path, when more than four alternatives are present inside a
395 bracket.
396
397 11. Empty match is not possible, when the minimum length is greater than zero,
398 and there is no \K in the pattern. JIT should avoid empty match checks in
399 such cases.
400
401 12. In a caseless character class with UCP support, when a character with more
402 than one alternative case was not the first character of a range, not all
403 the alternative cases were added to the class. For example, s and \x{17f}
404 are both alternative cases for S: the class [RST] was handled correctly,
405 but [R-T] was not.
406
407 13. The configure.ac file always checked for pthread support when JIT was
408 enabled. This is not used in Windows, so I have put this test inside a
409 check for the presence of windows.h (which was already tested for).
410
411 14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
412 The algorithm provides a way to skip certain starting offsets, and usually
413 faster than linear prefix searches.
414
415 15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
416 as for 'fr_FR' and 'french'. For some reason, however, it then used the
417 Windows-specific input and output files, which have 'french' screwed in.
418 So this could never have worked. One of the problems with locales is that
419 they aren't always the same. I have now updated RunTest so that it checks
420 the output of the locale test (test 3) against three different output
421 files, and it allows the test to pass if any one of them matches. With luck
422 this should make the test pass on some versions of Solaris where it was
423 failing. Because of the uncertainty, the script did not used to stop if
424 test 3 failed; it now does. If further versions of a French locale ever
425 come to light, they can now easily be added.
426
427 16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
428 there was a message during ./configure, but it did not stop. This now
429 provokes an error. The invalid example in README has been corrected.
430 If a value less than the minimum is given, the minimum value has always
431 been used, but now a warning is given.
432
433 17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
434 was a bug in the test system, which is now fixed. Also, the list of various
435 configurations that are tested for each release did not have one with both
436 16/32 bits and --enable-bar-anycrlf. It now does.
437
438 18. pcretest was missing "-C bsr" for displaying the \R default setting.
439
440 19. Little endian PowerPC systems are supported now by the JIT compiler.
441
442 20. The fast forward newline mechanism could enter to an infinite loop on
443 certain invalid UTF-8 input. Although we don't support these cases
444 this issue can be fixed by a performance optimization.
445
446 21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
447 not take account if existing stack usage. There is now a new global
448 variable called pcre_stack_guard that can be set to point to an external
449 function to check stack availability. It is called at the start of
450 processing every parenthesized group.
451
452 22. A typo in the code meant that in ungreedy mode the max/min qualifier
453 behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
454 not match "ab".
455
456 23. When UTF was disabled, the JIT program reported some incorrect compile
457 errors. These messages are silenced now.
458
459 24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
460 compiler.
461
462 25. Change all the temporary files used in RunGrepTest to be different to those
463 used by RunTest so that the tests can be run simultaneously, for example by
464 "make -j check".
465
466
467 Version 8.34 15-December-2013
468 -----------------------------
469
470 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
471 executable memory. Patch inspired by Carsten Klein.
472
473 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
474 this macro is never tested and has no effect, because the work to support
475 coverage involves only compiling and linking options and special targets in
476 the Makefile. The comment in config.h implied that defining the macro would
477 enable coverage support, which is totally false. There was also support for
478 setting this macro in the CMake files (my fault, I just copied it from
479 configure). SUPPORT_GCOV has now been removed.
480
481 3. Make a small performance improvement in strlen16() and strlen32() in
482 pcretest.
483
484 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
485 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
486 these cases). There was also one in pcretest.c.
487
488 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
489
490 6. In UTF mode, the code for checking whether a group could match an empty
491 string (which is used for indefinitely repeated groups to allow for
492 breaking an infinite loop) was broken when the group contained a repeated
493 negated single-character class with a character that occupied more than one
494 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
495 UTF-8 mode). The effect was undefined: the group might or might not be
496 deemed as matching an empty string, or the program might have crashed.
497
498 7. The code for checking whether a group could match an empty string was not
499 recognizing that \h, \H, \v, \V, and \R must match a character.
500
501 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
502 an empty string. If it can, pcretest shows this in its information output.
503
504 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
505 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
506 matched by pcre_exec() without using JIT:
507
508 (a) If the rest of the pattern did not match after a maximal run of
509 grapheme clusters, the code for backing up to try with fewer of them
510 did not always back up over a full grapheme when characters that do not
511 have the modifier quality were involved, e.g. Hangul syllables.
512
513 (b) If the match point in a subject started with modifier character, and
514 there was no match, the code could incorrectly back up beyond the match
515 point, and potentially beyond the first character in the subject,
516 leading to a segfault or an incorrect match result.
517
518 10. A conditional group with an assertion condition could lead to PCRE
519 recording an incorrect first data item for a match if no other first data
520 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
521 first data item, and therefore matched "ca" after "c" instead of at the
522 start.
523
524 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
525 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
526
527 12. The source of pcregrep now includes z/OS-specific code so that it can be
528 compiled for z/OS as part of the special z/OS distribution.
529
530 13. Added the -T and -TM options to pcretest.
531
532 14. The code in pcre_compile.c for creating the table of named capturing groups
533 has been refactored. Instead of creating the table dynamically during the
534 actual compiling pass, the information is remembered during the pre-compile
535 pass (on the stack unless there are more than 20 named groups, in which
536 case malloc() is used) and the whole table is created before the actual
537 compile happens. This has simplified the code (it is now nearly 150 lines
538 shorter) and prepared the way for better handling of references to groups
539 with duplicate names.
540
541 15. A back reference to a named subpattern when there is more than one of the
542 same name now checks them in the order in which they appear in the pattern.
543 The first one that is set is used for the reference. Previously only the
544 first one was inspected. This change makes PCRE more compatible with Perl.
545
546 16. Unicode character properties were updated from Unicode 6.3.0.
547
548 17. The compile-time code for auto-possessification has been refactored, based
549 on a patch by Zoltan Herczeg. It now happens after instead of during
550 compilation. The code is cleaner, and more cases are handled. The option
551 PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
552 options in pcretest are provided to set it. It can also be set by
553 (*NO_AUTO_POSSESS) at the start of a pattern.
554
555 18. The character VT has been added to the default ("C" locale) set of
556 characters that match \s and are generally treated as white space,
557 following this same change in Perl 5.18. There is now no difference between
558 "Perl space" and "POSIX space". Whether VT is treated as white space in
559 other locales depends on the locale.
560
561 19. The code for checking named groups as conditions, either for being set or
562 for being recursed, has been refactored (this is related to 14 and 15
563 above). Processing unduplicated named groups should now be as fast at
564 numerical groups, and processing duplicated groups should be faster than
565 before.
566
567 20. Two patches to the CMake build system, by Alexander Barkov:
568
569 (1) Replace the "source" command by "." in CMakeLists.txt because
570 "source" is a bash-ism.
571
572 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
573 without these the CMake build does not work on Solaris.
574
575 21. Perl has changed its handling of \8 and \9. If there is no previously
576 encountered capturing group of those numbers, they are treated as the
577 literal characters 8 and 9 instead of a binary zero followed by the
578 literals. PCRE now does the same.
579
580 22. Following Perl, added \o{} to specify codepoints in octal, making it
581 possible to specify values greater than 0777 and also making them
582 unambiguous.
583
584 23. Perl now gives an error for missing closing braces after \x{... instead of
585 treating the string as literal. PCRE now does the same.
586
587 24. RunTest used to grumble if an inappropriate test was selected explicitly,
588 but just skip it when running all tests. This make it awkward to run ranges
589 of tests when one of them was inappropriate. Now it just skips any
590 inappropriate tests, as it always did when running all tests.
591
592 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
593 character types such as \d or \w, too many callouts were inserted, and the
594 data that they returned was rubbish.
595
596 26. In UCP mode, \s was not matching two of the characters that Perl matches,
597 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
598 were matched by \h. The code has now been refactored so that the lists of
599 the horizontal and vertical whitespace characters used for \h and \v (which
600 are defined only in one place) are now also used for \s.
601
602 27. Add JIT support for the 64 bit TileGX architecture.
603 Patch by Jiong Wang (Tilera Corporation).
604
605 28. Possessive quantifiers for classes (both explicit and automatically
606 generated) now use special opcodes instead of wrapping in ONCE brackets.
607
608 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
609 (because it's meaningless), this was not happening when PCRE_CASELESS was
610 set. Not wrong, but inefficient.
611
612 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
613 properties for \w, \d, etc) is present in a test regex. Otherwise if the
614 test contains no characters greater than 255, Perl doesn't realise it
615 should be using Unicode semantics.
616
617 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
618 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
619 does in Unicode mode.
620
621 32. Added the "forbid" facility to pcretest so that putting tests into the
622 wrong test files can sometimes be quickly detected.
623
624 33. There is now a limit (default 250) on the depth of nesting of parentheses.
625 This limit is imposed to control the amount of system stack used at compile
626 time. It can be changed at build time by --with-parens-nest-limit=xxx or
627 the equivalent in CMake.
628
629 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
630 errors. Perl warns for these when in warning mode, but PCRE has no facility
631 for giving warnings.
632
633 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
634 However, this was not working for (?!) because it is optimized to (*FAIL),
635 for which PCRE does not allow quantifiers. The optimization is now disabled
636 when a quantifier follows (?!). I can't see any use for this, but it makes
637 things uniform.
638
639 36. Perl no longer allows group names to start with digits, so I have made this
640 change also in PCRE. It simplifies the code a bit.
641
642 37. In extended mode, Perl ignores spaces before a + that indicates a
643 possessive quantifier. PCRE allowed a space before the quantifier, but not
644 before the possessive +. It now does.
645
646 38. The use of \K (reset reported match start) within a repeated possessive
647 group such as (a\Kb)*+ was not working.
648
649 40. Document that the same character tables must be used at compile time and
650 run time, and that the facility to pass tables to pcre_exec() and
651 pcre_dfa_exec() is for use only with saved/restored patterns.
652
653 41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
654 features for Builds with MSVC:
655
656 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
657 builds). The .rc files can be used to set FileDescription and many other
658 attributes.
659
660 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
661 This allows higher-level build scripts which want .pdb files to avoid
662 hard-coding the exact files needed."
663
664 42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
665 mean "start of word" and "end of word", respectively, as a transition aid.
666
667 43. A minimizing repeat of a class containing codepoints greater than 255 in
668 non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
669 compiled to use the heap for recursion.
670
671 44. Got rid of some compiler warnings for unused variables when UTF but not UCP
672 is configured.
673
674
675 Version 8.33 28-May-2013
676 ------------------------
677
678 1. Added 'U' to some constants that are compared to unsigned integers, to
679 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
680 variables that are added to signed variables, to ensure the result is
681 signed and can be negated.
682
683 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
684 CMake config files.
685
686 3. Revise the creation of config.h.generic so that all boolean macros are
687 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
688 overriding via -D on the command line possible.
689
690 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
691 to unsigned int is reported to make a quite noticeable speed difference in
692 a specific Windows environment. Testing on Linux did also appear to show
693 some benefit (and it is clearly not harmful). Also fixed the definition of
694 Xop which should be unsigned.
695
696 5. Related to (4), changing the definition of the intermediate variable cc
697 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
698 improvements.
699
700 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
701 unnecessary spaces.
702
703 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
704 and later.
705
706 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
707
708 9. Optimizing fast_forward_start_bits in JIT.
709
710 10. Adding support for callouts in JIT, and fixing some issues revealed
711 during this work. Namely:
712
713 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
714
715 (b) Minimum length was not checked before the matching is started.
716
717 11. The value of capture_last that is passed to callouts was incorrect in some
718 cases when there was a capture on one path that was subsequently abandoned
719 after a backtrack. Also, the capture_last value is now reset after a
720 recursion, since all captures are also reset in this case.
721
722 12. The interpreter no longer returns the "too many substrings" error in the
723 case when an overflowing capture is in a branch that is subsequently
724 abandoned after a backtrack.
725
726 13. In the pathological case when an offset vector of size 2 is used, pcretest
727 now prints out the matched string after a yield of 0 or 1.
728
729 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
730 Only supported by the JIT compiler at the moment.
731
732 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
733
734 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
735 offset of the starting point of the matching process, provided the offsets
736 vector is large enough.
737
738 17. The \A escape now records a lookbehind value of 1, though its execution
739 does not actually inspect the previous character. This is to ensure that,
740 in partial multi-segment matching, at least one character from the old
741 segment is retained when a new segment is processed. Otherwise, if there
742 are no lookbehinds in the pattern, \A might match incorrectly at the start
743 of a new segment.
744
745 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
746
747 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
748 gives some modest performance improvement in 8-bit mode.
749
750 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
751 be expressed in certain programming languages using Universal Character
752 Names.
753
754 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
755 which points out that "non characters" are not "characters that may not
756 appear in Unicode strings" but rather "characters that are reserved for
757 internal use and have only local meaning".
758
759 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
760 there was a conditional group that depended on an assertion, if the
761 assertion was false, the callout that immediately followed the alternation
762 in the condition was skipped when pcre_exec() was used for matching.
763
764 23. Allow an explicit callout to be inserted before an assertion that is the
765 condition for a conditional group, for compatibility with automatic
766 callouts, which always insert a callout at this point.
767
768 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
769 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
770
771 25. (*PRUNE) is now supported by the JIT compiler.
772
773 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
774
775 27. Fix the case where there are two or more SKIPs with arguments that may be
776 ignored.
777
778 28. (*SKIP) is now supported by the JIT compiler.
779
780 29. (*THEN) is now supported by the JIT compiler.
781
782 30. Update RunTest with additional test selector options.
783
784 31. The way PCRE handles backtracking verbs has been changed in two ways.
785
786 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
787 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
788 backtracking. In some cases this makes it more Perl-compatible, but Perl's
789 rather obscure rules do not always do the same thing.
790
791 (2) Previously, backtracking verbs were confined within assertions. This is
792 no longer the case for positive assertions, except for (*ACCEPT). Again,
793 this sometimes improves Perl compatibility, and sometimes does not.
794
795 32. A number of tests that were in test 2 because Perl did things differently
796 have been moved to test 1, because either Perl or PCRE has changed, and
797 these tests are now compatible.
798
799 32. Backtracking control verbs are now handled in the same way in JIT and
800 interpreter.
801
802 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
803 contained a forward subroutine reference caused a compile error.
804
805 34. Auto-detect and optimize limited repetitions in JIT.
806
807 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
808 blocking (*UTF) etc.
809
810 36. In the interpreter, maximizing pattern repetitions for characters and
811 character types now use tail recursion, which reduces stack usage.
812
813 37. The value of the max lookbehind was not correctly preserved if a compiled
814 and saved regex was reloaded on a host of different endianness.
815
816 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
817 of the compiled pattern block, expand the flags field from 16 to 32 bits
818 because it was almost full.
819
820 39. Try madvise first before posix_madvise.
821
822 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
823 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
824 original change locked out all matches of empty strings. This has been
825 changed so that one match of an empty string per line is recognized.
826 Subsequent searches on the same line (for colouring or for --only-matching,
827 for example) do not recognize empty strings.
828
829 41. Applied a user patch to fix a number of spelling mistakes in comments.
830
831 42. Data lines longer than 65536 caused pcretest to crash.
832
833 43. Clarified the data type for length and startoffset arguments for pcre_exec
834 and pcre_dfa_exec in the function-specific man pages, where they were
835 explicitly stated to be in bytes, never having been updated. I also added
836 some clarification to the pcreapi man page.
837
838 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
839 a segmentation fault.
840
841
842 Version 8.32 30-November-2012
843 -----------------------------
844
845 1. Improved JIT compiler optimizations for first character search and single
846 character iterators.
847
848 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
849 Patch by Daniel Richard G.
850
851 3. Single character iterator optimizations in the JIT compiler.
852
853 4. Improved JIT compiler optimizations for character ranges.
854
855 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
856 Reported by Giuseppe D'Angelo.
857
858 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
859 of a line, was being set incorrectly in cases where .* appeared inside
860 atomic brackets at the start of a pattern, or where there was a subsequent
861 *PRUNE or *SKIP.
862
863 7. Improved instruction cache flush for POWER/PowerPC.
864 Patch by Daniel Richard G.
865
866 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
867 grep:
868
869 (a) There is now no limit to the number of patterns to be matched.
870
871 (b) An error is given if a pattern is too long.
872
873 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
874 are now supported.
875
876 (d) --exclude-from and --include-from (multiple use) have been added.
877
878 (e) Exclusions and inclusions now apply to all files and directories, not
879 just to those obtained from scanning a directory recursively.
880
881 (f) Multiple uses of -f and --file-list are now supported.
882
883 (g) In a Windows environment, the default for -d has been changed from
884 "read" (the GNU grep default) to "skip", because otherwise the presence
885 of a directory in the file list provokes an error.
886
887 (h) The documentation has been revised and clarified in places.
888
889 9. Improve the matching speed of capturing brackets.
890
891 10. Changed the meaning of \X so that it now matches a Unicode extended
892 grapheme cluster.
893
894 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
895 out POSIX threads when JIT support is configured.
896
897 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
898
899 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
900 structure could go wrong in environments where size_t is not the same size
901 as int.
902
903 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
904 set.
905
906 15. The EBCDIC support had decayed; later updates to the code had included
907 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
908 general tidy up of EBCDIC-related issues, and the documentation was also
909 not quite right. There is now a test that can be run on ASCII systems to
910 check some of the EBCDIC-related things (but is it not a full test).
911
912 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
913 in a small tidy to the code.
914
915 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
916
917 18. If the --only-matching (-o) option in pcregrep is specified multiple
918 times, each one causes appropriate output. For example, -o1 -o2 outputs the
919 substrings matched by the 1st and 2nd capturing parentheses. A separating
920 string can be specified by --om-separator (default empty).
921
922 19. Improving the first n character searches.
923
924 20. Turn case lists for horizontal and vertical white space into macros so that
925 they are defined only once.
926
927 21. This set of changes together give more compatible Unicode case-folding
928 behaviour for characters that have more than one other case when UCP
929 support is available.
930
931 (a) The Unicode property table now has offsets into a new table of sets of
932 three or more characters that are case-equivalent. The MultiStage2.py
933 script that generates these tables (the pcre_ucd.c file) now scans
934 CaseFolding.txt instead of UnicodeData.txt for character case
935 information.
936
937 (b) The code for adding characters or ranges of characters to a character
938 class has been abstracted into a generalized function that also handles
939 case-independence. In UTF-mode with UCP support, this uses the new data
940 to handle characters with more than one other case.
941
942 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
943 whose other case is greater than 256 are now correctly matched
944 caselessly. Previously, the high codepoint matched the low one, but not
945 vice versa.
946
947 (d) The processing of \h, \H, \v, and \ in character classes now makes use
948 of the new class addition function, using character lists defined as
949 macros alongside the case definitions of 20 above.
950
951 (e) Caseless back references now work with characters that have more than
952 one other case.
953
954 (f) General caseless matching of characters with more than one other case
955 is supported.
956
957 22. Unicode character properties were updated from Unicode 6.2.0
958
959 23. Improved CMake support under Windows. Patch by Daniel Richard G.
960
961 24. Add support for 32-bit character strings, and UTF-32
962
963 25. Major JIT compiler update (code refactoring and bugfixing).
964 Experimental Sparc 32 support is added.
965
966 26. Applied a modified version of Daniel Richard G's patch to create
967 pcre.h.generic and config.h.generic by "make" instead of in the
968 PrepareRelease script.
969
970 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
971 pcre_compile.c when checking for a zero character.
972
973 28. Introducing a native interface for JIT. Through this interface, the compiled
974 machine code can be directly executed. The purpose of this interface is to
975 provide fast pattern matching, so several sanity checks are not performed.
976 However, feature tests are still performed. The new interface provides
977 1.4x speedup compared to the old one.
978
979 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
980 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
981 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
982
983 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
984 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
985 the "old" RFC 2279). Instead, it ended up passing a negative length to
986 pcre_exec().
987
988 31. Add support for GCC's visibility feature to hide internal functions.
989
990 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
991 "unknown -C option" after outputting 0 or 1.
992
993 33. There is now support for generating a code coverage report for the test
994 suite in environments where gcc is the compiler and lcov is installed. This
995 is mainly for the benefit of the developers.
996
997 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
998 unaddressable using valgrind annotations, allowing valgrind to detect
999 invalid memory accesses. This is mainly for the benefit of the developers.
1000
1001 25. (*UTF) can now be used to start a pattern in any of the three libraries.
1002
1003 26. Give configure error if --enable-cpp but no C++ compiler found.
1004
1005
1006 Version 8.31 06-July-2012
1007 -------------------------
1008
1009 1. Fixing a wrong JIT test case and some compiler warnings.
1010
1011 2. Removed a bashism from the RunTest script.
1012
1013 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1014 to unsigned type, result still unsigned" that was given by an MS compiler
1015 on encountering the code "-sizeof(xxx)".
1016
1017 4. Partial matching support is added to the JIT compiler.
1018
1019 5. Fixed several bugs concerned with partial matching of items that consist
1020 of more than one character:
1021
1022 (a) /^(..)\1/ did not partially match "aba" because checking references was
1023 done on an "all or nothing" basis. This also applied to repeated
1024 references.
1025
1026 (b) \R did not give a hard partial match if \r was found at the end of the
1027 subject.
1028
1029 (c) \X did not give a hard partial match after matching one or more
1030 characters at the end of the subject.
1031
1032 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1033 a partial match for the string "\r".
1034
1035 (e) When newline was set to CRLF, the metacharacter "." did not recognize
1036 a partial match for a CR character at the end of the subject string.
1037
1038 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1039 running pcretest, the text "(JIT)" added to the output whenever JIT is
1040 actually used to run the match.
1041
1042 7. Individual JIT compile options can be set in pcretest by following -s+[+]
1043 or /S+[+] with a digit between 1 and 7.
1044
1045 8. OP_NOT now supports any UTF character not just single-byte ones.
1046
1047 9. (*MARK) control verb is now supported by the JIT compiler.
1048
1049 10. The command "./RunTest list" lists the available tests without actually
1050 running any of them. (Because I keep forgetting what they all are.)
1051
1052 11. Add PCRE_INFO_MAXLOOKBEHIND.
1053
1054 12. Applied a (slightly modified) user-supplied patch that improves performance
1055 when the heap is used for recursion (compiled with --disable-stack-for-
1056 recursion). Instead of malloc and free for each heap frame each time a
1057 logical recursion happens, frames are retained on a chain and re-used where
1058 possible. This sometimes gives as much as 30% improvement.
1059
1060 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1061 call.
1062
1063 14. As documented, (*COMMIT) is now confined to within a positive assertion.
1064
1065 15. It is now possible to link pcretest with libedit as an alternative to
1066 libreadline.
1067
1068 16. (*COMMIT) control verb is now supported by the JIT compiler.
1069
1070 17. The Unicode data tables have been updated to Unicode 6.1.0.
1071
1072 18. Added --file-list option to pcregrep.
1073
1074 19. Added binary file support to pcregrep, including the -a, --binary-files,
1075 -I, and --text options.
1076
1077 20. The madvise function is renamed for posix_madvise for QNX compatibility
1078 reasons. Fixed by Giuseppe D'Angelo.
1079
1080 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1081
1082 22. Changed the option for creating symbolic links for 16-bit man pages from
1083 -s to -sf so that re-installing does not cause issues.
1084
1085 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1086
1087 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1088 matches in certain environments (the workspace was not being correctly
1089 retained). Also added to pcre_dfa_exec() a simple plausibility check on
1090 some of the workspace data at the beginning of a restart.
1091
1092 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1093 was not doing so when it should - probably a typo introduced by SVN 528
1094 (change 8.10/14).
1095
1096 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1097 \w+ when the character tables indicated that \x{c4} was a word character.
1098 There were several related cases, all because the tests for doing a table
1099 lookup were testing for characters less than 127 instead of 255.
1100
1101 27. If a pattern contains capturing parentheses that are not used in a match,
1102 their slots in the ovector are set to -1. For those that are higher than
1103 any matched groups, this happens at the end of processing. In the case when
1104 there were back references that the ovector was too small to contain
1105 (causing temporary malloc'd memory to be used during matching), and the
1106 highest capturing number was not used, memory off the end of the ovector
1107 was incorrectly being set to -1. (It was using the size of the temporary
1108 memory instead of the true size.)
1109
1110 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1111 ovector size, it uses memory at the end of the block that it has got.
1112
1113 29. Check for an overlong MARK name and give an error at compile time. The
1114 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1115
1116 30. JIT compiler update.
1117
1118 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1119 Rill for the patch.
1120
1121 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1122
1123 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1124
1125 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1126 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1127 was enabled.
1128
1129 35. Improve JIT code generation for greedy plus quantifier.
1130
1131 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1132 1 to "aa" instead of to an empty string. The bug affected repeated groups
1133 that could potentially match an empty string.
1134
1135 37. Optimizing single character iterators in JIT.
1136
1137 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1138 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1139 codepoints that are too big for the mode are faulted, and in a UTF mode,
1140 disallowed codepoints are also faulted.
1141
1142 39. If PCRE was compiled with UTF support, in three places in the DFA
1143 matcher there was code that should only have been obeyed in UTF mode, but
1144 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1145 processing when bytes with values greater than 127 were present. In 16-bit
1146 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1147 both cases the values are those that cannot be the first data item in a UTF
1148 character. The three items that might have provoked this were recursions,
1149 possessively repeated groups, and atomic groups.
1150
1151 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1152 and pcregrep, because some OS require shared objects to be explicitly
1153 passed to ld, causing the link step to fail if they are not.
1154
1155 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1156 mode, patterns that started with \h* or \R* might be incorrectly matched.
1157
1158
1159 Version 8.30 04-February-2012
1160 -----------------------------
1161
1162 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
1163 name is defined in ctype.h.
1164
1165 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
1166 only in quite long subpatterns.
1167
1168 3. Removed the function pcre_info(), which has been obsolete and deprecated
1169 since it was replaced by pcre_fullinfo() in February 2000.
1170
1171 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
1172 match a (*MARK), and the match failed at the start of the subject, a
1173 reference to memory before the start of the subject could occur. This bug
1174 was introduced by fix 17 of release 8.21.
1175
1176 5. A reference to an unset group with zero minimum repetition was giving
1177 totally wrong answers (in non-JavaScript-compatibility mode). For example,
1178 /(another)?(\1?)test/ matched against "hello world test". This bug was
1179 introduced in release 8.13.
1180
1181 6. Add support for 16-bit character strings (a large amount of work involving
1182 many changes and refactorings).
1183
1184 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1185 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1186 from a file.
1187
1188 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1189 rounding is not applied in this particular case).
1190
1191 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1192 if they appear, or are escaped, in patterns.
1193
1194 10. Get rid of a number of -Wunused-but-set-variable warnings.
1195
1196 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1197 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1198 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1199 also returns the mark "x". This bug applied to capturing parentheses,
1200 non-capturing parentheses, and atomic parentheses. It also applied to some
1201 assertions.
1202
1203 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1204 information out of configure.ac instead of relying on pcre.h.generic, which
1205 is not stored in the repository.
1206
1207 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1208 -lreadline.
1209
1210 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1211
1212 15. Applied Graycode's patch to put the top-level frame on the stack rather
1213 than the heap when not using the stack for recursion. This gives a
1214 performance improvement in many cases when recursion is not deep.
1215
1216 16. Experimental code added to "pcretest -C" to output the stack frame size.
1217
1218
1219 Version 8.21 12-Dec-2011
1220 ------------------------
1221
1222 1. Updating the JIT compiler.
1223
1224 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1225 are added as well.
1226
1227 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1228 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1229 calling _pcre_jit_exec. Some extra comments are added.
1230
1231 4. (*MARK) settings inside atomic groups that do not contain any capturing
1232 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1233 was introduced by change 18 for 8.20.
1234
1235 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1236 ECMA-262 standard.
1237
1238 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1239 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1240 This bug was probably introduced by change 9 of 8.13.
1241
1242 7. While fixing 6 above, I noticed that a number of other items were being
1243 incorrectly rejected as "not fixed length". This arose partly because newer
1244 opcodes had not been added to the fixed-length checking code. I have (a)
1245 corrected the bug and added tests for these items, and (b) arranged for an
1246 error to occur if an unknown opcode is encountered while checking for fixed
1247 length instead of just assuming "not fixed length". The items that were
1248 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1249 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1250 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1251
1252 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1253 being incorrectly compiled and would have given unpredicatble results.
1254
1255 9. A possessively repeated subpattern with minimum repeat count greater than
1256 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1257 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1258 the first (A) could occur when it should not.
1259
1260 10. Add a cast and remove a redundant test from the code.
1261
1262 11. JIT should use pcre_malloc/pcre_free for allocation.
1263
1264 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1265 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1266 is anything other than /usr, -L is still shown).
1267
1268 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1269
1270 14. Perl does not support \N without a following name in a [] class; PCRE now
1271 also gives an error.
1272
1273 15. If a forward reference was repeated with an upper limit of around 2000,
1274 it caused the error "internal error: overran compiling workspace". The
1275 maximum number of forward references (including repeats) was limited by the
1276 internal workspace, and dependent on the LINK_SIZE. The code has been
1277 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1278 the default depends on LINK_SIZE. There is a new upper limit (for safety)
1279 of around 200,000 forward references. While doing this, I also speeded up
1280 the filling in of repeated forward references.
1281
1282 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1283 incorrectly expecting the subject to contain another "a" after the start.
1284
1285 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1286 in the match, the SKIP should be ignored. This was not happening; instead
1287 the SKIP was being treated as NOMATCH. For patterns such as
1288 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1289 tested.
1290
1291 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1292 now much more compatible with Perl, in particular in cases where the result
1293 is a non-match for a non-anchored pattern. For example, if
1294 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1295 "m", where previously it did not return a name. A side effect of this
1296 change is that for partial matches, the last encountered mark name is
1297 returned, as for non matches. A number of tests that were previously not
1298 Perl-compatible have been moved into the Perl-compatible test files. The
1299 refactoring has had the pleasing side effect of removing one argument from
1300 the match() function, thus reducing its stack requirements.
1301
1302 19. If the /S+ option was used in pcretest to study a pattern using JIT,
1303 subsequent uses of /S (without +) incorrectly behaved like /S+.
1304
1305 21. Retrieve executable code size support for the JIT compiler and fixing
1306 some warnings.
1307
1308 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1309 not work when the shorter character appeared right at the end of the
1310 subject string.
1311
1312 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1313 systems.
1314
1315 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1316 output it when the /M option is used in pcretest.
1317
1318 25. The CheckMan script was not being included in the distribution. Also, added
1319 an explicit "perl" to run Perl scripts from the PrepareRelease script
1320 because this is reportedly needed in Windows.
1321
1322 26. If study data was being save in a file and studying had not found a set of
1323 "starts with" bytes for the pattern, the data written to the file (though
1324 never used) was taken from uninitialized memory and so caused valgrind to
1325 complain.
1326
1327 27. Updated RunTest.bat as provided by Sheri Pierce.
1328
1329 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1330
1331 29. Computation of memory usage for the table of capturing group names was
1332 giving an unnecessarily large value.
1333
1334
1335 Version 8.20 21-Oct-2011
1336 ------------------------
1337
1338 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1339 a POSIX class. After further experiments with Perl, which convinced me that
1340 Perl has bugs and confusions, a closing square bracket is no longer allowed
1341 in a POSIX name. This bug also affected patterns with classes that started
1342 with full stops.
1343
1344 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1345 captured substring, but while checking the failing first alternative,
1346 substring 1 is temporarily captured. If the output vector supplied to
1347 pcre_exec() was not big enough for this capture, the yield of the function
1348 was still zero ("insufficient space for captured substrings"). This cannot
1349 be totally fixed without adding another stack variable, which seems a lot
1350 of expense for a edge case. However, I have improved the situation in cases
1351 such as /(a)(b)x|abc/ matched against "abc", where the return code
1352 indicates that fewer than the maximum number of slots in the ovector have
1353 been set.
1354
1355 3. Related to (2) above: when there are more back references in a pattern than
1356 slots in the output vector, pcre_exec() uses temporary memory during
1357 matching, and copies in the captures as far as possible afterwards. It was
1358 using the entire output vector, but this conflicts with the specification
1359 that only 2/3 is used for passing back captured substrings. Now it uses
1360 only the first 2/3, for compatibility. This is, of course, another edge
1361 case.
1362
1363 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
1364 main code base, and can be used by building with --enable-jit. When this is
1365 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1366 runtime --no-jit option is given.
1367
1368 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
1369 ovector, the return from the function was zero, implying that there were
1370 other matches that did not fit. The correct "exactly full" value is now
1371 returned.
1372
1373 6. If a subpattern that was called recursively or as a subroutine contained
1374 (*PRUNE) or any other control that caused it to give a non-standard return,
1375 invalid errors such as "Error -26 (nested recursion at the same subject
1376 position)" or even infinite loops could occur.
1377
1378 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1379 computing the minimum length on reaching *ACCEPT, and so ended up with the
1380 wrong value of 1 rather than 0. Further investigation indicates that
1381 computing a minimum subject length in the presence of *ACCEPT is difficult
1382 (think back references, subroutine calls), and so I have changed the code
1383 so that no minimum is registered for a pattern that contains *ACCEPT.
1384
1385 8. If (*THEN) was present in the first (true) branch of a conditional group,
1386 it was not handled as intended. [But see 16 below.]
1387
1388 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1389 Sheri Pierce.
1390
1391 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1392 the first byte in a match must be "a".
1393
1394 11. Change 17 for 8.13 increased the recursion depth for patterns like
1395 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1396 pattern contains any instances of (*THEN). If it does not, the old
1397 optimizations are restored. It would be nice to do this on a per-group
1398 basis, but at the moment that is not feasible.
1399
1400 12. In some environments, the output of pcretest -C is CRLF terminated. This
1401 broke RunTest's code that checks for the link size. A single white space
1402 character after the value is now allowed for.
1403
1404 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1405 For "fr", it uses the Windows-specific input and output files.
1406
1407 14. If (*THEN) appeared in a group that was called recursively or as a
1408 subroutine, it did not work as intended. [But see next item.]
1409
1410 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1411 pattern fragments (but not containing any | characters). If A and B are
1412 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1413 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1414 D. In other words, Perl considers parentheses that do not contain any |
1415 characters to be part of a surrounding alternative, whereas PCRE was
1416 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1417 differently. PCRE now behaves in the same way as Perl, except in the case
1418 of subroutine/recursion calls such as (?1) which have in any case always
1419 been different (but PCRE had them first :-).
1420
1421 16. Related to 15 above: Perl does not treat the | in a conditional group as
1422 creating alternatives. Such a group is treated in the same way as an
1423 ordinary group without any | characters when processing (*THEN). PCRE has
1424 been changed to match Perl's behaviour.
1425
1426 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1427 RunGrepTest script failed.
1428
1429 18. Change 22 for version 13 caused atomic groups to use more stack. This is
1430 inevitable for groups that contain captures, but it can lead to a lot of
1431 stack use in large patterns. The old behaviour has been restored for atomic
1432 groups that do not contain any capturing parentheses.
1433
1434 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1435 suppress the check for a minimum subject length at run time. (If it was
1436 given to pcre_exec() or pcre_dfa_exec() it did work.)
1437
1438 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1439 fail to work when decoding hex characters in data strings in EBCDIC
1440 environments.
1441
1442 21. It appears that in at least one Mac OS environment, the isxdigit() function
1443 is implemented as a macro that evaluates to its argument more than once,
1444 contravening the C 90 Standard (I haven't checked a later standard). There
1445 was an instance in pcretest which caused it to go wrong when processing
1446 \x{...} escapes in subject strings. The has been rewritten to avoid using
1447 things like p++ in the argument of isxdigit().
1448
1449
1450 Version 8.13 16-Aug-2011
1451 ------------------------
1452
1453 1. The Unicode data tables have been updated to Unicode 6.0.0.
1454
1455 2. Two minor typos in pcre_internal.h have been fixed.
1456
1457 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1458 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1459 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1460
1461 4. There were a number of related bugs in the code for matching backrefences
1462 caselessly in UTF-8 mode when codes for the characters concerned were
1463 different numbers of bytes. For example, U+023A and U+2C65 are an upper
1464 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1465 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1466 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1467 2-byte code at the end of the subject (it thought there wasn't enough data
1468 left).
1469
1470 5. Comprehensive information about what went wrong is now returned by
1471 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1472 as the output vector has at least 2 elements. The offset of the start of
1473 the failing character and a reason code are placed in the vector.
1474
1475 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
1476 now returned is for the first byte of the failing character, instead of the
1477 last byte inspected. This is an incompatible change, but I hope it is small
1478 enough not to be a problem. It makes the returned offset consistent with
1479 pcre_exec() and pcre_dfa_exec().
1480
1481 7. pcretest now gives a text phrase as well as the error number when
1482 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1483 failure, the offset and reason code are output.
1484
1485 8. When \R was used with a maximizing quantifier it failed to skip backwards
1486 over a \r\n pair if the subsequent match failed. Instead, it just skipped
1487 back over a single character (\n). This seems wrong (because it treated the
1488 two characters as a single entity when going forwards), conflicts with the
1489 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1490 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1491 has been changed.
1492
1493 9. Some internal refactoring has changed the processing so that the handling
1494 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1495 time (the PCRE_DOTALL option was changed this way some time ago: version
1496 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1497 which was always a bit of a fudge. It also means that there is one less
1498 argument for the match() function, which reduces its stack requirements
1499 slightly. This change also fixes an incompatibility with Perl: the pattern
1500 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1501
1502 10. More internal refactoring has drastically reduced the number of recursive
1503 calls to match() for possessively repeated groups such as (abc)++ when
1504 using pcre_exec().
1505
1506 11. While implementing 10, a number of bugs in the handling of groups were
1507 discovered and fixed:
1508
1509 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1510 (a|)*(?1) gave a compile-time internal error.
1511 ((a|)+)+ did not notice that the outer group could match an empty string.
1512 (^a|^)+ was not marked as anchored.
1513 (.*a|.*)+ was not marked as matching at start or after a newline.
1514
1515 12. Yet more internal refactoring has removed another argument from the match()
1516 function. Special calls to this function are now indicated by setting a
1517 value in a variable in the "match data" data block.
1518
1519 13. Be more explicit in pcre_study() instead of relying on "default" for
1520 opcodes that mean there is no starting character; this means that when new
1521 ones are added and accidentally left out of pcre_study(), testing should
1522 pick them up.
1523
1524 14. The -s option of pcretest has been documented for ages as being an old
1525 synonym of -m (show memory usage). I have changed it to mean "force study
1526 for every regex", that is, assume /S for every regex. This is similar to -i
1527 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1528 using it. It makes it easier to run collections of tests with and without
1529 study enabled, and thereby test pcre_study() more easily. All the standard
1530 tests are now run with and without -s (but some patterns can be marked as
1531 "never study" - see 20 below).
1532
1533 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1534 restoration of the capturing data to the outer values was not happening
1535 correctly.
1536
1537 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1538 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1539 pattern had matched an empty string, and so incorrectly returned a no
1540 match.
1541
1542 17. There was optimizing code for the last branch of non-capturing parentheses,
1543 and also for the obeyed branch of a conditional subexpression, which used
1544 tail recursion to cut down on stack usage. Unfortunately, now that there is
1545 the possibility of (*THEN) occurring in these branches, tail recursion is
1546 no longer possible because the return has to be checked for (*THEN). These
1547 two optimizations have therefore been removed. [But see 8.20/11 above.]
1548
1549 18. If a pattern containing \R was studied, it was assumed that \R always
1550 matched two bytes, thus causing the minimum subject length to be
1551 incorrectly computed because \R can also match just one byte.
1552
1553 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1554 was incorrectly computed.
1555
1556 20. If /S is present twice on a test pattern in pcretest input, it now
1557 *disables* studying, thereby overriding the use of -s on the command line
1558 (see 14 above). This is necessary for one or two tests to keep the output
1559 identical in both cases.
1560
1561 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1562 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1563
1564 22. When an atomic group that contained a capturing parenthesis was
1565 successfully matched, but the branch in which it appeared failed, the
1566 capturing was not being forgotten if a higher numbered group was later
1567 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1568 group 1 to "a", when in fact it should be unset. This applied to multi-
1569 branched capturing and non-capturing groups, repeated or not, and also to
1570 positive assertions (capturing in negative assertions does not happen
1571 in PCRE) and also to nested atomic groups.
1572
1573 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1574 subject after a captured substring, to make it easier to tell which of a
1575 number of identical substrings has been captured.
1576
1577 24. The way atomic groups are processed by pcre_exec() has been changed so that
1578 if they are repeated, backtracking one repetition now resets captured
1579 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1580 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1581 "aaa". Previously, it would have been "a". As part of this code
1582 refactoring, the way recursive calls are handled has also been changed.
1583
1584 25. If an assertion condition captured any substrings, they were not passed
1585 back unless some other capturing happened later. For example, if
1586 (?(?=(a))a) was matched against "a", no capturing was returned.
1587
1588 26. When studying a pattern that contained subroutine calls or assertions,
1589 the code for finding the minimum length of a possible match was handling
1590 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1591 group 1 called group 2 while simultaneously a separate group 2 called group
1592 1). A stack overflow occurred in this case. I have fixed this by limiting
1593 the recursion depth to 10.
1594
1595 27. Updated RunTest.bat in the distribution to the version supplied by Tom
1596 Fortmann. This supports explicit test numbers on the command line, and has
1597 argument validation and error reporting.
1598
1599 28. An instance of \X with an unlimited repeat could fail if at any point the
1600 first character it looked at was a mark character.
1601
1602 29. Some minor code refactoring concerning Unicode properties and scripts
1603 should reduce the stack requirement of match() slightly.
1604
1605 30. Added the '=' option to pcretest to check the setting of unused capturing
1606 slots at the end of the pattern, which are documented as being -1, but are
1607 not included in the return count.
1608
1609 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1610 compiled something random. Now it gives a compile-time error (as does
1611 Perl).
1612
1613 32. A *MARK encountered during the processing of a positive assertion is now
1614 recorded and passed back (compatible with Perl).
1615
1616 33. If --only-matching or --colour was set on a pcregrep call whose pattern
1617 had alternative anchored branches, the search for a second match in a line
1618 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1619 matched the line "0102" twice. The same bug affected patterns that started
1620 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1621 twice.
1622
1623 34. Previously, PCRE did not allow quantification of assertions. However, Perl
1624 does, and because of capturing effects, quantifying parenthesized
1625 assertions may at times be useful. Quantifiers are now allowed for
1626 parenthesized assertions.
1627
1628 35. A minor code tidy in pcre_compile() when checking options for \R usage.
1629
1630 36. \g was being checked for fancy things in a character class, when it should
1631 just be a literal "g".
1632
1633 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1634 appearance of a nested POSIX class supersedes an apparent external class.
1635 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1636 unescaped square brackets may also appear as part of class names. For
1637 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1638 more like Perl. (But see 8.20/1 above.)
1639
1640 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1641 was because it thought it was \N{name}, which is not supported).
1642
1643 39. Add minix to OS list not supporting the -S option in pcretest.
1644
1645 40. PCRE tries to detect cases of infinite recursion at compile time, but it
1646 cannot analyze patterns in sufficient detail to catch mutual recursions
1647 such as ((?1))((?2)). There is now a runtime test that gives an error if a
1648 subgroup is called recursively as a subpattern for a second time at the
1649 same position in the subject string. In previous releases this might have
1650 been caught by the recursion limit, or it might have run out of stack.
1651
1652 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1653 happen only once. PCRE was, however incorrectly giving a compile time error
1654 "recursive call could loop indefinitely" because it cannot analyze the
1655 pattern in sufficient detail. The compile time test no longer happens when
1656 PCRE is compiling a conditional subpattern, but actual runaway loops are
1657 now caught at runtime (see 40 above).
1658
1659 42. It seems that Perl allows any characters other than a closing parenthesis
1660 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1661 has been changed to be the same.
1662
1663 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1664 as not to get warnings when autogen.sh is called. Also changed
1665 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1666
1667 44. To help people who use pcregrep to scan files containing exceedingly long
1668 lines, the following changes have been made:
1669
1670 (a) The default value of the buffer size parameter has been increased from
1671 8K to 20K. (The actual buffer used is three times this size.)
1672
1673 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1674 PCRE is built.
1675
1676 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1677 to be set at run time.
1678
1679 (d) Numerical values in pcregrep options can be followed by K or M, for
1680 example --buffer-size=50K.
1681
1682 (e) If a line being scanned overflows pcregrep's buffer, an error is now
1683 given and the return code is set to 2.
1684
1685 45. Add a pointer to the latest mark to the callout data block.
1686
1687 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1688 partial match of an empty string instead of no match. This was specific to
1689 the use of ".".
1690
1691 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1692 complete match instead of a partial match. This bug was dependent on both
1693 the PCRE_UTF8 and PCRE_DOTALL options being set.
1694
1695 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1696 starting byte set, because \b was not being ignored.
1697
1698
1699 Version 8.12 15-Jan-2011
1700 ------------------------
1701
1702 1. Fixed some typos in the markup of the man pages, and wrote a script that
1703 checks for such things as part of the documentation building process.
1704
1705 2. On a big-endian 64-bit system, pcregrep did not correctly process the
1706 --match-limit and --recursion-limit options (added for 8.11). In
1707 particular, this made one of the standard tests fail. (The integer value
1708 went into the wrong half of a long int.)
1709
1710 3. If the --colour option was given to pcregrep with -v (invert match), it
1711 did strange things, either producing crazy output, or crashing. It should,
1712 of course, ignore a request for colour when reporting lines that do not
1713 match.
1714
1715 4. Another pcregrep bug caused similar problems if --colour was specified with
1716 -M (multiline) and the pattern match finished with a line ending.
1717
1718 5. In pcregrep, when a pattern that ended with a literal newline sequence was
1719 matched in multiline mode, the following line was shown as part of the
1720 match. This seems wrong, so I have changed it.
1721
1722 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
1723 the check for further matches in the same line (so they could be coloured)
1724 to overrun the end of the current line. If another match was found, it was
1725 incorrectly shown (and then shown again when found in the next line).
1726
1727 7. If pcregrep was compiled under Windows, there was a reference to the
1728 function pcregrep_exit() before it was defined. I am assuming this was
1729 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1730 reported by a user. I've moved the definition above the reference.
1731
1732
1733 Version 8.11 10-Dec-2010
1734 ------------------------
1735
1736 1. (*THEN) was not working properly if there were untried alternatives prior
1737 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1738 backtracked to try for "b" instead of moving to the next alternative branch
1739 at the same level (in this case, to look for "c"). The Perl documentation
1740 is clear that when (*THEN) is backtracked onto, it goes to the "next
1741 alternative in the innermost enclosing group".
1742
1743 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1744 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
1745 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1746 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1747 (*THEN).
1748
1749 3. If \s appeared in a character class, it removed the VT character from
1750 the class, even if it had been included by some previous item, for example
1751 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1752 of \s, but is part of the POSIX "space" class.)
1753
1754 4. A partial match never returns an empty string (because you can always
1755 match an empty string at the end of the subject); however the checking for
1756 an empty string was starting at the "start of match" point. This has been
1757 changed to the "earliest inspected character" point, because the returned
1758 data for a partial match starts at this character. This means that, for
1759 example, /(?<=abc)def/ gives a partial match for the subject "abc"
1760 (previously it gave "no match").
1761
1762 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1763 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1764 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1765 has an implication that the given string is incomplete (because a partial
1766 match is preferred over a full match). For this reason, these items now
1767 give a partial match in this situation. [Aside: previously, the one case
1768 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1769 match rather than a full match, which was wrong by the old rules, but is
1770 now correct.]
1771
1772 6. There was a bug in the handling of #-introduced comments, recognized when
1773 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1774 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1775 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1776 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1777 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1778 places in pcre_compile().
1779
1780 7. Related to (6) above, when pcre_compile() was skipping #-introduced
1781 comments when looking ahead for named forward references to subpatterns,
1782 the only newline sequence it recognized was NL. It now handles newlines
1783 according to the set newline convention.
1784
1785 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1786 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1787 cater for a lack of strerror(). These oversights have been fixed.
1788
1789 9. Added --match-limit and --recursion-limit to pcregrep.
1790
1791 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1792
1793 11. When the -o option was used, pcregrep was setting a return code of 1, even
1794 when matches were found, and --line-buffered was not being honoured.
1795
1796 12. Added an optional parentheses number to the -o and --only-matching options
1797 of pcregrep.
1798
1799 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1800 can match an empty string. The code to do it in pcretest and pcredemo
1801 needed fixing:
1802
1803 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1804 only one byte after an empty string match just before CRLF (this case
1805 just got forgotten; "any" and "anycrlf" were OK).
1806
1807 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1808 mode when an empty string match preceded an ASCII character followed by
1809 a non-ASCII character. (The code for advancing by one character rather
1810 than one byte was nonsense.)
1811
1812 (c) The pcredemo.c sample program did not have any code at all to handle
1813 the cases when CRLF is a valid newline sequence.
1814
1815 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1816 as a starting offset was within the subject string. There is now a new
1817 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1818 negative or greater than the length of the string. In order to test this,
1819 pcretest is extended to allow the setting of negative starting offsets.
1820
1821 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1822 starting offset points to the beginning of a UTF-8 character was
1823 unnecessarily clumsy. I tidied it up.
1824
1825 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1826 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1827
1828 17. Nobody had reported that the --include_dir option, which was added in
1829 release 7.7 should have been called --include-dir (hyphen, not underscore)
1830 for compatibility with GNU grep. I have changed it to --include-dir, but
1831 left --include_dir as an undocumented synonym, and the same for
1832 --exclude-dir, though that is not available in GNU grep, at least as of
1833 release 2.5.4.
1834
1835 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1836 characters from a string of bytes) have been redefined so as not to use
1837 loops, in order to improve performance in some environments. At the same
1838 time, I abstracted some of the common code into auxiliary macros to save
1839 repetition (this should not affect the compiled code).
1840
1841 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1842 compile-time error is now given if \c is not followed by an ASCII
1843 character, that is, a byte less than 128. (In EBCDIC mode, the code is
1844 different, and any byte value is allowed.)
1845
1846 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1847 START_OPTIMIZE option, which is now allowed at compile time - but just
1848 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1849 to pcregrep and other applications that have no direct access to PCRE
1850 options. The new /Y option in pcretest sets this option when calling
1851 pcre_compile().
1852
1853 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1854 back references. Groups containing recursive back references were forced to
1855 be atomic by that change, but in the case of named groups, the amount of
1856 memory required was incorrectly computed, leading to "Failed: internal
1857 error: code overflow". This has been fixed.
1858
1859 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1860 pcretest.c, to avoid build problems in some Borland environments.
1861
1862
1863 Version 8.10 25-Jun-2010
1864 ------------------------
1865
1866 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1867 THEN.
1868
1869 2. (*ACCEPT) was not working when inside an atomic group.
1870
1871 3. Inside a character class, \B is treated as a literal by default, but
1872 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1873 causes the error). The code is unchanged, but I tidied the documentation.
1874
1875 4. Inside a character class, PCRE always treated \R and \X as literals,
1876 whereas Perl faults them if its -w option is set. I have changed PCRE so
1877 that it faults them when PCRE_EXTRA is set.
1878
1879 5. Added support for \N, which always matches any character other than
1880 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1881
1882 6. When compiling pcregrep with newer versions of gcc which may have
1883 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1884 declared with attribute warn_unused_result" were given. Just casting the
1885 result to (void) does not stop the warnings; a more elaborate fudge is
1886 needed. I've used a macro to implement this.
1887
1888 7. Minor change to pcretest.c to avoid a compiler warning.
1889
1890 8. Added four artifical Unicode properties to help with an option to make
1891 \s etc use properties (see next item). The new properties are: Xan
1892 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1893
1894 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1895 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1896 this option. Modified pcretest to add /W to test this facility. Added
1897 REG_UCP to make it available via the POSIX interface.
1898
1899 10. Added --line-buffered to pcregrep.
1900
1901 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1902 studied, and the match started with a letter with a code point greater than
1903 127 whose first byte was different to the first byte of the other case of
1904 the letter, the other case of this starting letter was not recognized
1905 (#976).
1906
1907 12. If a pattern that was studied started with a repeated Unicode property
1908 test, for example, \p{Nd}+, there was the theoretical possibility of
1909 setting up an incorrect bitmap of starting bytes, but fortunately it could
1910 not have actually happened in practice until change 8 above was made (it
1911 added property types that matched character-matching opcodes).
1912
1913 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1914 possible starting bytes for non-anchored patterns.
1915
1916 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1917 \R, and also a number of cases that involve Unicode properties, both
1918 explicit and implicit when PCRE_UCP is set.
1919
1920 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1921 input, it could crash or give wrong results if characters with values
1922 greater than 0xc0 were present in the subject string. (Detail: it assumed
1923 UTF-8 input when processing these items.)
1924
1925 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1926 size_t is 64-bit (#991).
1927
1928 17. Added a check for running out of memory when PCRE is compiled with
1929 --disable-stack-for-recursion (#990).
1930
1931 18. If the last data line in a file for pcretest does not have a newline on
1932 the end, a newline was missing in the output.
1933
1934 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1935 less than 128) in its various bitmaps. However, there is a facility for
1936 generating tables according to the current locale when PCRE is compiled. It
1937 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1938 characters, are recognized by isspace() and therefore were getting set in
1939 these tables, and indeed these tables seem to approximate to ISO 8859. This
1940 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1941 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1942 which of course cannot start UTF-8 characters. I have changed the code so
1943 that only real ASCII characters (less than 128) and the correct starting
1944 bytes for UTF-8 encodings are set for characters greater than 127 when in
1945 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1946 altogether.)
1947
1948 20. Added the /T option to pcretest so as to be able to run tests with non-
1949 standard character tables, thus making it possible to include the tests
1950 used for 19 above in the standard set of tests.
1951
1952 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1953 reference to a subpattern the other side of a comment that contains an
1954 opening parenthesis caused either an internal compiling error, or a
1955 reference to the wrong subpattern.
1956
1957
1958 Version 8.02 19-Mar-2010
1959 ------------------------
1960
1961 1. The Unicode data tables have been updated to Unicode 5.2.0.
1962
1963 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
1964 configured.
1965
1966 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
1967 original author of that file, following a query about its status.
1968
1969 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
1970 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1971
1972 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1973 quantifier applied to a forward-referencing subroutine call, could compile
1974 incorrect code or give the error "internal error: previously-checked
1975 referenced subpattern not found".
1976
1977 6. Both MS Visual Studio and Symbian OS have problems with initializing
1978 variables to point to external functions. For these systems, therefore,
1979 pcre_malloc etc. are now initialized to local functions that call the
1980 relevant global functions.
1981
1982 7. There were two entries missing in the vectors called coptable and poptable
1983 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1984 I've fixed the data, and added a kludgy way of testing at compile time that
1985 the lengths are correct (equal to the number of opcodes).
1986
1987 8. Following on from 7, I added a similar kludge to check the length of the
1988 eint vector in pcreposix.c.
1989
1990 9. Error texts for pcre_compile() are held as one long string to avoid too
1991 much relocation at load time. To find a text, the string is searched,
1992 counting zeros. There was no check for running off the end of the string,
1993 which could happen if a new error number was added without updating the
1994 string.
1995
1996 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
1997
1998 11. \K was not working if it appeared in an atomic group or in a group that
1999 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
2000 \K is "not well defined" if used in an assertion. PCRE now accepts it if
2001 the assertion is positive, but not if it is negative.
2002
2003 12. Change 11 fortuitously reduced the size of the stack frame used in the
2004 "match()" function of pcre_exec.c by one pointer. Forthcoming
2005 implementation of support for (*MARK) will need an extra pointer on the
2006 stack; I have reserved it now, so that the stack frame size does not
2007 decrease.
2008
2009 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
2010 item in branch that calls a recursion is a subroutine call - as in the
2011 second branch in the above example - was incorrectly given the compile-
2012 time error "recursive call could loop indefinitely" because pcre_compile()
2013 was not correctly checking the subroutine for matching a non-empty string.
2014
2015 14. The checks for overrunning compiling workspace could trigger after an
2016 overrun had occurred. This is a "should never occur" error, but it can be
2017 triggered by pathological patterns such as hundreds of nested parentheses.
2018 The checks now trigger 100 bytes before the end of the workspace.
2019
2020 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
2021
2022
2023 Version 8.01 19-Jan-2010
2024 ------------------------
2025
2026 1. If a pattern contained a conditional subpattern with only one branch (in
2027 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
2028 computed the wrong minimum data length (which is of course zero for such
2029 subpatterns). This could cause incorrect "no match" results.
2030
2031 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
2032 the pattern is reset in the first branch, pcre_compile() failed with
2033 "internal error: code overflow at offset...". This happened only when
2034 the reset was to the original external option setting. (An optimization
2035 abstracts leading options settings into an external setting, which was the
2036 cause of this.)
2037
2038 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
2039 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
2040 assertion pattern did not match (meaning that the assertion was true), it
2041 was incorrectly treated as false if the SKIP had been reached during the
2042 matching. This also applied to assertions used as conditions.
2043
2044 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
2045 assertion subpattern, including such a pattern used as a condition,
2046 unpredictable results occurred, instead of the error return
2047 PCRE_ERROR_DFA_UITEM.
2048
2049 5. The C++ GlobalReplace function was not working like Perl for the special
2050 situation when an empty string is matched. It now does the fancy magic
2051 stuff that is necessary.
2052
2053 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
2054 removed. (These were left over from very, very early versions of PCRE.)
2055
2056 7. Some cosmetic changes to the code to make life easier when compiling it
2057 as part of something else:
2058
2059 (a) Change DEBUG to PCRE_DEBUG.
2060
2061 (b) In pcre_compile(), rename the member of the "branch_chain" structure
2062 called "current" as "current_branch", to prevent a collision with the
2063 Linux macro when compiled as a kernel module.
2064
2065 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
2066 prevent a collision with the Linux macro when compiled as a kernel
2067 module.
2068
2069 8. In pcre_compile() there are some checks for integer overflows that used to
2070 cast potentially large values to (double). This has been changed to that
2071 when building, a check for int64_t is made, and if it is found, it is used
2072 instead, thus avoiding the use of floating point arithmetic. (There is no
2073 other use of FP in PCRE.) If int64_t is not found, the fallback is to
2074 double.
2075
2076 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
2077 2005 (difference between two addresses compared to an unsigned value).
2078
2079 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
2080 custom one, because of the following reported problem in Windows:
2081
2082 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
2083 under Win32.
2084 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
2085 therefore missing the function definition.
2086 - The compiler thus generates a "C" signature for the test function.
2087 - The linker fails to find the "C" function.
2088 - PCRE fails to configure if asked to do so against libbz2.
2089
2090 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
2091 messages were output:
2092
2093 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
2094 rerunning libtoolize, to keep the correct libtool macros in-tree.
2095 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
2096
2097 I have done both of these things.
2098
2099 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
2100 most of the time, it *can* run out if it is given a pattern that contains a
2101 runaway infinite recursion. I updated the discussion in the pcrestack man
2102 page.
2103
2104 13. Now that we have gone to the x.xx style of version numbers, the minor
2105 version may start with zero. Using 08 or 09 is a bad idea because users
2106 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
2107 interpreted as invalid octal numbers. I've updated the previous comment in
2108 configure.ac, and also added a check that gives an error if 08 or 09 are
2109 used.
2110
2111 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
2112 causing partial matching to fail when the end of the subject matched \W
2113 in a UTF-8 pattern where \W was quantified with a minimum of 3.
2114
2115 15. There were some discrepancies between the declarations in pcre_internal.h
2116 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
2117 their definitions. The declarations used "const uschar *" and the
2118 definitions used USPTR. Even though USPTR is normally defined as "const
2119 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
2120 reported that: "This difference in casting confuses some C++ compilers, for
2121 example, SunCC recognizes above declarations as different functions and
2122 generates broken code for hbpcre." I have changed the declarations to use
2123 USPTR.
2124
2125 16. GNU libtool is named differently on some systems. The autogen.sh script now
2126 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
2127 (FreeBSD).
2128
2129 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
2130 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
2131 comment: "Figure out how to create a longlong from a string: strtoll and
2132 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
2133 instance, but it only takes 2 args instead of 3!"
2134
2135 18. A subtle bug concerned with back references has been fixed by a change of
2136 specification, with a corresponding code fix. A pattern such as
2137 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
2138 refers, was giving matches when it shouldn't. For example, xa=xaaa would
2139 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
2140 same bug. Such groups have to be quantified to be useful, or contained
2141 inside another quantified group. (If there's no repetition, the reference
2142 can never match.) The problem arises because, having left the group and
2143 moved on to the rest of the pattern, a later failure that backtracks into
2144 the group uses the captured value from the final iteration of the group
2145 rather than the correct earlier one. I have fixed this in PCRE by forcing
2146 any group that contains a reference to itself to be an atomic group; that
2147 is, there cannot be any backtracking into it once it has completed. This is
2148 similar to recursive and subroutine calls.
2149
2150
2151 Version 8.00 19-Oct-09
2152 ----------------------
2153
2154 1. The table for translating pcre_compile() error codes into POSIX error codes
2155 was out-of-date, and there was no check on the pcre_compile() error code
2156 being within the table. This could lead to an OK return being given in
2157 error.
2158
2159 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
2160 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
2161 in a Windows environment.
2162
2163 3. The pcregrep --count option prints the count for each file even when it is
2164 zero, as does GNU grep. However, pcregrep was also printing all files when
2165 --files-with-matches was added. Now, when both options are given, it prints
2166 counts only for those files that have at least one match. (GNU grep just
2167 prints the file name in this circumstance, but including the count seems
2168 more useful - otherwise, why use --count?) Also ensured that the
2169 combination -clh just lists non-zero counts, with no names.
2170
2171 4. The long form of the pcregrep -F option was incorrectly implemented as
2172 --fixed_strings instead of --fixed-strings. This is an incompatible change,
2173 but it seems right to fix it, and I didn't think it was worth preserving
2174 the old behaviour.
2175
2176 5. The command line items --regex=pattern and --regexp=pattern were not
2177 recognized by pcregrep, which required --regex pattern or --regexp pattern
2178 (with a space rather than an '='). The man page documented the '=' forms,
2179 which are compatible with GNU grep; these now work.
2180
2181 6. No libpcreposix.pc file was created for pkg-config; there was just
2182 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
2183
2184 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
2185 when UCP support is not needed, by modifying the Python script that
2186 generates it from Unicode data files. This should not matter if the module
2187 is correctly used as a library, but I received one complaint about 50K of
2188 unwanted data. My guess is that the person linked everything into his
2189 program rather than using a library. Anyway, it does no harm.
2190
2191 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
2192 was a minimum greater than 1 for a wide character in a possessive
2193 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
2194 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
2195 character. Chaos in the form of incorrect output or a compiling loop could
2196 result.
2197
2198 9. The restrictions on what a pattern can contain when partial matching is
2199 requested for pcre_exec() have been removed. All patterns can now be
2200 partially matched by this function. In addition, if there are at least two
2201 slots in the offset vector, the offset of the earliest inspected character
2202 for the match and the offset of the end of the subject are set in them when
2203 PCRE_ERROR_PARTIAL is returned.
2204
2205 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
2206 synonymous with PCRE_PARTIAL, for backwards compatibility, and
2207 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
2208 and may be more useful for multi-segment matching.
2209
2210 11. Partial matching with pcre_exec() is now more intuitive. A partial match
2211 used to be given if ever the end of the subject was reached; now it is
2212 given only if matching could not proceed because another character was
2213 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
2214 string "Z", which now yields "no match" instead of "partial match". In the
2215 case of pcre_dfa_exec(), "no match" is given if every matching path for the
2216 final character ended with (*FAIL).
2217
2218 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
2219 if the pattern had a "must contain" character that was already found in the
2220 earlier partial match, unless partial matching was again requested. For
2221 example, with the pattern /dog.(body)?/, the "must contain" character is
2222 "g". If the first part-match was for the string "dog", restarting with
2223 "sbody" failed. This bug has been fixed.
2224
2225 13. The string returned by pcre_dfa_exec() after a partial match has been
2226 changed so that it starts at the first inspected character rather than the
2227 first character of the match. This makes a difference only if the pattern
2228 starts with a lookbehind assertion or \b or \B (\K is not supported by
2229 pcre_dfa_exec()). It's an incompatible change, but it makes the two
2230 matching functions compatible, and I think it's the right thing to do.
2231
2232 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
2233 so that the demonstration program is easily available in environments where
2234 PCRE has not been installed from source.
2235
2236 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
2237 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
2238 library.
2239
2240 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
2241 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
2242 is not the first non-POSIX option to be added. Clearly some people find
2243 these options useful.
2244
2245 17. If a caller to the POSIX matching function regexec() passes a non-zero
2246 value for nmatch with a NULL value for pmatch, the value of
2247 nmatch is forced to zero.
2248
2249 18. RunGrepTest did not have a test for the availability of the -u option of
2250 the diff command, as RunTest does. It now checks in the same way as
2251 RunTest, and also checks for the -b option.
2252
2253 19. If an odd number of negated classes containing just a single character
2254 interposed, within parentheses, between a forward reference to a named
2255 subpattern and the definition of the subpattern, compilation crashed with
2256 an internal error, complaining that it could not find the referenced
2257 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
2258 [The bug was that it was starting one character too far in when skipping
2259 over the character class, thus treating the ] as data rather than
2260 terminating the class. This meant it could skip too much.]
2261
2262 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
2263 /g option in pcretest when the pattern contains \K, which makes it possible
2264 to have an empty string match not at the start, even when the pattern is
2265 anchored. Updated pcretest and pcredemo to use this option.
2266
2267 21. If the maximum number of capturing subpatterns in a recursion was greater
2268 than the maximum at the outer level, the higher number was returned, but
2269 with unset values at the outer level. The correct (outer level) value is
2270 now given.
2271
2272 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
2273 PCRE did not set those parentheses (unlike Perl). I have now found a way to
2274 make it do so. The string so far is captured, making this feature
2275 compatible with Perl.
2276
2277 23. The tests have been re-organized, adding tests 11 and 12, to make it
2278 possible to check the Perl 5.10 features against Perl 5.10.
2279
2280 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
2281 pattern matches a fixed length string. PCRE did not allow this; now it
2282 does. Neither allows recursion.
2283
2284 25. I finally figured out how to implement a request to provide the minimum
2285 length of subject string that was needed in order to match a given pattern.
2286 (It was back references and recursion that I had previously got hung up
2287 on.) This code has now been added to pcre_study(); it finds a lower bound
2288 to the length of subject needed. It is not necessarily the greatest lower
2289 bound, but using it to avoid searching strings that are too short does give
2290 some useful speed-ups. The value is available to calling programs via
2291 pcre_fullinfo().
2292
2293 26. While implementing 25, I discovered to my embarrassment that pcretest had
2294 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
2295 study optimizations had never been tested with that matching function.
2296 Oops. What is worse, even when it was passed study data, there was a bug in
2297 pcre_dfa_exec() that meant it never actually used it. Double oops. There
2298 were also very few tests of studied patterns with pcre_dfa_exec().
2299
2300 27. If (?| is used to create subpatterns with duplicate numbers, they are now
2301 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
2302 on the other side of the coin, they are no longer allowed to have different
2303 names, because these cannot be distinguished in PCRE, and this has caused
2304 confusion. (This is a difference from Perl.)
2305
2306 28. When duplicate subpattern names are present (necessarily with different
2307 numbers, as required by 27 above), and a test is made by name in a
2308 conditional pattern, either for a subpattern having been matched, or for
2309 recursion in such a pattern, all the associated numbered subpatterns are
2310 tested, and the overall condition is true if the condition is true for any
2311 one of them. This is the way Perl works, and is also more like the way
2312 testing by number works.
2313
2314
2315 Version 7.9 11-Apr-09
2316 ---------------------
2317
2318 1. When building with support for bzlib/zlib (pcregrep) and/or readline
2319 (pcretest), all targets were linked against these libraries. This included
2320 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
2321 libraries. This caused unwanted dependencies to be created. This problem
2322 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
2323 pcretest is linked with readline.
2324
2325 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
2326 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
2327 moved outside it again, because FALSE and TRUE are already defined in AIX,
2328 but BOOL is not.
2329
2330 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
2331 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
2332
2333 4. The pcregrep documentation said spaces were inserted as well as colons (or
2334 hyphens) following file names and line numbers when outputting matching
2335 lines. This is not true; no spaces are inserted. I have also clarified the
2336 wording for the --colour (or --color) option.
2337
2338 5. In pcregrep, when --colour was used with -o, the list of matching strings
2339 was not coloured; this is different to GNU grep, so I have changed it to be
2340 the same.
2341
2342 6. When --colo(u)r was used in pcregrep, only the first matching substring in
2343 each matching line was coloured. Now it goes on to look for further matches
2344 of any of the test patterns, which is the same behaviour as GNU grep.
2345
2346 7. A pattern that could match an empty string could cause pcregrep to loop; it
2347 doesn't make sense to accept an empty string match in pcregrep, so I have
2348 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2349 seems to be how GNU grep behaves. [But see later change 40 for release
2350 8.33.]
2351
2352 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2353 start or after a newline", because the conditional assertion was not being
2354 correctly handled. The rule now is that both the assertion and what follows
2355 in the first alternative must satisfy the test.
2356
2357 9. If auto-callout was enabled in a pattern with a conditional group whose
2358 condition was an assertion, PCRE could crash during matching, both with
2359 pcre_exec() and pcre_dfa_exec().
2360
2361 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
2362 used for matching.
2363
2364 11. Unicode property support in character classes was not working for
2365 characters (bytes) greater than 127 when not in UTF-8 mode.
2366
2367 12. Added the -M command line option to pcretest.
2368
2369 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
2370
2371 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
2372
2373 16. Added comments and documentation about mis-use of no_arg in the C++
2374 wrapper.
2375
2376 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
2377 from Martin Jerabek that uses macro names for all relevant character and
2378 string constants.
2379
2380 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
2381 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
2382 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
2383 these, but not everybody uses configure.
2384
2385 19. A conditional group that had only one branch was not being correctly
2386 recognized as an item that could match an empty string. This meant that an
2387 enclosing group might also not be so recognized, causing infinite looping
2388 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
2389 with the subject "ab", where knowledge that the repeated group can match
2390 nothing is needed in order to break the loop.
2391
2392 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
2393 exec(), but without supplying a callout function, matching went wrong.
2394
2395 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
2396 leak if the size of the offset vector was greater than 30. When the vector
2397 is smaller, the saved offsets during recursion go onto a local stack
2398 vector, but for larger vectors malloc() is used. It was failing to free
2399 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
2400 error, in fact).
2401
2402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
2403 heapframe that is used only when UTF-8 support is enabled. This caused no
2404 problem, but was untidy.
2405
2406 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
2407 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
2408 included within another project.
2409
2410 24. Steven Van Ingelgem's patches to add more options to the CMake support,
2411 slightly modified by me:
2412
2413 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
2414 not building pcregrep.
2415
2416 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
2417 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
2418
2419 25. Forward references, both numeric and by name, in patterns that made use of
2420 duplicate group numbers, could behave incorrectly or give incorrect errors,
2421 because when scanning forward to find the reference group, PCRE was not
2422 taking into account the duplicate group numbers. A pattern such as
2423 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
2424
2425 26. Changed a few more instances of "const unsigned char *" to USPTR, making
2426 the feature of a custom pointer more persuasive (as requested by a user).
2427
2428 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
2429 pcretest.c, inside #ifndefs, because it seems they are sometimes already
2430 pre-defined.
2431
2432 28. Added support for (*UTF8) at the start of a pattern.
2433
2434 29. Arrange for flags added by the "release type" setting in CMake to be shown
2435 in the configuration summary.
2436
2437
2438 Version 7.8 05-Sep-08
2439 ---------------------
2440
2441 1. Replaced UCP searching code with optimized version as implemented for Ad
2442 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
2443 stage table and inline lookup instead of a function, giving speed ups of 2
2444 to 5 times on some simple patterns that I tested. Permission was given to
2445 distribute the MultiStage2.py script that generates the tables (it's not in
2446 the tarball, but is in the Subversion repository).
2447
2448 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
2449 scripts.
2450
2451 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
2452 a group with a zero qualifier. The result of the study could be incorrect,
2453 or the function might crash, depending on the pattern.
2454
2455 4. Caseless matching was not working for non-ASCII characters in back
2456 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2457 It now works when Unicode Property Support is available.
2458
2459 5. In pcretest, an escape such as \x{de} in the data was always generating
2460 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2461 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2462 truncation.
2463
2464 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2465
2466 7. Added two (int) casts to pcregrep when printing the difference of two
2467 pointers, in case they are 64-bit values.
2468
2469 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
2470 test 2 if it fails.
2471
2472 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2473 and a #define of that name to empty if it is not externally set. This is to
2474 allow users of MSVC to set it if necessary.
2475
2476 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2477 the convenience functions in the pcre_get.c source file.
2478
2479 11. An option change at the start of a pattern that had top-level alternatives
2480 could cause overwriting and/or a crash. This command provoked a crash in
2481 some environments:
2482
2483 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2484
2485 This potential security problem was recorded as CVE-2008-2371.
2486
2487 12. For a pattern where the match had to start at the beginning or immediately
2488 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2489 pcre_dfa_exec() could read past the end of the passed subject if there was
2490 no match. To help with detecting such bugs (e.g. with valgrind), I modified
2491 pcretest so that it places the subject at the end of its malloc-ed buffer.
2492
2493 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2494 exec() might read past the end of the data buffer in UTF-8 mode.
2495
2496 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2497 the data contained the byte 0x85 as part of a UTF-8 character within its
2498 first line. This applied both to normal and DFA matching.
2499
2500 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2501 /^[^d]*?$/8 failed to match "abc".
2502
2503 16. Added a missing copyright notice to pcrecpp_internal.h.
2504
2505 17. Make it more clear in the documentation that values returned from
2506 pcre_exec() in ovector are byte offsets, not character counts.
2507
2508 18. Tidied a few places to stop certain compilers from issuing warnings.
2509
2510 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2511 supplied by Stefan Weber. I made a further small update for 7.8 because
2512 there is a change of source arrangements: the pcre_searchfuncs.c module is
2513 replaced by pcre_ucd.c.
2514
2515
2516 Version 7.7 07-May-08
2517 ---------------------
2518
2519 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2520 a string to a long long, pretend we don't even have a long long." This is
2521 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2522
2523 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2524 pre-7.6 versions, which defined a global no_arg variable instead of putting
2525 it in the RE class. (See also #8 below.)
2526
2527 3. Remove a line of dead code, identified by coverity and reported by Nuno
2528 Lopes.
2529
2530 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2531
2532 (1) The include/exclude patterns were being applied to the whole pathnames
2533 of files, instead of just to the final components.
2534
2535 (2) If there was more than one level of directory, the subdirectories were
2536 skipped unless they satisfied the include/exclude conditions. This is
2537 inconsistent with GNU grep (and could even be seen as contrary to the
2538 pcregrep specification - which I improved to make it absolutely clear).
2539 The action now is always to scan all levels of directory, and just
2540 apply the include/exclude patterns to regular files.
2541
2542 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2543 --exclude_dir in the tests to avoid scanning .svn directories.
2544
2545 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2546 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2547 doesn't support NULs in patterns.
2548
2549 7. Added some missing "const"s to declarations of static tables in
2550 pcre_compile.c and pcre_dfa_exec.c.
2551
2552 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2553 caused by fix #2 above. (Subsequently also a second patch to fix the
2554 first patch. And a third patch - this was a messy problem.)
2555
2556 9. Applied Craig's patch to remove the use of push_back().
2557
2558 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2559 matching function regexec().
2560
2561 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2562 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2563 references. PCRE supports relative numbers with this syntax (I don't think
2564 Oniguruma does).
2565
2566 12. Previously, a group with a zero repeat such as (...){0} was completely
2567 omitted from the compiled regex. However, this means that if the group
2568 was called as a subroutine from elsewhere in the pattern, things went wrong
2569 (an internal error was given). Such groups are now left in the compiled
2570 pattern, with a new opcode that causes them to be skipped at execution
2571 time.
2572
2573 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2574 to the way PCRE behaves:
2575
2576 (a) A lone ] character is dis-allowed (Perl treats it as data).
2577
2578 (b) A back reference to an unmatched subpattern matches an empty string
2579 (Perl fails the current match path).
2580
2581 (c) A data ] in a character class must be notated as \] because if the
2582 first data character in a class is ], it defines an empty class. (In
2583 Perl it is not possible to have an empty class.) The empty class []
2584 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2585 The negative empty class [^] matches any one character, independently
2586 of the DOTALL setting.
2587
2588 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2589 non-existent subpattern following a character class starting with ']' and
2590 containing () gave an internal compiling error instead of "reference to
2591 non-existent subpattern". Fortunately, when the pattern did exist, the
2592 compiled code was correct. (When scanning forwards to check for the
2593 existence of the subpattern, it was treating the data ']' as terminating
2594 the class, so got the count wrong. When actually compiling, the reference
2595 was subsequently set up correctly.)
2596
2597 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2598 it was being rejected as not supported by pcre_dfa_exec(), even though
2599 other assertions are supported. I have made pcre_dfa_exec() support
2600 (*FAIL).
2601
2602 16. The implementation of 13c above involved the invention of a new opcode,
2603 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2604 cannot be changed at match time, I realized I could make a small
2605 improvement to matching performance by compiling OP_ALLANY instead of
2606 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2607 on the OP_ANY path.
2608
2609 17. Compiling pcretest on Windows with readline support failed without the
2610 following two fixes: (1) Make the unistd.h include conditional on
2611 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2612
2613 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2614 ncurses library to be included for pcretest when ReadLine support is
2615 requested, but also to allow for it to be overridden. This patch came from
2616 Daniel Bergström.
2617
2618 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2619 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2620 any errors with the current Unicode tables. Thanks to Peter Kankowski for
2621 spotting this.
2622
2623
2624 Version 7.6 28-Jan-08
2625 ---------------------
2626
2627 1. A character class containing a very large number of characters with
2628 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2629 overflow.
2630
2631 2. Patch to cut out the "long long" test in pcrecpp_unittest when
2632 HAVE_LONG_LONG is not defined.
2633
2634 3. Applied Christian Ehrlicher's patch to update the CMake build files to
2635 bring them up to date and include new features. This patch includes:
2636
2637 - Fixed PH's badly added libz and libbz2 support.
2638 - Fixed a problem with static linking.
2639 - Added pcredemo. [But later removed - see 7 below.]
2640 - Fixed dftables problem and added an option.
2641 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2642 HAVE_LONG_LONG.
2643 - Added readline support for pcretest.
2644 - Added an listing of the option settings after cmake has run.
2645
2646 4. A user submitted a patch to Makefile that makes it easy to create
2647 "pcre.dll" under mingw when using Configure/Make. I added stuff to
2648 Makefile.am that cause it to include this special target, without
2649 affecting anything else. Note that the same mingw target plus all
2650 the other distribution libraries and programs are now supported
2651 when configuring with CMake (see 6 below) instead of with
2652 Configure/Make.
2653
2654 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2655 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2656 exported in the Windows port". It has not yet been confirmed that the patch
2657 solves the problem, but it does no harm.
2658
2659 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2660 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2661 with CMake, and also correct the comment about stack recursion.
2662
2663 7. Remove the automatic building of pcredemo from the ./configure system and
2664 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2665 of a program that users should build themselves after PCRE is installed, so
2666 building it automatically is not really right. What is more, it gave
2667 trouble in some build environments.
2668
2669 8. Further tidies to CMakeLists.txt from Sheri and Christian.
2670
2671
2672 Version 7.5 10-Jan-08
2673 ---------------------
2674
2675 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
2676 values in parens when parsing an RE using the C++ wrapper."
2677
2678 2. Negative specials like \S did not work in character classes in UTF-8 mode.
2679 Characters greater than 255 were excluded from the class instead of being
2680 included.
2681
2682 3. The same bug as (2) above applied to negated POSIX classes such as
2683 [:^space:].
2684
2685 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2686 defined or documented. It seems to have been a typo for PCRE_STATIC, so
2687 I have changed it.
2688
2689 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
2690 first named subpattern) and a construct such as (?&a) would reference the
2691 first named subpattern whose name started with "a" (in other words, the
2692 length check was missing). Both these problems are fixed. "Subpattern name
2693 expected" is now given for (?&) (a zero-length name), and this patch also
2694 makes it give the same error for \k'' (previously it complained that that
2695 was a reference to a non-existent subpattern).
2696
2697 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
2698 this is right because (?- can be followed by option settings as well as by
2699 digits. I have, however, made the messages clearer.
2700
2701 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2702 than the number used in the conditional) now cause a compile-time error.
2703 This is actually not compatible with Perl, which accepts such patterns, but
2704 treats the conditional as always being FALSE (as PCRE used to), but it
2705 seems to me that giving a diagnostic is better.
2706
2707 8. Change "alphameric" to the more common word "alphanumeric" in comments
2708 and messages.
2709
2710 9. Fix two occurrences of "backslash" in comments that should have been
2711 "backspace".
2712
2713 10. Remove two redundant lines of code that can never be obeyed (their function
2714 was moved elsewhere).
2715
2716 11. The program that makes PCRE's Unicode character property table had a bug
2717 which caused it to generate incorrect table entries for sequences of
2718 characters that have the same character type, but are in different scripts.
2719 It amalgamated them into a single range, with the script of the first of
2720 them. In other words, some characters were in the wrong script. There were
2721 thirteen such cases, affecting characters in the following ranges:
2722
2723 U+002b0 - U+002c1
2724 U+0060c - U+0060d
2725 U+0061e - U+00612
2726 U+0064b - U+0065e
2727 U+0074d - U+0076d
2728 U+01800 - U+01805
2729 U+01d00 - U+01d77
2730 U+01d9b - U+01dbf
2731 U+0200b - U+0200f
2732 U+030fc - U+030fe
2733 U+03260 - U+0327f
2734 U+0fb46 - U+0fbb1
2735 U+10450 - U+1049d
2736
2737 12. The -o option (show only the matching part of a line) for pcregrep was not
2738 compatible with GNU grep in that, if there was more than one match in a
2739 line, it showed only the first of them. It now behaves in the same way as
2740 GNU grep.
2741
2742 13. If the -o and -v options were combined for pcregrep, it printed a blank
2743 line for every non-matching line. GNU grep prints nothing, and pcregrep now
2744 does the same. The return code can be used to tell if there were any
2745 non-matching lines.
2746
2747 14. Added --file-offsets and --line-offsets to pcregrep.
2748
2749 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2750 infinitely looping recursion. The bug was that positive lookaheads were not
2751 being skipped when checking for a possible empty match (negative lookaheads
2752 and both kinds of lookbehind were skipped).
2753
2754 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2755 inclusion of <windows.h> to before rather than after the definition of
2756 INVALID_FILE_ATTRIBUTES (patch from David Byron).
2757
2758 17. Specifying a possessive quantifier with a specific limit for a Unicode
2759 character property caused pcre_compile() to compile bad code, which led at
2760 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2761 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2762 caused the error; without that there was no problem.
2763
2764 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2765
2766 19. Added --enable-pcretest-libreadline.
2767
2768 20. In pcrecpp.cc, the variable 'count' was incremented twice in
2769 RE::GlobalReplace(). As a result, the number of replacements returned was
2770 double what it should be. I removed one of the increments, but Craig sent a
2771 later patch that removed the other one (the right fix) and added unit tests
2772 that check the return values (which was not done before).
2773
2774 21. Several CMake things:
2775
2776 (1) Arranged that, when cmake is used on Unix, the libraries end up with
2777 the names libpcre and libpcreposix, not just pcre and pcreposix.
2778
2779 (2) The above change means that pcretest and pcregrep are now correctly
2780 linked with the newly-built libraries, not previously installed ones.
2781
2782 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2783
2784 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2785 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2786 UTF-8 newline character). The key issue is that the pattern starts .*;
2787 this means that the match must be either at the beginning, or after a
2788 newline. The bug was in the code for advancing after a failed match and
2789 checking that the new position followed a newline. It was not taking
2790 account of UTF-8 characters correctly.
2791
2792 23. PCRE was behaving differently from Perl in the way it recognized POSIX
2793 character classes. PCRE was not treating the sequence [:...:] as a
2794 character class unless the ... were all letters. Perl, however, seems to
2795 allow any characters between [: and :], though of course it rejects as
2796 unknown any "names" that contain non-letters, because all the known class
2797 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2798 for example, whereas PCRE did not - it did not recognize a POSIX character
2799 class. This seemed a bit dangerous, so the code has been changed to be
2800 closer to Perl. The behaviour is not identical to Perl, because PCRE will
2801 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2802 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2803 Perl does, and where it didn't before.
2804
2805 24. Rewrite so as to remove the single use of %n from pcregrep because in some
2806 Windows environments %n is disabled by default.
2807
2808
2809 Version 7.4 21-Sep-07
2810 ---------------------
2811
2812 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
2813 means that a class such as [\s] counted as "explicit reference to CR or
2814 LF". That isn't really right - the whole point of the change was to try to
2815 help when there was an actual mention of one of the two characters. So now
2816 the change happens only if \r or \n (or a literal CR or LF) character is
2817 encountered.
2818
2819 2. The 32-bit options word was also used for 6 internal flags, but the numbers
2820 of both had grown to the point where there were only 3 bits left.
2821 Fortunately, there was spare space in the data structure, and so I have
2822 moved the internal flags into a new 16-bit field to free up more option
2823 bits.
2824
2825 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2826 but did not set the internal JCHANGED flag - either of these is enough to
2827 control the way the "get" function works - but the PCRE_INFO_JCHANGED
2828 facility is supposed to tell if (?J) was ever used, so now (?J) at the
2829 start sets both bits.
2830
2831 4. Added options (at build time, compile time, exec time) to change \R from
2832 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2833
2834 5. doc/pcresyntax.html was missing from the distribution.
2835
2836 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2837 compatibility, even though it is no longer used.
2838
2839 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2840 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2841 windows.h file is present (where different names are used). [This was
2842 reversed later after testing - see 16 below.]
2843
2844 8. Changed all #include <config.h> to #include "config.h". There were also
2845 some further <pcre.h> cases that I changed to "pcre.h".
2846
2847 9. When pcregrep was used with the --colour option, it missed the line ending
2848 sequence off the lines that it output.
2849
2850 10. It was pointed out to me that arrays of string pointers cause lots of
2851 relocations when a shared library is dynamically loaded. A technique of
2852 using a single long string with a table of offsets can drastically reduce
2853 these. I have refactored PCRE in four places to do this. The result is
2854 dramatic:
2855
2856 Originally: 290
2857 After changing UCP table: 187
2858 After changing error message table: 43
2859 After changing table of "verbs" 36
2860 After changing table of Posix names 22
2861
2862 Thanks to the folks working on Gregex for glib for this insight.
2863
2864 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2865 unicode-properties was also set.
2866
2867 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2868
2869 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2870 checked only for CRLF.
2871
2872 14. Added casts to pcretest.c to avoid compiler warnings.
2873
2874 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2875
2876 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2877 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2878 entirely. This removes changes made in 7 above.
2879
2880 17. The CMake files have been updated, and there is now more information about
2881 building with CMake in the NON-UNIX-USE document.
2882
2883
2884 Version 7.3 28-Aug-07
2885 ---------------------
2886
2887 1. In the rejigging of the build system that eventually resulted in 7.1, the
2888 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2889 brackets there is not right, since it causes compilers to look for an
2890 installed pcre.h, not the version that is in the source that is being
2891 compiled (which of course may be different). I have changed it back to:
2892
2893 #include "pcre.h"
2894
2895 I have a vague recollection that the change was concerned with compiling in
2896 different directories, but in the new build system, that is taken care of
2897 by the VPATH setting the Makefile.
2898
2899 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2900 when the subject happened to end in the byte 0x85 (e.g. if the last
2901 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2902 characters but of course it shouldn't be taken as a newline when it is part
2903 of another character. The bug was that, for an unlimited repeat of . in
2904 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2905 characters when looking for a newline.
2906
2907 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2908
2909 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2910 in debug output.
2911
2912 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2913 long printing in the pcrecpp unittest when running under MinGW.
2914
2915 6. ESC_K was left out of the EBCDIC table.
2916
2917 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2918 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2919 limit also applies to "virtual nesting" when a pattern is recursive, and in
2920 this case 1000 isn't so big. I have been able to remove this limit at the
2921 expense of backing off one optimization in certain circumstances. Normally,
2922 when pcre_exec() would call its internal match() function recursively and
2923 immediately return the result unconditionally, it uses a "tail recursion"
2924 feature to save stack. However, when a subpattern that can match an empty
2925 string has an unlimited repetition quantifier, it no longer makes this
2926 optimization. That gives it a stack frame in which to save the data for
2927 checking that an empty string has been matched. Previously this was taken
2928 from the 1000-entry workspace that had been reserved. So now there is no
2929 explicit limit, but more stack is used.
2930
2931 8. Applied Daniel's patches to solve problems with the import/export magic
2932 syntax that is required for Windows, and which was going wrong for the
2933 pcreposix and pcrecpp parts of the library. These were overlooked when this
2934 problem was solved for the main library.
2935
2936 9. There were some crude static tests to avoid integer overflow when computing
2937 the size of patterns that contain repeated groups with explicit upper
2938 limits. As the maximum quantifier is 65535, the maximum group length was
2939 set at 30,000 so that the product of these two numbers did not overflow a
2940 32-bit integer. However, it turns out that people want to use groups that
2941 are longer than 30,000 bytes (though not repeat them that many times).
2942 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2943 made it possible to implement the integer overflow checks in a much more
2944 dynamic way, which I have now done. The artificial limitation on group
2945 length has been removed - we now have only the limit on the total length of
2946 the compiled pattern, which depends on the LINK_SIZE setting.
2947
2948 10. Fixed a bug in the documentation for get/copy named substring when
2949 duplicate names are permitted. If none of the named substrings are set, the
2950 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2951 empty string.
2952
2953 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2954 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2955 because the ] is interpreted as the first data character and the
2956 terminating ] is not found. PCRE has been made compatible with Perl in this
2957 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2958 cause memory overwriting.
2959
2960 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2961 string has been matched (to stop an infinite loop). It was not recognizing
2962 a conditional subpattern that could match an empty string if that
2963 subpattern was within another subpattern. For example, it looped when
2964 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
2965 condition was not nested. This bug has been fixed.
2966
2967 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2968 past the start of the subject in the presence of bytes with the top bit
2969 set, for example "\x8aBCD".
2970
2971 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2972 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2973
2974 14. Optimized (?!) to (*FAIL).
2975
2976 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2977 This restricts code points to be within the range 0 to 0x10FFFF, excluding
2978 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2979 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2980 does: it's just the validity check that is more restrictive.
2981
2982 16. Inserted checks for integer overflows during escape sequence (backslash)
2983 processing, and also fixed erroneous offset values for syntax errors during
2984 backslash processing.
2985
2986 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2987 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2988
2989 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
2990 caused an overrun.
2991
2992 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
2993 something other than just ASCII characters) inside a group that had an
2994 unlimited repeat caused a loop at compile time (while checking to see
2995 whether the group could match an empty string).
2996
2997 20. Debugging a pattern containing \p or \P could cause a crash. For example,
2998 [\P{Any}] did so. (Error in the code for printing property names.)
2999
3000 21. An orphan \E inside a character class could cause a crash.
3001
3002 22. A repeated capturing bracket such as (A)? could cause a wild memory
3003 reference during compilation.
3004
3005 23. There are several functions in pcre_compile() that scan along a compiled
3006 expression for various reasons (e.g. to see if it's fixed length for look
3007 behind). There were bugs in these functions when a repeated \p or \P was
3008 present in the pattern. These operators have additional parameters compared
3009 with \d, etc, and these were not being taken into account when moving along
3010 the compiled data. Specifically:
3011
3012 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
3013 length.
3014
3015 (b) An item such as \pL+ within a repeated group could cause crashes or
3016 loops.
3017
3018 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
3019 "reference to non-existent subpattern" error.
3020
3021 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
3022
3023 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
3024 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
3025
3026 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
3027
3028 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
3029 character were causing crashes (broken optimization).
3030
3031 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
3032 \p or \P) caused a compile-time loop.
3033
3034 28. More problems have arisen in unanchored patterns when CRLF is a valid line
3035 break. For example, the unstudied pattern [\r\n]A does not match the string
3036 "\r\nA" because change 7.0/46 below moves the current point on by two
3037 characters after failing to match at the start. However, the pattern \nA
3038 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
3039 the same is true. There doesn't seem any very clean way out of this, but
3040 what I have chosen to do makes the common cases work: PCRE now takes note
3041 of whether there can be an explicit match for \r or \n anywhere in the
3042 pattern, and if so, 7.0/46 no longer applies. As part of this change,
3043 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
3044 pattern has explicit CR or LF references.
3045
3046 29. Added (*CR) etc for changing newline setting at start of pattern.
3047
3048
3049 Version 7.2 19-Jun-07
3050 ---------------------
3051
3052 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
3053 which is apparently normally available under Windows.
3054
3055 2. Re-jig the pcregrep tests with different newline settings in an attempt
3056 to make them independent of the local environment's newline setting.
3057
3058 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
3059
3060 4. Some of the "internals" tests were previously cut out when the link size
3061 was not 2, because the output contained actual offsets. The recent new
3062 "Z" feature of pcretest means that these can be cut out, making the tests
3063 usable with all link sizes.
3064
3065 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
3066 stack recursion. This gives a massive performance boost under BSD, but just
3067 a small improvement under Linux. However, it saves one field in the frame
3068 in all cases.
3069
3070 6. Added more features from the forthcoming Perl 5.10:
3071
3072 (a) (?-n) (where n is a string of digits) is a relative subroutine or
3073 recursion call. It refers to the nth most recently opened parentheses.
3074
3075 (b) (?+n) is also a relative subroutine call; it refers to the nth next
3076 to be opened parentheses.
3077
3078 (c) Conditions that refer to capturing parentheses can be specified
3079 relatively, for example, (?(-2)... or (?(+3)...
3080
3081 (d) \K resets the start of the current match so that everything before
3082 is not part of it.
3083
3084 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
3085
3086 (f) \g{name} is another synonym - part of Perl 5.10's unification of
3087 reference syntax.
3088
3089 (g) (?| introduces a group in which the numbering of parentheses in each
3090 alternative starts with the same number.
3091
3092 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
3093
3094 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
3095 PCRE_INFO_JCHANGED.
3096
3097 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
3098 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
3099 for detecting groups that can match an empty string.
3100
3101 9. A pattern with a very large number of alternatives (more than several
3102 hundred) was running out of internal workspace during the pre-compile
3103 phase, where pcre_compile() figures out how much memory will be needed. A
3104 bit of new cunning has reduced the workspace needed for groups with
3105 alternatives. The 1000-alternative test pattern now uses 12 bytes of
3106 workspace instead of running out of the 4096 that are available.
3107
3108 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
3109
3110 11. Applied patch from Google to remove an optimization that didn't quite work.
3111 The report of the bug said:
3112
3113 pcrecpp::RE("a*").FullMatch("aaa") matches, while
3114 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
3115 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
3116
3117 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
3118 it matched the wrong number of bytes.
3119
3120
3121 Version 7.1 24-Apr-07
3122 ---------------------
3123
3124 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
3125 that is more "standard", making use of automake and other Autotools. There
3126 is some re-arrangement of the files and adjustment of comments consequent
3127 on this.
3128
3129 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
3130 for recursive directory scanning broke on some systems because the files
3131 are not scanned in any specific order and on different systems the order
3132 was different. A call to "sort" has been inserted into RunGrepTest for the
3133 approprate test as a short-term fix. In the longer term there may be an
3134 alternative.
3135
3136 3. I had an email from Eric Raymond about problems translating some of PCRE's
3137 man pages to HTML (despite the fact that I distribute HTML pages, some
3138 people do their own conversions for various reasons). The problems
3139 concerned the use of low-level troff macros .br and .in. I have therefore
3140 removed all such uses from the man pages (some were redundant, some could
3141 be replaced by .nf/.fi pairs). The 132html script that I use to generate
3142 HTML has been updated to handle .nf/.fi and to complain if it encounters
3143 .br or .in.
3144
3145 4. Updated comments in configure.ac that get placed in config.h.in and also
3146 arranged for config.h to be included in the distribution, with the name
3147 config.h.generic, for the benefit of those who have to compile without
3148 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
3149
3150 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
3151 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
3152 makevp.bat for the current PCRE, using the additional files
3153 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
3154
3155 6. A Windows user reported a minor discrepancy with test 2, which turned out
3156 to be caused by a trailing space on an input line that had got lost in his
3157 copy. The trailing space was an accident, so I've just removed it.
3158
3159 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
3160 that is needed.
3161
3162 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
3163 as "const" (a) because they are and (b) because it helps the PHP
3164 maintainers who have recently made a script to detect big data structures
3165 in the php code that should be moved to the .rodata section. I remembered
3166 to update Builducptable as well, so it won't revert if ucptable.h is ever
3167 re-created.
3168
3169 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
3170 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
3171 order to be able to cut out the UTF-8 tables in the latter when UTF-8
3172 support is not required. This saves 1.5-2K of code, which is important in
3173 some applications.
3174
3175 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
3176 so as not to refer to the tables, even though these functions will never be
3177 called when UTF-8 support is disabled. Otherwise there are problems with a
3178 shared library.
3179
3180 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
3181
3182 (a) It was defining its arguments as char * instead of void *.
3183
3184 (b) It was assuming that all moves were upwards in memory; this was true
3185 a long time ago when I wrote it, but is no longer the case.
3186
3187 The emulated memove() is provided for those environments that have neither
3188 memmove() nor bcopy(). I didn't think anyone used it these days, but that
3189 is clearly not the case, as these two bugs were recently reported.
3190
3191 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
3192 and Detrail to create the HTML documentation, the .txt form of the man
3193 pages, and it removes trailing spaces from listed files. It also creates
3194 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
3195 case, it wraps all the #defines with #ifndefs. This script should be run
3196 before "make dist".
3197
3198 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
3199 with Unicode property support.
3200
3201 (a) For a maximizing quantifier, if the two different cases of the
3202 character were of different lengths in their UTF-8 codings (there are
3203 some cases like this - I found 11), and the matching function had to
3204 back up over a mixture of the two cases, it incorrectly assumed they
3205 were both the same length.
3206
3207 (b) When PCRE was configured to use the heap rather than the stack for
3208 recursion during matching, it was not correctly preserving the data for
3209 the other case of a UTF-8 character when checking ahead for a match
3210 while processing a minimizing repeat. If the check also involved
3211 matching a wide character, but failed, corruption could cause an
3212 erroneous result when trying to check for a repeat of the original
3213 character.
3214
3215 13. Some tidying changes to the testing mechanism:
3216
3217 (a) The RunTest script now detects the internal link size and whether there
3218 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
3219 values substituted by "configure". (The RunGrepTest script already did
3220 this for UTF-8.) The configure.ac script no longer substitutes the
3221 relevant variables.
3222
3223 (b) The debugging options /B and /D in pcretest show the compiled bytecode
3224 with length and offset values. This means that the output is different
3225 for different internal link sizes. Test 2 is skipped for link sizes
3226 other than 2 because of this, bypassing the problem. Unfortunately,
3227 there was also a test in test 3 (the locale tests) that used /B and
3228 failed for link sizes other than 2. Rather than cut the whole test out,
3229 I have added a new /Z option to pcretest that replaces the length and
3230 offset values with spaces. This is now used to make test 3 independent
3231 of link size. (Test 2 will be tidied up later.)
3232
3233 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
3234 segmentation fault instead of returning the appropriate error message.
3235
3236 15. In multiline mode when the newline sequence was set to "any", the pattern
3237 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
3238 This doesn't seem right; it now treats the CRLF combination as the line
3239 ending, and so does not match in that case. It's only a pattern such as ^$
3240 that would hit this one: something like ^ABC$ would have failed after \r
3241 and then tried again after \r\n.
3242
3243 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
3244 in an attempt to make files that differ only in their line terminators
3245 compare equal. This works on Linux.
3246
3247 17. Under certain error circumstances pcregrep might try to free random memory
3248 as it exited. This is now fixed, thanks to valgrind.
3249
3250 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
3251 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
3252 was because its rules for how to advance for /g after matching an empty
3253 string at the end of a line did not allow for this case. They now check for
3254 it specially.
3255
3256 20. pcretest is supposed to handle patterns and data of any length, by
3257 extending its buffers when necessary. It was getting this wrong when the
3258 buffer for a data line had to be extended.
3259
3260 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
3261 CRLF as a newline sequence.
3262
3263 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
3264 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
3265 I have nevertheless tidied it up.
3266
3267 23. Added some casts to kill warnings from HP-UX ia64 compiler.
3268
3269 24. Added a man page for pcre-config.
3270
3271
3272 Version 7.0 19-Dec-06
3273 ---------------------
3274
3275 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
3276 moving to gcc 4.1.1.
3277
3278 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
3279 sys/time.h, which is documented as needed for this function. It doesn't
3280 seem to matter on Linux, but it showed up on some releases of OS X.
3281
3282 3. It seems that there are systems where bytes whose values are greater than
3283 127 match isprint() in the "C" locale. The "C" locale should be the
3284 default when a C program starts up. In most systems, only ASCII printing
3285 characters match isprint(). This difference caused the output from pcretest
3286 to vary, making some of the tests fail. I have changed pcretest so that:
3287
3288 (a) When it is outputting text in the compiled version of a pattern, bytes
3289 other than 32-126 are always shown as hex escapes.
3290
3291 (b) When it is outputting text that is a matched part of a subject string,
3292 it does the same, unless a different locale has been set for the match
3293 (using the /L modifier). In this case, it uses isprint() to decide.
3294
3295 4. Fixed a major bug that caused incorrect computation of the amount of memory
3296 required for a compiled pattern when options that changed within the
3297 pattern affected the logic of the preliminary scan that determines the
3298 length. The relevant options are -x, and -i in UTF-8 mode. The result was
3299 that the computed length was too small. The symptoms of this bug were
3300 either the PCRE error "internal error: code overflow" from pcre_compile(),
3301 or a glibc crash with a message such as "pcretest: free(): invalid next
3302 size (fast)". Examples of patterns that provoked this bug (shown in
3303 pcretest format) are:
3304
3305 /(?-x: )/x
3306 /(?x)(?-x: \s*#\s*)/
3307 /((?i)[\x{c0}])/8
3308 /(?i:[\x{c0}])/8
3309
3310 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
3311 is now done differently.
3312
3313 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
3314 wrapper classes; (b) implement a new function in the C++ scanner that is
3315 more efficient than the old way of doing things because it avoids levels of
3316 recursion in the regex matching; (c) add a paragraph to the documentation
3317 for the FullMatch() function.
3318
3319 6. The escape sequence \n was being treated as whatever was defined as
3320 "newline". Not only was this contrary to the documentation, which states
3321 that \n is character 10 (hex 0A), but it also went horribly wrong when
3322 "newline" was defined as CRLF. This has been fixed.
3323
3324 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
3325 was being set to -1 for the "end of line" case (supposedly a value that no
3326 character can have). Though this value is never used (the check for end of
3327 line is "zero bytes in current character"), it caused compiler complaints.
3328 I've changed it to 0xffffffff.
3329
3330 8. In pcre_version.c, the version string was being built by a sequence of
3331 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
3332 string (as it is for production releases) called a macro with an empty
3333 argument. The C standard says the result of this is undefined. The gcc
3334 compiler treats it as an empty string (which was what was wanted) but it is
3335 reported that Visual C gives an error. The source has been hacked around to
3336 avoid this problem.
3337
3338 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
3339 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
3340 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
3341 of them did).
3342
3343 10. Originally, pcretest opened its input and output without "b"; then I was
3344 told that "b" was needed in some environments, so it was added for release
3345 5.0 to both the input and output. (It makes no difference on Unix-like
3346 systems.) Later I was told that it is wrong for the input on Windows. I've
3347 now abstracted the modes into two macros, to make it easier to fiddle with
3348 them, and removed "b" from the input mode under Windows.
3349
3350 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
3351
3352 12. Added -help and --help to pcretest as an official way of being reminded
3353 of the options.
3354
3355 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
3356 and pcrecpp.cc because they annoy compilers at high warning levels.
3357
3358 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
3359
3360 15. Fixed an occurrence of == in configure.ac that should have been = (shell
3361 scripts are not C programs :-) and which was not noticed because it works
3362 on Linux.
3363
3364 16. pcretest is supposed to handle any length of pattern and data line (as one
3365 line or as a continued sequence of lines) by extending its input buffer if
3366 necessary. This feature was broken for very long pattern lines, leading to
3367 a string of junk being passed to pcre_compile() if the pattern was longer
3368 than about 50K.
3369
3370 17. I have done a major re-factoring of the way pcre_compile() computes the
3371 amount of memory needed for a compiled pattern. Previously, there was code
3372 that made a preliminary scan of the pattern in order to do this. That was
3373 OK when PCRE was new, but as the facilities have expanded, it has become
3374 harder and harder to keep it in step with the real compile phase, and there
3375 have been a number of bugs (see for example, 4 above). I have now found a
3376 cunning way of running the real compile function in a "fake" mode that
3377 enables it to compute how much memory it would need, while actually only
3378 ever using a few hundred bytes of working memory and without too many
3379 tests of the mode. This should make future maintenance and development
3380 easier. A side effect of this work is that the limit of 200 on the nesting
3381 depth of parentheses has been removed (though this was never a serious
3382 limitation, I suspect). However, there is a downside: pcre_compile() now
3383 runs more slowly than before (30% or more, depending on the pattern). I
3384 hope this isn't a big issue. There is no effect on runtime performance.
3385
3386 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
3387 newline (only possible for the last line of a file) and it was a
3388 pattern that set a locale (followed by /Lsomething), pcretest crashed.
3389
3390 19. Added additional timing features to pcretest. (1) The -tm option now times
3391 matching only, not compiling. (2) Both -t and -tm can be followed, as a
3392 separate command line item, by a number that specifies the number of
3393 repeats to use when timing. The default is 50000; this gives better
3394 precision, but takes uncomfortably long for very large patterns.
3395
3396 20. Extended pcre_study() to be more clever in cases where a branch of a
3397 subpattern has no definite first character. For example, (a*|b*)[cd] would
3398 previously give no result from pcre_study(). Now it recognizes that the
3399 first character must be a, b, c, or d.
3400
3401 21. There was an incorrect error "recursive call could loop indefinitely" if
3402 a subpattern (or the entire pattern) that was being tested for matching an
3403 empty string contained only one non-empty item after a nested subpattern.
3404 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
3405 incorrectly, because the \d was being skipped in the check.
3406
3407 22. The pcretest program now has a new pattern option /B and a command line
3408 option -b, which is equivalent to adding /B to every pattern. This causes
3409 it to show the compiled bytecode, without the additional information that
3410 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
3411 is the same as /B/I).
3412
3413 23. A new optimization is now able automatically to treat some sequences such
3414 as a*b as a*+b. More specifically, if something simple (such as a character
3415 or a simple class like \d) has an unlimited quantifier, and is followed by
3416 something that cannot possibly match the quantified thing, the quantifier
3417 is automatically "possessified".
3418
3419 24. A recursive reference to a subpattern whose number was greater than 39
3420 went wrong under certain circumstances in UTF-8 mode. This bug could also
3421 have affected the operation of pcre_study().
3422
3423 25. Realized that a little bit of performance could be had by replacing
3424 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
3425
3426 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
3427
3428 27. Possessive quantifiers such as a++ were previously implemented by turning
3429 them into atomic groups such as ($>a+). Now they have their own opcodes,
3430 which improves performance. This includes the automatically created ones
3431 from 23 above.
3432
3433 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
3434 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
3435 the first matched character to be a colon. This applied both to named and
3436 numbered groups.
3437
3438 29. The ucpinternal.h header file was missing its idempotency #ifdef.
3439
3440 30. I was sent a "project" file called libpcre.a.dev which I understand makes
3441 building PCRE on Windows easier, so I have included it in the distribution.
3442
3443 31. There is now a check in pcretest against a ridiculously large number being
3444 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
3445 loop, the loop is abandoned.
3446
3447 32. Forward references to subpatterns in conditions such as (?(2)...) where
3448 subpattern 2 is defined later cause pcre_compile() to search forwards in
3449 the pattern for the relevant set of parentheses. This search went wrong
3450 when there were unescaped parentheses in a character class, parentheses
3451 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
3452
3453 33. "Subroutine" calls and backreferences were previously restricted to
3454 referencing subpatterns earlier in the regex. This restriction has now
3455 been removed.
3456
3457 34. Added a number of extra features that are going to be in Perl 5.10. On the
3458 whole, these are just syntactic alternatives for features that PCRE had
3459 previously implemented using the Python syntax or my own invention. The
3460 other formats are all retained for compatibility.
3461
3462 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
3463 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
3464 also .NET compatible.
3465
3466 (b) A recursion or subroutine call to a named group can now be defined as
3467 (?&name) as well as (?P>name).
3468
3469 (c) A backreference to a named group can now be defined as \k<name> or
3470 \k'name' as well as (?P=name). The new forms, as well as being in Perl
3471 5.10, are also .NET compatible.
3472
3473 (d) A conditional reference to a named group can now use the syntax
3474 (?(<name>) or (?('name') as well as (?(name).
3475
3476 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
3477 groups (named and numbered) that are never evaluated inline, but can be
3478 called as "subroutines" from elsewhere. In effect, the DEFINE condition
3479 is always false. There may be only one alternative in such a group.
3480
3481 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
3482 as the simple (?(R). The condition is true only if the most recent
3483 recursion is that of the given number or name. It does not search out
3484 through the entire recursion stack.
3485
3486 (g) The escape \gN or \g{N} has been added, where N is a positive or
3487 negative number, specifying an absolute or relative reference.
3488
3489 35. Tidied to get rid of some further signed/unsigned compiler warnings and
3490 some "unreachable code" warnings.
3491
3492 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
3493 things, this adds five new scripts.
3494
3495 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
3496 There were also incompatibilities regarding the handling of \Q..\E inside
3497 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3498 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3499
3500 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3501 matches an empty string, and forcibly breaks the loop. There were bugs in
3502 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3503 against aaaa the result was just "a" rather than "aaaa", for example. Two
3504 separate and independent bugs (that affected different cases) have been
3505 fixed.
3506
3507 39. Refactored the code to abolish the use of different opcodes for small
3508 capturing bracket numbers. This is a tidy that I avoided doing when I
3509 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3510 The new approach is not only tidier, it makes it possible to reduce the
3511 memory needed to fix the previous bug (38).
3512
3513 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3514 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3515 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3516 mode.
3517
3518 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3519 report.
3520
3521 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3522 copy construction and assignment in the C++ wrapper.
3523
3524 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3525 couple of bugs that could have given wrong results in the "--newline=crlf"
3526 case.
3527
3528 44. Added a number of casts and did some reorganization of signed/unsigned int
3529 variables following suggestions from Dair Grant. Also renamed the variable
3530 "this" as "item" because it is a C++ keyword.
3531
3532 45. Arranged for dftables to add
3533
3534 #include "pcre_internal.h"
3535
3536 to pcre_chartables.c because without it, gcc 4.x may remove the array
3537 definition from the final binary if PCRE is built into a static library and
3538 dead code stripping is activated.
3539
3540 46. For an unanchored pattern, if a match attempt fails at the start of a
3541 newline sequence, and the newline setting is CRLF or ANY, and the next two
3542 characters are CRLF, advance by two characters instead of one.
3543
3544
3545 Version 6.7 04-Jul-06
3546 ---------------------
3547
3548 1. In order to handle tests when input lines are enormously long, pcretest has
3549 been re-factored so that it automatically extends its buffers when
3550 necessary. The code is crude, but this _is_ just a test program. The
3551 default size has been increased from 32K to 50K.
3552
3553 2. The code in pcre_study() was using the value of the re argument before
3554 testing it for NULL. (Of course, in any sensible call of the function, it
3555 won't be NULL.)
3556
3557 3. The memmove() emulation function in pcre_internal.h, which is used on
3558 systems that lack both memmove() and bcopy() - that is, hardly ever -
3559 was missing a "static" storage class specifier.
3560
3561 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3562 containing an extended class (one that cannot be represented by a bitmap
3563 because it contains high-valued characters or Unicode property items, e.g.
3564 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3565 pattern, but PCRE should not loop if you do not (it no longer does).
3566 [Detail: two cases were found: (a) a repeated subpattern containing an
3567 extended class; (b) a recursive reference to a subpattern that followed a
3568 previous extended class. It wasn't skipping over the extended class
3569 correctly when UTF-8 mode was not set.]
3570
3571 5. A negated single-character class was not being recognized as fixed-length
3572 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3573 compile error "lookbehind assertion is not fixed length".
3574
3575 6. The RunPerlTest auxiliary script was showing an unexpected difference
3576 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3577 write a Perl script that can interpret lines of an input file either as
3578 byte characters or as UTF-8, which is what "perltest" was being required to
3579 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3580 can't do is switch easily at run time between having the "use utf8;" pragma
3581 or not. In the end, I fudged it by using the RunPerlTest script to insert
3582 "use utf8;" explicitly for the UTF-8 tests.
3583
3584 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3585 the end of the subject string, contrary to the documentation and to what
3586 Perl does. This was true of both matching functions. Now it matches only at
3587 the start of the subject and immediately after *internal* newlines.
3588
3589 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3590 a pointer to an int instead of a pointer to an unsigned long int. This
3591 caused problems on 64-bit systems.
3592
3593 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
3594 instance of the 'standard' template library not being so standard".
3595
3596 10. There was no check on the number of named subpatterns nor the maximum
3597 length of a subpattern name. The product of these values is used to compute
3598 the size of the memory block for a compiled pattern. By supplying a very
3599 long subpattern name and a large number of named subpatterns, the size
3600 computation could be caused to overflow. This is now prevented by limiting
3601 the length of names to 32 characters, and the number of named subpatterns
3602 to 10,000.
3603
3604 11. Subpatterns that are repeated with specific counts have to be replicated in
3605 the compiled pattern. The size of memory for this was computed from the
3606 length of the subpattern and the repeat count. The latter is limited to
3607 65535, but there was no limit on the former, meaning that integer overflow
3608 could in principle occur. The compiled length of a repeated subpattern is
3609 now limited to 30,000 bytes in order to prevent this.
3610
3611 12. Added the optional facility to have named substrings with the same name.
3612
3613 13. Added the ability to use a named substring as a condition, using the
3614 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
3615 are numbers (not recommended). Forward references are permitted.
3616
3617 14. Added forward references in named backreferences (if you see what I mean).
3618
3619 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
3620 pattern could run off the end of the subject. For example, the pattern
3621 "(?s)(.{1,5})"8 did this with the subject "ab".
3622
3623 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
3624 PCRE_CASELESS was set when matching characters that were quantified with ?
3625 or *.
3626
3627 17. A character class other than a single negated character that had a minimum
3628 but no maximum quantifier - for example [ab]{6,} - was not handled
3629 correctly by pce_dfa_exec(). It would match only one character.
3630
3631 18. A valid (though odd) pattern that looked like a POSIX character
3632 class but used an invalid character after [ (for example [[,abc,]]) caused
3633 pcre_compile() to give the error "Failed: internal error: code overflow" or
3634 in some cases to crash with a glibc free() error. This could even happen if
3635 the pattern terminated after [[ but there just happened to be a sequence of
3636 letters, a binary zero, and a closing ] in the memory that followed.
3637
3638 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
3639 over the years. Originally (before any Unicode support), just the bottom 8
3640 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
3641 output from "man perlunicode" includes this:
3642
3643 The regular expression compiler produces polymorphic opcodes. That
3644 is, the pattern adapts to the data and automatically switches to
3645 the Unicode character scheme when presented with Unicode data--or
3646 instead uses a traditional byte scheme when presented with byte
3647 data.
3648
3649 Sadly, a wide octal escape does not cause a switch, and in a string with
3650 no other multibyte characters, these octal escapes are treated as before.
3651 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
3652 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
3653 Unicode string.
3654
3655 I have not perpetrated such confusion in PCRE. Up till now, it took just
3656 the bottom 8 bits, as in old Perl. I have now made octal escapes with
3657 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
3658 translate to the appropriate multibyte character.
3659
3660 29. Applied some refactoring to reduce the number of warnings from Microsoft
3661 and Borland compilers. This has included removing the fudge introduced
3662 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
3663 a warning about an unused variable.
3664
3665 21. PCRE has not included VT (character 0x0b) in the set of whitespace
3666 characters since release 4.0, because Perl (from release 5.004) does not.
3667 [Or at least, is documented not to: some releases seem to be in conflict
3668 with the documentation.] However, when a pattern was studied with
3669 pcre_study() and all its branches started with \s, PCRE still included VT
3670 as a possible starting character. Of course, this did no harm; it just
3671 caused an unnecessary match attempt.
3672
3673 22. Removed a now-redundant internal flag bit that recorded the fact that case
3674 dependency changed within the pattern. This was once needed for "required
3675 byte" processing, but is no longer used. This recovers a now-scarce options
3676 bit. Also moved the least significant internal flag bit to the most-
3677 significant bit of the word, which was not previously used (hangover from
3678 the days when it was an int rather than a uint) to free up another bit for
3679 the future.
3680
3681 23. Added support for CRLF line endings as well as CR and LF. As well as the
3682 default being selectable at build time, it can now be changed at runtime
3683 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
3684 specify that it is scanning data with non-default line endings.
3685
3686 24. Changed the definition of CXXLINK to make it agree with the definition of
3687 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
3688
3689 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
3690 recursions. This makes a big different to stack usage for some patterns.
3691
3692 26. If a subpattern containing a named recursion or subroutine reference such
3693 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
3694 the space required for the compiled pattern went wrong and gave too small a
3695 value. Depending on the environment, this could lead to "Failed: internal
3696 error: code overflow at offset 49" or "glibc detected double free or
3697 corruption" errors.
3698
3699 27. Applied patches from Google (a) to support the new newline modes and (b) to
3700 advance over multibyte UTF-8 characters in GlobalReplace.
3701
3702 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
3703 difference for some implementation of PCRE in some Windows version.
3704
3705 29. Added some extra testing facilities to pcretest:
3706
3707 \q<number> in a data line sets the "match limit" value
3708 \Q<number> in a data line sets the "match recursion limt" value
3709 -S <number> sets the stack size, where <number> is in megabytes
3710
3711 The -S option isn't available for Windows.
3712
3713
3714 Version 6.6 06-Feb-06
3715 ---------------------
3716
3717 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
3718 in pcreposix.h. I have copied the definition from pcre.h.
3719
3720 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
3721 because pcre.h is no longer a built file.
3722
3723 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
3724 not normally included in the compiled code.
3725
3726
3727 Version 6.5 01-Feb-06
3728 ---------------------
3729
3730 1. When using the partial match feature with pcre_dfa_exec(), it was not
3731 anchoring the second and subsequent partial matches at the new starting
3732 point. This could lead to incorrect results. For example, with the pattern
3733 /1234/, partially matching against "123" and then "a4" gave a match.
3734
3735 2. Changes to pcregrep:
3736
3737 (a) All non-match returns from pcre_exec() were being treated as failures
3738 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
3739 error message is output. Some extra information is given for the
3740 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
3741 probably the only errors that are likely to be caused by users (by
3742 specifying a regex that has nested indefinite repeats, for instance).
3743 If there are more than 20 of these errors, pcregrep is abandoned.
3744
3745 (b) A binary zero was treated as data while matching, but terminated the
3746 output line if it was written out. This has been fixed: binary zeroes
3747 are now no different to any other data bytes.
3748
3749 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
3750 used to set a locale for matching. The --locale=xxxx long option has
3751 been added (no short equivalent) to specify a locale explicitly on the
3752 pcregrep command, overriding the environment variables.
3753
3754 (d) When -B was used with -n, some line numbers in the output were one less
3755 than they should have been.
3756
3757 (e) Added the -o (--only-matching) option.
3758
3759 (f) If -A or -C was used with -c (count only), some lines of context were
3760 accidentally printed for the final match.
3761
3762 (g) Added the -H (--with-filename) option.
3763
3764 (h) The combination of options -rh failed to suppress file names for files
3765 that were found from directory arguments.
3766
3767 (i) Added the -D (--devices) and -d (--directories) options.
3768
3769 (j) Added the -F (--fixed-strings) option.
3770
3771 (k) Allow "-" to be used as a file name for -f as well as for a data file.
3772
3773 (l) Added the --colo(u)r option.
3774
3775 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
3776 is not present by default.
3777
3778 3. A nasty bug was discovered in the handling of recursive patterns, that is,
3779 items such as (?R) or (?1), when the recursion could match a number of
3780 alternatives. If it matched one of the alternatives, but subsequently,
3781 outside the recursion, there was a failure, the code tried to back up into
3782 the recursion. However, because of the way PCRE is implemented, this is not
3783 possible, and the result was an incorrect result from the match.
3784
3785 In order to prevent this happening, the specification of recursion has
3786 been changed so that all such subpatterns are automatically treated as
3787 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
3788
3789 4. I had overlooked the fact that, in some locales, there are characters for
3790 which isalpha() is true but neither isupper() nor islower() are true. In
3791 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
3792 and ordfeminine) are like this. This affected the treatment of \w and \W
3793 when they appeared in character classes, but not when they appeared outside
3794 a character class. The bit map for "word" characters is now created
3795 separately from the results of isalnum() instead of just taking it from the
3796 upper, lower, and digit maps. (Plus the underscore character, of course.)
3797
3798 5. The above bug also affected the handling of POSIX character classes such as
3799 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
3800 permanent tables. Instead, the bit maps for such a class were previously
3801 created as the appropriate unions of the upper, lower, and digit bitmaps.
3802 Now they are created by subtraction from the [[:word:]] class, which has
3803 its own bitmap.
3804
3805 6. The [[:blank:]] character class matches horizontal, but not vertical space.
3806 It is created by subtracting the vertical space characters (\x09, \x0a,
3807 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
3808 subtraction was done in the overall bitmap for a character class, meaning
3809 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
3810 be recognized. This bug has been fixed.
3811
3812 7. Patches from the folks at Google:
3813
3814 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
3815 real life, but is still worth protecting against".
3816
3817 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
3818 regular expressions".
3819
3820 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
3821 have it.
3822
3823 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
3824 "configure" and the latter not, in order to fix a problem somebody had
3825 with compiling the Arg class on HP-UX.
3826
3827 (e) Improve the error-handling of the C++ wrapper a little bit.
3828
3829 (f) New tests for checking recursion limiting.
3830
3831 8. The pcre_memmove() function, which is used only if the environment does not
3832 have a standard memmove() function (and is therefore rarely compiled),
3833 contained two bugs: (a) use of int instead of size_t, and (b) it was not
3834 returning a result (though PCRE never actually uses the result).
3835
3836 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
3837 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
3838 returned instead of calling malloc() with an overflowing number that would
3839 most likely cause subsequent chaos.
3840
3841 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
3842
3843 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
3844 with this option is matched, the nmatch and pmatch options of regexec() are
3845 ignored.
3846
3847 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
3848 provided in case anyone wants to the the POSIX interface with UTF-8
3849 strings.
3850
3851 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
3852 C++ linking (needed for some HP-UX environments).
3853
3854 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
3855 (unused parameter) and in the pcre_printint() function (omitted "default"
3856 switch label when the default is to do nothing).
3857
3858 15. Added some code to make it possible, when PCRE is compiled as a C++
3859 library, to replace subject pointers for pcre_exec() with a smart pointer
3860 class, thus making it possible to process discontinuous strings.
3861
3862 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
3863 much the same function. They were added by different people who were trying
3864 to make PCRE easy to compile on non-Unix systems. It has been suggested
3865 that PCRE_EXPORT be abolished now that there is more automatic apparatus
3866 for compiling on Windows systems. I have therefore replaced it with
3867 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
3868 defaults to "extern" for C or "extern C" for C++, which works fine on
3869 Unix-like systems. It is now possible to override the value of PCRE_DATA_
3870 SCOPE with something explicit in config.h. In addition:
3871
3872 (a) pcreposix.h still had just "extern" instead of either of these macros;
3873 I have replaced it with PCRE_DATA_SCOPE.
3874
3875 (b) Functions such as _pcre_xclass(), which are internal to the library,
3876 but external in the C sense, all had PCRE_EXPORT in their definitions.
3877 This is apparently wrong for the Windows case, so I have removed it.
3878 (It makes no difference on Unix-like systems.)
3879
3880 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3881 of recursive calls to match(). This is different to MATCH_LIMIT because
3882 that limits the total number of calls to match(), not all of which increase
3883 the depth of recursion. Limiting the recursion depth limits the amount of
3884 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3885 when PCRE is compiled, and changed at run time. A patch from Google adds
3886 this functionality to the C++ interface.
3887
3888 18. Changes to the handling of Unicode character properties:
3889
3890 (a) Updated the table to Unicode 4.1.0.
3891
3892 (b) Recognize characters that are not in the table as "Cn" (undefined).
3893
3894 (c) I revised the way the table is implemented to a much improved format
3895 which includes recognition of ranges. It now supports the ranges that
3896 are defined in UnicodeData.txt, and it also amalgamates other
3897 characters into ranges. This has reduced the number of entries in the
3898 table from around 16,000 to around 3,000, thus reducing its size
3899 considerably. I realized I did not need to use a tree structure after
3900 all - a binary chop search is just as efficient. Having reduced the
3901 number of entries, I extended their size from 6 bytes to 8 bytes to
3902 allow for more data.
3903
3904 (d) Added support for Unicode script names via properties such as \p{Han}.
3905
3906 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3907 matching that character.
3908
3909 20. When matching a repeated Unicode property with a minimum greater than zero,
3910 (for example \pL{2,}), PCRE could look past the end of the subject if it
3911 reached it while seeking the minimum number of characters. This could
3912 happen only if some of the characters were more than one byte long, because
3913 there is a check for at least the minimum number of bytes.
3914
3915 21. Refactored the implementation of \p and \P so as to be more general, to
3916 allow for more different types of property in future. This has changed the
3917 compiled form incompatibly. Anybody with saved compiled patterns that use
3918 \p or \P will have to recompile them.
3919
3920 22. Added "Any" and "L&" to the supported property types.
3921
3922 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3923 but give a compile time error if the value is greater than 0xff.
3924
3925 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3926 accidentally not being installed or uninstalled.
3927
3928 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3929 made were to insert the current release number. This seemed silly, because
3930 it made things harder for people building PCRE on systems that don't run
3931 "configure". I have turned pcre.h into a distributed file, no longer built
3932 by "configure", with the version identification directly included. There is
3933 no longer a pcre.h.in file.
3934
3935 However, this change necessitated a change to the pcre-config script as
3936 well. It is built from pcre-config.in, and one of the substitutions was the
3937 release number. I have updated configure.ac so that ./configure now finds
3938 the release number by grepping pcre.h.
3939
3940 26. Added the ability to run the tests under valgrind.
3941
3942
3943 Version 6.4 05-Sep-05
3944 ---------------------
3945
3946 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3947 "--" to be printed when multiple files were scanned, even when none of the
3948 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3949 consider it to be a bug, and have restored the previous behaviour.
3950
3951 2. A couple of code tidies to get rid of compiler warnings.
3952
3953 3. The pcretest program used to cheat by referring to symbols in the library
3954 whose names begin with _pcre_. These are internal symbols that are not
3955 really supposed to be visible externally, and in some environments it is
3956 possible to suppress them. The cheating is now confined to including
3957 certain files from the library's source, which is a bit cleaner.
3958
3959 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
3960 file's purpose clearer.
3961
3962 5. Reorganized pcre_ucp_findchar().
3963
3964
3965 Version 6.3 15-Aug-05
3966 ---------------------
3967
3968 1. The file libpcre.pc.in did not have general read permission in the tarball.
3969
3970 2. There were some problems when building without C++ support:
3971
3972 (a) If C++ support was not built, "make install" and "make test" still
3973 tried to test it.
3974
3975 (b) There were problems when the value of CXX was explicitly set. Some
3976 changes have been made to try to fix these, and ...
3977
3978 (c) --disable-cpp can now be used to explicitly disable C++ support.
3979
3980 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
3981 backslash in a target when C++ was disabled. This confuses some
3982 versions of "make", apparently. Using an intermediate variable solves
3983 this. (Same for CPP_LOBJ.)
3984
3985 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
3986 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
3987 necessary on certain architectures.
3988
3989 4. Added a setting of -export-symbols-regex to the link command to remove
3990 those symbols that are exported in the C sense, but actually are local
3991 within the library, and not documented. Their names all begin with
3992 "_pcre_". This is not a perfect job, because (a) we have to except some
3993 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
3994 available (and never for static libraries). I have made a note to try to
3995 find a way round (a) in the future.
3996
3997
3998 Version 6.2 01-Aug-05
3999 ---------------------
4000
4001 1. There was no test for integer overflow of quantifier values. A construction
4002 such as {1111111111111111} would give undefined results. What is worse, if
4003 a minimum quantifier for a parenthesized subpattern overflowed and became
4004 negative, the calculation of the memory size went wrong. This could have
4005 led to memory overwriting.
4006
4007 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
4008
4009 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
4010 operating environments where this matters.
4011
4012 4. Applied Giuseppe Maxia's patch to add additional features for controlling
4013 PCRE options from within the C++ wrapper.
4014
4015 5. Named capturing subpatterns were not being correctly counted when a pattern
4016 was compiled. This caused two problems: (a) If there were more than 100
4017 such subpatterns, the calculation of the memory needed for the whole
4018 compiled pattern went wrong, leading to an overflow error. (b) Numerical
4019 back references of the form \12, where the number was greater than 9, were
4020 not recognized as back references, even though there were sufficient
4021 previous subpatterns.
4022
4023 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
4024 versions of gcc, e.g. 2.95.4.
4025
4026
4027 Version 6.1 21-Jun-05
4028 ---------------------
4029
4030 1. There was one reference to the variable "posix" in pcretest.c that was not
4031 surrounded by "#if !defined NOPOSIX".
4032
4033 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
4034 the cross-check on the old pcre_info() function, for the benefit of the
4035 cut-down version of PCRE that is currently imported into Exim.
4036
4037 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
4038 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
4039 patterns that start (?i) but I don't think that matters. The use of (?i) is
4040 just an example; this all applies to the other options as well.
4041
4042 4. Since libtool seems to echo the compile commands it is issuing, the output
4043 from "make" can be reduced a bit by putting "@" in front of each libtool
4044 compile command.
4045
4046 5. Patch from the folks at Google for configure.in to be a bit more thorough
4047 in checking for a suitable C++ installation before trying to compile the
4048 C++ stuff. This should fix a reported problem when a compiler was present,
4049 but no suitable headers.
4050
4051 6. The man pages all had just "PCRE" as their title. I have changed them to
4052 be the relevant file name. I have also arranged that these names are
4053 retained in the file doc/pcre.txt, which is a concatenation in text format
4054 of all the man pages except the little individual ones for each function.
4055
4056 7. The NON-UNIX-USE file had not been updated for the different set of source
4057 files that come with release 6. I also added a few comments about the C++
4058 wrapper.
4059
4060
4061 Version 6.0 07-Jun-05
4062 ---------------------
4063
4064 1. Some minor internal re-organization to help with my DFA experiments.
4065
4066 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
4067 didn't matter for the library itself when fully configured, but did matter
4068 when compiling without UCP support, or within Exim, where the ucp files are
4069 not imported.
4070
4071 3. Refactoring of the library code to split up the various functions into
4072 different source modules. The addition of the new DFA matching code (see
4073 below) to a single monolithic source would have made it really too
4074 unwieldy, quite apart from causing all the code to be include in a
4075 statically linked application, when only some functions are used. This is
4076 relevant even without the DFA addition now that patterns can be compiled in
4077 one application and matched in another.
4078
4079 The downside of splitting up is that there have to be some external
4080 functions and data tables that are used internally in different modules of
4081 the library but which are not part of the API. These have all had their
4082 names changed to start with "_pcre_" so that they are unlikely to clash
4083 with other external names.
4084
4085 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
4086 a different (DFA) algorithm. Although it is slower than the original
4087 function, it does have some advantages for certain types of matching
4088 problem.
4089
4090 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
4091 including restarting after a partial match.
4092
4093 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
4094 defined when compiling for Windows was sent to me. I have put it into the
4095 code, though I have no means of testing or verifying it.
4096
4097 7. Added the pcre_refcount() auxiliary function.
4098
4099 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
4100 match before or at the first newline in the subject string. In pcretest,
4101 the /f option on a pattern can be used to set this.
4102
4103 9. A repeated \w when used in UTF-8 mode with characters greater than 256
4104 would behave wrongly. This has been present in PCRE since release 4.0.
4105
4106 10. A number of changes to the pcregrep command:
4107
4108 (a) Refactored how -x works; insert ^(...)$ instead of setting
4109 PCRE_ANCHORED and checking the length, in preparation for adding
4110 something similar for -w.
4111
4112 (b) Added the -w (match as a word) option.
4113
4114 (c) Refactored the way lines are read and buffered so as to have more
4115 than one at a time available.
4116
4117 (d) Implemented a pcregrep test script.
4118
4119 (e) Added the -M (multiline match) option. This allows patterns to match
4120 over several lines of the subject. The buffering ensures that at least
4121 8K, or the rest of the document (whichever is the shorter) is available
4122 for matching (and similarly the previous 8K for lookbehind assertions).
4123
4124 (f) Changed the --help output so that it now says
4125
4126 -w, --word-regex(p)
4127
4128 instead of two lines, one with "regex" and the other with "regexp"
4129 because that confused at least one person since the short forms are the
4130 same. (This required a bit of code, as the output is generated
4131 automatically from a table. It wasn't just a text change.)
4132
4133 (g) -- can be used to terminate pcregrep options if the next thing isn't an
4134 option but starts with a hyphen. Could be a pattern or a path name
4135 starting with a hyphen, for instance.
4136
4137 (h) "-" can be given as a file name to represent stdin.
4138
4139 (i) When file names are being printed, "(standard input)" is used for
4140 the standard input, for compatibility with GNU grep. Previously
4141 "<stdin>" was used.
4142
4143 (j) The option --label=xxx can be used to supply a name to be used for
4144 stdin when file names are being printed. There is no short form.
4145
4146 (k) Re-factored the options decoding logic because we are going to add
4147 two more options that take data. Such options can now be given in four
4148 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
4149
4150 (l) Added the -A, -B, and -C options for requesting that lines of context
4151 around matches be printed.
4152
4153 (m) Added the -L option to print the names of files that do not contain
4154 any matching lines, that is, the complement of -l.
4155
4156 (n) The return code is 2 if any file cannot be opened, but pcregrep does
4157 continue to scan other files.
4158
4159 (o) The -s option was incorrectly implemented. For compatibility with other
4160 greps, it now suppresses the error message for a non-existent or non-
4161 accessible file (but not the return code). There is a new option called
4162 -q that suppresses the output of matching lines, which was what -s was
4163 previously doing.
4164
4165 (p) Added --include and --exclude options to specify files for inclusion
4166 and exclusion when recursing.
4167
4168 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
4169 Hopefully, it now does.
4170
4171 12. Missing cast in pcre_study().
4172
4173 13. Added an "uninstall" target to the makefile.
4174
4175 14. Replaced "extern" in the function prototypes in Makefile.in with
4176 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
4177 world, but is set differently for Windows.
4178
4179 15. Added a second compiling function called pcre_compile2(). The only
4180 difference is that it has an extra argument, which is a pointer to an
4181 integer error code. When there is a compile-time failure, this is set
4182 non-zero, in addition to the error test pointer being set to point to an
4183 error message. The new argument may be NULL if no error number is required
4184 (but then you may as well call pcre_compile(), which is now just a
4185 wrapper). This facility is provided because some applications need a
4186 numeric error indication, but it has also enabled me to tidy up the way
4187 compile-time errors are handled in the POSIX wrapper.
4188
4189 16. Added VPATH=.libs to the makefile; this should help when building with one
4190 prefix path and installing with another. (Or so I'm told by someone who
4191 knows more about this stuff than I do.)
4192
4193 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
4194 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
4195 match everything, including newlines. This is not POSIX-compatible, but
4196 somebody wanted the feature. From pcretest it can be activated by using
4197 both the P and the s flags.
4198
4199 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
4200
4201 19. libpcre.pc was being incorrectly installed as executable.
4202
4203 20. A couple of places in pcretest check for end-of-line by looking for '\n';
4204 it now also looks for '\r' so that it will work unmodified on Windows.
4205
4206 21. Added Google's contributed C++ wrapper to the distribution.
4207
4208 22. Added some untidy missing memory free() calls in pcretest, to keep
4209 Electric Fence happy when testing.
4210
4211
4212
4213 Version 5.0 13-Sep-04
4214 ---------------------
4215
4216 1. Internal change: literal characters are no longer packed up into items
4217 containing multiple characters in a single byte-string. Each character
4218 is now matched using a separate opcode. However, there may be more than one
4219 byte in the character in UTF-8 mode.
4220
4221 2. The pcre_callout_block structure has two new fields: pattern_position and
4222 next_item_length. These contain the offset in the pattern to the next match
4223 item, and its length, respectively.
4224
4225 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
4226 insertion of callouts before each pattern item. Added the /C option to
4227 pcretest to make use of this.
4228
4229 4. On the advice of a Windows user, the lines
4230
4231 #if defined(_WIN32) || defined(WIN32)
4232 _setmode( _fileno( stdout ), 0x8000 );
4233 #endif /* defined(_WIN32) || defined(WIN32) */
4234
4235 have been added to the source of pcretest. This apparently does useful
4236 magic in relation to line terminators.
4237
4238 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
4239 for the benefit of those environments where the "b" makes a difference.
4240
4241 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
4242 to know about it. I have put a hack into configure.in that adds in code
4243 to set GCC=yes if CC=icc. This seems to end up at a point in the
4244 generated configure script that is early enough to affect the setting of
4245 compiler options, which is what is needed, but I have no means of testing
4246 whether it really works. (The user who reported this had patched the
4247 generated configure script, which of course I cannot do.)
4248
4249 LATER: After change 22 below (new libtool files), the configure script
4250 seems to know about icc (and also ecc). Therefore, I have commented out
4251 this hack in configure.in.
4252
4253 7. Added support for pkg-config (2 patches were sent in).
4254
4255 8. Negated POSIX character classes that used a combination of internal tables
4256 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
4257 [[:^ascii]]. Typically, they would match almost any characters. The other
4258 POSIX classes were not broken in this way.
4259
4260 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
4261 to find the match, as PCRE was deluded into thinking that the match had to
4262 start at the start point or following a newline. The same bug applied to
4263 patterns with negative forward assertions or any backward assertions
4264 preceding ".*" at the start, unless the pattern required a fixed first
4265 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
4266
4267 10. In UTF-8 mode, when moving forwards in the subject after a failed match
4268 starting at the last subject character, bytes beyond the end of the subject
4269 string were read.
4270
4271 11. Renamed the variable "class" as "classbits" to make life easier for C++
4272 users. (Previously there was a macro definition, but it apparently wasn't
4273 enough.)
4274
4275 12. Added the new field "tables" to the extra data so that tables can be passed
4276 in at exec time, or the internal tables can be re-selected. This allows
4277 a compiled regex to be saved and re-used at a later time by a different
4278 program that might have everything at different addresses.
4279
4280 13. Modified the pcre-config script so that, when run on Solaris, it shows a
4281 -R library as well as a -L library.
4282
4283 14. The debugging options of pcretest (-d on the command line or D on a
4284 pattern) showed incorrect output for anything following an extended class
4285 that contained multibyte characters and which was followed by a quantifier.
4286
4287 15. Added optional support for general category Unicode character properties
4288 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
4289 support. It adds about 90K to the size of the library. The meanings of the
4290 inbuilt class escapes such as \d and \s have NOT been changed.
4291
4292 16. Updated pcredemo.c to include calls to free() to release the memory for the
4293 compiled pattern.
4294
4295 17. The generated file chartables.c was being created in the source directory
4296 instead of in the building directory. This caused the build to fail if the
4297 source directory was different from the building directory, and was
4298 read-only.
4299
4300 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
4301 file. No doubt somebody will tell me if they don't make sense... Also added
4302 Dan Mooney's comments about building on OpenVMS.
4303
4304 19. Added support for partial matching via the PCRE_PARTIAL option for
4305 pcre_exec() and the \P data escape in pcretest.
4306
4307 20. Extended pcretest with 3 new pattern features:
4308
4309 (i) A pattern option of the form ">rest-of-line" causes pcretest to
4310 write the compiled pattern to the file whose name is "rest-of-line".
4311 This is a straight binary dump of the data, with the saved pointer to
4312 the character tables forced to be NULL. The study data, if any, is
4313 written too. After writing, pcretest reads a new pattern.
4314
4315 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
4316 compiled pattern from the given file. There must not be any
4317 occurrences of "<" in the file name (pretty unlikely); if there are,
4318 pcretest will instead treat the initial "<" as a pattern delimiter.
4319 After reading in the pattern, pcretest goes on to read data lines as
4320 usual.
4321
4322 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
4323 and 16-bit fields in a compiled pattern, to simulate a pattern that
4324 was compiled on a host of opposite endianness.
4325
4326 21. The pcre-exec() function can now cope with patterns that were compiled on
4327 hosts of opposite endianness, with this restriction:
4328
4329 As for any compiled expression that is saved and used later, the tables
4330 pointer field cannot be preserved; the extra_data field in the arguments
4331 to pcre_exec() should be used to pass in a tables address if a value
4332 other than the default internal tables were used at compile time.
4333
4334 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
4335 now diagnosed as an error. Previously, most of the time, a negative number
4336 would have been treated as zero, but if in addition "ovector" was passed as
4337 NULL, a crash could occur.
4338
4339 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
4340 new versions from the libtool 1.5 distribution (the last one is a copy of
4341 a file called libtool.m4). This seems to have fixed the need to patch
4342 "configure" to support Darwin 1.3 (which I used to do). However, I still
4343 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
4344 workstation).
4345
4346 24. Changed the PCRE licence to be the more standard "BSD" licence.
4347
4348
4349 Version 4.5 01-Dec-03
4350 ---------------------
4351
4352 1. There has been some re-arrangement of the code for the match() function so
4353 that it can be compiled in a version that does not call itself recursively.
4354 Instead, it keeps those local variables that need separate instances for
4355 each "recursion" in a frame on the heap, and gets/frees frames whenever it
4356 needs to "recurse". Keeping track of where control must go is done by means
4357 of setjmp/longjmp. The whole thing is implemented by a set of macros that
4358 hide most of the details from the main code, and operates only if
4359 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
4360 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
4361 operating.
4362
4363 To make it easier for callers to provide specially tailored get/free
4364 functions for this usage, two new functions, pcre_stack_malloc, and
4365 pcre_stack_free, are used. They are always called in strict stacking order,
4366 and the size of block requested is always the same.
4367
4368 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
4369 PCRE has been compiled to use the stack or the heap for recursion. The
4370 -C option of pcretest uses this to show which version is compiled.
4371
4372 A new data escape \S, is added to pcretest; it causes the amounts of store
4373 obtained and freed by both kinds of malloc/free at match time to be added
4374 to the output.
4375
4376 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
4377 what's available on my current Linux desktop machine.
4378
4379 3. When matching a UTF-8 string, the test for a valid string at the start has
4380 been extended. If start_offset is not zero, PCRE now checks that it points
4381 to a byte that is the start of a UTF-8 character. If not, it returns
4382 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
4383 this is necessary because there may be backward assertions in the pattern.
4384 When matching the same subject several times, it may save resources to use
4385 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4386
4387 4. The code for checking the validity of UTF-8 strings has been tightened so
4388 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
4389 containing "overlong sequences".
4390
4391 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
4392 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
4393 should have been "&", but it just so happened that all the cases this let
4394 through by mistake were picked up later in the function.
4395
4396 6. I had used a variable called "isblank" - this is a C99 function, causing
4397 some compilers to warn. To avoid this, I renamed it (as "blankclass").
4398
4399 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
4400 prompting; (b) run "./pcretest /dev/null" at the start of the test script
4401 so the version is shown; (c) stop "make test" echoing "./RunTest".
4402
4403 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
4404
4405 9. The prototype for memmove() for systems that don't have it was using
4406 size_t, but the inclusion of the header that defines size_t was later. I've
4407 moved the #includes for the C headers earlier to avoid this.
4408
4409 10. Added some adjustments to the code to make it easier to compiler on certain
4410 special systems:
4411
4412 (a) Some "const" qualifiers were missing.
4413 (b) Added the macro EXPORT before all exported functions; by default this
4414 is defined to be empty.
4415 (c) Changed the dftables auxiliary program (that builds chartables.c) so
4416 that it reads its output file name as an argument instead of writing
4417 to the standard output and assuming this can be redirected.
4418
4419 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
4420 class containing characters with values greater than 255, PCRE compilation
4421 went into a loop.
4422
4423 12. A recursive reference to a subpattern that was within another subpattern
4424 that had a minimum quantifier of zero caused PCRE to crash. For example,
4425 (x(y(?2))z)? provoked this bug with a subject that got as far as the
4426 recursion. If the recursively-called subpattern itself had a zero repeat,
4427 that was OK.
4428
4429 13. In pcretest, the buffer for reading a data line was set at 30K, but the
4430 buffer into which it was copied (for escape processing) was still set at
4431 1024, so long lines caused crashes.
4432
4433 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
4434 "internal error: code overflow...". This applied to any character class
4435 that was followed by a possessive quantifier.
4436
4437 15. Modified the Makefile to add libpcre.la as a prerequisite for
4438 libpcreposix.la because I was told this is needed for a parallel build to
4439 work.
4440
4441 16. If a pattern that contained .* following optional items at the start was
4442 studied, the wrong optimizing data was generated, leading to matching
4443 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
4444 matching string must start with a or b or c. The correct conclusion for
4445 this pattern is that a match can start with any character.
4446
4447
4448 Version 4.4 13-Aug-03
4449 ---------------------
4450
4451 1. In UTF-8 mode, a character class containing characters with values between
4452 127 and 255 was not handled correctly if the compiled pattern was studied.
4453 In fixing this, I have also improved the studying algorithm for such
4454 classes (slightly).
4455
4456 2. Three internal functions had redundant arguments passed to them. Removal
4457 might give a very teeny performance improvement.
4458
4459 3. Documentation bug: the value of the capture_top field in a callout is *one
4460 more than* the number of the hightest numbered captured substring.
4461
4462 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
4463 in incorrectly linking with a previously installed version. They now link
4464 explicitly with libpcre.la.
4465
4466 5. configure.in no longer needs to recognize Cygwin specially.
4467
4468 6. A problem in pcre.in for Windows platforms is fixed.
4469
4470 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
4471 pcretest, it used to include the size of the study block as part of its
4472 output. Unfortunately, the structure contains a field that has a different
4473 size on different hardware architectures. This meant that the tests that
4474 showed this size failed. As the block is currently always of a fixed size,
4475 this information isn't actually particularly useful in pcretest output, so
4476 I have just removed it.
4477
4478 8. Three pre-processor statements accidentally did not start in column 1.
4479 Sadly, there are *still* compilers around that complain, even though
4480 standard C has not required this for well over a decade. Sigh.
4481
4482 9. In pcretest, the code for checking callouts passed small integers in the
4483 callout_data field, which is a void * field. However, some picky compilers
4484 complained about the casts involved for this on 64-bit systems. Now
4485 pcretest passes the address of the small integer instead, which should get
4486 rid of the warnings.
4487
4488 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
4489 both compile and run time, and gives an error if an invalid UTF-8 sequence
4490 is found. There is a option for disabling this check in cases where the
4491 string is known to be correct and/or the maximum performance is wanted.
4492
4493 11. In response to a bug report, I changed one line in Makefile.in from
4494
4495 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
4496 to
4497 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4498
4499 to look similar to other lines, but I have no way of telling whether this
4500 is the right thing to do, as I do not use Windows. No doubt I'll get told
4501 if it's wrong...
4502
4503
4504 Version 4.3 21-May-03
4505 ---------------------
4506
4507 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4508 Makefile.
4509
4510 2. Some refactoring to improve the quality of the code:
4511
4512 (i) The utf8_table... variables are now declared "const".
4513
4514 (ii) The code for \cx, which used the "case flipping" table to upper case
4515 lower case letters, now just substracts 32. This is ASCII-specific,
4516 but the whole concept of \cx is ASCII-specific, so it seems
4517 reasonable.
4518
4519 (iii) PCRE was using its character types table to recognize decimal and
4520 hexadecimal digits in the pattern. This is silly, because it handles
4521 only 0-9, a-f, and A-F, but the character types table is locale-
4522 specific, which means strange things might happen. A private
4523 table is now used for this - though it costs 256 bytes, a table is
4524 much faster than multiple explicit tests. Of course, the standard
4525 character types table is still used for matching digits in subject
4526 strings against \d.
4527
4528 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4529 ending in _t are). So I've renamed it as ESC_tee.
4530
4531 3. The first argument for regexec() in the POSIX wrapper should have been
4532 defined as "const".
4533
4534 4. Changed pcretest to use malloc() for its buffers so that they can be
4535 Electric Fenced for debugging.
4536
4537 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4538 to read one or more bytes before the start of the subject string. Often this
4539 had no effect on PCRE's behaviour, but in some circumstances it could
4540 provoke a segmentation fault.
4541
4542 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4543 to try to read one or more bytes before the start of the subject string.
4544
4545 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4546 UTF-8 support could misbehave in various ways if the subject string
4547 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4548 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4549 back over UTF-8 characters.)
4550
4551
4552 Version 4.2 14-Apr-03
4553 ---------------------
4554
4555 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4556
4557 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4558 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4559 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4560 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4561 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4562 and BUILD_EXEEXT
4563 Note: automatic setting of the BUILD variables is not yet working
4564 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4565 compile-time but not at link-time
4566 [LINK]: use for linking executables only
4567 make different versions for Windows and non-Windows
4568 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4569 libraries
4570 [LINK_FOR_BUILD]: new variable
4571 [OBJEXT]: use throughout
4572 [EXEEXT]: use throughout
4573 <winshared>: new target
4574 <wininstall>: new target
4575 <dftables.o>: use native compiler
4576 <dftables>: use native linker
4577 <install>: handle Windows platform correctly
4578 <clean>: ditto
4579 <check>: ditto
4580 copy DLL to top builddir before testing
4581
4582 As part of these changes, -no-undefined was removed again. This was reported
4583 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4584 in any case.
4585
4586 3. Some tidies to get rid of compiler warnings:
4587
4588 . In the match_data structure, match_limit was an unsigned long int, whereas
4589 match_call_count was an int. I've made them both unsigned long ints.
4590
4591 . In pcretest the fact that a const uschar * doesn't automatically cast to
4592 a void * provoked a warning.
4593
4594 . Turning on some more compiler warnings threw up some "shadow" variables
4595 and a few more missing casts.
4596
4597 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
4598 option, a class that contained a single character with a value between 128
4599 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
4600
4601 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
4602 option, a class that contained several characters, but with at least one
4603 whose value was between 128 and 255 caused PCRE to crash.
4604
4605
4606 Version 4.1 12-Mar-03
4607 ---------------------
4608
4609 1. Compiling with gcc -pedantic found a couple of places where casts were
4610 needed, and a string in dftables.c that was longer than standard compilers are
4611 required to support.
4612
4613 2. Compiling with Sun's compiler found a few more places where the code could
4614 be tidied up in order to avoid warnings.
4615
4616 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
4617 first of these names is deprecated in the latest Autoconf in favour of the name
4618 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
4619 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
4620 analogy I have changed it to CFLAGS_FOR_BUILD.
4621
4622 4. Added -no-undefined to the linking command in the Makefile, because this is
4623 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
4624 linking step for the pcreposix library.
4625
4626 5. PCRE was failing to diagnose the case of two named groups with the same
4627 name.
4628
4629 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
4630 literal character that is needed in the subject for a match, and scans along to
4631 ensure that it is present before embarking on the full matching process. This
4632 saves time in cases of nested unlimited repeats that are never going to match.
4633 Problem: the scan can take a lot of time if the subject is very long (e.g.
4634 megabytes), thus penalizing straightforward matches. It is now done only if the
4635 amount of subject to be scanned is less than 1000 bytes.
4636
4637 7. A lesser problem with the same optimization is that it was recording the
4638 first character of an anchored pattern as "needed", thus provoking a search
4639 right along the subject, even when the first match of the pattern was going to
4640 fail. The "needed" character is now not set for anchored patterns, unless it
4641 follows something in the pattern that is of non-fixed length. Thus, it still
4642 fulfils its original purpose of finding quick non-matches in cases of nested
4643 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
4644
4645
4646 Version 4.0 17-Feb-03
4647 ---------------------
4648
4649 1. If a comment in an extended regex that started immediately after a meta-item
4650 extended to the end of string, PCRE compiled incorrect data. This could lead to
4651 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
4652
4653 2. Moved to autoconf 2.53 and libtool 1.4.2.
4654
4655 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
4656 the special perltest8 script is no longer needed - all the tests can be run
4657 from a single perltest script.
4658
4659 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
4660 by \s. It has now been removed in PCRE. This means it isn't recognized as
4661 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
4662 class [:space:] *does* include VT, thereby creating a mess.
4663
4664 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
4665 space and tab.
4666
4667 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
4668 its new features into the main test script, reducing the number of scripts.
4669
4670 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
4671 were backward compatible, and made the (?i) apply to the whole pattern, as if
4672 /i were given. Now it behaves more logically, and applies the option setting
4673 only to what follows. PCRE has been changed to follow suit. However, if it
4674 finds options settings right at the start of the pattern, it extracts them into
4675 the global options, as before. Thus, they show up in the info data.
4676
4677 8. Added support for the \Q...\E escape sequence. Characters in between are
4678 treated as literals. This is slightly different from Perl in that $ and @ are
4679 also handled as literals inside the quotes. In Perl, they will cause variable
4680 interpolation. Note the following examples:
4681
4682 Pattern PCRE matches Perl matches
4683
4684 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
4685 \Qabc\$xyz\E abc\$xyz abc\$xyz
4686 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
4687
4688 For compatibility with Perl, \Q...\E sequences are recognized inside character
4689 classes as well as outside them.
4690
4691 9. Re-organized 3 code statements in pcretest to avoid "overflow in
4692 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
4693 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
4694 signed/unsigned warnings.
4695
4696 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
4697 option for pcretest, so I've replaced it by a simple function that does just
4698 that job.
4699
4700 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
4701 "pcregrep -".
4702
4703 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
4704 Java package. This provides some syntactic sugar for simple cases of what my
4705 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
4706 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
4707 item, you can use this simplified notation. Note that only makes sense with
4708 greedy quantifiers. Consequently, the use of the possessive quantifier forces
4709 greediness, whatever the setting of the PCRE_UNGREEDY option.
4710
4711 13. A change of greediness default within a pattern was not taking effect at
4712 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
4713 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
4714 was abstracted outside.
4715
4716 14. PCRE now supports the \G assertion. It is true when the current matching
4717 position is at the start point of the match. This differs from \A when the
4718 starting offset is non-zero. Used with the /g option of pcretest (or similar
4719 code), it works in the same way as it does for Perl's /g option. If all
4720 alternatives of a regex begin with \G, the expression is anchored to the start
4721 match position, and the "anchored" flag is set in the compiled expression.
4722
4723 15. Some bugs concerning the handling of certain option changes within patterns
4724 have been fixed. These applied to options other than (?ims). For example,
4725 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
4726 been the other way round. Some of this was related to change 7 above.
4727
4728 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
4729 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
4730 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
4731 POSIX classes only within a class (e.g. /[[:alpha:]]/).
4732
4733 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
4734 mode. Unlike ".", it always matches newline, whatever the setting of
4735 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
4736 assertions. Perl allows it, but it doesn't (in general) work because it can't
4737 calculate the length of the lookbehind. At least, that's the case for Perl
4738 5.8.0 - I've been told they are going to document that it doesn't work in
4739 future.
4740
4741 18. Added an error diagnosis for escapes that PCRE does not support: these are
4742 \L, \l, \N, \P, \p, \U, \u, and \X.
4743
4744 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
4745 reading past the end of the pattern in cases such as /[abcd/.
4746
4747 20. PCRE was getting more memory than necessary for patterns with classes that
4748 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
4749
4750 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
4751 compiling PCRE for use with Virtual Pascal.
4752
4753 22. Small fix to the Makefile to make it work properly if the build is done
4754 outside the source tree.
4755
4756 23. Added a new extension: a condition to go with recursion. If a conditional
4757 subpattern starts with (?(R) the "true" branch is used if recursion has
4758 happened, whereas the "false" branch is used only at the top level.
4759
4760 24. When there was a very long string of literal characters (over 255 bytes
4761 without UTF support, over 250 bytes with UTF support), the computation of how
4762 much memory was required could be incorrect, leading to segfaults or other
4763 strange effects.
4764
4765 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
4766 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
4767 there was a subsequent back reference to those brackets. This meant that, for
4768 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
4769 possible to check for precisely this case. All we can do is abandon the
4770 optimization if .* occurs inside capturing brackets when there are any back
4771 references whatsoever. (See below for a better fix that came later.)
4772
4773 26. The handling of the optimization for finding the first character of a
4774 non-anchored pattern, and for finding a character that is required later in the
4775 match were failing in some cases. This didn't break the matching; it just
4776 failed to optimize when it could. The way this is done has been re-implemented.
4777
4778 27. Fixed typo in error message for invalid (?R item (it said "(?p").
4779
4780 28. Added a new feature that provides some of the functionality that Perl
4781 provides with (?{...}). The facility is termed a "callout". The way it is done
4782 in PCRE is for the caller to provide an optional function, by setting
4783 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
4784 global variable. By default it is unset, which disables all calling out. To get
4785 the function called, the regex must include (?C) at appropriate points. This
4786 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
4787 This provides a means of identifying different callout points. When PCRE
4788 reaches such a point in the regex, if pcre_callout has been set, the external
4789 function is called. It is provided with data in a structure called
4790 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
4791 matching continues; if it returns a non-zero value, the match at the current
4792 point fails. However, backtracking will occur if possible. [This was changed
4793 later and other features added - see item 49 below.]
4794
4795 29. pcretest is upgraded to test the callout functionality. It provides a
4796 callout function that displays information. By default, it shows the start of
4797 the match and the current position in the text. There are some new data escapes
4798 to vary what happens:
4799
4800 \C+ in addition, show current contents of captured substrings
4801 \C- do not supply a callout function
4802 \C!n return 1 when callout number n is reached
4803 \C!n!m return 1 when callout number n is reached for the mth time
4804
4805 30. If pcregrep was called with the -l option and just a single file name, it
4806 output "<stdin>" if a match was found, instead of the file name.
4807
4808 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
4809 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
4810 pcre_exec(). This saves a malloc/free per call. The default value of
4811 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
4812 when configuring.
4813
4814 32. The default maximum size of a compiled pattern is 64K. There have been a
4815 few cases of people hitting this limit. The code now uses macros to handle the
4816 storing of links as offsets within the compiled pattern. It defaults to 2-byte
4817 links, but this can be changed to 3 or 4 bytes by --with-link-size when
4818 configuring. Tests 2 and 5 work only with 2-byte links because they output
4819 debugging information about compiled patterns.
4820
4821 33. Internal code re-arrangements:
4822
4823 (a) Moved the debugging function for printing out a compiled regex into
4824 its own source file (printint.c) and used #include to pull it into
4825 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
4826 separate copies.
4827
4828 (b) Defined the list of op-code names for debugging as a macro in
4829 internal.h so that it is next to the definition of the opcodes.
4830
4831 (c) Defined a table of op-code lengths for simpler skipping along compiled
4832 code. This is again a macro in internal.h so that it is next to the
4833 definition of the opcodes.
4834
4835 34. Added support for recursive calls to individual subpatterns, along the
4836 lines of Robin Houston's patch (but implemented somewhat differently).
4837
4838 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
4839 allow it to read and process whole directories in Win32. This code was
4840 contributed by Lionel Fourquaux; it has not been tested by me.
4841
4842 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
4843 used to name a group. Names consist of alphanumerics and underscores, and must
4844 be unique. Back references use the syntax (?P=name) and recursive calls use
4845 (?P>name) which is a PCRE extension to the Python extension. Groups still have
4846 numbers. The function pcre_fullinfo() can be used after compilation to extract
4847 a name/number map. There are three relevant calls:
4848
4849 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
4850 PCRE_INFO_NAMECOUNT yields the number of entries
4851 PCRE_INFO_NAMETABLE yields a pointer to the map.
4852
4853 The map is a vector of fixed-size entries. The size of each entry depends on
4854 the length of the longest name used. The first two bytes of each entry are the
4855 group number, most significant byte first. There follows the corresponding
4856 name, zero terminated. The names are in alphabetical order.
4857
4858 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
4859 case instead of 255. Making it the same both with and without UTF-8 support
4860 means that the same test output works with both.
4861
4862 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
4863 calling malloc() with a zero argument.
4864
4865 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
4866 optimization. I've improved things by keeping a bitmap of backreferences with
4867 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
4868 fact referenced, the optimization can be applied. It is unlikely that a
4869 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
4870 the match to follow \n) will appear inside brackets with a number greater than
4871 31, but if it does, any back reference > 31 suppresses the optimization.
4872
4873 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
4874 of disabling numbered capturing parentheses. Any opening parenthesis that is
4875 not followed by ? behaves as if it were followed by ?: but named parentheses
4876 can still be used for capturing (and they will acquire numbers in the usual
4877 way).
4878
4879 41. Redesigned the return codes from the match() function into yes/no/error so
4880 that errors can be passed back from deep inside the nested calls. A malloc
4881 failure while inside a recursive subpattern call now causes the
4882 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4883
4884 42. It is now possible to set a limit on the number of times the match()
4885 function is called in a call to pcre_exec(). This facility makes it possible to
4886 limit the amount of recursion and backtracking, though not in a directly
4887 obvious way, because the match() function is used in a number of different
4888 circumstances. The count starts from zero for each position in the subject
4889 string (for non-anchored patterns). The default limit is, for compatibility, a
4890 large number, namely 10 000 000. You can change this in two ways:
4891
4892 (a) When configuring PCRE before making, you can use --with-match-limit=n
4893 to set a default value for the compiled library.
4894
4895 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4896 a different value is set. See 45 below.
4897
4898 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4899
4900 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4901 of things that can be changed at compile time. The first argument specifies
4902 what is wanted and the second points to where the information is to be placed.
4903 The current list of available information is:
4904
4905 PCRE_CONFIG_UTF8
4906
4907 The output is an integer that is set to one if UTF-8 support is available;
4908 otherwise it is set to zero.
4909
4910 PCRE_CONFIG_NEWLINE
4911
4912 The output is an integer that it set to the value of the code that is used for
4913 newline. It is either LF (10) or CR (13).
4914
4915 PCRE_CONFIG_LINK_SIZE
4916
4917 The output is an integer that contains the number of bytes used for internal
4918 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4919
4920 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4921
4922 The output is an integer that contains the threshold above which the POSIX
4923 interface uses malloc() for output vectors. See item 31 above.
4924
4925 PCRE_CONFIG_MATCH_LIMIT
4926
4927 The output is an unsigned integer that contains the default limit of the number
4928 of match() calls in a pcre_exec() execution. See 42 above.
4929
4930 44. pcretest has been upgraded by the addition of the -C option. This causes it
4931 to extract all the available output from the new pcre_config() function, and to
4932 output it. The program then exits immediately.
4933
4934 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4935 order to support additional features. One way would have been to define
4936 pcre_exec2() (for example) with extra arguments, but this would not have been
4937 extensible, and would also have required all calls to the original function to
4938 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4939 is used for passing in "extra" data from pcre_study().
4940
4941 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4942 contains the following fields:
4943
4944 flags a bitmap indicating which of the following fields are set
4945 study_data opaque data from pcre_study()
4946 match_limit a way of specifying a limit on match() calls for a specific
4947 call to pcre_exec()
4948 callout_data data for callouts (see 49 below)
4949
4950 The flag bits are also defined in pcre.h, and are
4951
4952 PCRE_EXTRA_STUDY_DATA
4953 PCRE_EXTRA_MATCH_LIMIT
4954 PCRE_EXTRA_CALLOUT_DATA
4955
4956 The pcre_study() function now returns one of these new pcre_extra blocks, with
4957 the actual study data pointed to by the study_data field, and the
4958 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
4959 before. That is, this change is entirely upwards-compatible and requires no
4960 change to existing code.
4961
4962 If you want to pass in additional data to pcre_exec(), you can either place it
4963 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
4964 block.
4965
4966 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
4967 data string contains the escape sequence \M, pcretest calls pcre_exec() several
4968 times with different match limits, until it finds the minimum value needed for
4969 pcre_exec() to complete. The value is then output. This can be instructive; for
4970 most simple matches the number is quite small, but for pathological cases it
4971 gets very large very quickly.
4972
4973 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
4974 returns the size of the data block pointed to by the study_data field in a
4975 pcre_extra block, that is, the value that was passed as the argument to
4976 pcre_malloc() when PCRE was getting memory in which to place the information
4977 created by pcre_study(). The fourth argument should point to a size_t variable.
4978 pcretest has been extended so that this information is shown after a successful
4979 pcre_study() call when information about the compiled regex is being displayed.
4980
4981 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
4982 because what follows is always an absolute path. (Later: it turns out that this
4983 is more than cosmetic for MinGW, because it doesn't like empty path
4984 components.)
4985
4986 49. Some changes have been made to the callout feature (see 28 above):
4987
4988 (i) A callout function now has three choices for what it returns:
4989
4990 0 => success, carry on matching
4991 > 0 => failure at this point, but backtrack if possible
4992 < 0 => serious error, return this value from pcre_exec()
4993
4994 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
4995 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
4996 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
4997 use by callout functions. It will never be used by PCRE itself.
4998
4999 (ii) The pcre_extra structure (see 45 above) has a void * field called
5000 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
5001 pcre_callout_block structure has a field of the same name. The contents of
5002 the field passed in the pcre_extra structure are passed to the callout
5003 function in the corresponding field in the callout block. This makes it
5004 easier to use the same callout-containing regex from multiple threads. For
5005 testing, the pcretest program has a new data escape
5006
5007 \C*n pass the number n (may be negative) as callout_data
5008
5009 If the callout function in pcretest receives a non-zero value as
5010 callout_data, it returns that value.
5011
5012 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
5013 there were some redundant $(CFLAGS) in commands that are now specified as
5014 $(LINK), which already includes $(CFLAGS).
5015
5016 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
5017 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
5018 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
5019 one-byte characters throughout. Note that case-insensitive matching applies
5020 only to characters whose values are less than 256. PCRE doesn't support the
5021 notion of cases for higher-valued characters.
5022
5023 (i) A character class whose characters are all within 0-255 is handled as
5024 a bit map, and the map is inverted for negative classes. Previously, a
5025 character > 255 always failed to match such a class; however it should
5026 match if the class was a negative one (e.g. [^ab]). This has been fixed.
5027
5028 (ii) A negated character class with a single character < 255 is coded as
5029 "not this character" (OP_NOT). This wasn't working properly when the test
5030 character was multibyte, either singly or repeated.
5031
5032 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
5033 mode, for example: \x{100}{2,3}.
5034
5035 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
5036 singly or repeated) now correctly test multibyte characters. However,
5037 PCRE doesn't recognize any characters with values greater than 255 as
5038 digits, spaces, or word characters. Such characters always match \D, \S,
5039 and \W, and never match \d, \s, or \w.
5040
5041 (v) Classes may now contain characters and character ranges with values
5042 greater than 255. For example: [ab\x{100}-\x{400}].
5043
5044 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
5045 PCRE in UTF-8 mode.
5046
5047 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
5048 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
5049 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
5050 value.)
5051
5052 53. The single man page has become too large. I have therefore split it up into
5053 a number of separate man pages. These also give rise to individual HTML pages;
5054 these are now put in a separate directory, and there is an index.html page that
5055 lists them all. Some hyperlinking between the pages has been installed.
5056
5057 54. Added convenience functions for handling named capturing parentheses.
5058
5059 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
5060 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
5061 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
5062 are faulted.
5063
5064 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
5065 calling configure. These values are used when compiling the dftables.c program
5066 which is run to generate the source of the default character tables. They
5067 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
5068 you will need to set these values.
5069
5070 57. Updated the building process for Windows DLL, as provided by Fred Cox.
5071
5072
5073 Version 3.9 02-Jan-02
5074 ---------------------
5075
5076 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
5077
5078 2. If --disable-static was given, the building process failed when trying to
5079 build pcretest and pcregrep. (For some reason it was using libtool to compile
5080 them, which is not right, as they aren't part of the library.)
5081
5082
5083 Version 3.8 18-Dec-01
5084 ---------------------
5085
5086 1. The experimental UTF-8 code was completely screwed up. It was packing the
5087 bytes in the wrong order. How dumb can you get?
5088
5089
5090 Version 3.7 29-Oct-01
5091 ---------------------
5092
5093 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
5094 This caused pcretest, when used on the test data, to segfault. Unfortunately,
5095 this didn't happen under Solaris 8, where I normally test things.
5096
5097 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
5098 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
5099 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
5100 this fix an hour or so after the initial 3.7 release.)
5101
5102
5103 Version 3.6 23-Oct-01
5104 ---------------------
5105
5106 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
5107 offsets passed as NULL with zero offset count.
5108
5109 2. The config.guess and config.sub files had not been updated when I moved to
5110 the latest autoconf.
5111
5112
5113 Version 3.5 15-Aug-01
5114 ---------------------
5115
5116 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
5117 had been forgotten.
5118
5119 2. By using declared but undefined structures, we can avoid using "void"
5120 definitions in pcre.h while keeping the internal definitions of the structures
5121 private.
5122
5123 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
5124 user point of view, this means that both static and shared libraries are built
5125 by default, but this can be individually controlled. More of the work of
5126 handling this static/shared cases is now inside libtool instead of PCRE's make
5127 file.
5128
5129 4. The pcretest utility is now installed along with pcregrep because it is
5130 useful for users (to test regexs) and by doing this, it automatically gets
5131 relinked by libtool. The documentation has been turned into a man page, so
5132 there are now .1, .txt, and .html versions in /doc.
5133
5134 5. Upgrades to pcregrep:
5135 (i) Added long-form option names like gnu grep.
5136 (ii) Added --help to list all options with an explanatory phrase.
5137 (iii) Added -r, --recursive to recurse into sub-directories.
5138 (iv) Added -f, --file to read patterns from a file.
5139
5140 6. pcre_exec() was referring to its "code" argument before testing that
5141 argument for NULL (and giving an error if it was NULL).
5142
5143 7. Upgraded Makefile.in to allow for compiling in a different directory from
5144 the source directory.
5145
5146 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
5147 options bits, the pointer it was passed was to an int instead of to an unsigned
5148 long int. This mattered only on 64-bit systems.
5149
5150 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
5151 generated) instead of pcre.in, which it its source. Also made the same change
5152 in several of the .c files.
5153
5154 10. A new release of gcc defines printf() as a macro, which broke pcretest
5155 because it had an ifdef in the middle of a string argument for printf(). Fixed
5156 by using separate calls to printf().
5157
5158 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
5159 script, to force use of CR or LF instead of \n in the source. On non-Unix
5160 systems, the value can be set in config.h.
5161
5162 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
5163 absolute limit. Changed the text of the error message to make this clear, and
5164 likewise updated the man page.
5165
5166 13. The limit of 99 on the number of capturing subpatterns has been removed.
5167 The new limit is 65535, which I hope will not be a "real" limit.
5168
5169
5170 Version 3.4 22-Aug-00
5171 ---------------------
5172
5173 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
5174
5175 2. Diagnose condition (?(0) as an error instead of crashing on matching.
5176
5177
5178 Version 3.3 01-Aug-00
5179 ---------------------
5180
5181 1. If an octal character was given, but the value was greater than \377, it
5182 was not getting masked to the least significant bits, as documented. This could
5183 lead to crashes in some systems.
5184
5185 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
5186 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
5187
5188 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
5189 These just pass their arguments on to (pcre_free)(), but they are provided
5190 because some uses of PCRE bind it to non-C systems that can call its functions,
5191 but cannot call free() or pcre_free() directly.
5192
5193 4. Add "make test" as a synonym for "make check". Corrected some comments in
5194 the Makefile.
5195
5196 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
5197 Makefile.
5198
5199 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
5200 command called pgrep for grepping around the active processes.
5201
5202 7. Added the beginnings of support for UTF-8 character strings.
5203
5204 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
5205 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
5206 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
5207 out for the ar command.)
5208
5209
5210 Version 3.2 12-May-00
5211 ---------------------
5212
5213 This is purely a bug fixing release.
5214
5215 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
5216 of ZA. This was just one example of several cases that could provoke this bug,
5217 which was introduced by change 9 of version 2.00. The code for breaking
5218 infinite loops after an iteration that matches an empty string was't working
5219 correctly.
5220
5221 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
5222 when matched against abbab (for example). After matching an empty string, it
5223 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
5224 caused it to match further down the string than it should.
5225
5226 3. The code contained an inclusion of sys/types.h. It isn't clear why this
5227 was there because it doesn't seem to be needed, and it causes trouble on some
5228 systems, as it is not a Standard C header. It has been removed.
5229
5230 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
5231 were reported on the Macintosh. The changes were from
5232
5233 while ((c = *(++ptr)) != 0 && c != '\n');
5234 to
5235 while ((c = *(++ptr)) != 0 && c != '\n') ;
5236
5237 Totally extraordinary, but if that's what it takes...
5238
5239 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
5240 available. Added HAVE_BCOPY and an autoconf test for it; if neither
5241 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
5242 assumes the way PCRE uses memmove() (always moving upwards).
5243
5244 6. PCRE is being used in one environment where strchr() is not available. There
5245 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
5246 faster code anyway.
5247
5248
5249 Version 3.1 09-Feb-00
5250 ---------------------
5251
5252 The only change in this release is the fixing of some bugs in Makefile.in for
5253 the "install" target:
5254
5255 (1) It was failing to install pcreposix.h.
5256
5257 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
5258
5259
5260 Version 3.0 01-Feb-00
5261 ---------------------
5262
5263 1. Add support for the /+ modifier to perltest (to output $` like it does in
5264 pcretest).
5265
5266 2. Add support for the /g modifier to perltest.
5267
5268 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
5269 matches null strings.
5270
5271 4. Fix perltest so that it doesn't do unwanted things when fed an empty
5272 pattern. Perl treats empty patterns specially - it reuses the most recent
5273 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
5274 effect.
5275
5276 5. The POSIX interface was broken in that it was just handing over the POSIX
5277 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
5278 required a bigger vector, with some working space on the end. This means that
5279 the POSIX wrapper now has to get and free some memory, and copy the results.
5280
5281 6. Added some simple autoconf support, placing the test data and the
5282 documentation in separate directories, re-organizing some of the
5283 information files, and making it build pcre-config (a GNU standard). Also added
5284 libtool support for building PCRE as a shared library, which is now the
5285 default.
5286
5287 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
5288 09 are not valid octal constants. Single digits will be used for minor values
5289 less than 10.
5290
5291 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
5292 existing programs that set these in the POSIX interface can use PCRE without
5293 modification.
5294
5295 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
5296 return all that pcre_info() returns, plus additional data. The pcre_info()
5297 function is retained for compatibility, but is considered to be obsolete.
5298
5299 10. Added experimental recursion feature (?R) to handle one common case that
5300 Perl 5.6 will be able to do with (?p{...}).
5301
5302 11. Added support for POSIX character classes like [:alpha:], which Perl is
5303 adopting.
5304
5305
5306 Version 2.08 31-Aug-99
5307 ----------------------
5308
5309 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
5310 trying to match at the startoffset position, but instead was moving forward to
5311 the next newline as if a previous match had failed.
5312
5313 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
5314 and could get into a loop if a null string was matched other than at the start
5315 of the subject.
5316
5317 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
5318 be distinguished at compile time, and for completeness also added PCRE_DATE.
5319
5320 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
5321 in GnuWin32 environments.
5322
5323
5324 Version 2.07 29-Jul-99
5325 ----------------------
5326
5327 1. The documentation is now supplied in plain text form and HTML as well as in
5328 the form of man page sources.
5329
5330 2. C++ compilers don't like assigning (void *) values to other pointer types.
5331 In particular this affects malloc(). Although there is no problem in Standard
5332 C, I've put in casts to keep C++ compilers happy.
5333
5334 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
5335 should be (const char *).
5336
5337 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
5338 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
5339 However, I haven't made this a standard facility. The documentation doesn't
5340 mention it, and the Makefile doesn't support it.
5341
5342 5. The Makefile now contains an "install" target, with editable destinations at
5343 the top of the file. The pcretest program is not installed.
5344
5345 6. pgrep -V now gives the PCRE version number and date.
5346
5347 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
5348 causing the entire string to be ignored, instead of just the last character.
5349
5350 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
5351 non-matching string, it can take a very, very long time, even for strings of
5352 quite modest length, because of the nested recursion. PCRE now does better in
5353 some of these cases. It does this by remembering the last required literal
5354 character in the pattern, and pre-searching the subject to ensure it is present
5355 before running the real match. In other words, it applies a heuristic to detect
5356 some types of certain failure quickly, and in the above example, if presented
5357 with a string that has no trailing " it gives "no match" very quickly.
5358
5359 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
5360 other alternatives are tried instead.
5361
5362
5363 Version 2.06 09-Jun-99
5364 ----------------------
5365
5366 1. Change pcretest's output for amount of store used to show just the code
5367 space, because the remainder (the data block) varies in size between 32-bit and
5368 64-bit systems.
5369
5370 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
5371 start matching at. This allows lookbehinds to work when searching for multiple
5372 occurrences in a string.
5373
5374 3. Added additional options to pcretest for testing multiple occurrences:
5375
5376 /+ outputs the rest of the string that follows a match
5377 /g loops for multiple occurrences, using the new startoffset argument
5378 /G loops for multiple occurrences by passing an incremented pointer
5379
5380 4. PCRE wasn't doing the "first character" optimization for patterns starting
5381 with \b or \B, though it was doing it for other lookbehind assertions. That is,
5382 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
5383 the letter 'x'. On long subject strings, this gives a significant speed-up.
5384
5385
5386 Version 2.05 21-Apr-99
5387 ----------------------
5388
5389 1. Changed the type of magic_number from int to long int so that it works
5390 properly on 16-bit systems.
5391
5392 2. Fixed a bug which caused patterns starting with .* not to work correctly
5393 when the subject string contained newline characters. PCRE was assuming
5394 anchoring for such patterns in all cases, which is not correct because .* will
5395 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
5396 DOTALL is set at top level; otherwise it knows that patterns starting with .*
5397 must be retried after every newline in the subject.
5398
5399
5400 Version 2.04 18-Feb-99
5401 ----------------------
5402
5403 1. For parenthesized subpatterns with repeats whose minimum was zero, the
5404 computation of the store needed to hold the pattern was incorrect (too large).
5405 If such patterns were nested a few deep, this could multiply and become a real
5406 problem.
5407
5408 2. Added /M option to pcretest to show the memory requirement of a specific
5409 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
5410
5411 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
5412 compiled in such a way that the backtracking after subsequent failure was
5413 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
5414 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
5415
5416
5417 Version 2.03 02-Feb-99
5418 ----------------------
5419
5420 1. Fixed typo and small mistake in man page.
5421
5422 2. Added 4th condition (GPL supersedes if conflict) and created separate
5423 LICENCE file containing the conditions.
5424
5425 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
5426 Perl, that is the internal \ allows the delimiter to be included in the
5427 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
5428 the final delimiter, add \ to the end of the pattern (to test the error).
5429
5430 4. Added the convenience functions for extracting substrings after a successful
5431 match. Updated pcretest to make it able to test these functions.
5432
5433
5434 Version 2.02 14-Jan-99
5435 ----------------------
5436
5437 1. Initialized the working variables associated with each extraction so that
5438 their saving and restoring doesn't refer to uninitialized store.
5439
5440 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
5441 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
5442 fix the problem.
5443
5444 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
5445 calls, and wasn't printing the correct value for compiling calls. Increased the
5446 default value of LOOPREPEAT, and the number of significant figures in the
5447 times.
5448
5449 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
5450
5451 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
5452 a building problem on Windows NT with a FAT file system.
5453
5454
5455 Version 2.01 21-Oct-98
5456 ----------------------
5457
5458 1. Changed the API for pcre_compile() to allow for the provision of a pointer
5459 to character tables built by pcre_maketables() in the current locale. If NULL
5460 is passed, the default tables are used.
5461
5462
5463 Version 2.00 24-Sep-98
5464 ----------------------
5465
5466 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
5467 it any more.
5468
5469 2. Allow quantification of (?>) groups, and make it work correctly.
5470
5471 3. The first character computation wasn't working for (?>) groups.
5472
5473 4. Correct the implementation of \Z (it is permitted to match on the \n at the
5474 end of the subject) and add 5.005's \z, which really does match only at the
5475 very end of the subject.
5476
5477 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
5478
5479 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
5480 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
5481 localized options. All options to pcre_study() were also removed.
5482
5483 7. Add other new features from 5.005:
5484
5485 $(?<= positive lookbehind
5486 $(?<! negative lookbehind
5487 (?imsx-imsx) added the unsetting capability
5488 such a setting is global if at outer level; local otherwise
5489 (?imsx-imsx:) non-capturing groups with option setting
5490 (?(cond)re|re) conditional pattern matching
5491
5492 A backreference to itself in a repeated group matches the previous
5493 captured string.
5494
5495 8. General tidying up of studying (both automatic and via "study")
5496 consequential on the addition of new assertions.
5497
5498 9. As in 5.005, unlimited repeated groups that could match an empty substring
5499 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5500 runtime if any iteration does actually match an empty substring.
5501
5502 10. Include the RunTest script in the distribution.
5503
5504 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5505 discrepancies, some of which were old and were also with respect to 5.004. They
5506 have now been fixed.
5507
5508
5509 Version 1.09 28-Apr-98
5510 ----------------------
5511
5512 1. A negated single character class followed by a quantifier with a minimum
5513 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5514 program crashes, or just wrong answers. This did not apply to negated classes
5515 containing more than one character, or to minima other than one.
5516
5517
5518 Version 1.08 27-Mar-98
5519 ----------------------
5520
5521 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5522
5523 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5524 latter must appear before anything that relies on it in the pattern.
5525
5526
5527 Version 1.07 16-Feb-98
5528 ----------------------
5529
5530 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5531 repeat of a potentially empty string).
5532
5533
5534 Version 1.06 23-Jan-98
5535 ----------------------
5536
5537 1. Added Markus Oberhumer's little patches for C++.
5538
5539 2. Literal strings longer than 255 characters were broken.
5540
5541
5542 Version 1.05 23-Dec-97
5543 ----------------------
5544
5545 1. Negated character classes containing more than one character were failing if
5546 PCRE_CASELESS was set at run time.
5547
5548
5549 Version 1.04 19-Dec-97
5550 ----------------------
5551
5552 1. Corrected the man page, where some "const" qualifiers had been omitted.
5553
5554 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5555 input syntax.
5556
5557 3. Fixed memory leak which occurred when a regex with back references was
5558 matched with an offsets vector that wasn't big enough. The temporary memory
5559 that is used in this case wasn't being freed if the match failed.
5560
5561 4. Tidied pcretest to ensure it frees memory that it gets.
5562
5563 5. Temporary memory was being obtained in the case where the passed offsets
5564 vector was exactly big enough.
5565
5566 6. Corrected definition of offsetof() from change 5 below.
5567
5568 7. I had screwed up change 6 below and broken the rules for the use of
5569 setjmp(). Now fixed.
5570
5571
5572 Version 1.03 18-Dec-97
5573 ----------------------
5574
5575 1. A erroneous regex with a missing opening parenthesis was correctly
5576 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5577 on some systems.
5578
5579 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5580 it was reported that one broken compiler failed on the former because "code" is
5581 also an independent variable.
5582
5583 3. The erroneous regex a[]b caused an array overrun reference.
5584
5585 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5586 fail on data ending with that character. (It was going on too far, and checking
5587 the next character, typically a binary zero.) This was specific to the
5588 optimized code for single-character negative classes.
5589
5590 5. Added a contributed patch from the TIN world which does the following:
5591
5592 + Add an undef for memmove, in case the the system defines a macro for it.
5593
5594 + Add a definition of offsetof(), in case there isn't one. (I don't know
5595 the reason behind this - offsetof() is part of the ANSI standard - but
5596 it does no harm).
5597
5598 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
5599 most of the places where whitespace preceded '#'. I have given up and
5600 allowed the remaining 2 cases to be at the margin.
5601
5602 + Rename some variables in pcre to eliminate shadowing. This seems very
5603 pedantic, but does no harm, of course.
5604
5605 6. Moved the call to setjmp() into its own function, to get rid of warnings
5606 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
5607
5608 7. Constructs such as \d{8,} were compiling into the equivalent of
5609 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
5610 outcome, but in this particular case used more store than had been allocated,
5611 which caused the bug to be discovered because it threw up an internal error.
5612
5613 8. The debugging code in both pcre and pcretest for outputting the compiled
5614 form of a regex was going wrong in the case of back references followed by
5615 curly-bracketed repeats.
5616
5617
5618 Version 1.02 12-Dec-97
5619 ----------------------
5620
5621 1. Typos in pcre.3 and comments in the source fixed.
5622
5623 2. Applied a contributed patch to get rid of places where it used to remove
5624 'const' from variables, and fixed some signed/unsigned and uninitialized
5625 variable warnings.
5626
5627 3. Added the "runtest" target to Makefile.
5628
5629 4. Set default compiler flag to -O2 rather than just -O.
5630
5631
5632 Version 1.01 19-Nov-97
5633 ----------------------
5634
5635 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
5636 like /([ab]*)*/, that is, for classes with more than one character in them.
5637
5638 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
5639 as /((?>a*))*/ (a PCRE_EXTRA facility).
5640
5641
5642 Version 1.00 18-Nov-97
5643 ----------------------
5644
5645 1. Added compile-time macros to support systems such as SunOS4 which don't have
5646 memmove() or strerror() but have other things that can be used instead.
5647
5648 2. Arranged that "make clean" removes the executables.
5649
5650
5651 Version 0.99 27-Oct-97
5652 ----------------------
5653
5654 1. Fixed bug in code for optimizing classes with only one character. It was
5655 initializing a 32-byte map regardless, which could cause it to run off the end
5656 of the memory it had got.
5657
5658 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
5659
5660
5661 Version 0.98 22-Oct-97
5662 ----------------------
5663
5664 1. Fixed bug in code for handling temporary memory usage when there are more
5665 back references than supplied space in the ovector. This could cause segfaults.
5666
5667
5668 Version 0.97 21-Oct-97
5669 ----------------------
5670
5671 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
5672
5673 2. Optimized negated single characters not to use a bit map.
5674
5675 3. Brought error texts together as macro definitions; clarified some of them;
5676 fixed one that was wrong - it said "range out of order" when it meant "invalid
5677 escape sequence".
5678
5679 4. Changed some char * arguments to const char *.
5680
5681 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
5682
5683 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
5684 pcretest.
5685
5686
5687 Version 0.96 16-Oct-97
5688 ----------------------
5689
5690 1. Added a simple "pgrep" utility to the distribution.
5691
5692 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
5693 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
5694 where "ddd" means "one or more decimal digits".
5695
5696 3. Fixed serious bug. If a pattern had a back reference, but the call to
5697 pcre_exec() didn't supply a large enough ovector to record the related
5698 identifying subpattern, the match always failed. PCRE now remembers the number
5699 of the largest back reference, and gets some temporary memory in which to save
5700 the offsets during matching if necessary, in order to ensure that
5701 backreferences always work.
5702
5703 4. Increased the compatibility with Perl in a number of ways:
5704
5705 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
5706 to request this handling. The option can be set at compile or exec time.
5707
5708 (b) $ matches before a terminating newline by default; an option
5709 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
5710 mode). The option can be set at compile or exec time.
5711
5712 (c) The handling of \ followed by a digit other than 0 is now supposed to be
5713 the same as Perl's. If the decimal number it represents is less than 10
5714 or there aren't that many previous left capturing parentheses, an octal
5715 escape is read. Inside a character class, it's always an octal escape,
5716 even if it is a single digit.
5717
5718 (d) An escaped but undefined alphabetic character is taken as a literal,
5719 unless PCRE_EXTRA is set. Currently this just reserves the remaining
5720 escapes.
5721
5722 (e) {0} is now permitted. (The previous item is removed from the compiled
5723 pattern).
5724
5725 5. Changed all the names of code files so that the basic parts are no longer
5726 than 10 characters, and abolished the teeny "globals.c" file.
5727
5728 6. Changed the handling of character classes; they are now done with a 32-byte
5729 bit map always.
5730
5731 7. Added the -d and /D options to pcretest to make it possible to look at the
5732 internals of compilation without having to recompile pcre.
5733
5734
5735 Version 0.95 23-Sep-97
5736 ----------------------
5737
5738 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
5739 \x20 at the start of a run of normal characters. These were being treated as
5740 real characters, instead of the source characters being re-checked.
5741
5742
5743 Version 0.94 18-Sep-97
5744 ----------------------
5745
5746 1. The functions are now thread-safe, with the caveat that the global variables
5747 containing pointers to malloc() and free() or alternative functions are the
5748 same for all threads.
5749
5750 2. Get pcre_study() to generate a bitmap of initial characters for non-
5751 anchored patterns when this is possible, and use it if passed to pcre_exec().
5752
5753
5754 Version 0.93 15-Sep-97
5755 ----------------------
5756
5757 1. /(b)|(:+)/ was computing an incorrect first character.
5758
5759 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
5760 but not actually doing anything yet.
5761
5762 3. Treat "-" characters in classes that cannot be part of ranges as literals,
5763 as Perl does (e.g. [-az] or [az-]).
5764
5765 4. Set the anchored flag if a branch starts with .* or .*? because that tests
5766 all possible positions.
5767
5768 5. Split up into different modules to avoid including unneeded functions in a
5769 compiled binary. However, compile and exec are still in one module. The "study"
5770 function is split off.
5771
5772 6. The character tables are now in a separate module whose source is generated
5773 by an auxiliary program - but can then be edited by hand if required. There are
5774 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
5775 toupper() in the code.
5776
5777 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
5778 make them global. Abolish the function for setting them, as the caller can now
5779 set them directly.
5780
5781
5782 Version 0.92 11-Sep-97
5783 ----------------------
5784
5785 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
5786 (e.g. /a{1,3}/) was broken (I mis-optimized it).
5787
5788 2. Caseless matching was not working in character classes if the characters in
5789 the pattern were in upper case.
5790
5791 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
5792
5793 4. Make PCRE_ANCHORED public and accept as a compile option.
5794
5795 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
5796 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
5797 pass them.
5798
5799 6. Give an error if bad option bits passed at compile or run time.
5800
5801 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
5802 pcretest to cause it to pass that flag.
5803
5804 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
5805 options, and the first character, if set.
5806
5807 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
5808
5809
5810 Version 0.91 10-Sep-97
5811 ----------------------
5812
5813 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
5814 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
5815
5816 2. PCRE was looping on encountering an indefinitely repeated back reference to
5817 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
5818 Perl does - treats the match as successful.
5819
5820 ****

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