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Revision 1763 - (show annotations)
Wed Feb 12 17:37:05 2020 UTC (3 months, 2 weeks ago) by ph10
File size: 299143 byte(s)
Error occurred while calculating annotation data.
Final tidies and documentation updates for 8.44.
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
8 Version 8.44 12 February-2020
9 -----------------------------
10
11 1. Setting --enable-jit=auto for an out-of-tree build failed because the
12 source directory wasn't in the search path for AC_TRY_COMPILE always. Patch
13 from Ross Burton.
14
15 2. Applied a patch from Michael Shigorin to fix 8.43 build on e2k arch
16 with lcc compiler (EDG frontend based); the problem it fixes is:
17
18 lcc: "pcrecpp.cc", line 74: error: declaration aliased to undefined entity
19 "_ZN7pcrecpp2RE6no_argE" [-Werror]
20
21 3. Change 2 for 8.43 omitted (*LF) from the list of start-of-pattern items. Now
22 added.
23
24 4. Fix ARMv5 JIT improper handling of labels right after a constant pool.
25
26 5. Small patch to pcreposix.c to set the erroroffset field to -1 immediately
27 after a successful compile, instead of at the start of matching to avoid a
28 sanitizer complaint (regexec is supposed to be thread safe).
29
30 6. Check the size of the number after (?C as it is read, in order to avoid
31 integer overflow.
32
33 7. Tidy up left shifts to avoid sanitize warnings; also fix one NULL deference
34 in pcretest.
35
36
37 Version 8.43 23-February-2019
38 -----------------------------
39
40 1. Some time ago the config macro SUPPORT_UTF8 was changed to SUPPORT_UTF
41 because it also applies to UTF-16 and UTF-32. However, this change was not made
42 in the pcre2cpp files; consequently the C++ wrapper has from then been compiled
43 with a bug in it, which would have been picked up by the unit test except that
44 it also had its UTF8 code cut out. The bug was in a global replace when moving
45 forward after matching an empty string.
46
47 2. The C++ wrapper got broken a long time ago (version 7.3, August 2007) when
48 (*CR) was invented (assuming it was the first such start-of-pattern option).
49 The wrapper could never handle such patterns because it wraps patterns in
50 (?:...)\z in order to support end anchoring. I have hacked in some code to fix
51 this, that is, move the wrapping till after any existing start-of-pattern
52 special settings.
53
54 3. "pcre2grep" (sic) was accidentally mentioned in an error message (fix was
55 ported from PCRE2).
56
57 4. Typo LCC_ALL for LC_ALL fixed in pcregrep.
58
59 5. In a pattern such as /[^\x{100}-\x{ffff}]*[\x80-\xff]/ which has a repeated
60 negative class with no characters less than 0x100 followed by a positive class
61 with only characters less than 0x100, the first class was incorrectly being
62 auto-possessified, causing incorrect match failures.
63
64 6. If the only branch in a conditional subpattern was anchored, the whole
65 subpattern was treated as anchored, when it should not have been, since the
66 assumed empty second branch cannot be anchored. Demonstrated by test patterns
67 such as /(?(1)^())b/ or /(?(?=^))b/.
68
69 7. Fix subject buffer overread in JIT when UTF is disabled and \X or \R has
70 a greater than 1 fixed quantifier. This issue was found by Yunho Kim.
71
72 8. If a pattern started with a subroutine call that had a quantifier with a
73 minimum of zero, an incorrect "match must start with this character" could be
74 recorded. Example: /(?&xxx)*ABC(?<xxx>XYZ)/ would (incorrectly) expect 'A' to
75 be the first character of a match.
76
77 9. Improve MAP_JIT flag usage on MacOS. Patch by Rich Siegel.
78
79
80 Version 8.42 20-March-2018
81 --------------------------
82
83 1. Fixed a MIPS issue in the JIT compiler reported by Joshua Kinard.
84
85 2. Fixed outdated real_pcre definitions in pcre.h.in (patch by Evgeny Kotkov).
86
87 3. pcregrep was truncating components of file names to 128 characters when
88 processing files with the -r option, and also (some very odd code) truncating
89 path names to 512 characters. There is now a check on the absolute length of
90 full path file names, which may be up to 2047 characters long.
91
92 4. Using pcre_dfa_exec(), in UTF mode when UCP support was not defined, there
93 was the possibility of a false positive match when caselessly matching a "not
94 this character" item such as [^\x{1234}] (with a code point greater than 127)
95 because the "other case" variable was not being initialized.
96
97 5. Although pcre_jit_exec checks whether the pattern is compiled
98 in a given mode, it was also expected that at least one mode is available.
99 This is fixed and pcre_jit_exec returns with PCRE_ERROR_JIT_BADOPTION
100 when the pattern is not optimized by JIT at all.
101
102 6. The line number and related variables such as match counts in pcregrep
103 were all int variables, causing overflow when files with more than 2147483647
104 lines were processed (assuming 32-bit ints). They have all been changed to
105 unsigned long ints.
106
107 7. If a backreference with a minimum repeat count of zero was first in a
108 pattern, apart from assertions, an incorrect first matching character could be
109 recorded. For example, for the pattern /(?=(a))\1?b/, "b" was incorrectly set
110 as the first character of a match.
111
112 8. Fix out-of-bounds read for partial matching of /./ against an empty string
113 when the newline type is CRLF.
114
115 9. When matching using the the REG_STARTEND feature of the POSIX API with a
116 non-zero starting offset, unset capturing groups with lower numbers than a
117 group that did capture something were not being correctly returned as "unset"
118 (that is, with offset values of -1).
119
120 10. Matching the pattern /(*UTF)\C[^\v]+\x80/ against an 8-bit string
121 containing multi-code-unit characters caused bad behaviour and possibly a
122 crash. This issue was fixed for other kinds of repeat in release 8.37 by change
123 38, but repeating character classes were overlooked.
124
125 11. A small fix to pcregrep to avoid compiler warnings for -Wformat-overflow=2.
126
127 12. Added --enable-jit=auto support to configure.ac.
128
129 13. Fix misleading error message in configure.ac.
130
131
132 Version 8.41 05-July-2017
133 -------------------------
134
135 1. Fixed typo in CMakeLists.txt (wrong number of arguments for
136 PCRE_STATIC_RUNTIME (affects MSVC only).
137
138 2. Issue 1 for 8.40 below was not correctly fixed. If pcregrep in multiline
139 mode with --only-matching matched several lines, it restarted scanning at the
140 next line instead of moving on to the end of the matched string, which can be
141 several lines after the start.
142
143 3. Fix a missing else in the JIT compiler reported by 'idaifish'.
144
145 4. A (?# style comment is now ignored between a basic quantifier and a
146 following '+' or '?' (example: /X+(?#comment)?Y/.
147
148 5. Avoid use of a potentially overflowing buffer in pcregrep (patch by Petr
149 Pisar).
150
151 6. Fuzzers have reported issues in pcretest. These are NOT serious (it is,
152 after all, just a test program). However, to stop the reports, some easy ones
153 are fixed:
154
155 (a) Check for values < 256 when calling isprint() in pcretest.
156 (b) Give an error for too big a number after \O.
157
158 7. In the 32-bit library in non-UTF mode, an attempt to find a Unicode
159 property for a character with a code point greater than 0x10ffff (the Unicode
160 maximum) caused a crash.
161
162 8. The alternative matching function, pcre_dfa_exec() misbehaved if it
163 encountered a character class with a possessive repeat, for example [a-f]{3}+.
164
165 9. When pcretest called pcre_copy_substring() in 32-bit mode, it set the buffer
166 length incorrectly, which could result in buffer overflow.
167
168 10. Remove redundant line of code (accidentally left in ages ago).
169
170 11. Applied C++ patch from Irfan Adilovic to guard 'using std::' directives
171 with namespace pcrecpp (Bugzilla #2084).
172
173 12. Remove a duplication typo in pcre_tables.c.
174
175 13. Fix returned offsets from regexec() when REG_STARTEND is used with a
176 starting offset greater than zero.
177
178
179 Version 8.40 11-January-2017
180 ----------------------------
181
182 1. Using -o with -M in pcregrep could cause unnecessary repeated output when
183 the match extended over a line boundary.
184
185 2. Applied Chris Wilson's second patch (Bugzilla #1681) to CMakeLists.txt for
186 MSVC static compilation, putting the first patch under a new option.
187
188 3. Fix register overwite in JIT when SSE2 acceleration is enabled.
189
190 4. Ignore "show all captures" (/=) for DFA matching.
191
192 5. Fix JIT unaligned accesses on x86. Patch by Marc Mutz.
193
194 6. In any wide-character mode (8-bit UTF or any 16-bit or 32-bit mode),
195 without PCRE_UCP set, a negative character type such as \D in a positive
196 class should cause all characters greater than 255 to match, whatever else
197 is in the class. There was a bug that caused this not to happen if a
198 Unicode property item was added to such a class, for example [\D\P{Nd}] or
199 [\W\pL].
200
201 7. When pcretest was outputing information from a callout, the caret indicator
202 for the current position in the subject line was incorrect if it was after
203 an escape sequence for a character whose code point was greater than
204 \x{ff}.
205
206 8. A pattern such as (?<RA>abc)(?(R)xyz) was incorrectly compiled such that
207 the conditional was interpreted as a reference to capturing group 1 instead
208 of a test for recursion. Any group whose name began with R was
209 misinterpreted in this way. (The reference interpretation should only
210 happen if the group's name is precisely "R".)
211
212 9. A number of bugs have been mended relating to match start-up optimizations
213 when the first thing in a pattern is a positive lookahead. These all
214 applied only when PCRE_NO_START_OPTIMIZE was *not* set:
215
216 (a) A pattern such as (?=.*X)X$ was incorrectly optimized as if it needed
217 both an initial 'X' and a following 'X'.
218 (b) Some patterns starting with an assertion that started with .* were
219 incorrectly optimized as having to match at the start of the subject or
220 after a newline. There are cases where this is not true, for example,
221 (?=.*[A-Z])(?=.{8,16})(?!.*[\s]) matches after the start in lines that
222 start with spaces. Starting .* in an assertion is no longer taken as an
223 indication of matching at the start (or after a newline).
224
225
226 Version 8.39 14-June-2016
227 -------------------------
228
229 1. If PCRE_AUTO_CALLOUT was set on a pattern that had a (?# comment between
230 an item and its qualifier (for example, A(?#comment)?B) pcre_compile()
231 misbehaved. This bug was found by the LLVM fuzzer.
232
233 2. Similar to the above, if an isolated \E was present between an item and its
234 qualifier when PCRE_AUTO_CALLOUT was set, pcre_compile() misbehaved. This
235 bug was found by the LLVM fuzzer.
236
237 3. Further to 8.38/46, negated classes such as [^[:^ascii:]\d] were also not
238 working correctly in UCP mode.
239
240 4. The POSIX wrapper function regexec() crashed if the option REG_STARTEND
241 was set when the pmatch argument was NULL. It now returns REG_INVARG.
242
243 5. Allow for up to 32-bit numbers in the ordin() function in pcregrep.
244
245 6. An empty \Q\E sequence between an item and its qualifier caused
246 pcre_compile() to misbehave when auto callouts were enabled. This bug was
247 found by the LLVM fuzzer.
248
249 7. If a pattern that was compiled with PCRE_EXTENDED started with white
250 space or a #-type comment that was followed by (?-x), which turns off
251 PCRE_EXTENDED, and there was no subsequent (?x) to turn it on again,
252 pcre_compile() assumed that (?-x) applied to the whole pattern and
253 consequently mis-compiled it. This bug was found by the LLVM fuzzer.
254
255 8. A call of pcre_copy_named_substring() for a named substring whose number
256 was greater than the space in the ovector could cause a crash.
257
258 9. Yet another buffer overflow bug involved duplicate named groups with a
259 group that reset capture numbers (compare 8.38/7 below). Once again, I have
260 just allowed for more memory, even if not needed. (A proper fix is
261 implemented in PCRE2, but it involves a lot of refactoring.)
262
263 10. pcre_get_substring_list() crashed if the use of \K in a match caused the
264 start of the match to be earlier than the end.
265
266 11. Migrating appropriate PCRE2 JIT improvements to PCRE.
267
268 12. A pattern such as /(?<=((?C)0))/, which has a callout inside a lookbehind
269 assertion, caused pcretest to generate incorrect output, and also to read
270 uninitialized memory (detected by ASAN or valgrind).
271
272 13. A pattern that included (*ACCEPT) in the middle of a sufficiently deeply
273 nested set of parentheses of sufficient size caused an overflow of the
274 compiling workspace (which was diagnosed, but of course is not desirable).
275
276 14. And yet another buffer overflow bug involving duplicate named groups, this
277 time nested, with a nested back reference. Yet again, I have just allowed
278 for more memory, because anything more needs all the refactoring that has
279 been done for PCRE2. An example pattern that provoked this bug is:
280 /((?J)(?'R'(?'R'(?'R'(?'R'(?'R'(?|(\k'R'))))))))/ and the bug was
281 registered as CVE-2016-1283.
282
283 15. pcretest went into a loop if global matching was requested with an ovector
284 size less than 2. It now gives an error message. This bug was found by
285 afl-fuzz.
286
287 16. An invalid pattern fragment such as (?(?C)0 was not diagnosing an error
288 ("assertion expected") when (?(?C) was not followed by an opening
289 parenthesis.
290
291 17. Fixed typo ("&&" for "&") in pcre_study(). Fortunately, this could not
292 actually affect anything, by sheer luck.
293
294 18. Applied Chris Wilson's patch (Bugzilla #1681) to CMakeLists.txt for MSVC
295 static compilation.
296
297 19. Modified the RunTest script to incorporate a valgrind suppressions file so
298 that certain errors, provoked by the SSE2 instruction set when JIT is used,
299 are ignored.
300
301 20. A racing condition is fixed in JIT reported by Mozilla.
302
303 21. Minor code refactor to avoid "array subscript is below array bounds"
304 compiler warning.
305
306 22. Minor code refactor to avoid "left shift of negative number" warning.
307
308 23. Fix typo causing compile error when 16- or 32-bit JIT is compiled without
309 UCP support.
310
311 24. Refactor to avoid compiler warnings in pcrecpp.cc.
312
313 25. Refactor to fix a typo in pcre_jit_test.c
314
315 26. Patch to support compiling pcrecpp.cc with Intel compiler.
316
317
318 Version 8.38 23-November-2015
319 -----------------------------
320
321 1. If a group that contained a recursive back reference also contained a
322 forward reference subroutine call followed by a non-forward-reference
323 subroutine call, for example /.((?2)(?R)\1)()/, pcre_compile() failed to
324 compile correct code, leading to undefined behaviour or an internally
325 detected error. This bug was discovered by the LLVM fuzzer.
326
327 2. Quantification of certain items (e.g. atomic back references) could cause
328 incorrect code to be compiled when recursive forward references were
329 involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
330 This bug was discovered by the LLVM fuzzer.
331
332 3. A repeated conditional group whose condition was a reference by name caused
333 a buffer overflow if there was more than one group with the given name.
334 This bug was discovered by the LLVM fuzzer.
335
336 4. A recursive back reference by name within a group that had the same name as
337 another group caused a buffer overflow. For example:
338 /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
339
340 5. A forward reference by name to a group whose number is the same as the
341 current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
342 a buffer overflow at compile time. This bug was discovered by the LLVM
343 fuzzer.
344
345 6. A lookbehind assertion within a set of mutually recursive subpatterns could
346 provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
347
348 7. Another buffer overflow bug involved duplicate named groups with a
349 reference between their definition, with a group that reset capture
350 numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
351 fixed by always allowing for more memory, even if not needed. (A proper fix
352 is implemented in PCRE2, but it involves more refactoring.)
353
354 8. There was no check for integer overflow in subroutine calls such as (?123).
355
356 9. The table entry for \l in EBCDIC environments was incorrect, leading to its
357 being treated as a literal 'l' instead of causing an error.
358
359 10. There was a buffer overflow if pcre_exec() was called with an ovector of
360 size 1. This bug was found by american fuzzy lop.
361
362 11. If a non-capturing group containing a conditional group that could match
363 an empty string was repeated, it was not identified as matching an empty
364 string itself. For example: /^(?:(?(1)x|)+)+$()/.
365
366 12. In an EBCDIC environment, pcretest was mishandling the escape sequences
367 \a and \e in test subject lines.
368
369 13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
370 instead of the EBCDIC value.
371
372 14. The handling of \c in an EBCDIC environment has been revised so that it is
373 now compatible with the specification in Perl's perlebcdic page.
374
375 15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
376 ASCII/Unicode. This has now been added to the list of characters that are
377 recognized as white space in EBCDIC.
378
379 16. When PCRE was compiled without UCP support, the use of \p and \P gave an
380 error (correctly) when used outside a class, but did not give an error
381 within a class.
382
383 17. \h within a class was incorrectly compiled in EBCDIC environments.
384
385 18. A pattern with an unmatched closing parenthesis that contained a backward
386 assertion which itself contained a forward reference caused buffer
387 overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
388
389 19. JIT should return with error when the compiled pattern requires more stack
390 space than the maximum.
391
392 20. A possessively repeated conditional group that could match an empty string,
393 for example, /(?(R))*+/, was incorrectly compiled.
394
395 21. Fix infinite recursion in the JIT compiler when certain patterns such as
396 /(?:|a|){100}x/ are analysed.
397
398 22. Some patterns with character classes involving [: and \\ were incorrectly
399 compiled and could cause reading from uninitialized memory or an incorrect
400 error diagnosis.
401
402 23. Pathological patterns containing many nested occurrences of [: caused
403 pcre_compile() to run for a very long time.
404
405 24. A conditional group with only one branch has an implicit empty alternative
406 branch and must therefore be treated as potentially matching an empty
407 string.
408
409 25. If (?R was followed by - or + incorrect behaviour happened instead of a
410 diagnostic.
411
412 26. Arrange to give up on finding the minimum matching length for overly
413 complex patterns.
414
415 27. Similar to (4) above: in a pattern with duplicated named groups and an
416 occurrence of (?| it is possible for an apparently non-recursive back
417 reference to become recursive if a later named group with the relevant
418 number is encountered. This could lead to a buffer overflow. Wen Guanxing
419 from Venustech ADLAB discovered this bug.
420
421 28. If pcregrep was given the -q option with -c or -l, or when handling a
422 binary file, it incorrectly wrote output to stdout.
423
424 29. The JIT compiler did not restore the control verb head in case of *THEN
425 control verbs. This issue was found by Karl Skomski with a custom LLVM
426 fuzzer.
427
428 30. Error messages for syntax errors following \g and \k were giving inaccurate
429 offsets in the pattern.
430
431 31. Added a check for integer overflow in conditions (?(<digits>) and
432 (?(R<digits>). This omission was discovered by Karl Skomski with the LLVM
433 fuzzer.
434
435 32. Handling recursive references such as (?2) when the reference is to a group
436 later in the pattern uses code that is very hacked about and error-prone.
437 It has been re-written for PCRE2. Here in PCRE1, a check has been added to
438 give an internal error if it is obvious that compiling has gone wrong.
439
440 33. The JIT compiler should not check repeats after a {0,1} repeat byte code.
441 This issue was found by Karl Skomski with a custom LLVM fuzzer.
442
443 34. The JIT compiler should restore the control chain for empty possessive
444 repeats. This issue was found by Karl Skomski with a custom LLVM fuzzer.
445
446 35. Match limit check added to JIT recursion. This issue was found by Karl
447 Skomski with a custom LLVM fuzzer.
448
449 36. Yet another case similar to 27 above has been circumvented by an
450 unconditional allocation of extra memory. This issue is fixed "properly" in
451 PCRE2 by refactoring the way references are handled. Wen Guanxing
452 from Venustech ADLAB discovered this bug.
453
454 37. Fix two assertion fails in JIT. These issues were found by Karl Skomski
455 with a custom LLVM fuzzer.
456
457 38. Fixed a corner case of range optimization in JIT.
458
459 39. An incorrect error "overran compiling workspace" was given if there were
460 exactly enough group forward references such that the last one extended
461 into the workspace safety margin. The next one would have expanded the
462 workspace. The test for overflow was not including the safety margin.
463
464 40. A match limit issue is fixed in JIT which was found by Karl Skomski
465 with a custom LLVM fuzzer.
466
467 41. Remove the use of /dev/null in testdata/testinput2, because it doesn't
468 work under Windows. (Why has it taken so long for anyone to notice?)
469
470 42. In a character class such as [\W\p{Any}] where both a negative-type escape
471 ("not a word character") and a property escape were present, the property
472 escape was being ignored.
473
474 43. Fix crash caused by very long (*MARK) or (*THEN) names.
475
476 44. A sequence such as [[:punct:]b] that is, a POSIX character class followed
477 by a single ASCII character in a class item, was incorrectly compiled in
478 UCP mode. The POSIX class got lost, but only if the single character
479 followed it.
480
481 45. [:punct:] in UCP mode was matching some characters in the range 128-255
482 that should not have been matched.
483
484 46. If [:^ascii:] or [:^xdigit:] or [:^cntrl:] are present in a non-negated
485 class, all characters with code points greater than 255 are in the class.
486 When a Unicode property was also in the class (if PCRE_UCP is set, escapes
487 such as \w are turned into Unicode properties), wide characters were not
488 correctly handled, and could fail to match.
489
490
491 Version 8.37 28-April-2015
492 --------------------------
493
494 1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
495 for those parentheses to be closed with whatever has been captured so far.
496 However, it was failing to mark any other groups between the hightest
497 capture so far and the currrent group as "unset". Thus, the ovector for
498 those groups contained whatever was previously there. An example is the
499 pattern /(x)|((*ACCEPT))/ when matched against "abcd".
500
501 2. If an assertion condition was quantified with a minimum of zero (an odd
502 thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
503
504 3. If a pattern in pcretest input had the P (POSIX) modifier followed by an
505 unrecognized modifier, a crash could occur.
506
507 4. An attempt to do global matching in pcretest with a zero-length ovector
508 caused a crash.
509
510 5. Fixed a memory leak during matching that could occur for a subpattern
511 subroutine call (recursive or otherwise) if the number of captured groups
512 that had to be saved was greater than ten.
513
514 6. Catch a bad opcode during auto-possessification after compiling a bad UTF
515 string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
516 UTF with NO_UTF_CHECK is documented as having an undefined outcome.
517
518 7. A UTF pattern containing a "not" match of a non-ASCII character and a
519 subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
520
521 8. When a pattern is compiled, it remembers the highest back reference so that
522 when matching, if the ovector is too small, extra memory can be obtained to
523 use instead. A conditional subpattern whose condition is a check on a
524 capture having happened, such as, for example in the pattern
525 /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
526 setting the highest backreference number. This mattered only if pcre_exec()
527 was called with an ovector that was too small to hold the capture, and there
528 was no other kind of back reference (a situation which is probably quite
529 rare). The effect of the bug was that the condition was always treated as
530 FALSE when the capture could not be consulted, leading to a incorrect
531 behaviour by pcre_exec(). This bug has been fixed.
532
533 9. A reference to a duplicated named group (either a back reference or a test
534 for being set in a conditional) that occurred in a part of the pattern where
535 PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
536 to be incorrectly calculated, leading to overwriting.
537
538 10. A mutually recursive set of back references such as (\2)(\1) caused a
539 segfault at study time (while trying to find the minimum matching length).
540 The infinite loop is now broken (with the minimum length unset, that is,
541 zero).
542
543 11. If an assertion that was used as a condition was quantified with a minimum
544 of zero, matching went wrong. In particular, if the whole group had
545 unlimited repetition and could match an empty string, a segfault was
546 likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
547 assertions to be quantified, but not if they are being used as conditions,
548 so the above pattern is faulted by Perl. PCRE has now been changed so that
549 it also rejects such patterns.
550
551 12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
552 failed to allow the zero-repeat case if pcre2_exec() was called with an
553 ovector too small to capture the group.
554
555 13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
556 Red Hat Product Security:
557
558 (a) A crash if /K and /F were both set with the option to save the compiled
559 pattern.
560
561 (b) Another crash if the option to print captured substrings in a callout
562 was combined with setting a null ovector, for example \O\C+ as a subject
563 string.
564
565 14. A pattern such as "((?2){0,1999}())?", which has a group containing a
566 forward reference repeated a large (but limited) number of times within a
567 repeated outer group that has a zero minimum quantifier, caused incorrect
568 code to be compiled, leading to the error "internal error:
569 previously-checked referenced subpattern not found" when an incorrect
570 memory address was read. This bug was reported as "heap overflow",
571 discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
572 CVE-2015-2325.
573
574 23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
575 call within a group that also contained a recursive back reference caused
576 incorrect code to be compiled. This bug was reported as "heap overflow",
577 discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
578 number CVE-2015-2326.
579
580 24. Computing the size of the JIT read-only data in advance has been a source
581 of various issues, and new ones are still appear unfortunately. To fix
582 existing and future issues, size computation is eliminated from the code,
583 and replaced by on-demand memory allocation.
584
585 25. A pattern such as /(?i)[A-`]/, where characters in the other case are
586 adjacent to the end of the range, and the range contained characters with
587 more than one other case, caused incorrect behaviour when compiled in UTF
588 mode. In that example, the range a-j was left out of the class.
589
590 26. Fix JIT compilation of conditional blocks, which assertion
591 is converted to (*FAIL). E.g: /(?(?!))/.
592
593 27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
594 discovered by the LLVM fuzzer.
595
596 28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
597 when this assertion was used as a condition, for example (?(?!)a|b). In
598 pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
599 error about an unsupported item.
600
601 29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
602 possessification code could take exponential time to complete. A recursion
603 depth limit of 1000 has been imposed to limit the resources used by this
604 optimization.
605
606 30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
607 such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
608 because \S ensures they are all in the class. The code for doing this was
609 interacting badly with the code for computing the amount of space needed to
610 compile the pattern, leading to a buffer overflow. This bug was discovered
611 by the LLVM fuzzer.
612
613 31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
614 other kinds of group caused stack overflow at compile time. This bug was
615 discovered by the LLVM fuzzer.
616
617 32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
618 between a subroutine call and its quantifier was incorrectly compiled,
619 leading to buffer overflow or other errors. This bug was discovered by the
620 LLVM fuzzer.
621
622 33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
623 assertion after (?(. The code was failing to check the character after
624 (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
625 was discovered by the LLVM fuzzer.
626
627 34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
628 a fixed maximum following a group that contains a subroutine reference was
629 incorrectly compiled and could trigger buffer overflow. This bug was
630 discovered by the LLVM fuzzer.
631
632 35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
633 caused a stack overflow instead of the diagnosis of a non-fixed length
634 lookbehind assertion. This bug was discovered by the LLVM fuzzer.
635
636 36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
637 (e.g. /(?<=\Ka)/) could make pcregrep loop.
638
639 37. There was a similar problem to 36 in pcretest for global matches.
640
641 38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
642 and a subsequent item in the pattern caused a non-match, backtracking over
643 the repeated \X did not stop, but carried on past the start of the subject,
644 causing reference to random memory and/or a segfault. There were also some
645 other cases where backtracking after \C could crash. This set of bugs was
646 discovered by the LLVM fuzzer.
647
648 39. The function for finding the minimum length of a matching string could take
649 a very long time if mutual recursion was present many times in a pattern,
650 for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
651 method has been implemented. This infelicity was discovered by the LLVM
652 fuzzer.
653
654 40. Static linking against the PCRE library using the pkg-config module was
655 failing on missing pthread symbols.
656
657
658 Version 8.36 26-September-2014
659 ------------------------------
660
661 1. Got rid of some compiler warnings in the C++ modules that were shown up by
662 -Wmissing-field-initializers and -Wunused-parameter.
663
664 2. The tests for quantifiers being too big (greater than 65535) were being
665 applied after reading the number, and stupidly assuming that integer
666 overflow would give a negative number. The tests are now applied as the
667 numbers are read.
668
669 3. Tidy code in pcre_exec.c where two branches that used to be different are
670 now the same.
671
672 4. The JIT compiler did not generate match limit checks for certain
673 bracketed expressions with quantifiers. This may lead to exponential
674 backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
675 issue should be resolved now.
676
677 5. Fixed an issue, which occures when nested alternatives are optimized
678 with table jumps.
679
680 6. Inserted two casts and changed some ints to size_t in the light of some
681 reported 64-bit compiler warnings (Bugzilla 1477).
682
683 7. Fixed a bug concerned with zero-minimum possessive groups that could match
684 an empty string, which sometimes were behaving incorrectly in the
685 interpreter (though correctly in the JIT matcher). This pcretest input is
686 an example:
687
688 '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
689 NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
690
691 the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
692 JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
693 for an empty string was breaking the inner loop and carrying on at a lower
694 level, when possessive repeated groups should always return to a higher
695 level as they have no backtrack points in them. The empty string test now
696 occurs at the outer level.
697
698 8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
699 ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
700
701 9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
702 doesn't).
703
704 10. Change 8.34/15 introduced a bug that caused the amount of memory needed
705 to hold a pattern to be incorrectly computed (too small) when there were
706 named back references to duplicated names. This could cause "internal
707 error: code overflow" or "double free or corruption" or other memory
708 handling errors.
709
710 11. When named subpatterns had the same prefixes, back references could be
711 confused. For example, in this pattern:
712
713 /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
714
715 the reference to 'Name' was incorrectly treated as a reference to a
716 duplicate name.
717
718 12. A pattern such as /^s?c/mi8 where the optional character has more than
719 one "other case" was incorrectly compiled such that it would only try to
720 match starting at "c".
721
722 13. When a pattern starting with \s was studied, VT was not included in the
723 list of possible starting characters; this should have been part of the
724 8.34/18 patch.
725
726 14. If a character class started [\Qx]... where x is any character, the class
727 was incorrectly terminated at the ].
728
729 15. If a pattern that started with a caseless match for a character with more
730 than one "other case" was studied, PCRE did not set up the starting code
731 unit bit map for the list of possible characters. Now it does. This is an
732 optimization improvement, not a bug fix.
733
734 16. The Unicode data tables have been updated to Unicode 7.0.0.
735
736 17. Fixed a number of memory leaks in pcregrep.
737
738 18. Avoid a compiler warning (from some compilers) for a function call with
739 a cast that removes "const" from an lvalue by using an intermediate
740 variable (to which the compiler does not object).
741
742 19. Incorrect code was compiled if a group that contained an internal recursive
743 back reference was optional (had quantifier with a minimum of zero). This
744 example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
745 caused segmentation faults because of stack overflows at compile time.
746
747 20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
748 group that is quantified with an indefinite repeat, caused a compile-time
749 loop which used up all the system stack and provoked a segmentation fault.
750 This was not the same bug as 19 above.
751
752 21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
753 Patch by Mike Frysinger.
754
755
756 Version 8.35 04-April-2014
757 --------------------------
758
759 1. A new flag is set, when property checks are present in an XCLASS.
760 When this flag is not set, PCRE can perform certain optimizations
761 such as studying these XCLASS-es.
762
763 2. The auto-possessification of character sets were improved: a normal
764 and an extended character set can be compared now. Furthermore
765 the JIT compiler optimizes more character set checks.
766
767 3. Got rid of some compiler warnings for potentially uninitialized variables
768 that show up only when compiled with -O2.
769
770 4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
771 of a match later then the end of the match. The pcretest program was not
772 handling the case sensibly - it was outputting from the start to the next
773 binary zero. It now reports this situation in a message, and outputs the
774 text from the end to the start.
775
776 5. Fast forward search is improved in JIT. Instead of the first three
777 characters, any three characters with fixed position can be searched.
778 Search order: first, last, middle.
779
780 6. Improve character range checks in JIT. Characters are read by an inprecise
781 function now, which returns with an unknown value if the character code is
782 above a certain threshold (e.g: 256). The only limitation is that the value
783 must be bigger than the threshold as well. This function is useful when
784 the characters above the threshold are handled in the same way.
785
786 7. The macros whose names start with RAWUCHAR are placeholders for a future
787 mode in which only the bottom 21 bits of 32-bit data items are used. To
788 make this more memorable for those maintaining the code, the names have
789 been changed to start with UCHAR21, and an extensive comment has been added
790 to their definition.
791
792 8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
793 to the export list in Makefile.am (they were accidentally omitted from the
794 8.34 tarball).
795
796 9. The informational output from pcretest used the phrase "starting byte set"
797 which is inappropriate for the 16-bit and 32-bit libraries. As the output
798 for "first char" and "need char" really means "non-UTF-char", I've changed
799 "byte" to "char", and slightly reworded the output. The documentation about
800 these values has also been (I hope) clarified.
801
802 10. Another JIT related optimization: use table jumps for selecting the correct
803 backtracking path, when more than four alternatives are present inside a
804 bracket.
805
806 11. Empty match is not possible, when the minimum length is greater than zero,
807 and there is no \K in the pattern. JIT should avoid empty match checks in
808 such cases.
809
810 12. In a caseless character class with UCP support, when a character with more
811 than one alternative case was not the first character of a range, not all
812 the alternative cases were added to the class. For example, s and \x{17f}
813 are both alternative cases for S: the class [RST] was handled correctly,
814 but [R-T] was not.
815
816 13. The configure.ac file always checked for pthread support when JIT was
817 enabled. This is not used in Windows, so I have put this test inside a
818 check for the presence of windows.h (which was already tested for).
819
820 14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
821 The algorithm provides a way to skip certain starting offsets, and usually
822 faster than linear prefix searches.
823
824 15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
825 as for 'fr_FR' and 'french'. For some reason, however, it then used the
826 Windows-specific input and output files, which have 'french' screwed in.
827 So this could never have worked. One of the problems with locales is that
828 they aren't always the same. I have now updated RunTest so that it checks
829 the output of the locale test (test 3) against three different output
830 files, and it allows the test to pass if any one of them matches. With luck
831 this should make the test pass on some versions of Solaris where it was
832 failing. Because of the uncertainty, the script did not used to stop if
833 test 3 failed; it now does. If further versions of a French locale ever
834 come to light, they can now easily be added.
835
836 16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
837 there was a message during ./configure, but it did not stop. This now
838 provokes an error. The invalid example in README has been corrected.
839 If a value less than the minimum is given, the minimum value has always
840 been used, but now a warning is given.
841
842 17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
843 was a bug in the test system, which is now fixed. Also, the list of various
844 configurations that are tested for each release did not have one with both
845 16/32 bits and --enable-bar-anycrlf. It now does.
846
847 18. pcretest was missing "-C bsr" for displaying the \R default setting.
848
849 19. Little endian PowerPC systems are supported now by the JIT compiler.
850
851 20. The fast forward newline mechanism could enter to an infinite loop on
852 certain invalid UTF-8 input. Although we don't support these cases
853 this issue can be fixed by a performance optimization.
854
855 21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
856 not take account if existing stack usage. There is now a new global
857 variable called pcre_stack_guard that can be set to point to an external
858 function to check stack availability. It is called at the start of
859 processing every parenthesized group.
860
861 22. A typo in the code meant that in ungreedy mode the max/min qualifier
862 behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
863 not match "ab".
864
865 23. When UTF was disabled, the JIT program reported some incorrect compile
866 errors. These messages are silenced now.
867
868 24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
869 compiler.
870
871 25. Change all the temporary files used in RunGrepTest to be different to those
872 used by RunTest so that the tests can be run simultaneously, for example by
873 "make -j check".
874
875
876 Version 8.34 15-December-2013
877 -----------------------------
878
879 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
880 executable memory. Patch inspired by Carsten Klein.
881
882 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
883 this macro is never tested and has no effect, because the work to support
884 coverage involves only compiling and linking options and special targets in
885 the Makefile. The comment in config.h implied that defining the macro would
886 enable coverage support, which is totally false. There was also support for
887 setting this macro in the CMake files (my fault, I just copied it from
888 configure). SUPPORT_GCOV has now been removed.
889
890 3. Make a small performance improvement in strlen16() and strlen32() in
891 pcretest.
892
893 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
894 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
895 these cases). There was also one in pcretest.c.
896
897 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
898
899 6. In UTF mode, the code for checking whether a group could match an empty
900 string (which is used for indefinitely repeated groups to allow for
901 breaking an infinite loop) was broken when the group contained a repeated
902 negated single-character class with a character that occupied more than one
903 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
904 UTF-8 mode). The effect was undefined: the group might or might not be
905 deemed as matching an empty string, or the program might have crashed.
906
907 7. The code for checking whether a group could match an empty string was not
908 recognizing that \h, \H, \v, \V, and \R must match a character.
909
910 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
911 an empty string. If it can, pcretest shows this in its information output.
912
913 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
914 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
915 matched by pcre_exec() without using JIT:
916
917 (a) If the rest of the pattern did not match after a maximal run of
918 grapheme clusters, the code for backing up to try with fewer of them
919 did not always back up over a full grapheme when characters that do not
920 have the modifier quality were involved, e.g. Hangul syllables.
921
922 (b) If the match point in a subject started with modifier character, and
923 there was no match, the code could incorrectly back up beyond the match
924 point, and potentially beyond the first character in the subject,
925 leading to a segfault or an incorrect match result.
926
927 10. A conditional group with an assertion condition could lead to PCRE
928 recording an incorrect first data item for a match if no other first data
929 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
930 first data item, and therefore matched "ca" after "c" instead of at the
931 start.
932
933 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
934 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
935
936 12. The source of pcregrep now includes z/OS-specific code so that it can be
937 compiled for z/OS as part of the special z/OS distribution.
938
939 13. Added the -T and -TM options to pcretest.
940
941 14. The code in pcre_compile.c for creating the table of named capturing groups
942 has been refactored. Instead of creating the table dynamically during the
943 actual compiling pass, the information is remembered during the pre-compile
944 pass (on the stack unless there are more than 20 named groups, in which
945 case malloc() is used) and the whole table is created before the actual
946 compile happens. This has simplified the code (it is now nearly 150 lines
947 shorter) and prepared the way for better handling of references to groups
948 with duplicate names.
949
950 15. A back reference to a named subpattern when there is more than one of the
951 same name now checks them in the order in which they appear in the pattern.
952 The first one that is set is used for the reference. Previously only the
953 first one was inspected. This change makes PCRE more compatible with Perl.
954
955 16. Unicode character properties were updated from Unicode 6.3.0.
956
957 17. The compile-time code for auto-possessification has been refactored, based
958 on a patch by Zoltan Herczeg. It now happens after instead of during
959 compilation. The code is cleaner, and more cases are handled. The option
960 PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
961 options in pcretest are provided to set it. It can also be set by
962 (*NO_AUTO_POSSESS) at the start of a pattern.
963
964 18. The character VT has been added to the default ("C" locale) set of
965 characters that match \s and are generally treated as white space,
966 following this same change in Perl 5.18. There is now no difference between
967 "Perl space" and "POSIX space". Whether VT is treated as white space in
968 other locales depends on the locale.
969
970 19. The code for checking named groups as conditions, either for being set or
971 for being recursed, has been refactored (this is related to 14 and 15
972 above). Processing unduplicated named groups should now be as fast at
973 numerical groups, and processing duplicated groups should be faster than
974 before.
975
976 20. Two patches to the CMake build system, by Alexander Barkov:
977
978 (1) Replace the "source" command by "." in CMakeLists.txt because
979 "source" is a bash-ism.
980
981 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
982 without these the CMake build does not work on Solaris.
983
984 21. Perl has changed its handling of \8 and \9. If there is no previously
985 encountered capturing group of those numbers, they are treated as the
986 literal characters 8 and 9 instead of a binary zero followed by the
987 literals. PCRE now does the same.
988
989 22. Following Perl, added \o{} to specify codepoints in octal, making it
990 possible to specify values greater than 0777 and also making them
991 unambiguous.
992
993 23. Perl now gives an error for missing closing braces after \x{... instead of
994 treating the string as literal. PCRE now does the same.
995
996 24. RunTest used to grumble if an inappropriate test was selected explicitly,
997 but just skip it when running all tests. This make it awkward to run ranges
998 of tests when one of them was inappropriate. Now it just skips any
999 inappropriate tests, as it always did when running all tests.
1000
1001 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
1002 character types such as \d or \w, too many callouts were inserted, and the
1003 data that they returned was rubbish.
1004
1005 26. In UCP mode, \s was not matching two of the characters that Perl matches,
1006 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
1007 were matched by \h. The code has now been refactored so that the lists of
1008 the horizontal and vertical whitespace characters used for \h and \v (which
1009 are defined only in one place) are now also used for \s.
1010
1011 27. Add JIT support for the 64 bit TileGX architecture.
1012 Patch by Jiong Wang (Tilera Corporation).
1013
1014 28. Possessive quantifiers for classes (both explicit and automatically
1015 generated) now use special opcodes instead of wrapping in ONCE brackets.
1016
1017 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
1018 (because it's meaningless), this was not happening when PCRE_CASELESS was
1019 set. Not wrong, but inefficient.
1020
1021 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
1022 properties for \w, \d, etc) is present in a test regex. Otherwise if the
1023 test contains no characters greater than 255, Perl doesn't realise it
1024 should be using Unicode semantics.
1025
1026 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
1027 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
1028 does in Unicode mode.
1029
1030 32. Added the "forbid" facility to pcretest so that putting tests into the
1031 wrong test files can sometimes be quickly detected.
1032
1033 33. There is now a limit (default 250) on the depth of nesting of parentheses.
1034 This limit is imposed to control the amount of system stack used at compile
1035 time. It can be changed at build time by --with-parens-nest-limit=xxx or
1036 the equivalent in CMake.
1037
1038 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
1039 errors. Perl warns for these when in warning mode, but PCRE has no facility
1040 for giving warnings.
1041
1042 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
1043 However, this was not working for (?!) because it is optimized to (*FAIL),
1044 for which PCRE does not allow quantifiers. The optimization is now disabled
1045 when a quantifier follows (?!). I can't see any use for this, but it makes
1046 things uniform.
1047
1048 36. Perl no longer allows group names to start with digits, so I have made this
1049 change also in PCRE. It simplifies the code a bit.
1050
1051 37. In extended mode, Perl ignores spaces before a + that indicates a
1052 possessive quantifier. PCRE allowed a space before the quantifier, but not
1053 before the possessive +. It now does.
1054
1055 38. The use of \K (reset reported match start) within a repeated possessive
1056 group such as (a\Kb)*+ was not working.
1057
1058 40. Document that the same character tables must be used at compile time and
1059 run time, and that the facility to pass tables to pcre_exec() and
1060 pcre_dfa_exec() is for use only with saved/restored patterns.
1061
1062 41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
1063 features for Builds with MSVC:
1064
1065 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
1066 builds). The .rc files can be used to set FileDescription and many other
1067 attributes.
1068
1069 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
1070 This allows higher-level build scripts which want .pdb files to avoid
1071 hard-coding the exact files needed."
1072
1073 42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
1074 mean "start of word" and "end of word", respectively, as a transition aid.
1075
1076 43. A minimizing repeat of a class containing codepoints greater than 255 in
1077 non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
1078 compiled to use the heap for recursion.
1079
1080 44. Got rid of some compiler warnings for unused variables when UTF but not UCP
1081 is configured.
1082
1083
1084 Version 8.33 28-May-2013
1085 ------------------------
1086
1087 1. Added 'U' to some constants that are compared to unsigned integers, to
1088 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
1089 variables that are added to signed variables, to ensure the result is
1090 signed and can be negated.
1091
1092 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
1093 CMake config files.
1094
1095 3. Revise the creation of config.h.generic so that all boolean macros are
1096 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
1097 overriding via -D on the command line possible.
1098
1099 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
1100 to unsigned int is reported to make a quite noticeable speed difference in
1101 a specific Windows environment. Testing on Linux did also appear to show
1102 some benefit (and it is clearly not harmful). Also fixed the definition of
1103 Xop which should be unsigned.
1104
1105 5. Related to (4), changing the definition of the intermediate variable cc
1106 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
1107 improvements.
1108
1109 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
1110 unnecessary spaces.
1111
1112 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
1113 and later.
1114
1115 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
1116
1117 9. Optimizing fast_forward_start_bits in JIT.
1118
1119 10. Adding support for callouts in JIT, and fixing some issues revealed
1120 during this work. Namely:
1121
1122 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
1123
1124 (b) Minimum length was not checked before the matching is started.
1125
1126 11. The value of capture_last that is passed to callouts was incorrect in some
1127 cases when there was a capture on one path that was subsequently abandoned
1128 after a backtrack. Also, the capture_last value is now reset after a
1129 recursion, since all captures are also reset in this case.
1130
1131 12. The interpreter no longer returns the "too many substrings" error in the
1132 case when an overflowing capture is in a branch that is subsequently
1133 abandoned after a backtrack.
1134
1135 13. In the pathological case when an offset vector of size 2 is used, pcretest
1136 now prints out the matched string after a yield of 0 or 1.
1137
1138 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
1139 Only supported by the JIT compiler at the moment.
1140
1141 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
1142
1143 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
1144 offset of the starting point of the matching process, provided the offsets
1145 vector is large enough.
1146
1147 17. The \A escape now records a lookbehind value of 1, though its execution
1148 does not actually inspect the previous character. This is to ensure that,
1149 in partial multi-segment matching, at least one character from the old
1150 segment is retained when a new segment is processed. Otherwise, if there
1151 are no lookbehinds in the pattern, \A might match incorrectly at the start
1152 of a new segment.
1153
1154 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
1155
1156 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
1157 gives some modest performance improvement in 8-bit mode.
1158
1159 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
1160 be expressed in certain programming languages using Universal Character
1161 Names.
1162
1163 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
1164 which points out that "non characters" are not "characters that may not
1165 appear in Unicode strings" but rather "characters that are reserved for
1166 internal use and have only local meaning".
1167
1168 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
1169 there was a conditional group that depended on an assertion, if the
1170 assertion was false, the callout that immediately followed the alternation
1171 in the condition was skipped when pcre_exec() was used for matching.
1172
1173 23. Allow an explicit callout to be inserted before an assertion that is the
1174 condition for a conditional group, for compatibility with automatic
1175 callouts, which always insert a callout at this point.
1176
1177 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
1178 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
1179
1180 25. (*PRUNE) is now supported by the JIT compiler.
1181
1182 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
1183
1184 27. Fix the case where there are two or more SKIPs with arguments that may be
1185 ignored.
1186
1187 28. (*SKIP) is now supported by the JIT compiler.
1188
1189 29. (*THEN) is now supported by the JIT compiler.
1190
1191 30. Update RunTest with additional test selector options.
1192
1193 31. The way PCRE handles backtracking verbs has been changed in two ways.
1194
1195 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
1196 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
1197 backtracking. In some cases this makes it more Perl-compatible, but Perl's
1198 rather obscure rules do not always do the same thing.
1199
1200 (2) Previously, backtracking verbs were confined within assertions. This is
1201 no longer the case for positive assertions, except for (*ACCEPT). Again,
1202 this sometimes improves Perl compatibility, and sometimes does not.
1203
1204 32. A number of tests that were in test 2 because Perl did things differently
1205 have been moved to test 1, because either Perl or PCRE has changed, and
1206 these tests are now compatible.
1207
1208 32. Backtracking control verbs are now handled in the same way in JIT and
1209 interpreter.
1210
1211 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
1212 contained a forward subroutine reference caused a compile error.
1213
1214 34. Auto-detect and optimize limited repetitions in JIT.
1215
1216 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
1217 blocking (*UTF) etc.
1218
1219 36. In the interpreter, maximizing pattern repetitions for characters and
1220 character types now use tail recursion, which reduces stack usage.
1221
1222 37. The value of the max lookbehind was not correctly preserved if a compiled
1223 and saved regex was reloaded on a host of different endianness.
1224
1225 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
1226 of the compiled pattern block, expand the flags field from 16 to 32 bits
1227 because it was almost full.
1228
1229 39. Try madvise first before posix_madvise.
1230
1231 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
1232 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
1233 original change locked out all matches of empty strings. This has been
1234 changed so that one match of an empty string per line is recognized.
1235 Subsequent searches on the same line (for colouring or for --only-matching,
1236 for example) do not recognize empty strings.
1237
1238 41. Applied a user patch to fix a number of spelling mistakes in comments.
1239
1240 42. Data lines longer than 65536 caused pcretest to crash.
1241
1242 43. Clarified the data type for length and startoffset arguments for pcre_exec
1243 and pcre_dfa_exec in the function-specific man pages, where they were
1244 explicitly stated to be in bytes, never having been updated. I also added
1245 some clarification to the pcreapi man page.
1246
1247 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
1248 a segmentation fault.
1249
1250
1251 Version 8.32 30-November-2012
1252 -----------------------------
1253
1254 1. Improved JIT compiler optimizations for first character search and single
1255 character iterators.
1256
1257 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
1258 Patch by Daniel Richard G.
1259
1260 3. Single character iterator optimizations in the JIT compiler.
1261
1262 4. Improved JIT compiler optimizations for character ranges.
1263
1264 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
1265 Reported by Giuseppe D'Angelo.
1266
1267 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
1268 of a line, was being set incorrectly in cases where .* appeared inside
1269 atomic brackets at the start of a pattern, or where there was a subsequent
1270 *PRUNE or *SKIP.
1271
1272 7. Improved instruction cache flush for POWER/PowerPC.
1273 Patch by Daniel Richard G.
1274
1275 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
1276 grep:
1277
1278 (a) There is now no limit to the number of patterns to be matched.
1279
1280 (b) An error is given if a pattern is too long.
1281
1282 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
1283 are now supported.
1284
1285 (d) --exclude-from and --include-from (multiple use) have been added.
1286
1287 (e) Exclusions and inclusions now apply to all files and directories, not
1288 just to those obtained from scanning a directory recursively.
1289
1290 (f) Multiple uses of -f and --file-list are now supported.
1291
1292 (g) In a Windows environment, the default for -d has been changed from
1293 "read" (the GNU grep default) to "skip", because otherwise the presence
1294 of a directory in the file list provokes an error.
1295
1296 (h) The documentation has been revised and clarified in places.
1297
1298 9. Improve the matching speed of capturing brackets.
1299
1300 10. Changed the meaning of \X so that it now matches a Unicode extended
1301 grapheme cluster.
1302
1303 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
1304 out POSIX threads when JIT support is configured.
1305
1306 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
1307
1308 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
1309 structure could go wrong in environments where size_t is not the same size
1310 as int.
1311
1312 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
1313 set.
1314
1315 15. The EBCDIC support had decayed; later updates to the code had included
1316 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
1317 general tidy up of EBCDIC-related issues, and the documentation was also
1318 not quite right. There is now a test that can be run on ASCII systems to
1319 check some of the EBCDIC-related things (but is it not a full test).
1320
1321 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
1322 in a small tidy to the code.
1323
1324 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
1325
1326 18. If the --only-matching (-o) option in pcregrep is specified multiple
1327 times, each one causes appropriate output. For example, -o1 -o2 outputs the
1328 substrings matched by the 1st and 2nd capturing parentheses. A separating
1329 string can be specified by --om-separator (default empty).
1330
1331 19. Improving the first n character searches.
1332
1333 20. Turn case lists for horizontal and vertical white space into macros so that
1334 they are defined only once.
1335
1336 21. This set of changes together give more compatible Unicode case-folding
1337 behaviour for characters that have more than one other case when UCP
1338 support is available.
1339
1340 (a) The Unicode property table now has offsets into a new table of sets of
1341 three or more characters that are case-equivalent. The MultiStage2.py
1342 script that generates these tables (the pcre_ucd.c file) now scans
1343 CaseFolding.txt instead of UnicodeData.txt for character case
1344 information.
1345
1346 (b) The code for adding characters or ranges of characters to a character
1347 class has been abstracted into a generalized function that also handles
1348 case-independence. In UTF-mode with UCP support, this uses the new data
1349 to handle characters with more than one other case.
1350
1351 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
1352 whose other case is greater than 256 are now correctly matched
1353 caselessly. Previously, the high codepoint matched the low one, but not
1354 vice versa.
1355
1356 (d) The processing of \h, \H, \v, and \ in character classes now makes use
1357 of the new class addition function, using character lists defined as
1358 macros alongside the case definitions of 20 above.
1359
1360 (e) Caseless back references now work with characters that have more than
1361 one other case.
1362
1363 (f) General caseless matching of characters with more than one other case
1364 is supported.
1365
1366 22. Unicode character properties were updated from Unicode 6.2.0
1367
1368 23. Improved CMake support under Windows. Patch by Daniel Richard G.
1369
1370 24. Add support for 32-bit character strings, and UTF-32
1371
1372 25. Major JIT compiler update (code refactoring and bugfixing).
1373 Experimental Sparc 32 support is added.
1374
1375 26. Applied a modified version of Daniel Richard G's patch to create
1376 pcre.h.generic and config.h.generic by "make" instead of in the
1377 PrepareRelease script.
1378
1379 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
1380 pcre_compile.c when checking for a zero character.
1381
1382 28. Introducing a native interface for JIT. Through this interface, the compiled
1383 machine code can be directly executed. The purpose of this interface is to
1384 provide fast pattern matching, so several sanity checks are not performed.
1385 However, feature tests are still performed. The new interface provides
1386 1.4x speedup compared to the old one.
1387
1388 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
1389 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
1390 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
1391
1392 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
1393 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
1394 the "old" RFC 2279). Instead, it ended up passing a negative length to
1395 pcre_exec().
1396
1397 31. Add support for GCC's visibility feature to hide internal functions.
1398
1399 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
1400 "unknown -C option" after outputting 0 or 1.
1401
1402 33. There is now support for generating a code coverage report for the test
1403 suite in environments where gcc is the compiler and lcov is installed. This
1404 is mainly for the benefit of the developers.
1405
1406 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
1407 unaddressable using valgrind annotations, allowing valgrind to detect
1408 invalid memory accesses. This is mainly for the benefit of the developers.
1409
1410 25. (*UTF) can now be used to start a pattern in any of the three libraries.
1411
1412 26. Give configure error if --enable-cpp but no C++ compiler found.
1413
1414
1415 Version 8.31 06-July-2012
1416 -------------------------
1417
1418 1. Fixing a wrong JIT test case and some compiler warnings.
1419
1420 2. Removed a bashism from the RunTest script.
1421
1422 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1423 to unsigned type, result still unsigned" that was given by an MS compiler
1424 on encountering the code "-sizeof(xxx)".
1425
1426 4. Partial matching support is added to the JIT compiler.
1427
1428 5. Fixed several bugs concerned with partial matching of items that consist
1429 of more than one character:
1430
1431 (a) /^(..)\1/ did not partially match "aba" because checking references was
1432 done on an "all or nothing" basis. This also applied to repeated
1433 references.
1434
1435 (b) \R did not give a hard partial match if \r was found at the end of the
1436 subject.
1437
1438 (c) \X did not give a hard partial match after matching one or more
1439 characters at the end of the subject.
1440
1441 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1442 a partial match for the string "\r".
1443
1444 (e) When newline was set to CRLF, the metacharacter "." did not recognize
1445 a partial match for a CR character at the end of the subject string.
1446
1447 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1448 running pcretest, the text "(JIT)" added to the output whenever JIT is
1449 actually used to run the match.
1450
1451 7. Individual JIT compile options can be set in pcretest by following -s+[+]
1452 or /S+[+] with a digit between 1 and 7.
1453
1454 8. OP_NOT now supports any UTF character not just single-byte ones.
1455
1456 9. (*MARK) control verb is now supported by the JIT compiler.
1457
1458 10. The command "./RunTest list" lists the available tests without actually
1459 running any of them. (Because I keep forgetting what they all are.)
1460
1461 11. Add PCRE_INFO_MAXLOOKBEHIND.
1462
1463 12. Applied a (slightly modified) user-supplied patch that improves performance
1464 when the heap is used for recursion (compiled with --disable-stack-for-
1465 recursion). Instead of malloc and free for each heap frame each time a
1466 logical recursion happens, frames are retained on a chain and re-used where
1467 possible. This sometimes gives as much as 30% improvement.
1468
1469 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1470 call.
1471
1472 14. As documented, (*COMMIT) is now confined to within a positive assertion.
1473
1474 15. It is now possible to link pcretest with libedit as an alternative to
1475 libreadline.
1476
1477 16. (*COMMIT) control verb is now supported by the JIT compiler.
1478
1479 17. The Unicode data tables have been updated to Unicode 6.1.0.
1480
1481 18. Added --file-list option to pcregrep.
1482
1483 19. Added binary file support to pcregrep, including the -a, --binary-files,
1484 -I, and --text options.
1485
1486 20. The madvise function is renamed for posix_madvise for QNX compatibility
1487 reasons. Fixed by Giuseppe D'Angelo.
1488
1489 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1490
1491 22. Changed the option for creating symbolic links for 16-bit man pages from
1492 -s to -sf so that re-installing does not cause issues.
1493
1494 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1495
1496 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1497 matches in certain environments (the workspace was not being correctly
1498 retained). Also added to pcre_dfa_exec() a simple plausibility check on
1499 some of the workspace data at the beginning of a restart.
1500
1501 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1502 was not doing so when it should - probably a typo introduced by SVN 528
1503 (change 8.10/14).
1504
1505 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1506 \w+ when the character tables indicated that \x{c4} was a word character.
1507 There were several related cases, all because the tests for doing a table
1508 lookup were testing for characters less than 127 instead of 255.
1509
1510 27. If a pattern contains capturing parentheses that are not used in a match,
1511 their slots in the ovector are set to -1. For those that are higher than
1512 any matched groups, this happens at the end of processing. In the case when
1513 there were back references that the ovector was too small to contain
1514 (causing temporary malloc'd memory to be used during matching), and the
1515 highest capturing number was not used, memory off the end of the ovector
1516 was incorrectly being set to -1. (It was using the size of the temporary
1517 memory instead of the true size.)
1518
1519 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1520 ovector size, it uses memory at the end of the block that it has got.
1521
1522 29. Check for an overlong MARK name and give an error at compile time. The
1523 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1524
1525 30. JIT compiler update.
1526
1527 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1528 Rill for the patch.
1529
1530 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1531
1532 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1533
1534 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1535 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1536 was enabled.
1537
1538 35. Improve JIT code generation for greedy plus quantifier.
1539
1540 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1541 1 to "aa" instead of to an empty string. The bug affected repeated groups
1542 that could potentially match an empty string.
1543
1544 37. Optimizing single character iterators in JIT.
1545
1546 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1547 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1548 codepoints that are too big for the mode are faulted, and in a UTF mode,
1549 disallowed codepoints are also faulted.
1550
1551 39. If PCRE was compiled with UTF support, in three places in the DFA
1552 matcher there was code that should only have been obeyed in UTF mode, but
1553 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1554 processing when bytes with values greater than 127 were present. In 16-bit
1555 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1556 both cases the values are those that cannot be the first data item in a UTF
1557 character. The three items that might have provoked this were recursions,
1558 possessively repeated groups, and atomic groups.
1559
1560 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1561 and pcregrep, because some OS require shared objects to be explicitly
1562 passed to ld, causing the link step to fail if they are not.
1563
1564 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1565 mode, patterns that started with \h* or \R* might be incorrectly matched.
1566
1567
1568 Version 8.30 04-February-2012
1569 -----------------------------
1570
1571 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
1572 name is defined in ctype.h.
1573
1574 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
1575 only in quite long subpatterns.
1576
1577 3. Removed the function pcre_info(), which has been obsolete and deprecated
1578 since it was replaced by pcre_fullinfo() in February 2000.
1579
1580 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
1581 match a (*MARK), and the match failed at the start of the subject, a
1582 reference to memory before the start of the subject could occur. This bug
1583 was introduced by fix 17 of release 8.21.
1584
1585 5. A reference to an unset group with zero minimum repetition was giving
1586 totally wrong answers (in non-JavaScript-compatibility mode). For example,
1587 /(another)?(\1?)test/ matched against "hello world test". This bug was
1588 introduced in release 8.13.
1589
1590 6. Add support for 16-bit character strings (a large amount of work involving
1591 many changes and refactorings).
1592
1593 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1594 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1595 from a file.
1596
1597 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1598 rounding is not applied in this particular case).
1599
1600 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1601 if they appear, or are escaped, in patterns.
1602
1603 10. Get rid of a number of -Wunused-but-set-variable warnings.
1604
1605 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1606 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1607 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1608 also returns the mark "x". This bug applied to capturing parentheses,
1609 non-capturing parentheses, and atomic parentheses. It also applied to some
1610 assertions.
1611
1612 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1613 information out of configure.ac instead of relying on pcre.h.generic, which
1614 is not stored in the repository.
1615
1616 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1617 -lreadline.
1618
1619 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1620
1621 15. Applied Graycode's patch to put the top-level frame on the stack rather
1622 than the heap when not using the stack for recursion. This gives a
1623 performance improvement in many cases when recursion is not deep.
1624
1625 16. Experimental code added to "pcretest -C" to output the stack frame size.
1626
1627
1628 Version 8.21 12-Dec-2011
1629 ------------------------
1630
1631 1. Updating the JIT compiler.
1632
1633 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1634 are added as well.
1635
1636 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1637 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1638 calling _pcre_jit_exec. Some extra comments are added.
1639
1640 4. (*MARK) settings inside atomic groups that do not contain any capturing
1641 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1642 was introduced by change 18 for 8.20.
1643
1644 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1645 ECMA-262 standard.
1646
1647 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1648 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1649 This bug was probably introduced by change 9 of 8.13.
1650
1651 7. While fixing 6 above, I noticed that a number of other items were being
1652 incorrectly rejected as "not fixed length". This arose partly because newer
1653 opcodes had not been added to the fixed-length checking code. I have (a)
1654 corrected the bug and added tests for these items, and (b) arranged for an
1655 error to occur if an unknown opcode is encountered while checking for fixed
1656 length instead of just assuming "not fixed length". The items that were
1657 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1658 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1659 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1660
1661 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1662 being incorrectly compiled and would have given unpredicatble results.
1663
1664 9. A possessively repeated subpattern with minimum repeat count greater than
1665 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1666 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1667 the first (A) could occur when it should not.
1668
1669 10. Add a cast and remove a redundant test from the code.
1670
1671 11. JIT should use pcre_malloc/pcre_free for allocation.
1672
1673 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1674 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1675 is anything other than /usr, -L is still shown).
1676
1677 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1678
1679 14. Perl does not support \N without a following name in a [] class; PCRE now
1680 also gives an error.
1681
1682 15. If a forward reference was repeated with an upper limit of around 2000,
1683 it caused the error "internal error: overran compiling workspace". The
1684 maximum number of forward references (including repeats) was limited by the
1685 internal workspace, and dependent on the LINK_SIZE. The code has been
1686 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1687 the default depends on LINK_SIZE. There is a new upper limit (for safety)
1688 of around 200,000 forward references. While doing this, I also speeded up
1689 the filling in of repeated forward references.
1690
1691 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1692 incorrectly expecting the subject to contain another "a" after the start.
1693
1694 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1695 in the match, the SKIP should be ignored. This was not happening; instead
1696 the SKIP was being treated as NOMATCH. For patterns such as
1697 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1698 tested.
1699
1700 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1701 now much more compatible with Perl, in particular in cases where the result
1702 is a non-match for a non-anchored pattern. For example, if
1703 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1704 "m", where previously it did not return a name. A side effect of this
1705 change is that for partial matches, the last encountered mark name is
1706 returned, as for non matches. A number of tests that were previously not
1707 Perl-compatible have been moved into the Perl-compatible test files. The
1708 refactoring has had the pleasing side effect of removing one argument from
1709 the match() function, thus reducing its stack requirements.
1710
1711 19. If the /S+ option was used in pcretest to study a pattern using JIT,
1712 subsequent uses of /S (without +) incorrectly behaved like /S+.
1713
1714 21. Retrieve executable code size support for the JIT compiler and fixing
1715 some warnings.
1716
1717 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1718 not work when the shorter character appeared right at the end of the
1719 subject string.
1720
1721 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1722 systems.
1723
1724 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1725 output it when the /M option is used in pcretest.
1726
1727 25. The CheckMan script was not being included in the distribution. Also, added
1728 an explicit "perl" to run Perl scripts from the PrepareRelease script
1729 because this is reportedly needed in Windows.
1730
1731 26. If study data was being save in a file and studying had not found a set of
1732 "starts with" bytes for the pattern, the data written to the file (though
1733 never used) was taken from uninitialized memory and so caused valgrind to
1734 complain.
1735
1736 27. Updated RunTest.bat as provided by Sheri Pierce.
1737
1738 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1739
1740 29. Computation of memory usage for the table of capturing group names was
1741 giving an unnecessarily large value.
1742
1743
1744 Version 8.20 21-Oct-2011
1745 ------------------------
1746
1747 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1748 a POSIX class. After further experiments with Perl, which convinced me that
1749 Perl has bugs and confusions, a closing square bracket is no longer allowed
1750 in a POSIX name. This bug also affected patterns with classes that started
1751 with full stops.
1752
1753 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1754 captured substring, but while checking the failing first alternative,
1755 substring 1 is temporarily captured. If the output vector supplied to
1756 pcre_exec() was not big enough for this capture, the yield of the function
1757 was still zero ("insufficient space for captured substrings"). This cannot
1758 be totally fixed without adding another stack variable, which seems a lot
1759 of expense for a edge case. However, I have improved the situation in cases
1760 such as /(a)(b)x|abc/ matched against "abc", where the return code
1761 indicates that fewer than the maximum number of slots in the ovector have
1762 been set.
1763
1764 3. Related to (2) above: when there are more back references in a pattern than
1765 slots in the output vector, pcre_exec() uses temporary memory during
1766 matching, and copies in the captures as far as possible afterwards. It was
1767 using the entire output vector, but this conflicts with the specification
1768 that only 2/3 is used for passing back captured substrings. Now it uses
1769 only the first 2/3, for compatibility. This is, of course, another edge
1770 case.
1771
1772 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
1773 main code base, and can be used by building with --enable-jit. When this is
1774 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1775 runtime --no-jit option is given.
1776
1777 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
1778 ovector, the return from the function was zero, implying that there were
1779 other matches that did not fit. The correct "exactly full" value is now
1780 returned.
1781
1782 6. If a subpattern that was called recursively or as a subroutine contained
1783 (*PRUNE) or any other control that caused it to give a non-standard return,
1784 invalid errors such as "Error -26 (nested recursion at the same subject
1785 position)" or even infinite loops could occur.
1786
1787 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1788 computing the minimum length on reaching *ACCEPT, and so ended up with the
1789 wrong value of 1 rather than 0. Further investigation indicates that
1790 computing a minimum subject length in the presence of *ACCEPT is difficult
1791 (think back references, subroutine calls), and so I have changed the code
1792 so that no minimum is registered for a pattern that contains *ACCEPT.
1793
1794 8. If (*THEN) was present in the first (true) branch of a conditional group,
1795 it was not handled as intended. [But see 16 below.]
1796
1797 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1798 Sheri Pierce.
1799
1800 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1801 the first byte in a match must be "a".
1802
1803 11. Change 17 for 8.13 increased the recursion depth for patterns like
1804 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1805 pattern contains any instances of (*THEN). If it does not, the old
1806 optimizations are restored. It would be nice to do this on a per-group
1807 basis, but at the moment that is not feasible.
1808
1809 12. In some environments, the output of pcretest -C is CRLF terminated. This
1810 broke RunTest's code that checks for the link size. A single white space
1811 character after the value is now allowed for.
1812
1813 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1814 For "fr", it uses the Windows-specific input and output files.
1815
1816 14. If (*THEN) appeared in a group that was called recursively or as a
1817 subroutine, it did not work as intended. [But see next item.]
1818
1819 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1820 pattern fragments (but not containing any | characters). If A and B are
1821 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1822 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1823 D. In other words, Perl considers parentheses that do not contain any |
1824 characters to be part of a surrounding alternative, whereas PCRE was
1825 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1826 differently. PCRE now behaves in the same way as Perl, except in the case
1827 of subroutine/recursion calls such as (?1) which have in any case always
1828 been different (but PCRE had them first :-).
1829
1830 16. Related to 15 above: Perl does not treat the | in a conditional group as
1831 creating alternatives. Such a group is treated in the same way as an
1832 ordinary group without any | characters when processing (*THEN). PCRE has
1833 been changed to match Perl's behaviour.
1834
1835 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1836 RunGrepTest script failed.
1837
1838 18. Change 22 for version 13 caused atomic groups to use more stack. This is
1839 inevitable for groups that contain captures, but it can lead to a lot of
1840 stack use in large patterns. The old behaviour has been restored for atomic
1841 groups that do not contain any capturing parentheses.
1842
1843 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1844 suppress the check for a minimum subject length at run time. (If it was
1845 given to pcre_exec() or pcre_dfa_exec() it did work.)
1846
1847 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1848 fail to work when decoding hex characters in data strings in EBCDIC
1849 environments.
1850
1851 21. It appears that in at least one Mac OS environment, the isxdigit() function
1852 is implemented as a macro that evaluates to its argument more than once,
1853 contravening the C 90 Standard (I haven't checked a later standard). There
1854 was an instance in pcretest which caused it to go wrong when processing
1855 \x{...} escapes in subject strings. The has been rewritten to avoid using
1856 things like p++ in the argument of isxdigit().
1857
1858
1859 Version 8.13 16-Aug-2011
1860 ------------------------
1861
1862 1. The Unicode data tables have been updated to Unicode 6.0.0.
1863
1864 2. Two minor typos in pcre_internal.h have been fixed.
1865
1866 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1867 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1868 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1869
1870 4. There were a number of related bugs in the code for matching backrefences
1871 caselessly in UTF-8 mode when codes for the characters concerned were
1872 different numbers of bytes. For example, U+023A and U+2C65 are an upper
1873 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1874 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1875 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1876 2-byte code at the end of the subject (it thought there wasn't enough data
1877 left).
1878
1879 5. Comprehensive information about what went wrong is now returned by
1880 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1881 as the output vector has at least 2 elements. The offset of the start of
1882 the failing character and a reason code are placed in the vector.
1883
1884 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
1885 now returned is for the first byte of the failing character, instead of the
1886 last byte inspected. This is an incompatible change, but I hope it is small
1887 enough not to be a problem. It makes the returned offset consistent with
1888 pcre_exec() and pcre_dfa_exec().
1889
1890 7. pcretest now gives a text phrase as well as the error number when
1891 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1892 failure, the offset and reason code are output.
1893
1894 8. When \R was used with a maximizing quantifier it failed to skip backwards
1895 over a \r\n pair if the subsequent match failed. Instead, it just skipped
1896 back over a single character (\n). This seems wrong (because it treated the
1897 two characters as a single entity when going forwards), conflicts with the
1898 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1899 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1900 has been changed.
1901
1902 9. Some internal refactoring has changed the processing so that the handling
1903 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1904 time (the PCRE_DOTALL option was changed this way some time ago: version
1905 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1906 which was always a bit of a fudge. It also means that there is one less
1907 argument for the match() function, which reduces its stack requirements
1908 slightly. This change also fixes an incompatibility with Perl: the pattern
1909 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1910
1911 10. More internal refactoring has drastically reduced the number of recursive
1912 calls to match() for possessively repeated groups such as (abc)++ when
1913 using pcre_exec().
1914
1915 11. While implementing 10, a number of bugs in the handling of groups were
1916 discovered and fixed:
1917
1918 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1919 (a|)*(?1) gave a compile-time internal error.
1920 ((a|)+)+ did not notice that the outer group could match an empty string.
1921 (^a|^)+ was not marked as anchored.
1922 (.*a|.*)+ was not marked as matching at start or after a newline.
1923
1924 12. Yet more internal refactoring has removed another argument from the match()
1925 function. Special calls to this function are now indicated by setting a
1926 value in a variable in the "match data" data block.
1927
1928 13. Be more explicit in pcre_study() instead of relying on "default" for
1929 opcodes that mean there is no starting character; this means that when new
1930 ones are added and accidentally left out of pcre_study(), testing should
1931 pick them up.
1932
1933 14. The -s option of pcretest has been documented for ages as being an old
1934 synonym of -m (show memory usage). I have changed it to mean "force study
1935 for every regex", that is, assume /S for every regex. This is similar to -i
1936 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1937 using it. It makes it easier to run collections of tests with and without
1938 study enabled, and thereby test pcre_study() more easily. All the standard
1939 tests are now run with and without -s (but some patterns can be marked as
1940 "never study" - see 20 below).
1941
1942 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1943 restoration of the capturing data to the outer values was not happening
1944 correctly.
1945
1946 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1947 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1948 pattern had matched an empty string, and so incorrectly returned a no
1949 match.
1950
1951 17. There was optimizing code for the last branch of non-capturing parentheses,
1952 and also for the obeyed branch of a conditional subexpression, which used
1953 tail recursion to cut down on stack usage. Unfortunately, now that there is
1954 the possibility of (*THEN) occurring in these branches, tail recursion is
1955 no longer possible because the return has to be checked for (*THEN). These
1956 two optimizations have therefore been removed. [But see 8.20/11 above.]
1957
1958 18. If a pattern containing \R was studied, it was assumed that \R always
1959 matched two bytes, thus causing the minimum subject length to be
1960 incorrectly computed because \R can also match just one byte.
1961
1962 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1963 was incorrectly computed.
1964
1965 20. If /S is present twice on a test pattern in pcretest input, it now
1966 *disables* studying, thereby overriding the use of -s on the command line
1967 (see 14 above). This is necessary for one or two tests to keep the output
1968 identical in both cases.
1969
1970 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1971 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1972
1973 22. When an atomic group that contained a capturing parenthesis was
1974 successfully matched, but the branch in which it appeared failed, the
1975 capturing was not being forgotten if a higher numbered group was later
1976 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1977 group 1 to "a", when in fact it should be unset. This applied to multi-
1978 branched capturing and non-capturing groups, repeated or not, and also to
1979 positive assertions (capturing in negative assertions does not happen
1980 in PCRE) and also to nested atomic groups.
1981
1982 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1983 subject after a captured substring, to make it easier to tell which of a
1984 number of identical substrings has been captured.
1985
1986 24. The way atomic groups are processed by pcre_exec() has been changed so that
1987 if they are repeated, backtracking one repetition now resets captured
1988 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1989 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1990 "aaa". Previously, it would have been "a". As part of this code
1991 refactoring, the way recursive calls are handled has also been changed.
1992
1993 25. If an assertion condition captured any substrings, they were not passed
1994 back unless some other capturing happened later. For example, if
1995 (?(?=(a))a) was matched against "a", no capturing was returned.
1996
1997 26. When studying a pattern that contained subroutine calls or assertions,
1998 the code for finding the minimum length of a possible match was handling
1999 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
2000 group 1 called group 2 while simultaneously a separate group 2 called group
2001 1). A stack overflow occurred in this case. I have fixed this by limiting
2002 the recursion depth to 10.
2003
2004 27. Updated RunTest.bat in the distribution to the version supplied by Tom
2005 Fortmann. This supports explicit test numbers on the command line, and has
2006 argument validation and error reporting.
2007
2008 28. An instance of \X with an unlimited repeat could fail if at any point the
2009 first character it looked at was a mark character.
2010
2011 29. Some minor code refactoring concerning Unicode properties and scripts
2012 should reduce the stack requirement of match() slightly.
2013
2014 30. Added the '=' option to pcretest to check the setting of unused capturing
2015 slots at the end of the pattern, which are documented as being -1, but are
2016 not included in the return count.
2017
2018 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
2019 compiled something random. Now it gives a compile-time error (as does
2020 Perl).
2021
2022 32. A *MARK encountered during the processing of a positive assertion is now
2023 recorded and passed back (compatible with Perl).
2024
2025 33. If --only-matching or --colour was set on a pcregrep call whose pattern
2026 had alternative anchored branches, the search for a second match in a line
2027 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
2028 matched the line "0102" twice. The same bug affected patterns that started
2029 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
2030 twice.
2031
2032 34. Previously, PCRE did not allow quantification of assertions. However, Perl
2033 does, and because of capturing effects, quantifying parenthesized
2034 assertions may at times be useful. Quantifiers are now allowed for
2035 parenthesized assertions.
2036
2037 35. A minor code tidy in pcre_compile() when checking options for \R usage.
2038
2039 36. \g was being checked for fancy things in a character class, when it should
2040 just be a literal "g".
2041
2042 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
2043 appearance of a nested POSIX class supersedes an apparent external class.
2044 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
2045 unescaped square brackets may also appear as part of class names. For
2046 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
2047 more like Perl. (But see 8.20/1 above.)
2048
2049 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
2050 was because it thought it was \N{name}, which is not supported).
2051
2052 39. Add minix to OS list not supporting the -S option in pcretest.
2053
2054 40. PCRE tries to detect cases of infinite recursion at compile time, but it
2055 cannot analyze patterns in sufficient detail to catch mutual recursions
2056 such as ((?1))((?2)). There is now a runtime test that gives an error if a
2057 subgroup is called recursively as a subpattern for a second time at the
2058 same position in the subject string. In previous releases this might have
2059 been caught by the recursion limit, or it might have run out of stack.
2060
2061 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
2062 happen only once. PCRE was, however incorrectly giving a compile time error
2063 "recursive call could loop indefinitely" because it cannot analyze the
2064 pattern in sufficient detail. The compile time test no longer happens when
2065 PCRE is compiling a conditional subpattern, but actual runaway loops are
2066 now caught at runtime (see 40 above).
2067
2068 42. It seems that Perl allows any characters other than a closing parenthesis
2069 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
2070 has been changed to be the same.
2071
2072 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
2073 as not to get warnings when autogen.sh is called. Also changed
2074 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
2075
2076 44. To help people who use pcregrep to scan files containing exceedingly long
2077 lines, the following changes have been made:
2078
2079 (a) The default value of the buffer size parameter has been increased from
2080 8K to 20K. (The actual buffer used is three times this size.)
2081
2082 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
2083 PCRE is built.
2084
2085 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
2086 to be set at run time.
2087
2088 (d) Numerical values in pcregrep options can be followed by K or M, for
2089 example --buffer-size=50K.
2090
2091 (e) If a line being scanned overflows pcregrep's buffer, an error is now
2092 given and the return code is set to 2.
2093
2094 45. Add a pointer to the latest mark to the callout data block.
2095
2096 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
2097 partial match of an empty string instead of no match. This was specific to
2098 the use of ".".
2099
2100 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
2101 complete match instead of a partial match. This bug was dependent on both
2102 the PCRE_UTF8 and PCRE_DOTALL options being set.
2103
2104 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
2105 starting byte set, because \b was not being ignored.
2106
2107
2108 Version 8.12 15-Jan-2011
2109 ------------------------
2110
2111 1. Fixed some typos in the markup of the man pages, and wrote a script that
2112 checks for such things as part of the documentation building process.
2113
2114 2. On a big-endian 64-bit system, pcregrep did not correctly process the
2115 --match-limit and --recursion-limit options (added for 8.11). In
2116 particular, this made one of the standard tests fail. (The integer value
2117 went into the wrong half of a long int.)
2118
2119 3. If the --colour option was given to pcregrep with -v (invert match), it
2120 did strange things, either producing crazy output, or crashing. It should,
2121 of course, ignore a request for colour when reporting lines that do not
2122 match.
2123
2124 4. Another pcregrep bug caused similar problems if --colour was specified with
2125 -M (multiline) and the pattern match finished with a line ending.
2126
2127 5. In pcregrep, when a pattern that ended with a literal newline sequence was
2128 matched in multiline mode, the following line was shown as part of the
2129 match. This seems wrong, so I have changed it.
2130
2131 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
2132 the check for further matches in the same line (so they could be coloured)
2133 to overrun the end of the current line. If another match was found, it was
2134 incorrectly shown (and then shown again when found in the next line).
2135
2136 7. If pcregrep was compiled under Windows, there was a reference to the
2137 function pcregrep_exit() before it was defined. I am assuming this was
2138 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
2139 reported by a user. I've moved the definition above the reference.
2140
2141
2142 Version 8.11 10-Dec-2010
2143 ------------------------
2144
2145 1. (*THEN) was not working properly if there were untried alternatives prior
2146 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
2147 backtracked to try for "b" instead of moving to the next alternative branch
2148 at the same level (in this case, to look for "c"). The Perl documentation
2149 is clear that when (*THEN) is backtracked onto, it goes to the "next
2150 alternative in the innermost enclosing group".
2151
2152 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
2153 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
2154 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
2155 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
2156 (*THEN).
2157
2158 3. If \s appeared in a character class, it removed the VT character from
2159 the class, even if it had been included by some previous item, for example
2160 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
2161 of \s, but is part of the POSIX "space" class.)
2162
2163 4. A partial match never returns an empty string (because you can always
2164 match an empty string at the end of the subject); however the checking for
2165 an empty string was starting at the "start of match" point. This has been
2166 changed to the "earliest inspected character" point, because the returned
2167 data for a partial match starts at this character. This means that, for
2168 example, /(?<=abc)def/ gives a partial match for the subject "abc"
2169 (previously it gave "no match").
2170
2171 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
2172 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
2173 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
2174 has an implication that the given string is incomplete (because a partial
2175 match is preferred over a full match). For this reason, these items now
2176 give a partial match in this situation. [Aside: previously, the one case
2177 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
2178 match rather than a full match, which was wrong by the old rules, but is
2179 now correct.]
2180
2181 6. There was a bug in the handling of #-introduced comments, recognized when
2182 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
2183 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
2184 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
2185 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
2186 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
2187 places in pcre_compile().
2188
2189 7. Related to (6) above, when pcre_compile() was skipping #-introduced
2190 comments when looking ahead for named forward references to subpatterns,
2191 the only newline sequence it recognized was NL. It now handles newlines
2192 according to the set newline convention.
2193
2194 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
2195 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
2196 cater for a lack of strerror(). These oversights have been fixed.
2197
2198 9. Added --match-limit and --recursion-limit to pcregrep.
2199
2200 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
2201
2202 11. When the -o option was used, pcregrep was setting a return code of 1, even
2203 when matches were found, and --line-buffered was not being honoured.
2204
2205 12. Added an optional parentheses number to the -o and --only-matching options
2206 of pcregrep.
2207
2208 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
2209 can match an empty string. The code to do it in pcretest and pcredemo
2210 needed fixing:
2211
2212 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
2213 only one byte after an empty string match just before CRLF (this case
2214 just got forgotten; "any" and "anycrlf" were OK).
2215
2216 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
2217 mode when an empty string match preceded an ASCII character followed by
2218 a non-ASCII character. (The code for advancing by one character rather
2219 than one byte was nonsense.)
2220
2221 (c) The pcredemo.c sample program did not have any code at all to handle
2222 the cases when CRLF is a valid newline sequence.
2223
2224 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
2225 as a starting offset was within the subject string. There is now a new
2226 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
2227 negative or greater than the length of the string. In order to test this,
2228 pcretest is extended to allow the setting of negative starting offsets.
2229
2230 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
2231 starting offset points to the beginning of a UTF-8 character was
2232 unnecessarily clumsy. I tidied it up.
2233
2234 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
2235 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
2236
2237 17. Nobody had reported that the --include_dir option, which was added in
2238 release 7.7 should have been called --include-dir (hyphen, not underscore)
2239 for compatibility with GNU grep. I have changed it to --include-dir, but
2240 left --include_dir as an undocumented synonym, and the same for
2241 --exclude-dir, though that is not available in GNU grep, at least as of
2242 release 2.5.4.
2243
2244 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
2245 characters from a string of bytes) have been redefined so as not to use
2246 loops, in order to improve performance in some environments. At the same
2247 time, I abstracted some of the common code into auxiliary macros to save
2248 repetition (this should not affect the compiled code).
2249
2250 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
2251 compile-time error is now given if \c is not followed by an ASCII
2252 character, that is, a byte less than 128. (In EBCDIC mode, the code is
2253 different, and any byte value is allowed.)
2254
2255 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
2256 START_OPTIMIZE option, which is now allowed at compile time - but just
2257 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
2258 to pcregrep and other applications that have no direct access to PCRE
2259 options. The new /Y option in pcretest sets this option when calling
2260 pcre_compile().
2261
2262 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
2263 back references. Groups containing recursive back references were forced to
2264 be atomic by that change, but in the case of named groups, the amount of
2265 memory required was incorrectly computed, leading to "Failed: internal
2266 error: code overflow". This has been fixed.
2267
2268 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
2269 pcretest.c, to avoid build problems in some Borland environments.
2270
2271
2272 Version 8.10 25-Jun-2010
2273 ------------------------
2274
2275 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
2276 THEN.
2277
2278 2. (*ACCEPT) was not working when inside an atomic group.
2279
2280 3. Inside a character class, \B is treated as a literal by default, but
2281 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
2282 causes the error). The code is unchanged, but I tidied the documentation.
2283
2284 4. Inside a character class, PCRE always treated \R and \X as literals,
2285 whereas Perl faults them if its -w option is set. I have changed PCRE so
2286 that it faults them when PCRE_EXTRA is set.
2287
2288 5. Added support for \N, which always matches any character other than
2289 newline. (It is the same as "." when PCRE_DOTALL is not set.)
2290
2291 6. When compiling pcregrep with newer versions of gcc which may have
2292 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
2293 declared with attribute warn_unused_result" were given. Just casting the
2294 result to (void) does not stop the warnings; a more elaborate fudge is
2295 needed. I've used a macro to implement this.
2296
2297 7. Minor change to pcretest.c to avoid a compiler warning.
2298
2299 8. Added four artifical Unicode properties to help with an option to make
2300 \s etc use properties (see next item). The new properties are: Xan
2301 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
2302
2303 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
2304 use Unicode properties. (*UCP) at the start of a pattern can be used to set
2305 this option. Modified pcretest to add /W to test this facility. Added
2306 REG_UCP to make it available via the POSIX interface.
2307
2308 10. Added --line-buffered to pcregrep.
2309
2310 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
2311 studied, and the match started with a letter with a code point greater than
2312 127 whose first byte was different to the first byte of the other case of
2313 the letter, the other case of this starting letter was not recognized
2314 (#976).
2315
2316 12. If a pattern that was studied started with a repeated Unicode property
2317 test, for example, \p{Nd}+, there was the theoretical possibility of
2318 setting up an incorrect bitmap of starting bytes, but fortunately it could
2319 not have actually happened in practice until change 8 above was made (it
2320 added property types that matched character-matching opcodes).
2321
2322 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
2323 possible starting bytes for non-anchored patterns.
2324
2325 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
2326 \R, and also a number of cases that involve Unicode properties, both
2327 explicit and implicit when PCRE_UCP is set.
2328
2329 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
2330 input, it could crash or give wrong results if characters with values
2331 greater than 0xc0 were present in the subject string. (Detail: it assumed
2332 UTF-8 input when processing these items.)
2333
2334 16. Added a lot of (int) casts to avoid compiler warnings in systems where
2335 size_t is 64-bit (#991).
2336
2337 17. Added a check for running out of memory when PCRE is compiled with
2338 --disable-stack-for-recursion (#990).
2339
2340 18. If the last data line in a file for pcretest does not have a newline on
2341 the end, a newline was missing in the output.
2342
2343 19. The default pcre_chartables.c file recognizes only ASCII characters (values
2344 less than 128) in its various bitmaps. However, there is a facility for
2345 generating tables according to the current locale when PCRE is compiled. It
2346 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
2347 characters, are recognized by isspace() and therefore were getting set in
2348 these tables, and indeed these tables seem to approximate to ISO 8859. This
2349 caused a problem in UTF-8 mode when pcre_study() was used to create a list
2350 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
2351 which of course cannot start UTF-8 characters. I have changed the code so
2352 that only real ASCII characters (less than 128) and the correct starting
2353 bytes for UTF-8 encodings are set for characters greater than 127 when in
2354 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
2355 altogether.)
2356
2357 20. Added the /T option to pcretest so as to be able to run tests with non-
2358 standard character tables, thus making it possible to include the tests
2359 used for 19 above in the standard set of tests.
2360
2361 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
2362 reference to a subpattern the other side of a comment that contains an
2363 opening parenthesis caused either an internal compiling error, or a
2364 reference to the wrong subpattern.
2365
2366
2367 Version 8.02 19-Mar-2010
2368 ------------------------
2369
2370 1. The Unicode data tables have been updated to Unicode 5.2.0.
2371
2372 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
2373 configured.
2374
2375 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
2376 original author of that file, following a query about its status.
2377
2378 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
2379 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
2380
2381 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
2382 quantifier applied to a forward-referencing subroutine call, could compile
2383 incorrect code or give the error "internal error: previously-checked
2384 referenced subpattern not found".
2385
2386 6. Both MS Visual Studio and Symbian OS have problems with initializing
2387 variables to point to external functions. For these systems, therefore,
2388 pcre_malloc etc. are now initialized to local functions that call the
2389 relevant global functions.
2390
2391 7. There were two entries missing in the vectors called coptable and poptable
2392 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
2393 I've fixed the data, and added a kludgy way of testing at compile time that
2394 the lengths are correct (equal to the number of opcodes).
2395
2396 8. Following on from 7, I added a similar kludge to check the length of the
2397 eint vector in pcreposix.c.
2398
2399 9. Error texts for pcre_compile() are held as one long string to avoid too
2400 much relocation at load time. To find a text, the string is searched,
2401 counting zeros. There was no check for running off the end of the string,
2402 which could happen if a new error number was added without updating the
2403 string.
2404
2405 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
2406
2407 11. \K was not working if it appeared in an atomic group or in a group that
2408 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
2409 \K is "not well defined" if used in an assertion. PCRE now accepts it if
2410 the assertion is positive, but not if it is negative.
2411
2412 12. Change 11 fortuitously reduced the size of the stack frame used in the
2413 "match()" function of pcre_exec.c by one pointer. Forthcoming
2414 implementation of support for (*MARK) will need an extra pointer on the
2415 stack; I have reserved it now, so that the stack frame size does not
2416 decrease.
2417
2418 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
2419 item in branch that calls a recursion is a subroutine call - as in the
2420 second branch in the above example - was incorrectly given the compile-
2421 time error "recursive call could loop indefinitely" because pcre_compile()
2422 was not correctly checking the subroutine for matching a non-empty string.
2423
2424 14. The checks for overrunning compiling workspace could trigger after an
2425 overrun had occurred. This is a "should never occur" error, but it can be
2426 triggered by pathological patterns such as hundreds of nested parentheses.
2427 The checks now trigger 100 bytes before the end of the workspace.
2428
2429 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
2430
2431
2432 Version 8.01 19-Jan-2010
2433 ------------------------
2434
2435 1. If a pattern contained a conditional subpattern with only one branch (in
2436 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
2437 computed the wrong minimum data length (which is of course zero for such
2438 subpatterns). This could cause incorrect "no match" results.
2439
2440 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
2441 the pattern is reset in the first branch, pcre_compile() failed with
2442 "internal error: code overflow at offset...". This happened only when
2443 the reset was to the original external option setting. (An optimization
2444 abstracts leading options settings into an external setting, which was the
2445 cause of this.)
2446
2447 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
2448 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
2449 assertion pattern did not match (meaning that the assertion was true), it
2450 was incorrectly treated as false if the SKIP had been reached during the
2451 matching. This also applied to assertions used as conditions.
2452
2453 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
2454 assertion subpattern, including such a pattern used as a condition,
2455 unpredictable results occurred, instead of the error return
2456 PCRE_ERROR_DFA_UITEM.
2457
2458 5. The C++ GlobalReplace function was not working like Perl for the special
2459 situation when an empty string is matched. It now does the fancy magic
2460 stuff that is necessary.
2461
2462 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
2463 removed. (These were left over from very, very early versions of PCRE.)
2464
2465 7. Some cosmetic changes to the code to make life easier when compiling it
2466 as part of something else:
2467
2468 (a) Change DEBUG to PCRE_DEBUG.
2469
2470 (b) In pcre_compile(), rename the member of the "branch_chain" structure
2471 called "current" as "current_branch", to prevent a collision with the
2472 Linux macro when compiled as a kernel module.
2473
2474 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
2475 prevent a collision with the Linux macro when compiled as a kernel
2476 module.
2477
2478 8. In pcre_compile() there are some checks for integer overflows that used to
2479 cast potentially large values to (double). This has been changed to that
2480 when building, a check for int64_t is made, and if it is found, it is used
2481 instead, thus avoiding the use of floating point arithmetic. (There is no
2482 other use of FP in PCRE.) If int64_t is not found, the fallback is to
2483 double.
2484
2485 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
2486 2005 (difference between two addresses compared to an unsigned value).
2487
2488 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
2489 custom one, because of the following reported problem in Windows:
2490
2491 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
2492 under Win32.
2493 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
2494 therefore missing the function definition.
2495 - The compiler thus generates a "C" signature for the test function.
2496 - The linker fails to find the "C" function.
2497 - PCRE fails to configure if asked to do so against libbz2.
2498
2499 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
2500 messages were output:
2501
2502 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
2503 rerunning libtoolize, to keep the correct libtool macros in-tree.
2504 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
2505
2506 I have done both of these things.
2507
2508 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
2509 most of the time, it *can* run out if it is given a pattern that contains a
2510 runaway infinite recursion. I updated the discussion in the pcrestack man
2511 page.
2512
2513 13. Now that we have gone to the x.xx style of version numbers, the minor
2514 version may start with zero. Using 08 or 09 is a bad idea because users
2515 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
2516 interpreted as invalid octal numbers. I've updated the previous comment in
2517 configure.ac, and also added a check that gives an error if 08 or 09 are
2518 used.
2519
2520 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
2521 causing partial matching to fail when the end of the subject matched \W
2522 in a UTF-8 pattern where \W was quantified with a minimum of 3.
2523
2524 15. There were some discrepancies between the declarations in pcre_internal.h
2525 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
2526 their definitions. The declarations used "const uschar *" and the
2527 definitions used USPTR. Even though USPTR is normally defined as "const
2528 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
2529 reported that: "This difference in casting confuses some C++ compilers, for
2530 example, SunCC recognizes above declarations as different functions and
2531 generates broken code for hbpcre." I have changed the declarations to use
2532 USPTR.
2533
2534 16. GNU libtool is named differently on some systems. The autogen.sh script now
2535 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
2536 (FreeBSD).
2537
2538 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
2539 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
2540 comment: "Figure out how to create a longlong from a string: strtoll and
2541 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
2542 instance, but it only takes 2 args instead of 3!"
2543
2544 18. A subtle bug concerned with back references has been fixed by a change of
2545 specification, with a corresponding code fix. A pattern such as
2546 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
2547 refers, was giving matches when it shouldn't. For example, xa=xaaa would
2548 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
2549 same bug. Such groups have to be quantified to be useful, or contained
2550 inside another quantified group. (If there's no repetition, the reference
2551 can never match.) The problem arises because, having left the group and
2552 moved on to the rest of the pattern, a later failure that backtracks into
2553 the group uses the captured value from the final iteration of the group
2554 rather than the correct earlier one. I have fixed this in PCRE by forcing
2555 any group that contains a reference to itself to be an atomic group; that
2556 is, there cannot be any backtracking into it once it has completed. This is
2557 similar to recursive and subroutine calls.
2558
2559
2560 Version 8.00 19-Oct-09
2561 ----------------------
2562
2563 1. The table for translating pcre_compile() error codes into POSIX error codes
2564 was out-of-date, and there was no check on the pcre_compile() error code
2565 being within the table. This could lead to an OK return being given in
2566 error.
2567
2568 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
2569 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
2570 in a Windows environment.
2571
2572 3. The pcregrep --count option prints the count for each file even when it is
2573 zero, as does GNU grep. However, pcregrep was also printing all files when
2574 --files-with-matches was added. Now, when both options are given, it prints
2575 counts only for those files that have at least one match. (GNU grep just
2576 prints the file name in this circumstance, but including the count seems
2577 more useful - otherwise, why use --count?) Also ensured that the
2578 combination -clh just lists non-zero counts, with no names.
2579
2580 4. The long form of the pcregrep -F option was incorrectly implemented as
2581 --fixed_strings instead of --fixed-strings. This is an incompatible change,
2582 but it seems right to fix it, and I didn't think it was worth preserving
2583 the old behaviour.
2584
2585 5. The command line items --regex=pattern and --regexp=pattern were not
2586 recognized by pcregrep, which required --regex pattern or --regexp pattern
2587 (with a space rather than an '='). The man page documented the '=' forms,
2588 which are compatible with GNU grep; these now work.
2589
2590 6. No libpcreposix.pc file was created for pkg-config; there was just
2591 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
2592
2593 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
2594 when UCP support is not needed, by modifying the Python script that
2595 generates it from Unicode data files. This should not matter if the module
2596 is correctly used as a library, but I received one complaint about 50K of
2597 unwanted data. My guess is that the person linked everything into his
2598 program rather than using a library. Anyway, it does no harm.
2599
2600 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
2601 was a minimum greater than 1 for a wide character in a possessive
2602 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
2603 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
2604 character. Chaos in the form of incorrect output or a compiling loop could
2605 result.
2606
2607 9. The restrictions on what a pattern can contain when partial matching is
2608 requested for pcre_exec() have been removed. All patterns can now be
2609 partially matched by this function. In addition, if there are at least two
2610 slots in the offset vector, the offset of the earliest inspected character
2611 for the match and the offset of the end of the subject are set in them when
2612 PCRE_ERROR_PARTIAL is returned.
2613
2614 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
2615 synonymous with PCRE_PARTIAL, for backwards compatibility, and
2616 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
2617 and may be more useful for multi-segment matching.
2618
2619 11. Partial matching with pcre_exec() is now more intuitive. A partial match
2620 used to be given if ever the end of the subject was reached; now it is
2621 given only if matching could not proceed because another character was
2622 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
2623 string "Z", which now yields "no match" instead of "partial match". In the
2624 case of pcre_dfa_exec(), "no match" is given if every matching path for the
2625 final character ended with (*FAIL).
2626
2627 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
2628 if the pattern had a "must contain" character that was already found in the
2629 earlier partial match, unless partial matching was again requested. For
2630 example, with the pattern /dog.(body)?/, the "must contain" character is
2631 "g". If the first part-match was for the string "dog", restarting with
2632 "sbody" failed. This bug has been fixed.
2633
2634 13. The string returned by pcre_dfa_exec() after a partial match has been
2635 changed so that it starts at the first inspected character rather than the
2636 first character of the match. This makes a difference only if the pattern
2637 starts with a lookbehind assertion or \b or \B (\K is not supported by
2638 pcre_dfa_exec()). It's an incompatible change, but it makes the two
2639 matching functions compatible, and I think it's the right thing to do.
2640
2641 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
2642 so that the demonstration program is easily available in environments where
2643 PCRE has not been installed from source.
2644
2645 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
2646 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
2647 library.
2648
2649 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
2650 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
2651 is not the first non-POSIX option to be added. Clearly some people find
2652 these options useful.
2653
2654 17. If a caller to the POSIX matching function regexec() passes a non-zero
2655 value for nmatch with a NULL value for pmatch, the value of
2656 nmatch is forced to zero.
2657
2658 18. RunGrepTest did not have a test for the availability of the -u option of
2659 the diff command, as RunTest does. It now checks in the same way as
2660 RunTest, and also checks for the -b option.
2661
2662 19. If an odd number of negated classes containing just a single character
2663 interposed, within parentheses, between a forward reference to a named
2664 subpattern and the definition of the subpattern, compilation crashed with
2665 an internal error, complaining that it could not find the referenced
2666 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
2667 [The bug was that it was starting one character too far in when skipping
2668 over the character class, thus treating the ] as data rather than
2669 terminating the class. This meant it could skip too much.]
2670
2671 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
2672 /g option in pcretest when the pattern contains \K, which makes it possible
2673 to have an empty string match not at the start, even when the pattern is
2674 anchored. Updated pcretest and pcredemo to use this option.
2675
2676 21. If the maximum number of capturing subpatterns in a recursion was greater
2677 than the maximum at the outer level, the higher number was returned, but
2678 with unset values at the outer level. The correct (outer level) value is
2679 now given.
2680
2681 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
2682 PCRE did not set those parentheses (unlike Perl). I have now found a way to
2683 make it do so. The string so far is captured, making this feature
2684 compatible with Perl.
2685
2686 23. The tests have been re-organized, adding tests 11 and 12, to make it
2687 possible to check the Perl 5.10 features against Perl 5.10.
2688
2689 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
2690 pattern matches a fixed length string. PCRE did not allow this; now it
2691 does. Neither allows recursion.
2692
2693 25. I finally figured out how to implement a request to provide the minimum
2694 length of subject string that was needed in order to match a given pattern.
2695 (It was back references and recursion that I had previously got hung up
2696 on.) This code has now been added to pcre_study(); it finds a lower bound
2697 to the length of subject needed. It is not necessarily the greatest lower
2698 bound, but using it to avoid searching strings that are too short does give
2699 some useful speed-ups. The value is available to calling programs via
2700 pcre_fullinfo().
2701
2702 26. While implementing 25, I discovered to my embarrassment that pcretest had
2703 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
2704 study optimizations had never been tested with that matching function.
2705 Oops. What is worse, even when it was passed study data, there was a bug in
2706 pcre_dfa_exec() that meant it never actually used it. Double oops. There
2707 were also very few tests of studied patterns with pcre_dfa_exec().
2708
2709 27. If (?| is used to create subpatterns with duplicate numbers, they are now
2710 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
2711 on the other side of the coin, they are no longer allowed to have different
2712 names, because these cannot be distinguished in PCRE, and this has caused
2713 confusion. (This is a difference from Perl.)
2714
2715 28. When duplicate subpattern names are present (necessarily with different
2716 numbers, as required by 27 above), and a test is made by name in a
2717 conditional pattern, either for a subpattern having been matched, or for
2718 recursion in such a pattern, all the associated numbered subpatterns are
2719 tested, and the overall condition is true if the condition is true for any
2720 one of them. This is the way Perl works, and is also more like the way
2721 testing by number works.
2722
2723
2724 Version 7.9 11-Apr-09
2725 ---------------------
2726
2727 1. When building with support for bzlib/zlib (pcregrep) and/or readline
2728 (pcretest), all targets were linked against these libraries. This included
2729 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
2730 libraries. This caused unwanted dependencies to be created. This problem
2731 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
2732 pcretest is linked with readline.
2733
2734 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
2735 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
2736 moved outside it again, because FALSE and TRUE are already defined in AIX,
2737 but BOOL is not.
2738
2739 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
2740 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
2741
2742 4. The pcregrep documentation said spaces were inserted as well as colons (or
2743 hyphens) following file names and line numbers when outputting matching
2744 lines. This is not true; no spaces are inserted. I have also clarified the
2745 wording for the --colour (or --color) option.
2746
2747 5. In pcregrep, when --colour was used with -o, the list of matching strings
2748 was not coloured; this is different to GNU grep, so I have changed it to be
2749 the same.
2750
2751 6. When --colo(u)r was used in pcregrep, only the first matching substring in
2752 each matching line was coloured. Now it goes on to look for further matches
2753 of any of the test patterns, which is the same behaviour as GNU grep.
2754
2755 7. A pattern that could match an empty string could cause pcregrep to loop; it
2756 doesn't make sense to accept an empty string match in pcregrep, so I have
2757 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2758 seems to be how GNU grep behaves. [But see later change 40 for release
2759 8.33.]
2760
2761 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2762 start or after a newline", because the conditional assertion was not being
2763 correctly handled. The rule now is that both the assertion and what follows
2764 in the first alternative must satisfy the test.
2765
2766 9. If auto-callout was enabled in a pattern with a conditional group whose
2767 condition was an assertion, PCRE could crash during matching, both with
2768 pcre_exec() and pcre_dfa_exec().
2769
2770 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
2771 used for matching.
2772
2773 11. Unicode property support in character classes was not working for
2774 characters (bytes) greater than 127 when not in UTF-8 mode.
2775
2776 12. Added the -M command line option to pcretest.
2777
2778 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
2779
2780 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
2781
2782 16. Added comments and documentation about mis-use of no_arg in the C++
2783 wrapper.
2784
2785 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
2786 from Martin Jerabek that uses macro names for all relevant character and
2787 string constants.
2788
2789 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
2790 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
2791 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
2792 these, but not everybody uses configure.
2793
2794 19. A conditional group that had only one branch was not being correctly
2795 recognized as an item that could match an empty string. This meant that an
2796 enclosing group might also not be so recognized, causing infinite looping
2797 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
2798 with the subject "ab", where knowledge that the repeated group can match
2799 nothing is needed in order to break the loop.
2800
2801 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
2802 exec(), but without supplying a callout function, matching went wrong.
2803
2804 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
2805 leak if the size of the offset vector was greater than 30. When the vector
2806 is smaller, the saved offsets during recursion go onto a local stack
2807 vector, but for larger vectors malloc() is used. It was failing to free
2808 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
2809 error, in fact).
2810
2811 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
2812 heapframe that is used only when UTF-8 support is enabled. This caused no
2813 problem, but was untidy.
2814
2815 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
2816 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
2817 included within another project.
2818
2819 24. Steven Van Ingelgem's patches to add more options to the CMake support,
2820 slightly modified by me:
2821
2822 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
2823 not building pcregrep.
2824
2825 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
2826 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
2827
2828 25. Forward references, both numeric and by name, in patterns that made use of
2829 duplicate group numbers, could behave incorrectly or give incorrect errors,
2830 because when scanning forward to find the reference group, PCRE was not
2831 taking into account the duplicate group numbers. A pattern such as
2832 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
2833
2834 26. Changed a few more instances of "const unsigned char *" to USPTR, making
2835 the feature of a custom pointer more persuasive (as requested by a user).
2836
2837 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
2838 pcretest.c, inside #ifndefs, because it seems they are sometimes already
2839 pre-defined.
2840
2841 28. Added support for (*UTF8) at the start of a pattern.
2842
2843 29. Arrange for flags added by the "release type" setting in CMake to be shown
2844 in the configuration summary.
2845
2846
2847 Version 7.8 05-Sep-08
2848 ---------------------
2849
2850 1. Replaced UCP searching code with optimized version as implemented for Ad
2851 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
2852 stage table and inline lookup instead of a function, giving speed ups of 2
2853 to 5 times on some simple patterns that I tested. Permission was given to
2854 distribute the MultiStage2.py script that generates the tables (it's not in
2855 the tarball, but is in the Subversion repository).
2856
2857 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
2858 scripts.
2859
2860 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
2861 a group with a zero qualifier. The result of the study could be incorrect,
2862 or the function might crash, depending on the pattern.
2863
2864 4. Caseless matching was not working for non-ASCII characters in back
2865 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2866 It now works when Unicode Property Support is available.
2867
2868 5. In pcretest, an escape such as \x{de} in the data was always generating
2869 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2870 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2871 truncation.
2872
2873 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2874
2875 7. Added two (int) casts to pcregrep when printing the difference of two
2876 pointers, in case they are 64-bit values.
2877
2878 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
2879 test 2 if it fails.
2880
2881 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2882 and a #define of that name to empty if it is not externally set. This is to
2883 allow users of MSVC to set it if necessary.
2884
2885 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2886 the convenience functions in the pcre_get.c source file.
2887
2888 11. An option change at the start of a pattern that had top-level alternatives
2889 could cause overwriting and/or a crash. This command provoked a crash in
2890 some environments:
2891
2892 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2893
2894 This potential security problem was recorded as CVE-2008-2371.
2895
2896 12. For a pattern where the match had to start at the beginning or immediately
2897 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2898 pcre_dfa_exec() could read past the end of the passed subject if there was
2899 no match. To help with detecting such bugs (e.g. with valgrind), I modified
2900 pcretest so that it places the subject at the end of its malloc-ed buffer.
2901
2902 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2903 exec() might read past the end of the data buffer in UTF-8 mode.
2904
2905 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2906 the data contained the byte 0x85 as part of a UTF-8 character within its
2907 first line. This applied both to normal and DFA matching.
2908
2909 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2910 /^[^d]*?$/8 failed to match "abc".
2911
2912 16. Added a missing copyright notice to pcrecpp_internal.h.
2913
2914 17. Make it more clear in the documentation that values returned from
2915 pcre_exec() in ovector are byte offsets, not character counts.
2916
2917 18. Tidied a few places to stop certain compilers from issuing warnings.
2918
2919 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2920 supplied by Stefan Weber. I made a further small update for 7.8 because
2921 there is a change of source arrangements: the pcre_searchfuncs.c module is
2922 replaced by pcre_ucd.c.
2923
2924
2925 Version 7.7 07-May-08
2926 ---------------------
2927
2928 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2929 a string to a long long, pretend we don't even have a long long." This is
2930 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2931
2932 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2933 pre-7.6 versions, which defined a global no_arg variable instead of putting
2934 it in the RE class. (See also #8 below.)
2935
2936 3. Remove a line of dead code, identified by coverity and reported by Nuno
2937 Lopes.
2938
2939 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2940
2941 (1) The include/exclude patterns were being applied to the whole pathnames
2942 of files, instead of just to the final components.
2943
2944 (2) If there was more than one level of directory, the subdirectories were
2945 skipped unless they satisfied the include/exclude conditions. This is
2946 inconsistent with GNU grep (and could even be seen as contrary to the
2947 pcregrep specification - which I improved to make it absolutely clear).
2948 The action now is always to scan all levels of directory, and just
2949 apply the include/exclude patterns to regular files.
2950
2951 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2952 --exclude_dir in the tests to avoid scanning .svn directories.
2953
2954 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2955 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2956 doesn't support NULs in patterns.
2957
2958 7. Added some missing "const"s to declarations of static tables in
2959 pcre_compile.c and pcre_dfa_exec.c.
2960
2961 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2962 caused by fix #2 above. (Subsequently also a second patch to fix the
2963 first patch. And a third patch - this was a messy problem.)
2964
2965 9. Applied Craig's patch to remove the use of push_back().
2966
2967 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2968 matching function regexec().
2969
2970 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2971 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2972 references. PCRE supports relative numbers with this syntax (I don't think
2973 Oniguruma does).
2974
2975 12. Previously, a group with a zero repeat such as (...){0} was completely
2976 omitted from the compiled regex. However, this means that if the group
2977 was called as a subroutine from elsewhere in the pattern, things went wrong
2978 (an internal error was given). Such groups are now left in the compiled
2979 pattern, with a new opcode that causes them to be skipped at execution
2980 time.
2981
2982 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2983 to the way PCRE behaves:
2984
2985 (a) A lone ] character is dis-allowed (Perl treats it as data).
2986
2987 (b) A back reference to an unmatched subpattern matches an empty string
2988 (Perl fails the current match path).
2989
2990 (c) A data ] in a character class must be notated as \] because if the
2991 first data character in a class is ], it defines an empty class. (In
2992 Perl it is not possible to have an empty class.) The empty class []
2993 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2994 The negative empty class [^] matches any one character, independently
2995 of the DOTALL setting.
2996
2997 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2998 non-existent subpattern following a character class starting with ']' and
2999 containing () gave an internal compiling error instead of "reference to
3000 non-existent subpattern". Fortunately, when the pattern did exist, the
3001 compiled code was correct. (When scanning forwards to check for the
3002 existence of the subpattern, it was treating the data ']' as terminating
3003 the class, so got the count wrong. When actually compiling, the reference
3004 was subsequently set up correctly.)
3005
3006 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
3007 it was being rejected as not supported by pcre_dfa_exec(), even though
3008 other assertions are supported. I have made pcre_dfa_exec() support
3009 (*FAIL).
3010
3011 16. The implementation of 13c above involved the invention of a new opcode,
3012 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
3013 cannot be changed at match time, I realized I could make a small
3014 improvement to matching performance by compiling OP_ALLANY instead of
3015 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
3016 on the OP_ANY path.
3017
3018 17. Compiling pcretest on Windows with readline support failed without the
3019 following two fixes: (1) Make the unistd.h include conditional on
3020 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
3021
3022 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
3023 ncurses library to be included for pcretest when ReadLine support is
3024 requested, but also to allow for it to be overridden. This patch came from
3025 Daniel Bergström.
3026
3027 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
3028 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
3029 any errors with the current Unicode tables. Thanks to Peter Kankowski for
3030 spotting this.
3031
3032
3033 Version 7.6 28-Jan-08
3034 ---------------------
3035
3036 1. A character class containing a very large number of characters with
3037 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
3038 overflow.
3039
3040 2. Patch to cut out the "long long" test in pcrecpp_unittest when
3041 HAVE_LONG_LONG is not defined.
3042
3043 3. Applied Christian Ehrlicher's patch to update the CMake build files to
3044 bring them up to date and include new features. This patch includes:
3045
3046 - Fixed PH's badly added libz and libbz2 support.
3047 - Fixed a problem with static linking.
3048 - Added pcredemo. [But later removed - see 7 below.]
3049 - Fixed dftables problem and added an option.
3050 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
3051 HAVE_LONG_LONG.
3052 - Added readline support for pcretest.
3053 - Added an listing of the option settings after cmake has run.
3054
3055 4. A user submitted a patch to Makefile that makes it easy to create
3056 "pcre.dll" under mingw when using Configure/Make. I added stuff to
3057 Makefile.am that cause it to include this special target, without
3058 affecting anything else. Note that the same mingw target plus all
3059 the other distribution libraries and programs are now supported
3060 when configuring with CMake (see 6 below) instead of with
3061 Configure/Make.
3062
3063 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
3064 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
3065 exported in the Windows port". It has not yet been confirmed that the patch
3066 solves the problem, but it does no harm.
3067
3068 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
3069 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
3070 with CMake, and also correct the comment about stack recursion.
3071
3072 7. Remove the automatic building of pcredemo from the ./configure system and
3073 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
3074 of a program that users should build themselves after PCRE is installed, so
3075 building it automatically is not really right. What is more, it gave
3076 trouble in some build environments.
3077
3078 8. Further tidies to CMakeLists.txt from Sheri and Christian.
3079
3080
3081 Version 7.5 10-Jan-08
3082 ---------------------
3083
3084 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
3085 values in parens when parsing an RE using the C++ wrapper."
3086
3087 2. Negative specials like \S did not work in character classes in UTF-8 mode.
3088 Characters greater than 255 were excluded from the class instead of being
3089 included.
3090
3091 3. The same bug as (2) above applied to negated POSIX classes such as
3092 [:^space:].
3093
3094 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
3095 defined or documented. It seems to have been a typo for PCRE_STATIC, so
3096 I have changed it.
3097
3098 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
3099 first named subpattern) and a construct such as (?&a) would reference the
3100 first named subpattern whose name started with "a" (in other words, the
3101 length check was missing). Both these problems are fixed. "Subpattern name
3102 expected" is now given for (?&) (a zero-length name), and this patch also
3103 makes it give the same error for \k'' (previously it complained that that
3104 was a reference to a non-existent subpattern).
3105
3106 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
3107 this is right because (?- can be followed by option settings as well as by
3108 digits. I have, however, made the messages clearer.
3109
3110 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
3111 than the number used in the conditional) now cause a compile-time error.
3112 This is actually not compatible with Perl, which accepts such patterns, but
3113 treats the conditional as always being FALSE (as PCRE used to), but it
3114 seems to me that giving a diagnostic is better.
3115
3116 8. Change "alphameric" to the more common word "alphanumeric" in comments
3117 and messages.
3118
3119 9. Fix two occurrences of "backslash" in comments that should have been
3120 "backspace".
3121
3122 10. Remove two redundant lines of code that can never be obeyed (their function
3123 was moved elsewhere).
3124
3125 11. The program that makes PCRE's Unicode character property table had a bug
3126 which caused it to generate incorrect table entries for sequences of
3127 characters that have the same character type, but are in different scripts.
3128 It amalgamated them into a single range, with the script of the first of
3129 them. In other words, some characters were in the wrong script. There were
3130 thirteen such cases, affecting characters in the following ranges:
3131
3132 U+002b0 - U+002c1
3133 U+0060c - U+0060d
3134 U+0061e - U+00612
3135 U+0064b - U+0065e
3136 U+0074d - U+0076d
3137 U+01800 - U+01805
3138 U+01d00 - U+01d77
3139 U+01d9b - U+01dbf
3140 U+0200b - U+0200f
3141 U+030fc - U+030fe
3142 U+03260 - U+0327f
3143 U+0fb46 - U+0fbb1
3144 U+10450 - U+1049d
3145
3146 12. The -o option (show only the matching part of a line) for pcregrep was not
3147 compatible with GNU grep in that, if there was more than one match in a
3148 line, it showed only the first of them. It now behaves in the same way as
3149 GNU grep.
3150
3151 13. If the -o and -v options were combined for pcregrep, it printed a blank
3152 line for every non-matching line. GNU grep prints nothing, and pcregrep now
3153 does the same. The return code can be used to tell if there were any
3154 non-matching lines.
3155
3156 14. Added --file-offsets and --line-offsets to pcregrep.
3157
3158 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
3159 infinitely looping recursion. The bug was that positive lookaheads were not
3160 being skipped when checking for a possible empty match (negative lookaheads
3161 and both kinds of lookbehind were skipped).
3162
3163 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
3164 inclusion of <windows.h> to before rather than after the definition of
3165 INVALID_FILE_ATTRIBUTES (patch from David Byron).
3166
3167 17. Specifying a possessive quantifier with a specific limit for a Unicode
3168 character property caused pcre_compile() to compile bad code, which led at
3169 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
3170 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
3171 caused the error; without that there was no problem.
3172
3173 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
3174
3175 19. Added --enable-pcretest-libreadline.
3176
3177 20. In pcrecpp.cc, the variable 'count' was incremented twice in
3178 RE::GlobalReplace(). As a result, the number of replacements returned was
3179 double what it should be. I removed one of the increments, but Craig sent a
3180 later patch that removed the other one (the right fix) and added unit tests
3181 that check the return values (which was not done before).
3182
3183 21. Several CMake things:
3184
3185 (1) Arranged that, when cmake is used on Unix, the libraries end up with
3186 the names libpcre and libpcreposix, not just pcre and pcreposix.
3187
3188 (2) The above change means that pcretest and pcregrep are now correctly
3189 linked with the newly-built libraries, not previously installed ones.
3190
3191 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
3192
3193 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
3194 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
3195 UTF-8 newline character). The key issue is that the pattern starts .*;
3196 this means that the match must be either at the beginning, or after a
3197 newline. The bug was in the code for advancing after a failed match and
3198 checking that the new position followed a newline. It was not taking
3199 account of UTF-8 characters correctly.
3200
3201 23. PCRE was behaving differently from Perl in the way it recognized POSIX
3202 character classes. PCRE was not treating the sequence [:...:] as a
3203 character class unless the ... were all letters. Perl, however, seems to
3204 allow any characters between [: and :], though of course it rejects as
3205 unknown any "names" that contain non-letters, because all the known class
3206 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
3207 for example, whereas PCRE did not - it did not recognize a POSIX character
3208 class. This seemed a bit dangerous, so the code has been changed to be
3209 closer to Perl. The behaviour is not identical to Perl, because PCRE will
3210 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
3211 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
3212 Perl does, and where it didn't before.
3213
3214 24. Rewrite so as to remove the single use of %n from pcregrep because in some
3215 Windows environments %n is disabled by default.
3216
3217
3218 Version 7.4 21-Sep-07
3219 ---------------------
3220
3221 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
3222 means that a class such as [\s] counted as "explicit reference to CR or
3223 LF". That isn't really right - the whole point of the change was to try to
3224 help when there was an actual mention of one of the two characters. So now
3225 the change happens only if \r or \n (or a literal CR or LF) character is
3226 encountered.
3227
3228 2. The 32-bit options word was also used for 6 internal flags, but the numbers
3229 of both had grown to the point where there were only 3 bits left.
3230 Fortunately, there was spare space in the data structure, and so I have
3231 moved the internal flags into a new 16-bit field to free up more option
3232 bits.
3233
3234 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
3235 but did not set the internal JCHANGED flag - either of these is enough to
3236 control the way the "get" function works - but the PCRE_INFO_JCHANGED
3237 facility is supposed to tell if (?J) was ever used, so now (?J) at the
3238 start sets both bits.
3239
3240 4. Added options (at build time, compile time, exec time) to change \R from
3241 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
3242
3243 5. doc/pcresyntax.html was missing from the distribution.
3244
3245 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
3246 compatibility, even though it is no longer used.
3247
3248 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
3249 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
3250 windows.h file is present (where different names are used). [This was
3251 reversed later after testing - see 16 below.]
3252
3253 8. Changed all #include <config.h> to #include "config.h". There were also
3254 some further <pcre.h> cases that I changed to "pcre.h".
3255
3256 9. When pcregrep was used with the --colour option, it missed the line ending
3257 sequence off the lines that it output.
3258
3259 10. It was pointed out to me that arrays of string pointers cause lots of
3260 relocations when a shared library is dynamically loaded. A technique of
3261 using a single long string with a table of offsets can drastically reduce
3262 these. I have refactored PCRE in four places to do this. The result is
3263 dramatic:
3264
3265 Originally: 290
3266 After changing UCP table: 187
3267 After changing error message table: 43
3268 After changing table of "verbs" 36
3269 After changing table of Posix names 22
3270
3271 Thanks to the folks working on Gregex for glib for this insight.
3272
3273 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
3274 unicode-properties was also set.
3275
3276 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
3277
3278 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
3279 checked only for CRLF.
3280
3281 14. Added casts to pcretest.c to avoid compiler warnings.
3282
3283 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
3284
3285 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
3286 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
3287 entirely. This removes changes made in 7 above.
3288
3289 17. The CMake files have been updated, and there is now more information about
3290 building with CMake in the NON-UNIX-USE document.
3291
3292
3293 Version 7.3 28-Aug-07
3294 ---------------------
3295
3296 1. In the rejigging of the build system that eventually resulted in 7.1, the
3297 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
3298 brackets there is not right, since it causes compilers to look for an
3299 installed pcre.h, not the version that is in the source that is being
3300 compiled (which of course may be different). I have changed it back to:
3301
3302 #include "pcre.h"
3303
3304 I have a vague recollection that the change was concerned with compiling in
3305 different directories, but in the new build system, that is taken care of
3306 by the VPATH setting the Makefile.
3307
3308 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
3309 when the subject happened to end in the byte 0x85 (e.g. if the last
3310 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
3311 characters but of course it shouldn't be taken as a newline when it is part
3312 of another character. The bug was that, for an unlimited repeat of . in
3313 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
3314 characters when looking for a newline.
3315
3316 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
3317
3318 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
3319 in debug output.
3320
3321 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
3322 long printing in the pcrecpp unittest when running under MinGW.
3323
3324 6. ESC_K was left out of the EBCDIC table.
3325
3326 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
3327 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
3328 limit also applies to "virtual nesting" when a pattern is recursive, and in
3329 this case 1000 isn't so big. I have been able to remove this limit at the
3330 expense of backing off one optimization in certain circumstances. Normally,
3331 when pcre_exec() would call its internal match() function recursively and
3332 immediately return the result unconditionally, it uses a "tail recursion"
3333 feature to save stack. However, when a subpattern that can match an empty
3334 string has an unlimited repetition quantifier, it no longer makes this
3335 optimization. That gives it a stack frame in which to save the data for
3336 checking that an empty string has been matched. Previously this was taken
3337 from the 1000-entry workspace that had been reserved. So now there is no
3338 explicit limit, but more stack is used.
3339
3340 8. Applied Daniel's patches to solve problems with the import/export magic
3341 syntax that is required for Windows, and which was going wrong for the
3342 pcreposix and pcrecpp parts of the library. These were overlooked when this
3343 problem was solved for the main library.
3344
3345 9. There were some crude static tests to avoid integer overflow when computing
3346 the size of patterns that contain repeated groups with explicit upper
3347 limits. As the maximum quantifier is 65535, the maximum group length was
3348 set at 30,000 so that the product of these two numbers did not overflow a
3349 32-bit integer. However, it turns out that people want to use groups that
3350 are longer than 30,000 bytes (though not repeat them that many times).
3351 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
3352 made it possible to implement the integer overflow checks in a much more
3353 dynamic way, which I have now done. The artificial limitation on group
3354 length has been removed - we now have only the limit on the total length of
3355 the compiled pattern, which depends on the LINK_SIZE setting.
3356
3357 10. Fixed a bug in the documentation for get/copy named substring when
3358 duplicate names are permitted. If none of the named substrings are set, the
3359 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
3360 empty string.
3361
3362 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
3363 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
3364 because the ] is interpreted as the first data character and the
3365 terminating ] is not found. PCRE has been made compatible with Perl in this
3366 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
3367 cause memory overwriting.
3368
3369 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
3370 string has been matched (to stop an infinite loop). It was not recognizing
3371 a conditional subpattern that could match an empty string if that
3372 subpattern was within another subpattern. For example, it looped when
3373 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
3374 condition was not nested. This bug has been fixed.
3375
3376 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
3377 past the start of the subject in the presence of bytes with the top bit
3378 set, for example "\x8aBCD".
3379
3380 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
3381 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
3382
3383 14. Optimized (?!) to (*FAIL).
3384
3385 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
3386 This restricts code points to be within the range 0 to 0x10FFFF, excluding
3387 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
3388 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
3389 does: it's just the validity check that is more restrictive.
3390
3391 16. Inserted checks for integer overflows during escape sequence (backslash)
3392 processing, and also fixed erroneous offset values for syntax errors during
3393 backslash processing.
3394
3395 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
3396 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
3397
3398 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
3399 caused an overrun.
3400
3401 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
3402 something other than just ASCII characters) inside a group that had an
3403 unlimited repeat caused a loop at compile time (while checking to see
3404 whether the group could match an empty string).
3405
3406 20. Debugging a pattern containing \p or \P could cause a crash. For example,
3407 [\P{Any}] did so. (Error in the code for printing property names.)
3408
3409 21. An orphan \E inside a character class could cause a crash.
3410
3411 22. A repeated capturing bracket such as (A)? could cause a wild memory
3412 reference during compilation.
3413
3414 23. There are several functions in pcre_compile() that scan along a compiled
3415 expression for various reasons (e.g. to see if it's fixed length for look
3416 behind). There were bugs in these functions when a repeated \p or \P was
3417 present in the pattern. These operators have additional parameters compared
3418 with \d, etc, and these were not being taken into account when moving along
3419 the compiled data. Specifically:
3420
3421 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
3422 length.
3423
3424 (b) An item such as \pL+ within a repeated group could cause crashes or
3425 loops.
3426
3427 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
3428 "reference to non-existent subpattern" error.
3429
3430 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
3431
3432 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
3433 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
3434
3435 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
3436
3437 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
3438 character were causing crashes (broken optimization).
3439
3440 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
3441 \p or \P) caused a compile-time loop.
3442
3443 28. More problems have arisen in unanchored patterns when CRLF is a valid line
3444 break. For example, the unstudied pattern [\r\n]A does not match the string
3445 "\r\nA" because change 7.0/46 below moves the current point on by two
3446 characters after failing to match at the start. However, the pattern \nA
3447 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
3448 the same is true. There doesn't seem any very clean way out of this, but
3449 what I have chosen to do makes the common cases work: PCRE now takes note
3450 of whether there can be an explicit match for \r or \n anywhere in the
3451 pattern, and if so, 7.0/46 no longer applies. As part of this change,
3452 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
3453 pattern has explicit CR or LF references.
3454
3455 29. Added (*CR) etc for changing newline setting at start of pattern.
3456
3457
3458 Version 7.2 19-Jun-07
3459 ---------------------
3460
3461 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
3462 which is apparently normally available under Windows.
3463
3464 2. Re-jig the pcregrep tests with different newline settings in an attempt
3465 to make them independent of the local environment's newline setting.
3466
3467 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
3468
3469 4. Some of the "internals" tests were previously cut out when the link size
3470 was not 2, because the output contained actual offsets. The recent new
3471 "Z" feature of pcretest means that these can be cut out, making the tests
3472 usable with all link sizes.
3473
3474 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
3475 stack recursion. This gives a massive performance boost under BSD, but just
3476 a small improvement under Linux. However, it saves one field in the frame
3477 in all cases.
3478
3479 6. Added more features from the forthcoming Perl 5.10:
3480
3481 (a) (?-n) (where n is a string of digits) is a relative subroutine or
3482 recursion call. It refers to the nth most recently opened parentheses.
3483
3484 (b) (?+n) is also a relative subroutine call; it refers to the nth next
3485 to be opened parentheses.
3486
3487 (c) Conditions that refer to capturing parentheses can be specified
3488 relatively, for example, (?(-2)... or (?(+3)...
3489
3490 (d) \K resets the start of the current match so that everything before
3491 is not part of it.
3492
3493 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
3494
3495 (f) \g{name} is another synonym - part of Perl 5.10's unification of
3496 reference syntax.
3497
3498 (g) (?| introduces a group in which the numbering of parentheses in each
3499 alternative starts with the same number.
3500
3501 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
3502
3503 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
3504 PCRE_INFO_JCHANGED.
3505
3506 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
3507 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
3508 for detecting groups that can match an empty string.
3509
3510 9. A pattern with a very large number of alternatives (more than several
3511 hundred) was running out of internal workspace during the pre-compile
3512 phase, where pcre_compile() figures out how much memory will be needed. A
3513 bit of new cunning has reduced the workspace needed for groups with
3514 alternatives. The 1000-alternative test pattern now uses 12 bytes of
3515 workspace instead of running out of the 4096 that are available.
3516
3517 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
3518
3519 11. Applied patch from Google to remove an optimization that didn't quite work.
3520 The report of the bug said:
3521
3522 pcrecpp::RE("a*").FullMatch("aaa") matches, while
3523 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
3524 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
3525
3526 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
3527 it matched the wrong number of bytes.
3528
3529
3530 Version 7.1 24-Apr-07
3531 ---------------------
3532
3533 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
3534 that is more "standard", making use of automake and other Autotools. There
3535 is some re-arrangement of the files and adjustment of comments consequent
3536 on this.
3537
3538 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
3539 for recursive directory scanning broke on some systems because the files
3540 are not scanned in any specific order and on different systems the order
3541 was different. A call to "sort" has been inserted into RunGrepTest for the
3542 approprate test as a short-term fix. In the longer term there may be an
3543 alternative.
3544
3545 3. I had an email from Eric Raymond about problems translating some of PCRE's
3546 man pages to HTML (despite the fact that I distribute HTML pages, some
3547 people do their own conversions for various reasons). The problems
3548 concerned the use of low-level troff macros .br and .in. I have therefore
3549 removed all such uses from the man pages (some were redundant, some could
3550 be replaced by .nf/.fi pairs). The 132html script that I use to generate
3551 HTML has been updated to handle .nf/.fi and to complain if it encounters
3552 .br or .in.
3553
3554 4. Updated comments in configure.ac that get placed in config.h.in and also
3555 arranged for config.h to be included in the distribution, with the name
3556 config.h.generic, for the benefit of those who have to compile without
3557 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
3558
3559 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
3560 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
3561 makevp.bat for the current PCRE, using the additional files
3562 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
3563
3564 6. A Windows user reported a minor discrepancy with test 2, which turned out
3565 to be caused by a trailing space on an input line that had got lost in his
3566 copy. The trailing space was an accident, so I've just removed it.
3567
3568 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
3569 that is needed.
3570
3571 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
3572 as "const" (a) because they are and (b) because it helps the PHP
3573 maintainers who have recently made a script to detect big data structures
3574 in the php code that should be moved to the .rodata section. I remembered
3575 to update Builducptable as well, so it won't revert if ucptable.h is ever
3576 re-created.
3577
3578 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
3579 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
3580 order to be able to cut out the UTF-8 tables in the latter when UTF-8
3581 support is not required. This saves 1.5-2K of code, which is important in
3582 some applications.
3583
3584 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
3585 so as not to refer to the tables, even though these functions will never be
3586 called when UTF-8 support is disabled. Otherwise there are problems with a
3587 shared library.
3588
3589 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
3590
3591 (a) It was defining its arguments as char * instead of void *.
3592
3593 (b) It was assuming that all moves were upwards in memory; this was true
3594 a long time ago when I wrote it, but is no longer the case.
3595
3596 The emulated memove() is provided for those environments that have neither
3597 memmove() nor bcopy(). I didn't think anyone used it these days, but that
3598 is clearly not the case, as these two bugs were recently reported.
3599
3600 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
3601 and Detrail to create the HTML documentation, the .txt form of the man
3602 pages, and it removes trailing spaces from listed files. It also creates
3603 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
3604 case, it wraps all the #defines with #ifndefs. This script should be run
3605 before "make dist".
3606
3607 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
3608 with Unicode property support.
3609
3610 (a) For a maximizing quantifier, if the two different cases of the
3611 character were of different lengths in their UTF-8 codings (there are
3612 some cases like this - I found 11), and the matching function had to
3613 back up over a mixture of the two cases, it incorrectly assumed they
3614 were both the same length.
3615
3616 (b) When PCRE was configured to use the heap rather than the stack for
3617 recursion during matching, it was not correctly preserving the data for
3618 the other case of a UTF-8 character when checking ahead for a match
3619 while processing a minimizing repeat. If the check also involved
3620 matching a wide character, but failed, corruption could cause an
3621 erroneous result when trying to check for a repeat of the original
3622 character.
3623
3624 13. Some tidying changes to the testing mechanism:
3625
3626 (a) The RunTest script now detects the internal link size and whether there
3627 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
3628 values substituted by "configure". (The RunGrepTest script already did
3629 this for UTF-8.) The configure.ac script no longer substitutes the
3630 relevant variables.
3631
3632 (b) The debugging options /B and /D in pcretest show the compiled bytecode
3633 with length and offset values. This means that the output is different
3634 for different internal link sizes. Test 2 is skipped for link sizes
3635 other than 2 because of this, bypassing the problem. Unfortunately,
3636 there was also a test in test 3 (the locale tests) that used /B and
3637 failed for link sizes other than 2. Rather than cut the whole test out,
3638 I have added a new /Z option to pcretest that replaces the length and
3639 offset values with spaces. This is now used to make test 3 independent
3640 of link size. (Test 2 will be tidied up later.)
3641
3642 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
3643 segmentation fault instead of returning the appropriate error message.
3644
3645 15. In multiline mode when the newline sequence was set to "any", the pattern
3646 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
3647 This doesn't seem right; it now treats the CRLF combination as the line
3648 ending, and so does not match in that case. It's only a pattern such as ^$
3649 that would hit this one: something like ^ABC$ would have failed after \r
3650 and then tried again after \r\n.
3651
3652 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
3653 in an attempt to make files that differ only in their line terminators
3654 compare equal. This works on Linux.
3655
3656 17. Under certain error circumstances pcregrep might try to free random memory
3657 as it exited. This is now fixed, thanks to valgrind.
3658
3659 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
3660 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
3661 was because its rules for how to advance for /g after matching an empty
3662 string at the end of a line did not allow for this case. They now check for
3663 it specially.
3664
3665 20. pcretest is supposed to handle patterns and data of any length, by
3666 extending its buffers when necessary. It was getting this wrong when the
3667 buffer for a data line had to be extended.
3668
3669 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
3670 CRLF as a newline sequence.
3671
3672 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
3673 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
3674 I have nevertheless tidied it up.
3675
3676 23. Added some casts to kill warnings from HP-UX ia64 compiler.
3677
3678 24. Added a man page for pcre-config.
3679
3680
3681 Version 7.0 19-Dec-06
3682 ---------------------
3683
3684 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
3685 moving to gcc 4.1.1.
3686
3687 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
3688 sys/time.h, which is documented as needed for this function. It doesn't
3689 seem to matter on Linux, but it showed up on some releases of OS X.
3690
3691 3. It seems that there are systems where bytes whose values are greater than
3692 127 match isprint() in the "C" locale. The "C" locale should be the
3693 default when a C program starts up. In most systems, only ASCII printing
3694 characters match isprint(). This difference caused the output from pcretest
3695 to vary, making some of the tests fail. I have changed pcretest so that:
3696
3697 (a) When it is outputting text in the compiled version of a pattern, bytes
3698 other than 32-126 are always shown as hex escapes.
3699
3700 (b) When it is outputting text that is a matched part of a subject string,
3701 it does the same, unless a different locale has been set for the match
3702 (using the /L modifier). In this case, it uses isprint() to decide.
3703
3704 4. Fixed a major bug that caused incorrect computation of the amount of memory
3705 required for a compiled pattern when options that changed within the
3706 pattern affected the logic of the preliminary scan that determines the
3707 length. The relevant options are -x, and -i in UTF-8 mode. The result was
3708 that the computed length was too small. The symptoms of this bug were
3709 either the PCRE error "internal error: code overflow" from pcre_compile(),
3710 or a glibc crash with a message such as "pcretest: free(): invalid next
3711 size (fast)". Examples of patterns that provoked this bug (shown in
3712 pcretest format) are:
3713
3714 /(?-x: )/x
3715 /(?x)(?-x: \s*#\s*)/
3716 /((?i)[\x{c0}])/8
3717 /(?i:[\x{c0}])/8
3718
3719 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
3720 is now done differently.
3721
3722 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
3723 wrapper classes; (b) implement a new function in the C++ scanner that is
3724 more efficient than the old way of doing things because it avoids levels of
3725 recursion in the regex matching; (c) add a paragraph to the documentation
3726 for the FullMatch() function.
3727
3728 6. The escape sequence \n was being treated as whatever was defined as
3729 "newline". Not only was this contrary to the documentation, which states
3730 that \n is character 10 (hex 0A), but it also went horribly wrong when
3731 "newline" was defined as CRLF. This has been fixed.
3732
3733 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
3734 was being set to -1 for the "end of line" case (supposedly a value that no
3735 character can have). Though this value is never used (the check for end of
3736 line is "zero bytes in current character"), it caused compiler complaints.
3737 I've changed it to 0xffffffff.
3738
3739 8. In pcre_version.c, the version string was being built by a sequence of
3740 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
3741 string (as it is for production releases) called a macro with an empty
3742 argument. The C standard says the result of this is undefined. The gcc
3743 compiler treats it as an empty string (which was what was wanted) but it is
3744 reported that Visual C gives an error. The source has been hacked around to
3745 avoid this problem.
3746
3747 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
3748 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
3749 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
3750 of them did).
3751
3752 10. Originally, pcretest opened its input and output without "b"; then I was
3753 told that "b" was needed in some environments, so it was added for release
3754 5.0 to both the input and output. (It makes no difference on Unix-like
3755 systems.) Later I was told that it is wrong for the input on Windows. I've
3756 now abstracted the modes into two macros, to make it easier to fiddle with
3757 them, and removed "b" from the input mode under Windows.
3758
3759 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
3760
3761 12. Added -help and --help to pcretest as an official way of being reminded
3762 of the options.
3763
3764 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
3765 and pcrecpp.cc because they annoy compilers at high warning levels.
3766
3767 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
3768
3769 15. Fixed an occurrence of == in configure.ac that should have been = (shell
3770 scripts are not C programs :-) and which was not noticed because it works
3771 on Linux.
3772
3773 16. pcretest is supposed to handle any length of pattern and data line (as one
3774 line or as a continued sequence of lines) by extending its input buffer if
3775 necessary. This feature was broken for very long pattern lines, leading to
3776 a string of junk being passed to pcre_compile() if the pattern was longer
3777 than about 50K.
3778
3779 17. I have done a major re-factoring of the way pcre_compile() computes the
3780 amount of memory needed for a compiled pattern. Previously, there was code
3781 that made a preliminary scan of the pattern in order to do this. That was
3782 OK when PCRE was new, but as the facilities have expanded, it has become
3783 harder and harder to keep it in step with the real compile phase, and there
3784 have been a number of bugs (see for example, 4 above). I have now found a
3785 cunning way of running the real compile function in a "fake" mode that
3786 enables it to compute how much memory it would need, while actually only
3787 ever using a few hundred bytes of working memory and without too many
3788 tests of the mode. This should make future maintenance and development
3789 easier. A side effect of this work is that the limit of 200 on the nesting
3790 depth of parentheses has been removed (though this was never a serious
3791 limitation, I suspect). However, there is a downside: pcre_compile() now
3792 runs more slowly than before (30% or more, depending on the pattern). I
3793 hope this isn't a big issue. There is no effect on runtime performance.
3794
3795 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
3796 newline (only possible for the last line of a file) and it was a
3797 pattern that set a locale (followed by /Lsomething), pcretest crashed.
3798
3799 19. Added additional timing features to pcretest. (1) The -tm option now times
3800 matching only, not compiling. (2) Both -t and -tm can be followed, as a
3801 separate command line item, by a number that specifies the number of
3802 repeats to use when timing. The default is 50000; this gives better
3803 precision, but takes uncomfortably long for very large patterns.
3804
3805 20. Extended pcre_study() to be more clever in cases where a branch of a
3806 subpattern has no definite first character. For example, (a*|b*)[cd] would
3807 previously give no result from pcre_study(). Now it recognizes that the
3808 first character must be a, b, c, or d.
3809
3810 21. There was an incorrect error "recursive call could loop indefinitely" if
3811 a subpattern (or the entire pattern) that was being tested for matching an
3812 empty string contained only one non-empty item after a nested subpattern.
3813 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
3814 incorrectly, because the \d was being skipped in the check.
3815
3816 22. The pcretest program now has a new pattern option /B and a command line
3817 option -b, which is equivalent to adding /B to every pattern. This causes
3818 it to show the compiled bytecode, without the additional information that
3819 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
3820 is the same as /B/I).
3821
3822 23. A new optimization is now able automatically to treat some sequences such
3823 as a*b as a*+b. More specifically, if something simple (such as a character
3824 or a simple class like \d) has an unlimited quantifier, and is followed by
3825 something that cannot possibly match the quantified thing, the quantifier
3826 is automatically "possessified".
3827
3828 24. A recursive reference to a subpattern whose number was greater than 39
3829 went wrong under certain circumstances in UTF-8 mode. This bug could also
3830 have affected the operation of pcre_study().
3831
3832 25. Realized that a little bit of performance could be had by replacing
3833 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
3834
3835 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
3836
3837 27. Possessive quantifiers such as a++ were previously implemented by turning
3838 them into atomic groups such as ($>a+). Now they have their own opcodes,
3839 which improves performance. This includes the automatically created ones
3840 from 23 above.
3841
3842 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
3843 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
3844 the first matched character to be a colon. This applied both to named and
3845 numbered groups.
3846
3847 29. The ucpinternal.h header file was missing its idempotency #ifdef.
3848
3849 30. I was sent a "project" file called libpcre.a.dev which I understand makes
3850 building PCRE on Windows easier, so I have included it in the distribution.
3851
3852 31. There is now a check in pcretest against a ridiculously large number being
3853 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
3854 loop, the loop is abandoned.
3855
3856 32. Forward references to subpatterns in conditions such as (?(2)...) where
3857 subpattern 2 is defined later cause pcre_compile() to search forwards in
3858 the pattern for the relevant set of parentheses. This search went wrong
3859 when there were unescaped parentheses in a character class, parentheses
3860 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
3861
3862 33. "Subroutine" calls and backreferences were previously restricted to
3863 referencing subpatterns earlier in the regex. This restriction has now
3864 been removed.
3865
3866 34. Added a number of extra features that are going to be in Perl 5.10. On the
3867 whole, these are just syntactic alternatives for features that PCRE had
3868 previously implemented using the Python syntax or my own invention. The
3869 other formats are all retained for compatibility.
3870
3871 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
3872 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
3873 also .NET compatible.
3874
3875 (b) A recursion or subroutine call to a named group can now be defined as
3876 (?&name) as well as (?P>name).
3877
3878 (c) A backreference to a named group can now be defined as \k<name> or
3879 \k'name' as well as (?P=name). The new forms, as well as being in Perl
3880 5.10, are also .NET compatible.
3881
3882 (d) A conditional reference to a named group can now use the syntax
3883 (?(<name>) or (?('name') as well as (?(name).
3884
3885 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
3886 groups (named and numbered) that are never evaluated inline, but can be
3887 called as "subroutines" from elsewhere. In effect, the DEFINE condition
3888 is always false. There may be only one alternative in such a group.
3889
3890 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
3891 as the simple (?(R). The condition is true only if the most recent
3892 recursion is that of the given number or name. It does not search out
3893 through the entire recursion stack.
3894
3895 (g) The escape \gN or \g{N} has been added, where N is a positive or
3896 negative number, specifying an absolute or relative reference.
3897
3898 35. Tidied to get rid of some further signed/unsigned compiler warnings and
3899 some "unreachable code" warnings.
3900
3901 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
3902 things, this adds five new scripts.
3903
3904 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
3905 There were also incompatibilities regarding the handling of \Q..\E inside
3906 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3907 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3908
3909 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3910 matches an empty string, and forcibly breaks the loop. There were bugs in
3911 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3912 against aaaa the result was just "a" rather than "aaaa", for example. Two
3913 separate and independent bugs (that affected different cases) have been
3914 fixed.
3915
3916 39. Refactored the code to abolish the use of different opcodes for small
3917 capturing bracket numbers. This is a tidy that I avoided doing when I
3918 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3919 The new approach is not only tidier, it makes it possible to reduce the
3920 memory needed to fix the previous bug (38).
3921
3922 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3923 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3924 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3925 mode.
3926
3927 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3928 report.
3929
3930 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3931 copy construction and assignment in the C++ wrapper.
3932
3933 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3934 couple of bugs that could have given wrong results in the "--newline=crlf"
3935 case.
3936
3937 44. Added a number of casts and did some reorganization of signed/unsigned int
3938 variables following suggestions from Dair Grant. Also renamed the variable
3939 "this" as "item" because it is a C++ keyword.
3940
3941 45. Arranged for dftables to add
3942
3943 #include "pcre_internal.h"
3944
3945 to pcre_chartables.c because without it, gcc 4.x may remove the array
3946 definition from the final binary if PCRE is built into a static library and
3947 dead code stripping is activated.
3948
3949 46. For an unanchored pattern, if a match attempt fails at the start of a
3950 newline sequence, and the newline setting is CRLF or ANY, and the next two
3951 characters are CRLF, advance by two characters instead of one.
3952
3953
3954 Version 6.7 04-Jul-06
3955 ---------------------
3956
3957 1. In order to handle tests when input lines are enormously long, pcretest has
3958 been re-factored so that it automatically extends its buffers when
3959 necessary. The code is crude, but this _is_ just a test program. The
3960 default size has been increased from 32K to 50K.
3961
3962 2. The code in pcre_study() was using the value of the re argument before
3963 testing it for NULL. (Of course, in any sensible call of the function, it
3964 won't be NULL.)
3965
3966 3. The memmove() emulation function in pcre_internal.h, which is used on
3967 systems that lack both memmove() and bcopy() - that is, hardly ever -
3968 was missing a "static" storage class specifier.
3969
3970 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3971 containing an extended class (one that cannot be represented by a bitmap
3972 because it contains high-valued characters or Unicode property items, e.g.
3973 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3974 pattern, but PCRE should not loop if you do not (it no longer does).
3975 [Detail: two cases were found: (a) a repeated subpattern containing an
3976 extended class; (b) a recursive reference to a subpattern that followed a
3977 previous extended class. It wasn't skipping over the extended class
3978 correctly when UTF-8 mode was not set.]
3979
3980 5. A negated single-character class was not being recognized as fixed-length
3981 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3982 compile error "lookbehind assertion is not fixed length".
3983
3984 6. The RunPerlTest auxiliary script was showing an unexpected difference
3985 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3986 write a Perl script that can interpret lines of an input file either as
3987 byte characters or as UTF-8, which is what "perltest" was being required to
3988 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3989 can't do is switch easily at run time between having the "use utf8;" pragma
3990 or not. In the end, I fudged it by using the RunPerlTest script to insert
3991 "use utf8;" explicitly for the UTF-8 tests.
3992
3993 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3994 the end of the subject string, contrary to the documentation and to what
3995 Perl does. This was true of both matching functions. Now it matches only at
3996 the start of the subject and immediately after *internal* newlines.
3997
3998 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3999 a pointer to an int instead of a pointer to an unsigned long int. This
4000 caused problems on 64-bit systems.
4001
4002 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
4003 instance of the 'standard' template library not being so standard".
4004
4005 10. There was no check on the number of named subpatterns nor the maximum
4006 length of a subpattern name. The product of these values is used to compute
4007 the size of the memory block for a compiled pattern. By supplying a very
4008 long subpattern name and a large number of named subpatterns, the size
4009 computation could be caused to overflow. This is now prevented by limiting
4010 the length of names to 32 characters, and the number of named subpatterns
4011 to 10,000.
4012
4013 11. Subpatterns that are repeated with specific counts have to be replicated in
4014 the compiled pattern. The size of memory for this was computed from the
4015 length of the subpattern and the repeat count. The latter is limited to
4016 65535, but there was no limit on the former, meaning that integer overflow
4017 could in principle occur. The compiled length of a repeated subpattern is
4018 now limited to 30,000 bytes in order to prevent this.
4019
4020 12. Added the optional facility to have named substrings with the same name.
4021
4022 13. Added the ability to use a named substring as a condition, using the
4023 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
4024 are numbers (not recommended). Forward references are permitted.
4025
4026 14. Added forward references in named backreferences (if you see what I mean).
4027
4028 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
4029 pattern could run off the end of the subject. For example, the pattern
4030 "(?s)(.{1,5})"8 did this with the subject "ab".
4031
4032 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
4033 PCRE_CASELESS was set when matching characters that were quantified with ?
4034 or *.
4035
4036 17. A character class other than a single negated character that had a minimum
4037 but no maximum quantifier - for example [ab]{6,} - was not handled
4038 correctly by pce_dfa_exec(). It would match only one character.
4039
4040 18. A valid (though odd) pattern that looked like a POSIX character
4041 class but used an invalid character after [ (for example [[,abc,]]) caused
4042 pcre_compile() to give the error "Failed: internal error: code overflow" or
4043 in some cases to crash with a glibc free() error. This could even happen if
4044 the pattern terminated after [[ but there just happened to be a sequence of
4045 letters, a binary zero, and a closing ] in the memory that followed.
4046
4047 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
4048 over the years. Originally (before any Unicode support), just the bottom 8
4049 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
4050 output from "man perlunicode" includes this:
4051
4052 The regular expression compiler produces polymorphic opcodes. That
4053 is, the pattern adapts to the data and automatically switches to
4054 the Unicode character scheme when presented with Unicode data--or
4055 instead uses a traditional byte scheme when presented with byte
4056 data.
4057
4058 Sadly, a wide octal escape does not cause a switch, and in a string with
4059 no other multibyte characters, these octal escapes are treated as before.
4060 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
4061 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
4062 Unicode string.
4063
4064 I have not perpetrated such confusion in PCRE. Up till now, it took just
4065 the bottom 8 bits, as in old Perl. I have now made octal escapes with
4066 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
4067 translate to the appropriate multibyte character.
4068
4069 29. Applied some refactoring to reduce the number of warnings from Microsoft
4070 and Borland compilers. This has included removing the fudge introduced
4071 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
4072 a warning about an unused variable.
4073
4074 21. PCRE has not included VT (character 0x0b) in the set of whitespace
4075 characters since release 4.0, because Perl (from release 5.004) does not.
4076 [Or at least, is documented not to: some releases seem to be in conflict
4077 with the documentation.] However, when a pattern was studied with
4078 pcre_study() and all its branches started with \s, PCRE still included VT
4079 as a possible starting character. Of course, this did no harm; it just
4080 caused an unnecessary match attempt.
4081
4082 22. Removed a now-redundant internal flag bit that recorded the fact that case
4083 dependency changed within the pattern. This was once needed for "required
4084 byte" processing, but is no longer used. This recovers a now-scarce options
4085 bit. Also moved the least significant internal flag bit to the most-
4086 significant bit of the word, which was not previously used (hangover from
4087 the days when it was an int rather than a uint) to free up another bit for
4088 the future.
4089
4090 23. Added support for CRLF line endings as well as CR and LF. As well as the
4091 default being selectable at build time, it can now be changed at runtime
4092 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
4093 specify that it is scanning data with non-default line endings.
4094
4095 24. Changed the definition of CXXLINK to make it agree with the definition of
4096 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
4097
4098 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
4099 recursions. This makes a big different to stack usage for some patterns.
4100
4101 26. If a subpattern containing a named recursion or subroutine reference such
4102 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
4103 the space required for the compiled pattern went wrong and gave too small a
4104 value. Depending on the environment, this could lead to "Failed: internal
4105 error: code overflow at offset 49" or "glibc detected double free or
4106 corruption" errors.
4107
4108 27. Applied patches from Google (a) to support the new newline modes and (b) to
4109 advance over multibyte UTF-8 characters in GlobalReplace.
4110
4111 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
4112 difference for some implementation of PCRE in some Windows version.
4113
4114 29. Added some extra testing facilities to pcretest:
4115
4116 \q<number> in a data line sets the "match limit" value
4117 \Q<number> in a data line sets the "match recursion limt" value
4118 -S <number> sets the stack size, where <number> is in megabytes
4119
4120 The -S option isn't available for Windows.
4121
4122
4123 Version 6.6 06-Feb-06
4124 ---------------------
4125
4126 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
4127 in pcreposix.h. I have copied the definition from pcre.h.
4128
4129 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
4130 because pcre.h is no longer a built file.
4131
4132 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
4133 not normally included in the compiled code.
4134
4135
4136 Version 6.5 01-Feb-06
4137 ---------------------
4138
4139 1. When using the partial match feature with pcre_dfa_exec(), it was not
4140 anchoring the second and subsequent partial matches at the new starting
4141 point. This could lead to incorrect results. For example, with the pattern
4142 /1234/, partially matching against "123" and then "a4" gave a match.
4143
4144 2. Changes to pcregrep:
4145
4146 (a) All non-match returns from pcre_exec() were being treated as failures
4147 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
4148 error message is output. Some extra information is given for the
4149 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
4150 probably the only errors that are likely to be caused by users (by
4151 specifying a regex that has nested indefinite repeats, for instance).
4152 If there are more than 20 of these errors, pcregrep is abandoned.
4153
4154 (b) A binary zero was treated as data while matching, but terminated the
4155 output line if it was written out. This has been fixed: binary zeroes
4156 are now no different to any other data bytes.
4157
4158 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
4159 used to set a locale for matching. The --locale=xxxx long option has
4160 been added (no short equivalent) to specify a locale explicitly on the
4161 pcregrep command, overriding the environment variables.
4162
4163 (d) When -B was used with -n, some line numbers in the output were one less
4164 than they should have been.
4165
4166 (e) Added the -o (--only-matching) option.
4167
4168 (f) If -A or -C was used with -c (count only), some lines of context were
4169 accidentally printed for the final match.
4170
4171 (g) Added the -H (--with-filename) option.
4172
4173 (h) The combination of options -rh failed to suppress file names for files
4174 that were found from directory arguments.
4175
4176 (i) Added the -D (--devices) and -d (--directories) options.
4177
4178 (j) Added the -F (--fixed-strings) option.
4179
4180 (k) Allow "-" to be used as a file name for -f as well as for a data file.
4181
4182 (l) Added the --colo(u)r option.
4183
4184 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
4185 is not present by default.
4186
4187 3. A nasty bug was discovered in the handling of recursive patterns, that is,
4188 items such as (?R) or (?1), when the recursion could match a number of
4189 alternatives. If it matched one of the alternatives, but subsequently,
4190 outside the recursion, there was a failure, the code tried to back up into
4191 the recursion. However, because of the way PCRE is implemented, this is not
4192 possible, and the result was an incorrect result from the match.
4193
4194 In order to prevent this happening, the specification of recursion has
4195 been changed so that all such subpatterns are automatically treated as
4196 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
4197
4198 4. I had overlooked the fact that, in some locales, there are characters for
4199 which isalpha() is true but neither isupper() nor islower() are true. In
4200 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
4201 and ordfeminine) are like this. This affected the treatment of \w and \W
4202 when they appeared in character classes, but not when they appeared outside
4203 a character class. The bit map for "word" characters is now created
4204 separately from the results of isalnum() instead of just taking it from the
4205 upper, lower, and digit maps. (Plus the underscore character, of course.)
4206
4207 5. The above bug also affected the handling of POSIX character classes such as
4208 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
4209 permanent tables. Instead, the bit maps for such a class were previously
4210 created as the appropriate unions of the upper, lower, and digit bitmaps.
4211 Now they are created by subtraction from the [[:word:]] class, which has
4212 its own bitmap.
4213
4214 6. The [[:blank:]] character class matches horizontal, but not vertical space.
4215 It is created by subtracting the vertical space characters (\x09, \x0a,
4216 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
4217 subtraction was done in the overall bitmap for a character class, meaning
4218 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
4219 be recognized. This bug has been fixed.
4220
4221 7. Patches from the folks at Google:
4222
4223 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
4224 real life, but is still worth protecting against".
4225
4226 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
4227 regular expressions".
4228
4229 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
4230 have it.
4231
4232 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
4233 "configure" and the latter not, in order to fix a problem somebody had
4234 with compiling the Arg class on HP-UX.
4235
4236 (e) Improve the error-handling of the C++ wrapper a little bit.
4237
4238 (f) New tests for checking recursion limiting.
4239
4240 8. The pcre_memmove() function, which is used only if the environment does not
4241 have a standard memmove() function (and is therefore rarely compiled),
4242 contained two bugs: (a) use of int instead of size_t, and (b) it was not
4243 returning a result (though PCRE never actually uses the result).
4244
4245 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
4246 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
4247 returned instead of calling malloc() with an overflowing number that would
4248 most likely cause subsequent chaos.
4249
4250 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
4251
4252 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
4253 with this option is matched, the nmatch and pmatch options of regexec() are
4254 ignored.
4255
4256 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
4257 provided in case anyone wants to the the POSIX interface with UTF-8
4258 strings.
4259
4260 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
4261 C++ linking (needed for some HP-UX environments).
4262
4263 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
4264 (unused parameter) and in the pcre_printint() function (omitted "default"
4265 switch label when the default is to do nothing).
4266
4267 15. Added some code to make it possible, when PCRE is compiled as a C++
4268 library, to replace subject pointers for pcre_exec() with a smart pointer
4269 class, thus making it possible to process discontinuous strings.
4270
4271 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
4272 much the same function. They were added by different people who were trying
4273 to make PCRE easy to compile on non-Unix systems. It has been suggested
4274 that PCRE_EXPORT be abolished now that there is more automatic apparatus
4275 for compiling on Windows systems. I have therefore replaced it with
4276 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
4277 defaults to "extern" for C or "extern C" for C++, which works fine on
4278 Unix-like systems. It is now possible to override the value of PCRE_DATA_
4279 SCOPE with something explicit in config.h. In addition:
4280
4281 (a) pcreposix.h still had just "extern" instead of either of these macros;
4282 I have replaced it with PCRE_DATA_SCOPE.
4283
4284 (b) Functions such as _pcre_xclass(), which are internal to the library,
4285 but external in the C sense, all had PCRE_EXPORT in their definitions.
4286 This is apparently wrong for the Windows case, so I have removed it.
4287 (It makes no difference on Unix-like systems.)
4288
4289 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
4290 of recursive calls to match(). This is different to MATCH_LIMIT because
4291 that limits the total number of calls to match(), not all of which increase
4292 the depth of recursion. Limiting the recursion depth limits the amount of
4293 stack (or heap if NO_RECURSE is set) that is used. The default can be set
4294 when PCRE is compiled, and changed at run time. A patch from Google adds
4295 this functionality to the C++ interface.
4296
4297 18. Changes to the handling of Unicode character properties:
4298
4299 (a) Updated the table to Unicode 4.1.0.
4300
4301 (b) Recognize characters that are not in the table as "Cn" (undefined).
4302
4303 (c) I revised the way the table is implemented to a much improved format
4304 which includes recognition of ranges. It now supports the ranges that
4305 are defined in UnicodeData.txt, and it also amalgamates other
4306 characters into ranges. This has reduced the number of entries in the
4307 table from around 16,000 to around 3,000, thus reducing its size
4308 considerably. I realized I did not need to use a tree structure after
4309 all - a binary chop search is just as efficient. Having reduced the
4310 number of entries, I extended their size from 6 bytes to 8 bytes to
4311 allow for more data.
4312
4313 (d) Added support for Unicode script names via properties such as \p{Han}.
4314
4315 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
4316 matching that character.
4317
4318 20. When matching a repeated Unicode property with a minimum greater than zero,
4319 (for example \pL{2,}), PCRE could look past the end of the subject if it
4320 reached it while seeking the minimum number of characters. This could
4321 happen only if some of the characters were more than one byte long, because
4322 there is a check for at least the minimum number of bytes.
4323
4324 21. Refactored the implementation of \p and \P so as to be more general, to
4325 allow for more different types of property in future. This has changed the
4326 compiled form incompatibly. Anybody with saved compiled patterns that use
4327 \p or \P will have to recompile them.
4328
4329 22. Added "Any" and "L&" to the supported property types.
4330
4331 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
4332 but give a compile time error if the value is greater than 0xff.
4333
4334 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
4335 accidentally not being installed or uninstalled.
4336
4337 25. The pcre.h file was built from pcre.h.in, but the only changes that were
4338 made were to insert the current release number. This seemed silly, because
4339 it made things harder for people building PCRE on systems that don't run
4340 "configure". I have turned pcre.h into a distributed file, no longer built
4341 by "configure", with the version identification directly included. There is
4342 no longer a pcre.h.in file.
4343
4344 However, this change necessitated a change to the pcre-config script as
4345 well. It is built from pcre-config.in, and one of the substitutions was the
4346 release number. I have updated configure.ac so that ./configure now finds
4347 the release number by grepping pcre.h.
4348
4349 26. Added the ability to run the tests under valgrind.
4350
4351
4352 Version 6.4 05-Sep-05
4353 ---------------------
4354
4355 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
4356 "--" to be printed when multiple files were scanned, even when none of the
4357 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
4358 consider it to be a bug, and have restored the previous behaviour.
4359
4360 2. A couple of code tidies to get rid of compiler warnings.
4361
4362 3. The pcretest program used to cheat by referring to symbols in the library
4363 whose names begin with _pcre_. These are internal symbols that are not
4364 really supposed to be visible externally, and in some environments it is
4365 possible to suppress them. The cheating is now confined to including
4366 certain files from the library's source, which is a bit cleaner.
4367
4368 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
4369 file's purpose clearer.
4370
4371 5. Reorganized pcre_ucp_findchar().
4372
4373
4374 Version 6.3 15-Aug-05
4375 ---------------------
4376
4377 1. The file libpcre.pc.in did not have general read permission in the tarball.
4378
4379 2. There were some problems when building without C++ support:
4380
4381 (a) If C++ support was not built, "make install" and "make test" still
4382 tried to test it.
4383
4384 (b) There were problems when the value of CXX was explicitly set. Some
4385 changes have been made to try to fix these, and ...
4386
4387 (c) --disable-cpp can now be used to explicitly disable C++ support.
4388
4389 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
4390 backslash in a target when C++ was disabled. This confuses some
4391 versions of "make", apparently. Using an intermediate variable solves
4392 this. (Same for CPP_LOBJ.)
4393
4394 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
4395 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
4396 necessary on certain architectures.
4397
4398 4. Added a setting of -export-symbols-regex to the link command to remove
4399 those symbols that are exported in the C sense, but actually are local
4400 within the library, and not documented. Their names all begin with
4401 "_pcre_". This is not a perfect job, because (a) we have to except some
4402 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
4403 available (and never for static libraries). I have made a note to try to
4404 find a way round (a) in the future.
4405
4406
4407 Version 6.2 01-Aug-05
4408 ---------------------
4409
4410 1. There was no test for integer overflow of quantifier values. A construction
4411 such as {1111111111111111} would give undefined results. What is worse, if
4412 a minimum quantifier for a parenthesized subpattern overflowed and became
4413 negative, the calculation of the memory size went wrong. This could have
4414 led to memory overwriting.
4415
4416 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
4417
4418 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
4419 operating environments where this matters.
4420
4421 4. Applied Giuseppe Maxia's patch to add additional features for controlling
4422 PCRE options from within the C++ wrapper.
4423
4424 5. Named capturing subpatterns were not being correctly counted when a pattern
4425 was compiled. This caused two problems: (a) If there were more than 100
4426 such subpatterns, the calculation of the memory needed for the whole
4427 compiled pattern went wrong, leading to an overflow error. (b) Numerical
4428 back references of the form \12, where the number was greater than 9, were
4429 not recognized as back references, even though there were sufficient
4430 previous subpatterns.
4431
4432 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
4433 versions of gcc, e.g. 2.95.4.
4434
4435
4436 Version 6.1 21-Jun-05
4437 ---------------------
4438
4439 1. There was one reference to the variable "posix" in pcretest.c that was not
4440 surrounded by "#if !defined NOPOSIX".
4441
4442 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
4443 the cross-check on the old pcre_info() function, for the benefit of the
4444 cut-down version of PCRE that is currently imported into Exim.
4445
4446 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
4447 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
4448 patterns that start (?i) but I don't think that matters. The use of (?i) is
4449 just an example; this all applies to the other options as well.
4450
4451 4. Since libtool seems to echo the compile commands it is issuing, the output
4452 from "make" can be reduced a bit by putting "@" in front of each libtool
4453 compile command.
4454
4455 5. Patch from the folks at Google for configure.in to be a bit more thorough
4456 in checking for a suitable C++ installation before trying to compile the
4457 C++ stuff. This should fix a reported problem when a compiler was present,
4458 but no suitable headers.
4459
4460 6. The man pages all had just "PCRE" as their title. I have changed them to
4461 be the relevant file name. I have also arranged that these names are
4462 retained in the file doc/pcre.txt, which is a concatenation in text format
4463 of all the man pages except the little individual ones for each function.
4464
4465 7. The NON-UNIX-USE file had not been updated for the different set of source
4466 files that come with release 6. I also added a few comments about the C++
4467 wrapper.
4468
4469
4470 Version 6.0 07-Jun-05
4471 ---------------------
4472
4473 1. Some minor internal re-organization to help with my DFA experiments.
4474
4475 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
4476 didn't matter for the library itself when fully configured, but did matter
4477 when compiling without UCP support, or within Exim, where the ucp files are
4478 not imported.
4479
4480 3. Refactoring of the library code to split up the various functions into
4481 different source modules. The addition of the new DFA matching code (see
4482 below) to a single monolithic source would have made it really too
4483 unwieldy, quite apart from causing all the code to be include in a
4484 statically linked application, when only some functions are used. This is
4485 relevant even without the DFA addition now that patterns can be compiled in
4486 one application and matched in another.
4487
4488 The downside of splitting up is that there have to be some external
4489 functions and data tables that are used internally in different modules of
4490 the library but which are not part of the API. These have all had their
4491 names changed to start with "_pcre_" so that they are unlikely to clash
4492 with other external names.
4493
4494 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
4495 a different (DFA) algorithm. Although it is slower than the original
4496 function, it does have some advantages for certain types of matching
4497 problem.
4498
4499 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
4500 including restarting after a partial match.
4501
4502 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
4503 defined when compiling for Windows was sent to me. I have put it into the
4504 code, though I have no means of testing or verifying it.
4505
4506 7. Added the pcre_refcount() auxiliary function.
4507
4508 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
4509 match before or at the first newline in the subject string. In pcretest,
4510 the /f option on a pattern can be used to set this.
4511
4512 9. A repeated \w when used in UTF-8 mode with characters greater than 256
4513 would behave wrongly. This has been present in PCRE since release 4.0.
4514
4515 10. A number of changes to the pcregrep command:
4516
4517 (a) Refactored how -x works; insert ^(...)$ instead of setting
4518 PCRE_ANCHORED and checking the length, in preparation for adding
4519 something similar for -w.
4520
4521 (b) Added the -w (match as a word) option.
4522
4523 (c) Refactored the way lines are read and buffered so as to have more
4524 than one at a time available.
4525
4526 (d) Implemented a pcregrep test script.
4527
4528 (e) Added the -M (multiline match) option. This allows patterns to match
4529 over several lines of the subject. The buffering ensures that at least
4530 8K, or the rest of the document (whichever is the shorter) is available
4531 for matching (and similarly the previous 8K for lookbehind assertions).
4532
4533 (f) Changed the --help output so that it now says
4534
4535 -w, --word-regex(p)
4536
4537 instead of two lines, one with "regex" and the other with "regexp"
4538 because that confused at least one person since the short forms are the
4539 same. (This required a bit of code, as the output is generated
4540 automatically from a table. It wasn't just a text change.)
4541
4542 (g) -- can be used to terminate pcregrep options if the next thing isn't an
4543 option but starts with a hyphen. Could be a pattern or a path name
4544 starting with a hyphen, for instance.
4545
4546 (h) "-" can be given as a file name to represent stdin.
4547
4548 (i) When file names are being printed, "(standard input)" is used for
4549 the standard input, for compatibility with GNU grep. Previously
4550 "<stdin>" was used.
4551
4552 (j) The option --label=xxx can be used to supply a name to be used for
4553 stdin when file names are being printed. There is no short form.
4554
4555 (k) Re-factored the options decoding logic because we are going to add
4556 two more options that take data. Such options can now be given in four
4557 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
4558
4559 (l) Added the -A, -B, and -C options for requesting that lines of context
4560 around matches be printed.
4561
4562 (m) Added the -L option to print the names of files that do not contain
4563 any matching lines, that is, the complement of -l.
4564
4565 (n) The return code is 2 if any file cannot be opened, but pcregrep does
4566 continue to scan other files.
4567
4568 (o) The -s option was incorrectly implemented. For compatibility with other
4569 greps, it now suppresses the error message for a non-existent or non-
4570 accessible file (but not the return code). There is a new option called
4571 -q that suppresses the output of matching lines, which was what -s was
4572 previously doing.
4573
4574 (p) Added --include and --exclude options to specify files for inclusion
4575 and exclusion when recursing.
4576
4577 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
4578 Hopefully, it now does.
4579
4580 12. Missing cast in pcre_study().
4581
4582 13. Added an "uninstall" target to the makefile.
4583
4584 14. Replaced "extern" in the function prototypes in Makefile.in with
4585 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
4586 world, but is set differently for Windows.
4587
4588 15. Added a second compiling function called pcre_compile2(). The only
4589 difference is that it has an extra argument, which is a pointer to an
4590 integer error code. When there is a compile-time failure, this is set
4591 non-zero, in addition to the error test pointer being set to point to an
4592 error message. The new argument may be NULL if no error number is required
4593 (but then you may as well call pcre_compile(), which is now just a
4594 wrapper). This facility is provided because some applications need a
4595 numeric error indication, but it has also enabled me to tidy up the way
4596 compile-time errors are handled in the POSIX wrapper.
4597
4598 16. Added VPATH=.libs to the makefile; this should help when building with one
4599 prefix path and installing with another. (Or so I'm told by someone who
4600 knows more about this stuff than I do.)
4601
4602 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
4603 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
4604 match everything, including newlines. This is not POSIX-compatible, but
4605 somebody wanted the feature. From pcretest it can be activated by using
4606 both the P and the s flags.
4607
4608 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
4609
4610 19. libpcre.pc was being incorrectly installed as executable.
4611
4612 20. A couple of places in pcretest check for end-of-line by looking for '\n';
4613 it now also looks for '\r' so that it will work unmodified on Windows.
4614
4615 21. Added Google's contributed C++ wrapper to the distribution.
4616
4617 22. Added some untidy missing memory free() calls in pcretest, to keep
4618 Electric Fence happy when testing.
4619
4620
4621
4622 Version 5.0 13-Sep-04
4623 ---------------------
4624
4625 1. Internal change: literal characters are no longer packed up into items
4626 containing multiple characters in a single byte-string. Each character
4627 is now matched using a separate opcode. However, there may be more than one
4628 byte in the character in UTF-8 mode.
4629
4630 2. The pcre_callout_block structure has two new fields: pattern_position and
4631 next_item_length. These contain the offset in the pattern to the next match
4632 item, and its length, respectively.
4633
4634 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
4635 insertion of callouts before each pattern item. Added the /C option to
4636 pcretest to make use of this.
4637
4638 4. On the advice of a Windows user, the lines
4639
4640 #if defined(_WIN32) || defined(WIN32)
4641 _setmode( _fileno( stdout ), 0x8000 );
4642 #endif /* defined(_WIN32) || defined(WIN32) */
4643
4644 have been added to the source of pcretest. This apparently does useful
4645 magic in relation to line terminators.
4646
4647 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
4648 for the benefit of those environments where the "b" makes a difference.
4649
4650 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
4651 to know about it. I have put a hack into configure.in that adds in code
4652 to set GCC=yes if CC=icc. This seems to end up at a point in the
4653 generated configure script that is early enough to affect the setting of
4654 compiler options, which is what is needed, but I have no means of testing
4655 whether it really works. (The user who reported this had patched the
4656 generated configure script, which of course I cannot do.)
4657
4658 LATER: After change 22 below (new libtool files), the configure script
4659 seems to know about icc (and also ecc). Therefore, I have commented out
4660 this hack in configure.in.
4661
4662 7. Added support for pkg-config (2 patches were sent in).
4663
4664 8. Negated POSIX character classes that used a combination of internal tables
4665 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
4666 [[:^ascii]]. Typically, they would match almost any characters. The other
4667 POSIX classes were not broken in this way.
4668
4669 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
4670 to find the match, as PCRE was deluded into thinking that the match had to
4671 start at the start point or following a newline. The same bug applied to
4672 patterns with negative forward assertions or any backward assertions
4673 preceding ".*" at the start, unless the pattern required a fixed first
4674 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
4675
4676 10. In UTF-8 mode, when moving forwards in the subject after a failed match
4677 starting at the last subject character, bytes beyond the end of the subject
4678 string were read.
4679
4680 11. Renamed the variable "class" as "classbits" to make life easier for C++
4681 users. (Previously there was a macro definition, but it apparently wasn't
4682 enough.)
4683
4684 12. Added the new field "tables" to the extra data so that tables can be passed
4685 in at exec time, or the internal tables can be re-selected. This allows
4686 a compiled regex to be saved and re-used at a later time by a different
4687 program that might have everything at different addresses.
4688
4689 13. Modified the pcre-config script so that, when run on Solaris, it shows a
4690 -R library as well as a -L library.
4691
4692 14. The debugging options of pcretest (-d on the command line or D on a
4693 pattern) showed incorrect output for anything following an extended class
4694 that contained multibyte characters and which was followed by a quantifier.
4695
4696 15. Added optional support for general category Unicode character properties
4697 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
4698 support. It adds about 90K to the size of the library. The meanings of the
4699 inbuilt class escapes such as \d and \s have NOT been changed.
4700
4701 16. Updated pcredemo.c to include calls to free() to release the memory for the
4702 compiled pattern.
4703
4704 17. The generated file chartables.c was being created in the source directory
4705 instead of in the building directory. This caused the build to fail if the
4706 source directory was different from the building directory, and was
4707 read-only.
4708
4709 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
4710 file. No doubt somebody will tell me if they don't make sense... Also added
4711 Dan Mooney's comments about building on OpenVMS.
4712
4713 19. Added support for partial matching via the PCRE_PARTIAL option for
4714 pcre_exec() and the \P data escape in pcretest.
4715
4716 20. Extended pcretest with 3 new pattern features:
4717
4718 (i) A pattern option of the form ">rest-of-line" causes pcretest to
4719 write the compiled pattern to the file whose name is "rest-of-line".
4720 This is a straight binary dump of the data, with the saved pointer to
4721 the character tables forced to be NULL. The study data, if any, is
4722 written too. After writing, pcretest reads a new pattern.
4723
4724 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
4725 compiled pattern from the given file. There must not be any
4726 occurrences of "<" in the file name (pretty unlikely); if there are,
4727 pcretest will instead treat the initial "<" as a pattern delimiter.
4728 After reading in the pattern, pcretest goes on to read data lines as
4729 usual.
4730
4731 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
4732 and 16-bit fields in a compiled pattern, to simulate a pattern that
4733 was compiled on a host of opposite endianness.
4734
4735 21. The pcre-exec() function can now cope with patterns that were compiled on
4736 hosts of opposite endianness, with this restriction:
4737
4738 As for any compiled expression that is saved and used later, the tables
4739 pointer field cannot be preserved; the extra_data field in the arguments
4740 to pcre_exec() should be used to pass in a tables address if a value
4741 other than the default internal tables were used at compile time.
4742
4743 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
4744 now diagnosed as an error. Previously, most of the time, a negative number
4745 would have been treated as zero, but if in addition "ovector" was passed as
4746 NULL, a crash could occur.
4747
4748 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
4749 new versions from the libtool 1.5 distribution (the last one is a copy of
4750 a file called libtool.m4). This seems to have fixed the need to patch
4751 "configure" to support Darwin 1.3 (which I used to do). However, I still
4752 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
4753 workstation).
4754
4755 24. Changed the PCRE licence to be the more standard "BSD" licence.
4756
4757
4758 Version 4.5 01-Dec-03
4759 ---------------------
4760
4761 1. There has been some re-arrangement of the code for the match() function so
4762 that it can be compiled in a version that does not call itself recursively.
4763 Instead, it keeps those local variables that need separate instances for
4764 each "recursion" in a frame on the heap, and gets/frees frames whenever it
4765 needs to "recurse". Keeping track of where control must go is done by means
4766 of setjmp/longjmp. The whole thing is implemented by a set of macros that
4767 hide most of the details from the main code, and operates only if
4768 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
4769 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
4770 operating.
4771
4772 To make it easier for callers to provide specially tailored get/free
4773 functions for this usage, two new functions, pcre_stack_malloc, and
4774 pcre_stack_free, are used. They are always called in strict stacking order,
4775 and the size of block requested is always the same.
4776
4777 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
4778 PCRE has been compiled to use the stack or the heap for recursion. The
4779 -C option of pcretest uses this to show which version is compiled.
4780
4781 A new data escape \S, is added to pcretest; it causes the amounts of store
4782 obtained and freed by both kinds of malloc/free at match time to be added
4783 to the output.
4784
4785 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
4786 what's available on my current Linux desktop machine.
4787
4788 3. When matching a UTF-8 string, the test for a valid string at the start has
4789 been extended. If start_offset is not zero, PCRE now checks that it points
4790 to a byte that is the start of a UTF-8 character. If not, it returns
4791 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
4792 this is necessary because there may be backward assertions in the pattern.
4793 When matching the same subject several times, it may save resources to use
4794 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4795
4796 4. The code for checking the validity of UTF-8 strings has been tightened so
4797 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
4798 containing "overlong sequences".
4799
4800 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
4801 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
4802 should have been "&", but it just so happened that all the cases this let
4803 through by mistake were picked up later in the function.
4804
4805 6. I had used a variable called "isblank" - this is a C99 function, causing
4806 some compilers to warn. To avoid this, I renamed it (as "blankclass").
4807
4808 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
4809 prompting; (b) run "./pcretest /dev/null" at the start of the test script
4810 so the version is shown; (c) stop "make test" echoing "./RunTest".
4811
4812 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
4813
4814 9. The prototype for memmove() for systems that don't have it was using
4815 size_t, but the inclusion of the header that defines size_t was later. I've
4816 moved the #includes for the C headers earlier to avoid this.
4817
4818 10. Added some adjustments to the code to make it easier to compiler on certain
4819 special systems:
4820
4821 (a) Some "const" qualifiers were missing.
4822 (b) Added the macro EXPORT before all exported functions; by default this
4823 is defined to be empty.
4824 (c) Changed the dftables auxiliary program (that builds chartables.c) so
4825 that it reads its output file name as an argument instead of writing
4826 to the standard output and assuming this can be redirected.
4827
4828 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
4829 class containing characters with values greater than 255, PCRE compilation
4830 went into a loop.
4831
4832 12. A recursive reference to a subpattern that was within another subpattern
4833 that had a minimum quantifier of zero caused PCRE to crash. For example,
4834 (x(y(?2))z)? provoked this bug with a subject that got as far as the
4835 recursion. If the recursively-called subpattern itself had a zero repeat,
4836 that was OK.
4837
4838 13. In pcretest, the buffer for reading a data line was set at 30K, but the
4839 buffer into which it was copied (for escape processing) was still set at
4840 1024, so long lines caused crashes.
4841
4842 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
4843 "internal error: code overflow...". This applied to any character class
4844 that was followed by a possessive quantifier.
4845
4846 15. Modified the Makefile to add libpcre.la as a prerequisite for
4847 libpcreposix.la because I was told this is needed for a parallel build to
4848 work.
4849
4850 16. If a pattern that contained .* following optional items at the start was
4851 studied, the wrong optimizing data was generated, leading to matching
4852 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
4853 matching string must start with a or b or c. The correct conclusion for
4854 this pattern is that a match can start with any character.
4855
4856
4857 Version 4.4 13-Aug-03
4858 ---------------------
4859
4860 1. In UTF-8 mode, a character class containing characters with values between
4861 127 and 255 was not handled correctly if the compiled pattern was studied.
4862 In fixing this, I have also improved the studying algorithm for such
4863 classes (slightly).
4864
4865 2. Three internal functions had redundant arguments passed to them. Removal
4866 might give a very teeny performance improvement.
4867
4868 3. Documentation bug: the value of the capture_top field in a callout is *one
4869 more than* the number of the hightest numbered captured substring.
4870
4871 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
4872 in incorrectly linking with a previously installed version. They now link
4873 explicitly with libpcre.la.
4874
4875 5. configure.in no longer needs to recognize Cygwin specially.
4876
4877 6. A problem in pcre.in for Windows platforms is fixed.
4878
4879 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
4880 pcretest, it used to include the size of the study block as part of its
4881 output. Unfortunately, the structure contains a field that has a different
4882 size on different hardware architectures. This meant that the tests that
4883 showed this size failed. As the block is currently always of a fixed size,
4884 this information isn't actually particularly useful in pcretest output, so
4885 I have just removed it.
4886
4887 8. Three pre-processor statements accidentally did not start in column 1.
4888 Sadly, there are *still* compilers around that complain, even though
4889 standard C has not required this for well over a decade. Sigh.
4890
4891 9. In pcretest, the code for checking callouts passed small integers in the
4892 callout_data field, which is a void * field. However, some picky compilers
4893 complained about the casts involved for this on 64-bit systems. Now
4894 pcretest passes the address of the small integer instead, which should get
4895 rid of the warnings.
4896
4897 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
4898 both compile and run time, and gives an error if an invalid UTF-8 sequence
4899 is found. There is a option for disabling this check in cases where the
4900 string is known to be correct and/or the maximum performance is wanted.
4901
4902 11. In response to a bug report, I changed one line in Makefile.in from
4903
4904 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
4905 to
4906 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4907
4908 to look similar to other lines, but I have no way of telling whether this
4909 is the right thing to do, as I do not use Windows. No doubt I'll get told
4910 if it's wrong...
4911
4912
4913 Version 4.3 21-May-03
4914 ---------------------
4915
4916 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4917 Makefile.
4918
4919 2. Some refactoring to improve the quality of the code:
4920
4921 (i) The utf8_table... variables are now declared "const".
4922
4923 (ii) The code for \cx, which used the "case flipping" table to upper case
4924 lower case letters, now just substracts 32. This is ASCII-specific,
4925 but the whole concept of \cx is ASCII-specific, so it seems
4926 reasonable.
4927
4928 (iii) PCRE was using its character types table to recognize decimal and
4929 hexadecimal digits in the pattern. This is silly, because it handles
4930 only 0-9, a-f, and A-F, but the character types table is locale-
4931 specific, which means strange things might happen. A private
4932 table is now used for this - though it costs 256 bytes, a table is
4933 much faster than multiple explicit tests. Of course, the standard
4934 character types table is still used for matching digits in subject
4935 strings against \d.
4936
4937 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4938 ending in _t are). So I've renamed it as ESC_tee.
4939
4940 3. The first argument for regexec() in the POSIX wrapper should have been
4941 defined as "const".
4942
4943 4. Changed pcretest to use malloc() for its buffers so that they can be
4944 Electric Fenced for debugging.
4945
4946 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4947 to read one or more bytes before the start of the subject string. Often this
4948 had no effect on PCRE's behaviour, but in some circumstances it could
4949 provoke a segmentation fault.
4950
4951 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4952 to try to read one or more bytes before the start of the subject string.
4953
4954 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4955 UTF-8 support could misbehave in various ways if the subject string
4956 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4957 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4958 back over UTF-8 characters.)
4959
4960
4961 Version 4.2 14-Apr-03
4962 ---------------------
4963
4964 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4965
4966 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4967 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4968 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4969 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4970 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4971 and BUILD_EXEEXT
4972 Note: automatic setting of the BUILD variables is not yet working
4973 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4974 compile-time but not at link-time
4975 [LINK]: use for linking executables only
4976 make different versions for Windows and non-Windows
4977 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4978 libraries
4979 [LINK_FOR_BUILD]: new variable
4980 [OBJEXT]: use throughout
4981 [EXEEXT]: use throughout
4982 <winshared>: new target
4983 <wininstall>: new target
4984 <dftables.o>: use native compiler
4985 <dftables>: use native linker
4986 <install>: handle Windows platform correctly
4987 <clean>: ditto
4988 <check>: ditto
4989 copy DLL to top builddir before testing
4990
4991 As part of these changes, -no-undefined was removed again. This was reported
4992 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4993 in any case.
4994
4995 3. Some tidies to get rid of compiler warnings:
4996
4997 . In the match_data structure, match_limit was an unsigned long int, whereas
4998 match_call_count was an int. I've made them both unsigned long ints.
4999
5000 . In pcretest the fact that a const uschar * doesn't automatically cast to
5001 a void * provoked a warning.
5002
5003 . Turning on some more compiler warnings threw up some "shadow" variables
5004 and a few more missing casts.
5005
5006 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
5007 option, a class that contained a single character with a value between 128
5008 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
5009
5010 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
5011 option, a class that contained several characters, but with at least one
5012 whose value was between 128 and 255 caused PCRE to crash.
5013
5014
5015 Version 4.1 12-Mar-03
5016 ---------------------
5017
5018 1. Compiling with gcc -pedantic found a couple of places where casts were
5019 needed, and a string in dftables.c that was longer than standard compilers are
5020 required to support.
5021
5022 2. Compiling with Sun's compiler found a few more places where the code could
5023 be tidied up in order to avoid warnings.
5024
5025 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
5026 first of these names is deprecated in the latest Autoconf in favour of the name
5027 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
5028 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
5029 analogy I have changed it to CFLAGS_FOR_BUILD.
5030
5031 4. Added -no-undefined to the linking command in the Makefile, because this is
5032 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
5033 linking step for the pcreposix library.
5034
5035 5. PCRE was failing to diagnose the case of two named groups with the same
5036 name.
5037
5038 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
5039 literal character that is needed in the subject for a match, and scans along to
5040 ensure that it is present before embarking on the full matching process. This
5041 saves time in cases of nested unlimited repeats that are never going to match.
5042 Problem: the scan can take a lot of time if the subject is very long (e.g.
5043 megabytes), thus penalizing straightforward matches. It is now done only if the
5044 amount of subject to be scanned is less than 1000 bytes.
5045
5046 7. A lesser problem with the same optimization is that it was recording the
5047 first character of an anchored pattern as "needed", thus provoking a search
5048 right along the subject, even when the first match of the pattern was going to
5049 fail. The "needed" character is now not set for anchored patterns, unless it
5050 follows something in the pattern that is of non-fixed length. Thus, it still
5051 fulfils its original purpose of finding quick non-matches in cases of nested
5052 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
5053
5054
5055 Version 4.0 17-Feb-03
5056 ---------------------
5057
5058 1. If a comment in an extended regex that started immediately after a meta-item
5059 extended to the end of string, PCRE compiled incorrect data. This could lead to
5060 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
5061
5062 2. Moved to autoconf 2.53 and libtool 1.4.2.
5063
5064 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
5065 the special perltest8 script is no longer needed - all the tests can be run
5066 from a single perltest script.
5067
5068 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
5069 by \s. It has now been removed in PCRE. This means it isn't recognized as
5070 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
5071 class [:space:] *does* include VT, thereby creating a mess.
5072
5073 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
5074 space and tab.
5075
5076 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
5077 its new features into the main test script, reducing the number of scripts.
5078
5079 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
5080 were backward compatible, and made the (?i) apply to the whole pattern, as if
5081 /i were given. Now it behaves more logically, and applies the option setting
5082 only to what follows. PCRE has been changed to follow suit. However, if it
5083 finds options settings right at the start of the pattern, it extracts them into
5084 the global options, as before. Thus, they show up in the info data.
5085
5086 8. Added support for the \Q...\E escape sequence. Characters in between are
5087 treated as literals. This is slightly different from Perl in that $ and @ are
5088 also handled as literals inside the quotes. In Perl, they will cause variable
5089 interpolation. Note the following examples:
5090
5091 Pattern PCRE matches Perl matches
5092
5093 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
5094 \Qabc\$xyz\E abc\$xyz abc\$xyz
5095 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
5096
5097 For compatibility with Perl, \Q...\E sequences are recognized inside character
5098 classes as well as outside them.
5099
5100 9. Re-organized 3 code statements in pcretest to avoid "overflow in
5101 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
5102 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
5103 signed/unsigned warnings.
5104
5105 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
5106 option for pcretest, so I've replaced it by a simple function that does just
5107 that job.
5108
5109 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
5110 "pcregrep -".
5111
5112 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
5113 Java package. This provides some syntactic sugar for simple cases of what my
5114 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
5115 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
5116 item, you can use this simplified notation. Note that only makes sense with
5117 greedy quantifiers. Consequently, the use of the possessive quantifier forces
5118 greediness, whatever the setting of the PCRE_UNGREEDY option.
5119
5120 13. A change of greediness default within a pattern was not taking effect at
5121 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
5122 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
5123 was abstracted outside.
5124
5125 14. PCRE now supports the \G assertion. It is true when the current matching
5126 position is at the start point of the match. This differs from \A when the
5127 starting offset is non-zero. Used with the /g option of pcretest (or similar
5128 code), it works in the same way as it does for Perl's /g option. If all
5129 alternatives of a regex begin with \G, the expression is anchored to the start
5130 match position, and the "anchored" flag is set in the compiled expression.
5131
5132 15. Some bugs concerning the handling of certain option changes within patterns
5133 have been fixed. These applied to options other than (?ims). For example,
5134 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
5135 been the other way round. Some of this was related to change 7 above.
5136
5137 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
5138 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
5139 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
5140 POSIX classes only within a class (e.g. /[[:alpha:]]/).
5141
5142 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
5143 mode. Unlike ".", it always matches newline, whatever the setting of
5144 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
5145 assertions. Perl allows it, but it doesn't (in general) work because it can't
5146 calculate the length of the lookbehind. At least, that's the case for Perl
5147 5.8.0 - I've been told they are going to document that it doesn't work in
5148 future.
5149
5150 18. Added an error diagnosis for escapes that PCRE does not support: these are
5151 \L, \l, \N, \P, \p, \U, \u, and \X.
5152
5153 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
5154 reading past the end of the pattern in cases such as /[abcd/.
5155
5156 20. PCRE was getting more memory than necessary for patterns with classes that
5157 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
5158
5159 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
5160 compiling PCRE for use with Virtual Pascal.
5161
5162 22. Small fix to the Makefile to make it work properly if the build is done
5163 outside the source tree.
5164
5165 23. Added a new extension: a condition to go with recursion. If a conditional
5166 subpattern starts with (?(R) the "true" branch is used if recursion has
5167 happened, whereas the "false" branch is used only at the top level.
5168
5169 24. When there was a very long string of literal characters (over 255 bytes
5170 without UTF support, over 250 bytes with UTF support), the computation of how
5171 much memory was required could be incorrect, leading to segfaults or other
5172 strange effects.
5173
5174 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
5175 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
5176 there was a subsequent back reference to those brackets. This meant that, for
5177 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
5178 possible to check for precisely this case. All we can do is abandon the
5179 optimization if .* occurs inside capturing brackets when there are any back
5180 references whatsoever. (See below for a better fix that came later.)
5181
5182 26. The handling of the optimization for finding the first character of a
5183 non-anchored pattern, and for finding a character that is required later in the
5184 match were failing in some cases. This didn't break the matching; it just
5185 failed to optimize when it could. The way this is done has been re-implemented.
5186
5187 27. Fixed typo in error message for invalid (?R item (it said "(?p").
5188
5189 28. Added a new feature that provides some of the functionality that Perl
5190 provides with (?{...}). The facility is termed a "callout". The way it is done
5191 in PCRE is for the caller to provide an optional function, by setting
5192 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
5193 global variable. By default it is unset, which disables all calling out. To get
5194 the function called, the regex must include (?C) at appropriate points. This
5195 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
5196 This provides a means of identifying different callout points. When PCRE
5197 reaches such a point in the regex, if pcre_callout has been set, the external
5198 function is called. It is provided with data in a structure called
5199 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
5200 matching continues; if it returns a non-zero value, the match at the current
5201 point fails. However, backtracking will occur if possible. [This was changed
5202 later and other features added - see item 49 below.]
5203
5204 29. pcretest is upgraded to test the callout functionality. It provides a
5205 callout function that displays information. By default, it shows the start of
5206 the match and the current position in the text. There are some new data escapes
5207 to vary what happens:
5208
5209 \C+ in addition, show current contents of captured substrings
5210 \C- do not supply a callout function
5211 \C!n return 1 when callout number n is reached
5212 \C!n!m return 1 when callout number n is reached for the mth time
5213
5214 30. If pcregrep was called with the -l option and just a single file name, it
5215 output "<stdin>" if a match was found, instead of the file name.
5216
5217 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
5218 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
5219 pcre_exec(). This saves a malloc/free per call. The default value of
5220 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
5221 when configuring.
5222
5223 32. The default maximum size of a compiled pattern is 64K. There have been a
5224 few cases of people hitting this limit. The code now uses macros to handle the
5225 storing of links as offsets within the compiled pattern. It defaults to 2-byte
5226 links, but this can be changed to 3 or 4 bytes by --with-link-size when
5227 configuring. Tests 2 and 5 work only with 2-byte links because they output
5228 debugging information about compiled patterns.
5229
5230 33. Internal code re-arrangements:
5231
5232 (a) Moved the debugging function for printing out a compiled regex into
5233 its own source file (printint.c) and used #include to pull it into
5234 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
5235 separate copies.
5236
5237 (b) Defined the list of op-code names for debugging as a macro in
5238 internal.h so that it is next to the definition of the opcodes.
5239
5240 (c) Defined a table of op-code lengths for simpler skipping along compiled
5241 code. This is again a macro in internal.h so that it is next to the
5242 definition of the opcodes.
5243
5244 34. Added support for recursive calls to individual subpatterns, along the
5245 lines of Robin Houston's patch (but implemented somewhat differently).
5246
5247 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
5248 allow it to read and process whole directories in Win32. This code was
5249 contributed by Lionel Fourquaux; it has not been tested by me.
5250
5251 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
5252 used to name a group. Names consist of alphanumerics and underscores, and must
5253 be unique. Back references use the syntax (?P=name) and recursive calls use
5254 (?P>name) which is a PCRE extension to the Python extension. Groups still have
5255 numbers. The function pcre_fullinfo() can be used after compilation to extract
5256 a name/number map. There are three relevant calls:
5257
5258 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
5259 PCRE_INFO_NAMECOUNT yields the number of entries
5260 PCRE_INFO_NAMETABLE yields a pointer to the map.
5261
5262 The map is a vector of fixed-size entries. The size of each entry depends on
5263 the length of the longest name used. The first two bytes of each entry are the
5264 group number, most significant byte first. There follows the corresponding
5265 name, zero terminated. The names are in alphabetical order.
5266
5267 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
5268 case instead of 255. Making it the same both with and without UTF-8 support
5269 means that the same test output works with both.
5270
5271 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
5272 calling malloc() with a zero argument.
5273
5274 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
5275 optimization. I've improved things by keeping a bitmap of backreferences with
5276 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
5277 fact referenced, the optimization can be applied. It is unlikely that a
5278 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
5279 the match to follow \n) will appear inside brackets with a number greater than
5280 31, but if it does, any back reference > 31 suppresses the optimization.
5281
5282 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
5283 of disabling numbered capturing parentheses. Any opening parenthesis that is
5284 not followed by ? behaves as if it were followed by ?: but named parentheses
5285 can still be used for capturing (and they will acquire numbers in the usual
5286 way).
5287
5288 41. Redesigned the return codes from the match() function into yes/no/error so
5289 that errors can be passed back from deep inside the nested calls. A malloc
5290 failure while inside a recursive subpattern call now causes the
5291 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
5292
5293 42. It is now possible to set a limit on the number of times the match()
5294 function is called in a call to pcre_exec(). This facility makes it possible to
5295 limit the amount of recursion and backtracking, though not in a directly
5296 obvious way, because the match() function is used in a number of different
5297 circumstances. The count starts from zero for each position in the subject
5298 string (for non-anchored patterns). The default limit is, for compatibility, a
5299 large number, namely 10 000 000. You can change this in two ways:
5300
5301 (a) When configuring PCRE before making, you can use --with-match-limit=n
5302 to set a default value for the compiled library.
5303
5304 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
5305 a different value is set. See 45 below.
5306
5307 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
5308
5309 43. Added a new function pcre_config(int, void *) to enable run-time extraction
5310 of things that can be changed at compile time. The first argument specifies
5311 what is wanted and the second points to where the information is to be placed.
5312 The current list of available information is:
5313
5314 PCRE_CONFIG_UTF8
5315
5316 The output is an integer that is set to one if UTF-8 support is available;
5317 otherwise it is set to zero.
5318
5319 PCRE_CONFIG_NEWLINE
5320
5321 The output is an integer that it set to the value of the code that is used for
5322 newline. It is either LF (10) or CR (13).
5323
5324 PCRE_CONFIG_LINK_SIZE
5325
5326 The output is an integer that contains the number of bytes used for internal
5327 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
5328
5329 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
5330
5331 The output is an integer that contains the threshold above which the POSIX
5332 interface uses malloc() for output vectors. See item 31 above.
5333
5334 PCRE_CONFIG_MATCH_LIMIT
5335
5336 The output is an unsigned integer that contains the default limit of the number
5337 of match() calls in a pcre_exec() execution. See 42 above.
5338
5339 44. pcretest has been upgraded by the addition of the -C option. This causes it
5340 to extract all the available output from the new pcre_config() function, and to
5341 output it. The program then exits immediately.
5342
5343 45. A need has arisen to pass over additional data with calls to pcre_exec() in
5344 order to support additional features. One way would have been to define
5345 pcre_exec2() (for example) with extra arguments, but this would not have been
5346 extensible, and would also have required all calls to the original function to
5347 be mapped to the new one. Instead, I have chosen to extend the mechanism that
5348 is used for passing in "extra" data from pcre_study().
5349
5350 The pcre_extra structure is now exposed and defined in pcre.h. It currently
5351 contains the following fields:
5352
5353 flags a bitmap indicating which of the following fields are set
5354 study_data opaque data from pcre_study()
5355 match_limit a way of specifying a limit on match() calls for a specific
5356 call to pcre_exec()
5357 callout_data data for callouts (see 49 below)
5358
5359 The flag bits are also defined in pcre.h, and are
5360
5361 PCRE_EXTRA_STUDY_DATA
5362 PCRE_EXTRA_MATCH_LIMIT
5363 PCRE_EXTRA_CALLOUT_DATA
5364
5365 The pcre_study() function now returns one of these new pcre_extra blocks, with
5366 the actual study data pointed to by the study_data field, and the
5367 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
5368 before. That is, this change is entirely upwards-compatible and requires no
5369 change to existing code.
5370
5371 If you want to pass in additional data to pcre_exec(), you can either place it
5372 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
5373 block.
5374
5375 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
5376 data string contains the escape sequence \M, pcretest calls pcre_exec() several
5377 times with different match limits, until it finds the minimum value needed for
5378 pcre_exec() to complete. The value is then output. This can be instructive; for
5379 most simple matches the number is quite small, but for pathological cases it
5380 gets very large very quickly.
5381
5382 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
5383 returns the size of the data block pointed to by the study_data field in a
5384 pcre_extra block, that is, the value that was passed as the argument to
5385 pcre_malloc() when PCRE was getting memory in which to place the information
5386 created by pcre_study(). The fourth argument should point to a size_t variable.
5387 pcretest has been extended so that this information is shown after a successful
5388 pcre_study() call when information about the compiled regex is being displayed.
5389
5390 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
5391 because what follows is always an absolute path. (Later: it turns out that this
5392 is more than cosmetic for MinGW, because it doesn't like empty path
5393 components.)
5394
5395 49. Some changes have been made to the callout feature (see 28 above):
5396
5397 (i) A callout function now has three choices for what it returns:
5398
5399 0 => success, carry on matching
5400 > 0 => failure at this point, but backtrack if possible
5401 < 0 => serious error, return this value from pcre_exec()
5402
5403 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
5404 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
5405 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
5406 use by callout functions. It will never be used by PCRE itself.
5407
5408 (ii) The pcre_extra structure (see 45 above) has a void * field called
5409 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
5410 pcre_callout_block structure has a field of the same name. The contents of
5411 the field passed in the pcre_extra structure are passed to the callout
5412 function in the corresponding field in the callout block. This makes it
5413 easier to use the same callout-containing regex from multiple threads. For
5414 testing, the pcretest program has a new data escape
5415
5416 \C*n pass the number n (may be negative) as callout_data
5417
5418 If the callout function in pcretest receives a non-zero value as
5419 callout_data, it returns that value.
5420
5421 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
5422 there were some redundant $(CFLAGS) in commands that are now specified as
5423 $(LINK), which already includes $(CFLAGS).
5424
5425 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
5426 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
5427 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
5428 one-byte characters throughout. Note that case-insensitive matching applies
5429 only to characters whose values are less than 256. PCRE doesn't support the
5430 notion of cases for higher-valued characters.
5431
5432 (i) A character class whose characters are all within 0-255 is handled as
5433 a bit map, and the map is inverted for negative classes. Previously, a
5434 character > 255 always failed to match such a class; however it should
5435 match if the class was a negative one (e.g. [^ab]). This has been fixed.
5436
5437 (ii) A negated character class with a single character < 255 is coded as
5438 "not this character" (OP_NOT). This wasn't working properly when the test
5439 character was multibyte, either singly or repeated.
5440
5441 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
5442 mode, for example: \x{100}{2,3}.
5443
5444 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
5445 singly or repeated) now correctly test multibyte characters. However,
5446 PCRE doesn't recognize any characters with values greater than 255 as
5447 digits, spaces, or word characters. Such characters always match \D, \S,
5448 and \W, and never match \d, \s, or \w.
5449
5450 (v) Classes may now contain characters and character ranges with values
5451 greater than 255. For example: [ab\x{100}-\x{400}].
5452
5453 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
5454 PCRE in UTF-8 mode.
5455
5456 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
5457 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
5458 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
5459 value.)
5460
5461 53. The single man page has become too large. I have therefore split it up into
5462 a number of separate man pages. These also give rise to individual HTML pages;
5463 these are now put in a separate directory, and there is an index.html page that
5464 lists them all. Some hyperlinking between the pages has been installed.
5465
5466 54. Added convenience functions for handling named capturing parentheses.
5467
5468 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
5469 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
5470 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
5471 are faulted.
5472
5473 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
5474 calling configure. These values are used when compiling the dftables.c program
5475 which is run to generate the source of the default character tables. They
5476 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
5477 you will need to set these values.
5478
5479 57. Updated the building process for Windows DLL, as provided by Fred Cox.
5480
5481
5482 Version 3.9 02-Jan-02
5483 ---------------------
5484
5485 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
5486
5487 2. If --disable-static was given, the building process failed when trying to
5488 build pcretest and pcregrep. (For some reason it was using libtool to compile
5489 them, which is not right, as they aren't part of the library.)
5490
5491
5492 Version 3.8 18-Dec-01
5493 ---------------------
5494
5495 1. The experimental UTF-8 code was completely screwed up. It was packing the
5496 bytes in the wrong order. How dumb can you get?
5497
5498
5499 Version 3.7 29-Oct-01
5500 ---------------------
5501
5502 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
5503 This caused pcretest, when used on the test data, to segfault. Unfortunately,
5504 this didn't happen under Solaris 8, where I normally test things.
5505
5506 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
5507 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
5508 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
5509 this fix an hour or so after the initial 3.7 release.)
5510
5511
5512 Version 3.6 23-Oct-01
5513 ---------------------
5514
5515 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
5516 offsets passed as NULL with zero offset count.
5517
5518 2. The config.guess and config.sub files had not been updated when I moved to
5519 the latest autoconf.
5520
5521
5522 Version 3.5 15-Aug-01
5523 ---------------------
5524
5525 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
5526 had been forgotten.
5527
5528 2. By using declared but undefined structures, we can avoid using "void"
5529 definitions in pcre.h while keeping the internal definitions of the structures
5530 private.
5531
5532 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
5533 user point of view, this means that both static and shared libraries are built
5534 by default, but this can be individually controlled. More of the work of
5535 handling this static/shared cases is now inside libtool instead of PCRE's make
5536 file.
5537
5538 4. The pcretest utility is now installed along with pcregrep because it is
5539 useful for users (to test regexs) and by doing this, it automatically gets
5540 relinked by libtool. The documentation has been turned into a man page, so
5541 there are now .1, .txt, and .html versions in /doc.
5542
5543 5. Upgrades to pcregrep:
5544 (i) Added long-form option names like gnu grep.
5545 (ii) Added --help to list all options with an explanatory phrase.
5546 (iii) Added -r, --recursive to recurse into sub-directories.
5547 (iv) Added -f, --file to read patterns from a file.
5548
5549 6. pcre_exec() was referring to its "code" argument before testing that
5550 argument for NULL (and giving an error if it was NULL).
5551
5552 7. Upgraded Makefile.in to allow for compiling in a different directory from
5553 the source directory.
5554
5555 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
5556 options bits, the pointer it was passed was to an int instead of to an unsigned
5557 long int. This mattered only on 64-bit systems.
5558
5559 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
5560 generated) instead of pcre.in, which it its source. Also made the same change
5561 in several of the .c files.
5562
5563 10. A new release of gcc defines printf() as a macro, which broke pcretest
5564 because it had an ifdef in the middle of a string argument for printf(). Fixed
5565 by using separate calls to printf().
5566
5567 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
5568 script, to force use of CR or LF instead of \n in the source. On non-Unix
5569 systems, the value can be set in config.h.
5570
5571 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
5572 absolute limit. Changed the text of the error message to make this clear, and
5573 likewise updated the man page.
5574
5575 13. The limit of 99 on the number of capturing subpatterns has been removed.
5576 The new limit is 65535, which I hope will not be a "real" limit.
5577
5578
5579 Version 3.4 22-Aug-00
5580 ---------------------
5581
5582 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
5583
5584 2. Diagnose condition (?(0) as an error instead of crashing on matching.
5585
5586
5587 Version 3.3 01-Aug-00
5588 ---------------------
5589
5590 1. If an octal character was given, but the value was greater than \377, it
5591 was not getting masked to the least significant bits, as documented. This could
5592 lead to crashes in some systems.
5593
5594 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
5595 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
5596
5597 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
5598 These just pass their arguments on to (pcre_free)(), but they are provided
5599 because some uses of PCRE bind it to non-C systems that can call its functions,
5600 but cannot call free() or pcre_free() directly.
5601
5602 4. Add "make test" as a synonym for "make check". Corrected some comments in
5603 the Makefile.
5604
5605 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
5606 Makefile.
5607
5608 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
5609 command called pgrep for grepping around the active processes.
5610
5611 7. Added the beginnings of support for UTF-8 character strings.
5612
5613 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
5614 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
5615 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
5616 out for the ar command.)
5617
5618
5619 Version 3.2 12-May-00
5620 ---------------------
5621
5622 This is purely a bug fixing release.
5623
5624 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
5625 of ZA. This was just one example of several cases that could provoke this bug,
5626 which was introduced by change 9 of version 2.00. The code for breaking
5627 infinite loops after an iteration that matches an empty string was't working
5628 correctly.
5629
5630 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
5631 when matched against abbab (for example). After matching an empty string, it
5632 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
5633 caused it to match further down the string than it should.
5634
5635 3. The code contained an inclusion of sys/types.h. It isn't clear why this
5636 was there because it doesn't seem to be needed, and it causes trouble on some
5637 systems, as it is not a Standard C header. It has been removed.
5638
5639 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
5640 were reported on the Macintosh. The changes were from
5641
5642 while ((c = *(++ptr)) != 0 && c != '\n');
5643 to
5644 while ((c = *(++ptr)) != 0 && c != '\n') ;
5645
5646 Totally extraordinary, but if that's what it takes...
5647
5648 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
5649 available. Added HAVE_BCOPY and an autoconf test for it; if neither
5650 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
5651 assumes the way PCRE uses memmove() (always moving upwards).
5652
5653 6. PCRE is being used in one environment where strchr() is not available. There
5654 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
5655 faster code anyway.
5656
5657
5658 Version 3.1 09-Feb-00
5659 ---------------------
5660
5661 The only change in this release is the fixing of some bugs in Makefile.in for
5662 the "install" target:
5663
5664 (1) It was failing to install pcreposix.h.
5665
5666 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
5667
5668
5669 Version 3.0 01-Feb-00
5670 ---------------------
5671
5672 1. Add support for the /+ modifier to perltest (to output $` like it does in
5673 pcretest).
5674
5675 2. Add support for the /g modifier to perltest.
5676
5677 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
5678 matches null strings.
5679
5680 4. Fix perltest so that it doesn't do unwanted things when fed an empty
5681 pattern. Perl treats empty patterns specially - it reuses the most recent
5682 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
5683 effect.
5684
5685 5. The POSIX interface was broken in that it was just handing over the POSIX
5686 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
5687 required a bigger vector, with some working space on the end. This means that
5688 the POSIX wrapper now has to get and free some memory, and copy the results.
5689
5690 6. Added some simple autoconf support, placing the test data and the
5691 documentation in separate directories, re-organizing some of the
5692 information files, and making it build pcre-config (a GNU standard). Also added
5693 libtool support for building PCRE as a shared library, which is now the
5694 default.
5695
5696 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
5697 09 are not valid octal constants. Single digits will be used for minor values
5698 less than 10.
5699
5700 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
5701 existing programs that set these in the POSIX interface can use PCRE without
5702 modification.
5703
5704 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
5705 return all that pcre_info() returns, plus additional data. The pcre_info()
5706 function is retained for compatibility, but is considered to be obsolete.
5707
5708 10. Added experimental recursion feature (?R) to handle one common case that
5709 Perl 5.6 will be able to do with (?p{...}).
5710
5711 11. Added support for POSIX character classes like [:alpha:], which Perl is
5712 adopting.
5713
5714
5715 Version 2.08 31-Aug-99
5716 ----------------------
5717
5718 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
5719 trying to match at the startoffset position, but instead was moving forward to
5720 the next newline as if a previous match had failed.
5721
5722 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
5723 and could get into a loop if a null string was matched other than at the start
5724 of the subject.
5725
5726 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
5727 be distinguished at compile time, and for completeness also added PCRE_DATE.
5728
5729 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
5730 in GnuWin32 environments.
5731
5732
5733 Version 2.07 29-Jul-99
5734 ----------------------
5735
5736 1. The documentation is now supplied in plain text form and HTML as well as in
5737 the form of man page sources.
5738
5739 2. C++ compilers don't like assigning (void *) values to other pointer types.
5740 In particular this affects malloc(). Although there is no problem in Standard
5741 C, I've put in casts to keep C++ compilers happy.
5742
5743 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
5744 should be (const char *).
5745
5746 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
5747 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
5748 However, I haven't made this a standard facility. The documentation doesn't
5749 mention it, and the Makefile doesn't support it.
5750
5751 5. The Makefile now contains an "install" target, with editable destinations at
5752 the top of the file. The pcretest program is not installed.
5753
5754 6. pgrep -V now gives the PCRE version number and date.
5755
5756 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
5757 causing the entire string to be ignored, instead of just the last character.
5758
5759 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
5760 non-matching string, it can take a very, very long time, even for strings of
5761 quite modest length, because of the nested recursion. PCRE now does better in
5762 some of these cases. It does this by remembering the last required literal
5763 character in the pattern, and pre-searching the subject to ensure it is present
5764 before running the real match. In other words, it applies a heuristic to detect
5765 some types of certain failure quickly, and in the above example, if presented
5766 with a string that has no trailing " it gives "no match" very quickly.
5767
5768 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
5769 other alternatives are tried instead.
5770
5771
5772 Version 2.06 09-Jun-99
5773 ----------------------
5774
5775 1. Change pcretest's output for amount of store used to show just the code
5776 space, because the remainder (the data block) varies in size between 32-bit and
5777 64-bit systems.
5778
5779 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
5780 start matching at. This allows lookbehinds to work when searching for multiple
5781 occurrences in a string.
5782
5783 3. Added additional options to pcretest for testing multiple occurrences:
5784
5785 /+ outputs the rest of the string that follows a match
5786 /g loops for multiple occurrences, using the new startoffset argument
5787 /G loops for multiple occurrences by passing an incremented pointer
5788
5789 4. PCRE wasn't doing the "first character" optimization for patterns starting
5790 with \b or \B, though it was doing it for other lookbehind assertions. That is,
5791 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
5792 the letter 'x'. On long subject strings, this gives a significant speed-up.
5793
5794
5795 Version 2.05 21-Apr-99
5796 ----------------------
5797
5798 1. Changed the type of magic_number from int to long int so that it works
5799 properly on 16-bit systems.
5800
5801 2. Fixed a bug which caused patterns starting with .* not to work correctly
5802 when the subject string contained newline characters. PCRE was assuming
5803 anchoring for such patterns in all cases, which is not correct because .* will
5804 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
5805 DOTALL is set at top level; otherwise it knows that patterns starting with .*
5806 must be retried after every newline in the subject.
5807
5808
5809 Version 2.04 18-Feb-99
5810 ----------------------
5811
5812 1. For parenthesized subpatterns with repeats whose minimum was zero, the
5813 computation of the store needed to hold the pattern was incorrect (too large).
5814 If such patterns were nested a few deep, this could multiply and become a real
5815 problem.
5816
5817 2. Added /M option to pcretest to show the memory requirement of a specific
5818 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
5819
5820 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
5821 compiled in such a way that the backtracking after subsequent failure was
5822 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
5823 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
5824
5825
5826 Version 2.03 02-Feb-99
5827 ----------------------
5828
5829 1. Fixed typo and small mistake in man page.
5830
5831 2. Added 4th condition (GPL supersedes if conflict) and created separate
5832 LICENCE file containing the conditions.
5833
5834 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
5835 Perl, that is the internal \ allows the delimiter to be included in the
5836 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
5837 the final delimiter, add \ to the end of the pattern (to test the error).
5838
5839 4. Added the convenience functions for extracting substrings after a successful
5840 match. Updated pcretest to make it able to test these functions.
5841
5842
5843 Version 2.02 14-Jan-99
5844 ----------------------
5845
5846 1. Initialized the working variables associated with each extraction so that
5847 their saving and restoring doesn't refer to uninitialized store.
5848
5849 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
5850 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
5851 fix the problem.
5852
5853 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
5854 calls, and wasn't printing the correct value for compiling calls. Increased the
5855 default value of LOOPREPEAT, and the number of significant figures in the
5856 times.
5857
5858 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
5859
5860 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
5861 a building problem on Windows NT with a FAT file system.
5862
5863
5864 Version 2.01 21-Oct-98
5865 ----------------------
5866
5867 1. Changed the API for pcre_compile() to allow for the provision of a pointer
5868 to character tables built by pcre_maketables() in the current locale. If NULL
5869 is passed, the default tables are used.
5870
5871
5872 Version 2.00 24-Sep-98
5873 ----------------------
5874
5875 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
5876 it any more.
5877
5878 2. Allow quantification of (?>) groups, and make it work correctly.
5879
5880 3. The first character computation wasn't working for (?>) groups.
5881
5882 4. Correct the implementation of \Z (it is permitted to match on the \n at the
5883 end of the subject) and add 5.005's \z, which really does match only at the
5884 very end of the subject.
5885
5886 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
5887
5888 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
5889 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
5890 localized options. All options to pcre_study() were also removed.
5891
5892 7. Add other new features from 5.005:
5893
5894 $(?<= positive lookbehind
5895 $(?<! negative lookbehind
5896 (?imsx-imsx) added the unsetting capability
5897 such a setting is global if at outer level; local otherwise
5898 (?imsx-imsx:) non-capturing groups with option setting
5899 (?(cond)re|re) conditional pattern matching
5900
5901 A backreference to itself in a repeated group matches the previous
5902 captured string.
5903
5904 8. General tidying up of studying (both automatic and via "study")
5905 consequential on the addition of new assertions.
5906
5907 9. As in 5.005, unlimited repeated groups that could match an empty substring
5908 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5909 runtime if any iteration does actually match an empty substring.
5910
5911 10. Include the RunTest script in the distribution.
5912
5913 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5914 discrepancies, some of which were old and were also with respect to 5.004. They
5915 have now been fixed.
5916
5917
5918 Version 1.09 28-Apr-98
5919 ----------------------
5920
5921 1. A negated single character class followed by a quantifier with a minimum
5922 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5923 program crashes, or just wrong answers. This did not apply to negated classes
5924 containing more than one character, or to minima other than one.
5925
5926
5927 Version 1.08 27-Mar-98
5928 ----------------------
5929
5930 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5931
5932 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5933 latter must appear before anything that relies on it in the pattern.
5934
5935
5936 Version 1.07 16-Feb-98
5937 ----------------------
5938
5939 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5940 repeat of a potentially empty string).
5941
5942
5943 Version 1.06 23-Jan-98
5944 ----------------------
5945
5946 1. Added Markus Oberhumer's little patches for C++.
5947
5948 2. Literal strings longer than 255 characters were broken.
5949
5950
5951 Version 1.05 23-Dec-97
5952 ----------------------
5953
5954 1. Negated character classes containing more than one character were failing if
5955 PCRE_CASELESS was set at run time.
5956
5957
5958 Version 1.04 19-Dec-97
5959 ----------------------
5960
5961 1. Corrected the man page, where some "const" qualifiers had been omitted.
5962
5963 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5964 input syntax.
5965
5966 3. Fixed memory leak which occurred when a regex with back references was
5967 matched with an offsets vector that wasn't big enough. The temporary memory
5968 that is used in this case wasn't being freed if the match failed.
5969
5970 4. Tidied pcretest to ensure it frees memory that it gets.
5971
5972 5. Temporary memory was being obtained in the case where the passed offsets
5973 vector was exactly big enough.
5974
5975 6. Corrected definition of offsetof() from change 5 below.
5976
5977 7. I had screwed up change 6 below and broken the rules for the use of
5978 setjmp(). Now fixed.
5979
5980
5981 Version 1.03 18-Dec-97
5982 ----------------------
5983
5984 1. A erroneous regex with a missing opening parenthesis was correctly
5985 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5986 on some systems.
5987
5988 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5989 it was reported that one broken compiler failed on the former because "code" is
5990 also an independent variable.
5991
5992 3. The erroneous regex a[]b caused an array overrun reference.
5993
5994 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5995 fail on data ending with that character. (It was going on too far, and checking
5996 the next character, typically a binary zero.) This was specific to the
5997 optimized code for single-character negative classes.
5998
5999 5. Added a contributed patch from the TIN world which does the following:
6000
6001 + Add an undef for memmove, in case the the system defines a macro for it.
6002
6003 + Add a definition of offsetof(), in case there isn't one. (I don't know
6004 the reason behind this - offsetof() is part of the ANSI standard - but
6005 it does no harm).
6006
6007 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
6008 most of the places where whitespace preceded '#'. I have given up and
6009 allowed the remaining 2 cases to be at the margin.
6010
6011 + Rename some variables in pcre to eliminate shadowing. This seems very
6012 pedantic, but does no harm, of course.
6013
6014 6. Moved the call to setjmp() into its own function, to get rid of warnings
6015 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
6016
6017 7. Constructs such as \d{8,} were compiling into the equivalent of
6018 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
6019 outcome, but in this particular case used more store than had been allocated,
6020 which caused the bug to be discovered because it threw up an internal error.
6021
6022 8. The debugging code in both pcre and pcretest for outputting the compiled
6023 form of a regex was going wrong in the case of back references followed by
6024 curly-bracketed repeats.
6025
6026
6027 Version 1.02 12-Dec-97
6028 ----------------------
6029
6030 1. Typos in pcre.3 and comments in the source fixed.
6031
6032 2. Applied a contributed patch to get rid of places where it used to remove
6033 'const' from variables, and fixed some signed/unsigned and uninitialized
6034 variable warnings.
6035
6036 3. Added the "runtest" target to Makefile.
6037
6038 4. Set default compiler flag to -O2 rather than just -O.
6039
6040
6041 Version 1.01 19-Nov-97
6042 ----------------------
6043
6044 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
6045 like /([ab]*)*/, that is, for classes with more than one character in them.
6046
6047 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
6048 as /((?>a*))*/ (a PCRE_EXTRA facility).
6049
6050
6051 Version 1.00 18-Nov-97
6052 ----------------------
6053
6054 1. Added compile-time macros to support systems such as SunOS4 which don't have