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Revision 1590 - (show annotations)
Mon Aug 10 14:38:34 2015 UTC (4 years, 3 months ago) by ph10
File size: 283173 byte(s)
Add an internal error if handling forward referencing recursion calls has gone 
wrong.
1 ChangeLog for PCRE
2 ------------------
3
4 Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
5 development is happening in the PCRE2 10.xx series.
6
7 Version 8.38 xx-xxx-xxxx
8 ------------------------
9
10 1. If a group that contained a recursive back reference also contained a
11 forward reference subroutine call followed by a non-forward-reference
12 subroutine call, for example /.((?2)(?R)\1)()/, pcre2_compile() failed to
13 compile correct code, leading to undefined behaviour or an internally
14 detected error. This bug was discovered by the LLVM fuzzer.
15
16 2. Quantification of certain items (e.g. atomic back references) could cause
17 incorrect code to be compiled when recursive forward references were
18 involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
19 This bug was discovered by the LLVM fuzzer.
20
21 3. A repeated conditional group whose condition was a reference by name caused
22 a buffer overflow if there was more than one group with the given name.
23 This bug was discovered by the LLVM fuzzer.
24
25 4. A recursive back reference by name within a group that had the same name as
26 another group caused a buffer overflow. For example:
27 /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
28
29 5. A forward reference by name to a group whose number is the same as the
30 current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
31 a buffer overflow at compile time. This bug was discovered by the LLVM
32 fuzzer.
33
34 6. A lookbehind assertion within a set of mutually recursive subpatterns could
35 provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
36
37 7. Another buffer overflow bug involved duplicate named groups with a
38 reference between their definition, with a group that reset capture
39 numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
40 fixed by always allowing for more memory, even if not needed. (A proper fix
41 is implemented in PCRE2, but it involves more refactoring.)
42
43 8. There was no check for integer overflow in subroutine calls such as (?123).
44
45 9. The table entry for \l in EBCDIC environments was incorrect, leading to its
46 being treated as a literal 'l' instead of causing an error.
47
48 10. There was a buffer overflow if pcre_exec() was called with an ovector of
49 size 1. This bug was found by american fuzzy lop.
50
51 11. If a non-capturing group containing a conditional group that could match
52 an empty string was repeated, it was not identified as matching an empty
53 string itself. For example: /^(?:(?(1)x|)+)+$()/.
54
55 12. In an EBCDIC environment, pcretest was mishandling the escape sequences
56 \a and \e in test subject lines.
57
58 13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
59 instead of the EBCDIC value.
60
61 14. The handling of \c in an EBCDIC environment has been revised so that it is
62 now compatible with the specification in Perl's perlebcdic page.
63
64 15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
65 ASCII/Unicode. This has now been added to the list of characters that are
66 recognized as white space in EBCDIC.
67
68 16. When PCRE was compiled without UCP support, the use of \p and \P gave an
69 error (correctly) when used outside a class, but did not give an error
70 within a class.
71
72 17. \h within a class was incorrectly compiled in EBCDIC environments.
73
74 18. A pattern with an unmatched closing parenthesis that contained a backward
75 assertion which itself contained a forward reference caused buffer
76 overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
77
78 19. JIT should return with error when the compiled pattern requires more stack
79 space than the maximum.
80
81 20. A possessively repeated conditional group that could match an empty string,
82 for example, /(?(R))*+/, was incorrectly compiled.
83
84 21. Fix infinite recursion in the JIT compiler when certain patterns such as
85 /(?:|a|){100}x/ are analysed.
86
87 22. Some patterns with character classes involving [: and \\ were incorrectly
88 compiled and could cause reading from uninitialized memory or an incorrect
89 error diagnosis.
90
91 23. Pathological patterns containing many nested occurrences of [: caused
92 pcre_compile() to run for a very long time.
93
94 24. A conditional group with only one branch has an implicit empty alternative
95 branch and must therefore be treated as potentially matching an empty
96 string.
97
98 25. If (?R was followed by - or + incorrect behaviour happened instead of a
99 diagnostic.
100
101 26. Arrange to give up on finding the minimum matching length for overly
102 complex patterns.
103
104 27. Similar to (4) above: in a pattern with duplicated named groups and an
105 occurrence of (?| it is possible for an apparently non-recursive back
106 reference to become recursive if a later named group with the relevant
107 number is encountered. This could lead to a buffer overflow. Wen Guanxing
108 from Venustech ADLAB discovered this bug.
109
110 28. If pcregrep was given the -q option with -c or -l, or when handling a
111 binary file, it incorrectly wrote output to stdout.
112
113 29. The JIT compiler did not restore the control verb head in case of *THEN
114 control verbs. This issue was found by Karl Skomski with a custom LLVM
115 fuzzer.
116
117 30. Error messages for syntax errors following \g and \k were giving inaccurate
118 offsets in the pattern.
119
120 31. Added a check for integer overflow in conditions (?(<digits>) and
121 (?(R<digits>). This omission was discovered by Karl Skomski with the LLVM
122 fuzzer.
123
124 32. Handling recursive references such as (?2) when the reference is to a group
125 later in the pattern uses code that is very hacked about and error-prone.
126 It has been re-written for PCRE2. Here in PCRE1, a check has been added to
127 give an internal error if it is obvious that compiling has gone wrong.
128
129
130 Version 8.37 28-April-2015
131 --------------------------
132
133 1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
134 for those parentheses to be closed with whatever has been captured so far.
135 However, it was failing to mark any other groups between the hightest
136 capture so far and the currrent group as "unset". Thus, the ovector for
137 those groups contained whatever was previously there. An example is the
138 pattern /(x)|((*ACCEPT))/ when matched against "abcd".
139
140 2. If an assertion condition was quantified with a minimum of zero (an odd
141 thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
142
143 3. If a pattern in pcretest input had the P (POSIX) modifier followed by an
144 unrecognized modifier, a crash could occur.
145
146 4. An attempt to do global matching in pcretest with a zero-length ovector
147 caused a crash.
148
149 5. Fixed a memory leak during matching that could occur for a subpattern
150 subroutine call (recursive or otherwise) if the number of captured groups
151 that had to be saved was greater than ten.
152
153 6. Catch a bad opcode during auto-possessification after compiling a bad UTF
154 string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
155 UTF with NO_UTF_CHECK is documented as having an undefined outcome.
156
157 7. A UTF pattern containing a "not" match of a non-ASCII character and a
158 subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
159
160 8. When a pattern is compiled, it remembers the highest back reference so that
161 when matching, if the ovector is too small, extra memory can be obtained to
162 use instead. A conditional subpattern whose condition is a check on a
163 capture having happened, such as, for example in the pattern
164 /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
165 setting the highest backreference number. This mattered only if pcre_exec()
166 was called with an ovector that was too small to hold the capture, and there
167 was no other kind of back reference (a situation which is probably quite
168 rare). The effect of the bug was that the condition was always treated as
169 FALSE when the capture could not be consulted, leading to a incorrect
170 behaviour by pcre_exec(). This bug has been fixed.
171
172 9. A reference to a duplicated named group (either a back reference or a test
173 for being set in a conditional) that occurred in a part of the pattern where
174 PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
175 to be incorrectly calculated, leading to overwriting.
176
177 10. A mutually recursive set of back references such as (\2)(\1) caused a
178 segfault at study time (while trying to find the minimum matching length).
179 The infinite loop is now broken (with the minimum length unset, that is,
180 zero).
181
182 11. If an assertion that was used as a condition was quantified with a minimum
183 of zero, matching went wrong. In particular, if the whole group had
184 unlimited repetition and could match an empty string, a segfault was
185 likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
186 assertions to be quantified, but not if they are being used as conditions,
187 so the above pattern is faulted by Perl. PCRE has now been changed so that
188 it also rejects such patterns.
189
190 12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
191 failed to allow the zero-repeat case if pcre2_exec() was called with an
192 ovector too small to capture the group.
193
194 13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
195 Red Hat Product Security:
196
197 (a) A crash if /K and /F were both set with the option to save the compiled
198 pattern.
199
200 (b) Another crash if the option to print captured substrings in a callout
201 was combined with setting a null ovector, for example \O\C+ as a subject
202 string.
203
204 14. A pattern such as "((?2){0,1999}())?", which has a group containing a
205 forward reference repeated a large (but limited) number of times within a
206 repeated outer group that has a zero minimum quantifier, caused incorrect
207 code to be compiled, leading to the error "internal error:
208 previously-checked referenced subpattern not found" when an incorrect
209 memory address was read. This bug was reported as "heap overflow",
210 discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
211 CVE-2015-2325.
212
213 23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
214 call within a group that also contained a recursive back reference caused
215 incorrect code to be compiled. This bug was reported as "heap overflow",
216 discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
217 number CVE-2015-2326.
218
219 24. Computing the size of the JIT read-only data in advance has been a source
220 of various issues, and new ones are still appear unfortunately. To fix
221 existing and future issues, size computation is eliminated from the code,
222 and replaced by on-demand memory allocation.
223
224 25. A pattern such as /(?i)[A-`]/, where characters in the other case are
225 adjacent to the end of the range, and the range contained characters with
226 more than one other case, caused incorrect behaviour when compiled in UTF
227 mode. In that example, the range a-j was left out of the class.
228
229 26. Fix JIT compilation of conditional blocks, which assertion
230 is converted to (*FAIL). E.g: /(?(?!))/.
231
232 27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
233 discovered by the LLVM fuzzer.
234
235 28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
236 when this assertion was used as a condition, for example (?(?!)a|b). In
237 pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
238 error about an unsupported item.
239
240 29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
241 possessification code could take exponential time to complete. A recursion
242 depth limit of 1000 has been imposed to limit the resources used by this
243 optimization.
244
245 30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
246 such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
247 because \S ensures they are all in the class. The code for doing this was
248 interacting badly with the code for computing the amount of space needed to
249 compile the pattern, leading to a buffer overflow. This bug was discovered
250 by the LLVM fuzzer.
251
252 31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
253 other kinds of group caused stack overflow at compile time. This bug was
254 discovered by the LLVM fuzzer.
255
256 32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
257 between a subroutine call and its quantifier was incorrectly compiled,
258 leading to buffer overflow or other errors. This bug was discovered by the
259 LLVM fuzzer.
260
261 33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
262 assertion after (?(. The code was failing to check the character after
263 (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
264 was discovered by the LLVM fuzzer.
265
266 34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
267 a fixed maximum following a group that contains a subroutine reference was
268 incorrectly compiled and could trigger buffer overflow. This bug was
269 discovered by the LLVM fuzzer.
270
271 35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
272 caused a stack overflow instead of the diagnosis of a non-fixed length
273 lookbehind assertion. This bug was discovered by the LLVM fuzzer.
274
275 36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
276 (e.g. /(?<=\Ka)/) could make pcregrep loop.
277
278 37. There was a similar problem to 36 in pcretest for global matches.
279
280 38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
281 and a subsequent item in the pattern caused a non-match, backtracking over
282 the repeated \X did not stop, but carried on past the start of the subject,
283 causing reference to random memory and/or a segfault. There were also some
284 other cases where backtracking after \C could crash. This set of bugs was
285 discovered by the LLVM fuzzer.
286
287 39. The function for finding the minimum length of a matching string could take
288 a very long time if mutual recursion was present many times in a pattern,
289 for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
290 method has been implemented. This infelicity was discovered by the LLVM
291 fuzzer.
292
293 40. Static linking against the PCRE library using the pkg-config module was
294 failing on missing pthread symbols.
295
296
297 Version 8.36 26-September-2014
298 ------------------------------
299
300 1. Got rid of some compiler warnings in the C++ modules that were shown up by
301 -Wmissing-field-initializers and -Wunused-parameter.
302
303 2. The tests for quantifiers being too big (greater than 65535) were being
304 applied after reading the number, and stupidly assuming that integer
305 overflow would give a negative number. The tests are now applied as the
306 numbers are read.
307
308 3. Tidy code in pcre_exec.c where two branches that used to be different are
309 now the same.
310
311 4. The JIT compiler did not generate match limit checks for certain
312 bracketed expressions with quantifiers. This may lead to exponential
313 backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
314 issue should be resolved now.
315
316 5. Fixed an issue, which occures when nested alternatives are optimized
317 with table jumps.
318
319 6. Inserted two casts and changed some ints to size_t in the light of some
320 reported 64-bit compiler warnings (Bugzilla 1477).
321
322 7. Fixed a bug concerned with zero-minimum possessive groups that could match
323 an empty string, which sometimes were behaving incorrectly in the
324 interpreter (though correctly in the JIT matcher). This pcretest input is
325 an example:
326
327 '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
328 NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
329
330 the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
331 JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
332 for an empty string was breaking the inner loop and carrying on at a lower
333 level, when possessive repeated groups should always return to a higher
334 level as they have no backtrack points in them. The empty string test now
335 occurs at the outer level.
336
337 8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
338 ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
339
340 9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
341 doesn't).
342
343 10. Change 8.34/15 introduced a bug that caused the amount of memory needed
344 to hold a pattern to be incorrectly computed (too small) when there were
345 named back references to duplicated names. This could cause "internal
346 error: code overflow" or "double free or corruption" or other memory
347 handling errors.
348
349 11. When named subpatterns had the same prefixes, back references could be
350 confused. For example, in this pattern:
351
352 /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
353
354 the reference to 'Name' was incorrectly treated as a reference to a
355 duplicate name.
356
357 12. A pattern such as /^s?c/mi8 where the optional character has more than
358 one "other case" was incorrectly compiled such that it would only try to
359 match starting at "c".
360
361 13. When a pattern starting with \s was studied, VT was not included in the
362 list of possible starting characters; this should have been part of the
363 8.34/18 patch.
364
365 14. If a character class started [\Qx]... where x is any character, the class
366 was incorrectly terminated at the ].
367
368 15. If a pattern that started with a caseless match for a character with more
369 than one "other case" was studied, PCRE did not set up the starting code
370 unit bit map for the list of possible characters. Now it does. This is an
371 optimization improvement, not a bug fix.
372
373 16. The Unicode data tables have been updated to Unicode 7.0.0.
374
375 17. Fixed a number of memory leaks in pcregrep.
376
377 18. Avoid a compiler warning (from some compilers) for a function call with
378 a cast that removes "const" from an lvalue by using an intermediate
379 variable (to which the compiler does not object).
380
381 19. Incorrect code was compiled if a group that contained an internal recursive
382 back reference was optional (had quantifier with a minimum of zero). This
383 example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
384 caused segmentation faults because of stack overflows at compile time.
385
386 20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
387 group that is quantified with an indefinite repeat, caused a compile-time
388 loop which used up all the system stack and provoked a segmentation fault.
389 This was not the same bug as 19 above.
390
391 21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
392 Patch by Mike Frysinger.
393
394
395 Version 8.35 04-April-2014
396 --------------------------
397
398 1. A new flag is set, when property checks are present in an XCLASS.
399 When this flag is not set, PCRE can perform certain optimizations
400 such as studying these XCLASS-es.
401
402 2. The auto-possessification of character sets were improved: a normal
403 and an extended character set can be compared now. Furthermore
404 the JIT compiler optimizes more character set checks.
405
406 3. Got rid of some compiler warnings for potentially uninitialized variables
407 that show up only when compiled with -O2.
408
409 4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
410 of a match later then the end of the match. The pcretest program was not
411 handling the case sensibly - it was outputting from the start to the next
412 binary zero. It now reports this situation in a message, and outputs the
413 text from the end to the start.
414
415 5. Fast forward search is improved in JIT. Instead of the first three
416 characters, any three characters with fixed position can be searched.
417 Search order: first, last, middle.
418
419 6. Improve character range checks in JIT. Characters are read by an inprecise
420 function now, which returns with an unknown value if the character code is
421 above a certain threshold (e.g: 256). The only limitation is that the value
422 must be bigger than the threshold as well. This function is useful when
423 the characters above the threshold are handled in the same way.
424
425 7. The macros whose names start with RAWUCHAR are placeholders for a future
426 mode in which only the bottom 21 bits of 32-bit data items are used. To
427 make this more memorable for those maintaining the code, the names have
428 been changed to start with UCHAR21, and an extensive comment has been added
429 to their definition.
430
431 8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
432 to the export list in Makefile.am (they were accidentally omitted from the
433 8.34 tarball).
434
435 9. The informational output from pcretest used the phrase "starting byte set"
436 which is inappropriate for the 16-bit and 32-bit libraries. As the output
437 for "first char" and "need char" really means "non-UTF-char", I've changed
438 "byte" to "char", and slightly reworded the output. The documentation about
439 these values has also been (I hope) clarified.
440
441 10. Another JIT related optimization: use table jumps for selecting the correct
442 backtracking path, when more than four alternatives are present inside a
443 bracket.
444
445 11. Empty match is not possible, when the minimum length is greater than zero,
446 and there is no \K in the pattern. JIT should avoid empty match checks in
447 such cases.
448
449 12. In a caseless character class with UCP support, when a character with more
450 than one alternative case was not the first character of a range, not all
451 the alternative cases were added to the class. For example, s and \x{17f}
452 are both alternative cases for S: the class [RST] was handled correctly,
453 but [R-T] was not.
454
455 13. The configure.ac file always checked for pthread support when JIT was
456 enabled. This is not used in Windows, so I have put this test inside a
457 check for the presence of windows.h (which was already tested for).
458
459 14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
460 The algorithm provides a way to skip certain starting offsets, and usually
461 faster than linear prefix searches.
462
463 15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
464 as for 'fr_FR' and 'french'. For some reason, however, it then used the
465 Windows-specific input and output files, which have 'french' screwed in.
466 So this could never have worked. One of the problems with locales is that
467 they aren't always the same. I have now updated RunTest so that it checks
468 the output of the locale test (test 3) against three different output
469 files, and it allows the test to pass if any one of them matches. With luck
470 this should make the test pass on some versions of Solaris where it was
471 failing. Because of the uncertainty, the script did not used to stop if
472 test 3 failed; it now does. If further versions of a French locale ever
473 come to light, they can now easily be added.
474
475 16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
476 there was a message during ./configure, but it did not stop. This now
477 provokes an error. The invalid example in README has been corrected.
478 If a value less than the minimum is given, the minimum value has always
479 been used, but now a warning is given.
480
481 17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
482 was a bug in the test system, which is now fixed. Also, the list of various
483 configurations that are tested for each release did not have one with both
484 16/32 bits and --enable-bar-anycrlf. It now does.
485
486 18. pcretest was missing "-C bsr" for displaying the \R default setting.
487
488 19. Little endian PowerPC systems are supported now by the JIT compiler.
489
490 20. The fast forward newline mechanism could enter to an infinite loop on
491 certain invalid UTF-8 input. Although we don't support these cases
492 this issue can be fixed by a performance optimization.
493
494 21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
495 not take account if existing stack usage. There is now a new global
496 variable called pcre_stack_guard that can be set to point to an external
497 function to check stack availability. It is called at the start of
498 processing every parenthesized group.
499
500 22. A typo in the code meant that in ungreedy mode the max/min qualifier
501 behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
502 not match "ab".
503
504 23. When UTF was disabled, the JIT program reported some incorrect compile
505 errors. These messages are silenced now.
506
507 24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
508 compiler.
509
510 25. Change all the temporary files used in RunGrepTest to be different to those
511 used by RunTest so that the tests can be run simultaneously, for example by
512 "make -j check".
513
514
515 Version 8.34 15-December-2013
516 -----------------------------
517
518 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
519 executable memory. Patch inspired by Carsten Klein.
520
521 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
522 this macro is never tested and has no effect, because the work to support
523 coverage involves only compiling and linking options and special targets in
524 the Makefile. The comment in config.h implied that defining the macro would
525 enable coverage support, which is totally false. There was also support for
526 setting this macro in the CMake files (my fault, I just copied it from
527 configure). SUPPORT_GCOV has now been removed.
528
529 3. Make a small performance improvement in strlen16() and strlen32() in
530 pcretest.
531
532 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
533 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
534 these cases). There was also one in pcretest.c.
535
536 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
537
538 6. In UTF mode, the code for checking whether a group could match an empty
539 string (which is used for indefinitely repeated groups to allow for
540 breaking an infinite loop) was broken when the group contained a repeated
541 negated single-character class with a character that occupied more than one
542 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
543 UTF-8 mode). The effect was undefined: the group might or might not be
544 deemed as matching an empty string, or the program might have crashed.
545
546 7. The code for checking whether a group could match an empty string was not
547 recognizing that \h, \H, \v, \V, and \R must match a character.
548
549 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
550 an empty string. If it can, pcretest shows this in its information output.
551
552 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
553 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
554 matched by pcre_exec() without using JIT:
555
556 (a) If the rest of the pattern did not match after a maximal run of
557 grapheme clusters, the code for backing up to try with fewer of them
558 did not always back up over a full grapheme when characters that do not
559 have the modifier quality were involved, e.g. Hangul syllables.
560
561 (b) If the match point in a subject started with modifier character, and
562 there was no match, the code could incorrectly back up beyond the match
563 point, and potentially beyond the first character in the subject,
564 leading to a segfault or an incorrect match result.
565
566 10. A conditional group with an assertion condition could lead to PCRE
567 recording an incorrect first data item for a match if no other first data
568 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
569 first data item, and therefore matched "ca" after "c" instead of at the
570 start.
571
572 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
573 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
574
575 12. The source of pcregrep now includes z/OS-specific code so that it can be
576 compiled for z/OS as part of the special z/OS distribution.
577
578 13. Added the -T and -TM options to pcretest.
579
580 14. The code in pcre_compile.c for creating the table of named capturing groups
581 has been refactored. Instead of creating the table dynamically during the
582 actual compiling pass, the information is remembered during the pre-compile
583 pass (on the stack unless there are more than 20 named groups, in which
584 case malloc() is used) and the whole table is created before the actual
585 compile happens. This has simplified the code (it is now nearly 150 lines
586 shorter) and prepared the way for better handling of references to groups
587 with duplicate names.
588
589 15. A back reference to a named subpattern when there is more than one of the
590 same name now checks them in the order in which they appear in the pattern.
591 The first one that is set is used for the reference. Previously only the
592 first one was inspected. This change makes PCRE more compatible with Perl.
593
594 16. Unicode character properties were updated from Unicode 6.3.0.
595
596 17. The compile-time code for auto-possessification has been refactored, based
597 on a patch by Zoltan Herczeg. It now happens after instead of during
598 compilation. The code is cleaner, and more cases are handled. The option
599 PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
600 options in pcretest are provided to set it. It can also be set by
601 (*NO_AUTO_POSSESS) at the start of a pattern.
602
603 18. The character VT has been added to the default ("C" locale) set of
604 characters that match \s and are generally treated as white space,
605 following this same change in Perl 5.18. There is now no difference between
606 "Perl space" and "POSIX space". Whether VT is treated as white space in
607 other locales depends on the locale.
608
609 19. The code for checking named groups as conditions, either for being set or
610 for being recursed, has been refactored (this is related to 14 and 15
611 above). Processing unduplicated named groups should now be as fast at
612 numerical groups, and processing duplicated groups should be faster than
613 before.
614
615 20. Two patches to the CMake build system, by Alexander Barkov:
616
617 (1) Replace the "source" command by "." in CMakeLists.txt because
618 "source" is a bash-ism.
619
620 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
621 without these the CMake build does not work on Solaris.
622
623 21. Perl has changed its handling of \8 and \9. If there is no previously
624 encountered capturing group of those numbers, they are treated as the
625 literal characters 8 and 9 instead of a binary zero followed by the
626 literals. PCRE now does the same.
627
628 22. Following Perl, added \o{} to specify codepoints in octal, making it
629 possible to specify values greater than 0777 and also making them
630 unambiguous.
631
632 23. Perl now gives an error for missing closing braces after \x{... instead of
633 treating the string as literal. PCRE now does the same.
634
635 24. RunTest used to grumble if an inappropriate test was selected explicitly,
636 but just skip it when running all tests. This make it awkward to run ranges
637 of tests when one of them was inappropriate. Now it just skips any
638 inappropriate tests, as it always did when running all tests.
639
640 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
641 character types such as \d or \w, too many callouts were inserted, and the
642 data that they returned was rubbish.
643
644 26. In UCP mode, \s was not matching two of the characters that Perl matches,
645 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
646 were matched by \h. The code has now been refactored so that the lists of
647 the horizontal and vertical whitespace characters used for \h and \v (which
648 are defined only in one place) are now also used for \s.
649
650 27. Add JIT support for the 64 bit TileGX architecture.
651 Patch by Jiong Wang (Tilera Corporation).
652
653 28. Possessive quantifiers for classes (both explicit and automatically
654 generated) now use special opcodes instead of wrapping in ONCE brackets.
655
656 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
657 (because it's meaningless), this was not happening when PCRE_CASELESS was
658 set. Not wrong, but inefficient.
659
660 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
661 properties for \w, \d, etc) is present in a test regex. Otherwise if the
662 test contains no characters greater than 255, Perl doesn't realise it
663 should be using Unicode semantics.
664
665 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
666 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
667 does in Unicode mode.
668
669 32. Added the "forbid" facility to pcretest so that putting tests into the
670 wrong test files can sometimes be quickly detected.
671
672 33. There is now a limit (default 250) on the depth of nesting of parentheses.
673 This limit is imposed to control the amount of system stack used at compile
674 time. It can be changed at build time by --with-parens-nest-limit=xxx or
675 the equivalent in CMake.
676
677 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
678 errors. Perl warns for these when in warning mode, but PCRE has no facility
679 for giving warnings.
680
681 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
682 However, this was not working for (?!) because it is optimized to (*FAIL),
683 for which PCRE does not allow quantifiers. The optimization is now disabled
684 when a quantifier follows (?!). I can't see any use for this, but it makes
685 things uniform.
686
687 36. Perl no longer allows group names to start with digits, so I have made this
688 change also in PCRE. It simplifies the code a bit.
689
690 37. In extended mode, Perl ignores spaces before a + that indicates a
691 possessive quantifier. PCRE allowed a space before the quantifier, but not
692 before the possessive +. It now does.
693
694 38. The use of \K (reset reported match start) within a repeated possessive
695 group such as (a\Kb)*+ was not working.
696
697 40. Document that the same character tables must be used at compile time and
698 run time, and that the facility to pass tables to pcre_exec() and
699 pcre_dfa_exec() is for use only with saved/restored patterns.
700
701 41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
702 features for Builds with MSVC:
703
704 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
705 builds). The .rc files can be used to set FileDescription and many other
706 attributes.
707
708 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
709 This allows higher-level build scripts which want .pdb files to avoid
710 hard-coding the exact files needed."
711
712 42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
713 mean "start of word" and "end of word", respectively, as a transition aid.
714
715 43. A minimizing repeat of a class containing codepoints greater than 255 in
716 non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
717 compiled to use the heap for recursion.
718
719 44. Got rid of some compiler warnings for unused variables when UTF but not UCP
720 is configured.
721
722
723 Version 8.33 28-May-2013
724 ------------------------
725
726 1. Added 'U' to some constants that are compared to unsigned integers, to
727 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
728 variables that are added to signed variables, to ensure the result is
729 signed and can be negated.
730
731 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
732 CMake config files.
733
734 3. Revise the creation of config.h.generic so that all boolean macros are
735 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
736 overriding via -D on the command line possible.
737
738 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
739 to unsigned int is reported to make a quite noticeable speed difference in
740 a specific Windows environment. Testing on Linux did also appear to show
741 some benefit (and it is clearly not harmful). Also fixed the definition of
742 Xop which should be unsigned.
743
744 5. Related to (4), changing the definition of the intermediate variable cc
745 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
746 improvements.
747
748 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
749 unnecessary spaces.
750
751 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
752 and later.
753
754 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
755
756 9. Optimizing fast_forward_start_bits in JIT.
757
758 10. Adding support for callouts in JIT, and fixing some issues revealed
759 during this work. Namely:
760
761 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
762
763 (b) Minimum length was not checked before the matching is started.
764
765 11. The value of capture_last that is passed to callouts was incorrect in some
766 cases when there was a capture on one path that was subsequently abandoned
767 after a backtrack. Also, the capture_last value is now reset after a
768 recursion, since all captures are also reset in this case.
769
770 12. The interpreter no longer returns the "too many substrings" error in the
771 case when an overflowing capture is in a branch that is subsequently
772 abandoned after a backtrack.
773
774 13. In the pathological case when an offset vector of size 2 is used, pcretest
775 now prints out the matched string after a yield of 0 or 1.
776
777 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
778 Only supported by the JIT compiler at the moment.
779
780 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
781
782 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
783 offset of the starting point of the matching process, provided the offsets
784 vector is large enough.
785
786 17. The \A escape now records a lookbehind value of 1, though its execution
787 does not actually inspect the previous character. This is to ensure that,
788 in partial multi-segment matching, at least one character from the old
789 segment is retained when a new segment is processed. Otherwise, if there
790 are no lookbehinds in the pattern, \A might match incorrectly at the start
791 of a new segment.
792
793 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
794
795 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
796 gives some modest performance improvement in 8-bit mode.
797
798 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
799 be expressed in certain programming languages using Universal Character
800 Names.
801
802 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
803 which points out that "non characters" are not "characters that may not
804 appear in Unicode strings" but rather "characters that are reserved for
805 internal use and have only local meaning".
806
807 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
808 there was a conditional group that depended on an assertion, if the
809 assertion was false, the callout that immediately followed the alternation
810 in the condition was skipped when pcre_exec() was used for matching.
811
812 23. Allow an explicit callout to be inserted before an assertion that is the
813 condition for a conditional group, for compatibility with automatic
814 callouts, which always insert a callout at this point.
815
816 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
817 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
818
819 25. (*PRUNE) is now supported by the JIT compiler.
820
821 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
822
823 27. Fix the case where there are two or more SKIPs with arguments that may be
824 ignored.
825
826 28. (*SKIP) is now supported by the JIT compiler.
827
828 29. (*THEN) is now supported by the JIT compiler.
829
830 30. Update RunTest with additional test selector options.
831
832 31. The way PCRE handles backtracking verbs has been changed in two ways.
833
834 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
835 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
836 backtracking. In some cases this makes it more Perl-compatible, but Perl's
837 rather obscure rules do not always do the same thing.
838
839 (2) Previously, backtracking verbs were confined within assertions. This is
840 no longer the case for positive assertions, except for (*ACCEPT). Again,
841 this sometimes improves Perl compatibility, and sometimes does not.
842
843 32. A number of tests that were in test 2 because Perl did things differently
844 have been moved to test 1, because either Perl or PCRE has changed, and
845 these tests are now compatible.
846
847 32. Backtracking control verbs are now handled in the same way in JIT and
848 interpreter.
849
850 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
851 contained a forward subroutine reference caused a compile error.
852
853 34. Auto-detect and optimize limited repetitions in JIT.
854
855 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
856 blocking (*UTF) etc.
857
858 36. In the interpreter, maximizing pattern repetitions for characters and
859 character types now use tail recursion, which reduces stack usage.
860
861 37. The value of the max lookbehind was not correctly preserved if a compiled
862 and saved regex was reloaded on a host of different endianness.
863
864 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
865 of the compiled pattern block, expand the flags field from 16 to 32 bits
866 because it was almost full.
867
868 39. Try madvise first before posix_madvise.
869
870 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
871 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
872 original change locked out all matches of empty strings. This has been
873 changed so that one match of an empty string per line is recognized.
874 Subsequent searches on the same line (for colouring or for --only-matching,
875 for example) do not recognize empty strings.
876
877 41. Applied a user patch to fix a number of spelling mistakes in comments.
878
879 42. Data lines longer than 65536 caused pcretest to crash.
880
881 43. Clarified the data type for length and startoffset arguments for pcre_exec
882 and pcre_dfa_exec in the function-specific man pages, where they were
883 explicitly stated to be in bytes, never having been updated. I also added
884 some clarification to the pcreapi man page.
885
886 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
887 a segmentation fault.
888
889
890 Version 8.32 30-November-2012
891 -----------------------------
892
893 1. Improved JIT compiler optimizations for first character search and single
894 character iterators.
895
896 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
897 Patch by Daniel Richard G.
898
899 3. Single character iterator optimizations in the JIT compiler.
900
901 4. Improved JIT compiler optimizations for character ranges.
902
903 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
904 Reported by Giuseppe D'Angelo.
905
906 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
907 of a line, was being set incorrectly in cases where .* appeared inside
908 atomic brackets at the start of a pattern, or where there was a subsequent
909 *PRUNE or *SKIP.
910
911 7. Improved instruction cache flush for POWER/PowerPC.
912 Patch by Daniel Richard G.
913
914 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
915 grep:
916
917 (a) There is now no limit to the number of patterns to be matched.
918
919 (b) An error is given if a pattern is too long.
920
921 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
922 are now supported.
923
924 (d) --exclude-from and --include-from (multiple use) have been added.
925
926 (e) Exclusions and inclusions now apply to all files and directories, not
927 just to those obtained from scanning a directory recursively.
928
929 (f) Multiple uses of -f and --file-list are now supported.
930
931 (g) In a Windows environment, the default for -d has been changed from
932 "read" (the GNU grep default) to "skip", because otherwise the presence
933 of a directory in the file list provokes an error.
934
935 (h) The documentation has been revised and clarified in places.
936
937 9. Improve the matching speed of capturing brackets.
938
939 10. Changed the meaning of \X so that it now matches a Unicode extended
940 grapheme cluster.
941
942 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
943 out POSIX threads when JIT support is configured.
944
945 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
946
947 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
948 structure could go wrong in environments where size_t is not the same size
949 as int.
950
951 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
952 set.
953
954 15. The EBCDIC support had decayed; later updates to the code had included
955 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
956 general tidy up of EBCDIC-related issues, and the documentation was also
957 not quite right. There is now a test that can be run on ASCII systems to
958 check some of the EBCDIC-related things (but is it not a full test).
959
960 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
961 in a small tidy to the code.
962
963 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
964
965 18. If the --only-matching (-o) option in pcregrep is specified multiple
966 times, each one causes appropriate output. For example, -o1 -o2 outputs the
967 substrings matched by the 1st and 2nd capturing parentheses. A separating
968 string can be specified by --om-separator (default empty).
969
970 19. Improving the first n character searches.
971
972 20. Turn case lists for horizontal and vertical white space into macros so that
973 they are defined only once.
974
975 21. This set of changes together give more compatible Unicode case-folding
976 behaviour for characters that have more than one other case when UCP
977 support is available.
978
979 (a) The Unicode property table now has offsets into a new table of sets of
980 three or more characters that are case-equivalent. The MultiStage2.py
981 script that generates these tables (the pcre_ucd.c file) now scans
982 CaseFolding.txt instead of UnicodeData.txt for character case
983 information.
984
985 (b) The code for adding characters or ranges of characters to a character
986 class has been abstracted into a generalized function that also handles
987 case-independence. In UTF-mode with UCP support, this uses the new data
988 to handle characters with more than one other case.
989
990 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
991 whose other case is greater than 256 are now correctly matched
992 caselessly. Previously, the high codepoint matched the low one, but not
993 vice versa.
994
995 (d) The processing of \h, \H, \v, and \ in character classes now makes use
996 of the new class addition function, using character lists defined as
997 macros alongside the case definitions of 20 above.
998
999 (e) Caseless back references now work with characters that have more than
1000 one other case.
1001
1002 (f) General caseless matching of characters with more than one other case
1003 is supported.
1004
1005 22. Unicode character properties were updated from Unicode 6.2.0
1006
1007 23. Improved CMake support under Windows. Patch by Daniel Richard G.
1008
1009 24. Add support for 32-bit character strings, and UTF-32
1010
1011 25. Major JIT compiler update (code refactoring and bugfixing).
1012 Experimental Sparc 32 support is added.
1013
1014 26. Applied a modified version of Daniel Richard G's patch to create
1015 pcre.h.generic and config.h.generic by "make" instead of in the
1016 PrepareRelease script.
1017
1018 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
1019 pcre_compile.c when checking for a zero character.
1020
1021 28. Introducing a native interface for JIT. Through this interface, the compiled
1022 machine code can be directly executed. The purpose of this interface is to
1023 provide fast pattern matching, so several sanity checks are not performed.
1024 However, feature tests are still performed. The new interface provides
1025 1.4x speedup compared to the old one.
1026
1027 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
1028 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
1029 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
1030
1031 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
1032 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
1033 the "old" RFC 2279). Instead, it ended up passing a negative length to
1034 pcre_exec().
1035
1036 31. Add support for GCC's visibility feature to hide internal functions.
1037
1038 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
1039 "unknown -C option" after outputting 0 or 1.
1040
1041 33. There is now support for generating a code coverage report for the test
1042 suite in environments where gcc is the compiler and lcov is installed. This
1043 is mainly for the benefit of the developers.
1044
1045 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
1046 unaddressable using valgrind annotations, allowing valgrind to detect
1047 invalid memory accesses. This is mainly for the benefit of the developers.
1048
1049 25. (*UTF) can now be used to start a pattern in any of the three libraries.
1050
1051 26. Give configure error if --enable-cpp but no C++ compiler found.
1052
1053
1054 Version 8.31 06-July-2012
1055 -------------------------
1056
1057 1. Fixing a wrong JIT test case and some compiler warnings.
1058
1059 2. Removed a bashism from the RunTest script.
1060
1061 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1062 to unsigned type, result still unsigned" that was given by an MS compiler
1063 on encountering the code "-sizeof(xxx)".
1064
1065 4. Partial matching support is added to the JIT compiler.
1066
1067 5. Fixed several bugs concerned with partial matching of items that consist
1068 of more than one character:
1069
1070 (a) /^(..)\1/ did not partially match "aba" because checking references was
1071 done on an "all or nothing" basis. This also applied to repeated
1072 references.
1073
1074 (b) \R did not give a hard partial match if \r was found at the end of the
1075 subject.
1076
1077 (c) \X did not give a hard partial match after matching one or more
1078 characters at the end of the subject.
1079
1080 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1081 a partial match for the string "\r".
1082
1083 (e) When newline was set to CRLF, the metacharacter "." did not recognize
1084 a partial match for a CR character at the end of the subject string.
1085
1086 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1087 running pcretest, the text "(JIT)" added to the output whenever JIT is
1088 actually used to run the match.
1089
1090 7. Individual JIT compile options can be set in pcretest by following -s+[+]
1091 or /S+[+] with a digit between 1 and 7.
1092
1093 8. OP_NOT now supports any UTF character not just single-byte ones.
1094
1095 9. (*MARK) control verb is now supported by the JIT compiler.
1096
1097 10. The command "./RunTest list" lists the available tests without actually
1098 running any of them. (Because I keep forgetting what they all are.)
1099
1100 11. Add PCRE_INFO_MAXLOOKBEHIND.
1101
1102 12. Applied a (slightly modified) user-supplied patch that improves performance
1103 when the heap is used for recursion (compiled with --disable-stack-for-
1104 recursion). Instead of malloc and free for each heap frame each time a
1105 logical recursion happens, frames are retained on a chain and re-used where
1106 possible. This sometimes gives as much as 30% improvement.
1107
1108 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1109 call.
1110
1111 14. As documented, (*COMMIT) is now confined to within a positive assertion.
1112
1113 15. It is now possible to link pcretest with libedit as an alternative to
1114 libreadline.
1115
1116 16. (*COMMIT) control verb is now supported by the JIT compiler.
1117
1118 17. The Unicode data tables have been updated to Unicode 6.1.0.
1119
1120 18. Added --file-list option to pcregrep.
1121
1122 19. Added binary file support to pcregrep, including the -a, --binary-files,
1123 -I, and --text options.
1124
1125 20. The madvise function is renamed for posix_madvise for QNX compatibility
1126 reasons. Fixed by Giuseppe D'Angelo.
1127
1128 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1129
1130 22. Changed the option for creating symbolic links for 16-bit man pages from
1131 -s to -sf so that re-installing does not cause issues.
1132
1133 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1134
1135 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1136 matches in certain environments (the workspace was not being correctly
1137 retained). Also added to pcre_dfa_exec() a simple plausibility check on
1138 some of the workspace data at the beginning of a restart.
1139
1140 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1141 was not doing so when it should - probably a typo introduced by SVN 528
1142 (change 8.10/14).
1143
1144 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1145 \w+ when the character tables indicated that \x{c4} was a word character.
1146 There were several related cases, all because the tests for doing a table
1147 lookup were testing for characters less than 127 instead of 255.
1148
1149 27. If a pattern contains capturing parentheses that are not used in a match,
1150 their slots in the ovector are set to -1. For those that are higher than
1151 any matched groups, this happens at the end of processing. In the case when
1152 there were back references that the ovector was too small to contain
1153 (causing temporary malloc'd memory to be used during matching), and the
1154 highest capturing number was not used, memory off the end of the ovector
1155 was incorrectly being set to -1. (It was using the size of the temporary
1156 memory instead of the true size.)
1157
1158 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1159 ovector size, it uses memory at the end of the block that it has got.
1160
1161 29. Check for an overlong MARK name and give an error at compile time. The
1162 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1163
1164 30. JIT compiler update.
1165
1166 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1167 Rill for the patch.
1168
1169 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1170
1171 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1172
1173 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1174 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1175 was enabled.
1176
1177 35. Improve JIT code generation for greedy plus quantifier.
1178
1179 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1180 1 to "aa" instead of to an empty string. The bug affected repeated groups
1181 that could potentially match an empty string.
1182
1183 37. Optimizing single character iterators in JIT.
1184
1185 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1186 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1187 codepoints that are too big for the mode are faulted, and in a UTF mode,
1188 disallowed codepoints are also faulted.
1189
1190 39. If PCRE was compiled with UTF support, in three places in the DFA
1191 matcher there was code that should only have been obeyed in UTF mode, but
1192 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1193 processing when bytes with values greater than 127 were present. In 16-bit
1194 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1195 both cases the values are those that cannot be the first data item in a UTF
1196 character. The three items that might have provoked this were recursions,
1197 possessively repeated groups, and atomic groups.
1198
1199 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1200 and pcregrep, because some OS require shared objects to be explicitly
1201 passed to ld, causing the link step to fail if they are not.
1202
1203 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1204 mode, patterns that started with \h* or \R* might be incorrectly matched.
1205
1206
1207 Version 8.30 04-February-2012
1208 -----------------------------
1209
1210 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
1211 name is defined in ctype.h.
1212
1213 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
1214 only in quite long subpatterns.
1215
1216 3. Removed the function pcre_info(), which has been obsolete and deprecated
1217 since it was replaced by pcre_fullinfo() in February 2000.
1218
1219 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
1220 match a (*MARK), and the match failed at the start of the subject, a
1221 reference to memory before the start of the subject could occur. This bug
1222 was introduced by fix 17 of release 8.21.
1223
1224 5. A reference to an unset group with zero minimum repetition was giving
1225 totally wrong answers (in non-JavaScript-compatibility mode). For example,
1226 /(another)?(\1?)test/ matched against "hello world test". This bug was
1227 introduced in release 8.13.
1228
1229 6. Add support for 16-bit character strings (a large amount of work involving
1230 many changes and refactorings).
1231
1232 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1233 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1234 from a file.
1235
1236 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1237 rounding is not applied in this particular case).
1238
1239 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1240 if they appear, or are escaped, in patterns.
1241
1242 10. Get rid of a number of -Wunused-but-set-variable warnings.
1243
1244 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1245 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1246 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1247 also returns the mark "x". This bug applied to capturing parentheses,
1248 non-capturing parentheses, and atomic parentheses. It also applied to some
1249 assertions.
1250
1251 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1252 information out of configure.ac instead of relying on pcre.h.generic, which
1253 is not stored in the repository.
1254
1255 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1256 -lreadline.
1257
1258 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1259
1260 15. Applied Graycode's patch to put the top-level frame on the stack rather
1261 than the heap when not using the stack for recursion. This gives a
1262 performance improvement in many cases when recursion is not deep.
1263
1264 16. Experimental code added to "pcretest -C" to output the stack frame size.
1265
1266
1267 Version 8.21 12-Dec-2011
1268 ------------------------
1269
1270 1. Updating the JIT compiler.
1271
1272 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1273 are added as well.
1274
1275 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1276 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1277 calling _pcre_jit_exec. Some extra comments are added.
1278
1279 4. (*MARK) settings inside atomic groups that do not contain any capturing
1280 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1281 was introduced by change 18 for 8.20.
1282
1283 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1284 ECMA-262 standard.
1285
1286 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1287 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1288 This bug was probably introduced by change 9 of 8.13.
1289
1290 7. While fixing 6 above, I noticed that a number of other items were being
1291 incorrectly rejected as "not fixed length". This arose partly because newer
1292 opcodes had not been added to the fixed-length checking code. I have (a)
1293 corrected the bug and added tests for these items, and (b) arranged for an
1294 error to occur if an unknown opcode is encountered while checking for fixed
1295 length instead of just assuming "not fixed length". The items that were
1296 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1297 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1298 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1299
1300 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1301 being incorrectly compiled and would have given unpredicatble results.
1302
1303 9. A possessively repeated subpattern with minimum repeat count greater than
1304 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1305 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1306 the first (A) could occur when it should not.
1307
1308 10. Add a cast and remove a redundant test from the code.
1309
1310 11. JIT should use pcre_malloc/pcre_free for allocation.
1311
1312 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1313 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1314 is anything other than /usr, -L is still shown).
1315
1316 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1317
1318 14. Perl does not support \N without a following name in a [] class; PCRE now
1319 also gives an error.
1320
1321 15. If a forward reference was repeated with an upper limit of around 2000,
1322 it caused the error "internal error: overran compiling workspace". The
1323 maximum number of forward references (including repeats) was limited by the
1324 internal workspace, and dependent on the LINK_SIZE. The code has been
1325 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1326 the default depends on LINK_SIZE. There is a new upper limit (for safety)
1327 of around 200,000 forward references. While doing this, I also speeded up
1328 the filling in of repeated forward references.
1329
1330 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1331 incorrectly expecting the subject to contain another "a" after the start.
1332
1333 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1334 in the match, the SKIP should be ignored. This was not happening; instead
1335 the SKIP was being treated as NOMATCH. For patterns such as
1336 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1337 tested.
1338
1339 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1340 now much more compatible with Perl, in particular in cases where the result
1341 is a non-match for a non-anchored pattern. For example, if
1342 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1343 "m", where previously it did not return a name. A side effect of this
1344 change is that for partial matches, the last encountered mark name is
1345 returned, as for non matches. A number of tests that were previously not
1346 Perl-compatible have been moved into the Perl-compatible test files. The
1347 refactoring has had the pleasing side effect of removing one argument from
1348 the match() function, thus reducing its stack requirements.
1349
1350 19. If the /S+ option was used in pcretest to study a pattern using JIT,
1351 subsequent uses of /S (without +) incorrectly behaved like /S+.
1352
1353 21. Retrieve executable code size support for the JIT compiler and fixing
1354 some warnings.
1355
1356 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1357 not work when the shorter character appeared right at the end of the
1358 subject string.
1359
1360 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1361 systems.
1362
1363 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1364 output it when the /M option is used in pcretest.
1365
1366 25. The CheckMan script was not being included in the distribution. Also, added
1367 an explicit "perl" to run Perl scripts from the PrepareRelease script
1368 because this is reportedly needed in Windows.
1369
1370 26. If study data was being save in a file and studying had not found a set of
1371 "starts with" bytes for the pattern, the data written to the file (though
1372 never used) was taken from uninitialized memory and so caused valgrind to
1373 complain.
1374
1375 27. Updated RunTest.bat as provided by Sheri Pierce.
1376
1377 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1378
1379 29. Computation of memory usage for the table of capturing group names was
1380 giving an unnecessarily large value.
1381
1382
1383 Version 8.20 21-Oct-2011
1384 ------------------------
1385
1386 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1387 a POSIX class. After further experiments with Perl, which convinced me that
1388 Perl has bugs and confusions, a closing square bracket is no longer allowed
1389 in a POSIX name. This bug also affected patterns with classes that started
1390 with full stops.
1391
1392 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1393 captured substring, but while checking the failing first alternative,
1394 substring 1 is temporarily captured. If the output vector supplied to
1395 pcre_exec() was not big enough for this capture, the yield of the function
1396 was still zero ("insufficient space for captured substrings"). This cannot
1397 be totally fixed without adding another stack variable, which seems a lot
1398 of expense for a edge case. However, I have improved the situation in cases
1399 such as /(a)(b)x|abc/ matched against "abc", where the return code
1400 indicates that fewer than the maximum number of slots in the ovector have
1401 been set.
1402
1403 3. Related to (2) above: when there are more back references in a pattern than
1404 slots in the output vector, pcre_exec() uses temporary memory during
1405 matching, and copies in the captures as far as possible afterwards. It was
1406 using the entire output vector, but this conflicts with the specification
1407 that only 2/3 is used for passing back captured substrings. Now it uses
1408 only the first 2/3, for compatibility. This is, of course, another edge
1409 case.
1410
1411 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
1412 main code base, and can be used by building with --enable-jit. When this is
1413 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1414 runtime --no-jit option is given.
1415
1416 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
1417 ovector, the return from the function was zero, implying that there were
1418 other matches that did not fit. The correct "exactly full" value is now
1419 returned.
1420
1421 6. If a subpattern that was called recursively or as a subroutine contained
1422 (*PRUNE) or any other control that caused it to give a non-standard return,
1423 invalid errors such as "Error -26 (nested recursion at the same subject
1424 position)" or even infinite loops could occur.
1425
1426 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1427 computing the minimum length on reaching *ACCEPT, and so ended up with the
1428 wrong value of 1 rather than 0. Further investigation indicates that
1429 computing a minimum subject length in the presence of *ACCEPT is difficult
1430 (think back references, subroutine calls), and so I have changed the code
1431 so that no minimum is registered for a pattern that contains *ACCEPT.
1432
1433 8. If (*THEN) was present in the first (true) branch of a conditional group,
1434 it was not handled as intended. [But see 16 below.]
1435
1436 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1437 Sheri Pierce.
1438
1439 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1440 the first byte in a match must be "a".
1441
1442 11. Change 17 for 8.13 increased the recursion depth for patterns like
1443 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1444 pattern contains any instances of (*THEN). If it does not, the old
1445 optimizations are restored. It would be nice to do this on a per-group
1446 basis, but at the moment that is not feasible.
1447
1448 12. In some environments, the output of pcretest -C is CRLF terminated. This
1449 broke RunTest's code that checks for the link size. A single white space
1450 character after the value is now allowed for.
1451
1452 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1453 For "fr", it uses the Windows-specific input and output files.
1454
1455 14. If (*THEN) appeared in a group that was called recursively or as a
1456 subroutine, it did not work as intended. [But see next item.]
1457
1458 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1459 pattern fragments (but not containing any | characters). If A and B are
1460 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1461 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1462 D. In other words, Perl considers parentheses that do not contain any |
1463 characters to be part of a surrounding alternative, whereas PCRE was
1464 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1465 differently. PCRE now behaves in the same way as Perl, except in the case
1466 of subroutine/recursion calls such as (?1) which have in any case always
1467 been different (but PCRE had them first :-).
1468
1469 16. Related to 15 above: Perl does not treat the | in a conditional group as
1470 creating alternatives. Such a group is treated in the same way as an
1471 ordinary group without any | characters when processing (*THEN). PCRE has
1472 been changed to match Perl's behaviour.
1473
1474 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1475 RunGrepTest script failed.
1476
1477 18. Change 22 for version 13 caused atomic groups to use more stack. This is
1478 inevitable for groups that contain captures, but it can lead to a lot of
1479 stack use in large patterns. The old behaviour has been restored for atomic
1480 groups that do not contain any capturing parentheses.
1481
1482 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1483 suppress the check for a minimum subject length at run time. (If it was
1484 given to pcre_exec() or pcre_dfa_exec() it did work.)
1485
1486 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1487 fail to work when decoding hex characters in data strings in EBCDIC
1488 environments.
1489
1490 21. It appears that in at least one Mac OS environment, the isxdigit() function
1491 is implemented as a macro that evaluates to its argument more than once,
1492 contravening the C 90 Standard (I haven't checked a later standard). There
1493 was an instance in pcretest which caused it to go wrong when processing
1494 \x{...} escapes in subject strings. The has been rewritten to avoid using
1495 things like p++ in the argument of isxdigit().
1496
1497
1498 Version 8.13 16-Aug-2011
1499 ------------------------
1500
1501 1. The Unicode data tables have been updated to Unicode 6.0.0.
1502
1503 2. Two minor typos in pcre_internal.h have been fixed.
1504
1505 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1506 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1507 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1508
1509 4. There were a number of related bugs in the code for matching backrefences
1510 caselessly in UTF-8 mode when codes for the characters concerned were
1511 different numbers of bytes. For example, U+023A and U+2C65 are an upper
1512 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1513 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1514 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1515 2-byte code at the end of the subject (it thought there wasn't enough data
1516 left).
1517
1518 5. Comprehensive information about what went wrong is now returned by
1519 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1520 as the output vector has at least 2 elements. The offset of the start of
1521 the failing character and a reason code are placed in the vector.
1522
1523 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
1524 now returned is for the first byte of the failing character, instead of the
1525 last byte inspected. This is an incompatible change, but I hope it is small
1526 enough not to be a problem. It makes the returned offset consistent with
1527 pcre_exec() and pcre_dfa_exec().
1528
1529 7. pcretest now gives a text phrase as well as the error number when
1530 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1531 failure, the offset and reason code are output.
1532
1533 8. When \R was used with a maximizing quantifier it failed to skip backwards
1534 over a \r\n pair if the subsequent match failed. Instead, it just skipped
1535 back over a single character (\n). This seems wrong (because it treated the
1536 two characters as a single entity when going forwards), conflicts with the
1537 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1538 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1539 has been changed.
1540
1541 9. Some internal refactoring has changed the processing so that the handling
1542 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1543 time (the PCRE_DOTALL option was changed this way some time ago: version
1544 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1545 which was always a bit of a fudge. It also means that there is one less
1546 argument for the match() function, which reduces its stack requirements
1547 slightly. This change also fixes an incompatibility with Perl: the pattern
1548 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1549
1550 10. More internal refactoring has drastically reduced the number of recursive
1551 calls to match() for possessively repeated groups such as (abc)++ when
1552 using pcre_exec().
1553
1554 11. While implementing 10, a number of bugs in the handling of groups were
1555 discovered and fixed:
1556
1557 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1558 (a|)*(?1) gave a compile-time internal error.
1559 ((a|)+)+ did not notice that the outer group could match an empty string.
1560 (^a|^)+ was not marked as anchored.
1561 (.*a|.*)+ was not marked as matching at start or after a newline.
1562
1563 12. Yet more internal refactoring has removed another argument from the match()
1564 function. Special calls to this function are now indicated by setting a
1565 value in a variable in the "match data" data block.
1566
1567 13. Be more explicit in pcre_study() instead of relying on "default" for
1568 opcodes that mean there is no starting character; this means that when new
1569 ones are added and accidentally left out of pcre_study(), testing should
1570 pick them up.
1571
1572 14. The -s option of pcretest has been documented for ages as being an old
1573 synonym of -m (show memory usage). I have changed it to mean "force study
1574 for every regex", that is, assume /S for every regex. This is similar to -i
1575 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1576 using it. It makes it easier to run collections of tests with and without
1577 study enabled, and thereby test pcre_study() more easily. All the standard
1578 tests are now run with and without -s (but some patterns can be marked as
1579 "never study" - see 20 below).
1580
1581 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1582 restoration of the capturing data to the outer values was not happening
1583 correctly.
1584
1585 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1586 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1587 pattern had matched an empty string, and so incorrectly returned a no
1588 match.
1589
1590 17. There was optimizing code for the last branch of non-capturing parentheses,
1591 and also for the obeyed branch of a conditional subexpression, which used
1592 tail recursion to cut down on stack usage. Unfortunately, now that there is
1593 the possibility of (*THEN) occurring in these branches, tail recursion is
1594 no longer possible because the return has to be checked for (*THEN). These
1595 two optimizations have therefore been removed. [But see 8.20/11 above.]
1596
1597 18. If a pattern containing \R was studied, it was assumed that \R always
1598 matched two bytes, thus causing the minimum subject length to be
1599 incorrectly computed because \R can also match just one byte.
1600
1601 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1602 was incorrectly computed.
1603
1604 20. If /S is present twice on a test pattern in pcretest input, it now
1605 *disables* studying, thereby overriding the use of -s on the command line
1606 (see 14 above). This is necessary for one or two tests to keep the output
1607 identical in both cases.
1608
1609 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1610 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1611
1612 22. When an atomic group that contained a capturing parenthesis was
1613 successfully matched, but the branch in which it appeared failed, the
1614 capturing was not being forgotten if a higher numbered group was later
1615 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1616 group 1 to "a", when in fact it should be unset. This applied to multi-
1617 branched capturing and non-capturing groups, repeated or not, and also to
1618 positive assertions (capturing in negative assertions does not happen
1619 in PCRE) and also to nested atomic groups.
1620
1621 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1622 subject after a captured substring, to make it easier to tell which of a
1623 number of identical substrings has been captured.
1624
1625 24. The way atomic groups are processed by pcre_exec() has been changed so that
1626 if they are repeated, backtracking one repetition now resets captured
1627 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1628 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1629 "aaa". Previously, it would have been "a". As part of this code
1630 refactoring, the way recursive calls are handled has also been changed.
1631
1632 25. If an assertion condition captured any substrings, they were not passed
1633 back unless some other capturing happened later. For example, if
1634 (?(?=(a))a) was matched against "a", no capturing was returned.
1635
1636 26. When studying a pattern that contained subroutine calls or assertions,
1637 the code for finding the minimum length of a possible match was handling
1638 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1639 group 1 called group 2 while simultaneously a separate group 2 called group
1640 1). A stack overflow occurred in this case. I have fixed this by limiting
1641 the recursion depth to 10.
1642
1643 27. Updated RunTest.bat in the distribution to the version supplied by Tom
1644 Fortmann. This supports explicit test numbers on the command line, and has
1645 argument validation and error reporting.
1646
1647 28. An instance of \X with an unlimited repeat could fail if at any point the
1648 first character it looked at was a mark character.
1649
1650 29. Some minor code refactoring concerning Unicode properties and scripts
1651 should reduce the stack requirement of match() slightly.
1652
1653 30. Added the '=' option to pcretest to check the setting of unused capturing
1654 slots at the end of the pattern, which are documented as being -1, but are
1655 not included in the return count.
1656
1657 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1658 compiled something random. Now it gives a compile-time error (as does
1659 Perl).
1660
1661 32. A *MARK encountered during the processing of a positive assertion is now
1662 recorded and passed back (compatible with Perl).
1663
1664 33. If --only-matching or --colour was set on a pcregrep call whose pattern
1665 had alternative anchored branches, the search for a second match in a line
1666 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1667 matched the line "0102" twice. The same bug affected patterns that started
1668 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1669 twice.
1670
1671 34. Previously, PCRE did not allow quantification of assertions. However, Perl
1672 does, and because of capturing effects, quantifying parenthesized
1673 assertions may at times be useful. Quantifiers are now allowed for
1674 parenthesized assertions.
1675
1676 35. A minor code tidy in pcre_compile() when checking options for \R usage.
1677
1678 36. \g was being checked for fancy things in a character class, when it should
1679 just be a literal "g".
1680
1681 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1682 appearance of a nested POSIX class supersedes an apparent external class.
1683 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1684 unescaped square brackets may also appear as part of class names. For
1685 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1686 more like Perl. (But see 8.20/1 above.)
1687
1688 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1689 was because it thought it was \N{name}, which is not supported).
1690
1691 39. Add minix to OS list not supporting the -S option in pcretest.
1692
1693 40. PCRE tries to detect cases of infinite recursion at compile time, but it
1694 cannot analyze patterns in sufficient detail to catch mutual recursions
1695 such as ((?1))((?2)). There is now a runtime test that gives an error if a
1696 subgroup is called recursively as a subpattern for a second time at the
1697 same position in the subject string. In previous releases this might have
1698 been caught by the recursion limit, or it might have run out of stack.
1699
1700 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1701 happen only once. PCRE was, however incorrectly giving a compile time error
1702 "recursive call could loop indefinitely" because it cannot analyze the
1703 pattern in sufficient detail. The compile time test no longer happens when
1704 PCRE is compiling a conditional subpattern, but actual runaway loops are
1705 now caught at runtime (see 40 above).
1706
1707 42. It seems that Perl allows any characters other than a closing parenthesis
1708 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1709 has been changed to be the same.
1710
1711 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1712 as not to get warnings when autogen.sh is called. Also changed
1713 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1714
1715 44. To help people who use pcregrep to scan files containing exceedingly long
1716 lines, the following changes have been made:
1717
1718 (a) The default value of the buffer size parameter has been increased from
1719 8K to 20K. (The actual buffer used is three times this size.)
1720
1721 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1722 PCRE is built.
1723
1724 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1725 to be set at run time.
1726
1727 (d) Numerical values in pcregrep options can be followed by K or M, for
1728 example --buffer-size=50K.
1729
1730 (e) If a line being scanned overflows pcregrep's buffer, an error is now
1731 given and the return code is set to 2.
1732
1733 45. Add a pointer to the latest mark to the callout data block.
1734
1735 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1736 partial match of an empty string instead of no match. This was specific to
1737 the use of ".".
1738
1739 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1740 complete match instead of a partial match. This bug was dependent on both
1741 the PCRE_UTF8 and PCRE_DOTALL options being set.
1742
1743 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1744 starting byte set, because \b was not being ignored.
1745
1746
1747 Version 8.12 15-Jan-2011
1748 ------------------------
1749
1750 1. Fixed some typos in the markup of the man pages, and wrote a script that
1751 checks for such things as part of the documentation building process.
1752
1753 2. On a big-endian 64-bit system, pcregrep did not correctly process the
1754 --match-limit and --recursion-limit options (added for 8.11). In
1755 particular, this made one of the standard tests fail. (The integer value
1756 went into the wrong half of a long int.)
1757
1758 3. If the --colour option was given to pcregrep with -v (invert match), it
1759 did strange things, either producing crazy output, or crashing. It should,
1760 of course, ignore a request for colour when reporting lines that do not
1761 match.
1762
1763 4. Another pcregrep bug caused similar problems if --colour was specified with
1764 -M (multiline) and the pattern match finished with a line ending.
1765
1766 5. In pcregrep, when a pattern that ended with a literal newline sequence was
1767 matched in multiline mode, the following line was shown as part of the
1768 match. This seems wrong, so I have changed it.
1769
1770 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
1771 the check for further matches in the same line (so they could be coloured)
1772 to overrun the end of the current line. If another match was found, it was
1773 incorrectly shown (and then shown again when found in the next line).
1774
1775 7. If pcregrep was compiled under Windows, there was a reference to the
1776 function pcregrep_exit() before it was defined. I am assuming this was
1777 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1778 reported by a user. I've moved the definition above the reference.
1779
1780
1781 Version 8.11 10-Dec-2010
1782 ------------------------
1783
1784 1. (*THEN) was not working properly if there were untried alternatives prior
1785 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1786 backtracked to try for "b" instead of moving to the next alternative branch
1787 at the same level (in this case, to look for "c"). The Perl documentation
1788 is clear that when (*THEN) is backtracked onto, it goes to the "next
1789 alternative in the innermost enclosing group".
1790
1791 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1792 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
1793 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1794 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1795 (*THEN).
1796
1797 3. If \s appeared in a character class, it removed the VT character from
1798 the class, even if it had been included by some previous item, for example
1799 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1800 of \s, but is part of the POSIX "space" class.)
1801
1802 4. A partial match never returns an empty string (because you can always
1803 match an empty string at the end of the subject); however the checking for
1804 an empty string was starting at the "start of match" point. This has been
1805 changed to the "earliest inspected character" point, because the returned
1806 data for a partial match starts at this character. This means that, for
1807 example, /(?<=abc)def/ gives a partial match for the subject "abc"
1808 (previously it gave "no match").
1809
1810 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1811 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1812 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1813 has an implication that the given string is incomplete (because a partial
1814 match is preferred over a full match). For this reason, these items now
1815 give a partial match in this situation. [Aside: previously, the one case
1816 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1817 match rather than a full match, which was wrong by the old rules, but is
1818 now correct.]
1819
1820 6. There was a bug in the handling of #-introduced comments, recognized when
1821 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1822 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1823 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1824 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1825 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1826 places in pcre_compile().
1827
1828 7. Related to (6) above, when pcre_compile() was skipping #-introduced
1829 comments when looking ahead for named forward references to subpatterns,
1830 the only newline sequence it recognized was NL. It now handles newlines
1831 according to the set newline convention.
1832
1833 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1834 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1835 cater for a lack of strerror(). These oversights have been fixed.
1836
1837 9. Added --match-limit and --recursion-limit to pcregrep.
1838
1839 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1840
1841 11. When the -o option was used, pcregrep was setting a return code of 1, even
1842 when matches were found, and --line-buffered was not being honoured.
1843
1844 12. Added an optional parentheses number to the -o and --only-matching options
1845 of pcregrep.
1846
1847 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1848 can match an empty string. The code to do it in pcretest and pcredemo
1849 needed fixing:
1850
1851 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1852 only one byte after an empty string match just before CRLF (this case
1853 just got forgotten; "any" and "anycrlf" were OK).
1854
1855 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1856 mode when an empty string match preceded an ASCII character followed by
1857 a non-ASCII character. (The code for advancing by one character rather
1858 than one byte was nonsense.)
1859
1860 (c) The pcredemo.c sample program did not have any code at all to handle
1861 the cases when CRLF is a valid newline sequence.
1862
1863 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1864 as a starting offset was within the subject string. There is now a new
1865 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1866 negative or greater than the length of the string. In order to test this,
1867 pcretest is extended to allow the setting of negative starting offsets.
1868
1869 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1870 starting offset points to the beginning of a UTF-8 character was
1871 unnecessarily clumsy. I tidied it up.
1872
1873 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1874 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1875
1876 17. Nobody had reported that the --include_dir option, which was added in
1877 release 7.7 should have been called --include-dir (hyphen, not underscore)
1878 for compatibility with GNU grep. I have changed it to --include-dir, but
1879 left --include_dir as an undocumented synonym, and the same for
1880 --exclude-dir, though that is not available in GNU grep, at least as of
1881 release 2.5.4.
1882
1883 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1884 characters from a string of bytes) have been redefined so as not to use
1885 loops, in order to improve performance in some environments. At the same
1886 time, I abstracted some of the common code into auxiliary macros to save
1887 repetition (this should not affect the compiled code).
1888
1889 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1890 compile-time error is now given if \c is not followed by an ASCII
1891 character, that is, a byte less than 128. (In EBCDIC mode, the code is
1892 different, and any byte value is allowed.)
1893
1894 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1895 START_OPTIMIZE option, which is now allowed at compile time - but just
1896 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1897 to pcregrep and other applications that have no direct access to PCRE
1898 options. The new /Y option in pcretest sets this option when calling
1899 pcre_compile().
1900
1901 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1902 back references. Groups containing recursive back references were forced to
1903 be atomic by that change, but in the case of named groups, the amount of
1904 memory required was incorrectly computed, leading to "Failed: internal
1905 error: code overflow". This has been fixed.
1906
1907 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1908 pcretest.c, to avoid build problems in some Borland environments.
1909
1910
1911 Version 8.10 25-Jun-2010
1912 ------------------------
1913
1914 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1915 THEN.
1916
1917 2. (*ACCEPT) was not working when inside an atomic group.
1918
1919 3. Inside a character class, \B is treated as a literal by default, but
1920 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1921 causes the error). The code is unchanged, but I tidied the documentation.
1922
1923 4. Inside a character class, PCRE always treated \R and \X as literals,
1924 whereas Perl faults them if its -w option is set. I have changed PCRE so
1925 that it faults them when PCRE_EXTRA is set.
1926
1927 5. Added support for \N, which always matches any character other than
1928 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1929
1930 6. When compiling pcregrep with newer versions of gcc which may have
1931 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1932 declared with attribute warn_unused_result" were given. Just casting the
1933 result to (void) does not stop the warnings; a more elaborate fudge is
1934 needed. I've used a macro to implement this.
1935
1936 7. Minor change to pcretest.c to avoid a compiler warning.
1937
1938 8. Added four artifical Unicode properties to help with an option to make
1939 \s etc use properties (see next item). The new properties are: Xan
1940 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1941
1942 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1943 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1944 this option. Modified pcretest to add /W to test this facility. Added
1945 REG_UCP to make it available via the POSIX interface.
1946
1947 10. Added --line-buffered to pcregrep.
1948
1949 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1950 studied, and the match started with a letter with a code point greater than
1951 127 whose first byte was different to the first byte of the other case of
1952 the letter, the other case of this starting letter was not recognized
1953 (#976).
1954
1955 12. If a pattern that was studied started with a repeated Unicode property
1956 test, for example, \p{Nd}+, there was the theoretical possibility of
1957 setting up an incorrect bitmap of starting bytes, but fortunately it could
1958 not have actually happened in practice until change 8 above was made (it
1959 added property types that matched character-matching opcodes).
1960
1961 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1962 possible starting bytes for non-anchored patterns.
1963
1964 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1965 \R, and also a number of cases that involve Unicode properties, both
1966 explicit and implicit when PCRE_UCP is set.
1967
1968 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1969 input, it could crash or give wrong results if characters with values
1970 greater than 0xc0 were present in the subject string. (Detail: it assumed
1971 UTF-8 input when processing these items.)
1972
1973 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1974 size_t is 64-bit (#991).
1975
1976 17. Added a check for running out of memory when PCRE is compiled with
1977 --disable-stack-for-recursion (#990).
1978
1979 18. If the last data line in a file for pcretest does not have a newline on
1980 the end, a newline was missing in the output.
1981
1982 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1983 less than 128) in its various bitmaps. However, there is a facility for
1984 generating tables according to the current locale when PCRE is compiled. It
1985 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1986 characters, are recognized by isspace() and therefore were getting set in
1987 these tables, and indeed these tables seem to approximate to ISO 8859. This
1988 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1989 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1990 which of course cannot start UTF-8 characters. I have changed the code so
1991 that only real ASCII characters (less than 128) and the correct starting
1992 bytes for UTF-8 encodings are set for characters greater than 127 when in
1993 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1994 altogether.)
1995
1996 20. Added the /T option to pcretest so as to be able to run tests with non-
1997 standard character tables, thus making it possible to include the tests
1998 used for 19 above in the standard set of tests.
1999
2000 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
2001 reference to a subpattern the other side of a comment that contains an
2002 opening parenthesis caused either an internal compiling error, or a
2003 reference to the wrong subpattern.
2004
2005
2006 Version 8.02 19-Mar-2010
2007 ------------------------
2008
2009 1. The Unicode data tables have been updated to Unicode 5.2.0.
2010
2011 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
2012 configured.
2013
2014 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
2015 original author of that file, following a query about its status.
2016
2017 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
2018 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
2019
2020 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
2021 quantifier applied to a forward-referencing subroutine call, could compile
2022 incorrect code or give the error "internal error: previously-checked
2023 referenced subpattern not found".
2024
2025 6. Both MS Visual Studio and Symbian OS have problems with initializing
2026 variables to point to external functions. For these systems, therefore,
2027 pcre_malloc etc. are now initialized to local functions that call the
2028 relevant global functions.
2029
2030 7. There were two entries missing in the vectors called coptable and poptable
2031 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
2032 I've fixed the data, and added a kludgy way of testing at compile time that
2033 the lengths are correct (equal to the number of opcodes).
2034
2035 8. Following on from 7, I added a similar kludge to check the length of the
2036 eint vector in pcreposix.c.
2037
2038 9. Error texts for pcre_compile() are held as one long string to avoid too
2039 much relocation at load time. To find a text, the string is searched,
2040 counting zeros. There was no check for running off the end of the string,
2041 which could happen if a new error number was added without updating the
2042 string.
2043
2044 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
2045
2046 11. \K was not working if it appeared in an atomic group or in a group that
2047 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
2048 \K is "not well defined" if used in an assertion. PCRE now accepts it if
2049 the assertion is positive, but not if it is negative.
2050
2051 12. Change 11 fortuitously reduced the size of the stack frame used in the
2052 "match()" function of pcre_exec.c by one pointer. Forthcoming
2053 implementation of support for (*MARK) will need an extra pointer on the
2054 stack; I have reserved it now, so that the stack frame size does not
2055 decrease.
2056
2057 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
2058 item in branch that calls a recursion is a subroutine call - as in the
2059 second branch in the above example - was incorrectly given the compile-
2060 time error "recursive call could loop indefinitely" because pcre_compile()
2061 was not correctly checking the subroutine for matching a non-empty string.
2062
2063 14. The checks for overrunning compiling workspace could trigger after an
2064 overrun had occurred. This is a "should never occur" error, but it can be
2065 triggered by pathological patterns such as hundreds of nested parentheses.
2066 The checks now trigger 100 bytes before the end of the workspace.
2067
2068 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
2069
2070
2071 Version 8.01 19-Jan-2010
2072 ------------------------
2073
2074 1. If a pattern contained a conditional subpattern with only one branch (in
2075 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
2076 computed the wrong minimum data length (which is of course zero for such
2077 subpatterns). This could cause incorrect "no match" results.
2078
2079 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
2080 the pattern is reset in the first branch, pcre_compile() failed with
2081 "internal error: code overflow at offset...". This happened only when
2082 the reset was to the original external option setting. (An optimization
2083 abstracts leading options settings into an external setting, which was the
2084 cause of this.)
2085
2086 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
2087 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
2088 assertion pattern did not match (meaning that the assertion was true), it
2089 was incorrectly treated as false if the SKIP had been reached during the
2090 matching. This also applied to assertions used as conditions.
2091
2092 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
2093 assertion subpattern, including such a pattern used as a condition,
2094 unpredictable results occurred, instead of the error return
2095 PCRE_ERROR_DFA_UITEM.
2096
2097 5. The C++ GlobalReplace function was not working like Perl for the special
2098 situation when an empty string is matched. It now does the fancy magic
2099 stuff that is necessary.
2100
2101 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
2102 removed. (These were left over from very, very early versions of PCRE.)
2103
2104 7. Some cosmetic changes to the code to make life easier when compiling it
2105 as part of something else:
2106
2107 (a) Change DEBUG to PCRE_DEBUG.
2108
2109 (b) In pcre_compile(), rename the member of the "branch_chain" structure
2110 called "current" as "current_branch", to prevent a collision with the
2111 Linux macro when compiled as a kernel module.
2112
2113 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
2114 prevent a collision with the Linux macro when compiled as a kernel
2115 module.
2116
2117 8. In pcre_compile() there are some checks for integer overflows that used to
2118 cast potentially large values to (double). This has been changed to that
2119 when building, a check for int64_t is made, and if it is found, it is used
2120 instead, thus avoiding the use of floating point arithmetic. (There is no
2121 other use of FP in PCRE.) If int64_t is not found, the fallback is to
2122 double.
2123
2124 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
2125 2005 (difference between two addresses compared to an unsigned value).
2126
2127 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
2128 custom one, because of the following reported problem in Windows:
2129
2130 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
2131 under Win32.
2132 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
2133 therefore missing the function definition.
2134 - The compiler thus generates a "C" signature for the test function.
2135 - The linker fails to find the "C" function.
2136 - PCRE fails to configure if asked to do so against libbz2.
2137
2138 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
2139 messages were output:
2140
2141 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
2142 rerunning libtoolize, to keep the correct libtool macros in-tree.
2143 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
2144
2145 I have done both of these things.
2146
2147 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
2148 most of the time, it *can* run out if it is given a pattern that contains a
2149 runaway infinite recursion. I updated the discussion in the pcrestack man
2150 page.
2151
2152 13. Now that we have gone to the x.xx style of version numbers, the minor
2153 version may start with zero. Using 08 or 09 is a bad idea because users
2154 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
2155 interpreted as invalid octal numbers. I've updated the previous comment in
2156 configure.ac, and also added a check that gives an error if 08 or 09 are
2157 used.
2158
2159 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
2160 causing partial matching to fail when the end of the subject matched \W
2161 in a UTF-8 pattern where \W was quantified with a minimum of 3.
2162
2163 15. There were some discrepancies between the declarations in pcre_internal.h
2164 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
2165 their definitions. The declarations used "const uschar *" and the
2166 definitions used USPTR. Even though USPTR is normally defined as "const
2167 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
2168 reported that: "This difference in casting confuses some C++ compilers, for
2169 example, SunCC recognizes above declarations as different functions and
2170 generates broken code for hbpcre." I have changed the declarations to use
2171 USPTR.
2172
2173 16. GNU libtool is named differently on some systems. The autogen.sh script now
2174 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
2175 (FreeBSD).
2176
2177 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
2178 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
2179 comment: "Figure out how to create a longlong from a string: strtoll and
2180 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
2181 instance, but it only takes 2 args instead of 3!"
2182
2183 18. A subtle bug concerned with back references has been fixed by a change of
2184 specification, with a corresponding code fix. A pattern such as
2185 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
2186 refers, was giving matches when it shouldn't. For example, xa=xaaa would
2187 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
2188 same bug. Such groups have to be quantified to be useful, or contained
2189 inside another quantified group. (If there's no repetition, the reference
2190 can never match.) The problem arises because, having left the group and
2191 moved on to the rest of the pattern, a later failure that backtracks into
2192 the group uses the captured value from the final iteration of the group
2193 rather than the correct earlier one. I have fixed this in PCRE by forcing
2194 any group that contains a reference to itself to be an atomic group; that
2195 is, there cannot be any backtracking into it once it has completed. This is
2196 similar to recursive and subroutine calls.
2197
2198
2199 Version 8.00 19-Oct-09
2200 ----------------------
2201
2202 1. The table for translating pcre_compile() error codes into POSIX error codes
2203 was out-of-date, and there was no check on the pcre_compile() error code
2204 being within the table. This could lead to an OK return being given in
2205 error.
2206
2207 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
2208 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
2209 in a Windows environment.
2210
2211 3. The pcregrep --count option prints the count for each file even when it is
2212 zero, as does GNU grep. However, pcregrep was also printing all files when
2213 --files-with-matches was added. Now, when both options are given, it prints
2214 counts only for those files that have at least one match. (GNU grep just
2215 prints the file name in this circumstance, but including the count seems
2216 more useful - otherwise, why use --count?) Also ensured that the
2217 combination -clh just lists non-zero counts, with no names.
2218
2219 4. The long form of the pcregrep -F option was incorrectly implemented as
2220 --fixed_strings instead of --fixed-strings. This is an incompatible change,
2221 but it seems right to fix it, and I didn't think it was worth preserving
2222 the old behaviour.
2223
2224 5. The command line items --regex=pattern and --regexp=pattern were not
2225 recognized by pcregrep, which required --regex pattern or --regexp pattern
2226 (with a space rather than an '='). The man page documented the '=' forms,
2227 which are compatible with GNU grep; these now work.
2228
2229 6. No libpcreposix.pc file was created for pkg-config; there was just
2230 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
2231
2232 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
2233 when UCP support is not needed, by modifying the Python script that
2234 generates it from Unicode data files. This should not matter if the module
2235 is correctly used as a library, but I received one complaint about 50K of
2236 unwanted data. My guess is that the person linked everything into his
2237 program rather than using a library. Anyway, it does no harm.
2238
2239 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
2240 was a minimum greater than 1 for a wide character in a possessive
2241 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
2242 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
2243 character. Chaos in the form of incorrect output or a compiling loop could
2244 result.
2245
2246 9. The restrictions on what a pattern can contain when partial matching is
2247 requested for pcre_exec() have been removed. All patterns can now be
2248 partially matched by this function. In addition, if there are at least two
2249 slots in the offset vector, the offset of the earliest inspected character
2250 for the match and the offset of the end of the subject are set in them when
2251 PCRE_ERROR_PARTIAL is returned.
2252
2253 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
2254 synonymous with PCRE_PARTIAL, for backwards compatibility, and
2255 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
2256 and may be more useful for multi-segment matching.
2257
2258 11. Partial matching with pcre_exec() is now more intuitive. A partial match
2259 used to be given if ever the end of the subject was reached; now it is
2260 given only if matching could not proceed because another character was
2261 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
2262 string "Z", which now yields "no match" instead of "partial match". In the
2263 case of pcre_dfa_exec(), "no match" is given if every matching path for the
2264 final character ended with (*FAIL).
2265
2266 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
2267 if the pattern had a "must contain" character that was already found in the
2268 earlier partial match, unless partial matching was again requested. For
2269 example, with the pattern /dog.(body)?/, the "must contain" character is
2270 "g". If the first part-match was for the string "dog", restarting with
2271 "sbody" failed. This bug has been fixed.
2272
2273 13. The string returned by pcre_dfa_exec() after a partial match has been
2274 changed so that it starts at the first inspected character rather than the
2275 first character of the match. This makes a difference only if the pattern
2276 starts with a lookbehind assertion or \b or \B (\K is not supported by
2277 pcre_dfa_exec()). It's an incompatible change, but it makes the two
2278 matching functions compatible, and I think it's the right thing to do.
2279
2280 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
2281 so that the demonstration program is easily available in environments where
2282 PCRE has not been installed from source.
2283
2284 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
2285 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
2286 library.
2287
2288 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
2289 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
2290 is not the first non-POSIX option to be added. Clearly some people find
2291 these options useful.
2292
2293 17. If a caller to the POSIX matching function regexec() passes a non-zero
2294 value for nmatch with a NULL value for pmatch, the value of
2295 nmatch is forced to zero.
2296
2297 18. RunGrepTest did not have a test for the availability of the -u option of
2298 the diff command, as RunTest does. It now checks in the same way as
2299 RunTest, and also checks for the -b option.
2300
2301 19. If an odd number of negated classes containing just a single character
2302 interposed, within parentheses, between a forward reference to a named
2303 subpattern and the definition of the subpattern, compilation crashed with
2304 an internal error, complaining that it could not find the referenced
2305 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
2306 [The bug was that it was starting one character too far in when skipping
2307 over the character class, thus treating the ] as data rather than
2308 terminating the class. This meant it could skip too much.]
2309
2310 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
2311 /g option in pcretest when the pattern contains \K, which makes it possible
2312 to have an empty string match not at the start, even when the pattern is
2313 anchored. Updated pcretest and pcredemo to use this option.
2314
2315 21. If the maximum number of capturing subpatterns in a recursion was greater
2316 than the maximum at the outer level, the higher number was returned, but
2317 with unset values at the outer level. The correct (outer level) value is
2318 now given.
2319
2320 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
2321 PCRE did not set those parentheses (unlike Perl). I have now found a way to
2322 make it do so. The string so far is captured, making this feature
2323 compatible with Perl.
2324
2325 23. The tests have been re-organized, adding tests 11 and 12, to make it
2326 possible to check the Perl 5.10 features against Perl 5.10.
2327
2328 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
2329 pattern matches a fixed length string. PCRE did not allow this; now it
2330 does. Neither allows recursion.
2331
2332 25. I finally figured out how to implement a request to provide the minimum
2333 length of subject string that was needed in order to match a given pattern.
2334 (It was back references and recursion that I had previously got hung up
2335 on.) This code has now been added to pcre_study(); it finds a lower bound
2336 to the length of subject needed. It is not necessarily the greatest lower
2337 bound, but using it to avoid searching strings that are too short does give
2338 some useful speed-ups. The value is available to calling programs via
2339 pcre_fullinfo().
2340
2341 26. While implementing 25, I discovered to my embarrassment that pcretest had
2342 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
2343 study optimizations had never been tested with that matching function.
2344 Oops. What is worse, even when it was passed study data, there was a bug in
2345 pcre_dfa_exec() that meant it never actually used it. Double oops. There
2346 were also very few tests of studied patterns with pcre_dfa_exec().
2347
2348 27. If (?| is used to create subpatterns with duplicate numbers, they are now
2349 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
2350 on the other side of the coin, they are no longer allowed to have different
2351 names, because these cannot be distinguished in PCRE, and this has caused
2352 confusion. (This is a difference from Perl.)
2353
2354 28. When duplicate subpattern names are present (necessarily with different
2355 numbers, as required by 27 above), and a test is made by name in a
2356 conditional pattern, either for a subpattern having been matched, or for
2357 recursion in such a pattern, all the associated numbered subpatterns are
2358 tested, and the overall condition is true if the condition is true for any
2359 one of them. This is the way Perl works, and is also more like the way
2360 testing by number works.
2361
2362
2363 Version 7.9 11-Apr-09
2364 ---------------------
2365
2366 1. When building with support for bzlib/zlib (pcregrep) and/or readline
2367 (pcretest), all targets were linked against these libraries. This included
2368 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
2369 libraries. This caused unwanted dependencies to be created. This problem
2370 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
2371 pcretest is linked with readline.
2372
2373 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
2374 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
2375 moved outside it again, because FALSE and TRUE are already defined in AIX,
2376 but BOOL is not.
2377
2378 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
2379 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
2380
2381 4. The pcregrep documentation said spaces were inserted as well as colons (or
2382 hyphens) following file names and line numbers when outputting matching
2383 lines. This is not true; no spaces are inserted. I have also clarified the
2384 wording for the --colour (or --color) option.
2385
2386 5. In pcregrep, when --colour was used with -o, the list of matching strings
2387 was not coloured; this is different to GNU grep, so I have changed it to be
2388 the same.
2389
2390 6. When --colo(u)r was used in pcregrep, only the first matching substring in
2391 each matching line was coloured. Now it goes on to look for further matches
2392 of any of the test patterns, which is the same behaviour as GNU grep.
2393
2394 7. A pattern that could match an empty string could cause pcregrep to loop; it
2395 doesn't make sense to accept an empty string match in pcregrep, so I have
2396 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2397 seems to be how GNU grep behaves. [But see later change 40 for release
2398 8.33.]
2399
2400 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2401 start or after a newline", because the conditional assertion was not being
2402 correctly handled. The rule now is that both the assertion and what follows
2403 in the first alternative must satisfy the test.
2404
2405 9. If auto-callout was enabled in a pattern with a conditional group whose
2406 condition was an assertion, PCRE could crash during matching, both with
2407 pcre_exec() and pcre_dfa_exec().
2408
2409 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
2410 used for matching.
2411
2412 11. Unicode property support in character classes was not working for
2413 characters (bytes) greater than 127 when not in UTF-8 mode.
2414
2415 12. Added the -M command line option to pcretest.
2416
2417 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
2418
2419 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
2420
2421 16. Added comments and documentation about mis-use of no_arg in the C++
2422 wrapper.
2423
2424 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
2425 from Martin Jerabek that uses macro names for all relevant character and
2426 string constants.
2427
2428 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
2429 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
2430 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
2431 these, but not everybody uses configure.
2432
2433 19. A conditional group that had only one branch was not being correctly
2434 recognized as an item that could match an empty string. This meant that an
2435 enclosing group might also not be so recognized, causing infinite looping
2436 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
2437 with the subject "ab", where knowledge that the repeated group can match
2438 nothing is needed in order to break the loop.
2439
2440 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
2441 exec(), but without supplying a callout function, matching went wrong.
2442
2443 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
2444 leak if the size of the offset vector was greater than 30. When the vector
2445 is smaller, the saved offsets during recursion go onto a local stack
2446 vector, but for larger vectors malloc() is used. It was failing to free
2447 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
2448 error, in fact).
2449
2450 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
2451 heapframe that is used only when UTF-8 support is enabled. This caused no
2452 problem, but was untidy.
2453
2454 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
2455 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
2456 included within another project.
2457
2458 24. Steven Van Ingelgem's patches to add more options to the CMake support,
2459 slightly modified by me:
2460
2461 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
2462 not building pcregrep.
2463
2464 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
2465 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
2466
2467 25. Forward references, both numeric and by name, in patterns that made use of
2468 duplicate group numbers, could behave incorrectly or give incorrect errors,
2469 because when scanning forward to find the reference group, PCRE was not
2470 taking into account the duplicate group numbers. A pattern such as
2471 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
2472
2473 26. Changed a few more instances of "const unsigned char *" to USPTR, making
2474 the feature of a custom pointer more persuasive (as requested by a user).
2475
2476 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
2477 pcretest.c, inside #ifndefs, because it seems they are sometimes already
2478 pre-defined.
2479
2480 28. Added support for (*UTF8) at the start of a pattern.
2481
2482 29. Arrange for flags added by the "release type" setting in CMake to be shown
2483 in the configuration summary.
2484
2485
2486 Version 7.8 05-Sep-08
2487 ---------------------
2488
2489 1. Replaced UCP searching code with optimized version as implemented for Ad
2490 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
2491 stage table and inline lookup instead of a function, giving speed ups of 2
2492 to 5 times on some simple patterns that I tested. Permission was given to
2493 distribute the MultiStage2.py script that generates the tables (it's not in
2494 the tarball, but is in the Subversion repository).
2495
2496 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
2497 scripts.
2498
2499 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
2500 a group with a zero qualifier. The result of the study could be incorrect,
2501 or the function might crash, depending on the pattern.
2502
2503 4. Caseless matching was not working for non-ASCII characters in back
2504 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2505 It now works when Unicode Property Support is available.
2506
2507 5. In pcretest, an escape such as \x{de} in the data was always generating
2508 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2509 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2510 truncation.
2511
2512 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2513
2514 7. Added two (int) casts to pcregrep when printing the difference of two
2515 pointers, in case they are 64-bit values.
2516
2517 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
2518 test 2 if it fails.
2519
2520 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2521 and a #define of that name to empty if it is not externally set. This is to
2522 allow users of MSVC to set it if necessary.
2523
2524 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2525 the convenience functions in the pcre_get.c source file.
2526
2527 11. An option change at the start of a pattern that had top-level alternatives
2528 could cause overwriting and/or a crash. This command provoked a crash in
2529 some environments:
2530
2531 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2532
2533 This potential security problem was recorded as CVE-2008-2371.
2534
2535 12. For a pattern where the match had to start at the beginning or immediately
2536 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2537 pcre_dfa_exec() could read past the end of the passed subject if there was
2538 no match. To help with detecting such bugs (e.g. with valgrind), I modified
2539 pcretest so that it places the subject at the end of its malloc-ed buffer.
2540
2541 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2542 exec() might read past the end of the data buffer in UTF-8 mode.
2543
2544 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2545 the data contained the byte 0x85 as part of a UTF-8 character within its
2546 first line. This applied both to normal and DFA matching.
2547
2548 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2549 /^[^d]*?$/8 failed to match "abc".
2550
2551 16. Added a missing copyright notice to pcrecpp_internal.h.
2552
2553 17. Make it more clear in the documentation that values returned from
2554 pcre_exec() in ovector are byte offsets, not character counts.
2555
2556 18. Tidied a few places to stop certain compilers from issuing warnings.
2557
2558 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2559 supplied by Stefan Weber. I made a further small update for 7.8 because
2560 there is a change of source arrangements: the pcre_searchfuncs.c module is
2561 replaced by pcre_ucd.c.
2562
2563
2564 Version 7.7 07-May-08
2565 ---------------------
2566
2567 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2568 a string to a long long, pretend we don't even have a long long." This is
2569 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2570
2571 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2572 pre-7.6 versions, which defined a global no_arg variable instead of putting
2573 it in the RE class. (See also #8 below.)
2574
2575 3. Remove a line of dead code, identified by coverity and reported by Nuno
2576 Lopes.
2577
2578 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2579
2580 (1) The include/exclude patterns were being applied to the whole pathnames
2581 of files, instead of just to the final components.
2582
2583 (2) If there was more than one level of directory, the subdirectories were
2584 skipped unless they satisfied the include/exclude conditions. This is
2585 inconsistent with GNU grep (and could even be seen as contrary to the
2586 pcregrep specification - which I improved to make it absolutely clear).
2587 The action now is always to scan all levels of directory, and just
2588 apply the include/exclude patterns to regular files.
2589
2590 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2591 --exclude_dir in the tests to avoid scanning .svn directories.
2592
2593 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2594 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2595 doesn't support NULs in patterns.
2596
2597 7. Added some missing "const"s to declarations of static tables in
2598 pcre_compile.c and pcre_dfa_exec.c.
2599
2600 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2601 caused by fix #2 above. (Subsequently also a second patch to fix the
2602 first patch. And a third patch - this was a messy problem.)
2603
2604 9. Applied Craig's patch to remove the use of push_back().
2605
2606 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2607 matching function regexec().
2608
2609 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2610 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2611 references. PCRE supports relative numbers with this syntax (I don't think
2612 Oniguruma does).
2613
2614 12. Previously, a group with a zero repeat such as (...){0} was completely
2615 omitted from the compiled regex. However, this means that if the group
2616 was called as a subroutine from elsewhere in the pattern, things went wrong
2617 (an internal error was given). Such groups are now left in the compiled
2618 pattern, with a new opcode that causes them to be skipped at execution
2619 time.
2620
2621 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2622 to the way PCRE behaves:
2623
2624 (a) A lone ] character is dis-allowed (Perl treats it as data).
2625
2626 (b) A back reference to an unmatched subpattern matches an empty string
2627 (Perl fails the current match path).
2628
2629 (c) A data ] in a character class must be notated as \] because if the
2630 first data character in a class is ], it defines an empty class. (In
2631 Perl it is not possible to have an empty class.) The empty class []
2632 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2633 The negative empty class [^] matches any one character, independently
2634 of the DOTALL setting.
2635
2636 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2637 non-existent subpattern following a character class starting with ']' and
2638 containing () gave an internal compiling error instead of "reference to
2639 non-existent subpattern". Fortunately, when the pattern did exist, the
2640 compiled code was correct. (When scanning forwards to check for the
2641 existence of the subpattern, it was treating the data ']' as terminating
2642 the class, so got the count wrong. When actually compiling, the reference
2643 was subsequently set up correctly.)
2644
2645 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2646 it was being rejected as not supported by pcre_dfa_exec(), even though
2647 other assertions are supported. I have made pcre_dfa_exec() support
2648 (*FAIL).
2649
2650 16. The implementation of 13c above involved the invention of a new opcode,
2651 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2652 cannot be changed at match time, I realized I could make a small
2653 improvement to matching performance by compiling OP_ALLANY instead of
2654 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2655 on the OP_ANY path.
2656
2657 17. Compiling pcretest on Windows with readline support failed without the
2658 following two fixes: (1) Make the unistd.h include conditional on
2659 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2660
2661 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2662 ncurses library to be included for pcretest when ReadLine support is
2663 requested, but also to allow for it to be overridden. This patch came from
2664 Daniel Bergström.
2665
2666 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2667 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2668 any errors with the current Unicode tables. Thanks to Peter Kankowski for
2669 spotting this.
2670
2671
2672 Version 7.6 28-Jan-08
2673 ---------------------
2674
2675 1. A character class containing a very large number of characters with
2676 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2677 overflow.
2678
2679 2. Patch to cut out the "long long" test in pcrecpp_unittest when
2680 HAVE_LONG_LONG is not defined.
2681
2682 3. Applied Christian Ehrlicher's patch to update the CMake build files to
2683 bring them up to date and include new features. This patch includes:
2684
2685 - Fixed PH's badly added libz and libbz2 support.
2686 - Fixed a problem with static linking.
2687 - Added pcredemo. [But later removed - see 7 below.]
2688 - Fixed dftables problem and added an option.
2689 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2690 HAVE_LONG_LONG.
2691 - Added readline support for pcretest.
2692 - Added an listing of the option settings after cmake has run.
2693
2694 4. A user submitted a patch to Makefile that makes it easy to create
2695 "pcre.dll" under mingw when using Configure/Make. I added stuff to
2696 Makefile.am that cause it to include this special target, without
2697 affecting anything else. Note that the same mingw target plus all
2698 the other distribution libraries and programs are now supported
2699 when configuring with CMake (see 6 below) instead of with
2700 Configure/Make.
2701
2702 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2703 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2704 exported in the Windows port". It has not yet been confirmed that the patch
2705 solves the problem, but it does no harm.
2706
2707 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2708 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2709 with CMake, and also correct the comment about stack recursion.
2710
2711 7. Remove the automatic building of pcredemo from the ./configure system and
2712 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2713 of a program that users should build themselves after PCRE is installed, so
2714 building it automatically is not really right. What is more, it gave
2715 trouble in some build environments.
2716
2717 8. Further tidies to CMakeLists.txt from Sheri and Christian.
2718
2719
2720 Version 7.5 10-Jan-08
2721 ---------------------
2722
2723 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
2724 values in parens when parsing an RE using the C++ wrapper."
2725
2726 2. Negative specials like \S did not work in character classes in UTF-8 mode.
2727 Characters greater than 255 were excluded from the class instead of being
2728 included.
2729
2730 3. The same bug as (2) above applied to negated POSIX classes such as
2731 [:^space:].
2732
2733 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2734 defined or documented. It seems to have been a typo for PCRE_STATIC, so
2735 I have changed it.
2736
2737 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
2738 first named subpattern) and a construct such as (?&a) would reference the
2739 first named subpattern whose name started with "a" (in other words, the
2740 length check was missing). Both these problems are fixed. "Subpattern name
2741 expected" is now given for (?&) (a zero-length name), and this patch also
2742 makes it give the same error for \k'' (previously it complained that that
2743 was a reference to a non-existent subpattern).
2744
2745 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
2746 this is right because (?- can be followed by option settings as well as by
2747 digits. I have, however, made the messages clearer.
2748
2749 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2750 than the number used in the conditional) now cause a compile-time error.
2751 This is actually not compatible with Perl, which accepts such patterns, but
2752 treats the conditional as always being FALSE (as PCRE used to), but it
2753 seems to me that giving a diagnostic is better.
2754
2755 8. Change "alphameric" to the more common word "alphanumeric" in comments
2756 and messages.
2757
2758 9. Fix two occurrences of "backslash" in comments that should have been
2759 "backspace".
2760
2761 10. Remove two redundant lines of code that can never be obeyed (their function
2762 was moved elsewhere).
2763
2764 11. The program that makes PCRE's Unicode character property table had a bug
2765 which caused it to generate incorrect table entries for sequences of
2766 characters that have the same character type, but are in different scripts.
2767 It amalgamated them into a single range, with the script of the first of
2768 them. In other words, some characters were in the wrong script. There were
2769 thirteen such cases, affecting characters in the following ranges:
2770
2771 U+002b0 - U+002c1
2772 U+0060c - U+0060d
2773 U+0061e - U+00612
2774 U+0064b - U+0065e
2775 U+0074d - U+0076d
2776 U+01800 - U+01805
2777 U+01d00 - U+01d77
2778 U+01d9b - U+01dbf
2779 U+0200b - U+0200f
2780 U+030fc - U+030fe
2781 U+03260 - U+0327f
2782 U+0fb46 - U+0fbb1
2783 U+10450 - U+1049d
2784
2785 12. The -o option (show only the matching part of a line) for pcregrep was not
2786 compatible with GNU grep in that, if there was more than one match in a
2787 line, it showed only the first of them. It now behaves in the same way as
2788 GNU grep.
2789
2790 13. If the -o and -v options were combined for pcregrep, it printed a blank
2791 line for every non-matching line. GNU grep prints nothing, and pcregrep now
2792 does the same. The return code can be used to tell if there were any
2793 non-matching lines.
2794
2795 14. Added --file-offsets and --line-offsets to pcregrep.
2796
2797 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2798 infinitely looping recursion. The bug was that positive lookaheads were not
2799 being skipped when checking for a possible empty match (negative lookaheads
2800 and both kinds of lookbehind were skipped).
2801
2802 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2803 inclusion of <windows.h> to before rather than after the definition of
2804 INVALID_FILE_ATTRIBUTES (patch from David Byron).
2805
2806 17. Specifying a possessive quantifier with a specific limit for a Unicode
2807 character property caused pcre_compile() to compile bad code, which led at
2808 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2809 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2810 caused the error; without that there was no problem.
2811
2812 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2813
2814 19. Added --enable-pcretest-libreadline.
2815
2816 20. In pcrecpp.cc, the variable 'count' was incremented twice in
2817 RE::GlobalReplace(). As a result, the number of replacements returned was
2818 double what it should be. I removed one of the increments, but Craig sent a
2819 later patch that removed the other one (the right fix) and added unit tests
2820 that check the return values (which was not done before).
2821
2822 21. Several CMake things:
2823
2824 (1) Arranged that, when cmake is used on Unix, the libraries end up with
2825 the names libpcre and libpcreposix, not just pcre and pcreposix.
2826
2827 (2) The above change means that pcretest and pcregrep are now correctly
2828 linked with the newly-built libraries, not previously installed ones.
2829
2830 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2831
2832 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2833 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2834 UTF-8 newline character). The key issue is that the pattern starts .*;
2835 this means that the match must be either at the beginning, or after a
2836 newline. The bug was in the code for advancing after a failed match and
2837 checking that the new position followed a newline. It was not taking
2838 account of UTF-8 characters correctly.
2839
2840 23. PCRE was behaving differently from Perl in the way it recognized POSIX
2841 character classes. PCRE was not treating the sequence [:...:] as a
2842 character class unless the ... were all letters. Perl, however, seems to
2843 allow any characters between [: and :], though of course it rejects as
2844 unknown any "names" that contain non-letters, because all the known class
2845 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2846 for example, whereas PCRE did not - it did not recognize a POSIX character
2847 class. This seemed a bit dangerous, so the code has been changed to be
2848 closer to Perl. The behaviour is not identical to Perl, because PCRE will
2849 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2850 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2851 Perl does, and where it didn't before.
2852
2853 24. Rewrite so as to remove the single use of %n from pcregrep because in some
2854 Windows environments %n is disabled by default.
2855
2856
2857 Version 7.4 21-Sep-07
2858 ---------------------
2859
2860 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
2861 means that a class such as [\s] counted as "explicit reference to CR or
2862 LF". That isn't really right - the whole point of the change was to try to
2863 help when there was an actual mention of one of the two characters. So now
2864 the change happens only if \r or \n (or a literal CR or LF) character is
2865 encountered.
2866
2867 2. The 32-bit options word was also used for 6 internal flags, but the numbers
2868 of both had grown to the point where there were only 3 bits left.
2869 Fortunately, there was spare space in the data structure, and so I have
2870 moved the internal flags into a new 16-bit field to free up more option
2871 bits.
2872
2873 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2874 but did not set the internal JCHANGED flag - either of these is enough to
2875 control the way the "get" function works - but the PCRE_INFO_JCHANGED
2876 facility is supposed to tell if (?J) was ever used, so now (?J) at the
2877 start sets both bits.
2878
2879 4. Added options (at build time, compile time, exec time) to change \R from
2880 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2881
2882 5. doc/pcresyntax.html was missing from the distribution.
2883
2884 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2885 compatibility, even though it is no longer used.
2886
2887 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2888 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2889 windows.h file is present (where different names are used). [This was
2890 reversed later after testing - see 16 below.]
2891
2892 8. Changed all #include <config.h> to #include "config.h". There were also
2893 some further <pcre.h> cases that I changed to "pcre.h".
2894
2895 9. When pcregrep was used with the --colour option, it missed the line ending
2896 sequence off the lines that it output.
2897
2898 10. It was pointed out to me that arrays of string pointers cause lots of
2899 relocations when a shared library is dynamically loaded. A technique of
2900 using a single long string with a table of offsets can drastically reduce
2901 these. I have refactored PCRE in four places to do this. The result is
2902 dramatic:
2903
2904 Originally: 290
2905 After changing UCP table: 187
2906 After changing error message table: 43
2907 After changing table of "verbs" 36
2908 After changing table of Posix names 22
2909
2910 Thanks to the folks working on Gregex for glib for this insight.
2911
2912 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2913 unicode-properties was also set.
2914
2915 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2916
2917 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2918 checked only for CRLF.
2919
2920 14. Added casts to pcretest.c to avoid compiler warnings.
2921
2922 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2923
2924 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2925 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2926 entirely. This removes changes made in 7 above.
2927
2928 17. The CMake files have been updated, and there is now more information about
2929 building with CMake in the NON-UNIX-USE document.
2930
2931
2932 Version 7.3 28-Aug-07
2933 ---------------------
2934
2935 1. In the rejigging of the build system that eventually resulted in 7.1, the
2936 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2937 brackets there is not right, since it causes compilers to look for an
2938 installed pcre.h, not the version that is in the source that is being
2939 compiled (which of course may be different). I have changed it back to:
2940
2941 #include "pcre.h"
2942
2943 I have a vague recollection that the change was concerned with compiling in
2944 different directories, but in the new build system, that is taken care of
2945 by the VPATH setting the Makefile.
2946
2947 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2948 when the subject happened to end in the byte 0x85 (e.g. if the last
2949 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2950 characters but of course it shouldn't be taken as a newline when it is part
2951 of another character. The bug was that, for an unlimited repeat of . in
2952 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2953 characters when looking for a newline.
2954
2955 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2956
2957 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2958 in debug output.
2959
2960 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2961 long printing in the pcrecpp unittest when running under MinGW.
2962
2963 6. ESC_K was left out of the EBCDIC table.
2964
2965 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2966 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2967 limit also applies to "virtual nesting" when a pattern is recursive, and in
2968 this case 1000 isn't so big. I have been able to remove this limit at the
2969 expense of backing off one optimization in certain circumstances. Normally,
2970 when pcre_exec() would call its internal match() function recursively and
2971 immediately return the result unconditionally, it uses a "tail recursion"
2972 feature to save stack. However, when a subpattern that can match an empty
2973 string has an unlimited repetition quantifier, it no longer makes this
2974 optimization. That gives it a stack frame in which to save the data for
2975 checking that an empty string has been matched. Previously this was taken
2976 from the 1000-entry workspace that had been reserved. So now there is no
2977 explicit limit, but more stack is used.
2978
2979 8. Applied Daniel's patches to solve problems with the import/export magic
2980 syntax that is required for Windows, and which was going wrong for the
2981 pcreposix and pcrecpp parts of the library. These were overlooked when this
2982 problem was solved for the main library.
2983
2984 9. There were some crude static tests to avoid integer overflow when computing
2985 the size of patterns that contain repeated groups with explicit upper
2986 limits. As the maximum quantifier is 65535, the maximum group length was
2987 set at 30,000 so that the product of these two numbers did not overflow a
2988 32-bit integer. However, it turns out that people want to use groups that
2989 are longer than 30,000 bytes (though not repeat them that many times).
2990 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2991 made it possible to implement the integer overflow checks in a much more
2992 dynamic way, which I have now done. The artificial limitation on group
2993 length has been removed - we now have only the limit on the total length of
2994 the compiled pattern, which depends on the LINK_SIZE setting.
2995
2996 10. Fixed a bug in the documentation for get/copy named substring when
2997 duplicate names are permitted. If none of the named substrings are set, the
2998 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2999 empty string.
3000
3001 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
3002 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
3003 because the ] is interpreted as the first data character and the
3004 terminating ] is not found. PCRE has been made compatible with Perl in this
3005 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
3006 cause memory overwriting.
3007
3008 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
3009 string has been matched (to stop an infinite loop). It was not recognizing
3010 a conditional subpattern that could match an empty string if that
3011 subpattern was within another subpattern. For example, it looped when
3012 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
3013 condition was not nested. This bug has been fixed.
3014
3015 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
3016 past the start of the subject in the presence of bytes with the top bit
3017 set, for example "\x8aBCD".
3018
3019 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
3020 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
3021
3022 14. Optimized (?!) to (*FAIL).
3023
3024 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
3025 This restricts code points to be within the range 0 to 0x10FFFF, excluding
3026 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
3027 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
3028 does: it's just the validity check that is more restrictive.
3029
3030 16. Inserted checks for integer overflows during escape sequence (backslash)
3031 processing, and also fixed erroneous offset values for syntax errors during
3032 backslash processing.
3033
3034 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
3035 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
3036
3037 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
3038 caused an overrun.
3039
3040 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
3041 something other than just ASCII characters) inside a group that had an
3042 unlimited repeat caused a loop at compile time (while checking to see
3043 whether the group could match an empty string).
3044
3045 20. Debugging a pattern containing \p or \P could cause a crash. For example,
3046 [\P{Any}] did so. (Error in the code for printing property names.)
3047
3048 21. An orphan \E inside a character class could cause a crash.
3049
3050 22. A repeated capturing bracket such as (A)? could cause a wild memory
3051 reference during compilation.
3052
3053 23. There are several functions in pcre_compile() that scan along a compiled
3054 expression for various reasons (e.g. to see if it's fixed length for look
3055 behind). There were bugs in these functions when a repeated \p or \P was
3056 present in the pattern. These operators have additional parameters compared
3057 with \d, etc, and these were not being taken into account when moving along
3058 the compiled data. Specifically:
3059
3060 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
3061 length.
3062
3063 (b) An item such as \pL+ within a repeated group could cause crashes or
3064 loops.
3065
3066 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
3067 "reference to non-existent subpattern" error.
3068
3069 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
3070
3071 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
3072 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
3073
3074 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
3075
3076 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
3077 character were causing crashes (broken optimization).
3078
3079 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
3080 \p or \P) caused a compile-time loop.
3081
3082 28. More problems have arisen in unanchored patterns when CRLF is a valid line
3083 break. For example, the unstudied pattern [\r\n]A does not match the string
3084 "\r\nA" because change 7.0/46 below moves the current point on by two
3085 characters after failing to match at the start. However, the pattern \nA
3086 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
3087 the same is true. There doesn't seem any very clean way out of this, but
3088 what I have chosen to do makes the common cases work: PCRE now takes note
3089 of whether there can be an explicit match for \r or \n anywhere in the
3090 pattern, and if so, 7.0/46 no longer applies. As part of this change,
3091 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
3092 pattern has explicit CR or LF references.
3093
3094 29. Added (*CR) etc for changing newline setting at start of pattern.
3095
3096
3097 Version 7.2 19-Jun-07
3098 ---------------------
3099
3100 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
3101 which is apparently normally available under Windows.
3102
3103 2. Re-jig the pcregrep tests with different newline settings in an attempt
3104 to make them independent of the local environment's newline setting.
3105
3106 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
3107
3108 4. Some of the "internals" tests were previously cut out when the link size
3109 was not 2, because the output contained actual offsets. The recent new
3110 "Z" feature of pcretest means that these can be cut out, making the tests
3111 usable with all link sizes.
3112
3113 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
3114 stack recursion. This gives a massive performance boost under BSD, but just
3115 a small improvement under Linux. However, it saves one field in the frame
3116 in all cases.
3117
3118 6. Added more features from the forthcoming Perl 5.10:
3119
3120 (a) (?-n) (where n is a string of digits) is a relative subroutine or
3121 recursion call. It refers to the nth most recently opened parentheses.
3122
3123 (b) (?+n) is also a relative subroutine call; it refers to the nth next
3124 to be opened parentheses.
3125
3126 (c) Conditions that refer to capturing parentheses can be specified
3127 relatively, for example, (?(-2)... or (?(+3)...
3128
3129 (d) \K resets the start of the current match so that everything before
3130 is not part of it.
3131
3132 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
3133
3134 (f) \g{name} is another synonym - part of Perl 5.10's unification of
3135 reference syntax.
3136
3137 (g) (?| introduces a group in which the numbering of parentheses in each
3138 alternative starts with the same number.
3139
3140 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
3141
3142 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
3143 PCRE_INFO_JCHANGED.
3144
3145 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
3146 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
3147 for detecting groups that can match an empty string.
3148
3149 9. A pattern with a very large number of alternatives (more than several
3150 hundred) was running out of internal workspace during the pre-compile
3151 phase, where pcre_compile() figures out how much memory will be needed. A
3152 bit of new cunning has reduced the workspace needed for groups with
3153 alternatives. The 1000-alternative test pattern now uses 12 bytes of
3154 workspace instead of running out of the 4096 that are available.
3155
3156 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
3157
3158 11. Applied patch from Google to remove an optimization that didn't quite work.
3159 The report of the bug said:
3160
3161 pcrecpp::RE("a*").FullMatch("aaa") matches, while
3162 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
3163 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
3164
3165 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
3166 it matched the wrong number of bytes.
3167
3168
3169 Version 7.1 24-Apr-07
3170 ---------------------
3171
3172 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
3173 that is more "standard", making use of automake and other Autotools. There
3174 is some re-arrangement of the files and adjustment of comments consequent
3175 on this.
3176
3177 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
3178 for recursive directory scanning broke on some systems because the files
3179 are not scanned in any specific order and on different systems the order
3180 was different. A call to "sort" has been inserted into RunGrepTest for the
3181 approprate test as a short-term fix. In the longer term there may be an
3182 alternative.
3183
3184 3. I had an email from Eric Raymond about problems translating some of PCRE's
3185 man pages to HTML (despite the fact that I distribute HTML pages, some
3186 people do their own conversions for various reasons). The problems
3187 concerned the use of low-level troff macros .br and .in. I have therefore
3188 removed all such uses from the man pages (some were redundant, some could
3189 be replaced by .nf/.fi pairs). The 132html script that I use to generate
3190 HTML has been updated to handle .nf/.fi and to complain if it encounters
3191 .br or .in.
3192
3193 4. Updated comments in configure.ac that get placed in config.h.in and also
3194 arranged for config.h to be included in the distribution, with the name
3195 config.h.generic, for the benefit of those who have to compile without
3196 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
3197
3198 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
3199 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
3200 makevp.bat for the current PCRE, using the additional files
3201 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
3202
3203 6. A Windows user reported a minor discrepancy with test 2, which turned out
3204 to be caused by a trailing space on an input line that had got lost in his
3205 copy. The trailing space was an accident, so I've just removed it.
3206
3207 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
3208 that is needed.
3209
3210 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
3211 as "const" (a) because they are and (b) because it helps the PHP
3212 maintainers who have recently made a script to detect big data structures
3213 in the php code that should be moved to the .rodata section. I remembered
3214 to update Builducptable as well, so it won't revert if ucptable.h is ever
3215 re-created.
3216
3217 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
3218 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
3219 order to be able to cut out the UTF-8 tables in the latter when UTF-8
3220 support is not required. This saves 1.5-2K of code, which is important in
3221 some applications.
3222
3223 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
3224 so as not to refer to the tables, even though these functions will never be
3225 called when UTF-8 support is disabled. Otherwise there are problems with a
3226 shared library.
3227
3228 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
3229
3230 (a) It was defining its arguments as char * instead of void *.
3231
3232 (b) It was assuming that all moves were upwards in memory; this was true
3233 a long time ago when I wrote it, but is no longer the case.
3234
3235 The emulated memove() is provided for those environments that have neither
3236 memmove() nor bcopy(). I didn't think anyone used it these days, but that
3237 is clearly not the case, as these two bugs were recently reported.
3238
3239 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
3240 and Detrail to create the HTML documentation, the .txt form of the man
3241 pages, and it removes trailing spaces from listed files. It also creates
3242 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
3243 case, it wraps all the #defines with #ifndefs. This script should be run
3244 before "make dist".
3245
3246 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
3247 with Unicode property support.
3248
3249 (a) For a maximizing quantifier, if the two different cases of the
3250 character were of different lengths in their UTF-8 codings (there are
3251 some cases like this - I found 11), and the matching function had to
3252 back up over a mixture of the two cases, it incorrectly assumed they
3253 were both the same length.
3254
3255 (b) When PCRE was configured to use the heap rather than the stack for
3256 recursion during matching, it was not correctly preserving the data for
3257 the other case of a UTF-8 character when checking ahead for a match
3258 while processing a minimizing repeat. If the check also involved
3259 matching a wide character, but failed, corruption could cause an
3260 erroneous result when trying to check for a repeat of the original
3261 character.
3262
3263 13. Some tidying changes to the testing mechanism:
3264
3265 (a) The RunTest script now detects the internal link size and whether there
3266 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
3267 values substituted by "configure". (The RunGrepTest script already did
3268 this for UTF-8.) The configure.ac script no longer substitutes the
3269 relevant variables.
3270
3271 (b) The debugging options /B and /D in pcretest show the compiled bytecode
3272 with length and offset values. This means that the output is different
3273 for different internal link sizes. Test 2 is skipped for link sizes
3274 other than 2 because of this, bypassing the problem. Unfortunately,
3275 there was also a test in test 3 (the locale tests) that used /B and
3276 failed for link sizes other than 2. Rather than cut the whole test out,
3277 I have added a new /Z option to pcretest that replaces the length and
3278 offset values with spaces. This is now used to make test 3 independent
3279 of link size. (Test 2 will be tidied up later.)
3280
3281 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
3282 segmentation fault instead of returning the appropriate error message.
3283
3284 15. In multiline mode when the newline sequence was set to "any", the pattern
3285 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
3286 This doesn't seem right; it now treats the CRLF combination as the line
3287 ending, and so does not match in that case. It's only a pattern such as ^$
3288 that would hit this one: something like ^ABC$ would have failed after \r
3289 and then tried again after \r\n.
3290
3291 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
3292 in an attempt to make files that differ only in their line terminators
3293 compare equal. This works on Linux.
3294
3295 17. Under certain error circumstances pcregrep might try to free random memory
3296 as it exited. This is now fixed, thanks to valgrind.
3297
3298 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
3299 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
3300 was because its rules for how to advance for /g after matching an empty
3301 string at the end of a line did not allow for this case. They now check for
3302 it specially.
3303
3304 20. pcretest is supposed to handle patterns and data of any length, by
3305 extending its buffers when necessary. It was getting this wrong when the
3306 buffer for a data line had to be extended.
3307
3308 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
3309 CRLF as a newline sequence.
3310
3311 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
3312 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
3313 I have nevertheless tidied it up.
3314
3315 23. Added some casts to kill warnings from HP-UX ia64 compiler.
3316
3317 24. Added a man page for pcre-config.
3318
3319
3320 Version 7.0 19-Dec-06
3321 ---------------------
3322
3323 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
3324 moving to gcc 4.1.1.
3325
3326 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
3327 sys/time.h, which is documented as needed for this function. It doesn't
3328 seem to matter on Linux, but it showed up on some releases of OS X.
3329
3330 3. It seems that there are systems where bytes whose values are greater than
3331 127 match isprint() in the "C" locale. The "C" locale should be the
3332 default when a C program starts up. In most systems, only ASCII printing
3333 characters match isprint(). This difference caused the output from pcretest
3334 to vary, making some of the tests fail. I have changed pcretest so that:
3335
3336 (a) When it is outputting text in the compiled version of a pattern, bytes
3337 other than 32-126 are always shown as hex escapes.
3338
3339 (b) When it is outputting text that is a matched part of a subject string,
3340 it does the same, unless a different locale has been set for the match
3341 (using the /L modifier). In this case, it uses isprint() to decide.
3342
3343 4. Fixed a major bug that caused incorrect computation of the amount of memory
3344 required for a compiled pattern when options that changed within the
3345 pattern affected the logic of the preliminary scan that determines the
3346 length. The relevant options are -x, and -i in UTF-8 mode. The result was
3347 that the computed length was too small. The symptoms of this bug were
3348 either the PCRE error "internal error: code overflow" from pcre_compile(),
3349 or a glibc crash with a message such as "pcretest: free(): invalid next
3350 size (fast)". Examples of patterns that provoked this bug (shown in
3351 pcretest format) are:
3352
3353 /(?-x: )/x
3354 /(?x)(?-x: \s*#\s*)/
3355 /((?i)[\x{c0}])/8
3356 /(?i:[\x{c0}])/8
3357
3358 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
3359 is now done differently.
3360
3361 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
3362 wrapper classes; (b) implement a new function in the C++ scanner that is
3363 more efficient than the old way of doing things because it avoids levels of
3364 recursion in the regex matching; (c) add a paragraph to the documentation
3365 for the FullMatch() function.
3366
3367 6. The escape sequence \n was being treated as whatever was defined as
3368 "newline". Not only was this contrary to the documentation, which states
3369 that \n is character 10 (hex 0A), but it also went horribly wrong when
3370 "newline" was defined as CRLF. This has been fixed.
3371
3372 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
3373 was being set to -1 for the "end of line" case (supposedly a value that no
3374 character can have). Though this value is never used (the check for end of
3375 line is "zero bytes in current character"), it caused compiler complaints.
3376 I've changed it to 0xffffffff.
3377
3378 8. In pcre_version.c, the version string was being built by a sequence of
3379 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
3380 string (as it is for production releases) called a macro with an empty
3381 argument. The C standard says the result of this is undefined. The gcc
3382 compiler treats it as an empty string (which was what was wanted) but it is
3383 reported that Visual C gives an error. The source has been hacked around to
3384 avoid this problem.
3385
3386 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
3387 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
3388 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
3389 of them did).
3390
3391 10. Originally, pcretest opened its input and output without "b"; then I was
3392 told that "b" was needed in some environments, so it was added for release
3393 5.0 to both the input and output. (It makes no difference on Unix-like
3394 systems.) Later I was told that it is wrong for the input on Windows. I've
3395 now abstracted the modes into two macros, to make it easier to fiddle with
3396 them, and removed "b" from the input mode under Windows.
3397
3398 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
3399
3400 12. Added -help and --help to pcretest as an official way of being reminded
3401 of the options.
3402
3403 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
3404 and pcrecpp.cc because they annoy compilers at high warning levels.
3405
3406 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
3407
3408 15. Fixed an occurrence of == in configure.ac that should have been = (shell
3409 scripts are not C programs :-) and which was not noticed because it works
3410 on Linux.
3411
3412 16. pcretest is supposed to handle any length of pattern and data line (as one
3413 line or as a continued sequence of lines) by extending its input buffer if
3414 necessary. This feature was broken for very long pattern lines, leading to
3415 a string of junk being passed to pcre_compile() if the pattern was longer
3416 than about 50K.
3417
3418 17. I have done a major re-factoring of the way pcre_compile() computes the
3419 amount of memory needed for a compiled pattern. Previously, there was code
3420 that made a preliminary scan of the pattern in order to do this. That was
3421 OK when PCRE was new, but as the facilities have expanded, it has become
3422 harder and harder to keep it in step with the real compile phase, and there
3423 have been a number of bugs (see for example, 4 above). I have now found a
3424 cunning way of running the real compile function in a "fake" mode that
3425 enables it to compute how much memory it would need, while actually only
3426 ever using a few hundred bytes of working memory and without too many
3427 tests of the mode. This should make future maintenance and development
3428 easier. A side effect of this work is that the limit of 200 on the nesting
3429 depth of parentheses has been removed (though this was never a serious
3430 limitation, I suspect). However, there is a downside: pcre_compile() now
3431 runs more slowly than before (30% or more, depending on the pattern). I
3432 hope this isn't a big issue. There is no effect on runtime performance.
3433
3434 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
3435 newline (only possible for the last line of a file) and it was a
3436 pattern that set a locale (followed by /Lsomething), pcretest crashed.
3437
3438 19. Added additional timing features to pcretest. (1) The -tm option now times
3439 matching only, not compiling. (2) Both -t and -tm can be followed, as a
3440 separate command line item, by a number that specifies the number of
3441 repeats to use when timing. The default is 50000; this gives better
3442 precision, but takes uncomfortably long for very large patterns.
3443
3444 20. Extended pcre_study() to be more clever in cases where a branch of a
3445 subpattern has no definite first character. For example, (a*|b*)[cd] would
3446 previously give no result from pcre_study(). Now it recognizes that the
3447 first character must be a, b, c, or d.
3448
3449 21. There was an incorrect error "recursive call could loop indefinitely" if
3450 a subpattern (or the entire pattern) that was being tested for matching an
3451 empty string contained only one non-empty item after a nested subpattern.
3452 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
3453 incorrectly, because the \d was being skipped in the check.
3454
3455 22. The pcretest program now has a new pattern option /B and a command line
3456 option -b, which is equivalent to adding /B to every pattern. This causes
3457 it to show the compiled bytecode, without the additional information that
3458 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
3459 is the same as /B/I).
3460
3461 23. A new optimization is now able automatically to treat some sequences such
3462 as a*b as a*+b. More specifically, if something simple (such as a character
3463 or a simple class like \d) has an unlimited quantifier, and is followed by
3464 something that cannot possibly match the quantified thing, the quantifier
3465 is automatically "possessified".
3466
3467 24. A recursive reference to a subpattern whose number was greater than 39
3468 went wrong under certain circumstances in UTF-8 mode. This bug could also
3469 have affected the operation of pcre_study().
3470
3471 25. Realized that a little bit of performance could be had by replacing
3472 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
3473
3474 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
3475
3476 27. Possessive quantifiers such as a++ were previously implemented by turning
3477 them into atomic groups such as ($>a+). Now they have their own opcodes,
3478 which improves performance. This includes the automatically created ones
3479 from 23 above.
3480
3481 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
3482 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
3483 the first matched character to be a colon. This applied both to named and
3484 numbered groups.
3485
3486 29. The ucpinternal.h header file was missing its idempotency #ifdef.
3487
3488 30. I was sent a "project" file called libpcre.a.dev which I understand makes
3489 building PCRE on Windows easier, so I have included it in the distribution.
3490
3491 31. There is now a check in pcretest against a ridiculously large number being
3492 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
3493 loop, the loop is abandoned.
3494
3495 32. Forward references to subpatterns in conditions such as (?(2)...) where
3496 subpattern 2 is defined later cause pcre_compile() to search forwards in
3497 the pattern for the relevant set of parentheses. This search went wrong
3498 when there were unescaped parentheses in a character class, parentheses
3499 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
3500
3501 33. "Subroutine" calls and backreferences were previously restricted to
3502 referencing subpatterns earlier in the regex. This restriction has now
3503 been removed.
3504
3505 34. Added a number of extra features that are going to be in Perl 5.10. On the
3506 whole, these are just syntactic alternatives for features that PCRE had
3507 previously implemented using the Python syntax or my own invention. The
3508 other formats are all retained for compatibility.
3509
3510 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
3511 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
3512 also .NET compatible.
3513
3514 (b) A recursion or subroutine call to a named group can now be defined as
3515 (?&name) as well as (?P>name).
3516
3517 (c) A backreference to a named group can now be defined as \k<name> or
3518 \k'name' as well as (?P=name). The new forms, as well as being in Perl
3519 5.10, are also .NET compatible.
3520
3521 (d) A conditional reference to a named group can now use the syntax
3522 (?(<name>) or (?('name') as well as (?(name).
3523
3524 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
3525 groups (named and numbered) that are never evaluated inline, but can be
3526 called as "subroutines" from elsewhere. In effect, the DEFINE condition
3527 is always false. There may be only one alternative in such a group.
3528
3529 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
3530 as the simple (?(R). The condition is true only if the most recent
3531 recursion is that of the given number or name. It does not search out
3532 through the entire recursion stack.
3533
3534 (g) The escape \gN or \g{N} has been added, where N is a positive or
3535 negative number, specifying an absolute or relative reference.
3536
3537 35. Tidied to get rid of some further signed/unsigned compiler warnings and
3538 some "unreachable code" warnings.
3539
3540 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
3541 things, this adds five new scripts.
3542
3543 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
3544 There were also incompatibilities regarding the handling of \Q..\E inside
3545 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3546 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3547
3548 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3549 matches an empty string, and forcibly breaks the loop. There were bugs in
3550 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3551 against aaaa the result was just "a" rather than "aaaa", for example. Two
3552 separate and independent bugs (that affected different cases) have been
3553 fixed.
3554
3555 39. Refactored the code to abolish the use of different opcodes for small
3556 capturing bracket numbers. This is a tidy that I avoided doing when I
3557 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3558 The new approach is not only tidier, it makes it possible to reduce the
3559 memory needed to fix the previous bug (38).
3560
3561 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3562 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3563 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3564 mode.
3565
3566 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3567 report.
3568
3569 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3570 copy construction and assignment in the C++ wrapper.
3571
3572 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3573 couple of bugs that could have given wrong results in the "--newline=crlf"
3574 case.
3575
3576 44. Added a number of casts and did some reorganization of signed/unsigned int
3577 variables following suggestions from Dair Grant. Also renamed the variable
3578 "this" as "item" because it is a C++ keyword.
3579
3580 45. Arranged for dftables to add
3581
3582 #include "pcre_internal.h"
3583
3584 to pcre_chartables.c because without it, gcc 4.x may remove the array
3585 definition from the final binary if PCRE is built into a static library and
3586 dead code stripping is activated.
3587
3588 46. For an unanchored pattern, if a match attempt fails at the start of a
3589 newline sequence, and the newline setting is CRLF or ANY, and the next two
3590 characters are CRLF, advance by two characters instead of one.
3591
3592
3593 Version 6.7 04-Jul-06
3594 ---------------------
3595
3596 1. In order to handle tests when input lines are enormously long, pcretest has
3597 been re-factored so that it automatically extends its buffers when
3598 necessary. The code is crude, but this _is_ just a test program. The
3599 default size has been increased from 32K to 50K.
3600
3601 2. The code in pcre_study() was using the value of the re argument before
3602 testing it for NULL. (Of course, in any sensible call of the function, it
3603 won't be NULL.)
3604
3605 3. The memmove() emulation function in pcre_internal.h, which is used on
3606 systems that lack both memmove() and bcopy() - that is, hardly ever -
3607 was missing a "static" storage class specifier.
3608
3609 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3610 containing an extended class (one that cannot be represented by a bitmap
3611 because it contains high-valued characters or Unicode property items, e.g.
3612 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3613 pattern, but PCRE should not loop if you do not (it no longer does).
3614 [Detail: two cases were found: (a) a repeated subpattern containing an
3615 extended class; (b) a recursive reference to a subpattern that followed a
3616 previous extended class. It wasn't skipping over the extended class
3617 correctly when UTF-8 mode was not set.]
3618
3619 5. A negated single-character class was not being recognized as fixed-length
3620 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3621 compile error "lookbehind assertion is not fixed length".
3622
3623 6. The RunPerlTest auxiliary script was showing an unexpected difference
3624 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3625 write a Perl script that can interpret lines of an input file either as
3626 byte characters or as UTF-8, which is what "perltest" was being required to
3627 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3628 can't do is switch easily at run time between having the "use utf8;" pragma
3629 or not. In the end, I fudged it by using the RunPerlTest script to insert
3630 "use utf8;" explicitly for the UTF-8 tests.
3631
3632 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3633 the end of the subject string, contrary to the documentation and to what
3634 Perl does. This was true of both matching functions. Now it matches only at
3635 the start of the subject and immediately after *internal* newlines.
3636
3637 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3638 a pointer to an int instead of a pointer to an unsigned long int. This
3639 caused problems on 64-bit systems.
3640
3641 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
3642 instance of the 'standard' template library not being so standard".
3643
3644 10. There was no check on the number of named subpatterns nor the maximum
3645 length of a subpattern name. The product of these values is used to compute
3646 the size of the memory block for a compiled pattern. By supplying a very
3647 long subpattern name and a large number of named subpatterns, the size
3648 computation could be caused to overflow. This is now prevented by limiting
3649 the length of names to 32 characters, and the number of named subpatterns
3650 to 10,000.
3651
3652 11. Subpatterns that are repeated with specific counts have to be replicated in
3653 the compiled pattern. The size of memory for this was computed from the
3654 length of the subpattern and the repeat count. The latter is limited to
3655 65535, but there was no limit on the former, meaning that integer overflow
3656 could in principle occur. The compiled length of a repeated subpattern is
3657 now limited to 30,000 bytes in order to prevent this.
3658
3659 12. Added the optional facility to have named substrings with the same name.
3660
3661 13. Added the ability to use a named substring as a condition, using the
3662 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
3663 are numbers (not recommended). Forward references are permitted.
3664
3665 14. Added forward references in named backreferences (if you see what I mean).
3666
3667 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
3668 pattern could run off the end of the subject. For example, the pattern
3669 "(?s)(.{1,5})"8 did this with the subject "ab".
3670
3671 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
3672 PCRE_CASELESS was set when matching characters that were quantified with ?
3673 or *.
3674
3675 17. A character class other than a single negated character that had a minimum
3676 but no maximum quantifier - for example [ab]{6,} - was not handled
3677 correctly by pce_dfa_exec(). It would match only one character.
3678
3679 18. A valid (though odd) pattern that looked like a POSIX character
3680 class but used an invalid character after [ (for example [[,abc,]]) caused
3681 pcre_compile() to give the error "Failed: internal error: code overflow" or
3682 in some cases to crash with a glibc free() error. This could even happen if
3683 the pattern terminated after [[ but there just happened to be a sequence of
3684 letters, a binary zero, and a closing ] in the memory that followed.
3685
3686 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
3687 over the years. Originally (before any Unicode support), just the bottom 8
3688 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
3689 output from "man perlunicode" includes this:
3690
3691 The regular expression compiler produces polymorphic opcodes. That
3692 is, the pattern adapts to the data and automatically switches to
3693 the Unicode character scheme when presented with Unicode data--or
3694 instead uses a traditional byte scheme when presented with byte
3695 data.
3696
3697 Sadly, a wide octal escape does not cause a switch, and in a string with
3698 no other multibyte characters, these octal escapes are treated as before.
3699 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
3700 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
3701 Unicode string.
3702
3703 I have not perpetrated such confusion in PCRE. Up till now, it took just
3704 the bottom 8 bits, as in old Perl. I have now made octal escapes with
3705 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
3706 translate to the appropriate multibyte character.
3707
3708 29. Applied some refactoring to reduce the number of warnings from Microsoft
3709 and Borland compilers. This has included removing the fudge introduced
3710 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
3711 a warning about an unused variable.
3712
3713 21. PCRE has not included VT (character 0x0b) in the set of whitespace
3714 characters since release 4.0, because Perl (from release 5.004) does not.
3715 [Or at least, is documented not to: some releases seem to be in conflict
3716 with the documentation.] However, when a pattern was studied with
3717 pcre_study() and all its branches started with \s, PCRE still included VT
3718 as a possible starting character. Of course, this did no harm; it just
3719 caused an unnecessary match attempt.
3720
3721 22. Removed a now-redundant internal flag bit that recorded the fact that case
3722 dependency changed within the pattern. This was once needed for "required
3723 byte" processing, but is no longer used. This recovers a now-scarce options
3724 bit. Also moved the least significant internal flag bit to the most-
3725 significant bit of the word, which was not previously used (hangover from
3726 the days when it was an int rather than a uint) to free up another bit for
3727 the future.
3728
3729 23. Added support for CRLF line endings as well as CR and LF. As well as the
3730 default being selectable at build time, it can now be changed at runtime
3731 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
3732 specify that it is scanning data with non-default line endings.
3733
3734 24. Changed the definition of CXXLINK to make it agree with the definition of
3735 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
3736
3737 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
3738 recursions. This makes a big different to stack usage for some patterns.
3739
3740 26. If a subpattern containing a named recursion or subroutine reference such
3741 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
3742 the space required for the compiled pattern went wrong and gave too small a
3743 value. Depending on the environment, this could lead to "Failed: internal
3744 error: code overflow at offset 49" or "glibc detected double free or
3745 corruption" errors.
3746
3747 27. Applied patches from Google (a) to support the new newline modes and (b) to
3748 advance over multibyte UTF-8 characters in GlobalReplace.
3749
3750 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
3751 difference for some implementation of PCRE in some Windows version.
3752
3753 29. Added some extra testing facilities to pcretest:
3754
3755 \q<number> in a data line sets the "match limit" value
3756 \Q<number> in a data line sets the "match recursion limt" value
3757 -S <number> sets the stack size, where <number> is in megabytes
3758
3759 The -S option isn't available for Windows.
3760
3761
3762 Version 6.6 06-Feb-06
3763 ---------------------
3764
3765 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
3766 in pcreposix.h. I have copied the definition from pcre.h.
3767
3768 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
3769 because pcre.h is no longer a built file.
3770
3771 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
3772 not normally included in the compiled code.
3773
3774
3775 Version 6.5 01-Feb-06
3776 ---------------------
3777
3778 1. When using the partial match feature with pcre_dfa_exec(), it was not
3779 anchoring the second and subsequent partial matches at the new starting
3780 point. This could lead to incorrect results. For example, with the pattern
3781 /1234/, partially matching against "123" and then "a4" gave a match.
3782
3783 2. Changes to pcregrep:
3784
3785 (a) All non-match returns from pcre_exec() were being treated as failures
3786 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
3787 error message is output. Some extra information is given for the
3788 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
3789 probably the only errors that are likely to be caused by users (by
3790 specifying a regex that has nested indefinite repeats, for instance).
3791 If there are more than 20 of these errors, pcregrep is abandoned.
3792
3793 (b) A binary zero was treated as data while matching, but terminated the
3794 output line if it was written out. This has been fixed: binary zeroes
3795 are now no different to any other data bytes.
3796
3797 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
3798 used to set a locale for matching. The --locale=xxxx long option has
3799 been added (no short equivalent) to specify a locale explicitly on the
3800 pcregrep command, overriding the environment variables.
3801
3802 (d) When -B was used with -n, some line numbers in the output were one less
3803 than they should have been.
3804
3805 (e) Added the -o (--only-matching) option.
3806
3807 (f) If -A or -C was used with -c (count only), some lines of context were
3808 accidentally printed for the final match.
3809
3810 (g) Added the -H (--with-filename) option.
3811
3812 (h) The combination of options -rh failed to suppress file names for files
3813 that were found from directory arguments.
3814
3815 (i) Added the -D (--devices) and -d (--directories) options.
3816
3817 (j) Added the -F (--fixed-strings) option.
3818
3819 (k) Allow "-" to be used as a file name for -f as well as for a data file.
3820
3821 (l) Added the --colo(u)r option.
3822
3823 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
3824 is not present by default.
3825
3826 3. A nasty bug was discovered in the handling of recursive patterns, that is,
3827 items such as (?R) or (?1), when the recursion could match a number of
3828 alternatives. If it matched one of the alternatives, but subsequently,
3829 outside the recursion, there was a failure, the code tried to back up into
3830 the recursion. However, because of the way PCRE is implemented, this is not
3831 possible, and the result was an incorrect result from the match.
3832
3833 In order to prevent this happening, the specification of recursion has
3834 been changed so that all such subpatterns are automatically treated as
3835 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
3836
3837 4. I had overlooked the fact that, in some locales, there are characters for
3838 which isalpha() is true but neither isupper() nor islower() are true. In
3839 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
3840 and ordfeminine) are like this. This affected the treatment of \w and \W
3841 when they appeared in character classes, but not when they appeared outside
3842 a character class. The bit map for "word" characters is now created
3843 separately from the results of isalnum() instead of just taking it from the
3844 upper, lower, and digit maps. (Plus the underscore character, of course.)
3845
3846 5. The above bug also affected the handling of POSIX character classes such as
3847 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
3848 permanent tables. Instead, the bit maps for such a class were previously
3849 created as the appropriate unions of the upper, lower, and digit bitmaps.
3850 Now they are created by subtraction from the [[:word:]] class, which has
3851 its own bitmap.
3852
3853 6. The [[:blank:]] character class matches horizontal, but not vertical space.
3854 It is created by subtracting the vertical space characters (\x09, \x0a,
3855 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
3856 subtraction was done in the overall bitmap for a character class, meaning
3857 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
3858 be recognized. This bug has been fixed.
3859
3860 7. Patches from the folks at Google:
3861
3862 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
3863 real life, but is still worth protecting against".
3864
3865 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
3866 regular expressions".
3867
3868 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
3869 have it.
3870
3871 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
3872 "configure" and the latter not, in order to fix a problem somebody had
3873 with compiling the Arg class on HP-UX.
3874
3875 (e) Improve the error-handling of the C++ wrapper a little bit.
3876
3877 (f) New tests for checking recursion limiting.
3878
3879 8. The pcre_memmove() function, which is used only if the environment does not
3880 have a standard memmove() function (and is therefore rarely compiled),
3881 contained two bugs: (a) use of int instead of size_t, and (b) it was not
3882 returning a result (though PCRE never actually uses the result).
3883
3884 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
3885 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
3886 returned instead of calling malloc() with an overflowing number that would
3887 most likely cause subsequent chaos.
3888
3889 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
3890
3891 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
3892 with this option is matched, the nmatch and pmatch options of regexec() are
3893 ignored.
3894
3895 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
3896 provided in case anyone wants to the the POSIX interface with UTF-8
3897 strings.
3898
3899 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
3900 C++ linking (needed for some HP-UX environments).
3901
3902 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
3903 (unused parameter) and in the pcre_printint() function (omitted "default"
3904 switch label when the default is to do nothing).
3905
3906 15. Added some code to make it possible, when PCRE is compiled as a C++
3907 library, to replace subject pointers for pcre_exec() with a smart pointer
3908 class, thus making it possible to process discontinuous strings.
3909
3910 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
3911 much the same function. They were added by different people who were trying
3912 to make PCRE easy to compile on non-Unix systems. It has been suggested
3913 that PCRE_EXPORT be abolished now that there is more automatic apparatus
3914 for compiling on Windows systems. I have therefore replaced it with
3915 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
3916 defaults to "extern" for C or "extern C" for C++, which works fine on
3917 Unix-like systems. It is now possible to override the value of PCRE_DATA_
3918 SCOPE with something explicit in config.h. In addition:
3919
3920 (a) pcreposix.h still had just "extern" instead of either of these macros;
3921 I have replaced it with PCRE_DATA_SCOPE.
3922
3923 (b) Functions such as _pcre_xclass(), which are internal to the library,
3924 but external in the C sense, all had PCRE_EXPORT in their definitions.
3925 This is apparently wrong for the Windows case, so I have removed it.
3926 (It makes no difference on Unix-like systems.)
3927
3928 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3929 of recursive calls to match(). This is different to MATCH_LIMIT because
3930 that limits the total number of calls to match(), not all of which increase
3931 the depth of recursion. Limiting the recursion depth limits the amount of
3932 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3933 when PCRE is compiled, and changed at run time. A patch from Google adds
3934 this functionality to the C++ interface.
3935
3936 18. Changes to the handling of Unicode character properties:
3937
3938 (a) Updated the table to Unicode 4.1.0.
3939
3940 (b) Recognize characters that are not in the table as "Cn" (undefined).
3941
3942 (c) I revised the way the table is implemented to a much improved format
3943 which includes recognition of ranges. It now supports the ranges that
3944 are defined in UnicodeData.txt, and it also amalgamates other
3945 characters into ranges. This has reduced the number of entries in the
3946 table from around 16,000 to around 3,000, thus reducing its size
3947 considerably. I realized I did not need to use a tree structure after
3948 all - a binary chop search is just as efficient. Having reduced the
3949 number of entries, I extended their size from 6 bytes to 8 bytes to
3950 allow for more data.
3951
3952 (d) Added support for Unicode script names via properties such as \p{Han}.
3953
3954 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3955 matching that character.
3956
3957 20. When matching a repeated Unicode property with a minimum greater than zero,
3958 (for example \pL{2,}), PCRE could look past the end of the subject if it
3959 reached it while seeking the minimum number of characters. This could
3960 happen only if some of the characters were more than one byte long, because
3961 there is a check for at least the minimum number of bytes.
3962
3963 21. Refactored the implementation of \p and \P so as to be more general, to
3964 allow for more different types of property in future. This has changed the
3965 compiled form incompatibly. Anybody with saved compiled patterns that use
3966 \p or \P will have to recompile them.
3967
3968 22. Added "Any" and "L&" to the supported property types.
3969
3970 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3971 but give a compile time error if the value is greater than 0xff.
3972
3973 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3974 accidentally not being installed or uninstalled.
3975
3976 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3977 made were to insert the current release number. This seemed silly, because
3978 it made things harder for people building PCRE on systems that don't run
3979 "configure". I have turned pcre.h into a distributed file, no longer built
3980 by "configure", with the version identification directly included. There is
3981 no longer a pcre.h.in file.
3982
3983 However, this change necessitated a change to the pcre-config script as
3984 well. It is built from pcre-config.in, and one of the substitutions was the
3985 release number. I have updated configure.ac so that ./configure now finds
3986 the release number by grepping pcre.h.
3987
3988 26. Added the ability to run the tests under valgrind.
3989
3990
3991 Version 6.4 05-Sep-05
3992 ---------------------
3993
3994 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3995 "--" to be printed when multiple files were scanned, even when none of the
3996 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3997 consider it to be a bug, and have restored the previous behaviour.
3998
3999 2. A couple of code tidies to get rid of compiler warnings.
4000
4001 3. The pcretest program used to cheat by referring to symbols in the library
4002 whose names begin with _pcre_. These are internal symbols that are not
4003 really supposed to be visible externally, and in some environments it is
4004 possible to suppress them. The cheating is now confined to including
4005 certain files from the library's source, which is a bit cleaner.
4006
4007 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
4008 file's purpose clearer.
4009
4010 5. Reorganized pcre_ucp_findchar().
4011
4012
4013 Version 6.3 15-Aug-05
4014 ---------------------
4015
4016 1. The file libpcre.pc.in did not have general read permission in the tarball.
4017
4018 2. There were some problems when building without C++ support:
4019
4020 (a) If C++ support was not built, "make install" and "make test" still
4021 tried to test it.
4022
4023 (b) There were problems when the value of CXX was explicitly set. Some
4024 changes have been made to try to fix these, and ...
4025
4026 (c) --disable-cpp can now be used to explicitly disable C++ support.
4027
4028 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
4029 backslash in a target when C++ was disabled. This confuses some
4030 versions of "make", apparently. Using an intermediate variable solves
4031 this. (Same for CPP_LOBJ.)
4032
4033 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
4034 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
4035 necessary on certain architectures.
4036
4037 4. Added a setting of -export-symbols-regex to the link command to remove
4038 those symbols that are exported in the C sense, but actually are local
4039 within the library, and not documented. Their names all begin with
4040 "_pcre_". This is not a perfect job, because (a) we have to except some
4041 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
4042 available (and never for static libraries). I have made a note to try to
4043 find a way round (a) in the future.
4044
4045
4046 Version 6.2 01-Aug-05
4047 ---------------------
4048
4049 1. There was no test for integer overflow of quantifier values. A construction
4050 such as {1111111111111111} would give undefined results. What is worse, if
4051 a minimum quantifier for a parenthesized subpattern overflowed and became
4052 negative, the calculation of the memory size went wrong. This could have
4053 led to memory overwriting.
4054
4055 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
4056
4057 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
4058 operating environments where this matters.
4059
4060 4. Applied Giuseppe Maxia's patch to add additional features for controlling
4061 PCRE options from within the C++ wrapper.
4062
4063 5. Named capturing subpatterns were not being correctly counted when a pattern
4064 was compiled. This caused two problems: (a) If there were more than 100
4065 such subpatterns, the calculation of the memory needed for the whole
4066 compiled pattern went wrong, leading to an overflow error. (b) Numerical
4067 back references of the form \12, where the number was greater than 9, were
4068 not recognized as back references, even though there were sufficient
4069 previous subpatterns.
4070
4071 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
4072 versions of gcc, e.g. 2.95.4.
4073
4074
4075 Version 6.1 21-Jun-05
4076 ---------------------
4077
4078 1. There was one reference to the variable "posix" in pcretest.c that was not
4079 surrounded by "#if !defined NOPOSIX".
4080
4081 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
4082 the cross-check on the old pcre_info() function, for the benefit of the
4083 cut-down version of PCRE that is currently imported into Exim.
4084
4085 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
4086 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
4087 patterns that start (?i) but I don't think that matters. The use of (?i) is
4088 just an example; this all applies to the other options as well.
4089
4090 4. Since libtool seems to echo the compile commands it is issuing, the output
4091 from "make" can be reduced a bit by putting "@" in front of each libtool
4092 compile command.
4093
4094 5. Patch from the folks at Google for configure.in to be a bit more thorough
4095 in checking for a suitable C++ installation before trying to compile the
4096 C++ stuff. This should fix a reported problem when a compiler was present,
4097 but no suitable headers.
4098
4099 6. The man pages all had just "PCRE" as their title. I have changed them to
4100 be the relevant file name. I have also arranged that these names are
4101 retained in the file doc/pcre.txt, which is a concatenation in text format
4102 of all the man pages except the little individual ones for each function.
4103
4104 7. The NON-UNIX-USE file had not been updated for the different set of source
4105 files that come with release 6. I also added a few comments about the C++
4106 wrapper.
4107
4108
4109 Version 6.0 07-Jun-05
4110 ---------------------
4111
4112 1. Some minor internal re-organization to help with my DFA experiments.
4113
4114 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
4115 didn't matter for the library itself when fully configured, but did matter
4116 when compiling without UCP support, or within Exim, where the ucp files are
4117 not imported.
4118
4119 3. Refactoring of the library code to split up the various functions into
4120 different source modules. The addition of the new DFA matching code (see
4121 below) to a single monolithic source would have made it really too
4122 unwieldy, quite apart from causing all the code to be include in a
4123 statically linked application, when only some functions are used. This is
4124 relevant even without the DFA addition now that patterns can be compiled in
4125 one application and matched in another.
4126
4127 The downside of splitting up is that there have to be some external
4128 functions and data tables that are used internally in different modules of
4129 the library but which are not part of the API. These have all had their
4130 names changed to start with "_pcre_" so that they are unlikely to clash
4131 with other external names.
4132
4133 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
4134 a different (DFA) algorithm. Although it is slower than the original
4135 function, it does have some advantages for certain types of matching
4136 problem.
4137
4138 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
4139 including restarting after a partial match.
4140
4141 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
4142 defined when compiling for Windows was sent to me. I have put it into the
4143 code, though I have no means of testing or verifying it.
4144
4145 7. Added the pcre_refcount() auxiliary function.
4146
4147 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
4148 match before or at the first newline in the subject string. In pcretest,
4149 the /f option on a pattern can be used to set this.
4150
4151 9. A repeated \w when used in UTF-8 mode with characters greater than 256
4152 would behave wrongly. This has been present in PCRE since release 4.0.
4153
4154 10. A number of changes to the pcregrep command:
4155
4156 (a) Refactored how -x works; insert ^(...)$ instead of setting
4157 PCRE_ANCHORED and checking the length, in preparation for adding
4158 something similar for -w.
4159
4160 (b) Added the -w (match as a word) option.
4161
4162 (c) Refactored the way lines are read and buffered so as to have more
4163 than one at a time available.
4164
4165 (d) Implemented a pcregrep test script.
4166
4167 (e) Added the -M (multiline match) option. This allows patterns to match
4168 over several lines of the subject. The buffering ensures that at least
4169 8K, or the rest of the document (whichever is the shorter) is available
4170 for matching (and similarly the previous 8K for lookbehind assertions).
4171
4172 (f) Changed the --help output so that it now says
4173
4174 -w, --word-regex(p)
4175
4176 instead of two lines, one with "regex" and the other with "regexp"
4177 because that confused at least one person since the short forms are the
4178 same. (This required a bit of code, as the output is generated
4179 automatically from a table. It wasn't just a text change.)
4180
4181 (g) -- can be used to terminate pcregrep options if the next thing isn't an
4182 option but starts with a hyphen. Could be a pattern or a path name
4183 starting with a hyphen, for instance.
4184
4185 (h) "-" can be given as a file name to represent stdin.
4186
4187 (i) When file names are being printed, "(standard input)" is used for
4188 the standard input, for compatibility with GNU grep. Previously
4189 "<stdin>" was used.
4190
4191 (j) The option --label=xxx can be used to supply a name to be used for
4192 stdin when file names are being printed. There is no short form.
4193
4194 (k) Re-factored the options decoding logic because we are going to add
4195 two more options that take data. Such options can now be given in four
4196 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
4197
4198 (l) Added the -A, -B, and -C options for requesting that lines of context
4199 around matches be printed.
4200
4201 (m) Added the -L option to print the names of files that do not contain
4202 any matching lines, that is, the complement of -l.
4203
4204 (n) The return code is 2 if any file cannot be opened, but pcregrep does
4205 continue to scan other files.
4206
4207 (o) The -s option was incorrectly implemented. For compatibility with other
4208 greps, it now suppresses the error message for a non-existent or non-
4209 accessible file (but not the return code). There is a new option called
4210 -q that suppresses the output of matching lines, which was what -s was
4211 previously doing.
4212
4213 (p) Added --include and --exclude options to specify files for inclusion
4214 and exclusion when recursing.
4215
4216 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
4217 Hopefully, it now does.
4218
4219 12. Missing cast in pcre_study().
4220
4221 13. Added an "uninstall" target to the makefile.
4222
4223 14. Replaced "extern" in the function prototypes in Makefile.in with
4224 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
4225 world, but is set differently for Windows.
4226
4227 15. Added a second compiling function called pcre_compile2(). The only
4228 difference is that it has an extra argument, which is a pointer to an
4229 integer error code. When there is a compile-time failure, this is set
4230 non-zero, in addition to the error test pointer being set to point to an
4231 error message. The new argument may be NULL if no error number is required
4232 (but then you may as well call pcre_compile(), which is now just a
4233 wrapper). This facility is provided because some applications need a
4234 numeric error indication, but it has also enabled me to tidy up the way
4235 compile-time errors are handled in the POSIX wrapper.
4236
4237 16. Added VPATH=.libs to the makefile; this should help when building with one
4238 prefix path and installing with another. (Or so I'm told by someone who
4239 knows more about this stuff than I do.)
4240
4241 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
4242 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
4243 match everything, including newlines. This is not POSIX-compatible, but
4244 somebody wanted the feature. From pcretest it can be activated by using
4245 both the P and the s flags.
4246
4247 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
4248
4249 19. libpcre.pc was being incorrectly installed as executable.
4250
4251 20. A couple of places in pcretest check for end-of-line by looking for '\n';
4252 it now also looks for '\r' so that it will work unmodified on Windows.
4253
4254 21. Added Google's contributed C++ wrapper to the distribution.
4255
4256 22. Added some untidy missing memory free() calls in pcretest, to keep
4257 Electric Fence happy when testing.
4258
4259
4260
4261 Version 5.0 13-Sep-04
4262 ---------------------
4263
4264 1. Internal change: literal characters are no longer packed up into items
4265 containing multiple characters in a single byte-string. Each character
4266 is now matched using a separate opcode. However, there may be more than one
4267 byte in the character in UTF-8 mode.
4268
4269 2. The pcre_callout_block structure has two new fields: pattern_position and
4270 next_item_length. These contain the offset in the pattern to the next match
4271 item, and its length, respectively.
4272
4273 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
4274 insertion of callouts before each pattern item. Added the /C option to
4275 pcretest to make use of this.
4276
4277 4. On the advice of a Windows user, the lines
4278
4279 #if defined(_WIN32) || defined(WIN32)
4280 _setmode( _fileno( stdout ), 0x8000 );
4281 #endif /* defined(_WIN32) || defined(WIN32) */
4282
4283 have been added to the source of pcretest. This apparently does useful
4284 magic in relation to line terminators.
4285
4286 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
4287 for the benefit of those environments where the "b" makes a difference.
4288
4289 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
4290 to know about it. I have put a hack into configure.in that adds in code
4291 to set GCC=yes if CC=icc. This seems to end up at a point in the
4292 generated configure script that is early enough to affect the setting of
4293 compiler options, which is what is needed, but I have no means of testing
4294 whether it really works. (The user who reported this had patched the
4295 generated configure script, which of course I cannot do.)
4296
4297 LATER: After change 22 below (new libtool files), the configure script
4298 seems to know about icc (and also ecc). Therefore, I have commented out
4299 this hack in configure.in.
4300
4301 7. Added support for pkg-config (2 patches were sent in).
4302
4303 8. Negated POSIX character classes that used a combination of internal tables
4304 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
4305 [[:^ascii]]. Typically, they would match almost any characters. The other
4306 POSIX classes were not broken in this way.
4307
4308 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
4309 to find the match, as PCRE was deluded into thinking that the match had to
4310 start at the start point or following a newline. The same bug applied to
4311 patterns with negative forward assertions or any backward assertions
4312 preceding ".*" at the start, unless the pattern required a fixed first
4313 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
4314
4315 10. In UTF-8 mode, when moving forwards in the subject after a failed match
4316 starting at the last subject character, bytes beyond the end of the subject
4317 string were read.
4318
4319 11. Renamed the variable "class" as "classbits" to make life easier for C++
4320 users. (Previously there was a macro definition, but it apparently wasn't
4321 enough.)
4322
4323 12. Added the new field "tables" to the extra data so that tables can be passed
4324 in at exec time, or the internal tables can be re-selected. This allows
4325 a compiled regex to be saved and re-used at a later time by a different
4326 program that might have everything at different addresses.
4327
4328 13. Modified the pcre-config script so that, when run on Solaris, it shows a
4329 -R library as well as a -L library.
4330
4331 14. The debugging options of pcretest (-d on the command line or D on a
4332 pattern) showed incorrect output for anything following an extended class
4333 that contained multibyte characters and which was followed by a quantifier.
4334
4335 15. Added optional support for general category Unicode character properties
4336 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
4337 support. It adds about 90K to the size of the library. The meanings of the
4338 inbuilt class escapes such as \d and \s have NOT been changed.
4339
4340 16. Updated pcredemo.c to include calls to free() to release the memory for the
4341 compiled pattern.
4342
4343 17. The generated file chartables.c was being created in the source directory
4344 instead of in the building directory. This caused the build to fail if the
4345 source directory was different from the building directory, and was
4346 read-only.
4347
4348 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
4349 file. No doubt somebody will tell me if they don't make sense... Also added
4350 Dan Mooney's comments about building on OpenVMS.
4351
4352 19. Added support for partial matching via the PCRE_PARTIAL option for
4353 pcre_exec() and the \P data escape in pcretest.
4354
4355 20. Extended pcretest with 3 new pattern features:
4356
4357 (i) A pattern option of the form ">rest-of-line" causes pcretest to
4358 write the compiled pattern to the file whose name is "rest-of-line".
4359 This is a straight binary dump of the data, with the saved pointer to
4360 the character tables forced to be NULL. The study data, if any, is
4361 written too. After writing, pcretest reads a new pattern.
4362
4363 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
4364 compiled pattern from the given file. There must not be any
4365 occurrences of "<" in the file name (pretty unlikely); if there are,
4366 pcretest will instead treat the initial "<" as a pattern delimiter.
4367 After reading in the pattern, pcretest goes on to read data lines as
4368 usual.
4369
4370 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
4371 and 16-bit fields in a compiled pattern, to simulate a pattern that
4372 was compiled on a host of opposite endianness.
4373
4374 21. The pcre-exec() function can now cope with patterns that were compiled on
4375 hosts of opposite endianness, with this restriction:
4376
4377 As for any compiled expression that is saved and used later, the tables
4378 pointer field cannot be preserved; the extra_data field in the arguments
4379 to pcre_exec() should be used to pass in a tables address if a value
4380 other than the default internal tables were used at compile time.
4381
4382 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
4383 now diagnosed as an error. Previously, most of the time, a negative number
4384 would have been treated as zero, but if in addition "ovector" was passed as
4385 NULL, a crash could occur.
4386
4387 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
4388 new versions from the libtool 1.5 distribution (the last one is a copy of
4389 a file called libtool.m4). This seems to have fixed the need to patch
4390 "configure" to support Darwin 1.3 (which I used to do). However, I still
4391 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
4392 workstation).
4393
4394 24. Changed the PCRE licence to be the more standard "BSD" licence.
4395
4396
4397 Version 4.5 01-Dec-03
4398 ---------------------
4399
4400 1. There has been some re-arrangement of the code for the match() function so
4401 that it can be compiled in a version that does not call itself recursively.
4402 Instead, it keeps those local variables that need separate instances for
4403 each "recursion" in a frame on the heap, and gets/frees frames whenever it
4404 needs to "recurse". Keeping track of where control must go is done by means
4405 of setjmp/longjmp. The whole thing is implemented by a set of macros that
4406 hide most of the details from the main code, and operates only if
4407 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
4408 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
4409 operating.
4410
4411 To make it easier for callers to provide specially tailored get/free
4412 functions for this usage, two new functions, pcre_stack_malloc, and
4413 pcre_stack_free, are used. They are always called in strict stacking order,
4414 and the size of block requested is always the same.
4415
4416 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
4417 PCRE has been compiled to use the stack or the heap for recursion. The
4418 -C option of pcretest uses this to show which version is compiled.
4419
4420 A new data escape \S, is added to pcretest; it causes the amounts of store
4421 obtained and freed by both kinds of malloc/free at match time to be added
4422 to the output.
4423
4424 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
4425 what's available on my current Linux desktop machine.
4426
4427 3. When matching a UTF-8 string, the test for a valid string at the start has
4428 been extended. If start_offset is not zero, PCRE now checks that it points
4429 to a byte that is the start of a UTF-8 character. If not, it returns
4430 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
4431 this is necessary because there may be backward assertions in the pattern.
4432 When matching the same subject several times, it may save resources to use
4433 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4434
4435 4. The code for checking the validity of UTF-8 strings has been tightened so
4436 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
4437 containing "overlong sequences".
4438
4439 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
4440 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
4441 should have been "&", but it just so happened that all the cases this let
4442 through by mistake were picked up later in the function.
4443
4444 6. I had used a variable called "isblank" - this is a C99 function, causing
4445 some compilers to warn. To avoid this, I renamed it (as "blankclass").
4446
4447 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
4448 prompting; (b) run "./pcretest /dev/null" at the start of the test script
4449 so the version is shown; (c) stop "make test" echoing "./RunTest".
4450
4451 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
4452
4453 9. The prototype for memmove() for systems that don't have it was using
4454 size_t, but the inclusion of the header that defines size_t was later. I've
4455 moved the #includes for the C headers earlier to avoid this.
4456
4457 10. Added some adjustments to the code to make it easier to compiler on certain
4458 special systems:
4459
4460 (a) Some "const" qualifiers were missing.
4461 (b) Added the macro EXPORT before all exported functions; by default this
4462 is defined to be empty.
4463 (c) Changed the dftables auxiliary program (that builds chartables.c) so
4464 that it reads its output file name as an argument instead of writing
4465 to the standard output and assuming this can be redirected.
4466
4467 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
4468 class containing characters with values greater than 255, PCRE compilation
4469 went into a loop.
4470
4471 12. A recursive reference to a subpattern that was within another subpattern
4472 that had a minimum quantifier of zero caused PCRE to crash. For example,
4473 (x(y(?2))z)? provoked this bug with a subject that got as far as the
4474 recursion. If the recursively-called subpattern itself had a zero repeat,
4475 that was OK.
4476
4477 13. In pcretest, the buffer for reading a data line was set at 30K, but the
4478 buffer into which it was copied (for escape processing) was still set at
4479 1024, so long lines caused crashes.
4480
4481 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
4482 "internal error: code overflow...". This applied to any character class
4483 that was followed by a possessive quantifier.
4484
4485 15. Modified the Makefile to add libpcre.la as a prerequisite for
4486 libpcreposix.la because I was told this is needed for a parallel build to
4487 work.
4488
4489 16. If a pattern that contained .* following optional items at the start was
4490 studied, the wrong optimizing data was generated, leading to matching
4491 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
4492 matching string must start with a or b or c. The correct conclusion for
4493 this pattern is that a match can start with any character.
4494
4495
4496 Version 4.4 13-Aug-03
4497 ---------------------
4498
4499 1. In UTF-8 mode, a character class containing characters with values between
4500 127 and 255 was not handled correctly if the compiled pattern was studied.
4501 In fixing this, I have also improved the studying algorithm for such
4502 classes (slightly).
4503
4504 2. Three internal functions had redundant arguments passed to them. Removal
4505 might give a very teeny performance improvement.
4506
4507 3. Documentation bug: the value of the capture_top field in a callout is *one
4508 more than* the number of the hightest numbered captured substring.
4509
4510 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
4511 in incorrectly linking with a previously installed version. They now link
4512 explicitly with libpcre.la.
4513
4514 5. configure.in no longer needs to recognize Cygwin specially.
4515
4516 6. A problem in pcre.in for Windows platforms is fixed.
4517
4518 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
4519 pcretest, it used to include the size of the study block as part of its
4520 output. Unfortunately, the structure contains a field that has a different
4521 size on different hardware architectures. This meant that the tests that
4522 showed this size failed. As the block is currently always of a fixed size,
4523 this information isn't actually particularly useful in pcretest output, so
4524 I have just removed it.
4525
4526 8. Three pre-processor statements accidentally did not start in column 1.
4527 Sadly, there are *still* compilers around that complain, even though
4528 standard C has not required this for well over a decade. Sigh.
4529
4530 9. In pcretest, the code for checking callouts passed small integers in the
4531 callout_data field, which is a void * field. However, some picky compilers
4532 complained about the casts involved for this on 64-bit systems. Now
4533 pcretest passes the address of the small integer instead, which should get
4534 rid of the warnings.
4535
4536 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
4537 both compile and run time, and gives an error if an invalid UTF-8 sequence
4538 is found. There is a option for disabling this check in cases where the
4539 string is known to be correct and/or the maximum performance is wanted.
4540
4541 11. In response to a bug report, I changed one line in Makefile.in from
4542
4543 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
4544 to
4545 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4546
4547 to look similar to other lines, but I have no way of telling whether this
4548 is the right thing to do, as I do not use Windows. No doubt I'll get told
4549 if it's wrong...
4550
4551
4552 Version 4.3 21-May-03
4553 ---------------------
4554
4555 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4556 Makefile.
4557
4558 2. Some refactoring to improve the quality of the code:
4559
4560 (i) The utf8_table... variables are now declared "const".
4561
4562 (ii) The code for \cx, which used the "case flipping" table to upper case
4563 lower case letters, now just substracts 32. This is ASCII-specific,
4564 but the whole concept of \cx is ASCII-specific, so it seems
4565 reasonable.
4566
4567 (iii) PCRE was using its character types table to recognize decimal and
4568 hexadecimal digits in the pattern. This is silly, because it handles
4569 only 0-9, a-f, and A-F, but the character types table is locale-
4570 specific, which means strange things might happen. A private
4571 table is now used for this - though it costs 256 bytes, a table is
4572 much faster than multiple explicit tests. Of course, the standard
4573 character types table is still used for matching digits in subject
4574 strings against \d.
4575
4576 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4577 ending in _t are). So I've renamed it as ESC_tee.
4578
4579 3. The first argument for regexec() in the POSIX wrapper should have been
4580 defined as "const".
4581
4582 4. Changed pcretest to use malloc() for its buffers so that they can be
4583 Electric Fenced for debugging.
4584
4585 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4586 to read one or more bytes before the start of the subject string. Often this
4587 had no effect on PCRE's behaviour, but in some circumstances it could
4588 provoke a segmentation fault.
4589
4590 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4591 to try to read one or more bytes before the start of the subject string.
4592
4593 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4594 UTF-8 support could misbehave in various ways if the subject string
4595 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4596 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4597 back over UTF-8 characters.)
4598
4599
4600 Version 4.2 14-Apr-03
4601 ---------------------
4602
4603 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4604
4605 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4606 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4607 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4608 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4609 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4610 and BUILD_EXEEXT
4611 Note: automatic setting of the BUILD variables is not yet working
4612 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4613 compile-time but not at link-time
4614 [LINK]: use for linking executables only
4615 make different versions for Windows and non-Windows
4616 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4617 libraries
4618 [LINK_FOR_BUILD]: new variable
4619 [OBJEXT]: use throughout
4620 [EXEEXT]: use throughout
4621 <winshared>: new target
4622 <wininstall>: new target
4623 <dftables.o>: use native compiler
4624 <dftables>: use native linker
4625 <install>: handle Windows platform correctly
4626 <clean>: ditto
4627 <check>: ditto
4628 copy DLL to top builddir before testing
4629
4630 As part of these changes, -no-undefined was removed again. This was reported
4631 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4632 in any case.
4633
4634 3. Some tidies to get rid of compiler warnings:
4635
4636 . In the match_data structure, match_limit was an unsigned long int, whereas
4637 match_call_count was an int. I've made them both unsigned long ints.
4638
4639 . In pcretest the fact that a const uschar * doesn't automatically cast to
4640 a void * provoked a warning.
4641
4642 . Turning on some more compiler warnings threw up some "shadow" variables
4643 and a few more missing casts.
4644
4645 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
4646 option, a class that contained a single character with a value between 128
4647 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
4648
4649 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
4650 option, a class that contained several characters, but with at least one
4651 whose value was between 128 and 255 caused PCRE to crash.
4652
4653
4654 Version 4.1 12-Mar-03
4655 ---------------------
4656
4657 1. Compiling with gcc -pedantic found a couple of places where casts were
4658 needed, and a string in dftables.c that was longer than standard compilers are
4659 required to support.
4660
4661 2. Compiling with Sun's compiler found a few more places where the code could
4662 be tidied up in order to avoid warnings.
4663
4664 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
4665 first of these names is deprecated in the latest Autoconf in favour of the name
4666 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
4667 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
4668 analogy I have changed it to CFLAGS_FOR_BUILD.
4669
4670 4. Added -no-undefined to the linking command in the Makefile, because this is
4671 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
4672 linking step for the pcreposix library.
4673
4674 5. PCRE was failing to diagnose the case of two named groups with the same
4675 name.
4676
4677 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
4678 literal character that is needed in the subject for a match, and scans along to
4679 ensure that it is present before embarking on the full matching process. This
4680 saves time in cases of nested unlimited repeats that are never going to match.
4681 Problem: the scan can take a lot of time if the subject is very long (e.g.
4682 megabytes), thus penalizing straightforward matches. It is now done only if the
4683 amount of subject to be scanned is less than 1000 bytes.
4684
4685 7. A lesser problem with the same optimization is that it was recording the
4686 first character of an anchored pattern as "needed", thus provoking a search
4687 right along the subject, even when the first match of the pattern was going to
4688 fail. The "needed" character is now not set for anchored patterns, unless it
4689 follows something in the pattern that is of non-fixed length. Thus, it still
4690 fulfils its original purpose of finding quick non-matches in cases of nested
4691 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
4692
4693
4694 Version 4.0 17-Feb-03
4695 ---------------------
4696
4697 1. If a comment in an extended regex that started immediately after a meta-item
4698 extended to the end of string, PCRE compiled incorrect data. This could lead to
4699 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
4700
4701 2. Moved to autoconf 2.53 and libtool 1.4.2.
4702
4703 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
4704 the special perltest8 script is no longer needed - all the tests can be run
4705 from a single perltest script.
4706
4707 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
4708 by \s. It has now been removed in PCRE. This means it isn't recognized as
4709 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
4710 class [:space:] *does* include VT, thereby creating a mess.
4711
4712 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
4713 space and tab.
4714
4715 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
4716 its new features into the main test script, reducing the number of scripts.
4717
4718 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
4719 were backward compatible, and made the (?i) apply to the whole pattern, as if
4720 /i were given. Now it behaves more logically, and applies the option setting
4721 only to what follows. PCRE has been changed to follow suit. However, if it
4722 finds options settings right at the start of the pattern, it extracts them into
4723 the global options, as before. Thus, they show up in the info data.
4724
4725 8. Added support for the \Q...\E escape sequence. Characters in between are
4726 treated as literals. This is slightly different from Perl in that $ and @ are
4727 also handled as literals inside the quotes. In Perl, they will cause variable
4728 interpolation. Note the following examples:
4729
4730 Pattern PCRE matches Perl matches
4731
4732 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
4733 \Qabc\$xyz\E abc\$xyz abc\$xyz
4734 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
4735
4736 For compatibility with Perl, \Q...\E sequences are recognized inside character
4737 classes as well as outside them.
4738
4739 9. Re-organized 3 code statements in pcretest to avoid "overflow in
4740 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
4741 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
4742 signed/unsigned warnings.
4743
4744 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
4745 option for pcretest, so I've replaced it by a simple function that does just
4746 that job.
4747
4748 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
4749 "pcregrep -".
4750
4751 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
4752 Java package. This provides some syntactic sugar for simple cases of what my
4753 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
4754 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
4755 item, you can use this simplified notation. Note that only makes sense with
4756 greedy quantifiers. Consequently, the use of the possessive quantifier forces
4757 greediness, whatever the setting of the PCRE_UNGREEDY option.
4758
4759 13. A change of greediness default within a pattern was not taking effect at
4760 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
4761 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
4762 was abstracted outside.
4763
4764 14. PCRE now supports the \G assertion. It is true when the current matching
4765 position is at the start point of the match. This differs from \A when the
4766 starting offset is non-zero. Used with the /g option of pcretest (or similar
4767 code), it works in the same way as it does for Perl's /g option. If all
4768 alternatives of a regex begin with \G, the expression is anchored to the start
4769 match position, and the "anchored" flag is set in the compiled expression.
4770
4771 15. Some bugs concerning the handling of certain option changes within patterns
4772 have been fixed. These applied to options other than (?ims). For example,
4773 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
4774 been the other way round. Some of this was related to change 7 above.
4775
4776 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
4777 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
4778 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
4779 POSIX classes only within a class (e.g. /[[:alpha:]]/).
4780
4781 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
4782 mode. Unlike ".", it always matches newline, whatever the setting of
4783 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
4784 assertions. Perl allows it, but it doesn't (in general) work because it can't
4785 calculate the length of the lookbehind. At least, that's the case for Perl
4786 5.8.0 - I've been told they are going to document that it doesn't work in
4787 future.
4788
4789 18. Added an error diagnosis for escapes that PCRE does not support: these are
4790 \L, \l, \N, \P, \p, \U, \u, and \X.
4791
4792 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
4793 reading past the end of the pattern in cases such as /[abcd/.
4794
4795 20. PCRE was getting more memory than necessary for patterns with classes that
4796 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
4797
4798 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
4799 compiling PCRE for use with Virtual Pascal.
4800
4801 22. Small fix to the Makefile to make it work properly if the build is done
4802 outside the source tree.
4803
4804 23. Added a new extension: a condition to go with recursion. If a conditional
4805 subpattern starts with (?(R) the "true" branch is used if recursion has
4806 happened, whereas the "false" branch is used only at the top level.
4807
4808 24. When there was a very long string of literal characters (over 255 bytes
4809 without UTF support, over 250 bytes with UTF support), the computation of how
4810 much memory was required could be incorrect, leading to segfaults or other
4811 strange effects.
4812
4813 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
4814 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
4815 there was a subsequent back reference to those brackets. This meant that, for
4816 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
4817 possible to check for precisely this case. All we can do is abandon the
4818 optimization if .* occurs inside capturing brackets when there are any back
4819 references whatsoever. (See below for a better fix that came later.)
4820
4821 26. The handling of the optimization for finding the first character of a
4822 non-anchored pattern, and for finding a character that is required later in the
4823 match were failing in some cases. This didn't break the matching; it just
4824 failed to optimize when it could. The way this is done has been re-implemented.
4825
4826 27. Fixed typo in error message for invalid (?R item (it said "(?p").
4827
4828 28. Added a new feature that provides some of the functionality that Perl
4829 provides with (?{...}). The facility is termed a "callout". The way it is done
4830 in PCRE is for the caller to provide an optional function, by setting
4831 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
4832 global variable. By default it is unset, which disables all calling out. To get
4833 the function called, the regex must include (?C) at appropriate points. This
4834 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
4835 This provides a means of identifying different callout points. When PCRE
4836 reaches such a point in the regex, if pcre_callout has been set, the external
4837 function is called. It is provided with data in a structure called
4838 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
4839 matching continues; if it returns a non-zero value, the match at the current
4840 point fails. However, backtracking will occur if possible. [This was changed
4841 later and other features added - see item 49 below.]
4842
4843 29. pcretest is upgraded to test the callout functionality. It provides a
4844 callout function that displays information. By default, it shows the start of
4845 the match and the current position in the text. There are some new data escapes
4846 to vary what happens:
4847
4848 \C+ in addition, show current contents of captured substrings
4849 \C- do not supply a callout function
4850 \C!n return 1 when callout number n is reached
4851 \C!n!m return 1 when callout number n is reached for the mth time
4852
4853 30. If pcregrep was called with the -l option and just a single file name, it
4854 output "<stdin>" if a match was found, instead of the file name.
4855
4856 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
4857 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
4858 pcre_exec(). This saves a malloc/free per call. The default value of
4859 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
4860 when configuring.
4861
4862 32. The default maximum size of a compiled pattern is 64K. There have been a
4863 few cases of people hitting this limit. The code now uses macros to handle the
4864 storing of links as offsets within the compiled pattern. It defaults to 2-byte
4865 links, but this can be changed to 3 or 4 bytes by --with-link-size when
4866 configuring. Tests 2 and 5 work only with 2-byte links because they output
4867 debugging information about compiled patterns.
4868
4869 33. Internal code re-arrangements:
4870
4871 (a) Moved the debugging function for printing out a compiled regex into
4872 its own source file (printint.c) and used #include to pull it into
4873 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
4874 separate copies.
4875
4876 (b) Defined the list of op-code names for debugging as a macro in
4877 internal.h so that it is next to the definition of the opcodes.
4878
4879 (c) Defined a table of op-code lengths for simpler skipping along compiled
4880 code. This is again a macro in internal.h so that it is next to the
4881 definition of the opcodes.
4882
4883 34. Added support for recursive calls to individual subpatterns, along the
4884 lines of Robin Houston's patch (but implemented somewhat differently).
4885
4886 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
4887 allow it to read and process whole directories in Win32. This code was
4888 contributed by Lionel Fourquaux; it has not been tested by me.
4889
4890 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
4891 used to name a group. Names consist of alphanumerics and underscores, and must
4892 be unique. Back references use the syntax (?P=name) and recursive calls use
4893 (?P>name) which is a PCRE extension to the Python extension. Groups still have
4894 numbers. The function pcre_fullinfo() can be used after compilation to extract
4895 a name/number map. There are three relevant calls:
4896
4897 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
4898 PCRE_INFO_NAMECOUNT yields the number of entries
4899 PCRE_INFO_NAMETABLE yields a pointer to the map.
4900
4901 The map is a vector of fixed-size entries. The size of each entry depends on
4902 the length of the longest name used. The first two bytes of each entry are the
4903 group number, most significant byte first. There follows the corresponding
4904 name, zero terminated. The names are in alphabetical order.
4905
4906 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
4907 case instead of 255. Making it the same both with and without UTF-8 support
4908 means that the same test output works with both.
4909
4910 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
4911 calling malloc() with a zero argument.
4912
4913 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
4914 optimization. I've improved things by keeping a bitmap of backreferences with
4915 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
4916 fact referenced, the optimization can be applied. It is unlikely that a
4917 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
4918 the match to follow \n) will appear inside brackets with a number greater than
4919 31, but if it does, any back reference > 31 suppresses the optimization.
4920
4921 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
4922 of disabling numbered capturing parentheses. Any opening parenthesis that is
4923 not followed by ? behaves as if it were followed by ?: but named parentheses
4924 can still be used for capturing (and they will acquire numbers in the usual
4925 way).
4926
4927 41. Redesigned the return codes from the match() function into yes/no/error so
4928 that errors can be passed back from deep inside the nested calls. A malloc
4929 failure while inside a recursive subpattern call now causes the
4930 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4931
4932 42. It is now possible to set a limit on the number of times the match()
4933 function is called in a call to pcre_exec(). This facility makes it possible to
4934 limit the amount of recursion and backtracking, though not in a directly
4935 obvious way, because the match() function is used in a number of different
4936 circumstances. The count starts from zero for each position in the subject
4937 string (for non-anchored patterns). The default limit is, for compatibility, a
4938 large number, namely 10 000 000. You can change this in two ways:
4939
4940 (a) When configuring PCRE before making, you can use --with-match-limit=n
4941 to set a default value for the compiled library.
4942
4943 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4944 a different value is set. See 45 below.
4945
4946 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4947
4948 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4949 of things that can be changed at compile time. The first argument specifies
4950 what is wanted and the second points to where the information is to be placed.
4951 The current list of available information is:
4952
4953 PCRE_CONFIG_UTF8
4954
4955 The output is an integer that is set to one if UTF-8 support is available;
4956 otherwise it is set to zero.
4957
4958 PCRE_CONFIG_NEWLINE
4959
4960 The output is an integer that it set to the value of the code that is used for
4961 newline. It is either LF (10) or CR (13).
4962
4963 PCRE_CONFIG_LINK_SIZE
4964
4965 The output is an integer that contains the number of bytes used for internal
4966 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4967
4968 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4969
4970 The output is an integer that contains the threshold above which the POSIX
4971 interface uses malloc() for output vectors. See item 31 above.
4972
4973 PCRE_CONFIG_MATCH_LIMIT
4974
4975 The output is an unsigned integer that contains the default limit of the number
4976 of match() calls in a pcre_exec() execution. See 42 above.
4977
4978 44. pcretest has been upgraded by the addition of the -C option. This causes it
4979 to extract all the available output from the new pcre_config() function, and to
4980 output it. The program then exits immediately.
4981
4982 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4983 order to support additional features. One way would have been to define
4984 pcre_exec2() (for example) with extra arguments, but this would not have been
4985 extensible, and would also have required all calls to the original function to
4986 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4987 is used for passing in "extra" data from pcre_study().
4988
4989 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4990 contains the following fields:
4991
4992 flags a bitmap indicating which of the following fields are set
4993 study_data opaque data from pcre_study()
4994 match_limit a way of specifying a limit on match() calls for a specific
4995 call to pcre_exec()
4996 callout_data data for callouts (see 49 below)
4997
4998 The flag bits are also defined in pcre.h, and are
4999
5000 PCRE_EXTRA_STUDY_DATA
5001 PCRE_EXTRA_MATCH_LIMIT
5002 PCRE_EXTRA_CALLOUT_DATA
5003
5004 The pcre_study() function now returns one of these new pcre_extra blocks, with
5005 the actual study data pointed to by the study_data field, and the
5006 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
5007 before. That is, this change is entirely upwards-compatible and requires no
5008 change to existing code.
5009
5010 If you want to pass in additional data to pcre_exec(), you can either place it
5011 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
5012 block.
5013
5014 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
5015 data string contains the escape sequence \M, pcretest calls pcre_exec() several
5016 times with different match limits, until it finds the minimum value needed for
5017 pcre_exec() to complete. The value is then output. This can be instructive; for
5018 most simple matches the number is quite small, but for pathological cases it
5019 gets very large very quickly.
5020
5021 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
5022 returns the size of the data block pointed to by the study_data field in a
5023 pcre_extra block, that is, the value that was passed as the argument to
5024 pcre_malloc() when PCRE was getting memory in which to place the information
5025 created by pcre_study(). The fourth argument should point to a size_t variable.
5026 pcretest has been extended so that this information is shown after a successful
5027 pcre_study() call when information about the compiled regex is being displayed.
5028
5029 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
5030 because what follows is always an absolute path. (Later: it turns out that this
5031 is more than cosmetic for MinGW, because it doesn't like empty path
5032 components.)
5033
5034 49. Some changes have been made to the callout feature (see 28 above):
5035
5036 (i) A callout function now has three choices for what it returns:
5037
5038 0 => success, carry on matching
5039 > 0 => failure at this point, but backtrack if possible
5040 < 0 => serious error, return this value from pcre_exec()
5041
5042 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
5043 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
5044 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
5045 use by callout functions. It will never be used by PCRE itself.
5046
5047 (ii) The pcre_extra structure (see 45 above) has a void * field called
5048 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
5049 pcre_callout_block structure has a field of the same name. The contents of
5050 the field passed in the pcre_extra structure are passed to the callout
5051 function in the corresponding field in the callout block. This makes it
5052 easier to use the same callout-containing regex from multiple threads. For
5053 testing, the pcretest program has a new data escape
5054
5055 \C*n pass the number n (may be negative) as callout_data
5056
5057 If the callout function in pcretest receives a non-zero value as
5058 callout_data, it returns that value.
5059
5060 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
5061 there were some redundant $(CFLAGS) in commands that are now specified as
5062 $(LINK), which already includes $(CFLAGS).
5063
5064 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
5065 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
5066 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
5067 one-byte characters throughout. Note that case-insensitive matching applies
5068 only to characters whose values are less than 256. PCRE doesn't support the
5069 notion of cases for higher-valued characters.
5070
5071 (i) A character class whose characters are all within 0-255 is handled as
5072 a bit map, and the map is inverted for negative classes. Previously, a
5073 character > 255 always failed to match such a class; however it should
5074 match if the class was a negative one (e.g. [^ab]). This has been fixed.
5075
5076 (ii) A negated character class with a single character < 255 is coded as
5077 "not this character" (OP_NOT). This wasn't working properly when the test
5078 character was multibyte, either singly or repeated.
5079
5080 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
5081 mode, for example: \x{100}{2,3}.
5082
5083 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
5084 singly or repeated) now correctly test multibyte characters. However,
5085 PCRE doesn't recognize any characters with values greater than 255 as
5086 digits, spaces, or word characters. Such characters always match \D, \S,
5087 and \W, and never match \d, \s, or \w.
5088
5089 (v) Classes may now contain characters and character ranges with values
5090 greater than 255. For example: [ab\x{100}-\x{400}].
5091
5092 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
5093 PCRE in UTF-8 mode.
5094
5095 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
5096 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
5097 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
5098 value.)
5099
5100 53. The single man page has become too large. I have therefore split it up into
5101 a number of separate man pages. These also give rise to individual HTML pages;
5102 these are now put in a separate directory, and there is an index.html page that
5103 lists them all. Some hyperlinking between the pages has been installed.
5104
5105 54. Added convenience functions for handling named capturing parentheses.
5106
5107 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
5108 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
5109 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
5110 are faulted.
5111
5112 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
5113 calling configure. These values are used when compiling the dftables.c program
5114 which is run to generate the source of the default character tables. They
5115 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
5116 you will need to set these values.
5117
5118 57. Updated the building process for Windows DLL, as provided by Fred Cox.
5119
5120
5121 Version 3.9 02-Jan-02
5122 ---------------------
5123
5124 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
5125
5126 2. If --disable-static was given, the building process failed when trying to
5127 build pcretest and pcregrep. (For some reason it was using libtool to compile
5128 them, which is not right, as they aren't part of the library.)
5129
5130
5131 Version 3.8 18-Dec-01
5132 ---------------------
5133
5134 1. The experimental UTF-8 code was completely screwed up. It was packing the
5135 bytes in the wrong order. How dumb can you get?
5136
5137
5138 Version 3.7 29-Oct-01
5139 ---------------------
5140
5141 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
5142 This caused pcretest, when used on the test data, to segfault. Unfortunately,
5143 this didn't happen under Solaris 8, where I normally test things.
5144
5145 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
5146 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
5147 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
5148 this fix an hour or so after the initial 3.7 release.)
5149
5150
5151 Version 3.6 23-Oct-01
5152 ---------------------
5153
5154 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
5155 offsets passed as NULL with zero offset count.
5156
5157 2. The config.guess and config.sub files had not been updated when I moved to
5158 the latest autoconf.
5159
5160
5161 Version 3.5 15-Aug-01
5162 ---------------------
5163
5164 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
5165 had been forgotten.
5166
5167 2. By using declared but undefined structures, we can avoid using "void"
5168 definitions in pcre.h while keeping the internal definitions of the structures
5169 private.
5170
5171 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
5172 user point of view, this means that both static and shared libraries are built
5173 by default, but this can be individually controlled. More of the work of
5174 handling this static/shared cases is now inside libtool instead of PCRE's make
5175 file.
5176
5177 4. The pcretest utility is now installed along with pcregrep because it is
5178 useful for users (to test regexs) and by doing this, it automatically gets
5179 relinked by libtool. The documentation has been turned into a man page, so
5180 there are now .1, .txt, and .html versions in /doc.
5181
5182 5. Upgrades to pcregrep:
5183 (i) Added long-form option names like gnu grep.
5184 (ii) Added --help to list all options with an explanatory phrase.
5185 (iii) Added -r, --recursive to recurse into sub-directories.
5186 (iv) Added -f, --file to read patterns from a file.
5187
5188 6. pcre_exec() was referring to its "code" argument before testing that
5189 argument for NULL (and giving an error if it was NULL).
5190
5191 7. Upgraded Makefile.in to allow for compiling in a different directory from
5192 the source directory.
5193
5194 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
5195 options bits, the pointer it was passed was to an int instead of to an unsigned
5196 long int. This mattered only on 64-bit systems.
5197
5198 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
5199 generated) instead of pcre.in, which it its source. Also made the same change
5200 in several of the .c files.
5201
5202 10. A new release of gcc defines printf() as a macro, which broke pcretest
5203 because it had an ifdef in the middle of a string argument for printf(). Fixed
5204 by using separate calls to printf().
5205
5206 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
5207 script, to force use of CR or LF instead of \n in the source. On non-Unix
5208 systems, the value can be set in config.h.
5209
5210 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
5211 absolute limit. Changed the text of the error message to make this clear, and
5212 likewise updated the man page.
5213
5214 13. The limit of 99 on the number of capturing subpatterns has been removed.
5215 The new limit is 65535, which I hope will not be a "real" limit.
5216
5217
5218 Version 3.4 22-Aug-00
5219 ---------------------
5220
5221 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
5222
5223 2. Diagnose condition (?(0) as an error instead of crashing on matching.
5224
5225
5226 Version 3.3 01-Aug-00
5227 ---------------------
5228
5229 1. If an octal character was given, but the value was greater than \377, it
5230 was not getting masked to the least significant bits, as documented. This could
5231 lead to crashes in some systems.
5232
5233 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
5234 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
5235
5236 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
5237 These just pass their arguments on to (pcre_free)(), but they are provided
5238 because some uses of PCRE bind it to non-C systems that can call its functions,
5239 but cannot call free() or pcre_free() directly.
5240
5241 4. Add "make test" as a synonym for "make check". Corrected some comments in
5242 the Makefile.
5243
5244 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
5245 Makefile.
5246
5247 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
5248 command called pgrep for grepping around the active processes.
5249
5250 7. Added the beginnings of support for UTF-8 character strings.
5251
5252 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
5253 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
5254 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
5255 out for the ar command.)
5256
5257
5258 Version 3.2 12-May-00
5259 ---------------------
5260
5261 This is purely a bug fixing release.
5262
5263 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
5264 of ZA. This was just one example of several cases that could provoke this bug,
5265 which was introduced by change 9 of version 2.00. The code for breaking
5266 infinite loops after an iteration that matches an empty string was't working
5267 correctly.
5268
5269 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
5270 when matched against abbab (for example). After matching an empty string, it
5271 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
5272 caused it to match further down the string than it should.
5273
5274 3. The code contained an inclusion of sys/types.h. It isn't clear why this
5275 was there because it doesn't seem to be needed, and it causes trouble on some
5276 systems, as it is not a Standard C header. It has been removed.
5277
5278 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
5279 were reported on the Macintosh. The changes were from
5280
5281 while ((c = *(++ptr)) != 0 && c != '\n');
5282 to
5283 while ((c = *(++ptr)) != 0 && c != '\n') ;
5284
5285 Totally extraordinary, but if that's what it takes...
5286
5287 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
5288 available. Added HAVE_BCOPY and an autoconf test for it; if neither
5289 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
5290 assumes the way PCRE uses memmove() (always moving upwards).
5291
5292 6. PCRE is being used in one environment where strchr() is not available. There
5293 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
5294 faster code anyway.
5295
5296
5297 Version 3.1 09-Feb-00
5298 ---------------------
5299
5300 The only change in this release is the fixing of some bugs in Makefile.in for
5301 the "install" target:
5302
5303 (1) It was failing to install pcreposix.h.
5304
5305 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
5306
5307
5308 Version 3.0 01-Feb-00
5309 ---------------------
5310
5311 1. Add support for the /+ modifier to perltest (to output $` like it does in
5312 pcretest).
5313
5314 2. Add support for the /g modifier to perltest.
5315
5316 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
5317 matches null strings.
5318
5319 4. Fix perltest so that it doesn't do unwanted things when fed an empty
5320 pattern. Perl treats empty patterns specially - it reuses the most recent
5321 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
5322 effect.
5323
5324 5. The POSIX interface was broken in that it was just handing over the POSIX
5325 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
5326 required a bigger vector, with some working space on the end. This means that
5327 the POSIX wrapper now has to get and free some memory, and copy the results.
5328
5329 6. Added some simple autoconf support, placing the test data and the
5330 documentation in separate directories, re-organizing some of the
5331 information files, and making it build pcre-config (a GNU standard). Also added
5332 libtool support for building PCRE as a shared library, which is now the
5333 default.
5334
5335 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
5336 09 are not valid octal constants. Single digits will be used for minor values
5337 less than 10.
5338
5339 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
5340 existing programs that set these in the POSIX interface can use PCRE without
5341 modification.
5342
5343 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
5344 return all that pcre_info() returns, plus additional data. The pcre_info()
5345 function is retained for compatibility, but is considered to be obsolete.
5346
5347 10. Added experimental recursion feature (?R) to handle one common case that
5348 Perl 5.6 will be able to do with (?p{...}).
5349
5350 11. Added support for POSIX character classes like [:alpha:], which Perl is
5351 adopting.
5352
5353
5354 Version 2.08 31-Aug-99
5355 ----------------------
5356
5357 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
5358 trying to match at the startoffset position, but instead was moving forward to
5359 the next newline as if a previous match had failed.
5360
5361 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
5362 and could get into a loop if a null string was matched other than at the start
5363 of the subject.
5364
5365 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
5366 be distinguished at compile time, and for completeness also added PCRE_DATE.
5367
5368 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
5369 in GnuWin32 environments.
5370
5371
5372 Version 2.07 29-Jul-99
5373 ----------------------
5374
5375 1. The documentation is now supplied in plain text form and HTML as well as in
5376 the form of man page sources.
5377
5378 2. C++ compilers don't like assigning (void *) values to other pointer types.
5379 In particular this affects malloc(). Although there is no problem in Standard
5380 C, I've put in casts to keep C++ compilers happy.
5381
5382 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
5383 should be (const char *).
5384
5385 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
5386 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
5387 However, I haven't made this a standard facility. The documentation doesn't
5388 mention it, and the Makefile doesn't support it.
5389
5390 5. The Makefile now contains an "install" target, with editable destinations at
5391 the top of the file. The pcretest program is not installed.
5392
5393 6. pgrep -V now gives the PCRE version number and date.
5394
5395 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
5396 causing the entire string to be ignored, instead of just the last character.
5397
5398 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
5399 non-matching string, it can take a very, very long time, even for strings of
5400 quite modest length, because of the nested recursion. PCRE now does better in
5401 some of these cases. It does this by remembering the last required literal
5402 character in the pattern, and pre-searching the subject to ensure it is present
5403 before running the real match. In other words, it applies a heuristic to detect
5404 some types of certain failure quickly, and in the above example, if presented
5405 with a string that has no trailing " it gives "no match" very quickly.
5406
5407 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
5408 other alternatives are tried instead.
5409
5410
5411 Version 2.06 09-Jun-99
5412 ----------------------
5413
5414 1. Change pcretest's output for amount of store used to show just the code
5415 space, because the remainder (the data block) varies in size between 32-bit and
5416 64-bit systems.
5417
5418 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
5419 start matching at. This allows lookbehinds to work when searching for multiple
5420 occurrences in a string.
5421
5422 3. Added additional options to pcretest for testing multiple occurrences:
5423
5424 /+ outputs the rest of the string that follows a match
5425 /g loops for multiple occurrences, using the new startoffset argument
5426 /G loops for multiple occurrences by passing an incremented pointer
5427
5428 4. PCRE wasn't doing the "first character" optimization for patterns starting
5429 with \b or \B, though it was doing it for other lookbehind assertions. That is,
5430 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
5431 the letter 'x'. On long subject strings, this gives a significant speed-up.
5432
5433
5434 Version 2.05 21-Apr-99
5435 ----------------------
5436
5437 1. Changed the type of magic_number from int to long int so that it works
5438 properly on 16-bit systems.
5439
5440 2. Fixed a bug which caused patterns starting with .* not to work correctly
5441 when the subject string contained newline characters. PCRE was assuming
5442 anchoring for such patterns in all cases, which is not correct because .* will
5443 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
5444 DOTALL is set at top level; otherwise it knows that patterns starting with .*
5445 must be retried after every newline in the subject.
5446
5447
5448 Version 2.04 18-Feb-99
5449 ----------------------
5450
5451 1. For parenthesized subpatterns with repeats whose minimum was zero, the
5452 computation of the store needed to hold the pattern was incorrect (too large).
5453 If such patterns were nested a few deep, this could multiply and become a real
5454 problem.
5455
5456 2. Added /M option to pcretest to show the memory requirement of a specific
5457 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
5458
5459 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
5460 compiled in such a way that the backtracking after subsequent failure was
5461 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
5462 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
5463
5464
5465 Version 2.03 02-Feb-99
5466 ----------------------
5467
5468 1. Fixed typo and small mistake in man page.
5469
5470 2. Added 4th condition (GPL supersedes if conflict) and created separate
5471 LICENCE file containing the conditions.
5472
5473 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
5474 Perl, that is the internal \ allows the delimiter to be included in the
5475 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
5476 the final delimiter, add \ to the end of the pattern (to test the error).
5477
5478 4. Added the convenience functions for extracting substrings after a successful
5479 match. Updated pcretest to make it able to test these functions.
5480
5481
5482 Version 2.02 14-Jan-99
5483 ----------------------
5484
5485 1. Initialized the working variables associated with each extraction so that
5486 their saving and restoring doesn't refer to uninitialized store.
5487
5488 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
5489 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
5490 fix the problem.
5491
5492 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
5493 calls, and wasn't printing the correct value for compiling calls. Increased the
5494 default value of LOOPREPEAT, and the number of significant figures in the
5495 times.
5496
5497 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
5498
5499 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
5500 a building problem on Windows NT with a FAT file system.
5501
5502
5503 Version 2.01 21-Oct-98
5504 ----------------------
5505
5506 1. Changed the API for pcre_compile() to allow for the provision of a pointer
5507 to character tables built by pcre_maketables() in the current locale. If NULL
5508 is passed, the default tables are used.
5509
5510
5511 Version 2.00 24-Sep-98
5512 ----------------------
5513
5514 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
5515 it any more.
5516
5517 2. Allow quantification of (?>) groups, and make it work correctly.
5518
5519 3. The first character computation wasn't working for (?>) groups.
5520
5521 4. Correct the implementation of \Z (it is permitted to match on the \n at the
5522 end of the subject) and add 5.005's \z, which really does match only at the
5523 very end of the subject.
5524
5525 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
5526
5527 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
5528 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
5529 localized options. All options to pcre_study() were also removed.
5530
5531 7. Add other new features from 5.005:
5532
5533 $(?<= positive lookbehind
5534 $(?<! negative lookbehind
5535 (?imsx-imsx) added the unsetting capability
5536 such a setting is global if at outer level; local otherwise
5537 (?imsx-imsx:) non-capturing groups with option setting
5538 (?(cond)re|re) conditional pattern matching
5539
5540 A backreference to itself in a repeated group matches the previous
5541 captured string.
5542
5543 8. General tidying up of studying (both automatic and via "study")
5544 consequential on the addition of new assertions.
5545
5546 9. As in 5.005, unlimited repeated groups that could match an empty substring
5547 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5548 runtime if any iteration does actually match an empty substring.
5549
5550 10. Include the RunTest script in the distribution.
5551
5552 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5553 discrepancies, some of which were old and were also with respect to 5.004. They
5554 have now been fixed.
5555
5556
5557 Version 1.09 28-Apr-98
5558 ----------------------
5559
5560 1. A negated single character class followed by a quantifier with a minimum
5561 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5562 program crashes, or just wrong answers. This did not apply to negated classes
5563 containing more than one character, or to minima other than one.
5564
5565
5566 Version 1.08 27-Mar-98
5567 ----------------------
5568
5569 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5570
5571 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5572 latter must appear before anything that relies on it in the pattern.
5573
5574
5575 Version 1.07 16-Feb-98
5576 ----------------------
5577
5578 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5579 repeat of a potentially empty string).
5580
5581
5582 Version 1.06 23-Jan-98
5583 ----------------------
5584
5585 1. Added Markus Oberhumer's little patches for C++.
5586
5587 2. Literal strings longer than 255 characters were broken.
5588
5589
5590 Version 1.05 23-Dec-97
5591 ----------------------
5592
5593 1. Negated character classes containing more than one character were failing if
5594 PCRE_CASELESS was set at run time.
5595
5596
5597 Version 1.04 19-Dec-97
5598 ----------------------
5599
5600 1. Corrected the man page, where some "const" qualifiers had been omitted.
5601
5602 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5603 input syntax.
5604
5605 3. Fixed memory leak which occurred when a regex with back references was
5606 matched with an offsets vector that wasn't big enough. The temporary memory
5607 that is used in this case wasn't being freed if the match failed.
5608
5609 4. Tidied pcretest to ensure it frees memory that it gets.
5610
5611 5. Temporary memory was being obtained in the case where the passed offsets
5612 vector was exactly big enough.
5613
5614 6. Corrected definition of offsetof() from change 5 below.
5615
5616 7. I had screwed up change 6 below and broken the rules for the use of
5617 setjmp(). Now fixed.
5618
5619
5620 Version 1.03 18-Dec-97
5621 ----------------------
5622
5623 1. A erroneous regex with a missing opening parenthesis was correctly
5624 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5625 on some systems.
5626
5627 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5628 it was reported that one broken compiler failed on the former because "code" is
5629 also an independent variable.
5630
5631 3. The erroneous regex a[]b caused an array overrun reference.
5632
5633 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5634 fail on data ending with that character. (It was going on too far, and checking
5635 the next character, typically a binary zero.) This was specific to the
5636 optimized code for single-character negative classes.
5637
5638 5. Added a contributed patch from the TIN world which does the following:
5639
5640 + Add an undef for memmove, in case the the system defines a macro for it.
5641
5642 + Add a definition of offsetof(), in case there isn't one. (I don't know
5643 the reason behind this - offsetof() is part of the ANSI standard - but
5644 it does no harm).
5645
5646 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
5647 most of the places where whitespace preceded '#'. I have given up and
5648 allowed the remaining 2 cases to be at the margin.
5649
5650 + Rename some variables in pcre to eliminate shadowing. This seems very
5651 pedantic, but does no harm, of course.
5652
5653 6. Moved the call to setjmp() into its own function, to get rid of warnings
5654 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
5655
5656 7. Constructs such as \d{8,} were compiling into the equivalent of
5657 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
5658 outcome, but in this particular case used more store than had been allocated,
5659 which caused the bug to be discovered because it threw up an internal error.
5660
5661 8. The debugging code in both pcre and pcretest for outputting the compiled
5662 form of a regex was going wrong in the case of back references followed by
5663 curly-bracketed repeats.
5664
5665
5666 Version 1.02 12-Dec-97
5667 ----------------------
5668
5669 1. Typos in pcre.3 and comments in the source fixed.
5670
5671 2. Applied a contributed patch to get rid of places where it used to remove
5672 'const' from variables, and fixed some signed/unsigned and uninitialized
5673 variable warnings.
5674
5675 3. Added the "runtest" target to Makefile.
5676
5677 4. Set default compiler flag to -O2 rather than just -O.
5678
5679
5680 Version 1.01 19-Nov-97
5681 ----------------------
5682
5683 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
5684 like /([ab]*)*/, that is, for classes with more than one character in them.
5685
5686 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
5687 as /((?>a*))*/ (a PCRE_EXTRA facility).
5688
5689
5690 Version 1.00 18-Nov-97
5691 ----------------------
5692
5693 1. Added compile-time macros to support systems such as SunOS4 which don't have
5694 memmove() or strerror() but have other things that can be used instead.
5695
5696 2. Arranged that "make clean" removes the executables.
5697
5698
5699 Version 0.99 27-Oct-97
5700 ----------------------
5701
5702 1. Fixed bug in code for optimizing classes with only one character. It was
5703 initializing a 32-byte map regardless, which could cause it to run off the end
5704 of the memory it had got.
5705
5706 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
5707
5708
5709 Version 0.98 22-Oct-97
5710 ----------------------
5711
5712 1. Fixed bug in code for handling temporary memory usage when there are more
5713 back references than supplied space in the ovector. This could cause segfaults.
5714
5715
5716 Version 0.97 21-Oct-97
5717 ----------------------
5718
5719 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
5720
5721 2. Optimized negated single characters not to use a bit map.
5722
5723 3. Brought error texts together as macro definitions; clarified some of them;
5724 fixed one that was wrong - it said "range out of order" when it meant "invalid
5725 escape sequence".
5726
5727 4. Changed some char * arguments to const char *.
5728
5729 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
5730
5731 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
5732 pcretest.
5733
5734
5735 Version 0.96 16-Oct-97
5736 ----------------------
5737
5738 1. Added a simple "pgrep" utility to the distribution.
5739
5740 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
5741 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
5742 where "ddd" means "one or more decimal digits".
5743
5744 3. Fixed serious bug. If a pattern had a back reference, but the call to
5745 pcre_exec() didn't supply a large enough ovector to record the related
5746 identifying subpattern, the match always failed. PCRE now remembers the number
5747 of the largest back reference, and gets some temporary memory in which to save
5748 the offsets during matching if necessary, in order to ensure that
5749 backreferences always work.
5750
5751 4. Increased the compatibility with Perl in a number of ways:
5752
5753 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
5754 to request this handling. The option can be set at compile or exec time.
5755
5756 (b) $ matches before a terminating newline by default; an option
5757 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
5758 mode). The option can be set at compile or exec time.
5759
5760 (c) The handling of \ followed by a digit other than 0 is now supposed to be
5761 the same as Perl's. If the decimal number it represents is less than 10
5762 or there aren't that many previous left capturing parentheses, an octal
5763 escape is read. Inside a character class, it's always an octal escape,
5764 even if it is a single digit.
5765
5766 (d) An escaped but undefined alphabetic character is taken as a literal,
5767 unless PCRE_EXTRA is set. Currently this just reserves the remaining
5768 escapes.
5769
5770 (e) {0} is now permitted. (The previous item is removed from the compiled
5771 pattern).
5772
5773 5. Changed all the names of code files so that the basic parts are no longer
5774 than 10 characters, and abolished the teeny "globals.c" file.
5775
5776 6. Changed the handling of character classes; they are now done with a 32-byte
5777 bit map always.
5778
5779 7. Added the -d and /D options to pcretest to make it possible to look at the
5780 internals of compilation without having to recompile pcre.
5781
5782
5783 Version 0.95 23-Sep-97
5784 ----------------------
5785
5786 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
5787 \x20 at the start of a run of normal characters. These were being treated as
5788 real characters, instead of the source characters being re-checked.
5789
5790
5791 Version 0.94 18-Sep-97
5792 ----------------------
5793
5794 1. The functions are now thread-safe, with the caveat that the global variables
5795 containing pointers to malloc() and free() or alternative functions are the
5796 same for all threads.
5797
5798 2. Get pcre_study() to generate a bitmap of initial characters for non-
5799 anchored patterns when this is possible, and use it if passed to pcre_exec().
5800
5801
5802 Version 0.93 15-Sep-97
5803 ----------------------
5804
5805 1. /(b)|(:+)/ was computing an incorrect first character.
5806
5807 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
5808 but not actually doing anything yet.
5809
5810 3. Treat "-" characters in classes that cannot be part of ranges as literals,
5811 as Perl does (e.g. [-az] or [az-]).
5812
5813 4. Set the anchored flag if a branch starts with .* or .*? because that tests
5814 all possible positions.
5815
5816 5. Split up into different modules to avoid including unneeded functions in a
5817 compiled binary. However, compile and exec are still in one module. The "study"
5818 function is split off.
5819
5820 6. The character tables are now in a separate module whose source is generated
5821 by an auxiliary program - but can then be edited by hand if required. There are
5822 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
5823 toupper() in the code.
5824
5825 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
5826 make them global. Abolish the function for setting them, as the caller can now
5827 set them directly.
5828
5829
5830 Version 0.92 11-Sep-97
5831 ----------------------
5832
5833 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
5834 (e.g. /a{1,3}/) was broken (I mis-optimized it).
5835
5836 2. Caseless matching was not working in character classes if the characters in
5837 the pattern were in upper case.
5838
5839 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
5840
5841 4. Make PCRE_ANCHORED public and accept as a compile option.
5842
5843 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
5844 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
5845 pass them.
5846
5847 6. Give an error if bad option bits passed at compile or run time.
5848
5849 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
5850 pcretest to cause it to pass that flag.
5851
5852 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
5853 options, and the first character, if set.
5854
5855 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
5856
5857
5858 Version 0.91 10-Sep-97
5859 ----------------------
5860
5861 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
5862 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
5863
5864 2. PCRE was looping on encountering an indefinitely repeated back reference to
5865 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
5866 Perl does - treats the match as successful.
5867
5868 ****

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