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Revision 1578 - (show annotations)
Mon Jul 20 16:27:31 2015 UTC (4 years, 4 months ago) by ph10
File size: 281436 byte(s)
Fix bug for classes containing \\ sequences.
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
92 Version 8.37 28-April-2015
93 --------------------------
94
95 1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
96 for those parentheses to be closed with whatever has been captured so far.
97 However, it was failing to mark any other groups between the hightest
98 capture so far and the currrent group as "unset". Thus, the ovector for
99 those groups contained whatever was previously there. An example is the
100 pattern /(x)|((*ACCEPT))/ when matched against "abcd".
101
102 2. If an assertion condition was quantified with a minimum of zero (an odd
103 thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
104
105 3. If a pattern in pcretest input had the P (POSIX) modifier followed by an
106 unrecognized modifier, a crash could occur.
107
108 4. An attempt to do global matching in pcretest with a zero-length ovector
109 caused a crash.
110
111 5. Fixed a memory leak during matching that could occur for a subpattern
112 subroutine call (recursive or otherwise) if the number of captured groups
113 that had to be saved was greater than ten.
114
115 6. Catch a bad opcode during auto-possessification after compiling a bad UTF
116 string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
117 UTF with NO_UTF_CHECK is documented as having an undefined outcome.
118
119 7. A UTF pattern containing a "not" match of a non-ASCII character and a
120 subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
121
122 8. When a pattern is compiled, it remembers the highest back reference so that
123 when matching, if the ovector is too small, extra memory can be obtained to
124 use instead. A conditional subpattern whose condition is a check on a
125 capture having happened, such as, for example in the pattern
126 /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
127 setting the highest backreference number. This mattered only if pcre_exec()
128 was called with an ovector that was too small to hold the capture, and there
129 was no other kind of back reference (a situation which is probably quite
130 rare). The effect of the bug was that the condition was always treated as
131 FALSE when the capture could not be consulted, leading to a incorrect
132 behaviour by pcre_exec(). This bug has been fixed.
133
134 9. A reference to a duplicated named group (either a back reference or a test
135 for being set in a conditional) that occurred in a part of the pattern where
136 PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
137 to be incorrectly calculated, leading to overwriting.
138
139 10. A mutually recursive set of back references such as (\2)(\1) caused a
140 segfault at study time (while trying to find the minimum matching length).
141 The infinite loop is now broken (with the minimum length unset, that is,
142 zero).
143
144 11. If an assertion that was used as a condition was quantified with a minimum
145 of zero, matching went wrong. In particular, if the whole group had
146 unlimited repetition and could match an empty string, a segfault was
147 likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
148 assertions to be quantified, but not if they are being used as conditions,
149 so the above pattern is faulted by Perl. PCRE has now been changed so that
150 it also rejects such patterns.
151
152 12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
153 failed to allow the zero-repeat case if pcre2_exec() was called with an
154 ovector too small to capture the group.
155
156 13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
157 Red Hat Product Security:
158
159 (a) A crash if /K and /F were both set with the option to save the compiled
160 pattern.
161
162 (b) Another crash if the option to print captured substrings in a callout
163 was combined with setting a null ovector, for example \O\C+ as a subject
164 string.
165
166 14. A pattern such as "((?2){0,1999}())?", which has a group containing a
167 forward reference repeated a large (but limited) number of times within a
168 repeated outer group that has a zero minimum quantifier, caused incorrect
169 code to be compiled, leading to the error "internal error:
170 previously-checked referenced subpattern not found" when an incorrect
171 memory address was read. This bug was reported as "heap overflow",
172 discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
173 CVE-2015-2325.
174
175 23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
176 call within a group that also contained a recursive back reference caused
177 incorrect code to be compiled. This bug was reported as "heap overflow",
178 discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
179 number CVE-2015-2326.
180
181 24. Computing the size of the JIT read-only data in advance has been a source
182 of various issues, and new ones are still appear unfortunately. To fix
183 existing and future issues, size computation is eliminated from the code,
184 and replaced by on-demand memory allocation.
185
186 25. A pattern such as /(?i)[A-`]/, where characters in the other case are
187 adjacent to the end of the range, and the range contained characters with
188 more than one other case, caused incorrect behaviour when compiled in UTF
189 mode. In that example, the range a-j was left out of the class.
190
191 26. Fix JIT compilation of conditional blocks, which assertion
192 is converted to (*FAIL). E.g: /(?(?!))/.
193
194 27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
195 discovered by the LLVM fuzzer.
196
197 28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
198 when this assertion was used as a condition, for example (?(?!)a|b). In
199 pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
200 error about an unsupported item.
201
202 29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
203 possessification code could take exponential time to complete. A recursion
204 depth limit of 1000 has been imposed to limit the resources used by this
205 optimization.
206
207 30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
208 such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
209 because \S ensures they are all in the class. The code for doing this was
210 interacting badly with the code for computing the amount of space needed to
211 compile the pattern, leading to a buffer overflow. This bug was discovered
212 by the LLVM fuzzer.
213
214 31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
215 other kinds of group caused stack overflow at compile time. This bug was
216 discovered by the LLVM fuzzer.
217
218 32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
219 between a subroutine call and its quantifier was incorrectly compiled,
220 leading to buffer overflow or other errors. This bug was discovered by the
221 LLVM fuzzer.
222
223 33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
224 assertion after (?(. The code was failing to check the character after
225 (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
226 was discovered by the LLVM fuzzer.
227
228 34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
229 a fixed maximum following a group that contains a subroutine reference was
230 incorrectly compiled and could trigger buffer overflow. This bug was
231 discovered by the LLVM fuzzer.
232
233 35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
234 caused a stack overflow instead of the diagnosis of a non-fixed length
235 lookbehind assertion. This bug was discovered by the LLVM fuzzer.
236
237 36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
238 (e.g. /(?<=\Ka)/) could make pcregrep loop.
239
240 37. There was a similar problem to 36 in pcretest for global matches.
241
242 38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
243 and a subsequent item in the pattern caused a non-match, backtracking over
244 the repeated \X did not stop, but carried on past the start of the subject,
245 causing reference to random memory and/or a segfault. There were also some
246 other cases where backtracking after \C could crash. This set of bugs was
247 discovered by the LLVM fuzzer.
248
249 39. The function for finding the minimum length of a matching string could take
250 a very long time if mutual recursion was present many times in a pattern,
251 for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
252 method has been implemented. This infelicity was discovered by the LLVM
253 fuzzer.
254
255 40. Static linking against the PCRE library using the pkg-config module was
256 failing on missing pthread symbols.
257
258
259 Version 8.36 26-September-2014
260 ------------------------------
261
262 1. Got rid of some compiler warnings in the C++ modules that were shown up by
263 -Wmissing-field-initializers and -Wunused-parameter.
264
265 2. The tests for quantifiers being too big (greater than 65535) were being
266 applied after reading the number, and stupidly assuming that integer
267 overflow would give a negative number. The tests are now applied as the
268 numbers are read.
269
270 3. Tidy code in pcre_exec.c where two branches that used to be different are
271 now the same.
272
273 4. The JIT compiler did not generate match limit checks for certain
274 bracketed expressions with quantifiers. This may lead to exponential
275 backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
276 issue should be resolved now.
277
278 5. Fixed an issue, which occures when nested alternatives are optimized
279 with table jumps.
280
281 6. Inserted two casts and changed some ints to size_t in the light of some
282 reported 64-bit compiler warnings (Bugzilla 1477).
283
284 7. Fixed a bug concerned with zero-minimum possessive groups that could match
285 an empty string, which sometimes were behaving incorrectly in the
286 interpreter (though correctly in the JIT matcher). This pcretest input is
287 an example:
288
289 '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
290 NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
291
292 the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
293 JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
294 for an empty string was breaking the inner loop and carrying on at a lower
295 level, when possessive repeated groups should always return to a higher
296 level as they have no backtrack points in them. The empty string test now
297 occurs at the outer level.
298
299 8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
300 ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
301
302 9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
303 doesn't).
304
305 10. Change 8.34/15 introduced a bug that caused the amount of memory needed
306 to hold a pattern to be incorrectly computed (too small) when there were
307 named back references to duplicated names. This could cause "internal
308 error: code overflow" or "double free or corruption" or other memory
309 handling errors.
310
311 11. When named subpatterns had the same prefixes, back references could be
312 confused. For example, in this pattern:
313
314 /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
315
316 the reference to 'Name' was incorrectly treated as a reference to a
317 duplicate name.
318
319 12. A pattern such as /^s?c/mi8 where the optional character has more than
320 one "other case" was incorrectly compiled such that it would only try to
321 match starting at "c".
322
323 13. When a pattern starting with \s was studied, VT was not included in the
324 list of possible starting characters; this should have been part of the
325 8.34/18 patch.
326
327 14. If a character class started [\Qx]... where x is any character, the class
328 was incorrectly terminated at the ].
329
330 15. If a pattern that started with a caseless match for a character with more
331 than one "other case" was studied, PCRE did not set up the starting code
332 unit bit map for the list of possible characters. Now it does. This is an
333 optimization improvement, not a bug fix.
334
335 16. The Unicode data tables have been updated to Unicode 7.0.0.
336
337 17. Fixed a number of memory leaks in pcregrep.
338
339 18. Avoid a compiler warning (from some compilers) for a function call with
340 a cast that removes "const" from an lvalue by using an intermediate
341 variable (to which the compiler does not object).
342
343 19. Incorrect code was compiled if a group that contained an internal recursive
344 back reference was optional (had quantifier with a minimum of zero). This
345 example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
346 caused segmentation faults because of stack overflows at compile time.
347
348 20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
349 group that is quantified with an indefinite repeat, caused a compile-time
350 loop which used up all the system stack and provoked a segmentation fault.
351 This was not the same bug as 19 above.
352
353 21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
354 Patch by Mike Frysinger.
355
356
357 Version 8.35 04-April-2014
358 --------------------------
359
360 1. A new flag is set, when property checks are present in an XCLASS.
361 When this flag is not set, PCRE can perform certain optimizations
362 such as studying these XCLASS-es.
363
364 2. The auto-possessification of character sets were improved: a normal
365 and an extended character set can be compared now. Furthermore
366 the JIT compiler optimizes more character set checks.
367
368 3. Got rid of some compiler warnings for potentially uninitialized variables
369 that show up only when compiled with -O2.
370
371 4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
372 of a match later then the end of the match. The pcretest program was not
373 handling the case sensibly - it was outputting from the start to the next
374 binary zero. It now reports this situation in a message, and outputs the
375 text from the end to the start.
376
377 5. Fast forward search is improved in JIT. Instead of the first three
378 characters, any three characters with fixed position can be searched.
379 Search order: first, last, middle.
380
381 6. Improve character range checks in JIT. Characters are read by an inprecise
382 function now, which returns with an unknown value if the character code is
383 above a certain threshold (e.g: 256). The only limitation is that the value
384 must be bigger than the threshold as well. This function is useful when
385 the characters above the threshold are handled in the same way.
386
387 7. The macros whose names start with RAWUCHAR are placeholders for a future
388 mode in which only the bottom 21 bits of 32-bit data items are used. To
389 make this more memorable for those maintaining the code, the names have
390 been changed to start with UCHAR21, and an extensive comment has been added
391 to their definition.
392
393 8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
394 to the export list in Makefile.am (they were accidentally omitted from the
395 8.34 tarball).
396
397 9. The informational output from pcretest used the phrase "starting byte set"
398 which is inappropriate for the 16-bit and 32-bit libraries. As the output
399 for "first char" and "need char" really means "non-UTF-char", I've changed
400 "byte" to "char", and slightly reworded the output. The documentation about
401 these values has also been (I hope) clarified.
402
403 10. Another JIT related optimization: use table jumps for selecting the correct
404 backtracking path, when more than four alternatives are present inside a
405 bracket.
406
407 11. Empty match is not possible, when the minimum length is greater than zero,
408 and there is no \K in the pattern. JIT should avoid empty match checks in
409 such cases.
410
411 12. In a caseless character class with UCP support, when a character with more
412 than one alternative case was not the first character of a range, not all
413 the alternative cases were added to the class. For example, s and \x{17f}
414 are both alternative cases for S: the class [RST] was handled correctly,
415 but [R-T] was not.
416
417 13. The configure.ac file always checked for pthread support when JIT was
418 enabled. This is not used in Windows, so I have put this test inside a
419 check for the presence of windows.h (which was already tested for).
420
421 14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
422 The algorithm provides a way to skip certain starting offsets, and usually
423 faster than linear prefix searches.
424
425 15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
426 as for 'fr_FR' and 'french'. For some reason, however, it then used the
427 Windows-specific input and output files, which have 'french' screwed in.
428 So this could never have worked. One of the problems with locales is that
429 they aren't always the same. I have now updated RunTest so that it checks
430 the output of the locale test (test 3) against three different output
431 files, and it allows the test to pass if any one of them matches. With luck
432 this should make the test pass on some versions of Solaris where it was
433 failing. Because of the uncertainty, the script did not used to stop if
434 test 3 failed; it now does. If further versions of a French locale ever
435 come to light, they can now easily be added.
436
437 16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
438 there was a message during ./configure, but it did not stop. This now
439 provokes an error. The invalid example in README has been corrected.
440 If a value less than the minimum is given, the minimum value has always
441 been used, but now a warning is given.
442
443 17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
444 was a bug in the test system, which is now fixed. Also, the list of various
445 configurations that are tested for each release did not have one with both
446 16/32 bits and --enable-bar-anycrlf. It now does.
447
448 18. pcretest was missing "-C bsr" for displaying the \R default setting.
449
450 19. Little endian PowerPC systems are supported now by the JIT compiler.
451
452 20. The fast forward newline mechanism could enter to an infinite loop on
453 certain invalid UTF-8 input. Although we don't support these cases
454 this issue can be fixed by a performance optimization.
455
456 21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
457 not take account if existing stack usage. There is now a new global
458 variable called pcre_stack_guard that can be set to point to an external
459 function to check stack availability. It is called at the start of
460 processing every parenthesized group.
461
462 22. A typo in the code meant that in ungreedy mode the max/min qualifier
463 behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
464 not match "ab".
465
466 23. When UTF was disabled, the JIT program reported some incorrect compile
467 errors. These messages are silenced now.
468
469 24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
470 compiler.
471
472 25. Change all the temporary files used in RunGrepTest to be different to those
473 used by RunTest so that the tests can be run simultaneously, for example by
474 "make -j check".
475
476
477 Version 8.34 15-December-2013
478 -----------------------------
479
480 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
481 executable memory. Patch inspired by Carsten Klein.
482
483 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
484 this macro is never tested and has no effect, because the work to support
485 coverage involves only compiling and linking options and special targets in
486 the Makefile. The comment in config.h implied that defining the macro would
487 enable coverage support, which is totally false. There was also support for
488 setting this macro in the CMake files (my fault, I just copied it from
489 configure). SUPPORT_GCOV has now been removed.
490
491 3. Make a small performance improvement in strlen16() and strlen32() in
492 pcretest.
493
494 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
495 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
496 these cases). There was also one in pcretest.c.
497
498 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
499
500 6. In UTF mode, the code for checking whether a group could match an empty
501 string (which is used for indefinitely repeated groups to allow for
502 breaking an infinite loop) was broken when the group contained a repeated
503 negated single-character class with a character that occupied more than one
504 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
505 UTF-8 mode). The effect was undefined: the group might or might not be
506 deemed as matching an empty string, or the program might have crashed.
507
508 7. The code for checking whether a group could match an empty string was not
509 recognizing that \h, \H, \v, \V, and \R must match a character.
510
511 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
512 an empty string. If it can, pcretest shows this in its information output.
513
514 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
515 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
516 matched by pcre_exec() without using JIT:
517
518 (a) If the rest of the pattern did not match after a maximal run of
519 grapheme clusters, the code for backing up to try with fewer of them
520 did not always back up over a full grapheme when characters that do not
521 have the modifier quality were involved, e.g. Hangul syllables.
522
523 (b) If the match point in a subject started with modifier character, and
524 there was no match, the code could incorrectly back up beyond the match
525 point, and potentially beyond the first character in the subject,
526 leading to a segfault or an incorrect match result.
527
528 10. A conditional group with an assertion condition could lead to PCRE
529 recording an incorrect first data item for a match if no other first data
530 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
531 first data item, and therefore matched "ca" after "c" instead of at the
532 start.
533
534 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
535 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
536
537 12. The source of pcregrep now includes z/OS-specific code so that it can be
538 compiled for z/OS as part of the special z/OS distribution.
539
540 13. Added the -T and -TM options to pcretest.
541
542 14. The code in pcre_compile.c for creating the table of named capturing groups
543 has been refactored. Instead of creating the table dynamically during the
544 actual compiling pass, the information is remembered during the pre-compile
545 pass (on the stack unless there are more than 20 named groups, in which
546 case malloc() is used) and the whole table is created before the actual
547 compile happens. This has simplified the code (it is now nearly 150 lines
548 shorter) and prepared the way for better handling of references to groups
549 with duplicate names.
550
551 15. A back reference to a named subpattern when there is more than one of the
552 same name now checks them in the order in which they appear in the pattern.
553 The first one that is set is used for the reference. Previously only the
554 first one was inspected. This change makes PCRE more compatible with Perl.
555
556 16. Unicode character properties were updated from Unicode 6.3.0.
557
558 17. The compile-time code for auto-possessification has been refactored, based
559 on a patch by Zoltan Herczeg. It now happens after instead of during
560 compilation. The code is cleaner, and more cases are handled. The option
561 PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
562 options in pcretest are provided to set it. It can also be set by
563 (*NO_AUTO_POSSESS) at the start of a pattern.
564
565 18. The character VT has been added to the default ("C" locale) set of
566 characters that match \s and are generally treated as white space,
567 following this same change in Perl 5.18. There is now no difference between
568 "Perl space" and "POSIX space". Whether VT is treated as white space in
569 other locales depends on the locale.
570
571 19. The code for checking named groups as conditions, either for being set or
572 for being recursed, has been refactored (this is related to 14 and 15
573 above). Processing unduplicated named groups should now be as fast at
574 numerical groups, and processing duplicated groups should be faster than
575 before.
576
577 20. Two patches to the CMake build system, by Alexander Barkov:
578
579 (1) Replace the "source" command by "." in CMakeLists.txt because
580 "source" is a bash-ism.
581
582 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
583 without these the CMake build does not work on Solaris.
584
585 21. Perl has changed its handling of \8 and \9. If there is no previously
586 encountered capturing group of those numbers, they are treated as the
587 literal characters 8 and 9 instead of a binary zero followed by the
588 literals. PCRE now does the same.
589
590 22. Following Perl, added \o{} to specify codepoints in octal, making it
591 possible to specify values greater than 0777 and also making them
592 unambiguous.
593
594 23. Perl now gives an error for missing closing braces after \x{... instead of
595 treating the string as literal. PCRE now does the same.
596
597 24. RunTest used to grumble if an inappropriate test was selected explicitly,
598 but just skip it when running all tests. This make it awkward to run ranges
599 of tests when one of them was inappropriate. Now it just skips any
600 inappropriate tests, as it always did when running all tests.
601
602 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
603 character types such as \d or \w, too many callouts were inserted, and the
604 data that they returned was rubbish.
605
606 26. In UCP mode, \s was not matching two of the characters that Perl matches,
607 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
608 were matched by \h. The code has now been refactored so that the lists of
609 the horizontal and vertical whitespace characters used for \h and \v (which
610 are defined only in one place) are now also used for \s.
611
612 27. Add JIT support for the 64 bit TileGX architecture.
613 Patch by Jiong Wang (Tilera Corporation).
614
615 28. Possessive quantifiers for classes (both explicit and automatically
616 generated) now use special opcodes instead of wrapping in ONCE brackets.
617
618 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
619 (because it's meaningless), this was not happening when PCRE_CASELESS was
620 set. Not wrong, but inefficient.
621
622 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
623 properties for \w, \d, etc) is present in a test regex. Otherwise if the
624 test contains no characters greater than 255, Perl doesn't realise it
625 should be using Unicode semantics.
626
627 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
628 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
629 does in Unicode mode.
630
631 32. Added the "forbid" facility to pcretest so that putting tests into the
632 wrong test files can sometimes be quickly detected.
633
634 33. There is now a limit (default 250) on the depth of nesting of parentheses.
635 This limit is imposed to control the amount of system stack used at compile
636 time. It can be changed at build time by --with-parens-nest-limit=xxx or
637 the equivalent in CMake.
638
639 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
640 errors. Perl warns for these when in warning mode, but PCRE has no facility
641 for giving warnings.
642
643 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
644 However, this was not working for (?!) because it is optimized to (*FAIL),
645 for which PCRE does not allow quantifiers. The optimization is now disabled
646 when a quantifier follows (?!). I can't see any use for this, but it makes
647 things uniform.
648
649 36. Perl no longer allows group names to start with digits, so I have made this
650 change also in PCRE. It simplifies the code a bit.
651
652 37. In extended mode, Perl ignores spaces before a + that indicates a
653 possessive quantifier. PCRE allowed a space before the quantifier, but not
654 before the possessive +. It now does.
655
656 38. The use of \K (reset reported match start) within a repeated possessive
657 group such as (a\Kb)*+ was not working.
658
659 40. Document that the same character tables must be used at compile time and
660 run time, and that the facility to pass tables to pcre_exec() and
661 pcre_dfa_exec() is for use only with saved/restored patterns.
662
663 41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
664 features for Builds with MSVC:
665
666 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
667 builds). The .rc files can be used to set FileDescription and many other
668 attributes.
669
670 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
671 This allows higher-level build scripts which want .pdb files to avoid
672 hard-coding the exact files needed."
673
674 42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
675 mean "start of word" and "end of word", respectively, as a transition aid.
676
677 43. A minimizing repeat of a class containing codepoints greater than 255 in
678 non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
679 compiled to use the heap for recursion.
680
681 44. Got rid of some compiler warnings for unused variables when UTF but not UCP
682 is configured.
683
684
685 Version 8.33 28-May-2013
686 ------------------------
687
688 1. Added 'U' to some constants that are compared to unsigned integers, to
689 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
690 variables that are added to signed variables, to ensure the result is
691 signed and can be negated.
692
693 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
694 CMake config files.
695
696 3. Revise the creation of config.h.generic so that all boolean macros are
697 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
698 overriding via -D on the command line possible.
699
700 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
701 to unsigned int is reported to make a quite noticeable speed difference in
702 a specific Windows environment. Testing on Linux did also appear to show
703 some benefit (and it is clearly not harmful). Also fixed the definition of
704 Xop which should be unsigned.
705
706 5. Related to (4), changing the definition of the intermediate variable cc
707 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
708 improvements.
709
710 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
711 unnecessary spaces.
712
713 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
714 and later.
715
716 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
717
718 9. Optimizing fast_forward_start_bits in JIT.
719
720 10. Adding support for callouts in JIT, and fixing some issues revealed
721 during this work. Namely:
722
723 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
724
725 (b) Minimum length was not checked before the matching is started.
726
727 11. The value of capture_last that is passed to callouts was incorrect in some
728 cases when there was a capture on one path that was subsequently abandoned
729 after a backtrack. Also, the capture_last value is now reset after a
730 recursion, since all captures are also reset in this case.
731
732 12. The interpreter no longer returns the "too many substrings" error in the
733 case when an overflowing capture is in a branch that is subsequently
734 abandoned after a backtrack.
735
736 13. In the pathological case when an offset vector of size 2 is used, pcretest
737 now prints out the matched string after a yield of 0 or 1.
738
739 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
740 Only supported by the JIT compiler at the moment.
741
742 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
743
744 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
745 offset of the starting point of the matching process, provided the offsets
746 vector is large enough.
747
748 17. The \A escape now records a lookbehind value of 1, though its execution
749 does not actually inspect the previous character. This is to ensure that,
750 in partial multi-segment matching, at least one character from the old
751 segment is retained when a new segment is processed. Otherwise, if there
752 are no lookbehinds in the pattern, \A might match incorrectly at the start
753 of a new segment.
754
755 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
756
757 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
758 gives some modest performance improvement in 8-bit mode.
759
760 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
761 be expressed in certain programming languages using Universal Character
762 Names.
763
764 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
765 which points out that "non characters" are not "characters that may not
766 appear in Unicode strings" but rather "characters that are reserved for
767 internal use and have only local meaning".
768
769 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
770 there was a conditional group that depended on an assertion, if the
771 assertion was false, the callout that immediately followed the alternation
772 in the condition was skipped when pcre_exec() was used for matching.
773
774 23. Allow an explicit callout to be inserted before an assertion that is the
775 condition for a conditional group, for compatibility with automatic
776 callouts, which always insert a callout at this point.
777
778 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
779 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
780
781 25. (*PRUNE) is now supported by the JIT compiler.
782
783 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
784
785 27. Fix the case where there are two or more SKIPs with arguments that may be
786 ignored.
787
788 28. (*SKIP) is now supported by the JIT compiler.
789
790 29. (*THEN) is now supported by the JIT compiler.
791
792 30. Update RunTest with additional test selector options.
793
794 31. The way PCRE handles backtracking verbs has been changed in two ways.
795
796 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
797 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
798 backtracking. In some cases this makes it more Perl-compatible, but Perl's
799 rather obscure rules do not always do the same thing.
800
801 (2) Previously, backtracking verbs were confined within assertions. This is
802 no longer the case for positive assertions, except for (*ACCEPT). Again,
803 this sometimes improves Perl compatibility, and sometimes does not.
804
805 32. A number of tests that were in test 2 because Perl did things differently
806 have been moved to test 1, because either Perl or PCRE has changed, and
807 these tests are now compatible.
808
809 32. Backtracking control verbs are now handled in the same way in JIT and
810 interpreter.
811
812 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
813 contained a forward subroutine reference caused a compile error.
814
815 34. Auto-detect and optimize limited repetitions in JIT.
816
817 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
818 blocking (*UTF) etc.
819
820 36. In the interpreter, maximizing pattern repetitions for characters and
821 character types now use tail recursion, which reduces stack usage.
822
823 37. The value of the max lookbehind was not correctly preserved if a compiled
824 and saved regex was reloaded on a host of different endianness.
825
826 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
827 of the compiled pattern block, expand the flags field from 16 to 32 bits
828 because it was almost full.
829
830 39. Try madvise first before posix_madvise.
831
832 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
833 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
834 original change locked out all matches of empty strings. This has been
835 changed so that one match of an empty string per line is recognized.
836 Subsequent searches on the same line (for colouring or for --only-matching,
837 for example) do not recognize empty strings.
838
839 41. Applied a user patch to fix a number of spelling mistakes in comments.
840
841 42. Data lines longer than 65536 caused pcretest to crash.
842
843 43. Clarified the data type for length and startoffset arguments for pcre_exec
844 and pcre_dfa_exec in the function-specific man pages, where they were
845 explicitly stated to be in bytes, never having been updated. I also added
846 some clarification to the pcreapi man page.
847
848 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
849 a segmentation fault.
850
851
852 Version 8.32 30-November-2012
853 -----------------------------
854
855 1. Improved JIT compiler optimizations for first character search and single
856 character iterators.
857
858 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
859 Patch by Daniel Richard G.
860
861 3. Single character iterator optimizations in the JIT compiler.
862
863 4. Improved JIT compiler optimizations for character ranges.
864
865 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
866 Reported by Giuseppe D'Angelo.
867
868 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
869 of a line, was being set incorrectly in cases where .* appeared inside
870 atomic brackets at the start of a pattern, or where there was a subsequent
871 *PRUNE or *SKIP.
872
873 7. Improved instruction cache flush for POWER/PowerPC.
874 Patch by Daniel Richard G.
875
876 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
877 grep:
878
879 (a) There is now no limit to the number of patterns to be matched.
880
881 (b) An error is given if a pattern is too long.
882
883 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
884 are now supported.
885
886 (d) --exclude-from and --include-from (multiple use) have been added.
887
888 (e) Exclusions and inclusions now apply to all files and directories, not
889 just to those obtained from scanning a directory recursively.
890
891 (f) Multiple uses of -f and --file-list are now supported.
892
893 (g) In a Windows environment, the default for -d has been changed from
894 "read" (the GNU grep default) to "skip", because otherwise the presence
895 of a directory in the file list provokes an error.
896
897 (h) The documentation has been revised and clarified in places.
898
899 9. Improve the matching speed of capturing brackets.
900
901 10. Changed the meaning of \X so that it now matches a Unicode extended
902 grapheme cluster.
903
904 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
905 out POSIX threads when JIT support is configured.
906
907 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
908
909 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
910 structure could go wrong in environments where size_t is not the same size
911 as int.
912
913 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
914 set.
915
916 15. The EBCDIC support had decayed; later updates to the code had included
917 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
918 general tidy up of EBCDIC-related issues, and the documentation was also
919 not quite right. There is now a test that can be run on ASCII systems to
920 check some of the EBCDIC-related things (but is it not a full test).
921
922 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
923 in a small tidy to the code.
924
925 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
926
927 18. If the --only-matching (-o) option in pcregrep is specified multiple
928 times, each one causes appropriate output. For example, -o1 -o2 outputs the
929 substrings matched by the 1st and 2nd capturing parentheses. A separating
930 string can be specified by --om-separator (default empty).
931
932 19. Improving the first n character searches.
933
934 20. Turn case lists for horizontal and vertical white space into macros so that
935 they are defined only once.
936
937 21. This set of changes together give more compatible Unicode case-folding
938 behaviour for characters that have more than one other case when UCP
939 support is available.
940
941 (a) The Unicode property table now has offsets into a new table of sets of
942 three or more characters that are case-equivalent. The MultiStage2.py
943 script that generates these tables (the pcre_ucd.c file) now scans
944 CaseFolding.txt instead of UnicodeData.txt for character case
945 information.
946
947 (b) The code for adding characters or ranges of characters to a character
948 class has been abstracted into a generalized function that also handles
949 case-independence. In UTF-mode with UCP support, this uses the new data
950 to handle characters with more than one other case.
951
952 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
953 whose other case is greater than 256 are now correctly matched
954 caselessly. Previously, the high codepoint matched the low one, but not
955 vice versa.
956
957 (d) The processing of \h, \H, \v, and \ in character classes now makes use
958 of the new class addition function, using character lists defined as
959 macros alongside the case definitions of 20 above.
960
961 (e) Caseless back references now work with characters that have more than
962 one other case.
963
964 (f) General caseless matching of characters with more than one other case
965 is supported.
966
967 22. Unicode character properties were updated from Unicode 6.2.0
968
969 23. Improved CMake support under Windows. Patch by Daniel Richard G.
970
971 24. Add support for 32-bit character strings, and UTF-32
972
973 25. Major JIT compiler update (code refactoring and bugfixing).
974 Experimental Sparc 32 support is added.
975
976 26. Applied a modified version of Daniel Richard G's patch to create
977 pcre.h.generic and config.h.generic by "make" instead of in the
978 PrepareRelease script.
979
980 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
981 pcre_compile.c when checking for a zero character.
982
983 28. Introducing a native interface for JIT. Through this interface, the compiled
984 machine code can be directly executed. The purpose of this interface is to
985 provide fast pattern matching, so several sanity checks are not performed.
986 However, feature tests are still performed. The new interface provides
987 1.4x speedup compared to the old one.
988
989 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
990 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
991 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
992
993 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
994 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
995 the "old" RFC 2279). Instead, it ended up passing a negative length to
996 pcre_exec().
997
998 31. Add support for GCC's visibility feature to hide internal functions.
999
1000 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
1001 "unknown -C option" after outputting 0 or 1.
1002
1003 33. There is now support for generating a code coverage report for the test
1004 suite in environments where gcc is the compiler and lcov is installed. This
1005 is mainly for the benefit of the developers.
1006
1007 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
1008 unaddressable using valgrind annotations, allowing valgrind to detect
1009 invalid memory accesses. This is mainly for the benefit of the developers.
1010
1011 25. (*UTF) can now be used to start a pattern in any of the three libraries.
1012
1013 26. Give configure error if --enable-cpp but no C++ compiler found.
1014
1015
1016 Version 8.31 06-July-2012
1017 -------------------------
1018
1019 1. Fixing a wrong JIT test case and some compiler warnings.
1020
1021 2. Removed a bashism from the RunTest script.
1022
1023 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1024 to unsigned type, result still unsigned" that was given by an MS compiler
1025 on encountering the code "-sizeof(xxx)".
1026
1027 4. Partial matching support is added to the JIT compiler.
1028
1029 5. Fixed several bugs concerned with partial matching of items that consist
1030 of more than one character:
1031
1032 (a) /^(..)\1/ did not partially match "aba" because checking references was
1033 done on an "all or nothing" basis. This also applied to repeated
1034 references.
1035
1036 (b) \R did not give a hard partial match if \r was found at the end of the
1037 subject.
1038
1039 (c) \X did not give a hard partial match after matching one or more
1040 characters at the end of the subject.
1041
1042 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1043 a partial match for the string "\r".
1044
1045 (e) When newline was set to CRLF, the metacharacter "." did not recognize
1046 a partial match for a CR character at the end of the subject string.
1047
1048 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1049 running pcretest, the text "(JIT)" added to the output whenever JIT is
1050 actually used to run the match.
1051
1052 7. Individual JIT compile options can be set in pcretest by following -s+[+]
1053 or /S+[+] with a digit between 1 and 7.
1054
1055 8. OP_NOT now supports any UTF character not just single-byte ones.
1056
1057 9. (*MARK) control verb is now supported by the JIT compiler.
1058
1059 10. The command "./RunTest list" lists the available tests without actually
1060 running any of them. (Because I keep forgetting what they all are.)
1061
1062 11. Add PCRE_INFO_MAXLOOKBEHIND.
1063
1064 12. Applied a (slightly modified) user-supplied patch that improves performance
1065 when the heap is used for recursion (compiled with --disable-stack-for-
1066 recursion). Instead of malloc and free for each heap frame each time a
1067 logical recursion happens, frames are retained on a chain and re-used where
1068 possible. This sometimes gives as much as 30% improvement.
1069
1070 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1071 call.
1072
1073 14. As documented, (*COMMIT) is now confined to within a positive assertion.
1074
1075 15. It is now possible to link pcretest with libedit as an alternative to
1076 libreadline.
1077
1078 16. (*COMMIT) control verb is now supported by the JIT compiler.
1079
1080 17. The Unicode data tables have been updated to Unicode 6.1.0.
1081
1082 18. Added --file-list option to pcregrep.
1083
1084 19. Added binary file support to pcregrep, including the -a, --binary-files,
1085 -I, and --text options.
1086
1087 20. The madvise function is renamed for posix_madvise for QNX compatibility
1088 reasons. Fixed by Giuseppe D'Angelo.
1089
1090 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1091
1092 22. Changed the option for creating symbolic links for 16-bit man pages from
1093 -s to -sf so that re-installing does not cause issues.
1094
1095 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1096
1097 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1098 matches in certain environments (the workspace was not being correctly
1099 retained). Also added to pcre_dfa_exec() a simple plausibility check on
1100 some of the workspace data at the beginning of a restart.
1101
1102 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1103 was not doing so when it should - probably a typo introduced by SVN 528
1104 (change 8.10/14).
1105
1106 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1107 \w+ when the character tables indicated that \x{c4} was a word character.
1108 There were several related cases, all because the tests for doing a table
1109 lookup were testing for characters less than 127 instead of 255.
1110
1111 27. If a pattern contains capturing parentheses that are not used in a match,
1112 their slots in the ovector are set to -1. For those that are higher than
1113 any matched groups, this happens at the end of processing. In the case when
1114 there were back references that the ovector was too small to contain
1115 (causing temporary malloc'd memory to be used during matching), and the
1116 highest capturing number was not used, memory off the end of the ovector
1117 was incorrectly being set to -1. (It was using the size of the temporary
1118 memory instead of the true size.)
1119
1120 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1121 ovector size, it uses memory at the end of the block that it has got.
1122
1123 29. Check for an overlong MARK name and give an error at compile time. The
1124 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1125
1126 30. JIT compiler update.
1127
1128 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1129 Rill for the patch.
1130
1131 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1132
1133 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1134
1135 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1136 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1137 was enabled.
1138
1139 35. Improve JIT code generation for greedy plus quantifier.
1140
1141 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1142 1 to "aa" instead of to an empty string. The bug affected repeated groups
1143 that could potentially match an empty string.
1144
1145 37. Optimizing single character iterators in JIT.
1146
1147 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1148 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1149 codepoints that are too big for the mode are faulted, and in a UTF mode,
1150 disallowed codepoints are also faulted.
1151
1152 39. If PCRE was compiled with UTF support, in three places in the DFA
1153 matcher there was code that should only have been obeyed in UTF mode, but
1154 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1155 processing when bytes with values greater than 127 were present. In 16-bit
1156 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1157 both cases the values are those that cannot be the first data item in a UTF
1158 character. The three items that might have provoked this were recursions,
1159 possessively repeated groups, and atomic groups.
1160
1161 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1162 and pcregrep, because some OS require shared objects to be explicitly
1163 passed to ld, causing the link step to fail if they are not.
1164
1165 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1166 mode, patterns that started with \h* or \R* might be incorrectly matched.
1167
1168
1169 Version 8.30 04-February-2012
1170 -----------------------------
1171
1172 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
1173 name is defined in ctype.h.
1174
1175 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
1176 only in quite long subpatterns.
1177
1178 3. Removed the function pcre_info(), which has been obsolete and deprecated
1179 since it was replaced by pcre_fullinfo() in February 2000.
1180
1181 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
1182 match a (*MARK), and the match failed at the start of the subject, a
1183 reference to memory before the start of the subject could occur. This bug
1184 was introduced by fix 17 of release 8.21.
1185
1186 5. A reference to an unset group with zero minimum repetition was giving
1187 totally wrong answers (in non-JavaScript-compatibility mode). For example,
1188 /(another)?(\1?)test/ matched against "hello world test". This bug was
1189 introduced in release 8.13.
1190
1191 6. Add support for 16-bit character strings (a large amount of work involving
1192 many changes and refactorings).
1193
1194 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1195 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1196 from a file.
1197
1198 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1199 rounding is not applied in this particular case).
1200
1201 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1202 if they appear, or are escaped, in patterns.
1203
1204 10. Get rid of a number of -Wunused-but-set-variable warnings.
1205
1206 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1207 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1208 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1209 also returns the mark "x". This bug applied to capturing parentheses,
1210 non-capturing parentheses, and atomic parentheses. It also applied to some
1211 assertions.
1212
1213 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1214 information out of configure.ac instead of relying on pcre.h.generic, which
1215 is not stored in the repository.
1216
1217 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1218 -lreadline.
1219
1220 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1221
1222 15. Applied Graycode's patch to put the top-level frame on the stack rather
1223 than the heap when not using the stack for recursion. This gives a
1224 performance improvement in many cases when recursion is not deep.
1225
1226 16. Experimental code added to "pcretest -C" to output the stack frame size.
1227
1228
1229 Version 8.21 12-Dec-2011
1230 ------------------------
1231
1232 1. Updating the JIT compiler.
1233
1234 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1235 are added as well.
1236
1237 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1238 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1239 calling _pcre_jit_exec. Some extra comments are added.
1240
1241 4. (*MARK) settings inside atomic groups that do not contain any capturing
1242 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1243 was introduced by change 18 for 8.20.
1244
1245 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1246 ECMA-262 standard.
1247
1248 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1249 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1250 This bug was probably introduced by change 9 of 8.13.
1251
1252 7. While fixing 6 above, I noticed that a number of other items were being
1253 incorrectly rejected as "not fixed length". This arose partly because newer
1254 opcodes had not been added to the fixed-length checking code. I have (a)
1255 corrected the bug and added tests for these items, and (b) arranged for an
1256 error to occur if an unknown opcode is encountered while checking for fixed
1257 length instead of just assuming "not fixed length". The items that were
1258 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1259 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1260 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1261
1262 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1263 being incorrectly compiled and would have given unpredicatble results.
1264
1265 9. A possessively repeated subpattern with minimum repeat count greater than
1266 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1267 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1268 the first (A) could occur when it should not.
1269
1270 10. Add a cast and remove a redundant test from the code.
1271
1272 11. JIT should use pcre_malloc/pcre_free for allocation.
1273
1274 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1275 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1276 is anything other than /usr, -L is still shown).
1277
1278 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1279
1280 14. Perl does not support \N without a following name in a [] class; PCRE now
1281 also gives an error.
1282
1283 15. If a forward reference was repeated with an upper limit of around 2000,
1284 it caused the error "internal error: overran compiling workspace". The
1285 maximum number of forward references (including repeats) was limited by the
1286 internal workspace, and dependent on the LINK_SIZE. The code has been
1287 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1288 the default depends on LINK_SIZE. There is a new upper limit (for safety)
1289 of around 200,000 forward references. While doing this, I also speeded up
1290 the filling in of repeated forward references.
1291
1292 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1293 incorrectly expecting the subject to contain another "a" after the start.
1294
1295 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1296 in the match, the SKIP should be ignored. This was not happening; instead
1297 the SKIP was being treated as NOMATCH. For patterns such as
1298 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1299 tested.
1300
1301 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1302 now much more compatible with Perl, in particular in cases where the result
1303 is a non-match for a non-anchored pattern. For example, if
1304 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1305 "m", where previously it did not return a name. A side effect of this
1306 change is that for partial matches, the last encountered mark name is
1307 returned, as for non matches. A number of tests that were previously not
1308 Perl-compatible have been moved into the Perl-compatible test files. The
1309 refactoring has had the pleasing side effect of removing one argument from
1310 the match() function, thus reducing its stack requirements.
1311
1312 19. If the /S+ option was used in pcretest to study a pattern using JIT,
1313 subsequent uses of /S (without +) incorrectly behaved like /S+.
1314
1315 21. Retrieve executable code size support for the JIT compiler and fixing
1316 some warnings.
1317
1318 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1319 not work when the shorter character appeared right at the end of the
1320 subject string.
1321
1322 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1323 systems.
1324
1325 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1326 output it when the /M option is used in pcretest.
1327
1328 25. The CheckMan script was not being included in the distribution. Also, added
1329 an explicit "perl" to run Perl scripts from the PrepareRelease script
1330 because this is reportedly needed in Windows.
1331
1332 26. If study data was being save in a file and studying had not found a set of
1333 "starts with" bytes for the pattern, the data written to the file (though
1334 never used) was taken from uninitialized memory and so caused valgrind to
1335 complain.
1336
1337 27. Updated RunTest.bat as provided by Sheri Pierce.
1338
1339 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1340
1341 29. Computation of memory usage for the table of capturing group names was
1342 giving an unnecessarily large value.
1343
1344
1345 Version 8.20 21-Oct-2011
1346 ------------------------
1347
1348 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1349 a POSIX class. After further experiments with Perl, which convinced me that
1350 Perl has bugs and confusions, a closing square bracket is no longer allowed
1351 in a POSIX name. This bug also affected patterns with classes that started
1352 with full stops.
1353
1354 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1355 captured substring, but while checking the failing first alternative,
1356 substring 1 is temporarily captured. If the output vector supplied to
1357 pcre_exec() was not big enough for this capture, the yield of the function
1358 was still zero ("insufficient space for captured substrings"). This cannot
1359 be totally fixed without adding another stack variable, which seems a lot
1360 of expense for a edge case. However, I have improved the situation in cases
1361 such as /(a)(b)x|abc/ matched against "abc", where the return code
1362 indicates that fewer than the maximum number of slots in the ovector have
1363 been set.
1364
1365 3. Related to (2) above: when there are more back references in a pattern than
1366 slots in the output vector, pcre_exec() uses temporary memory during
1367 matching, and copies in the captures as far as possible afterwards. It was
1368 using the entire output vector, but this conflicts with the specification
1369 that only 2/3 is used for passing back captured substrings. Now it uses
1370 only the first 2/3, for compatibility. This is, of course, another edge
1371 case.
1372
1373 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
1374 main code base, and can be used by building with --enable-jit. When this is
1375 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1376 runtime --no-jit option is given.
1377
1378 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
1379 ovector, the return from the function was zero, implying that there were
1380 other matches that did not fit. The correct "exactly full" value is now
1381 returned.
1382
1383 6. If a subpattern that was called recursively or as a subroutine contained
1384 (*PRUNE) or any other control that caused it to give a non-standard return,
1385 invalid errors such as "Error -26 (nested recursion at the same subject
1386 position)" or even infinite loops could occur.
1387
1388 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1389 computing the minimum length on reaching *ACCEPT, and so ended up with the
1390 wrong value of 1 rather than 0. Further investigation indicates that
1391 computing a minimum subject length in the presence of *ACCEPT is difficult
1392 (think back references, subroutine calls), and so I have changed the code
1393 so that no minimum is registered for a pattern that contains *ACCEPT.
1394
1395 8. If (*THEN) was present in the first (true) branch of a conditional group,
1396 it was not handled as intended. [But see 16 below.]
1397
1398 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1399 Sheri Pierce.
1400
1401 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1402 the first byte in a match must be "a".
1403
1404 11. Change 17 for 8.13 increased the recursion depth for patterns like
1405 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1406 pattern contains any instances of (*THEN). If it does not, the old
1407 optimizations are restored. It would be nice to do this on a per-group
1408 basis, but at the moment that is not feasible.
1409
1410 12. In some environments, the output of pcretest -C is CRLF terminated. This
1411 broke RunTest's code that checks for the link size. A single white space
1412 character after the value is now allowed for.
1413
1414 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1415 For "fr", it uses the Windows-specific input and output files.
1416
1417 14. If (*THEN) appeared in a group that was called recursively or as a
1418 subroutine, it did not work as intended. [But see next item.]
1419
1420 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1421 pattern fragments (but not containing any | characters). If A and B are
1422 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1423 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1424 D. In other words, Perl considers parentheses that do not contain any |
1425 characters to be part of a surrounding alternative, whereas PCRE was
1426 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1427 differently. PCRE now behaves in the same way as Perl, except in the case
1428 of subroutine/recursion calls such as (?1) which have in any case always
1429 been different (but PCRE had them first :-).
1430
1431 16. Related to 15 above: Perl does not treat the | in a conditional group as
1432 creating alternatives. Such a group is treated in the same way as an
1433 ordinary group without any | characters when processing (*THEN). PCRE has
1434 been changed to match Perl's behaviour.
1435
1436 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1437 RunGrepTest script failed.
1438
1439 18. Change 22 for version 13 caused atomic groups to use more stack. This is
1440 inevitable for groups that contain captures, but it can lead to a lot of
1441 stack use in large patterns. The old behaviour has been restored for atomic
1442 groups that do not contain any capturing parentheses.
1443
1444 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1445 suppress the check for a minimum subject length at run time. (If it was
1446 given to pcre_exec() or pcre_dfa_exec() it did work.)
1447
1448 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1449 fail to work when decoding hex characters in data strings in EBCDIC
1450 environments.
1451
1452 21. It appears that in at least one Mac OS environment, the isxdigit() function
1453 is implemented as a macro that evaluates to its argument more than once,
1454 contravening the C 90 Standard (I haven't checked a later standard). There
1455 was an instance in pcretest which caused it to go wrong when processing
1456 \x{...} escapes in subject strings. The has been rewritten to avoid using
1457 things like p++ in the argument of isxdigit().
1458
1459
1460 Version 8.13 16-Aug-2011
1461 ------------------------
1462
1463 1. The Unicode data tables have been updated to Unicode 6.0.0.
1464
1465 2. Two minor typos in pcre_internal.h have been fixed.
1466
1467 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1468 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1469 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1470
1471 4. There were a number of related bugs in the code for matching backrefences
1472 caselessly in UTF-8 mode when codes for the characters concerned were
1473 different numbers of bytes. For example, U+023A and U+2C65 are an upper
1474 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1475 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1476 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1477 2-byte code at the end of the subject (it thought there wasn't enough data
1478 left).
1479
1480 5. Comprehensive information about what went wrong is now returned by
1481 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1482 as the output vector has at least 2 elements. The offset of the start of
1483 the failing character and a reason code are placed in the vector.
1484
1485 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
1486 now returned is for the first byte of the failing character, instead of the
1487 last byte inspected. This is an incompatible change, but I hope it is small
1488 enough not to be a problem. It makes the returned offset consistent with
1489 pcre_exec() and pcre_dfa_exec().
1490
1491 7. pcretest now gives a text phrase as well as the error number when
1492 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1493 failure, the offset and reason code are output.
1494
1495 8. When \R was used with a maximizing quantifier it failed to skip backwards
1496 over a \r\n pair if the subsequent match failed. Instead, it just skipped
1497 back over a single character (\n). This seems wrong (because it treated the
1498 two characters as a single entity when going forwards), conflicts with the
1499 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1500 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1501 has been changed.
1502
1503 9. Some internal refactoring has changed the processing so that the handling
1504 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1505 time (the PCRE_DOTALL option was changed this way some time ago: version
1506 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1507 which was always a bit of a fudge. It also means that there is one less
1508 argument for the match() function, which reduces its stack requirements
1509 slightly. This change also fixes an incompatibility with Perl: the pattern
1510 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1511
1512 10. More internal refactoring has drastically reduced the number of recursive
1513 calls to match() for possessively repeated groups such as (abc)++ when
1514 using pcre_exec().
1515
1516 11. While implementing 10, a number of bugs in the handling of groups were
1517 discovered and fixed:
1518
1519 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1520 (a|)*(?1) gave a compile-time internal error.
1521 ((a|)+)+ did not notice that the outer group could match an empty string.
1522 (^a|^)+ was not marked as anchored.
1523 (.*a|.*)+ was not marked as matching at start or after a newline.
1524
1525 12. Yet more internal refactoring has removed another argument from the match()
1526 function. Special calls to this function are now indicated by setting a
1527 value in a variable in the "match data" data block.
1528
1529 13. Be more explicit in pcre_study() instead of relying on "default" for
1530 opcodes that mean there is no starting character; this means that when new
1531 ones are added and accidentally left out of pcre_study(), testing should
1532 pick them up.
1533
1534 14. The -s option of pcretest has been documented for ages as being an old
1535 synonym of -m (show memory usage). I have changed it to mean "force study
1536 for every regex", that is, assume /S for every regex. This is similar to -i
1537 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1538 using it. It makes it easier to run collections of tests with and without
1539 study enabled, and thereby test pcre_study() more easily. All the standard
1540 tests are now run with and without -s (but some patterns can be marked as
1541 "never study" - see 20 below).
1542
1543 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1544 restoration of the capturing data to the outer values was not happening
1545 correctly.
1546
1547 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1548 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1549 pattern had matched an empty string, and so incorrectly returned a no
1550 match.
1551
1552 17. There was optimizing code for the last branch of non-capturing parentheses,
1553 and also for the obeyed branch of a conditional subexpression, which used
1554 tail recursion to cut down on stack usage. Unfortunately, now that there is
1555 the possibility of (*THEN) occurring in these branches, tail recursion is
1556 no longer possible because the return has to be checked for (*THEN). These
1557 two optimizations have therefore been removed. [But see 8.20/11 above.]
1558
1559 18. If a pattern containing \R was studied, it was assumed that \R always
1560 matched two bytes, thus causing the minimum subject length to be
1561 incorrectly computed because \R can also match just one byte.
1562
1563 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1564 was incorrectly computed.
1565
1566 20. If /S is present twice on a test pattern in pcretest input, it now
1567 *disables* studying, thereby overriding the use of -s on the command line
1568 (see 14 above). This is necessary for one or two tests to keep the output
1569 identical in both cases.
1570
1571 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1572 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1573
1574 22. When an atomic group that contained a capturing parenthesis was
1575 successfully matched, but the branch in which it appeared failed, the
1576 capturing was not being forgotten if a higher numbered group was later
1577 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1578 group 1 to "a", when in fact it should be unset. This applied to multi-
1579 branched capturing and non-capturing groups, repeated or not, and also to
1580 positive assertions (capturing in negative assertions does not happen
1581 in PCRE) and also to nested atomic groups.
1582
1583 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1584 subject after a captured substring, to make it easier to tell which of a
1585 number of identical substrings has been captured.
1586
1587 24. The way atomic groups are processed by pcre_exec() has been changed so that
1588 if they are repeated, backtracking one repetition now resets captured
1589 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1590 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1591 "aaa". Previously, it would have been "a". As part of this code
1592 refactoring, the way recursive calls are handled has also been changed.
1593
1594 25. If an assertion condition captured any substrings, they were not passed
1595 back unless some other capturing happened later. For example, if
1596 (?(?=(a))a) was matched against "a", no capturing was returned.
1597
1598 26. When studying a pattern that contained subroutine calls or assertions,
1599 the code for finding the minimum length of a possible match was handling
1600 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1601 group 1 called group 2 while simultaneously a separate group 2 called group
1602 1). A stack overflow occurred in this case. I have fixed this by limiting
1603 the recursion depth to 10.
1604
1605 27. Updated RunTest.bat in the distribution to the version supplied by Tom
1606 Fortmann. This supports explicit test numbers on the command line, and has
1607 argument validation and error reporting.
1608
1609 28. An instance of \X with an unlimited repeat could fail if at any point the
1610 first character it looked at was a mark character.
1611
1612 29. Some minor code refactoring concerning Unicode properties and scripts
1613 should reduce the stack requirement of match() slightly.
1614
1615 30. Added the '=' option to pcretest to check the setting of unused capturing
1616 slots at the end of the pattern, which are documented as being -1, but are
1617 not included in the return count.
1618
1619 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1620 compiled something random. Now it gives a compile-time error (as does
1621 Perl).
1622
1623 32. A *MARK encountered during the processing of a positive assertion is now
1624 recorded and passed back (compatible with Perl).
1625
1626 33. If --only-matching or --colour was set on a pcregrep call whose pattern
1627 had alternative anchored branches, the search for a second match in a line
1628 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1629 matched the line "0102" twice. The same bug affected patterns that started
1630 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1631 twice.
1632
1633 34. Previously, PCRE did not allow quantification of assertions. However, Perl
1634 does, and because of capturing effects, quantifying parenthesized
1635 assertions may at times be useful. Quantifiers are now allowed for
1636 parenthesized assertions.
1637
1638 35. A minor code tidy in pcre_compile() when checking options for \R usage.
1639
1640 36. \g was being checked for fancy things in a character class, when it should
1641 just be a literal "g".
1642
1643 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1644 appearance of a nested POSIX class supersedes an apparent external class.
1645 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1646 unescaped square brackets may also appear as part of class names. For
1647 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1648 more like Perl. (But see 8.20/1 above.)
1649
1650 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1651 was because it thought it was \N{name}, which is not supported).
1652
1653 39. Add minix to OS list not supporting the -S option in pcretest.
1654
1655 40. PCRE tries to detect cases of infinite recursion at compile time, but it
1656 cannot analyze patterns in sufficient detail to catch mutual recursions
1657 such as ((?1))((?2)). There is now a runtime test that gives an error if a
1658 subgroup is called recursively as a subpattern for a second time at the
1659 same position in the subject string. In previous releases this might have
1660 been caught by the recursion limit, or it might have run out of stack.
1661
1662 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1663 happen only once. PCRE was, however incorrectly giving a compile time error
1664 "recursive call could loop indefinitely" because it cannot analyze the
1665 pattern in sufficient detail. The compile time test no longer happens when
1666 PCRE is compiling a conditional subpattern, but actual runaway loops are
1667 now caught at runtime (see 40 above).
1668
1669 42. It seems that Perl allows any characters other than a closing parenthesis
1670 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1671 has been changed to be the same.
1672
1673 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1674 as not to get warnings when autogen.sh is called. Also changed
1675 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1676
1677 44. To help people who use pcregrep to scan files containing exceedingly long
1678 lines, the following changes have been made:
1679
1680 (a) The default value of the buffer size parameter has been increased from
1681 8K to 20K. (The actual buffer used is three times this size.)
1682
1683 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1684 PCRE is built.
1685
1686 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1687 to be set at run time.
1688
1689 (d) Numerical values in pcregrep options can be followed by K or M, for
1690 example --buffer-size=50K.
1691
1692 (e) If a line being scanned overflows pcregrep's buffer, an error is now
1693 given and the return code is set to 2.
1694
1695 45. Add a pointer to the latest mark to the callout data block.
1696
1697 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1698 partial match of an empty string instead of no match. This was specific to
1699 the use of ".".
1700
1701 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1702 complete match instead of a partial match. This bug was dependent on both
1703 the PCRE_UTF8 and PCRE_DOTALL options being set.
1704
1705 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1706 starting byte set, because \b was not being ignored.
1707
1708
1709 Version 8.12 15-Jan-2011
1710 ------------------------
1711
1712 1. Fixed some typos in the markup of the man pages, and wrote a script that
1713 checks for such things as part of the documentation building process.
1714
1715 2. On a big-endian 64-bit system, pcregrep did not correctly process the
1716 --match-limit and --recursion-limit options (added for 8.11). In
1717 particular, this made one of the standard tests fail. (The integer value
1718 went into the wrong half of a long int.)
1719
1720 3. If the --colour option was given to pcregrep with -v (invert match), it
1721 did strange things, either producing crazy output, or crashing. It should,
1722 of course, ignore a request for colour when reporting lines that do not
1723 match.
1724
1725 4. Another pcregrep bug caused similar problems if --colour was specified with
1726 -M (multiline) and the pattern match finished with a line ending.
1727
1728 5. In pcregrep, when a pattern that ended with a literal newline sequence was
1729 matched in multiline mode, the following line was shown as part of the
1730 match. This seems wrong, so I have changed it.
1731
1732 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
1733 the check for further matches in the same line (so they could be coloured)
1734 to overrun the end of the current line. If another match was found, it was
1735 incorrectly shown (and then shown again when found in the next line).
1736
1737 7. If pcregrep was compiled under Windows, there was a reference to the
1738 function pcregrep_exit() before it was defined. I am assuming this was
1739 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1740 reported by a user. I've moved the definition above the reference.
1741
1742
1743 Version 8.11 10-Dec-2010
1744 ------------------------
1745
1746 1. (*THEN) was not working properly if there were untried alternatives prior
1747 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1748 backtracked to try for "b" instead of moving to the next alternative branch
1749 at the same level (in this case, to look for "c"). The Perl documentation
1750 is clear that when (*THEN) is backtracked onto, it goes to the "next
1751 alternative in the innermost enclosing group".
1752
1753 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1754 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
1755 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1756 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1757 (*THEN).
1758
1759 3. If \s appeared in a character class, it removed the VT character from
1760 the class, even if it had been included by some previous item, for example
1761 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1762 of \s, but is part of the POSIX "space" class.)
1763
1764 4. A partial match never returns an empty string (because you can always
1765 match an empty string at the end of the subject); however the checking for
1766 an empty string was starting at the "start of match" point. This has been
1767 changed to the "earliest inspected character" point, because the returned
1768 data for a partial match starts at this character. This means that, for
1769 example, /(?<=abc)def/ gives a partial match for the subject "abc"
1770 (previously it gave "no match").
1771
1772 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1773 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1774 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1775 has an implication that the given string is incomplete (because a partial
1776 match is preferred over a full match). For this reason, these items now
1777 give a partial match in this situation. [Aside: previously, the one case
1778 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1779 match rather than a full match, which was wrong by the old rules, but is
1780 now correct.]
1781
1782 6. There was a bug in the handling of #-introduced comments, recognized when
1783 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1784 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1785 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1786 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1787 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1788 places in pcre_compile().
1789
1790 7. Related to (6) above, when pcre_compile() was skipping #-introduced
1791 comments when looking ahead for named forward references to subpatterns,
1792 the only newline sequence it recognized was NL. It now handles newlines
1793 according to the set newline convention.
1794
1795 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1796 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1797 cater for a lack of strerror(). These oversights have been fixed.
1798
1799 9. Added --match-limit and --recursion-limit to pcregrep.
1800
1801 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1802
1803 11. When the -o option was used, pcregrep was setting a return code of 1, even
1804 when matches were found, and --line-buffered was not being honoured.
1805
1806 12. Added an optional parentheses number to the -o and --only-matching options
1807 of pcregrep.
1808
1809 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1810 can match an empty string. The code to do it in pcretest and pcredemo
1811 needed fixing:
1812
1813 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1814 only one byte after an empty string match just before CRLF (this case
1815 just got forgotten; "any" and "anycrlf" were OK).
1816
1817 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1818 mode when an empty string match preceded an ASCII character followed by
1819 a non-ASCII character. (The code for advancing by one character rather
1820 than one byte was nonsense.)
1821
1822 (c) The pcredemo.c sample program did not have any code at all to handle
1823 the cases when CRLF is a valid newline sequence.
1824
1825 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1826 as a starting offset was within the subject string. There is now a new
1827 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1828 negative or greater than the length of the string. In order to test this,
1829 pcretest is extended to allow the setting of negative starting offsets.
1830
1831 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1832 starting offset points to the beginning of a UTF-8 character was
1833 unnecessarily clumsy. I tidied it up.
1834
1835 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1836 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1837
1838 17. Nobody had reported that the --include_dir option, which was added in
1839 release 7.7 should have been called --include-dir (hyphen, not underscore)
1840 for compatibility with GNU grep. I have changed it to --include-dir, but
1841 left --include_dir as an undocumented synonym, and the same for
1842 --exclude-dir, though that is not available in GNU grep, at least as of
1843 release 2.5.4.
1844
1845 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1846 characters from a string of bytes) have been redefined so as not to use
1847 loops, in order to improve performance in some environments. At the same
1848 time, I abstracted some of the common code into auxiliary macros to save
1849 repetition (this should not affect the compiled code).
1850
1851 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1852 compile-time error is now given if \c is not followed by an ASCII
1853 character, that is, a byte less than 128. (In EBCDIC mode, the code is
1854 different, and any byte value is allowed.)
1855
1856 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1857 START_OPTIMIZE option, which is now allowed at compile time - but just
1858 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1859 to pcregrep and other applications that have no direct access to PCRE
1860 options. The new /Y option in pcretest sets this option when calling
1861 pcre_compile().
1862
1863 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1864 back references. Groups containing recursive back references were forced to
1865 be atomic by that change, but in the case of named groups, the amount of
1866 memory required was incorrectly computed, leading to "Failed: internal
1867 error: code overflow". This has been fixed.
1868
1869 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1870 pcretest.c, to avoid build problems in some Borland environments.
1871
1872
1873 Version 8.10 25-Jun-2010
1874 ------------------------
1875
1876 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1877 THEN.
1878
1879 2. (*ACCEPT) was not working when inside an atomic group.
1880
1881 3. Inside a character class, \B is treated as a literal by default, but
1882 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1883 causes the error). The code is unchanged, but I tidied the documentation.
1884
1885 4. Inside a character class, PCRE always treated \R and \X as literals,
1886 whereas Perl faults them if its -w option is set. I have changed PCRE so
1887 that it faults them when PCRE_EXTRA is set.
1888
1889 5. Added support for \N, which always matches any character other than
1890 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1891
1892 6. When compiling pcregrep with newer versions of gcc which may have
1893 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1894 declared with attribute warn_unused_result" were given. Just casting the
1895 result to (void) does not stop the warnings; a more elaborate fudge is
1896 needed. I've used a macro to implement this.
1897
1898 7. Minor change to pcretest.c to avoid a compiler warning.
1899
1900 8. Added four artifical Unicode properties to help with an option to make
1901 \s etc use properties (see next item). The new properties are: Xan
1902 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1903
1904 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1905 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1906 this option. Modified pcretest to add /W to test this facility. Added
1907 REG_UCP to make it available via the POSIX interface.
1908
1909 10. Added --line-buffered to pcregrep.
1910
1911 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1912 studied, and the match started with a letter with a code point greater than
1913 127 whose first byte was different to the first byte of the other case of
1914 the letter, the other case of this starting letter was not recognized
1915 (#976).
1916
1917 12. If a pattern that was studied started with a repeated Unicode property
1918 test, for example, \p{Nd}+, there was the theoretical possibility of
1919 setting up an incorrect bitmap of starting bytes, but fortunately it could
1920 not have actually happened in practice until change 8 above was made (it
1921 added property types that matched character-matching opcodes).
1922
1923 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1924 possible starting bytes for non-anchored patterns.
1925
1926 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1927 \R, and also a number of cases that involve Unicode properties, both
1928 explicit and implicit when PCRE_UCP is set.
1929
1930 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1931 input, it could crash or give wrong results if characters with values
1932 greater than 0xc0 were present in the subject string. (Detail: it assumed
1933 UTF-8 input when processing these items.)
1934
1935 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1936 size_t is 64-bit (#991).
1937
1938 17. Added a check for running out of memory when PCRE is compiled with
1939 --disable-stack-for-recursion (#990).
1940
1941 18. If the last data line in a file for pcretest does not have a newline on
1942 the end, a newline was missing in the output.
1943
1944 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1945 less than 128) in its various bitmaps. However, there is a facility for
1946 generating tables according to the current locale when PCRE is compiled. It
1947 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1948 characters, are recognized by isspace() and therefore were getting set in
1949 these tables, and indeed these tables seem to approximate to ISO 8859. This
1950 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1951 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1952 which of course cannot start UTF-8 characters. I have changed the code so
1953 that only real ASCII characters (less than 128) and the correct starting
1954 bytes for UTF-8 encodings are set for characters greater than 127 when in
1955 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1956 altogether.)
1957
1958 20. Added the /T option to pcretest so as to be able to run tests with non-
1959 standard character tables, thus making it possible to include the tests
1960 used for 19 above in the standard set of tests.
1961
1962 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1963 reference to a subpattern the other side of a comment that contains an
1964 opening parenthesis caused either an internal compiling error, or a
1965 reference to the wrong subpattern.
1966
1967
1968 Version 8.02 19-Mar-2010
1969 ------------------------
1970
1971 1. The Unicode data tables have been updated to Unicode 5.2.0.
1972
1973 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
1974 configured.
1975
1976 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
1977 original author of that file, following a query about its status.
1978
1979 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
1980 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
1981
1982 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
1983 quantifier applied to a forward-referencing subroutine call, could compile
1984 incorrect code or give the error "internal error: previously-checked
1985 referenced subpattern not found".
1986
1987 6. Both MS Visual Studio and Symbian OS have problems with initializing
1988 variables to point to external functions. For these systems, therefore,
1989 pcre_malloc etc. are now initialized to local functions that call the
1990 relevant global functions.
1991
1992 7. There were two entries missing in the vectors called coptable and poptable
1993 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
1994 I've fixed the data, and added a kludgy way of testing at compile time that
1995 the lengths are correct (equal to the number of opcodes).
1996
1997 8. Following on from 7, I added a similar kludge to check the length of the
1998 eint vector in pcreposix.c.
1999
2000 9. Error texts for pcre_compile() are held as one long string to avoid too
2001 much relocation at load time. To find a text, the string is searched,
2002 counting zeros. There was no check for running off the end of the string,
2003 which could happen if a new error number was added without updating the
2004 string.
2005
2006 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
2007
2008 11. \K was not working if it appeared in an atomic group or in a group that
2009 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
2010 \K is "not well defined" if used in an assertion. PCRE now accepts it if
2011 the assertion is positive, but not if it is negative.
2012
2013 12. Change 11 fortuitously reduced the size of the stack frame used in the
2014 "match()" function of pcre_exec.c by one pointer. Forthcoming
2015 implementation of support for (*MARK) will need an extra pointer on the
2016 stack; I have reserved it now, so that the stack frame size does not
2017 decrease.
2018
2019 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
2020 item in branch that calls a recursion is a subroutine call - as in the
2021 second branch in the above example - was incorrectly given the compile-
2022 time error "recursive call could loop indefinitely" because pcre_compile()
2023 was not correctly checking the subroutine for matching a non-empty string.
2024
2025 14. The checks for overrunning compiling workspace could trigger after an
2026 overrun had occurred. This is a "should never occur" error, but it can be
2027 triggered by pathological patterns such as hundreds of nested parentheses.
2028 The checks now trigger 100 bytes before the end of the workspace.
2029
2030 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
2031
2032
2033 Version 8.01 19-Jan-2010
2034 ------------------------
2035
2036 1. If a pattern contained a conditional subpattern with only one branch (in
2037 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
2038 computed the wrong minimum data length (which is of course zero for such
2039 subpatterns). This could cause incorrect "no match" results.
2040
2041 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
2042 the pattern is reset in the first branch, pcre_compile() failed with
2043 "internal error: code overflow at offset...". This happened only when
2044 the reset was to the original external option setting. (An optimization
2045 abstracts leading options settings into an external setting, which was the
2046 cause of this.)
2047
2048 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
2049 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
2050 assertion pattern did not match (meaning that the assertion was true), it
2051 was incorrectly treated as false if the SKIP had been reached during the
2052 matching. This also applied to assertions used as conditions.
2053
2054 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
2055 assertion subpattern, including such a pattern used as a condition,
2056 unpredictable results occurred, instead of the error return
2057 PCRE_ERROR_DFA_UITEM.
2058
2059 5. The C++ GlobalReplace function was not working like Perl for the special
2060 situation when an empty string is matched. It now does the fancy magic
2061 stuff that is necessary.
2062
2063 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
2064 removed. (These were left over from very, very early versions of PCRE.)
2065
2066 7. Some cosmetic changes to the code to make life easier when compiling it
2067 as part of something else:
2068
2069 (a) Change DEBUG to PCRE_DEBUG.
2070
2071 (b) In pcre_compile(), rename the member of the "branch_chain" structure
2072 called "current" as "current_branch", to prevent a collision with the
2073 Linux macro when compiled as a kernel module.
2074
2075 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
2076 prevent a collision with the Linux macro when compiled as a kernel
2077 module.
2078
2079 8. In pcre_compile() there are some checks for integer overflows that used to
2080 cast potentially large values to (double). This has been changed to that
2081 when building, a check for int64_t is made, and if it is found, it is used
2082 instead, thus avoiding the use of floating point arithmetic. (There is no
2083 other use of FP in PCRE.) If int64_t is not found, the fallback is to
2084 double.
2085
2086 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
2087 2005 (difference between two addresses compared to an unsigned value).
2088
2089 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
2090 custom one, because of the following reported problem in Windows:
2091
2092 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
2093 under Win32.
2094 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
2095 therefore missing the function definition.
2096 - The compiler thus generates a "C" signature for the test function.
2097 - The linker fails to find the "C" function.
2098 - PCRE fails to configure if asked to do so against libbz2.
2099
2100 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
2101 messages were output:
2102
2103 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
2104 rerunning libtoolize, to keep the correct libtool macros in-tree.
2105 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
2106
2107 I have done both of these things.
2108
2109 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
2110 most of the time, it *can* run out if it is given a pattern that contains a
2111 runaway infinite recursion. I updated the discussion in the pcrestack man
2112 page.
2113
2114 13. Now that we have gone to the x.xx style of version numbers, the minor
2115 version may start with zero. Using 08 or 09 is a bad idea because users
2116 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
2117 interpreted as invalid octal numbers. I've updated the previous comment in
2118 configure.ac, and also added a check that gives an error if 08 or 09 are
2119 used.
2120
2121 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
2122 causing partial matching to fail when the end of the subject matched \W
2123 in a UTF-8 pattern where \W was quantified with a minimum of 3.
2124
2125 15. There were some discrepancies between the declarations in pcre_internal.h
2126 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
2127 their definitions. The declarations used "const uschar *" and the
2128 definitions used USPTR. Even though USPTR is normally defined as "const
2129 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
2130 reported that: "This difference in casting confuses some C++ compilers, for
2131 example, SunCC recognizes above declarations as different functions and
2132 generates broken code for hbpcre." I have changed the declarations to use
2133 USPTR.
2134
2135 16. GNU libtool is named differently on some systems. The autogen.sh script now
2136 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
2137 (FreeBSD).
2138
2139 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
2140 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
2141 comment: "Figure out how to create a longlong from a string: strtoll and
2142 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
2143 instance, but it only takes 2 args instead of 3!"
2144
2145 18. A subtle bug concerned with back references has been fixed by a change of
2146 specification, with a corresponding code fix. A pattern such as
2147 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
2148 refers, was giving matches when it shouldn't. For example, xa=xaaa would
2149 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
2150 same bug. Such groups have to be quantified to be useful, or contained
2151 inside another quantified group. (If there's no repetition, the reference
2152 can never match.) The problem arises because, having left the group and
2153 moved on to the rest of the pattern, a later failure that backtracks into
2154 the group uses the captured value from the final iteration of the group
2155 rather than the correct earlier one. I have fixed this in PCRE by forcing
2156 any group that contains a reference to itself to be an atomic group; that
2157 is, there cannot be any backtracking into it once it has completed. This is
2158 similar to recursive and subroutine calls.
2159
2160
2161 Version 8.00 19-Oct-09
2162 ----------------------
2163
2164 1. The table for translating pcre_compile() error codes into POSIX error codes
2165 was out-of-date, and there was no check on the pcre_compile() error code
2166 being within the table. This could lead to an OK return being given in
2167 error.
2168
2169 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
2170 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
2171 in a Windows environment.
2172
2173 3. The pcregrep --count option prints the count for each file even when it is
2174 zero, as does GNU grep. However, pcregrep was also printing all files when
2175 --files-with-matches was added. Now, when both options are given, it prints
2176 counts only for those files that have at least one match. (GNU grep just
2177 prints the file name in this circumstance, but including the count seems
2178 more useful - otherwise, why use --count?) Also ensured that the
2179 combination -clh just lists non-zero counts, with no names.
2180
2181 4. The long form of the pcregrep -F option was incorrectly implemented as
2182 --fixed_strings instead of --fixed-strings. This is an incompatible change,
2183 but it seems right to fix it, and I didn't think it was worth preserving
2184 the old behaviour.
2185
2186 5. The command line items --regex=pattern and --regexp=pattern were not
2187 recognized by pcregrep, which required --regex pattern or --regexp pattern
2188 (with a space rather than an '='). The man page documented the '=' forms,
2189 which are compatible with GNU grep; these now work.
2190
2191 6. No libpcreposix.pc file was created for pkg-config; there was just
2192 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
2193
2194 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
2195 when UCP support is not needed, by modifying the Python script that
2196 generates it from Unicode data files. This should not matter if the module
2197 is correctly used as a library, but I received one complaint about 50K of
2198 unwanted data. My guess is that the person linked everything into his
2199 program rather than using a library. Anyway, it does no harm.
2200
2201 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
2202 was a minimum greater than 1 for a wide character in a possessive
2203 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
2204 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
2205 character. Chaos in the form of incorrect output or a compiling loop could
2206 result.
2207
2208 9. The restrictions on what a pattern can contain when partial matching is
2209 requested for pcre_exec() have been removed. All patterns can now be
2210 partially matched by this function. In addition, if there are at least two
2211 slots in the offset vector, the offset of the earliest inspected character
2212 for the match and the offset of the end of the subject are set in them when
2213 PCRE_ERROR_PARTIAL is returned.
2214
2215 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
2216 synonymous with PCRE_PARTIAL, for backwards compatibility, and
2217 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
2218 and may be more useful for multi-segment matching.
2219
2220 11. Partial matching with pcre_exec() is now more intuitive. A partial match
2221 used to be given if ever the end of the subject was reached; now it is
2222 given only if matching could not proceed because another character was
2223 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
2224 string "Z", which now yields "no match" instead of "partial match". In the
2225 case of pcre_dfa_exec(), "no match" is given if every matching path for the
2226 final character ended with (*FAIL).
2227
2228 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
2229 if the pattern had a "must contain" character that was already found in the
2230 earlier partial match, unless partial matching was again requested. For
2231 example, with the pattern /dog.(body)?/, the "must contain" character is
2232 "g". If the first part-match was for the string "dog", restarting with
2233 "sbody" failed. This bug has been fixed.
2234
2235 13. The string returned by pcre_dfa_exec() after a partial match has been
2236 changed so that it starts at the first inspected character rather than the
2237 first character of the match. This makes a difference only if the pattern
2238 starts with a lookbehind assertion or \b or \B (\K is not supported by
2239 pcre_dfa_exec()). It's an incompatible change, but it makes the two
2240 matching functions compatible, and I think it's the right thing to do.
2241
2242 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
2243 so that the demonstration program is easily available in environments where
2244 PCRE has not been installed from source.
2245
2246 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
2247 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
2248 library.
2249
2250 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
2251 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
2252 is not the first non-POSIX option to be added. Clearly some people find
2253 these options useful.
2254
2255 17. If a caller to the POSIX matching function regexec() passes a non-zero
2256 value for nmatch with a NULL value for pmatch, the value of
2257 nmatch is forced to zero.
2258
2259 18. RunGrepTest did not have a test for the availability of the -u option of
2260 the diff command, as RunTest does. It now checks in the same way as
2261 RunTest, and also checks for the -b option.
2262
2263 19. If an odd number of negated classes containing just a single character
2264 interposed, within parentheses, between a forward reference to a named
2265 subpattern and the definition of the subpattern, compilation crashed with
2266 an internal error, complaining that it could not find the referenced
2267 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
2268 [The bug was that it was starting one character too far in when skipping
2269 over the character class, thus treating the ] as data rather than
2270 terminating the class. This meant it could skip too much.]
2271
2272 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
2273 /g option in pcretest when the pattern contains \K, which makes it possible
2274 to have an empty string match not at the start, even when the pattern is
2275 anchored. Updated pcretest and pcredemo to use this option.
2276
2277 21. If the maximum number of capturing subpatterns in a recursion was greater
2278 than the maximum at the outer level, the higher number was returned, but
2279 with unset values at the outer level. The correct (outer level) value is
2280 now given.
2281
2282 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
2283 PCRE did not set those parentheses (unlike Perl). I have now found a way to
2284 make it do so. The string so far is captured, making this feature
2285 compatible with Perl.
2286
2287 23. The tests have been re-organized, adding tests 11 and 12, to make it
2288 possible to check the Perl 5.10 features against Perl 5.10.
2289
2290 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
2291 pattern matches a fixed length string. PCRE did not allow this; now it
2292 does. Neither allows recursion.
2293
2294 25. I finally figured out how to implement a request to provide the minimum
2295 length of subject string that was needed in order to match a given pattern.
2296 (It was back references and recursion that I had previously got hung up
2297 on.) This code has now been added to pcre_study(); it finds a lower bound
2298 to the length of subject needed. It is not necessarily the greatest lower
2299 bound, but using it to avoid searching strings that are too short does give
2300 some useful speed-ups. The value is available to calling programs via
2301 pcre_fullinfo().
2302
2303 26. While implementing 25, I discovered to my embarrassment that pcretest had
2304 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
2305 study optimizations had never been tested with that matching function.
2306 Oops. What is worse, even when it was passed study data, there was a bug in
2307 pcre_dfa_exec() that meant it never actually used it. Double oops. There
2308 were also very few tests of studied patterns with pcre_dfa_exec().
2309
2310 27. If (?| is used to create subpatterns with duplicate numbers, they are now
2311 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
2312 on the other side of the coin, they are no longer allowed to have different
2313 names, because these cannot be distinguished in PCRE, and this has caused
2314 confusion. (This is a difference from Perl.)
2315
2316 28. When duplicate subpattern names are present (necessarily with different
2317 numbers, as required by 27 above), and a test is made by name in a
2318 conditional pattern, either for a subpattern having been matched, or for
2319 recursion in such a pattern, all the associated numbered subpatterns are
2320 tested, and the overall condition is true if the condition is true for any
2321 one of them. This is the way Perl works, and is also more like the way
2322 testing by number works.
2323
2324
2325 Version 7.9 11-Apr-09
2326 ---------------------
2327
2328 1. When building with support for bzlib/zlib (pcregrep) and/or readline
2329 (pcretest), all targets were linked against these libraries. This included
2330 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
2331 libraries. This caused unwanted dependencies to be created. This problem
2332 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
2333 pcretest is linked with readline.
2334
2335 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
2336 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
2337 moved outside it again, because FALSE and TRUE are already defined in AIX,
2338 but BOOL is not.
2339
2340 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
2341 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
2342
2343 4. The pcregrep documentation said spaces were inserted as well as colons (or
2344 hyphens) following file names and line numbers when outputting matching
2345 lines. This is not true; no spaces are inserted. I have also clarified the
2346 wording for the --colour (or --color) option.
2347
2348 5. In pcregrep, when --colour was used with -o, the list of matching strings
2349 was not coloured; this is different to GNU grep, so I have changed it to be
2350 the same.
2351
2352 6. When --colo(u)r was used in pcregrep, only the first matching substring in
2353 each matching line was coloured. Now it goes on to look for further matches
2354 of any of the test patterns, which is the same behaviour as GNU grep.
2355
2356 7. A pattern that could match an empty string could cause pcregrep to loop; it
2357 doesn't make sense to accept an empty string match in pcregrep, so I have
2358 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2359 seems to be how GNU grep behaves. [But see later change 40 for release
2360 8.33.]
2361
2362 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2363 start or after a newline", because the conditional assertion was not being
2364 correctly handled. The rule now is that both the assertion and what follows
2365 in the first alternative must satisfy the test.
2366
2367 9. If auto-callout was enabled in a pattern with a conditional group whose
2368 condition was an assertion, PCRE could crash during matching, both with
2369 pcre_exec() and pcre_dfa_exec().
2370
2371 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
2372 used for matching.
2373
2374 11. Unicode property support in character classes was not working for
2375 characters (bytes) greater than 127 when not in UTF-8 mode.
2376
2377 12. Added the -M command line option to pcretest.
2378
2379 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
2380
2381 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
2382
2383 16. Added comments and documentation about mis-use of no_arg in the C++
2384 wrapper.
2385
2386 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
2387 from Martin Jerabek that uses macro names for all relevant character and
2388 string constants.
2389
2390 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
2391 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
2392 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
2393 these, but not everybody uses configure.
2394
2395 19. A conditional group that had only one branch was not being correctly
2396 recognized as an item that could match an empty string. This meant that an
2397 enclosing group might also not be so recognized, causing infinite looping
2398 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
2399 with the subject "ab", where knowledge that the repeated group can match
2400 nothing is needed in order to break the loop.
2401
2402 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
2403 exec(), but without supplying a callout function, matching went wrong.
2404
2405 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
2406 leak if the size of the offset vector was greater than 30. When the vector
2407 is smaller, the saved offsets during recursion go onto a local stack
2408 vector, but for larger vectors malloc() is used. It was failing to free
2409 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
2410 error, in fact).
2411
2412 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
2413 heapframe that is used only when UTF-8 support is enabled. This caused no
2414 problem, but was untidy.
2415
2416 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
2417 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
2418 included within another project.
2419
2420 24. Steven Van Ingelgem's patches to add more options to the CMake support,
2421 slightly modified by me:
2422
2423 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
2424 not building pcregrep.
2425
2426 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
2427 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
2428
2429 25. Forward references, both numeric and by name, in patterns that made use of
2430 duplicate group numbers, could behave incorrectly or give incorrect errors,
2431 because when scanning forward to find the reference group, PCRE was not
2432 taking into account the duplicate group numbers. A pattern such as
2433 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
2434
2435 26. Changed a few more instances of "const unsigned char *" to USPTR, making
2436 the feature of a custom pointer more persuasive (as requested by a user).
2437
2438 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
2439 pcretest.c, inside #ifndefs, because it seems they are sometimes already
2440 pre-defined.
2441
2442 28. Added support for (*UTF8) at the start of a pattern.
2443
2444 29. Arrange for flags added by the "release type" setting in CMake to be shown
2445 in the configuration summary.
2446
2447
2448 Version 7.8 05-Sep-08
2449 ---------------------
2450
2451 1. Replaced UCP searching code with optimized version as implemented for Ad
2452 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
2453 stage table and inline lookup instead of a function, giving speed ups of 2
2454 to 5 times on some simple patterns that I tested. Permission was given to
2455 distribute the MultiStage2.py script that generates the tables (it's not in
2456 the tarball, but is in the Subversion repository).
2457
2458 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
2459 scripts.
2460
2461 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
2462 a group with a zero qualifier. The result of the study could be incorrect,
2463 or the function might crash, depending on the pattern.
2464
2465 4. Caseless matching was not working for non-ASCII characters in back
2466 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2467 It now works when Unicode Property Support is available.
2468
2469 5. In pcretest, an escape such as \x{de} in the data was always generating
2470 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2471 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2472 truncation.
2473
2474 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2475
2476 7. Added two (int) casts to pcregrep when printing the difference of two
2477 pointers, in case they are 64-bit values.
2478
2479 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
2480 test 2 if it fails.
2481
2482 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2483 and a #define of that name to empty if it is not externally set. This is to
2484 allow users of MSVC to set it if necessary.
2485
2486 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2487 the convenience functions in the pcre_get.c source file.
2488
2489 11. An option change at the start of a pattern that had top-level alternatives
2490 could cause overwriting and/or a crash. This command provoked a crash in
2491 some environments:
2492
2493 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2494
2495 This potential security problem was recorded as CVE-2008-2371.
2496
2497 12. For a pattern where the match had to start at the beginning or immediately
2498 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2499 pcre_dfa_exec() could read past the end of the passed subject if there was
2500 no match. To help with detecting such bugs (e.g. with valgrind), I modified
2501 pcretest so that it places the subject at the end of its malloc-ed buffer.
2502
2503 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2504 exec() might read past the end of the data buffer in UTF-8 mode.
2505
2506 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2507 the data contained the byte 0x85 as part of a UTF-8 character within its
2508 first line. This applied both to normal and DFA matching.
2509
2510 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2511 /^[^d]*?$/8 failed to match "abc".
2512
2513 16. Added a missing copyright notice to pcrecpp_internal.h.
2514
2515 17. Make it more clear in the documentation that values returned from
2516 pcre_exec() in ovector are byte offsets, not character counts.
2517
2518 18. Tidied a few places to stop certain compilers from issuing warnings.
2519
2520 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2521 supplied by Stefan Weber. I made a further small update for 7.8 because
2522 there is a change of source arrangements: the pcre_searchfuncs.c module is
2523 replaced by pcre_ucd.c.
2524
2525
2526 Version 7.7 07-May-08
2527 ---------------------
2528
2529 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2530 a string to a long long, pretend we don't even have a long long." This is
2531 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2532
2533 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2534 pre-7.6 versions, which defined a global no_arg variable instead of putting
2535 it in the RE class. (See also #8 below.)
2536
2537 3. Remove a line of dead code, identified by coverity and reported by Nuno
2538 Lopes.
2539
2540 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2541
2542 (1) The include/exclude patterns were being applied to the whole pathnames
2543 of files, instead of just to the final components.
2544
2545 (2) If there was more than one level of directory, the subdirectories were
2546 skipped unless they satisfied the include/exclude conditions. This is
2547 inconsistent with GNU grep (and could even be seen as contrary to the
2548 pcregrep specification - which I improved to make it absolutely clear).
2549 The action now is always to scan all levels of directory, and just
2550 apply the include/exclude patterns to regular files.
2551
2552 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2553 --exclude_dir in the tests to avoid scanning .svn directories.
2554
2555 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2556 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2557 doesn't support NULs in patterns.
2558
2559 7. Added some missing "const"s to declarations of static tables in
2560 pcre_compile.c and pcre_dfa_exec.c.
2561
2562 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2563 caused by fix #2 above. (Subsequently also a second patch to fix the
2564 first patch. And a third patch - this was a messy problem.)
2565
2566 9. Applied Craig's patch to remove the use of push_back().
2567
2568 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2569 matching function regexec().
2570
2571 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2572 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2573 references. PCRE supports relative numbers with this syntax (I don't think
2574 Oniguruma does).
2575
2576 12. Previously, a group with a zero repeat such as (...){0} was completely
2577 omitted from the compiled regex. However, this means that if the group
2578 was called as a subroutine from elsewhere in the pattern, things went wrong
2579 (an internal error was given). Such groups are now left in the compiled
2580 pattern, with a new opcode that causes them to be skipped at execution
2581 time.
2582
2583 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2584 to the way PCRE behaves:
2585
2586 (a) A lone ] character is dis-allowed (Perl treats it as data).
2587
2588 (b) A back reference to an unmatched subpattern matches an empty string
2589 (Perl fails the current match path).
2590
2591 (c) A data ] in a character class must be notated as \] because if the
2592 first data character in a class is ], it defines an empty class. (In
2593 Perl it is not possible to have an empty class.) The empty class []
2594 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2595 The negative empty class [^] matches any one character, independently
2596 of the DOTALL setting.
2597
2598 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2599 non-existent subpattern following a character class starting with ']' and
2600 containing () gave an internal compiling error instead of "reference to
2601 non-existent subpattern". Fortunately, when the pattern did exist, the
2602 compiled code was correct. (When scanning forwards to check for the
2603 existence of the subpattern, it was treating the data ']' as terminating
2604 the class, so got the count wrong. When actually compiling, the reference
2605 was subsequently set up correctly.)
2606
2607 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2608 it was being rejected as not supported by pcre_dfa_exec(), even though
2609 other assertions are supported. I have made pcre_dfa_exec() support
2610 (*FAIL).
2611
2612 16. The implementation of 13c above involved the invention of a new opcode,
2613 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2614 cannot be changed at match time, I realized I could make a small
2615 improvement to matching performance by compiling OP_ALLANY instead of
2616 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2617 on the OP_ANY path.
2618
2619 17. Compiling pcretest on Windows with readline support failed without the
2620 following two fixes: (1) Make the unistd.h include conditional on
2621 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2622
2623 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2624 ncurses library to be included for pcretest when ReadLine support is
2625 requested, but also to allow for it to be overridden. This patch came from
2626 Daniel Bergström.
2627
2628 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2629 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2630 any errors with the current Unicode tables. Thanks to Peter Kankowski for
2631 spotting this.
2632
2633
2634 Version 7.6 28-Jan-08
2635 ---------------------
2636
2637 1. A character class containing a very large number of characters with
2638 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2639 overflow.
2640
2641 2. Patch to cut out the "long long" test in pcrecpp_unittest when
2642 HAVE_LONG_LONG is not defined.
2643
2644 3. Applied Christian Ehrlicher's patch to update the CMake build files to
2645 bring them up to date and include new features. This patch includes:
2646
2647 - Fixed PH's badly added libz and libbz2 support.
2648 - Fixed a problem with static linking.
2649 - Added pcredemo. [But later removed - see 7 below.]
2650 - Fixed dftables problem and added an option.
2651 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2652 HAVE_LONG_LONG.
2653 - Added readline support for pcretest.
2654 - Added an listing of the option settings after cmake has run.
2655
2656 4. A user submitted a patch to Makefile that makes it easy to create
2657 "pcre.dll" under mingw when using Configure/Make. I added stuff to
2658 Makefile.am that cause it to include this special target, without
2659 affecting anything else. Note that the same mingw target plus all
2660 the other distribution libraries and programs are now supported
2661 when configuring with CMake (see 6 below) instead of with
2662 Configure/Make.
2663
2664 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2665 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2666 exported in the Windows port". It has not yet been confirmed that the patch
2667 solves the problem, but it does no harm.
2668
2669 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2670 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2671 with CMake, and also correct the comment about stack recursion.
2672
2673 7. Remove the automatic building of pcredemo from the ./configure system and
2674 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2675 of a program that users should build themselves after PCRE is installed, so
2676 building it automatically is not really right. What is more, it gave
2677 trouble in some build environments.
2678
2679 8. Further tidies to CMakeLists.txt from Sheri and Christian.
2680
2681
2682 Version 7.5 10-Jan-08
2683 ---------------------
2684
2685 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
2686 values in parens when parsing an RE using the C++ wrapper."
2687
2688 2. Negative specials like \S did not work in character classes in UTF-8 mode.
2689 Characters greater than 255 were excluded from the class instead of being
2690 included.
2691
2692 3. The same bug as (2) above applied to negated POSIX classes such as
2693 [:^space:].
2694
2695 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2696 defined or documented. It seems to have been a typo for PCRE_STATIC, so
2697 I have changed it.
2698
2699 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
2700 first named subpattern) and a construct such as (?&a) would reference the
2701 first named subpattern whose name started with "a" (in other words, the
2702 length check was missing). Both these problems are fixed. "Subpattern name
2703 expected" is now given for (?&) (a zero-length name), and this patch also
2704 makes it give the same error for \k'' (previously it complained that that
2705 was a reference to a non-existent subpattern).
2706
2707 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
2708 this is right because (?- can be followed by option settings as well as by
2709 digits. I have, however, made the messages clearer.
2710
2711 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2712 than the number used in the conditional) now cause a compile-time error.
2713 This is actually not compatible with Perl, which accepts such patterns, but
2714 treats the conditional as always being FALSE (as PCRE used to), but it
2715 seems to me that giving a diagnostic is better.
2716
2717 8. Change "alphameric" to the more common word "alphanumeric" in comments
2718 and messages.
2719
2720 9. Fix two occurrences of "backslash" in comments that should have been
2721 "backspace".
2722
2723 10. Remove two redundant lines of code that can never be obeyed (their function
2724 was moved elsewhere).
2725
2726 11. The program that makes PCRE's Unicode character property table had a bug
2727 which caused it to generate incorrect table entries for sequences of
2728 characters that have the same character type, but are in different scripts.
2729 It amalgamated them into a single range, with the script of the first of
2730 them. In other words, some characters were in the wrong script. There were
2731 thirteen such cases, affecting characters in the following ranges:
2732
2733 U+002b0 - U+002c1
2734 U+0060c - U+0060d
2735 U+0061e - U+00612
2736 U+0064b - U+0065e
2737 U+0074d - U+0076d
2738 U+01800 - U+01805
2739 U+01d00 - U+01d77
2740 U+01d9b - U+01dbf
2741 U+0200b - U+0200f
2742 U+030fc - U+030fe
2743 U+03260 - U+0327f
2744 U+0fb46 - U+0fbb1
2745 U+10450 - U+1049d
2746
2747 12. The -o option (show only the matching part of a line) for pcregrep was not
2748 compatible with GNU grep in that, if there was more than one match in a
2749 line, it showed only the first of them. It now behaves in the same way as
2750 GNU grep.
2751
2752 13. If the -o and -v options were combined for pcregrep, it printed a blank
2753 line for every non-matching line. GNU grep prints nothing, and pcregrep now
2754 does the same. The return code can be used to tell if there were any
2755 non-matching lines.
2756
2757 14. Added --file-offsets and --line-offsets to pcregrep.
2758
2759 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2760 infinitely looping recursion. The bug was that positive lookaheads were not
2761 being skipped when checking for a possible empty match (negative lookaheads
2762 and both kinds of lookbehind were skipped).
2763
2764 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2765 inclusion of <windows.h> to before rather than after the definition of
2766 INVALID_FILE_ATTRIBUTES (patch from David Byron).
2767
2768 17. Specifying a possessive quantifier with a specific limit for a Unicode
2769 character property caused pcre_compile() to compile bad code, which led at
2770 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2771 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2772 caused the error; without that there was no problem.
2773
2774 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2775
2776 19. Added --enable-pcretest-libreadline.
2777
2778 20. In pcrecpp.cc, the variable 'count' was incremented twice in
2779 RE::GlobalReplace(). As a result, the number of replacements returned was
2780 double what it should be. I removed one of the increments, but Craig sent a
2781 later patch that removed the other one (the right fix) and added unit tests
2782 that check the return values (which was not done before).
2783
2784 21. Several CMake things:
2785
2786 (1) Arranged that, when cmake is used on Unix, the libraries end up with
2787 the names libpcre and libpcreposix, not just pcre and pcreposix.
2788
2789 (2) The above change means that pcretest and pcregrep are now correctly
2790 linked with the newly-built libraries, not previously installed ones.
2791
2792 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2793
2794 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2795 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2796 UTF-8 newline character). The key issue is that the pattern starts .*;
2797 this means that the match must be either at the beginning, or after a
2798 newline. The bug was in the code for advancing after a failed match and
2799 checking that the new position followed a newline. It was not taking
2800 account of UTF-8 characters correctly.
2801
2802 23. PCRE was behaving differently from Perl in the way it recognized POSIX
2803 character classes. PCRE was not treating the sequence [:...:] as a
2804 character class unless the ... were all letters. Perl, however, seems to
2805 allow any characters between [: and :], though of course it rejects as
2806 unknown any "names" that contain non-letters, because all the known class
2807 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2808 for example, whereas PCRE did not - it did not recognize a POSIX character
2809 class. This seemed a bit dangerous, so the code has been changed to be
2810 closer to Perl. The behaviour is not identical to Perl, because PCRE will
2811 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2812 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2813 Perl does, and where it didn't before.
2814
2815 24. Rewrite so as to remove the single use of %n from pcregrep because in some
2816 Windows environments %n is disabled by default.
2817
2818
2819 Version 7.4 21-Sep-07
2820 ---------------------
2821
2822 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
2823 means that a class such as [\s] counted as "explicit reference to CR or
2824 LF". That isn't really right - the whole point of the change was to try to
2825 help when there was an actual mention of one of the two characters. So now
2826 the change happens only if \r or \n (or a literal CR or LF) character is
2827 encountered.
2828
2829 2. The 32-bit options word was also used for 6 internal flags, but the numbers
2830 of both had grown to the point where there were only 3 bits left.
2831 Fortunately, there was spare space in the data structure, and so I have
2832 moved the internal flags into a new 16-bit field to free up more option
2833 bits.
2834
2835 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2836 but did not set the internal JCHANGED flag - either of these is enough to
2837 control the way the "get" function works - but the PCRE_INFO_JCHANGED
2838 facility is supposed to tell if (?J) was ever used, so now (?J) at the
2839 start sets both bits.
2840
2841 4. Added options (at build time, compile time, exec time) to change \R from
2842 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2843
2844 5. doc/pcresyntax.html was missing from the distribution.
2845
2846 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2847 compatibility, even though it is no longer used.
2848
2849 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2850 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2851 windows.h file is present (where different names are used). [This was
2852 reversed later after testing - see 16 below.]
2853
2854 8. Changed all #include <config.h> to #include "config.h". There were also
2855 some further <pcre.h> cases that I changed to "pcre.h".
2856
2857 9. When pcregrep was used with the --colour option, it missed the line ending
2858 sequence off the lines that it output.
2859
2860 10. It was pointed out to me that arrays of string pointers cause lots of
2861 relocations when a shared library is dynamically loaded. A technique of
2862 using a single long string with a table of offsets can drastically reduce
2863 these. I have refactored PCRE in four places to do this. The result is
2864 dramatic:
2865
2866 Originally: 290
2867 After changing UCP table: 187
2868 After changing error message table: 43
2869 After changing table of "verbs" 36
2870 After changing table of Posix names 22
2871
2872 Thanks to the folks working on Gregex for glib for this insight.
2873
2874 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2875 unicode-properties was also set.
2876
2877 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2878
2879 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2880 checked only for CRLF.
2881
2882 14. Added casts to pcretest.c to avoid compiler warnings.
2883
2884 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2885
2886 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2887 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2888 entirely. This removes changes made in 7 above.
2889
2890 17. The CMake files have been updated, and there is now more information about
2891 building with CMake in the NON-UNIX-USE document.
2892
2893
2894 Version 7.3 28-Aug-07
2895 ---------------------
2896
2897 1. In the rejigging of the build system that eventually resulted in 7.1, the
2898 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2899 brackets there is not right, since it causes compilers to look for an
2900 installed pcre.h, not the version that is in the source that is being
2901 compiled (which of course may be different). I have changed it back to:
2902
2903 #include "pcre.h"
2904
2905 I have a vague recollection that the change was concerned with compiling in
2906 different directories, but in the new build system, that is taken care of
2907 by the VPATH setting the Makefile.
2908
2909 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2910 when the subject happened to end in the byte 0x85 (e.g. if the last
2911 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2912 characters but of course it shouldn't be taken as a newline when it is part
2913 of another character. The bug was that, for an unlimited repeat of . in
2914 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2915 characters when looking for a newline.
2916
2917 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2918
2919 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2920 in debug output.
2921
2922 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2923 long printing in the pcrecpp unittest when running under MinGW.
2924
2925 6. ESC_K was left out of the EBCDIC table.
2926
2927 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2928 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2929 limit also applies to "virtual nesting" when a pattern is recursive, and in
2930 this case 1000 isn't so big. I have been able to remove this limit at the
2931 expense of backing off one optimization in certain circumstances. Normally,
2932 when pcre_exec() would call its internal match() function recursively and
2933 immediately return the result unconditionally, it uses a "tail recursion"
2934 feature to save stack. However, when a subpattern that can match an empty
2935 string has an unlimited repetition quantifier, it no longer makes this
2936 optimization. That gives it a stack frame in which to save the data for
2937 checking that an empty string has been matched. Previously this was taken
2938 from the 1000-entry workspace that had been reserved. So now there is no
2939 explicit limit, but more stack is used.
2940
2941 8. Applied Daniel's patches to solve problems with the import/export magic
2942 syntax that is required for Windows, and which was going wrong for the
2943 pcreposix and pcrecpp parts of the library. These were overlooked when this
2944 problem was solved for the main library.
2945
2946 9. There were some crude static tests to avoid integer overflow when computing
2947 the size of patterns that contain repeated groups with explicit upper
2948 limits. As the maximum quantifier is 65535, the maximum group length was
2949 set at 30,000 so that the product of these two numbers did not overflow a
2950 32-bit integer. However, it turns out that people want to use groups that
2951 are longer than 30,000 bytes (though not repeat them that many times).
2952 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2953 made it possible to implement the integer overflow checks in a much more
2954 dynamic way, which I have now done. The artificial limitation on group
2955 length has been removed - we now have only the limit on the total length of
2956 the compiled pattern, which depends on the LINK_SIZE setting.
2957
2958 10. Fixed a bug in the documentation for get/copy named substring when
2959 duplicate names are permitted. If none of the named substrings are set, the
2960 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2961 empty string.
2962
2963 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2964 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2965 because the ] is interpreted as the first data character and the
2966 terminating ] is not found. PCRE has been made compatible with Perl in this
2967 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2968 cause memory overwriting.
2969
2970 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2971 string has been matched (to stop an infinite loop). It was not recognizing
2972 a conditional subpattern that could match an empty string if that
2973 subpattern was within another subpattern. For example, it looped when
2974 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
2975 condition was not nested. This bug has been fixed.
2976
2977 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
2978 past the start of the subject in the presence of bytes with the top bit
2979 set, for example "\x8aBCD".
2980
2981 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
2982 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
2983
2984 14. Optimized (?!) to (*FAIL).
2985
2986 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
2987 This restricts code points to be within the range 0 to 0x10FFFF, excluding
2988 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
2989 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
2990 does: it's just the validity check that is more restrictive.
2991
2992 16. Inserted checks for integer overflows during escape sequence (backslash)
2993 processing, and also fixed erroneous offset values for syntax errors during
2994 backslash processing.
2995
2996 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
2997 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
2998
2999 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
3000 caused an overrun.
3001
3002 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
3003 something other than just ASCII characters) inside a group that had an
3004 unlimited repeat caused a loop at compile time (while checking to see
3005 whether the group could match an empty string).
3006
3007 20. Debugging a pattern containing \p or \P could cause a crash. For example,
3008 [\P{Any}] did so. (Error in the code for printing property names.)
3009
3010 21. An orphan \E inside a character class could cause a crash.
3011
3012 22. A repeated capturing bracket such as (A)? could cause a wild memory
3013 reference during compilation.
3014
3015 23. There are several functions in pcre_compile() that scan along a compiled
3016 expression for various reasons (e.g. to see if it's fixed length for look
3017 behind). There were bugs in these functions when a repeated \p or \P was
3018 present in the pattern. These operators have additional parameters compared
3019 with \d, etc, and these were not being taken into account when moving along
3020 the compiled data. Specifically:
3021
3022 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
3023 length.
3024
3025 (b) An item such as \pL+ within a repeated group could cause crashes or
3026 loops.
3027
3028 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
3029 "reference to non-existent subpattern" error.
3030
3031 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
3032
3033 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
3034 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
3035
3036 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
3037
3038 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
3039 character were causing crashes (broken optimization).
3040
3041 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
3042 \p or \P) caused a compile-time loop.
3043
3044 28. More problems have arisen in unanchored patterns when CRLF is a valid line
3045 break. For example, the unstudied pattern [\r\n]A does not match the string
3046 "\r\nA" because change 7.0/46 below moves the current point on by two
3047 characters after failing to match at the start. However, the pattern \nA
3048 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
3049 the same is true. There doesn't seem any very clean way out of this, but
3050 what I have chosen to do makes the common cases work: PCRE now takes note
3051 of whether there can be an explicit match for \r or \n anywhere in the
3052 pattern, and if so, 7.0/46 no longer applies. As part of this change,
3053 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
3054 pattern has explicit CR or LF references.
3055
3056 29. Added (*CR) etc for changing newline setting at start of pattern.
3057
3058
3059 Version 7.2 19-Jun-07
3060 ---------------------
3061
3062 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
3063 which is apparently normally available under Windows.
3064
3065 2. Re-jig the pcregrep tests with different newline settings in an attempt
3066 to make them independent of the local environment's newline setting.
3067
3068 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
3069
3070 4. Some of the "internals" tests were previously cut out when the link size
3071 was not 2, because the output contained actual offsets. The recent new
3072 "Z" feature of pcretest means that these can be cut out, making the tests
3073 usable with all link sizes.
3074
3075 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
3076 stack recursion. This gives a massive performance boost under BSD, but just
3077 a small improvement under Linux. However, it saves one field in the frame
3078 in all cases.
3079
3080 6. Added more features from the forthcoming Perl 5.10:
3081
3082 (a) (?-n) (where n is a string of digits) is a relative subroutine or
3083 recursion call. It refers to the nth most recently opened parentheses.
3084
3085 (b) (?+n) is also a relative subroutine call; it refers to the nth next
3086 to be opened parentheses.
3087
3088 (c) Conditions that refer to capturing parentheses can be specified
3089 relatively, for example, (?(-2)... or (?(+3)...
3090
3091 (d) \K resets the start of the current match so that everything before
3092 is not part of it.
3093
3094 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
3095
3096 (f) \g{name} is another synonym - part of Perl 5.10's unification of
3097 reference syntax.
3098
3099 (g) (?| introduces a group in which the numbering of parentheses in each
3100 alternative starts with the same number.
3101
3102 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
3103
3104 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
3105 PCRE_INFO_JCHANGED.
3106
3107 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
3108 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
3109 for detecting groups that can match an empty string.
3110
3111 9. A pattern with a very large number of alternatives (more than several
3112 hundred) was running out of internal workspace during the pre-compile
3113 phase, where pcre_compile() figures out how much memory will be needed. A
3114 bit of new cunning has reduced the workspace needed for groups with
3115 alternatives. The 1000-alternative test pattern now uses 12 bytes of
3116 workspace instead of running out of the 4096 that are available.
3117
3118 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
3119
3120 11. Applied patch from Google to remove an optimization that didn't quite work.
3121 The report of the bug said:
3122
3123 pcrecpp::RE("a*").FullMatch("aaa") matches, while
3124 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
3125 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
3126
3127 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
3128 it matched the wrong number of bytes.
3129
3130
3131 Version 7.1 24-Apr-07
3132 ---------------------
3133
3134 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
3135 that is more "standard", making use of automake and other Autotools. There
3136 is some re-arrangement of the files and adjustment of comments consequent
3137 on this.
3138
3139 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
3140 for recursive directory scanning broke on some systems because the files
3141 are not scanned in any specific order and on different systems the order
3142 was different. A call to "sort" has been inserted into RunGrepTest for the
3143 approprate test as a short-term fix. In the longer term there may be an
3144 alternative.
3145
3146 3. I had an email from Eric Raymond about problems translating some of PCRE's
3147 man pages to HTML (despite the fact that I distribute HTML pages, some
3148 people do their own conversions for various reasons). The problems
3149 concerned the use of low-level troff macros .br and .in. I have therefore
3150 removed all such uses from the man pages (some were redundant, some could
3151 be replaced by .nf/.fi pairs). The 132html script that I use to generate
3152 HTML has been updated to handle .nf/.fi and to complain if it encounters
3153 .br or .in.
3154
3155 4. Updated comments in configure.ac that get placed in config.h.in and also
3156 arranged for config.h to be included in the distribution, with the name
3157 config.h.generic, for the benefit of those who have to compile without
3158 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
3159
3160 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
3161 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
3162 makevp.bat for the current PCRE, using the additional files
3163 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
3164
3165 6. A Windows user reported a minor discrepancy with test 2, which turned out
3166 to be caused by a trailing space on an input line that had got lost in his
3167 copy. The trailing space was an accident, so I've just removed it.
3168
3169 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
3170 that is needed.
3171
3172 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
3173 as "const" (a) because they are and (b) because it helps the PHP
3174 maintainers who have recently made a script to detect big data structures
3175 in the php code that should be moved to the .rodata section. I remembered
3176 to update Builducptable as well, so it won't revert if ucptable.h is ever
3177 re-created.
3178
3179 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
3180 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
3181 order to be able to cut out the UTF-8 tables in the latter when UTF-8
3182 support is not required. This saves 1.5-2K of code, which is important in
3183 some applications.
3184
3185 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
3186 so as not to refer to the tables, even though these functions will never be
3187 called when UTF-8 support is disabled. Otherwise there are problems with a
3188 shared library.
3189
3190 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
3191
3192 (a) It was defining its arguments as char * instead of void *.
3193
3194 (b) It was assuming that all moves were upwards in memory; this was true
3195 a long time ago when I wrote it, but is no longer the case.
3196
3197 The emulated memove() is provided for those environments that have neither
3198 memmove() nor bcopy(). I didn't think anyone used it these days, but that
3199 is clearly not the case, as these two bugs were recently reported.
3200
3201 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
3202 and Detrail to create the HTML documentation, the .txt form of the man
3203 pages, and it removes trailing spaces from listed files. It also creates
3204 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
3205 case, it wraps all the #defines with #ifndefs. This script should be run
3206 before "make dist".
3207
3208 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
3209 with Unicode property support.
3210
3211 (a) For a maximizing quantifier, if the two different cases of the
3212 character were of different lengths in their UTF-8 codings (there are
3213 some cases like this - I found 11), and the matching function had to
3214 back up over a mixture of the two cases, it incorrectly assumed they
3215 were both the same length.
3216
3217 (b) When PCRE was configured to use the heap rather than the stack for
3218 recursion during matching, it was not correctly preserving the data for
3219 the other case of a UTF-8 character when checking ahead for a match
3220 while processing a minimizing repeat. If the check also involved
3221 matching a wide character, but failed, corruption could cause an
3222 erroneous result when trying to check for a repeat of the original
3223 character.
3224
3225 13. Some tidying changes to the testing mechanism:
3226
3227 (a) The RunTest script now detects the internal link size and whether there
3228 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
3229 values substituted by "configure". (The RunGrepTest script already did
3230 this for UTF-8.) The configure.ac script no longer substitutes the
3231 relevant variables.
3232
3233 (b) The debugging options /B and /D in pcretest show the compiled bytecode
3234 with length and offset values. This means that the output is different
3235 for different internal link sizes. Test 2 is skipped for link sizes
3236 other than 2 because of this, bypassing the problem. Unfortunately,
3237 there was also a test in test 3 (the locale tests) that used /B and
3238 failed for link sizes other than 2. Rather than cut the whole test out,
3239 I have added a new /Z option to pcretest that replaces the length and
3240 offset values with spaces. This is now used to make test 3 independent
3241 of link size. (Test 2 will be tidied up later.)
3242
3243 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
3244 segmentation fault instead of returning the appropriate error message.
3245
3246 15. In multiline mode when the newline sequence was set to "any", the pattern
3247 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
3248 This doesn't seem right; it now treats the CRLF combination as the line
3249 ending, and so does not match in that case. It's only a pattern such as ^$
3250 that would hit this one: something like ^ABC$ would have failed after \r
3251 and then tried again after \r\n.
3252
3253 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
3254 in an attempt to make files that differ only in their line terminators
3255 compare equal. This works on Linux.
3256
3257 17. Under certain error circumstances pcregrep might try to free random memory
3258 as it exited. This is now fixed, thanks to valgrind.
3259
3260 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
3261 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
3262 was because its rules for how to advance for /g after matching an empty
3263 string at the end of a line did not allow for this case. They now check for
3264 it specially.
3265
3266 20. pcretest is supposed to handle patterns and data of any length, by
3267 extending its buffers when necessary. It was getting this wrong when the
3268 buffer for a data line had to be extended.
3269
3270 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
3271 CRLF as a newline sequence.
3272
3273 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
3274 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
3275 I have nevertheless tidied it up.
3276
3277 23. Added some casts to kill warnings from HP-UX ia64 compiler.
3278
3279 24. Added a man page for pcre-config.
3280
3281
3282 Version 7.0 19-Dec-06
3283 ---------------------
3284
3285 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
3286 moving to gcc 4.1.1.
3287
3288 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
3289 sys/time.h, which is documented as needed for this function. It doesn't
3290 seem to matter on Linux, but it showed up on some releases of OS X.
3291
3292 3. It seems that there are systems where bytes whose values are greater than
3293 127 match isprint() in the "C" locale. The "C" locale should be the
3294 default when a C program starts up. In most systems, only ASCII printing
3295 characters match isprint(). This difference caused the output from pcretest
3296 to vary, making some of the tests fail. I have changed pcretest so that:
3297
3298 (a) When it is outputting text in the compiled version of a pattern, bytes
3299 other than 32-126 are always shown as hex escapes.
3300
3301 (b) When it is outputting text that is a matched part of a subject string,
3302 it does the same, unless a different locale has been set for the match
3303 (using the /L modifier). In this case, it uses isprint() to decide.
3304
3305 4. Fixed a major bug that caused incorrect computation of the amount of memory
3306 required for a compiled pattern when options that changed within the
3307 pattern affected the logic of the preliminary scan that determines the
3308 length. The relevant options are -x, and -i in UTF-8 mode. The result was
3309 that the computed length was too small. The symptoms of this bug were
3310 either the PCRE error "internal error: code overflow" from pcre_compile(),
3311 or a glibc crash with a message such as "pcretest: free(): invalid next
3312 size (fast)". Examples of patterns that provoked this bug (shown in
3313 pcretest format) are:
3314
3315 /(?-x: )/x
3316 /(?x)(?-x: \s*#\s*)/
3317 /((?i)[\x{c0}])/8
3318 /(?i:[\x{c0}])/8
3319
3320 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
3321 is now done differently.
3322
3323 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
3324 wrapper classes; (b) implement a new function in the C++ scanner that is
3325 more efficient than the old way of doing things because it avoids levels of
3326 recursion in the regex matching; (c) add a paragraph to the documentation
3327 for the FullMatch() function.
3328
3329 6. The escape sequence \n was being treated as whatever was defined as
3330 "newline". Not only was this contrary to the documentation, which states
3331 that \n is character 10 (hex 0A), but it also went horribly wrong when
3332 "newline" was defined as CRLF. This has been fixed.
3333
3334 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
3335 was being set to -1 for the "end of line" case (supposedly a value that no
3336 character can have). Though this value is never used (the check for end of
3337 line is "zero bytes in current character"), it caused compiler complaints.
3338 I've changed it to 0xffffffff.
3339
3340 8. In pcre_version.c, the version string was being built by a sequence of
3341 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
3342 string (as it is for production releases) called a macro with an empty
3343 argument. The C standard says the result of this is undefined. The gcc
3344 compiler treats it as an empty string (which was what was wanted) but it is
3345 reported that Visual C gives an error. The source has been hacked around to
3346 avoid this problem.
3347
3348 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
3349 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
3350 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
3351 of them did).
3352
3353 10. Originally, pcretest opened its input and output without "b"; then I was
3354 told that "b" was needed in some environments, so it was added for release
3355 5.0 to both the input and output. (It makes no difference on Unix-like
3356 systems.) Later I was told that it is wrong for the input on Windows. I've
3357 now abstracted the modes into two macros, to make it easier to fiddle with
3358 them, and removed "b" from the input mode under Windows.
3359
3360 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
3361
3362 12. Added -help and --help to pcretest as an official way of being reminded
3363 of the options.
3364
3365 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
3366 and pcrecpp.cc because they annoy compilers at high warning levels.
3367
3368 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
3369
3370 15. Fixed an occurrence of == in configure.ac that should have been = (shell
3371 scripts are not C programs :-) and which was not noticed because it works
3372 on Linux.
3373
3374 16. pcretest is supposed to handle any length of pattern and data line (as one
3375 line or as a continued sequence of lines) by extending its input buffer if
3376 necessary. This feature was broken for very long pattern lines, leading to
3377 a string of junk being passed to pcre_compile() if the pattern was longer
3378 than about 50K.
3379
3380 17. I have done a major re-factoring of the way pcre_compile() computes the
3381 amount of memory needed for a compiled pattern. Previously, there was code
3382 that made a preliminary scan of the pattern in order to do this. That was
3383 OK when PCRE was new, but as the facilities have expanded, it has become
3384 harder and harder to keep it in step with the real compile phase, and there
3385 have been a number of bugs (see for example, 4 above). I have now found a
3386 cunning way of running the real compile function in a "fake" mode that
3387 enables it to compute how much memory it would need, while actually only
3388 ever using a few hundred bytes of working memory and without too many
3389 tests of the mode. This should make future maintenance and development
3390 easier. A side effect of this work is that the limit of 200 on the nesting
3391 depth of parentheses has been removed (though this was never a serious
3392 limitation, I suspect). However, there is a downside: pcre_compile() now
3393 runs more slowly than before (30% or more, depending on the pattern). I
3394 hope this isn't a big issue. There is no effect on runtime performance.
3395
3396 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
3397 newline (only possible for the last line of a file) and it was a
3398 pattern that set a locale (followed by /Lsomething), pcretest crashed.
3399
3400 19. Added additional timing features to pcretest. (1) The -tm option now times
3401 matching only, not compiling. (2) Both -t and -tm can be followed, as a
3402 separate command line item, by a number that specifies the number of
3403 repeats to use when timing. The default is 50000; this gives better
3404 precision, but takes uncomfortably long for very large patterns.
3405
3406 20. Extended pcre_study() to be more clever in cases where a branch of a
3407 subpattern has no definite first character. For example, (a*|b*)[cd] would
3408 previously give no result from pcre_study(). Now it recognizes that the
3409 first character must be a, b, c, or d.
3410
3411 21. There was an incorrect error "recursive call could loop indefinitely" if
3412 a subpattern (or the entire pattern) that was being tested for matching an
3413 empty string contained only one non-empty item after a nested subpattern.
3414 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
3415 incorrectly, because the \d was being skipped in the check.
3416
3417 22. The pcretest program now has a new pattern option /B and a command line
3418 option -b, which is equivalent to adding /B to every pattern. This causes
3419 it to show the compiled bytecode, without the additional information that
3420 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
3421 is the same as /B/I).
3422
3423 23. A new optimization is now able automatically to treat some sequences such
3424 as a*b as a*+b. More specifically, if something simple (such as a character
3425 or a simple class like \d) has an unlimited quantifier, and is followed by
3426 something that cannot possibly match the quantified thing, the quantifier
3427 is automatically "possessified".
3428
3429 24. A recursive reference to a subpattern whose number was greater than 39
3430 went wrong under certain circumstances in UTF-8 mode. This bug could also
3431 have affected the operation of pcre_study().
3432
3433 25. Realized that a little bit of performance could be had by replacing
3434 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
3435
3436 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
3437
3438 27. Possessive quantifiers such as a++ were previously implemented by turning
3439 them into atomic groups such as ($>a+). Now they have their own opcodes,
3440 which improves performance. This includes the automatically created ones
3441 from 23 above.
3442
3443 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
3444 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
3445 the first matched character to be a colon. This applied both to named and
3446 numbered groups.
3447
3448 29. The ucpinternal.h header file was missing its idempotency #ifdef.
3449
3450 30. I was sent a "project" file called libpcre.a.dev which I understand makes
3451 building PCRE on Windows easier, so I have included it in the distribution.
3452
3453 31. There is now a check in pcretest against a ridiculously large number being
3454 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
3455 loop, the loop is abandoned.
3456
3457 32. Forward references to subpatterns in conditions such as (?(2)...) where
3458 subpattern 2 is defined later cause pcre_compile() to search forwards in
3459 the pattern for the relevant set of parentheses. This search went wrong
3460 when there were unescaped parentheses in a character class, parentheses
3461 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
3462
3463 33. "Subroutine" calls and backreferences were previously restricted to
3464 referencing subpatterns earlier in the regex. This restriction has now
3465 been removed.
3466
3467 34. Added a number of extra features that are going to be in Perl 5.10. On the
3468 whole, these are just syntactic alternatives for features that PCRE had
3469 previously implemented using the Python syntax or my own invention. The
3470 other formats are all retained for compatibility.
3471
3472 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
3473 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
3474 also .NET compatible.
3475
3476 (b) A recursion or subroutine call to a named group can now be defined as
3477 (?&name) as well as (?P>name).
3478
3479 (c) A backreference to a named group can now be defined as \k<name> or
3480 \k'name' as well as (?P=name). The new forms, as well as being in Perl
3481 5.10, are also .NET compatible.
3482
3483 (d) A conditional reference to a named group can now use the syntax
3484 (?(<name>) or (?('name') as well as (?(name).
3485
3486 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
3487 groups (named and numbered) that are never evaluated inline, but can be
3488 called as "subroutines" from elsewhere. In effect, the DEFINE condition
3489 is always false. There may be only one alternative in such a group.
3490
3491 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
3492 as the simple (?(R). The condition is true only if the most recent
3493 recursion is that of the given number or name. It does not search out
3494 through the entire recursion stack.
3495
3496 (g) The escape \gN or \g{N} has been added, where N is a positive or
3497 negative number, specifying an absolute or relative reference.
3498
3499 35. Tidied to get rid of some further signed/unsigned compiler warnings and
3500 some "unreachable code" warnings.
3501
3502 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
3503 things, this adds five new scripts.
3504
3505 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
3506 There were also incompatibilities regarding the handling of \Q..\E inside
3507 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3508 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3509
3510 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3511 matches an empty string, and forcibly breaks the loop. There were bugs in
3512 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3513 against aaaa the result was just "a" rather than "aaaa", for example. Two
3514 separate and independent bugs (that affected different cases) have been
3515 fixed.
3516
3517 39. Refactored the code to abolish the use of different opcodes for small
3518 capturing bracket numbers. This is a tidy that I avoided doing when I
3519 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3520 The new approach is not only tidier, it makes it possible to reduce the
3521 memory needed to fix the previous bug (38).
3522
3523 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3524 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3525 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3526 mode.
3527
3528 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3529 report.
3530
3531 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3532 copy construction and assignment in the C++ wrapper.
3533
3534 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3535 couple of bugs that could have given wrong results in the "--newline=crlf"
3536 case.
3537
3538 44. Added a number of casts and did some reorganization of signed/unsigned int
3539 variables following suggestions from Dair Grant. Also renamed the variable
3540 "this" as "item" because it is a C++ keyword.
3541
3542 45. Arranged for dftables to add
3543
3544 #include "pcre_internal.h"
3545
3546 to pcre_chartables.c because without it, gcc 4.x may remove the array
3547 definition from the final binary if PCRE is built into a static library and
3548 dead code stripping is activated.
3549
3550 46. For an unanchored pattern, if a match attempt fails at the start of a
3551 newline sequence, and the newline setting is CRLF or ANY, and the next two
3552 characters are CRLF, advance by two characters instead of one.
3553
3554
3555 Version 6.7 04-Jul-06
3556 ---------------------
3557
3558 1. In order to handle tests when input lines are enormously long, pcretest has
3559 been re-factored so that it automatically extends its buffers when
3560 necessary. The code is crude, but this _is_ just a test program. The
3561 default size has been increased from 32K to 50K.
3562
3563 2. The code in pcre_study() was using the value of the re argument before
3564 testing it for NULL. (Of course, in any sensible call of the function, it
3565 won't be NULL.)
3566
3567 3. The memmove() emulation function in pcre_internal.h, which is used on
3568 systems that lack both memmove() and bcopy() - that is, hardly ever -
3569 was missing a "static" storage class specifier.
3570
3571 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3572 containing an extended class (one that cannot be represented by a bitmap
3573 because it contains high-valued characters or Unicode property items, e.g.
3574 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3575 pattern, but PCRE should not loop if you do not (it no longer does).
3576 [Detail: two cases were found: (a) a repeated subpattern containing an
3577 extended class; (b) a recursive reference to a subpattern that followed a
3578 previous extended class. It wasn't skipping over the extended class
3579 correctly when UTF-8 mode was not set.]
3580
3581 5. A negated single-character class was not being recognized as fixed-length
3582 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3583 compile error "lookbehind assertion is not fixed length".
3584
3585 6. The RunPerlTest auxiliary script was showing an unexpected difference
3586 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3587 write a Perl script that can interpret lines of an input file either as
3588 byte characters or as UTF-8, which is what "perltest" was being required to
3589 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3590 can't do is switch easily at run time between having the "use utf8;" pragma
3591 or not. In the end, I fudged it by using the RunPerlTest script to insert
3592 "use utf8;" explicitly for the UTF-8 tests.
3593
3594 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3595 the end of the subject string, contrary to the documentation and to what
3596 Perl does. This was true of both matching functions. Now it matches only at
3597 the start of the subject and immediately after *internal* newlines.
3598
3599 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3600 a pointer to an int instead of a pointer to an unsigned long int. This
3601 caused problems on 64-bit systems.
3602
3603 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
3604 instance of the 'standard' template library not being so standard".
3605
3606 10. There was no check on the number of named subpatterns nor the maximum
3607 length of a subpattern name. The product of these values is used to compute
3608 the size of the memory block for a compiled pattern. By supplying a very
3609 long subpattern name and a large number of named subpatterns, the size
3610 computation could be caused to overflow. This is now prevented by limiting
3611 the length of names to 32 characters, and the number of named subpatterns
3612 to 10,000.
3613
3614 11. Subpatterns that are repeated with specific counts have to be replicated in
3615 the compiled pattern. The size of memory for this was computed from the
3616 length of the subpattern and the repeat count. The latter is limited to
3617 65535, but there was no limit on the former, meaning that integer overflow
3618 could in principle occur. The compiled length of a repeated subpattern is
3619 now limited to 30,000 bytes in order to prevent this.
3620
3621 12. Added the optional facility to have named substrings with the same name.
3622
3623 13. Added the ability to use a named substring as a condition, using the
3624 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
3625 are numbers (not recommended). Forward references are permitted.
3626
3627 14. Added forward references in named backreferences (if you see what I mean).
3628
3629 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
3630 pattern could run off the end of the subject. For example, the pattern
3631 "(?s)(.{1,5})"8 did this with the subject "ab".
3632
3633 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
3634 PCRE_CASELESS was set when matching characters that were quantified with ?
3635 or *.
3636
3637 17. A character class other than a single negated character that had a minimum
3638 but no maximum quantifier - for example [ab]{6,} - was not handled
3639 correctly by pce_dfa_exec(). It would match only one character.
3640
3641 18. A valid (though odd) pattern that looked like a POSIX character
3642 class but used an invalid character after [ (for example [[,abc,]]) caused
3643 pcre_compile() to give the error "Failed: internal error: code overflow" or
3644 in some cases to crash with a glibc free() error. This could even happen if
3645 the pattern terminated after [[ but there just happened to be a sequence of
3646 letters, a binary zero, and a closing ] in the memory that followed.
3647
3648 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
3649 over the years. Originally (before any Unicode support), just the bottom 8
3650 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
3651 output from "man perlunicode" includes this:
3652
3653 The regular expression compiler produces polymorphic opcodes. That
3654 is, the pattern adapts to the data and automatically switches to
3655 the Unicode character scheme when presented with Unicode data--or
3656 instead uses a traditional byte scheme when presented with byte
3657 data.
3658
3659 Sadly, a wide octal escape does not cause a switch, and in a string with
3660 no other multibyte characters, these octal escapes are treated as before.
3661 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
3662 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
3663 Unicode string.
3664
3665 I have not perpetrated such confusion in PCRE. Up till now, it took just
3666 the bottom 8 bits, as in old Perl. I have now made octal escapes with
3667 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
3668 translate to the appropriate multibyte character.
3669
3670 29. Applied some refactoring to reduce the number of warnings from Microsoft
3671 and Borland compilers. This has included removing the fudge introduced
3672 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
3673 a warning about an unused variable.
3674
3675 21. PCRE has not included VT (character 0x0b) in the set of whitespace
3676 characters since release 4.0, because Perl (from release 5.004) does not.
3677 [Or at least, is documented not to: some releases seem to be in conflict
3678 with the documentation.] However, when a pattern was studied with
3679 pcre_study() and all its branches started with \s, PCRE still included VT
3680 as a possible starting character. Of course, this did no harm; it just
3681 caused an unnecessary match attempt.
3682
3683 22. Removed a now-redundant internal flag bit that recorded the fact that case
3684 dependency changed within the pattern. This was once needed for "required
3685 byte" processing, but is no longer used. This recovers a now-scarce options
3686 bit. Also moved the least significant internal flag bit to the most-
3687 significant bit of the word, which was not previously used (hangover from
3688 the days when it was an int rather than a uint) to free up another bit for
3689 the future.
3690
3691 23. Added support for CRLF line endings as well as CR and LF. As well as the
3692 default being selectable at build time, it can now be changed at runtime
3693 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
3694 specify that it is scanning data with non-default line endings.
3695
3696 24. Changed the definition of CXXLINK to make it agree with the definition of
3697 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
3698
3699 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
3700 recursions. This makes a big different to stack usage for some patterns.
3701
3702 26. If a subpattern containing a named recursion or subroutine reference such
3703 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
3704 the space required for the compiled pattern went wrong and gave too small a
3705 value. Depending on the environment, this could lead to "Failed: internal
3706 error: code overflow at offset 49" or "glibc detected double free or
3707 corruption" errors.
3708
3709 27. Applied patches from Google (a) to support the new newline modes and (b) to
3710 advance over multibyte UTF-8 characters in GlobalReplace.
3711
3712 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
3713 difference for some implementation of PCRE in some Windows version.
3714
3715 29. Added some extra testing facilities to pcretest:
3716
3717 \q<number> in a data line sets the "match limit" value
3718 \Q<number> in a data line sets the "match recursion limt" value
3719 -S <number> sets the stack size, where <number> is in megabytes
3720
3721 The -S option isn't available for Windows.
3722
3723
3724 Version 6.6 06-Feb-06
3725 ---------------------
3726
3727 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
3728 in pcreposix.h. I have copied the definition from pcre.h.
3729
3730 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
3731 because pcre.h is no longer a built file.
3732
3733 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
3734 not normally included in the compiled code.
3735
3736
3737 Version 6.5 01-Feb-06
3738 ---------------------
3739
3740 1. When using the partial match feature with pcre_dfa_exec(), it was not
3741 anchoring the second and subsequent partial matches at the new starting
3742 point. This could lead to incorrect results. For example, with the pattern
3743 /1234/, partially matching against "123" and then "a4" gave a match.
3744
3745 2. Changes to pcregrep:
3746
3747 (a) All non-match returns from pcre_exec() were being treated as failures
3748 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
3749 error message is output. Some extra information is given for the
3750 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
3751 probably the only errors that are likely to be caused by users (by
3752 specifying a regex that has nested indefinite repeats, for instance).
3753 If there are more than 20 of these errors, pcregrep is abandoned.
3754
3755 (b) A binary zero was treated as data while matching, but terminated the
3756 output line if it was written out. This has been fixed: binary zeroes
3757 are now no different to any other data bytes.
3758
3759 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
3760 used to set a locale for matching. The --locale=xxxx long option has
3761 been added (no short equivalent) to specify a locale explicitly on the
3762 pcregrep command, overriding the environment variables.
3763
3764 (d) When -B was used with -n, some line numbers in the output were one less
3765 than they should have been.
3766
3767 (e) Added the -o (--only-matching) option.
3768
3769 (f) If -A or -C was used with -c (count only), some lines of context were
3770 accidentally printed for the final match.
3771
3772 (g) Added the -H (--with-filename) option.
3773
3774 (h) The combination of options -rh failed to suppress file names for files
3775 that were found from directory arguments.
3776
3777 (i) Added the -D (--devices) and -d (--directories) options.
3778
3779 (j) Added the -F (--fixed-strings) option.
3780
3781 (k) Allow "-" to be used as a file name for -f as well as for a data file.
3782
3783 (l) Added the --colo(u)r option.
3784
3785 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
3786 is not present by default.
3787
3788 3. A nasty bug was discovered in the handling of recursive patterns, that is,
3789 items such as (?R) or (?1), when the recursion could match a number of
3790 alternatives. If it matched one of the alternatives, but subsequently,
3791 outside the recursion, there was a failure, the code tried to back up into
3792 the recursion. However, because of the way PCRE is implemented, this is not
3793 possible, and the result was an incorrect result from the match.
3794
3795 In order to prevent this happening, the specification of recursion has
3796 been changed so that all such subpatterns are automatically treated as
3797 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
3798
3799 4. I had overlooked the fact that, in some locales, there are characters for
3800 which isalpha() is true but neither isupper() nor islower() are true. In
3801 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
3802 and ordfeminine) are like this. This affected the treatment of \w and \W
3803 when they appeared in character classes, but not when they appeared outside
3804 a character class. The bit map for "word" characters is now created
3805 separately from the results of isalnum() instead of just taking it from the
3806 upper, lower, and digit maps. (Plus the underscore character, of course.)
3807
3808 5. The above bug also affected the handling of POSIX character classes such as
3809 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
3810 permanent tables. Instead, the bit maps for such a class were previously
3811 created as the appropriate unions of the upper, lower, and digit bitmaps.
3812 Now they are created by subtraction from the [[:word:]] class, which has
3813 its own bitmap.
3814
3815 6. The [[:blank:]] character class matches horizontal, but not vertical space.
3816 It is created by subtracting the vertical space characters (\x09, \x0a,
3817 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
3818 subtraction was done in the overall bitmap for a character class, meaning
3819 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
3820 be recognized. This bug has been fixed.
3821
3822 7. Patches from the folks at Google:
3823
3824 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
3825 real life, but is still worth protecting against".
3826
3827 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
3828 regular expressions".
3829
3830 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
3831 have it.
3832
3833 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
3834 "configure" and the latter not, in order to fix a problem somebody had
3835 with compiling the Arg class on HP-UX.
3836
3837 (e) Improve the error-handling of the C++ wrapper a little bit.
3838
3839 (f) New tests for checking recursion limiting.
3840
3841 8. The pcre_memmove() function, which is used only if the environment does not
3842 have a standard memmove() function (and is therefore rarely compiled),
3843 contained two bugs: (a) use of int instead of size_t, and (b) it was not
3844 returning a result (though PCRE never actually uses the result).
3845
3846 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
3847 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
3848 returned instead of calling malloc() with an overflowing number that would
3849 most likely cause subsequent chaos.
3850
3851 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
3852
3853 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
3854 with this option is matched, the nmatch and pmatch options of regexec() are
3855 ignored.
3856
3857 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
3858 provided in case anyone wants to the the POSIX interface with UTF-8
3859 strings.
3860
3861 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
3862 C++ linking (needed for some HP-UX environments).
3863
3864 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
3865 (unused parameter) and in the pcre_printint() function (omitted "default"
3866 switch label when the default is to do nothing).
3867
3868 15. Added some code to make it possible, when PCRE is compiled as a C++
3869 library, to replace subject pointers for pcre_exec() with a smart pointer
3870 class, thus making it possible to process discontinuous strings.
3871
3872 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
3873 much the same function. They were added by different people who were trying
3874 to make PCRE easy to compile on non-Unix systems. It has been suggested
3875 that PCRE_EXPORT be abolished now that there is more automatic apparatus
3876 for compiling on Windows systems. I have therefore replaced it with
3877 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
3878 defaults to "extern" for C or "extern C" for C++, which works fine on
3879 Unix-like systems. It is now possible to override the value of PCRE_DATA_
3880 SCOPE with something explicit in config.h. In addition:
3881
3882 (a) pcreposix.h still had just "extern" instead of either of these macros;
3883 I have replaced it with PCRE_DATA_SCOPE.
3884
3885 (b) Functions such as _pcre_xclass(), which are internal to the library,
3886 but external in the C sense, all had PCRE_EXPORT in their definitions.
3887 This is apparently wrong for the Windows case, so I have removed it.
3888 (It makes no difference on Unix-like systems.)
3889
3890 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3891 of recursive calls to match(). This is different to MATCH_LIMIT because
3892 that limits the total number of calls to match(), not all of which increase
3893 the depth of recursion. Limiting the recursion depth limits the amount of
3894 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3895 when PCRE is compiled, and changed at run time. A patch from Google adds
3896 this functionality to the C++ interface.
3897
3898 18. Changes to the handling of Unicode character properties:
3899
3900 (a) Updated the table to Unicode 4.1.0.
3901
3902 (b) Recognize characters that are not in the table as "Cn" (undefined).
3903
3904 (c) I revised the way the table is implemented to a much improved format
3905 which includes recognition of ranges. It now supports the ranges that
3906 are defined in UnicodeData.txt, and it also amalgamates other
3907 characters into ranges. This has reduced the number of entries in the
3908 table from around 16,000 to around 3,000, thus reducing its size
3909 considerably. I realized I did not need to use a tree structure after
3910 all - a binary chop search is just as efficient. Having reduced the
3911 number of entries, I extended their size from 6 bytes to 8 bytes to
3912 allow for more data.
3913
3914 (d) Added support for Unicode script names via properties such as \p{Han}.
3915
3916 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3917 matching that character.
3918
3919 20. When matching a repeated Unicode property with a minimum greater than zero,
3920 (for example \pL{2,}), PCRE could look past the end of the subject if it
3921 reached it while seeking the minimum number of characters. This could
3922 happen only if some of the characters were more than one byte long, because
3923 there is a check for at least the minimum number of bytes.
3924
3925 21. Refactored the implementation of \p and \P so as to be more general, to
3926 allow for more different types of property in future. This has changed the
3927 compiled form incompatibly. Anybody with saved compiled patterns that use
3928 \p or \P will have to recompile them.
3929
3930 22. Added "Any" and "L&" to the supported property types.
3931
3932 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3933 but give a compile time error if the value is greater than 0xff.
3934
3935 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3936 accidentally not being installed or uninstalled.
3937
3938 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3939 made were to insert the current release number. This seemed silly, because
3940 it made things harder for people building PCRE on systems that don't run
3941 "configure". I have turned pcre.h into a distributed file, no longer built
3942 by "configure", with the version identification directly included. There is
3943 no longer a pcre.h.in file.
3944
3945 However, this change necessitated a change to the pcre-config script as
3946 well. It is built from pcre-config.in, and one of the substitutions was the
3947 release number. I have updated configure.ac so that ./configure now finds
3948 the release number by grepping pcre.h.
3949
3950 26. Added the ability to run the tests under valgrind.
3951
3952
3953 Version 6.4 05-Sep-05
3954 ---------------------
3955
3956 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3957 "--" to be printed when multiple files were scanned, even when none of the
3958 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3959 consider it to be a bug, and have restored the previous behaviour.
3960
3961 2. A couple of code tidies to get rid of compiler warnings.
3962
3963 3. The pcretest program used to cheat by referring to symbols in the library
3964 whose names begin with _pcre_. These are internal symbols that are not
3965 really supposed to be visible externally, and in some environments it is
3966 possible to suppress them. The cheating is now confined to including
3967 certain files from the library's source, which is a bit cleaner.
3968
3969 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
3970 file's purpose clearer.
3971
3972 5. Reorganized pcre_ucp_findchar().
3973
3974
3975 Version 6.3 15-Aug-05
3976 ---------------------
3977
3978 1. The file libpcre.pc.in did not have general read permission in the tarball.
3979
3980 2. There were some problems when building without C++ support:
3981
3982 (a) If C++ support was not built, "make install" and "make test" still
3983 tried to test it.
3984
3985 (b) There were problems when the value of CXX was explicitly set. Some
3986 changes have been made to try to fix these, and ...
3987
3988 (c) --disable-cpp can now be used to explicitly disable C++ support.
3989
3990 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
3991 backslash in a target when C++ was disabled. This confuses some
3992 versions of "make", apparently. Using an intermediate variable solves
3993 this. (Same for CPP_LOBJ.)
3994
3995 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
3996 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
3997 necessary on certain architectures.
3998
3999 4. Added a setting of -export-symbols-regex to the link command to remove
4000 those symbols that are exported in the C sense, but actually are local
4001 within the library, and not documented. Their names all begin with
4002 "_pcre_". This is not a perfect job, because (a) we have to except some
4003 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
4004 available (and never for static libraries). I have made a note to try to
4005 find a way round (a) in the future.
4006
4007
4008 Version 6.2 01-Aug-05
4009 ---------------------
4010
4011 1. There was no test for integer overflow of quantifier values. A construction
4012 such as {1111111111111111} would give undefined results. What is worse, if
4013 a minimum quantifier for a parenthesized subpattern overflowed and became
4014 negative, the calculation of the memory size went wrong. This could have
4015 led to memory overwriting.
4016
4017 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
4018
4019 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
4020 operating environments where this matters.
4021
4022 4. Applied Giuseppe Maxia's patch to add additional features for controlling
4023 PCRE options from within the C++ wrapper.
4024
4025 5. Named capturing subpatterns were not being correctly counted when a pattern
4026 was compiled. This caused two problems: (a) If there were more than 100
4027 such subpatterns, the calculation of the memory needed for the whole
4028 compiled pattern went wrong, leading to an overflow error. (b) Numerical
4029 back references of the form \12, where the number was greater than 9, were
4030 not recognized as back references, even though there were sufficient
4031 previous subpatterns.
4032
4033 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
4034 versions of gcc, e.g. 2.95.4.
4035
4036
4037 Version 6.1 21-Jun-05
4038 ---------------------
4039
4040 1. There was one reference to the variable "posix" in pcretest.c that was not
4041 surrounded by "#if !defined NOPOSIX".
4042
4043 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
4044 the cross-check on the old pcre_info() function, for the benefit of the
4045 cut-down version of PCRE that is currently imported into Exim.
4046
4047 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
4048 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
4049 patterns that start (?i) but I don't think that matters. The use of (?i) is
4050 just an example; this all applies to the other options as well.
4051
4052 4. Since libtool seems to echo the compile commands it is issuing, the output
4053 from "make" can be reduced a bit by putting "@" in front of each libtool
4054 compile command.
4055
4056 5. Patch from the folks at Google for configure.in to be a bit more thorough
4057 in checking for a suitable C++ installation before trying to compile the
4058 C++ stuff. This should fix a reported problem when a compiler was present,
4059 but no suitable headers.
4060
4061 6. The man pages all had just "PCRE" as their title. I have changed them to
4062 be the relevant file name. I have also arranged that these names are
4063 retained in the file doc/pcre.txt, which is a concatenation in text format
4064 of all the man pages except the little individual ones for each function.
4065
4066 7. The NON-UNIX-USE file had not been updated for the different set of source
4067 files that come with release 6. I also added a few comments about the C++
4068 wrapper.
4069
4070
4071 Version 6.0 07-Jun-05
4072 ---------------------
4073
4074 1. Some minor internal re-organization to help with my DFA experiments.
4075
4076 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
4077 didn't matter for the library itself when fully configured, but did matter
4078 when compiling without UCP support, or within Exim, where the ucp files are
4079 not imported.
4080
4081 3. Refactoring of the library code to split up the various functions into
4082 different source modules. The addition of the new DFA matching code (see
4083 below) to a single monolithic source would have made it really too
4084 unwieldy, quite apart from causing all the code to be include in a
4085 statically linked application, when only some functions are used. This is
4086 relevant even without the DFA addition now that patterns can be compiled in
4087 one application and matched in another.
4088
4089 The downside of splitting up is that there have to be some external
4090 functions and data tables that are used internally in different modules of
4091 the library but which are not part of the API. These have all had their
4092 names changed to start with "_pcre_" so that they are unlikely to clash
4093 with other external names.
4094
4095 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
4096 a different (DFA) algorithm. Although it is slower than the original
4097 function, it does have some advantages for certain types of matching
4098 problem.
4099
4100 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
4101 including restarting after a partial match.
4102
4103 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
4104 defined when compiling for Windows was sent to me. I have put it into the
4105 code, though I have no means of testing or verifying it.
4106
4107 7. Added the pcre_refcount() auxiliary function.
4108
4109 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
4110 match before or at the first newline in the subject string. In pcretest,
4111 the /f option on a pattern can be used to set this.
4112
4113 9. A repeated \w when used in UTF-8 mode with characters greater than 256
4114 would behave wrongly. This has been present in PCRE since release 4.0.
4115
4116 10. A number of changes to the pcregrep command:
4117
4118 (a) Refactored how -x works; insert ^(...)$ instead of setting
4119 PCRE_ANCHORED and checking the length, in preparation for adding
4120 something similar for -w.
4121
4122 (b) Added the -w (match as a word) option.
4123
4124 (c) Refactored the way lines are read and buffered so as to have more
4125 than one at a time available.
4126
4127 (d) Implemented a pcregrep test script.
4128
4129 (e) Added the -M (multiline match) option. This allows patterns to match
4130 over several lines of the subject. The buffering ensures that at least
4131 8K, or the rest of the document (whichever is the shorter) is available
4132 for matching (and similarly the previous 8K for lookbehind assertions).
4133
4134 (f) Changed the --help output so that it now says
4135
4136 -w, --word-regex(p)
4137
4138 instead of two lines, one with "regex" and the other with "regexp"
4139 because that confused at least one person since the short forms are the
4140 same. (This required a bit of code, as the output is generated
4141 automatically from a table. It wasn't just a text change.)
4142
4143 (g) -- can be used to terminate pcregrep options if the next thing isn't an
4144 option but starts with a hyphen. Could be a pattern or a path name
4145 starting with a hyphen, for instance.
4146
4147 (h) "-" can be given as a file name to represent stdin.
4148
4149 (i) When file names are being printed, "(standard input)" is used for
4150 the standard input, for compatibility with GNU grep. Previously
4151 "<stdin>" was used.
4152
4153 (j) The option --label=xxx can be used to supply a name to be used for
4154 stdin when file names are being printed. There is no short form.
4155
4156 (k) Re-factored the options decoding logic because we are going to add
4157 two more options that take data. Such options can now be given in four
4158 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
4159
4160 (l) Added the -A, -B, and -C options for requesting that lines of context
4161 around matches be printed.
4162
4163 (m) Added the -L option to print the names of files that do not contain
4164 any matching lines, that is, the complement of -l.
4165
4166 (n) The return code is 2 if any file cannot be opened, but pcregrep does
4167 continue to scan other files.
4168
4169 (o) The -s option was incorrectly implemented. For compatibility with other
4170 greps, it now suppresses the error message for a non-existent or non-
4171 accessible file (but not the return code). There is a new option called
4172 -q that suppresses the output of matching lines, which was what -s was
4173 previously doing.
4174
4175 (p) Added --include and --exclude options to specify files for inclusion
4176 and exclusion when recursing.
4177
4178 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
4179 Hopefully, it now does.
4180
4181 12. Missing cast in pcre_study().
4182
4183 13. Added an "uninstall" target to the makefile.
4184
4185 14. Replaced "extern" in the function prototypes in Makefile.in with
4186 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
4187 world, but is set differently for Windows.
4188
4189 15. Added a second compiling function called pcre_compile2(). The only
4190 difference is that it has an extra argument, which is a pointer to an
4191 integer error code. When there is a compile-time failure, this is set
4192 non-zero, in addition to the error test pointer being set to point to an
4193 error message. The new argument may be NULL if no error number is required
4194 (but then you may as well call pcre_compile(), which is now just a
4195 wrapper). This facility is provided because some applications need a
4196 numeric error indication, but it has also enabled me to tidy up the way
4197 compile-time errors are handled in the POSIX wrapper.
4198
4199 16. Added VPATH=.libs to the makefile; this should help when building with one
4200 prefix path and installing with another. (Or so I'm told by someone who
4201 knows more about this stuff than I do.)
4202
4203 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
4204 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
4205 match everything, including newlines. This is not POSIX-compatible, but
4206 somebody wanted the feature. From pcretest it can be activated by using
4207 both the P and the s flags.
4208
4209 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
4210
4211 19. libpcre.pc was being incorrectly installed as executable.
4212
4213 20. A couple of places in pcretest check for end-of-line by looking for '\n';
4214 it now also looks for '\r' so that it will work unmodified on Windows.
4215
4216 21. Added Google's contributed C++ wrapper to the distribution.
4217
4218 22. Added some untidy missing memory free() calls in pcretest, to keep
4219 Electric Fence happy when testing.
4220
4221
4222
4223 Version 5.0 13-Sep-04
4224 ---------------------
4225
4226 1. Internal change: literal characters are no longer packed up into items
4227 containing multiple characters in a single byte-string. Each character
4228 is now matched using a separate opcode. However, there may be more than one
4229 byte in the character in UTF-8 mode.
4230
4231 2. The pcre_callout_block structure has two new fields: pattern_position and
4232 next_item_length. These contain the offset in the pattern to the next match
4233 item, and its length, respectively.
4234
4235 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
4236 insertion of callouts before each pattern item. Added the /C option to
4237 pcretest to make use of this.
4238
4239 4. On the advice of a Windows user, the lines
4240
4241 #if defined(_WIN32) || defined(WIN32)
4242 _setmode( _fileno( stdout ), 0x8000 );
4243 #endif /* defined(_WIN32) || defined(WIN32) */
4244
4245 have been added to the source of pcretest. This apparently does useful
4246 magic in relation to line terminators.
4247
4248 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
4249 for the benefit of those environments where the "b" makes a difference.
4250
4251 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
4252 to know about it. I have put a hack into configure.in that adds in code
4253 to set GCC=yes if CC=icc. This seems to end up at a point in the
4254 generated configure script that is early enough to affect the setting of
4255 compiler options, which is what is needed, but I have no means of testing
4256 whether it really works. (The user who reported this had patched the
4257 generated configure script, which of course I cannot do.)
4258
4259 LATER: After change 22 below (new libtool files), the configure script
4260 seems to know about icc (and also ecc). Therefore, I have commented out
4261 this hack in configure.in.
4262
4263 7. Added support for pkg-config (2 patches were sent in).
4264
4265 8. Negated POSIX character classes that used a combination of internal tables
4266 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
4267 [[:^ascii]]. Typically, they would match almost any characters. The other
4268 POSIX classes were not broken in this way.
4269
4270 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
4271 to find the match, as PCRE was deluded into thinking that the match had to
4272 start at the start point or following a newline. The same bug applied to
4273 patterns with negative forward assertions or any backward assertions
4274 preceding ".*" at the start, unless the pattern required a fixed first
4275 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
4276
4277 10. In UTF-8 mode, when moving forwards in the subject after a failed match
4278 starting at the last subject character, bytes beyond the end of the subject
4279 string were read.
4280
4281 11. Renamed the variable "class" as "classbits" to make life easier for C++
4282 users. (Previously there was a macro definition, but it apparently wasn't
4283 enough.)
4284
4285 12. Added the new field "tables" to the extra data so that tables can be passed
4286 in at exec time, or the internal tables can be re-selected. This allows
4287 a compiled regex to be saved and re-used at a later time by a different
4288 program that might have everything at different addresses.
4289
4290 13. Modified the pcre-config script so that, when run on Solaris, it shows a
4291 -R library as well as a -L library.
4292
4293 14. The debugging options of pcretest (-d on the command line or D on a
4294 pattern) showed incorrect output for anything following an extended class
4295 that contained multibyte characters and which was followed by a quantifier.
4296
4297 15. Added optional support for general category Unicode character properties
4298 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
4299 support. It adds about 90K to the size of the library. The meanings of the
4300 inbuilt class escapes such as \d and \s have NOT been changed.
4301
4302 16. Updated pcredemo.c to include calls to free() to release the memory for the
4303 compiled pattern.
4304
4305 17. The generated file chartables.c was being created in the source directory
4306 instead of in the building directory. This caused the build to fail if the
4307 source directory was different from the building directory, and was
4308 read-only.
4309
4310 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
4311 file. No doubt somebody will tell me if they don't make sense... Also added
4312 Dan Mooney's comments about building on OpenVMS.
4313
4314 19. Added support for partial matching via the PCRE_PARTIAL option for
4315 pcre_exec() and the \P data escape in pcretest.
4316
4317 20. Extended pcretest with 3 new pattern features:
4318
4319 (i) A pattern option of the form ">rest-of-line" causes pcretest to
4320 write the compiled pattern to the file whose name is "rest-of-line".
4321 This is a straight binary dump of the data, with the saved pointer to
4322 the character tables forced to be NULL. The study data, if any, is
4323 written too. After writing, pcretest reads a new pattern.
4324
4325 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
4326 compiled pattern from the given file. There must not be any
4327 occurrences of "<" in the file name (pretty unlikely); if there are,
4328 pcretest will instead treat the initial "<" as a pattern delimiter.
4329 After reading in the pattern, pcretest goes on to read data lines as
4330 usual.
4331
4332 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
4333 and 16-bit fields in a compiled pattern, to simulate a pattern that
4334 was compiled on a host of opposite endianness.
4335
4336 21. The pcre-exec() function can now cope with patterns that were compiled on
4337 hosts of opposite endianness, with this restriction:
4338
4339 As for any compiled expression that is saved and used later, the tables
4340 pointer field cannot be preserved; the extra_data field in the arguments
4341 to pcre_exec() should be used to pass in a tables address if a value
4342 other than the default internal tables were used at compile time.
4343
4344 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
4345 now diagnosed as an error. Previously, most of the time, a negative number
4346 would have been treated as zero, but if in addition "ovector" was passed as
4347 NULL, a crash could occur.
4348
4349 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
4350 new versions from the libtool 1.5 distribution (the last one is a copy of
4351 a file called libtool.m4). This seems to have fixed the need to patch
4352 "configure" to support Darwin 1.3 (which I used to do). However, I still
4353 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
4354 workstation).
4355
4356 24. Changed the PCRE licence to be the more standard "BSD" licence.
4357
4358
4359 Version 4.5 01-Dec-03
4360 ---------------------
4361
4362 1. There has been some re-arrangement of the code for the match() function so
4363 that it can be compiled in a version that does not call itself recursively.
4364 Instead, it keeps those local variables that need separate instances for
4365 each "recursion" in a frame on the heap, and gets/frees frames whenever it
4366 needs to "recurse". Keeping track of where control must go is done by means
4367 of setjmp/longjmp. The whole thing is implemented by a set of macros that
4368 hide most of the details from the main code, and operates only if
4369 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
4370 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
4371 operating.
4372
4373 To make it easier for callers to provide specially tailored get/free
4374 functions for this usage, two new functions, pcre_stack_malloc, and
4375 pcre_stack_free, are used. They are always called in strict stacking order,
4376 and the size of block requested is always the same.
4377
4378 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
4379 PCRE has been compiled to use the stack or the heap for recursion. The
4380 -C option of pcretest uses this to show which version is compiled.
4381
4382 A new data escape \S, is added to pcretest; it causes the amounts of store
4383 obtained and freed by both kinds of malloc/free at match time to be added
4384 to the output.
4385
4386 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
4387 what's available on my current Linux desktop machine.
4388
4389 3. When matching a UTF-8 string, the test for a valid string at the start has
4390 been extended. If start_offset is not zero, PCRE now checks that it points
4391 to a byte that is the start of a UTF-8 character. If not, it returns
4392 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
4393 this is necessary because there may be backward assertions in the pattern.
4394 When matching the same subject several times, it may save resources to use
4395 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4396
4397 4. The code for checking the validity of UTF-8 strings has been tightened so
4398 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
4399 containing "overlong sequences".
4400
4401 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
4402 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
4403 should have been "&", but it just so happened that all the cases this let
4404 through by mistake were picked up later in the function.
4405
4406 6. I had used a variable called "isblank" - this is a C99 function, causing
4407 some compilers to warn. To avoid this, I renamed it (as "blankclass").
4408
4409 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
4410 prompting; (b) run "./pcretest /dev/null" at the start of the test script
4411 so the version is shown; (c) stop "make test" echoing "./RunTest".
4412
4413 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
4414
4415 9. The prototype for memmove() for systems that don't have it was using
4416 size_t, but the inclusion of the header that defines size_t was later. I've
4417 moved the #includes for the C headers earlier to avoid this.
4418
4419 10. Added some adjustments to the code to make it easier to compiler on certain
4420 special systems:
4421
4422 (a) Some "const" qualifiers were missing.
4423 (b) Added the macro EXPORT before all exported functions; by default this
4424 is defined to be empty.
4425 (c) Changed the dftables auxiliary program (that builds chartables.c) so
4426 that it reads its output file name as an argument instead of writing
4427 to the standard output and assuming this can be redirected.
4428
4429 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
4430 class containing characters with values greater than 255, PCRE compilation
4431 went into a loop.
4432
4433 12. A recursive reference to a subpattern that was within another subpattern
4434 that had a minimum quantifier of zero caused PCRE to crash. For example,
4435 (x(y(?2))z)? provoked this bug with a subject that got as far as the
4436 recursion. If the recursively-called subpattern itself had a zero repeat,
4437 that was OK.
4438
4439 13. In pcretest, the buffer for reading a data line was set at 30K, but the
4440 buffer into which it was copied (for escape processing) was still set at
4441 1024, so long lines caused crashes.
4442
4443 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
4444 "internal error: code overflow...". This applied to any character class
4445 that was followed by a possessive quantifier.
4446
4447 15. Modified the Makefile to add libpcre.la as a prerequisite for
4448 libpcreposix.la because I was told this is needed for a parallel build to
4449 work.
4450
4451 16. If a pattern that contained .* following optional items at the start was
4452 studied, the wrong optimizing data was generated, leading to matching
4453 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
4454 matching string must start with a or b or c. The correct conclusion for
4455 this pattern is that a match can start with any character.
4456
4457
4458 Version 4.4 13-Aug-03
4459 ---------------------
4460
4461 1. In UTF-8 mode, a character class containing characters with values between
4462 127 and 255 was not handled correctly if the compiled pattern was studied.
4463 In fixing this, I have also improved the studying algorithm for such
4464 classes (slightly).
4465
4466 2. Three internal functions had redundant arguments passed to them. Removal
4467 might give a very teeny performance improvement.
4468
4469 3. Documentation bug: the value of the capture_top field in a callout is *one
4470 more than* the number of the hightest numbered captured substring.
4471
4472 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
4473 in incorrectly linking with a previously installed version. They now link
4474 explicitly with libpcre.la.
4475
4476 5. configure.in no longer needs to recognize Cygwin specially.
4477
4478 6. A problem in pcre.in for Windows platforms is fixed.
4479
4480 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
4481 pcretest, it used to include the size of the study block as part of its
4482 output. Unfortunately, the structure contains a field that has a different
4483 size on different hardware architectures. This meant that the tests that
4484 showed this size failed. As the block is currently always of a fixed size,
4485 this information isn't actually particularly useful in pcretest output, so
4486 I have just removed it.
4487
4488 8. Three pre-processor statements accidentally did not start in column 1.
4489 Sadly, there are *still* compilers around that complain, even though
4490 standard C has not required this for well over a decade. Sigh.
4491
4492 9. In pcretest, the code for checking callouts passed small integers in the
4493 callout_data field, which is a void * field. However, some picky compilers
4494 complained about the casts involved for this on 64-bit systems. Now
4495 pcretest passes the address of the small integer instead, which should get
4496 rid of the warnings.
4497
4498 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
4499 both compile and run time, and gives an error if an invalid UTF-8 sequence
4500 is found. There is a option for disabling this check in cases where the
4501 string is known to be correct and/or the maximum performance is wanted.
4502
4503 11. In response to a bug report, I changed one line in Makefile.in from
4504
4505 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
4506 to
4507 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4508
4509 to look similar to other lines, but I have no way of telling whether this
4510 is the right thing to do, as I do not use Windows. No doubt I'll get told
4511 if it's wrong...
4512
4513
4514 Version 4.3 21-May-03
4515 ---------------------
4516
4517 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4518 Makefile.
4519
4520 2. Some refactoring to improve the quality of the code:
4521
4522 (i) The utf8_table... variables are now declared "const".
4523
4524 (ii) The code for \cx, which used the "case flipping" table to upper case
4525 lower case letters, now just substracts 32. This is ASCII-specific,
4526 but the whole concept of \cx is ASCII-specific, so it seems
4527 reasonable.
4528
4529 (iii) PCRE was using its character types table to recognize decimal and
4530 hexadecimal digits in the pattern. This is silly, because it handles
4531 only 0-9, a-f, and A-F, but the character types table is locale-
4532 specific, which means strange things might happen. A private
4533 table is now used for this - though it costs 256 bytes, a table is
4534 much faster than multiple explicit tests. Of course, the standard
4535 character types table is still used for matching digits in subject
4536 strings against \d.
4537
4538 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4539 ending in _t are). So I've renamed it as ESC_tee.
4540
4541 3. The first argument for regexec() in the POSIX wrapper should have been
4542 defined as "const".
4543
4544 4. Changed pcretest to use malloc() for its buffers so that they can be
4545 Electric Fenced for debugging.
4546
4547 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4548 to read one or more bytes before the start of the subject string. Often this
4549 had no effect on PCRE's behaviour, but in some circumstances it could
4550 provoke a segmentation fault.
4551
4552 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4553 to try to read one or more bytes before the start of the subject string.
4554
4555 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4556 UTF-8 support could misbehave in various ways if the subject string
4557 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4558 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4559 back over UTF-8 characters.)
4560
4561
4562 Version 4.2 14-Apr-03
4563 ---------------------
4564
4565 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4566
4567 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4568 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4569 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4570 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4571 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4572 and BUILD_EXEEXT
4573 Note: automatic setting of the BUILD variables is not yet working
4574 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4575 compile-time but not at link-time
4576 [LINK]: use for linking executables only
4577 make different versions for Windows and non-Windows
4578 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4579 libraries
4580 [LINK_FOR_BUILD]: new variable
4581 [OBJEXT]: use throughout
4582 [EXEEXT]: use throughout
4583 <winshared>: new target
4584 <wininstall>: new target
4585 <dftables.o>: use native compiler
4586 <dftables>: use native linker
4587 <install>: handle Windows platform correctly
4588 <clean>: ditto
4589 <check>: ditto
4590 copy DLL to top builddir before testing
4591
4592 As part of these changes, -no-undefined was removed again. This was reported
4593 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4594 in any case.
4595
4596 3. Some tidies to get rid of compiler warnings:
4597
4598 . In the match_data structure, match_limit was an unsigned long int, whereas
4599 match_call_count was an int. I've made them both unsigned long ints.
4600
4601 . In pcretest the fact that a const uschar * doesn't automatically cast to
4602 a void * provoked a warning.
4603
4604 . Turning on some more compiler warnings threw up some "shadow" variables
4605 and a few more missing casts.
4606
4607 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
4608 option, a class that contained a single character with a value between 128
4609 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
4610
4611 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
4612 option, a class that contained several characters, but with at least one
4613 whose value was between 128 and 255 caused PCRE to crash.
4614
4615
4616 Version 4.1 12-Mar-03
4617 ---------------------
4618
4619 1. Compiling with gcc -pedantic found a couple of places where casts were
4620 needed, and a string in dftables.c that was longer than standard compilers are
4621 required to support.
4622
4623 2. Compiling with Sun's compiler found a few more places where the code could
4624 be tidied up in order to avoid warnings.
4625
4626 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
4627 first of these names is deprecated in the latest Autoconf in favour of the name
4628 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
4629 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
4630 analogy I have changed it to CFLAGS_FOR_BUILD.
4631
4632 4. Added -no-undefined to the linking command in the Makefile, because this is
4633 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
4634 linking step for the pcreposix library.
4635
4636 5. PCRE was failing to diagnose the case of two named groups with the same
4637 name.
4638
4639 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
4640 literal character that is needed in the subject for a match, and scans along to
4641 ensure that it is present before embarking on the full matching process. This
4642 saves time in cases of nested unlimited repeats that are never going to match.
4643 Problem: the scan can take a lot of time if the subject is very long (e.g.
4644 megabytes), thus penalizing straightforward matches. It is now done only if the
4645 amount of subject to be scanned is less than 1000 bytes.
4646
4647 7. A lesser problem with the same optimization is that it was recording the
4648 first character of an anchored pattern as "needed", thus provoking a search
4649 right along the subject, even when the first match of the pattern was going to
4650 fail. The "needed" character is now not set for anchored patterns, unless it
4651 follows something in the pattern that is of non-fixed length. Thus, it still
4652 fulfils its original purpose of finding quick non-matches in cases of nested
4653 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
4654
4655
4656 Version 4.0 17-Feb-03
4657 ---------------------
4658
4659 1. If a comment in an extended regex that started immediately after a meta-item
4660 extended to the end of string, PCRE compiled incorrect data. This could lead to
4661 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
4662
4663 2. Moved to autoconf 2.53 and libtool 1.4.2.
4664
4665 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
4666 the special perltest8 script is no longer needed - all the tests can be run
4667 from a single perltest script.
4668
4669 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
4670 by \s. It has now been removed in PCRE. This means it isn't recognized as
4671 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
4672 class [:space:] *does* include VT, thereby creating a mess.
4673
4674 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
4675 space and tab.
4676
4677 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
4678 its new features into the main test script, reducing the number of scripts.
4679
4680 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
4681 were backward compatible, and made the (?i) apply to the whole pattern, as if
4682 /i were given. Now it behaves more logically, and applies the option setting
4683 only to what follows. PCRE has been changed to follow suit. However, if it
4684 finds options settings right at the start of the pattern, it extracts them into
4685 the global options, as before. Thus, they show up in the info data.
4686
4687 8. Added support for the \Q...\E escape sequence. Characters in between are
4688 treated as literals. This is slightly different from Perl in that $ and @ are
4689 also handled as literals inside the quotes. In Perl, they will cause variable
4690 interpolation. Note the following examples:
4691
4692 Pattern PCRE matches Perl matches
4693
4694 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
4695 \Qabc\$xyz\E abc\$xyz abc\$xyz
4696 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
4697
4698 For compatibility with Perl, \Q...\E sequences are recognized inside character
4699 classes as well as outside them.
4700
4701 9. Re-organized 3 code statements in pcretest to avoid "overflow in
4702 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
4703 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
4704 signed/unsigned warnings.
4705
4706 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
4707 option for pcretest, so I've replaced it by a simple function that does just
4708 that job.
4709
4710 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
4711 "pcregrep -".
4712
4713 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
4714 Java package. This provides some syntactic sugar for simple cases of what my
4715 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
4716 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
4717 item, you can use this simplified notation. Note that only makes sense with
4718 greedy quantifiers. Consequently, the use of the possessive quantifier forces
4719 greediness, whatever the setting of the PCRE_UNGREEDY option.
4720
4721 13. A change of greediness default within a pattern was not taking effect at
4722 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
4723 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
4724 was abstracted outside.
4725
4726 14. PCRE now supports the \G assertion. It is true when the current matching
4727 position is at the start point of the match. This differs from \A when the
4728 starting offset is non-zero. Used with the /g option of pcretest (or similar
4729 code), it works in the same way as it does for Perl's /g option. If all
4730 alternatives of a regex begin with \G, the expression is anchored to the start
4731 match position, and the "anchored" flag is set in the compiled expression.
4732
4733 15. Some bugs concerning the handling of certain option changes within patterns
4734 have been fixed. These applied to options other than (?ims). For example,
4735 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
4736 been the other way round. Some of this was related to change 7 above.
4737
4738 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
4739 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
4740 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
4741 POSIX classes only within a class (e.g. /[[:alpha:]]/).
4742
4743 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
4744 mode. Unlike ".", it always matches newline, whatever the setting of
4745 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
4746 assertions. Perl allows it, but it doesn't (in general) work because it can't
4747 calculate the length of the lookbehind. At least, that's the case for Perl
4748 5.8.0 - I've been told they are going to document that it doesn't work in
4749 future.
4750
4751 18. Added an error diagnosis for escapes that PCRE does not support: these are
4752 \L, \l, \N, \P, \p, \U, \u, and \X.
4753
4754 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
4755 reading past the end of the pattern in cases such as /[abcd/.
4756
4757 20. PCRE was getting more memory than necessary for patterns with classes that
4758 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
4759
4760 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
4761 compiling PCRE for use with Virtual Pascal.
4762
4763 22. Small fix to the Makefile to make it work properly if the build is done
4764 outside the source tree.
4765
4766 23. Added a new extension: a condition to go with recursion. If a conditional
4767 subpattern starts with (?(R) the "true" branch is used if recursion has
4768 happened, whereas the "false" branch is used only at the top level.
4769
4770 24. When there was a very long string of literal characters (over 255 bytes
4771 without UTF support, over 250 bytes with UTF support), the computation of how
4772 much memory was required could be incorrect, leading to segfaults or other
4773 strange effects.
4774
4775 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
4776 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
4777 there was a subsequent back reference to those brackets. This meant that, for
4778 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
4779 possible to check for precisely this case. All we can do is abandon the
4780 optimization if .* occurs inside capturing brackets when there are any back
4781 references whatsoever. (See below for a better fix that came later.)
4782
4783 26. The handling of the optimization for finding the first character of a
4784 non-anchored pattern, and for finding a character that is required later in the
4785 match were failing in some cases. This didn't break the matching; it just
4786 failed to optimize when it could. The way this is done has been re-implemented.
4787
4788 27. Fixed typo in error message for invalid (?R item (it said "(?p").
4789
4790 28. Added a new feature that provides some of the functionality that Perl
4791 provides with (?{...}). The facility is termed a "callout". The way it is done
4792 in PCRE is for the caller to provide an optional function, by setting
4793 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
4794 global variable. By default it is unset, which disables all calling out. To get
4795 the function called, the regex must include (?C) at appropriate points. This
4796 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
4797 This provides a means of identifying different callout points. When PCRE
4798 reaches such a point in the regex, if pcre_callout has been set, the external
4799 function is called. It is provided with data in a structure called
4800 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
4801 matching continues; if it returns a non-zero value, the match at the current
4802 point fails. However, backtracking will occur if possible. [This was changed
4803 later and other features added - see item 49 below.]
4804
4805 29. pcretest is upgraded to test the callout functionality. It provides a
4806 callout function that displays information. By default, it shows the start of
4807 the match and the current position in the text. There are some new data escapes
4808 to vary what happens:
4809
4810 \C+ in addition, show current contents of captured substrings
4811 \C- do not supply a callout function
4812 \C!n return 1 when callout number n is reached
4813 \C!n!m return 1 when callout number n is reached for the mth time
4814
4815 30. If pcregrep was called with the -l option and just a single file name, it
4816 output "<stdin>" if a match was found, instead of the file name.
4817
4818 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
4819 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
4820 pcre_exec(). This saves a malloc/free per call. The default value of
4821 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
4822 when configuring.
4823
4824 32. The default maximum size of a compiled pattern is 64K. There have been a
4825 few cases of people hitting this limit. The code now uses macros to handle the
4826 storing of links as offsets within the compiled pattern. It defaults to 2-byte
4827 links, but this can be changed to 3 or 4 bytes by --with-link-size when
4828 configuring. Tests 2 and 5 work only with 2-byte links because they output
4829 debugging information about compiled patterns.
4830
4831 33. Internal code re-arrangements:
4832
4833 (a) Moved the debugging function for printing out a compiled regex into
4834 its own source file (printint.c) and used #include to pull it into
4835 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
4836 separate copies.
4837
4838 (b) Defined the list of op-code names for debugging as a macro in
4839 internal.h so that it is next to the definition of the opcodes.
4840
4841 (c) Defined a table of op-code lengths for simpler skipping along compiled
4842 code. This is again a macro in internal.h so that it is next to the
4843 definition of the opcodes.
4844
4845 34. Added support for recursive calls to individual subpatterns, along the
4846 lines of Robin Houston's patch (but implemented somewhat differently).
4847
4848 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
4849 allow it to read and process whole directories in Win32. This code was
4850 contributed by Lionel Fourquaux; it has not been tested by me.
4851
4852 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
4853 used to name a group. Names consist of alphanumerics and underscores, and must
4854 be unique. Back references use the syntax (?P=name) and recursive calls use
4855 (?P>name) which is a PCRE extension to the Python extension. Groups still have
4856 numbers. The function pcre_fullinfo() can be used after compilation to extract
4857 a name/number map. There are three relevant calls:
4858
4859 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
4860 PCRE_INFO_NAMECOUNT yields the number of entries
4861 PCRE_INFO_NAMETABLE yields a pointer to the map.
4862
4863 The map is a vector of fixed-size entries. The size of each entry depends on
4864 the length of the longest name used. The first two bytes of each entry are the
4865 group number, most significant byte first. There follows the corresponding
4866 name, zero terminated. The names are in alphabetical order.
4867
4868 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
4869 case instead of 255. Making it the same both with and without UTF-8 support
4870 means that the same test output works with both.
4871
4872 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
4873 calling malloc() with a zero argument.
4874
4875 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
4876 optimization. I've improved things by keeping a bitmap of backreferences with
4877 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
4878 fact referenced, the optimization can be applied. It is unlikely that a
4879 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
4880 the match to follow \n) will appear inside brackets with a number greater than
4881 31, but if it does, any back reference > 31 suppresses the optimization.
4882
4883 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
4884 of disabling numbered capturing parentheses. Any opening parenthesis that is
4885 not followed by ? behaves as if it were followed by ?: but named parentheses
4886 can still be used for capturing (and they will acquire numbers in the usual
4887 way).
4888
4889 41. Redesigned the return codes from the match() function into yes/no/error so
4890 that errors can be passed back from deep inside the nested calls. A malloc
4891 failure while inside a recursive subpattern call now causes the
4892 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4893
4894 42. It is now possible to set a limit on the number of times the match()
4895 function is called in a call to pcre_exec(). This facility makes it possible to
4896 limit the amount of recursion and backtracking, though not in a directly
4897 obvious way, because the match() function is used in a number of different
4898 circumstances. The count starts from zero for each position in the subject
4899 string (for non-anchored patterns). The default limit is, for compatibility, a
4900 large number, namely 10 000 000. You can change this in two ways:
4901
4902 (a) When configuring PCRE before making, you can use --with-match-limit=n
4903 to set a default value for the compiled library.
4904
4905 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4906 a different value is set. See 45 below.
4907
4908 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4909
4910 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4911 of things that can be changed at compile time. The first argument specifies
4912 what is wanted and the second points to where the information is to be placed.
4913 The current list of available information is:
4914
4915 PCRE_CONFIG_UTF8
4916
4917 The output is an integer that is set to one if UTF-8 support is available;
4918 otherwise it is set to zero.
4919
4920 PCRE_CONFIG_NEWLINE
4921
4922 The output is an integer that it set to the value of the code that is used for
4923 newline. It is either LF (10) or CR (13).
4924
4925 PCRE_CONFIG_LINK_SIZE
4926
4927 The output is an integer that contains the number of bytes used for internal
4928 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4929
4930 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4931
4932 The output is an integer that contains the threshold above which the POSIX
4933 interface uses malloc() for output vectors. See item 31 above.
4934
4935 PCRE_CONFIG_MATCH_LIMIT
4936
4937 The output is an unsigned integer that contains the default limit of the number
4938 of match() calls in a pcre_exec() execution. See 42 above.
4939
4940 44. pcretest has been upgraded by the addition of the -C option. This causes it
4941 to extract all the available output from the new pcre_config() function, and to
4942 output it. The program then exits immediately.
4943
4944 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4945 order to support additional features. One way would have been to define
4946 pcre_exec2() (for example) with extra arguments, but this would not have been
4947 extensible, and would also have required all calls to the original function to
4948 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4949 is used for passing in "extra" data from pcre_study().
4950
4951 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4952 contains the following fields:
4953
4954 flags a bitmap indicating which of the following fields are set
4955 study_data opaque data from pcre_study()
4956 match_limit a way of specifying a limit on match() calls for a specific
4957 call to pcre_exec()
4958 callout_data data for callouts (see 49 below)
4959
4960 The flag bits are also defined in pcre.h, and are
4961
4962 PCRE_EXTRA_STUDY_DATA
4963 PCRE_EXTRA_MATCH_LIMIT
4964 PCRE_EXTRA_CALLOUT_DATA
4965
4966 The pcre_study() function now returns one of these new pcre_extra blocks, with
4967 the actual study data pointed to by the study_data field, and the
4968 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
4969 before. That is, this change is entirely upwards-compatible and requires no
4970 change to existing code.
4971
4972 If you want to pass in additional data to pcre_exec(), you can either place it
4973 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
4974 block.
4975
4976 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
4977 data string contains the escape sequence \M, pcretest calls pcre_exec() several
4978 times with different match limits, until it finds the minimum value needed for
4979 pcre_exec() to complete. The value is then output. This can be instructive; for
4980 most simple matches the number is quite small, but for pathological cases it
4981 gets very large very quickly.
4982
4983 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
4984 returns the size of the data block pointed to by the study_data field in a
4985 pcre_extra block, that is, the value that was passed as the argument to
4986 pcre_malloc() when PCRE was getting memory in which to place the information
4987 created by pcre_study(). The fourth argument should point to a size_t variable.
4988 pcretest has been extended so that this information is shown after a successful
4989 pcre_study() call when information about the compiled regex is being displayed.
4990
4991 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
4992 because what follows is always an absolute path. (Later: it turns out that this
4993 is more than cosmetic for MinGW, because it doesn't like empty path
4994 components.)
4995
4996 49. Some changes have been made to the callout feature (see 28 above):
4997
4998 (i) A callout function now has three choices for what it returns:
4999
5000 0 => success, carry on matching
5001 > 0 => failure at this point, but backtrack if possible
5002 < 0 => serious error, return this value from pcre_exec()
5003
5004 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
5005 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
5006 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
5007 use by callout functions. It will never be used by PCRE itself.
5008
5009 (ii) The pcre_extra structure (see 45 above) has a void * field called
5010 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
5011 pcre_callout_block structure has a field of the same name. The contents of
5012 the field passed in the pcre_extra structure are passed to the callout
5013 function in the corresponding field in the callout block. This makes it
5014 easier to use the same callout-containing regex from multiple threads. For
5015 testing, the pcretest program has a new data escape
5016
5017 \C*n pass the number n (may be negative) as callout_data
5018
5019 If the callout function in pcretest receives a non-zero value as
5020 callout_data, it returns that value.
5021
5022 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
5023 there were some redundant $(CFLAGS) in commands that are now specified as
5024 $(LINK), which already includes $(CFLAGS).
5025
5026 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
5027 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
5028 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
5029 one-byte characters throughout. Note that case-insensitive matching applies
5030 only to characters whose values are less than 256. PCRE doesn't support the
5031 notion of cases for higher-valued characters.
5032
5033 (i) A character class whose characters are all within 0-255 is handled as
5034 a bit map, and the map is inverted for negative classes. Previously, a
5035 character > 255 always failed to match such a class; however it should
5036 match if the class was a negative one (e.g. [^ab]). This has been fixed.
5037
5038 (ii) A negated character class with a single character < 255 is coded as
5039 "not this character" (OP_NOT). This wasn't working properly when the test
5040 character was multibyte, either singly or repeated.
5041
5042 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
5043 mode, for example: \x{100}{2,3}.
5044
5045 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
5046 singly or repeated) now correctly test multibyte characters. However,
5047 PCRE doesn't recognize any characters with values greater than 255 as
5048 digits, spaces, or word characters. Such characters always match \D, \S,
5049 and \W, and never match \d, \s, or \w.
5050
5051 (v) Classes may now contain characters and character ranges with values
5052 greater than 255. For example: [ab\x{100}-\x{400}].
5053
5054 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
5055 PCRE in UTF-8 mode.
5056
5057 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
5058 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
5059 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
5060 value.)
5061
5062 53. The single man page has become too large. I have therefore split it up into
5063 a number of separate man pages. These also give rise to individual HTML pages;
5064 these are now put in a separate directory, and there is an index.html page that
5065 lists them all. Some hyperlinking between the pages has been installed.
5066
5067 54. Added convenience functions for handling named capturing parentheses.
5068
5069 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
5070 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
5071 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
5072 are faulted.
5073
5074 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
5075 calling configure. These values are used when compiling the dftables.c program
5076 which is run to generate the source of the default character tables. They
5077 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
5078 you will need to set these values.
5079
5080 57. Updated the building process for Windows DLL, as provided by Fred Cox.
5081
5082
5083 Version 3.9 02-Jan-02
5084 ---------------------
5085
5086 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
5087
5088 2. If --disable-static was given, the building process failed when trying to
5089 build pcretest and pcregrep. (For some reason it was using libtool to compile
5090 them, which is not right, as they aren't part of the library.)
5091
5092
5093 Version 3.8 18-Dec-01
5094 ---------------------
5095
5096 1. The experimental UTF-8 code was completely screwed up. It was packing the
5097 bytes in the wrong order. How dumb can you get?
5098
5099
5100 Version 3.7 29-Oct-01
5101 ---------------------
5102
5103 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
5104 This caused pcretest, when used on the test data, to segfault. Unfortunately,
5105 this didn't happen under Solaris 8, where I normally test things.
5106
5107 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
5108 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
5109 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
5110 this fix an hour or so after the initial 3.7 release.)
5111
5112
5113 Version 3.6 23-Oct-01
5114 ---------------------
5115
5116 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
5117 offsets passed as NULL with zero offset count.
5118
5119 2. The config.guess and config.sub files had not been updated when I moved to
5120 the latest autoconf.
5121
5122
5123 Version 3.5 15-Aug-01
5124 ---------------------
5125
5126 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
5127 had been forgotten.
5128
5129 2. By using declared but undefined structures, we can avoid using "void"
5130 definitions in pcre.h while keeping the internal definitions of the structures
5131 private.
5132
5133 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
5134 user point of view, this means that both static and shared libraries are built
5135 by default, but this can be individually controlled. More of the work of
5136 handling this static/shared cases is now inside libtool instead of PCRE's make
5137 file.
5138
5139 4. The pcretest utility is now installed along with pcregrep because it is
5140 useful for users (to test regexs) and by doing this, it automatically gets
5141 relinked by libtool. The documentation has been turned into a man page, so
5142 there are now .1, .txt, and .html versions in /doc.
5143
5144 5. Upgrades to pcregrep:
5145 (i) Added long-form option names like gnu grep.
5146 (ii) Added --help to list all options with an explanatory phrase.
5147 (iii) Added -r, --recursive to recurse into sub-directories.
5148 (iv) Added -f, --file to read patterns from a file.
5149
5150 6. pcre_exec() was referring to its "code" argument before testing that
5151 argument for NULL (and giving an error if it was NULL).
5152
5153 7. Upgraded Makefile.in to allow for compiling in a different directory from
5154 the source directory.
5155
5156 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
5157 options bits, the pointer it was passed was to an int instead of to an unsigned
5158 long int. This mattered only on 64-bit systems.
5159
5160 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
5161 generated) instead of pcre.in, which it its source. Also made the same change
5162 in several of the .c files.
5163
5164 10. A new release of gcc defines printf() as a macro, which broke pcretest
5165 because it had an ifdef in the middle of a string argument for printf(). Fixed
5166 by using separate calls to printf().
5167
5168 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
5169 script, to force use of CR or LF instead of \n in the source. On non-Unix
5170 systems, the value can be set in config.h.
5171
5172 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
5173 absolute limit. Changed the text of the error message to make this clear, and
5174 likewise updated the man page.
5175
5176 13. The limit of 99 on the number of capturing subpatterns has been removed.
5177 The new limit is 65535, which I hope will not be a "real" limit.
5178
5179
5180 Version 3.4 22-Aug-00
5181 ---------------------
5182
5183 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
5184
5185 2. Diagnose condition (?(0) as an error instead of crashing on matching.
5186
5187
5188 Version 3.3 01-Aug-00
5189 ---------------------
5190
5191 1. If an octal character was given, but the value was greater than \377, it
5192 was not getting masked to the least significant bits, as documented. This could
5193 lead to crashes in some systems.
5194
5195 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
5196 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
5197
5198 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
5199 These just pass their arguments on to (pcre_free)(), but they are provided
5200 because some uses of PCRE bind it to non-C systems that can call its functions,
5201 but cannot call free() or pcre_free() directly.
5202
5203 4. Add "make test" as a synonym for "make check". Corrected some comments in
5204 the Makefile.
5205
5206 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
5207 Makefile.
5208
5209 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
5210 command called pgrep for grepping around the active processes.
5211
5212 7. Added the beginnings of support for UTF-8 character strings.
5213
5214 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
5215 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
5216 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
5217 out for the ar command.)
5218
5219
5220 Version 3.2 12-May-00
5221 ---------------------
5222
5223 This is purely a bug fixing release.
5224
5225 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
5226 of ZA. This was just one example of several cases that could provoke this bug,
5227 which was introduced by change 9 of version 2.00. The code for breaking
5228 infinite loops after an iteration that matches an empty string was't working
5229 correctly.
5230
5231 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
5232 when matched against abbab (for example). After matching an empty string, it
5233 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
5234 caused it to match further down the string than it should.
5235
5236 3. The code contained an inclusion of sys/types.h. It isn't clear why this
5237 was there because it doesn't seem to be needed, and it causes trouble on some
5238 systems, as it is not a Standard C header. It has been removed.
5239
5240 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
5241 were reported on the Macintosh. The changes were from
5242
5243 while ((c = *(++ptr)) != 0 && c != '\n');
5244 to
5245 while ((c = *(++ptr)) != 0 && c != '\n') ;
5246
5247 Totally extraordinary, but if that's what it takes...
5248
5249 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
5250 available. Added HAVE_BCOPY and an autoconf test for it; if neither
5251 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
5252 assumes the way PCRE uses memmove() (always moving upwards).
5253
5254 6. PCRE is being used in one environment where strchr() is not available. There
5255 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
5256 faster code anyway.
5257
5258
5259 Version 3.1 09-Feb-00
5260 ---------------------
5261
5262 The only change in this release is the fixing of some bugs in Makefile.in for
5263 the "install" target:
5264
5265 (1) It was failing to install pcreposix.h.
5266
5267 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
5268
5269
5270 Version 3.0 01-Feb-00
5271 ---------------------
5272
5273 1. Add support for the /+ modifier to perltest (to output $` like it does in
5274 pcretest).
5275
5276 2. Add support for the /g modifier to perltest.
5277
5278 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
5279 matches null strings.
5280
5281 4. Fix perltest so that it doesn't do unwanted things when fed an empty
5282 pattern. Perl treats empty patterns specially - it reuses the most recent
5283 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
5284 effect.
5285
5286 5. The POSIX interface was broken in that it was just handing over the POSIX
5287 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
5288 required a bigger vector, with some working space on the end. This means that
5289 the POSIX wrapper now has to get and free some memory, and copy the results.
5290
5291 6. Added some simple autoconf support, placing the test data and the
5292 documentation in separate directories, re-organizing some of the
5293 information files, and making it build pcre-config (a GNU standard). Also added
5294 libtool support for building PCRE as a shared library, which is now the
5295 default.
5296
5297 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
5298 09 are not valid octal constants. Single digits will be used for minor values
5299 less than 10.
5300
5301 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
5302 existing programs that set these in the POSIX interface can use PCRE without
5303 modification.
5304
5305 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
5306 return all that pcre_info() returns, plus additional data. The pcre_info()
5307 function is retained for compatibility, but is considered to be obsolete.
5308
5309 10. Added experimental recursion feature (?R) to handle one common case that
5310 Perl 5.6 will be able to do with (?p{...}).
5311
5312 11. Added support for POSIX character classes like [:alpha:], which Perl is
5313 adopting.
5314
5315
5316 Version 2.08 31-Aug-99
5317 ----------------------
5318
5319 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
5320 trying to match at the startoffset position, but instead was moving forward to
5321 the next newline as if a previous match had failed.
5322
5323 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
5324 and could get into a loop if a null string was matched other than at the start
5325 of the subject.
5326
5327 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
5328 be distinguished at compile time, and for completeness also added PCRE_DATE.
5329
5330 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
5331 in GnuWin32 environments.
5332
5333
5334 Version 2.07 29-Jul-99
5335 ----------------------
5336
5337 1. The documentation is now supplied in plain text form and HTML as well as in
5338 the form of man page sources.
5339
5340 2. C++ compilers don't like assigning (void *) values to other pointer types.
5341 In particular this affects malloc(). Although there is no problem in Standard
5342 C, I've put in casts to keep C++ compilers happy.
5343
5344 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
5345 should be (const char *).
5346
5347 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
5348 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
5349 However, I haven't made this a standard facility. The documentation doesn't
5350 mention it, and the Makefile doesn't support it.
5351
5352 5. The Makefile now contains an "install" target, with editable destinations at
5353 the top of the file. The pcretest program is not installed.
5354
5355 6. pgrep -V now gives the PCRE version number and date.
5356
5357 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
5358 causing the entire string to be ignored, instead of just the last character.
5359
5360 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
5361 non-matching string, it can take a very, very long time, even for strings of
5362 quite modest length, because of the nested recursion. PCRE now does better in
5363 some of these cases. It does this by remembering the last required literal
5364 character in the pattern, and pre-searching the subject to ensure it is present
5365 before running the real match. In other words, it applies a heuristic to detect
5366 some types of certain failure quickly, and in the above example, if presented
5367 with a string that has no trailing " it gives "no match" very quickly.
5368
5369 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
5370 other alternatives are tried instead.
5371
5372
5373 Version 2.06 09-Jun-99
5374 ----------------------
5375
5376 1. Change pcretest's output for amount of store used to show just the code
5377 space, because the remainder (the data block) varies in size between 32-bit and
5378 64-bit systems.
5379
5380 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
5381 start matching at. This allows lookbehinds to work when searching for multiple
5382 occurrences in a string.
5383
5384 3. Added additional options to pcretest for testing multiple occurrences:
5385
5386 /+ outputs the rest of the string that follows a match
5387 /g loops for multiple occurrences, using the new startoffset argument
5388 /G loops for multiple occurrences by passing an incremented pointer
5389
5390 4. PCRE wasn't doing the "first character" optimization for patterns starting
5391 with \b or \B, though it was doing it for other lookbehind assertions. That is,
5392 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
5393 the letter 'x'. On long subject strings, this gives a significant speed-up.
5394
5395
5396 Version 2.05 21-Apr-99
5397 ----------------------
5398
5399 1. Changed the type of magic_number from int to long int so that it works
5400 properly on 16-bit systems.
5401
5402 2. Fixed a bug which caused patterns starting with .* not to work correctly
5403 when the subject string contained newline characters. PCRE was assuming
5404 anchoring for such patterns in all cases, which is not correct because .* will
5405 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
5406 DOTALL is set at top level; otherwise it knows that patterns starting with .*
5407 must be retried after every newline in the subject.
5408
5409
5410 Version 2.04 18-Feb-99
5411 ----------------------
5412
5413 1. For parenthesized subpatterns with repeats whose minimum was zero, the
5414 computation of the store needed to hold the pattern was incorrect (too large).
5415 If such patterns were nested a few deep, this could multiply and become a real
5416 problem.
5417
5418 2. Added /M option to pcretest to show the memory requirement of a specific
5419 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
5420
5421 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
5422 compiled in such a way that the backtracking after subsequent failure was
5423 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
5424 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
5425
5426
5427 Version 2.03 02-Feb-99
5428 ----------------------
5429
5430 1. Fixed typo and small mistake in man page.
5431
5432 2. Added 4th condition (GPL supersedes if conflict) and created separate
5433 LICENCE file containing the conditions.
5434
5435 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
5436 Perl, that is the internal \ allows the delimiter to be included in the
5437 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
5438 the final delimiter, add \ to the end of the pattern (to test the error).
5439
5440 4. Added the convenience functions for extracting substrings after a successful
5441 match. Updated pcretest to make it able to test these functions.
5442
5443
5444 Version 2.02 14-Jan-99
5445 ----------------------
5446
5447 1. Initialized the working variables associated with each extraction so that
5448 their saving and restoring doesn't refer to uninitialized store.
5449
5450 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
5451 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
5452 fix the problem.
5453
5454 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
5455 calls, and wasn't printing the correct value for compiling calls. Increased the
5456 default value of LOOPREPEAT, and the number of significant figures in the
5457 times.
5458
5459 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
5460
5461 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
5462 a building problem on Windows NT with a FAT file system.
5463
5464
5465 Version 2.01 21-Oct-98
5466 ----------------------
5467
5468 1. Changed the API for pcre_compile() to allow for the provision of a pointer
5469 to character tables built by pcre_maketables() in the current locale. If NULL
5470 is passed, the default tables are used.
5471
5472
5473 Version 2.00 24-Sep-98
5474 ----------------------
5475
5476 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
5477 it any more.
5478
5479 2. Allow quantification of (?>) groups, and make it work correctly.
5480
5481 3. The first character computation wasn't working for (?>) groups.
5482
5483 4. Correct the implementation of \Z (it is permitted to match on the \n at the
5484 end of the subject) and add 5.005's \z, which really does match only at the
5485 very end of the subject.
5486
5487 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
5488
5489 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
5490 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
5491 localized options. All options to pcre_study() were also removed.
5492
5493 7. Add other new features from 5.005:
5494
5495 $(?<= positive lookbehind
5496 $(?<! negative lookbehind
5497 (?imsx-imsx) added the unsetting capability
5498 such a setting is global if at outer level; local otherwise
5499 (?imsx-imsx:) non-capturing groups with option setting
5500 (?(cond)re|re) conditional pattern matching
5501
5502 A backreference to itself in a repeated group matches the previous
5503 captured string.
5504
5505 8. General tidying up of studying (both automatic and via "study")
5506 consequential on the addition of new assertions.
5507
5508 9. As in 5.005, unlimited repeated groups that could match an empty substring
5509 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5510 runtime if any iteration does actually match an empty substring.
5511
5512 10. Include the RunTest script in the distribution.
5513
5514 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5515 discrepancies, some of which were old and were also with respect to 5.004. They
5516 have now been fixed.
5517
5518
5519 Version 1.09 28-Apr-98
5520 ----------------------
5521
5522 1. A negated single character class followed by a quantifier with a minimum
5523 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5524 program crashes, or just wrong answers. This did not apply to negated classes
5525 containing more than one character, or to minima other than one.
5526
5527
5528 Version 1.08 27-Mar-98
5529 ----------------------
5530
5531 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5532
5533 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5534 latter must appear before anything that relies on it in the pattern.
5535
5536
5537 Version 1.07 16-Feb-98
5538 ----------------------
5539
5540 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5541 repeat of a potentially empty string).
5542
5543
5544 Version 1.06 23-Jan-98
5545 ----------------------
5546
5547 1. Added Markus Oberhumer's little patches for C++.
5548
5549 2. Literal strings longer than 255 characters were broken.
5550
5551
5552 Version 1.05 23-Dec-97
5553 ----------------------
5554
5555 1. Negated character classes containing more than one character were failing if
5556 PCRE_CASELESS was set at run time.
5557
5558
5559 Version 1.04 19-Dec-97
5560 ----------------------
5561
5562 1. Corrected the man page, where some "const" qualifiers had been omitted.
5563
5564 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5565 input syntax.
5566
5567 3. Fixed memory leak which occurred when a regex with back references was
5568 matched with an offsets vector that wasn't big enough. The temporary memory
5569 that is used in this case wasn't being freed if the match failed.
5570
5571 4. Tidied pcretest to ensure it frees memory that it gets.
5572
5573 5. Temporary memory was being obtained in the case where the passed offsets
5574 vector was exactly big enough.
5575
5576 6. Corrected definition of offsetof() from change 5 below.
5577
5578 7. I had screwed up change 6 below and broken the rules for the use of
5579 setjmp(). Now fixed.
5580
5581
5582 Version 1.03 18-Dec-97
5583 ----------------------
5584
5585 1. A erroneous regex with a missing opening parenthesis was correctly
5586 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5587 on some systems.
5588
5589 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5590 it was reported that one broken compiler failed on the former because "code" is
5591 also an independent variable.
5592
5593 3. The erroneous regex a[]b caused an array overrun reference.
5594
5595 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5596 fail on data ending with that character. (It was going on too far, and checking
5597 the next character, typically a binary zero.) This was specific to the
5598 optimized code for single-character negative classes.
5599
5600 5. Added a contributed patch from the TIN world which does the following:
5601
5602 + Add an undef for memmove, in case the the system defines a macro for it.
5603
5604 + Add a definition of offsetof(), in case there isn't one. (I don't know
5605 the reason behind this - offsetof() is part of the ANSI standard - but
5606 it does no harm).
5607
5608 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
5609 most of the places where whitespace preceded '#'. I have given up and
5610 allowed the remaining 2 cases to be at the margin.
5611
5612 + Rename some variables in pcre to eliminate shadowing. This seems very
5613 pedantic, but does no harm, of course.
5614
5615 6. Moved the call to setjmp() into its own function, to get rid of warnings
5616 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
5617
5618 7. Constructs such as \d{8,} were compiling into the equivalent of
5619 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
5620 outcome, but in this particular case used more store than had been allocated,
5621 which caused the bug to be discovered because it threw up an internal error.
5622
5623 8. The debugging code in both pcre and pcretest for outputting the compiled
5624 form of a regex was going wrong in the case of back references followed by
5625 curly-bracketed repeats.
5626
5627
5628 Version 1.02 12-Dec-97
5629 ----------------------
5630
5631 1. Typos in pcre.3 and comments in the source fixed.
5632
5633 2. Applied a contributed patch to get rid of places where it used to remove
5634 'const' from variables, and fixed some signed/unsigned and uninitialized
5635 variable warnings.
5636
5637 3. Added the "runtest" target to Makefile.
5638
5639 4. Set default compiler flag to -O2 rather than just -O.
5640
5641
5642 Version 1.01 19-Nov-97
5643 ----------------------
5644
5645 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
5646 like /([ab]*)*/, that is, for classes with more than one character in them.
5647
5648 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
5649 as /((?>a*))*/ (a PCRE_EXTRA facility).
5650
5651
5652 Version 1.00 18-Nov-97
5653 ----------------------
5654
5655 1. Added compile-time macros to support systems such as SunOS4 which don't have
5656 memmove() or strerror() but have other things that can be used instead.
5657
5658 2. Arranged that "make clean" removes the executables.
5659
5660
5661 Version 0.99 27-Oct-97
5662 ----------------------
5663
5664 1. Fixed bug in code for optimizing classes with only one character. It was
5665 initializing a 32-byte map regardless, which could cause it to run off the end
5666 of the memory it had got.
5667
5668 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
5669
5670
5671 Version 0.98 22-Oct-97
5672 ----------------------
5673
5674 1. Fixed bug in code for handling temporary memory usage when there are more
5675 back references than supplied space in the ovector. This could cause segfaults.
5676
5677
5678 Version 0.97 21-Oct-97
5679 ----------------------
5680
5681 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
5682
5683 2. Optimized negated single characters not to use a bit map.
5684
5685 3. Brought error texts together as macro definitions; clarified some of them;
5686 fixed one that was wrong - it said "range out of order" when it meant "invalid
5687 escape sequence".
5688
5689 4. Changed some char * arguments to const char *.
5690
5691 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
5692
5693 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
5694 pcretest.
5695
5696
5697 Version 0.96 16-Oct-97
5698 ----------------------
5699
5700 1. Added a simple "pgrep" utility to the distribution.
5701
5702 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
5703 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
5704 where "ddd" means "one or more decimal digits".
5705
5706 3. Fixed serious bug. If a pattern had a back reference, but the call to
5707 pcre_exec() didn't supply a large enough ovector to record the related
5708 identifying subpattern, the match always failed. PCRE now remembers the number
5709 of the largest back reference, and gets some temporary memory in which to save
5710 the offsets during matching if necessary, in order to ensure that
5711 backreferences always work.
5712
5713 4. Increased the compatibility with Perl in a number of ways:
5714
5715 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
5716 to request this handling. The option can be set at compile or exec time.
5717
5718 (b) $ matches before a terminating newline by default; an option
5719 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
5720 mode). The option can be set at compile or exec time.
5721
5722 (c) The handling of \ followed by a digit other than 0 is now supposed to be
5723 the same as Perl's. If the decimal number it represents is less than 10
5724 or there aren't that many previous left capturing parentheses, an octal
5725 escape is read. Inside a character class, it's always an octal escape,
5726 even if it is a single digit.
5727
5728 (d) An escaped but undefined alphabetic character is taken as a literal,
5729 unless PCRE_EXTRA is set. Currently this just reserves the remaining
5730 escapes.
5731
5732 (e) {0} is now permitted. (The previous item is removed from the compiled
5733 pattern).
5734
5735 5. Changed all the names of code files so that the basic parts are no longer
5736 than 10 characters, and abolished the teeny "globals.c" file.
5737
5738 6. Changed the handling of character classes; they are now done with a 32-byte
5739 bit map always.
5740
5741 7. Added the -d and /D options to pcretest to make it possible to look at the
5742 internals of compilation without having to recompile pcre.
5743
5744
5745 Version 0.95 23-Sep-97
5746 ----------------------
5747
5748 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
5749 \x20 at the start of a run of normal characters. These were being treated as
5750 real characters, instead of the source characters being re-checked.
5751
5752
5753 Version 0.94 18-Sep-97
5754 ----------------------
5755
5756 1. The functions are now thread-safe, with the caveat that the global variables
5757 containing pointers to malloc() and free() or alternative functions are the
5758 same for all threads.
5759
5760 2. Get pcre_study() to generate a bitmap of initial characters for non-
5761 anchored patterns when this is possible, and use it if passed to pcre_exec().
5762
5763
5764 Version 0.93 15-Sep-97
5765 ----------------------
5766
5767 1. /(b)|(:+)/ was computing an incorrect first character.
5768
5769 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
5770 but not actually doing anything yet.
5771
5772 3. Treat "-" characters in classes that cannot be part of ranges as literals,
5773 as Perl does (e.g. [-az] or [az-]).
5774
5775 4. Set the anchored flag if a branch starts with .* or .*? because that tests
5776 all possible positions.
5777
5778 5. Split up into different modules to avoid including unneeded functions in a
5779 compiled binary. However, compile and exec are still in one module. The "study"
5780 function is split off.
5781
5782 6. The character tables are now in a separate module whose source is generated
5783 by an auxiliary program - but can then be edited by hand if required. There are
5784 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
5785 toupper() in the code.
5786
5787 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
5788 make them global. Abolish the function for setting them, as the caller can now
5789 set them directly.
5790
5791
5792 Version 0.92 11-Sep-97
5793 ----------------------
5794
5795 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
5796 (e.g. /a{1,3}/) was broken (I mis-optimized it).
5797
5798 2. Caseless matching was not working in character classes if the characters in
5799 the pattern were in upper case.
5800
5801 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
5802
5803 4. Make PCRE_ANCHORED public and accept as a compile option.
5804
5805 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
5806 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
5807 pass them.
5808
5809 6. Give an error if bad option bits passed at compile or run time.
5810
5811 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
5812 pcretest to cause it to pass that flag.
5813
5814 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
5815 options, and the first character, if set.
5816
5817 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
5818
5819
5820 Version 0.91 10-Sep-97
5821 ----------------------
5822
5823 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
5824 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
5825
5826 2. PCRE was looping on encountering an indefinitely repeated back reference to
5827 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
5828 Perl does - treats the match as successful.
5829
5830 ****

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