/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1586 - (show annotations)
Wed Aug 5 17:43:19 2015 UTC (4 years, 3 months ago) by ph10
File size: 282416 byte(s)
Error occurred while calculating annotation data.
Make pcregrep -q override -l and -c for compatibility with other greps.
1 ChangeLog for PCRE
2 ------------------
3
4 Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
5 development is happening in the PCRE2 10.xx series.
6
7 Version 8.38 xx-xxx-xxxx
8 ------------------------
9
10 1. If a group that contained a recursive back reference also contained a
11 forward reference subroutine call followed by a non-forward-reference
12 subroutine call, for example /.((?2)(?R)\1)()/, pcre2_compile() failed to
13 compile correct code, leading to undefined behaviour or an internally
14 detected error. This bug was discovered by the LLVM fuzzer.
15
16 2. Quantification of certain items (e.g. atomic back references) could cause
17 incorrect code to be compiled when recursive forward references were
18 involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
19 This bug was discovered by the LLVM fuzzer.
20
21 3. A repeated conditional group whose condition was a reference by name caused
22 a buffer overflow if there was more than one group with the given name.
23 This bug was discovered by the LLVM fuzzer.
24
25 4. A recursive back reference by name within a group that had the same name as
26 another group caused a buffer overflow. For example:
27 /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
28
29 5. A forward reference by name to a group whose number is the same as the
30 current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
31 a buffer overflow at compile time. This bug was discovered by the LLVM
32 fuzzer.
33
34 6. A lookbehind assertion within a set of mutually recursive subpatterns could
35 provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
36
37 7. Another buffer overflow bug involved duplicate named groups with a
38 reference between their definition, with a group that reset capture
39 numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
40 fixed by always allowing for more memory, even if not needed. (A proper fix
41 is implemented in PCRE2, but it involves more refactoring.)
42
43 8. There was no check for integer overflow in subroutine calls such as (?123).
44
45 9. The table entry for \l in EBCDIC environments was incorrect, leading to its
46 being treated as a literal 'l' instead of causing an error.
47
48 10. There was a buffer overflow if pcre_exec() was called with an ovector of
49 size 1. This bug was found by american fuzzy lop.
50
51 11. If a non-capturing group containing a conditional group that could match
52 an empty string was repeated, it was not identified as matching an empty
53 string itself. For example: /^(?:(?(1)x|)+)+$()/.
54
55 12. In an EBCDIC environment, pcretest was mishandling the escape sequences
56 \a and \e in test subject lines.
57
58 13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
59 instead of the EBCDIC value.
60
61 14. The handling of \c in an EBCDIC environment has been revised so that it is
62 now compatible with the specification in Perl's perlebcdic page.
63
64 15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
65 ASCII/Unicode. This has now been added to the list of characters that are
66 recognized as white space in EBCDIC.
67
68 16. When PCRE was compiled without UCP support, the use of \p and \P gave an
69 error (correctly) when used outside a class, but did not give an error
70 within a class.
71
72 17. \h within a class was incorrectly compiled in EBCDIC environments.
73
74 18. A pattern with an unmatched closing parenthesis that contained a backward
75 assertion which itself contained a forward reference caused buffer
76 overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
77
78 19. JIT should return with error when the compiled pattern requires more stack
79 space than the maximum.
80
81 20. A possessively repeated conditional group that could match an empty string,
82 for example, /(?(R))*+/, was incorrectly compiled.
83
84 21. Fix infinite recursion in the JIT compiler when certain patterns such as
85 /(?:|a|){100}x/ are analysed.
86
87 22. Some patterns with character classes involving [: and \\ were incorrectly
88 compiled and could cause reading from uninitialized memory or an incorrect
89 error diagnosis.
90
91 23. Pathological patterns containing many nested occurrences of [: caused
92 pcre_compile() to run for a very long time.
93
94 24. A conditional group with only one branch has an implicit empty alternative
95 branch and must therefore be treated as potentially matching an empty
96 string.
97
98 25. If (?R was followed by - or + incorrect behaviour happened instead of a
99 diagnostic.
100
101 26. Arrange to give up on finding the minimum matching length for overly
102 complex patterns.
103
104 27. Similar to (4) above: in a pattern with duplicated named groups and an
105 occurrence of (?| it is possible for an apparently non-recursive back
106 reference to become recursive if a later named group with the relevant
107 number is encountered. This could lead to a buffer overflow. Wen Guanxing
108 from Venustech ADLAB discovered this bug.
109
110 28. If pcregrep was given the -q option with -c or -l, or when handling a
111 binary file, it incorrectly wrote output to stdout.
112
113
114 Version 8.37 28-April-2015
115 --------------------------
116
117 1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
118 for those parentheses to be closed with whatever has been captured so far.
119 However, it was failing to mark any other groups between the hightest
120 capture so far and the currrent group as "unset". Thus, the ovector for
121 those groups contained whatever was previously there. An example is the
122 pattern /(x)|((*ACCEPT))/ when matched against "abcd".
123
124 2. If an assertion condition was quantified with a minimum of zero (an odd
125 thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
126
127 3. If a pattern in pcretest input had the P (POSIX) modifier followed by an
128 unrecognized modifier, a crash could occur.
129
130 4. An attempt to do global matching in pcretest with a zero-length ovector
131 caused a crash.
132
133 5. Fixed a memory leak during matching that could occur for a subpattern
134 subroutine call (recursive or otherwise) if the number of captured groups
135 that had to be saved was greater than ten.
136
137 6. Catch a bad opcode during auto-possessification after compiling a bad UTF
138 string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
139 UTF with NO_UTF_CHECK is documented as having an undefined outcome.
140
141 7. A UTF pattern containing a "not" match of a non-ASCII character and a
142 subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
143
144 8. When a pattern is compiled, it remembers the highest back reference so that
145 when matching, if the ovector is too small, extra memory can be obtained to
146 use instead. A conditional subpattern whose condition is a check on a
147 capture having happened, such as, for example in the pattern
148 /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
149 setting the highest backreference number. This mattered only if pcre_exec()
150 was called with an ovector that was too small to hold the capture, and there
151 was no other kind of back reference (a situation which is probably quite
152 rare). The effect of the bug was that the condition was always treated as
153 FALSE when the capture could not be consulted, leading to a incorrect
154 behaviour by pcre_exec(). This bug has been fixed.
155
156 9. A reference to a duplicated named group (either a back reference or a test
157 for being set in a conditional) that occurred in a part of the pattern where
158 PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
159 to be incorrectly calculated, leading to overwriting.
160
161 10. A mutually recursive set of back references such as (\2)(\1) caused a
162 segfault at study time (while trying to find the minimum matching length).
163 The infinite loop is now broken (with the minimum length unset, that is,
164 zero).
165
166 11. If an assertion that was used as a condition was quantified with a minimum
167 of zero, matching went wrong. In particular, if the whole group had
168 unlimited repetition and could match an empty string, a segfault was
169 likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
170 assertions to be quantified, but not if they are being used as conditions,
171 so the above pattern is faulted by Perl. PCRE has now been changed so that
172 it also rejects such patterns.
173
174 12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
175 failed to allow the zero-repeat case if pcre2_exec() was called with an
176 ovector too small to capture the group.
177
178 13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
179 Red Hat Product Security:
180
181 (a) A crash if /K and /F were both set with the option to save the compiled
182 pattern.
183
184 (b) Another crash if the option to print captured substrings in a callout
185 was combined with setting a null ovector, for example \O\C+ as a subject
186 string.
187
188 14. A pattern such as "((?2){0,1999}())?", which has a group containing a
189 forward reference repeated a large (but limited) number of times within a
190 repeated outer group that has a zero minimum quantifier, caused incorrect
191 code to be compiled, leading to the error "internal error:
192 previously-checked referenced subpattern not found" when an incorrect
193 memory address was read. This bug was reported as "heap overflow",
194 discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
195 CVE-2015-2325.
196
197 23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
198 call within a group that also contained a recursive back reference caused
199 incorrect code to be compiled. This bug was reported as "heap overflow",
200 discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
201 number CVE-2015-2326.
202
203 24. Computing the size of the JIT read-only data in advance has been a source
204 of various issues, and new ones are still appear unfortunately. To fix
205 existing and future issues, size computation is eliminated from the code,
206 and replaced by on-demand memory allocation.
207
208 25. A pattern such as /(?i)[A-`]/, where characters in the other case are
209 adjacent to the end of the range, and the range contained characters with
210 more than one other case, caused incorrect behaviour when compiled in UTF
211 mode. In that example, the range a-j was left out of the class.
212
213 26. Fix JIT compilation of conditional blocks, which assertion
214 is converted to (*FAIL). E.g: /(?(?!))/.
215
216 27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
217 discovered by the LLVM fuzzer.
218
219 28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
220 when this assertion was used as a condition, for example (?(?!)a|b). In
221 pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
222 error about an unsupported item.
223
224 29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
225 possessification code could take exponential time to complete. A recursion
226 depth limit of 1000 has been imposed to limit the resources used by this
227 optimization.
228
229 30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
230 such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
231 because \S ensures they are all in the class. The code for doing this was
232 interacting badly with the code for computing the amount of space needed to
233 compile the pattern, leading to a buffer overflow. This bug was discovered
234 by the LLVM fuzzer.
235
236 31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
237 other kinds of group caused stack overflow at compile time. This bug was
238 discovered by the LLVM fuzzer.
239
240 32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
241 between a subroutine call and its quantifier was incorrectly compiled,
242 leading to buffer overflow or other errors. This bug was discovered by the
243 LLVM fuzzer.
244
245 33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
246 assertion after (?(. The code was failing to check the character after
247 (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
248 was discovered by the LLVM fuzzer.
249
250 34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
251 a fixed maximum following a group that contains a subroutine reference was
252 incorrectly compiled and could trigger buffer overflow. This bug was
253 discovered by the LLVM fuzzer.
254
255 35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
256 caused a stack overflow instead of the diagnosis of a non-fixed length
257 lookbehind assertion. This bug was discovered by the LLVM fuzzer.
258
259 36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
260 (e.g. /(?<=\Ka)/) could make pcregrep loop.
261
262 37. There was a similar problem to 36 in pcretest for global matches.
263
264 38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
265 and a subsequent item in the pattern caused a non-match, backtracking over
266 the repeated \X did not stop, but carried on past the start of the subject,
267 causing reference to random memory and/or a segfault. There were also some
268 other cases where backtracking after \C could crash. This set of bugs was
269 discovered by the LLVM fuzzer.
270
271 39. The function for finding the minimum length of a matching string could take
272 a very long time if mutual recursion was present many times in a pattern,
273 for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
274 method has been implemented. This infelicity was discovered by the LLVM
275 fuzzer.
276
277 40. Static linking against the PCRE library using the pkg-config module was
278 failing on missing pthread symbols.
279
280
281 Version 8.36 26-September-2014
282 ------------------------------
283
284 1. Got rid of some compiler warnings in the C++ modules that were shown up by
285 -Wmissing-field-initializers and -Wunused-parameter.
286
287 2. The tests for quantifiers being too big (greater than 65535) were being
288 applied after reading the number, and stupidly assuming that integer
289 overflow would give a negative number. The tests are now applied as the
290 numbers are read.
291
292 3. Tidy code in pcre_exec.c where two branches that used to be different are
293 now the same.
294
295 4. The JIT compiler did not generate match limit checks for certain
296 bracketed expressions with quantifiers. This may lead to exponential
297 backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
298 issue should be resolved now.
299
300 5. Fixed an issue, which occures when nested alternatives are optimized
301 with table jumps.
302
303 6. Inserted two casts and changed some ints to size_t in the light of some
304 reported 64-bit compiler warnings (Bugzilla 1477).
305
306 7. Fixed a bug concerned with zero-minimum possessive groups that could match
307 an empty string, which sometimes were behaving incorrectly in the
308 interpreter (though correctly in the JIT matcher). This pcretest input is
309 an example:
310
311 '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
312 NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
313
314 the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
315 JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
316 for an empty string was breaking the inner loop and carrying on at a lower
317 level, when possessive repeated groups should always return to a higher
318 level as they have no backtrack points in them. The empty string test now
319 occurs at the outer level.
320
321 8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
322 ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
323
324 9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
325 doesn't).
326
327 10. Change 8.34/15 introduced a bug that caused the amount of memory needed
328 to hold a pattern to be incorrectly computed (too small) when there were
329 named back references to duplicated names. This could cause "internal
330 error: code overflow" or "double free or corruption" or other memory
331 handling errors.
332
333 11. When named subpatterns had the same prefixes, back references could be
334 confused. For example, in this pattern:
335
336 /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
337
338 the reference to 'Name' was incorrectly treated as a reference to a
339 duplicate name.
340
341 12. A pattern such as /^s?c/mi8 where the optional character has more than
342 one "other case" was incorrectly compiled such that it would only try to
343 match starting at "c".
344
345 13. When a pattern starting with \s was studied, VT was not included in the
346 list of possible starting characters; this should have been part of the
347 8.34/18 patch.
348
349 14. If a character class started [\Qx]... where x is any character, the class
350 was incorrectly terminated at the ].
351
352 15. If a pattern that started with a caseless match for a character with more
353 than one "other case" was studied, PCRE did not set up the starting code
354 unit bit map for the list of possible characters. Now it does. This is an
355 optimization improvement, not a bug fix.
356
357 16. The Unicode data tables have been updated to Unicode 7.0.0.
358
359 17. Fixed a number of memory leaks in pcregrep.
360
361 18. Avoid a compiler warning (from some compilers) for a function call with
362 a cast that removes "const" from an lvalue by using an intermediate
363 variable (to which the compiler does not object).
364
365 19. Incorrect code was compiled if a group that contained an internal recursive
366 back reference was optional (had quantifier with a minimum of zero). This
367 example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
368 caused segmentation faults because of stack overflows at compile time.
369
370 20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
371 group that is quantified with an indefinite repeat, caused a compile-time
372 loop which used up all the system stack and provoked a segmentation fault.
373 This was not the same bug as 19 above.
374
375 21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
376 Patch by Mike Frysinger.
377
378
379 Version 8.35 04-April-2014
380 --------------------------
381
382 1. A new flag is set, when property checks are present in an XCLASS.
383 When this flag is not set, PCRE can perform certain optimizations
384 such as studying these XCLASS-es.
385
386 2. The auto-possessification of character sets were improved: a normal
387 and an extended character set can be compared now. Furthermore
388 the JIT compiler optimizes more character set checks.
389
390 3. Got rid of some compiler warnings for potentially uninitialized variables
391 that show up only when compiled with -O2.
392
393 4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
394 of a match later then the end of the match. The pcretest program was not
395 handling the case sensibly - it was outputting from the start to the next
396 binary zero. It now reports this situation in a message, and outputs the
397 text from the end to the start.
398
399 5. Fast forward search is improved in JIT. Instead of the first three
400 characters, any three characters with fixed position can be searched.
401 Search order: first, last, middle.
402
403 6. Improve character range checks in JIT. Characters are read by an inprecise
404 function now, which returns with an unknown value if the character code is
405 above a certain threshold (e.g: 256). The only limitation is that the value
406 must be bigger than the threshold as well. This function is useful when
407 the characters above the threshold are handled in the same way.
408
409 7. The macros whose names start with RAWUCHAR are placeholders for a future
410 mode in which only the bottom 21 bits of 32-bit data items are used. To
411 make this more memorable for those maintaining the code, the names have
412 been changed to start with UCHAR21, and an extensive comment has been added
413 to their definition.
414
415 8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
416 to the export list in Makefile.am (they were accidentally omitted from the
417 8.34 tarball).
418
419 9. The informational output from pcretest used the phrase "starting byte set"
420 which is inappropriate for the 16-bit and 32-bit libraries. As the output
421 for "first char" and "need char" really means "non-UTF-char", I've changed
422 "byte" to "char", and slightly reworded the output. The documentation about
423 these values has also been (I hope) clarified.
424
425 10. Another JIT related optimization: use table jumps for selecting the correct
426 backtracking path, when more than four alternatives are present inside a
427 bracket.
428
429 11. Empty match is not possible, when the minimum length is greater than zero,
430 and there is no \K in the pattern. JIT should avoid empty match checks in
431 such cases.
432
433 12. In a caseless character class with UCP support, when a character with more
434 than one alternative case was not the first character of a range, not all
435 the alternative cases were added to the class. For example, s and \x{17f}
436 are both alternative cases for S: the class [RST] was handled correctly,
437 but [R-T] was not.
438
439 13. The configure.ac file always checked for pthread support when JIT was
440 enabled. This is not used in Windows, so I have put this test inside a
441 check for the presence of windows.h (which was already tested for).
442
443 14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
444 The algorithm provides a way to skip certain starting offsets, and usually
445 faster than linear prefix searches.
446
447 15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
448 as for 'fr_FR' and 'french'. For some reason, however, it then used the
449 Windows-specific input and output files, which have 'french' screwed in.
450 So this could never have worked. One of the problems with locales is that
451 they aren't always the same. I have now updated RunTest so that it checks
452 the output of the locale test (test 3) against three different output
453 files, and it allows the test to pass if any one of them matches. With luck
454 this should make the test pass on some versions of Solaris where it was
455 failing. Because of the uncertainty, the script did not used to stop if
456 test 3 failed; it now does. If further versions of a French locale ever
457 come to light, they can now easily be added.
458
459 16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
460 there was a message during ./configure, but it did not stop. This now
461 provokes an error. The invalid example in README has been corrected.
462 If a value less than the minimum is given, the minimum value has always
463 been used, but now a warning is given.
464
465 17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
466 was a bug in the test system, which is now fixed. Also, the list of various
467 configurations that are tested for each release did not have one with both
468 16/32 bits and --enable-bar-anycrlf. It now does.
469
470 18. pcretest was missing "-C bsr" for displaying the \R default setting.
471
472 19. Little endian PowerPC systems are supported now by the JIT compiler.
473
474 20. The fast forward newline mechanism could enter to an infinite loop on
475 certain invalid UTF-8 input. Although we don't support these cases
476 this issue can be fixed by a performance optimization.
477
478 21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
479 not take account if existing stack usage. There is now a new global
480 variable called pcre_stack_guard that can be set to point to an external
481 function to check stack availability. It is called at the start of
482 processing every parenthesized group.
483
484 22. A typo in the code meant that in ungreedy mode the max/min qualifier
485 behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
486 not match "ab".
487
488 23. When UTF was disabled, the JIT program reported some incorrect compile
489 errors. These messages are silenced now.
490
491 24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
492 compiler.
493
494 25. Change all the temporary files used in RunGrepTest to be different to those
495 used by RunTest so that the tests can be run simultaneously, for example by
496 "make -j check".
497
498
499 Version 8.34 15-December-2013
500 -----------------------------
501
502 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
503 executable memory. Patch inspired by Carsten Klein.
504
505 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
506 this macro is never tested and has no effect, because the work to support
507 coverage involves only compiling and linking options and special targets in
508 the Makefile. The comment in config.h implied that defining the macro would
509 enable coverage support, which is totally false. There was also support for
510 setting this macro in the CMake files (my fault, I just copied it from
511 configure). SUPPORT_GCOV has now been removed.
512
513 3. Make a small performance improvement in strlen16() and strlen32() in
514 pcretest.
515
516 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
517 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
518 these cases). There was also one in pcretest.c.
519
520 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
521
522 6. In UTF mode, the code for checking whether a group could match an empty
523 string (which is used for indefinitely repeated groups to allow for
524 breaking an infinite loop) was broken when the group contained a repeated
525 negated single-character class with a character that occupied more than one
526 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
527 UTF-8 mode). The effect was undefined: the group might or might not be
528 deemed as matching an empty string, or the program might have crashed.
529
530 7. The code for checking whether a group could match an empty string was not
531 recognizing that \h, \H, \v, \V, and \R must match a character.
532
533 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
534 an empty string. If it can, pcretest shows this in its information output.
535
536 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
537 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
538 matched by pcre_exec() without using JIT:
539
540 (a) If the rest of the pattern did not match after a maximal run of
541 grapheme clusters, the code for backing up to try with fewer of them
542 did not always back up over a full grapheme when characters that do not
543 have the modifier quality were involved, e.g. Hangul syllables.
544
545 (b) If the match point in a subject started with modifier character, and
546 there was no match, the code could incorrectly back up beyond the match
547 point, and potentially beyond the first character in the subject,
548 leading to a segfault or an incorrect match result.
549
550 10. A conditional group with an assertion condition could lead to PCRE
551 recording an incorrect first data item for a match if no other first data
552 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
553 first data item, and therefore matched "ca" after "c" instead of at the
554 start.
555
556 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
557 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
558
559 12. The source of pcregrep now includes z/OS-specific code so that it can be
560 compiled for z/OS as part of the special z/OS distribution.
561
562 13. Added the -T and -TM options to pcretest.
563
564 14. The code in pcre_compile.c for creating the table of named capturing groups
565 has been refactored. Instead of creating the table dynamically during the
566 actual compiling pass, the information is remembered during the pre-compile
567 pass (on the stack unless there are more than 20 named groups, in which
568 case malloc() is used) and the whole table is created before the actual
569 compile happens. This has simplified the code (it is now nearly 150 lines
570 shorter) and prepared the way for better handling of references to groups
571 with duplicate names.
572
573 15. A back reference to a named subpattern when there is more than one of the
574 same name now checks them in the order in which they appear in the pattern.
575 The first one that is set is used for the reference. Previously only the
576 first one was inspected. This change makes PCRE more compatible with Perl.
577
578 16. Unicode character properties were updated from Unicode 6.3.0.
579
580 17. The compile-time code for auto-possessification has been refactored, based
581 on a patch by Zoltan Herczeg. It now happens after instead of during
582 compilation. The code is cleaner, and more cases are handled. The option
583 PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
584 options in pcretest are provided to set it. It can also be set by
585 (*NO_AUTO_POSSESS) at the start of a pattern.
586
587 18. The character VT has been added to the default ("C" locale) set of
588 characters that match \s and are generally treated as white space,
589 following this same change in Perl 5.18. There is now no difference between
590 "Perl space" and "POSIX space". Whether VT is treated as white space in
591 other locales depends on the locale.
592
593 19. The code for checking named groups as conditions, either for being set or
594 for being recursed, has been refactored (this is related to 14 and 15
595 above). Processing unduplicated named groups should now be as fast at
596 numerical groups, and processing duplicated groups should be faster than
597 before.
598
599 20. Two patches to the CMake build system, by Alexander Barkov:
600
601 (1) Replace the "source" command by "." in CMakeLists.txt because
602 "source" is a bash-ism.
603
604 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
605 without these the CMake build does not work on Solaris.
606
607 21. Perl has changed its handling of \8 and \9. If there is no previously
608 encountered capturing group of those numbers, they are treated as the
609 literal characters 8 and 9 instead of a binary zero followed by the
610 literals. PCRE now does the same.
611
612 22. Following Perl, added \o{} to specify codepoints in octal, making it
613 possible to specify values greater than 0777 and also making them
614 unambiguous.
615
616 23. Perl now gives an error for missing closing braces after \x{... instead of
617 treating the string as literal. PCRE now does the same.
618
619 24. RunTest used to grumble if an inappropriate test was selected explicitly,
620 but just skip it when running all tests. This make it awkward to run ranges
621 of tests when one of them was inappropriate. Now it just skips any
622 inappropriate tests, as it always did when running all tests.
623
624 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
625 character types such as \d or \w, too many callouts were inserted, and the
626 data that they returned was rubbish.
627
628 26. In UCP mode, \s was not matching two of the characters that Perl matches,
629 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
630 were matched by \h. The code has now been refactored so that the lists of
631 the horizontal and vertical whitespace characters used for \h and \v (which
632 are defined only in one place) are now also used for \s.
633
634 27. Add JIT support for the 64 bit TileGX architecture.
635 Patch by Jiong Wang (Tilera Corporation).
636
637 28. Possessive quantifiers for classes (both explicit and automatically
638 generated) now use special opcodes instead of wrapping in ONCE brackets.
639
640 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
641 (because it's meaningless), this was not happening when PCRE_CASELESS was
642 set. Not wrong, but inefficient.
643
644 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
645 properties for \w, \d, etc) is present in a test regex. Otherwise if the
646 test contains no characters greater than 255, Perl doesn't realise it
647 should be using Unicode semantics.
648
649 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
650 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
651 does in Unicode mode.
652
653 32. Added the "forbid" facility to pcretest so that putting tests into the
654 wrong test files can sometimes be quickly detected.
655
656 33. There is now a limit (default 250) on the depth of nesting of parentheses.
657 This limit is imposed to control the amount of system stack used at compile
658 time. It can be changed at build time by --with-parens-nest-limit=xxx or
659 the equivalent in CMake.
660
661 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
662 errors. Perl warns for these when in warning mode, but PCRE has no facility
663 for giving warnings.
664
665 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
666 However, this was not working for (?!) because it is optimized to (*FAIL),
667 for which PCRE does not allow quantifiers. The optimization is now disabled
668 when a quantifier follows (?!). I can't see any use for this, but it makes
669 things uniform.
670
671 36. Perl no longer allows group names to start with digits, so I have made this
672 change also in PCRE. It simplifies the code a bit.
673
674 37. In extended mode, Perl ignores spaces before a + that indicates a
675 possessive quantifier. PCRE allowed a space before the quantifier, but not
676 before the possessive +. It now does.
677
678 38. The use of \K (reset reported match start) within a repeated possessive
679 group such as (a\Kb)*+ was not working.
680
681 40. Document that the same character tables must be used at compile time and
682 run time, and that the facility to pass tables to pcre_exec() and
683 pcre_dfa_exec() is for use only with saved/restored patterns.
684
685 41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
686 features for Builds with MSVC:
687
688 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
689 builds). The .rc files can be used to set FileDescription and many other
690 attributes.
691
692 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
693 This allows higher-level build scripts which want .pdb files to avoid
694 hard-coding the exact files needed."
695
696 42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
697 mean "start of word" and "end of word", respectively, as a transition aid.
698
699 43. A minimizing repeat of a class containing codepoints greater than 255 in
700 non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
701 compiled to use the heap for recursion.
702
703 44. Got rid of some compiler warnings for unused variables when UTF but not UCP
704 is configured.
705
706
707 Version 8.33 28-May-2013
708 ------------------------
709
710 1. Added 'U' to some constants that are compared to unsigned integers, to
711 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
712 variables that are added to signed variables, to ensure the result is
713 signed and can be negated.
714
715 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
716 CMake config files.
717
718 3. Revise the creation of config.h.generic so that all boolean macros are
719 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
720 overriding via -D on the command line possible.
721
722 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
723 to unsigned int is reported to make a quite noticeable speed difference in
724 a specific Windows environment. Testing on Linux did also appear to show
725 some benefit (and it is clearly not harmful). Also fixed the definition of
726 Xop which should be unsigned.
727
728 5. Related to (4), changing the definition of the intermediate variable cc
729 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
730 improvements.
731
732 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
733 unnecessary spaces.
734
735 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
736 and later.
737
738 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
739
740 9. Optimizing fast_forward_start_bits in JIT.
741
742 10. Adding support for callouts in JIT, and fixing some issues revealed
743 during this work. Namely:
744
745 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
746
747 (b) Minimum length was not checked before the matching is started.
748
749 11. The value of capture_last that is passed to callouts was incorrect in some
750 cases when there was a capture on one path that was subsequently abandoned
751 after a backtrack. Also, the capture_last value is now reset after a
752 recursion, since all captures are also reset in this case.
753
754 12. The interpreter no longer returns the "too many substrings" error in the
755 case when an overflowing capture is in a branch that is subsequently
756 abandoned after a backtrack.
757
758 13. In the pathological case when an offset vector of size 2 is used, pcretest
759 now prints out the matched string after a yield of 0 or 1.
760
761 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
762 Only supported by the JIT compiler at the moment.
763
764 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
765
766 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
767 offset of the starting point of the matching process, provided the offsets
768 vector is large enough.
769
770 17. The \A escape now records a lookbehind value of 1, though its execution
771 does not actually inspect the previous character. This is to ensure that,
772 in partial multi-segment matching, at least one character from the old
773 segment is retained when a new segment is processed. Otherwise, if there
774 are no lookbehinds in the pattern, \A might match incorrectly at the start
775 of a new segment.
776
777 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
778
779 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
780 gives some modest performance improvement in 8-bit mode.
781
782 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
783 be expressed in certain programming languages using Universal Character
784 Names.
785
786 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
787 which points out that "non characters" are not "characters that may not
788 appear in Unicode strings" but rather "characters that are reserved for
789 internal use and have only local meaning".
790
791 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
792 there was a conditional group that depended on an assertion, if the
793 assertion was false, the callout that immediately followed the alternation
794 in the condition was skipped when pcre_exec() was used for matching.
795
796 23. Allow an explicit callout to be inserted before an assertion that is the
797 condition for a conditional group, for compatibility with automatic
798 callouts, which always insert a callout at this point.
799
800 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
801 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
802
803 25. (*PRUNE) is now supported by the JIT compiler.
804
805 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
806
807 27. Fix the case where there are two or more SKIPs with arguments that may be
808 ignored.
809
810 28. (*SKIP) is now supported by the JIT compiler.
811
812 29. (*THEN) is now supported by the JIT compiler.
813
814 30. Update RunTest with additional test selector options.
815
816 31. The way PCRE handles backtracking verbs has been changed in two ways.
817
818 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
819 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
820 backtracking. In some cases this makes it more Perl-compatible, but Perl's
821 rather obscure rules do not always do the same thing.
822
823 (2) Previously, backtracking verbs were confined within assertions. This is
824 no longer the case for positive assertions, except for (*ACCEPT). Again,
825 this sometimes improves Perl compatibility, and sometimes does not.
826
827 32. A number of tests that were in test 2 because Perl did things differently
828 have been moved to test 1, because either Perl or PCRE has changed, and
829 these tests are now compatible.
830
831 32. Backtracking control verbs are now handled in the same way in JIT and
832 interpreter.
833
834 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
835 contained a forward subroutine reference caused a compile error.
836
837 34. Auto-detect and optimize limited repetitions in JIT.
838
839 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
840 blocking (*UTF) etc.
841
842 36. In the interpreter, maximizing pattern repetitions for characters and
843 character types now use tail recursion, which reduces stack usage.
844
845 37. The value of the max lookbehind was not correctly preserved if a compiled
846 and saved regex was reloaded on a host of different endianness.
847
848 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
849 of the compiled pattern block, expand the flags field from 16 to 32 bits
850 because it was almost full.
851
852 39. Try madvise first before posix_madvise.
853
854 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
855 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
856 original change locked out all matches of empty strings. This has been
857 changed so that one match of an empty string per line is recognized.
858 Subsequent searches on the same line (for colouring or for --only-matching,
859 for example) do not recognize empty strings.
860
861 41. Applied a user patch to fix a number of spelling mistakes in comments.
862
863 42. Data lines longer than 65536 caused pcretest to crash.
864
865 43. Clarified the data type for length and startoffset arguments for pcre_exec
866 and pcre_dfa_exec in the function-specific man pages, where they were
867 explicitly stated to be in bytes, never having been updated. I also added
868 some clarification to the pcreapi man page.
869
870 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
871 a segmentation fault.
872
873
874 Version 8.32 30-November-2012
875 -----------------------------
876
877 1. Improved JIT compiler optimizations for first character search and single
878 character iterators.
879
880 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
881 Patch by Daniel Richard G.
882
883 3. Single character iterator optimizations in the JIT compiler.
884
885 4. Improved JIT compiler optimizations for character ranges.
886
887 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
888 Reported by Giuseppe D'Angelo.
889
890 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
891 of a line, was being set incorrectly in cases where .* appeared inside
892 atomic brackets at the start of a pattern, or where there was a subsequent
893 *PRUNE or *SKIP.
894
895 7. Improved instruction cache flush for POWER/PowerPC.
896 Patch by Daniel Richard G.
897
898 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
899 grep:
900
901 (a) There is now no limit to the number of patterns to be matched.
902
903 (b) An error is given if a pattern is too long.
904
905 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
906 are now supported.
907
908 (d) --exclude-from and --include-from (multiple use) have been added.
909
910 (e) Exclusions and inclusions now apply to all files and directories, not
911 just to those obtained from scanning a directory recursively.
912
913 (f) Multiple uses of -f and --file-list are now supported.
914
915 (g) In a Windows environment, the default for -d has been changed from
916 "read" (the GNU grep default) to "skip", because otherwise the presence
917 of a directory in the file list provokes an error.
918
919 (h) The documentation has been revised and clarified in places.
920
921 9. Improve the matching speed of capturing brackets.
922
923 10. Changed the meaning of \X so that it now matches a Unicode extended
924 grapheme cluster.
925
926 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
927 out POSIX threads when JIT support is configured.
928
929 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
930
931 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
932 structure could go wrong in environments where size_t is not the same size
933 as int.
934
935 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
936 set.
937
938 15. The EBCDIC support had decayed; later updates to the code had included
939 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
940 general tidy up of EBCDIC-related issues, and the documentation was also
941 not quite right. There is now a test that can be run on ASCII systems to
942 check some of the EBCDIC-related things (but is it not a full test).
943
944 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
945 in a small tidy to the code.
946
947 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
948
949 18. If the --only-matching (-o) option in pcregrep is specified multiple
950 times, each one causes appropriate output. For example, -o1 -o2 outputs the
951 substrings matched by the 1st and 2nd capturing parentheses. A separating
952 string can be specified by --om-separator (default empty).
953
954 19. Improving the first n character searches.
955
956 20. Turn case lists for horizontal and vertical white space into macros so that
957 they are defined only once.
958
959 21. This set of changes together give more compatible Unicode case-folding
960 behaviour for characters that have more than one other case when UCP
961 support is available.
962
963 (a) The Unicode property table now has offsets into a new table of sets of
964 three or more characters that are case-equivalent. The MultiStage2.py
965 script that generates these tables (the pcre_ucd.c file) now scans
966 CaseFolding.txt instead of UnicodeData.txt for character case
967 information.
968
969 (b) The code for adding characters or ranges of characters to a character
970 class has been abstracted into a generalized function that also handles
971 case-independence. In UTF-mode with UCP support, this uses the new data
972 to handle characters with more than one other case.
973
974 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
975 whose other case is greater than 256 are now correctly matched
976 caselessly. Previously, the high codepoint matched the low one, but not
977 vice versa.
978
979 (d) The processing of \h, \H, \v, and \ in character classes now makes use
980 of the new class addition function, using character lists defined as
981 macros alongside the case definitions of 20 above.
982
983 (e) Caseless back references now work with characters that have more than
984 one other case.
985
986 (f) General caseless matching of characters with more than one other case
987 is supported.
988
989 22. Unicode character properties were updated from Unicode 6.2.0
990
991 23. Improved CMake support under Windows. Patch by Daniel Richard G.
992
993 24. Add support for 32-bit character strings, and UTF-32
994
995 25. Major JIT compiler update (code refactoring and bugfixing).
996 Experimental Sparc 32 support is added.
997
998 26. Applied a modified version of Daniel Richard G's patch to create
999 pcre.h.generic and config.h.generic by "make" instead of in the
1000 PrepareRelease script.
1001
1002 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
1003 pcre_compile.c when checking for a zero character.
1004
1005 28. Introducing a native interface for JIT. Through this interface, the compiled
1006 machine code can be directly executed. The purpose of this interface is to
1007 provide fast pattern matching, so several sanity checks are not performed.
1008 However, feature tests are still performed. The new interface provides
1009 1.4x speedup compared to the old one.
1010
1011 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
1012 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
1013 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
1014
1015 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
1016 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
1017 the "old" RFC 2279). Instead, it ended up passing a negative length to
1018 pcre_exec().
1019
1020 31. Add support for GCC's visibility feature to hide internal functions.
1021
1022 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
1023 "unknown -C option" after outputting 0 or 1.
1024
1025 33. There is now support for generating a code coverage report for the test
1026 suite in environments where gcc is the compiler and lcov is installed. This
1027 is mainly for the benefit of the developers.
1028
1029 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
1030 unaddressable using valgrind annotations, allowing valgrind to detect
1031 invalid memory accesses. This is mainly for the benefit of the developers.
1032
1033 25. (*UTF) can now be used to start a pattern in any of the three libraries.
1034
1035 26. Give configure error if --enable-cpp but no C++ compiler found.
1036
1037
1038 Version 8.31 06-July-2012
1039 -------------------------
1040
1041 1. Fixing a wrong JIT test case and some compiler warnings.
1042
1043 2. Removed a bashism from the RunTest script.
1044
1045 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1046 to unsigned type, result still unsigned" that was given by an MS compiler
1047 on encountering the code "-sizeof(xxx)".
1048
1049 4. Partial matching support is added to the JIT compiler.
1050
1051 5. Fixed several bugs concerned with partial matching of items that consist
1052 of more than one character:
1053
1054 (a) /^(..)\1/ did not partially match "aba" because checking references was
1055 done on an "all or nothing" basis. This also applied to repeated
1056 references.
1057
1058 (b) \R did not give a hard partial match if \r was found at the end of the
1059 subject.
1060
1061 (c) \X did not give a hard partial match after matching one or more
1062 characters at the end of the subject.
1063
1064 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1065 a partial match for the string "\r".
1066
1067 (e) When newline was set to CRLF, the metacharacter "." did not recognize
1068 a partial match for a CR character at the end of the subject string.
1069
1070 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1071 running pcretest, the text "(JIT)" added to the output whenever JIT is
1072 actually used to run the match.
1073
1074 7. Individual JIT compile options can be set in pcretest by following -s+[+]
1075 or /S+[+] with a digit between 1 and 7.
1076
1077 8. OP_NOT now supports any UTF character not just single-byte ones.
1078
1079 9. (*MARK) control verb is now supported by the JIT compiler.
1080
1081 10. The command "./RunTest list" lists the available tests without actually
1082 running any of them. (Because I keep forgetting what they all are.)
1083
1084 11. Add PCRE_INFO_MAXLOOKBEHIND.
1085
1086 12. Applied a (slightly modified) user-supplied patch that improves performance
1087 when the heap is used for recursion (compiled with --disable-stack-for-
1088 recursion). Instead of malloc and free for each heap frame each time a
1089 logical recursion happens, frames are retained on a chain and re-used where
1090 possible. This sometimes gives as much as 30% improvement.
1091
1092 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1093 call.
1094
1095 14. As documented, (*COMMIT) is now confined to within a positive assertion.
1096
1097 15. It is now possible to link pcretest with libedit as an alternative to
1098 libreadline.
1099
1100 16. (*COMMIT) control verb is now supported by the JIT compiler.
1101
1102 17. The Unicode data tables have been updated to Unicode 6.1.0.
1103
1104 18. Added --file-list option to pcregrep.
1105
1106 19. Added binary file support to pcregrep, including the -a, --binary-files,
1107 -I, and --text options.
1108
1109 20. The madvise function is renamed for posix_madvise for QNX compatibility
1110 reasons. Fixed by Giuseppe D'Angelo.
1111
1112 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1113
1114 22. Changed the option for creating symbolic links for 16-bit man pages from
1115 -s to -sf so that re-installing does not cause issues.
1116
1117 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1118
1119 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1120 matches in certain environments (the workspace was not being correctly
1121 retained). Also added to pcre_dfa_exec() a simple plausibility check on
1122 some of the workspace data at the beginning of a restart.
1123
1124 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1125 was not doing so when it should - probably a typo introduced by SVN 528
1126 (change 8.10/14).
1127
1128 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1129 \w+ when the character tables indicated that \x{c4} was a word character.
1130 There were several related cases, all because the tests for doing a table
1131 lookup were testing for characters less than 127 instead of 255.
1132
1133 27. If a pattern contains capturing parentheses that are not used in a match,
1134 their slots in the ovector are set to -1. For those that are higher than
1135 any matched groups, this happens at the end of processing. In the case when
1136 there were back references that the ovector was too small to contain
1137 (causing temporary malloc'd memory to be used during matching), and the
1138 highest capturing number was not used, memory off the end of the ovector
1139 was incorrectly being set to -1. (It was using the size of the temporary
1140 memory instead of the true size.)
1141
1142 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1143 ovector size, it uses memory at the end of the block that it has got.
1144
1145 29. Check for an overlong MARK name and give an error at compile time. The
1146 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1147
1148 30. JIT compiler update.
1149
1150 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1151 Rill for the patch.
1152
1153 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1154
1155 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1156
1157 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1158 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1159 was enabled.
1160
1161 35. Improve JIT code generation for greedy plus quantifier.
1162
1163 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1164 1 to "aa" instead of to an empty string. The bug affected repeated groups
1165 that could potentially match an empty string.
1166
1167 37. Optimizing single character iterators in JIT.
1168
1169 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1170 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1171 codepoints that are too big for the mode are faulted, and in a UTF mode,
1172 disallowed codepoints are also faulted.
1173
1174 39. If PCRE was compiled with UTF support, in three places in the DFA
1175 matcher there was code that should only have been obeyed in UTF mode, but
1176 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1177 processing when bytes with values greater than 127 were present. In 16-bit
1178 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1179 both cases the values are those that cannot be the first data item in a UTF
1180 character. The three items that might have provoked this were recursions,
1181 possessively repeated groups, and atomic groups.
1182
1183 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1184 and pcregrep, because some OS require shared objects to be explicitly
1185 passed to ld, causing the link step to fail if they are not.
1186
1187 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1188 mode, patterns that started with \h* or \R* might be incorrectly matched.
1189
1190
1191 Version 8.30 04-February-2012
1192 -----------------------------
1193
1194 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
1195 name is defined in ctype.h.
1196
1197 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
1198 only in quite long subpatterns.
1199
1200 3. Removed the function pcre_info(), which has been obsolete and deprecated
1201 since it was replaced by pcre_fullinfo() in February 2000.
1202
1203 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
1204 match a (*MARK), and the match failed at the start of the subject, a
1205 reference to memory before the start of the subject could occur. This bug
1206 was introduced by fix 17 of release 8.21.
1207
1208 5. A reference to an unset group with zero minimum repetition was giving
1209 totally wrong answers (in non-JavaScript-compatibility mode). For example,
1210 /(another)?(\1?)test/ matched against "hello world test". This bug was
1211 introduced in release 8.13.
1212
1213 6. Add support for 16-bit character strings (a large amount of work involving
1214 many changes and refactorings).
1215
1216 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1217 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1218 from a file.
1219
1220 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1221 rounding is not applied in this particular case).
1222
1223 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1224 if they appear, or are escaped, in patterns.
1225
1226 10. Get rid of a number of -Wunused-but-set-variable warnings.
1227
1228 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1229 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1230 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1231 also returns the mark "x". This bug applied to capturing parentheses,
1232 non-capturing parentheses, and atomic parentheses. It also applied to some
1233 assertions.
1234
1235 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1236 information out of configure.ac instead of relying on pcre.h.generic, which
1237 is not stored in the repository.
1238
1239 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1240 -lreadline.
1241
1242 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1243
1244 15. Applied Graycode's patch to put the top-level frame on the stack rather
1245 than the heap when not using the stack for recursion. This gives a
1246 performance improvement in many cases when recursion is not deep.
1247
1248 16. Experimental code added to "pcretest -C" to output the stack frame size.
1249
1250
1251 Version 8.21 12-Dec-2011
1252 ------------------------
1253
1254 1. Updating the JIT compiler.
1255
1256 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1257 are added as well.
1258
1259 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1260 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1261 calling _pcre_jit_exec. Some extra comments are added.
1262
1263 4. (*MARK) settings inside atomic groups that do not contain any capturing
1264 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1265 was introduced by change 18 for 8.20.
1266
1267 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1268 ECMA-262 standard.
1269
1270 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1271 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1272 This bug was probably introduced by change 9 of 8.13.
1273
1274 7. While fixing 6 above, I noticed that a number of other items were being
1275 incorrectly rejected as "not fixed length". This arose partly because newer
1276 opcodes had not been added to the fixed-length checking code. I have (a)
1277 corrected the bug and added tests for these items, and (b) arranged for an
1278 error to occur if an unknown opcode is encountered while checking for fixed
1279 length instead of just assuming "not fixed length". The items that were
1280 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1281 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1282 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1283
1284 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1285 being incorrectly compiled and would have given unpredicatble results.
1286
1287 9. A possessively repeated subpattern with minimum repeat count greater than
1288 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1289 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1290 the first (A) could occur when it should not.
1291
1292 10. Add a cast and remove a redundant test from the code.
1293
1294 11. JIT should use pcre_malloc/pcre_free for allocation.
1295
1296 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1297 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1298 is anything other than /usr, -L is still shown).
1299
1300 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1301
1302 14. Perl does not support \N without a following name in a [] class; PCRE now
1303 also gives an error.
1304
1305 15. If a forward reference was repeated with an upper limit of around 2000,
1306 it caused the error "internal error: overran compiling workspace". The
1307 maximum number of forward references (including repeats) was limited by the
1308 internal workspace, and dependent on the LINK_SIZE. The code has been
1309 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1310 the default depends on LINK_SIZE. There is a new upper limit (for safety)
1311 of around 200,000 forward references. While doing this, I also speeded up
1312 the filling in of repeated forward references.
1313
1314 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1315 incorrectly expecting the subject to contain another "a" after the start.
1316
1317 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1318 in the match, the SKIP should be ignored. This was not happening; instead
1319 the SKIP was being treated as NOMATCH. For patterns such as
1320 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1321 tested.
1322
1323 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1324 now much more compatible with Perl, in particular in cases where the result
1325 is a non-match for a non-anchored pattern. For example, if
1326 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1327 "m", where previously it did not return a name. A side effect of this
1328 change is that for partial matches, the last encountered mark name is
1329 returned, as for non matches. A number of tests that were previously not
1330 Perl-compatible have been moved into the Perl-compatible test files. The
1331 refactoring has had the pleasing side effect of removing one argument from
1332 the match() function, thus reducing its stack requirements.
1333
1334 19. If the /S+ option was used in pcretest to study a pattern using JIT,
1335 subsequent uses of /S (without +) incorrectly behaved like /S+.
1336
1337 21. Retrieve executable code size support for the JIT compiler and fixing
1338 some warnings.
1339
1340 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1341 not work when the shorter character appeared right at the end of the
1342 subject string.
1343
1344 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1345 systems.
1346
1347 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1348 output it when the /M option is used in pcretest.
1349
1350 25. The CheckMan script was not being included in the distribution. Also, added
1351 an explicit "perl" to run Perl scripts from the PrepareRelease script
1352 because this is reportedly needed in Windows.
1353
1354 26. If study data was being save in a file and studying had not found a set of
1355 "starts with" bytes for the pattern, the data written to the file (though
1356 never used) was taken from uninitialized memory and so caused valgrind to
1357 complain.
1358
1359 27. Updated RunTest.bat as provided by Sheri Pierce.
1360
1361 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1362
1363 29. Computation of memory usage for the table of capturing group names was
1364 giving an unnecessarily large value.
1365
1366
1367 Version 8.20 21-Oct-2011
1368 ------------------------
1369
1370 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1371 a POSIX class. After further experiments with Perl, which convinced me that
1372 Perl has bugs and confusions, a closing square bracket is no longer allowed
1373 in a POSIX name. This bug also affected patterns with classes that started
1374 with full stops.
1375
1376 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1377 captured substring, but while checking the failing first alternative,
1378 substring 1 is temporarily captured. If the output vector supplied to
1379 pcre_exec() was not big enough for this capture, the yield of the function
1380 was still zero ("insufficient space for captured substrings"). This cannot
1381 be totally fixed without adding another stack variable, which seems a lot
1382 of expense for a edge case. However, I have improved the situation in cases
1383 such as /(a)(b)x|abc/ matched against "abc", where the return code
1384 indicates that fewer than the maximum number of slots in the ovector have
1385 been set.
1386
1387 3. Related to (2) above: when there are more back references in a pattern than
1388 slots in the output vector, pcre_exec() uses temporary memory during
1389 matching, and copies in the captures as far as possible afterwards. It was
1390 using the entire output vector, but this conflicts with the specification
1391 that only 2/3 is used for passing back captured substrings. Now it uses
1392 only the first 2/3, for compatibility. This is, of course, another edge
1393 case.
1394
1395 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
1396 main code base, and can be used by building with --enable-jit. When this is
1397 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1398 runtime --no-jit option is given.
1399
1400 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
1401 ovector, the return from the function was zero, implying that there were
1402 other matches that did not fit. The correct "exactly full" value is now
1403 returned.
1404
1405 6. If a subpattern that was called recursively or as a subroutine contained
1406 (*PRUNE) or any other control that caused it to give a non-standard return,
1407 invalid errors such as "Error -26 (nested recursion at the same subject
1408 position)" or even infinite loops could occur.
1409
1410 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1411 computing the minimum length on reaching *ACCEPT, and so ended up with the
1412 wrong value of 1 rather than 0. Further investigation indicates that
1413 computing a minimum subject length in the presence of *ACCEPT is difficult
1414 (think back references, subroutine calls), and so I have changed the code
1415 so that no minimum is registered for a pattern that contains *ACCEPT.
1416
1417 8. If (*THEN) was present in the first (true) branch of a conditional group,
1418 it was not handled as intended. [But see 16 below.]
1419
1420 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1421 Sheri Pierce.
1422
1423 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1424 the first byte in a match must be "a".
1425
1426 11. Change 17 for 8.13 increased the recursion depth for patterns like
1427 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1428 pattern contains any instances of (*THEN). If it does not, the old
1429 optimizations are restored. It would be nice to do this on a per-group
1430 basis, but at the moment that is not feasible.
1431
1432 12. In some environments, the output of pcretest -C is CRLF terminated. This
1433 broke RunTest's code that checks for the link size. A single white space
1434 character after the value is now allowed for.
1435
1436 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1437 For "fr", it uses the Windows-specific input and output files.
1438
1439 14. If (*THEN) appeared in a group that was called recursively or as a
1440 subroutine, it did not work as intended. [But see next item.]
1441
1442 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1443 pattern fragments (but not containing any | characters). If A and B are
1444 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1445 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1446 D. In other words, Perl considers parentheses that do not contain any |
1447 characters to be part of a surrounding alternative, whereas PCRE was
1448 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1449 differently. PCRE now behaves in the same way as Perl, except in the case
1450 of subroutine/recursion calls such as (?1) which have in any case always
1451 been different (but PCRE had them first :-).
1452
1453 16. Related to 15 above: Perl does not treat the | in a conditional group as
1454 creating alternatives. Such a group is treated in the same way as an
1455 ordinary group without any | characters when processing (*THEN). PCRE has
1456 been changed to match Perl's behaviour.
1457
1458 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1459 RunGrepTest script failed.
1460
1461 18. Change 22 for version 13 caused atomic groups to use more stack. This is
1462 inevitable for groups that contain captures, but it can lead to a lot of
1463 stack use in large patterns. The old behaviour has been restored for atomic
1464 groups that do not contain any capturing parentheses.
1465
1466 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1467 suppress the check for a minimum subject length at run time. (If it was
1468 given to pcre_exec() or pcre_dfa_exec() it did work.)
1469
1470 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1471 fail to work when decoding hex characters in data strings in EBCDIC
1472 environments.
1473
1474 21. It appears that in at least one Mac OS environment, the isxdigit() function
1475 is implemented as a macro that evaluates to its argument more than once,
1476 contravening the C 90 Standard (I haven't checked a later standard). There
1477 was an instance in pcretest which caused it to go wrong when processing
1478 \x{...} escapes in subject strings. The has been rewritten to avoid using
1479 things like p++ in the argument of isxdigit().
1480
1481
1482 Version 8.13 16-Aug-2011
1483 ------------------------
1484
1485 1. The Unicode data tables have been updated to Unicode 6.0.0.
1486
1487 2. Two minor typos in pcre_internal.h have been fixed.
1488
1489 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1490 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1491 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1492
1493 4. There were a number of related bugs in the code for matching backrefences
1494 caselessly in UTF-8 mode when codes for the characters concerned were
1495 different numbers of bytes. For example, U+023A and U+2C65 are an upper
1496 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1497 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1498 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1499 2-byte code at the end of the subject (it thought there wasn't enough data
1500 left).
1501
1502 5. Comprehensive information about what went wrong is now returned by
1503 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1504 as the output vector has at least 2 elements. The offset of the start of
1505 the failing character and a reason code are placed in the vector.
1506
1507 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
1508 now returned is for the first byte of the failing character, instead of the
1509 last byte inspected. This is an incompatible change, but I hope it is small
1510 enough not to be a problem. It makes the returned offset consistent with
1511 pcre_exec() and pcre_dfa_exec().
1512
1513 7. pcretest now gives a text phrase as well as the error number when
1514 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1515 failure, the offset and reason code are output.
1516
1517 8. When \R was used with a maximizing quantifier it failed to skip backwards
1518 over a \r\n pair if the subsequent match failed. Instead, it just skipped
1519 back over a single character (\n). This seems wrong (because it treated the
1520 two characters as a single entity when going forwards), conflicts with the
1521 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1522 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1523 has been changed.
1524
1525 9. Some internal refactoring has changed the processing so that the handling
1526 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1527 time (the PCRE_DOTALL option was changed this way some time ago: version
1528 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1529 which was always a bit of a fudge. It also means that there is one less
1530 argument for the match() function, which reduces its stack requirements
1531 slightly. This change also fixes an incompatibility with Perl: the pattern
1532 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1533
1534 10. More internal refactoring has drastically reduced the number of recursive
1535 calls to match() for possessively repeated groups such as (abc)++ when
1536 using pcre_exec().
1537
1538 11. While implementing 10, a number of bugs in the handling of groups were
1539 discovered and fixed:
1540
1541 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1542 (a|)*(?1) gave a compile-time internal error.
1543 ((a|)+)+ did not notice that the outer group could match an empty string.
1544 (^a|^)+ was not marked as anchored.
1545 (.*a|.*)+ was not marked as matching at start or after a newline.
1546
1547 12. Yet more internal refactoring has removed another argument from the match()
1548 function. Special calls to this function are now indicated by setting a
1549 value in a variable in the "match data" data block.
1550
1551 13. Be more explicit in pcre_study() instead of relying on "default" for
1552 opcodes that mean there is no starting character; this means that when new
1553 ones are added and accidentally left out of pcre_study(), testing should
1554 pick them up.
1555
1556 14. The -s option of pcretest has been documented for ages as being an old
1557 synonym of -m (show memory usage). I have changed it to mean "force study
1558 for every regex", that is, assume /S for every regex. This is similar to -i
1559 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1560 using it. It makes it easier to run collections of tests with and without
1561 study enabled, and thereby test pcre_study() more easily. All the standard
1562 tests are now run with and without -s (but some patterns can be marked as
1563 "never study" - see 20 below).
1564
1565 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1566 restoration of the capturing data to the outer values was not happening
1567 correctly.
1568
1569 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1570 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1571 pattern had matched an empty string, and so incorrectly returned a no
1572 match.
1573
1574 17. There was optimizing code for the last branch of non-capturing parentheses,
1575 and also for the obeyed branch of a conditional subexpression, which used
1576 tail recursion to cut down on stack usage. Unfortunately, now that there is
1577 the possibility of (*THEN) occurring in these branches, tail recursion is
1578 no longer possible because the return has to be checked for (*THEN). These
1579 two optimizations have therefore been removed. [But see 8.20/11 above.]
1580
1581 18. If a pattern containing \R was studied, it was assumed that \R always
1582 matched two bytes, thus causing the minimum subject length to be
1583 incorrectly computed because \R can also match just one byte.
1584
1585 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1586 was incorrectly computed.
1587
1588 20. If /S is present twice on a test pattern in pcretest input, it now
1589 *disables* studying, thereby overriding the use of -s on the command line
1590 (see 14 above). This is necessary for one or two tests to keep the output
1591 identical in both cases.
1592
1593 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1594 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1595
1596 22. When an atomic group that contained a capturing parenthesis was
1597 successfully matched, but the branch in which it appeared failed, the
1598 capturing was not being forgotten if a higher numbered group was later
1599 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1600 group 1 to "a", when in fact it should be unset. This applied to multi-
1601 branched capturing and non-capturing groups, repeated or not, and also to
1602 positive assertions (capturing in negative assertions does not happen
1603 in PCRE) and also to nested atomic groups.
1604
1605 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1606 subject after a captured substring, to make it easier to tell which of a
1607 number of identical substrings has been captured.
1608
1609 24. The way atomic groups are processed by pcre_exec() has been changed so that
1610 if they are repeated, backtracking one repetition now resets captured
1611 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1612 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1613 "aaa". Previously, it would have been "a". As part of this code
1614 refactoring, the way recursive calls are handled has also been changed.
1615
1616 25. If an assertion condition captured any substrings, they were not passed
1617 back unless some other capturing happened later. For example, if
1618 (?(?=(a))a) was matched against "a", no capturing was returned.
1619
1620 26. When studying a pattern that contained subroutine calls or assertions,
1621 the code for finding the minimum length of a possible match was handling
1622 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1623 group 1 called group 2 while simultaneously a separate group 2 called group
1624 1). A stack overflow occurred in this case. I have fixed this by limiting
1625 the recursion depth to 10.
1626
1627 27. Updated RunTest.bat in the distribution to the version supplied by Tom
1628 Fortmann. This supports explicit test numbers on the command line, and has
1629 argument validation and error reporting.
1630
1631 28. An instance of \X with an unlimited repeat could fail if at any point the
1632 first character it looked at was a mark character.
1633
1634 29. Some minor code refactoring concerning Unicode properties and scripts
1635 should reduce the stack requirement of match() slightly.
1636
1637 30. Added the '=' option to pcretest to check the setting of unused capturing
1638 slots at the end of the pattern, which are documented as being -1, but are
1639 not included in the return count.
1640
1641 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1642 compiled something random. Now it gives a compile-time error (as does
1643 Perl).
1644
1645 32. A *MARK encountered during the processing of a positive assertion is now
1646 recorded and passed back (compatible with Perl).
1647
1648 33. If --only-matching or --colour was set on a pcregrep call whose pattern
1649 had alternative anchored branches, the search for a second match in a line
1650 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1651 matched the line "0102" twice. The same bug affected patterns that started
1652 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1653 twice.
1654
1655 34. Previously, PCRE did not allow quantification of assertions. However, Perl
1656 does, and because of capturing effects, quantifying parenthesized
1657 assertions may at times be useful. Quantifiers are now allowed for
1658 parenthesized assertions.
1659
1660 35. A minor code tidy in pcre_compile() when checking options for \R usage.
1661
1662 36. \g was being checked for fancy things in a character class, when it should
1663 just be a literal "g".
1664
1665 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1666 appearance of a nested POSIX class supersedes an apparent external class.
1667 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1668 unescaped square brackets may also appear as part of class names. For
1669 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1670 more like Perl. (But see 8.20/1 above.)
1671
1672 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1673 was because it thought it was \N{name}, which is not supported).
1674
1675 39. Add minix to OS list not supporting the -S option in pcretest.
1676
1677 40. PCRE tries to detect cases of infinite recursion at compile time, but it
1678 cannot analyze patterns in sufficient detail to catch mutual recursions
1679 such as ((?1))((?2)). There is now a runtime test that gives an error if a
1680 subgroup is called recursively as a subpattern for a second time at the
1681 same position in the subject string. In previous releases this might have
1682 been caught by the recursion limit, or it might have run out of stack.
1683
1684 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1685 happen only once. PCRE was, however incorrectly giving a compile time error
1686 "recursive call could loop indefinitely" because it cannot analyze the
1687 pattern in sufficient detail. The compile time test no longer happens when
1688 PCRE is compiling a conditional subpattern, but actual runaway loops are
1689 now caught at runtime (see 40 above).
1690
1691 42. It seems that Perl allows any characters other than a closing parenthesis
1692 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1693 has been changed to be the same.
1694
1695 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1696 as not to get warnings when autogen.sh is called. Also changed
1697 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1698
1699 44. To help people who use pcregrep to scan files containing exceedingly long
1700 lines, the following changes have been made:
1701
1702 (a) The default value of the buffer size parameter has been increased from
1703 8K to 20K. (The actual buffer used is three times this size.)
1704
1705 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1706 PCRE is built.
1707
1708 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1709 to be set at run time.
1710
1711 (d) Numerical values in pcregrep options can be followed by K or M, for
1712 example --buffer-size=50K.
1713
1714 (e) If a line being scanned overflows pcregrep's buffer, an error is now
1715 given and the return code is set to 2.
1716
1717 45. Add a pointer to the latest mark to the callout data block.
1718
1719 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1720 partial match of an empty string instead of no match. This was specific to
1721 the use of ".".
1722
1723 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1724 complete match instead of a partial match. This bug was dependent on both
1725 the PCRE_UTF8 and PCRE_DOTALL options being set.
1726
1727 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1728 starting byte set, because \b was not being ignored.
1729
1730
1731 Version 8.12 15-Jan-2011
1732 ------------------------
1733
1734 1. Fixed some typos in the markup of the man pages, and wrote a script that
1735 checks for such things as part of the documentation building process.
1736
1737 2. On a big-endian 64-bit system, pcregrep did not correctly process the
1738 --match-limit and --recursion-limit options (added for 8.11). In
1739 particular, this made one of the standard tests fail. (The integer value
1740 went into the wrong half of a long int.)
1741
1742 3. If the --colour option was given to pcregrep with -v (invert match), it
1743 did strange things, either producing crazy output, or crashing. It should,
1744 of course, ignore a request for colour when reporting lines that do not
1745 match.
1746
1747 4. Another pcregrep bug caused similar problems if --colour was specified with
1748 -M (multiline) and the pattern match finished with a line ending.
1749
1750 5. In pcregrep, when a pattern that ended with a literal newline sequence was
1751 matched in multiline mode, the following line was shown as part of the
1752 match. This seems wrong, so I have changed it.
1753
1754 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
1755 the check for further matches in the same line (so they could be coloured)
1756 to overrun the end of the current line. If another match was found, it was
1757 incorrectly shown (and then shown again when found in the next line).
1758
1759 7. If pcregrep was compiled under Windows, there was a reference to the
1760 function pcregrep_exit() before it was defined. I am assuming this was
1761 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1762 reported by a user. I've moved the definition above the reference.
1763
1764
1765 Version 8.11 10-Dec-2010
1766 ------------------------
1767
1768 1. (*THEN) was not working properly if there were untried alternatives prior
1769 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1770 backtracked to try for "b" instead of moving to the next alternative branch
1771 at the same level (in this case, to look for "c"). The Perl documentation
1772 is clear that when (*THEN) is backtracked onto, it goes to the "next
1773 alternative in the innermost enclosing group".
1774
1775 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1776 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
1777 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1778 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1779 (*THEN).
1780
1781 3. If \s appeared in a character class, it removed the VT character from
1782 the class, even if it had been included by some previous item, for example
1783 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1784 of \s, but is part of the POSIX "space" class.)
1785
1786 4. A partial match never returns an empty string (because you can always
1787 match an empty string at the end of the subject); however the checking for
1788 an empty string was starting at the "start of match" point. This has been
1789 changed to the "earliest inspected character" point, because the returned
1790 data for a partial match starts at this character. This means that, for
1791 example, /(?<=abc)def/ gives a partial match for the subject "abc"
1792 (previously it gave "no match").
1793
1794 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1795 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1796 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1797 has an implication that the given string is incomplete (because a partial
1798 match is preferred over a full match). For this reason, these items now
1799 give a partial match in this situation. [Aside: previously, the one case
1800 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1801 match rather than a full match, which was wrong by the old rules, but is
1802 now correct.]
1803
1804 6. There was a bug in the handling of #-introduced comments, recognized when
1805 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1806 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1807 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1808 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1809 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1810 places in pcre_compile().
1811
1812 7. Related to (6) above, when pcre_compile() was skipping #-introduced
1813 comments when looking ahead for named forward references to subpatterns,
1814 the only newline sequence it recognized was NL. It now handles newlines
1815 according to the set newline convention.
1816
1817 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1818 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1819 cater for a lack of strerror(). These oversights have been fixed.
1820
1821 9. Added --match-limit and --recursion-limit to pcregrep.
1822
1823 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1824
1825 11. When the -o option was used, pcregrep was setting a return code of 1, even
1826 when matches were found, and --line-buffered was not being honoured.
1827
1828 12. Added an optional parentheses number to the -o and --only-matching options
1829 of pcregrep.
1830
1831 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1832 can match an empty string. The code to do it in pcretest and pcredemo
1833 needed fixing:
1834
1835 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1836 only one byte after an empty string match just before CRLF (this case
1837 just got forgotten; "any" and "anycrlf" were OK).
1838
1839 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1840 mode when an empty string match preceded an ASCII character followed by
1841 a non-ASCII character. (The code for advancing by one character rather
1842 than one byte was nonsense.)
1843
1844 (c) The pcredemo.c sample program did not have any code at all to handle
1845 the cases when CRLF is a valid newline sequence.
1846
1847 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1848 as a starting offset was within the subject string. There is now a new
1849 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1850 negative or greater than the length of the string. In order to test this,
1851 pcretest is extended to allow the setting of negative starting offsets.
1852
1853 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1854 starting offset points to the beginning of a UTF-8 character was
1855 unnecessarily clumsy. I tidied it up.
1856
1857 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1858 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1859
1860 17. Nobody had reported that the --include_dir option, which was added in
1861 release 7.7 should have been called --include-dir (hyphen, not underscore)
1862 for compatibility with GNU grep. I have changed it to --include-dir, but
1863 left --include_dir as an undocumented synonym, and the same for
1864 --exclude-dir, though that is not available in GNU grep, at least as of
1865 release 2.5.4.
1866
1867 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1868 characters from a string of bytes) have been redefined so as not to use
1869 loops, in order to improve performance in some environments. At the same
1870 time, I abstracted some of the common code into auxiliary macros to save
1871 repetition (this should not affect the compiled code).
1872
1873 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1874 compile-time error is now given if \c is not followed by an ASCII
1875 character, that is, a byte less than 128. (In EBCDIC mode, the code is
1876 different, and any byte value is allowed.)
1877
1878 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1879 START_OPTIMIZE option, which is now allowed at compile time - but just
1880 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1881 to pcregrep and other applications that have no direct access to PCRE
1882 options. The new /Y option in pcretest sets this option when calling
1883 pcre_compile().
1884
1885 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1886 back references. Groups containing recursive back references were forced to
1887 be atomic by that change, but in the case of named groups, the amount of
1888 memory required was incorrectly computed, leading to "Failed: internal
1889 error: code overflow". This has been fixed.
1890
1891 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1892 pcretest.c, to avoid build problems in some Borland environments.
1893
1894
1895 Version 8.10 25-Jun-2010
1896 ------------------------
1897
1898 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1899 THEN.
1900
1901 2. (*ACCEPT) was not working when inside an atomic group.
1902
1903 3. Inside a character class, \B is treated as a literal by default, but
1904 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1905 causes the error). The code is unchanged, but I tidied the documentation.
1906
1907 4. Inside a character class, PCRE always treated \R and \X as literals,
1908 whereas Perl faults them if its -w option is set. I have changed PCRE so
1909 that it faults them when PCRE_EXTRA is set.
1910
1911 5. Added support for \N, which always matches any character other than
1912 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1913
1914 6. When compiling pcregrep with newer versions of gcc which may have
1915 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1916 declared with attribute warn_unused_result" were given. Just casting the
1917 result to (void) does not stop the warnings; a more elaborate fudge is
1918 needed. I've used a macro to implement this.
1919
1920 7. Minor change to pcretest.c to avoid a compiler warning.
1921
1922 8. Added four artifical Unicode properties to help with an option to make
1923 \s etc use properties (see next item). The new properties are: Xan
1924 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1925
1926 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1927 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1928 this option. Modified pcretest to add /W to test this facility. Added
1929 REG_UCP to make it available via the POSIX interface.
1930
1931 10. Added --line-buffered to pcregrep.
1932
1933 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1934 studied, and the match started with a letter with a code point greater than
1935 127 whose first byte was different to the first byte of the other case of
1936 the letter, the other case of this starting letter was not recognized
1937 (#976).
1938
1939 12. If a pattern that was studied started with a repeated Unicode property
1940 test, for example, \p{Nd}+, there was the theoretical possibility of
1941 setting up an incorrect bitmap of starting bytes, but fortunately it could
1942 not have actually happened in practice until change 8 above was made (it
1943 added property types that matched character-matching opcodes).
1944
1945 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1946 possible starting bytes for non-anchored patterns.
1947
1948 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1949 \R, and also a number of cases that involve Unicode properties, both
1950 explicit and implicit when PCRE_UCP is set.
1951
1952 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1953 input, it could crash or give wrong results if characters with values
1954 greater than 0xc0 were present in the subject string. (Detail: it assumed
1955 UTF-8 input when processing these items.)
1956
1957 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1958 size_t is 64-bit (#991).
1959
1960 17. Added a check for running out of memory when PCRE is compiled with
1961 --disable-stack-for-recursion (#990).
1962
1963 18. If the last data line in a file for pcretest does not have a newline on
1964 the end, a newline was missing in the output.
1965
1966 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1967 less than 128) in its various bitmaps. However, there is a facility for
1968 generating tables according to the current locale when PCRE is compiled. It
1969 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
1970 characters, are recognized by isspace() and therefore were getting set in
1971 these tables, and indeed these tables seem to approximate to ISO 8859. This
1972 caused a problem in UTF-8 mode when pcre_study() was used to create a list
1973 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
1974 which of course cannot start UTF-8 characters. I have changed the code so
1975 that only real ASCII characters (less than 128) and the correct starting
1976 bytes for UTF-8 encodings are set for characters greater than 127 when in
1977 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
1978 altogether.)
1979
1980 20. Added the /T option to pcretest so as to be able to run tests with non-
1981 standard character tables, thus making it possible to include the tests
1982 used for 19 above in the standard set of tests.
1983
1984 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
1985 reference to a subpattern the other side of a comment that contains an
1986 opening parenthesis caused either an internal compiling error, or a
1987 reference to the wrong subpattern.
1988
1989
1990 Version 8.02 19-Mar-2010
1991 ------------------------
1992
1993 1. The Unicode data tables have been updated to Unicode 5.2.0.
1994
1995 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
1996 configured.
1997
1998 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
1999 original author of that file, following a query about its status.
2000
2001 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
2002 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
2003
2004 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
2005 quantifier applied to a forward-referencing subroutine call, could compile
2006 incorrect code or give the error "internal error: previously-checked
2007 referenced subpattern not found".
2008
2009 6. Both MS Visual Studio and Symbian OS have problems with initializing
2010 variables to point to external functions. For these systems, therefore,
2011 pcre_malloc etc. are now initialized to local functions that call the
2012 relevant global functions.
2013
2014 7. There were two entries missing in the vectors called coptable and poptable
2015 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
2016 I've fixed the data, and added a kludgy way of testing at compile time that
2017 the lengths are correct (equal to the number of opcodes).
2018
2019 8. Following on from 7, I added a similar kludge to check the length of the
2020 eint vector in pcreposix.c.
2021
2022 9. Error texts for pcre_compile() are held as one long string to avoid too
2023 much relocation at load time. To find a text, the string is searched,
2024 counting zeros. There was no check for running off the end of the string,
2025 which could happen if a new error number was added without updating the
2026 string.
2027
2028 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
2029
2030 11. \K was not working if it appeared in an atomic group or in a group that
2031 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
2032 \K is "not well defined" if used in an assertion. PCRE now accepts it if
2033 the assertion is positive, but not if it is negative.
2034
2035 12. Change 11 fortuitously reduced the size of the stack frame used in the
2036 "match()" function of pcre_exec.c by one pointer. Forthcoming
2037 implementation of support for (*MARK) will need an extra pointer on the
2038 stack; I have reserved it now, so that the stack frame size does not
2039 decrease.
2040
2041 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
2042 item in branch that calls a recursion is a subroutine call - as in the
2043 second branch in the above example - was incorrectly given the compile-
2044 time error "recursive call could loop indefinitely" because pcre_compile()
2045 was not correctly checking the subroutine for matching a non-empty string.
2046
2047 14. The checks for overrunning compiling workspace could trigger after an
2048 overrun had occurred. This is a "should never occur" error, but it can be
2049 triggered by pathological patterns such as hundreds of nested parentheses.
2050 The checks now trigger 100 bytes before the end of the workspace.
2051
2052 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
2053
2054
2055 Version 8.01 19-Jan-2010
2056 ------------------------
2057
2058 1. If a pattern contained a conditional subpattern with only one branch (in
2059 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
2060 computed the wrong minimum data length (which is of course zero for such
2061 subpatterns). This could cause incorrect "no match" results.
2062
2063 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
2064 the pattern is reset in the first branch, pcre_compile() failed with
2065 "internal error: code overflow at offset...". This happened only when
2066 the reset was to the original external option setting. (An optimization
2067 abstracts leading options settings into an external setting, which was the
2068 cause of this.)
2069
2070 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
2071 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
2072 assertion pattern did not match (meaning that the assertion was true), it
2073 was incorrectly treated as false if the SKIP had been reached during the
2074 matching. This also applied to assertions used as conditions.
2075
2076 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
2077 assertion subpattern, including such a pattern used as a condition,
2078 unpredictable results occurred, instead of the error return
2079 PCRE_ERROR_DFA_UITEM.
2080
2081 5. The C++ GlobalReplace function was not working like Perl for the special
2082 situation when an empty string is matched. It now does the fancy magic
2083 stuff that is necessary.
2084
2085 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
2086 removed. (These were left over from very, very early versions of PCRE.)
2087
2088 7. Some cosmetic changes to the code to make life easier when compiling it
2089 as part of something else:
2090
2091 (a) Change DEBUG to PCRE_DEBUG.
2092
2093 (b) In pcre_compile(), rename the member of the "branch_chain" structure
2094 called "current" as "current_branch", to prevent a collision with the
2095 Linux macro when compiled as a kernel module.
2096
2097 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
2098 prevent a collision with the Linux macro when compiled as a kernel
2099 module.
2100
2101 8. In pcre_compile() there are some checks for integer overflows that used to
2102 cast potentially large values to (double). This has been changed to that
2103 when building, a check for int64_t is made, and if it is found, it is used
2104 instead, thus avoiding the use of floating point arithmetic. (There is no
2105 other use of FP in PCRE.) If int64_t is not found, the fallback is to
2106 double.
2107
2108 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
2109 2005 (difference between two addresses compared to an unsigned value).
2110
2111 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
2112 custom one, because of the following reported problem in Windows:
2113
2114 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
2115 under Win32.
2116 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
2117 therefore missing the function definition.
2118 - The compiler thus generates a "C" signature for the test function.
2119 - The linker fails to find the "C" function.
2120 - PCRE fails to configure if asked to do so against libbz2.
2121
2122 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
2123 messages were output:
2124
2125 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
2126 rerunning libtoolize, to keep the correct libtool macros in-tree.
2127 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
2128
2129 I have done both of these things.
2130
2131 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
2132 most of the time, it *can* run out if it is given a pattern that contains a
2133 runaway infinite recursion. I updated the discussion in the pcrestack man
2134 page.
2135
2136 13. Now that we have gone to the x.xx style of version numbers, the minor
2137 version may start with zero. Using 08 or 09 is a bad idea because users
2138 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
2139 interpreted as invalid octal numbers. I've updated the previous comment in
2140 configure.ac, and also added a check that gives an error if 08 or 09 are
2141 used.
2142
2143 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
2144 causing partial matching to fail when the end of the subject matched \W
2145 in a UTF-8 pattern where \W was quantified with a minimum of 3.
2146
2147 15. There were some discrepancies between the declarations in pcre_internal.h
2148 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
2149 their definitions. The declarations used "const uschar *" and the
2150 definitions used USPTR. Even though USPTR is normally defined as "const
2151 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
2152 reported that: "This difference in casting confuses some C++ compilers, for
2153 example, SunCC recognizes above declarations as different functions and
2154 generates broken code for hbpcre." I have changed the declarations to use
2155 USPTR.
2156
2157 16. GNU libtool is named differently on some systems. The autogen.sh script now
2158 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
2159 (FreeBSD).
2160
2161 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
2162 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
2163 comment: "Figure out how to create a longlong from a string: strtoll and
2164 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
2165 instance, but it only takes 2 args instead of 3!"
2166
2167 18. A subtle bug concerned with back references has been fixed by a change of
2168 specification, with a corresponding code fix. A pattern such as
2169 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
2170 refers, was giving matches when it shouldn't. For example, xa=xaaa would
2171 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
2172 same bug. Such groups have to be quantified to be useful, or contained
2173 inside another quantified group. (If there's no repetition, the reference
2174 can never match.) The problem arises because, having left the group and
2175 moved on to the rest of the pattern, a later failure that backtracks into
2176 the group uses the captured value from the final iteration of the group
2177 rather than the correct earlier one. I have fixed this in PCRE by forcing
2178 any group that contains a reference to itself to be an atomic group; that
2179 is, there cannot be any backtracking into it once it has completed. This is
2180 similar to recursive and subroutine calls.
2181
2182
2183 Version 8.00 19-Oct-09
2184 ----------------------
2185
2186 1. The table for translating pcre_compile() error codes into POSIX error codes
2187 was out-of-date, and there was no check on the pcre_compile() error code
2188 being within the table. This could lead to an OK return being given in
2189 error.
2190
2191 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
2192 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
2193 in a Windows environment.
2194
2195 3. The pcregrep --count option prints the count for each file even when it is
2196 zero, as does GNU grep. However, pcregrep was also printing all files when
2197 --files-with-matches was added. Now, when both options are given, it prints
2198 counts only for those files that have at least one match. (GNU grep just
2199 prints the file name in this circumstance, but including the count seems
2200 more useful - otherwise, why use --count?) Also ensured that the
2201 combination -clh just lists non-zero counts, with no names.
2202
2203 4. The long form of the pcregrep -F option was incorrectly implemented as
2204 --fixed_strings instead of --fixed-strings. This is an incompatible change,
2205 but it seems right to fix it, and I didn't think it was worth preserving
2206 the old behaviour.
2207
2208 5. The command line items --regex=pattern and --regexp=pattern were not
2209 recognized by pcregrep, which required --regex pattern or --regexp pattern
2210 (with a space rather than an '='). The man page documented the '=' forms,
2211 which are compatible with GNU grep; these now work.
2212
2213 6. No libpcreposix.pc file was created for pkg-config; there was just
2214 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
2215
2216 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
2217 when UCP support is not needed, by modifying the Python script that
2218 generates it from Unicode data files. This should not matter if the module
2219 is correctly used as a library, but I received one complaint about 50K of
2220 unwanted data. My guess is that the person linked everything into his
2221 program rather than using a library. Anyway, it does no harm.
2222
2223 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
2224 was a minimum greater than 1 for a wide character in a possessive
2225 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
2226 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
2227 character. Chaos in the form of incorrect output or a compiling loop could
2228 result.
2229
2230 9. The restrictions on what a pattern can contain when partial matching is
2231 requested for pcre_exec() have been removed. All patterns can now be
2232 partially matched by this function. In addition, if there are at least two
2233 slots in the offset vector, the offset of the earliest inspected character
2234 for the match and the offset of the end of the subject are set in them when
2235 PCRE_ERROR_PARTIAL is returned.
2236
2237 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
2238 synonymous with PCRE_PARTIAL, for backwards compatibility, and
2239 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
2240 and may be more useful for multi-segment matching.
2241
2242 11. Partial matching with pcre_exec() is now more intuitive. A partial match
2243 used to be given if ever the end of the subject was reached; now it is
2244 given only if matching could not proceed because another character was
2245 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
2246 string "Z", which now yields "no match" instead of "partial match". In the
2247 case of pcre_dfa_exec(), "no match" is given if every matching path for the
2248 final character ended with (*FAIL).
2249
2250 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
2251 if the pattern had a "must contain" character that was already found in the
2252 earlier partial match, unless partial matching was again requested. For
2253 example, with the pattern /dog.(body)?/, the "must contain" character is
2254 "g". If the first part-match was for the string "dog", restarting with
2255 "sbody" failed. This bug has been fixed.
2256
2257 13. The string returned by pcre_dfa_exec() after a partial match has been
2258 changed so that it starts at the first inspected character rather than the
2259 first character of the match. This makes a difference only if the pattern
2260 starts with a lookbehind assertion or \b or \B (\K is not supported by
2261 pcre_dfa_exec()). It's an incompatible change, but it makes the two
2262 matching functions compatible, and I think it's the right thing to do.
2263
2264 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
2265 so that the demonstration program is easily available in environments where
2266 PCRE has not been installed from source.
2267
2268 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
2269 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
2270 library.
2271
2272 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
2273 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
2274 is not the first non-POSIX option to be added. Clearly some people find
2275 these options useful.
2276
2277 17. If a caller to the POSIX matching function regexec() passes a non-zero
2278 value for nmatch with a NULL value for pmatch, the value of
2279 nmatch is forced to zero.
2280
2281 18. RunGrepTest did not have a test for the availability of the -u option of
2282 the diff command, as RunTest does. It now checks in the same way as
2283 RunTest, and also checks for the -b option.
2284
2285 19. If an odd number of negated classes containing just a single character
2286 interposed, within parentheses, between a forward reference to a named
2287 subpattern and the definition of the subpattern, compilation crashed with
2288 an internal error, complaining that it could not find the referenced
2289 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
2290 [The bug was that it was starting one character too far in when skipping
2291 over the character class, thus treating the ] as data rather than
2292 terminating the class. This meant it could skip too much.]
2293
2294 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
2295 /g option in pcretest when the pattern contains \K, which makes it possible
2296 to have an empty string match not at the start, even when the pattern is
2297 anchored. Updated pcretest and pcredemo to use this option.
2298
2299 21. If the maximum number of capturing subpatterns in a recursion was greater
2300 than the maximum at the outer level, the higher number was returned, but
2301 with unset values at the outer level. The correct (outer level) value is
2302 now given.
2303
2304 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
2305 PCRE did not set those parentheses (unlike Perl). I have now found a way to
2306 make it do so. The string so far is captured, making this feature
2307 compatible with Perl.
2308
2309 23. The tests have been re-organized, adding tests 11 and 12, to make it
2310 possible to check the Perl 5.10 features against Perl 5.10.
2311
2312 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
2313 pattern matches a fixed length string. PCRE did not allow this; now it
2314 does. Neither allows recursion.
2315
2316 25. I finally figured out how to implement a request to provide the minimum
2317 length of subject string that was needed in order to match a given pattern.
2318 (It was back references and recursion that I had previously got hung up
2319 on.) This code has now been added to pcre_study(); it finds a lower bound
2320 to the length of subject needed. It is not necessarily the greatest lower
2321 bound, but using it to avoid searching strings that are too short does give
2322 some useful speed-ups. The value is available to calling programs via
2323 pcre_fullinfo().
2324
2325 26. While implementing 25, I discovered to my embarrassment that pcretest had
2326 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
2327 study optimizations had never been tested with that matching function.
2328 Oops. What is worse, even when it was passed study data, there was a bug in
2329 pcre_dfa_exec() that meant it never actually used it. Double oops. There
2330 were also very few tests of studied patterns with pcre_dfa_exec().
2331
2332 27. If (?| is used to create subpatterns with duplicate numbers, they are now
2333 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
2334 on the other side of the coin, they are no longer allowed to have different
2335 names, because these cannot be distinguished in PCRE, and this has caused
2336 confusion. (This is a difference from Perl.)
2337
2338 28. When duplicate subpattern names are present (necessarily with different
2339 numbers, as required by 27 above), and a test is made by name in a
2340 conditional pattern, either for a subpattern having been matched, or for
2341 recursion in such a pattern, all the associated numbered subpatterns are
2342 tested, and the overall condition is true if the condition is true for any
2343 one of them. This is the way Perl works, and is also more like the way
2344 testing by number works.
2345
2346
2347 Version 7.9 11-Apr-09
2348 ---------------------
2349
2350 1. When building with support for bzlib/zlib (pcregrep) and/or readline
2351 (pcretest), all targets were linked against these libraries. This included
2352 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
2353 libraries. This caused unwanted dependencies to be created. This problem
2354 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
2355 pcretest is linked with readline.
2356
2357 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
2358 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
2359 moved outside it again, because FALSE and TRUE are already defined in AIX,
2360 but BOOL is not.
2361
2362 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
2363 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
2364
2365 4. The pcregrep documentation said spaces were inserted as well as colons (or
2366 hyphens) following file names and line numbers when outputting matching
2367 lines. This is not true; no spaces are inserted. I have also clarified the
2368 wording for the --colour (or --color) option.
2369
2370 5. In pcregrep, when --colour was used with -o, the list of matching strings
2371 was not coloured; this is different to GNU grep, so I have changed it to be
2372 the same.
2373
2374 6. When --colo(u)r was used in pcregrep, only the first matching substring in
2375 each matching line was coloured. Now it goes on to look for further matches
2376 of any of the test patterns, which is the same behaviour as GNU grep.
2377
2378 7. A pattern that could match an empty string could cause pcregrep to loop; it
2379 doesn't make sense to accept an empty string match in pcregrep, so I have
2380 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2381 seems to be how GNU grep behaves. [But see later change 40 for release
2382 8.33.]
2383
2384 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2385 start or after a newline", because the conditional assertion was not being
2386 correctly handled. The rule now is that both the assertion and what follows
2387 in the first alternative must satisfy the test.
2388
2389 9. If auto-callout was enabled in a pattern with a conditional group whose
2390 condition was an assertion, PCRE could crash during matching, both with
2391 pcre_exec() and pcre_dfa_exec().
2392
2393 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
2394 used for matching.
2395
2396 11. Unicode property support in character classes was not working for
2397 characters (bytes) greater than 127 when not in UTF-8 mode.
2398
2399 12. Added the -M command line option to pcretest.
2400
2401 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
2402
2403 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
2404
2405 16. Added comments and documentation about mis-use of no_arg in the C++
2406 wrapper.
2407
2408 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
2409 from Martin Jerabek that uses macro names for all relevant character and
2410 string constants.
2411
2412 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
2413 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
2414 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
2415 these, but not everybody uses configure.
2416
2417 19. A conditional group that had only one branch was not being correctly
2418 recognized as an item that could match an empty string. This meant that an
2419 enclosing group might also not be so recognized, causing infinite looping
2420 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
2421 with the subject "ab", where knowledge that the repeated group can match
2422 nothing is needed in order to break the loop.
2423
2424 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
2425 exec(), but without supplying a callout function, matching went wrong.
2426
2427 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
2428 leak if the size of the offset vector was greater than 30. When the vector
2429 is smaller, the saved offsets during recursion go onto a local stack
2430 vector, but for larger vectors malloc() is used. It was failing to free
2431 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
2432 error, in fact).
2433
2434 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
2435 heapframe that is used only when UTF-8 support is enabled. This caused no
2436 problem, but was untidy.
2437
2438 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
2439 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
2440 included within another project.
2441
2442 24. Steven Van Ingelgem's patches to add more options to the CMake support,
2443 slightly modified by me:
2444
2445 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
2446 not building pcregrep.
2447
2448 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
2449 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
2450
2451 25. Forward references, both numeric and by name, in patterns that made use of
2452 duplicate group numbers, could behave incorrectly or give incorrect errors,
2453 because when scanning forward to find the reference group, PCRE was not
2454 taking into account the duplicate group numbers. A pattern such as
2455 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
2456
2457 26. Changed a few more instances of "const unsigned char *" to USPTR, making
2458 the feature of a custom pointer more persuasive (as requested by a user).
2459
2460 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
2461 pcretest.c, inside #ifndefs, because it seems they are sometimes already
2462 pre-defined.
2463
2464 28. Added support for (*UTF8) at the start of a pattern.
2465
2466 29. Arrange for flags added by the "release type" setting in CMake to be shown
2467 in the configuration summary.
2468
2469
2470 Version 7.8 05-Sep-08
2471 ---------------------
2472
2473 1. Replaced UCP searching code with optimized version as implemented for Ad
2474 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
2475 stage table and inline lookup instead of a function, giving speed ups of 2
2476 to 5 times on some simple patterns that I tested. Permission was given to
2477 distribute the MultiStage2.py script that generates the tables (it's not in
2478 the tarball, but is in the Subversion repository).
2479
2480 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
2481 scripts.
2482
2483 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
2484 a group with a zero qualifier. The result of the study could be incorrect,
2485 or the function might crash, depending on the pattern.
2486
2487 4. Caseless matching was not working for non-ASCII characters in back
2488 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2489 It now works when Unicode Property Support is available.
2490
2491 5. In pcretest, an escape such as \x{de} in the data was always generating
2492 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2493 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2494 truncation.
2495
2496 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2497
2498 7. Added two (int) casts to pcregrep when printing the difference of two
2499 pointers, in case they are 64-bit values.
2500
2501 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
2502 test 2 if it fails.
2503
2504 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2505 and a #define of that name to empty if it is not externally set. This is to
2506 allow users of MSVC to set it if necessary.
2507
2508 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2509 the convenience functions in the pcre_get.c source file.
2510
2511 11. An option change at the start of a pattern that had top-level alternatives
2512 could cause overwriting and/or a crash. This command provoked a crash in
2513 some environments:
2514
2515 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2516
2517 This potential security problem was recorded as CVE-2008-2371.
2518
2519 12. For a pattern where the match had to start at the beginning or immediately
2520 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2521 pcre_dfa_exec() could read past the end of the passed subject if there was
2522 no match. To help with detecting such bugs (e.g. with valgrind), I modified
2523 pcretest so that it places the subject at the end of its malloc-ed buffer.
2524
2525 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2526 exec() might read past the end of the data buffer in UTF-8 mode.
2527
2528 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2529 the data contained the byte 0x85 as part of a UTF-8 character within its
2530 first line. This applied both to normal and DFA matching.
2531
2532 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2533 /^[^d]*?$/8 failed to match "abc".
2534
2535 16. Added a missing copyright notice to pcrecpp_internal.h.
2536
2537 17. Make it more clear in the documentation that values returned from
2538 pcre_exec() in ovector are byte offsets, not character counts.
2539
2540 18. Tidied a few places to stop certain compilers from issuing warnings.
2541
2542 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2543 supplied by Stefan Weber. I made a further small update for 7.8 because
2544 there is a change of source arrangements: the pcre_searchfuncs.c module is
2545 replaced by pcre_ucd.c.
2546
2547
2548 Version 7.7 07-May-08
2549 ---------------------
2550
2551 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2552 a string to a long long, pretend we don't even have a long long." This is
2553 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2554
2555 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2556 pre-7.6 versions, which defined a global no_arg variable instead of putting
2557 it in the RE class. (See also #8 below.)
2558
2559 3. Remove a line of dead code, identified by coverity and reported by Nuno
2560 Lopes.
2561
2562 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2563
2564 (1) The include/exclude patterns were being applied to the whole pathnames
2565 of files, instead of just to the final components.
2566
2567 (2) If there was more than one level of directory, the subdirectories were
2568 skipped unless they satisfied the include/exclude conditions. This is
2569 inconsistent with GNU grep (and could even be seen as contrary to the
2570 pcregrep specification - which I improved to make it absolutely clear).
2571 The action now is always to scan all levels of directory, and just
2572 apply the include/exclude patterns to regular files.
2573
2574 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2575 --exclude_dir in the tests to avoid scanning .svn directories.
2576
2577 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2578 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2579 doesn't support NULs in patterns.
2580
2581 7. Added some missing "const"s to declarations of static tables in
2582 pcre_compile.c and pcre_dfa_exec.c.
2583
2584 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2585 caused by fix #2 above. (Subsequently also a second patch to fix the
2586 first patch. And a third patch - this was a messy problem.)
2587
2588 9. Applied Craig's patch to remove the use of push_back().
2589
2590 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2591 matching function regexec().
2592
2593 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2594 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2595 references. PCRE supports relative numbers with this syntax (I don't think
2596 Oniguruma does).
2597
2598 12. Previously, a group with a zero repeat such as (...){0} was completely
2599 omitted from the compiled regex. However, this means that if the group
2600 was called as a subroutine from elsewhere in the pattern, things went wrong
2601 (an internal error was given). Such groups are now left in the compiled
2602 pattern, with a new opcode that causes them to be skipped at execution
2603 time.
2604
2605 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2606 to the way PCRE behaves:
2607
2608 (a) A lone ] character is dis-allowed (Perl treats it as data).
2609
2610 (b) A back reference to an unmatched subpattern matches an empty string
2611 (Perl fails the current match path).
2612
2613 (c) A data ] in a character class must be notated as \] because if the
2614 first data character in a class is ], it defines an empty class. (In
2615 Perl it is not possible to have an empty class.) The empty class []
2616 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2617 The negative empty class [^] matches any one character, independently
2618 of the DOTALL setting.
2619
2620 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2621 non-existent subpattern following a character class starting with ']' and
2622 containing () gave an internal compiling error instead of "reference to
2623 non-existent subpattern". Fortunately, when the pattern did exist, the
2624 compiled code was correct. (When scanning forwards to check for the
2625 existence of the subpattern, it was treating the data ']' as terminating
2626 the class, so got the count wrong. When actually compiling, the reference
2627 was subsequently set up correctly.)
2628
2629 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2630 it was being rejected as not supported by pcre_dfa_exec(), even though
2631 other assertions are supported. I have made pcre_dfa_exec() support
2632 (*FAIL).
2633
2634 16. The implementation of 13c above involved the invention of a new opcode,
2635 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2636 cannot be changed at match time, I realized I could make a small
2637 improvement to matching performance by compiling OP_ALLANY instead of
2638 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2639 on the OP_ANY path.
2640
2641 17. Compiling pcretest on Windows with readline support failed without the
2642 following two fixes: (1) Make the unistd.h include conditional on
2643 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2644
2645 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2646 ncurses library to be included for pcretest when ReadLine support is
2647 requested, but also to allow for it to be overridden. This patch came from
2648 Daniel Bergström.
2649
2650 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2651 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2652 any errors with the current Unicode tables. Thanks to Peter Kankowski for
2653 spotting this.
2654
2655
2656 Version 7.6 28-Jan-08
2657 ---------------------
2658
2659 1. A character class containing a very large number of characters with
2660 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2661 overflow.
2662
2663 2. Patch to cut out the "long long" test in pcrecpp_unittest when
2664 HAVE_LONG_LONG is not defined.
2665
2666 3. Applied Christian Ehrlicher's patch to update the CMake build files to
2667 bring them up to date and include new features. This patch includes:
2668
2669 - Fixed PH's badly added libz and libbz2 support.
2670 - Fixed a problem with static linking.
2671 - Added pcredemo. [But later removed - see 7 below.]
2672 - Fixed dftables problem and added an option.
2673 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2674 HAVE_LONG_LONG.
2675 - Added readline support for pcretest.
2676 - Added an listing of the option settings after cmake has run.
2677
2678 4. A user submitted a patch to Makefile that makes it easy to create
2679 "pcre.dll" under mingw when using Configure/Make. I added stuff to
2680 Makefile.am that cause it to include this special target, without
2681 affecting anything else. Note that the same mingw target plus all
2682 the other distribution libraries and programs are now supported
2683 when configuring with CMake (see 6 below) instead of with
2684 Configure/Make.
2685
2686 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2687 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2688 exported in the Windows port". It has not yet been confirmed that the patch
2689 solves the problem, but it does no harm.
2690
2691 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2692 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2693 with CMake, and also correct the comment about stack recursion.
2694
2695 7. Remove the automatic building of pcredemo from the ./configure system and
2696 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2697 of a program that users should build themselves after PCRE is installed, so
2698 building it automatically is not really right. What is more, it gave
2699 trouble in some build environments.
2700
2701 8. Further tidies to CMakeLists.txt from Sheri and Christian.
2702
2703
2704 Version 7.5 10-Jan-08
2705 ---------------------
2706
2707 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
2708 values in parens when parsing an RE using the C++ wrapper."
2709
2710 2. Negative specials like \S did not work in character classes in UTF-8 mode.
2711 Characters greater than 255 were excluded from the class instead of being
2712 included.
2713
2714 3. The same bug as (2) above applied to negated POSIX classes such as
2715 [:^space:].
2716
2717 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2718 defined or documented. It seems to have been a typo for PCRE_STATIC, so
2719 I have changed it.
2720
2721 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
2722 first named subpattern) and a construct such as (?&a) would reference the
2723 first named subpattern whose name started with "a" (in other words, the
2724 length check was missing). Both these problems are fixed. "Subpattern name
2725 expected" is now given for (?&) (a zero-length name), and this patch also
2726 makes it give the same error for \k'' (previously it complained that that
2727 was a reference to a non-existent subpattern).
2728
2729 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
2730 this is right because (?- can be followed by option settings as well as by
2731 digits. I have, however, made the messages clearer.
2732
2733 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2734 than the number used in the conditional) now cause a compile-time error.
2735 This is actually not compatible with Perl, which accepts such patterns, but
2736 treats the conditional as always being FALSE (as PCRE used to), but it
2737 seems to me that giving a diagnostic is better.
2738
2739 8. Change "alphameric" to the more common word "alphanumeric" in comments
2740 and messages.
2741
2742 9. Fix two occurrences of "backslash" in comments that should have been
2743 "backspace".
2744
2745 10. Remove two redundant lines of code that can never be obeyed (their function
2746 was moved elsewhere).
2747
2748 11. The program that makes PCRE's Unicode character property table had a bug
2749 which caused it to generate incorrect table entries for sequences of
2750 characters that have the same character type, but are in different scripts.
2751 It amalgamated them into a single range, with the script of the first of
2752 them. In other words, some characters were in the wrong script. There were
2753 thirteen such cases, affecting characters in the following ranges:
2754
2755 U+002b0 - U+002c1
2756 U+0060c - U+0060d
2757 U+0061e - U+00612
2758 U+0064b - U+0065e
2759 U+0074d - U+0076d
2760 U+01800 - U+01805
2761 U+01d00 - U+01d77
2762 U+01d9b - U+01dbf
2763 U+0200b - U+0200f
2764 U+030fc - U+030fe
2765 U+03260 - U+0327f
2766 U+0fb46 - U+0fbb1
2767 U+10450 - U+1049d
2768
2769 12. The -o option (show only the matching part of a line) for pcregrep was not
2770 compatible with GNU grep in that, if there was more than one match in a
2771 line, it showed only the first of them. It now behaves in the same way as
2772 GNU grep.
2773
2774 13. If the -o and -v options were combined for pcregrep, it printed a blank
2775 line for every non-matching line. GNU grep prints nothing, and pcregrep now
2776 does the same. The return code can be used to tell if there were any
2777 non-matching lines.
2778
2779 14. Added --file-offsets and --line-offsets to pcregrep.
2780
2781 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2782 infinitely looping recursion. The bug was that positive lookaheads were not
2783 being skipped when checking for a possible empty match (negative lookaheads
2784 and both kinds of lookbehind were skipped).
2785
2786 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2787 inclusion of <windows.h> to before rather than after the definition of
2788 INVALID_FILE_ATTRIBUTES (patch from David Byron).
2789
2790 17. Specifying a possessive quantifier with a specific limit for a Unicode
2791 character property caused pcre_compile() to compile bad code, which led at
2792 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2793 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2794 caused the error; without that there was no problem.
2795
2796 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2797
2798 19. Added --enable-pcretest-libreadline.
2799
2800 20. In pcrecpp.cc, the variable 'count' was incremented twice in
2801 RE::GlobalReplace(). As a result, the number of replacements returned was
2802 double what it should be. I removed one of the increments, but Craig sent a
2803 later patch that removed the other one (the right fix) and added unit tests
2804 that check the return values (which was not done before).
2805
2806 21. Several CMake things:
2807
2808 (1) Arranged that, when cmake is used on Unix, the libraries end up with
2809 the names libpcre and libpcreposix, not just pcre and pcreposix.
2810
2811 (2) The above change means that pcretest and pcregrep are now correctly
2812 linked with the newly-built libraries, not previously installed ones.
2813
2814 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2815
2816 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2817 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2818 UTF-8 newline character). The key issue is that the pattern starts .*;
2819 this means that the match must be either at the beginning, or after a
2820 newline. The bug was in the code for advancing after a failed match and
2821 checking that the new position followed a newline. It was not taking
2822 account of UTF-8 characters correctly.
2823
2824 23. PCRE was behaving differently from Perl in the way it recognized POSIX
2825 character classes. PCRE was not treating the sequence [:...:] as a
2826 character class unless the ... were all letters. Perl, however, seems to
2827 allow any characters between [: and :], though of course it rejects as
2828 unknown any "names" that contain non-letters, because all the known class
2829 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2830 for example, whereas PCRE did not - it did not recognize a POSIX character
2831 class. This seemed a bit dangerous, so the code has been changed to be
2832 closer to Perl. The behaviour is not identical to Perl, because PCRE will
2833 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2834 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2835 Perl does, and where it didn't before.
2836
2837 24. Rewrite so as to remove the single use of %n from pcregrep because in some
2838 Windows environments %n is disabled by default.
2839
2840
2841 Version 7.4 21-Sep-07
2842 ---------------------
2843
2844 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
2845 means that a class such as [\s] counted as "explicit reference to CR or
2846 LF". That isn't really right - the whole point of the change was to try to
2847 help when there was an actual mention of one of the two characters. So now
2848 the change happens only if \r or \n (or a literal CR or LF) character is
2849 encountered.
2850
2851 2. The 32-bit options word was also used for 6 internal flags, but the numbers
2852 of both had grown to the point where there were only 3 bits left.
2853 Fortunately, there was spare space in the data structure, and so I have
2854 moved the internal flags into a new 16-bit field to free up more option
2855 bits.
2856
2857 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2858 but did not set the internal JCHANGED flag - either of these is enough to
2859 control the way the "get" function works - but the PCRE_INFO_JCHANGED
2860 facility is supposed to tell if (?J) was ever used, so now (?J) at the
2861 start sets both bits.
2862
2863 4. Added options (at build time, compile time, exec time) to change \R from
2864 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2865
2866 5. doc/pcresyntax.html was missing from the distribution.
2867
2868 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2869 compatibility, even though it is no longer used.
2870
2871 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2872 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2873 windows.h file is present (where different names are used). [This was
2874 reversed later after testing - see 16 below.]
2875
2876 8. Changed all #include <config.h> to #include "config.h". There were also
2877 some further <pcre.h> cases that I changed to "pcre.h".
2878
2879 9. When pcregrep was used with the --colour option, it missed the line ending
2880 sequence off the lines that it output.
2881
2882 10. It was pointed out to me that arrays of string pointers cause lots of
2883 relocations when a shared library is dynamically loaded. A technique of
2884 using a single long string with a table of offsets can drastically reduce
2885 these. I have refactored PCRE in four places to do this. The result is
2886 dramatic:
2887
2888 Originally: 290
2889 After changing UCP table: 187
2890 After changing error message table: 43
2891 After changing table of "verbs" 36
2892 After changing table of Posix names 22
2893
2894 Thanks to the folks working on Gregex for glib for this insight.
2895
2896 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2897 unicode-properties was also set.
2898
2899 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2900
2901 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2902 checked only for CRLF.
2903
2904 14. Added casts to pcretest.c to avoid compiler warnings.
2905
2906 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2907
2908 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2909 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2910 entirely. This removes changes made in 7 above.
2911
2912 17. The CMake files have been updated, and there is now more information about
2913 building with CMake in the NON-UNIX-USE document.
2914
2915
2916 Version 7.3 28-Aug-07
2917 ---------------------
2918
2919 1. In the rejigging of the build system that eventually resulted in 7.1, the
2920 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2921 brackets there is not right, since it causes compilers to look for an
2922 installed pcre.h, not the version that is in the source that is being
2923 compiled (which of course may be different). I have changed it back to:
2924
2925 #include "pcre.h"
2926
2927 I have a vague recollection that the change was concerned with compiling in
2928 different directories, but in the new build system, that is taken care of
2929 by the VPATH setting the Makefile.
2930
2931 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2932 when the subject happened to end in the byte 0x85 (e.g. if the last
2933 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2934 characters but of course it shouldn't be taken as a newline when it is part
2935 of another character. The bug was that, for an unlimited repeat of . in
2936 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2937 characters when looking for a newline.
2938
2939 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2940
2941 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2942 in debug output.
2943
2944 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2945 long printing in the pcrecpp unittest when running under MinGW.
2946
2947 6. ESC_K was left out of the EBCDIC table.
2948
2949 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2950 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2951 limit also applies to "virtual nesting" when a pattern is recursive, and in
2952 this case 1000 isn't so big. I have been able to remove this limit at the
2953 expense of backing off one optimization in certain circumstances. Normally,
2954 when pcre_exec() would call its internal match() function recursively and
2955 immediately return the result unconditionally, it uses a "tail recursion"
2956 feature to save stack. However, when a subpattern that can match an empty
2957 string has an unlimited repetition quantifier, it no longer makes this
2958 optimization. That gives it a stack frame in which to save the data for
2959 checking that an empty string has been matched. Previously this was taken
2960 from the 1000-entry workspace that had been reserved. So now there is no
2961 explicit limit, but more stack is used.
2962
2963 8. Applied Daniel's patches to solve problems with the import/export magic
2964 syntax that is required for Windows, and which was going wrong for the
2965 pcreposix and pcrecpp parts of the library. These were overlooked when this
2966 problem was solved for the main library.
2967
2968 9. There were some crude static tests to avoid integer overflow when computing
2969 the size of patterns that contain repeated groups with explicit upper
2970 limits. As the maximum quantifier is 65535, the maximum group length was
2971 set at 30,000 so that the product of these two numbers did not overflow a
2972 32-bit integer. However, it turns out that people want to use groups that
2973 are longer than 30,000 bytes (though not repeat them that many times).
2974 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
2975 made it possible to implement the integer overflow checks in a much more
2976 dynamic way, which I have now done. The artificial limitation on group
2977 length has been removed - we now have only the limit on the total length of
2978 the compiled pattern, which depends on the LINK_SIZE setting.
2979
2980 10. Fixed a bug in the documentation for get/copy named substring when
2981 duplicate names are permitted. If none of the named substrings are set, the
2982 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
2983 empty string.
2984
2985 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
2986 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
2987 because the ] is interpreted as the first data character and the
2988 terminating ] is not found. PCRE has been made compatible with Perl in this
2989 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
2990 cause memory overwriting.
2991
2992 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
2993 string has been matched (to stop an infinite loop). It was not recognizing
2994 a conditional subpattern that could match an empty string if that
2995 subpattern was within another subpattern. For example, it looped when
2996 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
2997 condition was not nested. This bug has been fixed.
2998
2999 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
3000 past the start of the subject in the presence of bytes with the top bit
3001 set, for example "\x8aBCD".
3002
3003 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
3004 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
3005
3006 14. Optimized (?!) to (*FAIL).
3007
3008 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
3009 This restricts code points to be within the range 0 to 0x10FFFF, excluding
3010 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
3011 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
3012 does: it's just the validity check that is more restrictive.
3013
3014 16. Inserted checks for integer overflows during escape sequence (backslash)
3015 processing, and also fixed erroneous offset values for syntax errors during
3016 backslash processing.
3017
3018 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
3019 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
3020
3021 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
3022 caused an overrun.
3023
3024 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
3025 something other than just ASCII characters) inside a group that had an
3026 unlimited repeat caused a loop at compile time (while checking to see
3027 whether the group could match an empty string).
3028
3029 20. Debugging a pattern containing \p or \P could cause a crash. For example,
3030 [\P{Any}] did so. (Error in the code for printing property names.)
3031
3032 21. An orphan \E inside a character class could cause a crash.
3033
3034 22. A repeated capturing bracket such as (A)? could cause a wild memory
3035 reference during compilation.
3036
3037 23. There are several functions in pcre_compile() that scan along a compiled
3038 expression for various reasons (e.g. to see if it's fixed length for look
3039 behind). There were bugs in these functions when a repeated \p or \P was
3040 present in the pattern. These operators have additional parameters compared
3041 with \d, etc, and these were not being taken into account when moving along
3042 the compiled data. Specifically:
3043
3044 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
3045 length.
3046
3047 (b) An item such as \pL+ within a repeated group could cause crashes or
3048 loops.
3049
3050 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
3051 "reference to non-existent subpattern" error.
3052
3053 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
3054
3055 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
3056 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
3057
3058 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
3059
3060 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
3061 character were causing crashes (broken optimization).
3062
3063 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
3064 \p or \P) caused a compile-time loop.
3065
3066 28. More problems have arisen in unanchored patterns when CRLF is a valid line
3067 break. For example, the unstudied pattern [\r\n]A does not match the string
3068 "\r\nA" because change 7.0/46 below moves the current point on by two
3069 characters after failing to match at the start. However, the pattern \nA
3070 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
3071 the same is true. There doesn't seem any very clean way out of this, but
3072 what I have chosen to do makes the common cases work: PCRE now takes note
3073 of whether there can be an explicit match for \r or \n anywhere in the
3074 pattern, and if so, 7.0/46 no longer applies. As part of this change,
3075 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
3076 pattern has explicit CR or LF references.
3077
3078 29. Added (*CR) etc for changing newline setting at start of pattern.
3079
3080
3081 Version 7.2 19-Jun-07
3082 ---------------------
3083
3084 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
3085 which is apparently normally available under Windows.
3086
3087 2. Re-jig the pcregrep tests with different newline settings in an attempt
3088 to make them independent of the local environment's newline setting.
3089
3090 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
3091
3092 4. Some of the "internals" tests were previously cut out when the link size
3093 was not 2, because the output contained actual offsets. The recent new
3094 "Z" feature of pcretest means that these can be cut out, making the tests
3095 usable with all link sizes.
3096
3097 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
3098 stack recursion. This gives a massive performance boost under BSD, but just
3099 a small improvement under Linux. However, it saves one field in the frame
3100 in all cases.
3101
3102 6. Added more features from the forthcoming Perl 5.10:
3103
3104 (a) (?-n) (where n is a string of digits) is a relative subroutine or
3105 recursion call. It refers to the nth most recently opened parentheses.
3106
3107 (b) (?+n) is also a relative subroutine call; it refers to the nth next
3108 to be opened parentheses.
3109
3110 (c) Conditions that refer to capturing parentheses can be specified
3111 relatively, for example, (?(-2)... or (?(+3)...
3112
3113 (d) \K resets the start of the current match so that everything before
3114 is not part of it.
3115
3116 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
3117
3118 (f) \g{name} is another synonym - part of Perl 5.10's unification of
3119 reference syntax.
3120
3121 (g) (?| introduces a group in which the numbering of parentheses in each
3122 alternative starts with the same number.
3123
3124 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
3125
3126 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
3127 PCRE_INFO_JCHANGED.
3128
3129 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
3130 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
3131 for detecting groups that can match an empty string.
3132
3133 9. A pattern with a very large number of alternatives (more than several
3134 hundred) was running out of internal workspace during the pre-compile
3135 phase, where pcre_compile() figures out how much memory will be needed. A
3136 bit of new cunning has reduced the workspace needed for groups with
3137 alternatives. The 1000-alternative test pattern now uses 12 bytes of
3138 workspace instead of running out of the 4096 that are available.
3139
3140 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
3141
3142 11. Applied patch from Google to remove an optimization that didn't quite work.
3143 The report of the bug said:
3144
3145 pcrecpp::RE("a*").FullMatch("aaa") matches, while
3146 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
3147 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
3148
3149 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
3150 it matched the wrong number of bytes.
3151
3152
3153 Version 7.1 24-Apr-07
3154 ---------------------
3155
3156 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
3157 that is more "standard", making use of automake and other Autotools. There
3158 is some re-arrangement of the files and adjustment of comments consequent
3159 on this.
3160
3161 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
3162 for recursive directory scanning broke on some systems because the files
3163 are not scanned in any specific order and on different systems the order
3164 was different. A call to "sort" has been inserted into RunGrepTest for the
3165 approprate test as a short-term fix. In the longer term there may be an
3166 alternative.
3167
3168 3. I had an email from Eric Raymond about problems translating some of PCRE's
3169 man pages to HTML (despite the fact that I distribute HTML pages, some
3170 people do their own conversions for various reasons). The problems
3171 concerned the use of low-level troff macros .br and .in. I have therefore
3172 removed all such uses from the man pages (some were redundant, some could
3173 be replaced by .nf/.fi pairs). The 132html script that I use to generate
3174 HTML has been updated to handle .nf/.fi and to complain if it encounters
3175 .br or .in.
3176
3177 4. Updated comments in configure.ac that get placed in config.h.in and also
3178 arranged for config.h to be included in the distribution, with the name
3179 config.h.generic, for the benefit of those who have to compile without
3180 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
3181
3182 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
3183 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
3184 makevp.bat for the current PCRE, using the additional files
3185 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
3186
3187 6. A Windows user reported a minor discrepancy with test 2, which turned out
3188 to be caused by a trailing space on an input line that had got lost in his
3189 copy. The trailing space was an accident, so I've just removed it.
3190
3191 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
3192 that is needed.
3193
3194 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
3195 as "const" (a) because they are and (b) because it helps the PHP
3196 maintainers who have recently made a script to detect big data structures
3197 in the php code that should be moved to the .rodata section. I remembered
3198 to update Builducptable as well, so it won't revert if ucptable.h is ever
3199 re-created.
3200
3201 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
3202 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
3203 order to be able to cut out the UTF-8 tables in the latter when UTF-8
3204 support is not required. This saves 1.5-2K of code, which is important in
3205 some applications.
3206
3207 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
3208 so as not to refer to the tables, even though these functions will never be
3209 called when UTF-8 support is disabled. Otherwise there are problems with a
3210 shared library.
3211
3212 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
3213
3214 (a) It was defining its arguments as char * instead of void *.
3215
3216 (b) It was assuming that all moves were upwards in memory; this was true
3217 a long time ago when I wrote it, but is no longer the case.
3218
3219 The emulated memove() is provided for those environments that have neither
3220 memmove() nor bcopy(). I didn't think anyone used it these days, but that
3221 is clearly not the case, as these two bugs were recently reported.
3222
3223 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
3224 and Detrail to create the HTML documentation, the .txt form of the man
3225 pages, and it removes trailing spaces from listed files. It also creates
3226 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
3227 case, it wraps all the #defines with #ifndefs. This script should be run
3228 before "make dist".
3229
3230 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
3231 with Unicode property support.
3232
3233 (a) For a maximizing quantifier, if the two different cases of the
3234 character were of different lengths in their UTF-8 codings (there are
3235 some cases like this - I found 11), and the matching function had to
3236 back up over a mixture of the two cases, it incorrectly assumed they
3237 were both the same length.
3238
3239 (b) When PCRE was configured to use the heap rather than the stack for
3240 recursion during matching, it was not correctly preserving the data for
3241 the other case of a UTF-8 character when checking ahead for a match
3242 while processing a minimizing repeat. If the check also involved
3243 matching a wide character, but failed, corruption could cause an
3244 erroneous result when trying to check for a repeat of the original
3245 character.
3246
3247 13. Some tidying changes to the testing mechanism:
3248
3249 (a) The RunTest script now detects the internal link size and whether there
3250 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
3251 values substituted by "configure". (The RunGrepTest script already did
3252 this for UTF-8.) The configure.ac script no longer substitutes the
3253 relevant variables.
3254
3255 (b) The debugging options /B and /D in pcretest show the compiled bytecode
3256 with length and offset values. This means that the output is different
3257 for different internal link sizes. Test 2 is skipped for link sizes
3258 other than 2 because of this, bypassing the problem. Unfortunately,
3259 there was also a test in test 3 (the locale tests) that used /B and
3260 failed for link sizes other than 2. Rather than cut the whole test out,
3261 I have added a new /Z option to pcretest that replaces the length and
3262 offset values with spaces. This is now used to make test 3 independent
3263 of link size. (Test 2 will be tidied up later.)
3264
3265 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
3266 segmentation fault instead of returning the appropriate error message.
3267
3268 15. In multiline mode when the newline sequence was set to "any", the pattern
3269 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
3270 This doesn't seem right; it now treats the CRLF combination as the line
3271 ending, and so does not match in that case. It's only a pattern such as ^$
3272 that would hit this one: something like ^ABC$ would have failed after \r
3273 and then tried again after \r\n.
3274
3275 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
3276 in an attempt to make files that differ only in their line terminators
3277 compare equal. This works on Linux.
3278
3279 17. Under certain error circumstances pcregrep might try to free random memory
3280 as it exited. This is now fixed, thanks to valgrind.
3281
3282 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
3283 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
3284 was because its rules for how to advance for /g after matching an empty
3285 string at the end of a line did not allow for this case. They now check for
3286 it specially.
3287
3288 20. pcretest is supposed to handle patterns and data of any length, by
3289 extending its buffers when necessary. It was getting this wrong when the
3290 buffer for a data line had to be extended.
3291
3292 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
3293 CRLF as a newline sequence.
3294
3295 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
3296 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
3297 I have nevertheless tidied it up.
3298
3299 23. Added some casts to kill warnings from HP-UX ia64 compiler.
3300
3301 24. Added a man page for pcre-config.
3302
3303
3304 Version 7.0 19-Dec-06
3305 ---------------------
3306
3307 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
3308 moving to gcc 4.1.1.
3309
3310 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
3311 sys/time.h, which is documented as needed for this function. It doesn't
3312 seem to matter on Linux, but it showed up on some releases of OS X.
3313
3314 3. It seems that there are systems where bytes whose values are greater than
3315 127 match isprint() in the "C" locale. The "C" locale should be the
3316 default when a C program starts up. In most systems, only ASCII printing
3317 characters match isprint(). This difference caused the output from pcretest
3318 to vary, making some of the tests fail. I have changed pcretest so that:
3319
3320 (a) When it is outputting text in the compiled version of a pattern, bytes
3321 other than 32-126 are always shown as hex escapes.
3322
3323 (b) When it is outputting text that is a matched part of a subject string,
3324 it does the same, unless a different locale has been set for the match
3325 (using the /L modifier). In this case, it uses isprint() to decide.
3326
3327 4. Fixed a major bug that caused incorrect computation of the amount of memory
3328 required for a compiled pattern when options that changed within the
3329 pattern affected the logic of the preliminary scan that determines the
3330 length. The relevant options are -x, and -i in UTF-8 mode. The result was
3331 that the computed length was too small. The symptoms of this bug were
3332 either the PCRE error "internal error: code overflow" from pcre_compile(),
3333 or a glibc crash with a message such as "pcretest: free(): invalid next
3334 size (fast)". Examples of patterns that provoked this bug (shown in
3335 pcretest format) are:
3336
3337 /(?-x: )/x
3338 /(?x)(?-x: \s*#\s*)/
3339 /((?i)[\x{c0}])/8
3340 /(?i:[\x{c0}])/8
3341
3342 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
3343 is now done differently.
3344
3345 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
3346 wrapper classes; (b) implement a new function in the C++ scanner that is
3347 more efficient than the old way of doing things because it avoids levels of
3348 recursion in the regex matching; (c) add a paragraph to the documentation
3349 for the FullMatch() function.
3350
3351 6. The escape sequence \n was being treated as whatever was defined as
3352 "newline". Not only was this contrary to the documentation, which states
3353 that \n is character 10 (hex 0A), but it also went horribly wrong when
3354 "newline" was defined as CRLF. This has been fixed.
3355
3356 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
3357 was being set to -1 for the "end of line" case (supposedly a value that no
3358 character can have). Though this value is never used (the check for end of
3359 line is "zero bytes in current character"), it caused compiler complaints.
3360 I've changed it to 0xffffffff.
3361
3362 8. In pcre_version.c, the version string was being built by a sequence of
3363 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
3364 string (as it is for production releases) called a macro with an empty
3365 argument. The C standard says the result of this is undefined. The gcc
3366 compiler treats it as an empty string (which was what was wanted) but it is
3367 reported that Visual C gives an error. The source has been hacked around to
3368 avoid this problem.
3369
3370 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
3371 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
3372 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
3373 of them did).
3374
3375 10. Originally, pcretest opened its input and output without "b"; then I was
3376 told that "b" was needed in some environments, so it was added for release
3377 5.0 to both the input and output. (It makes no difference on Unix-like
3378 systems.) Later I was told that it is wrong for the input on Windows. I've
3379 now abstracted the modes into two macros, to make it easier to fiddle with
3380 them, and removed "b" from the input mode under Windows.
3381
3382 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
3383
3384 12. Added -help and --help to pcretest as an official way of being reminded
3385 of the options.
3386
3387 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
3388 and pcrecpp.cc because they annoy compilers at high warning levels.
3389
3390 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
3391
3392 15. Fixed an occurrence of == in configure.ac that should have been = (shell
3393 scripts are not C programs :-) and which was not noticed because it works
3394 on Linux.
3395
3396 16. pcretest is supposed to handle any length of pattern and data line (as one
3397 line or as a continued sequence of lines) by extending its input buffer if
3398 necessary. This feature was broken for very long pattern lines, leading to
3399 a string of junk being passed to pcre_compile() if the pattern was longer
3400 than about 50K.
3401
3402 17. I have done a major re-factoring of the way pcre_compile() computes the
3403 amount of memory needed for a compiled pattern. Previously, there was code
3404 that made a preliminary scan of the pattern in order to do this. That was
3405 OK when PCRE was new, but as the facilities have expanded, it has become
3406 harder and harder to keep it in step with the real compile phase, and there
3407 have been a number of bugs (see for example, 4 above). I have now found a
3408 cunning way of running the real compile function in a "fake" mode that
3409 enables it to compute how much memory it would need, while actually only
3410 ever using a few hundred bytes of working memory and without too many
3411 tests of the mode. This should make future maintenance and development
3412 easier. A side effect of this work is that the limit of 200 on the nesting
3413 depth of parentheses has been removed (though this was never a serious
3414 limitation, I suspect). However, there is a downside: pcre_compile() now
3415 runs more slowly than before (30% or more, depending on the pattern). I
3416 hope this isn't a big issue. There is no effect on runtime performance.
3417
3418 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
3419 newline (only possible for the last line of a file) and it was a
3420 pattern that set a locale (followed by /Lsomething), pcretest crashed.
3421
3422 19. Added additional timing features to pcretest. (1) The -tm option now times
3423 matching only, not compiling. (2) Both -t and -tm can be followed, as a
3424 separate command line item, by a number that specifies the number of
3425 repeats to use when timing. The default is 50000; this gives better
3426 precision, but takes uncomfortably long for very large patterns.
3427
3428 20. Extended pcre_study() to be more clever in cases where a branch of a
3429 subpattern has no definite first character. For example, (a*|b*)[cd] would
3430 previously give no result from pcre_study(). Now it recognizes that the
3431 first character must be a, b, c, or d.
3432
3433 21. There was an incorrect error "recursive call could loop indefinitely" if
3434 a subpattern (or the entire pattern) that was being tested for matching an
3435 empty string contained only one non-empty item after a nested subpattern.
3436 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
3437 incorrectly, because the \d was being skipped in the check.
3438
3439 22. The pcretest program now has a new pattern option /B and a command line
3440 option -b, which is equivalent to adding /B to every pattern. This causes
3441 it to show the compiled bytecode, without the additional information that
3442 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
3443 is the same as /B/I).
3444
3445 23. A new optimization is now able automatically to treat some sequences such
3446 as a*b as a*+b. More specifically, if something simple (such as a character
3447 or a simple class like \d) has an unlimited quantifier, and is followed by
3448 something that cannot possibly match the quantified thing, the quantifier
3449 is automatically "possessified".
3450
3451 24. A recursive reference to a subpattern whose number was greater than 39
3452 went wrong under certain circumstances in UTF-8 mode. This bug could also
3453 have affected the operation of pcre_study().
3454
3455 25. Realized that a little bit of performance could be had by replacing
3456 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
3457
3458 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
3459
3460 27. Possessive quantifiers such as a++ were previously implemented by turning
3461 them into atomic groups such as ($>a+). Now they have their own opcodes,
3462 which improves performance. This includes the automatically created ones
3463 from 23 above.
3464
3465 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
3466 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
3467 the first matched character to be a colon. This applied both to named and
3468 numbered groups.
3469
3470 29. The ucpinternal.h header file was missing its idempotency #ifdef.
3471
3472 30. I was sent a "project" file called libpcre.a.dev which I understand makes
3473 building PCRE on Windows easier, so I have included it in the distribution.
3474
3475 31. There is now a check in pcretest against a ridiculously large number being
3476 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
3477 loop, the loop is abandoned.
3478
3479 32. Forward references to subpatterns in conditions such as (?(2)...) where
3480 subpattern 2 is defined later cause pcre_compile() to search forwards in
3481 the pattern for the relevant set of parentheses. This search went wrong
3482 when there were unescaped parentheses in a character class, parentheses
3483 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
3484
3485 33. "Subroutine" calls and backreferences were previously restricted to
3486 referencing subpatterns earlier in the regex. This restriction has now
3487 been removed.
3488
3489 34. Added a number of extra features that are going to be in Perl 5.10. On the
3490 whole, these are just syntactic alternatives for features that PCRE had
3491 previously implemented using the Python syntax or my own invention. The
3492 other formats are all retained for compatibility.
3493
3494 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
3495 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
3496 also .NET compatible.
3497
3498 (b) A recursion or subroutine call to a named group can now be defined as
3499 (?&name) as well as (?P>name).
3500
3501 (c) A backreference to a named group can now be defined as \k<name> or
3502 \k'name' as well as (?P=name). The new forms, as well as being in Perl
3503 5.10, are also .NET compatible.
3504
3505 (d) A conditional reference to a named group can now use the syntax
3506 (?(<name>) or (?('name') as well as (?(name).
3507
3508 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
3509 groups (named and numbered) that are never evaluated inline, but can be
3510 called as "subroutines" from elsewhere. In effect, the DEFINE condition
3511 is always false. There may be only one alternative in such a group.
3512
3513 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
3514 as the simple (?(R). The condition is true only if the most recent
3515 recursion is that of the given number or name. It does not search out
3516 through the entire recursion stack.
3517
3518 (g) The escape \gN or \g{N} has been added, where N is a positive or
3519 negative number, specifying an absolute or relative reference.
3520
3521 35. Tidied to get rid of some further signed/unsigned compiler warnings and
3522 some "unreachable code" warnings.
3523
3524 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
3525 things, this adds five new scripts.
3526
3527 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
3528 There were also incompatibilities regarding the handling of \Q..\E inside
3529 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3530 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3531
3532 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3533 matches an empty string, and forcibly breaks the loop. There were bugs in
3534 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3535 against aaaa the result was just "a" rather than "aaaa", for example. Two
3536 separate and independent bugs (that affected different cases) have been
3537 fixed.
3538
3539 39. Refactored the code to abolish the use of different opcodes for small
3540 capturing bracket numbers. This is a tidy that I avoided doing when I
3541 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3542 The new approach is not only tidier, it makes it possible to reduce the
3543 memory needed to fix the previous bug (38).
3544
3545 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3546 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3547 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3548 mode.
3549
3550 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3551 report.
3552
3553 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3554 copy construction and assignment in the C++ wrapper.
3555
3556 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3557 couple of bugs that could have given wrong results in the "--newline=crlf"
3558 case.
3559
3560 44. Added a number of casts and did some reorganization of signed/unsigned int
3561 variables following suggestions from Dair Grant. Also renamed the variable
3562 "this" as "item" because it is a C++ keyword.
3563
3564 45. Arranged for dftables to add
3565
3566 #include "pcre_internal.h"
3567
3568 to pcre_chartables.c because without it, gcc 4.x may remove the array
3569 definition from the final binary if PCRE is built into a static library and
3570 dead code stripping is activated.
3571
3572 46. For an unanchored pattern, if a match attempt fails at the start of a
3573 newline sequence, and the newline setting is CRLF or ANY, and the next two
3574 characters are CRLF, advance by two characters instead of one.
3575
3576
3577 Version 6.7 04-Jul-06
3578 ---------------------
3579
3580 1. In order to handle tests when input lines are enormously long, pcretest has
3581 been re-factored so that it automatically extends its buffers when
3582 necessary. The code is crude, but this _is_ just a test program. The
3583 default size has been increased from 32K to 50K.
3584
3585 2. The code in pcre_study() was using the value of the re argument before
3586 testing it for NULL. (Of course, in any sensible call of the function, it
3587 won't be NULL.)
3588
3589 3. The memmove() emulation function in pcre_internal.h, which is used on
3590 systems that lack both memmove() and bcopy() - that is, hardly ever -
3591 was missing a "static" storage class specifier.
3592
3593 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3594 containing an extended class (one that cannot be represented by a bitmap
3595 because it contains high-valued characters or Unicode property items, e.g.
3596 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3597 pattern, but PCRE should not loop if you do not (it no longer does).
3598 [Detail: two cases were found: (a) a repeated subpattern containing an
3599 extended class; (b) a recursive reference to a subpattern that followed a
3600 previous extended class. It wasn't skipping over the extended class
3601 correctly when UTF-8 mode was not set.]
3602
3603 5. A negated single-character class was not being recognized as fixed-length
3604 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3605 compile error "lookbehind assertion is not fixed length".
3606
3607 6. The RunPerlTest auxiliary script was showing an unexpected difference
3608 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3609 write a Perl script that can interpret lines of an input file either as
3610 byte characters or as UTF-8, which is what "perltest" was being required to
3611 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3612 can't do is switch easily at run time between having the "use utf8;" pragma
3613 or not. In the end, I fudged it by using the RunPerlTest script to insert
3614 "use utf8;" explicitly for the UTF-8 tests.
3615
3616 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3617 the end of the subject string, contrary to the documentation and to what
3618 Perl does. This was true of both matching functions. Now it matches only at
3619 the start of the subject and immediately after *internal* newlines.
3620
3621 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3622 a pointer to an int instead of a pointer to an unsigned long int. This
3623 caused problems on 64-bit systems.
3624
3625 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
3626 instance of the 'standard' template library not being so standard".
3627
3628 10. There was no check on the number of named subpatterns nor the maximum
3629 length of a subpattern name. The product of these values is used to compute
3630 the size of the memory block for a compiled pattern. By supplying a very
3631 long subpattern name and a large number of named subpatterns, the size
3632 computation could be caused to overflow. This is now prevented by limiting
3633 the length of names to 32 characters, and the number of named subpatterns
3634 to 10,000.
3635
3636 11. Subpatterns that are repeated with specific counts have to be replicated in
3637 the compiled pattern. The size of memory for this was computed from the
3638 length of the subpattern and the repeat count. The latter is limited to
3639 65535, but there was no limit on the former, meaning that integer overflow
3640 could in principle occur. The compiled length of a repeated subpattern is
3641 now limited to 30,000 bytes in order to prevent this.
3642
3643 12. Added the optional facility to have named substrings with the same name.
3644
3645 13. Added the ability to use a named substring as a condition, using the
3646 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
3647 are numbers (not recommended). Forward references are permitted.
3648
3649 14. Added forward references in named backreferences (if you see what I mean).
3650
3651 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
3652 pattern could run off the end of the subject. For example, the pattern
3653 "(?s)(.{1,5})"8 did this with the subject "ab".
3654
3655 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
3656 PCRE_CASELESS was set when matching characters that were quantified with ?
3657 or *.
3658
3659 17. A character class other than a single negated character that had a minimum
3660 but no maximum quantifier - for example [ab]{6,} - was not handled
3661 correctly by pce_dfa_exec(). It would match only one character.
3662
3663 18. A valid (though odd) pattern that looked like a POSIX character
3664 class but used an invalid character after [ (for example [[,abc,]]) caused
3665 pcre_compile() to give the error "Failed: internal error: code overflow" or
3666 in some cases to crash with a glibc free() error. This could even happen if
3667 the pattern terminated after [[ but there just happened to be a sequence of
3668 letters, a binary zero, and a closing ] in the memory that followed.
3669
3670 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
3671 over the years. Originally (before any Unicode support), just the bottom 8
3672 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
3673 output from "man perlunicode" includes this:
3674
3675 The regular expression compiler produces polymorphic opcodes. That
3676 is, the pattern adapts to the data and automatically switches to
3677 the Unicode character scheme when presented with Unicode data--or
3678 instead uses a traditional byte scheme when presented with byte
3679 data.
3680
3681 Sadly, a wide octal escape does not cause a switch, and in a string with
3682 no other multibyte characters, these octal escapes are treated as before.
3683 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
3684 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
3685 Unicode string.
3686
3687 I have not perpetrated such confusion in PCRE. Up till now, it took just
3688 the bottom 8 bits, as in old Perl. I have now made octal escapes with
3689 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
3690 translate to the appropriate multibyte character.
3691
3692 29. Applied some refactoring to reduce the number of warnings from Microsoft
3693 and Borland compilers. This has included removing the fudge introduced
3694 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
3695 a warning about an unused variable.
3696
3697 21. PCRE has not included VT (character 0x0b) in the set of whitespace
3698 characters since release 4.0, because Perl (from release 5.004) does not.
3699 [Or at least, is documented not to: some releases seem to be in conflict
3700 with the documentation.] However, when a pattern was studied with
3701 pcre_study() and all its branches started with \s, PCRE still included VT
3702 as a possible starting character. Of course, this did no harm; it just
3703 caused an unnecessary match attempt.
3704
3705 22. Removed a now-redundant internal flag bit that recorded the fact that case
3706 dependency changed within the pattern. This was once needed for "required
3707 byte" processing, but is no longer used. This recovers a now-scarce options
3708 bit. Also moved the least significant internal flag bit to the most-
3709 significant bit of the word, which was not previously used (hangover from
3710 the days when it was an int rather than a uint) to free up another bit for
3711 the future.
3712
3713 23. Added support for CRLF line endings as well as CR and LF. As well as the
3714 default being selectable at build time, it can now be changed at runtime
3715 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
3716 specify that it is scanning data with non-default line endings.
3717
3718 24. Changed the definition of CXXLINK to make it agree with the definition of
3719 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
3720
3721 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
3722 recursions. This makes a big different to stack usage for some patterns.
3723
3724 26. If a subpattern containing a named recursion or subroutine reference such
3725 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
3726 the space required for the compiled pattern went wrong and gave too small a
3727 value. Depending on the environment, this could lead to "Failed: internal
3728 error: code overflow at offset 49" or "glibc detected double free or
3729 corruption" errors.
3730
3731 27. Applied patches from Google (a) to support the new newline modes and (b) to
3732 advance over multibyte UTF-8 characters in GlobalReplace.
3733
3734 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
3735 difference for some implementation of PCRE in some Windows version.
3736
3737 29. Added some extra testing facilities to pcretest:
3738
3739 \q<number> in a data line sets the "match limit" value
3740 \Q<number> in a data line sets the "match recursion limt" value
3741 -S <number> sets the stack size, where <number> is in megabytes
3742
3743 The -S option isn't available for Windows.
3744
3745
3746 Version 6.6 06-Feb-06
3747 ---------------------
3748
3749 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
3750 in pcreposix.h. I have copied the definition from pcre.h.
3751
3752 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
3753 because pcre.h is no longer a built file.
3754
3755 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
3756 not normally included in the compiled code.
3757
3758
3759 Version 6.5 01-Feb-06
3760 ---------------------
3761
3762 1. When using the partial match feature with pcre_dfa_exec(), it was not
3763 anchoring the second and subsequent partial matches at the new starting
3764 point. This could lead to incorrect results. For example, with the pattern
3765 /1234/, partially matching against "123" and then "a4" gave a match.
3766
3767 2. Changes to pcregrep:
3768
3769 (a) All non-match returns from pcre_exec() were being treated as failures
3770 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
3771 error message is output. Some extra information is given for the
3772 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
3773 probably the only errors that are likely to be caused by users (by
3774 specifying a regex that has nested indefinite repeats, for instance).
3775 If there are more than 20 of these errors, pcregrep is abandoned.
3776
3777 (b) A binary zero was treated as data while matching, but terminated the
3778 output line if it was written out. This has been fixed: binary zeroes
3779 are now no different to any other data bytes.
3780
3781 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
3782 used to set a locale for matching. The --locale=xxxx long option has
3783 been added (no short equivalent) to specify a locale explicitly on the
3784 pcregrep command, overriding the environment variables.
3785
3786 (d) When -B was used with -n, some line numbers in the output were one less
3787 than they should have been.
3788
3789 (e) Added the -o (--only-matching) option.
3790
3791 (f) If -A or -C was used with -c (count only), some lines of context were
3792 accidentally printed for the final match.
3793
3794 (g) Added the -H (--with-filename) option.
3795
3796 (h) The combination of options -rh failed to suppress file names for files
3797 that were found from directory arguments.
3798
3799 (i) Added the -D (--devices) and -d (--directories) options.
3800
3801 (j) Added the -F (--fixed-strings) option.
3802
3803 (k) Allow "-" to be used as a file name for -f as well as for a data file.
3804
3805 (l) Added the --colo(u)r option.
3806
3807 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
3808 is not present by default.
3809
3810 3. A nasty bug was discovered in the handling of recursive patterns, that is,
3811 items such as (?R) or (?1), when the recursion could match a number of
3812 alternatives. If it matched one of the alternatives, but subsequently,
3813 outside the recursion, there was a failure, the code tried to back up into
3814 the recursion. However, because of the way PCRE is implemented, this is not
3815 possible, and the result was an incorrect result from the match.
3816
3817 In order to prevent this happening, the specification of recursion has
3818 been changed so that all such subpatterns are automatically treated as
3819 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
3820
3821 4. I had overlooked the fact that, in some locales, there are characters for
3822 which isalpha() is true but neither isupper() nor islower() are true. In
3823 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
3824 and ordfeminine) are like this. This affected the treatment of \w and \W
3825 when they appeared in character classes, but not when they appeared outside
3826 a character class. The bit map for "word" characters is now created
3827 separately from the results of isalnum() instead of just taking it from the
3828 upper, lower, and digit maps. (Plus the underscore character, of course.)
3829
3830 5. The above bug also affected the handling of POSIX character classes such as
3831 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
3832 permanent tables. Instead, the bit maps for such a class were previously
3833 created as the appropriate unions of the upper, lower, and digit bitmaps.
3834 Now they are created by subtraction from the [[:word:]] class, which has
3835 its own bitmap.
3836
3837 6. The [[:blank:]] character class matches horizontal, but not vertical space.
3838 It is created by subtracting the vertical space characters (\x09, \x0a,
3839 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
3840 subtraction was done in the overall bitmap for a character class, meaning
3841 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
3842 be recognized. This bug has been fixed.
3843
3844 7. Patches from the folks at Google:
3845
3846 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
3847 real life, but is still worth protecting against".
3848
3849 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
3850 regular expressions".
3851
3852 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
3853 have it.
3854
3855 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
3856 "configure" and the latter not, in order to fix a problem somebody had
3857 with compiling the Arg class on HP-UX.
3858
3859 (e) Improve the error-handling of the C++ wrapper a little bit.
3860
3861 (f) New tests for checking recursion limiting.
3862
3863 8. The pcre_memmove() function, which is used only if the environment does not
3864 have a standard memmove() function (and is therefore rarely compiled),
3865 contained two bugs: (a) use of int instead of size_t, and (b) it was not
3866 returning a result (though PCRE never actually uses the result).
3867
3868 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
3869 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
3870 returned instead of calling malloc() with an overflowing number that would
3871 most likely cause subsequent chaos.
3872
3873 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
3874
3875 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
3876 with this option is matched, the nmatch and pmatch options of regexec() are
3877 ignored.
3878
3879 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
3880 provided in case anyone wants to the the POSIX interface with UTF-8
3881 strings.
3882
3883 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
3884 C++ linking (needed for some HP-UX environments).
3885
3886 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
3887 (unused parameter) and in the pcre_printint() function (omitted "default"
3888 switch label when the default is to do nothing).
3889
3890 15. Added some code to make it possible, when PCRE is compiled as a C++
3891 library, to replace subject pointers for pcre_exec() with a smart pointer
3892 class, thus making it possible to process discontinuous strings.
3893
3894 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
3895 much the same function. They were added by different people who were trying
3896 to make PCRE easy to compile on non-Unix systems. It has been suggested
3897 that PCRE_EXPORT be abolished now that there is more automatic apparatus
3898 for compiling on Windows systems. I have therefore replaced it with
3899 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
3900 defaults to "extern" for C or "extern C" for C++, which works fine on
3901 Unix-like systems. It is now possible to override the value of PCRE_DATA_
3902 SCOPE with something explicit in config.h. In addition:
3903
3904 (a) pcreposix.h still had just "extern" instead of either of these macros;
3905 I have replaced it with PCRE_DATA_SCOPE.
3906
3907 (b) Functions such as _pcre_xclass(), which are internal to the library,
3908 but external in the C sense, all had PCRE_EXPORT in their definitions.
3909 This is apparently wrong for the Windows case, so I have removed it.
3910 (It makes no difference on Unix-like systems.)
3911
3912 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3913 of recursive calls to match(). This is different to MATCH_LIMIT because
3914 that limits the total number of calls to match(), not all of which increase
3915 the depth of recursion. Limiting the recursion depth limits the amount of
3916 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3917 when PCRE is compiled, and changed at run time. A patch from Google adds
3918 this functionality to the C++ interface.
3919
3920 18. Changes to the handling of Unicode character properties:
3921
3922 (a) Updated the table to Unicode 4.1.0.
3923
3924 (b) Recognize characters that are not in the table as "Cn" (undefined).
3925
3926 (c) I revised the way the table is implemented to a much improved format
3927 which includes recognition of ranges. It now supports the ranges that
3928 are defined in UnicodeData.txt, and it also amalgamates other
3929 characters into ranges. This has reduced the number of entries in the
3930 table from around 16,000 to around 3,000, thus reducing its size
3931 considerably. I realized I did not need to use a tree structure after
3932 all - a binary chop search is just as efficient. Having reduced the
3933 number of entries, I extended their size from 6 bytes to 8 bytes to
3934 allow for more data.
3935
3936 (d) Added support for Unicode script names via properties such as \p{Han}.
3937
3938 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3939 matching that character.
3940
3941 20. When matching a repeated Unicode property with a minimum greater than zero,
3942 (for example \pL{2,}), PCRE could look past the end of the subject if it
3943 reached it while seeking the minimum number of characters. This could
3944 happen only if some of the characters were more than one byte long, because
3945 there is a check for at least the minimum number of bytes.
3946
3947 21. Refactored the implementation of \p and \P so as to be more general, to
3948 allow for more different types of property in future. This has changed the
3949 compiled form incompatibly. Anybody with saved compiled patterns that use
3950 \p or \P will have to recompile them.
3951
3952 22. Added "Any" and "L&" to the supported property types.
3953
3954 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3955 but give a compile time error if the value is greater than 0xff.
3956
3957 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3958 accidentally not being installed or uninstalled.
3959
3960 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3961 made were to insert the current release number. This seemed silly, because
3962 it made things harder for people building PCRE on systems that don't run
3963 "configure". I have turned pcre.h into a distributed file, no longer built
3964 by "configure", with the version identification directly included. There is
3965 no longer a pcre.h.in file.
3966
3967 However, this change necessitated a change to the pcre-config script as
3968 well. It is built from pcre-config.in, and one of the substitutions was the
3969 release number. I have updated configure.ac so that ./configure now finds
3970 the release number by grepping pcre.h.
3971
3972 26. Added the ability to run the tests under valgrind.
3973
3974
3975 Version 6.4 05-Sep-05
3976 ---------------------
3977
3978 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
3979 "--" to be printed when multiple files were scanned, even when none of the
3980 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
3981 consider it to be a bug, and have restored the previous behaviour.
3982
3983 2. A couple of code tidies to get rid of compiler warnings.
3984
3985 3. The pcretest program used to cheat by referring to symbols in the library
3986 whose names begin with _pcre_. These are internal symbols that are not
3987 really supposed to be visible externally, and in some environments it is
3988 possible to suppress them. The cheating is now confined to including
3989 certain files from the library's source, which is a bit cleaner.
3990
3991 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
3992 file's purpose clearer.
3993
3994 5. Reorganized pcre_ucp_findchar().
3995
3996
3997 Version 6.3 15-Aug-05
3998 ---------------------
3999
4000 1. The file libpcre.pc.in did not have general read permission in the tarball.
4001
4002 2. There were some problems when building without C++ support:
4003
4004 (a) If C++ support was not built, "make install" and "make test" still
4005 tried to test it.
4006
4007 (b) There were problems when the value of CXX was explicitly set. Some
4008 changes have been made to try to fix these, and ...
4009
4010 (c) --disable-cpp can now be used to explicitly disable C++ support.
4011
4012 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
4013 backslash in a target when C++ was disabled. This confuses some
4014 versions of "make", apparently. Using an intermediate variable solves
4015 this. (Same for CPP_LOBJ.)
4016
4017 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
4018 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
4019 necessary on certain architectures.
4020
4021 4. Added a setting of -export-symbols-regex to the link command to remove
4022 those symbols that are exported in the C sense, but actually are local
4023 within the library, and not documented. Their names all begin with
4024 "_pcre_". This is not a perfect job, because (a) we have to except some
4025 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
4026 available (and never for static libraries). I have made a note to try to
4027 find a way round (a) in the future.
4028
4029
4030 Version 6.2 01-Aug-05
4031 ---------------------
4032
4033 1. There was no test for integer overflow of quantifier values. A construction
4034 such as {1111111111111111} would give undefined results. What is worse, if
4035 a minimum quantifier for a parenthesized subpattern overflowed and became
4036 negative, the calculation of the memory size went wrong. This could have
4037 led to memory overwriting.
4038
4039 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
4040
4041 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
4042 operating environments where this matters.
4043
4044 4. Applied Giuseppe Maxia's patch to add additional features for controlling
4045 PCRE options from within the C++ wrapper.
4046
4047 5. Named capturing subpatterns were not being correctly counted when a pattern
4048 was compiled. This caused two problems: (a) If there were more than 100
4049 such subpatterns, the calculation of the memory needed for the whole
4050 compiled pattern went wrong, leading to an overflow error. (b) Numerical
4051 back references of the form \12, where the number was greater than 9, were
4052 not recognized as back references, even though there were sufficient
4053 previous subpatterns.
4054
4055 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
4056 versions of gcc, e.g. 2.95.4.
4057
4058
4059 Version 6.1 21-Jun-05
4060 ---------------------
4061
4062 1. There was one reference to the variable "posix" in pcretest.c that was not
4063 surrounded by "#if !defined NOPOSIX".
4064
4065 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
4066 the cross-check on the old pcre_info() function, for the benefit of the
4067 cut-down version of PCRE that is currently imported into Exim.
4068
4069 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
4070 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
4071 patterns that start (?i) but I don't think that matters. The use of (?i) is
4072 just an example; this all applies to the other options as well.
4073
4074 4. Since libtool seems to echo the compile commands it is issuing, the output
4075 from "make" can be reduced a bit by putting "@" in front of each libtool
4076 compile command.
4077
4078 5. Patch from the folks at Google for configure.in to be a bit more thorough
4079 in checking for a suitable C++ installation before trying to compile the
4080 C++ stuff. This should fix a reported problem when a compiler was present,
4081 but no suitable headers.
4082
4083 6. The man pages all had just "PCRE" as their title. I have changed them to
4084 be the relevant file name. I have also arranged that these names are
4085 retained in the file doc/pcre.txt, which is a concatenation in text format
4086 of all the man pages except the little individual ones for each function.
4087
4088 7. The NON-UNIX-USE file had not been updated for the different set of source
4089 files that come with release 6. I also added a few comments about the C++
4090 wrapper.
4091
4092
4093 Version 6.0 07-Jun-05
4094 ---------------------
4095
4096 1. Some minor internal re-organization to help with my DFA experiments.
4097
4098 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
4099 didn't matter for the library itself when fully configured, but did matter
4100 when compiling without UCP support, or within Exim, where the ucp files are
4101 not imported.
4102
4103 3. Refactoring of the library code to split up the various functions into
4104 different source modules. The addition of the new DFA matching code (see
4105 below) to a single monolithic source would have made it really too
4106 unwieldy, quite apart from causing all the code to be include in a
4107 statically linked application, when only some functions are used. This is
4108 relevant even without the DFA addition now that patterns can be compiled in
4109 one application and matched in another.
4110
4111 The downside of splitting up is that there have to be some external
4112 functions and data tables that are used internally in different modules of
4113 the library but which are not part of the API. These have all had their
4114 names changed to start with "_pcre_" so that they are unlikely to clash
4115 with other external names.
4116
4117 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
4118 a different (DFA) algorithm. Although it is slower than the original
4119 function, it does have some advantages for certain types of matching
4120 problem.
4121
4122 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
4123 including restarting after a partial match.
4124
4125 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
4126 defined when compiling for Windows was sent to me. I have put it into the
4127 code, though I have no means of testing or verifying it.
4128
4129 7. Added the pcre_refcount() auxiliary function.
4130
4131 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
4132 match before or at the first newline in the subject string. In pcretest,
4133 the /f option on a pattern can be used to set this.
4134
4135 9. A repeated \w when used in UTF-8 mode with characters greater than 256
4136 would behave wrongly. This has been present in PCRE since release 4.0.
4137
4138 10. A number of changes to the pcregrep command:
4139
4140 (a) Refactored how -x works; insert ^(...)$ instead of setting
4141 PCRE_ANCHORED and checking the length, in preparation for adding
4142 something similar for -w.
4143
4144 (b) Added the -w (match as a word) option.
4145
4146 (c) Refactored the way lines are read and buffered so as to have more
4147 than one at a time available.
4148
4149 (d) Implemented a pcregrep test script.
4150
4151 (e) Added the -M (multiline match) option. This allows patterns to match
4152 over several lines of the subject. The buffering ensures that at least
4153 8K, or the rest of the document (whichever is the shorter) is available
4154 for matching (and similarly the previous 8K for lookbehind assertions).
4155
4156 (f) Changed the --help output so that it now says
4157
4158 -w, --word-regex(p)
4159
4160 instead of two lines, one with "regex" and the other with "regexp"
4161 because that confused at least one person since the short forms are the
4162 same. (This required a bit of code, as the output is generated
4163 automatically from a table. It wasn't just a text change.)
4164
4165 (g) -- can be used to terminate pcregrep options if the next thing isn't an
4166 option but starts with a hyphen. Could be a pattern or a path name
4167 starting with a hyphen, for instance.
4168
4169 (h) "-" can be given as a file name to represent stdin.
4170
4171 (i) When file names are being printed, "(standard input)" is used for
4172 the standard input, for compatibility with GNU grep. Previously
4173 "<stdin>" was used.
4174
4175 (j) The option --label=xxx can be used to supply a name to be used for
4176 stdin when file names are being printed. There is no short form.
4177
4178 (k) Re-factored the options decoding logic because we are going to add
4179 two more options that take data. Such options can now be given in four
4180 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
4181
4182 (l) Added the -A, -B, and -C options for requesting that lines of context
4183 around matches be printed.
4184
4185 (m) Added the -L option to print the names of files that do not contain
4186 any matching lines, that is, the complement of -l.
4187
4188 (n) The return code is 2 if any file cannot be opened, but pcregrep does
4189 continue to scan other files.
4190
4191 (o) The -s option was incorrectly implemented. For compatibility with other
4192 greps, it now suppresses the error message for a non-existent or non-
4193 accessible file (but not the return code). There is a new option called
4194 -q that suppresses the output of matching lines, which was what -s was
4195 previously doing.
4196
4197 (p) Added --include and --exclude options to specify files for inclusion
4198 and exclusion when recursing.
4199
4200 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
4201 Hopefully, it now does.
4202
4203 12. Missing cast in pcre_study().
4204
4205 13. Added an "uninstall" target to the makefile.
4206
4207 14. Replaced "extern" in the function prototypes in Makefile.in with
4208 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
4209 world, but is set differently for Windows.
4210
4211 15. Added a second compiling function called pcre_compile2(). The only
4212 difference is that it has an extra argument, which is a pointer to an
4213 integer error code. When there is a compile-time failure, this is set
4214 non-zero, in addition to the error test pointer being set to point to an
4215 error message. The new argument may be NULL if no error number is required
4216 (but then you may as well call pcre_compile(), which is now just a
4217 wrapper). This facility is provided because some applications need a
4218 numeric error indication, but it has also enabled me to tidy up the way
4219 compile-time errors are handled in the POSIX wrapper.
4220
4221 16. Added VPATH=.libs to the makefile; this should help when building with one
4222 prefix path and installing with another. (Or so I'm told by someone who
4223 knows more about this stuff than I do.)
4224
4225 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
4226 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
4227 match everything, including newlines. This is not POSIX-compatible, but
4228 somebody wanted the feature. From pcretest it can be activated by using
4229 both the P and the s flags.
4230
4231 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
4232
4233 19. libpcre.pc was being incorrectly installed as executable.
4234
4235 20. A couple of places in pcretest check for end-of-line by looking for '\n';
4236 it now also looks for '\r' so that it will work unmodified on Windows.
4237
4238 21. Added Google's contributed C++ wrapper to the distribution.
4239
4240 22. Added some untidy missing memory free() calls in pcretest, to keep
4241 Electric Fence happy when testing.
4242
4243
4244
4245 Version 5.0 13-Sep-04
4246 ---------------------
4247
4248 1. Internal change: literal characters are no longer packed up into items
4249 containing multiple characters in a single byte-string. Each character
4250 is now matched using a separate opcode. However, there may be more than one
4251 byte in the character in UTF-8 mode.
4252
4253 2. The pcre_callout_block structure has two new fields: pattern_position and
4254 next_item_length. These contain the offset in the pattern to the next match
4255 item, and its length, respectively.
4256
4257 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
4258 insertion of callouts before each pattern item. Added the /C option to
4259 pcretest to make use of this.
4260
4261 4. On the advice of a Windows user, the lines
4262
4263 #if defined(_WIN32) || defined(WIN32)
4264 _setmode( _fileno( stdout ), 0x8000 );
4265 #endif /* defined(_WIN32) || defined(WIN32) */
4266
4267 have been added to the source of pcretest. This apparently does useful
4268 magic in relation to line terminators.
4269
4270 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
4271 for the benefit of those environments where the "b" makes a difference.
4272
4273 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
4274 to know about it. I have put a hack into configure.in that adds in code
4275 to set GCC=yes if CC=icc. This seems to end up at a point in the
4276 generated configure script that is early enough to affect the setting of
4277 compiler options, which is what is needed, but I have no means of testing
4278 whether it really works. (The user who reported this had patched the
4279 generated configure script, which of course I cannot do.)
4280
4281 LATER: After change 22 below (new libtool files), the configure script
4282 seems to know about icc (and also ecc). Therefore, I have commented out
4283 this hack in configure.in.
4284
4285 7. Added support for pkg-config (2 patches were sent in).
4286
4287 8. Negated POSIX character classes that used a combination of internal tables
4288 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
4289 [[:^ascii]]. Typically, they would match almost any characters. The other
4290 POSIX classes were not broken in this way.
4291
4292 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
4293 to find the match, as PCRE was deluded into thinking that the match had to
4294 start at the start point or following a newline. The same bug applied to
4295 patterns with negative forward assertions or any backward assertions
4296 preceding ".*" at the start, unless the pattern required a fixed first
4297 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
4298
4299 10. In UTF-8 mode, when moving forwards in the subject after a failed match
4300 starting at the last subject character, bytes beyond the end of the subject
4301 string were read.
4302
4303 11. Renamed the variable "class" as "classbits" to make life easier for C++
4304 users. (Previously there was a macro definition, but it apparently wasn't
4305 enough.)
4306
4307 12. Added the new field "tables" to the extra data so that tables can be passed
4308 in at exec time, or the internal tables can be re-selected. This allows
4309 a compiled regex to be saved and re-used at a later time by a different
4310 program that might have everything at different addresses.
4311
4312 13. Modified the pcre-config script so that, when run on Solaris, it shows a
4313 -R library as well as a -L library.
4314
4315 14. The debugging options of pcretest (-d on the command line or D on a
4316 pattern) showed incorrect output for anything following an extended class
4317 that contained multibyte characters and which was followed by a quantifier.
4318
4319 15. Added optional support for general category Unicode character properties
4320 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
4321 support. It adds about 90K to the size of the library. The meanings of the
4322 inbuilt class escapes such as \d and \s have NOT been changed.
4323
4324 16. Updated pcredemo.c to include calls to free() to release the memory for the
4325 compiled pattern.
4326
4327 17. The generated file chartables.c was being created in the source directory
4328 instead of in the building directory. This caused the build to fail if the
4329 source directory was different from the building directory, and was
4330 read-only.
4331
4332 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
4333 file. No doubt somebody will tell me if they don't make sense... Also added
4334 Dan Mooney's comments about building on OpenVMS.
4335
4336 19. Added support for partial matching via the PCRE_PARTIAL option for
4337 pcre_exec() and the \P data escape in pcretest.
4338
4339 20. Extended pcretest with 3 new pattern features:
4340
4341 (i) A pattern option of the form ">rest-of-line" causes pcretest to
4342 write the compiled pattern to the file whose name is "rest-of-line".
4343 This is a straight binary dump of the data, with the saved pointer to
4344 the character tables forced to be NULL. The study data, if any, is
4345 written too. After writing, pcretest reads a new pattern.
4346
4347 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
4348 compiled pattern from the given file. There must not be any
4349 occurrences of "<" in the file name (pretty unlikely); if there are,
4350 pcretest will instead treat the initial "<" as a pattern delimiter.
4351 After reading in the pattern, pcretest goes on to read data lines as
4352 usual.
4353
4354 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
4355 and 16-bit fields in a compiled pattern, to simulate a pattern that
4356 was compiled on a host of opposite endianness.
4357
4358 21. The pcre-exec() function can now cope with patterns that were compiled on
4359 hosts of opposite endianness, with this restriction:
4360
4361 As for any compiled expression that is saved and used later, the tables
4362 pointer field cannot be preserved; the extra_data field in the arguments
4363 to pcre_exec() should be used to pass in a tables address if a value
4364 other than the default internal tables were used at compile time.
4365
4366 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
4367 now diagnosed as an error. Previously, most of the time, a negative number
4368 would have been treated as zero, but if in addition "ovector" was passed as
4369 NULL, a crash could occur.
4370
4371 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
4372 new versions from the libtool 1.5 distribution (the last one is a copy of
4373 a file called libtool.m4). This seems to have fixed the need to patch
4374 "configure" to support Darwin 1.3 (which I used to do). However, I still
4375 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
4376 workstation).
4377
4378 24. Changed the PCRE licence to be the more standard "BSD" licence.
4379
4380
4381 Version 4.5 01-Dec-03
4382 ---------------------
4383
4384 1. There has been some re-arrangement of the code for the match() function so
4385 that it can be compiled in a version that does not call itself recursively.
4386 Instead, it keeps those local variables that need separate instances for
4387 each "recursion" in a frame on the heap, and gets/frees frames whenever it
4388 needs to "recurse". Keeping track of where control must go is done by means
4389 of setjmp/longjmp. The whole thing is implemented by a set of macros that
4390 hide most of the details from the main code, and operates only if
4391 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
4392 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
4393 operating.
4394
4395 To make it easier for callers to provide specially tailored get/free
4396 functions for this usage, two new functions, pcre_stack_malloc, and
4397 pcre_stack_free, are used. They are always called in strict stacking order,
4398 and the size of block requested is always the same.
4399
4400 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
4401 PCRE has been compiled to use the stack or the heap for recursion. The
4402 -C option of pcretest uses this to show which version is compiled.
4403
4404 A new data escape \S, is added to pcretest; it causes the amounts of store
4405 obtained and freed by both kinds of malloc/free at match time to be added
4406 to the output.
4407
4408 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
4409 what's available on my current Linux desktop machine.
4410
4411 3. When matching a UTF-8 string, the test for a valid string at the start has
4412 been extended. If start_offset is not zero, PCRE now checks that it points
4413 to a byte that is the start of a UTF-8 character. If not, it returns
4414 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
4415 this is necessary because there may be backward assertions in the pattern.
4416 When matching the same subject several times, it may save resources to use
4417 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4418
4419 4. The code for checking the validity of UTF-8 strings has been tightened so
4420 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
4421 containing "overlong sequences".
4422
4423 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
4424 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
4425 should have been "&", but it just so happened that all the cases this let
4426 through by mistake were picked up later in the function.
4427
4428 6. I had used a variable called "isblank" - this is a C99 function, causing
4429 some compilers to warn. To avoid this, I renamed it (as "blankclass").
4430
4431 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
4432 prompting; (b) run "./pcretest /dev/null" at the start of the test script
4433 so the version is shown; (c) stop "make test" echoing "./RunTest".
4434
4435 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
4436
4437 9. The prototype for memmove() for systems that don't have it was using
4438 size_t, but the inclusion of the header that defines size_t was later. I've
4439 moved the #includes for the C headers earlier to avoid this.
4440
4441 10. Added some adjustments to the code to make it easier to compiler on certain
4442 special systems:
4443
4444 (a) Some "const" qualifiers were missing.
4445 (b) Added the macro EXPORT before all exported functions; by default this
4446 is defined to be empty.
4447 (c) Changed the dftables auxiliary program (that builds chartables.c) so
4448 that it reads its output file name as an argument instead of writing
4449 to the standard output and assuming this can be redirected.
4450
4451 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
4452 class containing characters with values greater than 255, PCRE compilation
4453 went into a loop.
4454
4455 12. A recursive reference to a subpattern that was within another subpattern
4456 that had a minimum quantifier of zero caused PCRE to crash. For example,
4457 (x(y(?2))z)? provoked this bug with a subject that got as far as the
4458 recursion. If the recursively-called subpattern itself had a zero repeat,
4459 that was OK.
4460
4461 13. In pcretest, the buffer for reading a data line was set at 30K, but the
4462 buffer into which it was copied (for escape processing) was still set at
4463 1024, so long lines caused crashes.
4464
4465 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
4466 "internal error: code overflow...". This applied to any character class
4467 that was followed by a possessive quantifier.
4468
4469 15. Modified the Makefile to add libpcre.la as a prerequisite for
4470 libpcreposix.la because I was told this is needed for a parallel build to
4471 work.
4472
4473 16. If a pattern that contained .* following optional items at the start was
4474 studied, the wrong optimizing data was generated, leading to matching
4475 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
4476 matching string must start with a or b or c. The correct conclusion for
4477 this pattern is that a match can start with any character.
4478
4479
4480 Version 4.4 13-Aug-03
4481 ---------------------
4482
4483 1. In UTF-8 mode, a character class containing characters with values between
4484 127 and 255 was not handled correctly if the compiled pattern was studied.
4485 In fixing this, I have also improved the studying algorithm for such
4486 classes (slightly).
4487
4488 2. Three internal functions had redundant arguments passed to them. Removal
4489 might give a very teeny performance improvement.
4490
4491 3. Documentation bug: the value of the capture_top field in a callout is *one
4492 more than* the number of the hightest numbered captured substring.
4493
4494 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
4495 in incorrectly linking with a previously installed version. They now link
4496 explicitly with libpcre.la.
4497
4498 5. configure.in no longer needs to recognize Cygwin specially.
4499
4500 6. A problem in pcre.in for Windows platforms is fixed.
4501
4502 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
4503 pcretest, it used to include the size of the study block as part of its
4504 output. Unfortunately, the structure contains a field that has a different
4505 size on different hardware architectures. This meant that the tests that
4506 showed this size failed. As the block is currently always of a fixed size,
4507 this information isn't actually particularly useful in pcretest output, so
4508 I have just removed it.
4509
4510 8. Three pre-processor statements accidentally did not start in column 1.
4511 Sadly, there are *still* compilers around that complain, even though
4512 standard C has not required this for well over a decade. Sigh.
4513
4514 9. In pcretest, the code for checking callouts passed small integers in the
4515 callout_data field, which is a void * field. However, some picky compilers
4516 complained about the casts involved for this on 64-bit systems. Now
4517 pcretest passes the address of the small integer instead, which should get
4518 rid of the warnings.
4519
4520 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
4521 both compile and run time, and gives an error if an invalid UTF-8 sequence
4522 is found. There is a option for disabling this check in cases where the
4523 string is known to be correct and/or the maximum performance is wanted.
4524
4525 11. In response to a bug report, I changed one line in Makefile.in from
4526
4527 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
4528 to
4529 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4530
4531 to look similar to other lines, but I have no way of telling whether this
4532 is the right thing to do, as I do not use Windows. No doubt I'll get told
4533 if it's wrong...
4534
4535
4536 Version 4.3 21-May-03
4537 ---------------------
4538
4539 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4540 Makefile.
4541
4542 2. Some refactoring to improve the quality of the code:
4543
4544 (i) The utf8_table... variables are now declared "const".
4545
4546 (ii) The code for \cx, which used the "case flipping" table to upper case
4547 lower case letters, now just substracts 32. This is ASCII-specific,
4548 but the whole concept of \cx is ASCII-specific, so it seems
4549 reasonable.
4550
4551 (iii) PCRE was using its character types table to recognize decimal and
4552 hexadecimal digits in the pattern. This is silly, because it handles
4553 only 0-9, a-f, and A-F, but the character types table is locale-
4554 specific, which means strange things might happen. A private
4555 table is now used for this - though it costs 256 bytes, a table is
4556 much faster than multiple explicit tests. Of course, the standard
4557 character types table is still used for matching digits in subject
4558 strings against \d.
4559
4560 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4561 ending in _t are). So I've renamed it as ESC_tee.
4562
4563 3. The first argument for regexec() in the POSIX wrapper should have been
4564 defined as "const".
4565
4566 4. Changed pcretest to use malloc() for its buffers so that they can be
4567 Electric Fenced for debugging.
4568
4569 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4570 to read one or more bytes before the start of the subject string. Often this
4571 had no effect on PCRE's behaviour, but in some circumstances it could
4572 provoke a segmentation fault.
4573
4574 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4575 to try to read one or more bytes before the start of the subject string.
4576
4577 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4578 UTF-8 support could misbehave in various ways if the subject string
4579 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4580 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4581 back over UTF-8 characters.)
4582
4583
4584 Version 4.2 14-Apr-03
4585 ---------------------
4586
4587 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4588
4589 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4590 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4591 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4592 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4593 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4594 and BUILD_EXEEXT
4595 Note: automatic setting of the BUILD variables is not yet working
4596 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4597 compile-time but not at link-time
4598 [LINK]: use for linking executables only
4599 make different versions for Windows and non-Windows
4600 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4601 libraries
4602 [LINK_FOR_BUILD]: new variable
4603 [OBJEXT]: use throughout
4604 [EXEEXT]: use throughout
4605 <winshared>: new target
4606 <wininstall>: new target
4607 <dftables.o>: use native compiler
4608 <dftables>: use native linker
4609 <install>: handle Windows platform correctly
4610 <clean>: ditto
4611 <check>: ditto
4612 copy DLL to top builddir before testing
4613
4614 As part of these changes, -no-undefined was removed again. This was reported
4615 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4616 in any case.
4617
4618 3. Some tidies to get rid of compiler warnings:
4619
4620 . In the match_data structure, match_limit was an unsigned long int, whereas
4621 match_call_count was an int. I've made them both unsigned long ints.
4622
4623 . In pcretest the fact that a const uschar * doesn't automatically cast to
4624 a void * provoked a warning.
4625
4626 . Turning on some more compiler warnings threw up some "shadow" variables
4627 and a few more missing casts.
4628
4629 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
4630 option, a class that contained a single character with a value between 128
4631 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
4632
4633 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
4634 option, a class that contained several characters, but with at least one
4635 whose value was between 128 and 255 caused PCRE to crash.
4636
4637
4638 Version 4.1 12-Mar-03
4639 ---------------------
4640
4641 1. Compiling with gcc -pedantic found a couple of places where casts were
4642 needed, and a string in dftables.c that was longer than standard compilers are
4643 required to support.
4644
4645 2. Compiling with Sun's compiler found a few more places where the code could
4646 be tidied up in order to avoid warnings.
4647
4648 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
4649 first of these names is deprecated in the latest Autoconf in favour of the name
4650 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
4651 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
4652 analogy I have changed it to CFLAGS_FOR_BUILD.
4653
4654 4. Added -no-undefined to the linking command in the Makefile, because this is
4655 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
4656 linking step for the pcreposix library.
4657
4658 5. PCRE was failing to diagnose the case of two named groups with the same
4659 name.
4660
4661 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
4662 literal character that is needed in the subject for a match, and scans along to
4663 ensure that it is present before embarking on the full matching process. This
4664 saves time in cases of nested unlimited repeats that are never going to match.
4665 Problem: the scan can take a lot of time if the subject is very long (e.g.
4666 megabytes), thus penalizing straightforward matches. It is now done only if the
4667 amount of subject to be scanned is less than 1000 bytes.
4668
4669 7. A lesser problem with the same optimization is that it was recording the
4670 first character of an anchored pattern as "needed", thus provoking a search
4671 right along the subject, even when the first match of the pattern was going to
4672 fail. The "needed" character is now not set for anchored patterns, unless it
4673 follows something in the pattern that is of non-fixed length. Thus, it still
4674 fulfils its original purpose of finding quick non-matches in cases of nested
4675 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
4676
4677
4678 Version 4.0 17-Feb-03
4679 ---------------------
4680
4681 1. If a comment in an extended regex that started immediately after a meta-item
4682 extended to the end of string, PCRE compiled incorrect data. This could lead to
4683 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
4684
4685 2. Moved to autoconf 2.53 and libtool 1.4.2.
4686
4687 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
4688 the special perltest8 script is no longer needed - all the tests can be run
4689 from a single perltest script.
4690
4691 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
4692 by \s. It has now been removed in PCRE. This means it isn't recognized as
4693 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
4694 class [:space:] *does* include VT, thereby creating a mess.
4695
4696 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
4697 space and tab.
4698
4699 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
4700 its new features into the main test script, reducing the number of scripts.
4701
4702 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
4703 were backward compatible, and made the (?i) apply to the whole pattern, as if
4704 /i were given. Now it behaves more logically, and applies the option setting
4705 only to what follows. PCRE has been changed to follow suit. However, if it
4706 finds options settings right at the start of the pattern, it extracts them into
4707 the global options, as before. Thus, they show up in the info data.
4708
4709 8. Added support for the \Q...\E escape sequence. Characters in between are
4710 treated as literals. This is slightly different from Perl in that $ and @ are
4711 also handled as literals inside the quotes. In Perl, they will cause variable
4712 interpolation. Note the following examples:
4713
4714 Pattern PCRE matches Perl matches
4715
4716 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
4717 \Qabc\$xyz\E abc\$xyz abc\$xyz
4718 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
4719
4720 For compatibility with Perl, \Q...\E sequences are recognized inside character
4721 classes as well as outside them.
4722
4723 9. Re-organized 3 code statements in pcretest to avoid "overflow in
4724 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
4725 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
4726 signed/unsigned warnings.
4727
4728 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
4729 option for pcretest, so I've replaced it by a simple function that does just
4730 that job.
4731
4732 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
4733 "pcregrep -".
4734
4735 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
4736 Java package. This provides some syntactic sugar for simple cases of what my
4737 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
4738 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
4739 item, you can use this simplified notation. Note that only makes sense with
4740 greedy quantifiers. Consequently, the use of the possessive quantifier forces
4741 greediness, whatever the setting of the PCRE_UNGREEDY option.
4742
4743 13. A change of greediness default within a pattern was not taking effect at
4744 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
4745 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
4746 was abstracted outside.
4747
4748 14. PCRE now supports the \G assertion. It is true when the current matching
4749 position is at the start point of the match. This differs from \A when the
4750 starting offset is non-zero. Used with the /g option of pcretest (or similar
4751 code), it works in the same way as it does for Perl's /g option. If all
4752 alternatives of a regex begin with \G, the expression is anchored to the start
4753 match position, and the "anchored" flag is set in the compiled expression.
4754
4755 15. Some bugs concerning the handling of certain option changes within patterns
4756 have been fixed. These applied to options other than (?ims). For example,
4757 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
4758 been the other way round. Some of this was related to change 7 above.
4759
4760 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
4761 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
4762 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
4763 POSIX classes only within a class (e.g. /[[:alpha:]]/).
4764
4765 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
4766 mode. Unlike ".", it always matches newline, whatever the setting of
4767 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
4768 assertions. Perl allows it, but it doesn't (in general) work because it can't
4769 calculate the length of the lookbehind. At least, that's the case for Perl
4770 5.8.0 - I've been told they are going to document that it doesn't work in
4771 future.
4772
4773 18. Added an error diagnosis for escapes that PCRE does not support: these are
4774 \L, \l, \N, \P, \p, \U, \u, and \X.
4775
4776 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
4777 reading past the end of the pattern in cases such as /[abcd/.
4778
4779 20. PCRE was getting more memory than necessary for patterns with classes that
4780 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
4781
4782 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
4783 compiling PCRE for use with Virtual Pascal.
4784
4785 22. Small fix to the Makefile to make it work properly if the build is done
4786 outside the source tree.
4787
4788 23. Added a new extension: a condition to go with recursion. If a conditional
4789 subpattern starts with (?(R) the "true" branch is used if recursion has
4790 happened, whereas the "false" branch is used only at the top level.
4791
4792 24. When there was a very long string of literal characters (over 255 bytes
4793 without UTF support, over 250 bytes with UTF support), the computation of how
4794 much memory was required could be incorrect, leading to segfaults or other
4795 strange effects.
4796
4797 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
4798 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
4799 there was a subsequent back reference to those brackets. This meant that, for
4800 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
4801 possible to check for precisely this case. All we can do is abandon the
4802 optimization if .* occurs inside capturing brackets when there are any back
4803 references whatsoever. (See below for a better fix that came later.)
4804
4805 26. The handling of the optimization for finding the first character of a
4806 non-anchored pattern, and for finding a character that is required later in the
4807 match were failing in some cases. This didn't break the matching; it just
4808 failed to optimize when it could. The way this is done has been re-implemented.
4809
4810 27. Fixed typo in error message for invalid (?R item (it said "(?p").
4811
4812 28. Added a new feature that provides some of the functionality that Perl
4813 provides with (?{...}). The facility is termed a "callout". The way it is done
4814 in PCRE is for the caller to provide an optional function, by setting
4815 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
4816 global variable. By default it is unset, which disables all calling out. To get
4817 the function called, the regex must include (?C) at appropriate points. This
4818 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
4819 This provides a means of identifying different callout points. When PCRE
4820 reaches such a point in the regex, if pcre_callout has been set, the external
4821 function is called. It is provided with data in a structure called
4822 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
4823 matching continues; if it returns a non-zero value, the match at the current
4824 point fails. However, backtracking will occur if possible. [This was changed
4825 later and other features added - see item 49 below.]
4826
4827 29. pcretest is upgraded to test the callout functionality. It provides a
4828 callout function that displays information. By default, it shows the start of
4829 the match and the current position in the text. There are some new data escapes
4830 to vary what happens:
4831
4832 \C+ in addition, show current contents of captured substrings
4833 \C- do not supply a callout function
4834 \C!n return 1 when callout number n is reached
4835 \C!n!m return 1 when callout number n is reached for the mth time
4836
4837 30. If pcregrep was called with the -l option and just a single file name, it
4838 output "<stdin>" if a match was found, instead of the file name.
4839
4840 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
4841 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
4842 pcre_exec(). This saves a malloc/free per call. The default value of
4843 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
4844 when configuring.
4845
4846 32. The default maximum size of a compiled pattern is 64K. There have been a
4847 few cases of people hitting this limit. The code now uses macros to handle the
4848 storing of links as offsets within the compiled pattern. It defaults to 2-byte
4849 links, but this can be changed to 3 or 4 bytes by --with-link-size when
4850 configuring. Tests 2 and 5 work only with 2-byte links because they output
4851 debugging information about compiled patterns.
4852
4853 33. Internal code re-arrangements:
4854
4855 (a) Moved the debugging function for printing out a compiled regex into
4856 its own source file (printint.c) and used #include to pull it into
4857 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
4858 separate copies.
4859
4860 (b) Defined the list of op-code names for debugging as a macro in
4861 internal.h so that it is next to the definition of the opcodes.
4862
4863 (c) Defined a table of op-code lengths for simpler skipping along compiled
4864 code. This is again a macro in internal.h so that it is next to the
4865 definition of the opcodes.
4866
4867 34. Added support for recursive calls to individual subpatterns, along the
4868 lines of Robin Houston's patch (but implemented somewhat differently).
4869
4870 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
4871 allow it to read and process whole directories in Win32. This code was
4872 contributed by Lionel Fourquaux; it has not been tested by me.
4873
4874 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
4875 used to name a group. Names consist of alphanumerics and underscores, and must
4876 be unique. Back references use the syntax (?P=name) and recursive calls use
4877 (?P>name) which is a PCRE extension to the Python extension. Groups still have
4878 numbers. The function pcre_fullinfo() can be used after compilation to extract
4879 a name/number map. There are three relevant calls:
4880
4881 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
4882 PCRE_INFO_NAMECOUNT yields the number of entries
4883 PCRE_INFO_NAMETABLE yields a pointer to the map.
4884
4885 The map is a vector of fixed-size entries. The size of each entry depends on
4886 the length of the longest name used. The first two bytes of each entry are the
4887 group number, most significant byte first. There follows the corresponding
4888 name, zero terminated. The names are in alphabetical order.
4889
4890 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
4891 case instead of 255. Making it the same both with and without UTF-8 support
4892 means that the same test output works with both.
4893
4894 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
4895 calling malloc() with a zero argument.
4896
4897 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
4898 optimization. I've improved things by keeping a bitmap of backreferences with
4899 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
4900 fact referenced, the optimization can be applied. It is unlikely that a
4901 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
4902 the match to follow \n) will appear inside brackets with a number greater than
4903 31, but if it does, any back reference > 31 suppresses the optimization.
4904
4905 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
4906 of disabling numbered capturing parentheses. Any opening parenthesis that is
4907 not followed by ? behaves as if it were followed by ?: but named parentheses
4908 can still be used for capturing (and they will acquire numbers in the usual
4909 way).
4910
4911 41. Redesigned the return codes from the match() function into yes/no/error so
4912 that errors can be passed back from deep inside the nested calls. A malloc
4913 failure while inside a recursive subpattern call now causes the
4914 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4915
4916 42. It is now possible to set a limit on the number of times the match()
4917 function is called in a call to pcre_exec(). This facility makes it possible to
4918 limit the amount of recursion and backtracking, though not in a directly
4919 obvious way, because the match() function is used in a number of different
4920 circumstances. The count starts from zero for each position in the subject
4921 string (for non-anchored patterns). The default limit is, for compatibility, a
4922 large number, namely 10 000 000. You can change this in two ways:
4923
4924 (a) When configuring PCRE before making, you can use --with-match-limit=n
4925 to set a default value for the compiled library.
4926
4927 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4928 a different value is set. See 45 below.
4929
4930 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4931
4932 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4933 of things that can be changed at compile time. The first argument specifies
4934 what is wanted and the second points to where the information is to be placed.
4935 The current list of available information is:
4936
4937 PCRE_CONFIG_UTF8
4938
4939 The output is an integer that is set to one if UTF-8 support is available;
4940 otherwise it is set to zero.
4941
4942 PCRE_CONFIG_NEWLINE
4943
4944 The output is an integer that it set to the value of the code that is used for
4945 newline. It is either LF (10) or CR (13).
4946
4947 PCRE_CONFIG_LINK_SIZE
4948
4949 The output is an integer that contains the number of bytes used for internal
4950 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4951
4952 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4953
4954 The output is an integer that contains the threshold above which the POSIX
4955 interface uses malloc() for output vectors. See item 31 above.
4956
4957 PCRE_CONFIG_MATCH_LIMIT
4958
4959 The output is an unsigned integer that contains the default limit of the number
4960 of match() calls in a pcre_exec() execution. See 42 above.
4961
4962 44. pcretest has been upgraded by the addition of the -C option. This causes it
4963 to extract all the available output from the new pcre_config() function, and to
4964 output it. The program then exits immediately.
4965
4966 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4967 order to support additional features. One way would have been to define
4968 pcre_exec2() (for example) with extra arguments, but this would not have been
4969 extensible, and would also have required all calls to the original function to
4970 be mapped to the new one. Instead, I have chosen to extend the mechanism that
4971 is used for passing in "extra" data from pcre_study().
4972
4973 The pcre_extra structure is now exposed and defined in pcre.h. It currently
4974 contains the following fields:
4975
4976 flags a bitmap indicating which of the following fields are set
4977 study_data opaque data from pcre_study()
4978 match_limit a way of specifying a limit on match() calls for a specific
4979 call to pcre_exec()
4980 callout_data data for callouts (see 49 below)
4981
4982 The flag bits are also defined in pcre.h, and are
4983
4984 PCRE_EXTRA_STUDY_DATA
4985 PCRE_EXTRA_MATCH_LIMIT
4986 PCRE_EXTRA_CALLOUT_DATA
4987
4988 The pcre_study() function now returns one of these new pcre_extra blocks, with
4989 the actual study data pointed to by the study_data field, and the
4990 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
4991 before. That is, this change is entirely upwards-compatible and requires no
4992 change to existing code.
4993
4994 If you want to pass in additional data to pcre_exec(), you can either place it
4995 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
4996 block.
4997
4998 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
4999 data string contains the escape sequence \M, pcretest calls pcre_exec() several
5000 times with different match limits, until it finds the minimum value needed for
5001 pcre_exec() to complete. The value is then output. This can be instructive; for
5002 most simple matches the number is quite small, but for pathological cases it
5003 gets very large very quickly.
5004
5005 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
5006 returns the size of the data block pointed to by the study_data field in a
5007 pcre_extra block, that is, the value that was passed as the argument to
5008 pcre_malloc() when PCRE was getting memory in which to place the information
5009 created by pcre_study(). The fourth argument should point to a size_t variable.
5010 pcretest has been extended so that this information is shown after a successful
5011 pcre_study() call when information about the compiled regex is being displayed.
5012
5013 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
5014 because what follows is always an absolute path. (Later: it turns out that this
5015 is more than cosmetic for MinGW, because it doesn't like empty path
5016 components.)
5017
5018 49. Some changes have been made to the callout feature (see 28 above):
5019
5020 (i) A callout function now has three choices for what it returns:
5021
5022 0 => success, carry on matching
5023 > 0 => failure at this point, but backtrack if possible
5024 < 0 => serious error, return this value from pcre_exec()
5025
5026 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
5027 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
5028 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
5029 use by callout functions. It will never be used by PCRE itself.
5030
5031 (ii) The pcre_extra structure (see 45 above) has a void * field called
5032 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
5033 pcre_callout_block structure has a field of the same name. The contents of
5034 the field passed in the pcre_extra structure are passed to the callout
5035 function in the corresponding field in the callout block. This makes it
5036 easier to use the same callout-containing regex from multiple threads. For
5037 testing, the pcretest program has a new data escape
5038
5039 \C*n pass the number n (may be negative) as callout_data
5040
5041 If the callout function in pcretest receives a non-zero value as
5042 callout_data, it returns that value.
5043
5044 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
5045 there were some redundant $(CFLAGS) in commands that are now specified as
5046 $(LINK), which already includes $(CFLAGS).
5047
5048 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
5049 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
5050 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
5051 one-byte characters throughout. Note that case-insensitive matching applies
5052 only to characters whose values are less than 256. PCRE doesn't support the
5053 notion of cases for higher-valued characters.
5054
5055 (i) A character class whose characters are all within 0-255 is handled as
5056 a bit map, and the map is inverted for negative classes. Previously, a
5057 character > 255 always failed to match such a class; however it should
5058 match if the class was a negative one (e.g. [^ab]). This has been fixed.
5059
5060 (ii) A negated character class with a single character < 255 is coded as
5061 "not this character" (OP_NOT). This wasn't working properly when the test
5062 character was multibyte, either singly or repeated.
5063
5064 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
5065 mode, for example: \x{100}{2,3}.
5066
5067 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
5068 singly or repeated) now correctly test multibyte characters. However,
5069 PCRE doesn't recognize any characters with values greater than 255 as
5070 digits, spaces, or word characters. Such characters always match \D, \S,
5071 and \W, and never match \d, \s, or \w.
5072
5073 (v) Classes may now contain characters and character ranges with values
5074 greater than 255. For example: [ab\x{100}-\x{400}].
5075
5076 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
5077 PCRE in UTF-8 mode.
5078
5079 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
5080 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
5081 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
5082 value.)
5083
5084 53. The single man page has become too large. I have therefore split it up into
5085 a number of separate man pages. These also give rise to individual HTML pages;
5086 these are now put in a separate directory, and there is an index.html page that
5087 lists them all. Some hyperlinking between the pages has been installed.
5088
5089 54. Added convenience functions for handling named capturing parentheses.
5090
5091 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
5092 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
5093 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
5094 are faulted.
5095
5096 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
5097 calling configure. These values are used when compiling the dftables.c program
5098 which is run to generate the source of the default character tables. They
5099 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
5100 you will need to set these values.
5101
5102 57. Updated the building process for Windows DLL, as provided by Fred Cox.
5103
5104
5105 Version 3.9 02-Jan-02
5106 ---------------------
5107
5108 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
5109
5110 2. If --disable-static was given, the building process failed when trying to
5111 build pcretest and pcregrep. (For some reason it was using libtool to compile
5112 them, which is not right, as they aren't part of the library.)
5113
5114
5115 Version 3.8 18-Dec-01
5116 ---------------------
5117
5118 1. The experimental UTF-8 code was completely screwed up. It was packing the
5119 bytes in the wrong order. How dumb can you get?
5120
5121
5122 Version 3.7 29-Oct-01
5123 ---------------------
5124
5125 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
5126 This caused pcretest, when used on the test data, to segfault. Unfortunately,
5127 this didn't happen under Solaris 8, where I normally test things.
5128
5129 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
5130 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
5131 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
5132 this fix an hour or so after the initial 3.7 release.)
5133
5134
5135 Version 3.6 23-Oct-01
5136 ---------------------
5137
5138 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
5139 offsets passed as NULL with zero offset count.
5140
5141 2. The config.guess and config.sub files had not been updated when I moved to
5142 the latest autoconf.
5143
5144
5145 Version 3.5 15-Aug-01
5146 ---------------------
5147
5148 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
5149 had been forgotten.
5150
5151 2. By using declared but undefined structures, we can avoid using "void"
5152 definitions in pcre.h while keeping the internal definitions of the structures
5153 private.
5154
5155 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
5156 user point of view, this means that both static and shared libraries are built
5157 by default, but this can be individually controlled. More of the work of
5158 handling this static/shared cases is now inside libtool instead of PCRE's make
5159 file.
5160
5161 4. The pcretest utility is now installed along with pcregrep because it is
5162 useful for users (to test regexs) and by doing this, it automatically gets
5163 relinked by libtool. The documentation has been turned into a man page, so
5164 there are now .1, .txt, and .html versions in /doc.
5165
5166 5. Upgrades to pcregrep:
5167 (i) Added long-form option names like gnu grep.
5168 (ii) Added --help to list all options with an explanatory phrase.
5169 (iii) Added -r, --recursive to recurse into sub-directories.
5170 (iv) Added -f, --file to read patterns from a file.
5171
5172 6. pcre_exec() was referring to its "code" argument before testing that
5173 argument for NULL (and giving an error if it was NULL).
5174
5175 7. Upgraded Makefile.in to allow for compiling in a different directory from
5176 the source directory.
5177
5178 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
5179 options bits, the pointer it was passed was to an int instead of to an unsigned
5180 long int. This mattered only on 64-bit systems.
5181
5182 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
5183 generated) instead of pcre.in, which it its source. Also made the same change
5184 in several of the .c files.
5185
5186 10. A new release of gcc defines printf() as a macro, which broke pcretest
5187 because it had an ifdef in the middle of a string argument for printf(). Fixed
5188 by using separate calls to printf().
5189
5190 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
5191 script, to force use of CR or LF instead of \n in the source. On non-Unix
5192 systems, the value can be set in config.h.
5193
5194 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
5195 absolute limit. Changed the text of the error message to make this clear, and
5196 likewise updated the man page.
5197
5198 13. The limit of 99 on the number of capturing subpatterns has been removed.
5199 The new limit is 65535, which I hope will not be a "real" limit.
5200
5201
5202 Version 3.4 22-Aug-00
5203 ---------------------
5204
5205 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
5206
5207 2. Diagnose condition (?(0) as an error instead of crashing on matching.
5208
5209
5210 Version 3.3 01-Aug-00
5211 ---------------------
5212
5213 1. If an octal character was given, but the value was greater than \377, it
5214 was not getting masked to the least significant bits, as documented. This could
5215 lead to crashes in some systems.
5216
5217 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
5218 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
5219
5220 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
5221 These just pass their arguments on to (pcre_free)(), but they are provided
5222 because some uses of PCRE bind it to non-C systems that can call its functions,
5223 but cannot call free() or pcre_free() directly.
5224
5225 4. Add "make test" as a synonym for "make check". Corrected some comments in
5226 the Makefile.
5227
5228 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
5229 Makefile.
5230
5231 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
5232 command called pgrep for grepping around the active processes.
5233
5234 7. Added the beginnings of support for UTF-8 character strings.
5235
5236 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
5237 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
5238 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
5239 out for the ar command.)
5240
5241
5242 Version 3.2 12-May-00
5243 ---------------------
5244
5245 This is purely a bug fixing release.
5246
5247 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
5248 of ZA. This was just one example of several cases that could provoke this bug,
5249 which was introduced by change 9 of version 2.00. The code for breaking
5250 infinite loops after an iteration that matches an empty string was't working
5251 correctly.
5252
5253 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
5254 when matched against abbab (for example). After matching an empty string, it
5255 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
5256 caused it to match further down the string than it should.
5257
5258 3. The code contained an inclusion of sys/types.h. It isn't clear why this
5259 was there because it doesn't seem to be needed, and it causes trouble on some
5260 systems, as it is not a Standard C header. It has been removed.
5261
5262 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
5263 were reported on the Macintosh. The changes were from
5264
5265 while ((c = *(++ptr)) != 0 && c != '\n');
5266 to
5267 while ((c = *(++ptr)) != 0 && c != '\n') ;
5268
5269 Totally extraordinary, but if that's what it takes...
5270
5271 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
5272 available. Added HAVE_BCOPY and an autoconf test for it; if neither
5273 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
5274 assumes the way PCRE uses memmove() (always moving upwards).
5275
5276 6. PCRE is being used in one environment where strchr() is not available. There
5277 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
5278 faster code anyway.
5279
5280
5281 Version 3.1 09-Feb-00
5282 ---------------------
5283
5284 The only change in this release is the fixing of some bugs in Makefile.in for
5285 the "install" target:
5286
5287 (1) It was failing to install pcreposix.h.
5288
5289 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
5290
5291
5292 Version 3.0 01-Feb-00
5293 ---------------------
5294
5295 1. Add support for the /+ modifier to perltest (to output $` like it does in
5296 pcretest).
5297
5298 2. Add support for the /g modifier to perltest.
5299
5300 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
5301 matches null strings.
5302
5303 4. Fix perltest so that it doesn't do unwanted things when fed an empty
5304 pattern. Perl treats empty patterns specially - it reuses the most recent
5305 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
5306 effect.
5307
5308 5. The POSIX interface was broken in that it was just handing over the POSIX
5309 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
5310 required a bigger vector, with some working space on the end. This means that
5311 the POSIX wrapper now has to get and free some memory, and copy the results.
5312
5313 6. Added some simple autoconf support, placing the test data and the
5314 documentation in separate directories, re-organizing some of the
5315 information files, and making it build pcre-config (a GNU standard). Also added
5316 libtool support for building PCRE as a shared library, which is now the
5317 default.
5318
5319 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
5320 09 are not valid octal constants. Single digits will be used for minor values
5321 less than 10.
5322
5323 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
5324 existing programs that set these in the POSIX interface can use PCRE without
5325 modification.
5326
5327 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
5328 return all that pcre_info() returns, plus additional data. The pcre_info()
5329 function is retained for compatibility, but is considered to be obsolete.
5330
5331 10. Added experimental recursion feature (?R) to handle one common case that
5332 Perl 5.6 will be able to do with (?p{...}).
5333
5334 11. Added support for POSIX character classes like [:alpha:], which Perl is
5335 adopting.
5336
5337
5338 Version 2.08 31-Aug-99
5339 ----------------------
5340
5341 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
5342 trying to match at the startoffset position, but instead was moving forward to
5343 the next newline as if a previous match had failed.
5344
5345 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
5346 and could get into a loop if a null string was matched other than at the start
5347 of the subject.
5348
5349 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
5350 be distinguished at compile time, and for completeness also added PCRE_DATE.
5351
5352 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
5353 in GnuWin32 environments.
5354
5355
5356 Version 2.07 29-Jul-99
5357 ----------------------
5358
5359 1. The documentation is now supplied in plain text form and HTML as well as in
5360 the form of man page sources.
5361
5362 2. C++ compilers don't like assigning (void *) values to other pointer types.
5363 In particular this affects malloc(). Although there is no problem in Standard
5364 C, I've put in casts to keep C++ compilers happy.
5365
5366 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
5367 should be (const char *).
5368
5369 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
5370 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
5371 However, I haven't made this a standard facility. The documentation doesn't
5372 mention it, and the Makefile doesn't support it.
5373
5374 5. The Makefile now contains an "install" target, with editable destinations at
5375 the top of the file. The pcretest program is not installed.
5376
5377 6. pgrep -V now gives the PCRE version number and date.
5378
5379 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
5380 causing the entire string to be ignored, instead of just the last character.
5381
5382 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
5383 non-matching string, it can take a very, very long time, even for strings of
5384 quite modest length, because of the nested recursion. PCRE now does better in
5385 some of these cases. It does this by remembering the last required literal
5386 character in the pattern, and pre-searching the subject to ensure it is present
5387 before running the real match. In other words, it applies a heuristic to detect
5388 some types of certain failure quickly, and in the above example, if presented
5389 with a string that has no trailing " it gives "no match" very quickly.
5390
5391 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
5392 other alternatives are tried instead.
5393
5394
5395 Version 2.06 09-Jun-99
5396 ----------------------
5397
5398 1. Change pcretest's output for amount of store used to show just the code
5399 space, because the remainder (the data block) varies in size between 32-bit and
5400 64-bit systems.
5401
5402 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
5403 start matching at. This allows lookbehinds to work when searching for multiple
5404 occurrences in a string.
5405
5406 3. Added additional options to pcretest for testing multiple occurrences:
5407
5408 /+ outputs the rest of the string that follows a match
5409 /g loops for multiple occurrences, using the new startoffset argument
5410 /G loops for multiple occurrences by passing an incremented pointer
5411
5412 4. PCRE wasn't doing the "first character" optimization for patterns starting
5413 with \b or \B, though it was doing it for other lookbehind assertions. That is,
5414 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
5415 the letter 'x'. On long subject strings, this gives a significant speed-up.
5416
5417
5418 Version 2.05 21-Apr-99
5419 ----------------------
5420
5421 1. Changed the type of magic_number from int to long int so that it works
5422 properly on 16-bit systems.
5423
5424 2. Fixed a bug which caused patterns starting with .* not to work correctly
5425 when the subject string contained newline characters. PCRE was assuming
5426 anchoring for such patterns in all cases, which is not correct because .* will
5427 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
5428 DOTALL is set at top level; otherwise it knows that patterns starting with .*
5429 must be retried after every newline in the subject.
5430
5431
5432 Version 2.04 18-Feb-99
5433 ----------------------
5434
5435 1. For parenthesized subpatterns with repeats whose minimum was zero, the
5436 computation of the store needed to hold the pattern was incorrect (too large).
5437 If such patterns were nested a few deep, this could multiply and become a real
5438 problem.
5439
5440 2. Added /M option to pcretest to show the memory requirement of a specific
5441 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
5442
5443 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
5444 compiled in such a way that the backtracking after subsequent failure was
5445 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
5446 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
5447
5448
5449 Version 2.03 02-Feb-99
5450 ----------------------
5451
5452 1. Fixed typo and small mistake in man page.
5453
5454 2. Added 4th condition (GPL supersedes if conflict) and created separate
5455 LICENCE file containing the conditions.
5456
5457 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
5458 Perl, that is the internal \ allows the delimiter to be included in the
5459 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
5460 the final delimiter, add \ to the end of the pattern (to test the error).
5461
5462 4. Added the convenience functions for extracting substrings after a successful
5463 match. Updated pcretest to make it able to test these functions.
5464
5465
5466 Version 2.02 14-Jan-99
5467 ----------------------
5468
5469 1. Initialized the working variables associated with each extraction so that
5470 their saving and restoring doesn't refer to uninitialized store.
5471
5472 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
5473 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
5474 fix the problem.
5475
5476 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
5477 calls, and wasn't printing the correct value for compiling calls. Increased the
5478 default value of LOOPREPEAT, and the number of significant figures in the
5479 times.
5480
5481 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
5482
5483 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
5484 a building problem on Windows NT with a FAT file system.
5485
5486
5487 Version 2.01 21-Oct-98
5488 ----------------------
5489
5490 1. Changed the API for pcre_compile() to allow for the provision of a pointer
5491 to character tables built by pcre_maketables() in the current locale. If NULL
5492 is passed, the default tables are used.
5493
5494
5495 Version 2.00 24-Sep-98
5496 ----------------------
5497
5498 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
5499 it any more.
5500
5501 2. Allow quantification of (?>) groups, and make it work correctly.
5502
5503 3. The first character computation wasn't working for (?>) groups.
5504
5505 4. Correct the implementation of \Z (it is permitted to match on the \n at the
5506 end of the subject) and add 5.005's \z, which really does match only at the
5507 very end of the subject.
5508
5509 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
5510
5511 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
5512 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
5513 localized options. All options to pcre_study() were also removed.
5514
5515 7. Add other new features from 5.005:
5516
5517 $(?<= positive lookbehind
5518 $(?<! negative lookbehind
5519 (?imsx-imsx) added the unsetting capability
5520 such a setting is global if at outer level; local otherwise
5521 (?imsx-imsx:) non-capturing groups with option setting
5522 (?(cond)re|re) conditional pattern matching
5523
5524 A backreference to itself in a repeated group matches the previous
5525 captured string.
5526
5527 8. General tidying up of studying (both automatic and via "study")
5528 consequential on the addition of new assertions.
5529
5530 9. As in 5.005, unlimited repeated groups that could match an empty substring
5531 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5532 runtime if any iteration does actually match an empty substring.
5533
5534 10. Include the RunTest script in the distribution.
5535
5536 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5537 discrepancies, some of which were old and were also with respect to 5.004. They
5538 have now been fixed.
5539
5540
5541 Version 1.09 28-Apr-98
5542 ----------------------
5543
5544 1. A negated single character class followed by a quantifier with a minimum
5545 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5546 program crashes, or just wrong answers. This did not apply to negated classes
5547 containing more than one character, or to minima other than one.
5548
5549
5550 Version 1.08 27-Mar-98
5551 ----------------------
5552
5553 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5554
5555 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5556 latter must appear before anything that relies on it in the pattern.
5557
5558
5559 Version 1.07 16-Feb-98
5560 ----------------------
5561
5562 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5563 repeat of a potentially empty string).
5564
5565
5566 Version 1.06 23-Jan-98
5567 ----------------------
5568
5569 1. Added Markus Oberhumer's little patches for C++.
5570
5571 2. Literal strings longer than 255 characters were broken.
5572
5573
5574 Version 1.05 23-Dec-97
5575 ----------------------
5576
5577 1. Negated character classes containing more than one character were failing if
5578 PCRE_CASELESS was set at run time.
5579
5580
5581 Version 1.04 19-Dec-97
5582 ----------------------
5583
5584 1. Corrected the man page, where some "const" qualifiers had been omitted.
5585
5586 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5587 input syntax.
5588
5589 3. Fixed memory leak which occurred when a regex with back references was
5590 matched with an offsets vector that wasn't big enough. The temporary memory
5591 that is used in this case wasn't being freed if the match failed.
5592
5593 4. Tidied pcretest to ensure it frees memory that it gets.
5594
5595 5. Temporary memory was being obtained in the case where the passed offsets
5596 vector was exactly big enough.
5597
5598 6. Corrected definition of offsetof() from change 5 below.
5599
5600 7. I had screwed up change 6 below and broken the rules for the use of
5601 setjmp(). Now fixed.
5602
5603
5604 Version 1.03 18-Dec-97
5605 ----------------------
5606
5607 1. A erroneous regex with a missing opening parenthesis was correctly
5608 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5609 on some systems.
5610
5611 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5612 it was reported that one broken compiler failed on the former because "code" is
5613 also an independent variable.
5614
5615 3. The erroneous regex a[]b caused an array overrun reference.
5616
5617 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5618 fail on data ending with that character. (It was going on too far, and checking
5619 the next character, typically a binary zero.) This was specific to the
5620 optimized code for single-character negative classes.
5621
5622 5. Added a contributed patch from the TIN world which does the following:
5623
5624 + Add an undef for memmove, in case the the system defines a macro for it.
5625
5626 + Add a definition of offsetof(), in case there isn't one. (I don't know
5627 the reason behind this - offsetof() is part of the ANSI standard - but
5628 it does no harm).
5629
5630 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
5631 most of the places where whitespace preceded '#'. I have given up and
5632 allowed the remaining 2 cases to be at the margin.
5633
5634 + Rename some variables in pcre to eliminate shadowing. This seems very
5635 pedantic, but does no harm, of course.
5636
5637 6. Moved the call to setjmp() into its own function, to get rid of warnings
5638 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
5639
5640 7. Constructs such as \d{8,} were compiling into the equivalent of
5641 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
5642 outcome, but in this particular case used more store than had been allocated,
5643 which caused the bug to be discovered because it threw up an internal error.
5644
5645 8. The debugging code in both pcre and pcretest for outputting the compiled
5646 form of a regex was going wrong in the case of back references followed by
5647 curly-bracketed repeats.
5648
5649
5650 Version 1.02 12-Dec-97
5651 ----------------------
5652
5653 1. Typos in pcre.3 and comments in the source fixed.
5654
5655 2. Applied a contributed patch to get rid of places where it used to remove
5656 'const' from variables, and fixed some signed/unsigned and uninitialized
5657 variable warnings.
5658
5659 3. Added the "runtest" target to Makefile.
5660
5661 4. Set default compiler flag to -O2 rather than just -O.
5662
5663
5664 Version 1.01 19-Nov-97
5665 ----------------------
5666
5667 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
5668 like /([ab]*)*/, that is, for classes with more than one character in them.
5669
5670 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
5671 as /((?>a*))*/ (a PCRE_EXTRA facility).
5672
5673
5674 Version 1.00 18-Nov-97
5675 ----------------------
5676
5677 1. Added compile-time macros to support systems such as SunOS4 which don't have
5678 memmove() or strerror() but have other things that can be used instead.
5679
5680 2. Arranged that "make clean" removes the executables.
5681
5682
5683 Version 0.99 27-Oct-97
5684 ----------------------
5685
5686 1. Fixed bug in code for optimizing classes with only one character. It was
5687 initializing a 32-byte map regardless, which could cause it to run off the end
5688 of the memory it had got.
5689
5690 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
5691
5692
5693 Version 0.98 22-Oct-97
5694 ----------------------
5695
5696 1. Fixed bug in code for handling temporary memory usage when there are more
5697 back references than supplied space in the ovector. This could cause segfaults.
5698
5699
5700 Version 0.97 21-Oct-97
5701 ----------------------
5702
5703 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
5704
5705 2. Optimized negated single characters not to use a bit map.
5706
5707 3. Brought error texts together as macro definitions; clarified some of them;
5708 fixed one that was wrong - it said "range out of order" when it meant "invalid
5709 escape sequence".
5710
5711 4. Changed some char * arguments to const char *.
5712
5713 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
5714
5715 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
5716 pcretest.
5717
5718
5719 Version 0.96 16-Oct-97
5720 ----------------------
5721
5722 1. Added a simple "pgrep" utility to the distribution.
5723
5724 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
5725 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
5726 where "ddd" means "one or more decimal digits".
5727
5728 3. Fixed serious bug. If a pattern had a back reference, but the call to
5729 pcre_exec() didn't supply a large enough ovector to record the related
5730 identifying subpattern, the match always failed. PCRE now remembers the number
5731 of the largest back reference, and gets some temporary memory in which to save
5732 the offsets during matching if necessary, in order to ensure that
5733 backreferences always work.
5734
5735 4. Increased the compatibility with Perl in a number of ways:
5736
5737 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
5738 to request this handling. The option can be set at compile or exec time.
5739
5740 (b) $ matches before a terminating newline by default; an option
5741 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
5742 mode). The option can be set at compile or exec time.
5743
5744 (c) The handling of \ followed by a digit other than 0 is now supposed to be
5745 the same as Perl's. If the decimal number it represents is less than 10
5746 or there aren't that many previous left capturing parentheses, an octal
5747 escape is read. Inside a character class, it's always an octal escape,
5748 even if it is a single digit.
5749
5750 (d) An escaped but undefined alphabetic character is taken as a literal,
5751 unless PCRE_EXTRA is set. Currently this just reserves the remaining
5752 escapes.
5753
5754 (e) {0} is now permitted. (The previous item is removed from the compiled
5755 pattern).
5756
5757 5. Changed all the names of code files so that the basic parts are no longer
5758 than 10 characters, and abolished the teeny "globals.c" file.
5759
5760 6. Changed the handling of character classes; they are now done with a 32-byte
5761 bit map always.
5762
5763 7. Added the -d and /D options to pcretest to make it possible to look at the
5764 internals of compilation without having to recompile pcre.
5765
5766
5767 Version 0.95 23-Sep-97
5768 ----------------------
5769
5770 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
5771 \x20 at the start of a run of normal characters. These were being treated as
5772 real characters, instead of the source characters being re-checked.
5773
5774
5775 Version 0.94 18-Sep-97
5776 ----------------------
5777
5778 1. The functions are now thread-safe, with the caveat that the global variables
5779 containing pointers to malloc() and free() or alternative functions are the
5780 same for all threads.
5781
5782 2. Get pcre_study() to generate a bitmap of initial characters for non-
5783 anchored patterns when this is possible, and use it if passed to pcre_exec().
5784
5785
5786 Version 0.93 15-Sep-97
5787 ----------------------
5788
5789 1. /(b)|(:+)/ was computing an incorrect first character.
5790
5791 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
5792 but not actually doing anything yet.
5793
5794 3. Treat "-" characters in classes that cannot be part of ranges as literals,
5795 as Perl does (e.g. [-az] or [az-]).
5796
5797 4. Set the anchored flag if a branch starts with .* or .*? because that tests
5798 all possible positions.
5799
5800 5. Split up into different modules to avoid including unneeded functions in a
5801 compiled binary. However, compile and exec are still in one module. The "study"
5802 function is split off.
5803
5804 6. The character tables are now in a separate module whose source is generated
5805 by an auxiliary program - but can then be edited by hand if required. There are
5806 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
5807 toupper() in the code.
5808
5809 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
5810 make them global. Abolish the function for setting them, as the caller can now
5811 set them directly.
5812
5813
5814 Version 0.92 11-Sep-97
5815 ----------------------
5816
5817 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
5818 (e.g. /a{1,3}/) was broken (I mis-optimized it).
5819
5820 2. Caseless matching was not working in character classes if the characters in
5821 the pattern were in upper case.
5822
5823 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
5824
5825 4. Make PCRE_ANCHORED public and accept as a compile option.
5826
5827 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
5828 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
5829 pass them.
5830
5831 6. Give an error if bad option bits passed at compile or run time.
5832
5833 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
5834 pcretest to cause it to pass that flag.
5835
5836 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
5837 options, and the first character, if set.
5838
5839 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
5840
5841
5842 Version 0.91 10-Sep-97
5843 ----------------------
5844
5845 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
5846 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
5847
5848 2. PCRE was looping on encountering an indefinitely repeated back reference to
5849 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
5850 Perl does - treats the match as successful.
5851
5852 ****

Properties

Name Value
svn:eol-style native
svn:keywords "Author Date Id Revision Url"

  ViewVC Help
Powered by ViewVC 1.1.5