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Revision 642 - (show annotations)
Thu Jul 28 18:59:40 2011 UTC (8 years, 1 month ago) by ph10
File size: 209784 byte(s)
Error occurred while calculating annotation data.
Avoid false positive for infinite recursion by not checking conditionals at 
compile time, but add tests at runtime that also catch infinite mutual 
recursion.
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.13 30-Apr-2011
5 ------------------------
6
7 1. The Unicode data tables have been updated to Unicode 6.0.0.
8
9 2. Two minor typos in pcre_internal.h have been fixed.
10
11 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
14
15 4. There were a number of related bugs in the code for matching backrefences
16 caselessly in UTF-8 mode when codes for the characters concerned were
17 different numbers of bytes. For example, U+023A and U+2C65 are an upper
18 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21 2-byte code at the end of the subject (it thought there wasn't enough data
22 left).
23
24 5. Comprehensive information about what went wrong is now returned by
25 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26 as the output vector has at least 2 elements. The offset of the start of
27 the failing character and a reason code are placed in the vector.
28
29 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
30 now returned is for the first byte of the failing character, instead of the
31 last byte inspected. This is an incompatible change, but I hope it is small
32 enough not to be a problem. It makes the returned offset consistent with
33 pcre_exec() and pcre_dfa_exec().
34
35 7. pcretest now gives a text phrase as well as the error number when
36 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37 failure, the offset and reason code are output.
38
39 8. When \R was used with a maximizing quantifier it failed to skip backwards
40 over a \r\n pair if the subsequent match failed. Instead, it just skipped
41 back over a single character (\n). This seems wrong (because it treated the
42 two characters as a single entity when going forwards), conflicts with the
43 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45 has been changed.
46
47 9. Some internal refactoring has changed the processing so that the handling
48 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49 time (the PCRE_DOTALL option was changed this way some time ago: version
50 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51 which was always a bit of a fudge. It also means that there is one less
52 argument for the match() function, which reduces its stack requirements
53 slightly. This change also fixes an incompatibility with Perl: the pattern
54 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
55
56 10. More internal refactoring has drastically reduced the number of recursive
57 calls to match() for possessively repeated groups such as (abc)++ when
58 using pcre_exec().
59
60 11. While implementing 10, a number of bugs in the handling of groups were
61 discovered and fixed:
62
63 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64 (a|)*(?1) gave a compile-time internal error.
65 ((a|)+)+ did not notice that the outer group could match an empty string.
66 (^a|^)+ was not marked as anchored.
67 (.*a|.*)+ was not marked as matching at start or after a newline.
68
69 12. Yet more internal refactoring has removed another argument from the match()
70 function. Special calls to this function are now indicated by setting a
71 value in a variable in the "match data" data block.
72
73 13. Be more explicit in pcre_study() instead of relying on "default" for
74 opcodes that mean there is no starting character; this means that when new
75 ones are added and accidentally left out of pcre_study(), testing should
76 pick them up.
77
78 14. The -s option of pcretest has been documented for ages as being an old
79 synonym of -m (show memory usage). I have changed it to mean "force study
80 for every regex", that is, assume /S for every regex. This is similar to -i
81 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82 using it. It makes it easier to run collections of tests with and without
83 study enabled, and thereby test pcre_study() more easily. All the standard
84 tests are now run with and without -s (but some patterns can be marked as
85 "never study" - see 20 below).
86
87 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88 restoration of the capturing data to the outer values was not happening
89 correctly.
90
91 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93 pattern had matched an empty string, and so incorrectly returned a no
94 match.
95
96 17. There was optimizing code for the last branch of non-capturing parentheses,
97 and also for the obeyed branch of a conditional subexpression, which used
98 tail recursion to cut down on stack usage. Unfortunately, not that there is
99 the possibility of (*THEN) occurring in these branches, tail recursion is
100 no longer possible because the return has to be checked for (*THEN). These
101 two optimizations have therefore been removed.
102
103 18. If a pattern containing \R was studied, it was assumed that \R always
104 matched two bytes, thus causing the minimum subject length to be
105 incorrectly computed because \R can also match just one byte.
106
107 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108 was incorrectly computed.
109
110 20. If /S is present twice on a test pattern in pcretest input, it *disables*
111 studying, thereby overriding the use of -s on the command line. This is
112 necessary for one or two tests to keep the output identical in both cases.
113
114 21. When (*ACCEPT) was used in an assertion that matched an empty string and
115 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
116
117 22. When an atomic group that contained a capturing parenthesis was
118 successfully matched, but the branch in which it appeared failed, the
119 capturing was not being forgotten if a higher numbered group was later
120 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121 group 1 to "a", when in fact it should be unset. This applied to multi-
122 branched capturing and non-capturing groups, repeated or not, and also to
123 positive assertions (capturing in negative assertions is not well defined
124 in PCRE) and also to nested atomic groups.
125
126 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
127 subject after a captured substring (to make it easier to tell which of a
128 number of identical substrings has been captured).
129
130 24. The way atomic groups are processed by pcre_exec() has been changed so that
131 if they are repeated, backtracking one repetition now resets captured
132 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
133 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
134 "aaa". Previously, it would have been "a". As part of this code
135 refactoring, the way recursive calls are handled has also been changed.
136
137 24. If an assertion condition captured any substrings, they were not passed
138 back unless some other capturing happened later. For example, if
139 (?(?=(a))a) was matched against "a", no capturing was returned.
140
141 25. When studying a pattern that contained subroutine calls or assertions,
142 the code for finding the minimum length of a possible match was handling
143 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
144 group 1 called group 2 while simultaneously a separate group 2 called group
145 1). A stack overflow occurred in this case. I have fixed this by limiting
146 the recursion depth to 10.
147
148 26. Updated RunTest.bat in the distribution to the version supplied by Tom
149 Fortmann. This supports explicit test numbers on the command line, and has
150 argument validation and error reporting.
151
152 27. An instance of \X with an unlimited repeat could fail if at any point the
153 first character it looked at was a mark character.
154
155 28. Some minor code refactoring concerning Unicode properties and scripts
156 should reduce the stack requirement of match() slightly.
157
158 29. Added the '=' option to pcretest to check the setting of unused capturing
159 slots at the end of the pattern, which are documented as being -1, but are
160 not included in the return count.
161
162 30. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
163 compiled something random. Now it gives a compile-time error (as does
164 Perl).
165
166 31. A *MARK encountered during the processing of a positive assertion is now
167 recorded and passed back (compatible with Perl).
168
169 32. If --only-matching or --colour was set on a pcregrep call whose pattern
170 had alternative anchored branches, the search for a second match in a line
171 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
172 matched the line "0102" twice. The same bug affected patterns that started
173 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
174 twice.
175
176 33. Previously, PCRE did not allow quantification of assertions. However, Perl
177 does, and because of capturing effects, quantifying parenthesized
178 assertions may at times be useful. Quantifiers are now allowed for
179 parenthesized assertions.
180
181 34. A minor code tidy in pcre_compile() when checking options for \R usage.
182
183 35. \g was being checked for fancy things in a character class, when it should
184 just be a literal "g".
185
186 36. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
187 appearance of a nested POSIX class supersedes an apparent external class.
188 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
189 unescaped square brackets may also appear as part of class names. For
190 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
191 more like Perl.
192
193 37. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
194 was because it thought it was \N{name}, which is not supported).
195
196 38. Add minix to OS list not supporting the -S option in pcretest.
197
198 39. PCRE tries to detect cases of infinite recursion at compile time, but it
199 cannot analyze patterns in sufficient detail to catch mutual recursions
200 such as ((?1))((?2)). There is now a runtime test that gives an error if a
201 subgroup is called recursively as a subpattern for a second time at the
202 same position in the subject string. In previous releases this might have
203 been caught by the recursion limit, or it might have run out of stack.
204
205 40. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
206 happen only once. PCRE was, however incorrectly giving a compile time error
207 "recursive call could loop indefinitely" because it cannot analyze the
208 pattern in sufficient detail. The compile time test no longer happens when
209 PCRE is compiling a conditional subpattern, but actual runaway loops are
210 now caught at runtime (see 39 above).
211
212
213 Version 8.12 15-Jan-2011
214 ------------------------
215
216 1. Fixed some typos in the markup of the man pages, and wrote a script that
217 checks for such things as part of the documentation building process.
218
219 2. On a big-endian 64-bit system, pcregrep did not correctly process the
220 --match-limit and --recursion-limit options (added for 8.11). In
221 particular, this made one of the standard tests fail. (The integer value
222 went into the wrong half of a long int.)
223
224 3. If the --colour option was given to pcregrep with -v (invert match), it
225 did strange things, either producing crazy output, or crashing. It should,
226 of course, ignore a request for colour when reporting lines that do not
227 match.
228
229 4. Another pcregrep bug caused similar problems if --colour was specified with
230 -M (multiline) and the pattern match finished with a line ending.
231
232 5. In pcregrep, when a pattern that ended with a literal newline sequence was
233 matched in multiline mode, the following line was shown as part of the
234 match. This seems wrong, so I have changed it.
235
236 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
237 the check for further matches in the same line (so they could be coloured)
238 to overrun the end of the current line. If another match was found, it was
239 incorrectly shown (and then shown again when found in the next line).
240
241 7. If pcregrep was compiled under Windows, there was a reference to the
242 function pcregrep_exit() before it was defined. I am assuming this was
243 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
244 reported by a user. I've moved the definition above the reference.
245
246
247 Version 8.11 10-Dec-2010
248 ------------------------
249
250 1. (*THEN) was not working properly if there were untried alternatives prior
251 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
252 backtracked to try for "b" instead of moving to the next alternative branch
253 at the same level (in this case, to look for "c"). The Perl documentation
254 is clear that when (*THEN) is backtracked onto, it goes to the "next
255 alternative in the innermost enclosing group".
256
257 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
258 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
259 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
260 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
261 (*THEN).
262
263 3. If \s appeared in a character class, it removed the VT character from
264 the class, even if it had been included by some previous item, for example
265 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
266 of \s, but is part of the POSIX "space" class.)
267
268 4. A partial match never returns an empty string (because you can always
269 match an empty string at the end of the subject); however the checking for
270 an empty string was starting at the "start of match" point. This has been
271 changed to the "earliest inspected character" point, because the returned
272 data for a partial match starts at this character. This means that, for
273 example, /(?<=abc)def/ gives a partial match for the subject "abc"
274 (previously it gave "no match").
275
276 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
277 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
278 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
279 has an implication that the given string is incomplete (because a partial
280 match is preferred over a full match). For this reason, these items now
281 give a partial match in this situation. [Aside: previously, the one case
282 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
283 match rather than a full match, which was wrong by the old rules, but is
284 now correct.]
285
286 6. There was a bug in the handling of #-introduced comments, recognized when
287 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
288 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
289 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
290 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
291 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
292 places in pcre_compile().
293
294 7. Related to (6) above, when pcre_compile() was skipping #-introduced
295 comments when looking ahead for named forward references to subpatterns,
296 the only newline sequence it recognized was NL. It now handles newlines
297 according to the set newline convention.
298
299 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
300 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
301 cater for a lack of strerror(). These oversights have been fixed.
302
303 9. Added --match-limit and --recursion-limit to pcregrep.
304
305 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
306
307 11. When the -o option was used, pcregrep was setting a return code of 1, even
308 when matches were found, and --line-buffered was not being honoured.
309
310 12. Added an optional parentheses number to the -o and --only-matching options
311 of pcregrep.
312
313 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
314 can match an empty string. The code to do it in pcretest and pcredemo
315 needed fixing:
316
317 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
318 only one byte after an empty string match just before CRLF (this case
319 just got forgotten; "any" and "anycrlf" were OK).
320
321 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
322 mode when an empty string match preceded an ASCII character followed by
323 a non-ASCII character. (The code for advancing by one character rather
324 than one byte was nonsense.)
325
326 (c) The pcredemo.c sample program did not have any code at all to handle
327 the cases when CRLF is a valid newline sequence.
328
329 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
330 as a starting offset was within the subject string. There is now a new
331 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
332 negative or greater than the length of the string. In order to test this,
333 pcretest is extended to allow the setting of negative starting offsets.
334
335 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
336 starting offset points to the beginning of a UTF-8 character was
337 unnecessarily clumsy. I tidied it up.
338
339 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
340 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
341
342 17. Nobody had reported that the --include_dir option, which was added in
343 release 7.7 should have been called --include-dir (hyphen, not underscore)
344 for compatibility with GNU grep. I have changed it to --include-dir, but
345 left --include_dir as an undocumented synonym, and the same for
346 --exclude-dir, though that is not available in GNU grep, at least as of
347 release 2.5.4.
348
349 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
350 characters from a string of bytes) have been redefined so as not to use
351 loops, in order to improve performance in some environments. At the same
352 time, I abstracted some of the common code into auxiliary macros to save
353 repetition (this should not affect the compiled code).
354
355 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
356 compile-time error is now given if \c is not followed by an ASCII
357 character, that is, a byte less than 128. (In EBCDIC mode, the code is
358 different, and any byte value is allowed.)
359
360 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
361 START_OPTIMIZE option, which is now allowed at compile time - but just
362 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
363 to pcregrep and other applications that have no direct access to PCRE
364 options. The new /Y option in pcretest sets this option when calling
365 pcre_compile().
366
367 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
368 back references. Groups containing recursive back references were forced to
369 be atomic by that change, but in the case of named groups, the amount of
370 memory required was incorrectly computed, leading to "Failed: internal
371 error: code overflow". This has been fixed.
372
373 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
374 pcretest.c, to avoid build problems in some Borland environments.
375
376
377 Version 8.10 25-Jun-2010
378 ------------------------
379
380 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
381 THEN.
382
383 2. (*ACCEPT) was not working when inside an atomic group.
384
385 3. Inside a character class, \B is treated as a literal by default, but
386 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
387 causes the error). The code is unchanged, but I tidied the documentation.
388
389 4. Inside a character class, PCRE always treated \R and \X as literals,
390 whereas Perl faults them if its -w option is set. I have changed PCRE so
391 that it faults them when PCRE_EXTRA is set.
392
393 5. Added support for \N, which always matches any character other than
394 newline. (It is the same as "." when PCRE_DOTALL is not set.)
395
396 6. When compiling pcregrep with newer versions of gcc which may have
397 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
398 declared with attribute warn_unused_result" were given. Just casting the
399 result to (void) does not stop the warnings; a more elaborate fudge is
400 needed. I've used a macro to implement this.
401
402 7. Minor change to pcretest.c to avoid a compiler warning.
403
404 8. Added four artifical Unicode properties to help with an option to make
405 \s etc use properties (see next item). The new properties are: Xan
406 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
407
408 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
409 use Unicode properties. (*UCP) at the start of a pattern can be used to set
410 this option. Modified pcretest to add /W to test this facility. Added
411 REG_UCP to make it available via the POSIX interface.
412
413 10. Added --line-buffered to pcregrep.
414
415 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
416 studied, and the match started with a letter with a code point greater than
417 127 whose first byte was different to the first byte of the other case of
418 the letter, the other case of this starting letter was not recognized
419 (#976).
420
421 12. If a pattern that was studied started with a repeated Unicode property
422 test, for example, \p{Nd}+, there was the theoretical possibility of
423 setting up an incorrect bitmap of starting bytes, but fortunately it could
424 not have actually happened in practice until change 8 above was made (it
425 added property types that matched character-matching opcodes).
426
427 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
428 possible starting bytes for non-anchored patterns.
429
430 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
431 \R, and also a number of cases that involve Unicode properties, both
432 explicit and implicit when PCRE_UCP is set.
433
434 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
435 input, it could crash or give wrong results if characters with values
436 greater than 0xc0 were present in the subject string. (Detail: it assumed
437 UTF-8 input when processing these items.)
438
439 16. Added a lot of (int) casts to avoid compiler warnings in systems where
440 size_t is 64-bit (#991).
441
442 17. Added a check for running out of memory when PCRE is compiled with
443 --disable-stack-for-recursion (#990).
444
445 18. If the last data line in a file for pcretest does not have a newline on
446 the end, a newline was missing in the output.
447
448 19. The default pcre_chartables.c file recognizes only ASCII characters (values
449 less than 128) in its various bitmaps. However, there is a facility for
450 generating tables according to the current locale when PCRE is compiled. It
451 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
452 characters, are recognized by isspace() and therefore were getting set in
453 these tables, and indeed these tables seem to approximate to ISO 8859. This
454 caused a problem in UTF-8 mode when pcre_study() was used to create a list
455 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
456 which of course cannot start UTF-8 characters. I have changed the code so
457 that only real ASCII characters (less than 128) and the correct starting
458 bytes for UTF-8 encodings are set for characters greater than 127 when in
459 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
460 altogether.)
461
462 20. Added the /T option to pcretest so as to be able to run tests with non-
463 standard character tables, thus making it possible to include the tests
464 used for 19 above in the standard set of tests.
465
466 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
467 reference to a subpattern the other side of a comment that contains an
468 opening parenthesis caused either an internal compiling error, or a
469 reference to the wrong subpattern.
470
471
472 Version 8.02 19-Mar-2010
473 ------------------------
474
475 1. The Unicode data tables have been updated to Unicode 5.2.0.
476
477 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
478 configured.
479
480 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
481 original author of that file, following a query about its status.
482
483 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
484 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
485
486 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
487 quantifier applied to a forward-referencing subroutine call, could compile
488 incorrect code or give the error "internal error: previously-checked
489 referenced subpattern not found".
490
491 6. Both MS Visual Studio and Symbian OS have problems with initializing
492 variables to point to external functions. For these systems, therefore,
493 pcre_malloc etc. are now initialized to local functions that call the
494 relevant global functions.
495
496 7. There were two entries missing in the vectors called coptable and poptable
497 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
498 I've fixed the data, and added a kludgy way of testing at compile time that
499 the lengths are correct (equal to the number of opcodes).
500
501 8. Following on from 7, I added a similar kludge to check the length of the
502 eint vector in pcreposix.c.
503
504 9. Error texts for pcre_compile() are held as one long string to avoid too
505 much relocation at load time. To find a text, the string is searched,
506 counting zeros. There was no check for running off the end of the string,
507 which could happen if a new error number was added without updating the
508 string.
509
510 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
511
512 11. \K was not working if it appeared in an atomic group or in a group that
513 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
514 \K is "not well defined" if used in an assertion. PCRE now accepts it if
515 the assertion is positive, but not if it is negative.
516
517 12. Change 11 fortuitously reduced the size of the stack frame used in the
518 "match()" function of pcre_exec.c by one pointer. Forthcoming
519 implementation of support for (*MARK) will need an extra pointer on the
520 stack; I have reserved it now, so that the stack frame size does not
521 decrease.
522
523 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
524 item in branch that calls a recursion is a subroutine call - as in the
525 second branch in the above example - was incorrectly given the compile-
526 time error "recursive call could loop indefinitely" because pcre_compile()
527 was not correctly checking the subroutine for matching a non-empty string.
528
529 14. The checks for overrunning compiling workspace could trigger after an
530 overrun had occurred. This is a "should never occur" error, but it can be
531 triggered by pathological patterns such as hundreds of nested parentheses.
532 The checks now trigger 100 bytes before the end of the workspace.
533
534 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
535
536
537 Version 8.01 19-Jan-2010
538 ------------------------
539
540 1. If a pattern contained a conditional subpattern with only one branch (in
541 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
542 computed the wrong minimum data length (which is of course zero for such
543 subpatterns). This could cause incorrect "no match" results.
544
545 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
546 the pattern is reset in the first branch, pcre_compile() failed with
547 "internal error: code overflow at offset...". This happened only when
548 the reset was to the original external option setting. (An optimization
549 abstracts leading options settings into an external setting, which was the
550 cause of this.)
551
552 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
553 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
554 assertion pattern did not match (meaning that the assertion was true), it
555 was incorrectly treated as false if the SKIP had been reached during the
556 matching. This also applied to assertions used as conditions.
557
558 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
559 assertion subpattern, including such a pattern used as a condition,
560 unpredictable results occurred, instead of the error return
561 PCRE_ERROR_DFA_UITEM.
562
563 5. The C++ GlobalReplace function was not working like Perl for the special
564 situation when an empty string is matched. It now does the fancy magic
565 stuff that is necessary.
566
567 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
568 removed. (These were left over from very, very early versions of PCRE.)
569
570 7. Some cosmetic changes to the code to make life easier when compiling it
571 as part of something else:
572
573 (a) Change DEBUG to PCRE_DEBUG.
574
575 (b) In pcre_compile(), rename the member of the "branch_chain" structure
576 called "current" as "current_branch", to prevent a collision with the
577 Linux macro when compiled as a kernel module.
578
579 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
580 prevent a collision with the Linux macro when compiled as a kernel
581 module.
582
583 8. In pcre_compile() there are some checks for integer overflows that used to
584 cast potentially large values to (double). This has been changed to that
585 when building, a check for int64_t is made, and if it is found, it is used
586 instead, thus avoiding the use of floating point arithmetic. (There is no
587 other use of FP in PCRE.) If int64_t is not found, the fallback is to
588 double.
589
590 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
591 2005 (difference between two addresses compared to an unsigned value).
592
593 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
594 custom one, because of the following reported problem in Windows:
595
596 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
597 under Win32.
598 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
599 therefore missing the function definition.
600 - The compiler thus generates a "C" signature for the test function.
601 - The linker fails to find the "C" function.
602 - PCRE fails to configure if asked to do so against libbz2.
603
604 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
605 messages were output:
606
607 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
608 rerunning libtoolize, to keep the correct libtool macros in-tree.
609 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
610
611 I have done both of these things.
612
613 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
614 most of the time, it *can* run out if it is given a pattern that contains a
615 runaway infinite recursion. I updated the discussion in the pcrestack man
616 page.
617
618 13. Now that we have gone to the x.xx style of version numbers, the minor
619 version may start with zero. Using 08 or 09 is a bad idea because users
620 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
621 interpreted as invalid octal numbers. I've updated the previous comment in
622 configure.ac, and also added a check that gives an error if 08 or 09 are
623 used.
624
625 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
626 causing partial matching to fail when the end of the subject matched \W
627 in a UTF-8 pattern where \W was quantified with a minimum of 3.
628
629 15. There were some discrepancies between the declarations in pcre_internal.h
630 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
631 their definitions. The declarations used "const uschar *" and the
632 definitions used USPTR. Even though USPTR is normally defined as "const
633 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
634 reported that: "This difference in casting confuses some C++ compilers, for
635 example, SunCC recognizes above declarations as different functions and
636 generates broken code for hbpcre." I have changed the declarations to use
637 USPTR.
638
639 16. GNU libtool is named differently on some systems. The autogen.sh script now
640 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
641 (FreeBSD).
642
643 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
644 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
645 comment: "Figure out how to create a longlong from a string: strtoll and
646 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
647 instance, but it only takes 2 args instead of 3!"
648
649 18. A subtle bug concerned with back references has been fixed by a change of
650 specification, with a corresponding code fix. A pattern such as
651 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
652 refers, was giving matches when it shouldn't. For example, xa=xaaa would
653 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
654 same bug. Such groups have to be quantified to be useful, or contained
655 inside another quantified group. (If there's no repetition, the reference
656 can never match.) The problem arises because, having left the group and
657 moved on to the rest of the pattern, a later failure that backtracks into
658 the group uses the captured value from the final iteration of the group
659 rather than the correct earlier one. I have fixed this in PCRE by forcing
660 any group that contains a reference to itself to be an atomic group; that
661 is, there cannot be any backtracking into it once it has completed. This is
662 similar to recursive and subroutine calls.
663
664
665 Version 8.00 19-Oct-09
666 ----------------------
667
668 1. The table for translating pcre_compile() error codes into POSIX error codes
669 was out-of-date, and there was no check on the pcre_compile() error code
670 being within the table. This could lead to an OK return being given in
671 error.
672
673 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
674 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
675 in a Windows environment.
676
677 3. The pcregrep --count option prints the count for each file even when it is
678 zero, as does GNU grep. However, pcregrep was also printing all files when
679 --files-with-matches was added. Now, when both options are given, it prints
680 counts only for those files that have at least one match. (GNU grep just
681 prints the file name in this circumstance, but including the count seems
682 more useful - otherwise, why use --count?) Also ensured that the
683 combination -clh just lists non-zero counts, with no names.
684
685 4. The long form of the pcregrep -F option was incorrectly implemented as
686 --fixed_strings instead of --fixed-strings. This is an incompatible change,
687 but it seems right to fix it, and I didn't think it was worth preserving
688 the old behaviour.
689
690 5. The command line items --regex=pattern and --regexp=pattern were not
691 recognized by pcregrep, which required --regex pattern or --regexp pattern
692 (with a space rather than an '='). The man page documented the '=' forms,
693 which are compatible with GNU grep; these now work.
694
695 6. No libpcreposix.pc file was created for pkg-config; there was just
696 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
697
698 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
699 when UCP support is not needed, by modifying the Python script that
700 generates it from Unicode data files. This should not matter if the module
701 is correctly used as a library, but I received one complaint about 50K of
702 unwanted data. My guess is that the person linked everything into his
703 program rather than using a library. Anyway, it does no harm.
704
705 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
706 was a minimum greater than 1 for a wide character in a possessive
707 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
708 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
709 character. Chaos in the form of incorrect output or a compiling loop could
710 result.
711
712 9. The restrictions on what a pattern can contain when partial matching is
713 requested for pcre_exec() have been removed. All patterns can now be
714 partially matched by this function. In addition, if there are at least two
715 slots in the offset vector, the offset of the earliest inspected character
716 for the match and the offset of the end of the subject are set in them when
717 PCRE_ERROR_PARTIAL is returned.
718
719 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
720 synonymous with PCRE_PARTIAL, for backwards compatibility, and
721 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
722 and may be more useful for multi-segment matching.
723
724 11. Partial matching with pcre_exec() is now more intuitive. A partial match
725 used to be given if ever the end of the subject was reached; now it is
726 given only if matching could not proceed because another character was
727 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
728 string "Z", which now yields "no match" instead of "partial match". In the
729 case of pcre_dfa_exec(), "no match" is given if every matching path for the
730 final character ended with (*FAIL).
731
732 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
733 if the pattern had a "must contain" character that was already found in the
734 earlier partial match, unless partial matching was again requested. For
735 example, with the pattern /dog.(body)?/, the "must contain" character is
736 "g". If the first part-match was for the string "dog", restarting with
737 "sbody" failed. This bug has been fixed.
738
739 13. The string returned by pcre_dfa_exec() after a partial match has been
740 changed so that it starts at the first inspected character rather than the
741 first character of the match. This makes a difference only if the pattern
742 starts with a lookbehind assertion or \b or \B (\K is not supported by
743 pcre_dfa_exec()). It's an incompatible change, but it makes the two
744 matching functions compatible, and I think it's the right thing to do.
745
746 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
747 so that the demonstration program is easily available in environments where
748 PCRE has not been installed from source.
749
750 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
751 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
752 library.
753
754 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
755 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
756 is not the first non-POSIX option to be added. Clearly some people find
757 these options useful.
758
759 17. If a caller to the POSIX matching function regexec() passes a non-zero
760 value for nmatch with a NULL value for pmatch, the value of
761 nmatch is forced to zero.
762
763 18. RunGrepTest did not have a test for the availability of the -u option of
764 the diff command, as RunTest does. It now checks in the same way as
765 RunTest, and also checks for the -b option.
766
767 19. If an odd number of negated classes containing just a single character
768 interposed, within parentheses, between a forward reference to a named
769 subpattern and the definition of the subpattern, compilation crashed with
770 an internal error, complaining that it could not find the referenced
771 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
772 [The bug was that it was starting one character too far in when skipping
773 over the character class, thus treating the ] as data rather than
774 terminating the class. This meant it could skip too much.]
775
776 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
777 /g option in pcretest when the pattern contains \K, which makes it possible
778 to have an empty string match not at the start, even when the pattern is
779 anchored. Updated pcretest and pcredemo to use this option.
780
781 21. If the maximum number of capturing subpatterns in a recursion was greater
782 than the maximum at the outer level, the higher number was returned, but
783 with unset values at the outer level. The correct (outer level) value is
784 now given.
785
786 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
787 PCRE did not set those parentheses (unlike Perl). I have now found a way to
788 make it do so. The string so far is captured, making this feature
789 compatible with Perl.
790
791 23. The tests have been re-organized, adding tests 11 and 12, to make it
792 possible to check the Perl 5.10 features against Perl 5.10.
793
794 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
795 pattern matches a fixed length string. PCRE did not allow this; now it
796 does. Neither allows recursion.
797
798 25. I finally figured out how to implement a request to provide the minimum
799 length of subject string that was needed in order to match a given pattern.
800 (It was back references and recursion that I had previously got hung up
801 on.) This code has now been added to pcre_study(); it finds a lower bound
802 to the length of subject needed. It is not necessarily the greatest lower
803 bound, but using it to avoid searching strings that are too short does give
804 some useful speed-ups. The value is available to calling programs via
805 pcre_fullinfo().
806
807 26. While implementing 25, I discovered to my embarrassment that pcretest had
808 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
809 study optimizations had never been tested with that matching function.
810 Oops. What is worse, even when it was passed study data, there was a bug in
811 pcre_dfa_exec() that meant it never actually used it. Double oops. There
812 were also very few tests of studied patterns with pcre_dfa_exec().
813
814 27. If (?| is used to create subpatterns with duplicate numbers, they are now
815 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
816 on the other side of the coin, they are no longer allowed to have different
817 names, because these cannot be distinguished in PCRE, and this has caused
818 confusion. (This is a difference from Perl.)
819
820 28. When duplicate subpattern names are present (necessarily with different
821 numbers, as required by 27 above), and a test is made by name in a
822 conditional pattern, either for a subpattern having been matched, or for
823 recursion in such a pattern, all the associated numbered subpatterns are
824 tested, and the overall condition is true if the condition is true for any
825 one of them. This is the way Perl works, and is also more like the way
826 testing by number works.
827
828
829 Version 7.9 11-Apr-09
830 ---------------------
831
832 1. When building with support for bzlib/zlib (pcregrep) and/or readline
833 (pcretest), all targets were linked against these libraries. This included
834 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
835 libraries. This caused unwanted dependencies to be created. This problem
836 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
837 pcretest is linked with readline.
838
839 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
840 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
841 moved outside it again, because FALSE and TRUE are already defined in AIX,
842 but BOOL is not.
843
844 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
845 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
846
847 4. The pcregrep documentation said spaces were inserted as well as colons (or
848 hyphens) following file names and line numbers when outputting matching
849 lines. This is not true; no spaces are inserted. I have also clarified the
850 wording for the --colour (or --color) option.
851
852 5. In pcregrep, when --colour was used with -o, the list of matching strings
853 was not coloured; this is different to GNU grep, so I have changed it to be
854 the same.
855
856 6. When --colo(u)r was used in pcregrep, only the first matching substring in
857 each matching line was coloured. Now it goes on to look for further matches
858 of any of the test patterns, which is the same behaviour as GNU grep.
859
860 7. A pattern that could match an empty string could cause pcregrep to loop; it
861 doesn't make sense to accept an empty string match in pcregrep, so I have
862 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
863 seems to be how GNU grep behaves.
864
865 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
866 start or after a newline", because the conditional assertion was not being
867 correctly handled. The rule now is that both the assertion and what follows
868 in the first alternative must satisfy the test.
869
870 9. If auto-callout was enabled in a pattern with a conditional group whose
871 condition was an assertion, PCRE could crash during matching, both with
872 pcre_exec() and pcre_dfa_exec().
873
874 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
875 used for matching.
876
877 11. Unicode property support in character classes was not working for
878 characters (bytes) greater than 127 when not in UTF-8 mode.
879
880 12. Added the -M command line option to pcretest.
881
882 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
883
884 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
885
886 16. Added comments and documentation about mis-use of no_arg in the C++
887 wrapper.
888
889 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
890 from Martin Jerabek that uses macro names for all relevant character and
891 string constants.
892
893 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
894 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
895 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
896 these, but not everybody uses configure.
897
898 19. A conditional group that had only one branch was not being correctly
899 recognized as an item that could match an empty string. This meant that an
900 enclosing group might also not be so recognized, causing infinite looping
901 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
902 with the subject "ab", where knowledge that the repeated group can match
903 nothing is needed in order to break the loop.
904
905 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
906 exec(), but without supplying a callout function, matching went wrong.
907
908 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
909 leak if the size of the offset vector was greater than 30. When the vector
910 is smaller, the saved offsets during recursion go onto a local stack
911 vector, but for larger vectors malloc() is used. It was failing to free
912 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
913 error, in fact).
914
915 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
916 heapframe that is used only when UTF-8 support is enabled. This caused no
917 problem, but was untidy.
918
919 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
920 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
921 included within another project.
922
923 24. Steven Van Ingelgem's patches to add more options to the CMake support,
924 slightly modified by me:
925
926 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
927 not building pcregrep.
928
929 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
930 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
931
932 25. Forward references, both numeric and by name, in patterns that made use of
933 duplicate group numbers, could behave incorrectly or give incorrect errors,
934 because when scanning forward to find the reference group, PCRE was not
935 taking into account the duplicate group numbers. A pattern such as
936 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
937
938 26. Changed a few more instances of "const unsigned char *" to USPTR, making
939 the feature of a custom pointer more persuasive (as requested by a user).
940
941 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
942 pcretest.c, inside #ifndefs, because it seems they are sometimes already
943 pre-defined.
944
945 28. Added support for (*UTF8) at the start of a pattern.
946
947 29. Arrange for flags added by the "release type" setting in CMake to be shown
948 in the configuration summary.
949
950
951 Version 7.8 05-Sep-08
952 ---------------------
953
954 1. Replaced UCP searching code with optimized version as implemented for Ad
955 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
956 stage table and inline lookup instead of a function, giving speed ups of 2
957 to 5 times on some simple patterns that I tested. Permission was given to
958 distribute the MultiStage2.py script that generates the tables (it's not in
959 the tarball, but is in the Subversion repository).
960
961 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
962 scripts.
963
964 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
965 a group with a zero qualifier. The result of the study could be incorrect,
966 or the function might crash, depending on the pattern.
967
968 4. Caseless matching was not working for non-ASCII characters in back
969 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
970 It now works when Unicode Property Support is available.
971
972 5. In pcretest, an escape such as \x{de} in the data was always generating
973 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
974 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
975 truncation.
976
977 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
978
979 7. Added two (int) casts to pcregrep when printing the difference of two
980 pointers, in case they are 64-bit values.
981
982 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
983 test 2 if it fails.
984
985 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
986 and a #define of that name to empty if it is not externally set. This is to
987 allow users of MSVC to set it if necessary.
988
989 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
990 the convenience functions in the pcre_get.c source file.
991
992 11. An option change at the start of a pattern that had top-level alternatives
993 could cause overwriting and/or a crash. This command provoked a crash in
994 some environments:
995
996 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
997
998 This potential security problem was recorded as CVE-2008-2371.
999
1000 12. For a pattern where the match had to start at the beginning or immediately
1001 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1002 pcre_dfa_exec() could read past the end of the passed subject if there was
1003 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1004 pcretest so that it places the subject at the end of its malloc-ed buffer.
1005
1006 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1007 exec() might read past the end of the data buffer in UTF-8 mode.
1008
1009 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1010 the data contained the byte 0x85 as part of a UTF-8 character within its
1011 first line. This applied both to normal and DFA matching.
1012
1013 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1014 /^[^d]*?$/8 failed to match "abc".
1015
1016 16. Added a missing copyright notice to pcrecpp_internal.h.
1017
1018 17. Make it more clear in the documentation that values returned from
1019 pcre_exec() in ovector are byte offsets, not character counts.
1020
1021 18. Tidied a few places to stop certain compilers from issuing warnings.
1022
1023 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1024 supplied by Stefan Weber. I made a further small update for 7.8 because
1025 there is a change of source arrangements: the pcre_searchfuncs.c module is
1026 replaced by pcre_ucd.c.
1027
1028
1029 Version 7.7 07-May-08
1030 ---------------------
1031
1032 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1033 a string to a long long, pretend we don't even have a long long." This is
1034 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1035
1036 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1037 pre-7.6 versions, which defined a global no_arg variable instead of putting
1038 it in the RE class. (See also #8 below.)
1039
1040 3. Remove a line of dead code, identified by coverity and reported by Nuno
1041 Lopes.
1042
1043 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1044
1045 (1) The include/exclude patterns were being applied to the whole pathnames
1046 of files, instead of just to the final components.
1047
1048 (2) If there was more than one level of directory, the subdirectories were
1049 skipped unless they satisfied the include/exclude conditions. This is
1050 inconsistent with GNU grep (and could even be seen as contrary to the
1051 pcregrep specification - which I improved to make it absolutely clear).
1052 The action now is always to scan all levels of directory, and just
1053 apply the include/exclude patterns to regular files.
1054
1055 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1056 --exclude_dir in the tests to avoid scanning .svn directories.
1057
1058 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1059 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1060 doesn't support NULs in patterns.
1061
1062 7. Added some missing "const"s to declarations of static tables in
1063 pcre_compile.c and pcre_dfa_exec.c.
1064
1065 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1066 caused by fix #2 above. (Subsequently also a second patch to fix the
1067 first patch. And a third patch - this was a messy problem.)
1068
1069 9. Applied Craig's patch to remove the use of push_back().
1070
1071 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1072 matching function regexec().
1073
1074 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1075 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1076 references. PCRE supports relative numbers with this syntax (I don't think
1077 Oniguruma does).
1078
1079 12. Previously, a group with a zero repeat such as (...){0} was completely
1080 omitted from the compiled regex. However, this means that if the group
1081 was called as a subroutine from elsewhere in the pattern, things went wrong
1082 (an internal error was given). Such groups are now left in the compiled
1083 pattern, with a new opcode that causes them to be skipped at execution
1084 time.
1085
1086 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1087 to the way PCRE behaves:
1088
1089 (a) A lone ] character is dis-allowed (Perl treats it as data).
1090
1091 (b) A back reference to an unmatched subpattern matches an empty string
1092 (Perl fails the current match path).
1093
1094 (c) A data ] in a character class must be notated as \] because if the
1095 first data character in a class is ], it defines an empty class. (In
1096 Perl it is not possible to have an empty class.) The empty class []
1097 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1098 The negative empty class [^] matches any one character, independently
1099 of the DOTALL setting.
1100
1101 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1102 non-existent subpattern following a character class starting with ']' and
1103 containing () gave an internal compiling error instead of "reference to
1104 non-existent subpattern". Fortunately, when the pattern did exist, the
1105 compiled code was correct. (When scanning forwards to check for the
1106 existencd of the subpattern, it was treating the data ']' as terminating
1107 the class, so got the count wrong. When actually compiling, the reference
1108 was subsequently set up correctly.)
1109
1110 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1111 it was being rejected as not supported by pcre_dfa_exec(), even though
1112 other assertions are supported. I have made pcre_dfa_exec() support
1113 (*FAIL).
1114
1115 16. The implementation of 13c above involved the invention of a new opcode,
1116 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1117 cannot be changed at match time, I realized I could make a small
1118 improvement to matching performance by compiling OP_ALLANY instead of
1119 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1120 on the OP_ANY path.
1121
1122 17. Compiling pcretest on Windows with readline support failed without the
1123 following two fixes: (1) Make the unistd.h include conditional on
1124 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1125
1126 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1127 ncurses library to be included for pcretest when ReadLine support is
1128 requested, but also to allow for it to be overridden. This patch came from
1129 Daniel Bergström.
1130
1131 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1132 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1133 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1134 spotting this.
1135
1136
1137 Version 7.6 28-Jan-08
1138 ---------------------
1139
1140 1. A character class containing a very large number of characters with
1141 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1142 overflow.
1143
1144 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1145 HAVE_LONG_LONG is not defined.
1146
1147 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1148 bring them up to date and include new features. This patch includes:
1149
1150 - Fixed PH's badly added libz and libbz2 support.
1151 - Fixed a problem with static linking.
1152 - Added pcredemo. [But later removed - see 7 below.]
1153 - Fixed dftables problem and added an option.
1154 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1155 HAVE_LONG_LONG.
1156 - Added readline support for pcretest.
1157 - Added an listing of the option settings after cmake has run.
1158
1159 4. A user submitted a patch to Makefile that makes it easy to create
1160 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1161 Makefile.am that cause it to include this special target, without
1162 affecting anything else. Note that the same mingw target plus all
1163 the other distribution libraries and programs are now supported
1164 when configuring with CMake (see 6 below) instead of with
1165 Configure/Make.
1166
1167 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1168 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1169 exported in the Windows port". It has not yet been confirmed that the patch
1170 solves the problem, but it does no harm.
1171
1172 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1173 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1174 with CMake, and also correct the comment about stack recursion.
1175
1176 7. Remove the automatic building of pcredemo from the ./configure system and
1177 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1178 of a program that users should build themselves after PCRE is installed, so
1179 building it automatically is not really right. What is more, it gave
1180 trouble in some build environments.
1181
1182 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1183
1184
1185 Version 7.5 10-Jan-08
1186 ---------------------
1187
1188 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1189 values in parens when parsing an RE using the C++ wrapper."
1190
1191 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1192 Characters greater than 255 were excluded from the class instead of being
1193 included.
1194
1195 3. The same bug as (2) above applied to negated POSIX classes such as
1196 [:^space:].
1197
1198 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1199 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1200 I have changed it.
1201
1202 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1203 first named subpattern) and a construct such as (?&a) would reference the
1204 first named subpattern whose name started with "a" (in other words, the
1205 length check was missing). Both these problems are fixed. "Subpattern name
1206 expected" is now given for (?&) (a zero-length name), and this patch also
1207 makes it give the same error for \k'' (previously it complained that that
1208 was a reference to a non-existent subpattern).
1209
1210 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1211 this is right because (?- can be followed by option settings as well as by
1212 digits. I have, however, made the messages clearer.
1213
1214 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1215 than the number used in the conditional) now cause a compile-time error.
1216 This is actually not compatible with Perl, which accepts such patterns, but
1217 treats the conditional as always being FALSE (as PCRE used to), but it
1218 seems to me that giving a diagnostic is better.
1219
1220 8. Change "alphameric" to the more common word "alphanumeric" in comments
1221 and messages.
1222
1223 9. Fix two occurrences of "backslash" in comments that should have been
1224 "backspace".
1225
1226 10. Remove two redundant lines of code that can never be obeyed (their function
1227 was moved elsewhere).
1228
1229 11. The program that makes PCRE's Unicode character property table had a bug
1230 which caused it to generate incorrect table entries for sequences of
1231 characters that have the same character type, but are in different scripts.
1232 It amalgamated them into a single range, with the script of the first of
1233 them. In other words, some characters were in the wrong script. There were
1234 thirteen such cases, affecting characters in the following ranges:
1235
1236 U+002b0 - U+002c1
1237 U+0060c - U+0060d
1238 U+0061e - U+00612
1239 U+0064b - U+0065e
1240 U+0074d - U+0076d
1241 U+01800 - U+01805
1242 U+01d00 - U+01d77
1243 U+01d9b - U+01dbf
1244 U+0200b - U+0200f
1245 U+030fc - U+030fe
1246 U+03260 - U+0327f
1247 U+0fb46 - U+0fbb1
1248 U+10450 - U+1049d
1249
1250 12. The -o option (show only the matching part of a line) for pcregrep was not
1251 compatible with GNU grep in that, if there was more than one match in a
1252 line, it showed only the first of them. It now behaves in the same way as
1253 GNU grep.
1254
1255 13. If the -o and -v options were combined for pcregrep, it printed a blank
1256 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1257 does the same. The return code can be used to tell if there were any
1258 non-matching lines.
1259
1260 14. Added --file-offsets and --line-offsets to pcregrep.
1261
1262 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1263 infinitely looping recursion. The bug was that positive lookaheads were not
1264 being skipped when checking for a possible empty match (negative lookaheads
1265 and both kinds of lookbehind were skipped).
1266
1267 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1268 inclusion of <windows.h> to before rather than after the definition of
1269 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1270
1271 17. Specifying a possessive quantifier with a specific limit for a Unicode
1272 character property caused pcre_compile() to compile bad code, which led at
1273 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1274 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1275 caused the error; without that there was no problem.
1276
1277 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1278
1279 19. Added --enable-pcretest-libreadline.
1280
1281 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1282 RE::GlobalReplace(). As a result, the number of replacements returned was
1283 double what it should be. I removed one of the increments, but Craig sent a
1284 later patch that removed the other one (the right fix) and added unit tests
1285 that check the return values (which was not done before).
1286
1287 21. Several CMake things:
1288
1289 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1290 the names libpcre and libpcreposix, not just pcre and pcreposix.
1291
1292 (2) The above change means that pcretest and pcregrep are now correctly
1293 linked with the newly-built libraries, not previously installed ones.
1294
1295 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1296
1297 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1298 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1299 UTF-8 newline character). The key issue is that the pattern starts .*;
1300 this means that the match must be either at the beginning, or after a
1301 newline. The bug was in the code for advancing after a failed match and
1302 checking that the new position followed a newline. It was not taking
1303 account of UTF-8 characters correctly.
1304
1305 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1306 character classes. PCRE was not treating the sequence [:...:] as a
1307 character class unless the ... were all letters. Perl, however, seems to
1308 allow any characters between [: and :], though of course it rejects as
1309 unknown any "names" that contain non-letters, because all the known class
1310 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1311 for example, whereas PCRE did not - it did not recognize a POSIX character
1312 class. This seemed a bit dangerous, so the code has been changed to be
1313 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1314 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1315 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1316 Perl does, and where it didn't before.
1317
1318 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1319 Windows environments %n is disabled by default.
1320
1321
1322 Version 7.4 21-Sep-07
1323 ---------------------
1324
1325 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1326 means that a class such as [\s] counted as "explicit reference to CR or
1327 LF". That isn't really right - the whole point of the change was to try to
1328 help when there was an actual mention of one of the two characters. So now
1329 the change happens only if \r or \n (or a literal CR or LF) character is
1330 encountered.
1331
1332 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1333 of both had grown to the point where there were only 3 bits left.
1334 Fortunately, there was spare space in the data structure, and so I have
1335 moved the internal flags into a new 16-bit field to free up more option
1336 bits.
1337
1338 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1339 but did not set the internal JCHANGED flag - either of these is enough to
1340 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1341 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1342 start sets both bits.
1343
1344 4. Added options (at build time, compile time, exec time) to change \R from
1345 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1346
1347 5. doc/pcresyntax.html was missing from the distribution.
1348
1349 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1350 compatibility, even though it is no longer used.
1351
1352 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1353 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1354 windows.h file is present (where different names are used). [This was
1355 reversed later after testing - see 16 below.]
1356
1357 8. Changed all #include <config.h> to #include "config.h". There were also
1358 some further <pcre.h> cases that I changed to "pcre.h".
1359
1360 9. When pcregrep was used with the --colour option, it missed the line ending
1361 sequence off the lines that it output.
1362
1363 10. It was pointed out to me that arrays of string pointers cause lots of
1364 relocations when a shared library is dynamically loaded. A technique of
1365 using a single long string with a table of offsets can drastically reduce
1366 these. I have refactored PCRE in four places to do this. The result is
1367 dramatic:
1368
1369 Originally: 290
1370 After changing UCP table: 187
1371 After changing error message table: 43
1372 After changing table of "verbs" 36
1373 After changing table of Posix names 22
1374
1375 Thanks to the folks working on Gregex for glib for this insight.
1376
1377 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1378 unicode-properties was also set.
1379
1380 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1381
1382 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1383 checked only for CRLF.
1384
1385 14. Added casts to pcretest.c to avoid compiler warnings.
1386
1387 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1388
1389 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1390 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1391 entirely. This removes changes made in 7 above.
1392
1393 17. The CMake files have been updated, and there is now more information about
1394 building with CMake in the NON-UNIX-USE document.
1395
1396
1397 Version 7.3 28-Aug-07
1398 ---------------------
1399
1400 1. In the rejigging of the build system that eventually resulted in 7.1, the
1401 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1402 brackets there is not right, since it causes compilers to look for an
1403 installed pcre.h, not the version that is in the source that is being
1404 compiled (which of course may be different). I have changed it back to:
1405
1406 #include "pcre.h"
1407
1408 I have a vague recollection that the change was concerned with compiling in
1409 different directories, but in the new build system, that is taken care of
1410 by the VPATH setting the Makefile.
1411
1412 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1413 when the subject happened to end in the byte 0x85 (e.g. if the last
1414 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1415 characters but of course it shouldn't be taken as a newline when it is part
1416 of another character. The bug was that, for an unlimited repeat of . in
1417 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1418 characters when looking for a newline.
1419
1420 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1421
1422 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1423 in debug output.
1424
1425 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1426 long printing in the pcrecpp unittest when running under MinGW.
1427
1428 6. ESC_K was left out of the EBCDIC table.
1429
1430 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1431 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1432 limit also applies to "virtual nesting" when a pattern is recursive, and in
1433 this case 1000 isn't so big. I have been able to remove this limit at the
1434 expense of backing off one optimization in certain circumstances. Normally,
1435 when pcre_exec() would call its internal match() function recursively and
1436 immediately return the result unconditionally, it uses a "tail recursion"
1437 feature to save stack. However, when a subpattern that can match an empty
1438 string has an unlimited repetition quantifier, it no longer makes this
1439 optimization. That gives it a stack frame in which to save the data for
1440 checking that an empty string has been matched. Previously this was taken
1441 from the 1000-entry workspace that had been reserved. So now there is no
1442 explicit limit, but more stack is used.
1443
1444 8. Applied Daniel's patches to solve problems with the import/export magic
1445 syntax that is required for Windows, and which was going wrong for the
1446 pcreposix and pcrecpp parts of the library. These were overlooked when this
1447 problem was solved for the main library.
1448
1449 9. There were some crude static tests to avoid integer overflow when computing
1450 the size of patterns that contain repeated groups with explicit upper
1451 limits. As the maximum quantifier is 65535, the maximum group length was
1452 set at 30,000 so that the product of these two numbers did not overflow a
1453 32-bit integer. However, it turns out that people want to use groups that
1454 are longer than 30,000 bytes (though not repeat them that many times).
1455 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1456 made it possible to implement the integer overflow checks in a much more
1457 dynamic way, which I have now done. The artificial limitation on group
1458 length has been removed - we now have only the limit on the total length of
1459 the compiled pattern, which depends on the LINK_SIZE setting.
1460
1461 10. Fixed a bug in the documentation for get/copy named substring when
1462 duplicate names are permitted. If none of the named substrings are set, the
1463 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1464 empty string.
1465
1466 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1467 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1468 because the ] is interpreted as the first data character and the
1469 terminating ] is not found. PCRE has been made compatible with Perl in this
1470 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1471 cause memory overwriting.
1472
1473 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1474 string has been matched (to stop an infinite loop). It was not recognizing
1475 a conditional subpattern that could match an empty string if that
1476 subpattern was within another subpattern. For example, it looped when
1477 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1478 condition was not nested. This bug has been fixed.
1479
1480 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1481 past the start of the subject in the presence of bytes with the top bit
1482 set, for example "\x8aBCD".
1483
1484 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1485 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1486
1487 14. Optimized (?!) to (*FAIL).
1488
1489 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1490 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1491 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1492 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1493 does: it's just the validity check that is more restrictive.
1494
1495 16. Inserted checks for integer overflows during escape sequence (backslash)
1496 processing, and also fixed erroneous offset values for syntax errors during
1497 backslash processing.
1498
1499 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1500 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1501
1502 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1503 caused an overrun.
1504
1505 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1506 something other than just ASCII characters) inside a group that had an
1507 unlimited repeat caused a loop at compile time (while checking to see
1508 whether the group could match an empty string).
1509
1510 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1511 [\P{Any}] did so. (Error in the code for printing property names.)
1512
1513 21. An orphan \E inside a character class could cause a crash.
1514
1515 22. A repeated capturing bracket such as (A)? could cause a wild memory
1516 reference during compilation.
1517
1518 23. There are several functions in pcre_compile() that scan along a compiled
1519 expression for various reasons (e.g. to see if it's fixed length for look
1520 behind). There were bugs in these functions when a repeated \p or \P was
1521 present in the pattern. These operators have additional parameters compared
1522 with \d, etc, and these were not being taken into account when moving along
1523 the compiled data. Specifically:
1524
1525 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1526 length.
1527
1528 (b) An item such as \pL+ within a repeated group could cause crashes or
1529 loops.
1530
1531 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1532 "reference to non-existent subpattern" error.
1533
1534 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1535
1536 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1537 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1538
1539 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1540
1541 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1542 character were causing crashes (broken optimization).
1543
1544 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1545 \p or \P) caused a compile-time loop.
1546
1547 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1548 break. For example, the unstudied pattern [\r\n]A does not match the string
1549 "\r\nA" because change 7.0/46 below moves the current point on by two
1550 characters after failing to match at the start. However, the pattern \nA
1551 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1552 the same is true. There doesn't seem any very clean way out of this, but
1553 what I have chosen to do makes the common cases work: PCRE now takes note
1554 of whether there can be an explicit match for \r or \n anywhere in the
1555 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1556 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1557 pattern has explicit CR or LF references.
1558
1559 29. Added (*CR) etc for changing newline setting at start of pattern.
1560
1561
1562 Version 7.2 19-Jun-07
1563 ---------------------
1564
1565 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1566 which is apparently normally available under Windows.
1567
1568 2. Re-jig the pcregrep tests with different newline settings in an attempt
1569 to make them independent of the local environment's newline setting.
1570
1571 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1572
1573 4. Some of the "internals" tests were previously cut out when the link size
1574 was not 2, because the output contained actual offsets. The recent new
1575 "Z" feature of pcretest means that these can be cut out, making the tests
1576 usable with all link sizes.
1577
1578 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1579 stack recursion. This gives a massive performance boost under BSD, but just
1580 a small improvement under Linux. However, it saves one field in the frame
1581 in all cases.
1582
1583 6. Added more features from the forthcoming Perl 5.10:
1584
1585 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1586 recursion call. It refers to the nth most recently opened parentheses.
1587
1588 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1589 to be opened parentheses.
1590
1591 (c) Conditions that refer to capturing parentheses can be specified
1592 relatively, for example, (?(-2)... or (?(+3)...
1593
1594 (d) \K resets the start of the current match so that everything before
1595 is not part of it.
1596
1597 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1598
1599 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1600 reference syntax.
1601
1602 (g) (?| introduces a group in which the numbering of parentheses in each
1603 alternative starts with the same number.
1604
1605 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1606
1607 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1608 PCRE_INFO_JCHANGED.
1609
1610 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1611 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1612 for detecting groups that can match an empty string.
1613
1614 9. A pattern with a very large number of alternatives (more than several
1615 hundred) was running out of internal workspace during the pre-compile
1616 phase, where pcre_compile() figures out how much memory will be needed. A
1617 bit of new cunning has reduced the workspace needed for groups with
1618 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1619 workspace instead of running out of the 4096 that are available.
1620
1621 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1622
1623 11. Applied patch from Google to remove an optimization that didn't quite work.
1624 The report of the bug said:
1625
1626 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1627 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1628 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1629
1630 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1631 it matched the wrong number of bytes.
1632
1633
1634 Version 7.1 24-Apr-07
1635 ---------------------
1636
1637 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1638 that is more "standard", making use of automake and other Autotools. There
1639 is some re-arrangement of the files and adjustment of comments consequent
1640 on this.
1641
1642 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1643 for recursive directory scanning broke on some systems because the files
1644 are not scanned in any specific order and on different systems the order
1645 was different. A call to "sort" has been inserted into RunGrepTest for the
1646 approprate test as a short-term fix. In the longer term there may be an
1647 alternative.
1648
1649 3. I had an email from Eric Raymond about problems translating some of PCRE's
1650 man pages to HTML (despite the fact that I distribute HTML pages, some
1651 people do their own conversions for various reasons). The problems
1652 concerned the use of low-level troff macros .br and .in. I have therefore
1653 removed all such uses from the man pages (some were redundant, some could
1654 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1655 HTML has been updated to handle .nf/.fi and to complain if it encounters
1656 .br or .in.
1657
1658 4. Updated comments in configure.ac that get placed in config.h.in and also
1659 arranged for config.h to be included in the distribution, with the name
1660 config.h.generic, for the benefit of those who have to compile without
1661 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1662
1663 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1664 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1665 makevp.bat for the current PCRE, using the additional files
1666 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1667
1668 6. A Windows user reported a minor discrepancy with test 2, which turned out
1669 to be caused by a trailing space on an input line that had got lost in his
1670 copy. The trailing space was an accident, so I've just removed it.
1671
1672 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1673 that is needed.
1674
1675 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1676 as "const" (a) because they are and (b) because it helps the PHP
1677 maintainers who have recently made a script to detect big data structures
1678 in the php code that should be moved to the .rodata section. I remembered
1679 to update Builducptable as well, so it won't revert if ucptable.h is ever
1680 re-created.
1681
1682 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1683 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1684 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1685 support is not required. This saves 1.5-2K of code, which is important in
1686 some applications.
1687
1688 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1689 so as not to refer to the tables, even though these functions will never be
1690 called when UTF-8 support is disabled. Otherwise there are problems with a
1691 shared library.
1692
1693 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1694
1695 (a) It was defining its arguments as char * instead of void *.
1696
1697 (b) It was assuming that all moves were upwards in memory; this was true
1698 a long time ago when I wrote it, but is no longer the case.
1699
1700 The emulated memove() is provided for those environments that have neither
1701 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1702 is clearly not the case, as these two bugs were recently reported.
1703
1704 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1705 and Detrail to create the HTML documentation, the .txt form of the man
1706 pages, and it removes trailing spaces from listed files. It also creates
1707 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1708 case, it wraps all the #defines with #ifndefs. This script should be run
1709 before "make dist".
1710
1711 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1712 with Unicode property support.
1713
1714 (a) For a maximizing quantifier, if the two different cases of the
1715 character were of different lengths in their UTF-8 codings (there are
1716 some cases like this - I found 11), and the matching function had to
1717 back up over a mixture of the two cases, it incorrectly assumed they
1718 were both the same length.
1719
1720 (b) When PCRE was configured to use the heap rather than the stack for
1721 recursion during matching, it was not correctly preserving the data for
1722 the other case of a UTF-8 character when checking ahead for a match
1723 while processing a minimizing repeat. If the check also involved
1724 matching a wide character, but failed, corruption could cause an
1725 erroneous result when trying to check for a repeat of the original
1726 character.
1727
1728 13. Some tidying changes to the testing mechanism:
1729
1730 (a) The RunTest script now detects the internal link size and whether there
1731 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1732 values substituted by "configure". (The RunGrepTest script already did
1733 this for UTF-8.) The configure.ac script no longer substitutes the
1734 relevant variables.
1735
1736 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1737 with length and offset values. This means that the output is different
1738 for different internal link sizes. Test 2 is skipped for link sizes
1739 other than 2 because of this, bypassing the problem. Unfortunately,
1740 there was also a test in test 3 (the locale tests) that used /B and
1741 failed for link sizes other than 2. Rather than cut the whole test out,
1742 I have added a new /Z option to pcretest that replaces the length and
1743 offset values with spaces. This is now used to make test 3 independent
1744 of link size. (Test 2 will be tidied up later.)
1745
1746 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1747 segmentation fault instead of returning the appropriate error message.
1748
1749 15. In multiline mode when the newline sequence was set to "any", the pattern
1750 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1751 This doesn't seem right; it now treats the CRLF combination as the line
1752 ending, and so does not match in that case. It's only a pattern such as ^$
1753 that would hit this one: something like ^ABC$ would have failed after \r
1754 and then tried again after \r\n.
1755
1756 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1757 in an attempt to make files that differ only in their line terminators
1758 compare equal. This works on Linux.
1759
1760 17. Under certain error circumstances pcregrep might try to free random memory
1761 as it exited. This is now fixed, thanks to valgrind.
1762
1763 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1764 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1765 was because its rules for how to advance for /g after matching an empty
1766 string at the end of a line did not allow for this case. They now check for
1767 it specially.
1768
1769 20. pcretest is supposed to handle patterns and data of any length, by
1770 extending its buffers when necessary. It was getting this wrong when the
1771 buffer for a data line had to be extended.
1772
1773 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1774 CRLF as a newline sequence.
1775
1776 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1777 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1778 I have nevertheless tidied it up.
1779
1780 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1781
1782 24. Added a man page for pcre-config.
1783
1784
1785 Version 7.0 19-Dec-06
1786 ---------------------
1787
1788 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1789 moving to gcc 4.1.1.
1790
1791 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1792 sys/time.h, which is documented as needed for this function. It doesn't
1793 seem to matter on Linux, but it showed up on some releases of OS X.
1794
1795 3. It seems that there are systems where bytes whose values are greater than
1796 127 match isprint() in the "C" locale. The "C" locale should be the
1797 default when a C program starts up. In most systems, only ASCII printing
1798 characters match isprint(). This difference caused the output from pcretest
1799 to vary, making some of the tests fail. I have changed pcretest so that:
1800
1801 (a) When it is outputting text in the compiled version of a pattern, bytes
1802 other than 32-126 are always shown as hex escapes.
1803
1804 (b) When it is outputting text that is a matched part of a subject string,
1805 it does the same, unless a different locale has been set for the match
1806 (using the /L modifier). In this case, it uses isprint() to decide.
1807
1808 4. Fixed a major bug that caused incorrect computation of the amount of memory
1809 required for a compiled pattern when options that changed within the
1810 pattern affected the logic of the preliminary scan that determines the
1811 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1812 that the computed length was too small. The symptoms of this bug were
1813 either the PCRE error "internal error: code overflow" from pcre_compile(),
1814 or a glibc crash with a message such as "pcretest: free(): invalid next
1815 size (fast)". Examples of patterns that provoked this bug (shown in
1816 pcretest format) are:
1817
1818 /(?-x: )/x
1819 /(?x)(?-x: \s*#\s*)/
1820 /((?i)[\x{c0}])/8
1821 /(?i:[\x{c0}])/8
1822
1823 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1824 is now done differently.
1825
1826 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1827 wrapper classes; (b) implement a new function in the C++ scanner that is
1828 more efficient than the old way of doing things because it avoids levels of
1829 recursion in the regex matching; (c) add a paragraph to the documentation
1830 for the FullMatch() function.
1831
1832 6. The escape sequence \n was being treated as whatever was defined as
1833 "newline". Not only was this contrary to the documentation, which states
1834 that \n is character 10 (hex 0A), but it also went horribly wrong when
1835 "newline" was defined as CRLF. This has been fixed.
1836
1837 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1838 was being set to -1 for the "end of line" case (supposedly a value that no
1839 character can have). Though this value is never used (the check for end of
1840 line is "zero bytes in current character"), it caused compiler complaints.
1841 I've changed it to 0xffffffff.
1842
1843 8. In pcre_version.c, the version string was being built by a sequence of
1844 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1845 string (as it is for production releases) called a macro with an empty
1846 argument. The C standard says the result of this is undefined. The gcc
1847 compiler treats it as an empty string (which was what was wanted) but it is
1848 reported that Visual C gives an error. The source has been hacked around to
1849 avoid this problem.
1850
1851 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1852 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1853 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1854 of them did).
1855
1856 10. Originally, pcretest opened its input and output without "b"; then I was
1857 told that "b" was needed in some environments, so it was added for release
1858 5.0 to both the input and output. (It makes no difference on Unix-like
1859 systems.) Later I was told that it is wrong for the input on Windows. I've
1860 now abstracted the modes into two macros, to make it easier to fiddle with
1861 them, and removed "b" from the input mode under Windows.
1862
1863 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1864
1865 12. Added -help and --help to pcretest as an official way of being reminded
1866 of the options.
1867
1868 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1869 and pcrecpp.cc because they annoy compilers at high warning levels.
1870
1871 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1872
1873 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1874 scripts are not C programs :-) and which was not noticed because it works
1875 on Linux.
1876
1877 16. pcretest is supposed to handle any length of pattern and data line (as one
1878 line or as a continued sequence of lines) by extending its input buffer if
1879 necessary. This feature was broken for very long pattern lines, leading to
1880 a string of junk being passed to pcre_compile() if the pattern was longer
1881 than about 50K.
1882
1883 17. I have done a major re-factoring of the way pcre_compile() computes the
1884 amount of memory needed for a compiled pattern. Previously, there was code
1885 that made a preliminary scan of the pattern in order to do this. That was
1886 OK when PCRE was new, but as the facilities have expanded, it has become
1887 harder and harder to keep it in step with the real compile phase, and there
1888 have been a number of bugs (see for example, 4 above). I have now found a
1889 cunning way of running the real compile function in a "fake" mode that
1890 enables it to compute how much memory it would need, while actually only
1891 ever using a few hundred bytes of working memory and without too many
1892 tests of the mode. This should make future maintenance and development
1893 easier. A side effect of this work is that the limit of 200 on the nesting
1894 depth of parentheses has been removed (though this was never a serious
1895 limitation, I suspect). However, there is a downside: pcre_compile() now
1896 runs more slowly than before (30% or more, depending on the pattern). I
1897 hope this isn't a big issue. There is no effect on runtime performance.
1898
1899 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1900 newline (only possible for the last line of a file) and it was a
1901 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1902
1903 19. Added additional timing features to pcretest. (1) The -tm option now times
1904 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1905 separate command line item, by a number that specifies the number of
1906 repeats to use when timing. The default is 50000; this gives better
1907 precision, but takes uncomfortably long for very large patterns.
1908
1909 20. Extended pcre_study() to be more clever in cases where a branch of a
1910 subpattern has no definite first character. For example, (a*|b*)[cd] would
1911 previously give no result from pcre_study(). Now it recognizes that the
1912 first character must be a, b, c, or d.
1913
1914 21. There was an incorrect error "recursive call could loop indefinitely" if
1915 a subpattern (or the entire pattern) that was being tested for matching an
1916 empty string contained only one non-empty item after a nested subpattern.
1917 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1918 incorrectly, because the \d was being skipped in the check.
1919
1920 22. The pcretest program now has a new pattern option /B and a command line
1921 option -b, which is equivalent to adding /B to every pattern. This causes
1922 it to show the compiled bytecode, without the additional information that
1923 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1924 is the same as /B/I).
1925
1926 23. A new optimization is now able automatically to treat some sequences such
1927 as a*b as a*+b. More specifically, if something simple (such as a character
1928 or a simple class like \d) has an unlimited quantifier, and is followed by
1929 something that cannot possibly match the quantified thing, the quantifier
1930 is automatically "possessified".
1931
1932 24. A recursive reference to a subpattern whose number was greater than 39
1933 went wrong under certain circumstances in UTF-8 mode. This bug could also
1934 have affected the operation of pcre_study().
1935
1936 25. Realized that a little bit of performance could be had by replacing
1937 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1938
1939 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1940
1941 27. Possessive quantifiers such as a++ were previously implemented by turning
1942 them into atomic groups such as ($>a+). Now they have their own opcodes,
1943 which improves performance. This includes the automatically created ones
1944 from 23 above.
1945
1946 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1947 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1948 the first matched character to be a colon. This applied both to named and
1949 numbered groups.
1950
1951 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1952
1953 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1954 building PCRE on Windows easier, so I have included it in the distribution.
1955
1956 31. There is now a check in pcretest against a ridiculously large number being
1957 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1958 loop, the loop is abandoned.
1959
1960 32. Forward references to subpatterns in conditions such as (?(2)...) where
1961 subpattern 2 is defined later cause pcre_compile() to search forwards in
1962 the pattern for the relevant set of parentheses. This search went wrong
1963 when there were unescaped parentheses in a character class, parentheses
1964 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1965
1966 33. "Subroutine" calls and backreferences were previously restricted to
1967 referencing subpatterns earlier in the regex. This restriction has now
1968 been removed.
1969
1970 34. Added a number of extra features that are going to be in Perl 5.10. On the
1971 whole, these are just syntactic alternatives for features that PCRE had
1972 previously implemented using the Python syntax or my own invention. The
1973 other formats are all retained for compatibility.
1974
1975 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1976 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1977 also .NET compatible.
1978
1979 (b) A recursion or subroutine call to a named group can now be defined as
1980 (?&name) as well as (?P>name).
1981
1982 (c) A backreference to a named group can now be defined as \k<name> or
1983 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1984 5.10, are also .NET compatible.
1985
1986 (d) A conditional reference to a named group can now use the syntax
1987 (?(<name>) or (?('name') as well as (?(name).
1988
1989 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1990 groups (named and numbered) that are never evaluated inline, but can be
1991 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1992 is always false. There may be only one alternative in such a group.
1993
1994 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1995 as the simple (?(R). The condition is true only if the most recent
1996 recursion is that of the given number or name. It does not search out
1997 through the entire recursion stack.
1998
1999 (g) The escape \gN or \g{N} has been added, where N is a positive or
2000 negative number, specifying an absolute or relative reference.
2001
2002 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2003 some "unreachable code" warnings.
2004
2005 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2006 things, this adds five new scripts.
2007
2008 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2009 There were also incompatibilities regarding the handling of \Q..\E inside
2010 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2011 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2012
2013 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2014 matches an empty string, and forcibly breaks the loop. There were bugs in
2015 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2016 against aaaa the result was just "a" rather than "aaaa", for example. Two
2017 separate and independent bugs (that affected different cases) have been
2018 fixed.
2019
2020 39. Refactored the code to abolish the use of different opcodes for small
2021 capturing bracket numbers. This is a tidy that I avoided doing when I
2022 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2023 The new approach is not only tidier, it makes it possible to reduce the
2024 memory needed to fix the previous bug (38).
2025
2026 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2027 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2028 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2029 mode.
2030
2031 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2032 report.
2033
2034 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2035 copy construction and assignment in the C++ wrapper.
2036
2037 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2038 couple of bugs that could have given wrong results in the "--newline=crlf"
2039 case.
2040
2041 44. Added a number of casts and did some reorganization of signed/unsigned int
2042 variables following suggestions from Dair Grant. Also renamed the variable
2043 "this" as "item" because it is a C++ keyword.
2044
2045 45. Arranged for dftables to add
2046
2047 #include "pcre_internal.h"
2048
2049 to pcre_chartables.c because without it, gcc 4.x may remove the array
2050 definition from the final binary if PCRE is built into a static library and
2051 dead code stripping is activated.
2052
2053 46. For an unanchored pattern, if a match attempt fails at the start of a
2054 newline sequence, and the newline setting is CRLF or ANY, and the next two
2055 characters are CRLF, advance by two characters instead of one.
2056
2057
2058 Version 6.7 04-Jul-06
2059 ---------------------
2060
2061 1. In order to handle tests when input lines are enormously long, pcretest has
2062 been re-factored so that it automatically extends its buffers when
2063 necessary. The code is crude, but this _is_ just a test program. The
2064 default size has been increased from 32K to 50K.
2065
2066 2. The code in pcre_study() was using the value of the re argument before
2067 testing it for NULL. (Of course, in any sensible call of the function, it
2068 won't be NULL.)
2069
2070 3. The memmove() emulation function in pcre_internal.h, which is used on
2071 systems that lack both memmove() and bcopy() - that is, hardly ever -
2072 was missing a "static" storage class specifier.
2073
2074 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2075 containing an extended class (one that cannot be represented by a bitmap
2076 because it contains high-valued characters or Unicode property items, e.g.
2077 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2078 pattern, but PCRE should not loop if you do not (it no longer does).
2079 [Detail: two cases were found: (a) a repeated subpattern containing an
2080 extended class; (b) a recursive reference to a subpattern that followed a
2081 previous extended class. It wasn't skipping over the extended class
2082 correctly when UTF-8 mode was not set.]
2083
2084 5. A negated single-character class was not being recognized as fixed-length
2085 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2086 compile error "lookbehind assertion is not fixed length".
2087
2088 6. The RunPerlTest auxiliary script was showing an unexpected difference
2089 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2090 write a Perl script that can interpret lines of an input file either as
2091 byte characters or as UTF-8, which is what "perltest" was being required to
2092 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2093 can't do is switch easily at run time between having the "use utf8;" pragma
2094 or not. In the end, I fudged it by using the RunPerlTest script to insert
2095 "use utf8;" explicitly for the UTF-8 tests.
2096
2097 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2098 the end of the subject string, contrary to the documentation and to what
2099 Perl does. This was true of both matching functions. Now it matches only at
2100 the start of the subject and immediately after *internal* newlines.
2101
2102 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2103 a pointer to an int instead of a pointer to an unsigned long int. This
2104 caused problems on 64-bit systems.
2105
2106 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2107 instance of the 'standard' template library not being so standard".
2108
2109 10. There was no check on the number of named subpatterns nor the maximum
2110 length of a subpattern name. The product of these values is used to compute
2111 the size of the memory block for a compiled pattern. By supplying a very
2112 long subpattern name and a large number of named subpatterns, the size
2113 computation could be caused to overflow. This is now prevented by limiting
2114 the length of names to 32 characters, and the number of named subpatterns
2115 to 10,000.
2116
2117 11. Subpatterns that are repeated with specific counts have to be replicated in
2118 the compiled pattern. The size of memory for this was computed from the
2119 length of the subpattern and the repeat count. The latter is limited to
2120 65535, but there was no limit on the former, meaning that integer overflow
2121 could in principle occur. The compiled length of a repeated subpattern is
2122 now limited to 30,000 bytes in order to prevent this.
2123
2124 12. Added the optional facility to have named substrings with the same name.
2125
2126 13. Added the ability to use a named substring as a condition, using the
2127 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2128 are numbers (not recommended). Forward references are permitted.
2129
2130 14. Added forward references in named backreferences (if you see what I mean).
2131
2132 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2133 pattern could run off the end of the subject. For example, the pattern
2134 "(?s)(.{1,5})"8 did this with the subject "ab".
2135
2136 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2137 PCRE_CASELESS was set when matching characters that were quantified with ?
2138 or *.
2139
2140 17. A character class other than a single negated character that had a minimum
2141 but no maximum quantifier - for example [ab]{6,} - was not handled
2142 correctly by pce_dfa_exec(). It would match only one character.
2143
2144 18. A valid (though odd) pattern that looked like a POSIX character
2145 class but used an invalid character after [ (for example [[,abc,]]) caused
2146 pcre_compile() to give the error "Failed: internal error: code overflow" or
2147 in some cases to crash with a glibc free() error. This could even happen if
2148 the pattern terminated after [[ but there just happened to be a sequence of
2149 letters, a binary zero, and a closing ] in the memory that followed.
2150
2151 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2152 over the years. Originally (before any Unicode support), just the bottom 8
2153 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2154 output from "man perlunicode" includes this:
2155
2156 The regular expression compiler produces polymorphic opcodes. That
2157 is, the pattern adapts to the data and automatically switches to
2158 the Unicode character scheme when presented with Unicode data--or
2159 instead uses a traditional byte scheme when presented with byte
2160 data.
2161
2162 Sadly, a wide octal escape does not cause a switch, and in a string with
2163 no other multibyte characters, these octal escapes are treated as before.
2164 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2165 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2166 Unicode string.
2167
2168 I have not perpetrated such confusion in PCRE. Up till now, it took just
2169 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2170 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2171 translate to the appropriate multibyte character.
2172
2173 29. Applied some refactoring to reduce the number of warnings from Microsoft
2174 and Borland compilers. This has included removing the fudge introduced
2175 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2176 a warning about an unused variable.
2177
2178 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2179 characters since release 4.0, because Perl (from release 5.004) does not.
2180 [Or at least, is documented not to: some releases seem to be in conflict
2181 with the documentation.] However, when a pattern was studied with
2182 pcre_study() and all its branches started with \s, PCRE still included VT
2183 as a possible starting character. Of course, this did no harm; it just
2184 caused an unnecessary match attempt.
2185
2186 22. Removed a now-redundant internal flag bit that recorded the fact that case
2187 dependency changed within the pattern. This was once needed for "required
2188 byte" processing, but is no longer used. This recovers a now-scarce options
2189 bit. Also moved the least significant internal flag bit to the most-
2190 significant bit of the word, which was not previously used (hangover from
2191 the days when it was an int rather than a uint) to free up another bit for
2192 the future.
2193
2194 23. Added support for CRLF line endings as well as CR and LF. As well as the
2195 default being selectable at build time, it can now be changed at runtime
2196 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2197 specify that it is scanning data with non-default line endings.
2198
2199 24. Changed the definition of CXXLINK to make it agree with the definition of
2200 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2201
2202 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2203 recursions. This makes a big different to stack usage for some patterns.
2204
2205 26. If a subpattern containing a named recursion or subroutine reference such
2206 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2207 the space required for the compiled pattern went wrong and gave too small a
2208 value. Depending on the environment, this could lead to "Failed: internal
2209 error: code overflow at offset 49" or "glibc detected double free or
2210 corruption" errors.
2211
2212 27. Applied patches from Google (a) to support the new newline modes and (b) to
2213 advance over multibyte UTF-8 characters in GlobalReplace.
2214
2215 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2216 difference for some implementation of PCRE in some Windows version.
2217
2218 29. Added some extra testing facilities to pcretest:
2219
2220 \q<number> in a data line sets the "match limit" value
2221 \Q<number> in a data line sets the "match recursion limt" value
2222 -S <number> sets the stack size, where <number> is in megabytes
2223
2224 The -S option isn't available for Windows.
2225
2226
2227 Version 6.6 06-Feb-06
2228 ---------------------
2229
2230 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2231 in pcreposix.h. I have copied the definition from pcre.h.
2232
2233 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2234 because pcre.h is no longer a built file.
2235
2236 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2237 not normally included in the compiled code.
2238
2239
2240 Version 6.5 01-Feb-06
2241 ---------------------
2242
2243 1. When using the partial match feature with pcre_dfa_exec(), it was not
2244 anchoring the second and subsequent partial matches at the new starting
2245 point. This could lead to incorrect results. For example, with the pattern
2246 /1234/, partially matching against "123" and then "a4" gave a match.
2247
2248 2. Changes to pcregrep:
2249
2250 (a) All non-match returns from pcre_exec() were being treated as failures
2251 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2252 error message is output. Some extra information is given for the
2253 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2254 probably the only errors that are likely to be caused by users (by
2255 specifying a regex that has nested indefinite repeats, for instance).
2256 If there are more than 20 of these errors, pcregrep is abandoned.
2257
2258 (b) A binary zero was treated as data while matching, but terminated the
2259 output line if it was written out. This has been fixed: binary zeroes
2260 are now no different to any other data bytes.
2261
2262 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2263 used to set a locale for matching. The --locale=xxxx long option has
2264 been added (no short equivalent) to specify a locale explicitly on the
2265 pcregrep command, overriding the environment variables.
2266
2267 (d) When -B was used with -n, some line numbers in the output were one less
2268 than they should have been.
2269
2270 (e) Added the -o (--only-matching) option.
2271
2272 (f) If -A or -C was used with -c (count only), some lines of context were
2273 accidentally printed for the final match.
2274
2275 (g) Added the -H (--with-filename) option.
2276
2277 (h) The combination of options -rh failed to suppress file names for files
2278 that were found from directory arguments.
2279
2280 (i) Added the -D (--devices) and -d (--directories) options.
2281
2282 (j) Added the -F (--fixed-strings) option.
2283
2284 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2285
2286 (l) Added the --colo(u)r option.
2287
2288 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2289 is not present by default.
2290
2291 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2292 items such as (?R) or (?1), when the recursion could match a number of
2293 alternatives. If it matched one of the alternatives, but subsequently,
2294 outside the recursion, there was a failure, the code tried to back up into
2295 the recursion. However, because of the way PCRE is implemented, this is not
2296 possible, and the result was an incorrect result from the match.
2297
2298 In order to prevent this happening, the specification of recursion has
2299 been changed so that all such subpatterns are automatically treated as
2300 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2301
2302 4. I had overlooked the fact that, in some locales, there are characters for
2303 which isalpha() is true but neither isupper() nor islower() are true. In
2304 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2305 and ordfeminine) are like this. This affected the treatment of \w and \W
2306 when they appeared in character classes, but not when they appeared outside
2307 a character class. The bit map for "word" characters is now created
2308 separately from the results of isalnum() instead of just taking it from the
2309 upper, lower, and digit maps. (Plus the underscore character, of course.)
2310
2311 5. The above bug also affected the handling of POSIX character classes such as
2312 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2313 permanent tables. Instead, the bit maps for such a class were previously
2314 created as the appropriate unions of the upper, lower, and digit bitmaps.
2315 Now they are created by subtraction from the [[:word:]] class, which has
2316 its own bitmap.
2317
2318 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2319 It is created by subtracting the vertical space characters (\x09, \x0a,
2320 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2321 subtraction was done in the overall bitmap for a character class, meaning
2322 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2323 be recognized. This bug has been fixed.
2324
2325 7. Patches from the folks at Google:
2326
2327 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2328 real life, but is still worth protecting against".
2329
2330 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2331 regular expressions".
2332
2333 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2334 have it.
2335
2336 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2337 "configure" and the latter not, in order to fix a problem somebody had
2338 with compiling the Arg class on HP-UX.
2339
2340 (e) Improve the error-handling of the C++ wrapper a little bit.
2341
2342 (f) New tests for checking recursion limiting.
2343
2344 8. The pcre_memmove() function, which is used only if the environment does not
2345 have a standard memmove() function (and is therefore rarely compiled),
2346 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2347 returning a result (though PCRE never actually uses the result).
2348
2349 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2350 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2351 returned instead of calling malloc() with an overflowing number that would
2352 most likely cause subsequent chaos.
2353
2354 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2355
2356 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2357 with this option is matched, the nmatch and pmatch options of regexec() are
2358 ignored.
2359
2360 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2361 provided in case anyone wants to the the POSIX interface with UTF-8
2362 strings.
2363
2364 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2365 C++ linking (needed for some HP-UX environments).
2366
2367 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2368 (unused parameter) and in the pcre_printint() function (omitted "default"
2369 switch label when the default is to do nothing).
2370
2371 15. Added some code to make it possible, when PCRE is compiled as a C++
2372 library, to replace subject pointers for pcre_exec() with a smart pointer
2373 class, thus making it possible to process discontinuous strings.
2374
2375 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2376 much the same function. They were added by different people who were trying
2377 to make PCRE easy to compile on non-Unix systems. It has been suggested
2378 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2379 for compiling on Windows systems. I have therefore replaced it with
2380 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2381 defaults to "extern" for C or "extern C" for C++, which works fine on
2382 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2383 SCOPE with something explicit in config.h. In addition:
2384
2385 (a) pcreposix.h still had just "extern" instead of either of these macros;
2386 I have replaced it with PCRE_DATA_SCOPE.
2387
2388 (b) Functions such as _pcre_xclass(), which are internal to the library,
2389 but external in the C sense, all had PCRE_EXPORT in their definitions.
2390 This is apparently wrong for the Windows case, so I have removed it.
2391 (It makes no difference on Unix-like systems.)
2392
2393 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2394 of recursive calls to match(). This is different to MATCH_LIMIT because
2395 that limits the total number of calls to match(), not all of which increase
2396 the depth of recursion. Limiting the recursion depth limits the amount of
2397 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2398 when PCRE is compiled, and changed at run time. A patch from Google adds
2399 this functionality to the C++ interface.
2400
2401 18. Changes to the handling of Unicode character properties:
2402
2403 (a) Updated the table to Unicode 4.1.0.
2404
2405 (b) Recognize characters that are not in the table as "Cn" (undefined).
2406
2407 (c) I revised the way the table is implemented to a much improved format
2408 which includes recognition of ranges. It now supports the ranges that
2409 are defined in UnicodeData.txt, and it also amalgamates other
2410 characters into ranges. This has reduced the number of entries in the
2411 table from around 16,000 to around 3,000, thus reducing its size
2412 considerably. I realized I did not need to use a tree structure after
2413 all - a binary chop search is just as efficient. Having reduced the
2414 number of entries, I extended their size from 6 bytes to 8 bytes to
2415 allow for more data.
2416
2417 (d) Added support for Unicode script names via properties such as \p{Han}.
2418
2419 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2420 matching that character.
2421
2422 20. When matching a repeated Unicode property with a minimum greater than zero,
2423 (for example \pL{2,}), PCRE could look past the end of the subject if it
2424 reached it while seeking the minimum number of characters. This could
2425 happen only if some of the characters were more than one byte long, because
2426 there is a check for at least the minimum number of bytes.
2427
2428 21. Refactored the implementation of \p and \P so as to be more general, to
2429 allow for more different types of property in future. This has changed the
2430 compiled form incompatibly. Anybody with saved compiled patterns that use
2431 \p or \P will have to recompile them.
2432
2433 22. Added "Any" and "L&" to the supported property types.
2434
2435 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2436 but give a compile time error if the value is greater than 0xff.
2437
2438 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2439 accidentally not being installed or uninstalled.
2440
2441 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2442 made were to insert the current release number. This seemed silly, because
2443 it made things harder for people building PCRE on systems that don't run
2444 "configure". I have turned pcre.h into a distributed file, no longer built
2445 by "configure", with the version identification directly included. There is
2446 no longer a pcre.h.in file.
2447
2448 However, this change necessitated a change to the pcre-config script as
2449 well. It is built from pcre-config.in, and one of the substitutions was the
2450 release number. I have updated configure.ac so that ./configure now finds
2451 the release number by grepping pcre.h.
2452
2453 26. Added the ability to run the tests under valgrind.
2454
2455
2456 Version 6.4 05-Sep-05
2457 ---------------------
2458
2459 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2460 "--" to be printed when multiple files were scanned, even when none of the
2461 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2462 consider it to be a bug, and have restored the previous behaviour.
2463
2464 2. A couple of code tidies to get rid of compiler warnings.
2465
2466 3. The pcretest program used to cheat by referring to symbols in the library
2467 whose names begin with _pcre_. These are internal symbols that are not
2468 really supposed to be visible externally, and in some environments it is
2469 possible to suppress them. The cheating is now confined to including
2470 certain files from the library's source, which is a bit cleaner.
2471
2472 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2473 file's purpose clearer.
2474
2475 5. Reorganized pcre_ucp_findchar().
2476
2477
2478 Version 6.3 15-Aug-05
2479 ---------------------
2480
2481 1. The file libpcre.pc.in did not have general read permission in the tarball.
2482
2483 2. There were some problems when building without C++ support:
2484
2485 (a) If C++ support was not built, "make install" and "make test" still
2486 tried to test it.
2487
2488 (b) There were problems when the value of CXX was explicitly set. Some
2489 changes have been made to try to fix these, and ...
2490
2491 (c) --disable-cpp can now be used to explicitly disable C++ support.
2492
2493 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2494 backslash in a target when C++ was disabled. This confuses some
2495 versions of "make", apparently. Using an intermediate variable solves
2496 this. (Same for CPP_LOBJ.)
2497
2498 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2499 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2500 necessary on certain architectures.
2501
2502 4. Added a setting of -export-symbols-regex to the link command to remove
2503 those symbols that are exported in the C sense, but actually are local
2504 within the library, and not documented. Their names all begin with
2505 "_pcre_". This is not a perfect job, because (a) we have to except some
2506 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2507 available (and never for static libraries). I have made a note to try to
2508 find a way round (a) in the future.
2509
2510
2511 Version 6.2 01-Aug-05
2512 ---------------------
2513
2514 1. There was no test for integer overflow of quantifier values. A construction
2515 such as {1111111111111111} would give undefined results. What is worse, if
2516 a minimum quantifier for a parenthesized subpattern overflowed and became
2517 negative, the calculation of the memory size went wrong. This could have
2518 led to memory overwriting.
2519
2520 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2521
2522 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2523 operating environments where this matters.
2524
2525 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2526 PCRE options from within the C++ wrapper.
2527
2528 5. Named capturing subpatterns were not being correctly counted when a pattern
2529 was compiled. This caused two problems: (a) If there were more than 100
2530 such subpatterns, the calculation of the memory needed for the whole
2531 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2532 back references of the form \12, where the number was greater than 9, were
2533 not recognized as back references, even though there were sufficient
2534 previous subpatterns.
2535
2536 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2537 versions of gcc, e.g. 2.95.4.
2538
2539
2540 Version 6.1 21-Jun-05
2541 ---------------------
2542
2543 1. There was one reference to the variable "posix" in pcretest.c that was not
2544 surrounded by "#if !defined NOPOSIX".
2545
2546 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2547 the cross-check on the old pcre_info() function, for the benefit of the
2548 cut-down version of PCRE that is currently imported into Exim.
2549
2550 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2551 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2552 patterns that start (?i) but I don't think that matters. The use of (?i) is
2553 just an example; this all applies to the other options as well.
2554
2555 4. Since libtool seems to echo the compile commands it is issuing, the output
2556 from "make" can be reduced a bit by putting "@" in front of each libtool
2557 compile command.
2558
2559 5. Patch from the folks at Google for configure.in to be a bit more thorough
2560 in checking for a suitable C++ installation before trying to compile the
2561 C++ stuff. This should fix a reported problem when a compiler was present,
2562 but no suitable headers.
2563
2564 6. The man pages all had just "PCRE" as their title. I have changed them to
2565 be the relevant file name. I have also arranged that these names are
2566 retained in the file doc/pcre.txt, which is a concatenation in text format
2567 of all the man pages except the little individual ones for each function.
2568
2569 7. The NON-UNIX-USE file had not been updated for the different set of source
2570 files that come with release 6. I also added a few comments about the C++
2571 wrapper.
2572
2573
2574 Version 6.0 07-Jun-05
2575 ---------------------
2576
2577 1. Some minor internal re-organization to help with my DFA experiments.
2578
2579 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2580 didn't matter for the library itself when fully configured, but did matter
2581 when compiling without UCP support, or within Exim, where the ucp files are
2582 not imported.
2583
2584 3. Refactoring of the library code to split up the various functions into
2585 different source modules. The addition of the new DFA matching code (see
2586 below) to a single monolithic source would have made it really too
2587 unwieldy, quite apart from causing all the code to be include in a
2588 statically linked application, when only some functions are used. This is
2589 relevant even without the DFA addition now that patterns can be compiled in
2590 one application and matched in another.
2591
2592 The downside of splitting up is that there have to be some external
2593 functions and data tables that are used internally in different modules of
2594 the library but which are not part of the API. These have all had their
2595 names changed to start with "_pcre_" so that they are unlikely to clash
2596 with other external names.
2597
2598 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2599 a different (DFA) algorithm. Although it is slower than the original
2600 function, it does have some advantages for certain types of matching
2601 problem.
2602
2603 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2604 including restarting after a partial match.
2605
2606 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2607 defined when compiling for Windows was sent to me. I have put it into the
2608 code, though I have no means of testing or verifying it.
2609
2610 7. Added the pcre_refcount() auxiliary function.
2611
2612 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2613 match before or at the first newline in the subject string. In pcretest,
2614 the /f option on a pattern can be used to set this.
2615
2616 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2617 would behave wrongly. This has been present in PCRE since release 4.0.
2618
2619 10. A number of changes to the pcregrep command:
2620
2621 (a) Refactored how -x works; insert ^(...)$ instead of setting
2622 PCRE_ANCHORED and checking the length, in preparation for adding
2623 something similar for -w.
2624
2625 (b) Added the -w (match as a word) option.
2626
2627 (c) Refactored the way lines are read and buffered so as to have more
2628 than one at a time available.
2629
2630 (d) Implemented a pcregrep test script.
2631
2632 (e) Added the -M (multiline match) option. This allows patterns to match
2633 over several lines of the subject. The buffering ensures that at least
2634 8K, or the rest of the document (whichever is the shorter) is available
2635 for matching (and similarly the previous 8K for lookbehind assertions).
2636
2637 (f) Changed the --help output so that it now says
2638
2639 -w, --word-regex(p)
2640
2641 instead of two lines, one with "regex" and the other with "regexp"
2642 because that confused at least one person since the short forms are the
2643 same. (This required a bit of code, as the output is generated
2644 automatically from a table. It wasn't just a text change.)
2645
2646 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2647 option but starts with a hyphen. Could be a pattern or a path name
2648 starting with a hyphen, for instance.
2649
2650 (h) "-" can be given as a file name to represent stdin.
2651
2652 (i) When file names are being printed, "(standard input)" is used for
2653 the standard input, for compatibility with GNU grep. Previously
2654 "<stdin>" was used.
2655
2656 (j) The option --label=xxx can be used to supply a name to be used for
2657 stdin when file names are being printed. There is no short form.
2658
2659 (k) Re-factored the options decoding logic because we are going to add
2660 two more options that take data. Such options can now be given in four
2661 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2662
2663 (l) Added the -A, -B, and -C options for requesting that lines of context
2664 around matches be printed.
2665
2666 (m) Added the -L option to print the names of files that do not contain
2667 any matching lines, that is, the complement of -l.
2668
2669 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2670 continue to scan other files.
2671
2672 (o) The -s option was incorrectly implemented. For compatibility with other
2673 greps, it now suppresses the error message for a non-existent or non-
2674 accessible file (but not the return code). There is a new option called
2675 -q that suppresses the output of matching lines, which was what -s was
2676 previously doing.
2677
2678 (p) Added --include and --exclude options to specify files for inclusion
2679 and exclusion when recursing.
2680
2681 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2682 Hopefully, it now does.
2683
2684 12. Missing cast in pcre_study().
2685
2686 13. Added an "uninstall" target to the makefile.
2687
2688 14. Replaced "extern" in the function prototypes in Makefile.in with
2689 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2690 world, but is set differently for Windows.
2691
2692 15. Added a second compiling function called pcre_compile2(). The only
2693 difference is that it has an extra argument, which is a pointer to an
2694 integer error code. When there is a compile-time failure, this is set
2695 non-zero, in addition to the error test pointer being set to point to an
2696 error message. The new argument may be NULL if no error number is required
2697 (but then you may as well call pcre_compile(), which is now just a
2698 wrapper). This facility is provided because some applications need a
2699 numeric error indication, but it has also enabled me to tidy up the way
2700 compile-time errors are handled in the POSIX wrapper.
2701
2702 16. Added VPATH=.libs to the makefile; this should help when building with one
2703 prefix path and installing with another. (Or so I'm told by someone who
2704 knows more about this stuff than I do.)
2705
2706 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2707 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2708 match everything, including newlines. This is not POSIX-compatible, but
2709 somebody wanted the feature. From pcretest it can be activated by using
2710 both the P and the s flags.
2711
2712 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2713
2714 19. libpcre.pc was being incorrectly installed as executable.
2715
2716 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2717 it now also looks for '\r' so that it will work unmodified on Windows.
2718
2719 21. Added Google's contributed C++ wrapper to the distribution.
2720
2721 22. Added some untidy missing memory free() calls in pcretest, to keep
2722 Electric Fence happy when testing.
2723
2724
2725
2726 Version 5.0 13-Sep-04
2727 ---------------------
2728
2729 1. Internal change: literal characters are no longer packed up into items
2730 containing multiple characters in a single byte-string. Each character
2731 is now matched using a separate opcode. However, there may be more than one
2732 byte in the character in UTF-8 mode.
2733
2734 2. The pcre_callout_block structure has two new fields: pattern_position and
2735 next_item_length. These contain the offset in the pattern to the next match
2736 item, and its length, respectively.
2737
2738 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2739 insertion of callouts before each pattern item. Added the /C option to
2740 pcretest to make use of this.
2741
2742 4. On the advice of a Windows user, the lines
2743
2744 #if defined(_WIN32) || defined(WIN32)
2745 _setmode( _fileno( stdout ), 0x8000 );
2746 #endif /* defined(_WIN32) || defined(WIN32) */
2747
2748 have been added to the source of pcretest. This apparently does useful
2749 magic in relation to line terminators.
2750
2751 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2752 for the benefit of those environments where the "b" makes a difference.
2753
2754 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2755 to know about it. I have put a hack into configure.in that adds in code
2756 to set GCC=yes if CC=icc. This seems to end up at a point in the
2757 generated configure script that is early enough to affect the setting of
2758 compiler options, which is what is needed, but I have no means of testing
2759 whether it really works. (The user who reported this had patched the
2760 generated configure script, which of course I cannot do.)
2761
2762 LATER: After change 22 below (new libtool files), the configure script
2763 seems to know about icc (and also ecc). Therefore, I have commented out
2764 this hack in configure.in.
2765
2766 7. Added support for pkg-config (2 patches were sent in).
2767
2768 8. Negated POSIX character classes that used a combination of internal tables
2769 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2770 [[:^ascii]]. Typically, they would match almost any characters. The other
2771 POSIX classes were not broken in this way.
2772
2773 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2774 to find the match, as PCRE was deluded into thinking that the match had to
2775 start at the start point or following a newline. The same bug applied to
2776 patterns with negative forward assertions or any backward assertions
2777 preceding ".*" at the start, unless the pattern required a fixed first
2778 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2779
2780 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2781 starting at the last subject character, bytes beyond the end of the subject
2782 string were read.
2783
2784 11. Renamed the variable "class" as "classbits" to make life easier for C++
2785 users. (Previously there was a macro definition, but it apparently wasn't
2786 enough.)
2787
2788 12. Added the new field "tables" to the extra data so that tables can be passed
2789 in at exec time, or the internal tables can be re-selected. This allows
2790 a compiled regex to be saved and re-used at a later time by a different
2791 program that might have everything at different addresses.
2792
2793 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2794 -R library as well as a -L library.
2795
2796 14. The debugging options of pcretest (-d on the command line or D on a
2797 pattern) showed incorrect output for anything following an extended class
2798 that contained multibyte characters and which was followed by a quantifier.
2799
2800 15. Added optional support for general category Unicode character properties
2801 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2802 support. It adds about 90K to the size of the library. The meanings of the
2803 inbuilt class escapes such as \d and \s have NOT been changed.
2804
2805 16. Updated pcredemo.c to include calls to free() to release the memory for the
2806 compiled pattern.
2807
2808 17. The generated file chartables.c was being created in the source directory
2809 instead of in the building directory. This caused the build to fail if the
2810 source directory was different from the building directory, and was
2811 read-only.
2812
2813 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2814 file. No doubt somebody will tell me if they don't make sense... Also added
2815 Dan Mooney's comments about building on OpenVMS.
2816
2817 19. Added support for partial matching via the PCRE_PARTIAL option for
2818 pcre_exec() and the \P data escape in pcretest.
2819
2820 20. Extended pcretest with 3 new pattern features:
2821
2822 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2823 write the compiled pattern to the file whose name is "rest-of-line".
2824 This is a straight binary dump of the data, with the saved pointer to
2825 the character tables forced to be NULL. The study data, if any, is
2826 written too. After writing, pcretest reads a new pattern.
2827
2828 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2829 compiled pattern from the given file. There must not be any
2830 occurrences of "<" in the file name (pretty unlikely); if there are,
2831 pcretest will instead treat the initial "<" as a pattern delimiter.
2832 After reading in the pattern, pcretest goes on to read data lines as
2833 usual.
2834
2835 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2836 and 16-bit fields in a compiled pattern, to simulate a pattern that
2837 was compiled on a host of opposite endianness.
2838
2839 21. The pcre-exec() function can now cope with patterns that were compiled on
2840 hosts of opposite endianness, with this restriction:
2841
2842 As for any compiled expression that is saved and used later, the tables
2843 pointer field cannot be preserved; the extra_data field in the arguments
2844 to pcre_exec() should be used to pass in a tables address if a value
2845 other than the default internal tables were used at compile time.
2846
2847 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2848 now diagnosed as an error. Previously, most of the time, a negative number
2849 would have been treated as zero, but if in addition "ovector" was passed as
2850 NULL, a crash could occur.
2851
2852 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2853 new versions from the libtool 1.5 distribution (the last one is a copy of
2854 a file called libtool.m4). This seems to have fixed the need to patch
2855 "configure" to support Darwin 1.3 (which I used to do). However, I still
2856 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2857 workstation).
2858
2859 24. Changed the PCRE licence to be the more standard "BSD" licence.
2860
2861
2862 Version 4.5 01-Dec-03
2863 ---------------------
2864
2865 1. There has been some re-arrangement of the code for the match() function so
2866 that it can be compiled in a version that does not call itself recursively.
2867 Instead, it keeps those local variables that need separate instances for
2868 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2869 needs to "recurse". Keeping track of where control must go is done by means
2870 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2871 hide most of the details from the main code, and operates only if
2872 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2873 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2874 operating.
2875
2876 To make it easier for callers to provide specially tailored get/free
2877 functions for this usage, two new functions, pcre_stack_malloc, and
2878 pcre_stack_free, are used. They are always called in strict stacking order,
2879 and the size of block requested is always the same.
2880
2881 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2882 PCRE has been compiled to use the stack or the heap for recursion. The
2883 -C option of pcretest uses this to show which version is compiled.
2884
2885 A new data escape \S, is added to pcretest; it causes the amounts of store
2886 obtained and freed by both kinds of malloc/free at match time to be added
2887 to the output.
2888
2889 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2890 what's available on my current Linux desktop machine.
2891
2892 3. When matching a UTF-8 string, the test for a valid string at the start has
2893 been extended. If start_offset is not zero, PCRE now checks that it points
2894 to a byte that is the start of a UTF-8 character. If not, it returns
2895 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2896 this is necessary because there may be backward assertions in the pattern.
2897 When matching the same subject several times, it may save resources to use
2898 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2899
2900 4. The code for checking the validity of UTF-8 strings has been tightened so
2901 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2902 containing "overlong sequences".
2903
2904 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2905 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2906 should have been "&", but it just so happened that all the cases this let
2907 through by mistake were picked up later in the function.
2908
2909 6. I had used a variable called "isblank" - this is a C99 function, causing
2910 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2911
2912 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2913 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2914 so the version is shown; (c) stop "make test" echoing "./RunTest".
2915
2916 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2917
2918 9. The prototype for memmove() for systems that don't have it was using
2919 size_t, but the inclusion of the header that defines size_t was later. I've
2920 moved the #includes for the C headers earlier to avoid this.
2921
2922 10. Added some adjustments to the code to make it easier to compiler on certain
2923 special systems:
2924
2925 (a) Some "const" qualifiers were missing.
2926 (b) Added the macro EXPORT before all exported functions; by default this
2927 is defined to be empty.
2928 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2929 that it reads its output file name as an argument instead of writing
2930 to the standard output and assuming this can be redirected.
2931
2932 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2933 class containing characters with values greater than 255, PCRE compilation
2934 went into a loop.
2935
2936 12. A recursive reference to a subpattern that was within another subpattern
2937 that had a minimum quantifier of zero caused PCRE to crash. For example,
2938 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2939 recursion. If the recursively-called subpattern itself had a zero repeat,
2940 that was OK.
2941
2942 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2943 buffer into which it was copied (for escape processing) was still set at
2944 1024, so long lines caused crashes.
2945
2946 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2947 "internal error: code overflow...". This applied to any character class
2948 that was followed by a possessive quantifier.
2949
2950 15. Modified the Makefile to add libpcre.la as a prerequisite for
2951 libpcreposix.la because I was told this is needed for a parallel build to
2952 work.
2953
2954 16. If a pattern that contained .* following optional items at the start was
2955 studied, the wrong optimizing data was generated, leading to matching
2956 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2957 matching string must start with a or b or c. The correct conclusion for
2958 this pattern is that a match can start with any character.
2959
2960
2961 Version 4.4 13-Aug-03
2962 ---------------------
2963
2964 1. In UTF-8 mode, a character class containing characters with values between
2965 127 and 255 was not handled correctly if the compiled pattern was studied.
2966 In fixing this, I have also improved the studying algorithm for such
2967 classes (slightly).
2968
2969 2. Three internal functions had redundant arguments passed to them. Removal
2970 might give a very teeny performance improvement.
2971
2972 3. Documentation bug: the value of the capture_top field in a callout is *one
2973 more than* the number of the hightest numbered captured substring.
2974
2975 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2976 in incorrectly linking with a previously installed version. They now link
2977 explicitly with libpcre.la.
2978
2979 5. configure.in no longer needs to recognize Cygwin specially.
2980
2981 6. A problem in pcre.in for Windows platforms is fixed.
2982
2983 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2984 pcretest, it used to include the size of the study block as part of its
2985 output. Unfortunately, the structure contains a field that has a different
2986 size on different hardware architectures. This meant that the tests that
2987 showed this size failed. As the block is currently always of a fixed size,
2988 this information isn't actually particularly useful in pcretest output, so
2989 I have just removed it.
2990
2991 8. Three pre-processor statements accidentally did not start in column 1.
2992 Sadly, there are *still* compilers around that complain, even though
2993 standard C has not required this for well over a decade. Sigh.
2994
2995 9. In pcretest, the code for checking callouts passed small integers in the
2996 callout_data field, which is a void * field. However, some picky compilers
2997 complained about the casts involved for this on 64-bit systems. Now
2998 pcretest passes the address of the small integer instead, which should get
2999 rid of the warnings.
3000
3001 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3002 both compile and run time, and gives an error if an invalid UTF-8 sequence
3003 is found. There is a option for disabling this check in cases where the
3004 string is known to be correct and/or the maximum performance is wanted.
3005
3006 11. In response to a bug report, I changed one line in Makefile.in from
3007
3008 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3009 to
3010 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3011
3012 to look similar to other lines, but I have no way of telling whether this
3013 is the right thing to do, as I do not use Windows. No doubt I'll get told
3014 if it's wrong...
3015
3016
3017 Version 4.3 21-May-03
3018 ---------------------
3019
3020 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3021 Makefile.
3022
3023 2. Some refactoring to improve the quality of the code:
3024
3025 (i) The utf8_table... variables are now declared "const".
3026
3027 (ii) The code for \cx, which used the "case flipping" table to upper case
3028 lower case letters, now just substracts 32. This is ASCII-specific,
3029 but the whole concept of \cx is ASCII-specific, so it seems
3030 reasonable.
3031
3032 (iii) PCRE was using its character types table to recognize decimal and
3033 hexadecimal digits in the pattern. This is silly, because it handles
3034 only 0-9, a-f, and A-F, but the character types table is locale-
3035 specific, which means strange things might happen. A private
3036 table is now used for this - though it costs 256 bytes, a table is
3037 much faster than multiple explicit tests. Of course, the standard
3038 character types table is still used for matching digits in subject
3039 strings against \d.
3040
3041 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3042 ending in _t are). So I've renamed it as ESC_tee.
3043
3044 3. The first argument for regexec() in the POSIX wrapper should have been
3045 defined as "const".
3046
3047 4. Changed pcretest to use malloc() for its buffers so that they can be
3048 Electric Fenced for debugging.
3049
3050 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3051 to read one or more bytes before the start of the subject string. Often this
3052 had no effect on PCRE's behaviour, but in some circumstances it could
3053 provoke a segmentation fault.
3054
3055 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3056 to try to read one or more bytes before the start of the subject string.
3057
3058 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3059 UTF-8 support could misbehave in various ways if the subject string
3060 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3061 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3062 back over UTF-8 characters.)
3063
3064
3065 Version 4.2 14-Apr-03
3066 ---------------------
3067
3068 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3069
3070 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3071 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3072 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3073 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3074 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3075 and BUILD_EXEEXT
3076 Note: automatic setting of the BUILD variables is not yet working
3077 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3078 compile-time but not at link-time
3079 [LINK]: use for linking executables only
3080 make different versions for Windows and non-Windows
3081 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3082 libraries
3083 [LINK_FOR_BUILD]: new variable
3084 [OBJEXT]: use throughout
3085 [EXEEXT]: use throughout
3086 <winshared>: new target
3087 <wininstall>: new target
3088 <dftables.o>: use native compiler
3089 <dftables>: use native linker
3090 <install>: handle Windows platform correctly
3091 <clean>: ditto
3092 <check>: ditto
3093 copy DLL to top builddir before testing
3094
3095 As part of these changes, -no-undefined was removed again. This was reported
3096 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3097 in any case.
3098
3099 3. Some tidies to get rid of compiler warnings:
3100
3101 . In the match_data structure, match_limit was an unsigned long int, whereas
3102 match_call_count was an int. I've made them both unsigned long ints.
3103
3104 . In pcretest the fact that a const uschar * doesn't automatically cast to
3105 a void * provoked a warning.
3106
3107 . Turning on some more compiler warnings threw up some "shadow" variables
3108 and a few more missing casts.
3109
3110 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3111 option, a class that contained a single character with a value between 128
3112 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3113
3114 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3115 option, a class that contained several characters, but with at least one
3116 whose value was between 128 and 255 caused PCRE to crash.
3117
3118
3119 Version 4.1 12-Mar-03
3120 ---------------------
3121
3122 1. Compiling with gcc -pedantic found a couple of places where casts were
3123 needed, and a string in dftables.c that was longer than standard compilers are
3124 required to support.
3125
3126 2. Compiling with Sun's compiler found a few more places where the code could
3127 be tidied up in order to avoid warnings.
3128
3129 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3130 first of these names is deprecated in the latest Autoconf in favour of the name
3131 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3132 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3133 analogy I have changed it to CFLAGS_FOR_BUILD.
3134
3135 4. Added -no-undefined to the linking command in the Makefile, because this is
3136 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3137 linking step for the pcreposix library.
3138
3139 5. PCRE was failing to diagnose the case of two named groups with the same
3140 name.
3141
3142 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3143 literal character that is needed in the subject for a match, and scans along to
3144 ensure that it is present before embarking on the full matching process. This
3145 saves time in cases of nested unlimited repeats that are never going to match.
3146 Problem: the scan can take a lot of time if the subject is very long (e.g.
3147 megabytes), thus penalizing straightforward matches. It is now done only if the
3148 amount of subject to be scanned is less than 1000 bytes.
3149
3150 7. A lesser problem with the same optimization is that it was recording the
3151 first character of an anchored pattern as "needed", thus provoking a search
3152 right along the subject, even when the first match of the pattern was going to
3153 fail. The "needed" character is now not set for anchored patterns, unless it
3154 follows something in the pattern that is of non-fixed length. Thus, it still
3155 fulfils its original purpose of finding quick non-matches in cases of nested
3156 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3157
3158
3159 Version 4.0 17-Feb-03
3160 ---------------------
3161
3162 1. If a comment in an extended regex that started immediately after a meta-item
3163 extended to the end of string, PCRE compiled incorrect data. This could lead to
3164 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3165
3166 2. Moved to autoconf 2.53 and libtool 1.4.2.
3167
3168 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3169 the special perltest8 script is no longer needed - all the tests can be run
3170 from a single perltest script.
3171
3172 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3173 by \s. It has now been removed in PCRE. This means it isn't recognized as
3174 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3175 class [:space:] *does* include VT, thereby creating a mess.
3176
3177 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3178 space and tab.
3179
3180 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3181 its new features into the main test script, reducing the number of scripts.
3182
3183 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3184 were backward compatible, and made the (?i) apply to the whole pattern, as if
3185 /i were given. Now it behaves more logically, and applies the option setting
3186 only to what follows. PCRE has been changed to follow suit. However, if it
3187 finds options settings right at the start of the pattern, it extracts them into
3188 the global options, as before. Thus, they show up in the info data.
3189
3190 8. Added support for the \Q...\E escape sequence. Characters in between are
3191 treated as literals. This is slightly different from Perl in that $ and @ are
3192 also handled as literals inside the quotes. In Perl, they will cause variable
3193 interpolation. Note the following examples:
3194
3195 Pattern PCRE matches Perl matches
3196
3197 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3198 \Qabc\$xyz\E abc\$xyz abc\$xyz
3199 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3200
3201 For compatibility with Perl, \Q...\E sequences are recognized inside character
3202 classes as well as outside them.
3203
3204 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3205 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3206 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3207 signed/unsigned warnings.
3208
3209 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3210 option for pcretest, so I've replaced it by a simple function that does just
3211 that job.
3212
3213 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3214 "pcregrep -".
3215
3216 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3217 Java package. This provides some syntactic sugar for simple cases of what my
3218 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3219 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3220 item, you can use this simplified notation. Note that only makes sense with
3221 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3222 greediness, whatever the setting of the PCRE_UNGREEDY option.
3223
3224 13. A change of greediness default within a pattern was not taking effect at
3225 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3226 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3227 was abstracted outside.
3228
3229 14. PCRE now supports the \G assertion. It is true when the current matching
3230 position is at the start point of the match. This differs from \A when the
3231 starting offset is non-zero. Used with the /g option of pcretest (or similar
3232 code), it works in the same way as it does for Perl's /g option. If all
3233 alternatives of a regex begin with \G, the expression is anchored to the start
3234 match position, and the "anchored" flag is set in the compiled expression.
3235
3236 15. Some bugs concerning the handling of certain option changes within patterns
3237 have been fixed. These applied to options other than (?ims). For example,
3238 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3239 been the other way round. Some of this was related to change 7 above.
3240
3241 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3242 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3243 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3244 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3245
3246 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3247 mode. Unlike ".", it always matches newline, whatever the setting of
3248 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3249 assertions. Perl allows it, but it doesn't (in general) work because it can't
3250 calculate the length of the lookbehind. At least, that's the case for Perl
3251 5.8.0 - I've been told they are going to document that it doesn't work in
3252 future.
3253
3254 18. Added an error diagnosis for escapes that PCRE does not support: these are
3255 \L, \l, \N, \P, \p, \U, \u, and \X.
3256
3257 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3258 reading past the end of the pattern in cases such as /[abcd/.
3259
3260 20. PCRE was getting more memory than necessary for patterns with classes that
3261 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3262
3263 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3264 compiling PCRE for use with Virtual Pascal.
3265
3266 22. Small fix to the Makefile to make it work properly if the build is done
3267 outside the source tree.
3268
3269 23. Added a new extension: a condition to go with recursion. If a conditional
3270 subpattern starts with (?(R) the "true" branch is used if recursion has
3271 happened, whereas the "false" branch is used only at the top level.
3272
3273 24. When there was a very long string of literal characters (over 255 bytes
3274 without UTF support, over 250 bytes with UTF support), the computation of how
3275 much memory was required could be incorrect, leading to segfaults or other
3276 strange effects.
3277
3278 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3279 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3280 there was a subsequent back reference to those brackets. This meant that, for
3281 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3282 possible to check for precisely this case. All we can do is abandon the
3283 optimization if .* occurs inside capturing brackets when there are any back
3284 references whatsoever. (See below for a better fix that came later.)
3285
3286 26. The handling of the optimization for finding the first character of a
3287 non-anchored pattern, and for finding a character that is required later in the
3288 match were failing in some cases. This didn't break the matching; it just
3289 failed to optimize when it could. The way this is done has been re-implemented.
3290
3291 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3292
3293 28. Added a new feature that provides some of the functionality that Perl
3294 provides with (?{...}). The facility is termed a "callout". The way it is done
3295 in PCRE is for the caller to provide an optional function, by setting
3296 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3297 global variable. By default it is unset, which disables all calling out. To get
3298 the function called, the regex must include (?C) at appropriate points. This
3299 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3300 This provides a means of identifying different callout points. When PCRE
3301 reaches such a point in the regex, if pcre_callout has been set, the external
3302 function is called. It is provided with data in a structure called
3303 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3304 matching continues; if it returns a non-zero value, the match at the current
3305 point fails. However, backtracking will occur if possible. [This was changed
3306 later and other features added - see item 49 below.]
3307
3308 29. pcretest is upgraded to test the callout functionality. It provides a
3309 callout function that displays information. By default, it shows the start of
3310 the match and the current position in the text. There are some new data escapes
3311 to vary what happens:
3312
3313 \C+ in addition, show current contents of captured substrings
3314 \C- do not supply a callout function
3315 \C!n return 1 when callout number n is reached
3316 \C!n!m return 1 when callout number n is reached for the mth time
3317
3318 30. If pcregrep was called with the -l option and just a single file name, it
3319 output "<stdin>" if a match was found, instead of the file name.
3320
3321 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3322 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3323 pcre_exec(). This saves a malloc/free per call. The default value of
3324 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3325 when configuring.
3326
3327 32. The default maximum size of a compiled pattern is 64K. There have been a
3328 few cases of people hitting this limit. The code now uses macros to handle the
3329 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3330 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3331 configuring. Tests 2 and 5 work only with 2-byte links because they output
3332 debugging information about compiled patterns.
3333
3334 33. Internal code re-arrangements:
3335
3336 (a) Moved the debugging function for printing out a compiled regex into
3337 its own source file (printint.c) and used #include to pull it into
3338 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3339 separate copies.
3340
3341 (b) Defined the list of op-code names for debugging as a macro in
3342 internal.h so that it is next to the definition of the opcodes.
3343
3344 (c) Defined a table of op-code lengths for simpler skipping along compiled
3345 code. This is again a macro in internal.h so that it is next to the
3346 definition of the opcodes.
3347
3348 34. Added support for recursive calls to individual subpatterns, along the
3349 lines of Robin Houston's patch (but implemented somewhat differently).
3350
3351 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3352 allow it to read and process whole directories in Win32. This code was
3353 contributed by Lionel Fourquaux; it has not been tested by me.
3354
3355 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3356 used to name a group. Names consist of alphanumerics and underscores, and must
3357 be unique. Back references use the syntax (?P=name) and recursive calls use
3358 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3359 numbers. The function pcre_fullinfo() can be used after compilation to extract
3360 a name/number map. There are three relevant calls:
3361
3362 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3363 PCRE_INFO_NAMECOUNT yields the number of entries
3364 PCRE_INFO_NAMETABLE yields a pointer to the map.
3365
3366 The map is a vector of fixed-size entries. The size of each entry depends on
3367 the length of the longest name used. The first two bytes of each entry are the
3368 group number, most significant byte first. There follows the corresponding
3369 name, zero terminated. The names are in alphabetical order.
3370
3371 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3372 case instead of 255. Making it the same both with and without UTF-8 support
3373 means that the same test output works with both.
3374
3375 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3376 calling malloc() with a zero argument.
3377
3378 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3379 optimization. I've improved things by keeping a bitmap of backreferences with
3380 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3381 fact referenced, the optimization can be applied. It is unlikely that a
3382 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3383 the match to follow \n) will appear inside brackets with a number greater than
3384 31, but if it does, any back reference > 31 suppresses the optimization.
3385
3386 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3387 of disabling numbered capturing parentheses. Any opening parenthesis that is
3388 not followed by ? behaves as if it were followed by ?: but named parentheses
3389 can still be used for capturing (and they will acquire numbers in the usual
3390 way).
3391
3392 41. Redesigned the return codes from the match() function into yes/no/error so
3393 that errors can be passed back from deep inside the nested calls. A malloc
3394 failure while inside a recursive subpattern call now causes the
3395 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3396
3397 42. It is now possible to set a limit on the number of times the match()
3398 function is called in a call to pcre_exec(). This facility makes it possible to
3399 limit the amount of recursion and backtracking, though not in a directly
3400 obvious way, because the match() function is used in a number of different
3401 circumstances. The count starts from zero for each position in the subject
3402 string (for non-anchored patterns). The default limit is, for compatibility, a
3403 large number, namely 10 000 000. You can change this in two ways:
3404
3405 (a) When configuring PCRE before making, you can use --with-match-limit=n
3406 to set a default value for the compiled library.
3407
3408 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3409 a different value is set. See 45 below.
3410
3411 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3412
3413 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3414 of things that can be changed at compile time. The first argument specifies
3415 what is wanted and the second points to where the information is to be placed.
3416 The current list of available information is:
3417
3418 PCRE_CONFIG_UTF8
3419
3420 The output is an integer that is set to one if UTF-8 support is available;
3421 otherwise it is set to zero.
3422
3423 PCRE_CONFIG_NEWLINE
3424
3425 The output is an integer that it set to the value of the code that is used for
3426 newline. It is either LF (10) or CR (13).
3427
3428 PCRE_CONFIG_LINK_SIZE
3429
3430 The output is an integer that contains the number of bytes used for internal
3431 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3432
3433 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3434
3435 The output is an integer that contains the threshold above which the POSIX
3436 interface uses malloc() for output vectors. See item 31 above.
3437
3438 PCRE_CONFIG_MATCH_LIMIT
3439
3440 The output is an unsigned integer that contains the default limit of the number
3441 of match() calls in a pcre_exec() execution. See 42 above.
3442
3443 44. pcretest has been upgraded by the addition of the -C option. This causes it
3444 to extract all the available output from the new pcre_config() function, and to
3445 output it. The program then exits immediately.
3446
3447 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3448 order to support additional features. One way would have been to define
3449 pcre_exec2() (for example) with extra arguments, but this would not have been
3450 extensible, and would also have required all calls to the original function to
3451 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3452 is used for passing in "extra" data from pcre_study().
3453
3454 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3455 contains the following fields:
3456
3457 flags a bitmap indicating which of the following fields are set
3458 study_data opaque data from pcre_study()
3459 match_limit a way of specifying a limit on match() calls for a specific
3460 call to pcre_exec()
3461 callout_data data for callouts (see 49 below)
3462
3463 The flag bits are also defined in pcre.h, and are
3464
3465 PCRE_EXTRA_STUDY_DATA
3466 PCRE_EXTRA_MATCH_LIMIT
3467 PCRE_EXTRA_CALLOUT_DATA
3468
3469 The pcre_study() function now returns one of these new pcre_extra blocks, with
3470 the actual study data pointed to by the study_data field, and the
3471 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3472 before. That is, this change is entirely upwards-compatible and requires no
3473 change to existing code.
3474
3475 If you want to pass in additional data to pcre_exec(), you can either place it
3476 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3477 block.
3478
3479 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3480 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3481 times with different match limits, until it finds the minimum value needed for
3482 pcre_exec() to complete. The value is then output. This can be instructive; for
3483 most simple matches the number is quite small, but for pathological cases it
3484 gets very large very quickly.
3485
3486 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3487 returns the size of the data block pointed to by the study_data field in a
3488 pcre_extra block, that is, the value that was passed as the argument to
3489 pcre_malloc() when PCRE was getting memory in which to place the information
3490 created by pcre_study(). The fourth argument should point to a size_t variable.
3491 pcretest has been extended so that this information is shown after a successful
3492 pcre_study() call when information about the compiled regex is being displayed.
3493
3494 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3495 because what follows is always an absolute path. (Later: it turns out that this
3496 is more than cosmetic for MinGW, because it doesn't like empty path
3497 components.)
3498
3499 49. Some changes have been made to the callout feature (see 28 above):
3500
3501 (i) A callout function now has three choices for what it returns:
3502
3503 0 => success, carry on matching
3504 > 0 => failure at this point, but backtrack if possible
3505 < 0 => serious error, return this value from pcre_exec()
3506
3507 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3508 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3509 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3510 use by callout functions. It will never be used by PCRE itself.
3511
3512 (ii) The pcre_extra structure (see 45 above) has a void * field called
3513 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3514 pcre_callout_block structure has a field of the same name. The contents of
3515 the field passed in the pcre_extra structure are passed to the callout
3516 function in the corresponding field in the callout block. This makes it
3517 easier to use the same callout-containing regex from multiple threads. For
3518 testing, the pcretest program has a new data escape
3519
3520 \C*n pass the number n (may be negative) as callout_data
3521
3522 If the callout function in pcretest receives a non-zero value as
3523 callout_data, it returns that value.
3524
3525 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3526 there were some redundant $(CFLAGS) in commands that are now specified as
3527 $(LINK), which already includes $(CFLAGS).
3528
3529 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3530 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3531 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3532 one-byte characters throughout. Note that case-insensitive matching applies
3533 only to characters whose values are less than 256. PCRE doesn't support the
3534 notion of cases for higher-valued characters.
3535
3536 (i) A character class whose characters are all within 0-255 is handled as
3537 a bit map, and the map is inverted for negative classes. Previously, a
3538 character > 255 always failed to match such a class; however it should
3539 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3540
3541 (ii) A negated character class with a single character < 255 is coded as
3542 "not this character" (OP_NOT). This wasn't working properly when the test
3543 character was multibyte, either singly or repeated.
3544
3545 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3546 mode, for example: \x{100}{2,3}.
3547
3548 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3549 singly or repeated) now correctly test multibyte characters. However,
3550 PCRE doesn't recognize any characters with values greater than 255 as
3551 digits, spaces, or word characters. Such characters always match \D, \S,
3552 and \W, and never match \d, \s, or \w.
3553
3554 (v) Classes may now contain characters and character ranges with values
3555 greater than 255. For example: [ab\x{100}-\x{400}].
3556
3557 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3558 PCRE in UTF-8 mode.
3559
3560 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3561 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3562 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3563 value.)
3564
3565 53. The single man page has become too large. I have therefore split it up into
3566 a number of separate man pages. These also give rise to individual HTML pages;
3567 these are now put in a separate directory, and there is an index.html page that
3568 lists them all. Some hyperlinking between the pages has been installed.
3569
3570 54. Added convenience functions for handling named capturing parentheses.
3571
3572 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3573 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3574 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3575 are faulted.
3576
3577 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3578 calling configure. These values are used when compiling the dftables.c program
3579 which is run to generate the source of the default character tables. They
3580 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3581 you will need to set these values.
3582
3583 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3584
3585
3586 Version 3.9 02-Jan-02
3587 ---------------------
3588
3589 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3590
3591 2. If --disable-static was given, the building process failed when trying to
3592 build pcretest and pcregrep. (For some reason it was using libtool to compile
3593 them, which is not right, as they aren't part of the library.)
3594
3595
3596 Version 3.8 18-Dec-01
3597 ---------------------
3598
3599 1. The experimental UTF-8 code was completely screwed up. It was packing the
3600 bytes in the wrong order. How dumb can you get?
3601
3602
3603 Version 3.7 29-Oct-01
3604 ---------------------
3605
3606 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3607 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3608 this didn't happen under Solaris 8, where I normally test things.
3609
3610 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3611 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3612 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3613 this fix an hour or so after the initial 3.7 release.)
3614
3615
3616 Version 3.6 23-Oct-01
3617 ---------------------
3618
3619 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3620 offsets passed as NULL with zero offset count.
3621
3622 2. The config.guess and config.sub files had not been updated when I moved to
3623 the latest autoconf.
3624
3625
3626 Version 3.5 15-Aug-01
3627 ---------------------
3628
3629 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3630 had been forgotten.
3631
3632 2. By using declared but undefined structures, we can avoid using "void"
3633 definitions in pcre.h while keeping the internal definitions of the structures
3634 private.
3635
3636 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3637 user point of view, this means that both static and shared libraries are built
3638 by default, but this can be individually controlled. More of the work of
3639 handling this static/shared cases is now inside libtool instead of PCRE's make
3640 file.
3641
3642 4. The pcretest utility is now installed along with pcregrep because it is
3643 useful for users (to test regexs) and by doing this, it automatically gets
3644 relinked by libtool. The documentation has been turned into a man page, so
3645 there are now .1, .txt, and .html versions in /doc.
3646
3647 5. Upgrades to pcregrep:
3648 (i) Added long-form option names like gnu grep.
3649 (ii) Added --help to list all options with an explanatory phrase.
3650 (iii) Added -r, --recursive to recurse into sub-directories.
3651 (iv) Added -f, --file to read patterns from a file.
3652
3653 6. pcre_exec() was referring to its "code" argument before testing that
3654 argument for NULL (and giving an error if it was NULL).
3655
3656 7. Upgraded Makefile.in to allow for compiling in a different directory from
3657 the source directory.
3658
3659 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3660 options bits, the pointer it was passed was to an int instead of to an unsigned
3661 long int. This mattered only on 64-bit systems.
3662
3663 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3664 generated) instead of pcre.in, which it its source. Also made the same change
3665 in several of the .c files.
3666
3667 10. A new release of gcc defines printf() as a macro, which broke pcretest
3668 because it had an ifdef in the middle of a string argument for printf(). Fixed
3669 by using separate calls to printf().
3670
3671 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3672 script, to force use of CR or LF instead of \n in the source. On non-Unix
3673 systems, the value can be set in config.h.
3674
3675 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3676 absolute limit. Changed the text of the error message to make this clear, and
3677 likewise updated the man page.
3678
3679 13. The limit of 99 on the number of capturing subpatterns has been removed.
3680 The new limit is 65535, which I hope will not be a "real" limit.
3681
3682
3683 Version 3.4 22-Aug-00
3684 ---------------------
3685
3686 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3687
3688 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3689
3690
3691 Version 3.3 01-Aug-00
3692 ---------------------
3693
3694 1. If an octal character was given, but the value was greater than \377, it
3695 was not getting masked to the least significant bits, as documented. This could
3696 lead to crashes in some systems.
3697
3698 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3699 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3700
3701 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3702 These just pass their arguments on to (pcre_free)(), but they are provided
3703 because some uses of PCRE bind it to non-C systems that can call its functions,
3704 but cannot call free() or pcre_free() directly.
3705
3706 4. Add "make test" as a synonym for "make check". Corrected some comments in
3707 the Makefile.
3708
3709 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3710 Makefile.
3711
3712 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3713 command called pgrep for grepping around the active processes.
3714
3715 7. Added the beginnings of support for UTF-8 character strings.
3716
3717 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3718 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3719 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3720 out for the ar command.)
3721
3722
3723 Version 3.2 12-May-00
3724 ---------------------
3725
3726 This is purely a bug fixing release.
3727
3728 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3729 of ZA. This was just one example of several cases that could provoke this bug,
3730 which was introduced by change 9 of version 2.00. The code for breaking
3731 infinite loops after an iteration that matches an empty string was't working
3732 correctly.
3733
3734 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3735 when matched against abbab (for example). After matching an empty string, it
3736 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3737 caused it to match further down the string than it should.
3738
3739 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3740 was there because it doesn't seem to be needed, and it causes trouble on some
3741 systems, as it is not a Standard C header. It has been removed.
3742
3743 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3744 were reported on the Macintosh. The changes were from
3745
3746 while ((c = *(++ptr)) != 0 && c != '\n');
3747 to
3748 while ((c = *(++ptr)) != 0 && c != '\n') ;
3749
3750 Totally extraordinary, but if that's what it takes...
3751
3752 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3753 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3754 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3755 assumes the way PCRE uses memmove() (always moving upwards).
3756
3757 6. PCRE is being used in one environment where strchr() is not available. There
3758 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3759 faster code anyway.
3760
3761
3762 Version 3.1 09-Feb-00
3763 ---------------------
3764
3765 The only change in this release is the fixing of some bugs in Makefile.in for
3766 the "install" target:
3767
3768 (1) It was failing to install pcreposix.h.
3769
3770 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3771
3772
3773 Version 3.0 01-Feb-00
3774 ---------------------
3775
3776 1. Add support for the /+ modifier to perltest (to output $` like it does in
3777 pcretest).
3778
3779 2. Add support for the /g modifier to perltest.
3780
3781 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3782 matches null strings.
3783
3784 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3785 pattern. Perl treats empty patterns specially - it reuses the most recent
3786 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3787 effect.
3788
3789 5. The POSIX interface was broken in that it was just handing over the POSIX
3790 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3791 required a bigger vector, with some working space on the end. This means that
3792 the POSIX wrapper now has to get and free some memory, and copy the results.
3793
3794 6. Added some simple autoconf support, placing the test data and the
3795 documentation in separate directories, re-organizing some of the
3796 information files, and making it build pcre-config (a GNU standard). Also added
3797 libtool support for building PCRE as a shared library, which is now the
3798 default.
3799
3800 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3801 09 are not valid octal constants. Single digits will be used for minor values
3802 less than 10.
3803
3804 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3805 existing programs that set these in the POSIX interface can use PCRE without
3806 modification.
3807
3808 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3809 return all that pcre_info() returns, plus additional data. The pcre_info()
3810 function is retained for compatibility, but is considered to be obsolete.
3811
3812 10. Added experimental recursion feature (?R) to handle one common case that
3813 Perl 5.6 will be able to do with (?p{...}).
3814
3815 11. Added support for POSIX character classes like [:alpha:], which Perl is
3816 adopting.
3817
3818
3819 Version 2.08 31-Aug-99
3820 ----------------------
3821
3822 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3823 trying to match at the startoffset position, but instead was moving forward to
3824 the next newline as if a previous match had failed.
3825
3826 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3827 and could get into a loop if a null string was matched other than at the start
3828 of the subject.
3829
3830 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3831 be distinguished at compile time, and for completeness also added PCRE_DATE.
3832
3833 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3834 in GnuWin32 environments.
3835
3836
3837 Version 2.07 29-Jul-99
3838 ----------------------
3839
3840 1. The documentation is now supplied in plain text form and HTML as well as in
3841 the form of man page sources.
3842
3843 2. C++ compilers don't like assigning (void *) values to other pointer types.
3844 In particular this affects malloc(). Although there is no problem in Standard
3845 C, I've put in casts to keep C++ compilers happy.
3846
3847 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3848 should be (const char *).
3849
3850 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3851 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3852 However, I haven't made this a standard facility. The documentation doesn't
3853 mention it, and the Makefile doesn't support it.
3854
3855 5. The Makefile now contains an "install" target, with editable destinations at
3856 the top of the file. The pcretest program is not installed.
3857
3858 6. pgrep -V now gives the PCRE version number and date.
3859
3860 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3861 causing the entire string to be ignored, instead of just the last character.
3862
3863 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3864 non-matching string, it can take a very, very long time, even for strings of
3865 quite modest length, because of the nested recursion. PCRE now does better in
3866 some of these cases. It does this by remembering the last required literal
3867 character in the pattern, and pre-searching the subject to ensure it is present
3868 before running the real match. In other words, it applies a heuristic to detect
3869 some types of certain failure quickly, and in the above example, if presented
3870 with a string that has no trailing " it gives "no match" very quickly.
3871
3872 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3873 other alternatives are tried instead.
3874
3875
3876 Version 2.06 09-Jun-99
3877 ----------------------
3878
3879 1. Change pcretest's output for amount of store used to show just the code
3880 space, because the remainder (the data block) varies in size between 32-bit and
3881 64-bit systems.
3882
3883 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3884 start matching at. This allows lookbehinds to work when searching for multiple
3885 occurrences in a string.
3886
3887 3. Added additional options to pcretest for testing multiple occurrences:
3888
3889 /+ outputs the rest of the string that follows a match
3890 /g loops for multiple occurrences, using the new startoffset argument
3891 /G loops for multiple occurrences by passing an incremented pointer
3892
3893 4. PCRE wasn't doing the "first character" optimization for patterns starting
3894 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3895 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3896 the letter 'x'. On long subject strings, this gives a significant speed-up.
3897
3898
3899 Version 2.05 21-Apr-99
3900 ----------------------
3901
3902 1. Changed the type of magic_number from int to long int so that it works
3903 properly on 16-bit systems.
3904
3905 2. Fixed a bug which caused patterns starting with .* not to work correctly
3906 when the subject string contained newline characters. PCRE was assuming
3907 anchoring for such patterns in all cases, which is not correct because .* will
3908 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3909 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3910 must be retried after every newline in the subject.
3911
3912
3913 Version 2.04 18-Feb-99
3914 ----------------------
3915
3916 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3917 computation of the store needed to hold the pattern was incorrect (too large).
3918 If such patterns were nested a few deep, this could multiply and become a real
3919 problem.
3920
3921 2. Added /M option to pcretest to show the memory requirement of a specific
3922 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3923
3924 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3925 compiled in such a way that the backtracking after subsequent failure was
3926 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3927 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3928
3929
3930 Version 2.03 02-Feb-99
3931 ----------------------
3932
3933 1. Fixed typo and small mistake in man page.
3934
3935 2. Added 4th condition (GPL supersedes if conflict) and created separate
3936 LICENCE file containing the conditions.
3937
3938 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3939 Perl, that is the internal \ allows the delimiter to be included in the
3940 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3941 the final delimiter, add \ to the end of the pattern (to test the error).
3942
3943 4. Added the convenience functions for extracting substrings after a successful
3944 match. Updated pcretest to make it able to test these functions.
3945
3946
3947 Version 2.02 14-Jan-99
3948 ----------------------
3949
3950 1. Initialized the working variables associated with each extraction so that
3951 their saving and restoring doesn't refer to uninitialized store.
3952
3953 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3954 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3955 fix the problem.
3956
3957 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3958 calls, and wasn't printing the correct value for compiling calls. Increased the
3959 default value of LOOPREPEAT, and the number of significant figures in the
3960 times.
3961
3962 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3963
3964 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3965 a building problem on Windows NT with a FAT file system.
3966
3967
3968 Version 2.01 21-Oct-98
3969 ----------------------
3970
3971 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3972 to character tables built by pcre_maketables() in the current locale. If NULL
3973 is passed, the default tables are used.
3974
3975
3976 Version 2.00 24-Sep-98
3977 ----------------------
3978
3979 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3980 it any more.
3981
3982 2. Allow quantification of (?>) groups, and make it work correctly.
3983
3984 3. The first character computation wasn't working for (?>) groups.
3985
3986 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3987 end of the subject) and add 5.005's \z, which really does match only at the
3988 very end of the subject.
3989
3990 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3991
3992 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3993 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3994 localized options. All options to pcre_study() were also removed.
3995
3996 7. Add other new features from 5.005:
3997
3998 $(?<= positive lookbehind
3999 $(?<! negative lookbehind
4000 (?imsx-imsx) added the unsetting capability
4001 such a setting is global if at outer level; local otherwise
4002 (?imsx-imsx:) non-capturing groups with option setting
4003 (?(cond)re|re) conditional pattern matching
4004
4005 A backreference to itself in a repeated group matches the previous
4006 captured string.
4007
4008 8. General tidying up of studying (both automatic and via "study")
4009 consequential on the addition of new assertions.
4010
4011 9. As in 5.005, unlimited repeated groups that could match an empty substring
4012 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4013 runtime if any iteration does actually match an empty substring.
4014
4015 10. Include the RunTest script in the distribution.
4016
4017 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4018 discrepancies, some of which were old and were also with respect to 5.004. They
4019 have now been fixed.
4020
4021
4022 Version 1.09 28-Apr-98
4023 ----------------------
4024
4025 1. A negated single character class followed by a quantifier with a minimum
4026 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4027 program crashes, or just wrong answers. This did not apply to negated classes
4028 containing more than one character, or to minima other than one.
4029
4030
4031 Version 1.08 27-Mar-98
4032 ----------------------
4033
4034 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4035
4036 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4037 latter must appear before anything that relies on it in the pattern.
4038
4039
4040 Version 1.07 16-Feb-98
4041 ----------------------
4042
4043 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4044 repeat of a potentially empty string).
4045
4046
4047 Version 1.06 23-Jan-98
4048 ----------------------
4049
4050 1. Added Markus Oberhumer's little patches for C++.
4051
4052 2. Literal strings longer than 255 characters were broken.
4053
4054
4055 Version 1.05 23-Dec-97
4056 ----------------------
4057
4058 1. Negated character classes containing more than one character were failing if
4059 PCRE_CASELESS was set at run time.
4060
4061
4062 Version 1.04 19-Dec-97
4063 ----------------------
4064
4065 1. Corrected the man page, where some "const" qualifiers had been omitted.
4066
4067 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4068 input syntax.
4069
4070 3. Fixed memory leak which occurred when a regex with back references was
4071 matched with an offsets vector that wasn't big enough. The temporary memory
4072 that is used in this case wasn't being freed if the match failed.
4073
4074 4. Tidied pcretest to ensure it frees memory that it gets.
4075
4076 5. Temporary memory was being obtained in the case where the passed offsets
4077 vector was exactly big enough.
4078
4079 6. Corrected definition of offsetof() from change 5 below.
4080
4081 7. I had screwed up change 6 below and broken the rules for the use of
4082 setjmp(). Now fixed.
4083
4084
4085 Version 1.03 18-Dec-97
4086 ----------------------
4087
4088 1. A erroneous regex with a missing opening parenthesis was correctly
4089 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4090 on some systems.
4091
4092 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4093 it was reported that one broken compiler failed on the former because "code" is
4094 also an independent variable.
4095
4096 3. The erroneous regex a[]b caused an array overrun reference.
4097
4098 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4099 fail on data ending with that character. (It was going on too far, and checking
4100 the next character, typically a binary zero.) This was specific to the
4101 optimized code for single-character negative classes.
4102
4103 5. Added a contributed patch from the TIN world which does the following:
4104
4105 + Add an undef for memmove, in case the the system defines a macro for it.
4106
4107 + Add a definition of offsetof(), in case there isn't one. (I don't know
4108 the reason behind this - offsetof() is part of the ANSI standard - but
4109 it does no harm).
4110
4111 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4112 most of the places where whitespace preceded '#'. I have given up and
4113 allowed the remaining 2 cases to be at the margin.
4114
4115 + Rename some variables in pcre to eliminate shadowing. This seems very
4116 pedantic, but does no harm, of course.
4117
4118 6. Moved the call to setjmp() into its own function, to get rid of warnings
4119 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4120
4121 7. Constructs such as \d{8,} were compiling into the equivalent of
4122 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4123 outcome, but in this particular case used more store than had been allocated,
4124 which caused the bug to be discovered because it threw up an internal error.
4125
4126 8. The debugging code in both pcre and pcretest for outputting the compiled
4127 form of a regex was going wrong in the case of back references followed by
4128 curly-bracketed repeats.
4129
4130
4131 Version 1.02 12-Dec-97
4132 ----------------------
4133
4134 1. Typos in pcre.3 and comments in the source fixed.
4135
4136 2. Applied a contributed patch to get rid of places where it used to remove
4137 'const' from variables, and fixed some signed/unsigned and uninitialized
4138 variable warnings.
4139
4140 3. Added the "runtest" target to Makefile.
4141
4142 4. Set default compiler flag to -O2 rather than just -O.
4143
4144
4145 Version 1.01 19-Nov-97
4146 ----------------------
4147
4148 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4149 like /([ab]*)*/, that is, for classes with more than one character in them.
4150
4151 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4152 as /((?>a*))*/ (a PCRE_EXTRA facility).
4153
4154
4155 Version 1.00 18-Nov-97
4156 ----------------------
4157
4158 1. Added compile-time macros to support systems such as SunOS4 which don't have
4159 memmove() or strerror() but have other things that can be used instead.
4160
4161 2. Arranged that "make clean" removes the executables.
4162
4163
4164 Version 0.99 27-Oct-97
4165 ----------------------
4166
4167 1. Fixed bug in code for optimizing classes with only one character. It was
4168 initializing a 32-byte map regardless, which could cause it to run off the end
4169 of the memory it had got.
4170
4171 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4172
4173
4174 Version 0.98 22-Oct-97
4175 ----------------------
4176
4177 1. Fixed bug in code for handling temporary memory usage when there are more
4178 back references than supplied space in the ovector. This could cause segfaults.
4179
4180
4181 Version 0.97 21-Oct-97
4182 ----------------------
4183
4184 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4185
4186 2. Optimized negated single characters not to use a bit map.
4187
4188 3. Brought error texts together as macro definitions; clarified some of them;
4189 fixed one that was wrong - it said "range out of order" when it meant "invalid
4190 escape sequence".
4191
4192 4. Changed some char * arguments to const char *.
4193
4194 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4195
4196 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4197 pcretest.
4198
4199
4200 Version 0.96 16-Oct-97
4201 ----------------------
4202
4203 1. Added a simple "pgrep" utility to the distribution.
4204
4205 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4206 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4207 where "ddd" means "one or more decimal digits".
4208
4209 3. Fixed serious bug. If a pattern had a back reference, but the call to
4210 pcre_exec() didn't supply a large enough ovector to record the related
4211 identifying subpattern, the match always failed. PCRE now remembers the number
4212 of the largest back reference, and gets some temporary memory in which to save
4213 the offsets during matching if necessary, in order to ensure that
4214 backreferences always work.
4215
4216 4. Increased the compatibility with Perl in a number of ways:
4217
4218 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4219 to request this handling. The option can be set at compile or exec time.
4220
4221 (b) $ matches before a terminating newline by default; an option
4222 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4223 mode). The option can be set at compile or exec time.
4224
4225 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4226 the same as Perl's. If the decimal number it represents is less than 10
4227 or there aren't that many previous left capturing parentheses, an octal
4228 escape is read. Inside a character class, it's always an octal escape,
4229 even if it is a single digit.
4230
4231 (d) An escaped but undefined alphabetic character is taken as a literal,
4232 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4233 escapes.
4234
4235 (e) {0} is now permitted. (The previous item is removed from the compiled
4236 pattern).
4237
4238 5. Changed all the names of code files so that the basic parts are no longer
4239 than 10 characters, and abolished the teeny "globals.c" file.
4240
4241 6. Changed the handling of character classes; they are now done with a 32-byte
4242 bit map always.
4243
4244 7. Added the -d and /D options to pcretest to make it possible to look at the
4245 internals of compilation without having to recompile pcre.
4246
4247
4248 Version 0.95 23-Sep-97
4249 ----------------------
4250
4251 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4252 \x20 at the start of a run of normal characters. These were being treated as
4253 real characters, instead of the source characters being re-checked.
4254
4255
4256 Version 0.94 18-Sep-97
4257 ----------------------
4258
4259 1. The functions are now thread-safe, with the caveat that the global variables
4260 containing pointers to malloc() and free() or alternative functions are the
4261 same for all threads.
4262
4263 2. Get pcre_study() to generate a bitmap of initial characters for non-
4264 anchored patterns when this is possible, and use it if passed to pcre_exec().
4265
4266
4267 Version 0.93 15-Sep-97
4268 ----------------------
4269
4270 1. /(b)|(:+)/ was computing an incorrect first character.
4271
4272 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4273 but not actually doing anything yet.
4274
4275 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4276 as Perl does (e.g. [-az] or [az-]).
4277
4278 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4279 all possible positions.
4280
4281 5. Split up into different modules to avoid including unneeded functions in a
4282 compiled binary. However, compile and exec are still in one module. The "study"
4283 function is split off.
4284
4285 6. The character tables are now in a separate module whose source is generated
4286 by an auxiliary program - but can then be edited by hand if required. There are
4287 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4288 toupper() in the code.
4289
4290 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4291 make them global. Abolish the function for setting them, as the caller can now
4292 set them directly.
4293
4294
4295 Version 0.92 11-Sep-97
4296 ----------------------
4297
4298 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4299 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4300
4301 2. Caseless matching was not working in character classes if the characters in
4302 the pattern were in upper case.
4303
4304 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4305
4306 4. Make PCRE_ANCHORED public and accept as a compile option.
4307
4308 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4309 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4310 pass them.
4311
4312 6. Give an error if bad option bits passed at compile or run time.
4313
4314 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4315 pcretest to cause it to pass that flag.
4316
4317 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4318 options, and the first character, if set.
4319
4320 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4321
4322
4323 Version 0.91 10-Sep-97
4324 ----------------------
4325
4326 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4327 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4328
4329 2. PCRE was looping on encountering an indefinitely repeated back reference to
4330 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4331 Perl does - treats the match as successful.
4332
4333 ****

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