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Revision 632 - (show annotations) (download)
Fri Jul 22 17:47:49 2011 UTC (2 years, 9 months ago) by ph10
File size: 207799 byte(s)
Fix pcregrep repeated match in same line bug.

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

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