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Revision 629 - (show annotations) (download)
Fri Jul 22 09:18:11 2011 UTC (2 years, 8 months ago) by ph10
File size: 207257 byte(s)
Fix isolated \k 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
167 Version 8.12 15-Jan-2011
168 ------------------------
169
170 1. Fixed some typos in the markup of the man pages, and wrote a script that
171 checks for such things as part of the documentation building process.
172
173 2. On a big-endian 64-bit system, pcregrep did not correctly process the
174 --match-limit and --recursion-limit options (added for 8.11). In
175 particular, this made one of the standard tests fail. (The integer value
176 went into the wrong half of a long int.)
177
178 3. If the --colour option was given to pcregrep with -v (invert match), it
179 did strange things, either producing crazy output, or crashing. It should,
180 of course, ignore a request for colour when reporting lines that do not
181 match.
182
183 4. Another pcregrep bug caused similar problems if --colour was specified with
184 -M (multiline) and the pattern match finished with a line ending.
185
186 5. In pcregrep, when a pattern that ended with a literal newline sequence was
187 matched in multiline mode, the following line was shown as part of the
188 match. This seems wrong, so I have changed it.
189
190 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
191 the check for further matches in the same line (so they could be coloured)
192 to overrun the end of the current line. If another match was found, it was
193 incorrectly shown (and then shown again when found in the next line).
194
195 7. If pcregrep was compiled under Windows, there was a reference to the
196 function pcregrep_exit() before it was defined. I am assuming this was
197 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
198 reported by a user. I've moved the definition above the reference.
199
200
201 Version 8.11 10-Dec-2010
202 ------------------------
203
204 1. (*THEN) was not working properly if there were untried alternatives prior
205 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
206 backtracked to try for "b" instead of moving to the next alternative branch
207 at the same level (in this case, to look for "c"). The Perl documentation
208 is clear that when (*THEN) is backtracked onto, it goes to the "next
209 alternative in the innermost enclosing group".
210
211 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
212 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
213 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
214 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
215 (*THEN).
216
217 3. If \s appeared in a character class, it removed the VT character from
218 the class, even if it had been included by some previous item, for example
219 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
220 of \s, but is part of the POSIX "space" class.)
221
222 4. A partial match never returns an empty string (because you can always
223 match an empty string at the end of the subject); however the checking for
224 an empty string was starting at the "start of match" point. This has been
225 changed to the "earliest inspected character" point, because the returned
226 data for a partial match starts at this character. This means that, for
227 example, /(?<=abc)def/ gives a partial match for the subject "abc"
228 (previously it gave "no match").
229
230 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
231 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
232 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
233 has an implication that the given string is incomplete (because a partial
234 match is preferred over a full match). For this reason, these items now
235 give a partial match in this situation. [Aside: previously, the one case
236 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
237 match rather than a full match, which was wrong by the old rules, but is
238 now correct.]
239
240 6. There was a bug in the handling of #-introduced comments, recognized when
241 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
242 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
243 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
244 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
245 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
246 places in pcre_compile().
247
248 7. Related to (6) above, when pcre_compile() was skipping #-introduced
249 comments when looking ahead for named forward references to subpatterns,
250 the only newline sequence it recognized was NL. It now handles newlines
251 according to the set newline convention.
252
253 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
254 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
255 cater for a lack of strerror(). These oversights have been fixed.
256
257 9. Added --match-limit and --recursion-limit to pcregrep.
258
259 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
260
261 11. When the -o option was used, pcregrep was setting a return code of 1, even
262 when matches were found, and --line-buffered was not being honoured.
263
264 12. Added an optional parentheses number to the -o and --only-matching options
265 of pcregrep.
266
267 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
268 can match an empty string. The code to do it in pcretest and pcredemo
269 needed fixing:
270
271 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
272 only one byte after an empty string match just before CRLF (this case
273 just got forgotten; "any" and "anycrlf" were OK).
274
275 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
276 mode when an empty string match preceded an ASCII character followed by
277 a non-ASCII character. (The code for advancing by one character rather
278 than one byte was nonsense.)
279
280 (c) The pcredemo.c sample program did not have any code at all to handle
281 the cases when CRLF is a valid newline sequence.
282
283 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
284 as a starting offset was within the subject string. There is now a new
285 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
286 negative or greater than the length of the string. In order to test this,
287 pcretest is extended to allow the setting of negative starting offsets.
288
289 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
290 starting offset points to the beginning of a UTF-8 character was
291 unnecessarily clumsy. I tidied it up.
292
293 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
294 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
295
296 17. Nobody had reported that the --include_dir option, which was added in
297 release 7.7 should have been called --include-dir (hyphen, not underscore)
298 for compatibility with GNU grep. I have changed it to --include-dir, but
299 left --include_dir as an undocumented synonym, and the same for
300 --exclude-dir, though that is not available in GNU grep, at least as of
301 release 2.5.4.
302
303 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
304 characters from a string of bytes) have been redefined so as not to use
305 loops, in order to improve performance in some environments. At the same
306 time, I abstracted some of the common code into auxiliary macros to save
307 repetition (this should not affect the compiled code).
308
309 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
310 compile-time error is now given if \c is not followed by an ASCII
311 character, that is, a byte less than 128. (In EBCDIC mode, the code is
312 different, and any byte value is allowed.)
313
314 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
315 START_OPTIMIZE option, which is now allowed at compile time - but just
316 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
317 to pcregrep and other applications that have no direct access to PCRE
318 options. The new /Y option in pcretest sets this option when calling
319 pcre_compile().
320
321 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
322 back references. Groups containing recursive back references were forced to
323 be atomic by that change, but in the case of named groups, the amount of
324 memory required was incorrectly computed, leading to "Failed: internal
325 error: code overflow". This has been fixed.
326
327 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
328 pcretest.c, to avoid build problems in some Borland environments.
329
330
331 Version 8.10 25-Jun-2010
332 ------------------------
333
334 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
335 THEN.
336
337 2. (*ACCEPT) was not working when inside an atomic group.
338
339 3. Inside a character class, \B is treated as a literal by default, but
340 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
341 causes the error). The code is unchanged, but I tidied the documentation.
342
343 4. Inside a character class, PCRE always treated \R and \X as literals,
344 whereas Perl faults them if its -w option is set. I have changed PCRE so
345 that it faults them when PCRE_EXTRA is set.
346
347 5. Added support for \N, which always matches any character other than
348 newline. (It is the same as "." when PCRE_DOTALL is not set.)
349
350 6. When compiling pcregrep with newer versions of gcc which may have
351 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
352 declared with attribute warn_unused_result" were given. Just casting the
353 result to (void) does not stop the warnings; a more elaborate fudge is
354 needed. I've used a macro to implement this.
355
356 7. Minor change to pcretest.c to avoid a compiler warning.
357
358 8. Added four artifical Unicode properties to help with an option to make
359 \s etc use properties (see next item). The new properties are: Xan
360 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
361
362 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
363 use Unicode properties. (*UCP) at the start of a pattern can be used to set
364 this option. Modified pcretest to add /W to test this facility. Added
365 REG_UCP to make it available via the POSIX interface.
366
367 10. Added --line-buffered to pcregrep.
368
369 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
370 studied, and the match started with a letter with a code point greater than
371 127 whose first byte was different to the first byte of the other case of
372 the letter, the other case of this starting letter was not recognized
373 (#976).
374
375 12. If a pattern that was studied started with a repeated Unicode property
376 test, for example, \p{Nd}+, there was the theoretical possibility of
377 setting up an incorrect bitmap of starting bytes, but fortunately it could
378 not have actually happened in practice until change 8 above was made (it
379 added property types that matched character-matching opcodes).
380
381 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
382 possible starting bytes for non-anchored patterns.
383
384 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
385 \R, and also a number of cases that involve Unicode properties, both
386 explicit and implicit when PCRE_UCP is set.
387
388 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
389 input, it could crash or give wrong results if characters with values
390 greater than 0xc0 were present in the subject string. (Detail: it assumed
391 UTF-8 input when processing these items.)
392
393 16. Added a lot of (int) casts to avoid compiler warnings in systems where
394 size_t is 64-bit (#991).
395
396 17. Added a check for running out of memory when PCRE is compiled with
397 --disable-stack-for-recursion (#990).
398
399 18. If the last data line in a file for pcretest does not have a newline on
400 the end, a newline was missing in the output.
401
402 19. The default pcre_chartables.c file recognizes only ASCII characters (values
403 less than 128) in its various bitmaps. However, there is a facility for
404 generating tables according to the current locale when PCRE is compiled. It
405 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
406 characters, are recognized by isspace() and therefore were getting set in
407 these tables, and indeed these tables seem to approximate to ISO 8859. This
408 caused a problem in UTF-8 mode when pcre_study() was used to create a list
409 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
410 which of course cannot start UTF-8 characters. I have changed the code so
411 that only real ASCII characters (less than 128) and the correct starting
412 bytes for UTF-8 encodings are set for characters greater than 127 when in
413 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
414 altogether.)
415
416 20. Added the /T option to pcretest so as to be able to run tests with non-
417 standard character tables, thus making it possible to include the tests
418 used for 19 above in the standard set of tests.
419
420 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
421 reference to a subpattern the other side of a comment that contains an
422 opening parenthesis caused either an internal compiling error, or a
423 reference to the wrong subpattern.
424
425
426 Version 8.02 19-Mar-2010
427 ------------------------
428
429 1. The Unicode data tables have been updated to Unicode 5.2.0.
430
431 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
432 configured.
433
434 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
435 original author of that file, following a query about its status.
436
437 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
438 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
439
440 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
441 quantifier applied to a forward-referencing subroutine call, could compile
442 incorrect code or give the error "internal error: previously-checked
443 referenced subpattern not found".
444
445 6. Both MS Visual Studio and Symbian OS have problems with initializing
446 variables to point to external functions. For these systems, therefore,
447 pcre_malloc etc. are now initialized to local functions that call the
448 relevant global functions.
449
450 7. There were two entries missing in the vectors called coptable and poptable
451 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
452 I've fixed the data, and added a kludgy way of testing at compile time that
453 the lengths are correct (equal to the number of opcodes).
454
455 8. Following on from 7, I added a similar kludge to check the length of the
456 eint vector in pcreposix.c.
457
458 9. Error texts for pcre_compile() are held as one long string to avoid too
459 much relocation at load time. To find a text, the string is searched,
460 counting zeros. There was no check for running off the end of the string,
461 which could happen if a new error number was added without updating the
462 string.
463
464 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
465
466 11. \K was not working if it appeared in an atomic group or in a group that
467 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
468 \K is "not well defined" if used in an assertion. PCRE now accepts it if
469 the assertion is positive, but not if it is negative.
470
471 12. Change 11 fortuitously reduced the size of the stack frame used in the
472 "match()" function of pcre_exec.c by one pointer. Forthcoming
473 implementation of support for (*MARK) will need an extra pointer on the
474 stack; I have reserved it now, so that the stack frame size does not
475 decrease.
476
477 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
478 item in branch that calls a recursion is a subroutine call - as in the
479 second branch in the above example - was incorrectly given the compile-
480 time error "recursive call could loop indefinitely" because pcre_compile()
481 was not correctly checking the subroutine for matching a non-empty string.
482
483 14. The checks for overrunning compiling workspace could trigger after an
484 overrun had occurred. This is a "should never occur" error, but it can be
485 triggered by pathological patterns such as hundreds of nested parentheses.
486 The checks now trigger 100 bytes before the end of the workspace.
487
488 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
489
490
491 Version 8.01 19-Jan-2010
492 ------------------------
493
494 1. If a pattern contained a conditional subpattern with only one branch (in
495 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
496 computed the wrong minimum data length (which is of course zero for such
497 subpatterns). This could cause incorrect "no match" results.
498
499 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
500 the pattern is reset in the first branch, pcre_compile() failed with
501 "internal error: code overflow at offset...". This happened only when
502 the reset was to the original external option setting. (An optimization
503 abstracts leading options settings into an external setting, which was the
504 cause of this.)
505
506 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
507 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
508 assertion pattern did not match (meaning that the assertion was true), it
509 was incorrectly treated as false if the SKIP had been reached during the
510 matching. This also applied to assertions used as conditions.
511
512 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
513 assertion subpattern, including such a pattern used as a condition,
514 unpredictable results occurred, instead of the error return
515 PCRE_ERROR_DFA_UITEM.
516
517 5. The C++ GlobalReplace function was not working like Perl for the special
518 situation when an empty string is matched. It now does the fancy magic
519 stuff that is necessary.
520
521 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
522 removed. (These were left over from very, very early versions of PCRE.)
523
524 7. Some cosmetic changes to the code to make life easier when compiling it
525 as part of something else:
526
527 (a) Change DEBUG to PCRE_DEBUG.
528
529 (b) In pcre_compile(), rename the member of the "branch_chain" structure
530 called "current" as "current_branch", to prevent a collision with the
531 Linux macro when compiled as a kernel module.
532
533 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
534 prevent a collision with the Linux macro when compiled as a kernel
535 module.
536
537 8. In pcre_compile() there are some checks for integer overflows that used to
538 cast potentially large values to (double). This has been changed to that
539 when building, a check for int64_t is made, and if it is found, it is used
540 instead, thus avoiding the use of floating point arithmetic. (There is no
541 other use of FP in PCRE.) If int64_t is not found, the fallback is to
542 double.
543
544 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
545 2005 (difference between two addresses compared to an unsigned value).
546
547 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
548 custom one, because of the following reported problem in Windows:
549
550 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
551 under Win32.
552 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
553 therefore missing the function definition.
554 - The compiler thus generates a "C" signature for the test function.
555 - The linker fails to find the "C" function.
556 - PCRE fails to configure if asked to do so against libbz2.
557
558 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
559 messages were output:
560
561 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
562 rerunning libtoolize, to keep the correct libtool macros in-tree.
563 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
564
565 I have done both of these things.
566
567 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
568 most of the time, it *can* run out if it is given a pattern that contains a
569 runaway infinite recursion. I updated the discussion in the pcrestack man
570 page.
571
572 13. Now that we have gone to the x.xx style of version numbers, the minor
573 version may start with zero. Using 08 or 09 is a bad idea because users
574 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
575 interpreted as invalid octal numbers. I've updated the previous comment in
576 configure.ac, and also added a check that gives an error if 08 or 09 are
577 used.
578
579 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
580 causing partial matching to fail when the end of the subject matched \W
581 in a UTF-8 pattern where \W was quantified with a minimum of 3.
582
583 15. There were some discrepancies between the declarations in pcre_internal.h
584 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
585 their definitions. The declarations used "const uschar *" and the
586 definitions used USPTR. Even though USPTR is normally defined as "const
587 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
588 reported that: "This difference in casting confuses some C++ compilers, for
589 example, SunCC recognizes above declarations as different functions and
590 generates broken code for hbpcre." I have changed the declarations to use
591 USPTR.
592
593 16. GNU libtool is named differently on some systems. The autogen.sh script now
594 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
595 (FreeBSD).
596
597 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
598 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
599 comment: "Figure out how to create a longlong from a string: strtoll and
600 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
601 instance, but it only takes 2 args instead of 3!"
602
603 18. A subtle bug concerned with back references has been fixed by a change of
604 specification, with a corresponding code fix. A pattern such as
605 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
606 refers, was giving matches when it shouldn't. For example, xa=xaaa would
607 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
608 same bug. Such groups have to be quantified to be useful, or contained
609 inside another quantified group. (If there's no repetition, the reference
610 can never match.) The problem arises because, having left the group and
611 moved on to the rest of the pattern, a later failure that backtracks into
612 the group uses the captured value from the final iteration of the group
613 rather than the correct earlier one. I have fixed this in PCRE by forcing
614 any group that contains a reference to itself to be an atomic group; that
615 is, there cannot be any backtracking into it once it has completed. This is
616 similar to recursive and subroutine calls.
617
618
619 Version 8.00 19-Oct-09
620 ----------------------
621
622 1. The table for translating pcre_compile() error codes into POSIX error codes
623 was out-of-date, and there was no check on the pcre_compile() error code
624 being within the table. This could lead to an OK return being given in
625 error.
626
627 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
628 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
629 in a Windows environment.
630
631 3. The pcregrep --count option prints the count for each file even when it is
632 zero, as does GNU grep. However, pcregrep was also printing all files when
633 --files-with-matches was added. Now, when both options are given, it prints
634 counts only for those files that have at least one match. (GNU grep just
635 prints the file name in this circumstance, but including the count seems
636 more useful - otherwise, why use --count?) Also ensured that the
637 combination -clh just lists non-zero counts, with no names.
638
639 4. The long form of the pcregrep -F option was incorrectly implemented as
640 --fixed_strings instead of --fixed-strings. This is an incompatible change,
641 but it seems right to fix it, and I didn't think it was worth preserving
642 the old behaviour.
643
644 5. The command line items --regex=pattern and --regexp=pattern were not
645 recognized by pcregrep, which required --regex pattern or --regexp pattern
646 (with a space rather than an '='). The man page documented the '=' forms,
647 which are compatible with GNU grep; these now work.
648
649 6. No libpcreposix.pc file was created for pkg-config; there was just
650 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
651
652 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
653 when UCP support is not needed, by modifying the Python script that
654 generates it from Unicode data files. This should not matter if the module
655 is correctly used as a library, but I received one complaint about 50K of
656 unwanted data. My guess is that the person linked everything into his
657 program rather than using a library. Anyway, it does no harm.
658
659 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
660 was a minimum greater than 1 for a wide character in a possessive
661 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
662 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
663 character. Chaos in the form of incorrect output or a compiling loop could
664 result.
665
666 9. The restrictions on what a pattern can contain when partial matching is
667 requested for pcre_exec() have been removed. All patterns can now be
668 partially matched by this function. In addition, if there are at least two
669 slots in the offset vector, the offset of the earliest inspected character
670 for the match and the offset of the end of the subject are set in them when
671 PCRE_ERROR_PARTIAL is returned.
672
673 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
674 synonymous with PCRE_PARTIAL, for backwards compatibility, and
675 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
676 and may be more useful for multi-segment matching.
677
678 11. Partial matching with pcre_exec() is now more intuitive. A partial match
679 used to be given if ever the end of the subject was reached; now it is
680 given only if matching could not proceed because another character was
681 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
682 string "Z", which now yields "no match" instead of "partial match". In the
683 case of pcre_dfa_exec(), "no match" is given if every matching path for the
684 final character ended with (*FAIL).
685
686 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
687 if the pattern had a "must contain" character that was already found in the
688 earlier partial match, unless partial matching was again requested. For
689 example, with the pattern /dog.(body)?/, the "must contain" character is
690 "g". If the first part-match was for the string "dog", restarting with
691 "sbody" failed. This bug has been fixed.
692
693 13. The string returned by pcre_dfa_exec() after a partial match has been
694 changed so that it starts at the first inspected character rather than the
695 first character of the match. This makes a difference only if the pattern
696 starts with a lookbehind assertion or \b or \B (\K is not supported by
697 pcre_dfa_exec()). It's an incompatible change, but it makes the two
698 matching functions compatible, and I think it's the right thing to do.
699
700 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
701 so that the demonstration program is easily available in environments where
702 PCRE has not been installed from source.
703
704 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
705 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
706 library.
707
708 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
709 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
710 is not the first non-POSIX option to be added. Clearly some people find
711 these options useful.
712
713 17. If a caller to the POSIX matching function regexec() passes a non-zero
714 value for nmatch with a NULL value for pmatch, the value of
715 nmatch is forced to zero.
716
717 18. RunGrepTest did not have a test for the availability of the -u option of
718 the diff command, as RunTest does. It now checks in the same way as
719 RunTest, and also checks for the -b option.
720
721 19. If an odd number of negated classes containing just a single character
722 interposed, within parentheses, between a forward reference to a named
723 subpattern and the definition of the subpattern, compilation crashed with
724 an internal error, complaining that it could not find the referenced
725 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
726 [The bug was that it was starting one character too far in when skipping
727 over the character class, thus treating the ] as data rather than
728 terminating the class. This meant it could skip too much.]
729
730 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
731 /g option in pcretest when the pattern contains \K, which makes it possible
732 to have an empty string match not at the start, even when the pattern is
733 anchored. Updated pcretest and pcredemo to use this option.
734
735 21. If the maximum number of capturing subpatterns in a recursion was greater
736 than the maximum at the outer level, the higher number was returned, but
737 with unset values at the outer level. The correct (outer level) value is
738 now given.
739
740 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
741 PCRE did not set those parentheses (unlike Perl). I have now found a way to
742 make it do so. The string so far is captured, making this feature
743 compatible with Perl.
744
745 23. The tests have been re-organized, adding tests 11 and 12, to make it
746 possible to check the Perl 5.10 features against Perl 5.10.
747
748 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
749 pattern matches a fixed length string. PCRE did not allow this; now it
750 does. Neither allows recursion.
751
752 25. I finally figured out how to implement a request to provide the minimum
753 length of subject string that was needed in order to match a given pattern.
754 (It was back references and recursion that I had previously got hung up
755 on.) This code has now been added to pcre_study(); it finds a lower bound
756 to the length of subject needed. It is not necessarily the greatest lower
757 bound, but using it to avoid searching strings that are too short does give
758 some useful speed-ups. The value is available to calling programs via
759 pcre_fullinfo().
760
761 26. While implementing 25, I discovered to my embarrassment that pcretest had
762 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
763 study optimizations had never been tested with that matching function.
764 Oops. What is worse, even when it was passed study data, there was a bug in
765 pcre_dfa_exec() that meant it never actually used it. Double oops. There
766 were also very few tests of studied patterns with pcre_dfa_exec().
767
768 27. If (?| is used to create subpatterns with duplicate numbers, they are now
769 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
770 on the other side of the coin, they are no longer allowed to have different
771 names, because these cannot be distinguished in PCRE, and this has caused
772 confusion. (This is a difference from Perl.)
773
774 28. When duplicate subpattern names are present (necessarily with different
775 numbers, as required by 27 above), and a test is made by name in a
776 conditional pattern, either for a subpattern having been matched, or for
777 recursion in such a pattern, all the associated numbered subpatterns are
778 tested, and the overall condition is true if the condition is true for any
779 one of them. This is the way Perl works, and is also more like the way
780 testing by number works.
781
782
783 Version 7.9 11-Apr-09
784 ---------------------
785
786 1. When building with support for bzlib/zlib (pcregrep) and/or readline
787 (pcretest), all targets were linked against these libraries. This included
788 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
789 libraries. This caused unwanted dependencies to be created. This problem
790 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
791 pcretest is linked with readline.
792
793 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
794 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
795 moved outside it again, because FALSE and TRUE are already defined in AIX,
796 but BOOL is not.
797
798 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
799 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
800
801 4. The pcregrep documentation said spaces were inserted as well as colons (or
802 hyphens) following file names and line numbers when outputting matching
803 lines. This is not true; no spaces are inserted. I have also clarified the
804 wording for the --colour (or --color) option.
805
806 5. In pcregrep, when --colour was used with -o, the list of matching strings
807 was not coloured; this is different to GNU grep, so I have changed it to be
808 the same.
809
810 6. When --colo(u)r was used in pcregrep, only the first matching substring in
811 each matching line was coloured. Now it goes on to look for further matches
812 of any of the test patterns, which is the same behaviour as GNU grep.
813
814 7. A pattern that could match an empty string could cause pcregrep to loop; it
815 doesn't make sense to accept an empty string match in pcregrep, so I have
816 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
817 seems to be how GNU grep behaves.
818
819 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
820 start or after a newline", because the conditional assertion was not being
821 correctly handled. The rule now is that both the assertion and what follows
822 in the first alternative must satisfy the test.
823
824 9. If auto-callout was enabled in a pattern with a conditional group whose
825 condition was an assertion, PCRE could crash during matching, both with
826 pcre_exec() and pcre_dfa_exec().
827
828 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
829 used for matching.
830
831 11. Unicode property support in character classes was not working for
832 characters (bytes) greater than 127 when not in UTF-8 mode.
833
834 12. Added the -M command line option to pcretest.
835
836 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
837
838 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
839
840 16. Added comments and documentation about mis-use of no_arg in the C++
841 wrapper.
842
843 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
844 from Martin Jerabek that uses macro names for all relevant character and
845 string constants.
846
847 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
848 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
849 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
850 these, but not everybody uses configure.
851
852 19. A conditional group that had only one branch was not being correctly
853 recognized as an item that could match an empty string. This meant that an
854 enclosing group might also not be so recognized, causing infinite looping
855 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
856 with the subject "ab", where knowledge that the repeated group can match
857 nothing is needed in order to break the loop.
858
859 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
860 exec(), but without supplying a callout function, matching went wrong.
861
862 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
863 leak if the size of the offset vector was greater than 30. When the vector
864 is smaller, the saved offsets during recursion go onto a local stack
865 vector, but for larger vectors malloc() is used. It was failing to free
866 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
867 error, in fact).
868
869 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
870 heapframe that is used only when UTF-8 support is enabled. This caused no
871 problem, but was untidy.
872
873 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
874 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
875 included within another project.
876
877 24. Steven Van Ingelgem's patches to add more options to the CMake support,
878 slightly modified by me:
879
880 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
881 not building pcregrep.
882
883 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
884 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
885
886 25. Forward references, both numeric and by name, in patterns that made use of
887 duplicate group numbers, could behave incorrectly or give incorrect errors,
888 because when scanning forward to find the reference group, PCRE was not
889 taking into account the duplicate group numbers. A pattern such as
890 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
891
892 26. Changed a few more instances of "const unsigned char *" to USPTR, making
893 the feature of a custom pointer more persuasive (as requested by a user).
894
895 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
896 pcretest.c, inside #ifndefs, because it seems they are sometimes already
897 pre-defined.
898
899 28. Added support for (*UTF8) at the start of a pattern.
900
901 29. Arrange for flags added by the "release type" setting in CMake to be shown
902 in the configuration summary.
903
904
905 Version 7.8 05-Sep-08
906 ---------------------
907
908 1. Replaced UCP searching code with optimized version as implemented for Ad
909 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
910 stage table and inline lookup instead of a function, giving speed ups of 2
911 to 5 times on some simple patterns that I tested. Permission was given to
912 distribute the MultiStage2.py script that generates the tables (it's not in
913 the tarball, but is in the Subversion repository).
914
915 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
916 scripts.
917
918 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
919 a group with a zero qualifier. The result of the study could be incorrect,
920 or the function might crash, depending on the pattern.
921
922 4. Caseless matching was not working for non-ASCII characters in back
923 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
924 It now works when Unicode Property Support is available.
925
926 5. In pcretest, an escape such as \x{de} in the data was always generating
927 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
928 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
929 truncation.
930
931 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
932
933 7. Added two (int) casts to pcregrep when printing the difference of two
934 pointers, in case they are 64-bit values.
935
936 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
937 test 2 if it fails.
938
939 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
940 and a #define of that name to empty if it is not externally set. This is to
941 allow users of MSVC to set it if necessary.
942
943 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
944 the convenience functions in the pcre_get.c source file.
945
946 11. An option change at the start of a pattern that had top-level alternatives
947 could cause overwriting and/or a crash. This command provoked a crash in
948 some environments:
949
950 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
951
952 This potential security problem was recorded as CVE-2008-2371.
953
954 12. For a pattern where the match had to start at the beginning or immediately
955 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
956 pcre_dfa_exec() could read past the end of the passed subject if there was
957 no match. To help with detecting such bugs (e.g. with valgrind), I modified
958 pcretest so that it places the subject at the end of its malloc-ed buffer.
959
960 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
961 exec() might read past the end of the data buffer in UTF-8 mode.
962
963 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
964 the data contained the byte 0x85 as part of a UTF-8 character within its
965 first line. This applied both to normal and DFA matching.
966
967 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
968 /^[^d]*?$/8 failed to match "abc".
969
970 16. Added a missing copyright notice to pcrecpp_internal.h.
971
972 17. Make it more clear in the documentation that values returned from
973 pcre_exec() in ovector are byte offsets, not character counts.
974
975 18. Tidied a few places to stop certain compilers from issuing warnings.
976
977 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
978 supplied by Stefan Weber. I made a further small update for 7.8 because
979 there is a change of source arrangements: the pcre_searchfuncs.c module is
980 replaced by pcre_ucd.c.
981
982
983 Version 7.7 07-May-08
984 ---------------------
985
986 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
987 a string to a long long, pretend we don't even have a long long." This is
988 done by checking for the strtoq, strtoll, and _strtoi64 functions.
989
990 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
991 pre-7.6 versions, which defined a global no_arg variable instead of putting
992 it in the RE class. (See also #8 below.)
993
994 3. Remove a line of dead code, identified by coverity and reported by Nuno
995 Lopes.
996
997 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
998
999 (1) The include/exclude patterns were being applied to the whole pathnames
1000 of files, instead of just to the final components.
1001
1002 (2) If there was more than one level of directory, the subdirectories were
1003 skipped unless they satisfied the include/exclude conditions. This is
1004 inconsistent with GNU grep (and could even be seen as contrary to the
1005 pcregrep specification - which I improved to make it absolutely clear).
1006 The action now is always to scan all levels of directory, and just
1007 apply the include/exclude patterns to regular files.
1008
1009 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1010 --exclude_dir in the tests to avoid scanning .svn directories.
1011
1012 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1013 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1014 doesn't support NULs in patterns.
1015
1016 7. Added some missing "const"s to declarations of static tables in
1017 pcre_compile.c and pcre_dfa_exec.c.
1018
1019 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1020 caused by fix #2 above. (Subsequently also a second patch to fix the
1021 first patch. And a third patch - this was a messy problem.)
1022
1023 9. Applied Craig's patch to remove the use of push_back().
1024
1025 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1026 matching function regexec().
1027
1028 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1029 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1030 references. PCRE supports relative numbers with this syntax (I don't think
1031 Oniguruma does).
1032
1033 12. Previously, a group with a zero repeat such as (...){0} was completely
1034 omitted from the compiled regex. However, this means that if the group
1035 was called as a subroutine from elsewhere in the pattern, things went wrong
1036 (an internal error was given). Such groups are now left in the compiled
1037 pattern, with a new opcode that causes them to be skipped at execution
1038 time.
1039
1040 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1041 to the way PCRE behaves:
1042
1043 (a) A lone ] character is dis-allowed (Perl treats it as data).
1044
1045 (b) A back reference to an unmatched subpattern matches an empty string
1046 (Perl fails the current match path).
1047
1048 (c) A data ] in a character class must be notated as \] because if the
1049 first data character in a class is ], it defines an empty class. (In
1050 Perl it is not possible to have an empty class.) The empty class []
1051 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1052 The negative empty class [^] matches any one character, independently
1053 of the DOTALL setting.
1054
1055 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1056 non-existent subpattern following a character class starting with ']' and
1057 containing () gave an internal compiling error instead of "reference to
1058 non-existent subpattern". Fortunately, when the pattern did exist, the
1059 compiled code was correct. (When scanning forwards to check for the
1060 existencd of the subpattern, it was treating the data ']' as terminating
1061 the class, so got the count wrong. When actually compiling, the reference
1062 was subsequently set up correctly.)
1063
1064 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1065 it was being rejected as not supported by pcre_dfa_exec(), even though
1066 other assertions are supported. I have made pcre_dfa_exec() support
1067 (*FAIL).
1068
1069 16. The implementation of 13c above involved the invention of a new opcode,
1070 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1071 cannot be changed at match time, I realized I could make a small
1072 improvement to matching performance by compiling OP_ALLANY instead of
1073 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1074 on the OP_ANY path.
1075
1076 17. Compiling pcretest on Windows with readline support failed without the
1077 following two fixes: (1) Make the unistd.h include conditional on
1078 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1079
1080 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1081 ncurses library to be included for pcretest when ReadLine support is
1082 requested, but also to allow for it to be overridden. This patch came from
1083 Daniel Bergström.
1084
1085 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1086 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1087 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1088 spotting this.
1089
1090
1091 Version 7.6 28-Jan-08
1092 ---------------------
1093
1094 1. A character class containing a very large number of characters with
1095 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1096 overflow.
1097
1098 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1099 HAVE_LONG_LONG is not defined.
1100
1101 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1102 bring them up to date and include new features. This patch includes:
1103
1104 - Fixed PH's badly added libz and libbz2 support.
1105 - Fixed a problem with static linking.
1106 - Added pcredemo. [But later removed - see 7 below.]
1107 - Fixed dftables problem and added an option.
1108 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1109 HAVE_LONG_LONG.
1110 - Added readline support for pcretest.
1111 - Added an listing of the option settings after cmake has run.
1112
1113 4. A user submitted a patch to Makefile that makes it easy to create
1114 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1115 Makefile.am that cause it to include this special target, without
1116 affecting anything else. Note that the same mingw target plus all
1117 the other distribution libraries and programs are now supported
1118 when configuring with CMake (see 6 below) instead of with
1119 Configure/Make.
1120
1121 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1122 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1123 exported in the Windows port". It has not yet been confirmed that the patch
1124 solves the problem, but it does no harm.
1125
1126 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1127 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1128 with CMake, and also correct the comment about stack recursion.
1129
1130 7. Remove the automatic building of pcredemo from the ./configure system and
1131 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1132 of a program that users should build themselves after PCRE is installed, so
1133 building it automatically is not really right. What is more, it gave
1134 trouble in some build environments.
1135
1136 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1137
1138
1139 Version 7.5 10-Jan-08
1140 ---------------------
1141
1142 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1143 values in parens when parsing an RE using the C++ wrapper."
1144
1145 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1146 Characters greater than 255 were excluded from the class instead of being
1147 included.
1148
1149 3. The same bug as (2) above applied to negated POSIX classes such as
1150 [:^space:].
1151
1152 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1153 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1154 I have changed it.
1155
1156 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1157 first named subpattern) and a construct such as (?&a) would reference the
1158 first named subpattern whose name started with "a" (in other words, the
1159 length check was missing). Both these problems are fixed. "Subpattern name
1160 expected" is now given for (?&) (a zero-length name), and this patch also
1161 makes it give the same error for \k'' (previously it complained that that
1162 was a reference to a non-existent subpattern).
1163
1164 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1165 this is right because (?- can be followed by option settings as well as by
1166 digits. I have, however, made the messages clearer.
1167
1168 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1169 than the number used in the conditional) now cause a compile-time error.
1170 This is actually not compatible with Perl, which accepts such patterns, but
1171 treats the conditional as always being FALSE (as PCRE used to), but it
1172 seems to me that giving a diagnostic is better.
1173
1174 8. Change "alphameric" to the more common word "alphanumeric" in comments
1175 and messages.
1176
1177 9. Fix two occurrences of "backslash" in comments that should have been
1178 "backspace".
1179
1180 10. Remove two redundant lines of code that can never be obeyed (their function
1181 was moved elsewhere).
1182
1183 11. The program that makes PCRE's Unicode character property table had a bug
1184 which caused it to generate incorrect table entries for sequences of
1185 characters that have the same character type, but are in different scripts.
1186 It amalgamated them into a single range, with the script of the first of
1187 them. In other words, some characters were in the wrong script. There were
1188 thirteen such cases, affecting characters in the following ranges:
1189
1190 U+002b0 - U+002c1
1191 U+0060c - U+0060d
1192 U+0061e - U+00612
1193 U+0064b - U+0065e
1194 U+0074d - U+0076d
1195 U+01800 - U+01805
1196 U+01d00 - U+01d77
1197 U+01d9b - U+01dbf
1198 U+0200b - U+0200f
1199 U+030fc - U+030fe
1200 U+03260 - U+0327f
1201 U+0fb46 - U+0fbb1
1202 U+10450 - U+1049d
1203
1204 12. The -o option (show only the matching part of a line) for pcregrep was not
1205 compatible with GNU grep in that, if there was more than one match in a
1206 line, it showed only the first of them. It now behaves in the same way as
1207 GNU grep.
1208
1209 13. If the -o and -v options were combined for pcregrep, it printed a blank
1210 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1211 does the same. The return code can be used to tell if there were any
1212 non-matching lines.
1213
1214 14. Added --file-offsets and --line-offsets to pcregrep.
1215
1216 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1217 infinitely looping recursion. The bug was that positive lookaheads were not
1218 being skipped when checking for a possible empty match (negative lookaheads
1219 and both kinds of lookbehind were skipped).
1220
1221 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1222 inclusion of <windows.h> to before rather than after the definition of
1223 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1224
1225 17. Specifying a possessive quantifier with a specific limit for a Unicode
1226 character property caused pcre_compile() to compile bad code, which led at
1227 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1228 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1229 caused the error; without that there was no problem.
1230
1231 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1232
1233 19. Added --enable-pcretest-libreadline.
1234
1235 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1236 RE::GlobalReplace(). As a result, the number of replacements returned was
1237 double what it should be. I removed one of the increments, but Craig sent a
1238 later patch that removed the other one (the right fix) and added unit tests
1239 that check the return values (which was not done before).
1240
1241 21. Several CMake things:
1242
1243 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1244 the names libpcre and libpcreposix, not just pcre and pcreposix.
1245
1246 (2) The above change means that pcretest and pcregrep are now correctly
1247 linked with the newly-built libraries, not previously installed ones.
1248
1249 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1250
1251 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1252 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1253 UTF-8 newline character). The key issue is that the pattern starts .*;
1254 this means that the match must be either at the beginning, or after a
1255 newline. The bug was in the code for advancing after a failed match and
1256 checking that the new position followed a newline. It was not taking
1257 account of UTF-8 characters correctly.
1258
1259 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1260 character classes. PCRE was not treating the sequence [:...:] as a
1261 character class unless the ... were all letters. Perl, however, seems to
1262 allow any characters between [: and :], though of course it rejects as
1263 unknown any "names" that contain non-letters, because all the known class
1264 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1265 for example, whereas PCRE did not - it did not recognize a POSIX character
1266 class. This seemed a bit dangerous, so the code has been changed to be
1267 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1268 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1269 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1270 Perl does, and where it didn't before.
1271
1272 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1273 Windows environments %n is disabled by default.
1274
1275
1276 Version 7.4 21-Sep-07
1277 ---------------------
1278
1279 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1280 means that a class such as [\s] counted as "explicit reference to CR or
1281 LF". That isn't really right - the whole point of the change was to try to
1282 help when there was an actual mention of one of the two characters. So now
1283 the change happens only if \r or \n (or a literal CR or LF) character is
1284 encountered.
1285
1286 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1287 of both had grown to the point where there were only 3 bits left.
1288 Fortunately, there was spare space in the data structure, and so I have
1289 moved the internal flags into a new 16-bit field to free up more option
1290 bits.
1291
1292 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1293 but did not set the internal JCHANGED flag - either of these is enough to
1294 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1295 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1296 start sets both bits.
1297
1298 4. Added options (at build time, compile time, exec time) to change \R from
1299 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1300
1301 5. doc/pcresyntax.html was missing from the distribution.
1302
1303 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1304 compatibility, even though it is no longer used.
1305
1306 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1307 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1308 windows.h file is present (where different names are used). [This was
1309 reversed later after testing - see 16 below.]
1310
1311 8. Changed all #include <config.h> to #include "config.h". There were also
1312 some further <pcre.h> cases that I changed to "pcre.h".
1313
1314 9. When pcregrep was used with the --colour option, it missed the line ending
1315 sequence off the lines that it output.
1316
1317 10. It was pointed out to me that arrays of string pointers cause lots of
1318 relocations when a shared library is dynamically loaded. A technique of
1319 using a single long string with a table of offsets can drastically reduce
1320 these. I have refactored PCRE in four places to do this. The result is
1321 dramatic:
1322
1323 Originally: 290
1324 After changing UCP table: 187
1325 After changing error message table: 43
1326 After changing table of "verbs" 36
1327 After changing table of Posix names 22
1328
1329 Thanks to the folks working on Gregex for glib for this insight.
1330
1331 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1332 unicode-properties was also set.
1333
1334 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1335
1336 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1337 checked only for CRLF.
1338
1339 14. Added casts to pcretest.c to avoid compiler warnings.
1340
1341 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1342
1343 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1344 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1345 entirely. This removes changes made in 7 above.
1346
1347 17. The CMake files have been updated, and there is now more information about
1348 building with CMake in the NON-UNIX-USE document.
1349
1350
1351 Version 7.3 28-Aug-07
1352 ---------------------
1353
1354 1. In the rejigging of the build system that eventually resulted in 7.1, the
1355 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1356 brackets there is not right, since it causes compilers to look for an
1357 installed pcre.h, not the version that is in the source that is being
1358 compiled (which of course may be different). I have changed it back to:
1359
1360 #include "pcre.h"
1361
1362 I have a vague recollection that the change was concerned with compiling in
1363 different directories, but in the new build system, that is taken care of
1364 by the VPATH setting the Makefile.
1365
1366 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1367 when the subject happened to end in the byte 0x85 (e.g. if the last
1368 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1369 characters but of course it shouldn't be taken as a newline when it is part
1370 of another character. The bug was that, for an unlimited repeat of . in
1371 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1372 characters when looking for a newline.
1373
1374 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1375
1376 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1377 in debug output.
1378
1379 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1380 long printing in the pcrecpp unittest when running under MinGW.
1381
1382 6. ESC_K was left out of the EBCDIC table.
1383
1384 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1385 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1386 limit also applies to "virtual nesting" when a pattern is recursive, and in
1387 this case 1000 isn't so big. I have been able to remove this limit at the
1388 expense of backing off one optimization in certain circumstances. Normally,
1389 when pcre_exec() would call its internal match() function recursively and
1390 immediately return the result unconditionally, it uses a "tail recursion"
1391 feature to save stack. However, when a subpattern that can match an empty
1392 string has an unlimited repetition quantifier, it no longer makes this
1393 optimization. That gives it a stack frame in which to save the data for
1394 checking that an empty string has been matched. Previously this was taken
1395 from the 1000-entry workspace that had been reserved. So now there is no
1396 explicit limit, but more stack is used.
1397
1398 8. Applied Daniel's patches to solve problems with the import/export magic
1399 syntax that is required for Windows, and which was going wrong for the
1400 pcreposix and pcrecpp parts of the library. These were overlooked when this
1401 problem was solved for the main library.
1402
1403 9. There were some crude static tests to avoid integer overflow when computing
1404 the size of patterns that contain repeated groups with explicit upper
1405 limits. As the maximum quantifier is 65535, the maximum group length was
1406 set at 30,000 so that the product of these two numbers did not overflow a
1407 32-bit integer. However, it turns out that people want to use groups that
1408 are longer than 30,000 bytes (though not repeat them that many times).
1409 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1410 made it possible to implement the integer overflow checks in a much more
1411 dynamic way, which I have now done. The artificial limitation on group
1412 length has been removed - we now have only the limit on the total length of
1413 the compiled pattern, which depends on the LINK_SIZE setting.
1414
1415 10. Fixed a bug in the documentation for get/copy named substring when
1416 duplicate names are permitted. If none of the named substrings are set, the
1417 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1418 empty string.
1419
1420 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1421 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1422 because the ] is interpreted as the first data character and the
1423 terminating ] is not found. PCRE has been made compatible with Perl in this
1424 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1425 cause memory overwriting.
1426
1427 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1428 string has been matched (to stop an infinite loop). It was not recognizing
1429 a conditional subpattern that could match an empty string if that
1430 subpattern was within another subpattern. For example, it looped when
1431 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1432 condition was not nested. This bug has been fixed.
1433
1434 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1435 past the start of the subject in the presence of bytes with the top bit
1436 set, for example "\x8aBCD".
1437
1438 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1439 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1440
1441 14. Optimized (?!) to (*FAIL).
1442
1443 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1444 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1445 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1446 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1447 does: it's just the validity check that is more restrictive.
1448
1449 16. Inserted checks for integer overflows during escape sequence (backslash)
1450 processing, and also fixed erroneous offset values for syntax errors during
1451 backslash processing.
1452
1453 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1454 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1455
1456 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1457 caused an overrun.
1458
1459 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1460 something other than just ASCII characters) inside a group that had an
1461 unlimited repeat caused a loop at compile time (while checking to see
1462 whether the group could match an empty string).
1463
1464 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1465 [\P{Any}] did so. (Error in the code for printing property names.)
1466
1467 21. An orphan \E inside a character class could cause a crash.
1468
1469 22. A repeated capturing bracket such as (A)? could cause a wild memory
1470 reference during compilation.
1471
1472 23. There are several functions in pcre_compile() that scan along a compiled
1473 expression for various reasons (e.g. to see if it's fixed length for look
1474 behind). There were bugs in these functions when a repeated \p or \P was
1475 present in the pattern. These operators have additional parameters compared
1476 with \d, etc, and these were not being taken into account when moving along
1477 the compiled data. Specifically:
1478
1479 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1480 length.
1481
1482 (b) An item such as \pL+ within a repeated group could cause crashes or
1483 loops.
1484
1485 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1486 "reference to non-existent subpattern" error.
1487
1488 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1489
1490 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1491 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1492
1493 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1494
1495 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1496 character were causing crashes (broken optimization).
1497
1498 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1499 \p or \P) caused a compile-time loop.
1500
1501 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1502 break. For example, the unstudied pattern [\r\n]A does not match the string
1503 "\r\nA" because change 7.0/46 below moves the current point on by two
1504 characters after failing to match at the start. However, the pattern \nA
1505 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1506 the same is true. There doesn't seem any very clean way out of this, but
1507 what I have chosen to do makes the common cases work: PCRE now takes note
1508 of whether there can be an explicit match for \r or \n anywhere in the
1509 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1510 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1511 pattern has explicit CR or LF references.
1512
1513 29. Added (*CR) etc for changing newline setting at start of pattern.
1514
1515
1516 Version 7.2 19-Jun-07
1517 ---------------------
1518
1519 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1520 which is apparently normally available under Windows.
1521
1522 2. Re-jig the pcregrep tests with different newline settings in an attempt
1523 to make them independent of the local environment's newline setting.
1524
1525 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1526
1527 4. Some of the "internals" tests were previously cut out when the link size
1528 was not 2, because the output contained actual offsets. The recent new
1529 "Z" feature of pcretest means that these can be cut out, making the tests
1530 usable with all link sizes.
1531
1532 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1533 stack recursion. This gives a massive performance boost under BSD, but just
1534 a small improvement under Linux. However, it saves one field in the frame
1535 in all cases.
1536
1537 6. Added more features from the forthcoming Perl 5.10:
1538
1539 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1540 recursion call. It refers to the nth most recently opened parentheses.
1541
1542 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1543 to be opened parentheses.
1544
1545 (c) Conditions that refer to capturing parentheses can be specified
1546 relatively, for example, (?(-2)... or (?(+3)...
1547
1548 (d) \K resets the start of the current match so that everything before
1549 is not part of it.
1550
1551 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1552
1553 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1554 reference syntax.
1555
1556 (g) (?| introduces a group in which the numbering of parentheses in each
1557 alternative starts with the same number.
1558
1559 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1560
1561 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1562 PCRE_INFO_JCHANGED.
1563
1564 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1565 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1566 for detecting groups that can match an empty string.
1567
1568 9. A pattern with a very large number of alternatives (more than several
1569 hundred) was running out of internal workspace during the pre-compile
1570 phase, where pcre_compile() figures out how much memory will be needed. A
1571 bit of new cunning has reduced the workspace needed for groups with
1572 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1573 workspace instead of running out of the 4096 that are available.
1574
1575 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1576
1577 11. Applied patch from Google to remove an optimization that didn't quite work.
1578 The report of the bug said:
1579
1580 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1581 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1582 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1583
1584 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1585 it matched the wrong number of bytes.
1586
1587
1588 Version 7.1 24-Apr-07
1589 ---------------------
1590
1591 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1592 that is more "standard", making use of automake and other Autotools. There
1593 is some re-arrangement of the files and adjustment of comments consequent
1594 on this.
1595
1596 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1597 for recursive directory scanning broke on some systems because the files
1598 are not scanned in any specific order and on different systems the order
1599 was different. A call to "sort" has been inserted into RunGrepTest for the
1600 approprate test as a short-term fix. In the longer term there may be an
1601 alternative.
1602
1603 3. I had an email from Eric Raymond about problems translating some of PCRE's
1604 man pages to HTML (despite the fact that I distribute HTML pages, some
1605 people do their own conversions for various reasons). The problems
1606 concerned the use of low-level troff macros .br and .in. I have therefore
1607 removed all such uses from the man pages (some were redundant, some could
1608 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1609 HTML has been updated to handle .nf/.fi and to complain if it encounters
1610 .br or .in.
1611
1612 4. Updated comments in configure.ac that get placed in config.h.in and also
1613 arranged for config.h to be included in the distribution, with the name
1614 config.h.generic, for the benefit of those who have to compile without
1615 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1616
1617 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1618 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1619 makevp.bat for the current PCRE, using the additional files
1620 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1621
1622 6. A Windows user reported a minor discrepancy with test 2, which turned out
1623 to be caused by a trailing space on an input line that had got lost in his
1624 copy. The trailing space was an accident, so I've just removed it.
1625
1626 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1627 that is needed.
1628
1629 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1630 as "const" (a) because they are and (b) because it helps the PHP
1631 maintainers who have recently made a script to detect big data structures
1632 in the php code that should be moved to the .rodata section. I remembered
1633 to update Builducptable as well, so it won't revert if ucptable.h is ever
1634 re-created.
1635
1636 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1637 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1638 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1639 support is not required. This saves 1.5-2K of code, which is important in
1640 some applications.
1641
1642 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1643 so as not to refer to the tables, even though these functions will never be
1644 called when UTF-8 support is disabled. Otherwise there are problems with a
1645 shared library.
1646
1647 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1648
1649 (a) It was defining its arguments as char * instead of void *.
1650
1651 (b) It was assuming that all moves were upwards in memory; this was true
1652 a long time ago when I wrote it, but is no longer the case.
1653
1654 The emulated memove() is provided for those environments that have neither
1655 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1656 is clearly not the case, as these two bugs were recently reported.
1657
1658 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1659 and Detrail to create the HTML documentation, the .txt form of the man
1660 pages, and it removes trailing spaces from listed files. It also creates
1661 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1662 case, it wraps all the #defines with #ifndefs. This script should be run
1663 before "make dist".
1664
1665 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1666 with Unicode property support.
1667
1668 (a) For a maximizing quantifier, if the two different cases of the
1669 character were of different lengths in their UTF-8 codings (there are
1670 some cases like this - I found 11), and the matching function had to
1671 back up over a mixture of the two cases, it incorrectly assumed they
1672 were both the same length.
1673
1674 (b) When PCRE was configured to use the heap rather than the stack for
1675 recursion during matching, it was not correctly preserving the data for
1676 the other case of a UTF-8 character when checking ahead for a match
1677 while processing a minimizing repeat. If the check also involved
1678 matching a wide character, but failed, corruption could cause an
1679 erroneous result when trying to check for a repeat of the original
1680 character.
1681
1682 13. Some tidying changes to the testing mechanism:
1683
1684 (a) The RunTest script now detects the internal link size and whether there
1685 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1686 values substituted by "configure". (The RunGrepTest script already did
1687 this for UTF-8.) The configure.ac script no longer substitutes the
1688 relevant variables.
1689
1690 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1691 with length and offset values. This means that the output is different
1692 for different internal link sizes. Test 2 is skipped for link sizes
1693 other than 2 because of this, bypassing the problem. Unfortunately,
1694 there was also a test in test 3 (the locale tests) that used /B and
1695 failed for link sizes other than 2. Rather than cut the whole test out,
1696 I have added a new /Z option to pcretest that replaces the length and
1697 offset values with spaces. This is now used to make test 3 independent
1698 of link size. (Test 2 will be tidied up later.)
1699
1700 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1701 segmentation fault instead of returning the appropriate error message.
1702
1703 15. In multiline mode when the newline sequence was set to "any", the pattern
1704 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1705 This doesn't seem right; it now treats the CRLF combination as the line
1706 ending, and so does not match in that case. It's only a pattern such as ^$
1707 that would hit this one: something like ^ABC$ would have failed after \r
1708 and then tried again after \r\n.
1709
1710 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1711 in an attempt to make files that differ only in their line terminators
1712 compare equal. This works on Linux.
1713
1714 17. Under certain error circumstances pcregrep might try to free random memory
1715 as it exited. This is now fixed, thanks to valgrind.
1716
1717 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1718 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1719 was because its rules for how to advance for /g after matching an empty
1720 string at the end of a line did not allow for this case. They now check for
1721 it specially.
1722
1723 20. pcretest is supposed to handle patterns and data of any length, by
1724 extending its buffers when necessary. It was getting this wrong when the
1725 buffer for a data line had to be extended.
1726
1727 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1728 CRLF as a newline sequence.
1729
1730 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1731 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1732 I have nevertheless tidied it up.
1733
1734 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1735
1736 24. Added a man page for pcre-config.
1737
1738
1739 Version 7.0 19-Dec-06
1740 ---------------------
1741
1742 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1743 moving to gcc 4.1.1.
1744
1745 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1746 sys/time.h, which is documented as needed for this function. It doesn't
1747 seem to matter on Linux, but it showed up on some releases of OS X.
1748
1749 3. It seems that there are systems where bytes whose values are greater than
1750 127 match isprint() in the "C" locale. The "C" locale should be the
1751 default when a C program starts up. In most systems, only ASCII printing
1752 characters match isprint(). This difference caused the output from pcretest
1753 to vary, making some of the tests fail. I have changed pcretest so that:
1754
1755 (a) When it is outputting text in the compiled version of a pattern, bytes
1756 other than 32-126 are always shown as hex escapes.
1757
1758 (b) When it is outputting text that is a matched part of a subject string,
1759 it does the same, unless a different locale has been set for the match
1760 (using the /L modifier). In this case, it uses isprint() to decide.
1761
1762 4. Fixed a major bug that caused incorrect computation of the amount of memory
1763 required for a compiled pattern when options that changed within the
1764 pattern affected the logic of the preliminary scan that determines the
1765 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1766 that the computed length was too small. The symptoms of this bug were
1767 either the PCRE error "internal error: code overflow" from pcre_compile(),
1768 or a glibc crash with a message such as "pcretest: free(): invalid next
1769 size (fast)". Examples of patterns that provoked this bug (shown in
1770 pcretest format) are:
1771
1772 /(?-x: )/x
1773 /(?x)(?-x: \s*#\s*)/
1774 /((?i)[\x{c0}])/8
1775 /(?i:[\x{c0}])/8
1776
1777 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1778 is now done differently.
1779
1780 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1781 wrapper classes; (b) implement a new function in the C++ scanner that is
1782 more efficient than the old way of doing things because it avoids levels of
1783 recursion in the regex matching; (c) add a paragraph to the documentation
1784 for the FullMatch() function.
1785
1786 6. The escape sequence \n was being treated as whatever was defined as
1787 "newline". Not only was this contrary to the documentation, which states
1788 that \n is character 10 (hex 0A), but it also went horribly wrong when
1789 "newline" was defined as CRLF. This has been fixed.
1790
1791 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1792 was being set to -1 for the "end of line" case (supposedly a value that no
1793 character can have). Though this value is never used (the check for end of
1794 line is "zero bytes in current character"), it caused compiler complaints.
1795 I've changed it to 0xffffffff.
1796
1797 8. In pcre_version.c, the version string was being built by a sequence of
1798 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1799 string (as it is for production releases) called a macro with an empty
1800 argument. The C standard says the result of this is undefined. The gcc
1801 compiler treats it as an empty string (which was what was wanted) but it is
1802 reported that Visual C gives an error. The source has been hacked around to
1803 avoid this problem.
1804
1805 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1806 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1807 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1808 of them did).
1809
1810 10. Originally, pcretest opened its input and output without "b"; then I was
1811 told that "b" was needed in some environments, so it was added for release
1812 5.0 to both the input and output. (It makes no difference on Unix-like
1813 systems.) Later I was told that it is wrong for the input on Windows. I've
1814 now abstracted the modes into two macros, to make it easier to fiddle with
1815 them, and removed "b" from the input mode under Windows.
1816
1817 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1818
1819 12. Added -help and --help to pcretest as an official way of being reminded
1820 of the options.
1821
1822 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1823 and pcrecpp.cc because they annoy compilers at high warning levels.
1824
1825 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1826
1827 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1828 scripts are not C programs :-) and which was not noticed because it works
1829 on Linux.
1830
1831 16. pcretest is supposed to handle any length of pattern and data line (as one
1832 line or as a continued sequence of lines) by extending its input buffer if
1833 necessary. This feature was broken for very long pattern lines, leading to
1834 a string of junk being passed to pcre_compile() if the pattern was longer
1835 than about 50K.
1836
1837 17. I have done a major re-factoring of the way pcre_compile() computes the
1838 amount of memory needed for a compiled pattern. Previously, there was code
1839 that made a preliminary scan of the pattern in order to do this. That was
1840 OK when PCRE was new, but as the facilities have expanded, it has become
1841 harder and harder to keep it in step with the real compile phase, and there
1842 have been a number of bugs (see for example, 4 above). I have now found a
1843 cunning way of running the real compile function in a "fake" mode that
1844 enables it to compute how much memory it would need, while actually only
1845 ever using a few hundred bytes of working memory and without too many
1846 tests of the mode. This should make future maintenance and development
1847 easier. A side effect of this work is that the limit of 200 on the nesting
1848 depth of parentheses has been removed (though this was never a serious
1849 limitation, I suspect). However, there is a downside: pcre_compile() now
1850 runs more slowly than before (30% or more, depending on the pattern). I
1851 hope this isn't a big issue. There is no effect on runtime performance.
1852
1853 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1854 newline (only possible for the last line of a file) and it was a
1855 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1856
1857 19. Added additional timing features to pcretest. (1) The -tm option now times
1858 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1859 separate command line item, by a number that specifies the number of
1860 repeats to use when timing. The default is 50000; this gives better
1861 precision, but takes uncomfortably long for very large patterns.
1862
1863 20. Extended pcre_study() to be more clever in cases where a branch of a
1864 subpattern has no definite first character. For example, (a*|b*)[cd] would
1865 previously give no result from pcre_study(). Now it recognizes that the
1866 first character must be a, b, c, or d.
1867
1868 21. There was an incorrect error "recursive call could loop indefinitely" if
1869 a subpattern (or the entire pattern) that was being tested for matching an
1870 empty string contained only one non-empty item after a nested subpattern.
1871 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1872 incorrectly, because the \d was being skipped in the check.
1873
1874 22. The pcretest program now has a new pattern option /B and a command line
1875 option -b, which is equivalent to adding /B to every pattern. This causes
1876 it to show the compiled bytecode, without the additional information that
1877 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1878 is the same as /B/I).
1879
1880 23. A new optimization is now able automatically to treat some sequences such
1881 as a*b as a*+b. More specifically, if something simple (such as a character
1882 or a simple class like \d) has an unlimited quantifier, and is followed by
1883 something that cannot possibly match the quantified thing, the quantifier
1884 is automatically "possessified".
1885
1886 24. A recursive reference to a subpattern whose number was greater than 39
1887 went wrong under certain circumstances in UTF-8 mode. This bug could also
1888 have affected the operation of pcre_study().
1889
1890 25. Realized that a little bit of performance could be had by replacing
1891 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1892
1893 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1894
1895 27. Possessive quantifiers such as a++ were previously implemented by turning
1896 them into atomic groups such as ($>a+). Now they have their own opcodes,
1897 which improves performance. This includes the automatically created ones
1898 from 23 above.
1899
1900 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1901 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1902 the first matched character to be a colon. This applied both to named and
1903 numbered groups.
1904
1905 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1906
1907 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1908 building PCRE on Windows easier, so I have included it in the distribution.
1909
1910 31. There is now a check in pcretest against a ridiculously large number being
1911 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1912 loop, the loop is abandoned.
1913
1914 32. Forward references to subpatterns in conditions such as (?(2)...) where
1915 subpattern 2 is defined later cause pcre_compile() to search forwards in
1916 the pattern for the relevant set of parentheses. This search went wrong
1917 when there were unescaped parentheses in a character class, parentheses
1918 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1919
1920 33. "Subroutine" calls and backreferences were previously restricted to
1921 referencing subpatterns earlier in the regex. This restriction has now
1922 been removed.
1923
1924 34. Added a number of extra features that are going to be in Perl 5.10. On the
1925 whole, these are just syntactic alternatives for features that PCRE had
1926 previously implemented using the Python syntax or my own invention. The
1927 other formats are all retained for compatibility.
1928
1929 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1930 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1931 also .NET compatible.
1932
1933 (b) A recursion or subroutine call to a named group can now be defined as
1934 (?&name) as well as (?P>name).
1935
1936 (c) A backreference to a named group can now be defined as \k<name> or
1937 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1938 5.10, are also .NET compatible.
1939
1940 (d) A conditional reference to a named group can now use the syntax
1941 (?(<name>) or (?('name') as well as (?(name).
1942
1943 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1944 groups (named and numbered) that are never evaluated inline, but can be
1945 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1946 is always false. There may be only one alternative in such a group.
1947
1948 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1949 as the simple (?(R). The condition is true only if the most recent
1950 recursion is that of the given number or name. It does not search out
1951 through the entire recursion stack.
1952
1953 (g) The escape \gN or \g{N} has been added, where N is a positive or
1954 negative number, specifying an absolute or relative reference.
1955
1956 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1957 some "unreachable code" warnings.
1958
1959 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1960 things, this adds five new scripts.
1961
1962 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1963 There were also incompatibilities regarding the handling of \Q..\E inside
1964 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1965 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1966
1967 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1968 matches an empty string, and forcibly breaks the loop. There were bugs in
1969 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1970 against aaaa the result was just "a" rather than "aaaa", for example. Two
1971 separate and independent bugs (that affected different cases) have been
1972 fixed.
1973
1974 39. Refactored the code to abolish the use of different opcodes for small
1975 capturing bracket numbers. This is a tidy that I avoided doing when I
1976 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1977 The new approach is not only tidier, it makes it possible to reduce the
1978 memory needed to fix the previous bug (38).
1979
1980 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1981 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1982 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1983 mode.
1984
1985 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1986 report.
1987
1988 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1989 copy construction and assignment in the C++ wrapper.
1990
1991 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1992 couple of bugs that could have given wrong results in the "--newline=crlf"
1993 case.
1994
1995 44. Added a number of casts and did some reorganization of signed/unsigned int
1996 variables following suggestions from Dair Grant. Also renamed the variable
1997 "this" as "item" because it is a C++ keyword.
1998
1999 45. Arranged for dftables to add
2000
2001 #include "pcre_internal.h"
2002
2003 to pcre_chartables.c because without it, gcc 4.x may remove the array
2004 definition from the final binary if PCRE is built into a static library and
2005 dead code stripping is activated.
2006
2007 46. For an unanchored pattern, if a match attempt fails at the start of a
2008 newline sequence, and the newline setting is CRLF or ANY, and the next two
2009 characters are CRLF, advance by two characters instead of one.
2010
2011
2012 Version 6.7 04-Jul-06
2013 ---------------------
2014
2015 1. In order to handle tests when input lines are enormously long, pcretest has
2016 been re-factored so that it automatically extends its buffers when
2017 necessary. The code is crude, but this _is_ just a test program. The
2018 default size has been increased from 32K to 50K.
2019
2020 2. The code in pcre_study() was using the value of the re argument before
2021 testing it for NULL. (Of course, in any sensible call of the function, it
2022 won't be NULL.)
2023
2024 3. The memmove() emulation function in pcre_internal.h, which is used on
2025 systems that lack both memmove() and bcopy() - that is, hardly ever -
2026 was missing a "static" storage class specifier.
2027
2028 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2029 containing an extended class (one that cannot be represented by a bitmap
2030 because it contains high-valued characters or Unicode property items, e.g.
2031 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2032 pattern, but PCRE should not loop if you do not (it no longer does).
2033 [Detail: two cases were found: (a) a repeated subpattern containing an
2034 extended class; (b) a recursive reference to a subpattern that followed a
2035 previous extended class. It wasn't skipping over the extended class
2036 correctly when UTF-8 mode was not set.]
2037
2038 5. A negated single-character class was not being recognized as fixed-length
2039 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2040 compile error "lookbehind assertion is not fixed length".
2041
2042 6. The RunPerlTest auxiliary script was showing an unexpected difference
2043 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2044 write a Perl script that can interpret lines of an input file either as
2045 byte characters or as UTF-8, which is what "perltest" was being required to
2046 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2047 can't do is switch easily at run time between having the "use utf8;" pragma
2048 or not. In the end, I fudged it by using the RunPerlTest script to insert
2049 "use utf8;" explicitly for the UTF-8 tests.
2050
2051 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2052 the end of the subject string, contrary to the documentation and to what
2053 Perl does. This was true of both matching functions. Now it matches only at
2054 the start of the subject and immediately after *internal* newlines.
2055
2056 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2057 a pointer to an int instead of a pointer to an unsigned long int. This
2058 caused problems on 64-bit systems.
2059
2060 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2061 instance of the 'standard' template library not being so standard".
2062
2063 10. There was no check on the number of named subpatterns nor the maximum
2064 length of a subpattern name. The product of these values is used to compute
2065 the size of the memory block for a compiled pattern. By supplying a very
2066 long subpattern name and a large number of named subpatterns, the size
2067 computation could be caused to overflow. This is now prevented by limiting
2068 the length of names to 32 characters, and the number of named subpatterns
2069 to 10,000.
2070
2071 11. Subpatterns that are repeated with specific counts have to be replicated in
2072 the compiled pattern. The size of memory for this was computed from the
2073 length of the subpattern and the repeat count. The latter is limited to
2074 65535, but there was no limit on the former, meaning that integer overflow
2075 could in principle occur. The compiled length of a repeated subpattern is
2076 now limited to 30,000 bytes in order to prevent this.
2077
2078 12. Added the optional facility to have named substrings with the same name.
2079
2080 13. Added the ability to use a named substring as a condition, using the
2081 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2082 are numbers (not recommended). Forward references are permitted.
2083
2084 14. Added forward references in named backreferences (if you see what I mean).
2085
2086 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2087 pattern could run off the end of the subject. For example, the pattern
2088 "(?s)(.{1,5})"8 did this with the subject "ab".
2089
2090 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2091 PCRE_CASELESS was set when matching characters that were quantified with ?
2092 or *.
2093
2094 17. A character class other than a single negated character that had a minimum
2095 but no maximum quantifier - for example [ab]{6,} - was not handled
2096 correctly by pce_dfa_exec(). It would match only one character.
2097
2098 18. A valid (though odd) pattern that looked like a POSIX character
2099 class but used an invalid character after [ (for example [[,abc,]]) caused
2100 pcre_compile() to give the error "Failed: internal error: code overflow" or
2101 in some cases to crash with a glibc free() error. This could even happen if
2102 the pattern terminated after [[ but there just happened to be a sequence of
2103 letters, a binary zero, and a closing ] in the memory that followed.
2104
2105 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2106 over the years. Originally (before any Unicode support), just the bottom 8
2107 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2108 output from "man perlunicode" includes this:
2109
2110 The regular expression compiler produces polymorphic opcodes. That
2111 is, the pattern adapts to the data and automatically switches to
2112 the Unicode character scheme when presented with Unicode data--or
2113 instead uses a traditional byte scheme when presented with byte
2114 data.
2115
2116 Sadly, a wide octal escape does not cause a switch, and in a string with
2117 no other multibyte characters, these octal escapes are treated as before.
2118 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2119 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2120 Unicode string.
2121
2122 I have not perpetrated such confusion in PCRE. Up till now, it took just
2123 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2124 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2125 translate to the appropriate multibyte character.
2126
2127 29. Applied some refactoring to reduce the number of warnings from Microsoft
2128 and Borland compilers. This has included removing the fudge introduced
2129 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2130 a warning about an unused variable.
2131
2132 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2133 characters since release 4.0, because Perl (from release 5.004) does not.
2134 [Or at least, is documented not to: some releases seem to be in conflict
2135 with the documentation.] However, when a pattern was studied with
2136 pcre_study() and all its branches started with \s, PCRE still included VT
2137 as a possible starting character. Of course, this did no harm; it just
2138 caused an unnecessary match attempt.
2139
2140 22. Removed a now-redundant internal flag bit that recorded the fact that case
2141 dependency changed within the pattern. This was once needed for "required
2142 byte" processing, but is no longer used. This recovers a now-scarce options
2143 bit. Also moved the least significant internal flag bit to the most-
2144 significant bit of the word, which was not previously used (hangover from
2145 the days when it was an int rather than a uint) to free up another bit for
2146 the future.
2147
2148 23. Added support for CRLF line endings as well as CR and LF. As well as the
2149 default being selectable at build time, it can now be changed at runtime
2150 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2151 specify that it is scanning data with non-default line endings.
2152
2153 24. Changed the definition of CXXLINK to make it agree with the definition of
2154 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2155
2156 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2157 recursions. This makes a big different to stack usage for some patterns.
2158
2159 26. If a subpattern containing a named recursion or subroutine reference such
2160 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2161 the space required for the compiled pattern went wrong and gave too small a
2162 value. Depending on the environment, this could lead to "Failed: internal
2163 error: code overflow at offset 49" or "glibc detected double free or
2164 corruption" errors.
2165
2166 27. Applied patches from Google (a) to support the new newline modes and (b) to
2167 advance over multibyte UTF-8 characters in GlobalReplace.
2168
2169 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2170 difference for some implementation of PCRE in some Windows version.
2171
2172 29. Added some extra testing facilities to pcretest:
2173
2174 \q<number> in a data line sets the "match limit" value
2175 \Q<number> in a data line sets the "match recursion limt" value
2176 -S <number> sets the stack size, where <number> is in megabytes
2177
2178 The -S option isn't available for Windows.
2179
2180
2181 Version 6.6 06-Feb-06
2182 ---------------------
2183
2184 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2185 in pcreposix.h. I have copied the definition from pcre.h.
2186
2187 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2188 because pcre.h is no longer a built file.
2189
2190 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2191 not normally included in the compiled code.
2192
2193
2194 Version 6.5 01-Feb-06
2195 ---------------------
2196
2197 1. When using the partial match feature with pcre_dfa_exec(), it was not
2198 anchoring the second and subsequent partial matches at the new starting
2199 point. This could lead to incorrect results. For example, with the pattern
2200 /1234/, partially matching against "123" and then "a4" gave a match.
2201
2202 2. Changes to pcregrep:
2203
2204 (a) All non-match returns from pcre_exec() were being treated as failures
2205 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2206 error message is output. Some extra information is given for the
2207 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2208 probably the only errors that are likely to be caused by users (by
2209 specifying a regex that has nested indefinite repeats, for instance).
2210 If there are more than 20 of these errors, pcregrep is abandoned.
2211
2212 (b) A binary zero was treated as data while matching, but terminated the
2213 output line if it was written out. This has been fixed: binary zeroes
2214 are now no different to any other data bytes.
2215
2216 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2217 used to set a locale for matching. The --locale=xxxx long option has
2218 been added (no short equivalent) to specify a locale explicitly on the
2219 pcregrep command, overriding the environment variables.
2220
2221 (d) When -B was used with -n, some line numbers in the output were one less
2222 than they should have been.
2223
2224 (e) Added the -o (--only-matching) option.
2225
2226 (f) If -A or -C was used with -c (count only), some lines of context were
2227 accidentally printed for the final match.
2228
2229 (g) Added the -H (--with-filename) option.
2230
2231 (h) The combination of options -rh failed to suppress file names for files
2232 that were found from directory arguments.
2233
2234 (i) Added the -D (--devices) and -d (--directories) options.
2235
2236 (j) Added the -F (--fixed-strings) option.
2237
2238 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2239
2240 (l) Added the --colo(u)r option.
2241
2242 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2243 is not present by default.
2244
2245 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2246 items such as (?R) or (?1), when the recursion could match a number of
2247 alternatives. If it matched one of the alternatives, but subsequently,
2248 outside the recursion, there was a failure, the code tried to back up into
2249 the recursion. However, because of the way PCRE is implemented, this is not
2250 possible, and the result was an incorrect result from the match.
2251
2252 In order to prevent this happening, the specification of recursion has
2253 been changed so that all such subpatterns are automatically treated as
2254 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2255
2256 4. I had overlooked the fact that, in some locales, there are characters for
2257 which isalpha() is true but neither isupper() nor islower() are true. In
2258 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2259 and ordfeminine) are like this. This affected the treatment of \w and \W
2260 when they appeared in character classes, but not when they appeared outside
2261 a character class. The bit map for "word" characters is now created
2262 separately from the results of isalnum() instead of just taking it from the
2263 upper, lower, and digit maps. (Plus the underscore character, of course.)
2264
2265 5. The above bug also affected the handling of POSIX character classes such as
2266 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2267 permanent tables. Instead, the bit maps for such a class were previously
2268 created as the appropriate unions of the upper, lower, and digit bitmaps.
2269 Now they are created by subtraction from the [[:word:]] class, which has
2270 its own bitmap.
2271
2272 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2273 It is created by subtracting the vertical space characters (\x09, \x0a,
2274 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2275 subtraction was done in the overall bitmap for a character class, meaning
2276 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2277 be recognized. This bug has been fixed.
2278
2279 7. Patches from the folks at Google:
2280
2281 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2282 real life, but is still worth protecting against".
2283
2284 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2285 regular expressions".
2286
2287 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2288 have it.
2289
2290 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2291 "configure" and the latter not, in order to fix a problem somebody had
2292 with compiling the Arg class on HP-UX.
2293
2294 (e) Improve the error-handling of the C++ wrapper a little bit.
2295
2296 (f) New tests for checking recursion limiting.
2297
2298 8. The pcre_memmove() function, which is used only if the environment does not
2299 have a standard memmove() function (and is therefore rarely compiled),
2300 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2301 returning a result (though PCRE never actually uses the result).
2302
2303 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2304 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2305 returned instead of calling malloc() with an overflowing number that would
2306 most likely cause subsequent chaos.
2307
2308 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2309
2310 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2311 with this option is matched, the nmatch and pmatch options of regexec() are
2312 ignored.
2313
2314 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2315 provided in case anyone wants to the the POSIX interface with UTF-8
2316 strings.
2317
2318 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2319 C++ linking (needed for some HP-UX environments).
2320
2321 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2322 (unused parameter) and in the pcre_printint() function (omitted "default"
2323 switch label when the default is to do nothing).
2324
2325 15. Added some code to make it possible, when PCRE is compiled as a C++
2326 library, to replace subject pointers for pcre_exec() with a smart pointer
2327 class, thus making it possible to process discontinuous strings.
2328
2329 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2330 much the same function. They were added by different people who were trying
2331 to make PCRE easy to compile on non-Unix systems. It has been suggested
2332 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2333 for compiling on Windows systems. I have therefore replaced it with
2334 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2335 defaults to "extern" for C or "extern C" for C++, which works fine on
2336 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2337 SCOPE with something explicit in config.h. In addition:
2338
2339 (a) pcreposix.h still had just "extern" instead of either of these macros;
2340 I have replaced it with PCRE_DATA_SCOPE.
2341
2342 (b) Functions such as _pcre_xclass(), which are internal to the library,
2343 but external in the C sense, all had PCRE_EXPORT in their definitions.
2344 This is apparently wrong for the Windows case, so I have removed it.
2345 (It makes no difference on Unix-like systems.)
2346
2347 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2348 of recursive calls to match(). This is different to MATCH_LIMIT because
2349 that limits the total number of calls to match(), not all of which increase
2350 the depth of recursion. Limiting the recursion depth limits the amount of
2351 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2352 when PCRE is compiled, and changed at run time. A patch from Google adds
2353 this functionality to the C++ interface.
2354
2355 18. Changes to the handling of Unicode character properties:
2356
2357 (a) Updated the table to Unicode 4.1.0.
2358
2359 (b) Recognize characters that are not in the table as "Cn" (undefined).
2360
2361 (c) I revised the way the table is implemented to a much improved format
2362 which includes recognition of ranges. It now supports the ranges that
2363 are defined in UnicodeData.txt, and it also amalgamates other
2364 characters into ranges. This has reduced the number of entries in the
2365 table from around 16,000 to around 3,000, thus reducing its size
2366 considerably. I realized I did not need to use a tree structure after
2367 all - a binary chop search is just as efficient. Having reduced the
2368 number of entries, I extended their size from 6 bytes to 8 bytes to
2369 allow for more data.
2370
2371 (d) Added support for Unicode script names via properties such as \p{Han}.
2372
2373 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2374 matching that character.
2375
2376 20. When matching a repeated Unicode property with a minimum greater than zero,
2377 (for example \pL{2,}), PCRE could look past the end of the subject if it
2378 reached it while seeking the minimum number of characters. This could
2379 happen only if some of the characters were more than one byte long, because
2380 there is a check for at least the minimum number of bytes.
2381
2382 21. Refactored the implementation of \p and \P so as to be more general, to
2383 allow for more different types of property in future. This has changed the
2384 compiled form incompatibly. Anybody with saved compiled patterns that use
2385 \p or \P will have to recompile them.
2386
2387 22. Added "Any" and "L&" to the supported property types.
2388
2389 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2390 but give a compile time error if the value is greater than 0xff.
2391
2392 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2393 accidentally not being installed or uninstalled.
2394
2395 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2396 made were to insert the current release number. This seemed silly, because
2397 it made things harder for people building PCRE on systems that don't run
2398 "configure". I have turned pcre.h into a distributed file, no longer built
2399 by "configure", with the version identification directly included. There is
2400 no longer a pcre.h.in file.
2401
2402 However, this change necessitated a change to the pcre-config script as
2403 well. It is built from pcre-config.in, and one of the substitutions was the
2404 release number. I have updated configure.ac so that ./configure now finds
2405 the release number by grepping pcre.h.
2406
2407 26. Added the ability to run the tests under valgrind.
2408
2409
2410 Version 6.4 05-Sep-05
2411 ---------------------
2412
2413 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2414 "--" to be printed when multiple files were scanned, even when none of the
2415 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2416 consider it to be a bug, and have restored the previous behaviour.
2417
2418 2. A couple of code tidies to get rid of compiler warnings.
2419
2420 3. The pcretest program used to cheat by referring to symbols in the library
2421 whose names begin with _pcre_. These are internal symbols that are not
2422 really supposed to be visible externally, and in some environments it is
2423 possible to suppress them. The cheating is now confined to including
2424 certain files from the library's source, which is a bit cleaner.
2425
2426 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2427 file's purpose clearer.
2428
2429 5. Reorganized pcre_ucp_findchar().
2430
2431
2432 Version 6.3 15-Aug-05
2433 ---------------------
2434
2435 1. The file libpcre.pc.in did not have general read permission in the tarball.
2436
2437 2. There were some problems when building without C++ support:
2438
2439 (a) If C++ support was not built, "make install" and "make test" still
2440 tried to test it.
2441
2442 (b) There were problems when the value of CXX was explicitly set. Some
2443 changes have been made to try to fix these, and ...
2444
2445 (c) --disable-cpp can now be used to explicitly disable C++ support.
2446
2447 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2448 backslash in a target when C++ was disabled. This confuses some
2449 versions of "make", apparently. Using an intermediate variable solves
2450 this. (Same for CPP_LOBJ.)
2451
2452 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2453 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2454 necessary on certain architectures.
2455
2456 4. Added a setting of -export-symbols-regex to the link command to remove
2457 those symbols that are exported in the C sense, but actually are local
2458 within the library, and not documented. Their names all begin with
2459 "_pcre_". This is not a perfect job, because (a) we have to except some
2460 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2461 available (and never for static libraries). I have made a note to try to
2462 find a way round (a) in the future.
2463
2464
2465 Version 6.2 01-Aug-05
2466 ---------------------
2467
2468 1. There was no test for integer overflow of quantifier values. A construction
2469 such as {1111111111111111} would give undefined results. What is worse, if
2470 a minimum quantifier for a parenthesized subpattern overflowed and became
2471 negative, the calculation of the memory size went wrong. This could have
2472 led to memory overwriting.
2473
2474 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2475
2476 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2477 operating environments where this matters.
2478
2479 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2480 PCRE options from within the C++ wrapper.
2481
2482 5. Named capturing subpatterns were not being correctly counted when a pattern
2483 was compiled. This caused two problems: (a) If there were more than 100
2484 such subpatterns, the calculation of the memory needed for the whole
2485 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2486 back references of the form \12, where the number was greater than 9, were
2487 not recognized as back references, even though there were sufficient
2488 previous subpatterns.
2489
2490 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2491 versions of gcc, e.g. 2.95.4.
2492
2493
2494 Version 6.1 21-Jun-05
2495 ---------------------
2496
2497 1. There was one reference to the variable "posix" in pcretest.c that was not
2498 surrounded by "#if !defined NOPOSIX".
2499
2500 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2501 the cross-check on the old pcre_info() function, for the benefit of the
2502 cut-down version of PCRE that is currently imported into Exim.
2503
2504 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2505 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2506 patterns that start (?i) but I don't think that matters. The use of (?i) is
2507 just an example; this all applies to the other options as well.
2508
2509 4. Since libtool seems to echo the compile commands it is issuing, the output
2510 from "make" can be reduced a bit by putting "@" in front of each libtool
2511 compile command.
2512
2513 5. Patch from the folks at Google for configure.in to be a bit more thorough
2514 in checking for a suitable C++ installation before trying to compile the
2515 C++ stuff. This should fix a reported problem when a compiler was present,
2516 but no suitable headers.
2517
2518 6. The man pages all had just "PCRE" as their title. I have changed them to
2519 be the relevant file name. I have also arranged that these names are
2520 retained in the file doc/pcre.txt, which is a concatenation in text format
2521 of all the man pages except the little individual ones for each function.
2522
2523 7. The NON-UNIX-USE file had not been updated for the different set of source
2524 files that come with release 6. I also added a few comments about the C++
2525 wrapper.
2526
2527
2528 Version 6.0 07-Jun-05
2529 ---------------------
2530
2531 1. Some minor internal re-organization to help with my DFA experiments.
2532
2533 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2534 didn't matter for the library itself when fully configured, but did matter
2535 when compiling without UCP support, or within Exim, where the ucp files are
2536 not imported.
2537
2538 3. Refactoring of the library code to split up the various functions into
2539 different source modules. The addition of the new DFA matching code (see
2540 below) to a single monolithic source would have made it really too
2541 unwieldy, quite apart from causing all the code to be include in a
2542 statically linked application, when only some functions are used. This is
2543 relevant even without the DFA addition now that patterns can be compiled in
2544 one application and matched in another.
2545
2546 The downside of splitting up is that there have to be some external
2547 functions and data tables that are used internally in different modules of
2548 the library but which are not part of the API. These have all had their
2549 names changed to start with "_pcre_" so that they are unlikely to clash
2550 with other external names.
2551
2552 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2553 a different (DFA) algorithm. Although it is slower than the original
2554 function, it does have some advantages for certain types of matching
2555 problem.
2556
2557 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2558 including restarting after a partial match.
2559
2560 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2561 defined when compiling for Windows was sent to me. I have put it into the
2562 code, though I have no means of testing or verifying it.
2563
2564 7. Added the pcre_refcount() auxiliary function.
2565
2566 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2567 match before or at the first newline in the subject string. In pcretest,
2568 the /f option on a pattern can be used to set this.
2569
2570 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2571 would behave wrongly. This has been present in PCRE since release 4.0.
2572
2573 10. A number of changes to the pcregrep command:
2574
2575 (a) Refactored how -x works; insert ^(...)$ instead of setting
2576 PCRE_ANCHORED and checking the length, in preparation for adding
2577 something similar for -w.
2578
2579 (b) Added the -w (match as a word) option.
2580
2581 (c) Refactored the way lines are read and buffered so as to have more
2582 than one at a time available.
2583
2584 (d) Implemented a pcregrep test script.
2585
2586 (e) Added the -M (multiline match) option. This allows patterns to match
2587 over several lines of the subject. The buffering ensures that at least
2588 8K, or the rest of the document (whichever is the shorter) is available
2589 for matching (and similarly the previous 8K for lookbehind assertions).
2590
2591 (f) Changed the --help output so that it now says
2592
2593 -w, --word-regex(p)
2594
2595 instead of two lines, one with "regex" and the other with "regexp"
2596 because that confused at least one person since the short forms are the
2597 same. (This required a bit of code, as the output is generated
2598 automatically from a table. It wasn't just a text change.)
2599
2600 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2601 option but starts with a hyphen. Could be a pattern or a path name
2602 starting with a hyphen, for instance.
2603
2604 (h) "-" can be given as a file name to represent stdin.
2605
2606 (i) When file names are being printed, "(standard input)" is used for
2607 the standard input, for compatibility with GNU grep. Previously
2608 "<stdin>" was used.
2609
2610 (j) The option --label=xxx can be used to supply a name to be used for
2611 stdin when file names are being printed. There is no short form.
2612
2613 (k) Re-factored the options decoding logic because we are going to add
2614 two more options that take data. Such options can now be given in four
2615 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2616
2617 (l) Added the -A, -B, and -C options for requesting that lines of context
2618 around matches be printed.
2619
2620 (m) Added the -L option to print the names of files that do not contain
2621 any matching lines, that is, the complement of -l.
2622
2623 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2624 continue to scan other files.
2625
2626 (o) The -s option was incorrectly implemented. For compatibility with other
2627 greps, it now suppresses the error message for a non-existent or non-
2628 accessible file (but not the return code). There is a new option called
2629 -q that suppresses the output of matching lines, which was what -s was
2630 previously doing.
2631
2632 (p) Added --include and --exclude options to specify files for inclusion
2633 and exclusion when recursing.
2634
2635 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2636 Hopefully, it now does.
2637
2638 12. Missing cast in pcre_study().
2639
2640 13. Added an "uninstall" target to the makefile.
2641
2642 14. Replaced "extern" in the function prototypes in Makefile.in with
2643 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2644 world, but is set differently for Windows.
2645
2646 15. Added a second compiling function called pcre_compile2(). The only
2647 difference is that it has an extra argument, which is a pointer to an
2648 integer error code. When there is a compile-time failure, this is set
2649 non-zero, in addition to the error test pointer being set to point to an
2650 error message. The new argument may be NULL if no error number is required
2651 (but then you may as well call pcre_compile(), which is now just a
2652 wrapper). This facility is provided because some applications need a
2653 numeric error indication, but it has also enabled me to tidy up the way
2654 compile-time errors are handled in the POSIX wrapper.
2655
2656 16. Added VPATH=.libs to the makefile; this should help when building with one
2657 prefix path and installing with another. (Or so I'm told by someone who
2658 knows more about this stuff than I do.)
2659
2660 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2661 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2662 match everything, including newlines. This is not POSIX-compatible, but
2663 somebody wanted the feature. From pcretest it can be activated by using
2664 both the P and the s flags.
2665
2666 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2667
2668 19. libpcre.pc was being incorrectly installed as executable.
2669
2670 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2671 it now also looks for '\r' so that it will work unmodified on Windows.
2672
2673 21. Added Google's contributed C++ wrapper to the distribution.
2674
2675 22. Added some untidy missing memory free() calls in pcretest, to keep
2676 Electric Fence happy when testing.
2677
2678
2679
2680 Version 5.0 13-Sep-04
2681 ---------------------
2682
2683 1. Internal change: literal characters are no longer packed up into items
2684 containing multiple characters in a single byte-string. Each character
2685 is now matched using a separate opcode. However, there may be more than one
2686 byte in the character in UTF-8 mode.
2687
2688 2. The pcre_callout_block structure has two new fields: pattern_position and
2689 next_item_length. These contain the offset in the pattern to the next match
2690 item, and its length, respectively.
2691
2692 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2693 insertion of callouts before each pattern item. Added the /C option to
2694 pcretest to make use of this.
2695
2696 4. On the advice of a Windows user, the lines
2697
2698 #if defined(_WIN32) || defined(WIN32)
2699 _setmode( _fileno( stdout ), 0x8000 );
2700 #endif /* defined(_WIN32) || defined(WIN32) */
2701
2702 have been added to the source of pcretest. This apparently does useful
2703 magic in relation to line terminators.
2704
2705 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2706 for the benefit of those environments where the "b" makes a difference.
2707
2708 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2709 to know about it. I have put a hack into configure.in that adds in code
2710 to set GCC=yes if CC=icc. This seems to end up at a point in the
2711 generated configure script that is early enough to affect the setting of
2712 compiler options, which is what is needed, but I have no means of testing
2713 whether it really works. (The user who reported this had patched the
2714 generated configure script, which of course I cannot do.)
2715
2716 LATER: After change 22 below (new libtool files), the configure script
2717 seems to know about icc (and also ecc). Therefore, I have commented out
2718 this hack in configure.in.
2719
2720 7. Added support for pkg-config (2 patches were sent in).
2721
2722 8. Negated POSIX character classes that used a combination of internal tables
2723 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2724 [[:^ascii]]. Typically, they would match almost any characters. The other
2725 POSIX classes were not broken in this way.
2726
2727 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2728 to find the match, as PCRE was deluded into thinking that the match had to
2729 start at the start point or following a newline. The same bug applied to
2730 patterns with negative forward assertions or any backward assertions
2731 preceding ".*" at the start, unless the pattern required a fixed first
2732 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2733
2734 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2735 starting at the last subject character, bytes beyond the end of the subject
2736 string were read.
2737
2738 11. Renamed the variable "class" as "classbits" to make life easier for C++
2739 users. (Previously there was a macro definition, but it apparently wasn't
2740 enough.)
2741
2742 12. Added the new field "tables" to the extra data so that tables can be passed
2743 in at exec time, or the internal tables can be re-selected. This allows
2744 a compiled regex to be saved and re-used at a later time by a different
2745 program that might have everything at different addresses.
2746
2747 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2748 -R library as well as a -L library.
2749
2750 14. The debugging options of pcretest (-d on the command line or D on a
2751 pattern) showed incorrect output for anything following an extended class
2752 that contained multibyte characters and which was followed by a quantifier.
2753
2754 15. Added optional support for general category Unicode character properties
2755 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2756 support. It adds about 90K to the size of the library. The meanings of the
2757 inbuilt class escapes such as \d and \s have NOT been changed.
2758
2759 16. Updated pcredemo.c to include calls to free() to release the memory for the
2760 compiled pattern.
2761
2762 17. The generated file chartables.c was being created in the source directory
2763 instead of in the building directory. This caused the build to fail if the
2764 source directory was different from the building directory, and was
2765 read-only.
2766
2767 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2768 file. No doubt somebody will tell me if they don't make sense... Also added
2769 Dan Mooney's comments about building on OpenVMS.
2770
2771 19. Added support for partial matching via the PCRE_PARTIAL option for
2772 pcre_exec() and the \P data escape in pcretest.
2773
2774 20. Extended pcretest with 3 new pattern features:
2775
2776 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2777 write the compiled pattern to the file whose name is "rest-of-line".
2778 This is a straight binary dump of the data, with the saved pointer to
2779 the character tables forced to be NULL. The study data, if any, is
2780 written too. After writing, pcretest reads a new pattern.
2781
2782 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2783 compiled pattern from the given file. There must not be any
2784 occurrences of "<" in the file name (pretty unlikely); if there are,
2785 pcretest will instead treat the initial "<" as a pattern delimiter.
2786 After reading in the pattern, pcretest goes on to read data lines as
2787 usual.
2788
2789 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2790 and 16-bit fields in a compiled pattern, to simulate a pattern that
2791 was compiled on a host of opposite endianness.
2792
2793 21. The pcre-exec() function can now cope with patterns that were compiled on
2794 hosts of opposite endianness, with this restriction:
2795
2796 As for any compiled expression that is saved and used later, the tables
2797 pointer field cannot be preserved; the extra_data field in the arguments
2798 to pcre_exec() should be used to pass in a tables address if a value
2799 other than the default internal tables were used at compile time.
2800
2801 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2802 now diagnosed as an error. Previously, most of the time, a negative number
2803 would have been treated as zero, but if in addition "ovector" was passed as
2804 NULL, a crash could occur.
2805
2806 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2807 new versions from the libtool 1.5 distribution (the last one is a copy of
2808 a file called libtool.m4). This seems to have fixed the need to patch
2809 "configure" to support Darwin 1.3 (which I used to do). However, I still
2810 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2811 workstation).
2812
2813 24. Changed the PCRE licence to be the more standard "BSD" licence.
2814
2815
2816 Version 4.5 01-Dec-03
2817 ---------------------
2818
2819 1. There has been some re-arrangement of the code for the match() function so
2820 that it can be compiled in a version that does not call itself recursively.
2821 Instead, it keeps those local variables that need separate instances for
2822 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2823 needs to "recurse". Keeping track of where control must go is done by means
2824 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2825 hide most of the details from the main code, and operates only if
2826 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2827 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2828 operating.
2829
2830 To make it easier for callers to provide specially tailored get/free
2831 functions for this usage, two new functions, pcre_stack_malloc, and
2832 pcre_stack_free, are used. They are always called in strict stacking order,
2833 and the size of block requested is always the same.
2834
2835 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2836 PCRE has been compiled to use the stack or the heap for recursion. The
2837 -C option of pcretest uses this to show which version is compiled.
2838
2839 A new data escape \S, is added to pcretest; it causes the amounts of store
2840 obtained and freed by both kinds of malloc/free at match time to be added
2841 to the output.
2842
2843 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2844 what's available on my current Linux desktop machine.
2845
2846 3. When matching a UTF-8 string, the test for a valid string at the start has
2847 been extended. If start_offset is not zero, PCRE now checks that it points
2848 to a byte that is the start of a UTF-8 character. If not, it returns
2849 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2850 this is necessary because there may be backward assertions in the pattern.
2851 When matching the same subject several times, it may save resources to use
2852 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2853
2854 4. The code for checking the validity of UTF-8 strings has been tightened so
2855 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2856 containing "overlong sequences".
2857
2858 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2859 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2860 should have been "&", but it just so happened that all the cases this let
2861 through by mistake were picked up later in the function.
2862
2863 6. I had used a variable called "isblank" - this is a C99 function, causing
2864 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2865
2866 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2867 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2868 so the version is shown; (c) stop "make test" echoing "./RunTest".
2869
2870 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2871
2872 9. The prototype for memmove() for systems that don't have it was using
2873 size_t, but the inclusion of the header that defines size_t was later. I've
2874 moved the #includes for the C headers earlier to avoid this.
2875
2876 10. Added some adjustments to the code to make it easier to compiler on certain
2877 special systems:
2878
2879 (a) Some "const" qualifiers were missing.
2880 (b) Added the macro EXPORT before all exported functions; by default this
2881 is defined to be empty.
2882 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2883 that it reads its output file name as an argument instead of writing
2884 to the standard output and assuming this can be redirected.
2885
2886 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2887 class containing characters with values greater than 255, PCRE compilation
2888 went into a loop.
2889
2890 12. A recursive reference to a subpattern that was within another subpattern
2891 that had a minimum quantifier of zero caused PCRE to crash. For example,
2892 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2893 recursion. If the recursively-called subpattern itself had a zero repeat,
2894 that was OK.
2895
2896 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2897 buffer into which it was copied (for escape processing) was still set at
2898 1024, so long lines caused crashes.
2899
2900 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2901 "internal error: code overflow...". This applied to any character class
2902 that was followed by a possessive quantifier.
2903
2904 15. Modified the Makefile to add libpcre.la as a prerequisite for
2905 libpcreposix.la because I was told this is needed for a parallel build to
2906 work.
2907
2908 16. If a pattern that contained .* following optional items at the start was
2909 studied, the wrong optimizing data was generated, leading to matching
2910 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2911 matching string must start with a or b or c. The correct conclusion for
2912 this pattern is that a match can start with any character.
2913
2914
2915 Version 4.4 13-Aug-03
2916 ---------------------
2917
2918 1. In UTF-8 mode, a character class containing characters with values between
2919 127 and 255 was not handled correctly if the compiled pattern was studied.
2920 In fixing this, I have also improved the studying algorithm for such
2921 classes (slightly).
2922
2923 2. Three internal functions had redundant arguments passed to them. Removal
2924 might give a very teeny performance improvement.
2925
2926 3. Documentation bug: the value of the capture_top field in a callout is *one
2927 more than* the number of the hightest numbered captured substring.
2928
2929 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2930 in incorrectly linking with a previously installed version. They now link
2931 explicitly with libpcre.la.
2932
2933 5. configure.in no longer needs to recognize Cygwin specially.
2934
2935 6. A problem in pcre.in for Windows platforms is fixed.
2936
2937 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2938 pcretest, it used to include the size of the study block as part of its
2939 output. Unfortunately, the structure contains a field that has a different
2940 size on different hardware architectures. This meant that the tests that
2941 showed this size failed. As the block is currently always of a fixed size,
2942 this information isn't actually particularly useful in pcretest output, so
2943 I have just removed it.
2944
2945 8. Three pre-processor statements accidentally did not start in column 1.
2946 Sadly, there are *still* compilers around that complain, even though
2947 standard C has not required this for well over a decade. Sigh.
2948
2949 9. In pcretest, the code for checking callouts passed small integers in the
2950 callout_data field, which is a void * field. However, some picky compilers
2951 complained about the casts involved for this on 64-bit systems. Now
2952 pcretest passes the address of the small integer instead, which should get
2953 rid of the warnings.
2954
2955 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2956 both compile and run time, and gives an error if an invalid UTF-8 sequence
2957 is found. There is a option for disabling this check in cases where the
2958 string is known to be correct and/or the maximum performance is wanted.
2959
2960 11. In response to a bug report, I changed one line in Makefile.in from
2961
2962 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2963 to
2964 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2965
2966 to look similar to other lines, but I have no way of telling whether this
2967 is the right thing to do, as I do not use Windows. No doubt I'll get told
2968 if it's wrong...
2969
2970
2971 Version 4.3 21-May-03
2972 ---------------------
2973
2974 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2975 Makefile.
2976
2977 2. Some refactoring to improve the quality of the code:
2978
2979 (i) The utf8_table... variables are now declared "const".
2980
2981 (ii) The code for \cx, which used the "case flipping" table to upper case
2982 lower case letters, now just substracts 32. This is ASCII-specific,
2983 but the whole concept of \cx is ASCII-specific, so it seems
2984 reasonable.
2985
2986 (iii) PCRE was using its character types table to recognize decimal and
2987 hexadecimal digits in the pattern. This is silly, because it handles
2988 only 0-9, a-f, and A-F, but the character types table is locale-
2989 specific, which means strange things might happen. A private
2990 table is now used for this - though it costs 256 bytes, a table is
2991 much faster than multiple explicit tests. Of course, the standard
2992 character types table is still used for matching digits in subject
2993 strings against \d.
2994
2995 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2996 ending in _t are). So I've renamed it as ESC_tee.
2997
2998 3. The first argument for regexec() in the POSIX wrapper should have been
2999 defined as "const".
3000
3001 4. Changed pcretest to use malloc() for its buffers so that they can be
3002 Electric Fenced for debugging.
3003
3004 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3005 to read one or more bytes before the start of the subject string. Often this
3006 had no effect on PCRE's behaviour, but in some circumstances it could
3007 provoke a segmentation fault.
3008
3009 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3010 to try to read one or more bytes before the start of the subject string.
3011
3012 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3013 UTF-8 support could misbehave in various ways if the subject string
3014 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3015 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3016 back over UTF-8 characters.)
3017
3018
3019 Version 4.2 14-Apr-03
3020 ---------------------
3021
3022 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3023
3024 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3025 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3026 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3027 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3028 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3029 and BUILD_EXEEXT
3030 Note: automatic setting of the BUILD variables is not yet working
3031 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3032 compile-time but not at link-time
3033 [LINK]: use for linking executables only
3034 make different versions for Windows and non-Windows
3035 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3036 libraries
3037 [LINK_FOR_BUILD]: new variable
3038 [OBJEXT]: use throughout
3039 [EXEEXT]: use throughout
3040 <winshared>: new target
3041 <wininstall>: new target
3042 <dftables.o>: use native compiler
3043 <dftables>: use native linker
3044 <install>: handle Windows platform correctly
3045 <clean>: ditto
3046 <check>: ditto
3047 copy DLL to top builddir before testing
3048
3049 As part of these changes, -no-undefined was removed again. This was reported
3050 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3051 in any case.
3052
3053 3. Some tidies to get rid of compiler warnings:
3054
3055 . In the match_data structure, match_limit was an unsigned long int, whereas
3056 match_call_count was an int. I've made them both unsigned long ints.
3057
3058 . In pcretest the fact that a const uschar * doesn't automatically cast to
3059 a void * provoked a warning.
3060
3061 . Turning on some more compiler warnings threw up some "shadow" variables
3062 and a few more missing casts.
3063
3064 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3065 option, a class that contained a single character with a value between 128
3066 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3067
3068 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3069 option, a class that contained several characters, but with at least one
3070 whose value was between 128 and 255 caused PCRE to crash.
3071
3072
3073 Version 4.1 12-Mar-03
3074 ---------------------
3075
3076 1. Compiling with gcc -pedantic found a couple of places where casts were
3077 needed, and a string in dftables.c that was longer than standard compilers are
3078 required to support.
3079
3080 2. Compiling with Sun's compiler found a few more places where the code could
3081 be tidied up in order to avoid warnings.
3082
3083 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3084 first of these names is deprecated in the latest Autoconf in favour of the name
3085 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3086 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3087 analogy I have changed it to CFLAGS_FOR_BUILD.
3088
3089 4. Added -no-undefined to the linking command in the Makefile, because this is
3090 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3091 linking step for the pcreposix library.
3092
3093 5. PCRE was failing to diagnose the case of two named groups with the same
3094 name.
3095
3096 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3097 literal character that is needed in the subject for a match, and scans along to
3098 ensure that it is present before embarking on the full matching process. This
3099 saves time in cases of nested unlimited repeats that are never going to match.
3100 Problem: the scan can take a lot of time if the subject is very long (e.g.
3101 megabytes), thus penalizing straightforward matches. It is now done only if the
3102 amount of subject to be scanned is less than 1000 bytes.
3103
3104 7. A lesser problem with the same optimization is that it was recording the
3105 first character of an anchored pattern as "needed", thus provoking a search
3106 right along the subject, even when the first match of the pattern was going to
3107 fail. The "needed" character is now not set for anchored patterns, unless it
3108 follows something in the pattern that is of non-fixed length. Thus, it still
3109 fulfils its original purpose of finding quick non-matches in cases of nested
3110 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3111
3112
3113 Version 4.0 17-Feb-03
3114 ---------------------
3115
3116 1. If a comment in an extended regex that started immediately after a meta-item
3117 extended to the end of string, PCRE compiled incorrect data. This could lead to
3118 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3119
3120 2. Moved to autoconf 2.53 and libtool 1.4.2.
3121
3122 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3123 the special perltest8 script is no longer needed - all the tests can be run
3124 from a single perltest script.
3125
3126 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3127 by \s. It has now been removed in PCRE. This means it isn't recognized as
3128 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3129 class [:space:] *does* include VT, thereby creating a mess.
3130
3131 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3132 space and tab.
3133
3134 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3135 its new features into the main test script, reducing the number of scripts.
3136
3137 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3138 were backward compatible, and made the (?i) apply to the whole pattern, as if
3139 /i were given. Now it behaves more logically, and applies the option setting
3140 only to what follows. PCRE has been changed to follow suit. However, if it
3141 finds options settings right at the start of the pattern, it extracts them into
3142 the global options, as before. Thus, they show up in the info data.
3143
3144 8. Added support for the \Q...\E escape sequence. Characters in between are
3145 treated as literals. This is slightly different from Perl in that $ and @ are
3146 also handled as literals inside the quotes. In Perl, they will cause variable
3147 interpolation. Note the following examples:
3148
3149 Pattern PCRE matches Perl matches
3150
3151 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3152 \Qabc\$xyz\E abc\$xyz abc\$xyz
3153 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3154
3155 For compatibility with Perl, \Q...\E sequences are recognized inside character
3156 classes as well as outside them.
3157
3158 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3159 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3160 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3161 signed/unsigned warnings.
3162
3163 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3164 option for pcretest, so I've replaced it by a simple function that does just
3165 that job.
3166
3167 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3168 "pcregrep -".
3169
3170 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3171 Java package. This provides some syntactic sugar for simple cases of what my
3172 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3173 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3174 item, you can use this simplified notation. Note that only makes sense with
3175 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3176 greediness, whatever the setting of the PCRE_UNGREEDY option.
3177
3178 13. A change of greediness default within a pattern was not taking effect at
3179 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3180 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3181 was abstracted outside.
3182
3183 14. PCRE now supports the \G assertion. It is true when the current matching
3184 position is at the start point of the match. This differs from \A when the
3185 starting offset is non-zero. Used with the /g option of pcretest (or similar
3186 code), it works in the same way as it does for Perl's /g option. If all
3187 alternatives of a regex begin with \G, the expression is anchored to the start
3188 match position, and the "anchored" flag is set in the compiled expression.
3189
3190 15. Some bugs concerning the handling of certain option changes within patterns
3191 have been fixed. These applied to options other than (?ims). For example,
3192 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3193 been the other way round. Some of this was related to change 7 above.
3194
3195 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3196 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3197 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3198 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3199
3200 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3201 mode. Unlike ".", it always matches newline, whatever the setting of
3202 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3203 assertions. Perl allows it, but it doesn't (in general) work because it can't
3204 calculate the length of the lookbehind. At least, that's the case for Perl
3205 5.8.0 - I've been told they are going to document that it doesn't work in
3206 future.
3207
3208 18. Added an error diagnosis for escapes that PCRE does not support: these are
3209 \L, \l, \N, \P, \p, \U, \u, and \X.
3210
3211 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3212 reading past the end of the pattern in cases such as /[abcd/.
3213
3214 20. PCRE was getting more memory than necessary for patterns with classes that
3215 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3216
3217 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3218 compiling PCRE for use with Virtual Pascal.
3219
3220 22. Small fix to the Makefile to make it work properly if the build is done
3221 outside the source tree.
3222
3223 23. Added a new extension: a condition to go with recursion. If a conditional
3224 subpattern starts with (?(R) the "true" branch is used if recursion has
3225 happened, whereas the "false" branch is used only at the top level.
3226
3227 24. When there was a very long string of literal characters (over 255 bytes
3228 without UTF support, over 250 bytes with UTF support), the computation of how
3229 much memory was required could be incorrect, leading to segfaults or other
3230 strange effects.
3231
3232 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3233 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3234 there was a subsequent back reference to those brackets. This meant that, for
3235 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3236 possible to check for precisely this case. All we can do is abandon the
3237 optimization if .* occurs inside capturing brackets when there are any back
3238 references whatsoever. (See below for a better fix that came later.)
3239
3240 26. The handling of the optimization for finding the first character of a
3241 non-anchored pattern, and for finding a character that is required later in the
3242 match were failing in some cases. This didn't break the matching; it just
3243 failed to optimize when it could. The way this is done has been re-implemented.
3244
3245 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3246
3247 28. Added a new feature that provides some of the functionality that Perl
3248 provides with (?{...}). The facility is termed a "callout". The way it is done
3249 in PCRE is for the caller to provide an optional function, by setting
3250 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3251 global variable. By default it is unset, which disables all calling out. To get
3252 the function called, the regex must include (?C) at appropriate points. This
3253 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3254 This provides a means of identifying different callout points. When PCRE
3255 reaches such a point in the regex, if pcre_callout has been set, the external
3256 function is called. It is provided with data in a structure called
3257 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3258 matching continues; if it returns a non-zero value, the match at the current
3259 point fails. However, backtracking will occur if possible. [This was changed
3260 later and other features added - see item 49 below.]
3261
3262 29. pcretest is upgraded to test the callout functionality. It provides a
3263 callout function that displays information. By default, it shows the start of
3264 the match and the current position in the text. There are some new data escapes
3265 to vary what happens:
3266
3267 \C+ in addition, show current contents of captured substrings
3268 \C- do not supply a callout function
3269 \C!n return 1 when callout number n is reached
3270 \C!n!m return 1 when callout number n is reached for the mth time
3271
3272 30. If pcregrep was called with the -l option and just a single file name, it
3273 output "<stdin>" if a match was found, instead of the file name.
3274
3275 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3276 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3277 pcre_exec(). This saves a malloc/free per call. The default value of
3278 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3279 when configuring.
3280
3281 32. The default maximum size of a compiled pattern is 64K. There have been a
3282 few cases of people hitting this limit. The code now uses macros to handle the
3283 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3284 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3285 configuring. Tests 2 and 5 work only with 2-byte links because they output
3286 debugging information about compiled patterns.
3287
3288 33. Internal code re-arrangements:
3289
3290 (a) Moved the debugging function for printing out a compiled regex into
3291 its own source file (printint.c) and used #include to pull it into
3292 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3293 separate copies.
3294
3295 (b) Defined the list of op-code names for debugging as a macro in
3296 internal.h so that it is next to the definition of the opcodes.
3297
3298 (c) Defined a table of op-code lengths for simpler skipping along compiled
3299 code. This is again a macro in internal.h so that it is next to the
3300 definition of the opcodes.
3301
3302 34. Added support for recursive calls to individual subpatterns, along the
3303 lines of Robin Houston's patch (but implemented somewhat differently).
3304
3305 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3306 allow it to read and process whole directories in Win32. This code was
3307 contributed by Lionel Fourquaux; it has not been tested by me.
3308
3309 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3310 used to name a group. Names consist of alphanumerics and underscores, and must
3311 be unique. Back references use the syntax (?P=name) and recursive calls use
3312 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3313 numbers. The function pcre_fullinfo() can be used after compilation to extract
3314 a name/number map. There are three relevant calls:
3315
3316 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3317 PCRE_INFO_NAMECOUNT yields the number of entries
3318 PCRE_INFO_NAMETABLE yields a pointer to the map.
3319
3320 The map is a vector of fixed-size entries. The size of each entry depends on
3321 the length of the longest name used. The first two bytes of each entry are the
3322 group number, most significant byte first. There follows the corresponding
3323 name, zero terminated. The names are in alphabetical order.
3324
3325 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3326 case instead of 255. Making it the same both with and without UTF-8 support
3327 means that the same test output works with both.
3328
3329 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3330 calling malloc() with a zero argument.
3331
3332 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3333 optimization. I've improved things by keeping a bitmap of backreferences with
3334 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3335 fact referenced, the optimization can be applied. It is unlikely that a
3336 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3337 the match to follow \n) will appear inside brackets with a number greater than
3338 31, but if it does, any back reference > 31 suppresses the optimization.
3339
3340 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3341 of disabling numbered capturing parentheses. Any opening parenthesis that is
3342 not followed by ? behaves as if it were followed by ?: but named parentheses
3343 can still be used for capturing (and they will acquire numbers in the usual
3344 way).
3345
3346 41. Redesigned the return codes from the match() function into yes/no/error so
3347 that errors can be passed back from deep inside the nested calls. A malloc
3348 failure while inside a recursive subpattern call now causes the
3349 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3350
3351 42. It is now possible to set a limit on the number of times the match()
3352 function is called in a call to pcre_exec(). This facility makes it possible to
3353 limit the amount of recursion and backtracking, though not in a directly
3354 obvious way, because the match() function is used in a number of different
3355 circumstances. The count starts from zero for each position in the subject
3356 string (for non-anchored patterns). The default limit is, for compatibility, a
3357 large number, namely 10 000 000. You can change this in two ways:
3358
3359 (a) When configuring PCRE before making, you can use --with-match-limit=n
3360 to set a default value for the compiled library.
3361
3362 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3363 a different value is set. See 45 below.
3364
3365 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3366
3367 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3368 of things that can be changed at compile time. The first argument specifies
3369 what is wanted and the second points to where the information is to be placed.
3370 The current list of available information is:
3371
3372 PCRE_CONFIG_UTF8
3373
3374 The output is an integer that is set to one if UTF-8 support is available;
3375 otherwise it is set to zero.
3376
3377 PCRE_CONFIG_NEWLINE
3378
3379 The output is an integer that it set to the value of the code that is used for
3380 newline. It is either LF (10) or CR (13).
3381
3382 PCRE_CONFIG_LINK_SIZE
3383
3384 The output is an integer that contains the number of bytes used for internal
3385 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3386
3387 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3388
3389 The output is an integer that contains the threshold above which the POSIX
3390 interface uses malloc() for output vectors. See item 31 above.
3391
3392 PCRE_CONFIG_MATCH_LIMIT
3393
3394 The output is an unsigned integer that contains the default limit of the number
3395 of match() calls in a pcre_exec() execution. See 42 above.
3396
3397 44. pcretest has been upgraded by the addition of the -C option. This causes it
3398 to extract all the available output from the new pcre_config() function, and to
3399 output it. The program then exits immediately.
3400
3401 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3402 order to support additional features. One way would have been to define
3403 pcre_exec2() (for example) with extra arguments, but this would not have been
3404 extensible, and would also have required all calls to the original function to
3405 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3406 is used for passing in "extra" data from pcre_study().
3407
3408 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3409 contains the following fields:
3410
3411 flags a bitmap indicating which of the following fields are set
3412 study_data opaque data from pcre_study()
3413 match_limit a way of specifying a limit on match() calls for a specific
3414 call to pcre_exec()
3415 callout_data data for callouts (see 49 below)
3416
3417 The flag bits are also defined in pcre.h, and are
3418
3419 PCRE_EXTRA_STUDY_DATA
3420 PCRE_EXTRA_MATCH_LIMIT
3421 PCRE_EXTRA_CALLOUT_DATA
3422
3423 The pcre_study() function now returns one of these new pcre_extra blocks, with
3424 the actual study data pointed to by the study_data field, and the
3425 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3426 before. That is, this change is entirely upwards-compatible and requires no
3427 change to existing code.
3428
3429 If you want to pass in additional data to pcre_exec(), you can either place it
3430 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3431 block.
3432
3433 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3434 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3435 times with different match limits, until it finds the minimum value needed for
3436 pcre_exec() to complete. The value is then output. This can be instructive; for
3437 most simple matches the number is quite small, but for pathological cases it
3438 gets very large very quickly.
3439
3440 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3441 returns the size of the data block pointed to by the study_data field in a
3442 pcre_extra block, that is, the value that was passed as the argument to
3443 pcre_malloc() when PCRE was getting memory in which to place the information
3444 created by pcre_study(). The fourth argument should point to a size_t variable.
3445 pcretest has been extended so that this information is shown after a successful
3446 pcre_study() call when information about the compiled regex is being displayed.
3447
3448 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3449 because what follows is always an absolute path. (Later: it turns out that this
3450 is more than cosmetic for MinGW, because it doesn't like empty path
3451 components.)
3452
3453 49. Some changes have been made to the callout feature (see 28 above):
3454
3455 (i) A callout function now has three choices for what it returns:
3456
3457 0 => success, carry on matching
3458 > 0 => failure at this point, but backtrack if possible
3459 < 0 => serious error, return this value from pcre_exec()
3460
3461 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3462 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3463 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3464 use by callout functions. It will never be used by PCRE itself.
3465
3466 (ii) The pcre_extra structure (see 45 above) has a void * field called
3467 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3468 pcre_callout_block structure has a field of the same name. The contents of
3469 the field passed in the pcre_extra structure are passed to the callout
3470 function in the corresponding field in the callout block. This makes it
3471 easier to use the same callout-containing regex from multiple threads. For
3472 testing, the pcretest program has a new data escape
3473
3474 \C*n pass the number n (may be negative) as callout_data
3475
3476 If the callout function in pcretest receives a non-zero value as
3477 callout_data, it returns that value.
3478
3479 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3480 there were some redundant $(CFLAGS) in commands that are now specified as
3481 $(LINK), which already includes $(CFLAGS).
3482
3483 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3484 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3485 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3486 one-byte characters throughout. Note that case-insensitive matching applies
3487 only to characters whose values are less than 256. PCRE doesn't support the
3488 notion of cases for higher-valued characters.
3489
3490 (i) A character class whose characters are all within 0-255 is handled as
3491 a bit map, and the map is inverted for negative classes. Previously, a
3492 character > 255 always failed to match such a class; however it should
3493 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3494
3495 (ii) A negated character class with a single character < 255 is coded as
3496 "not this character" (OP_NOT). This wasn't working properly when the test
3497 character was multibyte, either singly or repeated.
3498
3499 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3500 mode, for example: \x{100}{2,3}.
3501
3502 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3503 singly or repeated) now correctly test multibyte characters. However,
3504 PCRE doesn't recognize any characters with values greater than 255 as
3505 digits, spaces, or word characters. Such characters always match \D, \S,
3506 and \W, and never match \d, \s, or \w.
3507
3508 (v) Classes may now contain characters and character ranges with values
3509 greater than 255. For example: [ab\x{100}-\x{400}].
3510
3511 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3512 PCRE in UTF-8 mode.
3513
3514 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3515 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3516 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3517 value.)
3518
3519 53. The single man page has become too large. I have therefore split it up into
3520 a number of separate man pages. These also give rise to individual HTML pages;
3521 these are now put in a separate directory, and there is an index.html page that
3522 lists them all. Some hyperlinking between the pages has been installed.
3523
3524 54. Added convenience functions for handling named capturing parentheses.
3525
3526 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3527 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3528 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3529 are faulted.
3530
3531 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3532 calling configure. These values are used when compiling the dftables.c program
3533 which is run to generate the source of the default character tables. They
3534 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3535 you will need to set these values.
3536
3537 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3538
3539
3540 Version 3.9 02-Jan-02
3541 ---------------------
3542
3543 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3544
3545 2. If --disable-static was given, the building process failed when trying to
3546 build pcretest and pcregrep. (For some reason it was using libtool to compile
3547 them, which is not right, as they aren't part of the library.)
3548
3549
3550 Version 3.8 18-Dec-01
3551 ---------------------
3552
3553 1. The experimental UTF-8 code was completely screwed up. It was packing the
3554 bytes in the wrong order. How dumb can you get?
3555
3556
3557 Version 3.7 29-Oct-01
3558 ---------------------
3559
3560 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3561 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3562 this didn't happen under Solaris 8, where I normally test things.
3563
3564 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3565 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3566 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3567 this fix an hour or so after the initial 3.7 release.)
3568
3569
3570 Version 3.6 23-Oct-01
3571 ---------------------
3572
3573 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3574 offsets passed as NULL with zero offset count.
3575
3576 2. The config.guess and config.sub files had not been updated when I moved to
3577 the latest autoconf.
3578
3579
3580 Version 3.5 15-Aug-01
3581 ---------------------
3582
3583 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3584 had been forgotten.
3585
3586 2. By using declared but undefined structures, we can avoid using "void"
3587 definitions in pcre.h while keeping the internal definitions of the structures
3588 private.
3589
3590 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3591 user point of view, this means that both static and shared libraries are built
3592 by default, but this can be individually controlled. More of the work of
3593 handling this static/shared cases is now inside libtool instead of PCRE's make
3594 file.
3595
3596 4. The pcretest utility is now installed along with pcregrep because it is
3597 useful for users (to test regexs) and by doing this, it automatically gets
3598 relinked by libtool. The documentation has been turned into a man page, so
3599 there are now .1, .txt, and .html versions in /doc.
3600
3601 5. Upgrades to pcregrep:
3602 (i) Added long-form option names like gnu grep.
3603 (ii) Added --help to list all options with an explanatory phrase.
3604 (iii) Added -r, --recursive to recurse into sub-directories.
3605 (iv) Added -f, --file to read patterns from a file.
3606
3607 6. pcre_exec() was referring to its "code" argument before testing that
3608 argument for NULL (and giving an error if it was NULL).
3609
3610 7. Upgraded Makefile.in to allow for compiling in a different directory from
3611 the source directory.
3612
3613 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3614 options bits, the pointer it was passed was to an int instead of to an unsigned
3615 long int. This mattered only on 64-bit systems.
3616
3617 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3618 generated) instead of pcre.in, which it its source. Also made the same change
3619 in several of the .c files.
3620
3621 10. A new release of gcc defines printf() as a macro, which broke pcretest
3622 because it had an ifdef in the middle of a string argument for printf(). Fixed
3623 by using separate calls to printf().
3624
3625 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3626 script, to force use of CR or LF instead of \n in the source. On non-Unix
3627 systems, the value can be set in config.h.
3628
3629 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3630 absolute limit. Changed the text of the error message to make this clear, and
3631 likewise updated the man page.
3632
3633 13. The limit of 99 on the number of capturing subpatterns has been removed.
3634 The new limit is 65535, which I hope will not be a "real" limit.
3635
3636
3637 Version 3.4 22-Aug-00
3638 ---------------------
3639
3640 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3641
3642 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3643
3644
3645 Version 3.3 01-Aug-00
3646 ---------------------
3647
3648 1. If an octal character was given, but the value was greater than \377, it
3649 was not getting masked to the least significant bits, as documented. This could
3650 lead to crashes in some systems.
3651
3652 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3653 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3654
3655 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3656 These just pass their arguments on to (pcre_free)(), but they are provided
3657 because some uses of PCRE bind it to non-C systems that can call its functions,
3658 but cannot call free() or pcre_free() directly.
3659
3660 4. Add "make test" as a synonym for "make check". Corrected some comments in
3661 the Makefile.
3662
3663 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3664 Makefile.
3665
3666 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3667 command called pgrep for grepping around the active processes.
3668
3669 7. Added the beginnings of support for UTF-8 character strings.
3670
3671 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3672 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3673 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3674 out for the ar command.)
3675
3676
3677 Version 3.2 12-May-00
3678 ---------------------
3679
3680 This is purely a bug fixing release.
3681
3682 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3683 of ZA. This was just one example of several cases that could provoke this bug,
3684 which was introduced by change 9 of version 2.00. The code for breaking
3685 infinite loops after an iteration that matches an empty string was't working
3686 correctly.
3687
3688 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3689 when matched against abbab (for example). After matching an empty string, it
3690 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3691 caused it to match further down the string than it should.
3692
3693 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3694 was there because it doesn't seem to be needed, and it causes trouble on some
3695 systems, as it is not a Standard C header. It has been removed.
3696
3697 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3698 were reported on the Macintosh. The changes were from
3699
3700 while ((c = *(++ptr)) != 0 && c != '\n');
3701 to
3702 while ((c = *(++ptr)) != 0 && c != '\n') ;
3703
3704 Totally extraordinary, but if that's what it takes...
3705
3706 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3707 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3708 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3709 assumes the way PCRE uses memmove() (always moving upwards).
3710
3711 6. PCRE is being used in one environment where strchr() is not available. There
3712 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3713 faster code anyway.
3714
3715
3716 Version 3.1 09-Feb-00
3717 ---------------------
3718
3719 The only change in this release is the fixing of some bugs in Makefile.in for
3720 the "install" target:
3721
3722 (1) It was failing to install pcreposix.h.
3723
3724 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3725
3726
3727 Version 3.0 01-Feb-00
3728 ---------------------
3729
3730 1. Add support for the /+ modifier to perltest (to output $` like it does in
3731 pcretest).
3732
3733 2. Add support for the /g modifier to perltest.
3734
3735 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3736 matches null strings.
3737
3738 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3739 pattern. Perl treats empty patterns specially - it reuses the most recent
3740 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3741 effect.
3742
3743 5. The POSIX interface was broken in that it was just handing over the POSIX
3744 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3745 required a bigger vector, with some working space on the end. This means that
3746 the POSIX wrapper now has to get and free some memory, and copy the results.
3747
3748 6. Added some simple autoconf support, placing the test data and the
3749 documentation in separate directories, re-organizing some of the
3750 information files, and making it build pcre-config (a GNU standard). Also added
3751 libtool support for building PCRE as a shared library, which is now the
3752 default.
3753
3754 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3755 09 are not valid octal constants. Single digits will be used for minor values
3756 less than 10.
3757
3758 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3759 existing programs that set these in the POSIX interface can use PCRE without
3760 modification.
3761
3762 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3763 return all that pcre_info() returns, plus additional data. The pcre_info()
3764 function is retained for compatibility, but is considered to be obsolete.
3765
3766 10. Added experimental recursion feature (?R) to handle one common case that
3767 Perl 5.6 will be able to do with (?p{...}).
3768
3769 11. Added support for POSIX character classes like [:alpha:], which Perl is
3770 adopting.
3771
3772
3773 Version 2.08 31-Aug-99
3774 ----------------------
3775
3776 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3777 trying to match at the startoffset position, but instead was moving forward to
3778 the next newline as if a previous match had failed.
3779
3780 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3781 and could get into a loop if a null string was matched other than at the start
3782 of the subject.
3783
3784 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3785 be distinguished at compile time, and for completeness also added PCRE_DATE.
3786
3787 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3788 in GnuWin32 environments.
3789
3790
3791 Version 2.07 29-Jul-99
3792 ----------------------
3793
3794 1. The documentation is now supplied in plain text form and HTML as well as in
3795 the form of man page sources.
3796
3797 2. C++ compilers don't like assigning (void *) values to other pointer types.
3798 In particular this affects malloc(). Although there is no problem in Standard
3799 C, I've put in casts to keep C++ compilers happy.
3800
3801 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3802 should be (const char *).
3803
3804 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3805 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3806 However, I haven't made this a standard facility. The documentation doesn't
3807 mention it, and the Makefile doesn't support it.
3808
3809 5. The Makefile now contains an "install" target, with editable destinations at
3810 the top of the file. The pcretest program is not installed.
3811
3812 6. pgrep -V now gives the PCRE version number and date.
3813
3814 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3815 causing the entire string to be ignored, instead of just the last character.
3816
3817 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3818 non-matching string, it can take a very, very long time, even for strings of
3819 quite modest length, because of the nested recursion. PCRE now does better in
3820 some of these cases. It does this by remembering the last required literal
3821 character in the pattern, and pre-searching the subject to ensure it is present
3822 before running the real match. In other words, it applies a heuristic to detect
3823 some types of certain failure quickly, and in the above example, if presented
3824 with a string that has no trailing " it gives "no match" very quickly.
3825
3826 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3827 other alternatives are tried instead.
3828
3829
3830 Version 2.06 09-Jun-99
3831 ----------------------
3832
3833 1. Change pcretest's output for amount of store used to show just the code
3834 space, because the remainder (the data block) varies in size between 32-bit and
3835 64-bit systems.
3836
3837 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3838 start matching at. This allows lookbehinds to work when searching for multiple
3839 occurrences in a string.
3840
3841 3. Added additional options to pcretest for testing multiple occurrences:
3842
3843 /+ outputs the rest of the string that follows a match
3844 /g loops for multiple occurrences, using the new startoffset argument
3845 /G loops for multiple occurrences by passing an incremented pointer
3846
3847 4. PCRE wasn't doing the "first character" optimization for patterns starting
3848 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3849 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3850 the letter 'x'. On long subject strings, this gives a significant speed-up.
3851
3852
3853 Version 2.05 21-Apr-99
3854 ----------------------
3855
3856 1. Changed the type of magic_number from int to long int so that it works
3857 properly on 16-bit systems.
3858
3859 2. Fixed a bug which caused patterns starting with .* not to work correctly
3860 when the subject string contained newline characters. PCRE was assuming
3861 anchoring for such patterns in all cases, which is not correct because .* will
3862 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3863 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3864 must be retried after every newline in the subject.
3865
3866
3867 Version 2.04 18-Feb-99
3868 ----------------------
3869
3870 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3871 computation of the store needed to hold the pattern was incorrect (too large).
3872 If such patterns were nested a few deep, this could multiply and become a real
3873 problem.
3874
3875 2. Added /M option to pcretest to show the memory requirement of a specific
3876 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3877
3878 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3879 compiled in such a way that the backtracking after subsequent failure was
3880 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3881 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3882
3883
3884 Version 2.03 02-Feb-99
3885 ----------------------
3886
3887 1. Fixed typo and small mistake in man page.
3888
3889 2. Added 4th condition (GPL supersedes if conflict) and created separate
3890 LICENCE file containing the conditions.
3891
3892 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3893 Perl, that is the internal \ allows the delimiter to be included in the
3894 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3895 the final delimiter, add \ to the end of the pattern (to test the error).
3896
3897 4. Added the convenience functions for extracting substrings after a successful
3898 match. Updated pcretest to make it able to test these functions.
3899
3900
3901 Version 2.02 14-Jan-99
3902 ----------------------
3903
3904 1. Initialized the working variables associated with each extraction so that
3905 their saving and restoring doesn't refer to uninitialized store.
3906
3907 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3908 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3909 fix the problem.
3910
3911 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3912 calls, and wasn't printing the correct value for compiling calls. Increased the
3913 default value of LOOPREPEAT, and the number of significant figures in the
3914 times.
3915
3916 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3917
3918 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3919 a building problem on Windows NT with a FAT file system.
3920
3921
3922 Version 2.01 21-Oct-98
3923 ----------------------
3924
3925 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3926 to character tables built by pcre_maketables() in the current locale. If NULL
3927 is passed, the default tables are used.
3928
3929
3930 Version 2.00 24-Sep-98
3931 ----------------------
3932
3933 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3934 it any more.
3935
3936 2. Allow quantification of (?>) groups, and make it work correctly.
3937
3938 3. The first character computation wasn't working for (?>) groups.
3939
3940 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3941 end of the subject) and add 5.005's \z, which really does match only at the
3942 very end of the subject.
3943
3944 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3945
3946 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3947 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3948 localized options. All options to pcre_study() were also removed.
3949
3950 7. Add other new features from 5.005:
3951
3952 $(?<= positive lookbehind
3953 $(?<! negative lookbehind
3954 (?imsx-imsx) added the unsetting capability
3955 such a setting is global if at outer level; local otherwise
3956 (?imsx-imsx:) non-capturing groups with option setting
3957 (?(cond)re|re) conditional pattern matching
3958
3959 A backreference to itself in a repeated group matches the previous
3960 captured string.
3961
3962 8. General tidying up of studying (both automatic and via "study")
3963 consequential on the addition of new assertions.
3964
3965 9. As in 5.005, unlimited repeated groups that could match an empty substring
3966 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3967 runtime if any iteration does actually match an empty substring.
3968
3969 10. Include the RunTest script in the distribution.
3970
3971 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3972 discrepancies, some of which were old and were also with respect to 5.004. They
3973 have now been fixed.
3974
3975
3976 Version 1.09 28-Apr-98
3977 ----------------------
3978
3979 1. A negated single character class followed by a quantifier with a minimum
3980 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3981 program crashes, or just wrong answers. This did not apply to negated classes
3982 containing more than one character, or to minima other than one.
3983
3984
3985 Version 1.08 27-Mar-98
3986 ----------------------
3987
3988 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3989
3990 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3991 latter must appear before anything that relies on it in the pattern.
3992
3993
3994 Version 1.07 16-Feb-98
3995 ----------------------
3996
3997 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3998 repeat of a potentially empty string).
3999
4000
4001 Version 1.06 23-Jan-98
4002 ----------------------
4003
4004 1. Added Markus Oberhumer's little patches for C++.
4005
4006 2. Literal strings longer than 255 characters were broken.
4007
4008
4009 Version 1.05 23-Dec-97
4010 ----------------------
4011
4012 1. Negated character classes containing more than one character were failing if
4013 PCRE_CASELESS was set at run time.
4014
4015
4016 Version 1.04 19-Dec-97
4017 ----------------------
4018
4019 1. Corrected the man page, where some "const" qualifiers had been omitted.
4020
4021 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4022 input syntax.
4023
4024 3. Fixed memory leak which occurred when a regex with back references was
4025 matched with an offsets vector that wasn't big enough. The temporary memory
4026 that is used in this case wasn't being freed if the match failed.
4027
4028 4. Tidied pcretest to ensure it frees memory that it gets.
4029
4030 5. Temporary memory was being obtained in the case where the passed offsets
4031 vector was exactly big enough.
4032
4033 6. Corrected definition of offsetof() from change 5 below.
4034
4035 7. I had screwed up change 6 below and broken the rules for the use of
4036 setjmp(). Now fixed.
4037
4038
4039 Version 1.03 18-Dec-97
4040 ----------------------
4041
4042 1. A erroneous regex with a missing opening parenthesis was correctly
4043 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4044 on some systems.
4045
4046 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4047 it was reported that one broken compiler failed on the former because "code" is
4048 also an independent variable.
4049
4050 3. The erroneous regex a[]b caused an array overrun reference.
4051
4052 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4053 fail on data ending with that character. (It was going on too far, and checking
4054 the next character, typically a binary zero.) This was specific to the
4055 optimized code for single-character negative classes.
4056
4057 5. Added a contributed patch from the TIN world which does the following:
4058
4059 + Add an undef for memmove, in case the the system defines a macro for it.
4060
4061 + Add a definition of offsetof(), in case there isn't one. (I don't know
4062 the reason behind this - offsetof() is part of the ANSI standard - but
4063 it does no harm).
4064
4065 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4066 most of the places where whitespace preceded '#'. I have given up and
4067 allowed the remaining 2 cases to be at the margin.
4068
4069 + Rename some variables in pcre to eliminate shadowing. This seems very
4070 pedantic, but does no harm, of course.
4071
4072 6. Moved the call to setjmp() into its own function, to get rid of warnings
4073 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4074
4075 7. Constructs such as \d{8,} were compiling into the equivalent of
4076 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4077 outcome, but in this particular case used more store than had been allocated,
4078 which caused the bug to be discovered because it threw up an internal error.
4079
4080 8. The debugging code in both pcre and pcretest for outputting the compiled
4081 form of a regex was going wrong in the case of back references followed by
4082 curly-bracketed repeats.
4083
4084
4085 Version 1.02 12-Dec-97
4086 ----------------------
4087
4088 1. Typos in pcre.3 and comments in the source fixed.
4089
4090 2. Applied a contributed patch to get rid of places where it used to remove
4091 'const' from variables, and fixed some signed/unsigned and uninitialized
4092 variable warnings.
4093
4094 3. Added the "runtest" target to Makefile.
4095
4096 4. Set default compiler flag to -O2 rather than just -O.
4097
4098
4099 Version 1.01 19-Nov-97
4100 ----------------------
4101
4102 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4103 like /([ab]*)*/, that is, for classes with more than one character in them.
4104
4105 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4106 as /((?>a*))*/ (a PCRE_EXTRA facility).
4107
4108
4109 Version 1.00 18-Nov-97
4110 ----------------------
4111
4112 1. Added compile-time macros to support systems such as SunOS4 which don't have
4113 memmove() or strerror() but have other things that can be used instead.
4114
4115 2. Arranged that "make clean" removes the executables.
4116
4117
4118 Version 0.99 27-Oct-97
4119 ----------------------
4120
4121 1. Fixed bug in code for optimizing classes with only one character. It was
4122 initializing a 32-byte map regardless, which could cause it to run off the end
4123 of the memory it had got.
4124
4125 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4126
4127
4128 Version 0.98 22-Oct-97
4129 ----------------------
4130
4131 1. Fixed bug in code for handling temporary memory usage when there are more
4132 back references than supplied space in the ovector. This could cause segfaults.
4133
4134
4135 Version 0.97 21-Oct-97
4136 ----------------------
4137
4138 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4139
4140 2. Optimized negated single characters not to use a bit map.
4141
4142 3. Brought error texts together as macro definitions; clarified some of them;
4143 fixed one that was wrong - it said "range out of order" when it meant "invalid
4144 escape sequence".
4145
4146 4. Changed some char * arguments to const char *.
4147
4148 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4149
4150 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4151 pcretest.
4152
4153
4154 Version 0.96 16-Oct-97
4155 ----------------------
4156
4157 1. Added a simple "pgrep" utility to the distribution.
4158
4159 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4160 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4161 where "ddd" means "one or more decimal digits".
4162
4163 3. Fixed serious bug. If a pattern had a back reference, but the call to
4164 pcre_exec() didn't supply a large enough ovector to record the related
4165 identifying subpattern, the match always failed. PCRE now remembers the number
4166 of the largest back reference, and gets some temporary memory in which to save
4167 the offsets during matching if necessary, in order to ensure that
4168 backreferences always work.
4169
4170 4. Increased the compatibility with Perl in a number of ways:
4171
4172 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4173 to request this handling. The option can be set at compile or exec time.
4174
4175 (b) $ matches before a terminating newline by default; an option
4176 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4177 mode). The option can be set at compile or exec time.
4178
4179 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4180 the same as Perl's. If the decimal number it represents is less than 10
4181 or there aren't that many previous left capturing parentheses, an octal
4182 escape is read. Inside a character class, it's always an octal escape,
4183 even if it is a single digit.
4184
4185 (d) An escaped but undefined alphabetic character is taken as a literal,
4186 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4187 escapes.
4188
4189 (e) {0} is now permitted. (The previous item is removed from the compiled
4190 pattern).
4191
4192 5. Changed all the names of code files so that the basic parts are no longer
4193 than 10 characters, and abolished the teeny "globals.c" file.
4194
4195 6. Changed the handling of character classes; they are now done with a 32-byte
4196 bit map always.
4197
4198 7. Added the -d and /D options to pcretest to make it possible to look at the
4199 internals of compilation without having to recompile pcre.
4200
4201
4202 Version 0.95 23-Sep-97
4203 ----------------------
4204
4205 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4206 \x20 at the start of a run of normal characters. These were being treated as
4207 real characters, instead of the source characters being re-checked.
4208
4209
4210 Version 0.94 18-Sep-97
4211 ----------------------
4212
4213 1. The functions are now thread-safe, with the caveat that the global variables
4214 containing pointers to malloc() and free() or alternative functions are the
4215 same for all threads.
4216
4217 2. Get pcre_study() to generate a bitmap of initial characters for non-
4218 anchored patterns when this is possible, and use it if passed to pcre_exec().
4219
4220
4221 Version 0.93 15-Sep-97
4222 ----------------------
4223
4224 1. /(b)|(:+)/ was computing an incorrect first character.
4225
4226 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4227 but not actually doing anything yet.
4228
4229 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4230 as Perl does (e.g. [-az] or [az-]).
4231
4232 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4233 all possible positions.
4234
4235 5. Split up into different modules to avoid including unneeded functions in a
4236 compiled binary. However, compile and exec are still in one module. The "study"
4237 function is split off.
4238
4239 6. The character tables are now in a separate module whose source is generated
4240 by an auxiliary program - but can then be edited by hand if required. There are
4241 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4242 toupper() in the code.
4243
4244 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4245 make them global. Abolish the function for setting them, as the caller can now
4246 set them directly.
4247
4248
4249 Version 0.92 11-Sep-97
4250 ----------------------
4251
4252 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4253 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4254
4255 2. Caseless matching was not working in character classes if the characters in
4256 the pattern were in upper case.
4257
4258 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4259
4260 4. Make PCRE_ANCHORED public and accept as a compile option.
4261
4262 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4263 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4264 pass them.
4265
4266 6. Give an error if bad option bits passed at compile or run time.
4267
4268 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4269 pcretest to cause it to pass that flag.
4270
4271 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4272 options, and the first character, if set.
4273
4274 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4275
4276
4277 Version 0.91 10-Sep-97
4278 ----------------------
4279
4280 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4281 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4282
4283 2. PCRE was looping on encountering an indefinitely repeated back reference to
4284 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4285 Perl does - treats the match as successful.
4286
4287 ****

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