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Revision 622 - (show annotations) (download)
Mon Jul 18 10:46:51 2011 UTC (3 years, 3 months ago) by ph10
File size: 206605 byte(s)
Updated RunTest.bat to Tom Fortmann's improved version.

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

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