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Revision 514 - (show annotations)
Mon May 3 12:54:22 2010 UTC (9 years, 3 months ago) by ph10
File size: 185504 byte(s)
Add support for \N.
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.10 03 May-2010
5 ------------------------
6
7 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8 THEN.
9
10 2. (*ACCEPT) was not working when inside an atomic group.
11
12 3. Inside a character class, \B is treated as a literal by default, but
13 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14 causes the error). The code is unchanged, but I tidied the documentation.
15
16 4. Inside a character class, PCRE always treated \R and \X as literals,
17 whereas Perl faults them if its -w option is set. I have changed PCRE so
18 that it faults them when PCRE_EXTRA is set.
19
20 5. Added support for \N, which always matches any character other than
21 newline. (It is the same as "." when PCRE_DOTALL is not set.)
22
23
24 Version 8.02 19-Mar-2010
25 ------------------------
26
27 1. The Unicode data tables have been updated to Unicode 5.2.0.
28
29 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
30 configured.
31
32 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
33 original author of that file, following a query about its status.
34
35 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
36 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
37
38 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
39 quantifier applied to a forward-referencing subroutine call, could compile
40 incorrect code or give the error "internal error: previously-checked
41 referenced subpattern not found".
42
43 6. Both MS Visual Studio and Symbian OS have problems with initializing
44 variables to point to external functions. For these systems, therefore,
45 pcre_malloc etc. are now initialized to local functions that call the
46 relevant global functions.
47
48 7. There were two entries missing in the vectors called coptable and poptable
49 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
50 I've fixed the data, and added a kludgy way of testing at compile time that
51 the lengths are correct (equal to the number of opcodes).
52
53 8. Following on from 7, I added a similar kludge to check the length of the
54 eint vector in pcreposix.c.
55
56 9. Error texts for pcre_compile() are held as one long string to avoid too
57 much relocation at load time. To find a text, the string is searched,
58 counting zeros. There was no check for running off the end of the string,
59 which could happen if a new error number was added without updating the
60 string.
61
62 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
63
64 11. \K was not working if it appeared in an atomic group or in a group that
65 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
66 \K is "not well defined" if used in an assertion. PCRE now accepts it if
67 the assertion is positive, but not if it is negative.
68
69 12. Change 11 fortuitously reduced the size of the stack frame used in the
70 "match()" function of pcre_exec.c by one pointer. Forthcoming
71 implementation of support for (*MARK) will need an extra pointer on the
72 stack; I have reserved it now, so that the stack frame size does not
73 decrease.
74
75 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
76 item in branch that calls a recursion is a subroutine call - as in the
77 second branch in the above example - was incorrectly given the compile-
78 time error "recursive call could loop indefinitely" because pcre_compile()
79 was not correctly checking the subroutine for matching a non-empty string.
80
81 14. The checks for overrunning compiling workspace could trigger after an
82 overrun had occurred. This is a "should never occur" error, but it can be
83 triggered by pathological patterns such as hundreds of nested parentheses.
84 The checks now trigger 100 bytes before the end of the workspace.
85
86 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
87
88
89 Version 8.01 19-Jan-2010
90 ------------------------
91
92 1. If a pattern contained a conditional subpattern with only one branch (in
93 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
94 computed the wrong minimum data length (which is of course zero for such
95 subpatterns). This could cause incorrect "no match" results.
96
97 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
98 the pattern is reset in the first branch, pcre_compile() failed with
99 "internal error: code overflow at offset...". This happened only when
100 the reset was to the original external option setting. (An optimization
101 abstracts leading options settings into an external setting, which was the
102 cause of this.)
103
104 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
105 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
106 assertion pattern did not match (meaning that the assertion was true), it
107 was incorrectly treated as false if the SKIP had been reached during the
108 matching. This also applied to assertions used as conditions.
109
110 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
111 assertion subpattern, including such a pattern used as a condition,
112 unpredictable results occurred, instead of the error return
113 PCRE_ERROR_DFA_UITEM.
114
115 5. The C++ GlobalReplace function was not working like Perl for the special
116 situation when an empty string is matched. It now does the fancy magic
117 stuff that is necessary.
118
119 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
120 removed. (These were left over from very, very early versions of PCRE.)
121
122 7. Some cosmetic changes to the code to make life easier when compiling it
123 as part of something else:
124
125 (a) Change DEBUG to PCRE_DEBUG.
126
127 (b) In pcre_compile(), rename the member of the "branch_chain" structure
128 called "current" as "current_branch", to prevent a collision with the
129 Linux macro when compiled as a kernel module.
130
131 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
132 prevent a collision with the Linux macro when compiled as a kernel
133 module.
134
135 8. In pcre_compile() there are some checks for integer overflows that used to
136 cast potentially large values to (double). This has been changed to that
137 when building, a check for int64_t is made, and if it is found, it is used
138 instead, thus avoiding the use of floating point arithmetic. (There is no
139 other use of FP in PCRE.) If int64_t is not found, the fallback is to
140 double.
141
142 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
143 2005 (difference between two addresses compared to an unsigned value).
144
145 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
146 custom one, because of the following reported problem in Windows:
147
148 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
149 under Win32.
150 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
151 therefore missing the function definition.
152 - The compiler thus generates a "C" signature for the test function.
153 - The linker fails to find the "C" function.
154 - PCRE fails to configure if asked to do so against libbz2.
155
156 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
157 messages were output:
158
159 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
160 rerunning libtoolize, to keep the correct libtool macros in-tree.
161 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
162
163 I have done both of these things.
164
165 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
166 most of the time, it *can* run out if it is given a pattern that contains a
167 runaway infinite recursion. I updated the discussion in the pcrestack man
168 page.
169
170 13. Now that we have gone to the x.xx style of version numbers, the minor
171 version may start with zero. Using 08 or 09 is a bad idea because users
172 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
173 interpreted as invalid octal numbers. I've updated the previous comment in
174 configure.ac, and also added a check that gives an error if 08 or 09 are
175 used.
176
177 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
178 causing partial matching to fail when the end of the subject matched \W
179 in a UTF-8 pattern where \W was quantified with a minimum of 3.
180
181 15. There were some discrepancies between the declarations in pcre_internal.h
182 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
183 their definitions. The declarations used "const uschar *" and the
184 definitions used USPTR. Even though USPTR is normally defined as "const
185 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
186 reported that: "This difference in casting confuses some C++ compilers, for
187 example, SunCC recognizes above declarations as different functions and
188 generates broken code for hbpcre." I have changed the declarations to use
189 USPTR.
190
191 16. GNU libtool is named differently on some systems. The autogen.sh script now
192 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
193 (FreeBSD).
194
195 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
196 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
197 comment: "Figure out how to create a longlong from a string: strtoll and
198 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
199 instance, but it only takes 2 args instead of 3!"
200
201 18. A subtle bug concerned with back references has been fixed by a change of
202 specification, with a corresponding code fix. A pattern such as
203 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
204 refers, was giving matches when it shouldn't. For example, xa=xaaa would
205 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
206 same bug. Such groups have to be quantified to be useful, or contained
207 inside another quantified group. (If there's no repetition, the reference
208 can never match.) The problem arises because, having left the group and
209 moved on to the rest of the pattern, a later failure that backtracks into
210 the group uses the captured value from the final iteration of the group
211 rather than the correct earlier one. I have fixed this in PCRE by forcing
212 any group that contains a reference to itself to be an atomic group; that
213 is, there cannot be any backtracking into it once it has completed. This is
214 similar to recursive and subroutine calls.
215
216
217 Version 8.00 19-Oct-09
218 ----------------------
219
220 1. The table for translating pcre_compile() error codes into POSIX error codes
221 was out-of-date, and there was no check on the pcre_compile() error code
222 being within the table. This could lead to an OK return being given in
223 error.
224
225 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
226 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
227 in a Windows environment.
228
229 3. The pcregrep --count option prints the count for each file even when it is
230 zero, as does GNU grep. However, pcregrep was also printing all files when
231 --files-with-matches was added. Now, when both options are given, it prints
232 counts only for those files that have at least one match. (GNU grep just
233 prints the file name in this circumstance, but including the count seems
234 more useful - otherwise, why use --count?) Also ensured that the
235 combination -clh just lists non-zero counts, with no names.
236
237 4. The long form of the pcregrep -F option was incorrectly implemented as
238 --fixed_strings instead of --fixed-strings. This is an incompatible change,
239 but it seems right to fix it, and I didn't think it was worth preserving
240 the old behaviour.
241
242 5. The command line items --regex=pattern and --regexp=pattern were not
243 recognized by pcregrep, which required --regex pattern or --regexp pattern
244 (with a space rather than an '='). The man page documented the '=' forms,
245 which are compatible with GNU grep; these now work.
246
247 6. No libpcreposix.pc file was created for pkg-config; there was just
248 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
249
250 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
251 when UCP support is not needed, by modifying the Python script that
252 generates it from Unicode data files. This should not matter if the module
253 is correctly used as a library, but I received one complaint about 50K of
254 unwanted data. My guess is that the person linked everything into his
255 program rather than using a library. Anyway, it does no harm.
256
257 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
258 was a minimum greater than 1 for a wide character in a possessive
259 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
260 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
261 character. Chaos in the form of incorrect output or a compiling loop could
262 result.
263
264 9. The restrictions on what a pattern can contain when partial matching is
265 requested for pcre_exec() have been removed. All patterns can now be
266 partially matched by this function. In addition, if there are at least two
267 slots in the offset vector, the offset of the earliest inspected character
268 for the match and the offset of the end of the subject are set in them when
269 PCRE_ERROR_PARTIAL is returned.
270
271 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
272 synonymous with PCRE_PARTIAL, for backwards compatibility, and
273 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
274 and may be more useful for multi-segment matching.
275
276 11. Partial matching with pcre_exec() is now more intuitive. A partial match
277 used to be given if ever the end of the subject was reached; now it is
278 given only if matching could not proceed because another character was
279 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
280 string "Z", which now yields "no match" instead of "partial match". In the
281 case of pcre_dfa_exec(), "no match" is given if every matching path for the
282 final character ended with (*FAIL).
283
284 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
285 if the pattern had a "must contain" character that was already found in the
286 earlier partial match, unless partial matching was again requested. For
287 example, with the pattern /dog.(body)?/, the "must contain" character is
288 "g". If the first part-match was for the string "dog", restarting with
289 "sbody" failed. This bug has been fixed.
290
291 13. The string returned by pcre_dfa_exec() after a partial match has been
292 changed so that it starts at the first inspected character rather than the
293 first character of the match. This makes a difference only if the pattern
294 starts with a lookbehind assertion or \b or \B (\K is not supported by
295 pcre_dfa_exec()). It's an incompatible change, but it makes the two
296 matching functions compatible, and I think it's the right thing to do.
297
298 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
299 so that the demonstration program is easily available in environments where
300 PCRE has not been installed from source.
301
302 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
303 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
304 library.
305
306 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
307 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
308 is not the first non-POSIX option to be added. Clearly some people find
309 these options useful.
310
311 17. If a caller to the POSIX matching function regexec() passes a non-zero
312 value for nmatch with a NULL value for pmatch, the value of
313 nmatch is forced to zero.
314
315 18. RunGrepTest did not have a test for the availability of the -u option of
316 the diff command, as RunTest does. It now checks in the same way as
317 RunTest, and also checks for the -b option.
318
319 19. If an odd number of negated classes containing just a single character
320 interposed, within parentheses, between a forward reference to a named
321 subpattern and the definition of the subpattern, compilation crashed with
322 an internal error, complaining that it could not find the referenced
323 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
324 [The bug was that it was starting one character too far in when skipping
325 over the character class, thus treating the ] as data rather than
326 terminating the class. This meant it could skip too much.]
327
328 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
329 /g option in pcretest when the pattern contains \K, which makes it possible
330 to have an empty string match not at the start, even when the pattern is
331 anchored. Updated pcretest and pcredemo to use this option.
332
333 21. If the maximum number of capturing subpatterns in a recursion was greater
334 than the maximum at the outer level, the higher number was returned, but
335 with unset values at the outer level. The correct (outer level) value is
336 now given.
337
338 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
339 PCRE did not set those parentheses (unlike Perl). I have now found a way to
340 make it do so. The string so far is captured, making this feature
341 compatible with Perl.
342
343 23. The tests have been re-organized, adding tests 11 and 12, to make it
344 possible to check the Perl 5.10 features against Perl 5.10.
345
346 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
347 pattern matches a fixed length string. PCRE did not allow this; now it
348 does. Neither allows recursion.
349
350 25. I finally figured out how to implement a request to provide the minimum
351 length of subject string that was needed in order to match a given pattern.
352 (It was back references and recursion that I had previously got hung up
353 on.) This code has now been added to pcre_study(); it finds a lower bound
354 to the length of subject needed. It is not necessarily the greatest lower
355 bound, but using it to avoid searching strings that are too short does give
356 some useful speed-ups. The value is available to calling programs via
357 pcre_fullinfo().
358
359 26. While implementing 25, I discovered to my embarrassment that pcretest had
360 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
361 study optimizations had never been tested with that matching function.
362 Oops. What is worse, even when it was passed study data, there was a bug in
363 pcre_dfa_exec() that meant it never actually used it. Double oops. There
364 were also very few tests of studied patterns with pcre_dfa_exec().
365
366 27. If (?| is used to create subpatterns with duplicate numbers, they are now
367 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
368 on the other side of the coin, they are no longer allowed to have different
369 names, because these cannot be distinguished in PCRE, and this has caused
370 confusion. (This is a difference from Perl.)
371
372 28. When duplicate subpattern names are present (necessarily with different
373 numbers, as required by 27 above), and a test is made by name in a
374 conditional pattern, either for a subpattern having been matched, or for
375 recursion in such a pattern, all the associated numbered subpatterns are
376 tested, and the overall condition is true if the condition is true for any
377 one of them. This is the way Perl works, and is also more like the way
378 testing by number works.
379
380
381 Version 7.9 11-Apr-09
382 ---------------------
383
384 1. When building with support for bzlib/zlib (pcregrep) and/or readline
385 (pcretest), all targets were linked against these libraries. This included
386 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
387 libraries. This caused unwanted dependencies to be created. This problem
388 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
389 pcretest is linked with readline.
390
391 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
392 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
393 moved outside it again, because FALSE and TRUE are already defined in AIX,
394 but BOOL is not.
395
396 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
397 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
398
399 4. The pcregrep documentation said spaces were inserted as well as colons (or
400 hyphens) following file names and line numbers when outputting matching
401 lines. This is not true; no spaces are inserted. I have also clarified the
402 wording for the --colour (or --color) option.
403
404 5. In pcregrep, when --colour was used with -o, the list of matching strings
405 was not coloured; this is different to GNU grep, so I have changed it to be
406 the same.
407
408 6. When --colo(u)r was used in pcregrep, only the first matching substring in
409 each matching line was coloured. Now it goes on to look for further matches
410 of any of the test patterns, which is the same behaviour as GNU grep.
411
412 7. A pattern that could match an empty string could cause pcregrep to loop; it
413 doesn't make sense to accept an empty string match in pcregrep, so I have
414 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
415 seems to be how GNU grep behaves.
416
417 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
418 start or after a newline", because the conditional assertion was not being
419 correctly handled. The rule now is that both the assertion and what follows
420 in the first alternative must satisfy the test.
421
422 9. If auto-callout was enabled in a pattern with a conditional group whose
423 condition was an assertion, PCRE could crash during matching, both with
424 pcre_exec() and pcre_dfa_exec().
425
426 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
427 used for matching.
428
429 11. Unicode property support in character classes was not working for
430 characters (bytes) greater than 127 when not in UTF-8 mode.
431
432 12. Added the -M command line option to pcretest.
433
434 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
435
436 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
437
438 16. Added comments and documentation about mis-use of no_arg in the C++
439 wrapper.
440
441 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
442 from Martin Jerabek that uses macro names for all relevant character and
443 string constants.
444
445 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
446 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
447 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
448 these, but not everybody uses configure.
449
450 19. A conditional group that had only one branch was not being correctly
451 recognized as an item that could match an empty string. This meant that an
452 enclosing group might also not be so recognized, causing infinite looping
453 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
454 with the subject "ab", where knowledge that the repeated group can match
455 nothing is needed in order to break the loop.
456
457 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
458 exec(), but without supplying a callout function, matching went wrong.
459
460 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
461 leak if the size of the offset vector was greater than 30. When the vector
462 is smaller, the saved offsets during recursion go onto a local stack
463 vector, but for larger vectors malloc() is used. It was failing to free
464 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
465 error, in fact).
466
467 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
468 heapframe that is used only when UTF-8 support is enabled. This caused no
469 problem, but was untidy.
470
471 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
472 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
473 included within another project.
474
475 24. Steven Van Ingelgem's patches to add more options to the CMake support,
476 slightly modified by me:
477
478 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
479 not building pcregrep.
480
481 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
482 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
483
484 25. Forward references, both numeric and by name, in patterns that made use of
485 duplicate group numbers, could behave incorrectly or give incorrect errors,
486 because when scanning forward to find the reference group, PCRE was not
487 taking into account the duplicate group numbers. A pattern such as
488 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
489
490 26. Changed a few more instances of "const unsigned char *" to USPTR, making
491 the feature of a custom pointer more persuasive (as requested by a user).
492
493 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
494 pcretest.c, inside #ifndefs, because it seems they are sometimes already
495 pre-defined.
496
497 28. Added support for (*UTF8) at the start of a pattern.
498
499 29. Arrange for flags added by the "release type" setting in CMake to be shown
500 in the configuration summary.
501
502
503 Version 7.8 05-Sep-08
504 ---------------------
505
506 1. Replaced UCP searching code with optimized version as implemented for Ad
507 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
508 stage table and inline lookup instead of a function, giving speed ups of 2
509 to 5 times on some simple patterns that I tested. Permission was given to
510 distribute the MultiStage2.py script that generates the tables (it's not in
511 the tarball, but is in the Subversion repository).
512
513 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
514 scripts.
515
516 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
517 a group with a zero qualifier. The result of the study could be incorrect,
518 or the function might crash, depending on the pattern.
519
520 4. Caseless matching was not working for non-ASCII characters in back
521 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
522 It now works when Unicode Property Support is available.
523
524 5. In pcretest, an escape such as \x{de} in the data was always generating
525 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
526 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
527 truncation.
528
529 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
530
531 7. Added two (int) casts to pcregrep when printing the difference of two
532 pointers, in case they are 64-bit values.
533
534 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
535 test 2 if it fails.
536
537 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
538 and a #define of that name to empty if it is not externally set. This is to
539 allow users of MSVC to set it if necessary.
540
541 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
542 the convenience functions in the pcre_get.c source file.
543
544 11. An option change at the start of a pattern that had top-level alternatives
545 could cause overwriting and/or a crash. This command provoked a crash in
546 some environments:
547
548 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
549
550 This potential security problem was recorded as CVE-2008-2371.
551
552 12. For a pattern where the match had to start at the beginning or immediately
553 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
554 pcre_dfa_exec() could read past the end of the passed subject if there was
555 no match. To help with detecting such bugs (e.g. with valgrind), I modified
556 pcretest so that it places the subject at the end of its malloc-ed buffer.
557
558 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
559 exec() might read past the end of the data buffer in UTF-8 mode.
560
561 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
562 the data contained the byte 0x85 as part of a UTF-8 character within its
563 first line. This applied both to normal and DFA matching.
564
565 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
566 /^[^d]*?$/8 failed to match "abc".
567
568 16. Added a missing copyright notice to pcrecpp_internal.h.
569
570 17. Make it more clear in the documentation that values returned from
571 pcre_exec() in ovector are byte offsets, not character counts.
572
573 18. Tidied a few places to stop certain compilers from issuing warnings.
574
575 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
576 supplied by Stefan Weber. I made a further small update for 7.8 because
577 there is a change of source arrangements: the pcre_searchfuncs.c module is
578 replaced by pcre_ucd.c.
579
580
581 Version 7.7 07-May-08
582 ---------------------
583
584 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
585 a string to a long long, pretend we don't even have a long long." This is
586 done by checking for the strtoq, strtoll, and _strtoi64 functions.
587
588 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
589 pre-7.6 versions, which defined a global no_arg variable instead of putting
590 it in the RE class. (See also #8 below.)
591
592 3. Remove a line of dead code, identified by coverity and reported by Nuno
593 Lopes.
594
595 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
596
597 (1) The include/exclude patterns were being applied to the whole pathnames
598 of files, instead of just to the final components.
599
600 (2) If there was more than one level of directory, the subdirectories were
601 skipped unless they satisfied the include/exclude conditions. This is
602 inconsistent with GNU grep (and could even be seen as contrary to the
603 pcregrep specification - which I improved to make it absolutely clear).
604 The action now is always to scan all levels of directory, and just
605 apply the include/exclude patterns to regular files.
606
607 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
608 --exclude_dir in the tests to avoid scanning .svn directories.
609
610 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
611 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
612 doesn't support NULs in patterns.
613
614 7. Added some missing "const"s to declarations of static tables in
615 pcre_compile.c and pcre_dfa_exec.c.
616
617 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
618 caused by fix #2 above. (Subsequently also a second patch to fix the
619 first patch. And a third patch - this was a messy problem.)
620
621 9. Applied Craig's patch to remove the use of push_back().
622
623 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
624 matching function regexec().
625
626 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
627 which, however, unlike Perl's \g{...}, are subroutine calls, not back
628 references. PCRE supports relative numbers with this syntax (I don't think
629 Oniguruma does).
630
631 12. Previously, a group with a zero repeat such as (...){0} was completely
632 omitted from the compiled regex. However, this means that if the group
633 was called as a subroutine from elsewhere in the pattern, things went wrong
634 (an internal error was given). Such groups are now left in the compiled
635 pattern, with a new opcode that causes them to be skipped at execution
636 time.
637
638 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
639 to the way PCRE behaves:
640
641 (a) A lone ] character is dis-allowed (Perl treats it as data).
642
643 (b) A back reference to an unmatched subpattern matches an empty string
644 (Perl fails the current match path).
645
646 (c) A data ] in a character class must be notated as \] because if the
647 first data character in a class is ], it defines an empty class. (In
648 Perl it is not possible to have an empty class.) The empty class []
649 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
650 The negative empty class [^] matches any one character, independently
651 of the DOTALL setting.
652
653 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
654 non-existent subpattern following a character class starting with ']' and
655 containing () gave an internal compiling error instead of "reference to
656 non-existent subpattern". Fortunately, when the pattern did exist, the
657 compiled code was correct. (When scanning forwards to check for the
658 existencd of the subpattern, it was treating the data ']' as terminating
659 the class, so got the count wrong. When actually compiling, the reference
660 was subsequently set up correctly.)
661
662 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
663 it was being rejected as not supported by pcre_dfa_exec(), even though
664 other assertions are supported. I have made pcre_dfa_exec() support
665 (*FAIL).
666
667 16. The implementation of 13c above involved the invention of a new opcode,
668 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
669 cannot be changed at match time, I realized I could make a small
670 improvement to matching performance by compiling OP_ALLANY instead of
671 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
672 on the OP_ANY path.
673
674 17. Compiling pcretest on Windows with readline support failed without the
675 following two fixes: (1) Make the unistd.h include conditional on
676 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
677
678 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
679 ncurses library to be included for pcretest when ReadLine support is
680 requested, but also to allow for it to be overridden. This patch came from
681 Daniel Bergström.
682
683 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
684 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
685 any errors with the current Unicode tables. Thanks to Peter Kankowski for
686 spotting this.
687
688
689 Version 7.6 28-Jan-08
690 ---------------------
691
692 1. A character class containing a very large number of characters with
693 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
694 overflow.
695
696 2. Patch to cut out the "long long" test in pcrecpp_unittest when
697 HAVE_LONG_LONG is not defined.
698
699 3. Applied Christian Ehrlicher's patch to update the CMake build files to
700 bring them up to date and include new features. This patch includes:
701
702 - Fixed PH's badly added libz and libbz2 support.
703 - Fixed a problem with static linking.
704 - Added pcredemo. [But later removed - see 7 below.]
705 - Fixed dftables problem and added an option.
706 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
707 HAVE_LONG_LONG.
708 - Added readline support for pcretest.
709 - Added an listing of the option settings after cmake has run.
710
711 4. A user submitted a patch to Makefile that makes it easy to create
712 "pcre.dll" under mingw when using Configure/Make. I added stuff to
713 Makefile.am that cause it to include this special target, without
714 affecting anything else. Note that the same mingw target plus all
715 the other distribution libraries and programs are now supported
716 when configuring with CMake (see 6 below) instead of with
717 Configure/Make.
718
719 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
720 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
721 exported in the Windows port". It has not yet been confirmed that the patch
722 solves the problem, but it does no harm.
723
724 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
725 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
726 with CMake, and also correct the comment about stack recursion.
727
728 7. Remove the automatic building of pcredemo from the ./configure system and
729 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
730 of a program that users should build themselves after PCRE is installed, so
731 building it automatically is not really right. What is more, it gave
732 trouble in some build environments.
733
734 8. Further tidies to CMakeLists.txt from Sheri and Christian.
735
736
737 Version 7.5 10-Jan-08
738 ---------------------
739
740 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
741 values in parens when parsing an RE using the C++ wrapper."
742
743 2. Negative specials like \S did not work in character classes in UTF-8 mode.
744 Characters greater than 255 were excluded from the class instead of being
745 included.
746
747 3. The same bug as (2) above applied to negated POSIX classes such as
748 [:^space:].
749
750 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
751 defined or documented. It seems to have been a typo for PCRE_STATIC, so
752 I have changed it.
753
754 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
755 first named subpattern) and a construct such as (?&a) would reference the
756 first named subpattern whose name started with "a" (in other words, the
757 length check was missing). Both these problems are fixed. "Subpattern name
758 expected" is now given for (?&) (a zero-length name), and this patch also
759 makes it give the same error for \k'' (previously it complained that that
760 was a reference to a non-existent subpattern).
761
762 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
763 this is right because (?- can be followed by option settings as well as by
764 digits. I have, however, made the messages clearer.
765
766 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
767 than the number used in the conditional) now cause a compile-time error.
768 This is actually not compatible with Perl, which accepts such patterns, but
769 treats the conditional as always being FALSE (as PCRE used to), but it
770 seems to me that giving a diagnostic is better.
771
772 8. Change "alphameric" to the more common word "alphanumeric" in comments
773 and messages.
774
775 9. Fix two occurrences of "backslash" in comments that should have been
776 "backspace".
777
778 10. Remove two redundant lines of code that can never be obeyed (their function
779 was moved elsewhere).
780
781 11. The program that makes PCRE's Unicode character property table had a bug
782 which caused it to generate incorrect table entries for sequences of
783 characters that have the same character type, but are in different scripts.
784 It amalgamated them into a single range, with the script of the first of
785 them. In other words, some characters were in the wrong script. There were
786 thirteen such cases, affecting characters in the following ranges:
787
788 U+002b0 - U+002c1
789 U+0060c - U+0060d
790 U+0061e - U+00612
791 U+0064b - U+0065e
792 U+0074d - U+0076d
793 U+01800 - U+01805
794 U+01d00 - U+01d77
795 U+01d9b - U+01dbf
796 U+0200b - U+0200f
797 U+030fc - U+030fe
798 U+03260 - U+0327f
799 U+0fb46 - U+0fbb1
800 U+10450 - U+1049d
801
802 12. The -o option (show only the matching part of a line) for pcregrep was not
803 compatible with GNU grep in that, if there was more than one match in a
804 line, it showed only the first of them. It now behaves in the same way as
805 GNU grep.
806
807 13. If the -o and -v options were combined for pcregrep, it printed a blank
808 line for every non-matching line. GNU grep prints nothing, and pcregrep now
809 does the same. The return code can be used to tell if there were any
810 non-matching lines.
811
812 14. Added --file-offsets and --line-offsets to pcregrep.
813
814 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
815 infinitely looping recursion. The bug was that positive lookaheads were not
816 being skipped when checking for a possible empty match (negative lookaheads
817 and both kinds of lookbehind were skipped).
818
819 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
820 inclusion of <windows.h> to before rather than after the definition of
821 INVALID_FILE_ATTRIBUTES (patch from David Byron).
822
823 17. Specifying a possessive quantifier with a specific limit for a Unicode
824 character property caused pcre_compile() to compile bad code, which led at
825 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
826 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
827 caused the error; without that there was no problem.
828
829 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
830
831 19. Added --enable-pcretest-libreadline.
832
833 20. In pcrecpp.cc, the variable 'count' was incremented twice in
834 RE::GlobalReplace(). As a result, the number of replacements returned was
835 double what it should be. I removed one of the increments, but Craig sent a
836 later patch that removed the other one (the right fix) and added unit tests
837 that check the return values (which was not done before).
838
839 21. Several CMake things:
840
841 (1) Arranged that, when cmake is used on Unix, the libraries end up with
842 the names libpcre and libpcreposix, not just pcre and pcreposix.
843
844 (2) The above change means that pcretest and pcregrep are now correctly
845 linked with the newly-built libraries, not previously installed ones.
846
847 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
848
849 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
850 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
851 UTF-8 newline character). The key issue is that the pattern starts .*;
852 this means that the match must be either at the beginning, or after a
853 newline. The bug was in the code for advancing after a failed match and
854 checking that the new position followed a newline. It was not taking
855 account of UTF-8 characters correctly.
856
857 23. PCRE was behaving differently from Perl in the way it recognized POSIX
858 character classes. PCRE was not treating the sequence [:...:] as a
859 character class unless the ... were all letters. Perl, however, seems to
860 allow any characters between [: and :], though of course it rejects as
861 unknown any "names" that contain non-letters, because all the known class
862 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
863 for example, whereas PCRE did not - it did not recognize a POSIX character
864 class. This seemed a bit dangerous, so the code has been changed to be
865 closer to Perl. The behaviour is not identical to Perl, because PCRE will
866 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
867 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
868 Perl does, and where it didn't before.
869
870 24. Rewrite so as to remove the single use of %n from pcregrep because in some
871 Windows environments %n is disabled by default.
872
873
874 Version 7.4 21-Sep-07
875 ---------------------
876
877 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
878 means that a class such as [\s] counted as "explicit reference to CR or
879 LF". That isn't really right - the whole point of the change was to try to
880 help when there was an actual mention of one of the two characters. So now
881 the change happens only if \r or \n (or a literal CR or LF) character is
882 encountered.
883
884 2. The 32-bit options word was also used for 6 internal flags, but the numbers
885 of both had grown to the point where there were only 3 bits left.
886 Fortunately, there was spare space in the data structure, and so I have
887 moved the internal flags into a new 16-bit field to free up more option
888 bits.
889
890 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
891 but did not set the internal JCHANGED flag - either of these is enough to
892 control the way the "get" function works - but the PCRE_INFO_JCHANGED
893 facility is supposed to tell if (?J) was ever used, so now (?J) at the
894 start sets both bits.
895
896 4. Added options (at build time, compile time, exec time) to change \R from
897 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
898
899 5. doc/pcresyntax.html was missing from the distribution.
900
901 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
902 compatibility, even though it is no longer used.
903
904 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
905 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
906 windows.h file is present (where different names are used). [This was
907 reversed later after testing - see 16 below.]
908
909 8. Changed all #include <config.h> to #include "config.h". There were also
910 some further <pcre.h> cases that I changed to "pcre.h".
911
912 9. When pcregrep was used with the --colour option, it missed the line ending
913 sequence off the lines that it output.
914
915 10. It was pointed out to me that arrays of string pointers cause lots of
916 relocations when a shared library is dynamically loaded. A technique of
917 using a single long string with a table of offsets can drastically reduce
918 these. I have refactored PCRE in four places to do this. The result is
919 dramatic:
920
921 Originally: 290
922 After changing UCP table: 187
923 After changing error message table: 43
924 After changing table of "verbs" 36
925 After changing table of Posix names 22
926
927 Thanks to the folks working on Gregex for glib for this insight.
928
929 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
930 unicode-properties was also set.
931
932 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
933
934 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
935 checked only for CRLF.
936
937 14. Added casts to pcretest.c to avoid compiler warnings.
938
939 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
940
941 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
942 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
943 entirely. This removes changes made in 7 above.
944
945 17. The CMake files have been updated, and there is now more information about
946 building with CMake in the NON-UNIX-USE document.
947
948
949 Version 7.3 28-Aug-07
950 ---------------------
951
952 1. In the rejigging of the build system that eventually resulted in 7.1, the
953 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
954 brackets there is not right, since it causes compilers to look for an
955 installed pcre.h, not the version that is in the source that is being
956 compiled (which of course may be different). I have changed it back to:
957
958 #include "pcre.h"
959
960 I have a vague recollection that the change was concerned with compiling in
961 different directories, but in the new build system, that is taken care of
962 by the VPATH setting the Makefile.
963
964 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
965 when the subject happened to end in the byte 0x85 (e.g. if the last
966 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
967 characters but of course it shouldn't be taken as a newline when it is part
968 of another character. The bug was that, for an unlimited repeat of . in
969 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
970 characters when looking for a newline.
971
972 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
973
974 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
975 in debug output.
976
977 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
978 long printing in the pcrecpp unittest when running under MinGW.
979
980 6. ESC_K was left out of the EBCDIC table.
981
982 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
983 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
984 limit also applies to "virtual nesting" when a pattern is recursive, and in
985 this case 1000 isn't so big. I have been able to remove this limit at the
986 expense of backing off one optimization in certain circumstances. Normally,
987 when pcre_exec() would call its internal match() function recursively and
988 immediately return the result unconditionally, it uses a "tail recursion"
989 feature to save stack. However, when a subpattern that can match an empty
990 string has an unlimited repetition quantifier, it no longer makes this
991 optimization. That gives it a stack frame in which to save the data for
992 checking that an empty string has been matched. Previously this was taken
993 from the 1000-entry workspace that had been reserved. So now there is no
994 explicit limit, but more stack is used.
995
996 8. Applied Daniel's patches to solve problems with the import/export magic
997 syntax that is required for Windows, and which was going wrong for the
998 pcreposix and pcrecpp parts of the library. These were overlooked when this
999 problem was solved for the main library.
1000
1001 9. There were some crude static tests to avoid integer overflow when computing
1002 the size of patterns that contain repeated groups with explicit upper
1003 limits. As the maximum quantifier is 65535, the maximum group length was
1004 set at 30,000 so that the product of these two numbers did not overflow a
1005 32-bit integer. However, it turns out that people want to use groups that
1006 are longer than 30,000 bytes (though not repeat them that many times).
1007 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1008 made it possible to implement the integer overflow checks in a much more
1009 dynamic way, which I have now done. The artificial limitation on group
1010 length has been removed - we now have only the limit on the total length of
1011 the compiled pattern, which depends on the LINK_SIZE setting.
1012
1013 10. Fixed a bug in the documentation for get/copy named substring when
1014 duplicate names are permitted. If none of the named substrings are set, the
1015 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1016 empty string.
1017
1018 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1019 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1020 because the ] is interpreted as the first data character and the
1021 terminating ] is not found. PCRE has been made compatible with Perl in this
1022 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1023 cause memory overwriting.
1024
1025 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1026 string has been matched (to stop an infinite loop). It was not recognizing
1027 a conditional subpattern that could match an empty string if that
1028 subpattern was within another subpattern. For example, it looped when
1029 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1030 condition was not nested. This bug has been fixed.
1031
1032 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1033 past the start of the subject in the presence of bytes with the top bit
1034 set, for example "\x8aBCD".
1035
1036 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1037 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1038
1039 14. Optimized (?!) to (*FAIL).
1040
1041 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1042 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1043 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1044 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1045 does: it's just the validity check that is more restrictive.
1046
1047 16. Inserted checks for integer overflows during escape sequence (backslash)
1048 processing, and also fixed erroneous offset values for syntax errors during
1049 backslash processing.
1050
1051 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1052 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1053
1054 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1055 caused an overrun.
1056
1057 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1058 something other than just ASCII characters) inside a group that had an
1059 unlimited repeat caused a loop at compile time (while checking to see
1060 whether the group could match an empty string).
1061
1062 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1063 [\P{Any}] did so. (Error in the code for printing property names.)
1064
1065 21. An orphan \E inside a character class could cause a crash.
1066
1067 22. A repeated capturing bracket such as (A)? could cause a wild memory
1068 reference during compilation.
1069
1070 23. There are several functions in pcre_compile() that scan along a compiled
1071 expression for various reasons (e.g. to see if it's fixed length for look
1072 behind). There were bugs in these functions when a repeated \p or \P was
1073 present in the pattern. These operators have additional parameters compared
1074 with \d, etc, and these were not being taken into account when moving along
1075 the compiled data. Specifically:
1076
1077 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1078 length.
1079
1080 (b) An item such as \pL+ within a repeated group could cause crashes or
1081 loops.
1082
1083 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1084 "reference to non-existent subpattern" error.
1085
1086 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1087
1088 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1089 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1090
1091 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1092
1093 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1094 character were causing crashes (broken optimization).
1095
1096 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1097 \p or \P) caused a compile-time loop.
1098
1099 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1100 break. For example, the unstudied pattern [\r\n]A does not match the string
1101 "\r\nA" because change 7.0/46 below moves the current point on by two
1102 characters after failing to match at the start. However, the pattern \nA
1103 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1104 the same is true. There doesn't seem any very clean way out of this, but
1105 what I have chosen to do makes the common cases work: PCRE now takes note
1106 of whether there can be an explicit match for \r or \n anywhere in the
1107 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1108 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1109 pattern has explicit CR or LF references.
1110
1111 29. Added (*CR) etc for changing newline setting at start of pattern.
1112
1113
1114 Version 7.2 19-Jun-07
1115 ---------------------
1116
1117 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1118 which is apparently normally available under Windows.
1119
1120 2. Re-jig the pcregrep tests with different newline settings in an attempt
1121 to make them independent of the local environment's newline setting.
1122
1123 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1124
1125 4. Some of the "internals" tests were previously cut out when the link size
1126 was not 2, because the output contained actual offsets. The recent new
1127 "Z" feature of pcretest means that these can be cut out, making the tests
1128 usable with all link sizes.
1129
1130 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1131 stack recursion. This gives a massive performance boost under BSD, but just
1132 a small improvement under Linux. However, it saves one field in the frame
1133 in all cases.
1134
1135 6. Added more features from the forthcoming Perl 5.10:
1136
1137 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1138 recursion call. It refers to the nth most recently opened parentheses.
1139
1140 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1141 to be opened parentheses.
1142
1143 (c) Conditions that refer to capturing parentheses can be specified
1144 relatively, for example, (?(-2)... or (?(+3)...
1145
1146 (d) \K resets the start of the current match so that everything before
1147 is not part of it.
1148
1149 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1150
1151 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1152 reference syntax.
1153
1154 (g) (?| introduces a group in which the numbering of parentheses in each
1155 alternative starts with the same number.
1156
1157 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1158
1159 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1160 PCRE_INFO_JCHANGED.
1161
1162 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1163 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1164 for detecting groups that can match an empty string.
1165
1166 9. A pattern with a very large number of alternatives (more than several
1167 hundred) was running out of internal workspace during the pre-compile
1168 phase, where pcre_compile() figures out how much memory will be needed. A
1169 bit of new cunning has reduced the workspace needed for groups with
1170 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1171 workspace instead of running out of the 4096 that are available.
1172
1173 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1174
1175 11. Applied patch from Google to remove an optimization that didn't quite work.
1176 The report of the bug said:
1177
1178 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1179 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1180 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1181
1182 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1183 it matched the wrong number of bytes.
1184
1185
1186 Version 7.1 24-Apr-07
1187 ---------------------
1188
1189 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1190 that is more "standard", making use of automake and other Autotools. There
1191 is some re-arrangement of the files and adjustment of comments consequent
1192 on this.
1193
1194 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1195 for recursive directory scanning broke on some systems because the files
1196 are not scanned in any specific order and on different systems the order
1197 was different. A call to "sort" has been inserted into RunGrepTest for the
1198 approprate test as a short-term fix. In the longer term there may be an
1199 alternative.
1200
1201 3. I had an email from Eric Raymond about problems translating some of PCRE's
1202 man pages to HTML (despite the fact that I distribute HTML pages, some
1203 people do their own conversions for various reasons). The problems
1204 concerned the use of low-level troff macros .br and .in. I have therefore
1205 removed all such uses from the man pages (some were redundant, some could
1206 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1207 HTML has been updated to handle .nf/.fi and to complain if it encounters
1208 .br or .in.
1209
1210 4. Updated comments in configure.ac that get placed in config.h.in and also
1211 arranged for config.h to be included in the distribution, with the name
1212 config.h.generic, for the benefit of those who have to compile without
1213 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1214
1215 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1216 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1217 makevp.bat for the current PCRE, using the additional files
1218 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1219
1220 6. A Windows user reported a minor discrepancy with test 2, which turned out
1221 to be caused by a trailing space on an input line that had got lost in his
1222 copy. The trailing space was an accident, so I've just removed it.
1223
1224 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1225 that is needed.
1226
1227 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1228 as "const" (a) because they are and (b) because it helps the PHP
1229 maintainers who have recently made a script to detect big data structures
1230 in the php code that should be moved to the .rodata section. I remembered
1231 to update Builducptable as well, so it won't revert if ucptable.h is ever
1232 re-created.
1233
1234 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1235 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1236 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1237 support is not required. This saves 1.5-2K of code, which is important in
1238 some applications.
1239
1240 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1241 so as not to refer to the tables, even though these functions will never be
1242 called when UTF-8 support is disabled. Otherwise there are problems with a
1243 shared library.
1244
1245 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1246
1247 (a) It was defining its arguments as char * instead of void *.
1248
1249 (b) It was assuming that all moves were upwards in memory; this was true
1250 a long time ago when I wrote it, but is no longer the case.
1251
1252 The emulated memove() is provided for those environments that have neither
1253 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1254 is clearly not the case, as these two bugs were recently reported.
1255
1256 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1257 and Detrail to create the HTML documentation, the .txt form of the man
1258 pages, and it removes trailing spaces from listed files. It also creates
1259 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1260 case, it wraps all the #defines with #ifndefs. This script should be run
1261 before "make dist".
1262
1263 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1264 with Unicode property support.
1265
1266 (a) For a maximizing quantifier, if the two different cases of the
1267 character were of different lengths in their UTF-8 codings (there are
1268 some cases like this - I found 11), and the matching function had to
1269 back up over a mixture of the two cases, it incorrectly assumed they
1270 were both the same length.
1271
1272 (b) When PCRE was configured to use the heap rather than the stack for
1273 recursion during matching, it was not correctly preserving the data for
1274 the other case of a UTF-8 character when checking ahead for a match
1275 while processing a minimizing repeat. If the check also involved
1276 matching a wide character, but failed, corruption could cause an
1277 erroneous result when trying to check for a repeat of the original
1278 character.
1279
1280 13. Some tidying changes to the testing mechanism:
1281
1282 (a) The RunTest script now detects the internal link size and whether there
1283 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1284 values substituted by "configure". (The RunGrepTest script already did
1285 this for UTF-8.) The configure.ac script no longer substitutes the
1286 relevant variables.
1287
1288 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1289 with length and offset values. This means that the output is different
1290 for different internal link sizes. Test 2 is skipped for link sizes
1291 other than 2 because of this, bypassing the problem. Unfortunately,
1292 there was also a test in test 3 (the locale tests) that used /B and
1293 failed for link sizes other than 2. Rather than cut the whole test out,
1294 I have added a new /Z option to pcretest that replaces the length and
1295 offset values with spaces. This is now used to make test 3 independent
1296 of link size. (Test 2 will be tidied up later.)
1297
1298 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1299 segmentation fault instead of returning the appropriate error message.
1300
1301 15. In multiline mode when the newline sequence was set to "any", the pattern
1302 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1303 This doesn't seem right; it now treats the CRLF combination as the line
1304 ending, and so does not match in that case. It's only a pattern such as ^$
1305 that would hit this one: something like ^ABC$ would have failed after \r
1306 and then tried again after \r\n.
1307
1308 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1309 in an attempt to make files that differ only in their line terminators
1310 compare equal. This works on Linux.
1311
1312 17. Under certain error circumstances pcregrep might try to free random memory
1313 as it exited. This is now fixed, thanks to valgrind.
1314
1315 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1316 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1317 was because its rules for how to advance for /g after matching an empty
1318 string at the end of a line did not allow for this case. They now check for
1319 it specially.
1320
1321 20. pcretest is supposed to handle patterns and data of any length, by
1322 extending its buffers when necessary. It was getting this wrong when the
1323 buffer for a data line had to be extended.
1324
1325 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1326 CRLF as a newline sequence.
1327
1328 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1329 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1330 I have nevertheless tidied it up.
1331
1332 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1333
1334 24. Added a man page for pcre-config.
1335
1336
1337 Version 7.0 19-Dec-06
1338 ---------------------
1339
1340 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1341 moving to gcc 4.1.1.
1342
1343 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1344 sys/time.h, which is documented as needed for this function. It doesn't
1345 seem to matter on Linux, but it showed up on some releases of OS X.
1346
1347 3. It seems that there are systems where bytes whose values are greater than
1348 127 match isprint() in the "C" locale. The "C" locale should be the
1349 default when a C program starts up. In most systems, only ASCII printing
1350 characters match isprint(). This difference caused the output from pcretest
1351 to vary, making some of the tests fail. I have changed pcretest so that:
1352
1353 (a) When it is outputting text in the compiled version of a pattern, bytes
1354 other than 32-126 are always shown as hex escapes.
1355
1356 (b) When it is outputting text that is a matched part of a subject string,
1357 it does the same, unless a different locale has been set for the match
1358 (using the /L modifier). In this case, it uses isprint() to decide.
1359
1360 4. Fixed a major bug that caused incorrect computation of the amount of memory
1361 required for a compiled pattern when options that changed within the
1362 pattern affected the logic of the preliminary scan that determines the
1363 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1364 that the computed length was too small. The symptoms of this bug were
1365 either the PCRE error "internal error: code overflow" from pcre_compile(),
1366 or a glibc crash with a message such as "pcretest: free(): invalid next
1367 size (fast)". Examples of patterns that provoked this bug (shown in
1368 pcretest format) are:
1369
1370 /(?-x: )/x
1371 /(?x)(?-x: \s*#\s*)/
1372 /((?i)[\x{c0}])/8
1373 /(?i:[\x{c0}])/8
1374
1375 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1376 is now done differently.
1377
1378 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1379 wrapper classes; (b) implement a new function in the C++ scanner that is
1380 more efficient than the old way of doing things because it avoids levels of
1381 recursion in the regex matching; (c) add a paragraph to the documentation
1382 for the FullMatch() function.
1383
1384 6. The escape sequence \n was being treated as whatever was defined as
1385 "newline". Not only was this contrary to the documentation, which states
1386 that \n is character 10 (hex 0A), but it also went horribly wrong when
1387 "newline" was defined as CRLF. This has been fixed.
1388
1389 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1390 was being set to -1 for the "end of line" case (supposedly a value that no
1391 character can have). Though this value is never used (the check for end of
1392 line is "zero bytes in current character"), it caused compiler complaints.
1393 I've changed it to 0xffffffff.
1394
1395 8. In pcre_version.c, the version string was being built by a sequence of
1396 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1397 string (as it is for production releases) called a macro with an empty
1398 argument. The C standard says the result of this is undefined. The gcc
1399 compiler treats it as an empty string (which was what was wanted) but it is
1400 reported that Visual C gives an error. The source has been hacked around to
1401 avoid this problem.
1402
1403 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1404 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1405 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1406 of them did).
1407
1408 10. Originally, pcretest opened its input and output without "b"; then I was
1409 told that "b" was needed in some environments, so it was added for release
1410 5.0 to both the input and output. (It makes no difference on Unix-like
1411 systems.) Later I was told that it is wrong for the input on Windows. I've
1412 now abstracted the modes into two macros, to make it easier to fiddle with
1413 them, and removed "b" from the input mode under Windows.
1414
1415 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1416
1417 12. Added -help and --help to pcretest as an official way of being reminded
1418 of the options.
1419
1420 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1421 and pcrecpp.cc because they annoy compilers at high warning levels.
1422
1423 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1424
1425 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1426 scripts are not C programs :-) and which was not noticed because it works
1427 on Linux.
1428
1429 16. pcretest is supposed to handle any length of pattern and data line (as one
1430 line or as a continued sequence of lines) by extending its input buffer if
1431 necessary. This feature was broken for very long pattern lines, leading to
1432 a string of junk being passed to pcre_compile() if the pattern was longer
1433 than about 50K.
1434
1435 17. I have done a major re-factoring of the way pcre_compile() computes the
1436 amount of memory needed for a compiled pattern. Previously, there was code
1437 that made a preliminary scan of the pattern in order to do this. That was
1438 OK when PCRE was new, but as the facilities have expanded, it has become
1439 harder and harder to keep it in step with the real compile phase, and there
1440 have been a number of bugs (see for example, 4 above). I have now found a
1441 cunning way of running the real compile function in a "fake" mode that
1442 enables it to compute how much memory it would need, while actually only
1443 ever using a few hundred bytes of working memory and without too many
1444 tests of the mode. This should make future maintenance and development
1445 easier. A side effect of this work is that the limit of 200 on the nesting
1446 depth of parentheses has been removed (though this was never a serious
1447 limitation, I suspect). However, there is a downside: pcre_compile() now
1448 runs more slowly than before (30% or more, depending on the pattern). I
1449 hope this isn't a big issue. There is no effect on runtime performance.
1450
1451 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1452 newline (only possible for the last line of a file) and it was a
1453 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1454
1455 19. Added additional timing features to pcretest. (1) The -tm option now times
1456 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1457 separate command line item, by a number that specifies the number of
1458 repeats to use when timing. The default is 50000; this gives better
1459 precision, but takes uncomfortably long for very large patterns.
1460
1461 20. Extended pcre_study() to be more clever in cases where a branch of a
1462 subpattern has no definite first character. For example, (a*|b*)[cd] would
1463 previously give no result from pcre_study(). Now it recognizes that the
1464 first character must be a, b, c, or d.
1465
1466 21. There was an incorrect error "recursive call could loop indefinitely" if
1467 a subpattern (or the entire pattern) that was being tested for matching an
1468 empty string contained only one non-empty item after a nested subpattern.
1469 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1470 incorrectly, because the \d was being skipped in the check.
1471
1472 22. The pcretest program now has a new pattern option /B and a command line
1473 option -b, which is equivalent to adding /B to every pattern. This causes
1474 it to show the compiled bytecode, without the additional information that
1475 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1476 is the same as /B/I).
1477
1478 23. A new optimization is now able automatically to treat some sequences such
1479 as a*b as a*+b. More specifically, if something simple (such as a character
1480 or a simple class like \d) has an unlimited quantifier, and is followed by
1481 something that cannot possibly match the quantified thing, the quantifier
1482 is automatically "possessified".
1483
1484 24. A recursive reference to a subpattern whose number was greater than 39
1485 went wrong under certain circumstances in UTF-8 mode. This bug could also
1486 have affected the operation of pcre_study().
1487
1488 25. Realized that a little bit of performance could be had by replacing
1489 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1490
1491 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1492
1493 27. Possessive quantifiers such as a++ were previously implemented by turning
1494 them into atomic groups such as ($>a+). Now they have their own opcodes,
1495 which improves performance. This includes the automatically created ones
1496 from 23 above.
1497
1498 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1499 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1500 the first matched character to be a colon. This applied both to named and
1501 numbered groups.
1502
1503 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1504
1505 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1506 building PCRE on Windows easier, so I have included it in the distribution.
1507
1508 31. There is now a check in pcretest against a ridiculously large number being
1509 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1510 loop, the loop is abandoned.
1511
1512 32. Forward references to subpatterns in conditions such as (?(2)...) where
1513 subpattern 2 is defined later cause pcre_compile() to search forwards in
1514 the pattern for the relevant set of parentheses. This search went wrong
1515 when there were unescaped parentheses in a character class, parentheses
1516 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1517
1518 33. "Subroutine" calls and backreferences were previously restricted to
1519 referencing subpatterns earlier in the regex. This restriction has now
1520 been removed.
1521
1522 34. Added a number of extra features that are going to be in Perl 5.10. On the
1523 whole, these are just syntactic alternatives for features that PCRE had
1524 previously implemented using the Python syntax or my own invention. The
1525 other formats are all retained for compatibility.
1526
1527 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1528 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1529 also .NET compatible.
1530
1531 (b) A recursion or subroutine call to a named group can now be defined as
1532 (?&name) as well as (?P>name).
1533
1534 (c) A backreference to a named group can now be defined as \k<name> or
1535 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1536 5.10, are also .NET compatible.
1537
1538 (d) A conditional reference to a named group can now use the syntax
1539 (?(<name>) or (?('name') as well as (?(name).
1540
1541 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1542 groups (named and numbered) that are never evaluated inline, but can be
1543 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1544 is always false. There may be only one alternative in such a group.
1545
1546 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1547 as the simple (?(R). The condition is true only if the most recent
1548 recursion is that of the given number or name. It does not search out
1549 through the entire recursion stack.
1550
1551 (g) The escape \gN or \g{N} has been added, where N is a positive or
1552 negative number, specifying an absolute or relative reference.
1553
1554 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1555 some "unreachable code" warnings.
1556
1557 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1558 things, this adds five new scripts.
1559
1560 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1561 There were also incompatibilities regarding the handling of \Q..\E inside
1562 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1563 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1564
1565 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1566 matches an empty string, and forcibly breaks the loop. There were bugs in
1567 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1568 against aaaa the result was just "a" rather than "aaaa", for example. Two
1569 separate and independent bugs (that affected different cases) have been
1570 fixed.
1571
1572 39. Refactored the code to abolish the use of different opcodes for small
1573 capturing bracket numbers. This is a tidy that I avoided doing when I
1574 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1575 The new approach is not only tidier, it makes it possible to reduce the
1576 memory needed to fix the previous bug (38).
1577
1578 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1579 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1580 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1581 mode.
1582
1583 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1584 report.
1585
1586 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1587 copy construction and assignment in the C++ wrapper.
1588
1589 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1590 couple of bugs that could have given wrong results in the "--newline=crlf"
1591 case.
1592
1593 44. Added a number of casts and did some reorganization of signed/unsigned int
1594 variables following suggestions from Dair Grant. Also renamed the variable
1595 "this" as "item" because it is a C++ keyword.
1596
1597 45. Arranged for dftables to add
1598
1599 #include "pcre_internal.h"
1600
1601 to pcre_chartables.c because without it, gcc 4.x may remove the array
1602 definition from the final binary if PCRE is built into a static library and
1603 dead code stripping is activated.
1604
1605 46. For an unanchored pattern, if a match attempt fails at the start of a
1606 newline sequence, and the newline setting is CRLF or ANY, and the next two
1607 characters are CRLF, advance by two characters instead of one.
1608
1609
1610 Version 6.7 04-Jul-06
1611 ---------------------
1612
1613 1. In order to handle tests when input lines are enormously long, pcretest has
1614 been re-factored so that it automatically extends its buffers when
1615 necessary. The code is crude, but this _is_ just a test program. The
1616 default size has been increased from 32K to 50K.
1617
1618 2. The code in pcre_study() was using the value of the re argument before
1619 testing it for NULL. (Of course, in any sensible call of the function, it
1620 won't be NULL.)
1621
1622 3. The memmove() emulation function in pcre_internal.h, which is used on
1623 systems that lack both memmove() and bcopy() - that is, hardly ever -
1624 was missing a "static" storage class specifier.
1625
1626 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1627 containing an extended class (one that cannot be represented by a bitmap
1628 because it contains high-valued characters or Unicode property items, e.g.
1629 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1630 pattern, but PCRE should not loop if you do not (it no longer does).
1631 [Detail: two cases were found: (a) a repeated subpattern containing an
1632 extended class; (b) a recursive reference to a subpattern that followed a
1633 previous extended class. It wasn't skipping over the extended class
1634 correctly when UTF-8 mode was not set.]
1635
1636 5. A negated single-character class was not being recognized as fixed-length
1637 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1638 compile error "lookbehind assertion is not fixed length".
1639
1640 6. The RunPerlTest auxiliary script was showing an unexpected difference
1641 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1642 write a Perl script that can interpret lines of an input file either as
1643 byte characters or as UTF-8, which is what "perltest" was being required to
1644 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1645 can't do is switch easily at run time between having the "use utf8;" pragma
1646 or not. In the end, I fudged it by using the RunPerlTest script to insert
1647 "use utf8;" explicitly for the UTF-8 tests.
1648
1649 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1650 the end of the subject string, contrary to the documentation and to what
1651 Perl does. This was true of both matching functions. Now it matches only at
1652 the start of the subject and immediately after *internal* newlines.
1653
1654 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1655 a pointer to an int instead of a pointer to an unsigned long int. This
1656 caused problems on 64-bit systems.
1657
1658 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1659 instance of the 'standard' template library not being so standard".
1660
1661 10. There was no check on the number of named subpatterns nor the maximum
1662 length of a subpattern name. The product of these values is used to compute
1663 the size of the memory block for a compiled pattern. By supplying a very
1664 long subpattern name and a large number of named subpatterns, the size
1665 computation could be caused to overflow. This is now prevented by limiting
1666 the length of names to 32 characters, and the number of named subpatterns
1667 to 10,000.
1668
1669 11. Subpatterns that are repeated with specific counts have to be replicated in
1670 the compiled pattern. The size of memory for this was computed from the
1671 length of the subpattern and the repeat count. The latter is limited to
1672 65535, but there was no limit on the former, meaning that integer overflow
1673 could in principle occur. The compiled length of a repeated subpattern is
1674 now limited to 30,000 bytes in order to prevent this.
1675
1676 12. Added the optional facility to have named substrings with the same name.
1677
1678 13. Added the ability to use a named substring as a condition, using the
1679 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1680 are numbers (not recommended). Forward references are permitted.
1681
1682 14. Added forward references in named backreferences (if you see what I mean).
1683
1684 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1685 pattern could run off the end of the subject. For example, the pattern
1686 "(?s)(.{1,5})"8 did this with the subject "ab".
1687
1688 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1689 PCRE_CASELESS was set when matching characters that were quantified with ?
1690 or *.
1691
1692 17. A character class other than a single negated character that had a minimum
1693 but no maximum quantifier - for example [ab]{6,} - was not handled
1694 correctly by pce_dfa_exec(). It would match only one character.
1695
1696 18. A valid (though odd) pattern that looked like a POSIX character
1697 class but used an invalid character after [ (for example [[,abc,]]) caused
1698 pcre_compile() to give the error "Failed: internal error: code overflow" or
1699 in some cases to crash with a glibc free() error. This could even happen if
1700 the pattern terminated after [[ but there just happened to be a sequence of
1701 letters, a binary zero, and a closing ] in the memory that followed.
1702
1703 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1704 over the years. Originally (before any Unicode support), just the bottom 8
1705 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1706 output from "man perlunicode" includes this:
1707
1708 The regular expression compiler produces polymorphic opcodes. That
1709 is, the pattern adapts to the data and automatically switches to
1710 the Unicode character scheme when presented with Unicode data--or
1711 instead uses a traditional byte scheme when presented with byte
1712 data.
1713
1714 Sadly, a wide octal escape does not cause a switch, and in a string with
1715 no other multibyte characters, these octal escapes are treated as before.
1716 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1717 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1718 Unicode string.
1719
1720 I have not perpetrated such confusion in PCRE. Up till now, it took just
1721 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1722 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1723 translate to the appropriate multibyte character.
1724
1725 29. Applied some refactoring to reduce the number of warnings from Microsoft
1726 and Borland compilers. This has included removing the fudge introduced
1727 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1728 a warning about an unused variable.
1729
1730 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1731 characters since release 4.0, because Perl (from release 5.004) does not.
1732 [Or at least, is documented not to: some releases seem to be in conflict
1733 with the documentation.] However, when a pattern was studied with
1734 pcre_study() and all its branches started with \s, PCRE still included VT
1735 as a possible starting character. Of course, this did no harm; it just
1736 caused an unnecessary match attempt.
1737
1738 22. Removed a now-redundant internal flag bit that recorded the fact that case
1739 dependency changed within the pattern. This was once needed for "required
1740 byte" processing, but is no longer used. This recovers a now-scarce options
1741 bit. Also moved the least significant internal flag bit to the most-
1742 significant bit of the word, which was not previously used (hangover from
1743 the days when it was an int rather than a uint) to free up another bit for
1744 the future.
1745
1746 23. Added support for CRLF line endings as well as CR and LF. As well as the
1747 default being selectable at build time, it can now be changed at runtime
1748 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1749 specify that it is scanning data with non-default line endings.
1750
1751 24. Changed the definition of CXXLINK to make it agree with the definition of
1752 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1753
1754 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1755 recursions. This makes a big different to stack usage for some patterns.
1756
1757 26. If a subpattern containing a named recursion or subroutine reference such
1758 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1759 the space required for the compiled pattern went wrong and gave too small a
1760 value. Depending on the environment, this could lead to "Failed: internal
1761 error: code overflow at offset 49" or "glibc detected double free or
1762 corruption" errors.
1763
1764 27. Applied patches from Google (a) to support the new newline modes and (b) to
1765 advance over multibyte UTF-8 characters in GlobalReplace.
1766
1767 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1768 difference for some implementation of PCRE in some Windows version.
1769
1770 29. Added some extra testing facilities to pcretest:
1771
1772 \q<number> in a data line sets the "match limit" value
1773 \Q<number> in a data line sets the "match recursion limt" value
1774 -S <number> sets the stack size, where <number> is in megabytes
1775
1776 The -S option isn't available for Windows.
1777
1778
1779 Version 6.6 06-Feb-06
1780 ---------------------
1781
1782 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1783 in pcreposix.h. I have copied the definition from pcre.h.
1784
1785 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1786 because pcre.h is no longer a built file.
1787
1788 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1789 not normally included in the compiled code.
1790
1791
1792 Version 6.5 01-Feb-06
1793 ---------------------
1794
1795 1. When using the partial match feature with pcre_dfa_exec(), it was not
1796 anchoring the second and subsequent partial matches at the new starting
1797 point. This could lead to incorrect results. For example, with the pattern
1798 /1234/, partially matching against "123" and then "a4" gave a match.
1799
1800 2. Changes to pcregrep:
1801
1802 (a) All non-match returns from pcre_exec() were being treated as failures
1803 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1804 error message is output. Some extra information is given for the
1805 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1806 probably the only errors that are likely to be caused by users (by
1807 specifying a regex that has nested indefinite repeats, for instance).
1808 If there are more than 20 of these errors, pcregrep is abandoned.
1809
1810 (b) A binary zero was treated as data while matching, but terminated the
1811 output line if it was written out. This has been fixed: binary zeroes
1812 are now no different to any other data bytes.
1813
1814 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1815 used to set a locale for matching. The --locale=xxxx long option has
1816 been added (no short equivalent) to specify a locale explicitly on the
1817 pcregrep command, overriding the environment variables.
1818
1819 (d) When -B was used with -n, some line numbers in the output were one less
1820 than they should have been.
1821
1822 (e) Added the -o (--only-matching) option.
1823
1824 (f) If -A or -C was used with -c (count only), some lines of context were
1825 accidentally printed for the final match.
1826
1827 (g) Added the -H (--with-filename) option.
1828
1829 (h) The combination of options -rh failed to suppress file names for files
1830 that were found from directory arguments.
1831
1832 (i) Added the -D (--devices) and -d (--directories) options.
1833
1834 (j) Added the -F (--fixed-strings) option.
1835
1836 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1837
1838 (l) Added the --colo(u)r option.
1839
1840 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1841 is not present by default.
1842
1843 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1844 items such as (?R) or (?1), when the recursion could match a number of
1845 alternatives. If it matched one of the alternatives, but subsequently,
1846 outside the recursion, there was a failure, the code tried to back up into
1847 the recursion. However, because of the way PCRE is implemented, this is not
1848 possible, and the result was an incorrect result from the match.
1849
1850 In order to prevent this happening, the specification of recursion has
1851 been changed so that all such subpatterns are automatically treated as
1852 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1853
1854 4. I had overlooked the fact that, in some locales, there are characters for
1855 which isalpha() is true but neither isupper() nor islower() are true. In
1856 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1857 and ordfeminine) are like this. This affected the treatment of \w and \W
1858 when they appeared in character classes, but not when they appeared outside
1859 a character class. The bit map for "word" characters is now created
1860 separately from the results of isalnum() instead of just taking it from the
1861 upper, lower, and digit maps. (Plus the underscore character, of course.)
1862
1863 5. The above bug also affected the handling of POSIX character classes such as
1864 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1865 permanent tables. Instead, the bit maps for such a class were previously
1866 created as the appropriate unions of the upper, lower, and digit bitmaps.
1867 Now they are created by subtraction from the [[:word:]] class, which has
1868 its own bitmap.
1869
1870 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1871 It is created by subtracting the vertical space characters (\x09, \x0a,
1872 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1873 subtraction was done in the overall bitmap for a character class, meaning
1874 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1875 be recognized. This bug has been fixed.
1876
1877 7. Patches from the folks at Google:
1878
1879 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1880 real life, but is still worth protecting against".
1881
1882 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1883 regular expressions".
1884
1885 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1886 have it.
1887
1888 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1889 "configure" and the latter not, in order to fix a problem somebody had
1890 with compiling the Arg class on HP-UX.
1891
1892 (e) Improve the error-handling of the C++ wrapper a little bit.
1893
1894 (f) New tests for checking recursion limiting.
1895
1896 8. The pcre_memmove() function, which is used only if the environment does not
1897 have a standard memmove() function (and is therefore rarely compiled),
1898 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1899 returning a result (though PCRE never actually uses the result).
1900
1901 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1902 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1903 returned instead of calling malloc() with an overflowing number that would
1904 most likely cause subsequent chaos.
1905
1906 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1907
1908 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1909 with this option is matched, the nmatch and pmatch options of regexec() are
1910 ignored.
1911
1912 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1913 provided in case anyone wants to the the POSIX interface with UTF-8
1914 strings.
1915
1916 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1917 C++ linking (needed for some HP-UX environments).
1918
1919 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1920 (unused parameter) and in the pcre_printint() function (omitted "default"
1921 switch label when the default is to do nothing).
1922
1923 15. Added some code to make it possible, when PCRE is compiled as a C++
1924 library, to replace subject pointers for pcre_exec() with a smart pointer
1925 class, thus making it possible to process discontinuous strings.
1926
1927 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1928 much the same function. They were added by different people who were trying
1929 to make PCRE easy to compile on non-Unix systems. It has been suggested
1930 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1931 for compiling on Windows systems. I have therefore replaced it with
1932 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1933 defaults to "extern" for C or "extern C" for C++, which works fine on
1934 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1935 SCOPE with something explicit in config.h. In addition:
1936
1937 (a) pcreposix.h still had just "extern" instead of either of these macros;
1938 I have replaced it with PCRE_DATA_SCOPE.
1939
1940 (b) Functions such as _pcre_xclass(), which are internal to the library,
1941 but external in the C sense, all had PCRE_EXPORT in their definitions.
1942 This is apparently wrong for the Windows case, so I have removed it.
1943 (It makes no difference on Unix-like systems.)
1944
1945 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1946 of recursive calls to match(). This is different to MATCH_LIMIT because
1947 that limits the total number of calls to match(), not all of which increase
1948 the depth of recursion. Limiting the recursion depth limits the amount of
1949 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1950 when PCRE is compiled, and changed at run time. A patch from Google adds
1951 this functionality to the C++ interface.
1952
1953 18. Changes to the handling of Unicode character properties:
1954
1955 (a) Updated the table to Unicode 4.1.0.
1956
1957 (b) Recognize characters that are not in the table as "Cn" (undefined).
1958
1959 (c) I revised the way the table is implemented to a much improved format
1960 which includes recognition of ranges. It now supports the ranges that
1961 are defined in UnicodeData.txt, and it also amalgamates other
1962 characters into ranges. This has reduced the number of entries in the
1963 table from around 16,000 to around 3,000, thus reducing its size
1964 considerably. I realized I did not need to use a tree structure after
1965 all - a binary chop search is just as efficient. Having reduced the
1966 number of entries, I extended their size from 6 bytes to 8 bytes to
1967 allow for more data.
1968
1969 (d) Added support for Unicode script names via properties such as \p{Han}.
1970
1971 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1972 matching that character.
1973
1974 20. When matching a repeated Unicode property with a minimum greater than zero,
1975 (for example \pL{2,}), PCRE could look past the end of the subject if it
1976 reached it while seeking the minimum number of characters. This could
1977 happen only if some of the characters were more than one byte long, because
1978 there is a check for at least the minimum number of bytes.
1979
1980 21. Refactored the implementation of \p and \P so as to be more general, to
1981 allow for more different types of property in future. This has changed the
1982 compiled form incompatibly. Anybody with saved compiled patterns that use
1983 \p or \P will have to recompile them.
1984
1985 22. Added "Any" and "L&" to the supported property types.
1986
1987 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1988 but give a compile time error if the value is greater than 0xff.
1989
1990 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1991 accidentally not being installed or uninstalled.
1992
1993 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1994 made were to insert the current release number. This seemed silly, because
1995 it made things harder for people building PCRE on systems that don't run
1996 "configure". I have turned pcre.h into a distributed file, no longer built
1997 by "configure", with the version identification directly included. There is
1998 no longer a pcre.h.in file.
1999
2000 However, this change necessitated a change to the pcre-config script as
2001 well. It is built from pcre-config.in, and one of the substitutions was the
2002 release number. I have updated configure.ac so that ./configure now finds
2003 the release number by grepping pcre.h.
2004
2005 26. Added the ability to run the tests under valgrind.
2006
2007
2008 Version 6.4 05-Sep-05
2009 ---------------------
2010
2011 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2012 "--" to be printed when multiple files were scanned, even when none of the
2013 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2014 consider it to be a bug, and have restored the previous behaviour.
2015
2016 2. A couple of code tidies to get rid of compiler warnings.
2017
2018 3. The pcretest program used to cheat by referring to symbols in the library
2019 whose names begin with _pcre_. These are internal symbols that are not
2020 really supposed to be visible externally, and in some environments it is
2021 possible to suppress them. The cheating is now confined to including
2022 certain files from the library's source, which is a bit cleaner.
2023
2024 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2025 file's purpose clearer.
2026
2027 5. Reorganized pcre_ucp_findchar().
2028
2029
2030 Version 6.3 15-Aug-05
2031 ---------------------
2032
2033 1. The file libpcre.pc.in did not have general read permission in the tarball.
2034
2035 2. There were some problems when building without C++ support:
2036
2037 (a) If C++ support was not built, "make install" and "make test" still
2038 tried to test it.
2039
2040 (b) There were problems when the value of CXX was explicitly set. Some
2041 changes have been made to try to fix these, and ...
2042
2043 (c) --disable-cpp can now be used to explicitly disable C++ support.
2044
2045 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2046 backslash in a target when C++ was disabled. This confuses some
2047 versions of "make", apparently. Using an intermediate variable solves
2048 this. (Same for CPP_LOBJ.)
2049
2050 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2051 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2052 necessary on certain architectures.
2053
2054 4. Added a setting of -export-symbols-regex to the link command to remove
2055 those symbols that are exported in the C sense, but actually are local
2056 within the library, and not documented. Their names all begin with
2057 "_pcre_". This is not a perfect job, because (a) we have to except some
2058 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2059 available (and never for static libraries). I have made a note to try to
2060 find a way round (a) in the future.
2061
2062
2063 Version 6.2 01-Aug-05
2064 ---------------------
2065
2066 1. There was no test for integer overflow of quantifier values. A construction
2067 such as {1111111111111111} would give undefined results. What is worse, if
2068 a minimum quantifier for a parenthesized subpattern overflowed and became
2069 negative, the calculation of the memory size went wrong. This could have
2070 led to memory overwriting.
2071
2072 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2073
2074 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2075 operating environments where this matters.
2076
2077 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2078 PCRE options from within the C++ wrapper.
2079
2080 5. Named capturing subpatterns were not being correctly counted when a pattern
2081 was compiled. This caused two problems: (a) If there were more than 100
2082 such subpatterns, the calculation of the memory needed for the whole
2083 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2084 back references of the form \12, where the number was greater than 9, were
2085 not recognized as back references, even though there were sufficient
2086 previous subpatterns.
2087
2088 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2089 versions of gcc, e.g. 2.95.4.
2090
2091
2092 Version 6.1 21-Jun-05
2093 ---------------------
2094
2095 1. There was one reference to the variable "posix" in pcretest.c that was not
2096 surrounded by "#if !defined NOPOSIX".
2097
2098 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2099 the cross-check on the old pcre_info() function, for the benefit of the
2100 cut-down version of PCRE that is currently imported into Exim.
2101
2102 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2103 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2104 patterns that start (?i) but I don't think that matters. The use of (?i) is
2105 just an example; this all applies to the other options as well.
2106
2107 4. Since libtool seems to echo the compile commands it is issuing, the output
2108 from "make" can be reduced a bit by putting "@" in front of each libtool
2109 compile command.
2110
2111 5. Patch from the folks at Google for configure.in to be a bit more thorough
2112 in checking for a suitable C++ installation before trying to compile the
2113 C++ stuff. This should fix a reported problem when a compiler was present,
2114 but no suitable headers.
2115
2116 6. The man pages all had just "PCRE" as their title. I have changed them to
2117 be the relevant file name. I have also arranged that these names are
2118 retained in the file doc/pcre.txt, which is a concatenation in text format
2119 of all the man pages except the little individual ones for each function.
2120
2121 7. The NON-UNIX-USE file had not been updated for the different set of source
2122 files that come with release 6. I also added a few comments about the C++
2123 wrapper.
2124
2125
2126 Version 6.0 07-Jun-05
2127 ---------------------
2128
2129 1. Some minor internal re-organization to help with my DFA experiments.
2130
2131 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2132 didn't matter for the library itself when fully configured, but did matter
2133 when compiling without UCP support, or within Exim, where the ucp files are
2134 not imported.
2135
2136 3. Refactoring of the library code to split up the various functions into
2137 different source modules. The addition of the new DFA matching code (see
2138 below) to a single monolithic source would have made it really too
2139 unwieldy, quite apart from causing all the code to be include in a
2140 statically linked application, when only some functions are used. This is
2141 relevant even without the DFA addition now that patterns can be compiled in
2142 one application and matched in another.
2143
2144 The downside of splitting up is that there have to be some external
2145 functions and data tables that are used internally in different modules of
2146 the library but which are not part of the API. These have all had their
2147 names changed to start with "_pcre_" so that they are unlikely to clash
2148 with other external names.
2149
2150 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2151 a different (DFA) algorithm. Although it is slower than the original
2152 function, it does have some advantages for certain types of matching
2153 problem.
2154
2155 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2156 including restarting after a partial match.
2157
2158 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2159 defined when compiling for Windows was sent to me. I have put it into the
2160 code, though I have no means of testing or verifying it.
2161
2162 7. Added the pcre_refcount() auxiliary function.
2163
2164 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2165 match before or at the first newline in the subject string. In pcretest,
2166 the /f option on a pattern can be used to set this.
2167
2168 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2169 would behave wrongly. This has been present in PCRE since release 4.0.
2170
2171 10. A number of changes to the pcregrep command:
2172
2173 (a) Refactored how -x works; insert ^(...)$ instead of setting
2174 PCRE_ANCHORED and checking the length, in preparation for adding
2175 something similar for -w.
2176
2177 (b) Added the -w (match as a word) option.
2178
2179 (c) Refactored the way lines are read and buffered so as to have more
2180 than one at a time available.
2181
2182 (d) Implemented a pcregrep test script.
2183
2184 (e) Added the -M (multiline match) option. This allows patterns to match
2185 over several lines of the subject. The buffering ensures that at least
2186 8K, or the rest of the document (whichever is the shorter) is available
2187 for matching (and similarly the previous 8K for lookbehind assertions).
2188
2189 (f) Changed the --help output so that it now says
2190
2191 -w, --word-regex(p)
2192
2193 instead of two lines, one with "regex" and the other with "regexp"
2194 because that confused at least one person since the short forms are the
2195 same. (This required a bit of code, as the output is generated
2196 automatically from a table. It wasn't just a text change.)
2197
2198 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2199 option but starts with a hyphen. Could be a pattern or a path name
2200 starting with a hyphen, for instance.
2201
2202 (h) "-" can be given as a file name to represent stdin.
2203
2204 (i) When file names are being printed, "(standard input)" is used for
2205 the standard input, for compatibility with GNU grep. Previously
2206 "<stdin>" was used.
2207
2208 (j) The option --label=xxx can be used to supply a name to be used for
2209 stdin when file names are being printed. There is no short form.
2210
2211 (k) Re-factored the options decoding logic because we are going to add
2212 two more options that take data. Such options can now be given in four
2213 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2214
2215 (l) Added the -A, -B, and -C options for requesting that lines of context
2216 around matches be printed.
2217
2218 (m) Added the -L option to print the names of files that do not contain
2219 any matching lines, that is, the complement of -l.
2220
2221 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2222 continue to scan other files.
2223
2224 (o) The -s option was incorrectly implemented. For compatibility with other
2225 greps, it now suppresses the error message for a non-existent or non-
2226 accessible file (but not the return code). There is a new option called
2227 -q that suppresses the output of matching lines, which was what -s was
2228 previously doing.
2229
2230 (p) Added --include and --exclude options to specify files for inclusion
2231 and exclusion when recursing.
2232
2233 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2234 Hopefully, it now does.
2235
2236 12. Missing cast in pcre_study().
2237
2238 13. Added an "uninstall" target to the makefile.
2239
2240 14. Replaced "extern" in the function prototypes in Makefile.in with
2241 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2242 world, but is set differently for Windows.
2243
2244 15. Added a second compiling function called pcre_compile2(). The only
2245 difference is that it has an extra argument, which is a pointer to an
2246 integer error code. When there is a compile-time failure, this is set
2247 non-zero, in addition to the error test pointer being set to point to an
2248 error message. The new argument may be NULL if no error number is required
2249 (but then you may as well call pcre_compile(), which is now just a
2250 wrapper). This facility is provided because some applications need a
2251 numeric error indication, but it has also enabled me to tidy up the way
2252 compile-time errors are handled in the POSIX wrapper.
2253
2254 16. Added VPATH=.libs to the makefile; this should help when building with one
2255 prefix path and installing with another. (Or so I'm told by someone who
2256 knows more about this stuff than I do.)
2257
2258 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2259 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2260 match everything, including newlines. This is not POSIX-compatible, but
2261 somebody wanted the feature. From pcretest it can be activated by using
2262 both the P and the s flags.
2263
2264 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2265
2266 19. libpcre.pc was being incorrectly installed as executable.
2267
2268 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2269 it now also looks for '\r' so that it will work unmodified on Windows.
2270
2271 21. Added Google's contributed C++ wrapper to the distribution.
2272
2273 22. Added some untidy missing memory free() calls in pcretest, to keep
2274 Electric Fence happy when testing.
2275
2276
2277
2278 Version 5.0 13-Sep-04
2279 ---------------------
2280
2281 1. Internal change: literal characters are no longer packed up into items
2282 containing multiple characters in a single byte-string. Each character
2283 is now matched using a separate opcode. However, there may be more than one
2284 byte in the character in UTF-8 mode.
2285
2286 2. The pcre_callout_block structure has two new fields: pattern_position and
2287 next_item_length. These contain the offset in the pattern to the next match
2288 item, and its length, respectively.
2289
2290 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2291 insertion of callouts before each pattern item. Added the /C option to
2292 pcretest to make use of this.
2293
2294 4. On the advice of a Windows user, the lines
2295
2296 #if defined(_WIN32) || defined(WIN32)
2297 _setmode( _fileno( stdout ), 0x8000 );
2298 #endif /* defined(_WIN32) || defined(WIN32) */
2299
2300 have been added to the source of pcretest. This apparently does useful
2301 magic in relation to line terminators.
2302
2303 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2304 for the benefit of those environments where the "b" makes a difference.
2305
2306 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2307 to know about it. I have put a hack into configure.in that adds in code
2308 to set GCC=yes if CC=icc. This seems to end up at a point in the
2309 generated configure script that is early enough to affect the setting of
2310 compiler options, which is what is needed, but I have no means of testing
2311 whether it really works. (The user who reported this had patched the
2312 generated configure script, which of course I cannot do.)
2313
2314 LATER: After change 22 below (new libtool files), the configure script
2315 seems to know about icc (and also ecc). Therefore, I have commented out
2316 this hack in configure.in.
2317
2318 7. Added support for pkg-config (2 patches were sent in).
2319
2320 8. Negated POSIX character classes that used a combination of internal tables
2321 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2322 [[:^ascii]]. Typically, they would match almost any characters. The other
2323 POSIX classes were not broken in this way.
2324
2325 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2326 to find the match, as PCRE was deluded into thinking that the match had to
2327 start at the start point or following a newline. The same bug applied to
2328 patterns with negative forward assertions or any backward assertions
2329 preceding ".*" at the start, unless the pattern required a fixed first
2330 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2331
2332 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2333 starting at the last subject character, bytes beyond the end of the subject
2334 string were read.
2335
2336 11. Renamed the variable "class" as "classbits" to make life easier for C++
2337 users. (Previously there was a macro definition, but it apparently wasn't
2338 enough.)
2339
2340 12. Added the new field "tables" to the extra data so that tables can be passed
2341 in at exec time, or the internal tables can be re-selected. This allows
2342 a compiled regex to be saved and re-used at a later time by a different
2343 program that might have everything at different addresses.
2344
2345 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2346 -R library as well as a -L library.
2347
2348 14. The debugging options of pcretest (-d on the command line or D on a
2349 pattern) showed incorrect output for anything following an extended class
2350 that contained multibyte characters and which was followed by a quantifier.
2351
2352 15. Added optional support for general category Unicode character properties
2353 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2354 support. It adds about 90K to the size of the library. The meanings of the
2355 inbuilt class escapes such as \d and \s have NOT been changed.
2356
2357 16. Updated pcredemo.c to include calls to free() to release the memory for the
2358 compiled pattern.
2359
2360 17. The generated file chartables.c was being created in the source directory
2361 instead of in the building directory. This caused the build to fail if the
2362 source directory was different from the building directory, and was
2363 read-only.
2364
2365 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2366 file. No doubt somebody will tell me if they don't make sense... Also added
2367 Dan Mooney's comments about building on OpenVMS.
2368
2369 19. Added support for partial matching via the PCRE_PARTIAL option for
2370 pcre_exec() and the \P data escape in pcretest.
2371
2372 20. Extended pcretest with 3 new pattern features:
2373
2374 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2375 write the compiled pattern to the file whose name is "rest-of-line".
2376 This is a straight binary dump of the data, with the saved pointer to
2377 the character tables forced to be NULL. The study data, if any, is
2378 written too. After writing, pcretest reads a new pattern.
2379
2380 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2381 compiled pattern from the given file. There must not be any
2382 occurrences of "<" in the file name (pretty unlikely); if there are,
2383 pcretest will instead treat the initial "<" as a pattern delimiter.
2384 After reading in the pattern, pcretest goes on to read data lines as
2385 usual.
2386
2387 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2388 and 16-bit fields in a compiled pattern, to simulate a pattern that
2389 was compiled on a host of opposite endianness.
2390
2391 21. The pcre-exec() function can now cope with patterns that were compiled on
2392 hosts of opposite endianness, with this restriction:
2393
2394 As for any compiled expression that is saved and used later, the tables
2395 pointer field cannot be preserved; the extra_data field in the arguments
2396 to pcre_exec() should be used to pass in a tables address if a value
2397 other than the default internal tables were used at compile time.
2398
2399 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2400 now diagnosed as an error. Previously, most of the time, a negative number
2401 would have been treated as zero, but if in addition "ovector" was passed as
2402 NULL, a crash could occur.
2403
2404 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2405 new versions from the libtool 1.5 distribution (the last one is a copy of
2406 a file called libtool.m4). This seems to have fixed the need to patch
2407 "configure" to support Darwin 1.3 (which I used to do). However, I still
2408 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2409 workstation).
2410
2411 24. Changed the PCRE licence to be the more standard "BSD" licence.
2412
2413
2414 Version 4.5 01-Dec-03
2415 ---------------------
2416
2417 1. There has been some re-arrangement of the code for the match() function so
2418 that it can be compiled in a version that does not call itself recursively.
2419 Instead, it keeps those local variables that need separate instances for
2420 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2421 needs to "recurse". Keeping track of where control must go is done by means
2422 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2423 hide most of the details from the main code, and operates only if
2424 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2425 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2426 operating.
2427
2428 To make it easier for callers to provide specially tailored get/free
2429 functions for this usage, two new functions, pcre_stack_malloc, and
2430 pcre_stack_free, are used. They are always called in strict stacking order,
2431 and the size of block requested is always the same.
2432
2433 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2434 PCRE has been compiled to use the stack or the heap for recursion. The
2435 -C option of pcretest uses this to show which version is compiled.
2436
2437 A new data escape \S, is added to pcretest; it causes the amounts of store
2438 obtained and freed by both kinds of malloc/free at match time to be added
2439 to the output.
2440
2441 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2442 what's available on my current Linux desktop machine.
2443
2444 3. When matching a UTF-8 string, the test for a valid string at the start has
2445 been extended. If start_offset is not zero, PCRE now checks that it points
2446 to a byte that is the start of a UTF-8 character. If not, it returns
2447 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2448 this is necessary because there may be backward assertions in the pattern.
2449 When matching the same subject several times, it may save resources to use
2450 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2451
2452 4. The code for checking the validity of UTF-8 strings has been tightened so
2453 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2454 containing "overlong sequences".
2455
2456 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2457 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2458 should have been "&", but it just so happened that all the cases this let
2459 through by mistake were picked up later in the function.
2460
2461 6. I had used a variable called "isblank" - this is a C99 function, causing
2462 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2463
2464 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2465 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2466 so the version is shown; (c) stop "make test" echoing "./RunTest".
2467
2468 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2469
2470 9. The prototype for memmove() for systems that don't have it was using
2471 size_t, but the inclusion of the header that defines size_t was later. I've
2472 moved the #includes for the C headers earlier to avoid this.
2473
2474 10. Added some adjustments to the code to make it easier to compiler on certain
2475 special systems:
2476
2477 (a) Some "const" qualifiers were missing.
2478 (b) Added the macro EXPORT before all exported functions; by default this
2479 is defined to be empty.
2480 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2481 that it reads its output file name as an argument instead of writing
2482 to the standard output and assuming this can be redirected.
2483
2484 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2485 class containing characters with values greater than 255, PCRE compilation
2486 went into a loop.
2487
2488 12. A recursive reference to a subpattern that was within another subpattern
2489 that had a minimum quantifier of zero caused PCRE to crash. For example,
2490 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2491 recursion. If the recursively-called subpattern itself had a zero repeat,
2492 that was OK.
2493
2494 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2495 buffer into which it was copied (for escape processing) was still set at
2496 1024, so long lines caused crashes.
2497
2498 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2499 "internal error: code overflow...". This applied to any character class
2500 that was followed by a possessive quantifier.
2501
2502 15. Modified the Makefile to add libpcre.la as a prerequisite for
2503 libpcreposix.la because I was told this is needed for a parallel build to
2504 work.
2505
2506 16. If a pattern that contained .* following optional items at the start was
2507 studied, the wrong optimizing data was generated, leading to matching
2508 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2509 matching string must start with a or b or c. The correct conclusion for
2510 this pattern is that a match can start with any character.
2511
2512
2513 Version 4.4 13-Aug-03
2514 ---------------------
2515
2516 1. In UTF-8 mode, a character class containing characters with values between
2517 127 and 255 was not handled correctly if the compiled pattern was studied.
2518 In fixing this, I have also improved the studying algorithm for such
2519 classes (slightly).
2520
2521 2. Three internal functions had redundant arguments passed to them. Removal
2522 might give a very teeny performance improvement.
2523
2524 3. Documentation bug: the value of the capture_top field in a callout is *one
2525 more than* the number of the hightest numbered captured substring.
2526
2527 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2528 in incorrectly linking with a previously installed version. They now link
2529 explicitly with libpcre.la.
2530
2531 5. configure.in no longer needs to recognize Cygwin specially.
2532
2533 6. A problem in pcre.in for Windows platforms is fixed.
2534
2535 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2536 pcretest, it used to include the size of the study block as part of its
2537 output. Unfortunately, the structure contains a field that has a different
2538 size on different hardware architectures. This meant that the tests that
2539 showed this size failed. As the block is currently always of a fixed size,
2540 this information isn't actually particularly useful in pcretest output, so
2541 I have just removed it.
2542
2543 8. Three pre-processor statements accidentally did not start in column 1.
2544 Sadly, there are *still* compilers around that complain, even though
2545 standard C has not required this for well over a decade. Sigh.
2546
2547 9. In pcretest, the code for checking callouts passed small integers in the
2548 callout_data field, which is a void * field. However, some picky compilers
2549 complained about the casts involved for this on 64-bit systems. Now
2550 pcretest passes the address of the small integer instead, which should get
2551 rid of the warnings.
2552
2553 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2554 both compile and run time, and gives an error if an invalid UTF-8 sequence
2555 is found. There is a option for disabling this check in cases where the
2556 string is known to be correct and/or the maximum performance is wanted.
2557
2558 11. In response to a bug report, I changed one line in Makefile.in from
2559
2560 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2561 to
2562 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2563
2564 to look similar to other lines, but I have no way of telling whether this
2565 is the right thing to do, as I do not use Windows. No doubt I'll get told
2566 if it's wrong...
2567
2568
2569 Version 4.3 21-May-03
2570 ---------------------
2571
2572 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2573 Makefile.
2574
2575 2. Some refactoring to improve the quality of the code:
2576
2577 (i) The utf8_table... variables are now declared "const".
2578
2579 (ii) The code for \cx, which used the "case flipping" table to upper case
2580 lower case letters, now just substracts 32. This is ASCII-specific,
2581 but the whole concept of \cx is ASCII-specific, so it seems
2582 reasonable.
2583
2584 (iii) PCRE was using its character types table to recognize decimal and
2585 hexadecimal digits in the pattern. This is silly, because it handles
2586 only 0-9, a-f, and A-F, but the character types table is locale-
2587 specific, which means strange things might happen. A private
2588 table is now used for this - though it costs 256 bytes, a table is
2589 much faster than multiple explicit tests. Of course, the standard
2590 character types table is still used for matching digits in subject
2591 strings against \d.
2592
2593 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2594 ending in _t are). So I've renamed it as ESC_tee.
2595
2596 3. The first argument for regexec() in the POSIX wrapper should have been
2597 defined as "const".
2598
2599 4. Changed pcretest to use malloc() for its buffers so that they can be
2600 Electric Fenced for debugging.
2601
2602 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2603 to read one or more bytes before the start of the subject string. Often this
2604 had no effect on PCRE's behaviour, but in some circumstances it could
2605 provoke a segmentation fault.
2606
2607 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2608 to try to read one or more bytes before the start of the subject string.
2609
2610 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2611 UTF-8 support could misbehave in various ways if the subject string
2612 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2613 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2614 back over UTF-8 characters.)
2615
2616
2617 Version 4.2 14-Apr-03
2618 ---------------------
2619
2620 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2621
2622 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2623 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2624 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2625 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2626 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2627 and BUILD_EXEEXT
2628 Note: automatic setting of the BUILD variables is not yet working
2629 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2630 compile-time but not at link-time
2631 [LINK]: use for linking executables only
2632 make different versions for Windows and non-Windows
2633 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2634 libraries
2635 [LINK_FOR_BUILD]: new variable
2636 [OBJEXT]: use throughout
2637 [EXEEXT]: use throughout
2638 <winshared>: new target
2639 <wininstall>: new target
2640 <dftables.o>: use native compiler
2641 <dftables>: use native linker
2642 <install>: handle Windows platform correctly
2643 <clean>: ditto
2644 <check>: ditto
2645 copy DLL to top builddir before testing
2646
2647 As part of these changes, -no-undefined was removed again. This was reported
2648 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2649 in any case.
2650
2651 3. Some tidies to get rid of compiler warnings:
2652
2653 . In the match_data structure, match_limit was an unsigned long int, whereas
2654 match_call_count was an int. I've made them both unsigned long ints.
2655
2656 . In pcretest the fact that a const uschar * doesn't automatically cast to
2657 a void * provoked a warning.
2658
2659 . Turning on some more compiler warnings threw up some "shadow" variables
2660 and a few more missing casts.
2661
2662 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2663 option, a class that contained a single character with a value between 128
2664 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2665
2666 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2667 option, a class that contained several characters, but with at least one
2668 whose value was between 128 and 255 caused PCRE to crash.
2669
2670
2671 Version 4.1 12-Mar-03
2672 ---------------------
2673
2674 1. Compiling with gcc -pedantic found a couple of places where casts were
2675 needed, and a string in dftables.c that was longer than standard compilers are
2676 required to support.
2677
2678 2. Compiling with Sun's compiler found a few more places where the code could
2679 be tidied up in order to avoid warnings.
2680
2681 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2682 first of these names is deprecated in the latest Autoconf in favour of the name
2683 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2684 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2685 analogy I have changed it to CFLAGS_FOR_BUILD.
2686
2687 4. Added -no-undefined to the linking command in the Makefile, because this is
2688 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2689 linking step for the pcreposix library.
2690
2691 5. PCRE was failing to diagnose the case of two named groups with the same
2692 name.
2693
2694 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2695 literal character that is needed in the subject for a match, and scans along to
2696 ensure that it is present before embarking on the full matching process. This
2697 saves time in cases of nested unlimited repeats that are never going to match.
2698 Problem: the scan can take a lot of time if the subject is very long (e.g.
2699 megabytes), thus penalizing straightforward matches. It is now done only if the
2700 amount of subject to be scanned is less than 1000 bytes.
2701
2702 7. A lesser problem with the same optimization is that it was recording the
2703 first character of an anchored pattern as "needed", thus provoking a search
2704 right along the subject, even when the first match of the pattern was going to
2705 fail. The "needed" character is now not set for anchored patterns, unless it
2706 follows something in the pattern that is of non-fixed length. Thus, it still
2707 fulfils its original purpose of finding quick non-matches in cases of nested
2708 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2709
2710
2711 Version 4.0 17-Feb-03
2712 ---------------------
2713
2714 1. If a comment in an extended regex that started immediately after a meta-item
2715 extended to the end of string, PCRE compiled incorrect data. This could lead to
2716 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2717
2718 2. Moved to autoconf 2.53 and libtool 1.4.2.
2719
2720 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2721 the special perltest8 script is no longer needed - all the tests can be run
2722 from a single perltest script.
2723
2724 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2725 by \s. It has now been removed in PCRE. This means it isn't recognized as
2726 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2727 class [:space:] *does* include VT, thereby creating a mess.
2728
2729 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2730 space and tab.
2731
2732 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2733 its new features into the main test script, reducing the number of scripts.
2734
2735 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2736 were backward compatible, and made the (?i) apply to the whole pattern, as if
2737 /i were given. Now it behaves more logically, and applies the option setting
2738 only to what follows. PCRE has been changed to follow suit. However, if it
2739 finds options settings right at the start of the pattern, it extracts them into
2740 the global options, as before. Thus, they show up in the info data.
2741
2742 8. Added support for the \Q...\E escape sequence. Characters in between are
2743 treated as literals. This is slightly different from Perl in that $ and @ are
2744 also handled as literals inside the quotes. In Perl, they will cause variable
2745 interpolation. Note the following examples:
2746
2747 Pattern PCRE matches Perl matches
2748
2749 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2750 \Qabc\$xyz\E abc\$xyz abc\$xyz
2751 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2752
2753 For compatibility with Perl, \Q...\E sequences are recognized inside character
2754 classes as well as outside them.
2755
2756 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2757 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2758 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2759 signed/unsigned warnings.
2760
2761 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2762 option for pcretest, so I've replaced it by a simple function that does just
2763 that job.
2764
2765 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2766 "pcregrep -".
2767
2768 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2769 Java package. This provides some syntactic sugar for simple cases of what my
2770 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2771 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2772 item, you can use this simplified notation. Note that only makes sense with
2773 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2774 greediness, whatever the setting of the PCRE_UNGREEDY option.
2775
2776 13. A change of greediness default within a pattern was not taking effect at
2777 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2778 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2779 was abstracted outside.
2780
2781 14. PCRE now supports the \G assertion. It is true when the current matching
2782 position is at the start point of the match. This differs from \A when the
2783 starting offset is non-zero. Used with the /g option of pcretest (or similar
2784 code), it works in the same way as it does for Perl's /g option. If all
2785 alternatives of a regex begin with \G, the expression is anchored to the start
2786 match position, and the "anchored" flag is set in the compiled expression.
2787
2788 15. Some bugs concerning the handling of certain option changes within patterns
2789 have been fixed. These applied to options other than (?ims). For example,
2790 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2791 been the other way round. Some of this was related to change 7 above.
2792
2793 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2794 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2795 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2796 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2797
2798 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2799 mode. Unlike ".", it always matches newline, whatever the setting of
2800 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2801 assertions. Perl allows it, but it doesn't (in general) work because it can't
2802 calculate the length of the lookbehind. At least, that's the case for Perl
2803 5.8.0 - I've been told they are going to document that it doesn't work in
2804 future.
2805
2806 18. Added an error diagnosis for escapes that PCRE does not support: these are
2807 \L, \l, \N, \P, \p, \U, \u, and \X.
2808
2809 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2810 reading past the end of the pattern in cases such as /[abcd/.
2811
2812 20. PCRE was getting more memory than necessary for patterns with classes that
2813 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2814
2815 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2816 compiling PCRE for use with Virtual Pascal.
2817
2818 22. Small fix to the Makefile to make it work properly if the build is done
2819 outside the source tree.
2820
2821 23. Added a new extension: a condition to go with recursion. If a conditional
2822 subpattern starts with (?(R) the "true" branch is used if recursion has
2823 happened, whereas the "false" branch is used only at the top level.
2824
2825 24. When there was a very long string of literal characters (over 255 bytes
2826 without UTF support, over 250 bytes with UTF support), the computation of how
2827 much memory was required could be incorrect, leading to segfaults or other
2828 strange effects.
2829
2830 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2831 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2832 there was a subsequent back reference to those brackets. This meant that, for
2833 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2834 possible to check for precisely this case. All we can do is abandon the
2835 optimization if .* occurs inside capturing brackets when there are any back
2836 references whatsoever. (See below for a better fix that came later.)
2837
2838 26. The handling of the optimization for finding the first character of a
2839 non-anchored pattern, and for finding a character that is required later in the
2840 match were failing in some cases. This didn't break the matching; it just
2841 failed to optimize when it could. The way this is done has been re-implemented.
2842
2843 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2844
2845 28. Added a new feature that provides some of the functionality that Perl
2846 provides with (?{...}). The facility is termed a "callout". The way it is done
2847 in PCRE is for the caller to provide an optional function, by setting
2848 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2849 global variable. By default it is unset, which disables all calling out. To get
2850 the function called, the regex must include (?C) at appropriate points. This
2851 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2852 This provides a means of identifying different callout points. When PCRE
2853 reaches such a point in the regex, if pcre_callout has been set, the external
2854 function is called. It is provided with data in a structure called
2855 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2856 matching continues; if it returns a non-zero value, the match at the current
2857 point fails. However, backtracking will occur if possible. [This was changed
2858 later and other features added - see item 49 below.]
2859
2860 29. pcretest is upgraded to test the callout functionality. It provides a
2861 callout function that displays information. By default, it shows the start of
2862 the match and the current position in the text. There are some new data escapes
2863 to vary what happens:
2864
2865 \C+ in addition, show current contents of captured substrings
2866 \C- do not supply a callout function
2867 \C!n return 1 when callout number n is reached
2868 \C!n!m return 1 when callout number n is reached for the mth time
2869
2870 30. If pcregrep was called with the -l option and just a single file name, it
2871 output "<stdin>" if a match was found, instead of the file name.
2872
2873 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2874 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2875 pcre_exec(). This saves a malloc/free per call. The default value of
2876 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2877 when configuring.
2878
2879 32. The default maximum size of a compiled pattern is 64K. There have been a
2880 few cases of people hitting this limit. The code now uses macros to handle the
2881 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2882 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2883 configuring. Tests 2 and 5 work only with 2-byte links because they output
2884 debugging information about compiled patterns.
2885
2886 33. Internal code re-arrangements:
2887
2888 (a) Moved the debugging function for printing out a compiled regex into
2889 its own source file (printint.c) and used #include to pull it into
2890 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2891 separate copies.
2892
2893 (b) Defined the list of op-code names for debugging as a macro in
2894 internal.h so that it is next to the definition of the opcodes.
2895
2896 (c) Defined a table of op-code lengths for simpler skipping along compiled
2897 code. This is again a macro in internal.h so that it is next to the
2898 definition of the opcodes.
2899
2900 34. Added support for recursive calls to individual subpatterns, along the
2901 lines of Robin Houston's patch (but implemented somewhat differently).
2902
2903 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2904 allow it to read and process whole directories in Win32. This code was
2905 contributed by Lionel Fourquaux; it has not been tested by me.
2906
2907 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2908 used to name a group. Names consist of alphanumerics and underscores, and must
2909 be unique. Back references use the syntax (?P=name) and recursive calls use
2910 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2911 numbers. The function pcre_fullinfo() can be used after compilation to extract
2912 a name/number map. There are three relevant calls:
2913
2914 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2915 PCRE_INFO_NAMECOUNT yields the number of entries
2916 PCRE_INFO_NAMETABLE yields a pointer to the map.
2917
2918 The map is a vector of fixed-size entries. The size of each entry depends on
2919 the length of the longest name used. The first two bytes of each entry are the
2920 group number, most significant byte first. There follows the corresponding
2921 name, zero terminated. The names are in alphabetical order.
2922
2923 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2924 case instead of 255. Making it the same both with and without UTF-8 support
2925 means that the same test output works with both.
2926
2927 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2928 calling malloc() with a zero argument.
2929
2930 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2931 optimization. I've improved things by keeping a bitmap of backreferences with
2932 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2933 fact referenced, the optimization can be applied. It is unlikely that a
2934 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2935 the match to follow \n) will appear inside brackets with a number greater than
2936 31, but if it does, any back reference > 31 suppresses the optimization.
2937
2938 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2939 of disabling numbered capturing parentheses. Any opening parenthesis that is
2940 not followed by ? behaves as if it were followed by ?: but named parentheses
2941 can still be used for capturing (and they will acquire numbers in the usual
2942 way).
2943
2944 41. Redesigned the return codes from the match() function into yes/no/error so
2945 that errors can be passed back from deep inside the nested calls. A malloc
2946 failure while inside a recursive subpattern call now causes the
2947 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2948
2949 42. It is now possible to set a limit on the number of times the match()
2950 function is called in a call to pcre_exec(). This facility makes it possible to
2951 limit the amount of recursion and backtracking, though not in a directly
2952 obvious way, because the match() function is used in a number of different
2953 circumstances. The count starts from zero for each position in the subject
2954 string (for non-anchored patterns). The default limit is, for compatibility, a
2955 large number, namely 10 000 000. You can change this in two ways:
2956
2957 (a) When configuring PCRE before making, you can use --with-match-limit=n
2958 to set a default value for the compiled library.
2959
2960 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2961 a different value is set. See 45 below.
2962
2963 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2964
2965 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2966 of things that can be changed at compile time. The first argument specifies
2967 what is wanted and the second points to where the information is to be placed.
2968 The current list of available information is:
2969
2970 PCRE_CONFIG_UTF8
2971
2972 The output is an integer that is set to one if UTF-8 support is available;
2973 otherwise it is set to zero.
2974
2975 PCRE_CONFIG_NEWLINE
2976
2977 The output is an integer that it set to the value of the code that is used for
2978 newline. It is either LF (10) or CR (13).
2979
2980 PCRE_CONFIG_LINK_SIZE
2981
2982 The output is an integer that contains the number of bytes used for internal
2983 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2984
2985 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2986
2987 The output is an integer that contains the threshold above which the POSIX
2988 interface uses malloc() for output vectors. See item 31 above.
2989
2990 PCRE_CONFIG_MATCH_LIMIT
2991
2992 The output is an unsigned integer that contains the default limit of the number
2993 of match() calls in a pcre_exec() execution. See 42 above.
2994
2995 44. pcretest has been upgraded by the addition of the -C option. This causes it
2996 to extract all the available output from the new pcre_config() function, and to
2997 output it. The program then exits immediately.
2998
2999 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3000 order to support additional features. One way would have been to define
3001 pcre_exec2() (for example) with extra arguments, but this would not have been
3002 extensible, and would also have required all calls to the original function to
3003 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3004 is used for passing in "extra" data from pcre_study().
3005
3006 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3007 contains the following fields:
3008
3009 flags a bitmap indicating which of the following fields are set
3010 study_data opaque data from pcre_study()
3011 match_limit a way of specifying a limit on match() calls for a specific
3012 call to pcre_exec()
3013 callout_data data for callouts (see 49 below)
3014
3015 The flag bits are also defined in pcre.h, and are
3016
3017 PCRE_EXTRA_STUDY_DATA
3018 PCRE_EXTRA_MATCH_LIMIT
3019 PCRE_EXTRA_CALLOUT_DATA
3020
3021 The pcre_study() function now returns one of these new pcre_extra blocks, with
3022 the actual study data pointed to by the study_data field, and the
3023 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3024 before. That is, this change is entirely upwards-compatible and requires no
3025 change to existing code.
3026
3027 If you want to pass in additional data to pcre_exec(), you can either place it
3028 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3029 block.
3030
3031 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3032 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3033 times with different match limits, until it finds the minimum value needed for
3034 pcre_exec() to complete. The value is then output. This can be instructive; for
3035 most simple matches the number is quite small, but for pathological cases it
3036 gets very large very quickly.
3037
3038 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3039 returns the size of the data block pointed to by the study_data field in a
3040 pcre_extra block, that is, the value that was passed as the argument to
3041 pcre_malloc() when PCRE was getting memory in which to place the information
3042 created by pcre_study(). The fourth argument should point to a size_t variable.
3043 pcretest has been extended so that this information is shown after a successful
3044 pcre_study() call when information about the compiled regex is being displayed.
3045
3046 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3047 because what follows is always an absolute path. (Later: it turns out that this
3048 is more than cosmetic for MinGW, because it doesn't like empty path
3049 components.)
3050
3051 49. Some changes have been made to the callout feature (see 28 above):
3052
3053 (i) A callout function now has three choices for what it returns:
3054
3055 0 => success, carry on matching
3056 > 0 => failure at this point, but backtrack if possible
3057 < 0 => serious error, return this value from pcre_exec()
3058
3059 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3060 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3061 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3062 use by callout functions. It will never be used by PCRE itself.
3063
3064 (ii) The pcre_extra structure (see 45 above) has a void * field called
3065 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3066 pcre_callout_block structure has a field of the same name. The contents of
3067 the field passed in the pcre_extra structure are passed to the callout
3068 function in the corresponding field in the callout block. This makes it
3069 easier to use the same callout-containing regex from multiple threads. For
3070 testing, the pcretest program has a new data escape
3071
3072 \C*n pass the number n (may be negative) as callout_data
3073
3074 If the callout function in pcretest receives a non-zero value as
3075 callout_data, it returns that value.
3076
3077 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3078 there were some redundant $(CFLAGS) in commands that are now specified as
3079 $(LINK), which already includes $(CFLAGS).
3080
3081 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3082 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3083 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3084 one-byte characters throughout. Note that case-insensitive matching applies
3085 only to characters whose values are less than 256. PCRE doesn't support the
3086 notion of cases for higher-valued characters.
3087
3088 (i) A character class whose characters are all within 0-255 is handled as
3089 a bit map, and the map is inverted for negative classes. Previously, a
3090 character > 255 always failed to match such a class; however it should
3091 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3092
3093 (ii) A negated character class with a single character < 255 is coded as
3094 "not this character" (OP_NOT). This wasn't working properly when the test
3095 character was multibyte, either singly or repeated.
3096
3097 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3098 mode, for example: \x{100}{2,3}.
3099
3100 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3101 singly or repeated) now correctly test multibyte characters. However,
3102 PCRE doesn't recognize any characters with values greater than 255 as
3103 digits, spaces, or word characters. Such characters always match \D, \S,
3104 and \W, and never match \d, \s, or \w.
3105
3106 (v) Classes may now contain characters and character ranges with values
3107 greater than 255. For example: [ab\x{100}-\x{400}].
3108
3109 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3110 PCRE in UTF-8 mode.
3111
3112 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3113 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3114 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3115 value.)
3116
3117 53. The single man page has become too large. I have therefore split it up into
3118 a number of separate man pages. These also give rise to individual HTML pages;
3119 these are now put in a separate directory, and there is an index.html page that
3120 lists them all. Some hyperlinking between the pages has been installed.
3121
3122 54. Added convenience functions for handling named capturing parentheses.
3123
3124 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3125 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3126 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3127 are faulted.
3128
3129 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3130 calling configure. These values are used when compiling the dftables.c program
3131 which is run to generate the source of the default character tables. They
3132 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3133 you will need to set these values.
3134
3135 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3136
3137
3138 Version 3.9 02-Jan-02
3139 ---------------------
3140
3141 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3142
3143 2. If --disable-static was given, the building process failed when trying to
3144 build pcretest and pcregrep. (For some reason it was using libtool to compile
3145 them, which is not right, as they aren't part of the library.)
3146
3147
3148 Version 3.8 18-Dec-01
3149 ---------------------
3150
3151 1. The experimental UTF-8 code was completely screwed up. It was packing the
3152 bytes in the wrong order. How dumb can you get?
3153
3154
3155 Version 3.7 29-Oct-01
3156 ---------------------
3157
3158 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3159 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3160 this didn't happen under Solaris 8, where I normally test things.
3161
3162 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3163 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3164 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3165 this fix an hour or so after the initial 3.7 release.)
3166
3167
3168 Version 3.6 23-Oct-01
3169 ---------------------
3170
3171 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3172 offsets passed as NULL with zero offset count.
3173
3174 2. The config.guess and config.sub files had not been updated when I moved to
3175 the latest autoconf.
3176
3177
3178 Version 3.5 15-Aug-01
3179 ---------------------
3180
3181 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3182 had been forgotten.
3183
3184 2. By using declared but undefined structures, we can avoid using "void"
3185 definitions in pcre.h while keeping the internal definitions of the structures
3186 private.
3187
3188 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3189 user point of view, this means that both static and shared libraries are built
3190 by default, but this can be individually controlled. More of the work of
3191 handling this static/shared cases is now inside libtool instead of PCRE's make
3192 file.
3193
3194 4. The pcretest utility is now installed along with pcregrep because it is
3195 useful for users (to test regexs) and by doing this, it automatically gets
3196 relinked by libtool. The documentation has been turned into a man page, so
3197 there are now .1, .txt, and .html versions in /doc.
3198
3199 5. Upgrades to pcregrep:
3200 (i) Added long-form option names like gnu grep.
3201 (ii) Added --help to list all options with an explanatory phrase.
3202 (iii) Added -r, --recursive to recurse into sub-directories.
3203 (iv) Added -f, --file to read patterns from a file.
3204
3205 6. pcre_exec() was referring to its "code" argument before testing that
3206 argument for NULL (and giving an error if it was NULL).
3207
3208 7. Upgraded Makefile.in to allow for compiling in a different directory from
3209 the source directory.
3210
3211 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3212 options bits, the pointer it was passed was to an int instead of to an unsigned
3213 long int. This mattered only on 64-bit systems.
3214
3215 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3216 generated) instead of pcre.in, which it its source. Also made the same change
3217 in several of the .c files.
3218
3219 10. A new release of gcc defines printf() as a macro, which broke pcretest
3220 because it had an ifdef in the middle of a string argument for printf(). Fixed
3221 by using separate calls to printf().
3222
3223 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3224 script, to force use of CR or LF instead of \n in the source. On non-Unix
3225 systems, the value can be set in config.h.
3226
3227 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3228 absolute limit. Changed the text of the error message to make this clear, and
3229 likewise updated the man page.
3230
3231 13. The limit of 99 on the number of capturing subpatterns has been removed.
3232 The new limit is 65535, which I hope will not be a "real" limit.
3233
3234
3235 Version 3.4 22-Aug-00
3236 ---------------------
3237
3238 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3239
3240 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3241
3242
3243 Version 3.3 01-Aug-00
3244 ---------------------
3245
3246 1. If an octal character was given, but the value was greater than \377, it
3247 was not getting masked to the least significant bits, as documented. This could
3248 lead to crashes in some systems.
3249
3250 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3251 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3252
3253 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3254 These just pass their arguments on to (pcre_free)(), but they are provided
3255 because some uses of PCRE bind it to non-C systems that can call its functions,
3256 but cannot call free() or pcre_free() directly.
3257
3258 4. Add "make test" as a synonym for "make check". Corrected some comments in
3259 the Makefile.
3260
3261 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3262 Makefile.
3263
3264 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3265 command called pgrep for grepping around the active processes.
3266
3267 7. Added the beginnings of support for UTF-8 character strings.
3268
3269 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3270 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3271 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3272 out for the ar command.)
3273
3274
3275 Version 3.2 12-May-00
3276 ---------------------
3277
3278 This is purely a bug fixing release.
3279
3280 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3281 of ZA. This was just one example of several cases that could provoke this bug,
3282 which was introduced by change 9 of version 2.00. The code for breaking
3283 infinite loops after an iteration that matches an empty string was't working
3284 correctly.
3285
3286 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3287 when matched against abbab (for example). After matching an empty string, it
3288 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3289 caused it to match further down the string than it should.
3290
3291 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3292 was there because it doesn't seem to be needed, and it causes trouble on some
3293 systems, as it is not a Standard C header. It has been removed.
3294
3295 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3296 were reported on the Macintosh. The changes were from
3297
3298 while ((c = *(++ptr)) != 0 && c != '\n');
3299 to
3300 while ((c = *(++ptr)) != 0 && c != '\n') ;
3301
3302 Totally extraordinary, but if that's what it takes...
3303
3304 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3305 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3306 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3307 assumes the way PCRE uses memmove() (always moving upwards).
3308
3309 6. PCRE is being used in one environment where strchr() is not available. There
3310 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3311 faster code anyway.
3312
3313
3314 Version 3.1 09-Feb-00
3315 ---------------------
3316
3317 The only change in this release is the fixing of some bugs in Makefile.in for
3318 the "install" target:
3319
3320 (1) It was failing to install pcreposix.h.
3321
3322 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3323
3324
3325 Version 3.0 01-Feb-00
3326 ---------------------
3327
3328 1. Add support for the /+ modifier to perltest (to output $` like it does in
3329 pcretest).
3330
3331 2. Add support for the /g modifier to perltest.
3332
3333 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3334 matches null strings.
3335
3336 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3337 pattern. Perl treats empty patterns specially - it reuses the most recent
3338 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3339 effect.
3340
3341 5. The POSIX interface was broken in that it was just handing over the POSIX
3342 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3343 required a bigger vector, with some working space on the end. This means that
3344 the POSIX wrapper now has to get and free some memory, and copy the results.
3345
3346 6. Added some simple autoconf support, placing the test data and the
3347 documentation in separate directories, re-organizing some of the
3348 information files, and making it build pcre-config (a GNU standard). Also added
3349 libtool support for building PCRE as a shared library, which is now the
3350 default.
3351
3352 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3353 09 are not valid octal constants. Single digits will be used for minor values
3354 less than 10.
3355
3356 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3357 existing programs that set these in the POSIX interface can use PCRE without
3358 modification.
3359
3360 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3361 return all that pcre_info() returns, plus additional data. The pcre_info()
3362 function is retained for compatibility, but is considered to be obsolete.
3363
3364 10. Added experimental recursion feature (?R) to handle one common case that
3365 Perl 5.6 will be able to do with (?p{...}).
3366
3367 11. Added support for POSIX character classes like [:alpha:], which Perl is
3368 adopting.
3369
3370
3371 Version 2.08 31-Aug-99
3372 ----------------------
3373
3374 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3375 trying to match at the startoffset position, but instead was moving forward to
3376 the next newline as if a previous match had failed.
3377
3378 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3379 and could get into a loop if a null string was matched other than at the start
3380 of the subject.
3381
3382 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3383 be distinguished at compile time, and for completeness also added PCRE_DATE.
3384
3385 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3386 in GnuWin32 environments.
3387
3388
3389 Version 2.07 29-Jul-99
3390 ----------------------
3391
3392 1. The documentation is now supplied in plain text form and HTML as well as in
3393 the form of man page sources.
3394
3395 2. C++ compilers don't like assigning (void *) values to other pointer types.
3396 In particular this affects malloc(). Although there is no problem in Standard
3397 C, I've put in casts to keep C++ compilers happy.
3398
3399 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3400 should be (const char *).
3401
3402 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3403 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3404 However, I haven't made this a standard facility. The documentation doesn't
3405 mention it, and the Makefile doesn't support it.
3406
3407 5. The Makefile now contains an "install" target, with editable destinations at
3408 the top of the file. The pcretest program is not installed.
3409
3410 6. pgrep -V now gives the PCRE version number and date.
3411
3412 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3413 causing the entire string to be ignored, instead of just the last character.
3414
3415 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3416 non-matching string, it can take a very, very long time, even for strings of
3417 quite modest length, because of the nested recursion. PCRE now does better in
3418 some of these cases. It does this by remembering the last required literal
3419 character in the pattern, and pre-searching the subject to ensure it is present
3420 before running the real match. In other words, it applies a heuristic to detect
3421 some types of certain failure quickly, and in the above example, if presented
3422 with a string that has no trailing " it gives "no match" very quickly.
3423
3424 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3425 other alternatives are tried instead.
3426
3427
3428 Version 2.06 09-Jun-99
3429 ----------------------
3430
3431 1. Change pcretest's output for amount of store used to show just the code
3432 space, because the remainder (the data block) varies in size between 32-bit and
3433 64-bit systems.
3434
3435 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3436 start matching at. This allows lookbehinds to work when searching for multiple
3437 occurrences in a string.
3438
3439 3. Added additional options to pcretest for testing multiple occurrences:
3440
3441 /+ outputs the rest of the string that follows a match
3442 /g loops for multiple occurrences, using the new startoffset argument
3443 /G loops for multiple occurrences by passing an incremented pointer
3444
3445 4. PCRE wasn't doing the "first character" optimization for patterns starting
3446 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3447 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3448 the letter 'x'. On long subject strings, this gives a significant speed-up.
3449
3450
3451 Version 2.05 21-Apr-99
3452 ----------------------
3453
3454 1. Changed the type of magic_number from int to long int so that it works
3455 properly on 16-bit systems.
3456
3457 2. Fixed a bug which caused patterns starting with .* not to work correctly
3458 when the subject string contained newline characters. PCRE was assuming
3459 anchoring for such patterns in all cases, which is not correct because .* will
3460 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3461 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3462 must be retried after every newline in the subject.
3463
3464
3465 Version 2.04 18-Feb-99
3466 ----------------------
3467
3468 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3469 computation of the store needed to hold the pattern was incorrect (too large).
3470 If such patterns were nested a few deep, this could multiply and become a real
3471 problem.
3472
3473 2. Added /M option to pcretest to show the memory requirement of a specific
3474 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3475
3476 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3477 compiled in such a way that the backtracking after subsequent failure was
3478 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3479 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3480
3481
3482 Version 2.03 02-Feb-99
3483 ----------------------
3484
3485 1. Fixed typo and small mistake in man page.
3486
3487 2. Added 4th condition (GPL supersedes if conflict) and created separate
3488 LICENCE file containing the conditions.
3489
3490 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3491 Perl, that is the internal \ allows the delimiter to be included in the
3492 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3493 the final delimiter, add \ to the end of the pattern (to test the error).
3494
3495 4. Added the convenience functions for extracting substrings after a successful
3496 match. Updated pcretest to make it able to test these functions.
3497
3498
3499 Version 2.02 14-Jan-99
3500 ----------------------
3501
3502 1. Initialized the working variables associated with each extraction so that
3503 their saving and restoring doesn't refer to uninitialized store.
3504
3505 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3506 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3507 fix the problem.
3508
3509 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3510 calls, and wasn't printing the correct value for compiling calls. Increased the
3511 default value of LOOPREPEAT, and the number of significant figures in the
3512 times.
3513
3514 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3515
3516 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3517 a building problem on Windows NT with a FAT file system.
3518
3519
3520 Version 2.01 21-Oct-98
3521 ----------------------
3522
3523 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3524 to character tables built by pcre_maketables() in the current locale. If NULL
3525 is passed, the default tables are used.
3526
3527
3528 Version 2.00 24-Sep-98
3529 ----------------------
3530
3531 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3532 it any more.
3533
3534 2. Allow quantification of (?>) groups, and make it work correctly.
3535
3536 3. The first character computation wasn't working for (?>) groups.
3537
3538 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3539 end of the subject) and add 5.005's \z, which really does match only at the
3540 very end of the subject.
3541
3542 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3543
3544 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3545 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3546 localized options. All options to pcre_study() were also removed.
3547
3548 7. Add other new features from 5.005:
3549
3550 $(?<= positive lookbehind
3551 $(?<! negative lookbehind
3552 (?imsx-imsx) added the unsetting capability
3553 such a setting is global if at outer level; local otherwise
3554 (?imsx-imsx:) non-capturing groups with option setting
3555 (?(cond)re|re) conditional pattern matching
3556
3557 A backreference to itself in a repeated group matches the previous
3558 captured string.
3559
3560 8. General tidying up of studying (both automatic and via "study")
3561 consequential on the addition of new assertions.
3562
3563 9. As in 5.005, unlimited repeated groups that could match an empty substring
3564 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3565 runtime if any iteration does actually match an empty substring.
3566
3567 10. Include the RunTest script in the distribution.
3568
3569 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3570 discrepancies, some of which were old and were also with respect to 5.004. They
3571 have now been fixed.
3572
3573
3574 Version 1.09 28-Apr-98
3575 ----------------------
3576
3577 1. A negated single character class followed by a quantifier with a minimum
3578 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3579 program crashes, or just wrong answers. This did not apply to negated classes
3580 containing more than one character, or to minima other than one.
3581
3582
3583 Version 1.08 27-Mar-98
3584 ----------------------
3585
3586 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3587
3588 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3589 latter must appear before anything that relies on it in the pattern.
3590
3591
3592 Version 1.07 16-Feb-98
3593 ----------------------
3594
3595 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3596 repeat of a potentially empty string).
3597
3598
3599 Version 1.06 23-Jan-98
3600 ----------------------
3601
3602 1. Added Markus Oberhumer's little patches for C++.
3603
3604 2. Literal strings longer than 255 characters were broken.
3605
3606
3607 Version 1.05 23-Dec-97
3608 ----------------------
3609
3610 1. Negated character classes containing more than one character were failing if
3611 PCRE_CASELESS was set at run time.
3612
3613
3614 Version 1.04 19-Dec-97
3615 ----------------------
3616
3617 1. Corrected the man page, where some "const" qualifiers had been omitted.
3618
3619 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3620 input syntax.
3621
3622 3. Fixed memory leak which occurred when a regex with back references was
3623 matched with an offsets vector that wasn't big enough. The temporary memory
3624 that is used in this case wasn't being freed if the match failed.
3625
3626 4. Tidied pcretest to ensure it frees memory that it gets.
3627
3628 5. Temporary memory was being obtained in the case where the passed offsets
3629 vector was exactly big enough.
3630
3631 6. Corrected definition of offsetof() from change 5 below.
3632
3633 7. I had screwed up change 6 below and broken the rules for the use of
3634 setjmp(). Now fixed.
3635
3636
3637 Version 1.03 18-Dec-97
3638 ----------------------
3639
3640 1. A erroneous regex with a missing opening parenthesis was correctly
3641 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3642 on some systems.
3643
3644 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3645 it was reported that one broken compiler failed on the former because "code" is
3646 also an independent variable.
3647
3648 3. The erroneous regex a[]b caused an array overrun reference.
3649
3650 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3651 fail on data ending with that character. (It was going on too far, and checking
3652 the next character, typically a binary zero.) This was specific to the
3653 optimized code for single-character negative classes.
3654
3655 5. Added a contributed patch from the TIN world which does the following:
3656
3657 + Add an undef for memmove, in case the the system defines a macro for it.
3658
3659 + Add a definition of offsetof(), in case there isn't one. (I don't know
3660 the reason behind this - offsetof() is part of the ANSI standard - but
3661 it does no harm).
3662
3663 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3664 most of the places where whitespace preceded '#'. I have given up and
3665 allowed the remaining 2 cases to be at the margin.
3666
3667 + Rename some variables in pcre to eliminate shadowing. This seems very
3668 pedantic, but does no harm, of course.
3669
3670 6. Moved the call to setjmp() into its own function, to get rid of warnings
3671 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3672
3673 7. Constructs such as \d{8,} were compiling into the equivalent of
3674 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3675 outcome, but in this particular case used more store than had been allocated,
3676 which caused the bug to be discovered because it threw up an internal error.
3677
3678 8. The debugging code in both pcre and pcretest for outputting the compiled
3679 form of a regex was going wrong in the case of back references followed by
3680 curly-bracketed repeats.
3681
3682
3683 Version 1.02 12-Dec-97
3684 ----------------------
3685
3686 1. Typos in pcre.3 and comments in the source fixed.
3687
3688 2. Applied a contributed patch to get rid of places where it used to remove
3689 'const' from variables, and fixed some signed/unsigned and uninitialized
3690 variable warnings.
3691
3692 3. Added the "runtest" target to Makefile.
3693
3694 4. Set default compiler flag to -O2 rather than just -O.
3695
3696
3697 Version 1.01 19-Nov-97
3698 ----------------------
3699
3700 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3701 like /([ab]*)*/, that is, for classes with more than one character in them.
3702
3703 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3704 as /((?>a*))*/ (a PCRE_EXTRA facility).
3705
3706
3707 Version 1.00 18-Nov-97
3708 ----------------------
3709
3710 1. Added compile-time macros to support systems such as SunOS4 which don't have
3711 memmove() or strerror() but have other things that can be used instead.
3712
3713 2. Arranged that "make clean" removes the executables.
3714
3715
3716 Version 0.99 27-Oct-97
3717 ----------------------
3718
3719 1. Fixed bug in code for optimizing classes with only one character. It was
3720 initializing a 32-byte map regardless, which could cause it to run off the end
3721 of the memory it had got.
3722
3723 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3724
3725
3726 Version 0.98 22-Oct-97
3727 ----------------------
3728
3729 1. Fixed bug in code for handling temporary memory usage when there are more
3730 back references than supplied space in the ovector. This could cause segfaults.
3731
3732
3733 Version 0.97 21-Oct-97
3734 ----------------------
3735
3736 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3737
3738 2. Optimized negated single characters not to use a bit map.
3739
3740 3. Brought error texts together as macro definitions; clarified some of them;
3741 fixed one that was wrong - it said "range out of order" when it meant "invalid
3742 escape sequence".
3743
3744 4. Changed some char * arguments to const char *.
3745
3746 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3747
3748 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3749 pcretest.
3750
3751
3752 Version 0.96 16-Oct-97
3753 ----------------------
3754
3755 1. Added a simple "pgrep" utility to the distribution.
3756
3757 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3758 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3759 where "ddd" means "one or more decimal digits".
3760
3761 3. Fixed serious bug. If a pattern had a back reference, but the call to
3762 pcre_exec() didn't supply a large enough ovector to record the related
3763 identifying subpattern, the match always failed. PCRE now remembers the number
3764 of the largest back reference, and gets some temporary memory in which to save
3765 the offsets during matching if necessary, in order to ensure that
3766 backreferences always work.
3767
3768 4. Increased the compatibility with Perl in a number of ways:
3769
3770 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3771 to request this handling. The option can be set at compile or exec time.
3772
3773 (b) $ matches before a terminating newline by default; an option
3774 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3775 mode). The option can be set at compile or exec time.
3776
3777 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3778 the same as Perl's. If the decimal number it represents is less than 10
3779 or there aren't that many previous left capturing parentheses, an octal
3780 escape is read. Inside a character class, it's always an octal escape,
3781 even if it is a single digit.
3782
3783 (d) An escaped but undefined alphabetic character is taken as a literal,
3784 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3785 escapes.
3786
3787 (e) {0} is now permitted. (The previous item is removed from the compiled
3788 pattern).
3789
3790 5. Changed all the names of code files so that the basic parts are no longer
3791 than 10 characters, and abolished the teeny "globals.c" file.
3792
3793 6. Changed the handling of character classes; they are now done with a 32-byte
3794 bit map always.
3795
3796 7. Added the -d and /D options to pcretest to make it possible to look at the
3797 internals of compilation without having to recompile pcre.
3798
3799
3800 Version 0.95 23-Sep-97
3801 ----------------------
3802
3803 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3804 \x20 at the start of a run of normal characters. These were being treated as
3805 real characters, instead of the source characters being re-checked.
3806
3807
3808 Version 0.94 18-Sep-97
3809 ----------------------
3810
3811 1. The functions are now thread-safe, with the caveat that the global variables
3812 containing pointers to malloc() and free() or alternative functions are the
3813 same for all threads.
3814
3815 2. Get pcre_study() to generate a bitmap of initial characters for non-
3816 anchored patterns when this is possible, and use it if passed to pcre_exec().
3817
3818
3819 Version 0.93 15-Sep-97
3820 ----------------------
3821
3822 1. /(b)|(:+)/ was computing an incorrect first character.
3823
3824 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3825 but not actually doing anything yet.
3826
3827 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3828 as Perl does (e.g. [-az] or [az-]).
3829
3830 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3831 all possible positions.
3832
3833 5. Split up into different modules to avoid including unneeded functions in a
3834 compiled binary. However, compile and exec are still in one module. The "study"
3835 function is split off.
3836
3837 6. The character tables are now in a separate module whose source is generated
3838 by an auxiliary program - but can then be edited by hand if required. There are
3839 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3840 toupper() in the code.
3841
3842 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3843 make them global. Abolish the function for setting them, as the caller can now
3844 set them directly.
3845
3846
3847 Version 0.92 11-Sep-97
3848 ----------------------
3849
3850 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3851 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3852
3853 2. Caseless matching was not working in character classes if the characters in
3854 the pattern were in upper case.
3855
3856 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3857
3858 4. Make PCRE_ANCHORED public and accept as a compile option.
3859
3860 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3861 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3862 pass them.
3863
3864 6. Give an error if bad option bits passed at compile or run time.
3865
3866 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3867 pcretest to cause it to pass that flag.
3868
3869 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3870 options, and the first character, if set.
3871
3872 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3873
3874
3875 Version 0.91 10-Sep-97
3876 ----------------------
3877
3878 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3879 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3880
3881 2. PCRE was looping on encountering an indefinitely repeated back reference to
3882 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3883 Perl does - treats the match as successful.
3884
3885 ****

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