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Revision 457 - (hide annotations) (download)
Sat Oct 3 16:24:08 2009 UTC (5 years, 6 months ago) by ph10
File size: 174499 byte(s)
Allow duplicate names for same-numbered groups; forbid different names.

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8     was out-of-date, and there was no check on the pcre_compile() error code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


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