ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log

Revision 431 - (hide annotations) (download)
Wed Sep 2 09:23:21 2009 UTC (5 years, 7 months ago) by ph10
File size: 170156 byte(s)
Updage ChangeLog for another bug, already fixed by previous patch.

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8     was out-of-date, and there was no check on the pcre_compile() error code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


Name Value
svn:eol-style native
svn:keywords "Author Date Id Revision Url"

ViewVC Help
Powered by ViewVC 1.1.12