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Revision 429 - (hide annotations) (download)
Tue Sep 1 16:10:16 2009 UTC (5 years, 7 months ago) by ph10
File size: 169779 byte(s)
Add pcredemo man page, containing a listing of pcredemo.c.

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8     was out-of-date, and there was no check on the pcre_compile() error code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


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