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Revision 433 - (hide annotations) (download)
Wed Sep 2 16:09:13 2009 UTC (5 years, 7 months ago) by ph10
File size: 170612 byte(s)
For regexec(), if pmatch is NULL, force nmatch to be zero.

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8     was out-of-date, and there was no check on the pcre_compile() error code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


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