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Revision 432 - (hide annotations) (download)
Wed Sep 2 16:02:56 2009 UTC (5 years, 7 months ago) by ph10
File size: 170420 byte(s)
Add REG_UNGREEDY (non-standard) to the POSIX interface.

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8     was out-of-date, and there was no check on the pcre_compile() error code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


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