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Revision 442 - (hide annotations) (download)
Fri Sep 11 10:21:02 2009 UTC (5 years, 7 months ago) by ph10
File size: 172245 byte(s)
Added PCRE_NOTEMPTY_ATSTART to fix /g bug when \K is present.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 418 Version 8.00 ??-???-??
5     ----------------------
7     1. The table for translating pcre_compile() error codes into POSIX error codes
8     was out-of-date, and there was no check on the pcre_compile() error code
9     being within the table. This could lead to an OK return being given in
10     error.
11 ph10 419
12     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
13     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14     in a Windows environment.
15 ph10 420
16     3. The pcregrep --count option prints the count for each file even when it is
17     zero, as does GNU grep. However, pcregrep was also printing all files when
18     --files-with-matches was added. Now, when both options are given, it prints
19     counts only for those files that have at least one match. (GNU grep just
20     prints the file name in this circumstance, but including the count seems
21     more useful - otherwise, why use --count?) Also ensured that the
22     combination -clh just lists non-zero counts, with no names.
24 ph10 421 4. The long form of the pcregrep -F option was incorrectly implemented as
25     --fixed_strings instead of --fixed-strings. This is an incompatible change,
26     but it seems right to fix it, and I didn't think it was worth preserving
27     the old behaviour.
29 ph10 422 5. The command line items --regex=pattern and --regexp=pattern were not
30     recognized by pcregrep, which required --regex pattern or --regexp pattern
31     (with a space rather than an '='). The man page documented the '=' forms,
32     which are compatible with GNU grep; these now work.
34 ph10 423 6. No libpcreposix.pc file was created for pkg-config; there was just
35     libpcre.pc and libpcrecpp.pc. The omission has been rectified.
37 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
38     when UCP support is not needed, by modifying the Python script that
39     generates it from Unicode data files. This should not matter if the module
40     is correctly used as a library, but I received one complaint about 50K of
41     unwanted data. My guess is that the person linked everything into his
42     program rather than using a library. Anyway, it does no harm.
44 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
45     was a minimum greater than 1 for a wide character in a possessive
46 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
47     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
48     character. Chaos in the form of incorrect output or a compiling loop could
49     result.
50 ph10 426
51     9. The restrictions on what a pattern can contain when partial matching is
52     requested for pcre_exec() have been removed. All patterns can now be
53     partially matched by this function. In addition, if there are at least two
54 ph10 435 slots in the offset vector, the offset of the earliest inspected character
55     for the match and the offset of the end of the subject are set in them when
56     PCRE_ERROR_PARTIAL is returned.
57 ph10 426
58 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
59     synonymous with PCRE_PARTIAL, for backwards compatibility, and
60     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
61     and may be more useful for multi-segment matching, especially with
62     pcre_exec().
63 ph10 427
64 ph10 428 11. Partial matching with pcre_exec() is now more intuitive. A partial match
65     used to be given if ever the end of the subject was reached; now it is
66     given only if matching could not proceed because another character was
67     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
68     string "Z", which now yields "no match" instead of "partial match". In the
69     case of pcre_dfa_exec(), "no match" is given if every matching path for the
70     final character ended with (*FAIL).
72     12. Restarting a match using pcre_dfa_exec() after a partial match did not work
73     if the pattern had a "must contain" character that was already found in the
74     earlier partial match, unless partial matching was again requested. For
75     example, with the pattern /dog.(body)?/, the "must contain" character is
76     "g". If the first part-match was for the string "dog", restarting with
77 ph10 435 "sbody" failed. This bug has been fixed.
78 ph10 428
79 ph10 435 13. The string returned by pcre_dfa_exec() after a partial match has been
80     changed so that it starts at the first inspected character rather than the
81     first character of the match. This makes a difference only if the pattern
82     starts with a lookbehind assertion or \b or \B (\K is not supported by
83     pcre_dfa_exec()). It's an incompatible change, but it makes the two
84     matching functions compatible, and I think it's the right thing to do.
86     14. Added a pcredemo man page, created automatically from the pcredemo.c file,
87 ph10 429 so that the demonstration program is easily available in environments where
88     PCRE has not been installed from source.
90 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
91 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
92     library.
94 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
95 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
96     is not the first non-POSIX option to be added. Clearly some people find
97 ph10 433 these options useful.
98 ph10 432
99 ph10 435 17. If a caller to the POSIX matching function regexec() passes a non-zero
100 ph10 438 value for nmatch with a NULL value for pmatch, the value of
101     nmatch is forced to zero.
102 ph10 433
103 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
104     the diff command, as RunTest does. It now checks in the same way as
105     RunTest, and also checks for the -b option.
107 ph10 438 19. If an odd number of negated classes containing just a single character
108     interposed, within parentheses, between a forward reference to a named
109     subpattern and the definition of the subpattern, compilation crashed with
110     an internal error, complaining that it could not find the referenced
111     subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
112     [The bug was that it was starting one character too far in when skipping
113     over the character class, thus treating the ] as data rather than
114     terminating the class. This meant it could skip too much.]
116 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
117     /g option in pcretest when the pattern contains \K, which makes it possible
118     to have an empty string match not at the start, even when the pattern is
119     anchored. Updated pcretest and pcredemo to use this option.
121 ph10 418
122 ph10 412 Version 7.9 11-Apr-09
123 ph10 376 ---------------------
125 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
126 ph10 376 (pcretest), all targets were linked against these libraries. This included
127     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
128     libraries. This caused unwanted dependencies to be created. This problem
129 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
130 ph10 376 pcretest is linked with readline.
131 ph10 392
132 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
133     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
134     moved outside it again, because FALSE and TRUE are already defined in AIX,
135     but BOOL is not.
136 ph10 392
137     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
138 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
139 ph10 392
140 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
141     hyphens) following file names and line numbers when outputting matching
142 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
143 ph10 376 wording for the --colour (or --color) option.
144 ph10 392
145 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
146     was not coloured; this is different to GNU grep, so I have changed it to be
147     the same.
148 ph10 392
149 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
150 ph10 392 each matching line was coloured. Now it goes on to look for further matches
151     of any of the test patterns, which is the same behaviour as GNU grep.
153     7. A pattern that could match an empty string could cause pcregrep to loop; it
154     doesn't make sense to accept an empty string match in pcregrep, so I have
155 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
156     seems to be how GNU grep behaves.
157 ph10 392
158 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
159 ph10 392 start or after a newline", because the conditional assertion was not being
160     correctly handled. The rule now is that both the assertion and what follows
161     in the first alternative must satisfy the test.
163 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
164 ph10 399 condition was an assertion, PCRE could crash during matching, both with
165     pcre_exec() and pcre_dfa_exec().
166 ph10 392
167     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
168     used for matching.
170     11. Unicode property support in character classes was not working for
171 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
172 ph10 388
173 ph10 392 12. Added the -M command line option to pcretest.
175 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
176 ph10 389
177     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
178 ph10 390
179 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
180 ph10 390 wrapper.
181 ph10 392
182 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
183 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
184 ph10 391 string constants.
185 ph10 405
186 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
187     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
188 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
189     these, but not everybody uses configure.
191     19. A conditional group that had only one branch was not being correctly
192     recognized as an item that could match an empty string. This meant that an
193     enclosing group might also not be so recognized, causing infinite looping
194     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
195     with the subject "ab", where knowledge that the repeated group can match
196 ph10 396 nothing is needed in order to break the loop.
197 ph10 405
198 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
199 ph10 405 exec(), but without supplying a callout function, matching went wrong.
201     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
202     leak if the size of the offset vector was greater than 30. When the vector
203     is smaller, the saved offsets during recursion go onto a local stack
204     vector, but for larger vectors malloc() is used. It was failing to free
205     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
206 ph10 400 error, in fact).
207 ph10 405
208 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
209 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
210     problem, but was untidy.
211 ph10 376
212 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
213     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
214     included within another project.
215 ph10 411
216 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
217     slightly modified by me:
218 ph10 411
219     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
220     not building pcregrep.
222 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
223 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
225 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
226     duplicate group numbers, could behave incorrectly or give incorrect errors,
227     because when scanning forward to find the reference group, PCRE was not
228     taking into account the duplicate group numbers. A pattern such as
229     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
230 ph10 411
231     26. Changed a few more instances of "const unsigned char *" to USPTR, making
232     the feature of a custom pointer more persuasive (as requested by a user).
233 ph10 416
234 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
235 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
236     pre-defined.
237 ph10 392
238 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
240 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
241     in the configuration summary.
242 ph10 405
243 ph10 411
244 ph10 374 Version 7.8 05-Sep-08
245 ph10 349 ---------------------
247     1. Replaced UCP searching code with optimized version as implemented for Ad
248     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
249 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
250     to 5 times on some simple patterns that I tested. Permission was given to
251     distribute the MultiStage2.py script that generates the tables (it's not in
252     the tarball, but is in the Subversion repository).
253 ph10 349
254 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
255     scripts.
256 ph10 358
257 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
258     a group with a zero qualifier. The result of the study could be incorrect,
259 ph10 358 or the function might crash, depending on the pattern.
261     4. Caseless matching was not working for non-ASCII characters in back
262 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
263 ph10 358 It now works when Unicode Property Support is available.
265 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
266     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
267     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
268 ph10 358 truncation.
269 ph10 349
270 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
272 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
273     pointers, in case they are 64-bit values.
274 ph10 371
275     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
276     test 2 if it fails.
278 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
279 ph10 371 and a #define of that name to empty if it is not externally set. This is to
280     allow users of MSVC to set it if necessary.
282     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
283 ph10 359 the convenience functions in the pcre_get.c source file.
284 ph10 371
285 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
286     could cause overwriting and/or a crash. This command provoked a crash in
287 ph10 371 some environments:
289     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
291 ph10 360 This potential security problem was recorded as CVE-2008-2371.
292 ph10 371
293 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
294     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
295 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
296 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
297     pcretest so that it places the subject at the end of its malloc-ed buffer.
298 ph10 371
299 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
300 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
302 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
303 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
304     first line. This applied both to normal and DFA matching.
306 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
307 ph10 371 /^[^d]*?$/8 failed to match "abc".
308 ph10 351
309 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
311     17. Make it more clear in the documentation that values returned from
312 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
313 ph10 357
314 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
315 ph10 368
316 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
317     supplied by Stefan Weber. I made a further small update for 7.8 because
318 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
319     replaced by pcre_ucd.c.
320 ph10 371
321 ph10 373
322 ph10 347 Version 7.7 07-May-08
323 ph10 321 ---------------------
325     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
326 ph10 345 a string to a long long, pretend we don't even have a long long." This is
327 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
328 ph10 345
329 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
330     pre-7.6 versions, which defined a global no_arg variable instead of putting
331 ph10 332 it in the RE class. (See also #8 below.)
332 ph10 345
333     3. Remove a line of dead code, identified by coverity and reported by Nuno
334     Lopes.
336 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
337 ph10 321
338 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
339 ph10 345 of files, instead of just to the final components.
341 ph10 324 (2) If there was more than one level of directory, the subdirectories were
342     skipped unless they satisfied the include/exclude conditions. This is
343     inconsistent with GNU grep (and could even be seen as contrary to the
344     pcregrep specification - which I improved to make it absolutely clear).
345     The action now is always to scan all levels of directory, and just
346     apply the include/exclude patterns to regular files.
347 ph10 345
348 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
349 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
351 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
352 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
353 ph10 326 doesn't support NULs in patterns.
354 ph10 345
355     7. Added some missing "const"s to declarations of static tables in
356     pcre_compile.c and pcre_dfa_exec.c.
358 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
359 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
360 ph10 345 first patch. And a third patch - this was a messy problem.)
361 ph10 321
362 ph10 345 9. Applied Craig's patch to remove the use of push_back().
364 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
365     matching function regexec().
366 ph10 345
367     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
368     which, however, unlike Perl's \g{...}, are subroutine calls, not back
369 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
370     Oniguruma does).
371 ph10 345
372     12. Previously, a group with a zero repeat such as (...){0} was completely
373 ph10 335 omitted from the compiled regex. However, this means that if the group
374     was called as a subroutine from elsewhere in the pattern, things went wrong
375 ph10 345 (an internal error was given). Such groups are now left in the compiled
376     pattern, with a new opcode that causes them to be skipped at execution
377 ph10 335 time.
378 ph10 345
379 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
380     to the way PCRE behaves:
381 ph10 345
382 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
383 ph10 345
384     (b) A back reference to an unmatched subpattern matches an empty string
385 ph10 336 (Perl fails the current match path).
386 ph10 345
387 ph10 341 (c) A data ] in a character class must be notated as \] because if the
388 ph10 345 first data character in a class is ], it defines an empty class. (In
389 ph10 341 Perl it is not possible to have an empty class.) The empty class []
390     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
391     The negative empty class [^] matches any one character, independently
392     of the DOTALL setting.
393 ph10 345
394     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
395 ph10 340 non-existent subpattern following a character class starting with ']' and
396     containing () gave an internal compiling error instead of "reference to
397     non-existent subpattern". Fortunately, when the pattern did exist, the
398 ph10 345 compiled code was correct. (When scanning forwards to check for the
399 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
400 ph10 345 the class, so got the count wrong. When actually compiling, the reference
401 ph10 340 was subsequently set up correctly.)
402 ph10 345
403 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
404 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
405     other assertions are supported. I have made pcre_dfa_exec() support
406     (*FAIL).
408 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
409 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
410     cannot be changed at match time, I realized I could make a small
411     improvement to matching performance by compiling OP_ALLANY instead of
412     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
413     on the OP_ANY path.
415     17. Compiling pcretest on Windows with readline support failed without the
416 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
417 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
419 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
420 ph10 345 ncurses library to be included for pcretest when ReadLine support is
421     requested, but also to allow for it to be overridden. This patch came from
422     Daniel Bergström.
423 ph10 347
424 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
425 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
426     any errors with the current Unicode tables. Thanks to Peter Kankowski for
427     spotting this.
428 ph10 324
429 ph10 332
430 ph10 319 Version 7.6 28-Jan-08
431 ph10 300 ---------------------
433 ph10 302 1. A character class containing a very large number of characters with
434     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
435     overflow.
436 ph10 309
437     2. Patch to cut out the "long long" test in pcrecpp_unittest when
438     HAVE_LONG_LONG is not defined.
440 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
441 ph10 304 bring them up to date and include new features. This patch includes:
442 ph10 309
443 ph10 304 - Fixed PH's badly added libz and libbz2 support.
444     - Fixed a problem with static linking.
445 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
446 ph10 304 - Fixed dftables problem and added an option.
447     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
449     - Added readline support for pcretest.
450 ph10 309 - Added an listing of the option settings after cmake has run.
452 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
453     "pcre.dll" under mingw when using Configure/Make. I added stuff to
454     Makefile.am that cause it to include this special target, without
455     affecting anything else. Note that the same mingw target plus all
456     the other distribution libraries and programs are now supported
457     when configuring with CMake (see 6 below) instead of with
458     Configure/Make.
459 ph10 309
460 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
461     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
462 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
463     solves the problem, but it does no harm.
464 ph10 313
465 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
466 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
467 ph10 314 with CMake, and also correct the comment about stack recursion.
468 ph10 313
469 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
470 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
471     of a program that users should build themselves after PCRE is installed, so
472     building it automatically is not really right. What is more, it gave
473 ph10 312 trouble in some build environments.
474 ph10 300
475 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
476 ph10 308
477 ph10 319
478 ph10 298 Version 7.5 10-Jan-08
479 ph10 263 ---------------------
481     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
482     values in parens when parsing an RE using the C++ wrapper."
483 ph10 286
484 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
485     Characters greater than 255 were excluded from the class instead of being
486     included.
487 ph10 286
488     3. The same bug as (2) above applied to negated POSIX classes such as
489 ph10 265 [:^space:].
490 ph10 286
491 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
492     defined or documented. It seems to have been a typo for PCRE_STATIC, so
493 ph10 286 I have changed it.
495 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
496 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
497     first named subpattern whose name started with "a" (in other words, the
498 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
499     expected" is now given for (?&) (a zero-length name), and this patch also
500     makes it give the same error for \k'' (previously it complained that that
501     was a reference to a non-existent subpattern).
502 ph10 286
503 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
504 ph10 286 this is right because (?- can be followed by option settings as well as by
505 ph10 269 digits. I have, however, made the messages clearer.
506 ph10 286
507 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
508     than the number used in the conditional) now cause a compile-time error.
509     This is actually not compatible with Perl, which accepts such patterns, but
510     treats the conditional as always being FALSE (as PCRE used to), but it
511     seems to me that giving a diagnostic is better.
512 ph10 286
513 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
514 ph10 275 and messages.
515 ph10 286
516     9. Fix two occurrences of "backslash" in comments that should have been
517     "backspace".
519     10. Remove two redundant lines of code that can never be obeyed (their function
520     was moved elsewhere).
522     11. The program that makes PCRE's Unicode character property table had a bug
523     which caused it to generate incorrect table entries for sequences of
524 ph10 277 characters that have the same character type, but are in different scripts.
525 ph10 286 It amalgamated them into a single range, with the script of the first of
526 ph10 277 them. In other words, some characters were in the wrong script. There were
527     thirteen such cases, affecting characters in the following ranges:
528 ph10 286
529 ph10 277 U+002b0 - U+002c1
530     U+0060c - U+0060d
531 ph10 286 U+0061e - U+00612
532 ph10 277 U+0064b - U+0065e
533     U+0074d - U+0076d
534     U+01800 - U+01805
535     U+01d00 - U+01d77
536     U+01d9b - U+01dbf
537     U+0200b - U+0200f
538     U+030fc - U+030fe
539     U+03260 - U+0327f
540     U+0fb46 - U+0fbb1
541     U+10450 - U+1049d
542 ph10 286
543 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
544     compatible with GNU grep in that, if there was more than one match in a
545     line, it showed only the first of them. It now behaves in the same way as
546     GNU grep.
547 ph10 286
548     13. If the -o and -v options were combined for pcregrep, it printed a blank
549     line for every non-matching line. GNU grep prints nothing, and pcregrep now
550     does the same. The return code can be used to tell if there were any
551     non-matching lines.
553 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
555     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
556 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
557 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
558     and both kinds of lookbehind were skipped).
560 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
561 ph10 284 inclusion of <windows.h> to before rather than after the definition of
562     INVALID_FILE_ATTRIBUTES (patch from David Byron).
563 ph10 263
564 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
565 ph10 286 character property caused pcre_compile() to compile bad code, which led at
566     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
567     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
568     caused the error; without that there was no problem.
569 ph10 263
570 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
571 ph10 286
572 ph10 289 19. Added --enable-pcretest-libreadline.
573 ph10 286
574 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
575 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
576 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
577     later patch that removed the other one (the right fix) and added unit tests
578     that check the return values (which was not done before).
579 ph10 292
580 ph10 291 21. Several CMake things:
581 ph10 287
582 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
583 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
584 ph10 288
585 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
586     linked with the newly-built libraries, not previously installed ones.
587 ph10 291
589 ph10 298
590     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
591     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
592     UTF-8 newline character). The key issue is that the pattern starts .*;
593     this means that the match must be either at the beginning, or after a
594     newline. The bug was in the code for advancing after a failed match and
595     checking that the new position followed a newline. It was not taking
596 ph10 294 account of UTF-8 characters correctly.
597 ph10 298
598     23. PCRE was behaving differently from Perl in the way it recognized POSIX
599     character classes. PCRE was not treating the sequence [:...:] as a
600     character class unless the ... were all letters. Perl, however, seems to
601     allow any characters between [: and :], though of course it rejects as
602     unknown any "names" that contain non-letters, because all the known class
603     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
604     for example, whereas PCRE did not - it did not recognize a POSIX character
605     class. This seemed a bit dangerous, so the code has been changed to be
606     closer to Perl. The behaviour is not identical to Perl, because PCRE will
607     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
608     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
609     Perl does, and where it didn't before.
611 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
612     Windows environments %n is disabled by default.
613 ph10 292
615 ph10 260 Version 7.4 21-Sep-07
616 ph10 230 ---------------------
618     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
619 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
620     LF". That isn't really right - the whole point of the change was to try to
621     help when there was an actual mention of one of the two characters. So now
622     the change happens only if \r or \n (or a literal CR or LF) character is
623 ph10 230 encountered.
624 ph10 231
625     2. The 32-bit options word was also used for 6 internal flags, but the numbers
626     of both had grown to the point where there were only 3 bits left.
627     Fortunately, there was spare space in the data structure, and so I have
628     moved the internal flags into a new 16-bit field to free up more option
629 ph10 230 bits.
630 ph10 231
631     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
632     but did not set the internal JCHANGED flag - either of these is enough to
633     control the way the "get" function works - but the PCRE_INFO_JCHANGED
634     facility is supposed to tell if (?J) was ever used, so now (?J) at the
635 ph10 230 start sets both bits.
637 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
638     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
639 ph10 230
640 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
642     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
643 ph10 233 compatibility, even though it is no longer used.
644 ph10 243
645     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
646 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
647 ph10 259 windows.h file is present (where different names are used). [This was
648 ph10 257 reversed later after testing - see 16 below.]
649 ph10 243
650     8. Changed all #include <config.h> to #include "config.h". There were also
651 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
652 ph10 243
653 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
654 ph10 243 sequence off the lines that it output.
656     10. It was pointed out to me that arrays of string pointers cause lots of
657     relocations when a shared library is dynamically loaded. A technique of
658     using a single long string with a table of offsets can drastically reduce
659     these. I have refactored PCRE in four places to do this. The result is
660 ph10 240 dramatic:
661 ph10 243
662 ph10 240 Originally: 290
663     After changing UCP table: 187
664 ph10 243 After changing error message table: 43
665 ph10 240 After changing table of "verbs" 36
666     After changing table of Posix names 22
667 ph10 243
668 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
669 ph10 247
670 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
671 ph10 247 unicode-properties was also set.
673 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
674 ph10 231
675 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
676     checked only for CRLF.
677 ph10 233
678 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
680 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
681 ph10 253
682 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
683 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
684     entirely. This removes changes made in 7 above.
685 ph10 256
686 ph10 261 17. The CMake files have been updated, and there is now more information about
687     building with CMake in the NON-UNIX-USE document.
688 ph10 257
689 ph10 261
690 ph10 228 Version 7.3 28-Aug-07
691 ph10 157 ---------------------
693 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
694     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
695     brackets there is not right, since it causes compilers to look for an
696     installed pcre.h, not the version that is in the source that is being
697     compiled (which of course may be different). I have changed it back to:
698 ph10 197
699 ph10 189 #include "pcre.h"
700 ph10 197
701     I have a vague recollection that the change was concerned with compiling in
702     different directories, but in the new build system, that is taken care of
703     by the VPATH setting the Makefile.
705 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
706     when the subject happened to end in the byte 0x85 (e.g. if the last
707     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
708     characters but of course it shouldn't be taken as a newline when it is part
709     of another character. The bug was that, for an unlimited repeat of . in
710     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
711     characters when looking for a newline.
712 ph10 197
713     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
715     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
716     in debug output.
718 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
719     long printing in the pcrecpp unittest when running under MinGW.
720 ph10 189
721 ph10 197 6. ESC_K was left out of the EBCDIC table.
722 ph10 189
723 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
724     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
725     limit also applies to "virtual nesting" when a pattern is recursive, and in
726     this case 1000 isn't so big. I have been able to remove this limit at the
727     expense of backing off one optimization in certain circumstances. Normally,
728     when pcre_exec() would call its internal match() function recursively and
729     immediately return the result unconditionally, it uses a "tail recursion"
730     feature to save stack. However, when a subpattern that can match an empty
731     string has an unlimited repetition quantifier, it no longer makes this
732     optimization. That gives it a stack frame in which to save the data for
733     checking that an empty string has been matched. Previously this was taken
734     from the 1000-entry workspace that had been reserved. So now there is no
735     explicit limit, but more stack is used.
736 ph10 189
737 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
738     syntax that is required for Windows, and which was going wrong for the
739     pcreposix and pcrecpp parts of the library. These were overlooked when this
740     problem was solved for the main library.
741 ph10 197
742 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
743     the size of patterns that contain repeated groups with explicit upper
744     limits. As the maximum quantifier is 65535, the maximum group length was
745     set at 30,000 so that the product of these two numbers did not overflow a
746     32-bit integer. However, it turns out that people want to use groups that
747     are longer than 30,000 bytes (though not repeat them that many times).
748     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
749     made it possible to implement the integer overflow checks in a much more
750     dynamic way, which I have now done. The artificial limitation on group
751     length has been removed - we now have only the limit on the total length of
752     the compiled pattern, which depends on the LINK_SIZE setting.
753 ph10 208
754     10. Fixed a bug in the documentation for get/copy named substring when
755     duplicate names are permitted. If none of the named substrings are set, the
756     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
757     empty string.
759     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
760     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
761     because the ] is interpreted as the first data character and the
762     terminating ] is not found. PCRE has been made compatible with Perl in this
763     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
764     cause memory overwriting.
766 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
767     string has been matched (to stop an infinite loop). It was not recognizing
768 ph10 208 a conditional subpattern that could match an empty string if that
769 ph10 206 subpattern was within another subpattern. For example, it looped when
770 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
771 ph10 206 condition was not nested. This bug has been fixed.
772 ph10 208
773 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
774     past the start of the subject in the presence of bytes with the top bit
775     set, for example "\x8aBCD".
776 ph10 211
777 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
778     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
779 ph10 200
780 ph10 211 14. Optimized (?!) to (*FAIL).
781 ph10 202
782 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
783     This restricts code points to be within the range 0 to 0x10FFFF, excluding
784     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
785     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
786     does: it's just the validity check that is more restrictive.
787 ph10 220
788     16. Inserted checks for integer overflows during escape sequence (backslash)
789     processing, and also fixed erroneous offset values for syntax errors during
790     backslash processing.
792 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
793 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
795 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
796     caused an overrun.
797 ph10 220
798     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
799     something other than just ASCII characters) inside a group that had an
800     unlimited repeat caused a loop at compile time (while checking to see
801     whether the group could match an empty string).
803 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
804     [\P{Any}] did so. (Error in the code for printing property names.)
805 ph10 210
806 ph10 220 21. An orphan \E inside a character class could cause a crash.
808     22. A repeated capturing bracket such as (A)? could cause a wild memory
809 ph10 218 reference during compilation.
810 ph10 220
811     23. There are several functions in pcre_compile() that scan along a compiled
812     expression for various reasons (e.g. to see if it's fixed length for look
813 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
814 ph10 220 present in the pattern. These operators have additional parameters compared
815     with \d, etc, and these were not being taken into account when moving along
816 ph10 218 the compiled data. Specifically:
817 ph10 220
818     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
819     length.
821     (b) An item such as \pL+ within a repeated group could cause crashes or
822 ph10 218 loops.
823 ph10 220
824 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
825 ph10 220 "reference to non-existent subpattern" error.
827 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
829 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
830 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
831 ph10 211
832 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
833 ph10 218
834 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
835 ph10 223 character were causing crashes (broken optimization).
836 ph10 227
837 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
838 ph10 227 \p or \P) caused a compile-time loop.
840 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
841     break. For example, the unstudied pattern [\r\n]A does not match the string
842     "\r\nA" because change 7.0/46 below moves the current point on by two
843     characters after failing to match at the start. However, the pattern \nA
844 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
845     the same is true. There doesn't seem any very clean way out of this, but
846     what I have chosen to do makes the common cases work: PCRE now takes note
847     of whether there can be an explicit match for \r or \n anywhere in the
848     pattern, and if so, 7.0/46 no longer applies. As part of this change,
849     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
850     pattern has explicit CR or LF references.
851 ph10 222
852 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
853 ph10 223
854 ph10 227
855 ph10 189 Version 7.2 19-Jun-07
856     ---------------------
858 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
859     which is apparently normally available under Windows.
860 ph10 159
861     2. Re-jig the pcregrep tests with different newline settings in an attempt
862     to make them independent of the local environment's newline setting.
863 ph10 157
864 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
865 ph10 165
866 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
867     was not 2, because the output contained actual offsets. The recent new
868 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
869     usable with all link sizes.
871 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
872     stack recursion. This gives a massive performance boost under BSD, but just
873 ph10 165 a small improvement under Linux. However, it saves one field in the frame
874 ph10 164 in all cases.
875 ph10 172
876 ph10 166 6. Added more features from the forthcoming Perl 5.10:
877 ph10 172
878 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
879     recursion call. It refers to the nth most recently opened parentheses.
880 ph10 172
881 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
882 ph10 172 to be opened parentheses.
884     (c) Conditions that refer to capturing parentheses can be specified
885 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
886 ph10 172
887 ph10 168 (d) \K resets the start of the current match so that everything before
888 ph10 172 is not part of it.
890 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
891 ph10 172
892 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
893 ph10 172 reference syntax.
894 ph10 182
895 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
896 ph10 182 alternative starts with the same number.
897 ph10 172
898 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
900 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
903     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
904     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
905 ph10 170 for detecting groups that can match an empty string.
906 ph10 159
907 ph10 172 9. A pattern with a very large number of alternatives (more than several
908     hundred) was running out of internal workspace during the pre-compile
909     phase, where pcre_compile() figures out how much memory will be needed. A
910     bit of new cunning has reduced the workspace needed for groups with
911     alternatives. The 1000-alternative test pattern now uses 12 bytes of
912     workspace instead of running out of the 4096 that are available.
913 ph10 182
914 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
915 ph10 172
916 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
917     The report of the bug said:
918 ph10 182
919 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
920     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
921 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
922 ph10 185
923 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
924 ph10 185 it matched the wrong number of bytes.
925 ph10 172
926 ph10 179
927 ph10 155 Version 7.1 24-Apr-07
928 ph10 98 ---------------------
930 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
931 ph10 122 that is more "standard", making use of automake and other Autotools. There
932 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
933     on this.
934 ph10 111
935     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
936     for recursive directory scanning broke on some systems because the files
937     are not scanned in any specific order and on different systems the order
938     was different. A call to "sort" has been inserted into RunGrepTest for the
939     approprate test as a short-term fix. In the longer term there may be an
940 ph10 100 alternative.
941 ph10 111
942 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
943 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
944     people do their own conversions for various reasons). The problems
945     concerned the use of low-level troff macros .br and .in. I have therefore
946     removed all such uses from the man pages (some were redundant, some could
947 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
948     HTML has been updated to handle .nf/.fi and to complain if it encounters
949     .br or .in.
950 ph10 111
951 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
952 ph10 123 arranged for config.h to be included in the distribution, with the name
953 ph10 111 config.h.generic, for the benefit of those who have to compile without
954     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
956     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
957     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
958 ph10 127 makevp.bat for the current PCRE, using the additional files
959 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
960 ph10 111
961     6. A Windows user reported a minor discrepancy with test 2, which turned out
962     to be caused by a trailing space on an input line that had got lost in his
963 ph10 102 copy. The trailing space was an accident, so I've just removed it.
964 ph10 111
965 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
966 ph10 111 that is needed.
968 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
969     as "const" (a) because they are and (b) because it helps the PHP
970     maintainers who have recently made a script to detect big data structures
971 ph10 111 in the php code that should be moved to the .rodata section. I remembered
972     to update Builducptable as well, so it won't revert if ucptable.h is ever
973 ph10 105 re-created.
974 ph10 111
975     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
976 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
977 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
978     support is not required. This saves 1.5-2K of code, which is important in
979 ph10 107 some applications.
980 ph10 111
981 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
982 ph10 111 so as not to refer to the tables, even though these functions will never be
983     called when UTF-8 support is disabled. Otherwise there are problems with a
984     shared library.
986 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
988     (a) It was defining its arguments as char * instead of void *.
990 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
991     a long time ago when I wrote it, but is no longer the case.
993 ph10 118 The emulated memove() is provided for those environments that have neither
994 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
995 ph10 118 is clearly not the case, as these two bugs were recently reported.
996 ph10 123
997 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
998 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
999     pages, and it removes trailing spaces from listed files. It also creates
1000     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1001     case, it wraps all the #defines with #ifndefs. This script should be run
1002 ph10 111 before "make dist".
1003 ph10 123
1004 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1005     with Unicode property support.
1006 ph10 123
1007     (a) For a maximizing quantifier, if the two different cases of the
1008     character were of different lengths in their UTF-8 codings (there are
1009     some cases like this - I found 11), and the matching function had to
1010 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1011     were both the same length.
1012 ph10 123
1013     (b) When PCRE was configured to use the heap rather than the stack for
1014     recursion during matching, it was not correctly preserving the data for
1015     the other case of a UTF-8 character when checking ahead for a match
1016     while processing a minimizing repeat. If the check also involved
1017 ph10 115 matching a wide character, but failed, corruption could cause an
1018     erroneous result when trying to check for a repeat of the original
1019     character.
1020 ph10 123
1021 ph10 116 13. Some tidying changes to the testing mechanism:
1022 ph10 98
1023 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1024     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1025 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1026     this for UTF-8.) The configure.ac script no longer substitutes the
1027     relevant variables.
1029 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1030     with length and offset values. This means that the output is different
1031     for different internal link sizes. Test 2 is skipped for link sizes
1032     other than 2 because of this, bypassing the problem. Unfortunately,
1033     there was also a test in test 3 (the locale tests) that used /B and
1034 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1035     I have added a new /Z option to pcretest that replaces the length and
1036     offset values with spaces. This is now used to make test 3 independent
1037 ph10 122 of link size. (Test 2 will be tidied up later.)
1038 ph10 123
1039     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1040 ph10 122 segmentation fault instead of returning the appropriate error message.
1041 ph10 134
1042 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1043 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1044     This doesn't seem right; it now treats the CRLF combination as the line
1045     ending, and so does not match in that case. It's only a pattern such as ^$
1046     that would hit this one: something like ^ABC$ would have failed after \r
1047     and then tried again after \r\n.
1049 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1050 ph10 134 in an attempt to make files that differ only in their line terminators
1051     compare equal. This works on Linux.
1052 ph10 142
1053 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1054     as it exited. This is now fixed, thanks to valgrind.
1055 ph10 142
1056 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1057 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1058     was because its rules for how to advance for /g after matching an empty
1059 ph10 143 string at the end of a line did not allow for this case. They now check for
1060     it specially.
1061 ph10 150
1062     20. pcretest is supposed to handle patterns and data of any length, by
1063     extending its buffers when necessary. It was getting this wrong when the
1064 ph10 147 buffer for a data line had to be extended.
1065 ph10 150
1066 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1067 ph10 150 CRLF as a newline sequence.
1068 ph10 152
1069 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1070 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1071     I have nevertheless tidied it up.
1072 ph10 111
1073 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1074 ph10 123
1075 ph10 153 24. Added a man page for pcre-config.
1076 ph10 152
1077 ph10 153
1078 nigel 93 Version 7.0 19-Dec-06
1079     ---------------------
1081     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1082     moving to gcc 4.1.1.
1084     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1085     sys/time.h, which is documented as needed for this function. It doesn't
1086     seem to matter on Linux, but it showed up on some releases of OS X.
1088     3. It seems that there are systems where bytes whose values are greater than
1089     127 match isprint() in the "C" locale. The "C" locale should be the
1090     default when a C program starts up. In most systems, only ASCII printing
1091     characters match isprint(). This difference caused the output from pcretest
1092     to vary, making some of the tests fail. I have changed pcretest so that:
1094     (a) When it is outputting text in the compiled version of a pattern, bytes
1095     other than 32-126 are always shown as hex escapes.
1097     (b) When it is outputting text that is a matched part of a subject string,
1098     it does the same, unless a different locale has been set for the match
1099     (using the /L modifier). In this case, it uses isprint() to decide.
1101     4. Fixed a major bug that caused incorrect computation of the amount of memory
1102     required for a compiled pattern when options that changed within the
1103     pattern affected the logic of the preliminary scan that determines the
1104     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1105     that the computed length was too small. The symptoms of this bug were
1106     either the PCRE error "internal error: code overflow" from pcre_compile(),
1107     or a glibc crash with a message such as "pcretest: free(): invalid next
1108     size (fast)". Examples of patterns that provoked this bug (shown in
1109     pcretest format) are:
1111     /(?-x: )/x
1112     /(?x)(?-x: \s*#\s*)/
1113     /((?i)[\x{c0}])/8
1114     /(?i:[\x{c0}])/8
1116     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1117     is now done differently.
1119     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1120     wrapper classes; (b) implement a new function in the C++ scanner that is
1121     more efficient than the old way of doing things because it avoids levels of
1122     recursion in the regex matching; (c) add a paragraph to the documentation
1123     for the FullMatch() function.
1125     6. The escape sequence \n was being treated as whatever was defined as
1126     "newline". Not only was this contrary to the documentation, which states
1127     that \n is character 10 (hex 0A), but it also went horribly wrong when
1128     "newline" was defined as CRLF. This has been fixed.
1130     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1131     was being set to -1 for the "end of line" case (supposedly a value that no
1132     character can have). Though this value is never used (the check for end of
1133     line is "zero bytes in current character"), it caused compiler complaints.
1134     I've changed it to 0xffffffff.
1136     8. In pcre_version.c, the version string was being built by a sequence of
1137     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1138     string (as it is for production releases) called a macro with an empty
1139     argument. The C standard says the result of this is undefined. The gcc
1140     compiler treats it as an empty string (which was what was wanted) but it is
1141     reported that Visual C gives an error. The source has been hacked around to
1142     avoid this problem.
1144     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1145     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1146     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1147     of them did).
1149     10. Originally, pcretest opened its input and output without "b"; then I was
1150     told that "b" was needed in some environments, so it was added for release
1151     5.0 to both the input and output. (It makes no difference on Unix-like
1152     systems.) Later I was told that it is wrong for the input on Windows. I've
1153     now abstracted the modes into two macros, to make it easier to fiddle with
1154     them, and removed "b" from the input mode under Windows.
1156     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1158     12. Added -help and --help to pcretest as an official way of being reminded
1159     of the options.
1161     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1162     and pcrecpp.cc because they annoy compilers at high warning levels.
1164     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1166     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1167     scripts are not C programs :-) and which was not noticed because it works
1168     on Linux.
1170     16. pcretest is supposed to handle any length of pattern and data line (as one
1171     line or as a continued sequence of lines) by extending its input buffer if
1172     necessary. This feature was broken for very long pattern lines, leading to
1173     a string of junk being passed to pcre_compile() if the pattern was longer
1174     than about 50K.
1176     17. I have done a major re-factoring of the way pcre_compile() computes the
1177     amount of memory needed for a compiled pattern. Previously, there was code
1178     that made a preliminary scan of the pattern in order to do this. That was
1179     OK when PCRE was new, but as the facilities have expanded, it has become
1180     harder and harder to keep it in step with the real compile phase, and there
1181     have been a number of bugs (see for example, 4 above). I have now found a
1182     cunning way of running the real compile function in a "fake" mode that
1183     enables it to compute how much memory it would need, while actually only
1184     ever using a few hundred bytes of working memory and without too many
1185     tests of the mode. This should make future maintenance and development
1186     easier. A side effect of this work is that the limit of 200 on the nesting
1187     depth of parentheses has been removed (though this was never a serious
1188     limitation, I suspect). However, there is a downside: pcre_compile() now
1189     runs more slowly than before (30% or more, depending on the pattern). I
1190     hope this isn't a big issue. There is no effect on runtime performance.
1192     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1193     newline (only possible for the last line of a file) and it was a
1194     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1196     19. Added additional timing features to pcretest. (1) The -tm option now times
1197     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1198     separate command line item, by a number that specifies the number of
1199     repeats to use when timing. The default is 50000; this gives better
1200     precision, but takes uncomfortably long for very large patterns.
1202     20. Extended pcre_study() to be more clever in cases where a branch of a
1203     subpattern has no definite first character. For example, (a*|b*)[cd] would
1204     previously give no result from pcre_study(). Now it recognizes that the
1205     first character must be a, b, c, or d.
1207     21. There was an incorrect error "recursive call could loop indefinitely" if
1208     a subpattern (or the entire pattern) that was being tested for matching an
1209     empty string contained only one non-empty item after a nested subpattern.
1210     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1211     incorrectly, because the \d was being skipped in the check.
1213     22. The pcretest program now has a new pattern option /B and a command line
1214     option -b, which is equivalent to adding /B to every pattern. This causes
1215     it to show the compiled bytecode, without the additional information that
1216     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1217     is the same as /B/I).
1219     23. A new optimization is now able automatically to treat some sequences such
1220     as a*b as a*+b. More specifically, if something simple (such as a character
1221     or a simple class like \d) has an unlimited quantifier, and is followed by
1222     something that cannot possibly match the quantified thing, the quantifier
1223     is automatically "possessified".
1225     24. A recursive reference to a subpattern whose number was greater than 39
1226     went wrong under certain circumstances in UTF-8 mode. This bug could also
1227     have affected the operation of pcre_study().
1229     25. Realized that a little bit of performance could be had by replacing
1230     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1232     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1234     27. Possessive quantifiers such as a++ were previously implemented by turning
1235     them into atomic groups such as ($>a+). Now they have their own opcodes,
1236     which improves performance. This includes the automatically created ones
1237     from 23 above.
1239     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1240     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1241     the first matched character to be a colon. This applied both to named and
1242     numbered groups.
1244     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1246     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1247     building PCRE on Windows easier, so I have included it in the distribution.
1249     31. There is now a check in pcretest against a ridiculously large number being
1250     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1251     loop, the loop is abandoned.
1253     32. Forward references to subpatterns in conditions such as (?(2)...) where
1254     subpattern 2 is defined later cause pcre_compile() to search forwards in
1255     the pattern for the relevant set of parentheses. This search went wrong
1256     when there were unescaped parentheses in a character class, parentheses
1257     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1259     33. "Subroutine" calls and backreferences were previously restricted to
1260     referencing subpatterns earlier in the regex. This restriction has now
1261     been removed.
1263     34. Added a number of extra features that are going to be in Perl 5.10. On the
1264     whole, these are just syntactic alternatives for features that PCRE had
1265     previously implemented using the Python syntax or my own invention. The
1266     other formats are all retained for compatibility.
1268     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1269     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1270     also .NET compatible.
1272     (b) A recursion or subroutine call to a named group can now be defined as
1273     (?&name) as well as (?P>name).
1275     (c) A backreference to a named group can now be defined as \k<name> or
1276     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1277     5.10, are also .NET compatible.
1279     (d) A conditional reference to a named group can now use the syntax
1280     (?(<name>) or (?('name') as well as (?(name).
1282     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1283     groups (named and numbered) that are never evaluated inline, but can be
1284     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1285     is always false. There may be only one alternative in such a group.
1287     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1288     as the simple (?(R). The condition is true only if the most recent
1289     recursion is that of the given number or name. It does not search out
1290     through the entire recursion stack.
1292     (g) The escape \gN or \g{N} has been added, where N is a positive or
1293     negative number, specifying an absolute or relative reference.
1295     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1296     some "unreachable code" warnings.
1298     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1299     things, this adds five new scripts.
1301     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1302     There were also incompatibilities regarding the handling of \Q..\E inside
1303     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1304     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1306     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1307     matches an empty string, and forcibly breaks the loop. There were bugs in
1308     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1309     against aaaa the result was just "a" rather than "aaaa", for example. Two
1310     separate and independent bugs (that affected different cases) have been
1311     fixed.
1313     39. Refactored the code to abolish the use of different opcodes for small
1314     capturing bracket numbers. This is a tidy that I avoided doing when I
1315     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1316     The new approach is not only tidier, it makes it possible to reduce the
1317     memory needed to fix the previous bug (38).
1319     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1320     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1321     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1322     mode.
1324     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1325     report.
1327     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1328     copy construction and assignment in the C++ wrapper.
1330     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1331     couple of bugs that could have given wrong results in the "--newline=crlf"
1332     case.
1334     44. Added a number of casts and did some reorganization of signed/unsigned int
1335     variables following suggestions from Dair Grant. Also renamed the variable
1336     "this" as "item" because it is a C++ keyword.
1338     45. Arranged for dftables to add
1340     #include "pcre_internal.h"
1342     to pcre_chartables.c because without it, gcc 4.x may remove the array
1343     definition from the final binary if PCRE is built into a static library and
1344     dead code stripping is activated.
1346     46. For an unanchored pattern, if a match attempt fails at the start of a
1347     newline sequence, and the newline setting is CRLF or ANY, and the next two
1348     characters are CRLF, advance by two characters instead of one.
1351 nigel 91 Version 6.7 04-Jul-06
1352     ---------------------
1354     1. In order to handle tests when input lines are enormously long, pcretest has
1355     been re-factored so that it automatically extends its buffers when
1356     necessary. The code is crude, but this _is_ just a test program. The
1357     default size has been increased from 32K to 50K.
1359     2. The code in pcre_study() was using the value of the re argument before
1360     testing it for NULL. (Of course, in any sensible call of the function, it
1361     won't be NULL.)
1363     3. The memmove() emulation function in pcre_internal.h, which is used on
1364     systems that lack both memmove() and bcopy() - that is, hardly ever -
1365     was missing a "static" storage class specifier.
1367     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1368     containing an extended class (one that cannot be represented by a bitmap
1369     because it contains high-valued characters or Unicode property items, e.g.
1370     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1371     pattern, but PCRE should not loop if you do not (it no longer does).
1372     [Detail: two cases were found: (a) a repeated subpattern containing an
1373     extended class; (b) a recursive reference to a subpattern that followed a
1374     previous extended class. It wasn't skipping over the extended class
1375     correctly when UTF-8 mode was not set.]
1377     5. A negated single-character class was not being recognized as fixed-length
1378     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1379     compile error "lookbehind assertion is not fixed length".
1381     6. The RunPerlTest auxiliary script was showing an unexpected difference
1382     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1383     write a Perl script that can interpret lines of an input file either as
1384     byte characters or as UTF-8, which is what "perltest" was being required to
1385     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1386     can't do is switch easily at run time between having the "use utf8;" pragma
1387     or not. In the end, I fudged it by using the RunPerlTest script to insert
1388     "use utf8;" explicitly for the UTF-8 tests.
1390     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1391     the end of the subject string, contrary to the documentation and to what
1392     Perl does. This was true of both matching functions. Now it matches only at
1393     the start of the subject and immediately after *internal* newlines.
1395     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1396     a pointer to an int instead of a pointer to an unsigned long int. This
1397     caused problems on 64-bit systems.
1399     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1400     instance of the 'standard' template library not being so standard".
1402     10. There was no check on the number of named subpatterns nor the maximum
1403     length of a subpattern name. The product of these values is used to compute
1404     the size of the memory block for a compiled pattern. By supplying a very
1405     long subpattern name and a large number of named subpatterns, the size
1406     computation could be caused to overflow. This is now prevented by limiting
1407     the length of names to 32 characters, and the number of named subpatterns
1408     to 10,000.
1410     11. Subpatterns that are repeated with specific counts have to be replicated in
1411     the compiled pattern. The size of memory for this was computed from the
1412     length of the subpattern and the repeat count. The latter is limited to
1413     65535, but there was no limit on the former, meaning that integer overflow
1414     could in principle occur. The compiled length of a repeated subpattern is
1415     now limited to 30,000 bytes in order to prevent this.
1417     12. Added the optional facility to have named substrings with the same name.
1419     13. Added the ability to use a named substring as a condition, using the
1420     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1421     are numbers (not recommended). Forward references are permitted.
1423     14. Added forward references in named backreferences (if you see what I mean).
1425     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1426     pattern could run off the end of the subject. For example, the pattern
1427     "(?s)(.{1,5})"8 did this with the subject "ab".
1429     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1430     PCRE_CASELESS was set when matching characters that were quantified with ?
1431     or *.
1433     17. A character class other than a single negated character that had a minimum
1434     but no maximum quantifier - for example [ab]{6,} - was not handled
1435     correctly by pce_dfa_exec(). It would match only one character.
1437     18. A valid (though odd) pattern that looked like a POSIX character
1438     class but used an invalid character after [ (for example [[,abc,]]) caused
1439     pcre_compile() to give the error "Failed: internal error: code overflow" or
1440     in some cases to crash with a glibc free() error. This could even happen if
1441     the pattern terminated after [[ but there just happened to be a sequence of
1442     letters, a binary zero, and a closing ] in the memory that followed.
1444     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1445     over the years. Originally (before any Unicode support), just the bottom 8
1446     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1447     output from "man perlunicode" includes this:
1449     The regular expression compiler produces polymorphic opcodes. That
1450     is, the pattern adapts to the data and automatically switches to
1451     the Unicode character scheme when presented with Unicode data--or
1452     instead uses a traditional byte scheme when presented with byte
1453     data.
1455     Sadly, a wide octal escape does not cause a switch, and in a string with
1456     no other multibyte characters, these octal escapes are treated as before.
1457     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1458     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1459     Unicode string.
1461     I have not perpetrated such confusion in PCRE. Up till now, it took just
1462     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1463     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1464     translate to the appropriate multibyte character.
1466     29. Applied some refactoring to reduce the number of warnings from Microsoft
1467     and Borland compilers. This has included removing the fudge introduced
1468     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1469     a warning about an unused variable.
1471     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1472     characters since release 4.0, because Perl (from release 5.004) does not.
1473     [Or at least, is documented not to: some releases seem to be in conflict
1474     with the documentation.] However, when a pattern was studied with
1475     pcre_study() and all its branches started with \s, PCRE still included VT
1476     as a possible starting character. Of course, this did no harm; it just
1477     caused an unnecessary match attempt.
1479     22. Removed a now-redundant internal flag bit that recorded the fact that case
1480     dependency changed within the pattern. This was once needed for "required
1481     byte" processing, but is no longer used. This recovers a now-scarce options
1482     bit. Also moved the least significant internal flag bit to the most-
1483     significant bit of the word, which was not previously used (hangover from
1484     the days when it was an int rather than a uint) to free up another bit for
1485     the future.
1487     23. Added support for CRLF line endings as well as CR and LF. As well as the
1488     default being selectable at build time, it can now be changed at runtime
1489     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1490     specify that it is scanning data with non-default line endings.
1492     24. Changed the definition of CXXLINK to make it agree with the definition of
1493     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1495     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1496     recursions. This makes a big different to stack usage for some patterns.
1498     26. If a subpattern containing a named recursion or subroutine reference such
1499     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1500     the space required for the compiled pattern went wrong and gave too small a
1501     value. Depending on the environment, this could lead to "Failed: internal
1502     error: code overflow at offset 49" or "glibc detected double free or
1503     corruption" errors.
1505     27. Applied patches from Google (a) to support the new newline modes and (b) to
1506     advance over multibyte UTF-8 characters in GlobalReplace.
1508     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1509     difference for some implementation of PCRE in some Windows version.
1511     29. Added some extra testing facilities to pcretest:
1513     \q<number> in a data line sets the "match limit" value
1514     \Q<number> in a data line sets the "match recursion limt" value
1515     -S <number> sets the stack size, where <number> is in megabytes
1517     The -S option isn't available for Windows.
1520 nigel 89 Version 6.6 06-Feb-06
1521     ---------------------
1523     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1524     in pcreposix.h. I have copied the definition from pcre.h.
1526     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1527     because pcre.h is no longer a built file.
1529     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1530     not normally included in the compiled code.
1533 nigel 87 Version 6.5 01-Feb-06
1534     ---------------------
1536     1. When using the partial match feature with pcre_dfa_exec(), it was not
1537     anchoring the second and subsequent partial matches at the new starting
1538     point. This could lead to incorrect results. For example, with the pattern
1539     /1234/, partially matching against "123" and then "a4" gave a match.
1541     2. Changes to pcregrep:
1543     (a) All non-match returns from pcre_exec() were being treated as failures
1544     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1545     error message is output. Some extra information is given for the
1547     probably the only errors that are likely to be caused by users (by
1548     specifying a regex that has nested indefinite repeats, for instance).
1549     If there are more than 20 of these errors, pcregrep is abandoned.
1551     (b) A binary zero was treated as data while matching, but terminated the
1552     output line if it was written out. This has been fixed: binary zeroes
1553     are now no different to any other data bytes.
1555     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1556     used to set a locale for matching. The --locale=xxxx long option has
1557     been added (no short equivalent) to specify a locale explicitly on the
1558     pcregrep command, overriding the environment variables.
1560     (d) When -B was used with -n, some line numbers in the output were one less
1561     than they should have been.
1563     (e) Added the -o (--only-matching) option.
1565     (f) If -A or -C was used with -c (count only), some lines of context were
1566     accidentally printed for the final match.
1568     (g) Added the -H (--with-filename) option.
1570     (h) The combination of options -rh failed to suppress file names for files
1571     that were found from directory arguments.
1573     (i) Added the -D (--devices) and -d (--directories) options.
1575     (j) Added the -F (--fixed-strings) option.
1577     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1579     (l) Added the --colo(u)r option.
1581     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1582     is not present by default.
1584     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1585     items such as (?R) or (?1), when the recursion could match a number of
1586     alternatives. If it matched one of the alternatives, but subsequently,
1587     outside the recursion, there was a failure, the code tried to back up into
1588     the recursion. However, because of the way PCRE is implemented, this is not
1589     possible, and the result was an incorrect result from the match.
1591     In order to prevent this happening, the specification of recursion has
1592     been changed so that all such subpatterns are automatically treated as
1593     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1595     4. I had overlooked the fact that, in some locales, there are characters for
1596     which isalpha() is true but neither isupper() nor islower() are true. In
1597     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1598     and ordfeminine) are like this. This affected the treatment of \w and \W
1599     when they appeared in character classes, but not when they appeared outside
1600     a character class. The bit map for "word" characters is now created
1601     separately from the results of isalnum() instead of just taking it from the
1602     upper, lower, and digit maps. (Plus the underscore character, of course.)
1604     5. The above bug also affected the handling of POSIX character classes such as
1605     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1606     permanent tables. Instead, the bit maps for such a class were previously
1607     created as the appropriate unions of the upper, lower, and digit bitmaps.
1608     Now they are created by subtraction from the [[:word:]] class, which has
1609     its own bitmap.
1611     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1612     It is created by subtracting the vertical space characters (\x09, \x0a,
1613     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1614     subtraction was done in the overall bitmap for a character class, meaning
1615     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1616     be recognized. This bug has been fixed.
1618     7. Patches from the folks at Google:
1620     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1621     real life, but is still worth protecting against".
1623     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1624     regular expressions".
1626     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1627     have it.
1629     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1630     "configure" and the latter not, in order to fix a problem somebody had
1631     with compiling the Arg class on HP-UX.
1633     (e) Improve the error-handling of the C++ wrapper a little bit.
1635     (f) New tests for checking recursion limiting.
1637     8. The pcre_memmove() function, which is used only if the environment does not
1638     have a standard memmove() function (and is therefore rarely compiled),
1639     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1640     returning a result (though PCRE never actually uses the result).
1642     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1643     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1644     returned instead of calling malloc() with an overflowing number that would
1645     most likely cause subsequent chaos.
1647     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1649     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1650     with this option is matched, the nmatch and pmatch options of regexec() are
1651     ignored.
1653     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1654     provided in case anyone wants to the the POSIX interface with UTF-8
1655     strings.
1657     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1658     C++ linking (needed for some HP-UX environments).
1660     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1661     (unused parameter) and in the pcre_printint() function (omitted "default"
1662     switch label when the default is to do nothing).
1664     15. Added some code to make it possible, when PCRE is compiled as a C++
1665     library, to replace subject pointers for pcre_exec() with a smart pointer
1666     class, thus making it possible to process discontinuous strings.
1668     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1669     much the same function. They were added by different people who were trying
1670     to make PCRE easy to compile on non-Unix systems. It has been suggested
1671     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1672     for compiling on Windows systems. I have therefore replaced it with
1673     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1674     defaults to "extern" for C or "extern C" for C++, which works fine on
1675     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1676     SCOPE with something explicit in config.h. In addition:
1678     (a) pcreposix.h still had just "extern" instead of either of these macros;
1679     I have replaced it with PCRE_DATA_SCOPE.
1681     (b) Functions such as _pcre_xclass(), which are internal to the library,
1682     but external in the C sense, all had PCRE_EXPORT in their definitions.
1683     This is apparently wrong for the Windows case, so I have removed it.
1684     (It makes no difference on Unix-like systems.)
1686     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1687     of recursive calls to match(). This is different to MATCH_LIMIT because
1688     that limits the total number of calls to match(), not all of which increase
1689     the depth of recursion. Limiting the recursion depth limits the amount of
1690     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1691     when PCRE is compiled, and changed at run time. A patch from Google adds
1692     this functionality to the C++ interface.
1694     18. Changes to the handling of Unicode character properties:
1696     (a) Updated the table to Unicode 4.1.0.
1698     (b) Recognize characters that are not in the table as "Cn" (undefined).
1700     (c) I revised the way the table is implemented to a much improved format
1701     which includes recognition of ranges. It now supports the ranges that
1702     are defined in UnicodeData.txt, and it also amalgamates other
1703     characters into ranges. This has reduced the number of entries in the
1704     table from around 16,000 to around 3,000, thus reducing its size
1705     considerably. I realized I did not need to use a tree structure after
1706     all - a binary chop search is just as efficient. Having reduced the
1707     number of entries, I extended their size from 6 bytes to 8 bytes to
1708     allow for more data.
1710     (d) Added support for Unicode script names via properties such as \p{Han}.
1712     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1713     matching that character.
1715     20. When matching a repeated Unicode property with a minimum greater than zero,
1716     (for example \pL{2,}), PCRE could look past the end of the subject if it
1717     reached it while seeking the minimum number of characters. This could
1718     happen only if some of the characters were more than one byte long, because
1719     there is a check for at least the minimum number of bytes.
1721     21. Refactored the implementation of \p and \P so as to be more general, to
1722     allow for more different types of property in future. This has changed the
1723     compiled form incompatibly. Anybody with saved compiled patterns that use
1724     \p or \P will have to recompile them.
1726     22. Added "Any" and "L&" to the supported property types.
1728     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1729     but give a compile time error if the value is greater than 0xff.
1731     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1732     accidentally not being installed or uninstalled.
1734     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1735     made were to insert the current release number. This seemed silly, because
1736     it made things harder for people building PCRE on systems that don't run
1737     "configure". I have turned pcre.h into a distributed file, no longer built
1738     by "configure", with the version identification directly included. There is
1739     no longer a pcre.h.in file.
1741     However, this change necessitated a change to the pcre-config script as
1742     well. It is built from pcre-config.in, and one of the substitutions was the
1743     release number. I have updated configure.ac so that ./configure now finds
1744     the release number by grepping pcre.h.
1746     26. Added the ability to run the tests under valgrind.
1749 nigel 85 Version 6.4 05-Sep-05
1750     ---------------------
1752     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1753     "--" to be printed when multiple files were scanned, even when none of the
1754     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1755     consider it to be a bug, and have restored the previous behaviour.
1757     2. A couple of code tidies to get rid of compiler warnings.
1759     3. The pcretest program used to cheat by referring to symbols in the library
1760     whose names begin with _pcre_. These are internal symbols that are not
1761     really supposed to be visible externally, and in some environments it is
1762     possible to suppress them. The cheating is now confined to including
1763     certain files from the library's source, which is a bit cleaner.
1765     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1766     file's purpose clearer.
1768     5. Reorganized pcre_ucp_findchar().
1771 nigel 83 Version 6.3 15-Aug-05
1772     ---------------------
1774     1. The file libpcre.pc.in did not have general read permission in the tarball.
1776     2. There were some problems when building without C++ support:
1778     (a) If C++ support was not built, "make install" and "make test" still
1779     tried to test it.
1781     (b) There were problems when the value of CXX was explicitly set. Some
1782     changes have been made to try to fix these, and ...
1784     (c) --disable-cpp can now be used to explicitly disable C++ support.
1786     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1787     backslash in a target when C++ was disabled. This confuses some
1788     versions of "make", apparently. Using an intermediate variable solves
1789     this. (Same for CPP_LOBJ.)
1791     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1792     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1793     necessary on certain architectures.
1795     4. Added a setting of -export-symbols-regex to the link command to remove
1796     those symbols that are exported in the C sense, but actually are local
1797     within the library, and not documented. Their names all begin with
1798     "_pcre_". This is not a perfect job, because (a) we have to except some
1799     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1800     available (and never for static libraries). I have made a note to try to
1801     find a way round (a) in the future.
1804 nigel 81 Version 6.2 01-Aug-05
1805     ---------------------
1807     1. There was no test for integer overflow of quantifier values. A construction
1808     such as {1111111111111111} would give undefined results. What is worse, if
1809     a minimum quantifier for a parenthesized subpattern overflowed and became
1810     negative, the calculation of the memory size went wrong. This could have
1811     led to memory overwriting.
1813     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1815     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1816     operating environments where this matters.
1818     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1819     PCRE options from within the C++ wrapper.
1821     5. Named capturing subpatterns were not being correctly counted when a pattern
1822     was compiled. This caused two problems: (a) If there were more than 100
1823     such subpatterns, the calculation of the memory needed for the whole
1824     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1825     back references of the form \12, where the number was greater than 9, were
1826     not recognized as back references, even though there were sufficient
1827     previous subpatterns.
1829     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1830     versions of gcc, e.g. 2.95.4.
1833 nigel 79 Version 6.1 21-Jun-05
1834     ---------------------
1836     1. There was one reference to the variable "posix" in pcretest.c that was not
1837     surrounded by "#if !defined NOPOSIX".
1839     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1840     the cross-check on the old pcre_info() function, for the benefit of the
1841     cut-down version of PCRE that is currently imported into Exim.
1843     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1844     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1845     patterns that start (?i) but I don't think that matters. The use of (?i) is
1846     just an example; this all applies to the other options as well.
1848     4. Since libtool seems to echo the compile commands it is issuing, the output
1849     from "make" can be reduced a bit by putting "@" in front of each libtool
1850     compile command.
1852     5. Patch from the folks at Google for configure.in to be a bit more thorough
1853     in checking for a suitable C++ installation before trying to compile the
1854     C++ stuff. This should fix a reported problem when a compiler was present,
1855     but no suitable headers.
1857     6. The man pages all had just "PCRE" as their title. I have changed them to
1858     be the relevant file name. I have also arranged that these names are
1859     retained in the file doc/pcre.txt, which is a concatenation in text format
1860     of all the man pages except the little individual ones for each function.
1862     7. The NON-UNIX-USE file had not been updated for the different set of source
1863     files that come with release 6. I also added a few comments about the C++
1864     wrapper.
1867 nigel 77 Version 6.0 07-Jun-05
1868     ---------------------
1870     1. Some minor internal re-organization to help with my DFA experiments.
1872     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1873     didn't matter for the library itself when fully configured, but did matter
1874     when compiling without UCP support, or within Exim, where the ucp files are
1875     not imported.
1877     3. Refactoring of the library code to split up the various functions into
1878     different source modules. The addition of the new DFA matching code (see
1879     below) to a single monolithic source would have made it really too
1880     unwieldy, quite apart from causing all the code to be include in a
1881     statically linked application, when only some functions are used. This is
1882     relevant even without the DFA addition now that patterns can be compiled in
1883     one application and matched in another.
1885     The downside of splitting up is that there have to be some external
1886     functions and data tables that are used internally in different modules of
1887     the library but which are not part of the API. These have all had their
1888     names changed to start with "_pcre_" so that they are unlikely to clash
1889     with other external names.
1891     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1892     a different (DFA) algorithm. Although it is slower than the original
1893     function, it does have some advantages for certain types of matching
1894     problem.
1896     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1897     including restarting after a partial match.
1899     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1900     defined when compiling for Windows was sent to me. I have put it into the
1901     code, though I have no means of testing or verifying it.
1903     7. Added the pcre_refcount() auxiliary function.
1905     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1906     match before or at the first newline in the subject string. In pcretest,
1907     the /f option on a pattern can be used to set this.
1909     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1910     would behave wrongly. This has been present in PCRE since release 4.0.
1912     10. A number of changes to the pcregrep command:
1914     (a) Refactored how -x works; insert ^(...)$ instead of setting
1915     PCRE_ANCHORED and checking the length, in preparation for adding
1916     something similar for -w.
1918     (b) Added the -w (match as a word) option.
1920     (c) Refactored the way lines are read and buffered so as to have more
1921     than one at a time available.
1923     (d) Implemented a pcregrep test script.
1925     (e) Added the -M (multiline match) option. This allows patterns to match
1926     over several lines of the subject. The buffering ensures that at least
1927     8K, or the rest of the document (whichever is the shorter) is available
1928     for matching (and similarly the previous 8K for lookbehind assertions).
1930     (f) Changed the --help output so that it now says
1932     -w, --word-regex(p)
1934     instead of two lines, one with "regex" and the other with "regexp"
1935     because that confused at least one person since the short forms are the
1936     same. (This required a bit of code, as the output is generated
1937     automatically from a table. It wasn't just a text change.)
1939     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1940     option but starts with a hyphen. Could be a pattern or a path name
1941     starting with a hyphen, for instance.
1943     (h) "-" can be given as a file name to represent stdin.
1945     (i) When file names are being printed, "(standard input)" is used for
1946     the standard input, for compatibility with GNU grep. Previously
1947     "<stdin>" was used.
1949     (j) The option --label=xxx can be used to supply a name to be used for
1950     stdin when file names are being printed. There is no short form.
1952     (k) Re-factored the options decoding logic because we are going to add
1953     two more options that take data. Such options can now be given in four
1954     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1956     (l) Added the -A, -B, and -C options for requesting that lines of context
1957     around matches be printed.
1959     (m) Added the -L option to print the names of files that do not contain
1960     any matching lines, that is, the complement of -l.
1962     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1963     continue to scan other files.
1965     (o) The -s option was incorrectly implemented. For compatibility with other
1966     greps, it now suppresses the error message for a non-existent or non-
1967     accessible file (but not the return code). There is a new option called
1968     -q that suppresses the output of matching lines, which was what -s was
1969     previously doing.
1971     (p) Added --include and --exclude options to specify files for inclusion
1972     and exclusion when recursing.
1974     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1975     Hopefully, it now does.
1977     12. Missing cast in pcre_study().
1979     13. Added an "uninstall" target to the makefile.
1981     14. Replaced "extern" in the function prototypes in Makefile.in with
1982     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1983     world, but is set differently for Windows.
1985     15. Added a second compiling function called pcre_compile2(). The only
1986     difference is that it has an extra argument, which is a pointer to an
1987     integer error code. When there is a compile-time failure, this is set
1988     non-zero, in addition to the error test pointer being set to point to an
1989     error message. The new argument may be NULL if no error number is required
1990     (but then you may as well call pcre_compile(), which is now just a
1991     wrapper). This facility is provided because some applications need a
1992     numeric error indication, but it has also enabled me to tidy up the way
1993     compile-time errors are handled in the POSIX wrapper.
1995     16. Added VPATH=.libs to the makefile; this should help when building with one
1996     prefix path and installing with another. (Or so I'm told by someone who
1997     knows more about this stuff than I do.)
1999     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2000     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2001     match everything, including newlines. This is not POSIX-compatible, but
2002     somebody wanted the feature. From pcretest it can be activated by using
2003     both the P and the s flags.
2005     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2007     19. libpcre.pc was being incorrectly installed as executable.
2009     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2010     it now also looks for '\r' so that it will work unmodified on Windows.
2012     21. Added Google's contributed C++ wrapper to the distribution.
2014     22. Added some untidy missing memory free() calls in pcretest, to keep
2015     Electric Fence happy when testing.
2019 nigel 75 Version 5.0 13-Sep-04
2020     ---------------------
2022     1. Internal change: literal characters are no longer packed up into items
2023     containing multiple characters in a single byte-string. Each character
2024     is now matched using a separate opcode. However, there may be more than one
2025     byte in the character in UTF-8 mode.
2027     2. The pcre_callout_block structure has two new fields: pattern_position and
2028     next_item_length. These contain the offset in the pattern to the next match
2029     item, and its length, respectively.
2031     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2032     insertion of callouts before each pattern item. Added the /C option to
2033     pcretest to make use of this.
2035     4. On the advice of a Windows user, the lines
2037     #if defined(_WIN32) || defined(WIN32)
2038     _setmode( _fileno( stdout ), 0x8000 );
2039     #endif /* defined(_WIN32) || defined(WIN32) */
2041     have been added to the source of pcretest. This apparently does useful
2042     magic in relation to line terminators.
2044     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2045     for the benefit of those environments where the "b" makes a difference.
2047     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2048     to know about it. I have put a hack into configure.in that adds in code
2049     to set GCC=yes if CC=icc. This seems to end up at a point in the
2050     generated configure script that is early enough to affect the setting of
2051     compiler options, which is what is needed, but I have no means of testing
2052     whether it really works. (The user who reported this had patched the
2053     generated configure script, which of course I cannot do.)
2055     LATER: After change 22 below (new libtool files), the configure script
2056     seems to know about icc (and also ecc). Therefore, I have commented out
2057     this hack in configure.in.
2059     7. Added support for pkg-config (2 patches were sent in).
2061     8. Negated POSIX character classes that used a combination of internal tables
2062     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2063     [[:^ascii]]. Typically, they would match almost any characters. The other
2064     POSIX classes were not broken in this way.
2066     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2067     to find the match, as PCRE was deluded into thinking that the match had to
2068     start at the start point or following a newline. The same bug applied to
2069     patterns with negative forward assertions or any backward assertions
2070     preceding ".*" at the start, unless the pattern required a fixed first
2071     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2073     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2074     starting at the last subject character, bytes beyond the end of the subject
2075     string were read.
2077     11. Renamed the variable "class" as "classbits" to make life easier for C++
2078     users. (Previously there was a macro definition, but it apparently wasn't
2079     enough.)
2081     12. Added the new field "tables" to the extra data so that tables can be passed
2082     in at exec time, or the internal tables can be re-selected. This allows
2083     a compiled regex to be saved and re-used at a later time by a different
2084     program that might have everything at different addresses.
2086     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2087     -R library as well as a -L library.
2089     14. The debugging options of pcretest (-d on the command line or D on a
2090     pattern) showed incorrect output for anything following an extended class
2091     that contained multibyte characters and which was followed by a quantifier.
2093     15. Added optional support for general category Unicode character properties
2094     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2095     support. It adds about 90K to the size of the library. The meanings of the
2096     inbuilt class escapes such as \d and \s have NOT been changed.
2098     16. Updated pcredemo.c to include calls to free() to release the memory for the
2099     compiled pattern.
2101     17. The generated file chartables.c was being created in the source directory
2102     instead of in the building directory. This caused the build to fail if the
2103     source directory was different from the building directory, and was
2104     read-only.
2106     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2107     file. No doubt somebody will tell me if they don't make sense... Also added
2108     Dan Mooney's comments about building on OpenVMS.
2110     19. Added support for partial matching via the PCRE_PARTIAL option for
2111     pcre_exec() and the \P data escape in pcretest.
2113     20. Extended pcretest with 3 new pattern features:
2115     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2116     write the compiled pattern to the file whose name is "rest-of-line".
2117     This is a straight binary dump of the data, with the saved pointer to
2118     the character tables forced to be NULL. The study data, if any, is
2119     written too. After writing, pcretest reads a new pattern.
2121     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2122     compiled pattern from the given file. There must not be any
2123     occurrences of "<" in the file name (pretty unlikely); if there are,
2124     pcretest will instead treat the initial "<" as a pattern delimiter.
2125     After reading in the pattern, pcretest goes on to read data lines as
2126     usual.
2128     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2129     and 16-bit fields in a compiled pattern, to simulate a pattern that
2130     was compiled on a host of opposite endianness.
2132     21. The pcre-exec() function can now cope with patterns that were compiled on
2133     hosts of opposite endianness, with this restriction:
2135     As for any compiled expression that is saved and used later, the tables
2136     pointer field cannot be preserved; the extra_data field in the arguments
2137     to pcre_exec() should be used to pass in a tables address if a value
2138     other than the default internal tables were used at compile time.
2140     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2141     now diagnosed as an error. Previously, most of the time, a negative number
2142     would have been treated as zero, but if in addition "ovector" was passed as
2143     NULL, a crash could occur.
2145     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2146     new versions from the libtool 1.5 distribution (the last one is a copy of
2147     a file called libtool.m4). This seems to have fixed the need to patch
2148     "configure" to support Darwin 1.3 (which I used to do). However, I still
2149     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2150     workstation).
2152     24. Changed the PCRE licence to be the more standard "BSD" licence.
2155 nigel 73 Version 4.5 01-Dec-03
2156     ---------------------
2158     1. There has been some re-arrangement of the code for the match() function so
2159     that it can be compiled in a version that does not call itself recursively.
2160     Instead, it keeps those local variables that need separate instances for
2161     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2162     needs to "recurse". Keeping track of where control must go is done by means
2163     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2164     hide most of the details from the main code, and operates only if
2165     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2166     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2167     operating.
2169     To make it easier for callers to provide specially tailored get/free
2170     functions for this usage, two new functions, pcre_stack_malloc, and
2171     pcre_stack_free, are used. They are always called in strict stacking order,
2172     and the size of block requested is always the same.
2174     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2175     PCRE has been compiled to use the stack or the heap for recursion. The
2176     -C option of pcretest uses this to show which version is compiled.
2178     A new data escape \S, is added to pcretest; it causes the amounts of store
2179     obtained and freed by both kinds of malloc/free at match time to be added
2180     to the output.
2182     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2183     what's available on my current Linux desktop machine.
2185     3. When matching a UTF-8 string, the test for a valid string at the start has
2186     been extended. If start_offset is not zero, PCRE now checks that it points
2187     to a byte that is the start of a UTF-8 character. If not, it returns
2188     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2189     this is necessary because there may be backward assertions in the pattern.
2190     When matching the same subject several times, it may save resources to use
2191     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2193     4. The code for checking the validity of UTF-8 strings has been tightened so
2194     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2195     containing "overlong sequences".
2197     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2198     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2199     should have been "&", but it just so happened that all the cases this let
2200     through by mistake were picked up later in the function.
2202     6. I had used a variable called "isblank" - this is a C99 function, causing
2203     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2205     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2206     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2207     so the version is shown; (c) stop "make test" echoing "./RunTest".
2209     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2211     9. The prototype for memmove() for systems that don't have it was using
2212     size_t, but the inclusion of the header that defines size_t was later. I've
2213     moved the #includes for the C headers earlier to avoid this.
2215     10. Added some adjustments to the code to make it easier to compiler on certain
2216     special systems:
2218     (a) Some "const" qualifiers were missing.
2219     (b) Added the macro EXPORT before all exported functions; by default this
2220     is defined to be empty.
2221     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2222     that it reads its output file name as an argument instead of writing
2223     to the standard output and assuming this can be redirected.
2225     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2226     class containing characters with values greater than 255, PCRE compilation
2227     went into a loop.
2229     12. A recursive reference to a subpattern that was within another subpattern
2230     that had a minimum quantifier of zero caused PCRE to crash. For example,
2231     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2232     recursion. If the recursively-called subpattern itself had a zero repeat,
2233     that was OK.
2235     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2236     buffer into which it was copied (for escape processing) was still set at
2237     1024, so long lines caused crashes.
2239     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2240     "internal error: code overflow...". This applied to any character class
2241     that was followed by a possessive quantifier.
2243     15. Modified the Makefile to add libpcre.la as a prerequisite for
2244     libpcreposix.la because I was told this is needed for a parallel build to
2245     work.
2247     16. If a pattern that contained .* following optional items at the start was
2248     studied, the wrong optimizing data was generated, leading to matching
2249     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2250     matching string must start with a or b or c. The correct conclusion for
2251     this pattern is that a match can start with any character.
2254 nigel 71 Version 4.4 13-Aug-03
2255     ---------------------
2257     1. In UTF-8 mode, a character class containing characters with values between
2258     127 and 255 was not handled correctly if the compiled pattern was studied.
2259     In fixing this, I have also improved the studying algorithm for such
2260     classes (slightly).
2262     2. Three internal functions had redundant arguments passed to them. Removal
2263     might give a very teeny performance improvement.
2265     3. Documentation bug: the value of the capture_top field in a callout is *one
2266     more than* the number of the hightest numbered captured substring.
2268     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2269     in incorrectly linking with a previously installed version. They now link
2270     explicitly with libpcre.la.
2272     5. configure.in no longer needs to recognize Cygwin specially.
2274     6. A problem in pcre.in for Windows platforms is fixed.
2276     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2277     pcretest, it used to include the size of the study block as part of its
2278     output. Unfortunately, the structure contains a field that has a different
2279     size on different hardware architectures. This meant that the tests that
2280     showed this size failed. As the block is currently always of a fixed size,
2281     this information isn't actually particularly useful in pcretest output, so
2282     I have just removed it.
2284     8. Three pre-processor statements accidentally did not start in column 1.
2285     Sadly, there are *still* compilers around that complain, even though
2286     standard C has not required this for well over a decade. Sigh.
2288     9. In pcretest, the code for checking callouts passed small integers in the
2289     callout_data field, which is a void * field. However, some picky compilers
2290     complained about the casts involved for this on 64-bit systems. Now
2291     pcretest passes the address of the small integer instead, which should get
2292     rid of the warnings.
2294     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2295     both compile and run time, and gives an error if an invalid UTF-8 sequence
2296     is found. There is a option for disabling this check in cases where the
2297     string is known to be correct and/or the maximum performance is wanted.
2299     11. In response to a bug report, I changed one line in Makefile.in from
2301     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2302     to
2303     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2305     to look similar to other lines, but I have no way of telling whether this
2306     is the right thing to do, as I do not use Windows. No doubt I'll get told
2307     if it's wrong...
2310 nigel 69 Version 4.3 21-May-03
2311     ---------------------
2313     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2314     Makefile.
2316     2. Some refactoring to improve the quality of the code:
2318     (i) The utf8_table... variables are now declared "const".
2320     (ii) The code for \cx, which used the "case flipping" table to upper case
2321     lower case letters, now just substracts 32. This is ASCII-specific,
2322     but the whole concept of \cx is ASCII-specific, so it seems
2323     reasonable.
2325     (iii) PCRE was using its character types table to recognize decimal and
2326     hexadecimal digits in the pattern. This is silly, because it handles
2327     only 0-9, a-f, and A-F, but the character types table is locale-
2328     specific, which means strange things might happen. A private
2329     table is now used for this - though it costs 256 bytes, a table is
2330     much faster than multiple explicit tests. Of course, the standard
2331     character types table is still used for matching digits in subject
2332     strings against \d.
2334     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2335     ending in _t are). So I've renamed it as ESC_tee.
2337     3. The first argument for regexec() in the POSIX wrapper should have been
2338     defined as "const".
2340     4. Changed pcretest to use malloc() for its buffers so that they can be
2341     Electric Fenced for debugging.
2343     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2344     to read one or more bytes before the start of the subject string. Often this
2345     had no effect on PCRE's behaviour, but in some circumstances it could
2346     provoke a segmentation fault.
2348     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2349     to try to read one or more bytes before the start of the subject string.
2351     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2352     UTF-8 support could misbehave in various ways if the subject string
2353     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2354     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2355     back over UTF-8 characters.)
2358 nigel 67 Version 4.2 14-Apr-03
2359     ---------------------
2361     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2363     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2364     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2365     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2366     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2367     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2368     and BUILD_EXEEXT
2369     Note: automatic setting of the BUILD variables is not yet working
2370     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2371     compile-time but not at link-time
2372     [LINK]: use for linking executables only
2373     make different versions for Windows and non-Windows
2374     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2375     libraries
2376     [LINK_FOR_BUILD]: new variable
2377     [OBJEXT]: use throughout
2378     [EXEEXT]: use throughout
2379     <winshared>: new target
2380     <wininstall>: new target
2381     <dftables.o>: use native compiler
2382     <dftables>: use native linker
2383     <install>: handle Windows platform correctly
2384     <clean>: ditto
2385     <check>: ditto
2386     copy DLL to top builddir before testing
2388     As part of these changes, -no-undefined was removed again. This was reported
2389     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2390     in any case.
2392     3. Some tidies to get rid of compiler warnings:
2394     . In the match_data structure, match_limit was an unsigned long int, whereas
2395     match_call_count was an int. I've made them both unsigned long ints.
2397     . In pcretest the fact that a const uschar * doesn't automatically cast to
2398     a void * provoked a warning.
2400     . Turning on some more compiler warnings threw up some "shadow" variables
2401     and a few more missing casts.
2403     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2404     option, a class that contained a single character with a value between 128
2405     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2407     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2408     option, a class that contained several characters, but with at least one
2409     whose value was between 128 and 255 caused PCRE to crash.
2412 nigel 65 Version 4.1 12-Mar-03
2413     ---------------------
2414 nigel 63
2415 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2416     needed, and a string in dftables.c that was longer than standard compilers are
2417     required to support.
2419     2. Compiling with Sun's compiler found a few more places where the code could
2420     be tidied up in order to avoid warnings.
2422     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2423     first of these names is deprecated in the latest Autoconf in favour of the name
2424     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2425     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2426     analogy I have changed it to CFLAGS_FOR_BUILD.
2428     4. Added -no-undefined to the linking command in the Makefile, because this is
2429     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2430     linking step for the pcreposix library.
2432     5. PCRE was failing to diagnose the case of two named groups with the same
2433     name.
2435     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2436     literal character that is needed in the subject for a match, and scans along to
2437     ensure that it is present before embarking on the full matching process. This
2438     saves time in cases of nested unlimited repeats that are never going to match.
2439     Problem: the scan can take a lot of time if the subject is very long (e.g.
2440     megabytes), thus penalizing straightforward matches. It is now done only if the
2441     amount of subject to be scanned is less than 1000 bytes.
2443     7. A lesser problem with the same optimization is that it was recording the
2444     first character of an anchored pattern as "needed", thus provoking a search
2445     right along the subject, even when the first match of the pattern was going to
2446     fail. The "needed" character is now not set for anchored patterns, unless it
2447     follows something in the pattern that is of non-fixed length. Thus, it still
2448     fulfils its original purpose of finding quick non-matches in cases of nested
2449     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2452     Version 4.0 17-Feb-03
2453     ---------------------
2455 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2456     extended to the end of string, PCRE compiled incorrect data. This could lead to
2457     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2459     2. Moved to autoconf 2.53 and libtool 1.4.2.
2461     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2462     the special perltest8 script is no longer needed - all the tests can be run
2463     from a single perltest script.
2465     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2466     by \s. It has now been removed in PCRE. This means it isn't recognized as
2467     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2468     class [:space:] *does* include VT, thereby creating a mess.
2470     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2471     space and tab.
2473     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2474     its new features into the main test script, reducing the number of scripts.
2476     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2477     were backward compatible, and made the (?i) apply to the whole pattern, as if
2478     /i were given. Now it behaves more logically, and applies the option setting
2479     only to what follows. PCRE has been changed to follow suit. However, if it
2480     finds options settings right at the start of the pattern, it extracts them into
2481     the global options, as before. Thus, they show up in the info data.
2483     8. Added support for the \Q...\E escape sequence. Characters in between are
2484     treated as literals. This is slightly different from Perl in that $ and @ are
2485     also handled as literals inside the quotes. In Perl, they will cause variable
2486     interpolation. Note the following examples:
2488     Pattern PCRE matches Perl matches
2490     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2491     \Qabc\$xyz\E abc\$xyz abc\$xyz
2492     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2494     For compatibility with Perl, \Q...\E sequences are recognized inside character
2495     classes as well as outside them.
2497     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2498     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2499     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2500     signed/unsigned warnings.
2502     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2503     option for pcretest, so I've replaced it by a simple function that does just
2504     that job.
2506     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2507     "pcregrep -".
2509     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2510     Java package. This provides some syntactic sugar for simple cases of what my
2511     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2512     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2513     item, you can use this simplified notation. Note that only makes sense with
2514     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2515     greediness, whatever the setting of the PCRE_UNGREEDY option.
2517     13. A change of greediness default within a pattern was not taking effect at
2518     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2519     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2520     was abstracted outside.
2522     14. PCRE now supports the \G assertion. It is true when the current matching
2523     position is at the start point of the match. This differs from \A when the
2524     starting offset is non-zero. Used with the /g option of pcretest (or similar
2525     code), it works in the same way as it does for Perl's /g option. If all
2526     alternatives of a regex begin with \G, the expression is anchored to the start
2527     match position, and the "anchored" flag is set in the compiled expression.
2529     15. Some bugs concerning the handling of certain option changes within patterns
2530     have been fixed. These applied to options other than (?ims). For example,
2531     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2532     been the other way round. Some of this was related to change 7 above.
2534     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2535     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2536     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2537     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2539     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2540     mode. Unlike ".", it always matches newline, whatever the setting of
2541     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2542     assertions. Perl allows it, but it doesn't (in general) work because it can't
2543     calculate the length of the lookbehind. At least, that's the case for Perl
2544     5.8.0 - I've been told they are going to document that it doesn't work in
2545     future.
2547     18. Added an error diagnosis for escapes that PCRE does not support: these are
2548     \L, \l, \N, \P, \p, \U, \u, and \X.
2550     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2551     reading past the end of the pattern in cases such as /[abcd/.
2553     20. PCRE was getting more memory than necessary for patterns with classes that
2554     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2556     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2557     compiling PCRE for use with Virtual Pascal.
2559     22. Small fix to the Makefile to make it work properly if the build is done
2560     outside the source tree.
2562     23. Added a new extension: a condition to go with recursion. If a conditional
2563     subpattern starts with (?(R) the "true" branch is used if recursion has
2564     happened, whereas the "false" branch is used only at the top level.
2566     24. When there was a very long string of literal characters (over 255 bytes
2567     without UTF support, over 250 bytes with UTF support), the computation of how
2568     much memory was required could be incorrect, leading to segfaults or other
2569     strange effects.
2571     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2572     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2573     there was a subsequent back reference to those brackets. This meant that, for
2574     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2575     possible to check for precisely this case. All we can do is abandon the
2576     optimization if .* occurs inside capturing brackets when there are any back
2577     references whatsoever. (See below for a better fix that came later.)
2579     26. The handling of the optimization for finding the first character of a
2580     non-anchored pattern, and for finding a character that is required later in the
2581     match were failing in some cases. This didn't break the matching; it just
2582     failed to optimize when it could. The way this is done has been re-implemented.
2584     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2586     28. Added a new feature that provides some of the functionality that Perl
2587     provides with (?{...}). The facility is termed a "callout". The way it is done
2588     in PCRE is for the caller to provide an optional function, by setting
2589     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2590     global variable. By default it is unset, which disables all calling out. To get
2591     the function called, the regex must include (?C) at appropriate points. This
2592     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2593     This provides a means of identifying different callout points. When PCRE
2594     reaches such a point in the regex, if pcre_callout has been set, the external
2595     function is called. It is provided with data in a structure called
2596     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2597     matching continues; if it returns a non-zero value, the match at the current
2598     point fails. However, backtracking will occur if possible. [This was changed
2599     later and other features added - see item 49 below.]
2601     29. pcretest is upgraded to test the callout functionality. It provides a
2602     callout function that displays information. By default, it shows the start of
2603     the match and the current position in the text. There are some new data escapes
2604     to vary what happens:
2606     \C+ in addition, show current contents of captured substrings
2607     \C- do not supply a callout function
2608     \C!n return 1 when callout number n is reached
2609     \C!n!m return 1 when callout number n is reached for the mth time
2611     30. If pcregrep was called with the -l option and just a single file name, it
2612     output "<stdin>" if a match was found, instead of the file name.
2614     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2615     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2616     pcre_exec(). This saves a malloc/free per call. The default value of
2617     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2618     when configuring.
2620     32. The default maximum size of a compiled pattern is 64K. There have been a
2621     few cases of people hitting this limit. The code now uses macros to handle the
2622     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2623     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2624     configuring. Tests 2 and 5 work only with 2-byte links because they output
2625     debugging information about compiled patterns.
2627     33. Internal code re-arrangements:
2629     (a) Moved the debugging function for printing out a compiled regex into
2630     its own source file (printint.c) and used #include to pull it into
2631     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2632     separate copies.
2634     (b) Defined the list of op-code names for debugging as a macro in
2635     internal.h so that it is next to the definition of the opcodes.
2637     (c) Defined a table of op-code lengths for simpler skipping along compiled
2638     code. This is again a macro in internal.h so that it is next to the
2639     definition of the opcodes.
2641     34. Added support for recursive calls to individual subpatterns, along the
2642     lines of Robin Houston's patch (but implemented somewhat differently).
2644     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2645     allow it to read and process whole directories in Win32. This code was
2646     contributed by Lionel Fourquaux; it has not been tested by me.
2648     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2649     used to name a group. Names consist of alphanumerics and underscores, and must
2650     be unique. Back references use the syntax (?P=name) and recursive calls use
2651     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2652     numbers. The function pcre_fullinfo() can be used after compilation to extract
2653     a name/number map. There are three relevant calls:
2655     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2656     PCRE_INFO_NAMECOUNT yields the number of entries
2657     PCRE_INFO_NAMETABLE yields a pointer to the map.
2659     The map is a vector of fixed-size entries. The size of each entry depends on
2660     the length of the longest name used. The first two bytes of each entry are the
2661     group number, most significant byte first. There follows the corresponding
2662     name, zero terminated. The names are in alphabetical order.
2664     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2665     case instead of 255. Making it the same both with and without UTF-8 support
2666     means that the same test output works with both.
2668     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2669     calling malloc() with a zero argument.
2671     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2672     optimization. I've improved things by keeping a bitmap of backreferences with
2673     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2674     fact referenced, the optimization can be applied. It is unlikely that a
2675     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2676     the match to follow \n) will appear inside brackets with a number greater than
2677     31, but if it does, any back reference > 31 suppresses the optimization.
2679     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2680     of disabling numbered capturing parentheses. Any opening parenthesis that is
2681     not followed by ? behaves as if it were followed by ?: but named parentheses
2682     can still be used for capturing (and they will acquire numbers in the usual
2683     way).
2685     41. Redesigned the return codes from the match() function into yes/no/error so
2686     that errors can be passed back from deep inside the nested calls. A malloc
2687     failure while inside a recursive subpattern call now causes the
2688     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2690     42. It is now possible to set a limit on the number of times the match()
2691     function is called in a call to pcre_exec(). This facility makes it possible to
2692     limit the amount of recursion and backtracking, though not in a directly
2693     obvious way, because the match() function is used in a number of different
2694     circumstances. The count starts from zero for each position in the subject
2695     string (for non-anchored patterns). The default limit is, for compatibility, a
2696     large number, namely 10 000 000. You can change this in two ways:
2698     (a) When configuring PCRE before making, you can use --with-match-limit=n
2699     to set a default value for the compiled library.
2701     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2702     a different value is set. See 45 below.
2704     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2706     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2707     of things that can be changed at compile time. The first argument specifies
2708     what is wanted and the second points to where the information is to be placed.
2709     The current list of available information is:
2713     The output is an integer that is set to one if UTF-8 support is available;
2714     otherwise it is set to zero.
2718     The output is an integer that it set to the value of the code that is used for
2719     newline. It is either LF (10) or CR (13).
2723     The output is an integer that contains the number of bytes used for internal
2724     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2728     The output is an integer that contains the threshold above which the POSIX
2729     interface uses malloc() for output vectors. See item 31 above.
2733     The output is an unsigned integer that contains the default limit of the number
2734     of match() calls in a pcre_exec() execution. See 42 above.
2736     44. pcretest has been upgraded by the addition of the -C option. This causes it
2737     to extract all the available output from the new pcre_config() function, and to
2738     output it. The program then exits immediately.
2740     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2741     order to support additional features. One way would have been to define
2742     pcre_exec2() (for example) with extra arguments, but this would not have been
2743     extensible, and would also have required all calls to the original function to
2744     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2745     is used for passing in "extra" data from pcre_study().
2747     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2748     contains the following fields:
2750     flags a bitmap indicating which of the following fields are set
2751     study_data opaque data from pcre_study()
2752     match_limit a way of specifying a limit on match() calls for a specific
2753     call to pcre_exec()
2754     callout_data data for callouts (see 49 below)
2756     The flag bits are also defined in pcre.h, and are
2762     The pcre_study() function now returns one of these new pcre_extra blocks, with
2763     the actual study data pointed to by the study_data field, and the
2764     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2765     before. That is, this change is entirely upwards-compatible and requires no
2766     change to existing code.
2768     If you want to pass in additional data to pcre_exec(), you can either place it
2769     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2770     block.
2772     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2773     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2774     times with different match limits, until it finds the minimum value needed for
2775     pcre_exec() to complete. The value is then output. This can be instructive; for
2776     most simple matches the number is quite small, but for pathological cases it
2777     gets very large very quickly.
2779     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2780     returns the size of the data block pointed to by the study_data field in a
2781     pcre_extra block, that is, the value that was passed as the argument to
2782     pcre_malloc() when PCRE was getting memory in which to place the information
2783     created by pcre_study(). The fourth argument should point to a size_t variable.
2784     pcretest has been extended so that this information is shown after a successful
2785     pcre_study() call when information about the compiled regex is being displayed.
2787     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2788     because what follows is always an absolute path. (Later: it turns out that this
2789     is more than cosmetic for MinGW, because it doesn't like empty path
2790     components.)
2792     49. Some changes have been made to the callout feature (see 28 above):
2794     (i) A callout function now has three choices for what it returns:
2796     0 => success, carry on matching
2797     > 0 => failure at this point, but backtrack if possible
2798     < 0 => serious error, return this value from pcre_exec()
2800     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2801     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2802     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2803     use by callout functions. It will never be used by PCRE itself.
2805     (ii) The pcre_extra structure (see 45 above) has a void * field called
2806     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2807     pcre_callout_block structure has a field of the same name. The contents of
2808     the field passed in the pcre_extra structure are passed to the callout
2809     function in the corresponding field in the callout block. This makes it
2810     easier to use the same callout-containing regex from multiple threads. For
2811     testing, the pcretest program has a new data escape
2813     \C*n pass the number n (may be negative) as callout_data
2815     If the callout function in pcretest receives a non-zero value as
2816     callout_data, it returns that value.
2818     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2819     there were some redundant $(CFLAGS) in commands that are now specified as
2820     $(LINK), which already includes $(CFLAGS).
2822     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2823     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2824     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2825     one-byte characters throughout. Note that case-insensitive matching applies
2826     only to characters whose values are less than 256. PCRE doesn't support the
2827     notion of cases for higher-valued characters.
2829     (i) A character class whose characters are all within 0-255 is handled as
2830     a bit map, and the map is inverted for negative classes. Previously, a
2831     character > 255 always failed to match such a class; however it should
2832     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2834     (ii) A negated character class with a single character < 255 is coded as
2835     "not this character" (OP_NOT). This wasn't working properly when the test
2836     character was multibyte, either singly or repeated.
2838     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2839     mode, for example: \x{100}{2,3}.
2841     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2842     singly or repeated) now correctly test multibyte characters. However,
2843     PCRE doesn't recognize any characters with values greater than 255 as
2844     digits, spaces, or word characters. Such characters always match \D, \S,
2845     and \W, and never match \d, \s, or \w.
2847     (v) Classes may now contain characters and character ranges with values
2848     greater than 255. For example: [ab\x{100}-\x{400}].
2850     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2851     PCRE in UTF-8 mode.
2853     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2854     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2855     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2856     value.)
2858     53. The single man page has become too large. I have therefore split it up into
2859     a number of separate man pages. These also give rise to individual HTML pages;
2860     these are now put in a separate directory, and there is an index.html page that
2861     lists them all. Some hyperlinking between the pages has been installed.
2863     54. Added convenience functions for handling named capturing parentheses.
2865     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2866     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2867     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2868     are faulted.
2870     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2871     calling configure. These values are used when compiling the dftables.c program
2872     which is run to generate the source of the default character tables. They
2873     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2874     you will need to set these values.
2876     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2879     Version 3.9 02-Jan-02
2880 nigel 61 ---------------------
2882     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2884     2. If --disable-static was given, the building process failed when trying to
2885     build pcretest and pcregrep. (For some reason it was using libtool to compile
2886     them, which is not right, as they aren't part of the library.)
2889 nigel 59 Version 3.8 18-Dec-01
2890     ---------------------
2892     1. The experimental UTF-8 code was completely screwed up. It was packing the
2893     bytes in the wrong order. How dumb can you get?
2896 nigel 57 Version 3.7 29-Oct-01
2897     ---------------------
2899     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2900     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2901     this didn't happen under Solaris 8, where I normally test things.
2903 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2904     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2905     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2906     this fix an hour or so after the initial 3.7 release.)
2907 nigel 57
2908 nigel 59
2909 nigel 55 Version 3.6 23-Oct-01
2910     ---------------------
2912     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2913     offsets passed as NULL with zero offset count.
2915     2. The config.guess and config.sub files had not been updated when I moved to
2916     the latest autoconf.
2919 nigel 53 Version 3.5 15-Aug-01
2920     ---------------------
2921 nigel 5
2922 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2923     had been forgotten.
2925     2. By using declared but undefined structures, we can avoid using "void"
2926     definitions in pcre.h while keeping the internal definitions of the structures
2927     private.
2929     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2930     user point of view, this means that both static and shared libraries are built
2931     by default, but this can be individually controlled. More of the work of
2932     handling this static/shared cases is now inside libtool instead of PCRE's make
2933     file.
2935     4. The pcretest utility is now installed along with pcregrep because it is
2936     useful for users (to test regexs) and by doing this, it automatically gets
2937     relinked by libtool. The documentation has been turned into a man page, so
2938     there are now .1, .txt, and .html versions in /doc.
2940     5. Upgrades to pcregrep:
2941     (i) Added long-form option names like gnu grep.
2942     (ii) Added --help to list all options with an explanatory phrase.
2943     (iii) Added -r, --recursive to recurse into sub-directories.
2944     (iv) Added -f, --file to read patterns from a file.
2946     6. pcre_exec() was referring to its "code" argument before testing that
2947     argument for NULL (and giving an error if it was NULL).
2949     7. Upgraded Makefile.in to allow for compiling in a different directory from
2950     the source directory.
2952     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2953     options bits, the pointer it was passed was to an int instead of to an unsigned
2954     long int. This mattered only on 64-bit systems.
2956     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2957     generated) instead of pcre.in, which it its source. Also made the same change
2958     in several of the .c files.
2960     10. A new release of gcc defines printf() as a macro, which broke pcretest
2961     because it had an ifdef in the middle of a string argument for printf(). Fixed
2962     by using separate calls to printf().
2964     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2965     script, to force use of CR or LF instead of \n in the source. On non-Unix
2966     systems, the value can be set in config.h.
2968     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2969     absolute limit. Changed the text of the error message to make this clear, and
2970     likewise updated the man page.
2972     13. The limit of 99 on the number of capturing subpatterns has been removed.
2973     The new limit is 65535, which I hope will not be a "real" limit.
2976 nigel 51 Version 3.4 22-Aug-00
2977     ---------------------
2979     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2981     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2984 nigel 49 Version 3.3 01-Aug-00
2985     ---------------------
2987     1. If an octal character was given, but the value was greater than \377, it
2988     was not getting masked to the least significant bits, as documented. This could
2989     lead to crashes in some systems.
2991     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2992     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2994     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2995     These just pass their arguments on to (pcre_free)(), but they are provided
2996     because some uses of PCRE bind it to non-C systems that can call its functions,
2997     but cannot call free() or pcre_free() directly.
2999     4. Add "make test" as a synonym for "make check". Corrected some comments in
3000     the Makefile.
3002     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3003     Makefile.
3005     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3006     command called pgrep for grepping around the active processes.
3008     7. Added the beginnings of support for UTF-8 character strings.
3010     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3011     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3012     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3013     out for the ar command.)
3016 nigel 47 Version 3.2 12-May-00
3017     ---------------------
3019     This is purely a bug fixing release.
3021     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3022     of ZA. This was just one example of several cases that could provoke this bug,
3023     which was introduced by change 9 of version 2.00. The code for breaking
3024     infinite loops after an iteration that matches an empty string was't working
3025     correctly.
3027     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3028     when matched against abbab (for example). After matching an empty string, it
3029     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3030     caused it to match further down the string than it should.
3032     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3033     was there because it doesn't seem to be needed, and it causes trouble on some
3034     systems, as it is not a Standard C header. It has been removed.
3036     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3037     were reported on the Macintosh. The changes were from
3039     while ((c = *(++ptr)) != 0 && c != '\n');
3040     to
3041     while ((c = *(++ptr)) != 0 && c != '\n') ;
3043     Totally extraordinary, but if that's what it takes...
3045     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3046     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3047     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3048     assumes the way PCRE uses memmove() (always moving upwards).
3050     6. PCRE is being used in one environment where strchr() is not available. There
3051     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3052     faster code anyway.
3055 nigel 45 Version 3.1 09-Feb-00
3056     ---------------------
3058     The only change in this release is the fixing of some bugs in Makefile.in for
3059     the "install" target:
3061     (1) It was failing to install pcreposix.h.
3063     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3066 nigel 43 Version 3.0 01-Feb-00
3067     ---------------------
3068 nigel 41
3069     1. Add support for the /+ modifier to perltest (to output $` like it does in
3070     pcretest).
3072     2. Add support for the /g modifier to perltest.
3074     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3075     matches null strings.
3077     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3078     pattern. Perl treats empty patterns specially - it reuses the most recent
3079     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3080     effect.
3082     5. The POSIX interface was broken in that it was just handing over the POSIX
3083     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3084     required a bigger vector, with some working space on the end. This means that
3085     the POSIX wrapper now has to get and free some memory, and copy the results.
3087 nigel 43 6. Added some simple autoconf support, placing the test data and the
3088     documentation in separate directories, re-organizing some of the
3089     information files, and making it build pcre-config (a GNU standard). Also added
3090     libtool support for building PCRE as a shared library, which is now the
3091     default.
3092 nigel 41
3093 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3094     09 are not valid octal constants. Single digits will be used for minor values
3095     less than 10.
3097     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3098     existing programs that set these in the POSIX interface can use PCRE without
3099     modification.
3101     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3102     return all that pcre_info() returns, plus additional data. The pcre_info()
3103     function is retained for compatibility, but is considered to be obsolete.
3105     10. Added experimental recursion feature (?R) to handle one common case that
3106     Perl 5.6 will be able to do with (?p{...}).
3108     11. Added support for POSIX character classes like [:alpha:], which Perl is
3109     adopting.
3112 nigel 39 Version 2.08 31-Aug-99
3113     ----------------------
3115     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3116     trying to match at the startoffset position, but instead was moving forward to
3117     the next newline as if a previous match had failed.
3119     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3120     and could get into a loop if a null string was matched other than at the start
3121     of the subject.
3123     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3124     be distinguished at compile time, and for completeness also added PCRE_DATE.
3126     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3127     in GnuWin32 environments.
3130 nigel 37 Version 2.07 29-Jul-99
3131     ----------------------
3133     1. The documentation is now supplied in plain text form and HTML as well as in
3134     the form of man page sources.
3136     2. C++ compilers don't like assigning (void *) values to other pointer types.
3137     In particular this affects malloc(). Although there is no problem in Standard
3138     C, I've put in casts to keep C++ compilers happy.
3140     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3141     should be (const char *).
3143     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3144     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3145     However, I haven't made this a standard facility. The documentation doesn't
3146     mention it, and the Makefile doesn't support it.
3148     5. The Makefile now contains an "install" target, with editable destinations at
3149     the top of the file. The pcretest program is not installed.
3151     6. pgrep -V now gives the PCRE version number and date.
3153     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3154     causing the entire string to be ignored, instead of just the last character.
3156     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3157     non-matching string, it can take a very, very long time, even for strings of
3158     quite modest length, because of the nested recursion. PCRE now does better in
3159     some of these cases. It does this by remembering the last required literal
3160     character in the pattern, and pre-searching the subject to ensure it is present
3161     before running the real match. In other words, it applies a heuristic to detect
3162     some types of certain failure quickly, and in the above example, if presented
3163     with a string that has no trailing " it gives "no match" very quickly.
3165     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3166     other alternatives are tried instead.
3169 nigel 35 Version 2.06 09-Jun-99
3170     ----------------------
3172     1. Change pcretest's output for amount of store used to show just the code
3173     space, because the remainder (the data block) varies in size between 32-bit and
3174     64-bit systems.
3176     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3177     start matching at. This allows lookbehinds to work when searching for multiple
3178     occurrences in a string.
3180     3. Added additional options to pcretest for testing multiple occurrences:
3182     /+ outputs the rest of the string that follows a match
3183     /g loops for multiple occurrences, using the new startoffset argument
3184     /G loops for multiple occurrences by passing an incremented pointer
3186     4. PCRE wasn't doing the "first character" optimization for patterns starting
3187     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3188     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3189     the letter 'x'. On long subject strings, this gives a significant speed-up.
3192 nigel 33 Version 2.05 21-Apr-99
3193     ----------------------
3195     1. Changed the type of magic_number from int to long int so that it works
3196     properly on 16-bit systems.
3198     2. Fixed a bug which caused patterns starting with .* not to work correctly
3199     when the subject string contained newline characters. PCRE was assuming
3200     anchoring for such patterns in all cases, which is not correct because .* will
3201     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3202     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3203     must be retried after every newline in the subject.
3206 nigel 31 Version 2.04 18-Feb-99
3207     ----------------------
3209     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3210     computation of the store needed to hold the pattern was incorrect (too large).
3211     If such patterns were nested a few deep, this could multiply and become a real
3212     problem.
3214     2. Added /M option to pcretest to show the memory requirement of a specific
3215     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3217     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3218     compiled in such a way that the backtracking after subsequent failure was
3219     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3220     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3223 nigel 29 Version 2.03 02-Feb-99
3224     ----------------------
3226     1. Fixed typo and small mistake in man page.
3228 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3229     LICENCE file containing the conditions.
3230 nigel 29
3231     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3232     Perl, that is the internal \ allows the delimiter to be included in the
3233     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3234     the final delimiter, add \ to the end of the pattern (to test the error).
3236     4. Added the convenience functions for extracting substrings after a successful
3237     match. Updated pcretest to make it able to test these functions.
3240 nigel 27 Version 2.02 14-Jan-99
3241     ----------------------
3243     1. Initialized the working variables associated with each extraction so that
3244     their saving and restoring doesn't refer to uninitialized store.
3246     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3247     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3248     fix the problem.
3250     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3251     calls, and wasn't printing the correct value for compiling calls. Increased the
3252     default value of LOOPREPEAT, and the number of significant figures in the
3253     times.
3255     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3257     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3258     a building problem on Windows NT with a FAT file system.
3261 nigel 25 Version 2.01 21-Oct-98
3262     ----------------------
3264     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3265     to character tables built by pcre_maketables() in the current locale. If NULL
3266     is passed, the default tables are used.
3269 nigel 23 Version 2.00 24-Sep-98
3270 nigel 21 ----------------------
3272 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3273     it any more.
3275     2. Allow quantification of (?>) groups, and make it work correctly.
3277     3. The first character computation wasn't working for (?>) groups.
3279     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3280     end of the subject) and add 5.005's \z, which really does match only at the
3281     very end of the subject.
3283     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3285     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3286     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3287     localized options. All options to pcre_study() were also removed.
3289     7. Add other new features from 5.005:
3291     $(?<= positive lookbehind
3292     $(?<! negative lookbehind
3293     (?imsx-imsx) added the unsetting capability
3294     such a setting is global if at outer level; local otherwise
3295     (?imsx-imsx:) non-capturing groups with option setting
3296     (?(cond)re|re) conditional pattern matching
3298     A backreference to itself in a repeated group matches the previous
3299     captured string.
3301     8. General tidying up of studying (both automatic and via "study")
3302     consequential on the addition of new assertions.
3304     9. As in 5.005, unlimited repeated groups that could match an empty substring
3305     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3306     runtime if any iteration does actually match an empty substring.
3308     10. Include the RunTest script in the distribution.
3310     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3311     discrepancies, some of which were old and were also with respect to 5.004. They
3312     have now been fixed.
3315     Version 1.09 28-Apr-98
3316     ----------------------
3318 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3319     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3320     program crashes, or just wrong answers. This did not apply to negated classes
3321     containing more than one character, or to minima other than one.
3324 nigel 19 Version 1.08 27-Mar-98
3325     ----------------------
3327     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3329     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3330     latter must appear before anything that relies on it in the pattern.
3333 nigel 17 Version 1.07 16-Feb-98
3334     ----------------------
3336     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3337     repeat of a potentially empty string).
3340 nigel 15 Version 1.06 23-Jan-98
3341     ----------------------
3343     1. Added Markus Oberhumer's little patches for C++.
3345     2. Literal strings longer than 255 characters were broken.
3348 nigel 13 Version 1.05 23-Dec-97
3349     ----------------------
3351     1. Negated character classes containing more than one character were failing if
3352     PCRE_CASELESS was set at run time.
3355 nigel 11 Version 1.04 19-Dec-97
3356     ----------------------
3358     1. Corrected the man page, where some "const" qualifiers had been omitted.
3360     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3361     input syntax.
3363     3. Fixed memory leak which occurred when a regex with back references was
3364     matched with an offsets vector that wasn't big enough. The temporary memory
3365     that is used in this case wasn't being freed if the match failed.
3367     4. Tidied pcretest to ensure it frees memory that it gets.
3369     5. Temporary memory was being obtained in the case where the passed offsets
3370     vector was exactly big enough.
3372     6. Corrected definition of offsetof() from change 5 below.
3374     7. I had screwed up change 6 below and broken the rules for the use of
3375     setjmp(). Now fixed.
3378 nigel 9 Version 1.03 18-Dec-97
3379     ----------------------
3381     1. A erroneous regex with a missing opening parenthesis was correctly
3382     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3383     on some systems.
3385     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3386     it was reported that one broken compiler failed on the former because "code" is
3387     also an independent variable.
3389     3. The erroneous regex a[]b caused an array overrun reference.
3391     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3392     fail on data ending with that character. (It was going on too far, and checking
3393     the next character, typically a binary zero.) This was specific to the
3394     optimized code for single-character negative classes.
3396     5. Added a contributed patch from the TIN world which does the following:
3398     + Add an undef for memmove, in case the the system defines a macro for it.
3400     + Add a definition of offsetof(), in case there isn't one. (I don't know
3401     the reason behind this - offsetof() is part of the ANSI standard - but
3402     it does no harm).
3404     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3405     most of the places where whitespace preceded '#'. I have given up and
3406     allowed the remaining 2 cases to be at the margin.
3408     + Rename some variables in pcre to eliminate shadowing. This seems very
3409     pedantic, but does no harm, of course.
3411     6. Moved the call to setjmp() into its own function, to get rid of warnings
3412     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3414     7. Constructs such as \d{8,} were compiling into the equivalent of
3415 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3416 nigel 9 outcome, but in this particular case used more store than had been allocated,
3417     which caused the bug to be discovered because it threw up an internal error.
3419     8. The debugging code in both pcre and pcretest for outputting the compiled
3420     form of a regex was going wrong in the case of back references followed by
3421     curly-bracketed repeats.
3424 nigel 7 Version 1.02 12-Dec-97
3425     ----------------------
3427     1. Typos in pcre.3 and comments in the source fixed.
3429     2. Applied a contributed patch to get rid of places where it used to remove
3430     'const' from variables, and fixed some signed/unsigned and uninitialized
3431     variable warnings.
3433     3. Added the "runtest" target to Makefile.
3435     4. Set default compiler flag to -O2 rather than just -O.
3438 nigel 5 Version 1.01 19-Nov-97
3439     ----------------------
3441     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3442     like /([ab]*)*/, that is, for classes with more than one character in them.
3444     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3445     as /((?>a*))*/ (a PCRE_EXTRA facility).
3448     Version 1.00 18-Nov-97
3449     ----------------------
3451     1. Added compile-time macros to support systems such as SunOS4 which don't have
3452     memmove() or strerror() but have other things that can be used instead.
3454     2. Arranged that "make clean" removes the executables.
3457 nigel 3 Version 0.99 27-Oct-97
3458     ----------------------
3460     1. Fixed bug in code for optimizing classes with only one character. It was
3461     initializing a 32-byte map regardless, which could cause it to run off the end
3462     of the memory it had got.
3464     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3467     Version 0.98 22-Oct-97
3468     ----------------------
3470     1. Fixed bug in code for handling temporary memory usage when there are more
3471     back references than supplied space in the ovector. This could cause segfaults.
3474     Version 0.97 21-Oct-97
3475     ----------------------
3477     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3479     2. Optimized negated single characters not to use a bit map.
3481     3. Brought error texts together as macro definitions; clarified some of them;
3482     fixed one that was wrong - it said "range out of order" when it meant "invalid
3483     escape sequence".
3485     4. Changed some char * arguments to const char *.
3487     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3489     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3490     pcretest.
3493     Version 0.96 16-Oct-97
3494     ----------------------
3496     1. Added a simple "pgrep" utility to the distribution.
3498     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3499     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3500     where "ddd" means "one or more decimal digits".
3502     3. Fixed serious bug. If a pattern had a back reference, but the call to
3503     pcre_exec() didn't supply a large enough ovector to record the related
3504     identifying subpattern, the match always failed. PCRE now remembers the number
3505     of the largest back reference, and gets some temporary memory in which to save
3506     the offsets during matching if necessary, in order to ensure that
3507     backreferences always work.
3509     4. Increased the compatibility with Perl in a number of ways:
3511     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3512     to request this handling. The option can be set at compile or exec time.
3514     (b) $ matches before a terminating newline by default; an option
3515     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3516     mode). The option can be set at compile or exec time.
3518     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3519     the same as Perl's. If the decimal number it represents is less than 10
3520     or there aren't that many previous left capturing parentheses, an octal
3521     escape is read. Inside a character class, it's always an octal escape,
3522     even if it is a single digit.
3524     (d) An escaped but undefined alphabetic character is taken as a literal,
3525     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3526     escapes.
3528     (e) {0} is now permitted. (The previous item is removed from the compiled
3529     pattern).
3531     5. Changed all the names of code files so that the basic parts are no longer
3532     than 10 characters, and abolished the teeny "globals.c" file.
3534     6. Changed the handling of character classes; they are now done with a 32-byte
3535     bit map always.
3537     7. Added the -d and /D options to pcretest to make it possible to look at the
3538     internals of compilation without having to recompile pcre.
3541     Version 0.95 23-Sep-97
3542     ----------------------
3544     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3545     \x20 at the start of a run of normal characters. These were being treated as
3546     real characters, instead of the source characters being re-checked.
3549     Version 0.94 18-Sep-97
3550     ----------------------
3552     1. The functions are now thread-safe, with the caveat that the global variables
3553     containing pointers to malloc() and free() or alternative functions are the
3554     same for all threads.
3556     2. Get pcre_study() to generate a bitmap of initial characters for non-
3557     anchored patterns when this is possible, and use it if passed to pcre_exec().
3560     Version 0.93 15-Sep-97
3561     ----------------------
3563     1. /(b)|(:+)/ was computing an incorrect first character.
3565     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3566     but not actually doing anything yet.
3568     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3569     as Perl does (e.g. [-az] or [az-]).
3571     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3572     all possible positions.
3574     5. Split up into different modules to avoid including unneeded functions in a
3575     compiled binary. However, compile and exec are still in one module. The "study"
3576     function is split off.
3578     6. The character tables are now in a separate module whose source is generated
3579     by an auxiliary program - but can then be edited by hand if required. There are
3580     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3581     toupper() in the code.
3583     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3584     make them global. Abolish the function for setting them, as the caller can now
3585     set them directly.
3588     Version 0.92 11-Sep-97
3589     ----------------------
3591     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3592     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3594     2. Caseless matching was not working in character classes if the characters in
3595     the pattern were in upper case.
3597     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3599     4. Make PCRE_ANCHORED public and accept as a compile option.
3601     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3602     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3603     pass them.
3605     6. Give an error if bad option bits passed at compile or run time.
3607     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3608     pcretest to cause it to pass that flag.
3610     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3611     options, and the first character, if set.
3613     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3616     Version 0.91 10-Sep-97
3617     ----------------------
3619     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3620     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3622     2. PCRE was looping on encountering an indefinitely repeated back reference to
3623     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3624     Perl does - treats the match as successful.
3626     ****


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