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Revision 448 - (hide annotations) (download)
Tue Sep 15 19:11:48 2009 UTC (5 years, 7 months ago) by ph10
File size: 172900 byte(s)
Re-organize tests to make is possible to test 5.10 features against Perl.

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8     was out-of-date, and there was no check on the pcre_compile() error code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 446 21. If the maximum number of capturing subpatterns in a recursion was greater
122     than the maximum at the outer level, the higher number was returned, but
123     with unset values at the outer level. The correct (outer level) value is
124     now given.
126 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
127     PCRE did not set those parentheses (unlike Perl). I have now found a way to
128     make it do so. The string so far is captured, making this feature
129     compatible with Perl.
131 ph10 448 23. The tests have been re-organized, adding tests 11 and 12, to make it
132     possible to check the Perl 5.10 features against Perl 5.10.
134 ph10 418
135 ph10 412 Version 7.9 11-Apr-09
136 ph10 376 ---------------------
138 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
139 ph10 376 (pcretest), all targets were linked against these libraries. This included
140     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
141     libraries. This caused unwanted dependencies to be created. This problem
142 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
143 ph10 376 pcretest is linked with readline.
144 ph10 392
145 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
146     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
147     moved outside it again, because FALSE and TRUE are already defined in AIX,
148     but BOOL is not.
149 ph10 392
150     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
151 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
152 ph10 392
153 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
154     hyphens) following file names and line numbers when outputting matching
155 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
156 ph10 376 wording for the --colour (or --color) option.
157 ph10 392
158 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
159     was not coloured; this is different to GNU grep, so I have changed it to be
160     the same.
161 ph10 392
162 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
163 ph10 392 each matching line was coloured. Now it goes on to look for further matches
164     of any of the test patterns, which is the same behaviour as GNU grep.
166     7. A pattern that could match an empty string could cause pcregrep to loop; it
167     doesn't make sense to accept an empty string match in pcregrep, so I have
168 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
169     seems to be how GNU grep behaves.
170 ph10 392
171 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
172 ph10 392 start or after a newline", because the conditional assertion was not being
173     correctly handled. The rule now is that both the assertion and what follows
174     in the first alternative must satisfy the test.
176 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
177 ph10 399 condition was an assertion, PCRE could crash during matching, both with
178     pcre_exec() and pcre_dfa_exec().
179 ph10 392
180     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
181     used for matching.
183     11. Unicode property support in character classes was not working for
184 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
185 ph10 388
186 ph10 392 12. Added the -M command line option to pcretest.
188 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
189 ph10 389
190     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
191 ph10 390
192 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
193 ph10 390 wrapper.
194 ph10 392
195 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
196 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
197 ph10 391 string constants.
198 ph10 405
199 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
200     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
201 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
202     these, but not everybody uses configure.
204     19. A conditional group that had only one branch was not being correctly
205     recognized as an item that could match an empty string. This meant that an
206     enclosing group might also not be so recognized, causing infinite looping
207     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
208     with the subject "ab", where knowledge that the repeated group can match
209 ph10 396 nothing is needed in order to break the loop.
210 ph10 405
211 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
212 ph10 405 exec(), but without supplying a callout function, matching went wrong.
214     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
215     leak if the size of the offset vector was greater than 30. When the vector
216     is smaller, the saved offsets during recursion go onto a local stack
217     vector, but for larger vectors malloc() is used. It was failing to free
218     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
219 ph10 400 error, in fact).
220 ph10 405
221 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
222 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
223     problem, but was untidy.
224 ph10 376
225 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
226     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
227     included within another project.
228 ph10 411
229 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
230     slightly modified by me:
231 ph10 411
232     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
233     not building pcregrep.
235 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
236 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
238 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
239     duplicate group numbers, could behave incorrectly or give incorrect errors,
240     because when scanning forward to find the reference group, PCRE was not
241     taking into account the duplicate group numbers. A pattern such as
242     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
243 ph10 411
244     26. Changed a few more instances of "const unsigned char *" to USPTR, making
245     the feature of a custom pointer more persuasive (as requested by a user).
246 ph10 416
247 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
248 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
249     pre-defined.
250 ph10 392
251 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
253 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
254     in the configuration summary.
255 ph10 405
256 ph10 411
257 ph10 374 Version 7.8 05-Sep-08
258 ph10 349 ---------------------
260     1. Replaced UCP searching code with optimized version as implemented for Ad
261     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
262 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
263     to 5 times on some simple patterns that I tested. Permission was given to
264     distribute the MultiStage2.py script that generates the tables (it's not in
265     the tarball, but is in the Subversion repository).
266 ph10 349
267 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
268     scripts.
269 ph10 358
270 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
271     a group with a zero qualifier. The result of the study could be incorrect,
272 ph10 358 or the function might crash, depending on the pattern.
274     4. Caseless matching was not working for non-ASCII characters in back
275 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
276 ph10 358 It now works when Unicode Property Support is available.
278 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
279     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
280     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
281 ph10 358 truncation.
282 ph10 349
283 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
285 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
286     pointers, in case they are 64-bit values.
287 ph10 371
288     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
289     test 2 if it fails.
291 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
292 ph10 371 and a #define of that name to empty if it is not externally set. This is to
293     allow users of MSVC to set it if necessary.
295     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
296 ph10 359 the convenience functions in the pcre_get.c source file.
297 ph10 371
298 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
299     could cause overwriting and/or a crash. This command provoked a crash in
300 ph10 371 some environments:
302     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
304 ph10 360 This potential security problem was recorded as CVE-2008-2371.
305 ph10 371
306 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
307     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
308 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
309 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
310     pcretest so that it places the subject at the end of its malloc-ed buffer.
311 ph10 371
312 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
313 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
315 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
316 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
317     first line. This applied both to normal and DFA matching.
319 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
320 ph10 371 /^[^d]*?$/8 failed to match "abc".
321 ph10 351
322 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
324     17. Make it more clear in the documentation that values returned from
325 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
326 ph10 357
327 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
328 ph10 368
329 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
330     supplied by Stefan Weber. I made a further small update for 7.8 because
331 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
332     replaced by pcre_ucd.c.
333 ph10 371
334 ph10 373
335 ph10 347 Version 7.7 07-May-08
336 ph10 321 ---------------------
338     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
339 ph10 345 a string to a long long, pretend we don't even have a long long." This is
340 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
341 ph10 345
342 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
343     pre-7.6 versions, which defined a global no_arg variable instead of putting
344 ph10 332 it in the RE class. (See also #8 below.)
345 ph10 345
346     3. Remove a line of dead code, identified by coverity and reported by Nuno
347     Lopes.
349 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
350 ph10 321
351 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
352 ph10 345 of files, instead of just to the final components.
354 ph10 324 (2) If there was more than one level of directory, the subdirectories were
355     skipped unless they satisfied the include/exclude conditions. This is
356     inconsistent with GNU grep (and could even be seen as contrary to the
357     pcregrep specification - which I improved to make it absolutely clear).
358     The action now is always to scan all levels of directory, and just
359     apply the include/exclude patterns to regular files.
360 ph10 345
361 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
362 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
364 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
365 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
366 ph10 326 doesn't support NULs in patterns.
367 ph10 345
368     7. Added some missing "const"s to declarations of static tables in
369     pcre_compile.c and pcre_dfa_exec.c.
371 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
372 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
373 ph10 345 first patch. And a third patch - this was a messy problem.)
374 ph10 321
375 ph10 345 9. Applied Craig's patch to remove the use of push_back().
377 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
378     matching function regexec().
379 ph10 345
380     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
381     which, however, unlike Perl's \g{...}, are subroutine calls, not back
382 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
383     Oniguruma does).
384 ph10 345
385     12. Previously, a group with a zero repeat such as (...){0} was completely
386 ph10 335 omitted from the compiled regex. However, this means that if the group
387     was called as a subroutine from elsewhere in the pattern, things went wrong
388 ph10 345 (an internal error was given). Such groups are now left in the compiled
389     pattern, with a new opcode that causes them to be skipped at execution
390 ph10 335 time.
391 ph10 345
392 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
393     to the way PCRE behaves:
394 ph10 345
395 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
396 ph10 345
397     (b) A back reference to an unmatched subpattern matches an empty string
398 ph10 336 (Perl fails the current match path).
399 ph10 345
400 ph10 341 (c) A data ] in a character class must be notated as \] because if the
401 ph10 345 first data character in a class is ], it defines an empty class. (In
402 ph10 341 Perl it is not possible to have an empty class.) The empty class []
403     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
404     The negative empty class [^] matches any one character, independently
405     of the DOTALL setting.
406 ph10 345
407     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
408 ph10 340 non-existent subpattern following a character class starting with ']' and
409     containing () gave an internal compiling error instead of "reference to
410     non-existent subpattern". Fortunately, when the pattern did exist, the
411 ph10 345 compiled code was correct. (When scanning forwards to check for the
412 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
413 ph10 345 the class, so got the count wrong. When actually compiling, the reference
414 ph10 340 was subsequently set up correctly.)
415 ph10 345
416 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
417 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
418     other assertions are supported. I have made pcre_dfa_exec() support
419     (*FAIL).
421 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
422 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
423     cannot be changed at match time, I realized I could make a small
424     improvement to matching performance by compiling OP_ALLANY instead of
425     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
426     on the OP_ANY path.
428     17. Compiling pcretest on Windows with readline support failed without the
429 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
430 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
432 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
433 ph10 345 ncurses library to be included for pcretest when ReadLine support is
434     requested, but also to allow for it to be overridden. This patch came from
435     Daniel Bergström.
436 ph10 347
437 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
438 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
439     any errors with the current Unicode tables. Thanks to Peter Kankowski for
440     spotting this.
441 ph10 324
442 ph10 332
443 ph10 319 Version 7.6 28-Jan-08
444 ph10 300 ---------------------
446 ph10 302 1. A character class containing a very large number of characters with
447     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
448     overflow.
449 ph10 309
450     2. Patch to cut out the "long long" test in pcrecpp_unittest when
451     HAVE_LONG_LONG is not defined.
453 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
454 ph10 304 bring them up to date and include new features. This patch includes:
455 ph10 309
456 ph10 304 - Fixed PH's badly added libz and libbz2 support.
457     - Fixed a problem with static linking.
458 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
459 ph10 304 - Fixed dftables problem and added an option.
460     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
462     - Added readline support for pcretest.
463 ph10 309 - Added an listing of the option settings after cmake has run.
465 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
466     "pcre.dll" under mingw when using Configure/Make. I added stuff to
467     Makefile.am that cause it to include this special target, without
468     affecting anything else. Note that the same mingw target plus all
469     the other distribution libraries and programs are now supported
470     when configuring with CMake (see 6 below) instead of with
471     Configure/Make.
472 ph10 309
473 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
474     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
475 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
476     solves the problem, but it does no harm.
477 ph10 313
478 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
479 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
480 ph10 314 with CMake, and also correct the comment about stack recursion.
481 ph10 313
482 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
483 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
484     of a program that users should build themselves after PCRE is installed, so
485     building it automatically is not really right. What is more, it gave
486 ph10 312 trouble in some build environments.
487 ph10 300
488 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
489 ph10 308
490 ph10 319
491 ph10 298 Version 7.5 10-Jan-08
492 ph10 263 ---------------------
494     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
495     values in parens when parsing an RE using the C++ wrapper."
496 ph10 286
497 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
498     Characters greater than 255 were excluded from the class instead of being
499     included.
500 ph10 286
501     3. The same bug as (2) above applied to negated POSIX classes such as
502 ph10 265 [:^space:].
503 ph10 286
504 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
505     defined or documented. It seems to have been a typo for PCRE_STATIC, so
506 ph10 286 I have changed it.
508 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
509 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
510     first named subpattern whose name started with "a" (in other words, the
511 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
512     expected" is now given for (?&) (a zero-length name), and this patch also
513     makes it give the same error for \k'' (previously it complained that that
514     was a reference to a non-existent subpattern).
515 ph10 286
516 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
517 ph10 286 this is right because (?- can be followed by option settings as well as by
518 ph10 269 digits. I have, however, made the messages clearer.
519 ph10 286
520 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
521     than the number used in the conditional) now cause a compile-time error.
522     This is actually not compatible with Perl, which accepts such patterns, but
523     treats the conditional as always being FALSE (as PCRE used to), but it
524     seems to me that giving a diagnostic is better.
525 ph10 286
526 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
527 ph10 275 and messages.
528 ph10 286
529     9. Fix two occurrences of "backslash" in comments that should have been
530     "backspace".
532     10. Remove two redundant lines of code that can never be obeyed (their function
533     was moved elsewhere).
535     11. The program that makes PCRE's Unicode character property table had a bug
536     which caused it to generate incorrect table entries for sequences of
537 ph10 277 characters that have the same character type, but are in different scripts.
538 ph10 286 It amalgamated them into a single range, with the script of the first of
539 ph10 277 them. In other words, some characters were in the wrong script. There were
540     thirteen such cases, affecting characters in the following ranges:
541 ph10 286
542 ph10 277 U+002b0 - U+002c1
543     U+0060c - U+0060d
544 ph10 286 U+0061e - U+00612
545 ph10 277 U+0064b - U+0065e
546     U+0074d - U+0076d
547     U+01800 - U+01805
548     U+01d00 - U+01d77
549     U+01d9b - U+01dbf
550     U+0200b - U+0200f
551     U+030fc - U+030fe
552     U+03260 - U+0327f
553     U+0fb46 - U+0fbb1
554     U+10450 - U+1049d
555 ph10 286
556 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
557     compatible with GNU grep in that, if there was more than one match in a
558     line, it showed only the first of them. It now behaves in the same way as
559     GNU grep.
560 ph10 286
561     13. If the -o and -v options were combined for pcregrep, it printed a blank
562     line for every non-matching line. GNU grep prints nothing, and pcregrep now
563     does the same. The return code can be used to tell if there were any
564     non-matching lines.
566 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
568     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
569 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
570 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
571     and both kinds of lookbehind were skipped).
573 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
574 ph10 284 inclusion of <windows.h> to before rather than after the definition of
575     INVALID_FILE_ATTRIBUTES (patch from David Byron).
576 ph10 263
577 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
578 ph10 286 character property caused pcre_compile() to compile bad code, which led at
579     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
580     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
581     caused the error; without that there was no problem.
582 ph10 263
583 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
584 ph10 286
585 ph10 289 19. Added --enable-pcretest-libreadline.
586 ph10 286
587 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
588 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
589 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
590     later patch that removed the other one (the right fix) and added unit tests
591     that check the return values (which was not done before).
592 ph10 292
593 ph10 291 21. Several CMake things:
594 ph10 287
595 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
596 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
597 ph10 288
598 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
599     linked with the newly-built libraries, not previously installed ones.
600 ph10 291
602 ph10 298
603     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
604     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
605     UTF-8 newline character). The key issue is that the pattern starts .*;
606     this means that the match must be either at the beginning, or after a
607     newline. The bug was in the code for advancing after a failed match and
608     checking that the new position followed a newline. It was not taking
609 ph10 294 account of UTF-8 characters correctly.
610 ph10 298
611     23. PCRE was behaving differently from Perl in the way it recognized POSIX
612     character classes. PCRE was not treating the sequence [:...:] as a
613     character class unless the ... were all letters. Perl, however, seems to
614     allow any characters between [: and :], though of course it rejects as
615     unknown any "names" that contain non-letters, because all the known class
616     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
617     for example, whereas PCRE did not - it did not recognize a POSIX character
618     class. This seemed a bit dangerous, so the code has been changed to be
619     closer to Perl. The behaviour is not identical to Perl, because PCRE will
620     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
621     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
622     Perl does, and where it didn't before.
624 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
625     Windows environments %n is disabled by default.
626 ph10 292
628 ph10 260 Version 7.4 21-Sep-07
629 ph10 230 ---------------------
631     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
632 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
633     LF". That isn't really right - the whole point of the change was to try to
634     help when there was an actual mention of one of the two characters. So now
635     the change happens only if \r or \n (or a literal CR or LF) character is
636 ph10 230 encountered.
637 ph10 231
638     2. The 32-bit options word was also used for 6 internal flags, but the numbers
639     of both had grown to the point where there were only 3 bits left.
640     Fortunately, there was spare space in the data structure, and so I have
641     moved the internal flags into a new 16-bit field to free up more option
642 ph10 230 bits.
643 ph10 231
644     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
645     but did not set the internal JCHANGED flag - either of these is enough to
646     control the way the "get" function works - but the PCRE_INFO_JCHANGED
647     facility is supposed to tell if (?J) was ever used, so now (?J) at the
648 ph10 230 start sets both bits.
650 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
651     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
652 ph10 230
653 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
655     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
656 ph10 233 compatibility, even though it is no longer used.
657 ph10 243
658     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
659 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
660 ph10 259 windows.h file is present (where different names are used). [This was
661 ph10 257 reversed later after testing - see 16 below.]
662 ph10 243
663     8. Changed all #include <config.h> to #include "config.h". There were also
664 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
665 ph10 243
666 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
667 ph10 243 sequence off the lines that it output.
669     10. It was pointed out to me that arrays of string pointers cause lots of
670     relocations when a shared library is dynamically loaded. A technique of
671     using a single long string with a table of offsets can drastically reduce
672     these. I have refactored PCRE in four places to do this. The result is
673 ph10 240 dramatic:
674 ph10 243
675 ph10 240 Originally: 290
676     After changing UCP table: 187
677 ph10 243 After changing error message table: 43
678 ph10 240 After changing table of "verbs" 36
679     After changing table of Posix names 22
680 ph10 243
681 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
682 ph10 247
683 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
684 ph10 247 unicode-properties was also set.
686 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
687 ph10 231
688 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
689     checked only for CRLF.
690 ph10 233
691 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
693 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
694 ph10 253
695 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
696 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
697     entirely. This removes changes made in 7 above.
698 ph10 256
699 ph10 261 17. The CMake files have been updated, and there is now more information about
700     building with CMake in the NON-UNIX-USE document.
701 ph10 257
702 ph10 261
703 ph10 228 Version 7.3 28-Aug-07
704 ph10 157 ---------------------
706 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
707     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
708     brackets there is not right, since it causes compilers to look for an
709     installed pcre.h, not the version that is in the source that is being
710     compiled (which of course may be different). I have changed it back to:
711 ph10 197
712 ph10 189 #include "pcre.h"
713 ph10 197
714     I have a vague recollection that the change was concerned with compiling in
715     different directories, but in the new build system, that is taken care of
716     by the VPATH setting the Makefile.
718 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
719     when the subject happened to end in the byte 0x85 (e.g. if the last
720     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
721     characters but of course it shouldn't be taken as a newline when it is part
722     of another character. The bug was that, for an unlimited repeat of . in
723     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
724     characters when looking for a newline.
725 ph10 197
726     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
728     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
729     in debug output.
731 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
732     long printing in the pcrecpp unittest when running under MinGW.
733 ph10 189
734 ph10 197 6. ESC_K was left out of the EBCDIC table.
735 ph10 189
736 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
737     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
738     limit also applies to "virtual nesting" when a pattern is recursive, and in
739     this case 1000 isn't so big. I have been able to remove this limit at the
740     expense of backing off one optimization in certain circumstances. Normally,
741     when pcre_exec() would call its internal match() function recursively and
742     immediately return the result unconditionally, it uses a "tail recursion"
743     feature to save stack. However, when a subpattern that can match an empty
744     string has an unlimited repetition quantifier, it no longer makes this
745     optimization. That gives it a stack frame in which to save the data for
746     checking that an empty string has been matched. Previously this was taken
747     from the 1000-entry workspace that had been reserved. So now there is no
748     explicit limit, but more stack is used.
749 ph10 189
750 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
751     syntax that is required for Windows, and which was going wrong for the
752     pcreposix and pcrecpp parts of the library. These were overlooked when this
753     problem was solved for the main library.
754 ph10 197
755 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
756     the size of patterns that contain repeated groups with explicit upper
757     limits. As the maximum quantifier is 65535, the maximum group length was
758     set at 30,000 so that the product of these two numbers did not overflow a
759     32-bit integer. However, it turns out that people want to use groups that
760     are longer than 30,000 bytes (though not repeat them that many times).
761     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
762     made it possible to implement the integer overflow checks in a much more
763     dynamic way, which I have now done. The artificial limitation on group
764     length has been removed - we now have only the limit on the total length of
765     the compiled pattern, which depends on the LINK_SIZE setting.
766 ph10 208
767     10. Fixed a bug in the documentation for get/copy named substring when
768     duplicate names are permitted. If none of the named substrings are set, the
769     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
770     empty string.
772     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
773     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
774     because the ] is interpreted as the first data character and the
775     terminating ] is not found. PCRE has been made compatible with Perl in this
776     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
777     cause memory overwriting.
779 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
780     string has been matched (to stop an infinite loop). It was not recognizing
781 ph10 208 a conditional subpattern that could match an empty string if that
782 ph10 206 subpattern was within another subpattern. For example, it looped when
783 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
784 ph10 206 condition was not nested. This bug has been fixed.
785 ph10 208
786 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
787     past the start of the subject in the presence of bytes with the top bit
788     set, for example "\x8aBCD".
789 ph10 211
790 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
791     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
792 ph10 200
793 ph10 211 14. Optimized (?!) to (*FAIL).
794 ph10 202
795 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
796     This restricts code points to be within the range 0 to 0x10FFFF, excluding
797     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
798     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
799     does: it's just the validity check that is more restrictive.
800 ph10 220
801     16. Inserted checks for integer overflows during escape sequence (backslash)
802     processing, and also fixed erroneous offset values for syntax errors during
803     backslash processing.
805 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
806 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
808 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
809     caused an overrun.
810 ph10 220
811     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
812     something other than just ASCII characters) inside a group that had an
813     unlimited repeat caused a loop at compile time (while checking to see
814     whether the group could match an empty string).
816 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
817     [\P{Any}] did so. (Error in the code for printing property names.)
818 ph10 210
819 ph10 220 21. An orphan \E inside a character class could cause a crash.
821     22. A repeated capturing bracket such as (A)? could cause a wild memory
822 ph10 218 reference during compilation.
823 ph10 220
824     23. There are several functions in pcre_compile() that scan along a compiled
825     expression for various reasons (e.g. to see if it's fixed length for look
826 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
827 ph10 220 present in the pattern. These operators have additional parameters compared
828     with \d, etc, and these were not being taken into account when moving along
829 ph10 218 the compiled data. Specifically:
830 ph10 220
831     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
832     length.
834     (b) An item such as \pL+ within a repeated group could cause crashes or
835 ph10 218 loops.
836 ph10 220
837 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
838 ph10 220 "reference to non-existent subpattern" error.
840 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
842 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
843 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
844 ph10 211
845 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
846 ph10 218
847 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
848 ph10 223 character were causing crashes (broken optimization).
849 ph10 227
850 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
851 ph10 227 \p or \P) caused a compile-time loop.
853 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
854     break. For example, the unstudied pattern [\r\n]A does not match the string
855     "\r\nA" because change 7.0/46 below moves the current point on by two
856     characters after failing to match at the start. However, the pattern \nA
857 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
858     the same is true. There doesn't seem any very clean way out of this, but
859     what I have chosen to do makes the common cases work: PCRE now takes note
860     of whether there can be an explicit match for \r or \n anywhere in the
861     pattern, and if so, 7.0/46 no longer applies. As part of this change,
862     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
863     pattern has explicit CR or LF references.
864 ph10 222
865 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
866 ph10 223
867 ph10 227
868 ph10 189 Version 7.2 19-Jun-07
869     ---------------------
871 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
872     which is apparently normally available under Windows.
873 ph10 159
874     2. Re-jig the pcregrep tests with different newline settings in an attempt
875     to make them independent of the local environment's newline setting.
876 ph10 157
877 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
878 ph10 165
879 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
880     was not 2, because the output contained actual offsets. The recent new
881 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
882     usable with all link sizes.
884 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
885     stack recursion. This gives a massive performance boost under BSD, but just
886 ph10 165 a small improvement under Linux. However, it saves one field in the frame
887 ph10 164 in all cases.
888 ph10 172
889 ph10 166 6. Added more features from the forthcoming Perl 5.10:
890 ph10 172
891 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
892     recursion call. It refers to the nth most recently opened parentheses.
893 ph10 172
894 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
895 ph10 172 to be opened parentheses.
897     (c) Conditions that refer to capturing parentheses can be specified
898 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
899 ph10 172
900 ph10 168 (d) \K resets the start of the current match so that everything before
901 ph10 172 is not part of it.
903 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
904 ph10 172
905 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
906 ph10 172 reference syntax.
907 ph10 182
908 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
909 ph10 182 alternative starts with the same number.
910 ph10 172
911 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
913 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
916     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
917     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
918 ph10 170 for detecting groups that can match an empty string.
919 ph10 159
920 ph10 172 9. A pattern with a very large number of alternatives (more than several
921     hundred) was running out of internal workspace during the pre-compile
922     phase, where pcre_compile() figures out how much memory will be needed. A
923     bit of new cunning has reduced the workspace needed for groups with
924     alternatives. The 1000-alternative test pattern now uses 12 bytes of
925     workspace instead of running out of the 4096 that are available.
926 ph10 182
927 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
928 ph10 172
929 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
930     The report of the bug said:
931 ph10 182
932 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
933     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
934 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
935 ph10 185
936 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
937 ph10 185 it matched the wrong number of bytes.
938 ph10 172
939 ph10 179
940 ph10 155 Version 7.1 24-Apr-07
941 ph10 98 ---------------------
943 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
944 ph10 122 that is more "standard", making use of automake and other Autotools. There
945 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
946     on this.
947 ph10 111
948     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
949     for recursive directory scanning broke on some systems because the files
950     are not scanned in any specific order and on different systems the order
951     was different. A call to "sort" has been inserted into RunGrepTest for the
952     approprate test as a short-term fix. In the longer term there may be an
953 ph10 100 alternative.
954 ph10 111
955 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
956 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
957     people do their own conversions for various reasons). The problems
958     concerned the use of low-level troff macros .br and .in. I have therefore
959     removed all such uses from the man pages (some were redundant, some could
960 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
961     HTML has been updated to handle .nf/.fi and to complain if it encounters
962     .br or .in.
963 ph10 111
964 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
965 ph10 123 arranged for config.h to be included in the distribution, with the name
966 ph10 111 config.h.generic, for the benefit of those who have to compile without
967     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
969     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
970     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
971 ph10 127 makevp.bat for the current PCRE, using the additional files
972 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
973 ph10 111
974     6. A Windows user reported a minor discrepancy with test 2, which turned out
975     to be caused by a trailing space on an input line that had got lost in his
976 ph10 102 copy. The trailing space was an accident, so I've just removed it.
977 ph10 111
978 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
979 ph10 111 that is needed.
981 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
982     as "const" (a) because they are and (b) because it helps the PHP
983     maintainers who have recently made a script to detect big data structures
984 ph10 111 in the php code that should be moved to the .rodata section. I remembered
985     to update Builducptable as well, so it won't revert if ucptable.h is ever
986 ph10 105 re-created.
987 ph10 111
988     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
989 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
990 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
991     support is not required. This saves 1.5-2K of code, which is important in
992 ph10 107 some applications.
993 ph10 111
994 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
995 ph10 111 so as not to refer to the tables, even though these functions will never be
996     called when UTF-8 support is disabled. Otherwise there are problems with a
997     shared library.
999 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1001     (a) It was defining its arguments as char * instead of void *.
1003 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1004     a long time ago when I wrote it, but is no longer the case.
1006 ph10 118 The emulated memove() is provided for those environments that have neither
1007 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1008 ph10 118 is clearly not the case, as these two bugs were recently reported.
1009 ph10 123
1010 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1011 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1012     pages, and it removes trailing spaces from listed files. It also creates
1013     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1014     case, it wraps all the #defines with #ifndefs. This script should be run
1015 ph10 111 before "make dist".
1016 ph10 123
1017 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1018     with Unicode property support.
1019 ph10 123
1020     (a) For a maximizing quantifier, if the two different cases of the
1021     character were of different lengths in their UTF-8 codings (there are
1022     some cases like this - I found 11), and the matching function had to
1023 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1024     were both the same length.
1025 ph10 123
1026     (b) When PCRE was configured to use the heap rather than the stack for
1027     recursion during matching, it was not correctly preserving the data for
1028     the other case of a UTF-8 character when checking ahead for a match
1029     while processing a minimizing repeat. If the check also involved
1030 ph10 115 matching a wide character, but failed, corruption could cause an
1031     erroneous result when trying to check for a repeat of the original
1032     character.
1033 ph10 123
1034 ph10 116 13. Some tidying changes to the testing mechanism:
1035 ph10 98
1036 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1037     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1038 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1039     this for UTF-8.) The configure.ac script no longer substitutes the
1040     relevant variables.
1042 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1043     with length and offset values. This means that the output is different
1044     for different internal link sizes. Test 2 is skipped for link sizes
1045     other than 2 because of this, bypassing the problem. Unfortunately,
1046     there was also a test in test 3 (the locale tests) that used /B and
1047 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1048     I have added a new /Z option to pcretest that replaces the length and
1049     offset values with spaces. This is now used to make test 3 independent
1050 ph10 122 of link size. (Test 2 will be tidied up later.)
1051 ph10 123
1052     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1053 ph10 122 segmentation fault instead of returning the appropriate error message.
1054 ph10 134
1055 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1056 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1057     This doesn't seem right; it now treats the CRLF combination as the line
1058     ending, and so does not match in that case. It's only a pattern such as ^$
1059     that would hit this one: something like ^ABC$ would have failed after \r
1060     and then tried again after \r\n.
1062 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1063 ph10 134 in an attempt to make files that differ only in their line terminators
1064     compare equal. This works on Linux.
1065 ph10 142
1066 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1067     as it exited. This is now fixed, thanks to valgrind.
1068 ph10 142
1069 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1070 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1071     was because its rules for how to advance for /g after matching an empty
1072 ph10 143 string at the end of a line did not allow for this case. They now check for
1073     it specially.
1074 ph10 150
1075     20. pcretest is supposed to handle patterns and data of any length, by
1076     extending its buffers when necessary. It was getting this wrong when the
1077 ph10 147 buffer for a data line had to be extended.
1078 ph10 150
1079 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1080 ph10 150 CRLF as a newline sequence.
1081 ph10 152
1082 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1083 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1084     I have nevertheless tidied it up.
1085 ph10 111
1086 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1087 ph10 123
1088 ph10 153 24. Added a man page for pcre-config.
1089 ph10 152
1090 ph10 153
1091 nigel 93 Version 7.0 19-Dec-06
1092     ---------------------
1094     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1095     moving to gcc 4.1.1.
1097     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1098     sys/time.h, which is documented as needed for this function. It doesn't
1099     seem to matter on Linux, but it showed up on some releases of OS X.
1101     3. It seems that there are systems where bytes whose values are greater than
1102     127 match isprint() in the "C" locale. The "C" locale should be the
1103     default when a C program starts up. In most systems, only ASCII printing
1104     characters match isprint(). This difference caused the output from pcretest
1105     to vary, making some of the tests fail. I have changed pcretest so that:
1107     (a) When it is outputting text in the compiled version of a pattern, bytes
1108     other than 32-126 are always shown as hex escapes.
1110     (b) When it is outputting text that is a matched part of a subject string,
1111     it does the same, unless a different locale has been set for the match
1112     (using the /L modifier). In this case, it uses isprint() to decide.
1114     4. Fixed a major bug that caused incorrect computation of the amount of memory
1115     required for a compiled pattern when options that changed within the
1116     pattern affected the logic of the preliminary scan that determines the
1117     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1118     that the computed length was too small. The symptoms of this bug were
1119     either the PCRE error "internal error: code overflow" from pcre_compile(),
1120     or a glibc crash with a message such as "pcretest: free(): invalid next
1121     size (fast)". Examples of patterns that provoked this bug (shown in
1122     pcretest format) are:
1124     /(?-x: )/x
1125     /(?x)(?-x: \s*#\s*)/
1126     /((?i)[\x{c0}])/8
1127     /(?i:[\x{c0}])/8
1129     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1130     is now done differently.
1132     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1133     wrapper classes; (b) implement a new function in the C++ scanner that is
1134     more efficient than the old way of doing things because it avoids levels of
1135     recursion in the regex matching; (c) add a paragraph to the documentation
1136     for the FullMatch() function.
1138     6. The escape sequence \n was being treated as whatever was defined as
1139     "newline". Not only was this contrary to the documentation, which states
1140     that \n is character 10 (hex 0A), but it also went horribly wrong when
1141     "newline" was defined as CRLF. This has been fixed.
1143     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1144     was being set to -1 for the "end of line" case (supposedly a value that no
1145     character can have). Though this value is never used (the check for end of
1146     line is "zero bytes in current character"), it caused compiler complaints.
1147     I've changed it to 0xffffffff.
1149     8. In pcre_version.c, the version string was being built by a sequence of
1150     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1151     string (as it is for production releases) called a macro with an empty
1152     argument. The C standard says the result of this is undefined. The gcc
1153     compiler treats it as an empty string (which was what was wanted) but it is
1154     reported that Visual C gives an error. The source has been hacked around to
1155     avoid this problem.
1157     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1158     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1159     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1160     of them did).
1162     10. Originally, pcretest opened its input and output without "b"; then I was
1163     told that "b" was needed in some environments, so it was added for release
1164     5.0 to both the input and output. (It makes no difference on Unix-like
1165     systems.) Later I was told that it is wrong for the input on Windows. I've
1166     now abstracted the modes into two macros, to make it easier to fiddle with
1167     them, and removed "b" from the input mode under Windows.
1169     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1171     12. Added -help and --help to pcretest as an official way of being reminded
1172     of the options.
1174     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1175     and pcrecpp.cc because they annoy compilers at high warning levels.
1177     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1179     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1180     scripts are not C programs :-) and which was not noticed because it works
1181     on Linux.
1183     16. pcretest is supposed to handle any length of pattern and data line (as one
1184     line or as a continued sequence of lines) by extending its input buffer if
1185     necessary. This feature was broken for very long pattern lines, leading to
1186     a string of junk being passed to pcre_compile() if the pattern was longer
1187     than about 50K.
1189     17. I have done a major re-factoring of the way pcre_compile() computes the
1190     amount of memory needed for a compiled pattern. Previously, there was code
1191     that made a preliminary scan of the pattern in order to do this. That was
1192     OK when PCRE was new, but as the facilities have expanded, it has become
1193     harder and harder to keep it in step with the real compile phase, and there
1194     have been a number of bugs (see for example, 4 above). I have now found a
1195     cunning way of running the real compile function in a "fake" mode that
1196     enables it to compute how much memory it would need, while actually only
1197     ever using a few hundred bytes of working memory and without too many
1198     tests of the mode. This should make future maintenance and development
1199     easier. A side effect of this work is that the limit of 200 on the nesting
1200     depth of parentheses has been removed (though this was never a serious
1201     limitation, I suspect). However, there is a downside: pcre_compile() now
1202     runs more slowly than before (30% or more, depending on the pattern). I
1203     hope this isn't a big issue. There is no effect on runtime performance.
1205     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1206     newline (only possible for the last line of a file) and it was a
1207     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1209     19. Added additional timing features to pcretest. (1) The -tm option now times
1210     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1211     separate command line item, by a number that specifies the number of
1212     repeats to use when timing. The default is 50000; this gives better
1213     precision, but takes uncomfortably long for very large patterns.
1215     20. Extended pcre_study() to be more clever in cases where a branch of a
1216     subpattern has no definite first character. For example, (a*|b*)[cd] would
1217     previously give no result from pcre_study(). Now it recognizes that the
1218     first character must be a, b, c, or d.
1220     21. There was an incorrect error "recursive call could loop indefinitely" if
1221     a subpattern (or the entire pattern) that was being tested for matching an
1222     empty string contained only one non-empty item after a nested subpattern.
1223     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1224     incorrectly, because the \d was being skipped in the check.
1226     22. The pcretest program now has a new pattern option /B and a command line
1227     option -b, which is equivalent to adding /B to every pattern. This causes
1228     it to show the compiled bytecode, without the additional information that
1229     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1230     is the same as /B/I).
1232     23. A new optimization is now able automatically to treat some sequences such
1233     as a*b as a*+b. More specifically, if something simple (such as a character
1234     or a simple class like \d) has an unlimited quantifier, and is followed by
1235     something that cannot possibly match the quantified thing, the quantifier
1236     is automatically "possessified".
1238     24. A recursive reference to a subpattern whose number was greater than 39
1239     went wrong under certain circumstances in UTF-8 mode. This bug could also
1240     have affected the operation of pcre_study().
1242     25. Realized that a little bit of performance could be had by replacing
1243     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1245     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1247     27. Possessive quantifiers such as a++ were previously implemented by turning
1248     them into atomic groups such as ($>a+). Now they have their own opcodes,
1249     which improves performance. This includes the automatically created ones
1250     from 23 above.
1252     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1253     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1254     the first matched character to be a colon. This applied both to named and
1255     numbered groups.
1257     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1259     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1260     building PCRE on Windows easier, so I have included it in the distribution.
1262     31. There is now a check in pcretest against a ridiculously large number being
1263     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1264     loop, the loop is abandoned.
1266     32. Forward references to subpatterns in conditions such as (?(2)...) where
1267     subpattern 2 is defined later cause pcre_compile() to search forwards in
1268     the pattern for the relevant set of parentheses. This search went wrong
1269     when there were unescaped parentheses in a character class, parentheses
1270     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1272     33. "Subroutine" calls and backreferences were previously restricted to
1273     referencing subpatterns earlier in the regex. This restriction has now
1274     been removed.
1276     34. Added a number of extra features that are going to be in Perl 5.10. On the
1277     whole, these are just syntactic alternatives for features that PCRE had
1278     previously implemented using the Python syntax or my own invention. The
1279     other formats are all retained for compatibility.
1281     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1282     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1283     also .NET compatible.
1285     (b) A recursion or subroutine call to a named group can now be defined as
1286     (?&name) as well as (?P>name).
1288     (c) A backreference to a named group can now be defined as \k<name> or
1289     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1290     5.10, are also .NET compatible.
1292     (d) A conditional reference to a named group can now use the syntax
1293     (?(<name>) or (?('name') as well as (?(name).
1295     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1296     groups (named and numbered) that are never evaluated inline, but can be
1297     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1298     is always false. There may be only one alternative in such a group.
1300     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1301     as the simple (?(R). The condition is true only if the most recent
1302     recursion is that of the given number or name. It does not search out
1303     through the entire recursion stack.
1305     (g) The escape \gN or \g{N} has been added, where N is a positive or
1306     negative number, specifying an absolute or relative reference.
1308     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1309     some "unreachable code" warnings.
1311     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1312     things, this adds five new scripts.
1314     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1315     There were also incompatibilities regarding the handling of \Q..\E inside
1316     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1317     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1319     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1320     matches an empty string, and forcibly breaks the loop. There were bugs in
1321     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1322     against aaaa the result was just "a" rather than "aaaa", for example. Two
1323     separate and independent bugs (that affected different cases) have been
1324     fixed.
1326     39. Refactored the code to abolish the use of different opcodes for small
1327     capturing bracket numbers. This is a tidy that I avoided doing when I
1328     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1329     The new approach is not only tidier, it makes it possible to reduce the
1330     memory needed to fix the previous bug (38).
1332     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1333     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1334     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1335     mode.
1337     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1338     report.
1340     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1341     copy construction and assignment in the C++ wrapper.
1343     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1344     couple of bugs that could have given wrong results in the "--newline=crlf"
1345     case.
1347     44. Added a number of casts and did some reorganization of signed/unsigned int
1348     variables following suggestions from Dair Grant. Also renamed the variable
1349     "this" as "item" because it is a C++ keyword.
1351     45. Arranged for dftables to add
1353     #include "pcre_internal.h"
1355     to pcre_chartables.c because without it, gcc 4.x may remove the array
1356     definition from the final binary if PCRE is built into a static library and
1357     dead code stripping is activated.
1359     46. For an unanchored pattern, if a match attempt fails at the start of a
1360     newline sequence, and the newline setting is CRLF or ANY, and the next two
1361     characters are CRLF, advance by two characters instead of one.
1364 nigel 91 Version 6.7 04-Jul-06
1365     ---------------------
1367     1. In order to handle tests when input lines are enormously long, pcretest has
1368     been re-factored so that it automatically extends its buffers when
1369     necessary. The code is crude, but this _is_ just a test program. The
1370     default size has been increased from 32K to 50K.
1372     2. The code in pcre_study() was using the value of the re argument before
1373     testing it for NULL. (Of course, in any sensible call of the function, it
1374     won't be NULL.)
1376     3. The memmove() emulation function in pcre_internal.h, which is used on
1377     systems that lack both memmove() and bcopy() - that is, hardly ever -
1378     was missing a "static" storage class specifier.
1380     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1381     containing an extended class (one that cannot be represented by a bitmap
1382     because it contains high-valued characters or Unicode property items, e.g.
1383     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1384     pattern, but PCRE should not loop if you do not (it no longer does).
1385     [Detail: two cases were found: (a) a repeated subpattern containing an
1386     extended class; (b) a recursive reference to a subpattern that followed a
1387     previous extended class. It wasn't skipping over the extended class
1388     correctly when UTF-8 mode was not set.]
1390     5. A negated single-character class was not being recognized as fixed-length
1391     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1392     compile error "lookbehind assertion is not fixed length".
1394     6. The RunPerlTest auxiliary script was showing an unexpected difference
1395     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1396     write a Perl script that can interpret lines of an input file either as
1397     byte characters or as UTF-8, which is what "perltest" was being required to
1398     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1399     can't do is switch easily at run time between having the "use utf8;" pragma
1400     or not. In the end, I fudged it by using the RunPerlTest script to insert
1401     "use utf8;" explicitly for the UTF-8 tests.
1403     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1404     the end of the subject string, contrary to the documentation and to what
1405     Perl does. This was true of both matching functions. Now it matches only at
1406     the start of the subject and immediately after *internal* newlines.
1408     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1409     a pointer to an int instead of a pointer to an unsigned long int. This
1410     caused problems on 64-bit systems.
1412     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1413     instance of the 'standard' template library not being so standard".
1415     10. There was no check on the number of named subpatterns nor the maximum
1416     length of a subpattern name. The product of these values is used to compute
1417     the size of the memory block for a compiled pattern. By supplying a very
1418     long subpattern name and a large number of named subpatterns, the size
1419     computation could be caused to overflow. This is now prevented by limiting
1420     the length of names to 32 characters, and the number of named subpatterns
1421     to 10,000.
1423     11. Subpatterns that are repeated with specific counts have to be replicated in
1424     the compiled pattern. The size of memory for this was computed from the
1425     length of the subpattern and the repeat count. The latter is limited to
1426     65535, but there was no limit on the former, meaning that integer overflow
1427     could in principle occur. The compiled length of a repeated subpattern is
1428     now limited to 30,000 bytes in order to prevent this.
1430     12. Added the optional facility to have named substrings with the same name.
1432     13. Added the ability to use a named substring as a condition, using the
1433     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1434     are numbers (not recommended). Forward references are permitted.
1436     14. Added forward references in named backreferences (if you see what I mean).
1438     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1439     pattern could run off the end of the subject. For example, the pattern
1440     "(?s)(.{1,5})"8 did this with the subject "ab".
1442     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1443     PCRE_CASELESS was set when matching characters that were quantified with ?
1444     or *.
1446     17. A character class other than a single negated character that had a minimum
1447     but no maximum quantifier - for example [ab]{6,} - was not handled
1448     correctly by pce_dfa_exec(). It would match only one character.
1450     18. A valid (though odd) pattern that looked like a POSIX character
1451     class but used an invalid character after [ (for example [[,abc,]]) caused
1452     pcre_compile() to give the error "Failed: internal error: code overflow" or
1453     in some cases to crash with a glibc free() error. This could even happen if
1454     the pattern terminated after [[ but there just happened to be a sequence of
1455     letters, a binary zero, and a closing ] in the memory that followed.
1457     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1458     over the years. Originally (before any Unicode support), just the bottom 8
1459     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1460     output from "man perlunicode" includes this:
1462     The regular expression compiler produces polymorphic opcodes. That
1463     is, the pattern adapts to the data and automatically switches to
1464     the Unicode character scheme when presented with Unicode data--or
1465     instead uses a traditional byte scheme when presented with byte
1466     data.
1468     Sadly, a wide octal escape does not cause a switch, and in a string with
1469     no other multibyte characters, these octal escapes are treated as before.
1470     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1471     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1472     Unicode string.
1474     I have not perpetrated such confusion in PCRE. Up till now, it took just
1475     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1476     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1477     translate to the appropriate multibyte character.
1479     29. Applied some refactoring to reduce the number of warnings from Microsoft
1480     and Borland compilers. This has included removing the fudge introduced
1481     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1482     a warning about an unused variable.
1484     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1485     characters since release 4.0, because Perl (from release 5.004) does not.
1486     [Or at least, is documented not to: some releases seem to be in conflict
1487     with the documentation.] However, when a pattern was studied with
1488     pcre_study() and all its branches started with \s, PCRE still included VT
1489     as a possible starting character. Of course, this did no harm; it just
1490     caused an unnecessary match attempt.
1492     22. Removed a now-redundant internal flag bit that recorded the fact that case
1493     dependency changed within the pattern. This was once needed for "required
1494     byte" processing, but is no longer used. This recovers a now-scarce options
1495     bit. Also moved the least significant internal flag bit to the most-
1496     significant bit of the word, which was not previously used (hangover from
1497     the days when it was an int rather than a uint) to free up another bit for
1498     the future.
1500     23. Added support for CRLF line endings as well as CR and LF. As well as the
1501     default being selectable at build time, it can now be changed at runtime
1502     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1503     specify that it is scanning data with non-default line endings.
1505     24. Changed the definition of CXXLINK to make it agree with the definition of
1506     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1508     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1509     recursions. This makes a big different to stack usage for some patterns.
1511     26. If a subpattern containing a named recursion or subroutine reference such
1512     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1513     the space required for the compiled pattern went wrong and gave too small a
1514     value. Depending on the environment, this could lead to "Failed: internal
1515     error: code overflow at offset 49" or "glibc detected double free or
1516     corruption" errors.
1518     27. Applied patches from Google (a) to support the new newline modes and (b) to
1519     advance over multibyte UTF-8 characters in GlobalReplace.
1521     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1522     difference for some implementation of PCRE in some Windows version.
1524     29. Added some extra testing facilities to pcretest:
1526     \q<number> in a data line sets the "match limit" value
1527     \Q<number> in a data line sets the "match recursion limt" value
1528     -S <number> sets the stack size, where <number> is in megabytes
1530     The -S option isn't available for Windows.
1533 nigel 89 Version 6.6 06-Feb-06
1534     ---------------------
1536     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1537     in pcreposix.h. I have copied the definition from pcre.h.
1539     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1540     because pcre.h is no longer a built file.
1542     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1543     not normally included in the compiled code.
1546 nigel 87 Version 6.5 01-Feb-06
1547     ---------------------
1549     1. When using the partial match feature with pcre_dfa_exec(), it was not
1550     anchoring the second and subsequent partial matches at the new starting
1551     point. This could lead to incorrect results. For example, with the pattern
1552     /1234/, partially matching against "123" and then "a4" gave a match.
1554     2. Changes to pcregrep:
1556     (a) All non-match returns from pcre_exec() were being treated as failures
1557     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1558     error message is output. Some extra information is given for the
1560     probably the only errors that are likely to be caused by users (by
1561     specifying a regex that has nested indefinite repeats, for instance).
1562     If there are more than 20 of these errors, pcregrep is abandoned.
1564     (b) A binary zero was treated as data while matching, but terminated the
1565     output line if it was written out. This has been fixed: binary zeroes
1566     are now no different to any other data bytes.
1568     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1569     used to set a locale for matching. The --locale=xxxx long option has
1570     been added (no short equivalent) to specify a locale explicitly on the
1571     pcregrep command, overriding the environment variables.
1573     (d) When -B was used with -n, some line numbers in the output were one less
1574     than they should have been.
1576     (e) Added the -o (--only-matching) option.
1578     (f) If -A or -C was used with -c (count only), some lines of context were
1579     accidentally printed for the final match.
1581     (g) Added the -H (--with-filename) option.
1583     (h) The combination of options -rh failed to suppress file names for files
1584     that were found from directory arguments.
1586     (i) Added the -D (--devices) and -d (--directories) options.
1588     (j) Added the -F (--fixed-strings) option.
1590     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1592     (l) Added the --colo(u)r option.
1594     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1595     is not present by default.
1597     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1598     items such as (?R) or (?1), when the recursion could match a number of
1599     alternatives. If it matched one of the alternatives, but subsequently,
1600     outside the recursion, there was a failure, the code tried to back up into
1601     the recursion. However, because of the way PCRE is implemented, this is not
1602     possible, and the result was an incorrect result from the match.
1604     In order to prevent this happening, the specification of recursion has
1605     been changed so that all such subpatterns are automatically treated as
1606     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1608     4. I had overlooked the fact that, in some locales, there are characters for
1609     which isalpha() is true but neither isupper() nor islower() are true. In
1610     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1611     and ordfeminine) are like this. This affected the treatment of \w and \W
1612     when they appeared in character classes, but not when they appeared outside
1613     a character class. The bit map for "word" characters is now created
1614     separately from the results of isalnum() instead of just taking it from the
1615     upper, lower, and digit maps. (Plus the underscore character, of course.)
1617     5. The above bug also affected the handling of POSIX character classes such as
1618     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1619     permanent tables. Instead, the bit maps for such a class were previously
1620     created as the appropriate unions of the upper, lower, and digit bitmaps.
1621     Now they are created by subtraction from the [[:word:]] class, which has
1622     its own bitmap.
1624     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1625     It is created by subtracting the vertical space characters (\x09, \x0a,
1626     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1627     subtraction was done in the overall bitmap for a character class, meaning
1628     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1629     be recognized. This bug has been fixed.
1631     7. Patches from the folks at Google:
1633     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1634     real life, but is still worth protecting against".
1636     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1637     regular expressions".
1639     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1640     have it.
1642     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1643     "configure" and the latter not, in order to fix a problem somebody had
1644     with compiling the Arg class on HP-UX.
1646     (e) Improve the error-handling of the C++ wrapper a little bit.
1648     (f) New tests for checking recursion limiting.
1650     8. The pcre_memmove() function, which is used only if the environment does not
1651     have a standard memmove() function (and is therefore rarely compiled),
1652     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1653     returning a result (though PCRE never actually uses the result).
1655     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1656     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1657     returned instead of calling malloc() with an overflowing number that would
1658     most likely cause subsequent chaos.
1660     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1662     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1663     with this option is matched, the nmatch and pmatch options of regexec() are
1664     ignored.
1666     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1667     provided in case anyone wants to the the POSIX interface with UTF-8
1668     strings.
1670     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1671     C++ linking (needed for some HP-UX environments).
1673     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1674     (unused parameter) and in the pcre_printint() function (omitted "default"
1675     switch label when the default is to do nothing).
1677     15. Added some code to make it possible, when PCRE is compiled as a C++
1678     library, to replace subject pointers for pcre_exec() with a smart pointer
1679     class, thus making it possible to process discontinuous strings.
1681     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1682     much the same function. They were added by different people who were trying
1683     to make PCRE easy to compile on non-Unix systems. It has been suggested
1684     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1685     for compiling on Windows systems. I have therefore replaced it with
1686     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1687     defaults to "extern" for C or "extern C" for C++, which works fine on
1688     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1689     SCOPE with something explicit in config.h. In addition:
1691     (a) pcreposix.h still had just "extern" instead of either of these macros;
1692     I have replaced it with PCRE_DATA_SCOPE.
1694     (b) Functions such as _pcre_xclass(), which are internal to the library,
1695     but external in the C sense, all had PCRE_EXPORT in their definitions.
1696     This is apparently wrong for the Windows case, so I have removed it.
1697     (It makes no difference on Unix-like systems.)
1699     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1700     of recursive calls to match(). This is different to MATCH_LIMIT because
1701     that limits the total number of calls to match(), not all of which increase
1702     the depth of recursion. Limiting the recursion depth limits the amount of
1703     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1704     when PCRE is compiled, and changed at run time. A patch from Google adds
1705     this functionality to the C++ interface.
1707     18. Changes to the handling of Unicode character properties:
1709     (a) Updated the table to Unicode 4.1.0.
1711     (b) Recognize characters that are not in the table as "Cn" (undefined).
1713     (c) I revised the way the table is implemented to a much improved format
1714     which includes recognition of ranges. It now supports the ranges that
1715     are defined in UnicodeData.txt, and it also amalgamates other
1716     characters into ranges. This has reduced the number of entries in the
1717     table from around 16,000 to around 3,000, thus reducing its size
1718     considerably. I realized I did not need to use a tree structure after
1719     all - a binary chop search is just as efficient. Having reduced the
1720     number of entries, I extended their size from 6 bytes to 8 bytes to
1721     allow for more data.
1723     (d) Added support for Unicode script names via properties such as \p{Han}.
1725     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1726     matching that character.
1728     20. When matching a repeated Unicode property with a minimum greater than zero,
1729     (for example \pL{2,}), PCRE could look past the end of the subject if it
1730     reached it while seeking the minimum number of characters. This could
1731     happen only if some of the characters were more than one byte long, because
1732     there is a check for at least the minimum number of bytes.
1734     21. Refactored the implementation of \p and \P so as to be more general, to
1735     allow for more different types of property in future. This has changed the
1736     compiled form incompatibly. Anybody with saved compiled patterns that use
1737     \p or \P will have to recompile them.
1739     22. Added "Any" and "L&" to the supported property types.
1741     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1742     but give a compile time error if the value is greater than 0xff.
1744     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1745     accidentally not being installed or uninstalled.
1747     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1748     made were to insert the current release number. This seemed silly, because
1749     it made things harder for people building PCRE on systems that don't run
1750     "configure". I have turned pcre.h into a distributed file, no longer built
1751     by "configure", with the version identification directly included. There is
1752     no longer a pcre.h.in file.
1754     However, this change necessitated a change to the pcre-config script as
1755     well. It is built from pcre-config.in, and one of the substitutions was the
1756     release number. I have updated configure.ac so that ./configure now finds
1757     the release number by grepping pcre.h.
1759     26. Added the ability to run the tests under valgrind.
1762 nigel 85 Version 6.4 05-Sep-05
1763     ---------------------
1765     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1766     "--" to be printed when multiple files were scanned, even when none of the
1767     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1768     consider it to be a bug, and have restored the previous behaviour.
1770     2. A couple of code tidies to get rid of compiler warnings.
1772     3. The pcretest program used to cheat by referring to symbols in the library
1773     whose names begin with _pcre_. These are internal symbols that are not
1774     really supposed to be visible externally, and in some environments it is
1775     possible to suppress them. The cheating is now confined to including
1776     certain files from the library's source, which is a bit cleaner.
1778     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1779     file's purpose clearer.
1781     5. Reorganized pcre_ucp_findchar().
1784 nigel 83 Version 6.3 15-Aug-05
1785     ---------------------
1787     1. The file libpcre.pc.in did not have general read permission in the tarball.
1789     2. There were some problems when building without C++ support:
1791     (a) If C++ support was not built, "make install" and "make test" still
1792     tried to test it.
1794     (b) There were problems when the value of CXX was explicitly set. Some
1795     changes have been made to try to fix these, and ...
1797     (c) --disable-cpp can now be used to explicitly disable C++ support.
1799     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1800     backslash in a target when C++ was disabled. This confuses some
1801     versions of "make", apparently. Using an intermediate variable solves
1802     this. (Same for CPP_LOBJ.)
1804     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1805     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1806     necessary on certain architectures.
1808     4. Added a setting of -export-symbols-regex to the link command to remove
1809     those symbols that are exported in the C sense, but actually are local
1810     within the library, and not documented. Their names all begin with
1811     "_pcre_". This is not a perfect job, because (a) we have to except some
1812     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1813     available (and never for static libraries). I have made a note to try to
1814     find a way round (a) in the future.
1817 nigel 81 Version 6.2 01-Aug-05
1818     ---------------------
1820     1. There was no test for integer overflow of quantifier values. A construction
1821     such as {1111111111111111} would give undefined results. What is worse, if
1822     a minimum quantifier for a parenthesized subpattern overflowed and became
1823     negative, the calculation of the memory size went wrong. This could have
1824     led to memory overwriting.
1826     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1828     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1829     operating environments where this matters.
1831     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1832     PCRE options from within the C++ wrapper.
1834     5. Named capturing subpatterns were not being correctly counted when a pattern
1835     was compiled. This caused two problems: (a) If there were more than 100
1836     such subpatterns, the calculation of the memory needed for the whole
1837     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1838     back references of the form \12, where the number was greater than 9, were
1839     not recognized as back references, even though there were sufficient
1840     previous subpatterns.
1842     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1843     versions of gcc, e.g. 2.95.4.
1846 nigel 79 Version 6.1 21-Jun-05
1847     ---------------------
1849     1. There was one reference to the variable "posix" in pcretest.c that was not
1850     surrounded by "#if !defined NOPOSIX".
1852     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1853     the cross-check on the old pcre_info() function, for the benefit of the
1854     cut-down version of PCRE that is currently imported into Exim.
1856     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1857     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1858     patterns that start (?i) but I don't think that matters. The use of (?i) is
1859     just an example; this all applies to the other options as well.
1861     4. Since libtool seems to echo the compile commands it is issuing, the output
1862     from "make" can be reduced a bit by putting "@" in front of each libtool
1863     compile command.
1865     5. Patch from the folks at Google for configure.in to be a bit more thorough
1866     in checking for a suitable C++ installation before trying to compile the
1867     C++ stuff. This should fix a reported problem when a compiler was present,
1868     but no suitable headers.
1870     6. The man pages all had just "PCRE" as their title. I have changed them to
1871     be the relevant file name. I have also arranged that these names are
1872     retained in the file doc/pcre.txt, which is a concatenation in text format
1873     of all the man pages except the little individual ones for each function.
1875     7. The NON-UNIX-USE file had not been updated for the different set of source
1876     files that come with release 6. I also added a few comments about the C++
1877     wrapper.
1880 nigel 77 Version 6.0 07-Jun-05
1881     ---------------------
1883     1. Some minor internal re-organization to help with my DFA experiments.
1885     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1886     didn't matter for the library itself when fully configured, but did matter
1887     when compiling without UCP support, or within Exim, where the ucp files are
1888     not imported.
1890     3. Refactoring of the library code to split up the various functions into
1891     different source modules. The addition of the new DFA matching code (see
1892     below) to a single monolithic source would have made it really too
1893     unwieldy, quite apart from causing all the code to be include in a
1894     statically linked application, when only some functions are used. This is
1895     relevant even without the DFA addition now that patterns can be compiled in
1896     one application and matched in another.
1898     The downside of splitting up is that there have to be some external
1899     functions and data tables that are used internally in different modules of
1900     the library but which are not part of the API. These have all had their
1901     names changed to start with "_pcre_" so that they are unlikely to clash
1902     with other external names.
1904     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1905     a different (DFA) algorithm. Although it is slower than the original
1906     function, it does have some advantages for certain types of matching
1907     problem.
1909     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1910     including restarting after a partial match.
1912     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1913     defined when compiling for Windows was sent to me. I have put it into the
1914     code, though I have no means of testing or verifying it.
1916     7. Added the pcre_refcount() auxiliary function.
1918     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1919     match before or at the first newline in the subject string. In pcretest,
1920     the /f option on a pattern can be used to set this.
1922     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1923     would behave wrongly. This has been present in PCRE since release 4.0.
1925     10. A number of changes to the pcregrep command:
1927     (a) Refactored how -x works; insert ^(...)$ instead of setting
1928     PCRE_ANCHORED and checking the length, in preparation for adding
1929     something similar for -w.
1931     (b) Added the -w (match as a word) option.
1933     (c) Refactored the way lines are read and buffered so as to have more
1934     than one at a time available.
1936     (d) Implemented a pcregrep test script.
1938     (e) Added the -M (multiline match) option. This allows patterns to match
1939     over several lines of the subject. The buffering ensures that at least
1940     8K, or the rest of the document (whichever is the shorter) is available
1941     for matching (and similarly the previous 8K for lookbehind assertions).
1943     (f) Changed the --help output so that it now says
1945     -w, --word-regex(p)
1947     instead of two lines, one with "regex" and the other with "regexp"
1948     because that confused at least one person since the short forms are the
1949     same. (This required a bit of code, as the output is generated
1950     automatically from a table. It wasn't just a text change.)
1952     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1953     option but starts with a hyphen. Could be a pattern or a path name
1954     starting with a hyphen, for instance.
1956     (h) "-" can be given as a file name to represent stdin.
1958     (i) When file names are being printed, "(standard input)" is used for
1959     the standard input, for compatibility with GNU grep. Previously
1960     "<stdin>" was used.
1962     (j) The option --label=xxx can be used to supply a name to be used for
1963     stdin when file names are being printed. There is no short form.
1965     (k) Re-factored the options decoding logic because we are going to add
1966     two more options that take data. Such options can now be given in four
1967     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1969     (l) Added the -A, -B, and -C options for requesting that lines of context
1970     around matches be printed.
1972     (m) Added the -L option to print the names of files that do not contain
1973     any matching lines, that is, the complement of -l.
1975     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1976     continue to scan other files.
1978     (o) The -s option was incorrectly implemented. For compatibility with other
1979     greps, it now suppresses the error message for a non-existent or non-
1980     accessible file (but not the return code). There is a new option called
1981     -q that suppresses the output of matching lines, which was what -s was
1982     previously doing.
1984     (p) Added --include and --exclude options to specify files for inclusion
1985     and exclusion when recursing.
1987     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1988     Hopefully, it now does.
1990     12. Missing cast in pcre_study().
1992     13. Added an "uninstall" target to the makefile.
1994     14. Replaced "extern" in the function prototypes in Makefile.in with
1995     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1996     world, but is set differently for Windows.
1998     15. Added a second compiling function called pcre_compile2(). The only
1999     difference is that it has an extra argument, which is a pointer to an
2000     integer error code. When there is a compile-time failure, this is set
2001     non-zero, in addition to the error test pointer being set to point to an
2002     error message. The new argument may be NULL if no error number is required
2003     (but then you may as well call pcre_compile(), which is now just a
2004     wrapper). This facility is provided because some applications need a
2005     numeric error indication, but it has also enabled me to tidy up the way
2006     compile-time errors are handled in the POSIX wrapper.
2008     16. Added VPATH=.libs to the makefile; this should help when building with one
2009     prefix path and installing with another. (Or so I'm told by someone who
2010     knows more about this stuff than I do.)
2012     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2013     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2014     match everything, including newlines. This is not POSIX-compatible, but
2015     somebody wanted the feature. From pcretest it can be activated by using
2016     both the P and the s flags.
2018     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2020     19. libpcre.pc was being incorrectly installed as executable.
2022     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2023     it now also looks for '\r' so that it will work unmodified on Windows.
2025     21. Added Google's contributed C++ wrapper to the distribution.
2027     22. Added some untidy missing memory free() calls in pcretest, to keep
2028     Electric Fence happy when testing.
2032 nigel 75 Version 5.0 13-Sep-04
2033     ---------------------
2035     1. Internal change: literal characters are no longer packed up into items
2036     containing multiple characters in a single byte-string. Each character
2037     is now matched using a separate opcode. However, there may be more than one
2038     byte in the character in UTF-8 mode.
2040     2. The pcre_callout_block structure has two new fields: pattern_position and
2041     next_item_length. These contain the offset in the pattern to the next match
2042     item, and its length, respectively.
2044     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2045     insertion of callouts before each pattern item. Added the /C option to
2046     pcretest to make use of this.
2048     4. On the advice of a Windows user, the lines
2050     #if defined(_WIN32) || defined(WIN32)
2051     _setmode( _fileno( stdout ), 0x8000 );
2052     #endif /* defined(_WIN32) || defined(WIN32) */
2054     have been added to the source of pcretest. This apparently does useful
2055     magic in relation to line terminators.
2057     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2058     for the benefit of those environments where the "b" makes a difference.
2060     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2061     to know about it. I have put a hack into configure.in that adds in code
2062     to set GCC=yes if CC=icc. This seems to end up at a point in the
2063     generated configure script that is early enough to affect the setting of
2064     compiler options, which is what is needed, but I have no means of testing
2065     whether it really works. (The user who reported this had patched the
2066     generated configure script, which of course I cannot do.)
2068     LATER: After change 22 below (new libtool files), the configure script
2069     seems to know about icc (and also ecc). Therefore, I have commented out
2070     this hack in configure.in.
2072     7. Added support for pkg-config (2 patches were sent in).
2074     8. Negated POSIX character classes that used a combination of internal tables
2075     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2076     [[:^ascii]]. Typically, they would match almost any characters. The other
2077     POSIX classes were not broken in this way.
2079     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2080     to find the match, as PCRE was deluded into thinking that the match had to
2081     start at the start point or following a newline. The same bug applied to
2082     patterns with negative forward assertions or any backward assertions
2083     preceding ".*" at the start, unless the pattern required a fixed first
2084     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2086     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2087     starting at the last subject character, bytes beyond the end of the subject
2088     string were read.
2090     11. Renamed the variable "class" as "classbits" to make life easier for C++
2091     users. (Previously there was a macro definition, but it apparently wasn't
2092     enough.)
2094     12. Added the new field "tables" to the extra data so that tables can be passed
2095     in at exec time, or the internal tables can be re-selected. This allows
2096     a compiled regex to be saved and re-used at a later time by a different
2097     program that might have everything at different addresses.
2099     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2100     -R library as well as a -L library.
2102     14. The debugging options of pcretest (-d on the command line or D on a
2103     pattern) showed incorrect output for anything following an extended class
2104     that contained multibyte characters and which was followed by a quantifier.
2106     15. Added optional support for general category Unicode character properties
2107     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2108     support. It adds about 90K to the size of the library. The meanings of the
2109     inbuilt class escapes such as \d and \s have NOT been changed.
2111     16. Updated pcredemo.c to include calls to free() to release the memory for the
2112     compiled pattern.
2114     17. The generated file chartables.c was being created in the source directory
2115     instead of in the building directory. This caused the build to fail if the
2116     source directory was different from the building directory, and was
2117     read-only.
2119     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2120     file. No doubt somebody will tell me if they don't make sense... Also added
2121     Dan Mooney's comments about building on OpenVMS.
2123     19. Added support for partial matching via the PCRE_PARTIAL option for
2124     pcre_exec() and the \P data escape in pcretest.
2126     20. Extended pcretest with 3 new pattern features:
2128     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2129     write the compiled pattern to the file whose name is "rest-of-line".
2130     This is a straight binary dump of the data, with the saved pointer to
2131     the character tables forced to be NULL. The study data, if any, is
2132     written too. After writing, pcretest reads a new pattern.
2134     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2135     compiled pattern from the given file. There must not be any
2136     occurrences of "<" in the file name (pretty unlikely); if there are,
2137     pcretest will instead treat the initial "<" as a pattern delimiter.
2138     After reading in the pattern, pcretest goes on to read data lines as
2139     usual.
2141     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2142     and 16-bit fields in a compiled pattern, to simulate a pattern that
2143     was compiled on a host of opposite endianness.
2145     21. The pcre-exec() function can now cope with patterns that were compiled on
2146     hosts of opposite endianness, with this restriction:
2148     As for any compiled expression that is saved and used later, the tables
2149     pointer field cannot be preserved; the extra_data field in the arguments
2150     to pcre_exec() should be used to pass in a tables address if a value
2151     other than the default internal tables were used at compile time.
2153     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2154     now diagnosed as an error. Previously, most of the time, a negative number
2155     would have been treated as zero, but if in addition "ovector" was passed as
2156     NULL, a crash could occur.
2158     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2159     new versions from the libtool 1.5 distribution (the last one is a copy of
2160     a file called libtool.m4). This seems to have fixed the need to patch
2161     "configure" to support Darwin 1.3 (which I used to do). However, I still
2162     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2163     workstation).
2165     24. Changed the PCRE licence to be the more standard "BSD" licence.
2168 nigel 73 Version 4.5 01-Dec-03
2169     ---------------------
2171     1. There has been some re-arrangement of the code for the match() function so
2172     that it can be compiled in a version that does not call itself recursively.
2173     Instead, it keeps those local variables that need separate instances for
2174     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2175     needs to "recurse". Keeping track of where control must go is done by means
2176     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2177     hide most of the details from the main code, and operates only if
2178     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2179     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2180     operating.
2182     To make it easier for callers to provide specially tailored get/free
2183     functions for this usage, two new functions, pcre_stack_malloc, and
2184     pcre_stack_free, are used. They are always called in strict stacking order,
2185     and the size of block requested is always the same.
2187     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2188     PCRE has been compiled to use the stack or the heap for recursion. The
2189     -C option of pcretest uses this to show which version is compiled.
2191     A new data escape \S, is added to pcretest; it causes the amounts of store
2192     obtained and freed by both kinds of malloc/free at match time to be added
2193     to the output.
2195     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2196     what's available on my current Linux desktop machine.
2198     3. When matching a UTF-8 string, the test for a valid string at the start has
2199     been extended. If start_offset is not zero, PCRE now checks that it points
2200     to a byte that is the start of a UTF-8 character. If not, it returns
2201     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2202     this is necessary because there may be backward assertions in the pattern.
2203     When matching the same subject several times, it may save resources to use
2204     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2206     4. The code for checking the validity of UTF-8 strings has been tightened so
2207     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2208     containing "overlong sequences".
2210     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2211     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2212     should have been "&", but it just so happened that all the cases this let
2213     through by mistake were picked up later in the function.
2215     6. I had used a variable called "isblank" - this is a C99 function, causing
2216     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2218     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2219     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2220     so the version is shown; (c) stop "make test" echoing "./RunTest".
2222     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2224     9. The prototype for memmove() for systems that don't have it was using
2225     size_t, but the inclusion of the header that defines size_t was later. I've
2226     moved the #includes for the C headers earlier to avoid this.
2228     10. Added some adjustments to the code to make it easier to compiler on certain
2229     special systems:
2231     (a) Some "const" qualifiers were missing.
2232     (b) Added the macro EXPORT before all exported functions; by default this
2233     is defined to be empty.
2234     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2235     that it reads its output file name as an argument instead of writing
2236     to the standard output and assuming this can be redirected.
2238     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2239     class containing characters with values greater than 255, PCRE compilation
2240     went into a loop.
2242     12. A recursive reference to a subpattern that was within another subpattern
2243     that had a minimum quantifier of zero caused PCRE to crash. For example,
2244     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2245     recursion. If the recursively-called subpattern itself had a zero repeat,
2246     that was OK.
2248     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2249     buffer into which it was copied (for escape processing) was still set at
2250     1024, so long lines caused crashes.
2252     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2253     "internal error: code overflow...". This applied to any character class
2254     that was followed by a possessive quantifier.
2256     15. Modified the Makefile to add libpcre.la as a prerequisite for
2257     libpcreposix.la because I was told this is needed for a parallel build to
2258     work.
2260     16. If a pattern that contained .* following optional items at the start was
2261     studied, the wrong optimizing data was generated, leading to matching
2262     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2263     matching string must start with a or b or c. The correct conclusion for
2264     this pattern is that a match can start with any character.
2267 nigel 71 Version 4.4 13-Aug-03
2268     ---------------------
2270     1. In UTF-8 mode, a character class containing characters with values between
2271     127 and 255 was not handled correctly if the compiled pattern was studied.
2272     In fixing this, I have also improved the studying algorithm for such
2273     classes (slightly).
2275     2. Three internal functions had redundant arguments passed to them. Removal
2276     might give a very teeny performance improvement.
2278     3. Documentation bug: the value of the capture_top field in a callout is *one
2279     more than* the number of the hightest numbered captured substring.
2281     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2282     in incorrectly linking with a previously installed version. They now link
2283     explicitly with libpcre.la.
2285     5. configure.in no longer needs to recognize Cygwin specially.
2287     6. A problem in pcre.in for Windows platforms is fixed.
2289     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2290     pcretest, it used to include the size of the study block as part of its
2291     output. Unfortunately, the structure contains a field that has a different
2292     size on different hardware architectures. This meant that the tests that
2293     showed this size failed. As the block is currently always of a fixed size,
2294     this information isn't actually particularly useful in pcretest output, so
2295     I have just removed it.
2297     8. Three pre-processor statements accidentally did not start in column 1.
2298     Sadly, there are *still* compilers around that complain, even though
2299     standard C has not required this for well over a decade. Sigh.
2301     9. In pcretest, the code for checking callouts passed small integers in the
2302     callout_data field, which is a void * field. However, some picky compilers
2303     complained about the casts involved for this on 64-bit systems. Now
2304     pcretest passes the address of the small integer instead, which should get
2305     rid of the warnings.
2307     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2308     both compile and run time, and gives an error if an invalid UTF-8 sequence
2309     is found. There is a option for disabling this check in cases where the
2310     string is known to be correct and/or the maximum performance is wanted.
2312     11. In response to a bug report, I changed one line in Makefile.in from
2314     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2315     to
2316     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2318     to look similar to other lines, but I have no way of telling whether this
2319     is the right thing to do, as I do not use Windows. No doubt I'll get told
2320     if it's wrong...
2323 nigel 69 Version 4.3 21-May-03
2324     ---------------------
2326     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2327     Makefile.
2329     2. Some refactoring to improve the quality of the code:
2331     (i) The utf8_table... variables are now declared "const".
2333     (ii) The code for \cx, which used the "case flipping" table to upper case
2334     lower case letters, now just substracts 32. This is ASCII-specific,
2335     but the whole concept of \cx is ASCII-specific, so it seems
2336     reasonable.
2338     (iii) PCRE was using its character types table to recognize decimal and
2339     hexadecimal digits in the pattern. This is silly, because it handles
2340     only 0-9, a-f, and A-F, but the character types table is locale-
2341     specific, which means strange things might happen. A private
2342     table is now used for this - though it costs 256 bytes, a table is
2343     much faster than multiple explicit tests. Of course, the standard
2344     character types table is still used for matching digits in subject
2345     strings against \d.
2347     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2348     ending in _t are). So I've renamed it as ESC_tee.
2350     3. The first argument for regexec() in the POSIX wrapper should have been
2351     defined as "const".
2353     4. Changed pcretest to use malloc() for its buffers so that they can be
2354     Electric Fenced for debugging.
2356     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2357     to read one or more bytes before the start of the subject string. Often this
2358     had no effect on PCRE's behaviour, but in some circumstances it could
2359     provoke a segmentation fault.
2361     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2362     to try to read one or more bytes before the start of the subject string.
2364     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2365     UTF-8 support could misbehave in various ways if the subject string
2366     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2367     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2368     back over UTF-8 characters.)
2371 nigel 67 Version 4.2 14-Apr-03
2372     ---------------------
2374     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2376     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2377     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2378     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2379     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2380     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2381     and BUILD_EXEEXT
2382     Note: automatic setting of the BUILD variables is not yet working
2383     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2384     compile-time but not at link-time
2385     [LINK]: use for linking executables only
2386     make different versions for Windows and non-Windows
2387     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2388     libraries
2389     [LINK_FOR_BUILD]: new variable
2390     [OBJEXT]: use throughout
2391     [EXEEXT]: use throughout
2392     <winshared>: new target
2393     <wininstall>: new target
2394     <dftables.o>: use native compiler
2395     <dftables>: use native linker
2396     <install>: handle Windows platform correctly
2397     <clean>: ditto
2398     <check>: ditto
2399     copy DLL to top builddir before testing
2401     As part of these changes, -no-undefined was removed again. This was reported
2402     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2403     in any case.
2405     3. Some tidies to get rid of compiler warnings:
2407     . In the match_data structure, match_limit was an unsigned long int, whereas
2408     match_call_count was an int. I've made them both unsigned long ints.
2410     . In pcretest the fact that a const uschar * doesn't automatically cast to
2411     a void * provoked a warning.
2413     . Turning on some more compiler warnings threw up some "shadow" variables
2414     and a few more missing casts.
2416     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2417     option, a class that contained a single character with a value between 128
2418     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2420     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2421     option, a class that contained several characters, but with at least one
2422     whose value was between 128 and 255 caused PCRE to crash.
2425 nigel 65 Version 4.1 12-Mar-03
2426     ---------------------
2427 nigel 63
2428 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2429     needed, and a string in dftables.c that was longer than standard compilers are
2430     required to support.
2432     2. Compiling with Sun's compiler found a few more places where the code could
2433     be tidied up in order to avoid warnings.
2435     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2436     first of these names is deprecated in the latest Autoconf in favour of the name
2437     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2438     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2439     analogy I have changed it to CFLAGS_FOR_BUILD.
2441     4. Added -no-undefined to the linking command in the Makefile, because this is
2442     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2443     linking step for the pcreposix library.
2445     5. PCRE was failing to diagnose the case of two named groups with the same
2446     name.
2448     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2449     literal character that is needed in the subject for a match, and scans along to
2450     ensure that it is present before embarking on the full matching process. This
2451     saves time in cases of nested unlimited repeats that are never going to match.
2452     Problem: the scan can take a lot of time if the subject is very long (e.g.
2453     megabytes), thus penalizing straightforward matches. It is now done only if the
2454     amount of subject to be scanned is less than 1000 bytes.
2456     7. A lesser problem with the same optimization is that it was recording the
2457     first character of an anchored pattern as "needed", thus provoking a search
2458     right along the subject, even when the first match of the pattern was going to
2459     fail. The "needed" character is now not set for anchored patterns, unless it
2460     follows something in the pattern that is of non-fixed length. Thus, it still
2461     fulfils its original purpose of finding quick non-matches in cases of nested
2462     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2465     Version 4.0 17-Feb-03
2466     ---------------------
2468 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2469     extended to the end of string, PCRE compiled incorrect data. This could lead to
2470     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2472     2. Moved to autoconf 2.53 and libtool 1.4.2.
2474     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2475     the special perltest8 script is no longer needed - all the tests can be run
2476     from a single perltest script.
2478     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2479     by \s. It has now been removed in PCRE. This means it isn't recognized as
2480     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2481     class [:space:] *does* include VT, thereby creating a mess.
2483     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2484     space and tab.
2486     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2487     its new features into the main test script, reducing the number of scripts.
2489     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2490     were backward compatible, and made the (?i) apply to the whole pattern, as if
2491     /i were given. Now it behaves more logically, and applies the option setting
2492     only to what follows. PCRE has been changed to follow suit. However, if it
2493     finds options settings right at the start of the pattern, it extracts them into
2494     the global options, as before. Thus, they show up in the info data.
2496     8. Added support for the \Q...\E escape sequence. Characters in between are
2497     treated as literals. This is slightly different from Perl in that $ and @ are
2498     also handled as literals inside the quotes. In Perl, they will cause variable
2499     interpolation. Note the following examples:
2501     Pattern PCRE matches Perl matches
2503     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2504     \Qabc\$xyz\E abc\$xyz abc\$xyz
2505     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2507     For compatibility with Perl, \Q...\E sequences are recognized inside character
2508     classes as well as outside them.
2510     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2511     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2512     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2513     signed/unsigned warnings.
2515     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2516     option for pcretest, so I've replaced it by a simple function that does just
2517     that job.
2519     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2520     "pcregrep -".
2522     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2523     Java package. This provides some syntactic sugar for simple cases of what my
2524     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2525     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2526     item, you can use this simplified notation. Note that only makes sense with
2527     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2528     greediness, whatever the setting of the PCRE_UNGREEDY option.
2530     13. A change of greediness default within a pattern was not taking effect at
2531     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2532     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2533     was abstracted outside.
2535     14. PCRE now supports the \G assertion. It is true when the current matching
2536     position is at the start point of the match. This differs from \A when the
2537     starting offset is non-zero. Used with the /g option of pcretest (or similar
2538     code), it works in the same way as it does for Perl's /g option. If all
2539     alternatives of a regex begin with \G, the expression is anchored to the start
2540     match position, and the "anchored" flag is set in the compiled expression.
2542     15. Some bugs concerning the handling of certain option changes within patterns
2543     have been fixed. These applied to options other than (?ims). For example,
2544     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2545     been the other way round. Some of this was related to change 7 above.
2547     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2548     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2549     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2550     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2552     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2553     mode. Unlike ".", it always matches newline, whatever the setting of
2554     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2555     assertions. Perl allows it, but it doesn't (in general) work because it can't
2556     calculate the length of the lookbehind. At least, that's the case for Perl
2557     5.8.0 - I've been told they are going to document that it doesn't work in
2558     future.
2560     18. Added an error diagnosis for escapes that PCRE does not support: these are
2561     \L, \l, \N, \P, \p, \U, \u, and \X.
2563     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2564     reading past the end of the pattern in cases such as /[abcd/.
2566     20. PCRE was getting more memory than necessary for patterns with classes that
2567     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2569     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2570     compiling PCRE for use with Virtual Pascal.
2572     22. Small fix to the Makefile to make it work properly if the build is done
2573     outside the source tree.
2575     23. Added a new extension: a condition to go with recursion. If a conditional
2576     subpattern starts with (?(R) the "true" branch is used if recursion has
2577     happened, whereas the "false" branch is used only at the top level.
2579     24. When there was a very long string of literal characters (over 255 bytes
2580     without UTF support, over 250 bytes with UTF support), the computation of how
2581     much memory was required could be incorrect, leading to segfaults or other
2582     strange effects.
2584     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2585     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2586     there was a subsequent back reference to those brackets. This meant that, for
2587     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2588     possible to check for precisely this case. All we can do is abandon the
2589     optimization if .* occurs inside capturing brackets when there are any back
2590     references whatsoever. (See below for a better fix that came later.)
2592     26. The handling of the optimization for finding the first character of a
2593     non-anchored pattern, and for finding a character that is required later in the
2594     match were failing in some cases. This didn't break the matching; it just
2595     failed to optimize when it could. The way this is done has been re-implemented.
2597     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2599     28. Added a new feature that provides some of the functionality that Perl
2600     provides with (?{...}). The facility is termed a "callout". The way it is done
2601     in PCRE is for the caller to provide an optional function, by setting
2602     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2603     global variable. By default it is unset, which disables all calling out. To get
2604     the function called, the regex must include (?C) at appropriate points. This
2605     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2606     This provides a means of identifying different callout points. When PCRE
2607     reaches such a point in the regex, if pcre_callout has been set, the external
2608     function is called. It is provided with data in a structure called
2609     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2610     matching continues; if it returns a non-zero value, the match at the current
2611     point fails. However, backtracking will occur if possible. [This was changed
2612     later and other features added - see item 49 below.]
2614     29. pcretest is upgraded to test the callout functionality. It provides a
2615     callout function that displays information. By default, it shows the start of
2616     the match and the current position in the text. There are some new data escapes
2617     to vary what happens:
2619     \C+ in addition, show current contents of captured substrings
2620     \C- do not supply a callout function
2621     \C!n return 1 when callout number n is reached
2622     \C!n!m return 1 when callout number n is reached for the mth time
2624     30. If pcregrep was called with the -l option and just a single file name, it
2625     output "<stdin>" if a match was found, instead of the file name.
2627     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2628     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2629     pcre_exec(). This saves a malloc/free per call. The default value of
2630     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2631     when configuring.
2633     32. The default maximum size of a compiled pattern is 64K. There have been a
2634     few cases of people hitting this limit. The code now uses macros to handle the
2635     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2636     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2637     configuring. Tests 2 and 5 work only with 2-byte links because they output
2638     debugging information about compiled patterns.
2640     33. Internal code re-arrangements:
2642     (a) Moved the debugging function for printing out a compiled regex into
2643     its own source file (printint.c) and used #include to pull it into
2644     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2645     separate copies.
2647     (b) Defined the list of op-code names for debugging as a macro in
2648     internal.h so that it is next to the definition of the opcodes.
2650     (c) Defined a table of op-code lengths for simpler skipping along compiled
2651     code. This is again a macro in internal.h so that it is next to the
2652     definition of the opcodes.
2654     34. Added support for recursive calls to individual subpatterns, along the
2655     lines of Robin Houston's patch (but implemented somewhat differently).
2657     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2658     allow it to read and process whole directories in Win32. This code was
2659     contributed by Lionel Fourquaux; it has not been tested by me.
2661     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2662     used to name a group. Names consist of alphanumerics and underscores, and must
2663     be unique. Back references use the syntax (?P=name) and recursive calls use
2664     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2665     numbers. The function pcre_fullinfo() can be used after compilation to extract
2666     a name/number map. There are three relevant calls:
2668     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2669     PCRE_INFO_NAMECOUNT yields the number of entries
2670     PCRE_INFO_NAMETABLE yields a pointer to the map.
2672     The map is a vector of fixed-size entries. The size of each entry depends on
2673     the length of the longest name used. The first two bytes of each entry are the
2674     group number, most significant byte first. There follows the corresponding
2675     name, zero terminated. The names are in alphabetical order.
2677     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2678     case instead of 255. Making it the same both with and without UTF-8 support
2679     means that the same test output works with both.
2681     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2682     calling malloc() with a zero argument.
2684     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2685     optimization. I've improved things by keeping a bitmap of backreferences with
2686     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2687     fact referenced, the optimization can be applied. It is unlikely that a
2688     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2689     the match to follow \n) will appear inside brackets with a number greater than
2690     31, but if it does, any back reference > 31 suppresses the optimization.
2692     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2693     of disabling numbered capturing parentheses. Any opening parenthesis that is
2694     not followed by ? behaves as if it were followed by ?: but named parentheses
2695     can still be used for capturing (and they will acquire numbers in the usual
2696     way).
2698     41. Redesigned the return codes from the match() function into yes/no/error so
2699     that errors can be passed back from deep inside the nested calls. A malloc
2700     failure while inside a recursive subpattern call now causes the
2701     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2703     42. It is now possible to set a limit on the number of times the match()
2704     function is called in a call to pcre_exec(). This facility makes it possible to
2705     limit the amount of recursion and backtracking, though not in a directly
2706     obvious way, because the match() function is used in a number of different
2707     circumstances. The count starts from zero for each position in the subject
2708     string (for non-anchored patterns). The default limit is, for compatibility, a
2709     large number, namely 10 000 000. You can change this in two ways:
2711     (a) When configuring PCRE before making, you can use --with-match-limit=n
2712     to set a default value for the compiled library.
2714     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2715     a different value is set. See 45 below.
2717     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2719     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2720     of things that can be changed at compile time. The first argument specifies
2721     what is wanted and the second points to where the information is to be placed.
2722     The current list of available information is:
2726     The output is an integer that is set to one if UTF-8 support is available;
2727     otherwise it is set to zero.
2731     The output is an integer that it set to the value of the code that is used for
2732     newline. It is either LF (10) or CR (13).
2736     The output is an integer that contains the number of bytes used for internal
2737     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2741     The output is an integer that contains the threshold above which the POSIX
2742     interface uses malloc() for output vectors. See item 31 above.
2746     The output is an unsigned integer that contains the default limit of the number
2747     of match() calls in a pcre_exec() execution. See 42 above.
2749     44. pcretest has been upgraded by the addition of the -C option. This causes it
2750     to extract all the available output from the new pcre_config() function, and to
2751     output it. The program then exits immediately.
2753     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2754     order to support additional features. One way would have been to define
2755     pcre_exec2() (for example) with extra arguments, but this would not have been
2756     extensible, and would also have required all calls to the original function to
2757     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2758     is used for passing in "extra" data from pcre_study().
2760     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2761     contains the following fields:
2763     flags a bitmap indicating which of the following fields are set
2764     study_data opaque data from pcre_study()
2765     match_limit a way of specifying a limit on match() calls for a specific
2766     call to pcre_exec()
2767     callout_data data for callouts (see 49 below)
2769     The flag bits are also defined in pcre.h, and are
2775     The pcre_study() function now returns one of these new pcre_extra blocks, with
2776     the actual study data pointed to by the study_data field, and the
2777     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2778     before. That is, this change is entirely upwards-compatible and requires no
2779     change to existing code.
2781     If you want to pass in additional data to pcre_exec(), you can either place it
2782     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2783     block.
2785     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2786     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2787     times with different match limits, until it finds the minimum value needed for
2788     pcre_exec() to complete. The value is then output. This can be instructive; for
2789     most simple matches the number is quite small, but for pathological cases it
2790     gets very large very quickly.
2792     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2793     returns the size of the data block pointed to by the study_data field in a
2794     pcre_extra block, that is, the value that was passed as the argument to
2795     pcre_malloc() when PCRE was getting memory in which to place the information
2796     created by pcre_study(). The fourth argument should point to a size_t variable.
2797     pcretest has been extended so that this information is shown after a successful
2798     pcre_study() call when information about the compiled regex is being displayed.
2800     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2801     because what follows is always an absolute path. (Later: it turns out that this
2802     is more than cosmetic for MinGW, because it doesn't like empty path
2803     components.)
2805     49. Some changes have been made to the callout feature (see 28 above):
2807     (i) A callout function now has three choices for what it returns:
2809     0 => success, carry on matching
2810     > 0 => failure at this point, but backtrack if possible
2811     < 0 => serious error, return this value from pcre_exec()
2813     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2814     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2815     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2816     use by callout functions. It will never be used by PCRE itself.
2818     (ii) The pcre_extra structure (see 45 above) has a void * field called
2819     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2820     pcre_callout_block structure has a field of the same name. The contents of
2821     the field passed in the pcre_extra structure are passed to the callout
2822     function in the corresponding field in the callout block. This makes it
2823     easier to use the same callout-containing regex from multiple threads. For
2824     testing, the pcretest program has a new data escape
2826     \C*n pass the number n (may be negative) as callout_data
2828     If the callout function in pcretest receives a non-zero value as
2829     callout_data, it returns that value.
2831     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2832     there were some redundant $(CFLAGS) in commands that are now specified as
2833     $(LINK), which already includes $(CFLAGS).
2835     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2836     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2837     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2838     one-byte characters throughout. Note that case-insensitive matching applies
2839     only to characters whose values are less than 256. PCRE doesn't support the
2840     notion of cases for higher-valued characters.
2842     (i) A character class whose characters are all within 0-255 is handled as
2843     a bit map, and the map is inverted for negative classes. Previously, a
2844     character > 255 always failed to match such a class; however it should
2845     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2847     (ii) A negated character class with a single character < 255 is coded as
2848     "not this character" (OP_NOT). This wasn't working properly when the test
2849     character was multibyte, either singly or repeated.
2851     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2852     mode, for example: \x{100}{2,3}.
2854     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2855     singly or repeated) now correctly test multibyte characters. However,
2856     PCRE doesn't recognize any characters with values greater than 255 as
2857     digits, spaces, or word characters. Such characters always match \D, \S,
2858     and \W, and never match \d, \s, or \w.
2860     (v) Classes may now contain characters and character ranges with values
2861     greater than 255. For example: [ab\x{100}-\x{400}].
2863     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2864     PCRE in UTF-8 mode.
2866     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2867     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2868     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2869     value.)
2871     53. The single man page has become too large. I have therefore split it up into
2872     a number of separate man pages. These also give rise to individual HTML pages;
2873     these are now put in a separate directory, and there is an index.html page that
2874     lists them all. Some hyperlinking between the pages has been installed.
2876     54. Added convenience functions for handling named capturing parentheses.
2878     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2879     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2880     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2881     are faulted.
2883     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2884     calling configure. These values are used when compiling the dftables.c program
2885     which is run to generate the source of the default character tables. They
2886     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2887     you will need to set these values.
2889     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2892     Version 3.9 02-Jan-02
2893 nigel 61 ---------------------
2895     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2897     2. If --disable-static was given, the building process failed when trying to
2898     build pcretest and pcregrep. (For some reason it was using libtool to compile
2899     them, which is not right, as they aren't part of the library.)
2902 nigel 59 Version 3.8 18-Dec-01
2903     ---------------------
2905     1. The experimental UTF-8 code was completely screwed up. It was packing the
2906     bytes in the wrong order. How dumb can you get?
2909 nigel 57 Version 3.7 29-Oct-01
2910     ---------------------
2912     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2913     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2914     this didn't happen under Solaris 8, where I normally test things.
2916 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2917     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2918     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2919     this fix an hour or so after the initial 3.7 release.)
2920 nigel 57
2921 nigel 59
2922 nigel 55 Version 3.6 23-Oct-01
2923     ---------------------
2925     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2926     offsets passed as NULL with zero offset count.
2928     2. The config.guess and config.sub files had not been updated when I moved to
2929     the latest autoconf.
2932 nigel 53 Version 3.5 15-Aug-01
2933     ---------------------
2934 nigel 5
2935 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2936     had been forgotten.
2938     2. By using declared but undefined structures, we can avoid using "void"
2939     definitions in pcre.h while keeping the internal definitions of the structures
2940     private.
2942     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2943     user point of view, this means that both static and shared libraries are built
2944     by default, but this can be individually controlled. More of the work of
2945     handling this static/shared cases is now inside libtool instead of PCRE's make
2946     file.
2948     4. The pcretest utility is now installed along with pcregrep because it is
2949     useful for users (to test regexs) and by doing this, it automatically gets
2950     relinked by libtool. The documentation has been turned into a man page, so
2951     there are now .1, .txt, and .html versions in /doc.
2953     5. Upgrades to pcregrep:
2954     (i) Added long-form option names like gnu grep.
2955     (ii) Added --help to list all options with an explanatory phrase.
2956     (iii) Added -r, --recursive to recurse into sub-directories.
2957     (iv) Added -f, --file to read patterns from a file.
2959     6. pcre_exec() was referring to its "code" argument before testing that
2960     argument for NULL (and giving an error if it was NULL).
2962     7. Upgraded Makefile.in to allow for compiling in a different directory from
2963     the source directory.
2965     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2966     options bits, the pointer it was passed was to an int instead of to an unsigned
2967     long int. This mattered only on 64-bit systems.
2969     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2970     generated) instead of pcre.in, which it its source. Also made the same change
2971     in several of the .c files.
2973     10. A new release of gcc defines printf() as a macro, which broke pcretest
2974     because it had an ifdef in the middle of a string argument for printf(). Fixed
2975     by using separate calls to printf().
2977     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2978     script, to force use of CR or LF instead of \n in the source. On non-Unix
2979     systems, the value can be set in config.h.
2981     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2982     absolute limit. Changed the text of the error message to make this clear, and
2983     likewise updated the man page.
2985     13. The limit of 99 on the number of capturing subpatterns has been removed.
2986     The new limit is 65535, which I hope will not be a "real" limit.
2989 nigel 51 Version 3.4 22-Aug-00
2990     ---------------------
2992     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2994     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2997 nigel 49 Version 3.3 01-Aug-00
2998     ---------------------
3000     1. If an octal character was given, but the value was greater than \377, it
3001     was not getting masked to the least significant bits, as documented. This could
3002     lead to crashes in some systems.
3004     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3005     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3007     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3008     These just pass their arguments on to (pcre_free)(), but they are provided
3009     because some uses of PCRE bind it to non-C systems that can call its functions,
3010     but cannot call free() or pcre_free() directly.
3012     4. Add "make test" as a synonym for "make check". Corrected some comments in
3013     the Makefile.
3015     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3016     Makefile.
3018     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3019     command called pgrep for grepping around the active processes.
3021     7. Added the beginnings of support for UTF-8 character strings.
3023     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3024     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3025     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3026     out for the ar command.)
3029 nigel 47 Version 3.2 12-May-00
3030     ---------------------
3032     This is purely a bug fixing release.
3034     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3035     of ZA. This was just one example of several cases that could provoke this bug,
3036     which was introduced by change 9 of version 2.00. The code for breaking
3037     infinite loops after an iteration that matches an empty string was't working
3038     correctly.
3040     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3041     when matched against abbab (for example). After matching an empty string, it
3042     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3043     caused it to match further down the string than it should.
3045     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3046     was there because it doesn't seem to be needed, and it causes trouble on some
3047     systems, as it is not a Standard C header. It has been removed.
3049     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3050     were reported on the Macintosh. The changes were from
3052     while ((c = *(++ptr)) != 0 && c != '\n');
3053     to
3054     while ((c = *(++ptr)) != 0 && c != '\n') ;
3056     Totally extraordinary, but if that's what it takes...
3058     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3059     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3060     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3061     assumes the way PCRE uses memmove() (always moving upwards).
3063     6. PCRE is being used in one environment where strchr() is not available. There
3064     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3065     faster code anyway.
3068 nigel 45 Version 3.1 09-Feb-00
3069     ---------------------
3071     The only change in this release is the fixing of some bugs in Makefile.in for
3072     the "install" target:
3074     (1) It was failing to install pcreposix.h.
3076     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3079 nigel 43 Version 3.0 01-Feb-00
3080     ---------------------
3081 nigel 41
3082     1. Add support for the /+ modifier to perltest (to output $` like it does in
3083     pcretest).
3085     2. Add support for the /g modifier to perltest.
3087     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3088     matches null strings.
3090     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3091     pattern. Perl treats empty patterns specially - it reuses the most recent
3092     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3093     effect.
3095     5. The POSIX interface was broken in that it was just handing over the POSIX
3096     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3097     required a bigger vector, with some working space on the end. This means that
3098     the POSIX wrapper now has to get and free some memory, and copy the results.
3100 nigel 43 6. Added some simple autoconf support, placing the test data and the
3101     documentation in separate directories, re-organizing some of the
3102     information files, and making it build pcre-config (a GNU standard). Also added
3103     libtool support for building PCRE as a shared library, which is now the
3104     default.
3105 nigel 41
3106 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3107     09 are not valid octal constants. Single digits will be used for minor values
3108     less than 10.
3110     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3111     existing programs that set these in the POSIX interface can use PCRE without
3112     modification.
3114     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3115     return all that pcre_info() returns, plus additional data. The pcre_info()
3116     function is retained for compatibility, but is considered to be obsolete.
3118     10. Added experimental recursion feature (?R) to handle one common case that
3119     Perl 5.6 will be able to do with (?p{...}).
3121     11. Added support for POSIX character classes like [:alpha:], which Perl is
3122     adopting.
3125 nigel 39 Version 2.08 31-Aug-99
3126     ----------------------
3128     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3129     trying to match at the startoffset position, but instead was moving forward to
3130     the next newline as if a previous match had failed.
3132     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3133     and could get into a loop if a null string was matched other than at the start
3134     of the subject.
3136     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3137     be distinguished at compile time, and for completeness also added PCRE_DATE.
3139     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3140     in GnuWin32 environments.
3143 nigel 37 Version 2.07 29-Jul-99
3144     ----------------------
3146     1. The documentation is now supplied in plain text form and HTML as well as in
3147     the form of man page sources.
3149     2. C++ compilers don't like assigning (void *) values to other pointer types.
3150     In particular this affects malloc(). Although there is no problem in Standard
3151     C, I've put in casts to keep C++ compilers happy.
3153     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3154     should be (const char *).
3156     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3157     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3158     However, I haven't made this a standard facility. The documentation doesn't
3159     mention it, and the Makefile doesn't support it.
3161     5. The Makefile now contains an "install" target, with editable destinations at
3162     the top of the file. The pcretest program is not installed.
3164     6. pgrep -V now gives the PCRE version number and date.
3166     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3167     causing the entire string to be ignored, instead of just the last character.
3169     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3170     non-matching string, it can take a very, very long time, even for strings of
3171     quite modest length, because of the nested recursion. PCRE now does better in
3172     some of these cases. It does this by remembering the last required literal
3173     character in the pattern, and pre-searching the subject to ensure it is present
3174     before running the real match. In other words, it applies a heuristic to detect
3175     some types of certain failure quickly, and in the above example, if presented
3176     with a string that has no trailing " it gives "no match" very quickly.
3178     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3179     other alternatives are tried instead.
3182 nigel 35 Version 2.06 09-Jun-99
3183     ----------------------
3185     1. Change pcretest's output for amount of store used to show just the code
3186     space, because the remainder (the data block) varies in size between 32-bit and
3187     64-bit systems.
3189     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3190     start matching at. This allows lookbehinds to work when searching for multiple
3191     occurrences in a string.
3193     3. Added additional options to pcretest for testing multiple occurrences:
3195     /+ outputs the rest of the string that follows a match
3196     /g loops for multiple occurrences, using the new startoffset argument
3197     /G loops for multiple occurrences by passing an incremented pointer
3199     4. PCRE wasn't doing the "first character" optimization for patterns starting
3200     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3201     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3202     the letter 'x'. On long subject strings, this gives a significant speed-up.
3205 nigel 33 Version 2.05 21-Apr-99
3206     ----------------------
3208     1. Changed the type of magic_number from int to long int so that it works
3209     properly on 16-bit systems.
3211     2. Fixed a bug which caused patterns starting with .* not to work correctly
3212     when the subject string contained newline characters. PCRE was assuming
3213     anchoring for such patterns in all cases, which is not correct because .* will
3214     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3215     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3216     must be retried after every newline in the subject.
3219 nigel 31 Version 2.04 18-Feb-99
3220     ----------------------
3222     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3223     computation of the store needed to hold the pattern was incorrect (too large).
3224     If such patterns were nested a few deep, this could multiply and become a real
3225     problem.
3227     2. Added /M option to pcretest to show the memory requirement of a specific
3228     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3230     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3231     compiled in such a way that the backtracking after subsequent failure was
3232     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3233     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3236 nigel 29 Version 2.03 02-Feb-99
3237     ----------------------
3239     1. Fixed typo and small mistake in man page.
3241 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3242     LICENCE file containing the conditions.
3243 nigel 29
3244     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3245     Perl, that is the internal \ allows the delimiter to be included in the
3246     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3247     the final delimiter, add \ to the end of the pattern (to test the error).
3249     4. Added the convenience functions for extracting substrings after a successful
3250     match. Updated pcretest to make it able to test these functions.
3253 nigel 27 Version 2.02 14-Jan-99
3254     ----------------------
3256     1. Initialized the working variables associated with each extraction so that
3257     their saving and restoring doesn't refer to uninitialized store.
3259     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3260     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3261     fix the problem.
3263     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3264     calls, and wasn't printing the correct value for compiling calls. Increased the
3265     default value of LOOPREPEAT, and the number of significant figures in the
3266     times.
3268     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3270     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3271     a building problem on Windows NT with a FAT file system.
3274 nigel 25 Version 2.01 21-Oct-98
3275     ----------------------
3277     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3278     to character tables built by pcre_maketables() in the current locale. If NULL
3279     is passed, the default tables are used.
3282 nigel 23 Version 2.00 24-Sep-98
3283 nigel 21 ----------------------
3285 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3286     it any more.
3288     2. Allow quantification of (?>) groups, and make it work correctly.
3290     3. The first character computation wasn't working for (?>) groups.
3292     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3293     end of the subject) and add 5.005's \z, which really does match only at the
3294     very end of the subject.
3296     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3298     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3299     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3300     localized options. All options to pcre_study() were also removed.
3302     7. Add other new features from 5.005:
3304     $(?<= positive lookbehind
3305     $(?<! negative lookbehind
3306     (?imsx-imsx) added the unsetting capability
3307     such a setting is global if at outer level; local otherwise
3308     (?imsx-imsx:) non-capturing groups with option setting
3309     (?(cond)re|re) conditional pattern matching
3311     A backreference to itself in a repeated group matches the previous
3312     captured string.
3314     8. General tidying up of studying (both automatic and via "study")
3315     consequential on the addition of new assertions.
3317     9. As in 5.005, unlimited repeated groups that could match an empty substring
3318     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3319     runtime if any iteration does actually match an empty substring.
3321     10. Include the RunTest script in the distribution.
3323     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3324     discrepancies, some of which were old and were also with respect to 5.004. They
3325     have now been fixed.
3328     Version 1.09 28-Apr-98
3329     ----------------------
3331 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3332     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3333     program crashes, or just wrong answers. This did not apply to negated classes
3334     containing more than one character, or to minima other than one.
3337 nigel 19 Version 1.08 27-Mar-98
3338     ----------------------
3340     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3342     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3343     latter must appear before anything that relies on it in the pattern.
3346 nigel 17 Version 1.07 16-Feb-98
3347     ----------------------
3349     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3350     repeat of a potentially empty string).
3353 nigel 15 Version 1.06 23-Jan-98
3354     ----------------------
3356     1. Added Markus Oberhumer's little patches for C++.
3358     2. Literal strings longer than 255 characters were broken.
3361 nigel 13 Version 1.05 23-Dec-97
3362     ----------------------
3364     1. Negated character classes containing more than one character were failing if
3365     PCRE_CASELESS was set at run time.
3368 nigel 11 Version 1.04 19-Dec-97
3369     ----------------------
3371     1. Corrected the man page, where some "const" qualifiers had been omitted.
3373     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3374     input syntax.
3376     3. Fixed memory leak which occurred when a regex with back references was
3377     matched with an offsets vector that wasn't big enough. The temporary memory
3378     that is used in this case wasn't being freed if the match failed.
3380     4. Tidied pcretest to ensure it frees memory that it gets.
3382     5. Temporary memory was being obtained in the case where the passed offsets
3383     vector was exactly big enough.
3385     6. Corrected definition of offsetof() from change 5 below.
3387     7. I had screwed up change 6 below and broken the rules for the use of
3388     setjmp(). Now fixed.
3391 nigel 9 Version 1.03 18-Dec-97
3392     ----------------------
3394     1. A erroneous regex with a missing opening parenthesis was correctly
3395     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3396     on some systems.
3398     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3399     it was reported that one broken compiler failed on the former because "code" is
3400     also an independent variable.
3402     3. The erroneous regex a[]b caused an array overrun reference.
3404     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3405     fail on data ending with that character. (It was going on too far, and checking
3406     the next character, typically a binary zero.) This was specific to the
3407     optimized code for single-character negative classes.
3409     5. Added a contributed patch from the TIN world which does the following:
3411     + Add an undef for memmove, in case the the system defines a macro for it.
3413     + Add a definition of offsetof(), in case there isn't one. (I don't know
3414     the reason behind this - offsetof() is part of the ANSI standard - but
3415     it does no harm).
3417     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3418     most of the places where whitespace preceded '#'. I have given up and
3419     allowed the remaining 2 cases to be at the margin.
3421     + Rename some variables in pcre to eliminate shadowing. This seems very
3422     pedantic, but does no harm, of course.
3424     6. Moved the call to setjmp() into its own function, to get rid of warnings
3425     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3427     7. Constructs such as \d{8,} were compiling into the equivalent of
3428 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3429 nigel 9 outcome, but in this particular case used more store than had been allocated,
3430     which caused the bug to be discovered because it threw up an internal error.
3432     8. The debugging code in both pcre and pcretest for outputting the compiled
3433     form of a regex was going wrong in the case of back references followed by
3434     curly-bracketed repeats.
3437 nigel 7 Version 1.02 12-Dec-97
3438     ----------------------
3440     1. Typos in pcre.3 and comments in the source fixed.
3442     2. Applied a contributed patch to get rid of places where it used to remove
3443     'const' from variables, and fixed some signed/unsigned and uninitialized
3444     variable warnings.
3446     3. Added the "runtest" target to Makefile.
3448     4. Set default compiler flag to -O2 rather than just -O.
3451 nigel 5 Version 1.01 19-Nov-97
3452     ----------------------
3454     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3455     like /([ab]*)*/, that is, for classes with more than one character in them.
3457     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3458     as /((?>a*))*/ (a PCRE_EXTRA facility).
3461     Version 1.00 18-Nov-97
3462     ----------------------
3464     1. Added compile-time macros to support systems such as SunOS4 which don't have
3465     memmove() or strerror() but have other things that can be used instead.
3467     2. Arranged that "make clean" removes the executables.
3470 nigel 3 Version 0.99 27-Oct-97
3471     ----------------------
3473     1. Fixed bug in code for optimizing classes with only one character. It was
3474     initializing a 32-byte map regardless, which could cause it to run off the end
3475     of the memory it had got.
3477     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3480     Version 0.98 22-Oct-97
3481     ----------------------
3483     1. Fixed bug in code for handling temporary memory usage when there are more
3484     back references than supplied space in the ovector. This could cause segfaults.
3487     Version 0.97 21-Oct-97
3488     ----------------------
3490     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3492     2. Optimized negated single characters not to use a bit map.
3494     3. Brought error texts together as macro definitions; clarified some of them;
3495     fixed one that was wrong - it said "range out of order" when it meant "invalid
3496     escape sequence".
3498     4. Changed some char * arguments to const char *.
3500     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3502     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3503     pcretest.
3506     Version 0.96 16-Oct-97
3507     ----------------------
3509     1. Added a simple "pgrep" utility to the distribution.
3511     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3512     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3513     where "ddd" means "one or more decimal digits".
3515     3. Fixed serious bug. If a pattern had a back reference, but the call to
3516     pcre_exec() didn't supply a large enough ovector to record the related
3517     identifying subpattern, the match always failed. PCRE now remembers the number
3518     of the largest back reference, and gets some temporary memory in which to save
3519     the offsets during matching if necessary, in order to ensure that
3520     backreferences always work.
3522     4. Increased the compatibility with Perl in a number of ways:
3524     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3525     to request this handling. The option can be set at compile or exec time.
3527     (b) $ matches before a terminating newline by default; an option
3528     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3529     mode). The option can be set at compile or exec time.
3531     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3532     the same as Perl's. If the decimal number it represents is less than 10
3533     or there aren't that many previous left capturing parentheses, an octal
3534     escape is read. Inside a character class, it's always an octal escape,
3535     even if it is a single digit.
3537     (d) An escaped but undefined alphabetic character is taken as a literal,
3538     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3539     escapes.
3541     (e) {0} is now permitted. (The previous item is removed from the compiled
3542     pattern).
3544     5. Changed all the names of code files so that the basic parts are no longer
3545     than 10 characters, and abolished the teeny "globals.c" file.
3547     6. Changed the handling of character classes; they are now done with a 32-byte
3548     bit map always.
3550     7. Added the -d and /D options to pcretest to make it possible to look at the
3551     internals of compilation without having to recompile pcre.
3554     Version 0.95 23-Sep-97
3555     ----------------------
3557     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3558     \x20 at the start of a run of normal characters. These were being treated as
3559     real characters, instead of the source characters being re-checked.
3562     Version 0.94 18-Sep-97
3563     ----------------------
3565     1. The functions are now thread-safe, with the caveat that the global variables
3566     containing pointers to malloc() and free() or alternative functions are the
3567     same for all threads.
3569     2. Get pcre_study() to generate a bitmap of initial characters for non-
3570     anchored patterns when this is possible, and use it if passed to pcre_exec().
3573     Version 0.93 15-Sep-97
3574     ----------------------
3576     1. /(b)|(:+)/ was computing an incorrect first character.
3578     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3579     but not actually doing anything yet.
3581     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3582     as Perl does (e.g. [-az] or [az-]).
3584     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3585     all possible positions.
3587     5. Split up into different modules to avoid including unneeded functions in a
3588     compiled binary. However, compile and exec are still in one module. The "study"
3589     function is split off.
3591     6. The character tables are now in a separate module whose source is generated
3592     by an auxiliary program - but can then be edited by hand if required. There are
3593     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3594     toupper() in the code.
3596     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3597     make them global. Abolish the function for setting them, as the caller can now
3598     set them directly.
3601     Version 0.92 11-Sep-97
3602     ----------------------
3604     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3605     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3607     2. Caseless matching was not working in character classes if the characters in
3608     the pattern were in upper case.
3610     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3612     4. Make PCRE_ANCHORED public and accept as a compile option.
3614     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3615     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3616     pass them.
3618     6. Give an error if bad option bits passed at compile or run time.
3620     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3621     pcretest to cause it to pass that flag.
3623     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3624     options, and the first character, if set.
3626     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3629     Version 0.91 10-Sep-97
3630     ----------------------
3632     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3633     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3635     2. PCRE was looping on encountering an indefinitely repeated back reference to
3636     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3637     Perl does - treats the match as successful.
3639     ****


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