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Revision 459 - (hide annotations) (download)
Sun Oct 4 09:21:39 2009 UTC (5 years, 6 months ago) by ph10
File size: 174992 byte(s)
Fix problems with conditional references to duplicate named subpatterns.

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8     was out-of-date, and there was no check on the pcre_compile() error code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 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
135     pattern matches a fixed length string. PCRE did not allow this; now it
136     does. Neither allows recursion.
138 ph10 455 25. I finally figured out how to implement a request to provide the minimum
139     length of subject string that was needed in order to match a given pattern.
140     (It was back references and recursion that I had previously got hung up
141     on.) This code has now been added to pcre_study(); it finds a lower bound
142     to the length of subject needed. It is not necessarily the greatest lower
143     bound, but using it to avoid searching strings that are too short does give
144     some useful speed-ups. The value is available to calling programs via
145     pcre_fullinfo().
147     26. While implementing 25, I discovered to my embarrassment that pcretest had
148     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
149     study optimizations had never been tested with that matching function.
150     Oops. What is worse, even when it was passed study data, there was a bug in
151     pcre_dfa_exec() that meant it never actually used it. Double oops. There
152     were also very few tests of studied patterns with pcre_dfa_exec().
154 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
155     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
156     on the other side of the coin, they are no longer allowed to have different
157     names, because these cannot be distinguished in PCRE, and this has caused
158     confusion. (This is a difference from Perl.)
160 ph10 459 28. When duplicate subpattern names are present (necessarily with different
161     numbers, as required by 27 above), and a test is made by name in a
162     conditional pattern, either for a subpattern having been matched, or for
163     recursion in such a pattern, all the associated numbered subpatterns are
164     tested, and the overall condition is true if the condition is true for any
165     one of them. This is the way Perl works, and is also more like the way
166     testing by number works.
168 ph10 418
169 ph10 412 Version 7.9 11-Apr-09
170 ph10 376 ---------------------
172 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
173 ph10 376 (pcretest), all targets were linked against these libraries. This included
174     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
175     libraries. This caused unwanted dependencies to be created. This problem
176 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
177 ph10 376 pcretest is linked with readline.
178 ph10 392
179 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
180     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
181     moved outside it again, because FALSE and TRUE are already defined in AIX,
182     but BOOL is not.
183 ph10 392
184     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
185 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
186 ph10 392
187 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
188     hyphens) following file names and line numbers when outputting matching
189 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
190 ph10 376 wording for the --colour (or --color) option.
191 ph10 392
192 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
193     was not coloured; this is different to GNU grep, so I have changed it to be
194     the same.
195 ph10 392
196 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
197 ph10 392 each matching line was coloured. Now it goes on to look for further matches
198     of any of the test patterns, which is the same behaviour as GNU grep.
200     7. A pattern that could match an empty string could cause pcregrep to loop; it
201     doesn't make sense to accept an empty string match in pcregrep, so I have
202 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
203     seems to be how GNU grep behaves.
204 ph10 392
205 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
206 ph10 392 start or after a newline", because the conditional assertion was not being
207     correctly handled. The rule now is that both the assertion and what follows
208     in the first alternative must satisfy the test.
210 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
211 ph10 399 condition was an assertion, PCRE could crash during matching, both with
212     pcre_exec() and pcre_dfa_exec().
213 ph10 392
214     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
215     used for matching.
217     11. Unicode property support in character classes was not working for
218 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
219 ph10 388
220 ph10 392 12. Added the -M command line option to pcretest.
222 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
223 ph10 389
224     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
225 ph10 390
226 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
227 ph10 390 wrapper.
228 ph10 392
229 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
230 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
231 ph10 391 string constants.
232 ph10 405
233 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
234     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
235 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
236     these, but not everybody uses configure.
238     19. A conditional group that had only one branch was not being correctly
239     recognized as an item that could match an empty string. This meant that an
240     enclosing group might also not be so recognized, causing infinite looping
241     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
242     with the subject "ab", where knowledge that the repeated group can match
243 ph10 396 nothing is needed in order to break the loop.
244 ph10 405
245 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
246 ph10 405 exec(), but without supplying a callout function, matching went wrong.
248     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
249     leak if the size of the offset vector was greater than 30. When the vector
250     is smaller, the saved offsets during recursion go onto a local stack
251     vector, but for larger vectors malloc() is used. It was failing to free
252     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
253 ph10 400 error, in fact).
254 ph10 405
255 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
256 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
257     problem, but was untidy.
258 ph10 376
259 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
260     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
261     included within another project.
262 ph10 411
263 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
264     slightly modified by me:
265 ph10 411
266     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
267     not building pcregrep.
269 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
270 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
272 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
273     duplicate group numbers, could behave incorrectly or give incorrect errors,
274     because when scanning forward to find the reference group, PCRE was not
275     taking into account the duplicate group numbers. A pattern such as
276     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
277 ph10 411
278     26. Changed a few more instances of "const unsigned char *" to USPTR, making
279     the feature of a custom pointer more persuasive (as requested by a user).
280 ph10 416
281 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
282 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
283     pre-defined.
284 ph10 392
285 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
287 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
288     in the configuration summary.
289 ph10 405
290 ph10 411
291 ph10 374 Version 7.8 05-Sep-08
292 ph10 349 ---------------------
294     1. Replaced UCP searching code with optimized version as implemented for Ad
295     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
296 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
297     to 5 times on some simple patterns that I tested. Permission was given to
298     distribute the MultiStage2.py script that generates the tables (it's not in
299     the tarball, but is in the Subversion repository).
300 ph10 349
301 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
302     scripts.
303 ph10 358
304 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
305     a group with a zero qualifier. The result of the study could be incorrect,
306 ph10 358 or the function might crash, depending on the pattern.
308     4. Caseless matching was not working for non-ASCII characters in back
309 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
310 ph10 358 It now works when Unicode Property Support is available.
312 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
313     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
314     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
315 ph10 358 truncation.
316 ph10 349
317 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
319 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
320     pointers, in case they are 64-bit values.
321 ph10 371
322     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
323     test 2 if it fails.
325 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
326 ph10 371 and a #define of that name to empty if it is not externally set. This is to
327     allow users of MSVC to set it if necessary.
329     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
330 ph10 359 the convenience functions in the pcre_get.c source file.
331 ph10 371
332 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
333     could cause overwriting and/or a crash. This command provoked a crash in
334 ph10 371 some environments:
336     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
338 ph10 360 This potential security problem was recorded as CVE-2008-2371.
339 ph10 371
340 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
341     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
342 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
343 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
344     pcretest so that it places the subject at the end of its malloc-ed buffer.
345 ph10 371
346 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
347 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
349 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
350 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
351     first line. This applied both to normal and DFA matching.
353 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
354 ph10 371 /^[^d]*?$/8 failed to match "abc".
355 ph10 351
356 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
358     17. Make it more clear in the documentation that values returned from
359 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
360 ph10 357
361 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
362 ph10 368
363 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
364     supplied by Stefan Weber. I made a further small update for 7.8 because
365 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
366     replaced by pcre_ucd.c.
367 ph10 371
368 ph10 373
369 ph10 347 Version 7.7 07-May-08
370 ph10 321 ---------------------
372     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
373 ph10 345 a string to a long long, pretend we don't even have a long long." This is
374 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
375 ph10 345
376 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
377     pre-7.6 versions, which defined a global no_arg variable instead of putting
378 ph10 332 it in the RE class. (See also #8 below.)
379 ph10 345
380     3. Remove a line of dead code, identified by coverity and reported by Nuno
381     Lopes.
383 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
384 ph10 321
385 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
386 ph10 345 of files, instead of just to the final components.
388 ph10 324 (2) If there was more than one level of directory, the subdirectories were
389     skipped unless they satisfied the include/exclude conditions. This is
390     inconsistent with GNU grep (and could even be seen as contrary to the
391     pcregrep specification - which I improved to make it absolutely clear).
392     The action now is always to scan all levels of directory, and just
393     apply the include/exclude patterns to regular files.
394 ph10 345
395 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
396 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
398 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
399 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
400 ph10 326 doesn't support NULs in patterns.
401 ph10 345
402     7. Added some missing "const"s to declarations of static tables in
403     pcre_compile.c and pcre_dfa_exec.c.
405 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
406 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
407 ph10 345 first patch. And a third patch - this was a messy problem.)
408 ph10 321
409 ph10 345 9. Applied Craig's patch to remove the use of push_back().
411 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
412     matching function regexec().
413 ph10 345
414     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
415     which, however, unlike Perl's \g{...}, are subroutine calls, not back
416 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
417     Oniguruma does).
418 ph10 345
419     12. Previously, a group with a zero repeat such as (...){0} was completely
420 ph10 335 omitted from the compiled regex. However, this means that if the group
421     was called as a subroutine from elsewhere in the pattern, things went wrong
422 ph10 345 (an internal error was given). Such groups are now left in the compiled
423     pattern, with a new opcode that causes them to be skipped at execution
424 ph10 335 time.
425 ph10 345
426 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
427     to the way PCRE behaves:
428 ph10 345
429 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
430 ph10 345
431     (b) A back reference to an unmatched subpattern matches an empty string
432 ph10 336 (Perl fails the current match path).
433 ph10 345
434 ph10 341 (c) A data ] in a character class must be notated as \] because if the
435 ph10 345 first data character in a class is ], it defines an empty class. (In
436 ph10 341 Perl it is not possible to have an empty class.) The empty class []
437     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
438     The negative empty class [^] matches any one character, independently
439     of the DOTALL setting.
440 ph10 345
441     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
442 ph10 340 non-existent subpattern following a character class starting with ']' and
443     containing () gave an internal compiling error instead of "reference to
444     non-existent subpattern". Fortunately, when the pattern did exist, the
445 ph10 345 compiled code was correct. (When scanning forwards to check for the
446 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
447 ph10 345 the class, so got the count wrong. When actually compiling, the reference
448 ph10 340 was subsequently set up correctly.)
449 ph10 345
450 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
451 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
452     other assertions are supported. I have made pcre_dfa_exec() support
453     (*FAIL).
455 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
456 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
457     cannot be changed at match time, I realized I could make a small
458     improvement to matching performance by compiling OP_ALLANY instead of
459     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
460     on the OP_ANY path.
462     17. Compiling pcretest on Windows with readline support failed without the
463 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
464 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
466 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
467 ph10 345 ncurses library to be included for pcretest when ReadLine support is
468     requested, but also to allow for it to be overridden. This patch came from
469     Daniel Bergström.
470 ph10 347
471 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
472 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
473     any errors with the current Unicode tables. Thanks to Peter Kankowski for
474     spotting this.
475 ph10 324
476 ph10 332
477 ph10 319 Version 7.6 28-Jan-08
478 ph10 300 ---------------------
480 ph10 302 1. A character class containing a very large number of characters with
481     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
482     overflow.
483 ph10 309
484     2. Patch to cut out the "long long" test in pcrecpp_unittest when
485     HAVE_LONG_LONG is not defined.
487 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
488 ph10 304 bring them up to date and include new features. This patch includes:
489 ph10 309
490 ph10 304 - Fixed PH's badly added libz and libbz2 support.
491     - Fixed a problem with static linking.
492 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
493 ph10 304 - Fixed dftables problem and added an option.
494     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
496     - Added readline support for pcretest.
497 ph10 309 - Added an listing of the option settings after cmake has run.
499 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
500     "pcre.dll" under mingw when using Configure/Make. I added stuff to
501     Makefile.am that cause it to include this special target, without
502     affecting anything else. Note that the same mingw target plus all
503     the other distribution libraries and programs are now supported
504     when configuring with CMake (see 6 below) instead of with
505     Configure/Make.
506 ph10 309
507 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
508     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
509 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
510     solves the problem, but it does no harm.
511 ph10 313
512 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
513 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
514 ph10 314 with CMake, and also correct the comment about stack recursion.
515 ph10 313
516 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
517 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
518     of a program that users should build themselves after PCRE is installed, so
519     building it automatically is not really right. What is more, it gave
520 ph10 312 trouble in some build environments.
521 ph10 300
522 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
523 ph10 308
524 ph10 319
525 ph10 298 Version 7.5 10-Jan-08
526 ph10 263 ---------------------
528     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
529     values in parens when parsing an RE using the C++ wrapper."
530 ph10 286
531 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
532     Characters greater than 255 were excluded from the class instead of being
533     included.
534 ph10 286
535     3. The same bug as (2) above applied to negated POSIX classes such as
536 ph10 265 [:^space:].
537 ph10 286
538 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
539     defined or documented. It seems to have been a typo for PCRE_STATIC, so
540 ph10 286 I have changed it.
542 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
543 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
544     first named subpattern whose name started with "a" (in other words, the
545 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
546     expected" is now given for (?&) (a zero-length name), and this patch also
547     makes it give the same error for \k'' (previously it complained that that
548     was a reference to a non-existent subpattern).
549 ph10 286
550 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
551 ph10 286 this is right because (?- can be followed by option settings as well as by
552 ph10 269 digits. I have, however, made the messages clearer.
553 ph10 286
554 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
555     than the number used in the conditional) now cause a compile-time error.
556     This is actually not compatible with Perl, which accepts such patterns, but
557     treats the conditional as always being FALSE (as PCRE used to), but it
558     seems to me that giving a diagnostic is better.
559 ph10 286
560 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
561 ph10 275 and messages.
562 ph10 286
563     9. Fix two occurrences of "backslash" in comments that should have been
564     "backspace".
566     10. Remove two redundant lines of code that can never be obeyed (their function
567     was moved elsewhere).
569     11. The program that makes PCRE's Unicode character property table had a bug
570     which caused it to generate incorrect table entries for sequences of
571 ph10 277 characters that have the same character type, but are in different scripts.
572 ph10 286 It amalgamated them into a single range, with the script of the first of
573 ph10 277 them. In other words, some characters were in the wrong script. There were
574     thirteen such cases, affecting characters in the following ranges:
575 ph10 286
576 ph10 277 U+002b0 - U+002c1
577     U+0060c - U+0060d
578 ph10 286 U+0061e - U+00612
579 ph10 277 U+0064b - U+0065e
580     U+0074d - U+0076d
581     U+01800 - U+01805
582     U+01d00 - U+01d77
583     U+01d9b - U+01dbf
584     U+0200b - U+0200f
585     U+030fc - U+030fe
586     U+03260 - U+0327f
587     U+0fb46 - U+0fbb1
588     U+10450 - U+1049d
589 ph10 286
590 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
591     compatible with GNU grep in that, if there was more than one match in a
592     line, it showed only the first of them. It now behaves in the same way as
593     GNU grep.
594 ph10 286
595     13. If the -o and -v options were combined for pcregrep, it printed a blank
596     line for every non-matching line. GNU grep prints nothing, and pcregrep now
597     does the same. The return code can be used to tell if there were any
598     non-matching lines.
600 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
602     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
603 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
604 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
605     and both kinds of lookbehind were skipped).
607 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
608 ph10 284 inclusion of <windows.h> to before rather than after the definition of
609     INVALID_FILE_ATTRIBUTES (patch from David Byron).
610 ph10 263
611 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
612 ph10 286 character property caused pcre_compile() to compile bad code, which led at
613     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
614     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
615     caused the error; without that there was no problem.
616 ph10 263
617 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
618 ph10 286
619 ph10 289 19. Added --enable-pcretest-libreadline.
620 ph10 286
621 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
622 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
623 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
624     later patch that removed the other one (the right fix) and added unit tests
625     that check the return values (which was not done before).
626 ph10 292
627 ph10 291 21. Several CMake things:
628 ph10 287
629 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
630 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
631 ph10 288
632 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
633     linked with the newly-built libraries, not previously installed ones.
634 ph10 291
636 ph10 298
637     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
638     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
639     UTF-8 newline character). The key issue is that the pattern starts .*;
640     this means that the match must be either at the beginning, or after a
641     newline. The bug was in the code for advancing after a failed match and
642     checking that the new position followed a newline. It was not taking
643 ph10 294 account of UTF-8 characters correctly.
644 ph10 298
645     23. PCRE was behaving differently from Perl in the way it recognized POSIX
646     character classes. PCRE was not treating the sequence [:...:] as a
647     character class unless the ... were all letters. Perl, however, seems to
648     allow any characters between [: and :], though of course it rejects as
649     unknown any "names" that contain non-letters, because all the known class
650     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
651     for example, whereas PCRE did not - it did not recognize a POSIX character
652     class. This seemed a bit dangerous, so the code has been changed to be
653     closer to Perl. The behaviour is not identical to Perl, because PCRE will
654     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
655     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
656     Perl does, and where it didn't before.
658 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
659     Windows environments %n is disabled by default.
660 ph10 292
662 ph10 260 Version 7.4 21-Sep-07
663 ph10 230 ---------------------
665     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
666 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
667     LF". That isn't really right - the whole point of the change was to try to
668     help when there was an actual mention of one of the two characters. So now
669     the change happens only if \r or \n (or a literal CR or LF) character is
670 ph10 230 encountered.
671 ph10 231
672     2. The 32-bit options word was also used for 6 internal flags, but the numbers
673     of both had grown to the point where there were only 3 bits left.
674     Fortunately, there was spare space in the data structure, and so I have
675     moved the internal flags into a new 16-bit field to free up more option
676 ph10 230 bits.
677 ph10 231
678     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
679     but did not set the internal JCHANGED flag - either of these is enough to
680     control the way the "get" function works - but the PCRE_INFO_JCHANGED
681     facility is supposed to tell if (?J) was ever used, so now (?J) at the
682 ph10 230 start sets both bits.
684 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
685     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
686 ph10 230
687 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
689     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
690 ph10 233 compatibility, even though it is no longer used.
691 ph10 243
692     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
693 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
694 ph10 259 windows.h file is present (where different names are used). [This was
695 ph10 257 reversed later after testing - see 16 below.]
696 ph10 243
697     8. Changed all #include <config.h> to #include "config.h". There were also
698 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
699 ph10 243
700 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
701 ph10 243 sequence off the lines that it output.
703     10. It was pointed out to me that arrays of string pointers cause lots of
704     relocations when a shared library is dynamically loaded. A technique of
705     using a single long string with a table of offsets can drastically reduce
706     these. I have refactored PCRE in four places to do this. The result is
707 ph10 240 dramatic:
708 ph10 243
709 ph10 240 Originally: 290
710     After changing UCP table: 187
711 ph10 243 After changing error message table: 43
712 ph10 240 After changing table of "verbs" 36
713     After changing table of Posix names 22
714 ph10 243
715 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
716 ph10 247
717 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
718 ph10 247 unicode-properties was also set.
720 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
721 ph10 231
722 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
723     checked only for CRLF.
724 ph10 233
725 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
727 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
728 ph10 253
729 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
730 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
731     entirely. This removes changes made in 7 above.
732 ph10 256
733 ph10 261 17. The CMake files have been updated, and there is now more information about
734     building with CMake in the NON-UNIX-USE document.
735 ph10 257
736 ph10 261
737 ph10 228 Version 7.3 28-Aug-07
738 ph10 157 ---------------------
740 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
741     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
742     brackets there is not right, since it causes compilers to look for an
743     installed pcre.h, not the version that is in the source that is being
744     compiled (which of course may be different). I have changed it back to:
745 ph10 197
746 ph10 189 #include "pcre.h"
747 ph10 197
748     I have a vague recollection that the change was concerned with compiling in
749     different directories, but in the new build system, that is taken care of
750     by the VPATH setting the Makefile.
752 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
753     when the subject happened to end in the byte 0x85 (e.g. if the last
754     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
755     characters but of course it shouldn't be taken as a newline when it is part
756     of another character. The bug was that, for an unlimited repeat of . in
757     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
758     characters when looking for a newline.
759 ph10 197
760     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
762     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
763     in debug output.
765 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
766     long printing in the pcrecpp unittest when running under MinGW.
767 ph10 189
768 ph10 197 6. ESC_K was left out of the EBCDIC table.
769 ph10 189
770 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
771     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
772     limit also applies to "virtual nesting" when a pattern is recursive, and in
773     this case 1000 isn't so big. I have been able to remove this limit at the
774     expense of backing off one optimization in certain circumstances. Normally,
775     when pcre_exec() would call its internal match() function recursively and
776     immediately return the result unconditionally, it uses a "tail recursion"
777     feature to save stack. However, when a subpattern that can match an empty
778     string has an unlimited repetition quantifier, it no longer makes this
779     optimization. That gives it a stack frame in which to save the data for
780     checking that an empty string has been matched. Previously this was taken
781     from the 1000-entry workspace that had been reserved. So now there is no
782     explicit limit, but more stack is used.
783 ph10 189
784 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
785     syntax that is required for Windows, and which was going wrong for the
786     pcreposix and pcrecpp parts of the library. These were overlooked when this
787     problem was solved for the main library.
788 ph10 197
789 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
790     the size of patterns that contain repeated groups with explicit upper
791     limits. As the maximum quantifier is 65535, the maximum group length was
792     set at 30,000 so that the product of these two numbers did not overflow a
793     32-bit integer. However, it turns out that people want to use groups that
794     are longer than 30,000 bytes (though not repeat them that many times).
795     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
796     made it possible to implement the integer overflow checks in a much more
797     dynamic way, which I have now done. The artificial limitation on group
798     length has been removed - we now have only the limit on the total length of
799     the compiled pattern, which depends on the LINK_SIZE setting.
800 ph10 208
801     10. Fixed a bug in the documentation for get/copy named substring when
802     duplicate names are permitted. If none of the named substrings are set, the
803     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
804     empty string.
806     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
807     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
808     because the ] is interpreted as the first data character and the
809     terminating ] is not found. PCRE has been made compatible with Perl in this
810     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
811     cause memory overwriting.
813 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
814     string has been matched (to stop an infinite loop). It was not recognizing
815 ph10 208 a conditional subpattern that could match an empty string if that
816 ph10 206 subpattern was within another subpattern. For example, it looped when
817 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
818 ph10 206 condition was not nested. This bug has been fixed.
819 ph10 208
820 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
821     past the start of the subject in the presence of bytes with the top bit
822     set, for example "\x8aBCD".
823 ph10 211
824 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
825     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
826 ph10 200
827 ph10 211 14. Optimized (?!) to (*FAIL).
828 ph10 202
829 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
830     This restricts code points to be within the range 0 to 0x10FFFF, excluding
831     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
832     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
833     does: it's just the validity check that is more restrictive.
834 ph10 220
835     16. Inserted checks for integer overflows during escape sequence (backslash)
836     processing, and also fixed erroneous offset values for syntax errors during
837     backslash processing.
839 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
840 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
842 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
843     caused an overrun.
844 ph10 220
845     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
846     something other than just ASCII characters) inside a group that had an
847     unlimited repeat caused a loop at compile time (while checking to see
848     whether the group could match an empty string).
850 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
851     [\P{Any}] did so. (Error in the code for printing property names.)
852 ph10 210
853 ph10 220 21. An orphan \E inside a character class could cause a crash.
855     22. A repeated capturing bracket such as (A)? could cause a wild memory
856 ph10 218 reference during compilation.
857 ph10 220
858     23. There are several functions in pcre_compile() that scan along a compiled
859     expression for various reasons (e.g. to see if it's fixed length for look
860 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
861 ph10 220 present in the pattern. These operators have additional parameters compared
862     with \d, etc, and these were not being taken into account when moving along
863 ph10 218 the compiled data. Specifically:
864 ph10 220
865     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
866     length.
868     (b) An item such as \pL+ within a repeated group could cause crashes or
869 ph10 218 loops.
870 ph10 220
871 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
872 ph10 220 "reference to non-existent subpattern" error.
874 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
876 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
877 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
878 ph10 211
879 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
880 ph10 218
881 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
882 ph10 223 character were causing crashes (broken optimization).
883 ph10 227
884 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
885 ph10 227 \p or \P) caused a compile-time loop.
887 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
888     break. For example, the unstudied pattern [\r\n]A does not match the string
889     "\r\nA" because change 7.0/46 below moves the current point on by two
890     characters after failing to match at the start. However, the pattern \nA
891 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
892     the same is true. There doesn't seem any very clean way out of this, but
893     what I have chosen to do makes the common cases work: PCRE now takes note
894     of whether there can be an explicit match for \r or \n anywhere in the
895     pattern, and if so, 7.0/46 no longer applies. As part of this change,
896     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
897     pattern has explicit CR or LF references.
898 ph10 222
899 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
900 ph10 223
901 ph10 227
902 ph10 189 Version 7.2 19-Jun-07
903     ---------------------
905 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
906     which is apparently normally available under Windows.
907 ph10 159
908     2. Re-jig the pcregrep tests with different newline settings in an attempt
909     to make them independent of the local environment's newline setting.
910 ph10 157
911 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
912 ph10 165
913 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
914     was not 2, because the output contained actual offsets. The recent new
915 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
916     usable with all link sizes.
918 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
919     stack recursion. This gives a massive performance boost under BSD, but just
920 ph10 165 a small improvement under Linux. However, it saves one field in the frame
921 ph10 164 in all cases.
922 ph10 172
923 ph10 166 6. Added more features from the forthcoming Perl 5.10:
924 ph10 172
925 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
926     recursion call. It refers to the nth most recently opened parentheses.
927 ph10 172
928 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
929 ph10 172 to be opened parentheses.
931     (c) Conditions that refer to capturing parentheses can be specified
932 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
933 ph10 172
934 ph10 168 (d) \K resets the start of the current match so that everything before
935 ph10 172 is not part of it.
937 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
938 ph10 172
939 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
940 ph10 172 reference syntax.
941 ph10 182
942 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
943 ph10 182 alternative starts with the same number.
944 ph10 172
945 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
947 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
950     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
951     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
952 ph10 170 for detecting groups that can match an empty string.
953 ph10 159
954 ph10 172 9. A pattern with a very large number of alternatives (more than several
955     hundred) was running out of internal workspace during the pre-compile
956     phase, where pcre_compile() figures out how much memory will be needed. A
957     bit of new cunning has reduced the workspace needed for groups with
958     alternatives. The 1000-alternative test pattern now uses 12 bytes of
959     workspace instead of running out of the 4096 that are available.
960 ph10 182
961 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
962 ph10 172
963 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
964     The report of the bug said:
965 ph10 182
966 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
967     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
968 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
969 ph10 185
970 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
971 ph10 185 it matched the wrong number of bytes.
972 ph10 172
973 ph10 179
974 ph10 155 Version 7.1 24-Apr-07
975 ph10 98 ---------------------
977 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
978 ph10 122 that is more "standard", making use of automake and other Autotools. There
979 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
980     on this.
981 ph10 111
982     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
983     for recursive directory scanning broke on some systems because the files
984     are not scanned in any specific order and on different systems the order
985     was different. A call to "sort" has been inserted into RunGrepTest for the
986     approprate test as a short-term fix. In the longer term there may be an
987 ph10 100 alternative.
988 ph10 111
989 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
990 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
991     people do their own conversions for various reasons). The problems
992     concerned the use of low-level troff macros .br and .in. I have therefore
993     removed all such uses from the man pages (some were redundant, some could
994 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
995     HTML has been updated to handle .nf/.fi and to complain if it encounters
996     .br or .in.
997 ph10 111
998 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
999 ph10 123 arranged for config.h to be included in the distribution, with the name
1000 ph10 111 config.h.generic, for the benefit of those who have to compile without
1001     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1003     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1004     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1005 ph10 127 makevp.bat for the current PCRE, using the additional files
1006 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1007 ph10 111
1008     6. A Windows user reported a minor discrepancy with test 2, which turned out
1009     to be caused by a trailing space on an input line that had got lost in his
1010 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1011 ph10 111
1012 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1013 ph10 111 that is needed.
1015 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1016     as "const" (a) because they are and (b) because it helps the PHP
1017     maintainers who have recently made a script to detect big data structures
1018 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1019     to update Builducptable as well, so it won't revert if ucptable.h is ever
1020 ph10 105 re-created.
1021 ph10 111
1022     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1023 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1024 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1025     support is not required. This saves 1.5-2K of code, which is important in
1026 ph10 107 some applications.
1027 ph10 111
1028 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1029 ph10 111 so as not to refer to the tables, even though these functions will never be
1030     called when UTF-8 support is disabled. Otherwise there are problems with a
1031     shared library.
1033 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1035     (a) It was defining its arguments as char * instead of void *.
1037 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1038     a long time ago when I wrote it, but is no longer the case.
1040 ph10 118 The emulated memove() is provided for those environments that have neither
1041 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1042 ph10 118 is clearly not the case, as these two bugs were recently reported.
1043 ph10 123
1044 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1045 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1046     pages, and it removes trailing spaces from listed files. It also creates
1047     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1048     case, it wraps all the #defines with #ifndefs. This script should be run
1049 ph10 111 before "make dist".
1050 ph10 123
1051 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1052     with Unicode property support.
1053 ph10 123
1054     (a) For a maximizing quantifier, if the two different cases of the
1055     character were of different lengths in their UTF-8 codings (there are
1056     some cases like this - I found 11), and the matching function had to
1057 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1058     were both the same length.
1059 ph10 123
1060     (b) When PCRE was configured to use the heap rather than the stack for
1061     recursion during matching, it was not correctly preserving the data for
1062     the other case of a UTF-8 character when checking ahead for a match
1063     while processing a minimizing repeat. If the check also involved
1064 ph10 115 matching a wide character, but failed, corruption could cause an
1065     erroneous result when trying to check for a repeat of the original
1066     character.
1067 ph10 123
1068 ph10 116 13. Some tidying changes to the testing mechanism:
1069 ph10 98
1070 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1071     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1072 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1073     this for UTF-8.) The configure.ac script no longer substitutes the
1074     relevant variables.
1076 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1077     with length and offset values. This means that the output is different
1078     for different internal link sizes. Test 2 is skipped for link sizes
1079     other than 2 because of this, bypassing the problem. Unfortunately,
1080     there was also a test in test 3 (the locale tests) that used /B and
1081 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1082     I have added a new /Z option to pcretest that replaces the length and
1083     offset values with spaces. This is now used to make test 3 independent
1084 ph10 122 of link size. (Test 2 will be tidied up later.)
1085 ph10 123
1086     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1087 ph10 122 segmentation fault instead of returning the appropriate error message.
1088 ph10 134
1089 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1090 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1091     This doesn't seem right; it now treats the CRLF combination as the line
1092     ending, and so does not match in that case. It's only a pattern such as ^$
1093     that would hit this one: something like ^ABC$ would have failed after \r
1094     and then tried again after \r\n.
1096 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1097 ph10 134 in an attempt to make files that differ only in their line terminators
1098     compare equal. This works on Linux.
1099 ph10 142
1100 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1101     as it exited. This is now fixed, thanks to valgrind.
1102 ph10 142
1103 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1104 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1105     was because its rules for how to advance for /g after matching an empty
1106 ph10 143 string at the end of a line did not allow for this case. They now check for
1107     it specially.
1108 ph10 150
1109     20. pcretest is supposed to handle patterns and data of any length, by
1110     extending its buffers when necessary. It was getting this wrong when the
1111 ph10 147 buffer for a data line had to be extended.
1112 ph10 150
1113 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1114 ph10 150 CRLF as a newline sequence.
1115 ph10 152
1116 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1117 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1118     I have nevertheless tidied it up.
1119 ph10 111
1120 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1121 ph10 123
1122 ph10 153 24. Added a man page for pcre-config.
1123 ph10 152
1124 ph10 153
1125 nigel 93 Version 7.0 19-Dec-06
1126     ---------------------
1128     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1129     moving to gcc 4.1.1.
1131     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1132     sys/time.h, which is documented as needed for this function. It doesn't
1133     seem to matter on Linux, but it showed up on some releases of OS X.
1135     3. It seems that there are systems where bytes whose values are greater than
1136     127 match isprint() in the "C" locale. The "C" locale should be the
1137     default when a C program starts up. In most systems, only ASCII printing
1138     characters match isprint(). This difference caused the output from pcretest
1139     to vary, making some of the tests fail. I have changed pcretest so that:
1141     (a) When it is outputting text in the compiled version of a pattern, bytes
1142     other than 32-126 are always shown as hex escapes.
1144     (b) When it is outputting text that is a matched part of a subject string,
1145     it does the same, unless a different locale has been set for the match
1146     (using the /L modifier). In this case, it uses isprint() to decide.
1148     4. Fixed a major bug that caused incorrect computation of the amount of memory
1149     required for a compiled pattern when options that changed within the
1150     pattern affected the logic of the preliminary scan that determines the
1151     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1152     that the computed length was too small. The symptoms of this bug were
1153     either the PCRE error "internal error: code overflow" from pcre_compile(),
1154     or a glibc crash with a message such as "pcretest: free(): invalid next
1155     size (fast)". Examples of patterns that provoked this bug (shown in
1156     pcretest format) are:
1158     /(?-x: )/x
1159     /(?x)(?-x: \s*#\s*)/
1160     /((?i)[\x{c0}])/8
1161     /(?i:[\x{c0}])/8
1163     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1164     is now done differently.
1166     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1167     wrapper classes; (b) implement a new function in the C++ scanner that is
1168     more efficient than the old way of doing things because it avoids levels of
1169     recursion in the regex matching; (c) add a paragraph to the documentation
1170     for the FullMatch() function.
1172     6. The escape sequence \n was being treated as whatever was defined as
1173     "newline". Not only was this contrary to the documentation, which states
1174     that \n is character 10 (hex 0A), but it also went horribly wrong when
1175     "newline" was defined as CRLF. This has been fixed.
1177     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1178     was being set to -1 for the "end of line" case (supposedly a value that no
1179     character can have). Though this value is never used (the check for end of
1180     line is "zero bytes in current character"), it caused compiler complaints.
1181     I've changed it to 0xffffffff.
1183     8. In pcre_version.c, the version string was being built by a sequence of
1184     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1185     string (as it is for production releases) called a macro with an empty
1186     argument. The C standard says the result of this is undefined. The gcc
1187     compiler treats it as an empty string (which was what was wanted) but it is
1188     reported that Visual C gives an error. The source has been hacked around to
1189     avoid this problem.
1191     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1192     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1193     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1194     of them did).
1196     10. Originally, pcretest opened its input and output without "b"; then I was
1197     told that "b" was needed in some environments, so it was added for release
1198     5.0 to both the input and output. (It makes no difference on Unix-like
1199     systems.) Later I was told that it is wrong for the input on Windows. I've
1200     now abstracted the modes into two macros, to make it easier to fiddle with
1201     them, and removed "b" from the input mode under Windows.
1203     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1205     12. Added -help and --help to pcretest as an official way of being reminded
1206     of the options.
1208     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1209     and pcrecpp.cc because they annoy compilers at high warning levels.
1211     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1213     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1214     scripts are not C programs :-) and which was not noticed because it works
1215     on Linux.
1217     16. pcretest is supposed to handle any length of pattern and data line (as one
1218     line or as a continued sequence of lines) by extending its input buffer if
1219     necessary. This feature was broken for very long pattern lines, leading to
1220     a string of junk being passed to pcre_compile() if the pattern was longer
1221     than about 50K.
1223     17. I have done a major re-factoring of the way pcre_compile() computes the
1224     amount of memory needed for a compiled pattern. Previously, there was code
1225     that made a preliminary scan of the pattern in order to do this. That was
1226     OK when PCRE was new, but as the facilities have expanded, it has become
1227     harder and harder to keep it in step with the real compile phase, and there
1228     have been a number of bugs (see for example, 4 above). I have now found a
1229     cunning way of running the real compile function in a "fake" mode that
1230     enables it to compute how much memory it would need, while actually only
1231     ever using a few hundred bytes of working memory and without too many
1232     tests of the mode. This should make future maintenance and development
1233     easier. A side effect of this work is that the limit of 200 on the nesting
1234     depth of parentheses has been removed (though this was never a serious
1235     limitation, I suspect). However, there is a downside: pcre_compile() now
1236     runs more slowly than before (30% or more, depending on the pattern). I
1237     hope this isn't a big issue. There is no effect on runtime performance.
1239     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1240     newline (only possible for the last line of a file) and it was a
1241     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1243     19. Added additional timing features to pcretest. (1) The -tm option now times
1244     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1245     separate command line item, by a number that specifies the number of
1246     repeats to use when timing. The default is 50000; this gives better
1247     precision, but takes uncomfortably long for very large patterns.
1249     20. Extended pcre_study() to be more clever in cases where a branch of a
1250     subpattern has no definite first character. For example, (a*|b*)[cd] would
1251     previously give no result from pcre_study(). Now it recognizes that the
1252     first character must be a, b, c, or d.
1254     21. There was an incorrect error "recursive call could loop indefinitely" if
1255     a subpattern (or the entire pattern) that was being tested for matching an
1256     empty string contained only one non-empty item after a nested subpattern.
1257     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1258     incorrectly, because the \d was being skipped in the check.
1260     22. The pcretest program now has a new pattern option /B and a command line
1261     option -b, which is equivalent to adding /B to every pattern. This causes
1262     it to show the compiled bytecode, without the additional information that
1263     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1264     is the same as /B/I).
1266     23. A new optimization is now able automatically to treat some sequences such
1267     as a*b as a*+b. More specifically, if something simple (such as a character
1268     or a simple class like \d) has an unlimited quantifier, and is followed by
1269     something that cannot possibly match the quantified thing, the quantifier
1270     is automatically "possessified".
1272     24. A recursive reference to a subpattern whose number was greater than 39
1273     went wrong under certain circumstances in UTF-8 mode. This bug could also
1274     have affected the operation of pcre_study().
1276     25. Realized that a little bit of performance could be had by replacing
1277     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1279     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1281     27. Possessive quantifiers such as a++ were previously implemented by turning
1282     them into atomic groups such as ($>a+). Now they have their own opcodes,
1283     which improves performance. This includes the automatically created ones
1284     from 23 above.
1286     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1287     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1288     the first matched character to be a colon. This applied both to named and
1289     numbered groups.
1291     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1293     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1294     building PCRE on Windows easier, so I have included it in the distribution.
1296     31. There is now a check in pcretest against a ridiculously large number being
1297     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1298     loop, the loop is abandoned.
1300     32. Forward references to subpatterns in conditions such as (?(2)...) where
1301     subpattern 2 is defined later cause pcre_compile() to search forwards in
1302     the pattern for the relevant set of parentheses. This search went wrong
1303     when there were unescaped parentheses in a character class, parentheses
1304     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1306     33. "Subroutine" calls and backreferences were previously restricted to
1307     referencing subpatterns earlier in the regex. This restriction has now
1308     been removed.
1310     34. Added a number of extra features that are going to be in Perl 5.10. On the
1311     whole, these are just syntactic alternatives for features that PCRE had
1312     previously implemented using the Python syntax or my own invention. The
1313     other formats are all retained for compatibility.
1315     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1316     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1317     also .NET compatible.
1319     (b) A recursion or subroutine call to a named group can now be defined as
1320     (?&name) as well as (?P>name).
1322     (c) A backreference to a named group can now be defined as \k<name> or
1323     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1324     5.10, are also .NET compatible.
1326     (d) A conditional reference to a named group can now use the syntax
1327     (?(<name>) or (?('name') as well as (?(name).
1329     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1330     groups (named and numbered) that are never evaluated inline, but can be
1331     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1332     is always false. There may be only one alternative in such a group.
1334     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1335     as the simple (?(R). The condition is true only if the most recent
1336     recursion is that of the given number or name. It does not search out
1337     through the entire recursion stack.
1339     (g) The escape \gN or \g{N} has been added, where N is a positive or
1340     negative number, specifying an absolute or relative reference.
1342     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1343     some "unreachable code" warnings.
1345     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1346     things, this adds five new scripts.
1348     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1349     There were also incompatibilities regarding the handling of \Q..\E inside
1350     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1351     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1353     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1354     matches an empty string, and forcibly breaks the loop. There were bugs in
1355     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1356     against aaaa the result was just "a" rather than "aaaa", for example. Two
1357     separate and independent bugs (that affected different cases) have been
1358     fixed.
1360     39. Refactored the code to abolish the use of different opcodes for small
1361     capturing bracket numbers. This is a tidy that I avoided doing when I
1362     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1363     The new approach is not only tidier, it makes it possible to reduce the
1364     memory needed to fix the previous bug (38).
1366     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1367     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1368     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1369     mode.
1371     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1372     report.
1374     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1375     copy construction and assignment in the C++ wrapper.
1377     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1378     couple of bugs that could have given wrong results in the "--newline=crlf"
1379     case.
1381     44. Added a number of casts and did some reorganization of signed/unsigned int
1382     variables following suggestions from Dair Grant. Also renamed the variable
1383     "this" as "item" because it is a C++ keyword.
1385     45. Arranged for dftables to add
1387     #include "pcre_internal.h"
1389     to pcre_chartables.c because without it, gcc 4.x may remove the array
1390     definition from the final binary if PCRE is built into a static library and
1391     dead code stripping is activated.
1393     46. For an unanchored pattern, if a match attempt fails at the start of a
1394     newline sequence, and the newline setting is CRLF or ANY, and the next two
1395     characters are CRLF, advance by two characters instead of one.
1398 nigel 91 Version 6.7 04-Jul-06
1399     ---------------------
1401     1. In order to handle tests when input lines are enormously long, pcretest has
1402     been re-factored so that it automatically extends its buffers when
1403     necessary. The code is crude, but this _is_ just a test program. The
1404     default size has been increased from 32K to 50K.
1406     2. The code in pcre_study() was using the value of the re argument before
1407     testing it for NULL. (Of course, in any sensible call of the function, it
1408     won't be NULL.)
1410     3. The memmove() emulation function in pcre_internal.h, which is used on
1411     systems that lack both memmove() and bcopy() - that is, hardly ever -
1412     was missing a "static" storage class specifier.
1414     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1415     containing an extended class (one that cannot be represented by a bitmap
1416     because it contains high-valued characters or Unicode property items, e.g.
1417     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1418     pattern, but PCRE should not loop if you do not (it no longer does).
1419     [Detail: two cases were found: (a) a repeated subpattern containing an
1420     extended class; (b) a recursive reference to a subpattern that followed a
1421     previous extended class. It wasn't skipping over the extended class
1422     correctly when UTF-8 mode was not set.]
1424     5. A negated single-character class was not being recognized as fixed-length
1425     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1426     compile error "lookbehind assertion is not fixed length".
1428     6. The RunPerlTest auxiliary script was showing an unexpected difference
1429     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1430     write a Perl script that can interpret lines of an input file either as
1431     byte characters or as UTF-8, which is what "perltest" was being required to
1432     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1433     can't do is switch easily at run time between having the "use utf8;" pragma
1434     or not. In the end, I fudged it by using the RunPerlTest script to insert
1435     "use utf8;" explicitly for the UTF-8 tests.
1437     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1438     the end of the subject string, contrary to the documentation and to what
1439     Perl does. This was true of both matching functions. Now it matches only at
1440     the start of the subject and immediately after *internal* newlines.
1442     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1443     a pointer to an int instead of a pointer to an unsigned long int. This
1444     caused problems on 64-bit systems.
1446     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1447     instance of the 'standard' template library not being so standard".
1449     10. There was no check on the number of named subpatterns nor the maximum
1450     length of a subpattern name. The product of these values is used to compute
1451     the size of the memory block for a compiled pattern. By supplying a very
1452     long subpattern name and a large number of named subpatterns, the size
1453     computation could be caused to overflow. This is now prevented by limiting
1454     the length of names to 32 characters, and the number of named subpatterns
1455     to 10,000.
1457     11. Subpatterns that are repeated with specific counts have to be replicated in
1458     the compiled pattern. The size of memory for this was computed from the
1459     length of the subpattern and the repeat count. The latter is limited to
1460     65535, but there was no limit on the former, meaning that integer overflow
1461     could in principle occur. The compiled length of a repeated subpattern is
1462     now limited to 30,000 bytes in order to prevent this.
1464     12. Added the optional facility to have named substrings with the same name.
1466     13. Added the ability to use a named substring as a condition, using the
1467     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1468     are numbers (not recommended). Forward references are permitted.
1470     14. Added forward references in named backreferences (if you see what I mean).
1472     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1473     pattern could run off the end of the subject. For example, the pattern
1474     "(?s)(.{1,5})"8 did this with the subject "ab".
1476     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1477     PCRE_CASELESS was set when matching characters that were quantified with ?
1478     or *.
1480     17. A character class other than a single negated character that had a minimum
1481     but no maximum quantifier - for example [ab]{6,} - was not handled
1482     correctly by pce_dfa_exec(). It would match only one character.
1484     18. A valid (though odd) pattern that looked like a POSIX character
1485     class but used an invalid character after [ (for example [[,abc,]]) caused
1486     pcre_compile() to give the error "Failed: internal error: code overflow" or
1487     in some cases to crash with a glibc free() error. This could even happen if
1488     the pattern terminated after [[ but there just happened to be a sequence of
1489     letters, a binary zero, and a closing ] in the memory that followed.
1491     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1492     over the years. Originally (before any Unicode support), just the bottom 8
1493     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1494     output from "man perlunicode" includes this:
1496     The regular expression compiler produces polymorphic opcodes. That
1497     is, the pattern adapts to the data and automatically switches to
1498     the Unicode character scheme when presented with Unicode data--or
1499     instead uses a traditional byte scheme when presented with byte
1500     data.
1502     Sadly, a wide octal escape does not cause a switch, and in a string with
1503     no other multibyte characters, these octal escapes are treated as before.
1504     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1505     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1506     Unicode string.
1508     I have not perpetrated such confusion in PCRE. Up till now, it took just
1509     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1510     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1511     translate to the appropriate multibyte character.
1513     29. Applied some refactoring to reduce the number of warnings from Microsoft
1514     and Borland compilers. This has included removing the fudge introduced
1515     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1516     a warning about an unused variable.
1518     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1519     characters since release 4.0, because Perl (from release 5.004) does not.
1520     [Or at least, is documented not to: some releases seem to be in conflict
1521     with the documentation.] However, when a pattern was studied with
1522     pcre_study() and all its branches started with \s, PCRE still included VT
1523     as a possible starting character. Of course, this did no harm; it just
1524     caused an unnecessary match attempt.
1526     22. Removed a now-redundant internal flag bit that recorded the fact that case
1527     dependency changed within the pattern. This was once needed for "required
1528     byte" processing, but is no longer used. This recovers a now-scarce options
1529     bit. Also moved the least significant internal flag bit to the most-
1530     significant bit of the word, which was not previously used (hangover from
1531     the days when it was an int rather than a uint) to free up another bit for
1532     the future.
1534     23. Added support for CRLF line endings as well as CR and LF. As well as the
1535     default being selectable at build time, it can now be changed at runtime
1536     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1537     specify that it is scanning data with non-default line endings.
1539     24. Changed the definition of CXXLINK to make it agree with the definition of
1540     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1542     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1543     recursions. This makes a big different to stack usage for some patterns.
1545     26. If a subpattern containing a named recursion or subroutine reference such
1546     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1547     the space required for the compiled pattern went wrong and gave too small a
1548     value. Depending on the environment, this could lead to "Failed: internal
1549     error: code overflow at offset 49" or "glibc detected double free or
1550     corruption" errors.
1552     27. Applied patches from Google (a) to support the new newline modes and (b) to
1553     advance over multibyte UTF-8 characters in GlobalReplace.
1555     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1556     difference for some implementation of PCRE in some Windows version.
1558     29. Added some extra testing facilities to pcretest:
1560     \q<number> in a data line sets the "match limit" value
1561     \Q<number> in a data line sets the "match recursion limt" value
1562     -S <number> sets the stack size, where <number> is in megabytes
1564     The -S option isn't available for Windows.
1567 nigel 89 Version 6.6 06-Feb-06
1568     ---------------------
1570     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1571     in pcreposix.h. I have copied the definition from pcre.h.
1573     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1574     because pcre.h is no longer a built file.
1576     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1577     not normally included in the compiled code.
1580 nigel 87 Version 6.5 01-Feb-06
1581     ---------------------
1583     1. When using the partial match feature with pcre_dfa_exec(), it was not
1584     anchoring the second and subsequent partial matches at the new starting
1585     point. This could lead to incorrect results. For example, with the pattern
1586     /1234/, partially matching against "123" and then "a4" gave a match.
1588     2. Changes to pcregrep:
1590     (a) All non-match returns from pcre_exec() were being treated as failures
1591     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1592     error message is output. Some extra information is given for the
1594     probably the only errors that are likely to be caused by users (by
1595     specifying a regex that has nested indefinite repeats, for instance).
1596     If there are more than 20 of these errors, pcregrep is abandoned.
1598     (b) A binary zero was treated as data while matching, but terminated the
1599     output line if it was written out. This has been fixed: binary zeroes
1600     are now no different to any other data bytes.
1602     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1603     used to set a locale for matching. The --locale=xxxx long option has
1604     been added (no short equivalent) to specify a locale explicitly on the
1605     pcregrep command, overriding the environment variables.
1607     (d) When -B was used with -n, some line numbers in the output were one less
1608     than they should have been.
1610     (e) Added the -o (--only-matching) option.
1612     (f) If -A or -C was used with -c (count only), some lines of context were
1613     accidentally printed for the final match.
1615     (g) Added the -H (--with-filename) option.
1617     (h) The combination of options -rh failed to suppress file names for files
1618     that were found from directory arguments.
1620     (i) Added the -D (--devices) and -d (--directories) options.
1622     (j) Added the -F (--fixed-strings) option.
1624     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1626     (l) Added the --colo(u)r option.
1628     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1629     is not present by default.
1631     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1632     items such as (?R) or (?1), when the recursion could match a number of
1633     alternatives. If it matched one of the alternatives, but subsequently,
1634     outside the recursion, there was a failure, the code tried to back up into
1635     the recursion. However, because of the way PCRE is implemented, this is not
1636     possible, and the result was an incorrect result from the match.
1638     In order to prevent this happening, the specification of recursion has
1639     been changed so that all such subpatterns are automatically treated as
1640     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1642     4. I had overlooked the fact that, in some locales, there are characters for
1643     which isalpha() is true but neither isupper() nor islower() are true. In
1644     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1645     and ordfeminine) are like this. This affected the treatment of \w and \W
1646     when they appeared in character classes, but not when they appeared outside
1647     a character class. The bit map for "word" characters is now created
1648     separately from the results of isalnum() instead of just taking it from the
1649     upper, lower, and digit maps. (Plus the underscore character, of course.)
1651     5. The above bug also affected the handling of POSIX character classes such as
1652     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1653     permanent tables. Instead, the bit maps for such a class were previously
1654     created as the appropriate unions of the upper, lower, and digit bitmaps.
1655     Now they are created by subtraction from the [[:word:]] class, which has
1656     its own bitmap.
1658     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1659     It is created by subtracting the vertical space characters (\x09, \x0a,
1660     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1661     subtraction was done in the overall bitmap for a character class, meaning
1662     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1663     be recognized. This bug has been fixed.
1665     7. Patches from the folks at Google:
1667     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1668     real life, but is still worth protecting against".
1670     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1671     regular expressions".
1673     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1674     have it.
1676     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1677     "configure" and the latter not, in order to fix a problem somebody had
1678     with compiling the Arg class on HP-UX.
1680     (e) Improve the error-handling of the C++ wrapper a little bit.
1682     (f) New tests for checking recursion limiting.
1684     8. The pcre_memmove() function, which is used only if the environment does not
1685     have a standard memmove() function (and is therefore rarely compiled),
1686     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1687     returning a result (though PCRE never actually uses the result).
1689     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1690     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1691     returned instead of calling malloc() with an overflowing number that would
1692     most likely cause subsequent chaos.
1694     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1696     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1697     with this option is matched, the nmatch and pmatch options of regexec() are
1698     ignored.
1700     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1701     provided in case anyone wants to the the POSIX interface with UTF-8
1702     strings.
1704     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1705     C++ linking (needed for some HP-UX environments).
1707     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1708     (unused parameter) and in the pcre_printint() function (omitted "default"
1709     switch label when the default is to do nothing).
1711     15. Added some code to make it possible, when PCRE is compiled as a C++
1712     library, to replace subject pointers for pcre_exec() with a smart pointer
1713     class, thus making it possible to process discontinuous strings.
1715     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1716     much the same function. They were added by different people who were trying
1717     to make PCRE easy to compile on non-Unix systems. It has been suggested
1718     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1719     for compiling on Windows systems. I have therefore replaced it with
1720     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1721     defaults to "extern" for C or "extern C" for C++, which works fine on
1722     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1723     SCOPE with something explicit in config.h. In addition:
1725     (a) pcreposix.h still had just "extern" instead of either of these macros;
1726     I have replaced it with PCRE_DATA_SCOPE.
1728     (b) Functions such as _pcre_xclass(), which are internal to the library,
1729     but external in the C sense, all had PCRE_EXPORT in their definitions.
1730     This is apparently wrong for the Windows case, so I have removed it.
1731     (It makes no difference on Unix-like systems.)
1733     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1734     of recursive calls to match(). This is different to MATCH_LIMIT because
1735     that limits the total number of calls to match(), not all of which increase
1736     the depth of recursion. Limiting the recursion depth limits the amount of
1737     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1738     when PCRE is compiled, and changed at run time. A patch from Google adds
1739     this functionality to the C++ interface.
1741     18. Changes to the handling of Unicode character properties:
1743     (a) Updated the table to Unicode 4.1.0.
1745     (b) Recognize characters that are not in the table as "Cn" (undefined).
1747     (c) I revised the way the table is implemented to a much improved format
1748     which includes recognition of ranges. It now supports the ranges that
1749     are defined in UnicodeData.txt, and it also amalgamates other
1750     characters into ranges. This has reduced the number of entries in the
1751     table from around 16,000 to around 3,000, thus reducing its size
1752     considerably. I realized I did not need to use a tree structure after
1753     all - a binary chop search is just as efficient. Having reduced the
1754     number of entries, I extended their size from 6 bytes to 8 bytes to
1755     allow for more data.
1757     (d) Added support for Unicode script names via properties such as \p{Han}.
1759     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1760     matching that character.
1762     20. When matching a repeated Unicode property with a minimum greater than zero,
1763     (for example \pL{2,}), PCRE could look past the end of the subject if it
1764     reached it while seeking the minimum number of characters. This could
1765     happen only if some of the characters were more than one byte long, because
1766     there is a check for at least the minimum number of bytes.
1768     21. Refactored the implementation of \p and \P so as to be more general, to
1769     allow for more different types of property in future. This has changed the
1770     compiled form incompatibly. Anybody with saved compiled patterns that use
1771     \p or \P will have to recompile them.
1773     22. Added "Any" and "L&" to the supported property types.
1775     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1776     but give a compile time error if the value is greater than 0xff.
1778     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1779     accidentally not being installed or uninstalled.
1781     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1782     made were to insert the current release number. This seemed silly, because
1783     it made things harder for people building PCRE on systems that don't run
1784     "configure". I have turned pcre.h into a distributed file, no longer built
1785     by "configure", with the version identification directly included. There is
1786     no longer a pcre.h.in file.
1788     However, this change necessitated a change to the pcre-config script as
1789     well. It is built from pcre-config.in, and one of the substitutions was the
1790     release number. I have updated configure.ac so that ./configure now finds
1791     the release number by grepping pcre.h.
1793     26. Added the ability to run the tests under valgrind.
1796 nigel 85 Version 6.4 05-Sep-05
1797     ---------------------
1799     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1800     "--" to be printed when multiple files were scanned, even when none of the
1801     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1802     consider it to be a bug, and have restored the previous behaviour.
1804     2. A couple of code tidies to get rid of compiler warnings.
1806     3. The pcretest program used to cheat by referring to symbols in the library
1807     whose names begin with _pcre_. These are internal symbols that are not
1808     really supposed to be visible externally, and in some environments it is
1809     possible to suppress them. The cheating is now confined to including
1810     certain files from the library's source, which is a bit cleaner.
1812     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1813     file's purpose clearer.
1815     5. Reorganized pcre_ucp_findchar().
1818 nigel 83 Version 6.3 15-Aug-05
1819     ---------------------
1821     1. The file libpcre.pc.in did not have general read permission in the tarball.
1823     2. There were some problems when building without C++ support:
1825     (a) If C++ support was not built, "make install" and "make test" still
1826     tried to test it.
1828     (b) There were problems when the value of CXX was explicitly set. Some
1829     changes have been made to try to fix these, and ...
1831     (c) --disable-cpp can now be used to explicitly disable C++ support.
1833     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1834     backslash in a target when C++ was disabled. This confuses some
1835     versions of "make", apparently. Using an intermediate variable solves
1836     this. (Same for CPP_LOBJ.)
1838     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1839     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1840     necessary on certain architectures.
1842     4. Added a setting of -export-symbols-regex to the link command to remove
1843     those symbols that are exported in the C sense, but actually are local
1844     within the library, and not documented. Their names all begin with
1845     "_pcre_". This is not a perfect job, because (a) we have to except some
1846     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1847     available (and never for static libraries). I have made a note to try to
1848     find a way round (a) in the future.
1851 nigel 81 Version 6.2 01-Aug-05
1852     ---------------------
1854     1. There was no test for integer overflow of quantifier values. A construction
1855     such as {1111111111111111} would give undefined results. What is worse, if
1856     a minimum quantifier for a parenthesized subpattern overflowed and became
1857     negative, the calculation of the memory size went wrong. This could have
1858     led to memory overwriting.
1860     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1862     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1863     operating environments where this matters.
1865     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1866     PCRE options from within the C++ wrapper.
1868     5. Named capturing subpatterns were not being correctly counted when a pattern
1869     was compiled. This caused two problems: (a) If there were more than 100
1870     such subpatterns, the calculation of the memory needed for the whole
1871     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1872     back references of the form \12, where the number was greater than 9, were
1873     not recognized as back references, even though there were sufficient
1874     previous subpatterns.
1876     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1877     versions of gcc, e.g. 2.95.4.
1880 nigel 79 Version 6.1 21-Jun-05
1881     ---------------------
1883     1. There was one reference to the variable "posix" in pcretest.c that was not
1884     surrounded by "#if !defined NOPOSIX".
1886     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1887     the cross-check on the old pcre_info() function, for the benefit of the
1888     cut-down version of PCRE that is currently imported into Exim.
1890     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1891     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1892     patterns that start (?i) but I don't think that matters. The use of (?i) is
1893     just an example; this all applies to the other options as well.
1895     4. Since libtool seems to echo the compile commands it is issuing, the output
1896     from "make" can be reduced a bit by putting "@" in front of each libtool
1897     compile command.
1899     5. Patch from the folks at Google for configure.in to be a bit more thorough
1900     in checking for a suitable C++ installation before trying to compile the
1901     C++ stuff. This should fix a reported problem when a compiler was present,
1902     but no suitable headers.
1904     6. The man pages all had just "PCRE" as their title. I have changed them to
1905     be the relevant file name. I have also arranged that these names are
1906     retained in the file doc/pcre.txt, which is a concatenation in text format
1907     of all the man pages except the little individual ones for each function.
1909     7. The NON-UNIX-USE file had not been updated for the different set of source
1910     files that come with release 6. I also added a few comments about the C++
1911     wrapper.
1914 nigel 77 Version 6.0 07-Jun-05
1915     ---------------------
1917     1. Some minor internal re-organization to help with my DFA experiments.
1919     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1920     didn't matter for the library itself when fully configured, but did matter
1921     when compiling without UCP support, or within Exim, where the ucp files are
1922     not imported.
1924     3. Refactoring of the library code to split up the various functions into
1925     different source modules. The addition of the new DFA matching code (see
1926     below) to a single monolithic source would have made it really too
1927     unwieldy, quite apart from causing all the code to be include in a
1928     statically linked application, when only some functions are used. This is
1929     relevant even without the DFA addition now that patterns can be compiled in
1930     one application and matched in another.
1932     The downside of splitting up is that there have to be some external
1933     functions and data tables that are used internally in different modules of
1934     the library but which are not part of the API. These have all had their
1935     names changed to start with "_pcre_" so that they are unlikely to clash
1936     with other external names.
1938     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1939     a different (DFA) algorithm. Although it is slower than the original
1940     function, it does have some advantages for certain types of matching
1941     problem.
1943     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1944     including restarting after a partial match.
1946     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1947     defined when compiling for Windows was sent to me. I have put it into the
1948     code, though I have no means of testing or verifying it.
1950     7. Added the pcre_refcount() auxiliary function.
1952     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1953     match before or at the first newline in the subject string. In pcretest,
1954     the /f option on a pattern can be used to set this.
1956     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1957     would behave wrongly. This has been present in PCRE since release 4.0.
1959     10. A number of changes to the pcregrep command:
1961     (a) Refactored how -x works; insert ^(...)$ instead of setting
1962     PCRE_ANCHORED and checking the length, in preparation for adding
1963     something similar for -w.
1965     (b) Added the -w (match as a word) option.
1967     (c) Refactored the way lines are read and buffered so as to have more
1968     than one at a time available.
1970     (d) Implemented a pcregrep test script.
1972     (e) Added the -M (multiline match) option. This allows patterns to match
1973     over several lines of the subject. The buffering ensures that at least
1974     8K, or the rest of the document (whichever is the shorter) is available
1975     for matching (and similarly the previous 8K for lookbehind assertions).
1977     (f) Changed the --help output so that it now says
1979     -w, --word-regex(p)
1981     instead of two lines, one with "regex" and the other with "regexp"
1982     because that confused at least one person since the short forms are the
1983     same. (This required a bit of code, as the output is generated
1984     automatically from a table. It wasn't just a text change.)
1986     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1987     option but starts with a hyphen. Could be a pattern or a path name
1988     starting with a hyphen, for instance.
1990     (h) "-" can be given as a file name to represent stdin.
1992     (i) When file names are being printed, "(standard input)" is used for
1993     the standard input, for compatibility with GNU grep. Previously
1994     "<stdin>" was used.
1996     (j) The option --label=xxx can be used to supply a name to be used for
1997     stdin when file names are being printed. There is no short form.
1999     (k) Re-factored the options decoding logic because we are going to add
2000     two more options that take data. Such options can now be given in four
2001     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2003     (l) Added the -A, -B, and -C options for requesting that lines of context
2004     around matches be printed.
2006     (m) Added the -L option to print the names of files that do not contain
2007     any matching lines, that is, the complement of -l.
2009     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2010     continue to scan other files.
2012     (o) The -s option was incorrectly implemented. For compatibility with other
2013     greps, it now suppresses the error message for a non-existent or non-
2014     accessible file (but not the return code). There is a new option called
2015     -q that suppresses the output of matching lines, which was what -s was
2016     previously doing.
2018     (p) Added --include and --exclude options to specify files for inclusion
2019     and exclusion when recursing.
2021     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2022     Hopefully, it now does.
2024     12. Missing cast in pcre_study().
2026     13. Added an "uninstall" target to the makefile.
2028     14. Replaced "extern" in the function prototypes in Makefile.in with
2029     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2030     world, but is set differently for Windows.
2032     15. Added a second compiling function called pcre_compile2(). The only
2033     difference is that it has an extra argument, which is a pointer to an
2034     integer error code. When there is a compile-time failure, this is set
2035     non-zero, in addition to the error test pointer being set to point to an
2036     error message. The new argument may be NULL if no error number is required
2037     (but then you may as well call pcre_compile(), which is now just a
2038     wrapper). This facility is provided because some applications need a
2039     numeric error indication, but it has also enabled me to tidy up the way
2040     compile-time errors are handled in the POSIX wrapper.
2042     16. Added VPATH=.libs to the makefile; this should help when building with one
2043     prefix path and installing with another. (Or so I'm told by someone who
2044     knows more about this stuff than I do.)
2046     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2047     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2048     match everything, including newlines. This is not POSIX-compatible, but
2049     somebody wanted the feature. From pcretest it can be activated by using
2050     both the P and the s flags.
2052     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2054     19. libpcre.pc was being incorrectly installed as executable.
2056     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2057     it now also looks for '\r' so that it will work unmodified on Windows.
2059     21. Added Google's contributed C++ wrapper to the distribution.
2061     22. Added some untidy missing memory free() calls in pcretest, to keep
2062     Electric Fence happy when testing.
2066 nigel 75 Version 5.0 13-Sep-04
2067     ---------------------
2069     1. Internal change: literal characters are no longer packed up into items
2070     containing multiple characters in a single byte-string. Each character
2071     is now matched using a separate opcode. However, there may be more than one
2072     byte in the character in UTF-8 mode.
2074     2. The pcre_callout_block structure has two new fields: pattern_position and
2075     next_item_length. These contain the offset in the pattern to the next match
2076     item, and its length, respectively.
2078     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2079     insertion of callouts before each pattern item. Added the /C option to
2080     pcretest to make use of this.
2082     4. On the advice of a Windows user, the lines
2084     #if defined(_WIN32) || defined(WIN32)
2085     _setmode( _fileno( stdout ), 0x8000 );
2086     #endif /* defined(_WIN32) || defined(WIN32) */
2088     have been added to the source of pcretest. This apparently does useful
2089     magic in relation to line terminators.
2091     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2092     for the benefit of those environments where the "b" makes a difference.
2094     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2095     to know about it. I have put a hack into configure.in that adds in code
2096     to set GCC=yes if CC=icc. This seems to end up at a point in the
2097     generated configure script that is early enough to affect the setting of
2098     compiler options, which is what is needed, but I have no means of testing
2099     whether it really works. (The user who reported this had patched the
2100     generated configure script, which of course I cannot do.)
2102     LATER: After change 22 below (new libtool files), the configure script
2103     seems to know about icc (and also ecc). Therefore, I have commented out
2104     this hack in configure.in.
2106     7. Added support for pkg-config (2 patches were sent in).
2108     8. Negated POSIX character classes that used a combination of internal tables
2109     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2110     [[:^ascii]]. Typically, they would match almost any characters. The other
2111     POSIX classes were not broken in this way.
2113     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2114     to find the match, as PCRE was deluded into thinking that the match had to
2115     start at the start point or following a newline. The same bug applied to
2116     patterns with negative forward assertions or any backward assertions
2117     preceding ".*" at the start, unless the pattern required a fixed first
2118     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2120     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2121     starting at the last subject character, bytes beyond the end of the subject
2122     string were read.
2124     11. Renamed the variable "class" as "classbits" to make life easier for C++
2125     users. (Previously there was a macro definition, but it apparently wasn't
2126     enough.)
2128     12. Added the new field "tables" to the extra data so that tables can be passed
2129     in at exec time, or the internal tables can be re-selected. This allows
2130     a compiled regex to be saved and re-used at a later time by a different
2131     program that might have everything at different addresses.
2133     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2134     -R library as well as a -L library.
2136     14. The debugging options of pcretest (-d on the command line or D on a
2137     pattern) showed incorrect output for anything following an extended class
2138     that contained multibyte characters and which was followed by a quantifier.
2140     15. Added optional support for general category Unicode character properties
2141     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2142     support. It adds about 90K to the size of the library. The meanings of the
2143     inbuilt class escapes such as \d and \s have NOT been changed.
2145     16. Updated pcredemo.c to include calls to free() to release the memory for the
2146     compiled pattern.
2148     17. The generated file chartables.c was being created in the source directory
2149     instead of in the building directory. This caused the build to fail if the
2150     source directory was different from the building directory, and was
2151     read-only.
2153     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2154     file. No doubt somebody will tell me if they don't make sense... Also added
2155     Dan Mooney's comments about building on OpenVMS.
2157     19. Added support for partial matching via the PCRE_PARTIAL option for
2158     pcre_exec() and the \P data escape in pcretest.
2160     20. Extended pcretest with 3 new pattern features:
2162     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2163     write the compiled pattern to the file whose name is "rest-of-line".
2164     This is a straight binary dump of the data, with the saved pointer to
2165     the character tables forced to be NULL. The study data, if any, is
2166     written too. After writing, pcretest reads a new pattern.
2168     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2169     compiled pattern from the given file. There must not be any
2170     occurrences of "<" in the file name (pretty unlikely); if there are,
2171     pcretest will instead treat the initial "<" as a pattern delimiter.
2172     After reading in the pattern, pcretest goes on to read data lines as
2173     usual.
2175     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2176     and 16-bit fields in a compiled pattern, to simulate a pattern that
2177     was compiled on a host of opposite endianness.
2179     21. The pcre-exec() function can now cope with patterns that were compiled on
2180     hosts of opposite endianness, with this restriction:
2182     As for any compiled expression that is saved and used later, the tables
2183     pointer field cannot be preserved; the extra_data field in the arguments
2184     to pcre_exec() should be used to pass in a tables address if a value
2185     other than the default internal tables were used at compile time.
2187     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2188     now diagnosed as an error. Previously, most of the time, a negative number
2189     would have been treated as zero, but if in addition "ovector" was passed as
2190     NULL, a crash could occur.
2192     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2193     new versions from the libtool 1.5 distribution (the last one is a copy of
2194     a file called libtool.m4). This seems to have fixed the need to patch
2195     "configure" to support Darwin 1.3 (which I used to do). However, I still
2196     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2197     workstation).
2199     24. Changed the PCRE licence to be the more standard "BSD" licence.
2202 nigel 73 Version 4.5 01-Dec-03
2203     ---------------------
2205     1. There has been some re-arrangement of the code for the match() function so
2206     that it can be compiled in a version that does not call itself recursively.
2207     Instead, it keeps those local variables that need separate instances for
2208     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2209     needs to "recurse". Keeping track of where control must go is done by means
2210     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2211     hide most of the details from the main code, and operates only if
2212     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2213     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2214     operating.
2216     To make it easier for callers to provide specially tailored get/free
2217     functions for this usage, two new functions, pcre_stack_malloc, and
2218     pcre_stack_free, are used. They are always called in strict stacking order,
2219     and the size of block requested is always the same.
2221     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2222     PCRE has been compiled to use the stack or the heap for recursion. The
2223     -C option of pcretest uses this to show which version is compiled.
2225     A new data escape \S, is added to pcretest; it causes the amounts of store
2226     obtained and freed by both kinds of malloc/free at match time to be added
2227     to the output.
2229     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2230     what's available on my current Linux desktop machine.
2232     3. When matching a UTF-8 string, the test for a valid string at the start has
2233     been extended. If start_offset is not zero, PCRE now checks that it points
2234     to a byte that is the start of a UTF-8 character. If not, it returns
2235     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2236     this is necessary because there may be backward assertions in the pattern.
2237     When matching the same subject several times, it may save resources to use
2238     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2240     4. The code for checking the validity of UTF-8 strings has been tightened so
2241     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2242     containing "overlong sequences".
2244     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2245     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2246     should have been "&", but it just so happened that all the cases this let
2247     through by mistake were picked up later in the function.
2249     6. I had used a variable called "isblank" - this is a C99 function, causing
2250     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2252     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2253     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2254     so the version is shown; (c) stop "make test" echoing "./RunTest".
2256     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2258     9. The prototype for memmove() for systems that don't have it was using
2259     size_t, but the inclusion of the header that defines size_t was later. I've
2260     moved the #includes for the C headers earlier to avoid this.
2262     10. Added some adjustments to the code to make it easier to compiler on certain
2263     special systems:
2265     (a) Some "const" qualifiers were missing.
2266     (b) Added the macro EXPORT before all exported functions; by default this
2267     is defined to be empty.
2268     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2269     that it reads its output file name as an argument instead of writing
2270     to the standard output and assuming this can be redirected.
2272     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2273     class containing characters with values greater than 255, PCRE compilation
2274     went into a loop.
2276     12. A recursive reference to a subpattern that was within another subpattern
2277     that had a minimum quantifier of zero caused PCRE to crash. For example,
2278     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2279     recursion. If the recursively-called subpattern itself had a zero repeat,
2280     that was OK.
2282     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2283     buffer into which it was copied (for escape processing) was still set at
2284     1024, so long lines caused crashes.
2286     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2287     "internal error: code overflow...". This applied to any character class
2288     that was followed by a possessive quantifier.
2290     15. Modified the Makefile to add libpcre.la as a prerequisite for
2291     libpcreposix.la because I was told this is needed for a parallel build to
2292     work.
2294     16. If a pattern that contained .* following optional items at the start was
2295     studied, the wrong optimizing data was generated, leading to matching
2296     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2297     matching string must start with a or b or c. The correct conclusion for
2298     this pattern is that a match can start with any character.
2301 nigel 71 Version 4.4 13-Aug-03
2302     ---------------------
2304     1. In UTF-8 mode, a character class containing characters with values between
2305     127 and 255 was not handled correctly if the compiled pattern was studied.
2306     In fixing this, I have also improved the studying algorithm for such
2307     classes (slightly).
2309     2. Three internal functions had redundant arguments passed to them. Removal
2310     might give a very teeny performance improvement.
2312     3. Documentation bug: the value of the capture_top field in a callout is *one
2313     more than* the number of the hightest numbered captured substring.
2315     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2316     in incorrectly linking with a previously installed version. They now link
2317     explicitly with libpcre.la.
2319     5. configure.in no longer needs to recognize Cygwin specially.
2321     6. A problem in pcre.in for Windows platforms is fixed.
2323     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2324     pcretest, it used to include the size of the study block as part of its
2325     output. Unfortunately, the structure contains a field that has a different
2326     size on different hardware architectures. This meant that the tests that
2327     showed this size failed. As the block is currently always of a fixed size,
2328     this information isn't actually particularly useful in pcretest output, so
2329     I have just removed it.
2331     8. Three pre-processor statements accidentally did not start in column 1.
2332     Sadly, there are *still* compilers around that complain, even though
2333     standard C has not required this for well over a decade. Sigh.
2335     9. In pcretest, the code for checking callouts passed small integers in the
2336     callout_data field, which is a void * field. However, some picky compilers
2337     complained about the casts involved for this on 64-bit systems. Now
2338     pcretest passes the address of the small integer instead, which should get
2339     rid of the warnings.
2341     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2342     both compile and run time, and gives an error if an invalid UTF-8 sequence
2343     is found. There is a option for disabling this check in cases where the
2344     string is known to be correct and/or the maximum performance is wanted.
2346     11. In response to a bug report, I changed one line in Makefile.in from
2348     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2349     to
2350     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2352     to look similar to other lines, but I have no way of telling whether this
2353     is the right thing to do, as I do not use Windows. No doubt I'll get told
2354     if it's wrong...
2357 nigel 69 Version 4.3 21-May-03
2358     ---------------------
2360     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2361     Makefile.
2363     2. Some refactoring to improve the quality of the code:
2365     (i) The utf8_table... variables are now declared "const".
2367     (ii) The code for \cx, which used the "case flipping" table to upper case
2368     lower case letters, now just substracts 32. This is ASCII-specific,
2369     but the whole concept of \cx is ASCII-specific, so it seems
2370     reasonable.
2372     (iii) PCRE was using its character types table to recognize decimal and
2373     hexadecimal digits in the pattern. This is silly, because it handles
2374     only 0-9, a-f, and A-F, but the character types table is locale-
2375     specific, which means strange things might happen. A private
2376     table is now used for this - though it costs 256 bytes, a table is
2377     much faster than multiple explicit tests. Of course, the standard
2378     character types table is still used for matching digits in subject
2379     strings against \d.
2381     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2382     ending in _t are). So I've renamed it as ESC_tee.
2384     3. The first argument for regexec() in the POSIX wrapper should have been
2385     defined as "const".
2387     4. Changed pcretest to use malloc() for its buffers so that they can be
2388     Electric Fenced for debugging.
2390     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2391     to read one or more bytes before the start of the subject string. Often this
2392     had no effect on PCRE's behaviour, but in some circumstances it could
2393     provoke a segmentation fault.
2395     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2396     to try to read one or more bytes before the start of the subject string.
2398     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2399     UTF-8 support could misbehave in various ways if the subject string
2400     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2401     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2402     back over UTF-8 characters.)
2405 nigel 67 Version 4.2 14-Apr-03
2406     ---------------------
2408     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2410     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2411     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2412     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2413     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2414     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2415     and BUILD_EXEEXT
2416     Note: automatic setting of the BUILD variables is not yet working
2417     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2418     compile-time but not at link-time
2419     [LINK]: use for linking executables only
2420     make different versions for Windows and non-Windows
2421     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2422     libraries
2423     [LINK_FOR_BUILD]: new variable
2424     [OBJEXT]: use throughout
2425     [EXEEXT]: use throughout
2426     <winshared>: new target
2427     <wininstall>: new target
2428     <dftables.o>: use native compiler
2429     <dftables>: use native linker
2430     <install>: handle Windows platform correctly
2431     <clean>: ditto
2432     <check>: ditto
2433     copy DLL to top builddir before testing
2435     As part of these changes, -no-undefined was removed again. This was reported
2436     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2437     in any case.
2439     3. Some tidies to get rid of compiler warnings:
2441     . In the match_data structure, match_limit was an unsigned long int, whereas
2442     match_call_count was an int. I've made them both unsigned long ints.
2444     . In pcretest the fact that a const uschar * doesn't automatically cast to
2445     a void * provoked a warning.
2447     . Turning on some more compiler warnings threw up some "shadow" variables
2448     and a few more missing casts.
2450     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2451     option, a class that contained a single character with a value between 128
2452     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2454     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2455     option, a class that contained several characters, but with at least one
2456     whose value was between 128 and 255 caused PCRE to crash.
2459 nigel 65 Version 4.1 12-Mar-03
2460     ---------------------
2461 nigel 63
2462 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2463     needed, and a string in dftables.c that was longer than standard compilers are
2464     required to support.
2466     2. Compiling with Sun's compiler found a few more places where the code could
2467     be tidied up in order to avoid warnings.
2469     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2470     first of these names is deprecated in the latest Autoconf in favour of the name
2471     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2472     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2473     analogy I have changed it to CFLAGS_FOR_BUILD.
2475     4. Added -no-undefined to the linking command in the Makefile, because this is
2476     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2477     linking step for the pcreposix library.
2479     5. PCRE was failing to diagnose the case of two named groups with the same
2480     name.
2482     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2483     literal character that is needed in the subject for a match, and scans along to
2484     ensure that it is present before embarking on the full matching process. This
2485     saves time in cases of nested unlimited repeats that are never going to match.
2486     Problem: the scan can take a lot of time if the subject is very long (e.g.
2487     megabytes), thus penalizing straightforward matches. It is now done only if the
2488     amount of subject to be scanned is less than 1000 bytes.
2490     7. A lesser problem with the same optimization is that it was recording the
2491     first character of an anchored pattern as "needed", thus provoking a search
2492     right along the subject, even when the first match of the pattern was going to
2493     fail. The "needed" character is now not set for anchored patterns, unless it
2494     follows something in the pattern that is of non-fixed length. Thus, it still
2495     fulfils its original purpose of finding quick non-matches in cases of nested
2496     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2499     Version 4.0 17-Feb-03
2500     ---------------------
2502 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2503     extended to the end of string, PCRE compiled incorrect data. This could lead to
2504     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2506     2. Moved to autoconf 2.53 and libtool 1.4.2.
2508     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2509     the special perltest8 script is no longer needed - all the tests can be run
2510     from a single perltest script.
2512     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2513     by \s. It has now been removed in PCRE. This means it isn't recognized as
2514     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2515     class [:space:] *does* include VT, thereby creating a mess.
2517     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2518     space and tab.
2520     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2521     its new features into the main test script, reducing the number of scripts.
2523     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2524     were backward compatible, and made the (?i) apply to the whole pattern, as if
2525     /i were given. Now it behaves more logically, and applies the option setting
2526     only to what follows. PCRE has been changed to follow suit. However, if it
2527     finds options settings right at the start of the pattern, it extracts them into
2528     the global options, as before. Thus, they show up in the info data.
2530     8. Added support for the \Q...\E escape sequence. Characters in between are
2531     treated as literals. This is slightly different from Perl in that $ and @ are
2532     also handled as literals inside the quotes. In Perl, they will cause variable
2533     interpolation. Note the following examples:
2535     Pattern PCRE matches Perl matches
2537     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2538     \Qabc\$xyz\E abc\$xyz abc\$xyz
2539     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2541     For compatibility with Perl, \Q...\E sequences are recognized inside character
2542     classes as well as outside them.
2544     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2545     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2546     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2547     signed/unsigned warnings.
2549     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2550     option for pcretest, so I've replaced it by a simple function that does just
2551     that job.
2553     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2554     "pcregrep -".
2556     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2557     Java package. This provides some syntactic sugar for simple cases of what my
2558     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2559     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2560     item, you can use this simplified notation. Note that only makes sense with
2561     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2562     greediness, whatever the setting of the PCRE_UNGREEDY option.
2564     13. A change of greediness default within a pattern was not taking effect at
2565     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2566     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2567     was abstracted outside.
2569     14. PCRE now supports the \G assertion. It is true when the current matching
2570     position is at the start point of the match. This differs from \A when the
2571     starting offset is non-zero. Used with the /g option of pcretest (or similar
2572     code), it works in the same way as it does for Perl's /g option. If all
2573     alternatives of a regex begin with \G, the expression is anchored to the start
2574     match position, and the "anchored" flag is set in the compiled expression.
2576     15. Some bugs concerning the handling of certain option changes within patterns
2577     have been fixed. These applied to options other than (?ims). For example,
2578     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2579     been the other way round. Some of this was related to change 7 above.
2581     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2582     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2583     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2584     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2586     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2587     mode. Unlike ".", it always matches newline, whatever the setting of
2588     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2589     assertions. Perl allows it, but it doesn't (in general) work because it can't
2590     calculate the length of the lookbehind. At least, that's the case for Perl
2591     5.8.0 - I've been told they are going to document that it doesn't work in
2592     future.
2594     18. Added an error diagnosis for escapes that PCRE does not support: these are
2595     \L, \l, \N, \P, \p, \U, \u, and \X.
2597     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2598     reading past the end of the pattern in cases such as /[abcd/.
2600     20. PCRE was getting more memory than necessary for patterns with classes that
2601     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2603     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2604     compiling PCRE for use with Virtual Pascal.
2606     22. Small fix to the Makefile to make it work properly if the build is done
2607     outside the source tree.
2609     23. Added a new extension: a condition to go with recursion. If a conditional
2610     subpattern starts with (?(R) the "true" branch is used if recursion has
2611     happened, whereas the "false" branch is used only at the top level.
2613     24. When there was a very long string of literal characters (over 255 bytes
2614     without UTF support, over 250 bytes with UTF support), the computation of how
2615     much memory was required could be incorrect, leading to segfaults or other
2616     strange effects.
2618     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2619     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2620     there was a subsequent back reference to those brackets. This meant that, for
2621     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2622     possible to check for precisely this case. All we can do is abandon the
2623     optimization if .* occurs inside capturing brackets when there are any back
2624     references whatsoever. (See below for a better fix that came later.)
2626     26. The handling of the optimization for finding the first character of a
2627     non-anchored pattern, and for finding a character that is required later in the
2628     match were failing in some cases. This didn't break the matching; it just
2629     failed to optimize when it could. The way this is done has been re-implemented.
2631     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2633     28. Added a new feature that provides some of the functionality that Perl
2634     provides with (?{...}). The facility is termed a "callout". The way it is done
2635     in PCRE is for the caller to provide an optional function, by setting
2636     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2637     global variable. By default it is unset, which disables all calling out. To get
2638     the function called, the regex must include (?C) at appropriate points. This
2639     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2640     This provides a means of identifying different callout points. When PCRE
2641     reaches such a point in the regex, if pcre_callout has been set, the external
2642     function is called. It is provided with data in a structure called
2643     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2644     matching continues; if it returns a non-zero value, the match at the current
2645     point fails. However, backtracking will occur if possible. [This was changed
2646     later and other features added - see item 49 below.]
2648     29. pcretest is upgraded to test the callout functionality. It provides a
2649     callout function that displays information. By default, it shows the start of
2650     the match and the current position in the text. There are some new data escapes
2651     to vary what happens:
2653     \C+ in addition, show current contents of captured substrings
2654     \C- do not supply a callout function
2655     \C!n return 1 when callout number n is reached
2656     \C!n!m return 1 when callout number n is reached for the mth time
2658     30. If pcregrep was called with the -l option and just a single file name, it
2659     output "<stdin>" if a match was found, instead of the file name.
2661     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2662     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2663     pcre_exec(). This saves a malloc/free per call. The default value of
2664     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2665     when configuring.
2667     32. The default maximum size of a compiled pattern is 64K. There have been a
2668     few cases of people hitting this limit. The code now uses macros to handle the
2669     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2670     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2671     configuring. Tests 2 and 5 work only with 2-byte links because they output
2672     debugging information about compiled patterns.
2674     33. Internal code re-arrangements:
2676     (a) Moved the debugging function for printing out a compiled regex into
2677     its own source file (printint.c) and used #include to pull it into
2678     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2679     separate copies.
2681     (b) Defined the list of op-code names for debugging as a macro in
2682     internal.h so that it is next to the definition of the opcodes.
2684     (c) Defined a table of op-code lengths for simpler skipping along compiled
2685     code. This is again a macro in internal.h so that it is next to the
2686     definition of the opcodes.
2688     34. Added support for recursive calls to individual subpatterns, along the
2689     lines of Robin Houston's patch (but implemented somewhat differently).
2691     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2692     allow it to read and process whole directories in Win32. This code was
2693     contributed by Lionel Fourquaux; it has not been tested by me.
2695     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2696     used to name a group. Names consist of alphanumerics and underscores, and must
2697     be unique. Back references use the syntax (?P=name) and recursive calls use
2698     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2699     numbers. The function pcre_fullinfo() can be used after compilation to extract
2700     a name/number map. There are three relevant calls:
2702     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2703     PCRE_INFO_NAMECOUNT yields the number of entries
2704     PCRE_INFO_NAMETABLE yields a pointer to the map.
2706     The map is a vector of fixed-size entries. The size of each entry depends on
2707     the length of the longest name used. The first two bytes of each entry are the
2708     group number, most significant byte first. There follows the corresponding
2709     name, zero terminated. The names are in alphabetical order.
2711     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2712     case instead of 255. Making it the same both with and without UTF-8 support
2713     means that the same test output works with both.
2715     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2716     calling malloc() with a zero argument.
2718     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2719     optimization. I've improved things by keeping a bitmap of backreferences with
2720     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2721     fact referenced, the optimization can be applied. It is unlikely that a
2722     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2723     the match to follow \n) will appear inside brackets with a number greater than
2724     31, but if it does, any back reference > 31 suppresses the optimization.
2726     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2727     of disabling numbered capturing parentheses. Any opening parenthesis that is
2728     not followed by ? behaves as if it were followed by ?: but named parentheses
2729     can still be used for capturing (and they will acquire numbers in the usual
2730     way).
2732     41. Redesigned the return codes from the match() function into yes/no/error so
2733     that errors can be passed back from deep inside the nested calls. A malloc
2734     failure while inside a recursive subpattern call now causes the
2735     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2737     42. It is now possible to set a limit on the number of times the match()
2738     function is called in a call to pcre_exec(). This facility makes it possible to
2739     limit the amount of recursion and backtracking, though not in a directly
2740     obvious way, because the match() function is used in a number of different
2741     circumstances. The count starts from zero for each position in the subject
2742     string (for non-anchored patterns). The default limit is, for compatibility, a
2743     large number, namely 10 000 000. You can change this in two ways:
2745     (a) When configuring PCRE before making, you can use --with-match-limit=n
2746     to set a default value for the compiled library.
2748     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2749     a different value is set. See 45 below.
2751     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2753     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2754     of things that can be changed at compile time. The first argument specifies
2755     what is wanted and the second points to where the information is to be placed.
2756     The current list of available information is:
2760     The output is an integer that is set to one if UTF-8 support is available;
2761     otherwise it is set to zero.
2765     The output is an integer that it set to the value of the code that is used for
2766     newline. It is either LF (10) or CR (13).
2770     The output is an integer that contains the number of bytes used for internal
2771     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2775     The output is an integer that contains the threshold above which the POSIX
2776     interface uses malloc() for output vectors. See item 31 above.
2780     The output is an unsigned integer that contains the default limit of the number
2781     of match() calls in a pcre_exec() execution. See 42 above.
2783     44. pcretest has been upgraded by the addition of the -C option. This causes it
2784     to extract all the available output from the new pcre_config() function, and to
2785     output it. The program then exits immediately.
2787     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2788     order to support additional features. One way would have been to define
2789     pcre_exec2() (for example) with extra arguments, but this would not have been
2790     extensible, and would also have required all calls to the original function to
2791     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2792     is used for passing in "extra" data from pcre_study().
2794     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2795     contains the following fields:
2797     flags a bitmap indicating which of the following fields are set
2798     study_data opaque data from pcre_study()
2799     match_limit a way of specifying a limit on match() calls for a specific
2800     call to pcre_exec()
2801     callout_data data for callouts (see 49 below)
2803     The flag bits are also defined in pcre.h, and are
2809     The pcre_study() function now returns one of these new pcre_extra blocks, with
2810     the actual study data pointed to by the study_data field, and the
2811     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2812     before. That is, this change is entirely upwards-compatible and requires no
2813     change to existing code.
2815     If you want to pass in additional data to pcre_exec(), you can either place it
2816     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2817     block.
2819     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2820     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2821     times with different match limits, until it finds the minimum value needed for
2822     pcre_exec() to complete. The value is then output. This can be instructive; for
2823     most simple matches the number is quite small, but for pathological cases it
2824     gets very large very quickly.
2826     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2827     returns the size of the data block pointed to by the study_data field in a
2828     pcre_extra block, that is, the value that was passed as the argument to
2829     pcre_malloc() when PCRE was getting memory in which to place the information
2830     created by pcre_study(). The fourth argument should point to a size_t variable.
2831     pcretest has been extended so that this information is shown after a successful
2832     pcre_study() call when information about the compiled regex is being displayed.
2834     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2835     because what follows is always an absolute path. (Later: it turns out that this
2836     is more than cosmetic for MinGW, because it doesn't like empty path
2837     components.)
2839     49. Some changes have been made to the callout feature (see 28 above):
2841     (i) A callout function now has three choices for what it returns:
2843     0 => success, carry on matching
2844     > 0 => failure at this point, but backtrack if possible
2845     < 0 => serious error, return this value from pcre_exec()
2847     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2848     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2849     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2850     use by callout functions. It will never be used by PCRE itself.
2852     (ii) The pcre_extra structure (see 45 above) has a void * field called
2853     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2854     pcre_callout_block structure has a field of the same name. The contents of
2855     the field passed in the pcre_extra structure are passed to the callout
2856     function in the corresponding field in the callout block. This makes it
2857     easier to use the same callout-containing regex from multiple threads. For
2858     testing, the pcretest program has a new data escape
2860     \C*n pass the number n (may be negative) as callout_data
2862     If the callout function in pcretest receives a non-zero value as
2863     callout_data, it returns that value.
2865     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2866     there were some redundant $(CFLAGS) in commands that are now specified as
2867     $(LINK), which already includes $(CFLAGS).
2869     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2870     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2871     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2872     one-byte characters throughout. Note that case-insensitive matching applies
2873     only to characters whose values are less than 256. PCRE doesn't support the
2874     notion of cases for higher-valued characters.
2876     (i) A character class whose characters are all within 0-255 is handled as
2877     a bit map, and the map is inverted for negative classes. Previously, a
2878     character > 255 always failed to match such a class; however it should
2879     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2881     (ii) A negated character class with a single character < 255 is coded as
2882     "not this character" (OP_NOT). This wasn't working properly when the test
2883     character was multibyte, either singly or repeated.
2885     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2886     mode, for example: \x{100}{2,3}.
2888     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2889     singly or repeated) now correctly test multibyte characters. However,
2890     PCRE doesn't recognize any characters with values greater than 255 as
2891     digits, spaces, or word characters. Such characters always match \D, \S,
2892     and \W, and never match \d, \s, or \w.
2894     (v) Classes may now contain characters and character ranges with values
2895     greater than 255. For example: [ab\x{100}-\x{400}].
2897     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2898     PCRE in UTF-8 mode.
2900     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2901     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2902     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2903     value.)
2905     53. The single man page has become too large. I have therefore split it up into
2906     a number of separate man pages. These also give rise to individual HTML pages;
2907     these are now put in a separate directory, and there is an index.html page that
2908     lists them all. Some hyperlinking between the pages has been installed.
2910     54. Added convenience functions for handling named capturing parentheses.
2912     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2913     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2914     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2915     are faulted.
2917     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2918     calling configure. These values are used when compiling the dftables.c program
2919     which is run to generate the source of the default character tables. They
2920     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2921     you will need to set these values.
2923     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2926     Version 3.9 02-Jan-02
2927 nigel 61 ---------------------
2929     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2931     2. If --disable-static was given, the building process failed when trying to
2932     build pcretest and pcregrep. (For some reason it was using libtool to compile
2933     them, which is not right, as they aren't part of the library.)
2936 nigel 59 Version 3.8 18-Dec-01
2937     ---------------------
2939     1. The experimental UTF-8 code was completely screwed up. It was packing the
2940     bytes in the wrong order. How dumb can you get?
2943 nigel 57 Version 3.7 29-Oct-01
2944     ---------------------
2946     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2947     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2948     this didn't happen under Solaris 8, where I normally test things.
2950 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2951     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2952     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2953     this fix an hour or so after the initial 3.7 release.)
2954 nigel 57
2955 nigel 59
2956 nigel 55 Version 3.6 23-Oct-01
2957     ---------------------
2959     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2960     offsets passed as NULL with zero offset count.
2962     2. The config.guess and config.sub files had not been updated when I moved to
2963     the latest autoconf.
2966 nigel 53 Version 3.5 15-Aug-01
2967     ---------------------
2968 nigel 5
2969 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2970     had been forgotten.
2972     2. By using declared but undefined structures, we can avoid using "void"
2973     definitions in pcre.h while keeping the internal definitions of the structures
2974     private.
2976     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2977     user point of view, this means that both static and shared libraries are built
2978     by default, but this can be individually controlled. More of the work of
2979     handling this static/shared cases is now inside libtool instead of PCRE's make
2980     file.
2982     4. The pcretest utility is now installed along with pcregrep because it is
2983     useful for users (to test regexs) and by doing this, it automatically gets
2984     relinked by libtool. The documentation has been turned into a man page, so
2985     there are now .1, .txt, and .html versions in /doc.
2987     5. Upgrades to pcregrep:
2988     (i) Added long-form option names like gnu grep.
2989     (ii) Added --help to list all options with an explanatory phrase.
2990     (iii) Added -r, --recursive to recurse into sub-directories.
2991     (iv) Added -f, --file to read patterns from a file.
2993     6. pcre_exec() was referring to its "code" argument before testing that
2994     argument for NULL (and giving an error if it was NULL).
2996     7. Upgraded Makefile.in to allow for compiling in a different directory from
2997     the source directory.
2999     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3000     options bits, the pointer it was passed was to an int instead of to an unsigned
3001     long int. This mattered only on 64-bit systems.
3003     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3004     generated) instead of pcre.in, which it its source. Also made the same change
3005     in several of the .c files.
3007     10. A new release of gcc defines printf() as a macro, which broke pcretest
3008     because it had an ifdef in the middle of a string argument for printf(). Fixed
3009     by using separate calls to printf().
3011     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3012     script, to force use of CR or LF instead of \n in the source. On non-Unix
3013     systems, the value can be set in config.h.
3015     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3016     absolute limit. Changed the text of the error message to make this clear, and
3017     likewise updated the man page.
3019     13. The limit of 99 on the number of capturing subpatterns has been removed.
3020     The new limit is 65535, which I hope will not be a "real" limit.
3023 nigel 51 Version 3.4 22-Aug-00
3024     ---------------------
3026     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3028     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3031 nigel 49 Version 3.3 01-Aug-00
3032     ---------------------
3034     1. If an octal character was given, but the value was greater than \377, it
3035     was not getting masked to the least significant bits, as documented. This could
3036     lead to crashes in some systems.
3038     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3039     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3041     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3042     These just pass their arguments on to (pcre_free)(), but they are provided
3043     because some uses of PCRE bind it to non-C systems that can call its functions,
3044     but cannot call free() or pcre_free() directly.
3046     4. Add "make test" as a synonym for "make check". Corrected some comments in
3047     the Makefile.
3049     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3050     Makefile.
3052     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3053     command called pgrep for grepping around the active processes.
3055     7. Added the beginnings of support for UTF-8 character strings.
3057     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3058     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3059     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3060     out for the ar command.)
3063 nigel 47 Version 3.2 12-May-00
3064     ---------------------
3066     This is purely a bug fixing release.
3068     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3069     of ZA. This was just one example of several cases that could provoke this bug,
3070     which was introduced by change 9 of version 2.00. The code for breaking
3071     infinite loops after an iteration that matches an empty string was't working
3072     correctly.
3074     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3075     when matched against abbab (for example). After matching an empty string, it
3076     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3077     caused it to match further down the string than it should.
3079     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3080     was there because it doesn't seem to be needed, and it causes trouble on some
3081     systems, as it is not a Standard C header. It has been removed.
3083     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3084     were reported on the Macintosh. The changes were from
3086     while ((c = *(++ptr)) != 0 && c != '\n');
3087     to
3088     while ((c = *(++ptr)) != 0 && c != '\n') ;
3090     Totally extraordinary, but if that's what it takes...
3092     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3093     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3094     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3095     assumes the way PCRE uses memmove() (always moving upwards).
3097     6. PCRE is being used in one environment where strchr() is not available. There
3098     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3099     faster code anyway.
3102 nigel 45 Version 3.1 09-Feb-00
3103     ---------------------
3105     The only change in this release is the fixing of some bugs in Makefile.in for
3106     the "install" target:
3108     (1) It was failing to install pcreposix.h.
3110     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3113 nigel 43 Version 3.0 01-Feb-00
3114     ---------------------
3115 nigel 41
3116     1. Add support for the /+ modifier to perltest (to output $` like it does in
3117     pcretest).
3119     2. Add support for the /g modifier to perltest.
3121     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3122     matches null strings.
3124     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3125     pattern. Perl treats empty patterns specially - it reuses the most recent
3126     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3127     effect.
3129     5. The POSIX interface was broken in that it was just handing over the POSIX
3130     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3131     required a bigger vector, with some working space on the end. This means that
3132     the POSIX wrapper now has to get and free some memory, and copy the results.
3134 nigel 43 6. Added some simple autoconf support, placing the test data and the
3135     documentation in separate directories, re-organizing some of the
3136     information files, and making it build pcre-config (a GNU standard). Also added
3137     libtool support for building PCRE as a shared library, which is now the
3138     default.
3139 nigel 41
3140 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3141     09 are not valid octal constants. Single digits will be used for minor values
3142     less than 10.
3144     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3145     existing programs that set these in the POSIX interface can use PCRE without
3146     modification.
3148     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3149     return all that pcre_info() returns, plus additional data. The pcre_info()
3150     function is retained for compatibility, but is considered to be obsolete.
3152     10. Added experimental recursion feature (?R) to handle one common case that
3153     Perl 5.6 will be able to do with (?p{...}).
3155     11. Added support for POSIX character classes like [:alpha:], which Perl is
3156     adopting.
3159 nigel 39 Version 2.08 31-Aug-99
3160     ----------------------
3162     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3163     trying to match at the startoffset position, but instead was moving forward to
3164     the next newline as if a previous match had failed.
3166     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3167     and could get into a loop if a null string was matched other than at the start
3168     of the subject.
3170     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3171     be distinguished at compile time, and for completeness also added PCRE_DATE.
3173     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3174     in GnuWin32 environments.
3177 nigel 37 Version 2.07 29-Jul-99
3178     ----------------------
3180     1. The documentation is now supplied in plain text form and HTML as well as in
3181     the form of man page sources.
3183     2. C++ compilers don't like assigning (void *) values to other pointer types.
3184     In particular this affects malloc(). Although there is no problem in Standard
3185     C, I've put in casts to keep C++ compilers happy.
3187     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3188     should be (const char *).
3190     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3191     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3192     However, I haven't made this a standard facility. The documentation doesn't
3193     mention it, and the Makefile doesn't support it.
3195     5. The Makefile now contains an "install" target, with editable destinations at
3196     the top of the file. The pcretest program is not installed.
3198     6. pgrep -V now gives the PCRE version number and date.
3200     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3201     causing the entire string to be ignored, instead of just the last character.
3203     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3204     non-matching string, it can take a very, very long time, even for strings of
3205     quite modest length, because of the nested recursion. PCRE now does better in
3206     some of these cases. It does this by remembering the last required literal
3207     character in the pattern, and pre-searching the subject to ensure it is present
3208     before running the real match. In other words, it applies a heuristic to detect
3209     some types of certain failure quickly, and in the above example, if presented
3210     with a string that has no trailing " it gives "no match" very quickly.
3212     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3213     other alternatives are tried instead.
3216 nigel 35 Version 2.06 09-Jun-99
3217     ----------------------
3219     1. Change pcretest's output for amount of store used to show just the code
3220     space, because the remainder (the data block) varies in size between 32-bit and
3221     64-bit systems.
3223     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3224     start matching at. This allows lookbehinds to work when searching for multiple
3225     occurrences in a string.
3227     3. Added additional options to pcretest for testing multiple occurrences:
3229     /+ outputs the rest of the string that follows a match
3230     /g loops for multiple occurrences, using the new startoffset argument
3231     /G loops for multiple occurrences by passing an incremented pointer
3233     4. PCRE wasn't doing the "first character" optimization for patterns starting
3234     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3235     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3236     the letter 'x'. On long subject strings, this gives a significant speed-up.
3239 nigel 33 Version 2.05 21-Apr-99
3240     ----------------------
3242     1. Changed the type of magic_number from int to long int so that it works
3243     properly on 16-bit systems.
3245     2. Fixed a bug which caused patterns starting with .* not to work correctly
3246     when the subject string contained newline characters. PCRE was assuming
3247     anchoring for such patterns in all cases, which is not correct because .* will
3248     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3249     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3250     must be retried after every newline in the subject.
3253 nigel 31 Version 2.04 18-Feb-99
3254     ----------------------
3256     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3257     computation of the store needed to hold the pattern was incorrect (too large).
3258     If such patterns were nested a few deep, this could multiply and become a real
3259     problem.
3261     2. Added /M option to pcretest to show the memory requirement of a specific
3262     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3264     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3265     compiled in such a way that the backtracking after subsequent failure was
3266     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3267     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3270 nigel 29 Version 2.03 02-Feb-99
3271     ----------------------
3273     1. Fixed typo and small mistake in man page.
3275 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3276     LICENCE file containing the conditions.
3277 nigel 29
3278     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3279     Perl, that is the internal \ allows the delimiter to be included in the
3280     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3281     the final delimiter, add \ to the end of the pattern (to test the error).
3283     4. Added the convenience functions for extracting substrings after a successful
3284     match. Updated pcretest to make it able to test these functions.
3287 nigel 27 Version 2.02 14-Jan-99
3288     ----------------------
3290     1. Initialized the working variables associated with each extraction so that
3291     their saving and restoring doesn't refer to uninitialized store.
3293     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3294     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3295     fix the problem.
3297     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3298     calls, and wasn't printing the correct value for compiling calls. Increased the
3299     default value of LOOPREPEAT, and the number of significant figures in the
3300     times.
3302     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3304     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3305     a building problem on Windows NT with a FAT file system.
3308 nigel 25 Version 2.01 21-Oct-98
3309     ----------------------
3311     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3312     to character tables built by pcre_maketables() in the current locale. If NULL
3313     is passed, the default tables are used.
3316 nigel 23 Version 2.00 24-Sep-98
3317 nigel 21 ----------------------
3319 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3320     it any more.
3322     2. Allow quantification of (?>) groups, and make it work correctly.
3324     3. The first character computation wasn't working for (?>) groups.
3326     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3327     end of the subject) and add 5.005's \z, which really does match only at the
3328     very end of the subject.
3330     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3332     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3333     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3334     localized options. All options to pcre_study() were also removed.
3336     7. Add other new features from 5.005:
3338     $(?<= positive lookbehind
3339     $(?<! negative lookbehind
3340     (?imsx-imsx) added the unsetting capability
3341     such a setting is global if at outer level; local otherwise
3342     (?imsx-imsx:) non-capturing groups with option setting
3343     (?(cond)re|re) conditional pattern matching
3345     A backreference to itself in a repeated group matches the previous
3346     captured string.
3348     8. General tidying up of studying (both automatic and via "study")
3349     consequential on the addition of new assertions.
3351     9. As in 5.005, unlimited repeated groups that could match an empty substring
3352     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3353     runtime if any iteration does actually match an empty substring.
3355     10. Include the RunTest script in the distribution.
3357     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3358     discrepancies, some of which were old and were also with respect to 5.004. They
3359     have now been fixed.
3362     Version 1.09 28-Apr-98
3363     ----------------------
3365 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3366     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3367     program crashes, or just wrong answers. This did not apply to negated classes
3368     containing more than one character, or to minima other than one.
3371 nigel 19 Version 1.08 27-Mar-98
3372     ----------------------
3374     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3376     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3377     latter must appear before anything that relies on it in the pattern.
3380 nigel 17 Version 1.07 16-Feb-98
3381     ----------------------
3383     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3384     repeat of a potentially empty string).
3387 nigel 15 Version 1.06 23-Jan-98
3388     ----------------------
3390     1. Added Markus Oberhumer's little patches for C++.
3392     2. Literal strings longer than 255 characters were broken.
3395 nigel 13 Version 1.05 23-Dec-97
3396     ----------------------
3398     1. Negated character classes containing more than one character were failing if
3399     PCRE_CASELESS was set at run time.
3402 nigel 11 Version 1.04 19-Dec-97
3403     ----------------------
3405     1. Corrected the man page, where some "const" qualifiers had been omitted.
3407     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3408     input syntax.
3410     3. Fixed memory leak which occurred when a regex with back references was
3411     matched with an offsets vector that wasn't big enough. The temporary memory
3412     that is used in this case wasn't being freed if the match failed.
3414     4. Tidied pcretest to ensure it frees memory that it gets.
3416     5. Temporary memory was being obtained in the case where the passed offsets
3417     vector was exactly big enough.
3419     6. Corrected definition of offsetof() from change 5 below.
3421     7. I had screwed up change 6 below and broken the rules for the use of
3422     setjmp(). Now fixed.
3425 nigel 9 Version 1.03 18-Dec-97
3426     ----------------------
3428     1. A erroneous regex with a missing opening parenthesis was correctly
3429     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3430     on some systems.
3432     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3433     it was reported that one broken compiler failed on the former because "code" is
3434     also an independent variable.
3436     3. The erroneous regex a[]b caused an array overrun reference.
3438     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3439     fail on data ending with that character. (It was going on too far, and checking
3440     the next character, typically a binary zero.) This was specific to the
3441     optimized code for single-character negative classes.
3443     5. Added a contributed patch from the TIN world which does the following:
3445     + Add an undef for memmove, in case the the system defines a macro for it.
3447     + Add a definition of offsetof(), in case there isn't one. (I don't know
3448     the reason behind this - offsetof() is part of the ANSI standard - but
3449     it does no harm).
3451     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3452     most of the places where whitespace preceded '#'. I have given up and
3453     allowed the remaining 2 cases to be at the margin.
3455     + Rename some variables in pcre to eliminate shadowing. This seems very
3456     pedantic, but does no harm, of course.
3458     6. Moved the call to setjmp() into its own function, to get rid of warnings
3459     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3461     7. Constructs such as \d{8,} were compiling into the equivalent of
3462 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3463 nigel 9 outcome, but in this particular case used more store than had been allocated,
3464     which caused the bug to be discovered because it threw up an internal error.
3466     8. The debugging code in both pcre and pcretest for outputting the compiled
3467     form of a regex was going wrong in the case of back references followed by
3468     curly-bracketed repeats.
3471 nigel 7 Version 1.02 12-Dec-97
3472     ----------------------
3474     1. Typos in pcre.3 and comments in the source fixed.
3476     2. Applied a contributed patch to get rid of places where it used to remove
3477     'const' from variables, and fixed some signed/unsigned and uninitialized
3478     variable warnings.
3480     3. Added the "runtest" target to Makefile.
3482     4. Set default compiler flag to -O2 rather than just -O.
3485 nigel 5 Version 1.01 19-Nov-97
3486     ----------------------
3488     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3489     like /([ab]*)*/, that is, for classes with more than one character in them.
3491     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3492     as /((?>a*))*/ (a PCRE_EXTRA facility).
3495     Version 1.00 18-Nov-97
3496     ----------------------
3498     1. Added compile-time macros to support systems such as SunOS4 which don't have
3499     memmove() or strerror() but have other things that can be used instead.
3501     2. Arranged that "make clean" removes the executables.
3504 nigel 3 Version 0.99 27-Oct-97
3505     ----------------------
3507     1. Fixed bug in code for optimizing classes with only one character. It was
3508     initializing a 32-byte map regardless, which could cause it to run off the end
3509     of the memory it had got.
3511     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3514     Version 0.98 22-Oct-97
3515     ----------------------
3517     1. Fixed bug in code for handling temporary memory usage when there are more
3518     back references than supplied space in the ovector. This could cause segfaults.
3521     Version 0.97 21-Oct-97
3522     ----------------------
3524     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3526     2. Optimized negated single characters not to use a bit map.
3528     3. Brought error texts together as macro definitions; clarified some of them;
3529     fixed one that was wrong - it said "range out of order" when it meant "invalid
3530     escape sequence".
3532     4. Changed some char * arguments to const char *.
3534     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3536     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3537     pcretest.
3540     Version 0.96 16-Oct-97
3541     ----------------------
3543     1. Added a simple "pgrep" utility to the distribution.
3545     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3546     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3547     where "ddd" means "one or more decimal digits".
3549     3. Fixed serious bug. If a pattern had a back reference, but the call to
3550     pcre_exec() didn't supply a large enough ovector to record the related
3551     identifying subpattern, the match always failed. PCRE now remembers the number
3552     of the largest back reference, and gets some temporary memory in which to save
3553     the offsets during matching if necessary, in order to ensure that
3554     backreferences always work.
3556     4. Increased the compatibility with Perl in a number of ways:
3558     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3559     to request this handling. The option can be set at compile or exec time.
3561     (b) $ matches before a terminating newline by default; an option
3562     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3563     mode). The option can be set at compile or exec time.
3565     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3566     the same as Perl's. If the decimal number it represents is less than 10
3567     or there aren't that many previous left capturing parentheses, an octal
3568     escape is read. Inside a character class, it's always an octal escape,
3569     even if it is a single digit.
3571     (d) An escaped but undefined alphabetic character is taken as a literal,
3572     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3573     escapes.
3575     (e) {0} is now permitted. (The previous item is removed from the compiled
3576     pattern).
3578     5. Changed all the names of code files so that the basic parts are no longer
3579     than 10 characters, and abolished the teeny "globals.c" file.
3581     6. Changed the handling of character classes; they are now done with a 32-byte
3582     bit map always.
3584     7. Added the -d and /D options to pcretest to make it possible to look at the
3585     internals of compilation without having to recompile pcre.
3588     Version 0.95 23-Sep-97
3589     ----------------------
3591     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3592     \x20 at the start of a run of normal characters. These were being treated as
3593     real characters, instead of the source characters being re-checked.
3596     Version 0.94 18-Sep-97
3597     ----------------------
3599     1. The functions are now thread-safe, with the caveat that the global variables
3600     containing pointers to malloc() and free() or alternative functions are the
3601     same for all threads.
3603     2. Get pcre_study() to generate a bitmap of initial characters for non-
3604     anchored patterns when this is possible, and use it if passed to pcre_exec().
3607     Version 0.93 15-Sep-97
3608     ----------------------
3610     1. /(b)|(:+)/ was computing an incorrect first character.
3612     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3613     but not actually doing anything yet.
3615     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3616     as Perl does (e.g. [-az] or [az-]).
3618     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3619     all possible positions.
3621     5. Split up into different modules to avoid including unneeded functions in a
3622     compiled binary. However, compile and exec are still in one module. The "study"
3623     function is split off.
3625     6. The character tables are now in a separate module whose source is generated
3626     by an auxiliary program - but can then be edited by hand if required. There are
3627     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3628     toupper() in the code.
3630     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3631     make them global. Abolish the function for setting them, as the caller can now
3632     set them directly.
3635     Version 0.92 11-Sep-97
3636     ----------------------
3638     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3639     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3641     2. Caseless matching was not working in character classes if the characters in
3642     the pattern were in upper case.
3644     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3646     4. Make PCRE_ANCHORED public and accept as a compile option.
3648     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3649     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3650     pass them.
3652     6. Give an error if bad option bits passed at compile or run time.
3654     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3655     pcretest to cause it to pass that flag.
3657     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3658     options, and the first character, if set.
3660     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3663     Version 0.91 10-Sep-97
3664     ----------------------
3666     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3667     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3669     2. PCRE was looping on encountering an indefinitely repeated back reference to
3670     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3671     Perl does - treats the match as successful.
3673     ****


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