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Revision 472 - (hide annotations) (download)
Fri Dec 11 16:42:50 2009 UTC (5 years, 4 months ago) by ph10
File size: 175497 byte(s)
Fix options set and reset at top level bug.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 471 Version 8.01 11-Dec-09
5     ----------------------
7     1. If a pattern contained a conditional subpattern with only one branch (in
8     particular, this includes all (DEFINE) patterns), a call to pcre_study()
9     computed the wrong minimum data length (which is of course zero for such
10     subpatterns).
11 ph10 472
12     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
13     the pattern is reset in the first branch, pcre_compile() failed with
14     "internal error: code overflow at offset...". This happened only when
15     the reset was to the original external option setting. (An optimization
16     abstracts leading options settings into an external setting, which was the
17     cause of this.)
18 ph10 471
20 ph10 469 Version 8.00 19-Oct-09
21 ph10 418 ----------------------
23     1. The table for translating pcre_compile() error codes into POSIX error codes
24 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
25     being within the table. This could lead to an OK return being given in
26 ph10 418 error.
27 ph10 461
28     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
29     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
30     in a Windows environment.
32 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
33     zero, as does GNU grep. However, pcregrep was also printing all files when
34     --files-with-matches was added. Now, when both options are given, it prints
35     counts only for those files that have at least one match. (GNU grep just
36 ph10 461 prints the file name in this circumstance, but including the count seems
37     more useful - otherwise, why use --count?) Also ensured that the
38 ph10 420 combination -clh just lists non-zero counts, with no names.
39 ph10 461
40     4. The long form of the pcregrep -F option was incorrectly implemented as
41     --fixed_strings instead of --fixed-strings. This is an incompatible change,
42     but it seems right to fix it, and I didn't think it was worth preserving
43     the old behaviour.
45     5. The command line items --regex=pattern and --regexp=pattern were not
46 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
47 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
48 ph10 422 which are compatible with GNU grep; these now work.
49 ph10 461
50     6. No libpcreposix.pc file was created for pkg-config; there was just
51 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
52 ph10 461
53 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
54 ph10 461 when UCP support is not needed, by modifying the Python script that
55 ph10 425 generates it from Unicode data files. This should not matter if the module
56     is correctly used as a library, but I received one complaint about 50K of
57     unwanted data. My guess is that the person linked everything into his
58     program rather than using a library. Anyway, it does no harm.
59 ph10 461
60 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
61 ph10 461 was a minimum greater than 1 for a wide character in a possessive
62 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
63     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
64     character. Chaos in the form of incorrect output or a compiling loop could
65     result.
66 ph10 461
67 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
68 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
69 ph10 426 partially matched by this function. In addition, if there are at least two
70 ph10 435 slots in the offset vector, the offset of the earliest inspected character
71     for the match and the offset of the end of the subject are set in them when
72 ph10 461 PCRE_ERROR_PARTIAL is returned.
74 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
75     synonymous with PCRE_PARTIAL, for backwards compatibility, and
76     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
77 ph10 462 and may be more useful for multi-segment matching.
78 ph10 461
79     11. Partial matching with pcre_exec() is now more intuitive. A partial match
80     used to be given if ever the end of the subject was reached; now it is
81     given only if matching could not proceed because another character was
82     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
83     string "Z", which now yields "no match" instead of "partial match". In the
84     case of pcre_dfa_exec(), "no match" is given if every matching path for the
85     final character ended with (*FAIL).
87 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
88 ph10 461 if the pattern had a "must contain" character that was already found in the
89 ph10 428 earlier partial match, unless partial matching was again requested. For
90     example, with the pattern /dog.(body)?/, the "must contain" character is
91     "g". If the first part-match was for the string "dog", restarting with
92 ph10 435 "sbody" failed. This bug has been fixed.
93 ph10 461
94     13. The string returned by pcre_dfa_exec() after a partial match has been
95     changed so that it starts at the first inspected character rather than the
96     first character of the match. This makes a difference only if the pattern
97     starts with a lookbehind assertion or \b or \B (\K is not supported by
98     pcre_dfa_exec()). It's an incompatible change, but it makes the two
99 ph10 435 matching functions compatible, and I think it's the right thing to do.
100 ph10 461
101 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
102 ph10 461 so that the demonstration program is easily available in environments where
103     PCRE has not been installed from source.
105 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
106 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
107     library.
108 ph10 461
109 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
110 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
111 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
112 ph10 433 these options useful.
113 ph10 461
114     17. If a caller to the POSIX matching function regexec() passes a non-zero
115 ph10 438 value for nmatch with a NULL value for pmatch, the value of
116 ph10 461 nmatch is forced to zero.
118 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
119 ph10 461 the diff command, as RunTest does. It now checks in the same way as
120 ph10 437 RunTest, and also checks for the -b option.
121 ph10 461
122 ph10 438 19. If an odd number of negated classes containing just a single character
123     interposed, within parentheses, between a forward reference to a named
124 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
125     an internal error, complaining that it could not find the referenced
126 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
127 ph10 461 [The bug was that it was starting one character too far in when skipping
128     over the character class, thus treating the ] as data rather than
129     terminating the class. This meant it could skip too much.]
131 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
132 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
133 ph10 442 to have an empty string match not at the start, even when the pattern is
134 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
136 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
137 ph10 461 than the maximum at the outer level, the higher number was returned, but
138     with unset values at the outer level. The correct (outer level) value is
139 ph10 446 now given.
140 ph10 461
141 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
142     PCRE did not set those parentheses (unlike Perl). I have now found a way to
143     make it do so. The string so far is captured, making this feature
144     compatible with Perl.
145 ph10 461
146     23. The tests have been re-organized, adding tests 11 and 12, to make it
147 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
148 ph10 461
149 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
150 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
151     does. Neither allows recursion.
153     25. I finally figured out how to implement a request to provide the minimum
154     length of subject string that was needed in order to match a given pattern.
155     (It was back references and recursion that I had previously got hung up
156     on.) This code has now been added to pcre_study(); it finds a lower bound
157 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
158     bound, but using it to avoid searching strings that are too short does give
159     some useful speed-ups. The value is available to calling programs via
160     pcre_fullinfo().
161 ph10 461
162 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
163     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
164     study optimizations had never been tested with that matching function.
165     Oops. What is worse, even when it was passed study data, there was a bug in
166     pcre_dfa_exec() that meant it never actually used it. Double oops. There
167     were also very few tests of studied patterns with pcre_dfa_exec().
168 ph10 461
169 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
170     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
171     on the other side of the coin, they are no longer allowed to have different
172     names, because these cannot be distinguished in PCRE, and this has caused
173     confusion. (This is a difference from Perl.)
174 ph10 461
175     28. When duplicate subpattern names are present (necessarily with different
176     numbers, as required by 27 above), and a test is made by name in a
177     conditional pattern, either for a subpattern having been matched, or for
178     recursion in such a pattern, all the associated numbered subpatterns are
179 ph10 459 tested, and the overall condition is true if the condition is true for any
180     one of them. This is the way Perl works, and is also more like the way
181     testing by number works.
182 ph10 418
183 ph10 461
184 ph10 412 Version 7.9 11-Apr-09
185 ph10 376 ---------------------
187 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
188 ph10 376 (pcretest), all targets were linked against these libraries. This included
189     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
190     libraries. This caused unwanted dependencies to be created. This problem
191 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
192 ph10 376 pcretest is linked with readline.
193 ph10 392
194 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
195     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
196     moved outside it again, because FALSE and TRUE are already defined in AIX,
197     but BOOL is not.
198 ph10 392
199     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
200 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
201 ph10 392
202 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
203     hyphens) following file names and line numbers when outputting matching
204 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
205 ph10 376 wording for the --colour (or --color) option.
206 ph10 392
207 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
208     was not coloured; this is different to GNU grep, so I have changed it to be
209     the same.
210 ph10 392
211 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
212 ph10 392 each matching line was coloured. Now it goes on to look for further matches
213     of any of the test patterns, which is the same behaviour as GNU grep.
215     7. A pattern that could match an empty string could cause pcregrep to loop; it
216     doesn't make sense to accept an empty string match in pcregrep, so I have
217 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
218     seems to be how GNU grep behaves.
219 ph10 392
220 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
221 ph10 392 start or after a newline", because the conditional assertion was not being
222     correctly handled. The rule now is that both the assertion and what follows
223     in the first alternative must satisfy the test.
225 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
226 ph10 399 condition was an assertion, PCRE could crash during matching, both with
227     pcre_exec() and pcre_dfa_exec().
228 ph10 392
229     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
230     used for matching.
232     11. Unicode property support in character classes was not working for
233 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
234 ph10 388
235 ph10 392 12. Added the -M command line option to pcretest.
237 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
238 ph10 389
239     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
240 ph10 390
241 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
242 ph10 390 wrapper.
243 ph10 392
244 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
245 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
246 ph10 391 string constants.
247 ph10 405
248 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
249     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
250 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
251     these, but not everybody uses configure.
253     19. A conditional group that had only one branch was not being correctly
254     recognized as an item that could match an empty string. This meant that an
255     enclosing group might also not be so recognized, causing infinite looping
256     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
257     with the subject "ab", where knowledge that the repeated group can match
258 ph10 396 nothing is needed in order to break the loop.
259 ph10 405
260 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
261 ph10 405 exec(), but without supplying a callout function, matching went wrong.
263     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
264     leak if the size of the offset vector was greater than 30. When the vector
265     is smaller, the saved offsets during recursion go onto a local stack
266     vector, but for larger vectors malloc() is used. It was failing to free
267     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
268 ph10 400 error, in fact).
269 ph10 405
270 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
271 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
272     problem, but was untidy.
273 ph10 376
274 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
275     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
276     included within another project.
277 ph10 411
278 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
279     slightly modified by me:
280 ph10 411
281     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
282     not building pcregrep.
284 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
285 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
287 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
288     duplicate group numbers, could behave incorrectly or give incorrect errors,
289     because when scanning forward to find the reference group, PCRE was not
290     taking into account the duplicate group numbers. A pattern such as
291     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
292 ph10 411
293     26. Changed a few more instances of "const unsigned char *" to USPTR, making
294     the feature of a custom pointer more persuasive (as requested by a user).
295 ph10 416
296 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
297 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
298     pre-defined.
299 ph10 392
300 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
302 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
303     in the configuration summary.
304 ph10 405
305 ph10 411
306 ph10 374 Version 7.8 05-Sep-08
307 ph10 349 ---------------------
309     1. Replaced UCP searching code with optimized version as implemented for Ad
310     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
311 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
312     to 5 times on some simple patterns that I tested. Permission was given to
313     distribute the MultiStage2.py script that generates the tables (it's not in
314     the tarball, but is in the Subversion repository).
315 ph10 349
316 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
317     scripts.
318 ph10 358
319 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
320     a group with a zero qualifier. The result of the study could be incorrect,
321 ph10 358 or the function might crash, depending on the pattern.
323     4. Caseless matching was not working for non-ASCII characters in back
324 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
325 ph10 358 It now works when Unicode Property Support is available.
327 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
328     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
329     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
330 ph10 358 truncation.
331 ph10 349
332 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
334 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
335     pointers, in case they are 64-bit values.
336 ph10 371
337     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
338     test 2 if it fails.
340 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
341 ph10 371 and a #define of that name to empty if it is not externally set. This is to
342     allow users of MSVC to set it if necessary.
344     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
345 ph10 359 the convenience functions in the pcre_get.c source file.
346 ph10 371
347 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
348     could cause overwriting and/or a crash. This command provoked a crash in
349 ph10 371 some environments:
351     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
353 ph10 360 This potential security problem was recorded as CVE-2008-2371.
354 ph10 371
355 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
356     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
357 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
358 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
359     pcretest so that it places the subject at the end of its malloc-ed buffer.
360 ph10 371
361 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
362 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
364 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
365 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
366     first line. This applied both to normal and DFA matching.
368 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
369 ph10 371 /^[^d]*?$/8 failed to match "abc".
370 ph10 351
371 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
373     17. Make it more clear in the documentation that values returned from
374 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
375 ph10 357
376 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
377 ph10 368
378 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
379     supplied by Stefan Weber. I made a further small update for 7.8 because
380 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
381     replaced by pcre_ucd.c.
382 ph10 371
383 ph10 373
384 ph10 347 Version 7.7 07-May-08
385 ph10 321 ---------------------
387     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
388 ph10 345 a string to a long long, pretend we don't even have a long long." This is
389 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
390 ph10 345
391 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
392     pre-7.6 versions, which defined a global no_arg variable instead of putting
393 ph10 332 it in the RE class. (See also #8 below.)
394 ph10 345
395     3. Remove a line of dead code, identified by coverity and reported by Nuno
396     Lopes.
398 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
399 ph10 321
400 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
401 ph10 345 of files, instead of just to the final components.
403 ph10 324 (2) If there was more than one level of directory, the subdirectories were
404     skipped unless they satisfied the include/exclude conditions. This is
405     inconsistent with GNU grep (and could even be seen as contrary to the
406     pcregrep specification - which I improved to make it absolutely clear).
407     The action now is always to scan all levels of directory, and just
408     apply the include/exclude patterns to regular files.
409 ph10 345
410 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
411 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
413 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
414 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
415 ph10 326 doesn't support NULs in patterns.
416 ph10 345
417     7. Added some missing "const"s to declarations of static tables in
418     pcre_compile.c and pcre_dfa_exec.c.
420 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
421 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
422 ph10 345 first patch. And a third patch - this was a messy problem.)
423 ph10 321
424 ph10 345 9. Applied Craig's patch to remove the use of push_back().
426 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
427     matching function regexec().
428 ph10 345
429     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
430     which, however, unlike Perl's \g{...}, are subroutine calls, not back
431 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
432     Oniguruma does).
433 ph10 345
434     12. Previously, a group with a zero repeat such as (...){0} was completely
435 ph10 335 omitted from the compiled regex. However, this means that if the group
436     was called as a subroutine from elsewhere in the pattern, things went wrong
437 ph10 345 (an internal error was given). Such groups are now left in the compiled
438     pattern, with a new opcode that causes them to be skipped at execution
439 ph10 335 time.
440 ph10 345
441 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
442     to the way PCRE behaves:
443 ph10 345
444 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
445 ph10 345
446     (b) A back reference to an unmatched subpattern matches an empty string
447 ph10 336 (Perl fails the current match path).
448 ph10 345
449 ph10 341 (c) A data ] in a character class must be notated as \] because if the
450 ph10 345 first data character in a class is ], it defines an empty class. (In
451 ph10 341 Perl it is not possible to have an empty class.) The empty class []
452     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
453     The negative empty class [^] matches any one character, independently
454     of the DOTALL setting.
455 ph10 345
456     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
457 ph10 340 non-existent subpattern following a character class starting with ']' and
458     containing () gave an internal compiling error instead of "reference to
459     non-existent subpattern". Fortunately, when the pattern did exist, the
460 ph10 345 compiled code was correct. (When scanning forwards to check for the
461 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
462 ph10 345 the class, so got the count wrong. When actually compiling, the reference
463 ph10 340 was subsequently set up correctly.)
464 ph10 345
465 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
466 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
467     other assertions are supported. I have made pcre_dfa_exec() support
468     (*FAIL).
470 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
471 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
472     cannot be changed at match time, I realized I could make a small
473     improvement to matching performance by compiling OP_ALLANY instead of
474     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
475     on the OP_ANY path.
477     17. Compiling pcretest on Windows with readline support failed without the
478 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
479 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
481 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
482 ph10 345 ncurses library to be included for pcretest when ReadLine support is
483     requested, but also to allow for it to be overridden. This patch came from
484     Daniel Bergström.
485 ph10 347
486 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
487 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
488     any errors with the current Unicode tables. Thanks to Peter Kankowski for
489     spotting this.
490 ph10 324
491 ph10 332
492 ph10 319 Version 7.6 28-Jan-08
493 ph10 300 ---------------------
495 ph10 302 1. A character class containing a very large number of characters with
496     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
497     overflow.
498 ph10 309
499     2. Patch to cut out the "long long" test in pcrecpp_unittest when
500     HAVE_LONG_LONG is not defined.
502 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
503 ph10 304 bring them up to date and include new features. This patch includes:
504 ph10 309
505 ph10 304 - Fixed PH's badly added libz and libbz2 support.
506     - Fixed a problem with static linking.
507 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
508 ph10 304 - Fixed dftables problem and added an option.
509     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
511     - Added readline support for pcretest.
512 ph10 309 - Added an listing of the option settings after cmake has run.
514 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
515     "pcre.dll" under mingw when using Configure/Make. I added stuff to
516     Makefile.am that cause it to include this special target, without
517     affecting anything else. Note that the same mingw target plus all
518     the other distribution libraries and programs are now supported
519     when configuring with CMake (see 6 below) instead of with
520     Configure/Make.
521 ph10 309
522 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
523     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
524 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
525     solves the problem, but it does no harm.
526 ph10 313
527 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
528 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
529 ph10 314 with CMake, and also correct the comment about stack recursion.
530 ph10 313
531 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
532 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
533     of a program that users should build themselves after PCRE is installed, so
534     building it automatically is not really right. What is more, it gave
535 ph10 312 trouble in some build environments.
536 ph10 300
537 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
538 ph10 308
539 ph10 319
540 ph10 298 Version 7.5 10-Jan-08
541 ph10 263 ---------------------
543     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
544     values in parens when parsing an RE using the C++ wrapper."
545 ph10 286
546 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
547     Characters greater than 255 were excluded from the class instead of being
548     included.
549 ph10 286
550     3. The same bug as (2) above applied to negated POSIX classes such as
551 ph10 265 [:^space:].
552 ph10 286
553 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
554     defined or documented. It seems to have been a typo for PCRE_STATIC, so
555 ph10 286 I have changed it.
557 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
558 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
559     first named subpattern whose name started with "a" (in other words, the
560 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
561     expected" is now given for (?&) (a zero-length name), and this patch also
562     makes it give the same error for \k'' (previously it complained that that
563     was a reference to a non-existent subpattern).
564 ph10 286
565 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
566 ph10 286 this is right because (?- can be followed by option settings as well as by
567 ph10 269 digits. I have, however, made the messages clearer.
568 ph10 286
569 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
570     than the number used in the conditional) now cause a compile-time error.
571     This is actually not compatible with Perl, which accepts such patterns, but
572     treats the conditional as always being FALSE (as PCRE used to), but it
573     seems to me that giving a diagnostic is better.
574 ph10 286
575 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
576 ph10 275 and messages.
577 ph10 286
578     9. Fix two occurrences of "backslash" in comments that should have been
579     "backspace".
581     10. Remove two redundant lines of code that can never be obeyed (their function
582     was moved elsewhere).
584     11. The program that makes PCRE's Unicode character property table had a bug
585     which caused it to generate incorrect table entries for sequences of
586 ph10 277 characters that have the same character type, but are in different scripts.
587 ph10 286 It amalgamated them into a single range, with the script of the first of
588 ph10 277 them. In other words, some characters were in the wrong script. There were
589     thirteen such cases, affecting characters in the following ranges:
590 ph10 286
591 ph10 277 U+002b0 - U+002c1
592     U+0060c - U+0060d
593 ph10 286 U+0061e - U+00612
594 ph10 277 U+0064b - U+0065e
595     U+0074d - U+0076d
596     U+01800 - U+01805
597     U+01d00 - U+01d77
598     U+01d9b - U+01dbf
599     U+0200b - U+0200f
600     U+030fc - U+030fe
601     U+03260 - U+0327f
602     U+0fb46 - U+0fbb1
603     U+10450 - U+1049d
604 ph10 286
605 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
606     compatible with GNU grep in that, if there was more than one match in a
607     line, it showed only the first of them. It now behaves in the same way as
608     GNU grep.
609 ph10 286
610     13. If the -o and -v options were combined for pcregrep, it printed a blank
611     line for every non-matching line. GNU grep prints nothing, and pcregrep now
612     does the same. The return code can be used to tell if there were any
613     non-matching lines.
615 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
617     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
618 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
619 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
620     and both kinds of lookbehind were skipped).
622 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
623 ph10 284 inclusion of <windows.h> to before rather than after the definition of
624     INVALID_FILE_ATTRIBUTES (patch from David Byron).
625 ph10 263
626 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
627 ph10 286 character property caused pcre_compile() to compile bad code, which led at
628     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
629     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
630     caused the error; without that there was no problem.
631 ph10 263
632 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
633 ph10 286
634 ph10 289 19. Added --enable-pcretest-libreadline.
635 ph10 286
636 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
637 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
638 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
639     later patch that removed the other one (the right fix) and added unit tests
640     that check the return values (which was not done before).
641 ph10 292
642 ph10 291 21. Several CMake things:
643 ph10 287
644 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
645 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
646 ph10 288
647 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
648     linked with the newly-built libraries, not previously installed ones.
649 ph10 291
651 ph10 298
652     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
653     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
654     UTF-8 newline character). The key issue is that the pattern starts .*;
655     this means that the match must be either at the beginning, or after a
656     newline. The bug was in the code for advancing after a failed match and
657     checking that the new position followed a newline. It was not taking
658 ph10 294 account of UTF-8 characters correctly.
659 ph10 298
660     23. PCRE was behaving differently from Perl in the way it recognized POSIX
661     character classes. PCRE was not treating the sequence [:...:] as a
662     character class unless the ... were all letters. Perl, however, seems to
663     allow any characters between [: and :], though of course it rejects as
664     unknown any "names" that contain non-letters, because all the known class
665     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
666     for example, whereas PCRE did not - it did not recognize a POSIX character
667     class. This seemed a bit dangerous, so the code has been changed to be
668     closer to Perl. The behaviour is not identical to Perl, because PCRE will
669     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
670     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
671     Perl does, and where it didn't before.
673 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
674     Windows environments %n is disabled by default.
675 ph10 292
677 ph10 260 Version 7.4 21-Sep-07
678 ph10 230 ---------------------
680     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
681 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
682     LF". That isn't really right - the whole point of the change was to try to
683     help when there was an actual mention of one of the two characters. So now
684     the change happens only if \r or \n (or a literal CR or LF) character is
685 ph10 230 encountered.
686 ph10 231
687     2. The 32-bit options word was also used for 6 internal flags, but the numbers
688     of both had grown to the point where there were only 3 bits left.
689     Fortunately, there was spare space in the data structure, and so I have
690     moved the internal flags into a new 16-bit field to free up more option
691 ph10 230 bits.
692 ph10 231
693     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
694     but did not set the internal JCHANGED flag - either of these is enough to
695     control the way the "get" function works - but the PCRE_INFO_JCHANGED
696     facility is supposed to tell if (?J) was ever used, so now (?J) at the
697 ph10 230 start sets both bits.
699 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
700     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
701 ph10 230
702 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
704     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
705 ph10 233 compatibility, even though it is no longer used.
706 ph10 243
707     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
708 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
709 ph10 259 windows.h file is present (where different names are used). [This was
710 ph10 257 reversed later after testing - see 16 below.]
711 ph10 243
712     8. Changed all #include <config.h> to #include "config.h". There were also
713 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
714 ph10 243
715 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
716 ph10 243 sequence off the lines that it output.
718     10. It was pointed out to me that arrays of string pointers cause lots of
719     relocations when a shared library is dynamically loaded. A technique of
720     using a single long string with a table of offsets can drastically reduce
721     these. I have refactored PCRE in four places to do this. The result is
722 ph10 240 dramatic:
723 ph10 243
724 ph10 240 Originally: 290
725     After changing UCP table: 187
726 ph10 243 After changing error message table: 43
727 ph10 240 After changing table of "verbs" 36
728     After changing table of Posix names 22
729 ph10 243
730 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
731 ph10 247
732 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
733 ph10 247 unicode-properties was also set.
735 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
736 ph10 231
737 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
738     checked only for CRLF.
739 ph10 233
740 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
742 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
743 ph10 253
744 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
745 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
746     entirely. This removes changes made in 7 above.
747 ph10 256
748 ph10 261 17. The CMake files have been updated, and there is now more information about
749     building with CMake in the NON-UNIX-USE document.
750 ph10 257
751 ph10 261
752 ph10 228 Version 7.3 28-Aug-07
753 ph10 157 ---------------------
755 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
756     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
757     brackets there is not right, since it causes compilers to look for an
758     installed pcre.h, not the version that is in the source that is being
759     compiled (which of course may be different). I have changed it back to:
760 ph10 197
761 ph10 189 #include "pcre.h"
762 ph10 197
763     I have a vague recollection that the change was concerned with compiling in
764     different directories, but in the new build system, that is taken care of
765     by the VPATH setting the Makefile.
767 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
768     when the subject happened to end in the byte 0x85 (e.g. if the last
769     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
770     characters but of course it shouldn't be taken as a newline when it is part
771     of another character. The bug was that, for an unlimited repeat of . in
772     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
773     characters when looking for a newline.
774 ph10 197
775     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
777     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
778     in debug output.
780 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
781     long printing in the pcrecpp unittest when running under MinGW.
782 ph10 189
783 ph10 197 6. ESC_K was left out of the EBCDIC table.
784 ph10 189
785 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
786     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
787     limit also applies to "virtual nesting" when a pattern is recursive, and in
788     this case 1000 isn't so big. I have been able to remove this limit at the
789     expense of backing off one optimization in certain circumstances. Normally,
790     when pcre_exec() would call its internal match() function recursively and
791     immediately return the result unconditionally, it uses a "tail recursion"
792     feature to save stack. However, when a subpattern that can match an empty
793     string has an unlimited repetition quantifier, it no longer makes this
794     optimization. That gives it a stack frame in which to save the data for
795     checking that an empty string has been matched. Previously this was taken
796     from the 1000-entry workspace that had been reserved. So now there is no
797     explicit limit, but more stack is used.
798 ph10 189
799 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
800     syntax that is required for Windows, and which was going wrong for the
801     pcreposix and pcrecpp parts of the library. These were overlooked when this
802     problem was solved for the main library.
803 ph10 197
804 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
805     the size of patterns that contain repeated groups with explicit upper
806     limits. As the maximum quantifier is 65535, the maximum group length was
807     set at 30,000 so that the product of these two numbers did not overflow a
808     32-bit integer. However, it turns out that people want to use groups that
809     are longer than 30,000 bytes (though not repeat them that many times).
810     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
811     made it possible to implement the integer overflow checks in a much more
812     dynamic way, which I have now done. The artificial limitation on group
813     length has been removed - we now have only the limit on the total length of
814     the compiled pattern, which depends on the LINK_SIZE setting.
815 ph10 208
816     10. Fixed a bug in the documentation for get/copy named substring when
817     duplicate names are permitted. If none of the named substrings are set, the
818     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
819     empty string.
821     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
822     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
823     because the ] is interpreted as the first data character and the
824     terminating ] is not found. PCRE has been made compatible with Perl in this
825     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
826     cause memory overwriting.
828 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
829     string has been matched (to stop an infinite loop). It was not recognizing
830 ph10 208 a conditional subpattern that could match an empty string if that
831 ph10 206 subpattern was within another subpattern. For example, it looped when
832 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
833 ph10 206 condition was not nested. This bug has been fixed.
834 ph10 208
835 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
836     past the start of the subject in the presence of bytes with the top bit
837     set, for example "\x8aBCD".
838 ph10 211
839 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
840     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
841 ph10 200
842 ph10 211 14. Optimized (?!) to (*FAIL).
843 ph10 202
844 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
845     This restricts code points to be within the range 0 to 0x10FFFF, excluding
846     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
847     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
848     does: it's just the validity check that is more restrictive.
849 ph10 220
850     16. Inserted checks for integer overflows during escape sequence (backslash)
851     processing, and also fixed erroneous offset values for syntax errors during
852     backslash processing.
854 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
855 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
857 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
858     caused an overrun.
859 ph10 220
860     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
861     something other than just ASCII characters) inside a group that had an
862     unlimited repeat caused a loop at compile time (while checking to see
863     whether the group could match an empty string).
865 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
866     [\P{Any}] did so. (Error in the code for printing property names.)
867 ph10 210
868 ph10 220 21. An orphan \E inside a character class could cause a crash.
870     22. A repeated capturing bracket such as (A)? could cause a wild memory
871 ph10 218 reference during compilation.
872 ph10 220
873     23. There are several functions in pcre_compile() that scan along a compiled
874     expression for various reasons (e.g. to see if it's fixed length for look
875 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
876 ph10 220 present in the pattern. These operators have additional parameters compared
877     with \d, etc, and these were not being taken into account when moving along
878 ph10 218 the compiled data. Specifically:
879 ph10 220
880     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
881     length.
883     (b) An item such as \pL+ within a repeated group could cause crashes or
884 ph10 218 loops.
885 ph10 220
886 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
887 ph10 220 "reference to non-existent subpattern" error.
889 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
891 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
892 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
893 ph10 211
894 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
895 ph10 218
896 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
897 ph10 223 character were causing crashes (broken optimization).
898 ph10 227
899 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
900 ph10 227 \p or \P) caused a compile-time loop.
902 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
903     break. For example, the unstudied pattern [\r\n]A does not match the string
904     "\r\nA" because change 7.0/46 below moves the current point on by two
905     characters after failing to match at the start. However, the pattern \nA
906 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
907     the same is true. There doesn't seem any very clean way out of this, but
908     what I have chosen to do makes the common cases work: PCRE now takes note
909     of whether there can be an explicit match for \r or \n anywhere in the
910     pattern, and if so, 7.0/46 no longer applies. As part of this change,
911     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
912     pattern has explicit CR or LF references.
913 ph10 222
914 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
915 ph10 223
916 ph10 227
917 ph10 189 Version 7.2 19-Jun-07
918     ---------------------
920 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
921     which is apparently normally available under Windows.
922 ph10 159
923     2. Re-jig the pcregrep tests with different newline settings in an attempt
924     to make them independent of the local environment's newline setting.
925 ph10 157
926 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
927 ph10 165
928 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
929     was not 2, because the output contained actual offsets. The recent new
930 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
931     usable with all link sizes.
933 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
934     stack recursion. This gives a massive performance boost under BSD, but just
935 ph10 165 a small improvement under Linux. However, it saves one field in the frame
936 ph10 164 in all cases.
937 ph10 172
938 ph10 166 6. Added more features from the forthcoming Perl 5.10:
939 ph10 172
940 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
941     recursion call. It refers to the nth most recently opened parentheses.
942 ph10 172
943 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
944 ph10 172 to be opened parentheses.
946     (c) Conditions that refer to capturing parentheses can be specified
947 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
948 ph10 172
949 ph10 168 (d) \K resets the start of the current match so that everything before
950 ph10 172 is not part of it.
952 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
953 ph10 172
954 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
955 ph10 172 reference syntax.
956 ph10 182
957 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
958 ph10 182 alternative starts with the same number.
959 ph10 172
960 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
962 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
965     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
966     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
967 ph10 170 for detecting groups that can match an empty string.
968 ph10 159
969 ph10 172 9. A pattern with a very large number of alternatives (more than several
970     hundred) was running out of internal workspace during the pre-compile
971     phase, where pcre_compile() figures out how much memory will be needed. A
972     bit of new cunning has reduced the workspace needed for groups with
973     alternatives. The 1000-alternative test pattern now uses 12 bytes of
974     workspace instead of running out of the 4096 that are available.
975 ph10 182
976 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
977 ph10 172
978 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
979     The report of the bug said:
980 ph10 182
981 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
982     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
983 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
984 ph10 185
985 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
986 ph10 185 it matched the wrong number of bytes.
987 ph10 172
988 ph10 179
989 ph10 155 Version 7.1 24-Apr-07
990 ph10 98 ---------------------
992 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
993 ph10 122 that is more "standard", making use of automake and other Autotools. There
994 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
995     on this.
996 ph10 111
997     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
998     for recursive directory scanning broke on some systems because the files
999     are not scanned in any specific order and on different systems the order
1000     was different. A call to "sort" has been inserted into RunGrepTest for the
1001     approprate test as a short-term fix. In the longer term there may be an
1002 ph10 100 alternative.
1003 ph10 111
1004 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1005 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1006     people do their own conversions for various reasons). The problems
1007     concerned the use of low-level troff macros .br and .in. I have therefore
1008     removed all such uses from the man pages (some were redundant, some could
1009 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1010     HTML has been updated to handle .nf/.fi and to complain if it encounters
1011     .br or .in.
1012 ph10 111
1013 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1014 ph10 123 arranged for config.h to be included in the distribution, with the name
1015 ph10 111 config.h.generic, for the benefit of those who have to compile without
1016     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1018     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1019     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1020 ph10 127 makevp.bat for the current PCRE, using the additional files
1021 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1022 ph10 111
1023     6. A Windows user reported a minor discrepancy with test 2, which turned out
1024     to be caused by a trailing space on an input line that had got lost in his
1025 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1026 ph10 111
1027 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1028 ph10 111 that is needed.
1030 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1031     as "const" (a) because they are and (b) because it helps the PHP
1032     maintainers who have recently made a script to detect big data structures
1033 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1034     to update Builducptable as well, so it won't revert if ucptable.h is ever
1035 ph10 105 re-created.
1036 ph10 111
1037     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1038 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1039 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1040     support is not required. This saves 1.5-2K of code, which is important in
1041 ph10 107 some applications.
1042 ph10 111
1043 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1044 ph10 111 so as not to refer to the tables, even though these functions will never be
1045     called when UTF-8 support is disabled. Otherwise there are problems with a
1046     shared library.
1048 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1050     (a) It was defining its arguments as char * instead of void *.
1052 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1053     a long time ago when I wrote it, but is no longer the case.
1055 ph10 118 The emulated memove() is provided for those environments that have neither
1056 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1057 ph10 118 is clearly not the case, as these two bugs were recently reported.
1058 ph10 123
1059 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1060 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1061     pages, and it removes trailing spaces from listed files. It also creates
1062     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1063     case, it wraps all the #defines with #ifndefs. This script should be run
1064 ph10 111 before "make dist".
1065 ph10 123
1066 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1067     with Unicode property support.
1068 ph10 123
1069     (a) For a maximizing quantifier, if the two different cases of the
1070     character were of different lengths in their UTF-8 codings (there are
1071     some cases like this - I found 11), and the matching function had to
1072 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1073     were both the same length.
1074 ph10 123
1075     (b) When PCRE was configured to use the heap rather than the stack for
1076     recursion during matching, it was not correctly preserving the data for
1077     the other case of a UTF-8 character when checking ahead for a match
1078     while processing a minimizing repeat. If the check also involved
1079 ph10 115 matching a wide character, but failed, corruption could cause an
1080     erroneous result when trying to check for a repeat of the original
1081     character.
1082 ph10 123
1083 ph10 116 13. Some tidying changes to the testing mechanism:
1084 ph10 98
1085 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1086     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1087 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1088     this for UTF-8.) The configure.ac script no longer substitutes the
1089     relevant variables.
1091 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1092     with length and offset values. This means that the output is different
1093     for different internal link sizes. Test 2 is skipped for link sizes
1094     other than 2 because of this, bypassing the problem. Unfortunately,
1095     there was also a test in test 3 (the locale tests) that used /B and
1096 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1097     I have added a new /Z option to pcretest that replaces the length and
1098     offset values with spaces. This is now used to make test 3 independent
1099 ph10 122 of link size. (Test 2 will be tidied up later.)
1100 ph10 123
1101     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1102 ph10 122 segmentation fault instead of returning the appropriate error message.
1103 ph10 134
1104 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1105 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1106     This doesn't seem right; it now treats the CRLF combination as the line
1107     ending, and so does not match in that case. It's only a pattern such as ^$
1108     that would hit this one: something like ^ABC$ would have failed after \r
1109     and then tried again after \r\n.
1111 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1112 ph10 134 in an attempt to make files that differ only in their line terminators
1113     compare equal. This works on Linux.
1114 ph10 142
1115 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1116     as it exited. This is now fixed, thanks to valgrind.
1117 ph10 142
1118 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1119 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1120     was because its rules for how to advance for /g after matching an empty
1121 ph10 143 string at the end of a line did not allow for this case. They now check for
1122     it specially.
1123 ph10 150
1124     20. pcretest is supposed to handle patterns and data of any length, by
1125     extending its buffers when necessary. It was getting this wrong when the
1126 ph10 147 buffer for a data line had to be extended.
1127 ph10 150
1128 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1129 ph10 150 CRLF as a newline sequence.
1130 ph10 152
1131 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1132 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1133     I have nevertheless tidied it up.
1134 ph10 111
1135 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1136 ph10 123
1137 ph10 153 24. Added a man page for pcre-config.
1138 ph10 152
1139 ph10 153
1140 nigel 93 Version 7.0 19-Dec-06
1141     ---------------------
1143     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1144     moving to gcc 4.1.1.
1146     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1147     sys/time.h, which is documented as needed for this function. It doesn't
1148     seem to matter on Linux, but it showed up on some releases of OS X.
1150     3. It seems that there are systems where bytes whose values are greater than
1151     127 match isprint() in the "C" locale. The "C" locale should be the
1152     default when a C program starts up. In most systems, only ASCII printing
1153     characters match isprint(). This difference caused the output from pcretest
1154     to vary, making some of the tests fail. I have changed pcretest so that:
1156     (a) When it is outputting text in the compiled version of a pattern, bytes
1157     other than 32-126 are always shown as hex escapes.
1159     (b) When it is outputting text that is a matched part of a subject string,
1160     it does the same, unless a different locale has been set for the match
1161     (using the /L modifier). In this case, it uses isprint() to decide.
1163     4. Fixed a major bug that caused incorrect computation of the amount of memory
1164     required for a compiled pattern when options that changed within the
1165     pattern affected the logic of the preliminary scan that determines the
1166     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1167     that the computed length was too small. The symptoms of this bug were
1168     either the PCRE error "internal error: code overflow" from pcre_compile(),
1169     or a glibc crash with a message such as "pcretest: free(): invalid next
1170     size (fast)". Examples of patterns that provoked this bug (shown in
1171     pcretest format) are:
1173     /(?-x: )/x
1174     /(?x)(?-x: \s*#\s*)/
1175     /((?i)[\x{c0}])/8
1176     /(?i:[\x{c0}])/8
1178     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1179     is now done differently.
1181     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1182     wrapper classes; (b) implement a new function in the C++ scanner that is
1183     more efficient than the old way of doing things because it avoids levels of
1184     recursion in the regex matching; (c) add a paragraph to the documentation
1185     for the FullMatch() function.
1187     6. The escape sequence \n was being treated as whatever was defined as
1188     "newline". Not only was this contrary to the documentation, which states
1189     that \n is character 10 (hex 0A), but it also went horribly wrong when
1190     "newline" was defined as CRLF. This has been fixed.
1192     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1193     was being set to -1 for the "end of line" case (supposedly a value that no
1194     character can have). Though this value is never used (the check for end of
1195     line is "zero bytes in current character"), it caused compiler complaints.
1196     I've changed it to 0xffffffff.
1198     8. In pcre_version.c, the version string was being built by a sequence of
1199     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1200     string (as it is for production releases) called a macro with an empty
1201     argument. The C standard says the result of this is undefined. The gcc
1202     compiler treats it as an empty string (which was what was wanted) but it is
1203     reported that Visual C gives an error. The source has been hacked around to
1204     avoid this problem.
1206     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1207     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1208     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1209     of them did).
1211     10. Originally, pcretest opened its input and output without "b"; then I was
1212     told that "b" was needed in some environments, so it was added for release
1213     5.0 to both the input and output. (It makes no difference on Unix-like
1214     systems.) Later I was told that it is wrong for the input on Windows. I've
1215     now abstracted the modes into two macros, to make it easier to fiddle with
1216     them, and removed "b" from the input mode under Windows.
1218     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1220     12. Added -help and --help to pcretest as an official way of being reminded
1221     of the options.
1223     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1224     and pcrecpp.cc because they annoy compilers at high warning levels.
1226     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1228     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1229     scripts are not C programs :-) and which was not noticed because it works
1230     on Linux.
1232     16. pcretest is supposed to handle any length of pattern and data line (as one
1233     line or as a continued sequence of lines) by extending its input buffer if
1234     necessary. This feature was broken for very long pattern lines, leading to
1235     a string of junk being passed to pcre_compile() if the pattern was longer
1236     than about 50K.
1238     17. I have done a major re-factoring of the way pcre_compile() computes the
1239     amount of memory needed for a compiled pattern. Previously, there was code
1240     that made a preliminary scan of the pattern in order to do this. That was
1241     OK when PCRE was new, but as the facilities have expanded, it has become
1242     harder and harder to keep it in step with the real compile phase, and there
1243     have been a number of bugs (see for example, 4 above). I have now found a
1244     cunning way of running the real compile function in a "fake" mode that
1245     enables it to compute how much memory it would need, while actually only
1246     ever using a few hundred bytes of working memory and without too many
1247     tests of the mode. This should make future maintenance and development
1248     easier. A side effect of this work is that the limit of 200 on the nesting
1249     depth of parentheses has been removed (though this was never a serious
1250     limitation, I suspect). However, there is a downside: pcre_compile() now
1251     runs more slowly than before (30% or more, depending on the pattern). I
1252     hope this isn't a big issue. There is no effect on runtime performance.
1254     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1255     newline (only possible for the last line of a file) and it was a
1256     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1258     19. Added additional timing features to pcretest. (1) The -tm option now times
1259     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1260     separate command line item, by a number that specifies the number of
1261     repeats to use when timing. The default is 50000; this gives better
1262     precision, but takes uncomfortably long for very large patterns.
1264     20. Extended pcre_study() to be more clever in cases where a branch of a
1265     subpattern has no definite first character. For example, (a*|b*)[cd] would
1266     previously give no result from pcre_study(). Now it recognizes that the
1267     first character must be a, b, c, or d.
1269     21. There was an incorrect error "recursive call could loop indefinitely" if
1270     a subpattern (or the entire pattern) that was being tested for matching an
1271     empty string contained only one non-empty item after a nested subpattern.
1272     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1273     incorrectly, because the \d was being skipped in the check.
1275     22. The pcretest program now has a new pattern option /B and a command line
1276     option -b, which is equivalent to adding /B to every pattern. This causes
1277     it to show the compiled bytecode, without the additional information that
1278     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1279     is the same as /B/I).
1281     23. A new optimization is now able automatically to treat some sequences such
1282     as a*b as a*+b. More specifically, if something simple (such as a character
1283     or a simple class like \d) has an unlimited quantifier, and is followed by
1284     something that cannot possibly match the quantified thing, the quantifier
1285     is automatically "possessified".
1287     24. A recursive reference to a subpattern whose number was greater than 39
1288     went wrong under certain circumstances in UTF-8 mode. This bug could also
1289     have affected the operation of pcre_study().
1291     25. Realized that a little bit of performance could be had by replacing
1292     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1294     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1296     27. Possessive quantifiers such as a++ were previously implemented by turning
1297     them into atomic groups such as ($>a+). Now they have their own opcodes,
1298     which improves performance. This includes the automatically created ones
1299     from 23 above.
1301     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1302     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1303     the first matched character to be a colon. This applied both to named and
1304     numbered groups.
1306     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1308     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1309     building PCRE on Windows easier, so I have included it in the distribution.
1311     31. There is now a check in pcretest against a ridiculously large number being
1312     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1313     loop, the loop is abandoned.
1315     32. Forward references to subpatterns in conditions such as (?(2)...) where
1316     subpattern 2 is defined later cause pcre_compile() to search forwards in
1317     the pattern for the relevant set of parentheses. This search went wrong
1318     when there were unescaped parentheses in a character class, parentheses
1319     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1321     33. "Subroutine" calls and backreferences were previously restricted to
1322     referencing subpatterns earlier in the regex. This restriction has now
1323     been removed.
1325     34. Added a number of extra features that are going to be in Perl 5.10. On the
1326     whole, these are just syntactic alternatives for features that PCRE had
1327     previously implemented using the Python syntax or my own invention. The
1328     other formats are all retained for compatibility.
1330     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1331     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1332     also .NET compatible.
1334     (b) A recursion or subroutine call to a named group can now be defined as
1335     (?&name) as well as (?P>name).
1337     (c) A backreference to a named group can now be defined as \k<name> or
1338     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1339     5.10, are also .NET compatible.
1341     (d) A conditional reference to a named group can now use the syntax
1342     (?(<name>) or (?('name') as well as (?(name).
1344     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1345     groups (named and numbered) that are never evaluated inline, but can be
1346     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1347     is always false. There may be only one alternative in such a group.
1349     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1350     as the simple (?(R). The condition is true only if the most recent
1351     recursion is that of the given number or name. It does not search out
1352     through the entire recursion stack.
1354     (g) The escape \gN or \g{N} has been added, where N is a positive or
1355     negative number, specifying an absolute or relative reference.
1357     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1358     some "unreachable code" warnings.
1360     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1361     things, this adds five new scripts.
1363     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1364     There were also incompatibilities regarding the handling of \Q..\E inside
1365     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1366     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1368     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1369     matches an empty string, and forcibly breaks the loop. There were bugs in
1370     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1371     against aaaa the result was just "a" rather than "aaaa", for example. Two
1372     separate and independent bugs (that affected different cases) have been
1373     fixed.
1375     39. Refactored the code to abolish the use of different opcodes for small
1376     capturing bracket numbers. This is a tidy that I avoided doing when I
1377     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1378     The new approach is not only tidier, it makes it possible to reduce the
1379     memory needed to fix the previous bug (38).
1381     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1382     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1383     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1384     mode.
1386     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1387     report.
1389     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1390     copy construction and assignment in the C++ wrapper.
1392     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1393     couple of bugs that could have given wrong results in the "--newline=crlf"
1394     case.
1396     44. Added a number of casts and did some reorganization of signed/unsigned int
1397     variables following suggestions from Dair Grant. Also renamed the variable
1398     "this" as "item" because it is a C++ keyword.
1400     45. Arranged for dftables to add
1402     #include "pcre_internal.h"
1404     to pcre_chartables.c because without it, gcc 4.x may remove the array
1405     definition from the final binary if PCRE is built into a static library and
1406     dead code stripping is activated.
1408     46. For an unanchored pattern, if a match attempt fails at the start of a
1409     newline sequence, and the newline setting is CRLF or ANY, and the next two
1410     characters are CRLF, advance by two characters instead of one.
1413 nigel 91 Version 6.7 04-Jul-06
1414     ---------------------
1416     1. In order to handle tests when input lines are enormously long, pcretest has
1417     been re-factored so that it automatically extends its buffers when
1418     necessary. The code is crude, but this _is_ just a test program. The
1419     default size has been increased from 32K to 50K.
1421     2. The code in pcre_study() was using the value of the re argument before
1422     testing it for NULL. (Of course, in any sensible call of the function, it
1423     won't be NULL.)
1425     3. The memmove() emulation function in pcre_internal.h, which is used on
1426     systems that lack both memmove() and bcopy() - that is, hardly ever -
1427     was missing a "static" storage class specifier.
1429     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1430     containing an extended class (one that cannot be represented by a bitmap
1431     because it contains high-valued characters or Unicode property items, e.g.
1432     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1433     pattern, but PCRE should not loop if you do not (it no longer does).
1434     [Detail: two cases were found: (a) a repeated subpattern containing an
1435     extended class; (b) a recursive reference to a subpattern that followed a
1436     previous extended class. It wasn't skipping over the extended class
1437     correctly when UTF-8 mode was not set.]
1439     5. A negated single-character class was not being recognized as fixed-length
1440     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1441     compile error "lookbehind assertion is not fixed length".
1443     6. The RunPerlTest auxiliary script was showing an unexpected difference
1444     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1445     write a Perl script that can interpret lines of an input file either as
1446     byte characters or as UTF-8, which is what "perltest" was being required to
1447     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1448     can't do is switch easily at run time between having the "use utf8;" pragma
1449     or not. In the end, I fudged it by using the RunPerlTest script to insert
1450     "use utf8;" explicitly for the UTF-8 tests.
1452     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1453     the end of the subject string, contrary to the documentation and to what
1454     Perl does. This was true of both matching functions. Now it matches only at
1455     the start of the subject and immediately after *internal* newlines.
1457     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1458     a pointer to an int instead of a pointer to an unsigned long int. This
1459     caused problems on 64-bit systems.
1461     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1462     instance of the 'standard' template library not being so standard".
1464     10. There was no check on the number of named subpatterns nor the maximum
1465     length of a subpattern name. The product of these values is used to compute
1466     the size of the memory block for a compiled pattern. By supplying a very
1467     long subpattern name and a large number of named subpatterns, the size
1468     computation could be caused to overflow. This is now prevented by limiting
1469     the length of names to 32 characters, and the number of named subpatterns
1470     to 10,000.
1472     11. Subpatterns that are repeated with specific counts have to be replicated in
1473     the compiled pattern. The size of memory for this was computed from the
1474     length of the subpattern and the repeat count. The latter is limited to
1475     65535, but there was no limit on the former, meaning that integer overflow
1476     could in principle occur. The compiled length of a repeated subpattern is
1477     now limited to 30,000 bytes in order to prevent this.
1479     12. Added the optional facility to have named substrings with the same name.
1481     13. Added the ability to use a named substring as a condition, using the
1482     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1483     are numbers (not recommended). Forward references are permitted.
1485     14. Added forward references in named backreferences (if you see what I mean).
1487     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1488     pattern could run off the end of the subject. For example, the pattern
1489     "(?s)(.{1,5})"8 did this with the subject "ab".
1491     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1492     PCRE_CASELESS was set when matching characters that were quantified with ?
1493     or *.
1495     17. A character class other than a single negated character that had a minimum
1496     but no maximum quantifier - for example [ab]{6,} - was not handled
1497     correctly by pce_dfa_exec(). It would match only one character.
1499     18. A valid (though odd) pattern that looked like a POSIX character
1500     class but used an invalid character after [ (for example [[,abc,]]) caused
1501     pcre_compile() to give the error "Failed: internal error: code overflow" or
1502     in some cases to crash with a glibc free() error. This could even happen if
1503     the pattern terminated after [[ but there just happened to be a sequence of
1504     letters, a binary zero, and a closing ] in the memory that followed.
1506     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1507     over the years. Originally (before any Unicode support), just the bottom 8
1508     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1509     output from "man perlunicode" includes this:
1511     The regular expression compiler produces polymorphic opcodes. That
1512     is, the pattern adapts to the data and automatically switches to
1513     the Unicode character scheme when presented with Unicode data--or
1514     instead uses a traditional byte scheme when presented with byte
1515     data.
1517     Sadly, a wide octal escape does not cause a switch, and in a string with
1518     no other multibyte characters, these octal escapes are treated as before.
1519     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1520     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1521     Unicode string.
1523     I have not perpetrated such confusion in PCRE. Up till now, it took just
1524     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1525     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1526     translate to the appropriate multibyte character.
1528     29. Applied some refactoring to reduce the number of warnings from Microsoft
1529     and Borland compilers. This has included removing the fudge introduced
1530     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1531     a warning about an unused variable.
1533     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1534     characters since release 4.0, because Perl (from release 5.004) does not.
1535     [Or at least, is documented not to: some releases seem to be in conflict
1536     with the documentation.] However, when a pattern was studied with
1537     pcre_study() and all its branches started with \s, PCRE still included VT
1538     as a possible starting character. Of course, this did no harm; it just
1539     caused an unnecessary match attempt.
1541     22. Removed a now-redundant internal flag bit that recorded the fact that case
1542     dependency changed within the pattern. This was once needed for "required
1543     byte" processing, but is no longer used. This recovers a now-scarce options
1544     bit. Also moved the least significant internal flag bit to the most-
1545     significant bit of the word, which was not previously used (hangover from
1546     the days when it was an int rather than a uint) to free up another bit for
1547     the future.
1549     23. Added support for CRLF line endings as well as CR and LF. As well as the
1550     default being selectable at build time, it can now be changed at runtime
1551     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1552     specify that it is scanning data with non-default line endings.
1554     24. Changed the definition of CXXLINK to make it agree with the definition of
1555     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1557     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1558     recursions. This makes a big different to stack usage for some patterns.
1560     26. If a subpattern containing a named recursion or subroutine reference such
1561     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1562     the space required for the compiled pattern went wrong and gave too small a
1563     value. Depending on the environment, this could lead to "Failed: internal
1564     error: code overflow at offset 49" or "glibc detected double free or
1565     corruption" errors.
1567     27. Applied patches from Google (a) to support the new newline modes and (b) to
1568     advance over multibyte UTF-8 characters in GlobalReplace.
1570     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1571     difference for some implementation of PCRE in some Windows version.
1573     29. Added some extra testing facilities to pcretest:
1575     \q<number> in a data line sets the "match limit" value
1576     \Q<number> in a data line sets the "match recursion limt" value
1577     -S <number> sets the stack size, where <number> is in megabytes
1579     The -S option isn't available for Windows.
1582 nigel 89 Version 6.6 06-Feb-06
1583     ---------------------
1585     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1586     in pcreposix.h. I have copied the definition from pcre.h.
1588     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1589     because pcre.h is no longer a built file.
1591     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1592     not normally included in the compiled code.
1595 nigel 87 Version 6.5 01-Feb-06
1596     ---------------------
1598     1. When using the partial match feature with pcre_dfa_exec(), it was not
1599     anchoring the second and subsequent partial matches at the new starting
1600     point. This could lead to incorrect results. For example, with the pattern
1601     /1234/, partially matching against "123" and then "a4" gave a match.
1603     2. Changes to pcregrep:
1605     (a) All non-match returns from pcre_exec() were being treated as failures
1606     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1607     error message is output. Some extra information is given for the
1609     probably the only errors that are likely to be caused by users (by
1610     specifying a regex that has nested indefinite repeats, for instance).
1611     If there are more than 20 of these errors, pcregrep is abandoned.
1613     (b) A binary zero was treated as data while matching, but terminated the
1614     output line if it was written out. This has been fixed: binary zeroes
1615     are now no different to any other data bytes.
1617     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1618     used to set a locale for matching. The --locale=xxxx long option has
1619     been added (no short equivalent) to specify a locale explicitly on the
1620     pcregrep command, overriding the environment variables.
1622     (d) When -B was used with -n, some line numbers in the output were one less
1623     than they should have been.
1625     (e) Added the -o (--only-matching) option.
1627     (f) If -A or -C was used with -c (count only), some lines of context were
1628     accidentally printed for the final match.
1630     (g) Added the -H (--with-filename) option.
1632     (h) The combination of options -rh failed to suppress file names for files
1633     that were found from directory arguments.
1635     (i) Added the -D (--devices) and -d (--directories) options.
1637     (j) Added the -F (--fixed-strings) option.
1639     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1641     (l) Added the --colo(u)r option.
1643     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1644     is not present by default.
1646     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1647     items such as (?R) or (?1), when the recursion could match a number of
1648     alternatives. If it matched one of the alternatives, but subsequently,
1649     outside the recursion, there was a failure, the code tried to back up into
1650     the recursion. However, because of the way PCRE is implemented, this is not
1651     possible, and the result was an incorrect result from the match.
1653     In order to prevent this happening, the specification of recursion has
1654     been changed so that all such subpatterns are automatically treated as
1655     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1657     4. I had overlooked the fact that, in some locales, there are characters for
1658     which isalpha() is true but neither isupper() nor islower() are true. In
1659     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1660     and ordfeminine) are like this. This affected the treatment of \w and \W
1661     when they appeared in character classes, but not when they appeared outside
1662     a character class. The bit map for "word" characters is now created
1663     separately from the results of isalnum() instead of just taking it from the
1664     upper, lower, and digit maps. (Plus the underscore character, of course.)
1666     5. The above bug also affected the handling of POSIX character classes such as
1667     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1668     permanent tables. Instead, the bit maps for such a class were previously
1669     created as the appropriate unions of the upper, lower, and digit bitmaps.
1670     Now they are created by subtraction from the [[:word:]] class, which has
1671     its own bitmap.
1673     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1674     It is created by subtracting the vertical space characters (\x09, \x0a,
1675     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1676     subtraction was done in the overall bitmap for a character class, meaning
1677     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1678     be recognized. This bug has been fixed.
1680     7. Patches from the folks at Google:
1682     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1683     real life, but is still worth protecting against".
1685     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1686     regular expressions".
1688     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1689     have it.
1691     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1692     "configure" and the latter not, in order to fix a problem somebody had
1693     with compiling the Arg class on HP-UX.
1695     (e) Improve the error-handling of the C++ wrapper a little bit.
1697     (f) New tests for checking recursion limiting.
1699     8. The pcre_memmove() function, which is used only if the environment does not
1700     have a standard memmove() function (and is therefore rarely compiled),
1701     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1702     returning a result (though PCRE never actually uses the result).
1704     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1705     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1706     returned instead of calling malloc() with an overflowing number that would
1707     most likely cause subsequent chaos.
1709     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1711     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1712     with this option is matched, the nmatch and pmatch options of regexec() are
1713     ignored.
1715     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1716     provided in case anyone wants to the the POSIX interface with UTF-8
1717     strings.
1719     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1720     C++ linking (needed for some HP-UX environments).
1722     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1723     (unused parameter) and in the pcre_printint() function (omitted "default"
1724     switch label when the default is to do nothing).
1726     15. Added some code to make it possible, when PCRE is compiled as a C++
1727     library, to replace subject pointers for pcre_exec() with a smart pointer
1728     class, thus making it possible to process discontinuous strings.
1730     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1731     much the same function. They were added by different people who were trying
1732     to make PCRE easy to compile on non-Unix systems. It has been suggested
1733     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1734     for compiling on Windows systems. I have therefore replaced it with
1735     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1736     defaults to "extern" for C or "extern C" for C++, which works fine on
1737     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1738     SCOPE with something explicit in config.h. In addition:
1740     (a) pcreposix.h still had just "extern" instead of either of these macros;
1741     I have replaced it with PCRE_DATA_SCOPE.
1743     (b) Functions such as _pcre_xclass(), which are internal to the library,
1744     but external in the C sense, all had PCRE_EXPORT in their definitions.
1745     This is apparently wrong for the Windows case, so I have removed it.
1746     (It makes no difference on Unix-like systems.)
1748     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1749     of recursive calls to match(). This is different to MATCH_LIMIT because
1750     that limits the total number of calls to match(), not all of which increase
1751     the depth of recursion. Limiting the recursion depth limits the amount of
1752     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1753     when PCRE is compiled, and changed at run time. A patch from Google adds
1754     this functionality to the C++ interface.
1756     18. Changes to the handling of Unicode character properties:
1758     (a) Updated the table to Unicode 4.1.0.
1760     (b) Recognize characters that are not in the table as "Cn" (undefined).
1762     (c) I revised the way the table is implemented to a much improved format
1763     which includes recognition of ranges. It now supports the ranges that
1764     are defined in UnicodeData.txt, and it also amalgamates other
1765     characters into ranges. This has reduced the number of entries in the
1766     table from around 16,000 to around 3,000, thus reducing its size
1767     considerably. I realized I did not need to use a tree structure after
1768     all - a binary chop search is just as efficient. Having reduced the
1769     number of entries, I extended their size from 6 bytes to 8 bytes to
1770     allow for more data.
1772     (d) Added support for Unicode script names via properties such as \p{Han}.
1774     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1775     matching that character.
1777     20. When matching a repeated Unicode property with a minimum greater than zero,
1778     (for example \pL{2,}), PCRE could look past the end of the subject if it
1779     reached it while seeking the minimum number of characters. This could
1780     happen only if some of the characters were more than one byte long, because
1781     there is a check for at least the minimum number of bytes.
1783     21. Refactored the implementation of \p and \P so as to be more general, to
1784     allow for more different types of property in future. This has changed the
1785     compiled form incompatibly. Anybody with saved compiled patterns that use
1786     \p or \P will have to recompile them.
1788     22. Added "Any" and "L&" to the supported property types.
1790     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1791     but give a compile time error if the value is greater than 0xff.
1793     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1794     accidentally not being installed or uninstalled.
1796     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1797     made were to insert the current release number. This seemed silly, because
1798     it made things harder for people building PCRE on systems that don't run
1799     "configure". I have turned pcre.h into a distributed file, no longer built
1800     by "configure", with the version identification directly included. There is
1801     no longer a pcre.h.in file.
1803     However, this change necessitated a change to the pcre-config script as
1804     well. It is built from pcre-config.in, and one of the substitutions was the
1805     release number. I have updated configure.ac so that ./configure now finds
1806     the release number by grepping pcre.h.
1808     26. Added the ability to run the tests under valgrind.
1811 nigel 85 Version 6.4 05-Sep-05
1812     ---------------------
1814     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1815     "--" to be printed when multiple files were scanned, even when none of the
1816     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1817     consider it to be a bug, and have restored the previous behaviour.
1819     2. A couple of code tidies to get rid of compiler warnings.
1821     3. The pcretest program used to cheat by referring to symbols in the library
1822     whose names begin with _pcre_. These are internal symbols that are not
1823     really supposed to be visible externally, and in some environments it is
1824     possible to suppress them. The cheating is now confined to including
1825     certain files from the library's source, which is a bit cleaner.
1827     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1828     file's purpose clearer.
1830     5. Reorganized pcre_ucp_findchar().
1833 nigel 83 Version 6.3 15-Aug-05
1834     ---------------------
1836     1. The file libpcre.pc.in did not have general read permission in the tarball.
1838     2. There were some problems when building without C++ support:
1840     (a) If C++ support was not built, "make install" and "make test" still
1841     tried to test it.
1843     (b) There were problems when the value of CXX was explicitly set. Some
1844     changes have been made to try to fix these, and ...
1846     (c) --disable-cpp can now be used to explicitly disable C++ support.
1848     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1849     backslash in a target when C++ was disabled. This confuses some
1850     versions of "make", apparently. Using an intermediate variable solves
1851     this. (Same for CPP_LOBJ.)
1853     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1854     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1855     necessary on certain architectures.
1857     4. Added a setting of -export-symbols-regex to the link command to remove
1858     those symbols that are exported in the C sense, but actually are local
1859     within the library, and not documented. Their names all begin with
1860     "_pcre_". This is not a perfect job, because (a) we have to except some
1861     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1862     available (and never for static libraries). I have made a note to try to
1863     find a way round (a) in the future.
1866 nigel 81 Version 6.2 01-Aug-05
1867     ---------------------
1869     1. There was no test for integer overflow of quantifier values. A construction
1870     such as {1111111111111111} would give undefined results. What is worse, if
1871     a minimum quantifier for a parenthesized subpattern overflowed and became
1872     negative, the calculation of the memory size went wrong. This could have
1873     led to memory overwriting.
1875     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1877     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1878     operating environments where this matters.
1880     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1881     PCRE options from within the C++ wrapper.
1883     5. Named capturing subpatterns were not being correctly counted when a pattern
1884     was compiled. This caused two problems: (a) If there were more than 100
1885     such subpatterns, the calculation of the memory needed for the whole
1886     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1887     back references of the form \12, where the number was greater than 9, were
1888     not recognized as back references, even though there were sufficient
1889     previous subpatterns.
1891     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1892     versions of gcc, e.g. 2.95.4.
1895 nigel 79 Version 6.1 21-Jun-05
1896     ---------------------
1898     1. There was one reference to the variable "posix" in pcretest.c that was not
1899     surrounded by "#if !defined NOPOSIX".
1901     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1902     the cross-check on the old pcre_info() function, for the benefit of the
1903     cut-down version of PCRE that is currently imported into Exim.
1905     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1906     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1907     patterns that start (?i) but I don't think that matters. The use of (?i) is
1908     just an example; this all applies to the other options as well.
1910     4. Since libtool seems to echo the compile commands it is issuing, the output
1911     from "make" can be reduced a bit by putting "@" in front of each libtool
1912     compile command.
1914     5. Patch from the folks at Google for configure.in to be a bit more thorough
1915     in checking for a suitable C++ installation before trying to compile the
1916     C++ stuff. This should fix a reported problem when a compiler was present,
1917     but no suitable headers.
1919     6. The man pages all had just "PCRE" as their title. I have changed them to
1920     be the relevant file name. I have also arranged that these names are
1921     retained in the file doc/pcre.txt, which is a concatenation in text format
1922     of all the man pages except the little individual ones for each function.
1924     7. The NON-UNIX-USE file had not been updated for the different set of source
1925     files that come with release 6. I also added a few comments about the C++
1926     wrapper.
1929 nigel 77 Version 6.0 07-Jun-05
1930     ---------------------
1932     1. Some minor internal re-organization to help with my DFA experiments.
1934     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1935     didn't matter for the library itself when fully configured, but did matter
1936     when compiling without UCP support, or within Exim, where the ucp files are
1937     not imported.
1939     3. Refactoring of the library code to split up the various functions into
1940     different source modules. The addition of the new DFA matching code (see
1941     below) to a single monolithic source would have made it really too
1942     unwieldy, quite apart from causing all the code to be include in a
1943     statically linked application, when only some functions are used. This is
1944     relevant even without the DFA addition now that patterns can be compiled in
1945     one application and matched in another.
1947     The downside of splitting up is that there have to be some external
1948     functions and data tables that are used internally in different modules of
1949     the library but which are not part of the API. These have all had their
1950     names changed to start with "_pcre_" so that they are unlikely to clash
1951     with other external names.
1953     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1954     a different (DFA) algorithm. Although it is slower than the original
1955     function, it does have some advantages for certain types of matching
1956     problem.
1958     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1959     including restarting after a partial match.
1961     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1962     defined when compiling for Windows was sent to me. I have put it into the
1963     code, though I have no means of testing or verifying it.
1965     7. Added the pcre_refcount() auxiliary function.
1967     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1968     match before or at the first newline in the subject string. In pcretest,
1969     the /f option on a pattern can be used to set this.
1971     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1972     would behave wrongly. This has been present in PCRE since release 4.0.
1974     10. A number of changes to the pcregrep command:
1976     (a) Refactored how -x works; insert ^(...)$ instead of setting
1977     PCRE_ANCHORED and checking the length, in preparation for adding
1978     something similar for -w.
1980     (b) Added the -w (match as a word) option.
1982     (c) Refactored the way lines are read and buffered so as to have more
1983     than one at a time available.
1985     (d) Implemented a pcregrep test script.
1987     (e) Added the -M (multiline match) option. This allows patterns to match
1988     over several lines of the subject. The buffering ensures that at least
1989     8K, or the rest of the document (whichever is the shorter) is available
1990     for matching (and similarly the previous 8K for lookbehind assertions).
1992     (f) Changed the --help output so that it now says
1994     -w, --word-regex(p)
1996     instead of two lines, one with "regex" and the other with "regexp"
1997     because that confused at least one person since the short forms are the
1998     same. (This required a bit of code, as the output is generated
1999     automatically from a table. It wasn't just a text change.)
2001     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2002     option but starts with a hyphen. Could be a pattern or a path name
2003     starting with a hyphen, for instance.
2005     (h) "-" can be given as a file name to represent stdin.
2007     (i) When file names are being printed, "(standard input)" is used for
2008     the standard input, for compatibility with GNU grep. Previously
2009     "<stdin>" was used.
2011     (j) The option --label=xxx can be used to supply a name to be used for
2012     stdin when file names are being printed. There is no short form.
2014     (k) Re-factored the options decoding logic because we are going to add
2015     two more options that take data. Such options can now be given in four
2016     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2018     (l) Added the -A, -B, and -C options for requesting that lines of context
2019     around matches be printed.
2021     (m) Added the -L option to print the names of files that do not contain
2022     any matching lines, that is, the complement of -l.
2024     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2025     continue to scan other files.
2027     (o) The -s option was incorrectly implemented. For compatibility with other
2028     greps, it now suppresses the error message for a non-existent or non-
2029     accessible file (but not the return code). There is a new option called
2030     -q that suppresses the output of matching lines, which was what -s was
2031     previously doing.
2033     (p) Added --include and --exclude options to specify files for inclusion
2034     and exclusion when recursing.
2036     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2037     Hopefully, it now does.
2039     12. Missing cast in pcre_study().
2041     13. Added an "uninstall" target to the makefile.
2043     14. Replaced "extern" in the function prototypes in Makefile.in with
2044     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2045     world, but is set differently for Windows.
2047     15. Added a second compiling function called pcre_compile2(). The only
2048     difference is that it has an extra argument, which is a pointer to an
2049     integer error code. When there is a compile-time failure, this is set
2050     non-zero, in addition to the error test pointer being set to point to an
2051     error message. The new argument may be NULL if no error number is required
2052     (but then you may as well call pcre_compile(), which is now just a
2053     wrapper). This facility is provided because some applications need a
2054     numeric error indication, but it has also enabled me to tidy up the way
2055     compile-time errors are handled in the POSIX wrapper.
2057     16. Added VPATH=.libs to the makefile; this should help when building with one
2058     prefix path and installing with another. (Or so I'm told by someone who
2059     knows more about this stuff than I do.)
2061     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2062     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2063     match everything, including newlines. This is not POSIX-compatible, but
2064     somebody wanted the feature. From pcretest it can be activated by using
2065     both the P and the s flags.
2067     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2069     19. libpcre.pc was being incorrectly installed as executable.
2071     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2072     it now also looks for '\r' so that it will work unmodified on Windows.
2074     21. Added Google's contributed C++ wrapper to the distribution.
2076     22. Added some untidy missing memory free() calls in pcretest, to keep
2077     Electric Fence happy when testing.
2081 nigel 75 Version 5.0 13-Sep-04
2082     ---------------------
2084     1. Internal change: literal characters are no longer packed up into items
2085     containing multiple characters in a single byte-string. Each character
2086     is now matched using a separate opcode. However, there may be more than one
2087     byte in the character in UTF-8 mode.
2089     2. The pcre_callout_block structure has two new fields: pattern_position and
2090     next_item_length. These contain the offset in the pattern to the next match
2091     item, and its length, respectively.
2093     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2094     insertion of callouts before each pattern item. Added the /C option to
2095     pcretest to make use of this.
2097     4. On the advice of a Windows user, the lines
2099     #if defined(_WIN32) || defined(WIN32)
2100     _setmode( _fileno( stdout ), 0x8000 );
2101     #endif /* defined(_WIN32) || defined(WIN32) */
2103     have been added to the source of pcretest. This apparently does useful
2104     magic in relation to line terminators.
2106     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2107     for the benefit of those environments where the "b" makes a difference.
2109     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2110     to know about it. I have put a hack into configure.in that adds in code
2111     to set GCC=yes if CC=icc. This seems to end up at a point in the
2112     generated configure script that is early enough to affect the setting of
2113     compiler options, which is what is needed, but I have no means of testing
2114     whether it really works. (The user who reported this had patched the
2115     generated configure script, which of course I cannot do.)
2117     LATER: After change 22 below (new libtool files), the configure script
2118     seems to know about icc (and also ecc). Therefore, I have commented out
2119     this hack in configure.in.
2121     7. Added support for pkg-config (2 patches were sent in).
2123     8. Negated POSIX character classes that used a combination of internal tables
2124     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2125     [[:^ascii]]. Typically, they would match almost any characters. The other
2126     POSIX classes were not broken in this way.
2128     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2129     to find the match, as PCRE was deluded into thinking that the match had to
2130     start at the start point or following a newline. The same bug applied to
2131     patterns with negative forward assertions or any backward assertions
2132     preceding ".*" at the start, unless the pattern required a fixed first
2133     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2135     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2136     starting at the last subject character, bytes beyond the end of the subject
2137     string were read.
2139     11. Renamed the variable "class" as "classbits" to make life easier for C++
2140     users. (Previously there was a macro definition, but it apparently wasn't
2141     enough.)
2143     12. Added the new field "tables" to the extra data so that tables can be passed
2144     in at exec time, or the internal tables can be re-selected. This allows
2145     a compiled regex to be saved and re-used at a later time by a different
2146     program that might have everything at different addresses.
2148     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2149     -R library as well as a -L library.
2151     14. The debugging options of pcretest (-d on the command line or D on a
2152     pattern) showed incorrect output for anything following an extended class
2153     that contained multibyte characters and which was followed by a quantifier.
2155     15. Added optional support for general category Unicode character properties
2156     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2157     support. It adds about 90K to the size of the library. The meanings of the
2158     inbuilt class escapes such as \d and \s have NOT been changed.
2160     16. Updated pcredemo.c to include calls to free() to release the memory for the
2161     compiled pattern.
2163     17. The generated file chartables.c was being created in the source directory
2164     instead of in the building directory. This caused the build to fail if the
2165     source directory was different from the building directory, and was
2166     read-only.
2168     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2169     file. No doubt somebody will tell me if they don't make sense... Also added
2170     Dan Mooney's comments about building on OpenVMS.
2172     19. Added support for partial matching via the PCRE_PARTIAL option for
2173     pcre_exec() and the \P data escape in pcretest.
2175     20. Extended pcretest with 3 new pattern features:
2177     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2178     write the compiled pattern to the file whose name is "rest-of-line".
2179     This is a straight binary dump of the data, with the saved pointer to
2180     the character tables forced to be NULL. The study data, if any, is
2181     written too. After writing, pcretest reads a new pattern.
2183     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2184     compiled pattern from the given file. There must not be any
2185     occurrences of "<" in the file name (pretty unlikely); if there are,
2186     pcretest will instead treat the initial "<" as a pattern delimiter.
2187     After reading in the pattern, pcretest goes on to read data lines as
2188     usual.
2190     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2191     and 16-bit fields in a compiled pattern, to simulate a pattern that
2192     was compiled on a host of opposite endianness.
2194     21. The pcre-exec() function can now cope with patterns that were compiled on
2195     hosts of opposite endianness, with this restriction:
2197     As for any compiled expression that is saved and used later, the tables
2198     pointer field cannot be preserved; the extra_data field in the arguments
2199     to pcre_exec() should be used to pass in a tables address if a value
2200     other than the default internal tables were used at compile time.
2202     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2203     now diagnosed as an error. Previously, most of the time, a negative number
2204     would have been treated as zero, but if in addition "ovector" was passed as
2205     NULL, a crash could occur.
2207     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2208     new versions from the libtool 1.5 distribution (the last one is a copy of
2209     a file called libtool.m4). This seems to have fixed the need to patch
2210     "configure" to support Darwin 1.3 (which I used to do). However, I still
2211     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2212     workstation).
2214     24. Changed the PCRE licence to be the more standard "BSD" licence.
2217 nigel 73 Version 4.5 01-Dec-03
2218     ---------------------
2220     1. There has been some re-arrangement of the code for the match() function so
2221     that it can be compiled in a version that does not call itself recursively.
2222     Instead, it keeps those local variables that need separate instances for
2223     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2224     needs to "recurse". Keeping track of where control must go is done by means
2225     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2226     hide most of the details from the main code, and operates only if
2227     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2228     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2229     operating.
2231     To make it easier for callers to provide specially tailored get/free
2232     functions for this usage, two new functions, pcre_stack_malloc, and
2233     pcre_stack_free, are used. They are always called in strict stacking order,
2234     and the size of block requested is always the same.
2236     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2237     PCRE has been compiled to use the stack or the heap for recursion. The
2238     -C option of pcretest uses this to show which version is compiled.
2240     A new data escape \S, is added to pcretest; it causes the amounts of store
2241     obtained and freed by both kinds of malloc/free at match time to be added
2242     to the output.
2244     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2245     what's available on my current Linux desktop machine.
2247     3. When matching a UTF-8 string, the test for a valid string at the start has
2248     been extended. If start_offset is not zero, PCRE now checks that it points
2249     to a byte that is the start of a UTF-8 character. If not, it returns
2250     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2251     this is necessary because there may be backward assertions in the pattern.
2252     When matching the same subject several times, it may save resources to use
2253     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2255     4. The code for checking the validity of UTF-8 strings has been tightened so
2256     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2257     containing "overlong sequences".
2259     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2260     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2261     should have been "&", but it just so happened that all the cases this let
2262     through by mistake were picked up later in the function.
2264     6. I had used a variable called "isblank" - this is a C99 function, causing
2265     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2267     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2268     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2269     so the version is shown; (c) stop "make test" echoing "./RunTest".
2271     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2273     9. The prototype for memmove() for systems that don't have it was using
2274     size_t, but the inclusion of the header that defines size_t was later. I've
2275     moved the #includes for the C headers earlier to avoid this.
2277     10. Added some adjustments to the code to make it easier to compiler on certain
2278     special systems:
2280     (a) Some "const" qualifiers were missing.
2281     (b) Added the macro EXPORT before all exported functions; by default this
2282     is defined to be empty.
2283     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2284     that it reads its output file name as an argument instead of writing
2285     to the standard output and assuming this can be redirected.
2287     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2288     class containing characters with values greater than 255, PCRE compilation
2289     went into a loop.
2291     12. A recursive reference to a subpattern that was within another subpattern
2292     that had a minimum quantifier of zero caused PCRE to crash. For example,
2293     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2294     recursion. If the recursively-called subpattern itself had a zero repeat,
2295     that was OK.
2297     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2298     buffer into which it was copied (for escape processing) was still set at
2299     1024, so long lines caused crashes.
2301     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2302     "internal error: code overflow...". This applied to any character class
2303     that was followed by a possessive quantifier.
2305     15. Modified the Makefile to add libpcre.la as a prerequisite for
2306     libpcreposix.la because I was told this is needed for a parallel build to
2307     work.
2309     16. If a pattern that contained .* following optional items at the start was
2310     studied, the wrong optimizing data was generated, leading to matching
2311     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2312     matching string must start with a or b or c. The correct conclusion for
2313     this pattern is that a match can start with any character.
2316 nigel 71 Version 4.4 13-Aug-03
2317     ---------------------
2319     1. In UTF-8 mode, a character class containing characters with values between
2320     127 and 255 was not handled correctly if the compiled pattern was studied.
2321     In fixing this, I have also improved the studying algorithm for such
2322     classes (slightly).
2324     2. Three internal functions had redundant arguments passed to them. Removal
2325     might give a very teeny performance improvement.
2327     3. Documentation bug: the value of the capture_top field in a callout is *one
2328     more than* the number of the hightest numbered captured substring.
2330     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2331     in incorrectly linking with a previously installed version. They now link
2332     explicitly with libpcre.la.
2334     5. configure.in no longer needs to recognize Cygwin specially.
2336     6. A problem in pcre.in for Windows platforms is fixed.
2338     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2339     pcretest, it used to include the size of the study block as part of its
2340     output. Unfortunately, the structure contains a field that has a different
2341     size on different hardware architectures. This meant that the tests that
2342     showed this size failed. As the block is currently always of a fixed size,
2343     this information isn't actually particularly useful in pcretest output, so
2344     I have just removed it.
2346     8. Three pre-processor statements accidentally did not start in column 1.
2347     Sadly, there are *still* compilers around that complain, even though
2348     standard C has not required this for well over a decade. Sigh.
2350     9. In pcretest, the code for checking callouts passed small integers in the
2351     callout_data field, which is a void * field. However, some picky compilers
2352     complained about the casts involved for this on 64-bit systems. Now
2353     pcretest passes the address of the small integer instead, which should get
2354     rid of the warnings.
2356     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2357     both compile and run time, and gives an error if an invalid UTF-8 sequence
2358     is found. There is a option for disabling this check in cases where the
2359     string is known to be correct and/or the maximum performance is wanted.
2361     11. In response to a bug report, I changed one line in Makefile.in from
2363     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2364     to
2365     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2367     to look similar to other lines, but I have no way of telling whether this
2368     is the right thing to do, as I do not use Windows. No doubt I'll get told
2369     if it's wrong...
2372 nigel 69 Version 4.3 21-May-03
2373     ---------------------
2375     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2376     Makefile.
2378     2. Some refactoring to improve the quality of the code:
2380     (i) The utf8_table... variables are now declared "const".
2382     (ii) The code for \cx, which used the "case flipping" table to upper case
2383     lower case letters, now just substracts 32. This is ASCII-specific,
2384     but the whole concept of \cx is ASCII-specific, so it seems
2385     reasonable.
2387     (iii) PCRE was using its character types table to recognize decimal and
2388     hexadecimal digits in the pattern. This is silly, because it handles
2389     only 0-9, a-f, and A-F, but the character types table is locale-
2390     specific, which means strange things might happen. A private
2391     table is now used for this - though it costs 256 bytes, a table is
2392     much faster than multiple explicit tests. Of course, the standard
2393     character types table is still used for matching digits in subject
2394     strings against \d.
2396     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2397     ending in _t are). So I've renamed it as ESC_tee.
2399     3. The first argument for regexec() in the POSIX wrapper should have been
2400     defined as "const".
2402     4. Changed pcretest to use malloc() for its buffers so that they can be
2403     Electric Fenced for debugging.
2405     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2406     to read one or more bytes before the start of the subject string. Often this
2407     had no effect on PCRE's behaviour, but in some circumstances it could
2408     provoke a segmentation fault.
2410     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2411     to try to read one or more bytes before the start of the subject string.
2413     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2414     UTF-8 support could misbehave in various ways if the subject string
2415     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2416     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2417     back over UTF-8 characters.)
2420 nigel 67 Version 4.2 14-Apr-03
2421     ---------------------
2423     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2425     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2426     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2427     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2428     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2429     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2430     and BUILD_EXEEXT
2431     Note: automatic setting of the BUILD variables is not yet working
2432     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2433     compile-time but not at link-time
2434     [LINK]: use for linking executables only
2435     make different versions for Windows and non-Windows
2436     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2437     libraries
2438     [LINK_FOR_BUILD]: new variable
2439     [OBJEXT]: use throughout
2440     [EXEEXT]: use throughout
2441     <winshared>: new target
2442     <wininstall>: new target
2443     <dftables.o>: use native compiler
2444     <dftables>: use native linker
2445     <install>: handle Windows platform correctly
2446     <clean>: ditto
2447     <check>: ditto
2448     copy DLL to top builddir before testing
2450     As part of these changes, -no-undefined was removed again. This was reported
2451     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2452     in any case.
2454     3. Some tidies to get rid of compiler warnings:
2456     . In the match_data structure, match_limit was an unsigned long int, whereas
2457     match_call_count was an int. I've made them both unsigned long ints.
2459     . In pcretest the fact that a const uschar * doesn't automatically cast to
2460     a void * provoked a warning.
2462     . Turning on some more compiler warnings threw up some "shadow" variables
2463     and a few more missing casts.
2465     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2466     option, a class that contained a single character with a value between 128
2467     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2469     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2470     option, a class that contained several characters, but with at least one
2471     whose value was between 128 and 255 caused PCRE to crash.
2474 nigel 65 Version 4.1 12-Mar-03
2475     ---------------------
2476 nigel 63
2477 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2478     needed, and a string in dftables.c that was longer than standard compilers are
2479     required to support.
2481     2. Compiling with Sun's compiler found a few more places where the code could
2482     be tidied up in order to avoid warnings.
2484     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2485     first of these names is deprecated in the latest Autoconf in favour of the name
2486     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2487     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2488     analogy I have changed it to CFLAGS_FOR_BUILD.
2490     4. Added -no-undefined to the linking command in the Makefile, because this is
2491     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2492     linking step for the pcreposix library.
2494     5. PCRE was failing to diagnose the case of two named groups with the same
2495     name.
2497     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2498     literal character that is needed in the subject for a match, and scans along to
2499     ensure that it is present before embarking on the full matching process. This
2500     saves time in cases of nested unlimited repeats that are never going to match.
2501     Problem: the scan can take a lot of time if the subject is very long (e.g.
2502     megabytes), thus penalizing straightforward matches. It is now done only if the
2503     amount of subject to be scanned is less than 1000 bytes.
2505     7. A lesser problem with the same optimization is that it was recording the
2506     first character of an anchored pattern as "needed", thus provoking a search
2507     right along the subject, even when the first match of the pattern was going to
2508     fail. The "needed" character is now not set for anchored patterns, unless it
2509     follows something in the pattern that is of non-fixed length. Thus, it still
2510     fulfils its original purpose of finding quick non-matches in cases of nested
2511     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2514     Version 4.0 17-Feb-03
2515     ---------------------
2517 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2518     extended to the end of string, PCRE compiled incorrect data. This could lead to
2519     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2521     2. Moved to autoconf 2.53 and libtool 1.4.2.
2523     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2524     the special perltest8 script is no longer needed - all the tests can be run
2525     from a single perltest script.
2527     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2528     by \s. It has now been removed in PCRE. This means it isn't recognized as
2529     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2530     class [:space:] *does* include VT, thereby creating a mess.
2532     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2533     space and tab.
2535     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2536     its new features into the main test script, reducing the number of scripts.
2538     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2539     were backward compatible, and made the (?i) apply to the whole pattern, as if
2540     /i were given. Now it behaves more logically, and applies the option setting
2541     only to what follows. PCRE has been changed to follow suit. However, if it
2542     finds options settings right at the start of the pattern, it extracts them into
2543     the global options, as before. Thus, they show up in the info data.
2545     8. Added support for the \Q...\E escape sequence. Characters in between are
2546     treated as literals. This is slightly different from Perl in that $ and @ are
2547     also handled as literals inside the quotes. In Perl, they will cause variable
2548     interpolation. Note the following examples:
2550     Pattern PCRE matches Perl matches
2552     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2553     \Qabc\$xyz\E abc\$xyz abc\$xyz
2554     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2556     For compatibility with Perl, \Q...\E sequences are recognized inside character
2557     classes as well as outside them.
2559     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2560     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2561     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2562     signed/unsigned warnings.
2564     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2565     option for pcretest, so I've replaced it by a simple function that does just
2566     that job.
2568     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2569     "pcregrep -".
2571     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2572     Java package. This provides some syntactic sugar for simple cases of what my
2573     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2574     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2575     item, you can use this simplified notation. Note that only makes sense with
2576     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2577     greediness, whatever the setting of the PCRE_UNGREEDY option.
2579     13. A change of greediness default within a pattern was not taking effect at
2580     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2581     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2582     was abstracted outside.
2584     14. PCRE now supports the \G assertion. It is true when the current matching
2585     position is at the start point of the match. This differs from \A when the
2586     starting offset is non-zero. Used with the /g option of pcretest (or similar
2587     code), it works in the same way as it does for Perl's /g option. If all
2588     alternatives of a regex begin with \G, the expression is anchored to the start
2589     match position, and the "anchored" flag is set in the compiled expression.
2591     15. Some bugs concerning the handling of certain option changes within patterns
2592     have been fixed. These applied to options other than (?ims). For example,
2593     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2594     been the other way round. Some of this was related to change 7 above.
2596     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2597     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2598     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2599     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2601     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2602     mode. Unlike ".", it always matches newline, whatever the setting of
2603     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2604     assertions. Perl allows it, but it doesn't (in general) work because it can't
2605     calculate the length of the lookbehind. At least, that's the case for Perl
2606     5.8.0 - I've been told they are going to document that it doesn't work in
2607     future.
2609     18. Added an error diagnosis for escapes that PCRE does not support: these are
2610     \L, \l, \N, \P, \p, \U, \u, and \X.
2612     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2613     reading past the end of the pattern in cases such as /[abcd/.
2615     20. PCRE was getting more memory than necessary for patterns with classes that
2616     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2618     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2619     compiling PCRE for use with Virtual Pascal.
2621     22. Small fix to the Makefile to make it work properly if the build is done
2622     outside the source tree.
2624     23. Added a new extension: a condition to go with recursion. If a conditional
2625     subpattern starts with (?(R) the "true" branch is used if recursion has
2626     happened, whereas the "false" branch is used only at the top level.
2628     24. When there was a very long string of literal characters (over 255 bytes
2629     without UTF support, over 250 bytes with UTF support), the computation of how
2630     much memory was required could be incorrect, leading to segfaults or other
2631     strange effects.
2633     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2634     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2635     there was a subsequent back reference to those brackets. This meant that, for
2636     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2637     possible to check for precisely this case. All we can do is abandon the
2638     optimization if .* occurs inside capturing brackets when there are any back
2639     references whatsoever. (See below for a better fix that came later.)
2641     26. The handling of the optimization for finding the first character of a
2642     non-anchored pattern, and for finding a character that is required later in the
2643     match were failing in some cases. This didn't break the matching; it just
2644     failed to optimize when it could. The way this is done has been re-implemented.
2646     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2648     28. Added a new feature that provides some of the functionality that Perl
2649     provides with (?{...}). The facility is termed a "callout". The way it is done
2650     in PCRE is for the caller to provide an optional function, by setting
2651     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2652     global variable. By default it is unset, which disables all calling out. To get
2653     the function called, the regex must include (?C) at appropriate points. This
2654     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2655     This provides a means of identifying different callout points. When PCRE
2656     reaches such a point in the regex, if pcre_callout has been set, the external
2657     function is called. It is provided with data in a structure called
2658     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2659     matching continues; if it returns a non-zero value, the match at the current
2660     point fails. However, backtracking will occur if possible. [This was changed
2661     later and other features added - see item 49 below.]
2663     29. pcretest is upgraded to test the callout functionality. It provides a
2664     callout function that displays information. By default, it shows the start of
2665     the match and the current position in the text. There are some new data escapes
2666     to vary what happens:
2668     \C+ in addition, show current contents of captured substrings
2669     \C- do not supply a callout function
2670     \C!n return 1 when callout number n is reached
2671     \C!n!m return 1 when callout number n is reached for the mth time
2673     30. If pcregrep was called with the -l option and just a single file name, it
2674     output "<stdin>" if a match was found, instead of the file name.
2676     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2677     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2678     pcre_exec(). This saves a malloc/free per call. The default value of
2679     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2680     when configuring.
2682     32. The default maximum size of a compiled pattern is 64K. There have been a
2683     few cases of people hitting this limit. The code now uses macros to handle the
2684     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2685     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2686     configuring. Tests 2 and 5 work only with 2-byte links because they output
2687     debugging information about compiled patterns.
2689     33. Internal code re-arrangements:
2691     (a) Moved the debugging function for printing out a compiled regex into
2692     its own source file (printint.c) and used #include to pull it into
2693     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2694     separate copies.
2696     (b) Defined the list of op-code names for debugging as a macro in
2697     internal.h so that it is next to the definition of the opcodes.
2699     (c) Defined a table of op-code lengths for simpler skipping along compiled
2700     code. This is again a macro in internal.h so that it is next to the
2701     definition of the opcodes.
2703     34. Added support for recursive calls to individual subpatterns, along the
2704     lines of Robin Houston's patch (but implemented somewhat differently).
2706     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2707     allow it to read and process whole directories in Win32. This code was
2708     contributed by Lionel Fourquaux; it has not been tested by me.
2710     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2711     used to name a group. Names consist of alphanumerics and underscores, and must
2712     be unique. Back references use the syntax (?P=name) and recursive calls use
2713     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2714     numbers. The function pcre_fullinfo() can be used after compilation to extract
2715     a name/number map. There are three relevant calls:
2717     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2718     PCRE_INFO_NAMECOUNT yields the number of entries
2719     PCRE_INFO_NAMETABLE yields a pointer to the map.
2721     The map is a vector of fixed-size entries. The size of each entry depends on
2722     the length of the longest name used. The first two bytes of each entry are the
2723     group number, most significant byte first. There follows the corresponding
2724     name, zero terminated. The names are in alphabetical order.
2726     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2727     case instead of 255. Making it the same both with and without UTF-8 support
2728     means that the same test output works with both.
2730     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2731     calling malloc() with a zero argument.
2733     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2734     optimization. I've improved things by keeping a bitmap of backreferences with
2735     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2736     fact referenced, the optimization can be applied. It is unlikely that a
2737     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2738     the match to follow \n) will appear inside brackets with a number greater than
2739     31, but if it does, any back reference > 31 suppresses the optimization.
2741     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2742     of disabling numbered capturing parentheses. Any opening parenthesis that is
2743     not followed by ? behaves as if it were followed by ?: but named parentheses
2744     can still be used for capturing (and they will acquire numbers in the usual
2745     way).
2747     41. Redesigned the return codes from the match() function into yes/no/error so
2748     that errors can be passed back from deep inside the nested calls. A malloc
2749     failure while inside a recursive subpattern call now causes the
2750     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2752     42. It is now possible to set a limit on the number of times the match()
2753     function is called in a call to pcre_exec(). This facility makes it possible to
2754     limit the amount of recursion and backtracking, though not in a directly
2755     obvious way, because the match() function is used in a number of different
2756     circumstances. The count starts from zero for each position in the subject
2757     string (for non-anchored patterns). The default limit is, for compatibility, a
2758     large number, namely 10 000 000. You can change this in two ways:
2760     (a) When configuring PCRE before making, you can use --with-match-limit=n
2761     to set a default value for the compiled library.
2763     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2764     a different value is set. See 45 below.
2766     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2768     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2769     of things that can be changed at compile time. The first argument specifies
2770     what is wanted and the second points to where the information is to be placed.
2771     The current list of available information is:
2775     The output is an integer that is set to one if UTF-8 support is available;
2776     otherwise it is set to zero.
2780     The output is an integer that it set to the value of the code that is used for
2781     newline. It is either LF (10) or CR (13).
2785     The output is an integer that contains the number of bytes used for internal
2786     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2790     The output is an integer that contains the threshold above which the POSIX
2791     interface uses malloc() for output vectors. See item 31 above.
2795     The output is an unsigned integer that contains the default limit of the number
2796     of match() calls in a pcre_exec() execution. See 42 above.
2798     44. pcretest has been upgraded by the addition of the -C option. This causes it
2799     to extract all the available output from the new pcre_config() function, and to
2800     output it. The program then exits immediately.
2802     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2803     order to support additional features. One way would have been to define
2804     pcre_exec2() (for example) with extra arguments, but this would not have been
2805     extensible, and would also have required all calls to the original function to
2806     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2807     is used for passing in "extra" data from pcre_study().
2809     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2810     contains the following fields:
2812     flags a bitmap indicating which of the following fields are set
2813     study_data opaque data from pcre_study()
2814     match_limit a way of specifying a limit on match() calls for a specific
2815     call to pcre_exec()
2816     callout_data data for callouts (see 49 below)
2818     The flag bits are also defined in pcre.h, and are
2824     The pcre_study() function now returns one of these new pcre_extra blocks, with
2825     the actual study data pointed to by the study_data field, and the
2826     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2827     before. That is, this change is entirely upwards-compatible and requires no
2828     change to existing code.
2830     If you want to pass in additional data to pcre_exec(), you can either place it
2831     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2832     block.
2834     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2835     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2836     times with different match limits, until it finds the minimum value needed for
2837     pcre_exec() to complete. The value is then output. This can be instructive; for
2838     most simple matches the number is quite small, but for pathological cases it
2839     gets very large very quickly.
2841     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2842     returns the size of the data block pointed to by the study_data field in a
2843     pcre_extra block, that is, the value that was passed as the argument to
2844     pcre_malloc() when PCRE was getting memory in which to place the information
2845     created by pcre_study(). The fourth argument should point to a size_t variable.
2846     pcretest has been extended so that this information is shown after a successful
2847     pcre_study() call when information about the compiled regex is being displayed.
2849     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2850     because what follows is always an absolute path. (Later: it turns out that this
2851     is more than cosmetic for MinGW, because it doesn't like empty path
2852     components.)
2854     49. Some changes have been made to the callout feature (see 28 above):
2856     (i) A callout function now has three choices for what it returns:
2858     0 => success, carry on matching
2859     > 0 => failure at this point, but backtrack if possible
2860     < 0 => serious error, return this value from pcre_exec()
2862     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2863     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2864     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2865     use by callout functions. It will never be used by PCRE itself.
2867     (ii) The pcre_extra structure (see 45 above) has a void * field called
2868     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2869     pcre_callout_block structure has a field of the same name. The contents of
2870     the field passed in the pcre_extra structure are passed to the callout
2871     function in the corresponding field in the callout block. This makes it
2872     easier to use the same callout-containing regex from multiple threads. For
2873     testing, the pcretest program has a new data escape
2875     \C*n pass the number n (may be negative) as callout_data
2877     If the callout function in pcretest receives a non-zero value as
2878     callout_data, it returns that value.
2880     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2881     there were some redundant $(CFLAGS) in commands that are now specified as
2882     $(LINK), which already includes $(CFLAGS).
2884     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2885     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2886     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2887     one-byte characters throughout. Note that case-insensitive matching applies
2888     only to characters whose values are less than 256. PCRE doesn't support the
2889     notion of cases for higher-valued characters.
2891     (i) A character class whose characters are all within 0-255 is handled as
2892     a bit map, and the map is inverted for negative classes. Previously, a
2893     character > 255 always failed to match such a class; however it should
2894     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2896     (ii) A negated character class with a single character < 255 is coded as
2897     "not this character" (OP_NOT). This wasn't working properly when the test
2898     character was multibyte, either singly or repeated.
2900     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2901     mode, for example: \x{100}{2,3}.
2903     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2904     singly or repeated) now correctly test multibyte characters. However,
2905     PCRE doesn't recognize any characters with values greater than 255 as
2906     digits, spaces, or word characters. Such characters always match \D, \S,
2907     and \W, and never match \d, \s, or \w.
2909     (v) Classes may now contain characters and character ranges with values
2910     greater than 255. For example: [ab\x{100}-\x{400}].
2912     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2913     PCRE in UTF-8 mode.
2915     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2916     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2917     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2918     value.)
2920     53. The single man page has become too large. I have therefore split it up into
2921     a number of separate man pages. These also give rise to individual HTML pages;
2922     these are now put in a separate directory, and there is an index.html page that
2923     lists them all. Some hyperlinking between the pages has been installed.
2925     54. Added convenience functions for handling named capturing parentheses.
2927     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2928     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2929     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2930     are faulted.
2932     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2933     calling configure. These values are used when compiling the dftables.c program
2934     which is run to generate the source of the default character tables. They
2935     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2936     you will need to set these values.
2938     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2941     Version 3.9 02-Jan-02
2942 nigel 61 ---------------------
2944     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2946     2. If --disable-static was given, the building process failed when trying to
2947     build pcretest and pcregrep. (For some reason it was using libtool to compile
2948     them, which is not right, as they aren't part of the library.)
2951 nigel 59 Version 3.8 18-Dec-01
2952     ---------------------
2954     1. The experimental UTF-8 code was completely screwed up. It was packing the
2955     bytes in the wrong order. How dumb can you get?
2958 nigel 57 Version 3.7 29-Oct-01
2959     ---------------------
2961     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2962     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2963     this didn't happen under Solaris 8, where I normally test things.
2965 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2966     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2967     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2968     this fix an hour or so after the initial 3.7 release.)
2969 nigel 57
2970 nigel 59
2971 nigel 55 Version 3.6 23-Oct-01
2972     ---------------------
2974     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2975     offsets passed as NULL with zero offset count.
2977     2. The config.guess and config.sub files had not been updated when I moved to
2978     the latest autoconf.
2981 nigel 53 Version 3.5 15-Aug-01
2982     ---------------------
2983 nigel 5
2984 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2985     had been forgotten.
2987     2. By using declared but undefined structures, we can avoid using "void"
2988     definitions in pcre.h while keeping the internal definitions of the structures
2989     private.
2991     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2992     user point of view, this means that both static and shared libraries are built
2993     by default, but this can be individually controlled. More of the work of
2994     handling this static/shared cases is now inside libtool instead of PCRE's make
2995     file.
2997     4. The pcretest utility is now installed along with pcregrep because it is
2998     useful for users (to test regexs) and by doing this, it automatically gets
2999     relinked by libtool. The documentation has been turned into a man page, so
3000     there are now .1, .txt, and .html versions in /doc.
3002     5. Upgrades to pcregrep:
3003     (i) Added long-form option names like gnu grep.
3004     (ii) Added --help to list all options with an explanatory phrase.
3005     (iii) Added -r, --recursive to recurse into sub-directories.
3006     (iv) Added -f, --file to read patterns from a file.
3008     6. pcre_exec() was referring to its "code" argument before testing that
3009     argument for NULL (and giving an error if it was NULL).
3011     7. Upgraded Makefile.in to allow for compiling in a different directory from
3012     the source directory.
3014     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3015     options bits, the pointer it was passed was to an int instead of to an unsigned
3016     long int. This mattered only on 64-bit systems.
3018     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3019     generated) instead of pcre.in, which it its source. Also made the same change
3020     in several of the .c files.
3022     10. A new release of gcc defines printf() as a macro, which broke pcretest
3023     because it had an ifdef in the middle of a string argument for printf(). Fixed
3024     by using separate calls to printf().
3026     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3027     script, to force use of CR or LF instead of \n in the source. On non-Unix
3028     systems, the value can be set in config.h.
3030     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3031     absolute limit. Changed the text of the error message to make this clear, and
3032     likewise updated the man page.
3034     13. The limit of 99 on the number of capturing subpatterns has been removed.
3035     The new limit is 65535, which I hope will not be a "real" limit.
3038 nigel 51 Version 3.4 22-Aug-00
3039     ---------------------
3041     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3043     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3046 nigel 49 Version 3.3 01-Aug-00
3047     ---------------------
3049     1. If an octal character was given, but the value was greater than \377, it
3050     was not getting masked to the least significant bits, as documented. This could
3051     lead to crashes in some systems.
3053     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3054     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3056     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3057     These just pass their arguments on to (pcre_free)(), but they are provided
3058     because some uses of PCRE bind it to non-C systems that can call its functions,
3059     but cannot call free() or pcre_free() directly.
3061     4. Add "make test" as a synonym for "make check". Corrected some comments in
3062     the Makefile.
3064     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3065     Makefile.
3067     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3068     command called pgrep for grepping around the active processes.
3070     7. Added the beginnings of support for UTF-8 character strings.
3072     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3073     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3074     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3075     out for the ar command.)
3078 nigel 47 Version 3.2 12-May-00
3079     ---------------------
3081     This is purely a bug fixing release.
3083     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3084     of ZA. This was just one example of several cases that could provoke this bug,
3085     which was introduced by change 9 of version 2.00. The code for breaking
3086     infinite loops after an iteration that matches an empty string was't working
3087     correctly.
3089     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3090     when matched against abbab (for example). After matching an empty string, it
3091     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3092     caused it to match further down the string than it should.
3094     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3095     was there because it doesn't seem to be needed, and it causes trouble on some
3096     systems, as it is not a Standard C header. It has been removed.
3098     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3099     were reported on the Macintosh. The changes were from
3101     while ((c = *(++ptr)) != 0 && c != '\n');
3102     to
3103     while ((c = *(++ptr)) != 0 && c != '\n') ;
3105     Totally extraordinary, but if that's what it takes...
3107     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3108     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3109     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3110     assumes the way PCRE uses memmove() (always moving upwards).
3112     6. PCRE is being used in one environment where strchr() is not available. There
3113     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3114     faster code anyway.
3117 nigel 45 Version 3.1 09-Feb-00
3118     ---------------------
3120     The only change in this release is the fixing of some bugs in Makefile.in for
3121     the "install" target:
3123     (1) It was failing to install pcreposix.h.
3125     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3128 nigel 43 Version 3.0 01-Feb-00
3129     ---------------------
3130 nigel 41
3131     1. Add support for the /+ modifier to perltest (to output $` like it does in
3132     pcretest).
3134     2. Add support for the /g modifier to perltest.
3136     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3137     matches null strings.
3139     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3140     pattern. Perl treats empty patterns specially - it reuses the most recent
3141     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3142     effect.
3144     5. The POSIX interface was broken in that it was just handing over the POSIX
3145     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3146     required a bigger vector, with some working space on the end. This means that
3147     the POSIX wrapper now has to get and free some memory, and copy the results.
3149 nigel 43 6. Added some simple autoconf support, placing the test data and the
3150     documentation in separate directories, re-organizing some of the
3151     information files, and making it build pcre-config (a GNU standard). Also added
3152     libtool support for building PCRE as a shared library, which is now the
3153     default.
3154 nigel 41
3155 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3156     09 are not valid octal constants. Single digits will be used for minor values
3157     less than 10.
3159     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3160     existing programs that set these in the POSIX interface can use PCRE without
3161     modification.
3163     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3164     return all that pcre_info() returns, plus additional data. The pcre_info()
3165     function is retained for compatibility, but is considered to be obsolete.
3167     10. Added experimental recursion feature (?R) to handle one common case that
3168     Perl 5.6 will be able to do with (?p{...}).
3170     11. Added support for POSIX character classes like [:alpha:], which Perl is
3171     adopting.
3174 nigel 39 Version 2.08 31-Aug-99
3175     ----------------------
3177     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3178     trying to match at the startoffset position, but instead was moving forward to
3179     the next newline as if a previous match had failed.
3181     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3182     and could get into a loop if a null string was matched other than at the start
3183     of the subject.
3185     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3186     be distinguished at compile time, and for completeness also added PCRE_DATE.
3188     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3189     in GnuWin32 environments.
3192 nigel 37 Version 2.07 29-Jul-99
3193     ----------------------
3195     1. The documentation is now supplied in plain text form and HTML as well as in
3196     the form of man page sources.
3198     2. C++ compilers don't like assigning (void *) values to other pointer types.
3199     In particular this affects malloc(). Although there is no problem in Standard
3200     C, I've put in casts to keep C++ compilers happy.
3202     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3203     should be (const char *).
3205     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3206     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3207     However, I haven't made this a standard facility. The documentation doesn't
3208     mention it, and the Makefile doesn't support it.
3210     5. The Makefile now contains an "install" target, with editable destinations at
3211     the top of the file. The pcretest program is not installed.
3213     6. pgrep -V now gives the PCRE version number and date.
3215     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3216     causing the entire string to be ignored, instead of just the last character.
3218     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3219     non-matching string, it can take a very, very long time, even for strings of
3220     quite modest length, because of the nested recursion. PCRE now does better in
3221     some of these cases. It does this by remembering the last required literal
3222     character in the pattern, and pre-searching the subject to ensure it is present
3223     before running the real match. In other words, it applies a heuristic to detect
3224     some types of certain failure quickly, and in the above example, if presented
3225     with a string that has no trailing " it gives "no match" very quickly.
3227     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3228     other alternatives are tried instead.
3231 nigel 35 Version 2.06 09-Jun-99
3232     ----------------------
3234     1. Change pcretest's output for amount of store used to show just the code
3235     space, because the remainder (the data block) varies in size between 32-bit and
3236     64-bit systems.
3238     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3239     start matching at. This allows lookbehinds to work when searching for multiple
3240     occurrences in a string.
3242     3. Added additional options to pcretest for testing multiple occurrences:
3244     /+ outputs the rest of the string that follows a match
3245     /g loops for multiple occurrences, using the new startoffset argument
3246     /G loops for multiple occurrences by passing an incremented pointer
3248     4. PCRE wasn't doing the "first character" optimization for patterns starting
3249     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3250     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3251     the letter 'x'. On long subject strings, this gives a significant speed-up.
3254 nigel 33 Version 2.05 21-Apr-99
3255     ----------------------
3257     1. Changed the type of magic_number from int to long int so that it works
3258     properly on 16-bit systems.
3260     2. Fixed a bug which caused patterns starting with .* not to work correctly
3261     when the subject string contained newline characters. PCRE was assuming
3262     anchoring for such patterns in all cases, which is not correct because .* will
3263     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3264     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3265     must be retried after every newline in the subject.
3268 nigel 31 Version 2.04 18-Feb-99
3269     ----------------------
3271     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3272     computation of the store needed to hold the pattern was incorrect (too large).
3273     If such patterns were nested a few deep, this could multiply and become a real
3274     problem.
3276     2. Added /M option to pcretest to show the memory requirement of a specific
3277     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3279     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3280     compiled in such a way that the backtracking after subsequent failure was
3281     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3282     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3285 nigel 29 Version 2.03 02-Feb-99
3286     ----------------------
3288     1. Fixed typo and small mistake in man page.
3290 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3291     LICENCE file containing the conditions.
3292 nigel 29
3293     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3294     Perl, that is the internal \ allows the delimiter to be included in the
3295     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3296     the final delimiter, add \ to the end of the pattern (to test the error).
3298     4. Added the convenience functions for extracting substrings after a successful
3299     match. Updated pcretest to make it able to test these functions.
3302 nigel 27 Version 2.02 14-Jan-99
3303     ----------------------
3305     1. Initialized the working variables associated with each extraction so that
3306     their saving and restoring doesn't refer to uninitialized store.
3308     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3309     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3310     fix the problem.
3312     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3313     calls, and wasn't printing the correct value for compiling calls. Increased the
3314     default value of LOOPREPEAT, and the number of significant figures in the
3315     times.
3317     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3319     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3320     a building problem on Windows NT with a FAT file system.
3323 nigel 25 Version 2.01 21-Oct-98
3324     ----------------------
3326     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3327     to character tables built by pcre_maketables() in the current locale. If NULL
3328     is passed, the default tables are used.
3331 nigel 23 Version 2.00 24-Sep-98
3332 nigel 21 ----------------------
3334 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3335     it any more.
3337     2. Allow quantification of (?>) groups, and make it work correctly.
3339     3. The first character computation wasn't working for (?>) groups.
3341     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3342     end of the subject) and add 5.005's \z, which really does match only at the
3343     very end of the subject.
3345     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3347     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3348     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3349     localized options. All options to pcre_study() were also removed.
3351     7. Add other new features from 5.005:
3353     $(?<= positive lookbehind
3354     $(?<! negative lookbehind
3355     (?imsx-imsx) added the unsetting capability
3356     such a setting is global if at outer level; local otherwise
3357     (?imsx-imsx:) non-capturing groups with option setting
3358     (?(cond)re|re) conditional pattern matching
3360     A backreference to itself in a repeated group matches the previous
3361     captured string.
3363     8. General tidying up of studying (both automatic and via "study")
3364     consequential on the addition of new assertions.
3366     9. As in 5.005, unlimited repeated groups that could match an empty substring
3367     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3368     runtime if any iteration does actually match an empty substring.
3370     10. Include the RunTest script in the distribution.
3372     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3373     discrepancies, some of which were old and were also with respect to 5.004. They
3374     have now been fixed.
3377     Version 1.09 28-Apr-98
3378     ----------------------
3380 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3381     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3382     program crashes, or just wrong answers. This did not apply to negated classes
3383     containing more than one character, or to minima other than one.
3386 nigel 19 Version 1.08 27-Mar-98
3387     ----------------------
3389     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3391     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3392     latter must appear before anything that relies on it in the pattern.
3395 nigel 17 Version 1.07 16-Feb-98
3396     ----------------------
3398     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3399     repeat of a potentially empty string).
3402 nigel 15 Version 1.06 23-Jan-98
3403     ----------------------
3405     1. Added Markus Oberhumer's little patches for C++.
3407     2. Literal strings longer than 255 characters were broken.
3410 nigel 13 Version 1.05 23-Dec-97
3411     ----------------------
3413     1. Negated character classes containing more than one character were failing if
3414     PCRE_CASELESS was set at run time.
3417 nigel 11 Version 1.04 19-Dec-97
3418     ----------------------
3420     1. Corrected the man page, where some "const" qualifiers had been omitted.
3422     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3423     input syntax.
3425     3. Fixed memory leak which occurred when a regex with back references was
3426     matched with an offsets vector that wasn't big enough. The temporary memory
3427     that is used in this case wasn't being freed if the match failed.
3429     4. Tidied pcretest to ensure it frees memory that it gets.
3431     5. Temporary memory was being obtained in the case where the passed offsets
3432     vector was exactly big enough.
3434     6. Corrected definition of offsetof() from change 5 below.
3436     7. I had screwed up change 6 below and broken the rules for the use of
3437     setjmp(). Now fixed.
3440 nigel 9 Version 1.03 18-Dec-97
3441     ----------------------
3443     1. A erroneous regex with a missing opening parenthesis was correctly
3444     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3445     on some systems.
3447     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3448     it was reported that one broken compiler failed on the former because "code" is
3449     also an independent variable.
3451     3. The erroneous regex a[]b caused an array overrun reference.
3453     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3454     fail on data ending with that character. (It was going on too far, and checking
3455     the next character, typically a binary zero.) This was specific to the
3456     optimized code for single-character negative classes.
3458     5. Added a contributed patch from the TIN world which does the following:
3460     + Add an undef for memmove, in case the the system defines a macro for it.
3462     + Add a definition of offsetof(), in case there isn't one. (I don't know
3463     the reason behind this - offsetof() is part of the ANSI standard - but
3464     it does no harm).
3466     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3467     most of the places where whitespace preceded '#'. I have given up and
3468     allowed the remaining 2 cases to be at the margin.
3470     + Rename some variables in pcre to eliminate shadowing. This seems very
3471     pedantic, but does no harm, of course.
3473     6. Moved the call to setjmp() into its own function, to get rid of warnings
3474     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3476     7. Constructs such as \d{8,} were compiling into the equivalent of
3477 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3478 nigel 9 outcome, but in this particular case used more store than had been allocated,
3479     which caused the bug to be discovered because it threw up an internal error.
3481     8. The debugging code in both pcre and pcretest for outputting the compiled
3482     form of a regex was going wrong in the case of back references followed by
3483     curly-bracketed repeats.
3486 nigel 7 Version 1.02 12-Dec-97
3487     ----------------------
3489     1. Typos in pcre.3 and comments in the source fixed.
3491     2. Applied a contributed patch to get rid of places where it used to remove
3492     'const' from variables, and fixed some signed/unsigned and uninitialized
3493     variable warnings.
3495     3. Added the "runtest" target to Makefile.
3497     4. Set default compiler flag to -O2 rather than just -O.
3500 nigel 5 Version 1.01 19-Nov-97
3501     ----------------------
3503     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3504     like /([ab]*)*/, that is, for classes with more than one character in them.
3506     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3507     as /((?>a*))*/ (a PCRE_EXTRA facility).
3510     Version 1.00 18-Nov-97
3511     ----------------------
3513     1. Added compile-time macros to support systems such as SunOS4 which don't have
3514     memmove() or strerror() but have other things that can be used instead.
3516     2. Arranged that "make clean" removes the executables.
3519 nigel 3 Version 0.99 27-Oct-97
3520     ----------------------
3522     1. Fixed bug in code for optimizing classes with only one character. It was
3523     initializing a 32-byte map regardless, which could cause it to run off the end
3524     of the memory it had got.
3526     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3529     Version 0.98 22-Oct-97
3530     ----------------------
3532     1. Fixed bug in code for handling temporary memory usage when there are more
3533     back references than supplied space in the ovector. This could cause segfaults.
3536     Version 0.97 21-Oct-97
3537     ----------------------
3539     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3541     2. Optimized negated single characters not to use a bit map.
3543     3. Brought error texts together as macro definitions; clarified some of them;
3544     fixed one that was wrong - it said "range out of order" when it meant "invalid
3545     escape sequence".
3547     4. Changed some char * arguments to const char *.
3549     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3551     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3552     pcretest.
3555     Version 0.96 16-Oct-97
3556     ----------------------
3558     1. Added a simple "pgrep" utility to the distribution.
3560     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3561     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3562     where "ddd" means "one or more decimal digits".
3564     3. Fixed serious bug. If a pattern had a back reference, but the call to
3565     pcre_exec() didn't supply a large enough ovector to record the related
3566     identifying subpattern, the match always failed. PCRE now remembers the number
3567     of the largest back reference, and gets some temporary memory in which to save
3568     the offsets during matching if necessary, in order to ensure that
3569     backreferences always work.
3571     4. Increased the compatibility with Perl in a number of ways:
3573     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3574     to request this handling. The option can be set at compile or exec time.
3576     (b) $ matches before a terminating newline by default; an option
3577     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3578     mode). The option can be set at compile or exec time.
3580     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3581     the same as Perl's. If the decimal number it represents is less than 10
3582     or there aren't that many previous left capturing parentheses, an octal
3583     escape is read. Inside a character class, it's always an octal escape,
3584     even if it is a single digit.
3586     (d) An escaped but undefined alphabetic character is taken as a literal,
3587     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3588     escapes.
3590     (e) {0} is now permitted. (The previous item is removed from the compiled
3591     pattern).
3593     5. Changed all the names of code files so that the basic parts are no longer
3594     than 10 characters, and abolished the teeny "globals.c" file.
3596     6. Changed the handling of character classes; they are now done with a 32-byte
3597     bit map always.
3599     7. Added the -d and /D options to pcretest to make it possible to look at the
3600     internals of compilation without having to recompile pcre.
3603     Version 0.95 23-Sep-97
3604     ----------------------
3606     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3607     \x20 at the start of a run of normal characters. These were being treated as
3608     real characters, instead of the source characters being re-checked.
3611     Version 0.94 18-Sep-97
3612     ----------------------
3614     1. The functions are now thread-safe, with the caveat that the global variables
3615     containing pointers to malloc() and free() or alternative functions are the
3616     same for all threads.
3618     2. Get pcre_study() to generate a bitmap of initial characters for non-
3619     anchored patterns when this is possible, and use it if passed to pcre_exec().
3622     Version 0.93 15-Sep-97
3623     ----------------------
3625     1. /(b)|(:+)/ was computing an incorrect first character.
3627     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3628     but not actually doing anything yet.
3630     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3631     as Perl does (e.g. [-az] or [az-]).
3633     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3634     all possible positions.
3636     5. Split up into different modules to avoid including unneeded functions in a
3637     compiled binary. However, compile and exec are still in one module. The "study"
3638     function is split off.
3640     6. The character tables are now in a separate module whose source is generated
3641     by an auxiliary program - but can then be edited by hand if required. There are
3642     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3643     toupper() in the code.
3645     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3646     make them global. Abolish the function for setting them, as the caller can now
3647     set them directly.
3650     Version 0.92 11-Sep-97
3651     ----------------------
3653     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3654     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3656     2. Caseless matching was not working in character classes if the characters in
3657     the pattern were in upper case.
3659     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3661     4. Make PCRE_ANCHORED public and accept as a compile option.
3663     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3664     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3665     pass them.
3667     6. Give an error if bad option bits passed at compile or run time.
3669     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3670     pcretest to cause it to pass that flag.
3672     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3673     options, and the first character, if set.
3675     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3678     Version 0.91 10-Sep-97
3679     ----------------------
3681     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3682     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3684     2. PCRE was looping on encountering an indefinitely repeated back reference to
3685     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3686     Perl does - treats the match as successful.
3688     ****


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