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Revision 438 - (hide annotations) (download)
Sun Sep 6 20:00:47 2009 UTC (5 years, 6 months ago) by ph10
File size: 171937 byte(s)
Fix internal error for forward reference with [^m] interposing.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 418 Version 8.00 ??-???-??
5     ----------------------
7     1. The table for translating pcre_compile() error codes into POSIX error codes
8     was out-of-date, and there was no check on the pcre_compile() error code
9     being within the table. This could lead to an OK return being given in
10     error.
11 ph10 419
12     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
13     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14     in a Windows environment.
15 ph10 420
16     3. The pcregrep --count option prints the count for each file even when it is
17     zero, as does GNU grep. However, pcregrep was also printing all files when
18     --files-with-matches was added. Now, when both options are given, it prints
19     counts only for those files that have at least one match. (GNU grep just
20     prints the file name in this circumstance, but including the count seems
21     more useful - otherwise, why use --count?) Also ensured that the
22     combination -clh just lists non-zero counts, with no names.
24 ph10 421 4. The long form of the pcregrep -F option was incorrectly implemented as
25     --fixed_strings instead of --fixed-strings. This is an incompatible change,
26     but it seems right to fix it, and I didn't think it was worth preserving
27     the old behaviour.
29 ph10 422 5. The command line items --regex=pattern and --regexp=pattern were not
30     recognized by pcregrep, which required --regex pattern or --regexp pattern
31     (with a space rather than an '='). The man page documented the '=' forms,
32     which are compatible with GNU grep; these now work.
34 ph10 423 6. No libpcreposix.pc file was created for pkg-config; there was just
35     libpcre.pc and libpcrecpp.pc. The omission has been rectified.
37 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
38     when UCP support is not needed, by modifying the Python script that
39     generates it from Unicode data files. This should not matter if the module
40     is correctly used as a library, but I received one complaint about 50K of
41     unwanted data. My guess is that the person linked everything into his
42     program rather than using a library. Anyway, it does no harm.
44 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
45     was a minimum greater than 1 for a wide character in a possessive
46 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
47     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
48     character. Chaos in the form of incorrect output or a compiling loop could
49     result.
50 ph10 426
51     9. The restrictions on what a pattern can contain when partial matching is
52     requested for pcre_exec() have been removed. All patterns can now be
53     partially matched by this function. In addition, if there are at least two
54 ph10 435 slots in the offset vector, the offset of the earliest inspected character
55     for the match and the offset of the end of the subject are set in them when
56     PCRE_ERROR_PARTIAL is returned.
57 ph10 426
58 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
59     synonymous with PCRE_PARTIAL, for backwards compatibility, and
60     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
61     and may be more useful for multi-segment matching, especially with
62     pcre_exec().
63 ph10 427
64 ph10 428 11. Partial matching with pcre_exec() is now more intuitive. A partial match
65     used to be given if ever the end of the subject was reached; now it is
66     given only if matching could not proceed because another character was
67     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
68     string "Z", which now yields "no match" instead of "partial match". In the
69     case of pcre_dfa_exec(), "no match" is given if every matching path for the
70     final character ended with (*FAIL).
72     12. Restarting a match using pcre_dfa_exec() after a partial match did not work
73     if the pattern had a "must contain" character that was already found in the
74     earlier partial match, unless partial matching was again requested. For
75     example, with the pattern /dog.(body)?/, the "must contain" character is
76     "g". If the first part-match was for the string "dog", restarting with
77 ph10 435 "sbody" failed. This bug has been fixed.
78 ph10 428
79 ph10 435 13. The string returned by pcre_dfa_exec() after a partial match has been
80     changed so that it starts at the first inspected character rather than the
81     first character of the match. This makes a difference only if the pattern
82     starts with a lookbehind assertion or \b or \B (\K is not supported by
83     pcre_dfa_exec()). It's an incompatible change, but it makes the two
84     matching functions compatible, and I think it's the right thing to do.
86     14. Added a pcredemo man page, created automatically from the pcredemo.c file,
87 ph10 429 so that the demonstration program is easily available in environments where
88     PCRE has not been installed from source.
90 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
91 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
92     library.
94 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
95 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
96     is not the first non-POSIX option to be added. Clearly some people find
97 ph10 433 these options useful.
98 ph10 432
99 ph10 435 17. If a caller to the POSIX matching function regexec() passes a non-zero
100 ph10 438 value for nmatch with a NULL value for pmatch, the value of
101     nmatch is forced to zero.
102 ph10 433
103 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
104     the diff command, as RunTest does. It now checks in the same way as
105     RunTest, and also checks for the -b option.
107 ph10 438 19. If an odd number of negated classes containing just a single character
108     interposed, within parentheses, between a forward reference to a named
109     subpattern and the definition of the subpattern, compilation crashed with
110     an internal error, complaining that it could not find the referenced
111     subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
112     [The bug was that it was starting one character too far in when skipping
113     over the character class, thus treating the ] as data rather than
114     terminating the class. This meant it could skip too much.]
116 ph10 418
117 ph10 412 Version 7.9 11-Apr-09
118 ph10 376 ---------------------
120 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
121 ph10 376 (pcretest), all targets were linked against these libraries. This included
122     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
123     libraries. This caused unwanted dependencies to be created. This problem
124 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
125 ph10 376 pcretest is linked with readline.
126 ph10 392
127 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
128     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
129     moved outside it again, because FALSE and TRUE are already defined in AIX,
130     but BOOL is not.
131 ph10 392
132     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
133 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
134 ph10 392
135 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
136     hyphens) following file names and line numbers when outputting matching
137 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
138 ph10 376 wording for the --colour (or --color) option.
139 ph10 392
140 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
141     was not coloured; this is different to GNU grep, so I have changed it to be
142     the same.
143 ph10 392
144 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
145 ph10 392 each matching line was coloured. Now it goes on to look for further matches
146     of any of the test patterns, which is the same behaviour as GNU grep.
148     7. A pattern that could match an empty string could cause pcregrep to loop; it
149     doesn't make sense to accept an empty string match in pcregrep, so I have
150 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
151     seems to be how GNU grep behaves.
152 ph10 392
153 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
154 ph10 392 start or after a newline", because the conditional assertion was not being
155     correctly handled. The rule now is that both the assertion and what follows
156     in the first alternative must satisfy the test.
158 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
159 ph10 399 condition was an assertion, PCRE could crash during matching, both with
160     pcre_exec() and pcre_dfa_exec().
161 ph10 392
162     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
163     used for matching.
165     11. Unicode property support in character classes was not working for
166 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
167 ph10 388
168 ph10 392 12. Added the -M command line option to pcretest.
170 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
171 ph10 389
172     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
173 ph10 390
174 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
175 ph10 390 wrapper.
176 ph10 392
177 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
178 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
179 ph10 391 string constants.
180 ph10 405
181 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
182     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
183 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
184     these, but not everybody uses configure.
186     19. A conditional group that had only one branch was not being correctly
187     recognized as an item that could match an empty string. This meant that an
188     enclosing group might also not be so recognized, causing infinite looping
189     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
190     with the subject "ab", where knowledge that the repeated group can match
191 ph10 396 nothing is needed in order to break the loop.
192 ph10 405
193 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
194 ph10 405 exec(), but without supplying a callout function, matching went wrong.
196     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
197     leak if the size of the offset vector was greater than 30. When the vector
198     is smaller, the saved offsets during recursion go onto a local stack
199     vector, but for larger vectors malloc() is used. It was failing to free
200     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
201 ph10 400 error, in fact).
202 ph10 405
203 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
204 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
205     problem, but was untidy.
206 ph10 376
207 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
208     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
209     included within another project.
210 ph10 411
211 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
212     slightly modified by me:
213 ph10 411
214     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
215     not building pcregrep.
217 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
218 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
220 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
221     duplicate group numbers, could behave incorrectly or give incorrect errors,
222     because when scanning forward to find the reference group, PCRE was not
223     taking into account the duplicate group numbers. A pattern such as
224     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
225 ph10 411
226     26. Changed a few more instances of "const unsigned char *" to USPTR, making
227     the feature of a custom pointer more persuasive (as requested by a user).
228 ph10 416
229 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
230 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
231     pre-defined.
232 ph10 392
233 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
235 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
236     in the configuration summary.
237 ph10 405
238 ph10 411
239 ph10 374 Version 7.8 05-Sep-08
240 ph10 349 ---------------------
242     1. Replaced UCP searching code with optimized version as implemented for Ad
243     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
244 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
245     to 5 times on some simple patterns that I tested. Permission was given to
246     distribute the MultiStage2.py script that generates the tables (it's not in
247     the tarball, but is in the Subversion repository).
248 ph10 349
249 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
250     scripts.
251 ph10 358
252 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
253     a group with a zero qualifier. The result of the study could be incorrect,
254 ph10 358 or the function might crash, depending on the pattern.
256     4. Caseless matching was not working for non-ASCII characters in back
257 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
258 ph10 358 It now works when Unicode Property Support is available.
260 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
261     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
262     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
263 ph10 358 truncation.
264 ph10 349
265 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
267 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
268     pointers, in case they are 64-bit values.
269 ph10 371
270     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
271     test 2 if it fails.
273 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
274 ph10 371 and a #define of that name to empty if it is not externally set. This is to
275     allow users of MSVC to set it if necessary.
277     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
278 ph10 359 the convenience functions in the pcre_get.c source file.
279 ph10 371
280 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
281     could cause overwriting and/or a crash. This command provoked a crash in
282 ph10 371 some environments:
284     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
286 ph10 360 This potential security problem was recorded as CVE-2008-2371.
287 ph10 371
288 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
289     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
290 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
291 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
292     pcretest so that it places the subject at the end of its malloc-ed buffer.
293 ph10 371
294 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
295 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
297 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
298 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
299     first line. This applied both to normal and DFA matching.
301 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
302 ph10 371 /^[^d]*?$/8 failed to match "abc".
303 ph10 351
304 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
306     17. Make it more clear in the documentation that values returned from
307 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
308 ph10 357
309 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
310 ph10 368
311 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
312     supplied by Stefan Weber. I made a further small update for 7.8 because
313 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
314     replaced by pcre_ucd.c.
315 ph10 371
316 ph10 373
317 ph10 347 Version 7.7 07-May-08
318 ph10 321 ---------------------
320     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
321 ph10 345 a string to a long long, pretend we don't even have a long long." This is
322 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
323 ph10 345
324 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
325     pre-7.6 versions, which defined a global no_arg variable instead of putting
326 ph10 332 it in the RE class. (See also #8 below.)
327 ph10 345
328     3. Remove a line of dead code, identified by coverity and reported by Nuno
329     Lopes.
331 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
332 ph10 321
333 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
334 ph10 345 of files, instead of just to the final components.
336 ph10 324 (2) If there was more than one level of directory, the subdirectories were
337     skipped unless they satisfied the include/exclude conditions. This is
338     inconsistent with GNU grep (and could even be seen as contrary to the
339     pcregrep specification - which I improved to make it absolutely clear).
340     The action now is always to scan all levels of directory, and just
341     apply the include/exclude patterns to regular files.
342 ph10 345
343 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
344 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
346 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
347 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
348 ph10 326 doesn't support NULs in patterns.
349 ph10 345
350     7. Added some missing "const"s to declarations of static tables in
351     pcre_compile.c and pcre_dfa_exec.c.
353 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
354 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
355 ph10 345 first patch. And a third patch - this was a messy problem.)
356 ph10 321
357 ph10 345 9. Applied Craig's patch to remove the use of push_back().
359 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
360     matching function regexec().
361 ph10 345
362     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
363     which, however, unlike Perl's \g{...}, are subroutine calls, not back
364 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
365     Oniguruma does).
366 ph10 345
367     12. Previously, a group with a zero repeat such as (...){0} was completely
368 ph10 335 omitted from the compiled regex. However, this means that if the group
369     was called as a subroutine from elsewhere in the pattern, things went wrong
370 ph10 345 (an internal error was given). Such groups are now left in the compiled
371     pattern, with a new opcode that causes them to be skipped at execution
372 ph10 335 time.
373 ph10 345
374 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
375     to the way PCRE behaves:
376 ph10 345
377 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
378 ph10 345
379     (b) A back reference to an unmatched subpattern matches an empty string
380 ph10 336 (Perl fails the current match path).
381 ph10 345
382 ph10 341 (c) A data ] in a character class must be notated as \] because if the
383 ph10 345 first data character in a class is ], it defines an empty class. (In
384 ph10 341 Perl it is not possible to have an empty class.) The empty class []
385     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
386     The negative empty class [^] matches any one character, independently
387     of the DOTALL setting.
388 ph10 345
389     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
390 ph10 340 non-existent subpattern following a character class starting with ']' and
391     containing () gave an internal compiling error instead of "reference to
392     non-existent subpattern". Fortunately, when the pattern did exist, the
393 ph10 345 compiled code was correct. (When scanning forwards to check for the
394 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
395 ph10 345 the class, so got the count wrong. When actually compiling, the reference
396 ph10 340 was subsequently set up correctly.)
397 ph10 345
398 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
399 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
400     other assertions are supported. I have made pcre_dfa_exec() support
401     (*FAIL).
403 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
404 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
405     cannot be changed at match time, I realized I could make a small
406     improvement to matching performance by compiling OP_ALLANY instead of
407     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
408     on the OP_ANY path.
410     17. Compiling pcretest on Windows with readline support failed without the
411 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
412 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
414 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
415 ph10 345 ncurses library to be included for pcretest when ReadLine support is
416     requested, but also to allow for it to be overridden. This patch came from
417     Daniel Bergström.
418 ph10 347
419 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
420 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
421     any errors with the current Unicode tables. Thanks to Peter Kankowski for
422     spotting this.
423 ph10 324
424 ph10 332
425 ph10 319 Version 7.6 28-Jan-08
426 ph10 300 ---------------------
428 ph10 302 1. A character class containing a very large number of characters with
429     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
430     overflow.
431 ph10 309
432     2. Patch to cut out the "long long" test in pcrecpp_unittest when
433     HAVE_LONG_LONG is not defined.
435 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
436 ph10 304 bring them up to date and include new features. This patch includes:
437 ph10 309
438 ph10 304 - Fixed PH's badly added libz and libbz2 support.
439     - Fixed a problem with static linking.
440 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
441 ph10 304 - Fixed dftables problem and added an option.
442     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
444     - Added readline support for pcretest.
445 ph10 309 - Added an listing of the option settings after cmake has run.
447 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
448     "pcre.dll" under mingw when using Configure/Make. I added stuff to
449     Makefile.am that cause it to include this special target, without
450     affecting anything else. Note that the same mingw target plus all
451     the other distribution libraries and programs are now supported
452     when configuring with CMake (see 6 below) instead of with
453     Configure/Make.
454 ph10 309
455 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
456     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
457 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
458     solves the problem, but it does no harm.
459 ph10 313
460 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
461 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
462 ph10 314 with CMake, and also correct the comment about stack recursion.
463 ph10 313
464 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
465 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
466     of a program that users should build themselves after PCRE is installed, so
467     building it automatically is not really right. What is more, it gave
468 ph10 312 trouble in some build environments.
469 ph10 300
470 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
471 ph10 308
472 ph10 319
473 ph10 298 Version 7.5 10-Jan-08
474 ph10 263 ---------------------
476     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
477     values in parens when parsing an RE using the C++ wrapper."
478 ph10 286
479 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
480     Characters greater than 255 were excluded from the class instead of being
481     included.
482 ph10 286
483     3. The same bug as (2) above applied to negated POSIX classes such as
484 ph10 265 [:^space:].
485 ph10 286
486 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
487     defined or documented. It seems to have been a typo for PCRE_STATIC, so
488 ph10 286 I have changed it.
490 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
491 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
492     first named subpattern whose name started with "a" (in other words, the
493 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
494     expected" is now given for (?&) (a zero-length name), and this patch also
495     makes it give the same error for \k'' (previously it complained that that
496     was a reference to a non-existent subpattern).
497 ph10 286
498 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
499 ph10 286 this is right because (?- can be followed by option settings as well as by
500 ph10 269 digits. I have, however, made the messages clearer.
501 ph10 286
502 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
503     than the number used in the conditional) now cause a compile-time error.
504     This is actually not compatible with Perl, which accepts such patterns, but
505     treats the conditional as always being FALSE (as PCRE used to), but it
506     seems to me that giving a diagnostic is better.
507 ph10 286
508 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
509 ph10 275 and messages.
510 ph10 286
511     9. Fix two occurrences of "backslash" in comments that should have been
512     "backspace".
514     10. Remove two redundant lines of code that can never be obeyed (their function
515     was moved elsewhere).
517     11. The program that makes PCRE's Unicode character property table had a bug
518     which caused it to generate incorrect table entries for sequences of
519 ph10 277 characters that have the same character type, but are in different scripts.
520 ph10 286 It amalgamated them into a single range, with the script of the first of
521 ph10 277 them. In other words, some characters were in the wrong script. There were
522     thirteen such cases, affecting characters in the following ranges:
523 ph10 286
524 ph10 277 U+002b0 - U+002c1
525     U+0060c - U+0060d
526 ph10 286 U+0061e - U+00612
527 ph10 277 U+0064b - U+0065e
528     U+0074d - U+0076d
529     U+01800 - U+01805
530     U+01d00 - U+01d77
531     U+01d9b - U+01dbf
532     U+0200b - U+0200f
533     U+030fc - U+030fe
534     U+03260 - U+0327f
535     U+0fb46 - U+0fbb1
536     U+10450 - U+1049d
537 ph10 286
538 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
539     compatible with GNU grep in that, if there was more than one match in a
540     line, it showed only the first of them. It now behaves in the same way as
541     GNU grep.
542 ph10 286
543     13. If the -o and -v options were combined for pcregrep, it printed a blank
544     line for every non-matching line. GNU grep prints nothing, and pcregrep now
545     does the same. The return code can be used to tell if there were any
546     non-matching lines.
548 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
550     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
551 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
552 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
553     and both kinds of lookbehind were skipped).
555 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
556 ph10 284 inclusion of <windows.h> to before rather than after the definition of
557     INVALID_FILE_ATTRIBUTES (patch from David Byron).
558 ph10 263
559 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
560 ph10 286 character property caused pcre_compile() to compile bad code, which led at
561     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
562     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
563     caused the error; without that there was no problem.
564 ph10 263
565 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
566 ph10 286
567 ph10 289 19. Added --enable-pcretest-libreadline.
568 ph10 286
569 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
570 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
571 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
572     later patch that removed the other one (the right fix) and added unit tests
573     that check the return values (which was not done before).
574 ph10 292
575 ph10 291 21. Several CMake things:
576 ph10 287
577 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
578 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
579 ph10 288
580 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
581     linked with the newly-built libraries, not previously installed ones.
582 ph10 291
584 ph10 298
585     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
586     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
587     UTF-8 newline character). The key issue is that the pattern starts .*;
588     this means that the match must be either at the beginning, or after a
589     newline. The bug was in the code for advancing after a failed match and
590     checking that the new position followed a newline. It was not taking
591 ph10 294 account of UTF-8 characters correctly.
592 ph10 298
593     23. PCRE was behaving differently from Perl in the way it recognized POSIX
594     character classes. PCRE was not treating the sequence [:...:] as a
595     character class unless the ... were all letters. Perl, however, seems to
596     allow any characters between [: and :], though of course it rejects as
597     unknown any "names" that contain non-letters, because all the known class
598     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
599     for example, whereas PCRE did not - it did not recognize a POSIX character
600     class. This seemed a bit dangerous, so the code has been changed to be
601     closer to Perl. The behaviour is not identical to Perl, because PCRE will
602     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
603     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
604     Perl does, and where it didn't before.
606 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
607     Windows environments %n is disabled by default.
608 ph10 292
610 ph10 260 Version 7.4 21-Sep-07
611 ph10 230 ---------------------
613     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
614 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
615     LF". That isn't really right - the whole point of the change was to try to
616     help when there was an actual mention of one of the two characters. So now
617     the change happens only if \r or \n (or a literal CR or LF) character is
618 ph10 230 encountered.
619 ph10 231
620     2. The 32-bit options word was also used for 6 internal flags, but the numbers
621     of both had grown to the point where there were only 3 bits left.
622     Fortunately, there was spare space in the data structure, and so I have
623     moved the internal flags into a new 16-bit field to free up more option
624 ph10 230 bits.
625 ph10 231
626     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
627     but did not set the internal JCHANGED flag - either of these is enough to
628     control the way the "get" function works - but the PCRE_INFO_JCHANGED
629     facility is supposed to tell if (?J) was ever used, so now (?J) at the
630 ph10 230 start sets both bits.
632 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
633     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
634 ph10 230
635 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
637     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
638 ph10 233 compatibility, even though it is no longer used.
639 ph10 243
640     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
641 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
642 ph10 259 windows.h file is present (where different names are used). [This was
643 ph10 257 reversed later after testing - see 16 below.]
644 ph10 243
645     8. Changed all #include <config.h> to #include "config.h". There were also
646 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
647 ph10 243
648 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
649 ph10 243 sequence off the lines that it output.
651     10. It was pointed out to me that arrays of string pointers cause lots of
652     relocations when a shared library is dynamically loaded. A technique of
653     using a single long string with a table of offsets can drastically reduce
654     these. I have refactored PCRE in four places to do this. The result is
655 ph10 240 dramatic:
656 ph10 243
657 ph10 240 Originally: 290
658     After changing UCP table: 187
659 ph10 243 After changing error message table: 43
660 ph10 240 After changing table of "verbs" 36
661     After changing table of Posix names 22
662 ph10 243
663 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
664 ph10 247
665 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
666 ph10 247 unicode-properties was also set.
668 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
669 ph10 231
670 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
671     checked only for CRLF.
672 ph10 233
673 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
675 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
676 ph10 253
677 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
678 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
679     entirely. This removes changes made in 7 above.
680 ph10 256
681 ph10 261 17. The CMake files have been updated, and there is now more information about
682     building with CMake in the NON-UNIX-USE document.
683 ph10 257
684 ph10 261
685 ph10 228 Version 7.3 28-Aug-07
686 ph10 157 ---------------------
688 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
689     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
690     brackets there is not right, since it causes compilers to look for an
691     installed pcre.h, not the version that is in the source that is being
692     compiled (which of course may be different). I have changed it back to:
693 ph10 197
694 ph10 189 #include "pcre.h"
695 ph10 197
696     I have a vague recollection that the change was concerned with compiling in
697     different directories, but in the new build system, that is taken care of
698     by the VPATH setting the Makefile.
700 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
701     when the subject happened to end in the byte 0x85 (e.g. if the last
702     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
703     characters but of course it shouldn't be taken as a newline when it is part
704     of another character. The bug was that, for an unlimited repeat of . in
705     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
706     characters when looking for a newline.
707 ph10 197
708     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
710     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
711     in debug output.
713 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
714     long printing in the pcrecpp unittest when running under MinGW.
715 ph10 189
716 ph10 197 6. ESC_K was left out of the EBCDIC table.
717 ph10 189
718 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
719     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
720     limit also applies to "virtual nesting" when a pattern is recursive, and in
721     this case 1000 isn't so big. I have been able to remove this limit at the
722     expense of backing off one optimization in certain circumstances. Normally,
723     when pcre_exec() would call its internal match() function recursively and
724     immediately return the result unconditionally, it uses a "tail recursion"
725     feature to save stack. However, when a subpattern that can match an empty
726     string has an unlimited repetition quantifier, it no longer makes this
727     optimization. That gives it a stack frame in which to save the data for
728     checking that an empty string has been matched. Previously this was taken
729     from the 1000-entry workspace that had been reserved. So now there is no
730     explicit limit, but more stack is used.
731 ph10 189
732 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
733     syntax that is required for Windows, and which was going wrong for the
734     pcreposix and pcrecpp parts of the library. These were overlooked when this
735     problem was solved for the main library.
736 ph10 197
737 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
738     the size of patterns that contain repeated groups with explicit upper
739     limits. As the maximum quantifier is 65535, the maximum group length was
740     set at 30,000 so that the product of these two numbers did not overflow a
741     32-bit integer. However, it turns out that people want to use groups that
742     are longer than 30,000 bytes (though not repeat them that many times).
743     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
744     made it possible to implement the integer overflow checks in a much more
745     dynamic way, which I have now done. The artificial limitation on group
746     length has been removed - we now have only the limit on the total length of
747     the compiled pattern, which depends on the LINK_SIZE setting.
748 ph10 208
749     10. Fixed a bug in the documentation for get/copy named substring when
750     duplicate names are permitted. If none of the named substrings are set, the
751     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
752     empty string.
754     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
755     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
756     because the ] is interpreted as the first data character and the
757     terminating ] is not found. PCRE has been made compatible with Perl in this
758     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
759     cause memory overwriting.
761 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
762     string has been matched (to stop an infinite loop). It was not recognizing
763 ph10 208 a conditional subpattern that could match an empty string if that
764 ph10 206 subpattern was within another subpattern. For example, it looped when
765 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
766 ph10 206 condition was not nested. This bug has been fixed.
767 ph10 208
768 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
769     past the start of the subject in the presence of bytes with the top bit
770     set, for example "\x8aBCD".
771 ph10 211
772 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
773     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
774 ph10 200
775 ph10 211 14. Optimized (?!) to (*FAIL).
776 ph10 202
777 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
778     This restricts code points to be within the range 0 to 0x10FFFF, excluding
779     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
780     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
781     does: it's just the validity check that is more restrictive.
782 ph10 220
783     16. Inserted checks for integer overflows during escape sequence (backslash)
784     processing, and also fixed erroneous offset values for syntax errors during
785     backslash processing.
787 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
788 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
790 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
791     caused an overrun.
792 ph10 220
793     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
794     something other than just ASCII characters) inside a group that had an
795     unlimited repeat caused a loop at compile time (while checking to see
796     whether the group could match an empty string).
798 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
799     [\P{Any}] did so. (Error in the code for printing property names.)
800 ph10 210
801 ph10 220 21. An orphan \E inside a character class could cause a crash.
803     22. A repeated capturing bracket such as (A)? could cause a wild memory
804 ph10 218 reference during compilation.
805 ph10 220
806     23. There are several functions in pcre_compile() that scan along a compiled
807     expression for various reasons (e.g. to see if it's fixed length for look
808 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
809 ph10 220 present in the pattern. These operators have additional parameters compared
810     with \d, etc, and these were not being taken into account when moving along
811 ph10 218 the compiled data. Specifically:
812 ph10 220
813     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
814     length.
816     (b) An item such as \pL+ within a repeated group could cause crashes or
817 ph10 218 loops.
818 ph10 220
819 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
820 ph10 220 "reference to non-existent subpattern" error.
822 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
824 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
825 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
826 ph10 211
827 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
828 ph10 218
829 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
830 ph10 223 character were causing crashes (broken optimization).
831 ph10 227
832 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
833 ph10 227 \p or \P) caused a compile-time loop.
835 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
836     break. For example, the unstudied pattern [\r\n]A does not match the string
837     "\r\nA" because change 7.0/46 below moves the current point on by two
838     characters after failing to match at the start. However, the pattern \nA
839 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
840     the same is true. There doesn't seem any very clean way out of this, but
841     what I have chosen to do makes the common cases work: PCRE now takes note
842     of whether there can be an explicit match for \r or \n anywhere in the
843     pattern, and if so, 7.0/46 no longer applies. As part of this change,
844     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
845     pattern has explicit CR or LF references.
846 ph10 222
847 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
848 ph10 223
849 ph10 227
850 ph10 189 Version 7.2 19-Jun-07
851     ---------------------
853 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
854     which is apparently normally available under Windows.
855 ph10 159
856     2. Re-jig the pcregrep tests with different newline settings in an attempt
857     to make them independent of the local environment's newline setting.
858 ph10 157
859 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
860 ph10 165
861 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
862     was not 2, because the output contained actual offsets. The recent new
863 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
864     usable with all link sizes.
866 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
867     stack recursion. This gives a massive performance boost under BSD, but just
868 ph10 165 a small improvement under Linux. However, it saves one field in the frame
869 ph10 164 in all cases.
870 ph10 172
871 ph10 166 6. Added more features from the forthcoming Perl 5.10:
872 ph10 172
873 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
874     recursion call. It refers to the nth most recently opened parentheses.
875 ph10 172
876 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
877 ph10 172 to be opened parentheses.
879     (c) Conditions that refer to capturing parentheses can be specified
880 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
881 ph10 172
882 ph10 168 (d) \K resets the start of the current match so that everything before
883 ph10 172 is not part of it.
885 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
886 ph10 172
887 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
888 ph10 172 reference syntax.
889 ph10 182
890 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
891 ph10 182 alternative starts with the same number.
892 ph10 172
893 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
895 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
898     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
899     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
900 ph10 170 for detecting groups that can match an empty string.
901 ph10 159
902 ph10 172 9. A pattern with a very large number of alternatives (more than several
903     hundred) was running out of internal workspace during the pre-compile
904     phase, where pcre_compile() figures out how much memory will be needed. A
905     bit of new cunning has reduced the workspace needed for groups with
906     alternatives. The 1000-alternative test pattern now uses 12 bytes of
907     workspace instead of running out of the 4096 that are available.
908 ph10 182
909 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
910 ph10 172
911 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
912     The report of the bug said:
913 ph10 182
914 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
915     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
916 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
917 ph10 185
918 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
919 ph10 185 it matched the wrong number of bytes.
920 ph10 172
921 ph10 179
922 ph10 155 Version 7.1 24-Apr-07
923 ph10 98 ---------------------
925 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
926 ph10 122 that is more "standard", making use of automake and other Autotools. There
927 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
928     on this.
929 ph10 111
930     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
931     for recursive directory scanning broke on some systems because the files
932     are not scanned in any specific order and on different systems the order
933     was different. A call to "sort" has been inserted into RunGrepTest for the
934     approprate test as a short-term fix. In the longer term there may be an
935 ph10 100 alternative.
936 ph10 111
937 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
938 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
939     people do their own conversions for various reasons). The problems
940     concerned the use of low-level troff macros .br and .in. I have therefore
941     removed all such uses from the man pages (some were redundant, some could
942 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
943     HTML has been updated to handle .nf/.fi and to complain if it encounters
944     .br or .in.
945 ph10 111
946 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
947 ph10 123 arranged for config.h to be included in the distribution, with the name
948 ph10 111 config.h.generic, for the benefit of those who have to compile without
949     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
951     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
952     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
953 ph10 127 makevp.bat for the current PCRE, using the additional files
954 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
955 ph10 111
956     6. A Windows user reported a minor discrepancy with test 2, which turned out
957     to be caused by a trailing space on an input line that had got lost in his
958 ph10 102 copy. The trailing space was an accident, so I've just removed it.
959 ph10 111
960 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
961 ph10 111 that is needed.
963 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
964     as "const" (a) because they are and (b) because it helps the PHP
965     maintainers who have recently made a script to detect big data structures
966 ph10 111 in the php code that should be moved to the .rodata section. I remembered
967     to update Builducptable as well, so it won't revert if ucptable.h is ever
968 ph10 105 re-created.
969 ph10 111
970     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
971 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
972 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
973     support is not required. This saves 1.5-2K of code, which is important in
974 ph10 107 some applications.
975 ph10 111
976 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
977 ph10 111 so as not to refer to the tables, even though these functions will never be
978     called when UTF-8 support is disabled. Otherwise there are problems with a
979     shared library.
981 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
983     (a) It was defining its arguments as char * instead of void *.
985 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
986     a long time ago when I wrote it, but is no longer the case.
988 ph10 118 The emulated memove() is provided for those environments that have neither
989 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
990 ph10 118 is clearly not the case, as these two bugs were recently reported.
991 ph10 123
992 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
993 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
994     pages, and it removes trailing spaces from listed files. It also creates
995     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
996     case, it wraps all the #defines with #ifndefs. This script should be run
997 ph10 111 before "make dist".
998 ph10 123
999 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1000     with Unicode property support.
1001 ph10 123
1002     (a) For a maximizing quantifier, if the two different cases of the
1003     character were of different lengths in their UTF-8 codings (there are
1004     some cases like this - I found 11), and the matching function had to
1005 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1006     were both the same length.
1007 ph10 123
1008     (b) When PCRE was configured to use the heap rather than the stack for
1009     recursion during matching, it was not correctly preserving the data for
1010     the other case of a UTF-8 character when checking ahead for a match
1011     while processing a minimizing repeat. If the check also involved
1012 ph10 115 matching a wide character, but failed, corruption could cause an
1013     erroneous result when trying to check for a repeat of the original
1014     character.
1015 ph10 123
1016 ph10 116 13. Some tidying changes to the testing mechanism:
1017 ph10 98
1018 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1019     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1020 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1021     this for UTF-8.) The configure.ac script no longer substitutes the
1022     relevant variables.
1024 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1025     with length and offset values. This means that the output is different
1026     for different internal link sizes. Test 2 is skipped for link sizes
1027     other than 2 because of this, bypassing the problem. Unfortunately,
1028     there was also a test in test 3 (the locale tests) that used /B and
1029 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1030     I have added a new /Z option to pcretest that replaces the length and
1031     offset values with spaces. This is now used to make test 3 independent
1032 ph10 122 of link size. (Test 2 will be tidied up later.)
1033 ph10 123
1034     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1035 ph10 122 segmentation fault instead of returning the appropriate error message.
1036 ph10 134
1037 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1038 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1039     This doesn't seem right; it now treats the CRLF combination as the line
1040     ending, and so does not match in that case. It's only a pattern such as ^$
1041     that would hit this one: something like ^ABC$ would have failed after \r
1042     and then tried again after \r\n.
1044 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1045 ph10 134 in an attempt to make files that differ only in their line terminators
1046     compare equal. This works on Linux.
1047 ph10 142
1048 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1049     as it exited. This is now fixed, thanks to valgrind.
1050 ph10 142
1051 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1052 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1053     was because its rules for how to advance for /g after matching an empty
1054 ph10 143 string at the end of a line did not allow for this case. They now check for
1055     it specially.
1056 ph10 150
1057     20. pcretest is supposed to handle patterns and data of any length, by
1058     extending its buffers when necessary. It was getting this wrong when the
1059 ph10 147 buffer for a data line had to be extended.
1060 ph10 150
1061 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1062 ph10 150 CRLF as a newline sequence.
1063 ph10 152
1064 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1065 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1066     I have nevertheless tidied it up.
1067 ph10 111
1068 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1069 ph10 123
1070 ph10 153 24. Added a man page for pcre-config.
1071 ph10 152
1072 ph10 153
1073 nigel 93 Version 7.0 19-Dec-06
1074     ---------------------
1076     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1077     moving to gcc 4.1.1.
1079     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1080     sys/time.h, which is documented as needed for this function. It doesn't
1081     seem to matter on Linux, but it showed up on some releases of OS X.
1083     3. It seems that there are systems where bytes whose values are greater than
1084     127 match isprint() in the "C" locale. The "C" locale should be the
1085     default when a C program starts up. In most systems, only ASCII printing
1086     characters match isprint(). This difference caused the output from pcretest
1087     to vary, making some of the tests fail. I have changed pcretest so that:
1089     (a) When it is outputting text in the compiled version of a pattern, bytes
1090     other than 32-126 are always shown as hex escapes.
1092     (b) When it is outputting text that is a matched part of a subject string,
1093     it does the same, unless a different locale has been set for the match
1094     (using the /L modifier). In this case, it uses isprint() to decide.
1096     4. Fixed a major bug that caused incorrect computation of the amount of memory
1097     required for a compiled pattern when options that changed within the
1098     pattern affected the logic of the preliminary scan that determines the
1099     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1100     that the computed length was too small. The symptoms of this bug were
1101     either the PCRE error "internal error: code overflow" from pcre_compile(),
1102     or a glibc crash with a message such as "pcretest: free(): invalid next
1103     size (fast)". Examples of patterns that provoked this bug (shown in
1104     pcretest format) are:
1106     /(?-x: )/x
1107     /(?x)(?-x: \s*#\s*)/
1108     /((?i)[\x{c0}])/8
1109     /(?i:[\x{c0}])/8
1111     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1112     is now done differently.
1114     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1115     wrapper classes; (b) implement a new function in the C++ scanner that is
1116     more efficient than the old way of doing things because it avoids levels of
1117     recursion in the regex matching; (c) add a paragraph to the documentation
1118     for the FullMatch() function.
1120     6. The escape sequence \n was being treated as whatever was defined as
1121     "newline". Not only was this contrary to the documentation, which states
1122     that \n is character 10 (hex 0A), but it also went horribly wrong when
1123     "newline" was defined as CRLF. This has been fixed.
1125     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1126     was being set to -1 for the "end of line" case (supposedly a value that no
1127     character can have). Though this value is never used (the check for end of
1128     line is "zero bytes in current character"), it caused compiler complaints.
1129     I've changed it to 0xffffffff.
1131     8. In pcre_version.c, the version string was being built by a sequence of
1132     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1133     string (as it is for production releases) called a macro with an empty
1134     argument. The C standard says the result of this is undefined. The gcc
1135     compiler treats it as an empty string (which was what was wanted) but it is
1136     reported that Visual C gives an error. The source has been hacked around to
1137     avoid this problem.
1139     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1140     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1141     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1142     of them did).
1144     10. Originally, pcretest opened its input and output without "b"; then I was
1145     told that "b" was needed in some environments, so it was added for release
1146     5.0 to both the input and output. (It makes no difference on Unix-like
1147     systems.) Later I was told that it is wrong for the input on Windows. I've
1148     now abstracted the modes into two macros, to make it easier to fiddle with
1149     them, and removed "b" from the input mode under Windows.
1151     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1153     12. Added -help and --help to pcretest as an official way of being reminded
1154     of the options.
1156     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1157     and pcrecpp.cc because they annoy compilers at high warning levels.
1159     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1161     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1162     scripts are not C programs :-) and which was not noticed because it works
1163     on Linux.
1165     16. pcretest is supposed to handle any length of pattern and data line (as one
1166     line or as a continued sequence of lines) by extending its input buffer if
1167     necessary. This feature was broken for very long pattern lines, leading to
1168     a string of junk being passed to pcre_compile() if the pattern was longer
1169     than about 50K.
1171     17. I have done a major re-factoring of the way pcre_compile() computes the
1172     amount of memory needed for a compiled pattern. Previously, there was code
1173     that made a preliminary scan of the pattern in order to do this. That was
1174     OK when PCRE was new, but as the facilities have expanded, it has become
1175     harder and harder to keep it in step with the real compile phase, and there
1176     have been a number of bugs (see for example, 4 above). I have now found a
1177     cunning way of running the real compile function in a "fake" mode that
1178     enables it to compute how much memory it would need, while actually only
1179     ever using a few hundred bytes of working memory and without too many
1180     tests of the mode. This should make future maintenance and development
1181     easier. A side effect of this work is that the limit of 200 on the nesting
1182     depth of parentheses has been removed (though this was never a serious
1183     limitation, I suspect). However, there is a downside: pcre_compile() now
1184     runs more slowly than before (30% or more, depending on the pattern). I
1185     hope this isn't a big issue. There is no effect on runtime performance.
1187     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1188     newline (only possible for the last line of a file) and it was a
1189     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1191     19. Added additional timing features to pcretest. (1) The -tm option now times
1192     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1193     separate command line item, by a number that specifies the number of
1194     repeats to use when timing. The default is 50000; this gives better
1195     precision, but takes uncomfortably long for very large patterns.
1197     20. Extended pcre_study() to be more clever in cases where a branch of a
1198     subpattern has no definite first character. For example, (a*|b*)[cd] would
1199     previously give no result from pcre_study(). Now it recognizes that the
1200     first character must be a, b, c, or d.
1202     21. There was an incorrect error "recursive call could loop indefinitely" if
1203     a subpattern (or the entire pattern) that was being tested for matching an
1204     empty string contained only one non-empty item after a nested subpattern.
1205     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1206     incorrectly, because the \d was being skipped in the check.
1208     22. The pcretest program now has a new pattern option /B and a command line
1209     option -b, which is equivalent to adding /B to every pattern. This causes
1210     it to show the compiled bytecode, without the additional information that
1211     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1212     is the same as /B/I).
1214     23. A new optimization is now able automatically to treat some sequences such
1215     as a*b as a*+b. More specifically, if something simple (such as a character
1216     or a simple class like \d) has an unlimited quantifier, and is followed by
1217     something that cannot possibly match the quantified thing, the quantifier
1218     is automatically "possessified".
1220     24. A recursive reference to a subpattern whose number was greater than 39
1221     went wrong under certain circumstances in UTF-8 mode. This bug could also
1222     have affected the operation of pcre_study().
1224     25. Realized that a little bit of performance could be had by replacing
1225     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1227     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1229     27. Possessive quantifiers such as a++ were previously implemented by turning
1230     them into atomic groups such as ($>a+). Now they have their own opcodes,
1231     which improves performance. This includes the automatically created ones
1232     from 23 above.
1234     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1235     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1236     the first matched character to be a colon. This applied both to named and
1237     numbered groups.
1239     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1241     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1242     building PCRE on Windows easier, so I have included it in the distribution.
1244     31. There is now a check in pcretest against a ridiculously large number being
1245     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1246     loop, the loop is abandoned.
1248     32. Forward references to subpatterns in conditions such as (?(2)...) where
1249     subpattern 2 is defined later cause pcre_compile() to search forwards in
1250     the pattern for the relevant set of parentheses. This search went wrong
1251     when there were unescaped parentheses in a character class, parentheses
1252     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1254     33. "Subroutine" calls and backreferences were previously restricted to
1255     referencing subpatterns earlier in the regex. This restriction has now
1256     been removed.
1258     34. Added a number of extra features that are going to be in Perl 5.10. On the
1259     whole, these are just syntactic alternatives for features that PCRE had
1260     previously implemented using the Python syntax or my own invention. The
1261     other formats are all retained for compatibility.
1263     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1264     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1265     also .NET compatible.
1267     (b) A recursion or subroutine call to a named group can now be defined as
1268     (?&name) as well as (?P>name).
1270     (c) A backreference to a named group can now be defined as \k<name> or
1271     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1272     5.10, are also .NET compatible.
1274     (d) A conditional reference to a named group can now use the syntax
1275     (?(<name>) or (?('name') as well as (?(name).
1277     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1278     groups (named and numbered) that are never evaluated inline, but can be
1279     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1280     is always false. There may be only one alternative in such a group.
1282     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1283     as the simple (?(R). The condition is true only if the most recent
1284     recursion is that of the given number or name. It does not search out
1285     through the entire recursion stack.
1287     (g) The escape \gN or \g{N} has been added, where N is a positive or
1288     negative number, specifying an absolute or relative reference.
1290     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1291     some "unreachable code" warnings.
1293     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1294     things, this adds five new scripts.
1296     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1297     There were also incompatibilities regarding the handling of \Q..\E inside
1298     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1299     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1301     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1302     matches an empty string, and forcibly breaks the loop. There were bugs in
1303     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1304     against aaaa the result was just "a" rather than "aaaa", for example. Two
1305     separate and independent bugs (that affected different cases) have been
1306     fixed.
1308     39. Refactored the code to abolish the use of different opcodes for small
1309     capturing bracket numbers. This is a tidy that I avoided doing when I
1310     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1311     The new approach is not only tidier, it makes it possible to reduce the
1312     memory needed to fix the previous bug (38).
1314     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1315     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1316     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1317     mode.
1319     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1320     report.
1322     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1323     copy construction and assignment in the C++ wrapper.
1325     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1326     couple of bugs that could have given wrong results in the "--newline=crlf"
1327     case.
1329     44. Added a number of casts and did some reorganization of signed/unsigned int
1330     variables following suggestions from Dair Grant. Also renamed the variable
1331     "this" as "item" because it is a C++ keyword.
1333     45. Arranged for dftables to add
1335     #include "pcre_internal.h"
1337     to pcre_chartables.c because without it, gcc 4.x may remove the array
1338     definition from the final binary if PCRE is built into a static library and
1339     dead code stripping is activated.
1341     46. For an unanchored pattern, if a match attempt fails at the start of a
1342     newline sequence, and the newline setting is CRLF or ANY, and the next two
1343     characters are CRLF, advance by two characters instead of one.
1346 nigel 91 Version 6.7 04-Jul-06
1347     ---------------------
1349     1. In order to handle tests when input lines are enormously long, pcretest has
1350     been re-factored so that it automatically extends its buffers when
1351     necessary. The code is crude, but this _is_ just a test program. The
1352     default size has been increased from 32K to 50K.
1354     2. The code in pcre_study() was using the value of the re argument before
1355     testing it for NULL. (Of course, in any sensible call of the function, it
1356     won't be NULL.)
1358     3. The memmove() emulation function in pcre_internal.h, which is used on
1359     systems that lack both memmove() and bcopy() - that is, hardly ever -
1360     was missing a "static" storage class specifier.
1362     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1363     containing an extended class (one that cannot be represented by a bitmap
1364     because it contains high-valued characters or Unicode property items, e.g.
1365     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1366     pattern, but PCRE should not loop if you do not (it no longer does).
1367     [Detail: two cases were found: (a) a repeated subpattern containing an
1368     extended class; (b) a recursive reference to a subpattern that followed a
1369     previous extended class. It wasn't skipping over the extended class
1370     correctly when UTF-8 mode was not set.]
1372     5. A negated single-character class was not being recognized as fixed-length
1373     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1374     compile error "lookbehind assertion is not fixed length".
1376     6. The RunPerlTest auxiliary script was showing an unexpected difference
1377     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1378     write a Perl script that can interpret lines of an input file either as
1379     byte characters or as UTF-8, which is what "perltest" was being required to
1380     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1381     can't do is switch easily at run time between having the "use utf8;" pragma
1382     or not. In the end, I fudged it by using the RunPerlTest script to insert
1383     "use utf8;" explicitly for the UTF-8 tests.
1385     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1386     the end of the subject string, contrary to the documentation and to what
1387     Perl does. This was true of both matching functions. Now it matches only at
1388     the start of the subject and immediately after *internal* newlines.
1390     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1391     a pointer to an int instead of a pointer to an unsigned long int. This
1392     caused problems on 64-bit systems.
1394     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1395     instance of the 'standard' template library not being so standard".
1397     10. There was no check on the number of named subpatterns nor the maximum
1398     length of a subpattern name. The product of these values is used to compute
1399     the size of the memory block for a compiled pattern. By supplying a very
1400     long subpattern name and a large number of named subpatterns, the size
1401     computation could be caused to overflow. This is now prevented by limiting
1402     the length of names to 32 characters, and the number of named subpatterns
1403     to 10,000.
1405     11. Subpatterns that are repeated with specific counts have to be replicated in
1406     the compiled pattern. The size of memory for this was computed from the
1407     length of the subpattern and the repeat count. The latter is limited to
1408     65535, but there was no limit on the former, meaning that integer overflow
1409     could in principle occur. The compiled length of a repeated subpattern is
1410     now limited to 30,000 bytes in order to prevent this.
1412     12. Added the optional facility to have named substrings with the same name.
1414     13. Added the ability to use a named substring as a condition, using the
1415     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1416     are numbers (not recommended). Forward references are permitted.
1418     14. Added forward references in named backreferences (if you see what I mean).
1420     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1421     pattern could run off the end of the subject. For example, the pattern
1422     "(?s)(.{1,5})"8 did this with the subject "ab".
1424     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1425     PCRE_CASELESS was set when matching characters that were quantified with ?
1426     or *.
1428     17. A character class other than a single negated character that had a minimum
1429     but no maximum quantifier - for example [ab]{6,} - was not handled
1430     correctly by pce_dfa_exec(). It would match only one character.
1432     18. A valid (though odd) pattern that looked like a POSIX character
1433     class but used an invalid character after [ (for example [[,abc,]]) caused
1434     pcre_compile() to give the error "Failed: internal error: code overflow" or
1435     in some cases to crash with a glibc free() error. This could even happen if
1436     the pattern terminated after [[ but there just happened to be a sequence of
1437     letters, a binary zero, and a closing ] in the memory that followed.
1439     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1440     over the years. Originally (before any Unicode support), just the bottom 8
1441     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1442     output from "man perlunicode" includes this:
1444     The regular expression compiler produces polymorphic opcodes. That
1445     is, the pattern adapts to the data and automatically switches to
1446     the Unicode character scheme when presented with Unicode data--or
1447     instead uses a traditional byte scheme when presented with byte
1448     data.
1450     Sadly, a wide octal escape does not cause a switch, and in a string with
1451     no other multibyte characters, these octal escapes are treated as before.
1452     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1453     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1454     Unicode string.
1456     I have not perpetrated such confusion in PCRE. Up till now, it took just
1457     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1458     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1459     translate to the appropriate multibyte character.
1461     29. Applied some refactoring to reduce the number of warnings from Microsoft
1462     and Borland compilers. This has included removing the fudge introduced
1463     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1464     a warning about an unused variable.
1466     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1467     characters since release 4.0, because Perl (from release 5.004) does not.
1468     [Or at least, is documented not to: some releases seem to be in conflict
1469     with the documentation.] However, when a pattern was studied with
1470     pcre_study() and all its branches started with \s, PCRE still included VT
1471     as a possible starting character. Of course, this did no harm; it just
1472     caused an unnecessary match attempt.
1474     22. Removed a now-redundant internal flag bit that recorded the fact that case
1475     dependency changed within the pattern. This was once needed for "required
1476     byte" processing, but is no longer used. This recovers a now-scarce options
1477     bit. Also moved the least significant internal flag bit to the most-
1478     significant bit of the word, which was not previously used (hangover from
1479     the days when it was an int rather than a uint) to free up another bit for
1480     the future.
1482     23. Added support for CRLF line endings as well as CR and LF. As well as the
1483     default being selectable at build time, it can now be changed at runtime
1484     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1485     specify that it is scanning data with non-default line endings.
1487     24. Changed the definition of CXXLINK to make it agree with the definition of
1488     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1490     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1491     recursions. This makes a big different to stack usage for some patterns.
1493     26. If a subpattern containing a named recursion or subroutine reference such
1494     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1495     the space required for the compiled pattern went wrong and gave too small a
1496     value. Depending on the environment, this could lead to "Failed: internal
1497     error: code overflow at offset 49" or "glibc detected double free or
1498     corruption" errors.
1500     27. Applied patches from Google (a) to support the new newline modes and (b) to
1501     advance over multibyte UTF-8 characters in GlobalReplace.
1503     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1504     difference for some implementation of PCRE in some Windows version.
1506     29. Added some extra testing facilities to pcretest:
1508     \q<number> in a data line sets the "match limit" value
1509     \Q<number> in a data line sets the "match recursion limt" value
1510     -S <number> sets the stack size, where <number> is in megabytes
1512     The -S option isn't available for Windows.
1515 nigel 89 Version 6.6 06-Feb-06
1516     ---------------------
1518     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1519     in pcreposix.h. I have copied the definition from pcre.h.
1521     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1522     because pcre.h is no longer a built file.
1524     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1525     not normally included in the compiled code.
1528 nigel 87 Version 6.5 01-Feb-06
1529     ---------------------
1531     1. When using the partial match feature with pcre_dfa_exec(), it was not
1532     anchoring the second and subsequent partial matches at the new starting
1533     point. This could lead to incorrect results. For example, with the pattern
1534     /1234/, partially matching against "123" and then "a4" gave a match.
1536     2. Changes to pcregrep:
1538     (a) All non-match returns from pcre_exec() were being treated as failures
1539     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1540     error message is output. Some extra information is given for the
1542     probably the only errors that are likely to be caused by users (by
1543     specifying a regex that has nested indefinite repeats, for instance).
1544     If there are more than 20 of these errors, pcregrep is abandoned.
1546     (b) A binary zero was treated as data while matching, but terminated the
1547     output line if it was written out. This has been fixed: binary zeroes
1548     are now no different to any other data bytes.
1550     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1551     used to set a locale for matching. The --locale=xxxx long option has
1552     been added (no short equivalent) to specify a locale explicitly on the
1553     pcregrep command, overriding the environment variables.
1555     (d) When -B was used with -n, some line numbers in the output were one less
1556     than they should have been.
1558     (e) Added the -o (--only-matching) option.
1560     (f) If -A or -C was used with -c (count only), some lines of context were
1561     accidentally printed for the final match.
1563     (g) Added the -H (--with-filename) option.
1565     (h) The combination of options -rh failed to suppress file names for files
1566     that were found from directory arguments.
1568     (i) Added the -D (--devices) and -d (--directories) options.
1570     (j) Added the -F (--fixed-strings) option.
1572     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1574     (l) Added the --colo(u)r option.
1576     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1577     is not present by default.
1579     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1580     items such as (?R) or (?1), when the recursion could match a number of
1581     alternatives. If it matched one of the alternatives, but subsequently,
1582     outside the recursion, there was a failure, the code tried to back up into
1583     the recursion. However, because of the way PCRE is implemented, this is not
1584     possible, and the result was an incorrect result from the match.
1586     In order to prevent this happening, the specification of recursion has
1587     been changed so that all such subpatterns are automatically treated as
1588     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1590     4. I had overlooked the fact that, in some locales, there are characters for
1591     which isalpha() is true but neither isupper() nor islower() are true. In
1592     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1593     and ordfeminine) are like this. This affected the treatment of \w and \W
1594     when they appeared in character classes, but not when they appeared outside
1595     a character class. The bit map for "word" characters is now created
1596     separately from the results of isalnum() instead of just taking it from the
1597     upper, lower, and digit maps. (Plus the underscore character, of course.)
1599     5. The above bug also affected the handling of POSIX character classes such as
1600     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1601     permanent tables. Instead, the bit maps for such a class were previously
1602     created as the appropriate unions of the upper, lower, and digit bitmaps.
1603     Now they are created by subtraction from the [[:word:]] class, which has
1604     its own bitmap.
1606     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1607     It is created by subtracting the vertical space characters (\x09, \x0a,
1608     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1609     subtraction was done in the overall bitmap for a character class, meaning
1610     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1611     be recognized. This bug has been fixed.
1613     7. Patches from the folks at Google:
1615     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1616     real life, but is still worth protecting against".
1618     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1619     regular expressions".
1621     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1622     have it.
1624     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1625     "configure" and the latter not, in order to fix a problem somebody had
1626     with compiling the Arg class on HP-UX.
1628     (e) Improve the error-handling of the C++ wrapper a little bit.
1630     (f) New tests for checking recursion limiting.
1632     8. The pcre_memmove() function, which is used only if the environment does not
1633     have a standard memmove() function (and is therefore rarely compiled),
1634     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1635     returning a result (though PCRE never actually uses the result).
1637     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1638     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1639     returned instead of calling malloc() with an overflowing number that would
1640     most likely cause subsequent chaos.
1642     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1644     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1645     with this option is matched, the nmatch and pmatch options of regexec() are
1646     ignored.
1648     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1649     provided in case anyone wants to the the POSIX interface with UTF-8
1650     strings.
1652     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1653     C++ linking (needed for some HP-UX environments).
1655     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1656     (unused parameter) and in the pcre_printint() function (omitted "default"
1657     switch label when the default is to do nothing).
1659     15. Added some code to make it possible, when PCRE is compiled as a C++
1660     library, to replace subject pointers for pcre_exec() with a smart pointer
1661     class, thus making it possible to process discontinuous strings.
1663     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1664     much the same function. They were added by different people who were trying
1665     to make PCRE easy to compile on non-Unix systems. It has been suggested
1666     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1667     for compiling on Windows systems. I have therefore replaced it with
1668     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1669     defaults to "extern" for C or "extern C" for C++, which works fine on
1670     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1671     SCOPE with something explicit in config.h. In addition:
1673     (a) pcreposix.h still had just "extern" instead of either of these macros;
1674     I have replaced it with PCRE_DATA_SCOPE.
1676     (b) Functions such as _pcre_xclass(), which are internal to the library,
1677     but external in the C sense, all had PCRE_EXPORT in their definitions.
1678     This is apparently wrong for the Windows case, so I have removed it.
1679     (It makes no difference on Unix-like systems.)
1681     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1682     of recursive calls to match(). This is different to MATCH_LIMIT because
1683     that limits the total number of calls to match(), not all of which increase
1684     the depth of recursion. Limiting the recursion depth limits the amount of
1685     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1686     when PCRE is compiled, and changed at run time. A patch from Google adds
1687     this functionality to the C++ interface.
1689     18. Changes to the handling of Unicode character properties:
1691     (a) Updated the table to Unicode 4.1.0.
1693     (b) Recognize characters that are not in the table as "Cn" (undefined).
1695     (c) I revised the way the table is implemented to a much improved format
1696     which includes recognition of ranges. It now supports the ranges that
1697     are defined in UnicodeData.txt, and it also amalgamates other
1698     characters into ranges. This has reduced the number of entries in the
1699     table from around 16,000 to around 3,000, thus reducing its size
1700     considerably. I realized I did not need to use a tree structure after
1701     all - a binary chop search is just as efficient. Having reduced the
1702     number of entries, I extended their size from 6 bytes to 8 bytes to
1703     allow for more data.
1705     (d) Added support for Unicode script names via properties such as \p{Han}.
1707     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1708     matching that character.
1710     20. When matching a repeated Unicode property with a minimum greater than zero,
1711     (for example \pL{2,}), PCRE could look past the end of the subject if it
1712     reached it while seeking the minimum number of characters. This could
1713     happen only if some of the characters were more than one byte long, because
1714     there is a check for at least the minimum number of bytes.
1716     21. Refactored the implementation of \p and \P so as to be more general, to
1717     allow for more different types of property in future. This has changed the
1718     compiled form incompatibly. Anybody with saved compiled patterns that use
1719     \p or \P will have to recompile them.
1721     22. Added "Any" and "L&" to the supported property types.
1723     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1724     but give a compile time error if the value is greater than 0xff.
1726     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1727     accidentally not being installed or uninstalled.
1729     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1730     made were to insert the current release number. This seemed silly, because
1731     it made things harder for people building PCRE on systems that don't run
1732     "configure". I have turned pcre.h into a distributed file, no longer built
1733     by "configure", with the version identification directly included. There is
1734     no longer a pcre.h.in file.
1736     However, this change necessitated a change to the pcre-config script as
1737     well. It is built from pcre-config.in, and one of the substitutions was the
1738     release number. I have updated configure.ac so that ./configure now finds
1739     the release number by grepping pcre.h.
1741     26. Added the ability to run the tests under valgrind.
1744 nigel 85 Version 6.4 05-Sep-05
1745     ---------------------
1747     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1748     "--" to be printed when multiple files were scanned, even when none of the
1749     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1750     consider it to be a bug, and have restored the previous behaviour.
1752     2. A couple of code tidies to get rid of compiler warnings.
1754     3. The pcretest program used to cheat by referring to symbols in the library
1755     whose names begin with _pcre_. These are internal symbols that are not
1756     really supposed to be visible externally, and in some environments it is
1757     possible to suppress them. The cheating is now confined to including
1758     certain files from the library's source, which is a bit cleaner.
1760     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1761     file's purpose clearer.
1763     5. Reorganized pcre_ucp_findchar().
1766 nigel 83 Version 6.3 15-Aug-05
1767     ---------------------
1769     1. The file libpcre.pc.in did not have general read permission in the tarball.
1771     2. There were some problems when building without C++ support:
1773     (a) If C++ support was not built, "make install" and "make test" still
1774     tried to test it.
1776     (b) There were problems when the value of CXX was explicitly set. Some
1777     changes have been made to try to fix these, and ...
1779     (c) --disable-cpp can now be used to explicitly disable C++ support.
1781     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1782     backslash in a target when C++ was disabled. This confuses some
1783     versions of "make", apparently. Using an intermediate variable solves
1784     this. (Same for CPP_LOBJ.)
1786     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1787     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1788     necessary on certain architectures.
1790     4. Added a setting of -export-symbols-regex to the link command to remove
1791     those symbols that are exported in the C sense, but actually are local
1792     within the library, and not documented. Their names all begin with
1793     "_pcre_". This is not a perfect job, because (a) we have to except some
1794     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1795     available (and never for static libraries). I have made a note to try to
1796     find a way round (a) in the future.
1799 nigel 81 Version 6.2 01-Aug-05
1800     ---------------------
1802     1. There was no test for integer overflow of quantifier values. A construction
1803     such as {1111111111111111} would give undefined results. What is worse, if
1804     a minimum quantifier for a parenthesized subpattern overflowed and became
1805     negative, the calculation of the memory size went wrong. This could have
1806     led to memory overwriting.
1808     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1810     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1811     operating environments where this matters.
1813     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1814     PCRE options from within the C++ wrapper.
1816     5. Named capturing subpatterns were not being correctly counted when a pattern
1817     was compiled. This caused two problems: (a) If there were more than 100
1818     such subpatterns, the calculation of the memory needed for the whole
1819     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1820     back references of the form \12, where the number was greater than 9, were
1821     not recognized as back references, even though there were sufficient
1822     previous subpatterns.
1824     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1825     versions of gcc, e.g. 2.95.4.
1828 nigel 79 Version 6.1 21-Jun-05
1829     ---------------------
1831     1. There was one reference to the variable "posix" in pcretest.c that was not
1832     surrounded by "#if !defined NOPOSIX".
1834     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1835     the cross-check on the old pcre_info() function, for the benefit of the
1836     cut-down version of PCRE that is currently imported into Exim.
1838     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1839     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1840     patterns that start (?i) but I don't think that matters. The use of (?i) is
1841     just an example; this all applies to the other options as well.
1843     4. Since libtool seems to echo the compile commands it is issuing, the output
1844     from "make" can be reduced a bit by putting "@" in front of each libtool
1845     compile command.
1847     5. Patch from the folks at Google for configure.in to be a bit more thorough
1848     in checking for a suitable C++ installation before trying to compile the
1849     C++ stuff. This should fix a reported problem when a compiler was present,
1850     but no suitable headers.
1852     6. The man pages all had just "PCRE" as their title. I have changed them to
1853     be the relevant file name. I have also arranged that these names are
1854     retained in the file doc/pcre.txt, which is a concatenation in text format
1855     of all the man pages except the little individual ones for each function.
1857     7. The NON-UNIX-USE file had not been updated for the different set of source
1858     files that come with release 6. I also added a few comments about the C++
1859     wrapper.
1862 nigel 77 Version 6.0 07-Jun-05
1863     ---------------------
1865     1. Some minor internal re-organization to help with my DFA experiments.
1867     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1868     didn't matter for the library itself when fully configured, but did matter
1869     when compiling without UCP support, or within Exim, where the ucp files are
1870     not imported.
1872     3. Refactoring of the library code to split up the various functions into
1873     different source modules. The addition of the new DFA matching code (see
1874     below) to a single monolithic source would have made it really too
1875     unwieldy, quite apart from causing all the code to be include in a
1876     statically linked application, when only some functions are used. This is
1877     relevant even without the DFA addition now that patterns can be compiled in
1878     one application and matched in another.
1880     The downside of splitting up is that there have to be some external
1881     functions and data tables that are used internally in different modules of
1882     the library but which are not part of the API. These have all had their
1883     names changed to start with "_pcre_" so that they are unlikely to clash
1884     with other external names.
1886     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1887     a different (DFA) algorithm. Although it is slower than the original
1888     function, it does have some advantages for certain types of matching
1889     problem.
1891     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1892     including restarting after a partial match.
1894     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1895     defined when compiling for Windows was sent to me. I have put it into the
1896     code, though I have no means of testing or verifying it.
1898     7. Added the pcre_refcount() auxiliary function.
1900     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1901     match before or at the first newline in the subject string. In pcretest,
1902     the /f option on a pattern can be used to set this.
1904     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1905     would behave wrongly. This has been present in PCRE since release 4.0.
1907     10. A number of changes to the pcregrep command:
1909     (a) Refactored how -x works; insert ^(...)$ instead of setting
1910     PCRE_ANCHORED and checking the length, in preparation for adding
1911     something similar for -w.
1913     (b) Added the -w (match as a word) option.
1915     (c) Refactored the way lines are read and buffered so as to have more
1916     than one at a time available.
1918     (d) Implemented a pcregrep test script.
1920     (e) Added the -M (multiline match) option. This allows patterns to match
1921     over several lines of the subject. The buffering ensures that at least
1922     8K, or the rest of the document (whichever is the shorter) is available
1923     for matching (and similarly the previous 8K for lookbehind assertions).
1925     (f) Changed the --help output so that it now says
1927     -w, --word-regex(p)
1929     instead of two lines, one with "regex" and the other with "regexp"
1930     because that confused at least one person since the short forms are the
1931     same. (This required a bit of code, as the output is generated
1932     automatically from a table. It wasn't just a text change.)
1934     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1935     option but starts with a hyphen. Could be a pattern or a path name
1936     starting with a hyphen, for instance.
1938     (h) "-" can be given as a file name to represent stdin.
1940     (i) When file names are being printed, "(standard input)" is used for
1941     the standard input, for compatibility with GNU grep. Previously
1942     "<stdin>" was used.
1944     (j) The option --label=xxx can be used to supply a name to be used for
1945     stdin when file names are being printed. There is no short form.
1947     (k) Re-factored the options decoding logic because we are going to add
1948     two more options that take data. Such options can now be given in four
1949     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1951     (l) Added the -A, -B, and -C options for requesting that lines of context
1952     around matches be printed.
1954     (m) Added the -L option to print the names of files that do not contain
1955     any matching lines, that is, the complement of -l.
1957     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1958     continue to scan other files.
1960     (o) The -s option was incorrectly implemented. For compatibility with other
1961     greps, it now suppresses the error message for a non-existent or non-
1962     accessible file (but not the return code). There is a new option called
1963     -q that suppresses the output of matching lines, which was what -s was
1964     previously doing.
1966     (p) Added --include and --exclude options to specify files for inclusion
1967     and exclusion when recursing.
1969     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1970     Hopefully, it now does.
1972     12. Missing cast in pcre_study().
1974     13. Added an "uninstall" target to the makefile.
1976     14. Replaced "extern" in the function prototypes in Makefile.in with
1977     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1978     world, but is set differently for Windows.
1980     15. Added a second compiling function called pcre_compile2(). The only
1981     difference is that it has an extra argument, which is a pointer to an
1982     integer error code. When there is a compile-time failure, this is set
1983     non-zero, in addition to the error test pointer being set to point to an
1984     error message. The new argument may be NULL if no error number is required
1985     (but then you may as well call pcre_compile(), which is now just a
1986     wrapper). This facility is provided because some applications need a
1987     numeric error indication, but it has also enabled me to tidy up the way
1988     compile-time errors are handled in the POSIX wrapper.
1990     16. Added VPATH=.libs to the makefile; this should help when building with one
1991     prefix path and installing with another. (Or so I'm told by someone who
1992     knows more about this stuff than I do.)
1994     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1995     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1996     match everything, including newlines. This is not POSIX-compatible, but
1997     somebody wanted the feature. From pcretest it can be activated by using
1998     both the P and the s flags.
2000     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2002     19. libpcre.pc was being incorrectly installed as executable.
2004     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2005     it now also looks for '\r' so that it will work unmodified on Windows.
2007     21. Added Google's contributed C++ wrapper to the distribution.
2009     22. Added some untidy missing memory free() calls in pcretest, to keep
2010     Electric Fence happy when testing.
2014 nigel 75 Version 5.0 13-Sep-04
2015     ---------------------
2017     1. Internal change: literal characters are no longer packed up into items
2018     containing multiple characters in a single byte-string. Each character
2019     is now matched using a separate opcode. However, there may be more than one
2020     byte in the character in UTF-8 mode.
2022     2. The pcre_callout_block structure has two new fields: pattern_position and
2023     next_item_length. These contain the offset in the pattern to the next match
2024     item, and its length, respectively.
2026     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2027     insertion of callouts before each pattern item. Added the /C option to
2028     pcretest to make use of this.
2030     4. On the advice of a Windows user, the lines
2032     #if defined(_WIN32) || defined(WIN32)
2033     _setmode( _fileno( stdout ), 0x8000 );
2034     #endif /* defined(_WIN32) || defined(WIN32) */
2036     have been added to the source of pcretest. This apparently does useful
2037     magic in relation to line terminators.
2039     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2040     for the benefit of those environments where the "b" makes a difference.
2042     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2043     to know about it. I have put a hack into configure.in that adds in code
2044     to set GCC=yes if CC=icc. This seems to end up at a point in the
2045     generated configure script that is early enough to affect the setting of
2046     compiler options, which is what is needed, but I have no means of testing
2047     whether it really works. (The user who reported this had patched the
2048     generated configure script, which of course I cannot do.)
2050     LATER: After change 22 below (new libtool files), the configure script
2051     seems to know about icc (and also ecc). Therefore, I have commented out
2052     this hack in configure.in.
2054     7. Added support for pkg-config (2 patches were sent in).
2056     8. Negated POSIX character classes that used a combination of internal tables
2057     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2058     [[:^ascii]]. Typically, they would match almost any characters. The other
2059     POSIX classes were not broken in this way.
2061     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2062     to find the match, as PCRE was deluded into thinking that the match had to
2063     start at the start point or following a newline. The same bug applied to
2064     patterns with negative forward assertions or any backward assertions
2065     preceding ".*" at the start, unless the pattern required a fixed first
2066     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2068     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2069     starting at the last subject character, bytes beyond the end of the subject
2070     string were read.
2072     11. Renamed the variable "class" as "classbits" to make life easier for C++
2073     users. (Previously there was a macro definition, but it apparently wasn't
2074     enough.)
2076     12. Added the new field "tables" to the extra data so that tables can be passed
2077     in at exec time, or the internal tables can be re-selected. This allows
2078     a compiled regex to be saved and re-used at a later time by a different
2079     program that might have everything at different addresses.
2081     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2082     -R library as well as a -L library.
2084     14. The debugging options of pcretest (-d on the command line or D on a
2085     pattern) showed incorrect output for anything following an extended class
2086     that contained multibyte characters and which was followed by a quantifier.
2088     15. Added optional support for general category Unicode character properties
2089     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2090     support. It adds about 90K to the size of the library. The meanings of the
2091     inbuilt class escapes such as \d and \s have NOT been changed.
2093     16. Updated pcredemo.c to include calls to free() to release the memory for the
2094     compiled pattern.
2096     17. The generated file chartables.c was being created in the source directory
2097     instead of in the building directory. This caused the build to fail if the
2098     source directory was different from the building directory, and was
2099     read-only.
2101     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2102     file. No doubt somebody will tell me if they don't make sense... Also added
2103     Dan Mooney's comments about building on OpenVMS.
2105     19. Added support for partial matching via the PCRE_PARTIAL option for
2106     pcre_exec() and the \P data escape in pcretest.
2108     20. Extended pcretest with 3 new pattern features:
2110     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2111     write the compiled pattern to the file whose name is "rest-of-line".
2112     This is a straight binary dump of the data, with the saved pointer to
2113     the character tables forced to be NULL. The study data, if any, is
2114     written too. After writing, pcretest reads a new pattern.
2116     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2117     compiled pattern from the given file. There must not be any
2118     occurrences of "<" in the file name (pretty unlikely); if there are,
2119     pcretest will instead treat the initial "<" as a pattern delimiter.
2120     After reading in the pattern, pcretest goes on to read data lines as
2121     usual.
2123     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2124     and 16-bit fields in a compiled pattern, to simulate a pattern that
2125     was compiled on a host of opposite endianness.
2127     21. The pcre-exec() function can now cope with patterns that were compiled on
2128     hosts of opposite endianness, with this restriction:
2130     As for any compiled expression that is saved and used later, the tables
2131     pointer field cannot be preserved; the extra_data field in the arguments
2132     to pcre_exec() should be used to pass in a tables address if a value
2133     other than the default internal tables were used at compile time.
2135     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2136     now diagnosed as an error. Previously, most of the time, a negative number
2137     would have been treated as zero, but if in addition "ovector" was passed as
2138     NULL, a crash could occur.
2140     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2141     new versions from the libtool 1.5 distribution (the last one is a copy of
2142     a file called libtool.m4). This seems to have fixed the need to patch
2143     "configure" to support Darwin 1.3 (which I used to do). However, I still
2144     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2145     workstation).
2147     24. Changed the PCRE licence to be the more standard "BSD" licence.
2150 nigel 73 Version 4.5 01-Dec-03
2151     ---------------------
2153     1. There has been some re-arrangement of the code for the match() function so
2154     that it can be compiled in a version that does not call itself recursively.
2155     Instead, it keeps those local variables that need separate instances for
2156     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2157     needs to "recurse". Keeping track of where control must go is done by means
2158     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2159     hide most of the details from the main code, and operates only if
2160     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2161     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2162     operating.
2164     To make it easier for callers to provide specially tailored get/free
2165     functions for this usage, two new functions, pcre_stack_malloc, and
2166     pcre_stack_free, are used. They are always called in strict stacking order,
2167     and the size of block requested is always the same.
2169     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2170     PCRE has been compiled to use the stack or the heap for recursion. The
2171     -C option of pcretest uses this to show which version is compiled.
2173     A new data escape \S, is added to pcretest; it causes the amounts of store
2174     obtained and freed by both kinds of malloc/free at match time to be added
2175     to the output.
2177     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2178     what's available on my current Linux desktop machine.
2180     3. When matching a UTF-8 string, the test for a valid string at the start has
2181     been extended. If start_offset is not zero, PCRE now checks that it points
2182     to a byte that is the start of a UTF-8 character. If not, it returns
2183     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2184     this is necessary because there may be backward assertions in the pattern.
2185     When matching the same subject several times, it may save resources to use
2186     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2188     4. The code for checking the validity of UTF-8 strings has been tightened so
2189     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2190     containing "overlong sequences".
2192     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2193     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2194     should have been "&", but it just so happened that all the cases this let
2195     through by mistake were picked up later in the function.
2197     6. I had used a variable called "isblank" - this is a C99 function, causing
2198     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2200     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2201     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2202     so the version is shown; (c) stop "make test" echoing "./RunTest".
2204     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2206     9. The prototype for memmove() for systems that don't have it was using
2207     size_t, but the inclusion of the header that defines size_t was later. I've
2208     moved the #includes for the C headers earlier to avoid this.
2210     10. Added some adjustments to the code to make it easier to compiler on certain
2211     special systems:
2213     (a) Some "const" qualifiers were missing.
2214     (b) Added the macro EXPORT before all exported functions; by default this
2215     is defined to be empty.
2216     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2217     that it reads its output file name as an argument instead of writing
2218     to the standard output and assuming this can be redirected.
2220     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2221     class containing characters with values greater than 255, PCRE compilation
2222     went into a loop.
2224     12. A recursive reference to a subpattern that was within another subpattern
2225     that had a minimum quantifier of zero caused PCRE to crash. For example,
2226     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2227     recursion. If the recursively-called subpattern itself had a zero repeat,
2228     that was OK.
2230     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2231     buffer into which it was copied (for escape processing) was still set at
2232     1024, so long lines caused crashes.
2234     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2235     "internal error: code overflow...". This applied to any character class
2236     that was followed by a possessive quantifier.
2238     15. Modified the Makefile to add libpcre.la as a prerequisite for
2239     libpcreposix.la because I was told this is needed for a parallel build to
2240     work.
2242     16. If a pattern that contained .* following optional items at the start was
2243     studied, the wrong optimizing data was generated, leading to matching
2244     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2245     matching string must start with a or b or c. The correct conclusion for
2246     this pattern is that a match can start with any character.
2249 nigel 71 Version 4.4 13-Aug-03
2250     ---------------------
2252     1. In UTF-8 mode, a character class containing characters with values between
2253     127 and 255 was not handled correctly if the compiled pattern was studied.
2254     In fixing this, I have also improved the studying algorithm for such
2255     classes (slightly).
2257     2. Three internal functions had redundant arguments passed to them. Removal
2258     might give a very teeny performance improvement.
2260     3. Documentation bug: the value of the capture_top field in a callout is *one
2261     more than* the number of the hightest numbered captured substring.
2263     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2264     in incorrectly linking with a previously installed version. They now link
2265     explicitly with libpcre.la.
2267     5. configure.in no longer needs to recognize Cygwin specially.
2269     6. A problem in pcre.in for Windows platforms is fixed.
2271     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2272     pcretest, it used to include the size of the study block as part of its
2273     output. Unfortunately, the structure contains a field that has a different
2274     size on different hardware architectures. This meant that the tests that
2275     showed this size failed. As the block is currently always of a fixed size,
2276     this information isn't actually particularly useful in pcretest output, so
2277     I have just removed it.
2279     8. Three pre-processor statements accidentally did not start in column 1.
2280     Sadly, there are *still* compilers around that complain, even though
2281     standard C has not required this for well over a decade. Sigh.
2283     9. In pcretest, the code for checking callouts passed small integers in the
2284     callout_data field, which is a void * field. However, some picky compilers
2285     complained about the casts involved for this on 64-bit systems. Now
2286     pcretest passes the address of the small integer instead, which should get
2287     rid of the warnings.
2289     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2290     both compile and run time, and gives an error if an invalid UTF-8 sequence
2291     is found. There is a option for disabling this check in cases where the
2292     string is known to be correct and/or the maximum performance is wanted.
2294     11. In response to a bug report, I changed one line in Makefile.in from
2296     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2297     to
2298     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2300     to look similar to other lines, but I have no way of telling whether this
2301     is the right thing to do, as I do not use Windows. No doubt I'll get told
2302     if it's wrong...
2305 nigel 69 Version 4.3 21-May-03
2306     ---------------------
2308     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2309     Makefile.
2311     2. Some refactoring to improve the quality of the code:
2313     (i) The utf8_table... variables are now declared "const".
2315     (ii) The code for \cx, which used the "case flipping" table to upper case
2316     lower case letters, now just substracts 32. This is ASCII-specific,
2317     but the whole concept of \cx is ASCII-specific, so it seems
2318     reasonable.
2320     (iii) PCRE was using its character types table to recognize decimal and
2321     hexadecimal digits in the pattern. This is silly, because it handles
2322     only 0-9, a-f, and A-F, but the character types table is locale-
2323     specific, which means strange things might happen. A private
2324     table is now used for this - though it costs 256 bytes, a table is
2325     much faster than multiple explicit tests. Of course, the standard
2326     character types table is still used for matching digits in subject
2327     strings against \d.
2329     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2330     ending in _t are). So I've renamed it as ESC_tee.
2332     3. The first argument for regexec() in the POSIX wrapper should have been
2333     defined as "const".
2335     4. Changed pcretest to use malloc() for its buffers so that they can be
2336     Electric Fenced for debugging.
2338     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2339     to read one or more bytes before the start of the subject string. Often this
2340     had no effect on PCRE's behaviour, but in some circumstances it could
2341     provoke a segmentation fault.
2343     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2344     to try to read one or more bytes before the start of the subject string.
2346     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2347     UTF-8 support could misbehave in various ways if the subject string
2348     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2349     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2350     back over UTF-8 characters.)
2353 nigel 67 Version 4.2 14-Apr-03
2354     ---------------------
2356     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2358     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2359     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2360     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2361     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2362     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2363     and BUILD_EXEEXT
2364     Note: automatic setting of the BUILD variables is not yet working
2365     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2366     compile-time but not at link-time
2367     [LINK]: use for linking executables only
2368     make different versions for Windows and non-Windows
2369     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2370     libraries
2371     [LINK_FOR_BUILD]: new variable
2372     [OBJEXT]: use throughout
2373     [EXEEXT]: use throughout
2374     <winshared>: new target
2375     <wininstall>: new target
2376     <dftables.o>: use native compiler
2377     <dftables>: use native linker
2378     <install>: handle Windows platform correctly
2379     <clean>: ditto
2380     <check>: ditto
2381     copy DLL to top builddir before testing
2383     As part of these changes, -no-undefined was removed again. This was reported
2384     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2385     in any case.
2387     3. Some tidies to get rid of compiler warnings:
2389     . In the match_data structure, match_limit was an unsigned long int, whereas
2390     match_call_count was an int. I've made them both unsigned long ints.
2392     . In pcretest the fact that a const uschar * doesn't automatically cast to
2393     a void * provoked a warning.
2395     . Turning on some more compiler warnings threw up some "shadow" variables
2396     and a few more missing casts.
2398     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2399     option, a class that contained a single character with a value between 128
2400     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2402     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2403     option, a class that contained several characters, but with at least one
2404     whose value was between 128 and 255 caused PCRE to crash.
2407 nigel 65 Version 4.1 12-Mar-03
2408     ---------------------
2409 nigel 63
2410 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2411     needed, and a string in dftables.c that was longer than standard compilers are
2412     required to support.
2414     2. Compiling with Sun's compiler found a few more places where the code could
2415     be tidied up in order to avoid warnings.
2417     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2418     first of these names is deprecated in the latest Autoconf in favour of the name
2419     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2420     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2421     analogy I have changed it to CFLAGS_FOR_BUILD.
2423     4. Added -no-undefined to the linking command in the Makefile, because this is
2424     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2425     linking step for the pcreposix library.
2427     5. PCRE was failing to diagnose the case of two named groups with the same
2428     name.
2430     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2431     literal character that is needed in the subject for a match, and scans along to
2432     ensure that it is present before embarking on the full matching process. This
2433     saves time in cases of nested unlimited repeats that are never going to match.
2434     Problem: the scan can take a lot of time if the subject is very long (e.g.
2435     megabytes), thus penalizing straightforward matches. It is now done only if the
2436     amount of subject to be scanned is less than 1000 bytes.
2438     7. A lesser problem with the same optimization is that it was recording the
2439     first character of an anchored pattern as "needed", thus provoking a search
2440     right along the subject, even when the first match of the pattern was going to
2441     fail. The "needed" character is now not set for anchored patterns, unless it
2442     follows something in the pattern that is of non-fixed length. Thus, it still
2443     fulfils its original purpose of finding quick non-matches in cases of nested
2444     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2447     Version 4.0 17-Feb-03
2448     ---------------------
2450 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2451     extended to the end of string, PCRE compiled incorrect data. This could lead to
2452     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2454     2. Moved to autoconf 2.53 and libtool 1.4.2.
2456     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2457     the special perltest8 script is no longer needed - all the tests can be run
2458     from a single perltest script.
2460     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2461     by \s. It has now been removed in PCRE. This means it isn't recognized as
2462     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2463     class [:space:] *does* include VT, thereby creating a mess.
2465     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2466     space and tab.
2468     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2469     its new features into the main test script, reducing the number of scripts.
2471     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2472     were backward compatible, and made the (?i) apply to the whole pattern, as if
2473     /i were given. Now it behaves more logically, and applies the option setting
2474     only to what follows. PCRE has been changed to follow suit. However, if it
2475     finds options settings right at the start of the pattern, it extracts them into
2476     the global options, as before. Thus, they show up in the info data.
2478     8. Added support for the \Q...\E escape sequence. Characters in between are
2479     treated as literals. This is slightly different from Perl in that $ and @ are
2480     also handled as literals inside the quotes. In Perl, they will cause variable
2481     interpolation. Note the following examples:
2483     Pattern PCRE matches Perl matches
2485     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2486     \Qabc\$xyz\E abc\$xyz abc\$xyz
2487     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2489     For compatibility with Perl, \Q...\E sequences are recognized inside character
2490     classes as well as outside them.
2492     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2493     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2494     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2495     signed/unsigned warnings.
2497     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2498     option for pcretest, so I've replaced it by a simple function that does just
2499     that job.
2501     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2502     "pcregrep -".
2504     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2505     Java package. This provides some syntactic sugar for simple cases of what my
2506     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2507     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2508     item, you can use this simplified notation. Note that only makes sense with
2509     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2510     greediness, whatever the setting of the PCRE_UNGREEDY option.
2512     13. A change of greediness default within a pattern was not taking effect at
2513     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2514     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2515     was abstracted outside.
2517     14. PCRE now supports the \G assertion. It is true when the current matching
2518     position is at the start point of the match. This differs from \A when the
2519     starting offset is non-zero. Used with the /g option of pcretest (or similar
2520     code), it works in the same way as it does for Perl's /g option. If all
2521     alternatives of a regex begin with \G, the expression is anchored to the start
2522     match position, and the "anchored" flag is set in the compiled expression.
2524     15. Some bugs concerning the handling of certain option changes within patterns
2525     have been fixed. These applied to options other than (?ims). For example,
2526     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2527     been the other way round. Some of this was related to change 7 above.
2529     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2530     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2531     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2532     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2534     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2535     mode. Unlike ".", it always matches newline, whatever the setting of
2536     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2537     assertions. Perl allows it, but it doesn't (in general) work because it can't
2538     calculate the length of the lookbehind. At least, that's the case for Perl
2539     5.8.0 - I've been told they are going to document that it doesn't work in
2540     future.
2542     18. Added an error diagnosis for escapes that PCRE does not support: these are
2543     \L, \l, \N, \P, \p, \U, \u, and \X.
2545     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2546     reading past the end of the pattern in cases such as /[abcd/.
2548     20. PCRE was getting more memory than necessary for patterns with classes that
2549     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2551     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2552     compiling PCRE for use with Virtual Pascal.
2554     22. Small fix to the Makefile to make it work properly if the build is done
2555     outside the source tree.
2557     23. Added a new extension: a condition to go with recursion. If a conditional
2558     subpattern starts with (?(R) the "true" branch is used if recursion has
2559     happened, whereas the "false" branch is used only at the top level.
2561     24. When there was a very long string of literal characters (over 255 bytes
2562     without UTF support, over 250 bytes with UTF support), the computation of how
2563     much memory was required could be incorrect, leading to segfaults or other
2564     strange effects.
2566     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2567     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2568     there was a subsequent back reference to those brackets. This meant that, for
2569     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2570     possible to check for precisely this case. All we can do is abandon the
2571     optimization if .* occurs inside capturing brackets when there are any back
2572     references whatsoever. (See below for a better fix that came later.)
2574     26. The handling of the optimization for finding the first character of a
2575     non-anchored pattern, and for finding a character that is required later in the
2576     match were failing in some cases. This didn't break the matching; it just
2577     failed to optimize when it could. The way this is done has been re-implemented.
2579     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2581     28. Added a new feature that provides some of the functionality that Perl
2582     provides with (?{...}). The facility is termed a "callout". The way it is done
2583     in PCRE is for the caller to provide an optional function, by setting
2584     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2585     global variable. By default it is unset, which disables all calling out. To get
2586     the function called, the regex must include (?C) at appropriate points. This
2587     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2588     This provides a means of identifying different callout points. When PCRE
2589     reaches such a point in the regex, if pcre_callout has been set, the external
2590     function is called. It is provided with data in a structure called
2591     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2592     matching continues; if it returns a non-zero value, the match at the current
2593     point fails. However, backtracking will occur if possible. [This was changed
2594     later and other features added - see item 49 below.]
2596     29. pcretest is upgraded to test the callout functionality. It provides a
2597     callout function that displays information. By default, it shows the start of
2598     the match and the current position in the text. There are some new data escapes
2599     to vary what happens:
2601     \C+ in addition, show current contents of captured substrings
2602     \C- do not supply a callout function
2603     \C!n return 1 when callout number n is reached
2604     \C!n!m return 1 when callout number n is reached for the mth time
2606     30. If pcregrep was called with the -l option and just a single file name, it
2607     output "<stdin>" if a match was found, instead of the file name.
2609     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2610     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2611     pcre_exec(). This saves a malloc/free per call. The default value of
2612     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2613     when configuring.
2615     32. The default maximum size of a compiled pattern is 64K. There have been a
2616     few cases of people hitting this limit. The code now uses macros to handle the
2617     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2618     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2619     configuring. Tests 2 and 5 work only with 2-byte links because they output
2620     debugging information about compiled patterns.
2622     33. Internal code re-arrangements:
2624     (a) Moved the debugging function for printing out a compiled regex into
2625     its own source file (printint.c) and used #include to pull it into
2626     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2627     separate copies.
2629     (b) Defined the list of op-code names for debugging as a macro in
2630     internal.h so that it is next to the definition of the opcodes.
2632     (c) Defined a table of op-code lengths for simpler skipping along compiled
2633     code. This is again a macro in internal.h so that it is next to the
2634     definition of the opcodes.
2636     34. Added support for recursive calls to individual subpatterns, along the
2637     lines of Robin Houston's patch (but implemented somewhat differently).
2639     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2640     allow it to read and process whole directories in Win32. This code was
2641     contributed by Lionel Fourquaux; it has not been tested by me.
2643     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2644     used to name a group. Names consist of alphanumerics and underscores, and must
2645     be unique. Back references use the syntax (?P=name) and recursive calls use
2646     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2647     numbers. The function pcre_fullinfo() can be used after compilation to extract
2648     a name/number map. There are three relevant calls:
2650     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2651     PCRE_INFO_NAMECOUNT yields the number of entries
2652     PCRE_INFO_NAMETABLE yields a pointer to the map.
2654     The map is a vector of fixed-size entries. The size of each entry depends on
2655     the length of the longest name used. The first two bytes of each entry are the
2656     group number, most significant byte first. There follows the corresponding
2657     name, zero terminated. The names are in alphabetical order.
2659     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2660     case instead of 255. Making it the same both with and without UTF-8 support
2661     means that the same test output works with both.
2663     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2664     calling malloc() with a zero argument.
2666     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2667     optimization. I've improved things by keeping a bitmap of backreferences with
2668     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2669     fact referenced, the optimization can be applied. It is unlikely that a
2670     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2671     the match to follow \n) will appear inside brackets with a number greater than
2672     31, but if it does, any back reference > 31 suppresses the optimization.
2674     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2675     of disabling numbered capturing parentheses. Any opening parenthesis that is
2676     not followed by ? behaves as if it were followed by ?: but named parentheses
2677     can still be used for capturing (and they will acquire numbers in the usual
2678     way).
2680     41. Redesigned the return codes from the match() function into yes/no/error so
2681     that errors can be passed back from deep inside the nested calls. A malloc
2682     failure while inside a recursive subpattern call now causes the
2683     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2685     42. It is now possible to set a limit on the number of times the match()
2686     function is called in a call to pcre_exec(). This facility makes it possible to
2687     limit the amount of recursion and backtracking, though not in a directly
2688     obvious way, because the match() function is used in a number of different
2689     circumstances. The count starts from zero for each position in the subject
2690     string (for non-anchored patterns). The default limit is, for compatibility, a
2691     large number, namely 10 000 000. You can change this in two ways:
2693     (a) When configuring PCRE before making, you can use --with-match-limit=n
2694     to set a default value for the compiled library.
2696     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2697     a different value is set. See 45 below.
2699     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2701     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2702     of things that can be changed at compile time. The first argument specifies
2703     what is wanted and the second points to where the information is to be placed.
2704     The current list of available information is:
2708     The output is an integer that is set to one if UTF-8 support is available;
2709     otherwise it is set to zero.
2713     The output is an integer that it set to the value of the code that is used for
2714     newline. It is either LF (10) or CR (13).
2718     The output is an integer that contains the number of bytes used for internal
2719     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2723     The output is an integer that contains the threshold above which the POSIX
2724     interface uses malloc() for output vectors. See item 31 above.
2728     The output is an unsigned integer that contains the default limit of the number
2729     of match() calls in a pcre_exec() execution. See 42 above.
2731     44. pcretest has been upgraded by the addition of the -C option. This causes it
2732     to extract all the available output from the new pcre_config() function, and to
2733     output it. The program then exits immediately.
2735     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2736     order to support additional features. One way would have been to define
2737     pcre_exec2() (for example) with extra arguments, but this would not have been
2738     extensible, and would also have required all calls to the original function to
2739     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2740     is used for passing in "extra" data from pcre_study().
2742     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2743     contains the following fields:
2745     flags a bitmap indicating which of the following fields are set
2746     study_data opaque data from pcre_study()
2747     match_limit a way of specifying a limit on match() calls for a specific
2748     call to pcre_exec()
2749     callout_data data for callouts (see 49 below)
2751     The flag bits are also defined in pcre.h, and are
2757     The pcre_study() function now returns one of these new pcre_extra blocks, with
2758     the actual study data pointed to by the study_data field, and the
2759     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2760     before. That is, this change is entirely upwards-compatible and requires no
2761     change to existing code.
2763     If you want to pass in additional data to pcre_exec(), you can either place it
2764     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2765     block.
2767     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2768     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2769     times with different match limits, until it finds the minimum value needed for
2770     pcre_exec() to complete. The value is then output. This can be instructive; for
2771     most simple matches the number is quite small, but for pathological cases it
2772     gets very large very quickly.
2774     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2775     returns the size of the data block pointed to by the study_data field in a
2776     pcre_extra block, that is, the value that was passed as the argument to
2777     pcre_malloc() when PCRE was getting memory in which to place the information
2778     created by pcre_study(). The fourth argument should point to a size_t variable.
2779     pcretest has been extended so that this information is shown after a successful
2780     pcre_study() call when information about the compiled regex is being displayed.
2782     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2783     because what follows is always an absolute path. (Later: it turns out that this
2784     is more than cosmetic for MinGW, because it doesn't like empty path
2785     components.)
2787     49. Some changes have been made to the callout feature (see 28 above):
2789     (i) A callout function now has three choices for what it returns:
2791     0 => success, carry on matching
2792     > 0 => failure at this point, but backtrack if possible
2793     < 0 => serious error, return this value from pcre_exec()
2795     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2796     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2797     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2798     use by callout functions. It will never be used by PCRE itself.
2800     (ii) The pcre_extra structure (see 45 above) has a void * field called
2801     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2802     pcre_callout_block structure has a field of the same name. The contents of
2803     the field passed in the pcre_extra structure are passed to the callout
2804     function in the corresponding field in the callout block. This makes it
2805     easier to use the same callout-containing regex from multiple threads. For
2806     testing, the pcretest program has a new data escape
2808     \C*n pass the number n (may be negative) as callout_data
2810     If the callout function in pcretest receives a non-zero value as
2811     callout_data, it returns that value.
2813     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2814     there were some redundant $(CFLAGS) in commands that are now specified as
2815     $(LINK), which already includes $(CFLAGS).
2817     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2818     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2819     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2820     one-byte characters throughout. Note that case-insensitive matching applies
2821     only to characters whose values are less than 256. PCRE doesn't support the
2822     notion of cases for higher-valued characters.
2824     (i) A character class whose characters are all within 0-255 is handled as
2825     a bit map, and the map is inverted for negative classes. Previously, a
2826     character > 255 always failed to match such a class; however it should
2827     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2829     (ii) A negated character class with a single character < 255 is coded as
2830     "not this character" (OP_NOT). This wasn't working properly when the test
2831     character was multibyte, either singly or repeated.
2833     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2834     mode, for example: \x{100}{2,3}.
2836     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2837     singly or repeated) now correctly test multibyte characters. However,
2838     PCRE doesn't recognize any characters with values greater than 255 as
2839     digits, spaces, or word characters. Such characters always match \D, \S,
2840     and \W, and never match \d, \s, or \w.
2842     (v) Classes may now contain characters and character ranges with values
2843     greater than 255. For example: [ab\x{100}-\x{400}].
2845     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2846     PCRE in UTF-8 mode.
2848     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2849     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2850     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2851     value.)
2853     53. The single man page has become too large. I have therefore split it up into
2854     a number of separate man pages. These also give rise to individual HTML pages;
2855     these are now put in a separate directory, and there is an index.html page that
2856     lists them all. Some hyperlinking between the pages has been installed.
2858     54. Added convenience functions for handling named capturing parentheses.
2860     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2861     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2862     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2863     are faulted.
2865     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2866     calling configure. These values are used when compiling the dftables.c program
2867     which is run to generate the source of the default character tables. They
2868     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2869     you will need to set these values.
2871     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2874     Version 3.9 02-Jan-02
2875 nigel 61 ---------------------
2877     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2879     2. If --disable-static was given, the building process failed when trying to
2880     build pcretest and pcregrep. (For some reason it was using libtool to compile
2881     them, which is not right, as they aren't part of the library.)
2884 nigel 59 Version 3.8 18-Dec-01
2885     ---------------------
2887     1. The experimental UTF-8 code was completely screwed up. It was packing the
2888     bytes in the wrong order. How dumb can you get?
2891 nigel 57 Version 3.7 29-Oct-01
2892     ---------------------
2894     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2895     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2896     this didn't happen under Solaris 8, where I normally test things.
2898 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2899     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2900     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2901     this fix an hour or so after the initial 3.7 release.)
2902 nigel 57
2903 nigel 59
2904 nigel 55 Version 3.6 23-Oct-01
2905     ---------------------
2907     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2908     offsets passed as NULL with zero offset count.
2910     2. The config.guess and config.sub files had not been updated when I moved to
2911     the latest autoconf.
2914 nigel 53 Version 3.5 15-Aug-01
2915     ---------------------
2916 nigel 5
2917 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2918     had been forgotten.
2920     2. By using declared but undefined structures, we can avoid using "void"
2921     definitions in pcre.h while keeping the internal definitions of the structures
2922     private.
2924     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2925     user point of view, this means that both static and shared libraries are built
2926     by default, but this can be individually controlled. More of the work of
2927     handling this static/shared cases is now inside libtool instead of PCRE's make
2928     file.
2930     4. The pcretest utility is now installed along with pcregrep because it is
2931     useful for users (to test regexs) and by doing this, it automatically gets
2932     relinked by libtool. The documentation has been turned into a man page, so
2933     there are now .1, .txt, and .html versions in /doc.
2935     5. Upgrades to pcregrep:
2936     (i) Added long-form option names like gnu grep.
2937     (ii) Added --help to list all options with an explanatory phrase.
2938     (iii) Added -r, --recursive to recurse into sub-directories.
2939     (iv) Added -f, --file to read patterns from a file.
2941     6. pcre_exec() was referring to its "code" argument before testing that
2942     argument for NULL (and giving an error if it was NULL).
2944     7. Upgraded Makefile.in to allow for compiling in a different directory from
2945     the source directory.
2947     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2948     options bits, the pointer it was passed was to an int instead of to an unsigned
2949     long int. This mattered only on 64-bit systems.
2951     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2952     generated) instead of pcre.in, which it its source. Also made the same change
2953     in several of the .c files.
2955     10. A new release of gcc defines printf() as a macro, which broke pcretest
2956     because it had an ifdef in the middle of a string argument for printf(). Fixed
2957     by using separate calls to printf().
2959     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2960     script, to force use of CR or LF instead of \n in the source. On non-Unix
2961     systems, the value can be set in config.h.
2963     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2964     absolute limit. Changed the text of the error message to make this clear, and
2965     likewise updated the man page.
2967     13. The limit of 99 on the number of capturing subpatterns has been removed.
2968     The new limit is 65535, which I hope will not be a "real" limit.
2971 nigel 51 Version 3.4 22-Aug-00
2972     ---------------------
2974     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2976     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2979 nigel 49 Version 3.3 01-Aug-00
2980     ---------------------
2982     1. If an octal character was given, but the value was greater than \377, it
2983     was not getting masked to the least significant bits, as documented. This could
2984     lead to crashes in some systems.
2986     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2987     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2989     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2990     These just pass their arguments on to (pcre_free)(), but they are provided
2991     because some uses of PCRE bind it to non-C systems that can call its functions,
2992     but cannot call free() or pcre_free() directly.
2994     4. Add "make test" as a synonym for "make check". Corrected some comments in
2995     the Makefile.
2997     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2998     Makefile.
3000     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3001     command called pgrep for grepping around the active processes.
3003     7. Added the beginnings of support for UTF-8 character strings.
3005     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3006     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3007     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3008     out for the ar command.)
3011 nigel 47 Version 3.2 12-May-00
3012     ---------------------
3014     This is purely a bug fixing release.
3016     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3017     of ZA. This was just one example of several cases that could provoke this bug,
3018     which was introduced by change 9 of version 2.00. The code for breaking
3019     infinite loops after an iteration that matches an empty string was't working
3020     correctly.
3022     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3023     when matched against abbab (for example). After matching an empty string, it
3024     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3025     caused it to match further down the string than it should.
3027     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3028     was there because it doesn't seem to be needed, and it causes trouble on some
3029     systems, as it is not a Standard C header. It has been removed.
3031     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3032     were reported on the Macintosh. The changes were from
3034     while ((c = *(++ptr)) != 0 && c != '\n');
3035     to
3036     while ((c = *(++ptr)) != 0 && c != '\n') ;
3038     Totally extraordinary, but if that's what it takes...
3040     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3041     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3042     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3043     assumes the way PCRE uses memmove() (always moving upwards).
3045     6. PCRE is being used in one environment where strchr() is not available. There
3046     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3047     faster code anyway.
3050 nigel 45 Version 3.1 09-Feb-00
3051     ---------------------
3053     The only change in this release is the fixing of some bugs in Makefile.in for
3054     the "install" target:
3056     (1) It was failing to install pcreposix.h.
3058     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3061 nigel 43 Version 3.0 01-Feb-00
3062     ---------------------
3063 nigel 41
3064     1. Add support for the /+ modifier to perltest (to output $` like it does in
3065     pcretest).
3067     2. Add support for the /g modifier to perltest.
3069     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3070     matches null strings.
3072     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3073     pattern. Perl treats empty patterns specially - it reuses the most recent
3074     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3075     effect.
3077     5. The POSIX interface was broken in that it was just handing over the POSIX
3078     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3079     required a bigger vector, with some working space on the end. This means that
3080     the POSIX wrapper now has to get and free some memory, and copy the results.
3082 nigel 43 6. Added some simple autoconf support, placing the test data and the
3083     documentation in separate directories, re-organizing some of the
3084     information files, and making it build pcre-config (a GNU standard). Also added
3085     libtool support for building PCRE as a shared library, which is now the
3086     default.
3087 nigel 41
3088 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3089     09 are not valid octal constants. Single digits will be used for minor values
3090     less than 10.
3092     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3093     existing programs that set these in the POSIX interface can use PCRE without
3094     modification.
3096     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3097     return all that pcre_info() returns, plus additional data. The pcre_info()
3098     function is retained for compatibility, but is considered to be obsolete.
3100     10. Added experimental recursion feature (?R) to handle one common case that
3101     Perl 5.6 will be able to do with (?p{...}).
3103     11. Added support for POSIX character classes like [:alpha:], which Perl is
3104     adopting.
3107 nigel 39 Version 2.08 31-Aug-99
3108     ----------------------
3110     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3111     trying to match at the startoffset position, but instead was moving forward to
3112     the next newline as if a previous match had failed.
3114     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3115     and could get into a loop if a null string was matched other than at the start
3116     of the subject.
3118     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3119     be distinguished at compile time, and for completeness also added PCRE_DATE.
3121     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3122     in GnuWin32 environments.
3125 nigel 37 Version 2.07 29-Jul-99
3126     ----------------------
3128     1. The documentation is now supplied in plain text form and HTML as well as in
3129     the form of man page sources.
3131     2. C++ compilers don't like assigning (void *) values to other pointer types.
3132     In particular this affects malloc(). Although there is no problem in Standard
3133     C, I've put in casts to keep C++ compilers happy.
3135     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3136     should be (const char *).
3138     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3139     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3140     However, I haven't made this a standard facility. The documentation doesn't
3141     mention it, and the Makefile doesn't support it.
3143     5. The Makefile now contains an "install" target, with editable destinations at
3144     the top of the file. The pcretest program is not installed.
3146     6. pgrep -V now gives the PCRE version number and date.
3148     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3149     causing the entire string to be ignored, instead of just the last character.
3151     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3152     non-matching string, it can take a very, very long time, even for strings of
3153     quite modest length, because of the nested recursion. PCRE now does better in
3154     some of these cases. It does this by remembering the last required literal
3155     character in the pattern, and pre-searching the subject to ensure it is present
3156     before running the real match. In other words, it applies a heuristic to detect
3157     some types of certain failure quickly, and in the above example, if presented
3158     with a string that has no trailing " it gives "no match" very quickly.
3160     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3161     other alternatives are tried instead.
3164 nigel 35 Version 2.06 09-Jun-99
3165     ----------------------
3167     1. Change pcretest's output for amount of store used to show just the code
3168     space, because the remainder (the data block) varies in size between 32-bit and
3169     64-bit systems.
3171     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3172     start matching at. This allows lookbehinds to work when searching for multiple
3173     occurrences in a string.
3175     3. Added additional options to pcretest for testing multiple occurrences:
3177     /+ outputs the rest of the string that follows a match
3178     /g loops for multiple occurrences, using the new startoffset argument
3179     /G loops for multiple occurrences by passing an incremented pointer
3181     4. PCRE wasn't doing the "first character" optimization for patterns starting
3182     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3183     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3184     the letter 'x'. On long subject strings, this gives a significant speed-up.
3187 nigel 33 Version 2.05 21-Apr-99
3188     ----------------------
3190     1. Changed the type of magic_number from int to long int so that it works
3191     properly on 16-bit systems.
3193     2. Fixed a bug which caused patterns starting with .* not to work correctly
3194     when the subject string contained newline characters. PCRE was assuming
3195     anchoring for such patterns in all cases, which is not correct because .* will
3196     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3197     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3198     must be retried after every newline in the subject.
3201 nigel 31 Version 2.04 18-Feb-99
3202     ----------------------
3204     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3205     computation of the store needed to hold the pattern was incorrect (too large).
3206     If such patterns were nested a few deep, this could multiply and become a real
3207     problem.
3209     2. Added /M option to pcretest to show the memory requirement of a specific
3210     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3212     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3213     compiled in such a way that the backtracking after subsequent failure was
3214     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3215     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3218 nigel 29 Version 2.03 02-Feb-99
3219     ----------------------
3221     1. Fixed typo and small mistake in man page.
3223 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3224     LICENCE file containing the conditions.
3225 nigel 29
3226     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3227     Perl, that is the internal \ allows the delimiter to be included in the
3228     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3229     the final delimiter, add \ to the end of the pattern (to test the error).
3231     4. Added the convenience functions for extracting substrings after a successful
3232     match. Updated pcretest to make it able to test these functions.
3235 nigel 27 Version 2.02 14-Jan-99
3236     ----------------------
3238     1. Initialized the working variables associated with each extraction so that
3239     their saving and restoring doesn't refer to uninitialized store.
3241     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3242     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3243     fix the problem.
3245     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3246     calls, and wasn't printing the correct value for compiling calls. Increased the
3247     default value of LOOPREPEAT, and the number of significant figures in the
3248     times.
3250     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3252     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3253     a building problem on Windows NT with a FAT file system.
3256 nigel 25 Version 2.01 21-Oct-98
3257     ----------------------
3259     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3260     to character tables built by pcre_maketables() in the current locale. If NULL
3261     is passed, the default tables are used.
3264 nigel 23 Version 2.00 24-Sep-98
3265 nigel 21 ----------------------
3267 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3268     it any more.
3270     2. Allow quantification of (?>) groups, and make it work correctly.
3272     3. The first character computation wasn't working for (?>) groups.
3274     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3275     end of the subject) and add 5.005's \z, which really does match only at the
3276     very end of the subject.
3278     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3280     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3281     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3282     localized options. All options to pcre_study() were also removed.
3284     7. Add other new features from 5.005:
3286     $(?<= positive lookbehind
3287     $(?<! negative lookbehind
3288     (?imsx-imsx) added the unsetting capability
3289     such a setting is global if at outer level; local otherwise
3290     (?imsx-imsx:) non-capturing groups with option setting
3291     (?(cond)re|re) conditional pattern matching
3293     A backreference to itself in a repeated group matches the previous
3294     captured string.
3296     8. General tidying up of studying (both automatic and via "study")
3297     consequential on the addition of new assertions.
3299     9. As in 5.005, unlimited repeated groups that could match an empty substring
3300     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3301     runtime if any iteration does actually match an empty substring.
3303     10. Include the RunTest script in the distribution.
3305     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3306     discrepancies, some of which were old and were also with respect to 5.004. They
3307     have now been fixed.
3310     Version 1.09 28-Apr-98
3311     ----------------------
3313 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3314     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3315     program crashes, or just wrong answers. This did not apply to negated classes
3316     containing more than one character, or to minima other than one.
3319 nigel 19 Version 1.08 27-Mar-98
3320     ----------------------
3322     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3324     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3325     latter must appear before anything that relies on it in the pattern.
3328 nigel 17 Version 1.07 16-Feb-98
3329     ----------------------
3331     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3332     repeat of a potentially empty string).
3335 nigel 15 Version 1.06 23-Jan-98
3336     ----------------------
3338     1. Added Markus Oberhumer's little patches for C++.
3340     2. Literal strings longer than 255 characters were broken.
3343 nigel 13 Version 1.05 23-Dec-97
3344     ----------------------
3346     1. Negated character classes containing more than one character were failing if
3347     PCRE_CASELESS was set at run time.
3350 nigel 11 Version 1.04 19-Dec-97
3351     ----------------------
3353     1. Corrected the man page, where some "const" qualifiers had been omitted.
3355     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3356     input syntax.
3358     3. Fixed memory leak which occurred when a regex with back references was
3359     matched with an offsets vector that wasn't big enough. The temporary memory
3360     that is used in this case wasn't being freed if the match failed.
3362     4. Tidied pcretest to ensure it frees memory that it gets.
3364     5. Temporary memory was being obtained in the case where the passed offsets
3365     vector was exactly big enough.
3367     6. Corrected definition of offsetof() from change 5 below.
3369     7. I had screwed up change 6 below and broken the rules for the use of
3370     setjmp(). Now fixed.
3373 nigel 9 Version 1.03 18-Dec-97
3374     ----------------------
3376     1. A erroneous regex with a missing opening parenthesis was correctly
3377     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3378     on some systems.
3380     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3381     it was reported that one broken compiler failed on the former because "code" is
3382     also an independent variable.
3384     3. The erroneous regex a[]b caused an array overrun reference.
3386     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3387     fail on data ending with that character. (It was going on too far, and checking
3388     the next character, typically a binary zero.) This was specific to the
3389     optimized code for single-character negative classes.
3391     5. Added a contributed patch from the TIN world which does the following:
3393     + Add an undef for memmove, in case the the system defines a macro for it.
3395     + Add a definition of offsetof(), in case there isn't one. (I don't know
3396     the reason behind this - offsetof() is part of the ANSI standard - but
3397     it does no harm).
3399     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3400     most of the places where whitespace preceded '#'. I have given up and
3401     allowed the remaining 2 cases to be at the margin.
3403     + Rename some variables in pcre to eliminate shadowing. This seems very
3404     pedantic, but does no harm, of course.
3406     6. Moved the call to setjmp() into its own function, to get rid of warnings
3407     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3409     7. Constructs such as \d{8,} were compiling into the equivalent of
3410 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3411 nigel 9 outcome, but in this particular case used more store than had been allocated,
3412     which caused the bug to be discovered because it threw up an internal error.
3414     8. The debugging code in both pcre and pcretest for outputting the compiled
3415     form of a regex was going wrong in the case of back references followed by
3416     curly-bracketed repeats.
3419 nigel 7 Version 1.02 12-Dec-97
3420     ----------------------
3422     1. Typos in pcre.3 and comments in the source fixed.
3424     2. Applied a contributed patch to get rid of places where it used to remove
3425     'const' from variables, and fixed some signed/unsigned and uninitialized
3426     variable warnings.
3428     3. Added the "runtest" target to Makefile.
3430     4. Set default compiler flag to -O2 rather than just -O.
3433 nigel 5 Version 1.01 19-Nov-97
3434     ----------------------
3436     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3437     like /([ab]*)*/, that is, for classes with more than one character in them.
3439     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3440     as /((?>a*))*/ (a PCRE_EXTRA facility).
3443     Version 1.00 18-Nov-97
3444     ----------------------
3446     1. Added compile-time macros to support systems such as SunOS4 which don't have
3447     memmove() or strerror() but have other things that can be used instead.
3449     2. Arranged that "make clean" removes the executables.
3452 nigel 3 Version 0.99 27-Oct-97
3453     ----------------------
3455     1. Fixed bug in code for optimizing classes with only one character. It was
3456     initializing a 32-byte map regardless, which could cause it to run off the end
3457     of the memory it had got.
3459     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3462     Version 0.98 22-Oct-97
3463     ----------------------
3465     1. Fixed bug in code for handling temporary memory usage when there are more
3466     back references than supplied space in the ovector. This could cause segfaults.
3469     Version 0.97 21-Oct-97
3470     ----------------------
3472     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3474     2. Optimized negated single characters not to use a bit map.
3476     3. Brought error texts together as macro definitions; clarified some of them;
3477     fixed one that was wrong - it said "range out of order" when it meant "invalid
3478     escape sequence".
3480     4. Changed some char * arguments to const char *.
3482     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3484     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3485     pcretest.
3488     Version 0.96 16-Oct-97
3489     ----------------------
3491     1. Added a simple "pgrep" utility to the distribution.
3493     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3494     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3495     where "ddd" means "one or more decimal digits".
3497     3. Fixed serious bug. If a pattern had a back reference, but the call to
3498     pcre_exec() didn't supply a large enough ovector to record the related
3499     identifying subpattern, the match always failed. PCRE now remembers the number
3500     of the largest back reference, and gets some temporary memory in which to save
3501     the offsets during matching if necessary, in order to ensure that
3502     backreferences always work.
3504     4. Increased the compatibility with Perl in a number of ways:
3506     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3507     to request this handling. The option can be set at compile or exec time.
3509     (b) $ matches before a terminating newline by default; an option
3510     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3511     mode). The option can be set at compile or exec time.
3513     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3514     the same as Perl's. If the decimal number it represents is less than 10
3515     or there aren't that many previous left capturing parentheses, an octal
3516     escape is read. Inside a character class, it's always an octal escape,
3517     even if it is a single digit.
3519     (d) An escaped but undefined alphabetic character is taken as a literal,
3520     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3521     escapes.
3523     (e) {0} is now permitted. (The previous item is removed from the compiled
3524     pattern).
3526     5. Changed all the names of code files so that the basic parts are no longer
3527     than 10 characters, and abolished the teeny "globals.c" file.
3529     6. Changed the handling of character classes; they are now done with a 32-byte
3530     bit map always.
3532     7. Added the -d and /D options to pcretest to make it possible to look at the
3533     internals of compilation without having to recompile pcre.
3536     Version 0.95 23-Sep-97
3537     ----------------------
3539     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3540     \x20 at the start of a run of normal characters. These were being treated as
3541     real characters, instead of the source characters being re-checked.
3544     Version 0.94 18-Sep-97
3545     ----------------------
3547     1. The functions are now thread-safe, with the caveat that the global variables
3548     containing pointers to malloc() and free() or alternative functions are the
3549     same for all threads.
3551     2. Get pcre_study() to generate a bitmap of initial characters for non-
3552     anchored patterns when this is possible, and use it if passed to pcre_exec().
3555     Version 0.93 15-Sep-97
3556     ----------------------
3558     1. /(b)|(:+)/ was computing an incorrect first character.
3560     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3561     but not actually doing anything yet.
3563     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3564     as Perl does (e.g. [-az] or [az-]).
3566     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3567     all possible positions.
3569     5. Split up into different modules to avoid including unneeded functions in a
3570     compiled binary. However, compile and exec are still in one module. The "study"
3571     function is split off.
3573     6. The character tables are now in a separate module whose source is generated
3574     by an auxiliary program - but can then be edited by hand if required. There are
3575     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3576     toupper() in the code.
3578     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3579     make them global. Abolish the function for setting them, as the caller can now
3580     set them directly.
3583     Version 0.92 11-Sep-97
3584     ----------------------
3586     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3587     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3589     2. Caseless matching was not working in character classes if the characters in
3590     the pattern were in upper case.
3592     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3594     4. Make PCRE_ANCHORED public and accept as a compile option.
3596     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3597     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3598     pass them.
3600     6. Give an error if bad option bits passed at compile or run time.
3602     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3603     pcretest to cause it to pass that flag.
3605     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3606     options, and the first character, if set.
3608     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3611     Version 0.91 10-Sep-97
3612     ----------------------
3614     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3615     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3617     2. PCRE was looping on encountering an indefinitely repeated back reference to
3618     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3619     Perl does - treats the match as successful.
3621     ****


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