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Revision 430 - (show annotations) (download)
Tue Sep 1 16:29:46 2009 UTC (4 years, 10 months ago) by ph10
File size: 169945 byte(s)
Add -DPCRE_STATIC to configuration files when no shared library is built.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.00 ??-???-??
5 ----------------------
6
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8 was out-of-date, and there was no check on the pcre_compile() error code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
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
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.
23
24 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.
28
29 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.
33
34 6. No libpcreposix.pc file was created for pkg-config; there was just
35 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
36
37 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.
43
44 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 repetition. Chaos could result.
47
48 9. The restrictions on what a pattern can contain when partial matching is
49 requested for pcre_exec() have been removed. All patterns can now be
50 partially matched by this function. In addition, if there are at least two
51 slots in the offset vector, the offsets of the first-encountered partial
52 match are set in them when PCRE_ERROR_PARTIAL is returned.
53
54 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
55 synonymous with PCRE_PARTIAL, for backwards compatibility, and
56 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
57 and may be more useful for multi-segment matching, especially with
58 pcre_exec().
59
60 11. Partial matching with pcre_exec() is now more intuitive. A partial match
61 used to be given if ever the end of the subject was reached; now it is
62 given only if matching could not proceed because another character was
63 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
64 string "Z", which now yields "no match" instead of "partial match". In the
65 case of pcre_dfa_exec(), "no match" is given if every matching path for the
66 final character ended with (*FAIL).
67
68 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
69 if the pattern had a "must contain" character that was already found in the
70 earlier partial match, unless partial matching was again requested. For
71 example, with the pattern /dog.(body)?/, the "must contain" character is
72 "g". If the first part-match was for the string "dog", restarting with
73 "sbody" failed.
74
75 13. Added a pcredemo man page, created automatically from the pcredemo.c file,
76 so that the demonstration program is easily available in environments where
77 PCRE has not been installed from source.
78
79 14. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
80 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
81 library.
82
83
84 Version 7.9 11-Apr-09
85 ---------------------
86
87 1. When building with support for bzlib/zlib (pcregrep) and/or readline
88 (pcretest), all targets were linked against these libraries. This included
89 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
90 libraries. This caused unwanted dependencies to be created. This problem
91 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
92 pcretest is linked with readline.
93
94 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
95 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
96 moved outside it again, because FALSE and TRUE are already defined in AIX,
97 but BOOL is not.
98
99 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
100 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
101
102 4. The pcregrep documentation said spaces were inserted as well as colons (or
103 hyphens) following file names and line numbers when outputting matching
104 lines. This is not true; no spaces are inserted. I have also clarified the
105 wording for the --colour (or --color) option.
106
107 5. In pcregrep, when --colour was used with -o, the list of matching strings
108 was not coloured; this is different to GNU grep, so I have changed it to be
109 the same.
110
111 6. When --colo(u)r was used in pcregrep, only the first matching substring in
112 each matching line was coloured. Now it goes on to look for further matches
113 of any of the test patterns, which is the same behaviour as GNU grep.
114
115 7. A pattern that could match an empty string could cause pcregrep to loop; it
116 doesn't make sense to accept an empty string match in pcregrep, so I have
117 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
118 seems to be how GNU grep behaves.
119
120 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
121 start or after a newline", because the conditional assertion was not being
122 correctly handled. The rule now is that both the assertion and what follows
123 in the first alternative must satisfy the test.
124
125 9. If auto-callout was enabled in a pattern with a conditional group whose
126 condition was an assertion, PCRE could crash during matching, both with
127 pcre_exec() and pcre_dfa_exec().
128
129 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
130 used for matching.
131
132 11. Unicode property support in character classes was not working for
133 characters (bytes) greater than 127 when not in UTF-8 mode.
134
135 12. Added the -M command line option to pcretest.
136
137 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
138
139 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
140
141 16. Added comments and documentation about mis-use of no_arg in the C++
142 wrapper.
143
144 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
145 from Martin Jerabek that uses macro names for all relevant character and
146 string constants.
147
148 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
149 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
150 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
151 these, but not everybody uses configure.
152
153 19. A conditional group that had only one branch was not being correctly
154 recognized as an item that could match an empty string. This meant that an
155 enclosing group might also not be so recognized, causing infinite looping
156 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
157 with the subject "ab", where knowledge that the repeated group can match
158 nothing is needed in order to break the loop.
159
160 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
161 exec(), but without supplying a callout function, matching went wrong.
162
163 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
164 leak if the size of the offset vector was greater than 30. When the vector
165 is smaller, the saved offsets during recursion go onto a local stack
166 vector, but for larger vectors malloc() is used. It was failing to free
167 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
168 error, in fact).
169
170 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
171 heapframe that is used only when UTF-8 support is enabled. This caused no
172 problem, but was untidy.
173
174 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
175 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
176 included within another project.
177
178 24. Steven Van Ingelgem's patches to add more options to the CMake support,
179 slightly modified by me:
180
181 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
182 not building pcregrep.
183
184 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
185 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
186
187 25. Forward references, both numeric and by name, in patterns that made use of
188 duplicate group numbers, could behave incorrectly or give incorrect errors,
189 because when scanning forward to find the reference group, PCRE was not
190 taking into account the duplicate group numbers. A pattern such as
191 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
192
193 26. Changed a few more instances of "const unsigned char *" to USPTR, making
194 the feature of a custom pointer more persuasive (as requested by a user).
195
196 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
197 pcretest.c, inside #ifndefs, because it seems they are sometimes already
198 pre-defined.
199
200 28. Added support for (*UTF8) at the start of a pattern.
201
202 29. Arrange for flags added by the "release type" setting in CMake to be shown
203 in the configuration summary.
204
205
206 Version 7.8 05-Sep-08
207 ---------------------
208
209 1. Replaced UCP searching code with optimized version as implemented for Ad
210 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
211 stage table and inline lookup instead of a function, giving speed ups of 2
212 to 5 times on some simple patterns that I tested. Permission was given to
213 distribute the MultiStage2.py script that generates the tables (it's not in
214 the tarball, but is in the Subversion repository).
215
216 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
217 scripts.
218
219 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
220 a group with a zero qualifier. The result of the study could be incorrect,
221 or the function might crash, depending on the pattern.
222
223 4. Caseless matching was not working for non-ASCII characters in back
224 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
225 It now works when Unicode Property Support is available.
226
227 5. In pcretest, an escape such as \x{de} in the data was always generating
228 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
229 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
230 truncation.
231
232 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
233
234 7. Added two (int) casts to pcregrep when printing the difference of two
235 pointers, in case they are 64-bit values.
236
237 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
238 test 2 if it fails.
239
240 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
241 and a #define of that name to empty if it is not externally set. This is to
242 allow users of MSVC to set it if necessary.
243
244 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
245 the convenience functions in the pcre_get.c source file.
246
247 11. An option change at the start of a pattern that had top-level alternatives
248 could cause overwriting and/or a crash. This command provoked a crash in
249 some environments:
250
251 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
252
253 This potential security problem was recorded as CVE-2008-2371.
254
255 12. For a pattern where the match had to start at the beginning or immediately
256 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
257 pcre_dfa_exec() could read past the end of the passed subject if there was
258 no match. To help with detecting such bugs (e.g. with valgrind), I modified
259 pcretest so that it places the subject at the end of its malloc-ed buffer.
260
261 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
262 exec() might read past the end of the data buffer in UTF-8 mode.
263
264 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
265 the data contained the byte 0x85 as part of a UTF-8 character within its
266 first line. This applied both to normal and DFA matching.
267
268 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
269 /^[^d]*?$/8 failed to match "abc".
270
271 16. Added a missing copyright notice to pcrecpp_internal.h.
272
273 17. Make it more clear in the documentation that values returned from
274 pcre_exec() in ovector are byte offsets, not character counts.
275
276 18. Tidied a few places to stop certain compilers from issuing warnings.
277
278 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
279 supplied by Stefan Weber. I made a further small update for 7.8 because
280 there is a change of source arrangements: the pcre_searchfuncs.c module is
281 replaced by pcre_ucd.c.
282
283
284 Version 7.7 07-May-08
285 ---------------------
286
287 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
288 a string to a long long, pretend we don't even have a long long." This is
289 done by checking for the strtoq, strtoll, and _strtoi64 functions.
290
291 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
292 pre-7.6 versions, which defined a global no_arg variable instead of putting
293 it in the RE class. (See also #8 below.)
294
295 3. Remove a line of dead code, identified by coverity and reported by Nuno
296 Lopes.
297
298 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
299
300 (1) The include/exclude patterns were being applied to the whole pathnames
301 of files, instead of just to the final components.
302
303 (2) If there was more than one level of directory, the subdirectories were
304 skipped unless they satisfied the include/exclude conditions. This is
305 inconsistent with GNU grep (and could even be seen as contrary to the
306 pcregrep specification - which I improved to make it absolutely clear).
307 The action now is always to scan all levels of directory, and just
308 apply the include/exclude patterns to regular files.
309
310 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
311 --exclude_dir in the tests to avoid scanning .svn directories.
312
313 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
314 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
315 doesn't support NULs in patterns.
316
317 7. Added some missing "const"s to declarations of static tables in
318 pcre_compile.c and pcre_dfa_exec.c.
319
320 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
321 caused by fix #2 above. (Subsequently also a second patch to fix the
322 first patch. And a third patch - this was a messy problem.)
323
324 9. Applied Craig's patch to remove the use of push_back().
325
326 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
327 matching function regexec().
328
329 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
330 which, however, unlike Perl's \g{...}, are subroutine calls, not back
331 references. PCRE supports relative numbers with this syntax (I don't think
332 Oniguruma does).
333
334 12. Previously, a group with a zero repeat such as (...){0} was completely
335 omitted from the compiled regex. However, this means that if the group
336 was called as a subroutine from elsewhere in the pattern, things went wrong
337 (an internal error was given). Such groups are now left in the compiled
338 pattern, with a new opcode that causes them to be skipped at execution
339 time.
340
341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
342 to the way PCRE behaves:
343
344 (a) A lone ] character is dis-allowed (Perl treats it as data).
345
346 (b) A back reference to an unmatched subpattern matches an empty string
347 (Perl fails the current match path).
348
349 (c) A data ] in a character class must be notated as \] because if the
350 first data character in a class is ], it defines an empty class. (In
351 Perl it is not possible to have an empty class.) The empty class []
352 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
353 The negative empty class [^] matches any one character, independently
354 of the DOTALL setting.
355
356 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
357 non-existent subpattern following a character class starting with ']' and
358 containing () gave an internal compiling error instead of "reference to
359 non-existent subpattern". Fortunately, when the pattern did exist, the
360 compiled code was correct. (When scanning forwards to check for the
361 existencd of the subpattern, it was treating the data ']' as terminating
362 the class, so got the count wrong. When actually compiling, the reference
363 was subsequently set up correctly.)
364
365 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
366 it was being rejected as not supported by pcre_dfa_exec(), even though
367 other assertions are supported. I have made pcre_dfa_exec() support
368 (*FAIL).
369
370 16. The implementation of 13c above involved the invention of a new opcode,
371 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
372 cannot be changed at match time, I realized I could make a small
373 improvement to matching performance by compiling OP_ALLANY instead of
374 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
375 on the OP_ANY path.
376
377 17. Compiling pcretest on Windows with readline support failed without the
378 following two fixes: (1) Make the unistd.h include conditional on
379 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
380
381 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
382 ncurses library to be included for pcretest when ReadLine support is
383 requested, but also to allow for it to be overridden. This patch came from
384 Daniel Bergström.
385
386 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
387 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
388 any errors with the current Unicode tables. Thanks to Peter Kankowski for
389 spotting this.
390
391
392 Version 7.6 28-Jan-08
393 ---------------------
394
395 1. A character class containing a very large number of characters with
396 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
397 overflow.
398
399 2. Patch to cut out the "long long" test in pcrecpp_unittest when
400 HAVE_LONG_LONG is not defined.
401
402 3. Applied Christian Ehrlicher's patch to update the CMake build files to
403 bring them up to date and include new features. This patch includes:
404
405 - Fixed PH's badly added libz and libbz2 support.
406 - Fixed a problem with static linking.
407 - Added pcredemo. [But later removed - see 7 below.]
408 - Fixed dftables problem and added an option.
409 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
410 HAVE_LONG_LONG.
411 - Added readline support for pcretest.
412 - Added an listing of the option settings after cmake has run.
413
414 4. A user submitted a patch to Makefile that makes it easy to create
415 "pcre.dll" under mingw when using Configure/Make. I added stuff to
416 Makefile.am that cause it to include this special target, without
417 affecting anything else. Note that the same mingw target plus all
418 the other distribution libraries and programs are now supported
419 when configuring with CMake (see 6 below) instead of with
420 Configure/Make.
421
422 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
423 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
424 exported in the Windows port". It has not yet been confirmed that the patch
425 solves the problem, but it does no harm.
426
427 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
428 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
429 with CMake, and also correct the comment about stack recursion.
430
431 7. Remove the automatic building of pcredemo from the ./configure system and
432 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
433 of a program that users should build themselves after PCRE is installed, so
434 building it automatically is not really right. What is more, it gave
435 trouble in some build environments.
436
437 8. Further tidies to CMakeLists.txt from Sheri and Christian.
438
439
440 Version 7.5 10-Jan-08
441 ---------------------
442
443 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
444 values in parens when parsing an RE using the C++ wrapper."
445
446 2. Negative specials like \S did not work in character classes in UTF-8 mode.
447 Characters greater than 255 were excluded from the class instead of being
448 included.
449
450 3. The same bug as (2) above applied to negated POSIX classes such as
451 [:^space:].
452
453 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
454 defined or documented. It seems to have been a typo for PCRE_STATIC, so
455 I have changed it.
456
457 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
458 first named subpattern) and a construct such as (?&a) would reference the
459 first named subpattern whose name started with "a" (in other words, the
460 length check was missing). Both these problems are fixed. "Subpattern name
461 expected" is now given for (?&) (a zero-length name), and this patch also
462 makes it give the same error for \k'' (previously it complained that that
463 was a reference to a non-existent subpattern).
464
465 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
466 this is right because (?- can be followed by option settings as well as by
467 digits. I have, however, made the messages clearer.
468
469 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
470 than the number used in the conditional) now cause a compile-time error.
471 This is actually not compatible with Perl, which accepts such patterns, but
472 treats the conditional as always being FALSE (as PCRE used to), but it
473 seems to me that giving a diagnostic is better.
474
475 8. Change "alphameric" to the more common word "alphanumeric" in comments
476 and messages.
477
478 9. Fix two occurrences of "backslash" in comments that should have been
479 "backspace".
480
481 10. Remove two redundant lines of code that can never be obeyed (their function
482 was moved elsewhere).
483
484 11. The program that makes PCRE's Unicode character property table had a bug
485 which caused it to generate incorrect table entries for sequences of
486 characters that have the same character type, but are in different scripts.
487 It amalgamated them into a single range, with the script of the first of
488 them. In other words, some characters were in the wrong script. There were
489 thirteen such cases, affecting characters in the following ranges:
490
491 U+002b0 - U+002c1
492 U+0060c - U+0060d
493 U+0061e - U+00612
494 U+0064b - U+0065e
495 U+0074d - U+0076d
496 U+01800 - U+01805
497 U+01d00 - U+01d77
498 U+01d9b - U+01dbf
499 U+0200b - U+0200f
500 U+030fc - U+030fe
501 U+03260 - U+0327f
502 U+0fb46 - U+0fbb1
503 U+10450 - U+1049d
504
505 12. The -o option (show only the matching part of a line) for pcregrep was not
506 compatible with GNU grep in that, if there was more than one match in a
507 line, it showed only the first of them. It now behaves in the same way as
508 GNU grep.
509
510 13. If the -o and -v options were combined for pcregrep, it printed a blank
511 line for every non-matching line. GNU grep prints nothing, and pcregrep now
512 does the same. The return code can be used to tell if there were any
513 non-matching lines.
514
515 14. Added --file-offsets and --line-offsets to pcregrep.
516
517 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
518 infinitely looping recursion. The bug was that positive lookaheads were not
519 being skipped when checking for a possible empty match (negative lookaheads
520 and both kinds of lookbehind were skipped).
521
522 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
523 inclusion of <windows.h> to before rather than after the definition of
524 INVALID_FILE_ATTRIBUTES (patch from David Byron).
525
526 17. Specifying a possessive quantifier with a specific limit for a Unicode
527 character property caused pcre_compile() to compile bad code, which led at
528 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
529 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
530 caused the error; without that there was no problem.
531
532 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
533
534 19. Added --enable-pcretest-libreadline.
535
536 20. In pcrecpp.cc, the variable 'count' was incremented twice in
537 RE::GlobalReplace(). As a result, the number of replacements returned was
538 double what it should be. I removed one of the increments, but Craig sent a
539 later patch that removed the other one (the right fix) and added unit tests
540 that check the return values (which was not done before).
541
542 21. Several CMake things:
543
544 (1) Arranged that, when cmake is used on Unix, the libraries end up with
545 the names libpcre and libpcreposix, not just pcre and pcreposix.
546
547 (2) The above change means that pcretest and pcregrep are now correctly
548 linked with the newly-built libraries, not previously installed ones.
549
550 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
551
552 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
553 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
554 UTF-8 newline character). The key issue is that the pattern starts .*;
555 this means that the match must be either at the beginning, or after a
556 newline. The bug was in the code for advancing after a failed match and
557 checking that the new position followed a newline. It was not taking
558 account of UTF-8 characters correctly.
559
560 23. PCRE was behaving differently from Perl in the way it recognized POSIX
561 character classes. PCRE was not treating the sequence [:...:] as a
562 character class unless the ... were all letters. Perl, however, seems to
563 allow any characters between [: and :], though of course it rejects as
564 unknown any "names" that contain non-letters, because all the known class
565 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
566 for example, whereas PCRE did not - it did not recognize a POSIX character
567 class. This seemed a bit dangerous, so the code has been changed to be
568 closer to Perl. The behaviour is not identical to Perl, because PCRE will
569 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
570 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
571 Perl does, and where it didn't before.
572
573 24. Rewrite so as to remove the single use of %n from pcregrep because in some
574 Windows environments %n is disabled by default.
575
576
577 Version 7.4 21-Sep-07
578 ---------------------
579
580 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
581 means that a class such as [\s] counted as "explicit reference to CR or
582 LF". That isn't really right - the whole point of the change was to try to
583 help when there was an actual mention of one of the two characters. So now
584 the change happens only if \r or \n (or a literal CR or LF) character is
585 encountered.
586
587 2. The 32-bit options word was also used for 6 internal flags, but the numbers
588 of both had grown to the point where there were only 3 bits left.
589 Fortunately, there was spare space in the data structure, and so I have
590 moved the internal flags into a new 16-bit field to free up more option
591 bits.
592
593 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
594 but did not set the internal JCHANGED flag - either of these is enough to
595 control the way the "get" function works - but the PCRE_INFO_JCHANGED
596 facility is supposed to tell if (?J) was ever used, so now (?J) at the
597 start sets both bits.
598
599 4. Added options (at build time, compile time, exec time) to change \R from
600 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
601
602 5. doc/pcresyntax.html was missing from the distribution.
603
604 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
605 compatibility, even though it is no longer used.
606
607 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
608 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
609 windows.h file is present (where different names are used). [This was
610 reversed later after testing - see 16 below.]
611
612 8. Changed all #include <config.h> to #include "config.h". There were also
613 some further <pcre.h> cases that I changed to "pcre.h".
614
615 9. When pcregrep was used with the --colour option, it missed the line ending
616 sequence off the lines that it output.
617
618 10. It was pointed out to me that arrays of string pointers cause lots of
619 relocations when a shared library is dynamically loaded. A technique of
620 using a single long string with a table of offsets can drastically reduce
621 these. I have refactored PCRE in four places to do this. The result is
622 dramatic:
623
624 Originally: 290
625 After changing UCP table: 187
626 After changing error message table: 43
627 After changing table of "verbs" 36
628 After changing table of Posix names 22
629
630 Thanks to the folks working on Gregex for glib for this insight.
631
632 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
633 unicode-properties was also set.
634
635 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
636
637 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
638 checked only for CRLF.
639
640 14. Added casts to pcretest.c to avoid compiler warnings.
641
642 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
643
644 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
645 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
646 entirely. This removes changes made in 7 above.
647
648 17. The CMake files have been updated, and there is now more information about
649 building with CMake in the NON-UNIX-USE document.
650
651
652 Version 7.3 28-Aug-07
653 ---------------------
654
655 1. In the rejigging of the build system that eventually resulted in 7.1, the
656 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
657 brackets there is not right, since it causes compilers to look for an
658 installed pcre.h, not the version that is in the source that is being
659 compiled (which of course may be different). I have changed it back to:
660
661 #include "pcre.h"
662
663 I have a vague recollection that the change was concerned with compiling in
664 different directories, but in the new build system, that is taken care of
665 by the VPATH setting the Makefile.
666
667 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
668 when the subject happened to end in the byte 0x85 (e.g. if the last
669 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
670 characters but of course it shouldn't be taken as a newline when it is part
671 of another character. The bug was that, for an unlimited repeat of . in
672 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
673 characters when looking for a newline.
674
675 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
676
677 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
678 in debug output.
679
680 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
681 long printing in the pcrecpp unittest when running under MinGW.
682
683 6. ESC_K was left out of the EBCDIC table.
684
685 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
686 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
687 limit also applies to "virtual nesting" when a pattern is recursive, and in
688 this case 1000 isn't so big. I have been able to remove this limit at the
689 expense of backing off one optimization in certain circumstances. Normally,
690 when pcre_exec() would call its internal match() function recursively and
691 immediately return the result unconditionally, it uses a "tail recursion"
692 feature to save stack. However, when a subpattern that can match an empty
693 string has an unlimited repetition quantifier, it no longer makes this
694 optimization. That gives it a stack frame in which to save the data for
695 checking that an empty string has been matched. Previously this was taken
696 from the 1000-entry workspace that had been reserved. So now there is no
697 explicit limit, but more stack is used.
698
699 8. Applied Daniel's patches to solve problems with the import/export magic
700 syntax that is required for Windows, and which was going wrong for the
701 pcreposix and pcrecpp parts of the library. These were overlooked when this
702 problem was solved for the main library.
703
704 9. There were some crude static tests to avoid integer overflow when computing
705 the size of patterns that contain repeated groups with explicit upper
706 limits. As the maximum quantifier is 65535, the maximum group length was
707 set at 30,000 so that the product of these two numbers did not overflow a
708 32-bit integer. However, it turns out that people want to use groups that
709 are longer than 30,000 bytes (though not repeat them that many times).
710 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
711 made it possible to implement the integer overflow checks in a much more
712 dynamic way, which I have now done. The artificial limitation on group
713 length has been removed - we now have only the limit on the total length of
714 the compiled pattern, which depends on the LINK_SIZE setting.
715
716 10. Fixed a bug in the documentation for get/copy named substring when
717 duplicate names are permitted. If none of the named substrings are set, the
718 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
719 empty string.
720
721 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
722 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
723 because the ] is interpreted as the first data character and the
724 terminating ] is not found. PCRE has been made compatible with Perl in this
725 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
726 cause memory overwriting.
727
728 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
729 string has been matched (to stop an infinite loop). It was not recognizing
730 a conditional subpattern that could match an empty string if that
731 subpattern was within another subpattern. For example, it looped when
732 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
733 condition was not nested. This bug has been fixed.
734
735 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
736 past the start of the subject in the presence of bytes with the top bit
737 set, for example "\x8aBCD".
738
739 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
740 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
741
742 14. Optimized (?!) to (*FAIL).
743
744 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
745 This restricts code points to be within the range 0 to 0x10FFFF, excluding
746 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
747 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
748 does: it's just the validity check that is more restrictive.
749
750 16. Inserted checks for integer overflows during escape sequence (backslash)
751 processing, and also fixed erroneous offset values for syntax errors during
752 backslash processing.
753
754 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
755 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
756
757 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
758 caused an overrun.
759
760 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
761 something other than just ASCII characters) inside a group that had an
762 unlimited repeat caused a loop at compile time (while checking to see
763 whether the group could match an empty string).
764
765 20. Debugging a pattern containing \p or \P could cause a crash. For example,
766 [\P{Any}] did so. (Error in the code for printing property names.)
767
768 21. An orphan \E inside a character class could cause a crash.
769
770 22. A repeated capturing bracket such as (A)? could cause a wild memory
771 reference during compilation.
772
773 23. There are several functions in pcre_compile() that scan along a compiled
774 expression for various reasons (e.g. to see if it's fixed length for look
775 behind). There were bugs in these functions when a repeated \p or \P was
776 present in the pattern. These operators have additional parameters compared
777 with \d, etc, and these were not being taken into account when moving along
778 the compiled data. Specifically:
779
780 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
781 length.
782
783 (b) An item such as \pL+ within a repeated group could cause crashes or
784 loops.
785
786 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
787 "reference to non-existent subpattern" error.
788
789 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
790
791 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
792 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
793
794 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
795
796 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
797 character were causing crashes (broken optimization).
798
799 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
800 \p or \P) caused a compile-time loop.
801
802 28. More problems have arisen in unanchored patterns when CRLF is a valid line
803 break. For example, the unstudied pattern [\r\n]A does not match the string
804 "\r\nA" because change 7.0/46 below moves the current point on by two
805 characters after failing to match at the start. However, the pattern \nA
806 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
807 the same is true. There doesn't seem any very clean way out of this, but
808 what I have chosen to do makes the common cases work: PCRE now takes note
809 of whether there can be an explicit match for \r or \n anywhere in the
810 pattern, and if so, 7.0/46 no longer applies. As part of this change,
811 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
812 pattern has explicit CR or LF references.
813
814 29. Added (*CR) etc for changing newline setting at start of pattern.
815
816
817 Version 7.2 19-Jun-07
818 ---------------------
819
820 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
821 which is apparently normally available under Windows.
822
823 2. Re-jig the pcregrep tests with different newline settings in an attempt
824 to make them independent of the local environment's newline setting.
825
826 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
827
828 4. Some of the "internals" tests were previously cut out when the link size
829 was not 2, because the output contained actual offsets. The recent new
830 "Z" feature of pcretest means that these can be cut out, making the tests
831 usable with all link sizes.
832
833 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
834 stack recursion. This gives a massive performance boost under BSD, but just
835 a small improvement under Linux. However, it saves one field in the frame
836 in all cases.
837
838 6. Added more features from the forthcoming Perl 5.10:
839
840 (a) (?-n) (where n is a string of digits) is a relative subroutine or
841 recursion call. It refers to the nth most recently opened parentheses.
842
843 (b) (?+n) is also a relative subroutine call; it refers to the nth next
844 to be opened parentheses.
845
846 (c) Conditions that refer to capturing parentheses can be specified
847 relatively, for example, (?(-2)... or (?(+3)...
848
849 (d) \K resets the start of the current match so that everything before
850 is not part of it.
851
852 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
853
854 (f) \g{name} is another synonym - part of Perl 5.10's unification of
855 reference syntax.
856
857 (g) (?| introduces a group in which the numbering of parentheses in each
858 alternative starts with the same number.
859
860 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
861
862 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
863 PCRE_INFO_JCHANGED.
864
865 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
866 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
867 for detecting groups that can match an empty string.
868
869 9. A pattern with a very large number of alternatives (more than several
870 hundred) was running out of internal workspace during the pre-compile
871 phase, where pcre_compile() figures out how much memory will be needed. A
872 bit of new cunning has reduced the workspace needed for groups with
873 alternatives. The 1000-alternative test pattern now uses 12 bytes of
874 workspace instead of running out of the 4096 that are available.
875
876 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
877
878 11. Applied patch from Google to remove an optimization that didn't quite work.
879 The report of the bug said:
880
881 pcrecpp::RE("a*").FullMatch("aaa") matches, while
882 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
883 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
884
885 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
886 it matched the wrong number of bytes.
887
888
889 Version 7.1 24-Apr-07
890 ---------------------
891
892 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
893 that is more "standard", making use of automake and other Autotools. There
894 is some re-arrangement of the files and adjustment of comments consequent
895 on this.
896
897 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
898 for recursive directory scanning broke on some systems because the files
899 are not scanned in any specific order and on different systems the order
900 was different. A call to "sort" has been inserted into RunGrepTest for the
901 approprate test as a short-term fix. In the longer term there may be an
902 alternative.
903
904 3. I had an email from Eric Raymond about problems translating some of PCRE's
905 man pages to HTML (despite the fact that I distribute HTML pages, some
906 people do their own conversions for various reasons). The problems
907 concerned the use of low-level troff macros .br and .in. I have therefore
908 removed all such uses from the man pages (some were redundant, some could
909 be replaced by .nf/.fi pairs). The 132html script that I use to generate
910 HTML has been updated to handle .nf/.fi and to complain if it encounters
911 .br or .in.
912
913 4. Updated comments in configure.ac that get placed in config.h.in and also
914 arranged for config.h to be included in the distribution, with the name
915 config.h.generic, for the benefit of those who have to compile without
916 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
917
918 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
919 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
920 makevp.bat for the current PCRE, using the additional files
921 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
922
923 6. A Windows user reported a minor discrepancy with test 2, which turned out
924 to be caused by a trailing space on an input line that had got lost in his
925 copy. The trailing space was an accident, so I've just removed it.
926
927 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
928 that is needed.
929
930 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
931 as "const" (a) because they are and (b) because it helps the PHP
932 maintainers who have recently made a script to detect big data structures
933 in the php code that should be moved to the .rodata section. I remembered
934 to update Builducptable as well, so it won't revert if ucptable.h is ever
935 re-created.
936
937 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
938 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
939 order to be able to cut out the UTF-8 tables in the latter when UTF-8
940 support is not required. This saves 1.5-2K of code, which is important in
941 some applications.
942
943 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
944 so as not to refer to the tables, even though these functions will never be
945 called when UTF-8 support is disabled. Otherwise there are problems with a
946 shared library.
947
948 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
949
950 (a) It was defining its arguments as char * instead of void *.
951
952 (b) It was assuming that all moves were upwards in memory; this was true
953 a long time ago when I wrote it, but is no longer the case.
954
955 The emulated memove() is provided for those environments that have neither
956 memmove() nor bcopy(). I didn't think anyone used it these days, but that
957 is clearly not the case, as these two bugs were recently reported.
958
959 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
960 and Detrail to create the HTML documentation, the .txt form of the man
961 pages, and it removes trailing spaces from listed files. It also creates
962 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
963 case, it wraps all the #defines with #ifndefs. This script should be run
964 before "make dist".
965
966 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
967 with Unicode property support.
968
969 (a) For a maximizing quantifier, if the two different cases of the
970 character were of different lengths in their UTF-8 codings (there are
971 some cases like this - I found 11), and the matching function had to
972 back up over a mixture of the two cases, it incorrectly assumed they
973 were both the same length.
974
975 (b) When PCRE was configured to use the heap rather than the stack for
976 recursion during matching, it was not correctly preserving the data for
977 the other case of a UTF-8 character when checking ahead for a match
978 while processing a minimizing repeat. If the check also involved
979 matching a wide character, but failed, corruption could cause an
980 erroneous result when trying to check for a repeat of the original
981 character.
982
983 13. Some tidying changes to the testing mechanism:
984
985 (a) The RunTest script now detects the internal link size and whether there
986 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
987 values substituted by "configure". (The RunGrepTest script already did
988 this for UTF-8.) The configure.ac script no longer substitutes the
989 relevant variables.
990
991 (b) The debugging options /B and /D in pcretest show the compiled bytecode
992 with length and offset values. This means that the output is different
993 for different internal link sizes. Test 2 is skipped for link sizes
994 other than 2 because of this, bypassing the problem. Unfortunately,
995 there was also a test in test 3 (the locale tests) that used /B and
996 failed for link sizes other than 2. Rather than cut the whole test out,
997 I have added a new /Z option to pcretest that replaces the length and
998 offset values with spaces. This is now used to make test 3 independent
999 of link size. (Test 2 will be tidied up later.)
1000
1001 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1002 segmentation fault instead of returning the appropriate error message.
1003
1004 15. In multiline mode when the newline sequence was set to "any", the pattern
1005 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1006 This doesn't seem right; it now treats the CRLF combination as the line
1007 ending, and so does not match in that case. It's only a pattern such as ^$
1008 that would hit this one: something like ^ABC$ would have failed after \r
1009 and then tried again after \r\n.
1010
1011 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1012 in an attempt to make files that differ only in their line terminators
1013 compare equal. This works on Linux.
1014
1015 17. Under certain error circumstances pcregrep might try to free random memory
1016 as it exited. This is now fixed, thanks to valgrind.
1017
1018 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1019 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1020 was because its rules for how to advance for /g after matching an empty
1021 string at the end of a line did not allow for this case. They now check for
1022 it specially.
1023
1024 20. pcretest is supposed to handle patterns and data of any length, by
1025 extending its buffers when necessary. It was getting this wrong when the
1026 buffer for a data line had to be extended.
1027
1028 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1029 CRLF as a newline sequence.
1030
1031 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1032 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1033 I have nevertheless tidied it up.
1034
1035 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1036
1037 24. Added a man page for pcre-config.
1038
1039
1040 Version 7.0 19-Dec-06
1041 ---------------------
1042
1043 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1044 moving to gcc 4.1.1.
1045
1046 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1047 sys/time.h, which is documented as needed for this function. It doesn't
1048 seem to matter on Linux, but it showed up on some releases of OS X.
1049
1050 3. It seems that there are systems where bytes whose values are greater than
1051 127 match isprint() in the "C" locale. The "C" locale should be the
1052 default when a C program starts up. In most systems, only ASCII printing
1053 characters match isprint(). This difference caused the output from pcretest
1054 to vary, making some of the tests fail. I have changed pcretest so that:
1055
1056 (a) When it is outputting text in the compiled version of a pattern, bytes
1057 other than 32-126 are always shown as hex escapes.
1058
1059 (b) When it is outputting text that is a matched part of a subject string,
1060 it does the same, unless a different locale has been set for the match
1061 (using the /L modifier). In this case, it uses isprint() to decide.
1062
1063 4. Fixed a major bug that caused incorrect computation of the amount of memory
1064 required for a compiled pattern when options that changed within the
1065 pattern affected the logic of the preliminary scan that determines the
1066 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1067 that the computed length was too small. The symptoms of this bug were
1068 either the PCRE error "internal error: code overflow" from pcre_compile(),
1069 or a glibc crash with a message such as "pcretest: free(): invalid next
1070 size (fast)". Examples of patterns that provoked this bug (shown in
1071 pcretest format) are:
1072
1073 /(?-x: )/x
1074 /(?x)(?-x: \s*#\s*)/
1075 /((?i)[\x{c0}])/8
1076 /(?i:[\x{c0}])/8
1077
1078 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1079 is now done differently.
1080
1081 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1082 wrapper classes; (b) implement a new function in the C++ scanner that is
1083 more efficient than the old way of doing things because it avoids levels of
1084 recursion in the regex matching; (c) add a paragraph to the documentation
1085 for the FullMatch() function.
1086
1087 6. The escape sequence \n was being treated as whatever was defined as
1088 "newline". Not only was this contrary to the documentation, which states
1089 that \n is character 10 (hex 0A), but it also went horribly wrong when
1090 "newline" was defined as CRLF. This has been fixed.
1091
1092 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1093 was being set to -1 for the "end of line" case (supposedly a value that no
1094 character can have). Though this value is never used (the check for end of
1095 line is "zero bytes in current character"), it caused compiler complaints.
1096 I've changed it to 0xffffffff.
1097
1098 8. In pcre_version.c, the version string was being built by a sequence of
1099 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1100 string (as it is for production releases) called a macro with an empty
1101 argument. The C standard says the result of this is undefined. The gcc
1102 compiler treats it as an empty string (which was what was wanted) but it is
1103 reported that Visual C gives an error. The source has been hacked around to
1104 avoid this problem.
1105
1106 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1107 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1108 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1109 of them did).
1110
1111 10. Originally, pcretest opened its input and output without "b"; then I was
1112 told that "b" was needed in some environments, so it was added for release
1113 5.0 to both the input and output. (It makes no difference on Unix-like
1114 systems.) Later I was told that it is wrong for the input on Windows. I've
1115 now abstracted the modes into two macros, to make it easier to fiddle with
1116 them, and removed "b" from the input mode under Windows.
1117
1118 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1119
1120 12. Added -help and --help to pcretest as an official way of being reminded
1121 of the options.
1122
1123 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1124 and pcrecpp.cc because they annoy compilers at high warning levels.
1125
1126 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1127
1128 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1129 scripts are not C programs :-) and which was not noticed because it works
1130 on Linux.
1131
1132 16. pcretest is supposed to handle any length of pattern and data line (as one
1133 line or as a continued sequence of lines) by extending its input buffer if
1134 necessary. This feature was broken for very long pattern lines, leading to
1135 a string of junk being passed to pcre_compile() if the pattern was longer
1136 than about 50K.
1137
1138 17. I have done a major re-factoring of the way pcre_compile() computes the
1139 amount of memory needed for a compiled pattern. Previously, there was code
1140 that made a preliminary scan of the pattern in order to do this. That was
1141 OK when PCRE was new, but as the facilities have expanded, it has become
1142 harder and harder to keep it in step with the real compile phase, and there
1143 have been a number of bugs (see for example, 4 above). I have now found a
1144 cunning way of running the real compile function in a "fake" mode that
1145 enables it to compute how much memory it would need, while actually only
1146 ever using a few hundred bytes of working memory and without too many
1147 tests of the mode. This should make future maintenance and development
1148 easier. A side effect of this work is that the limit of 200 on the nesting
1149 depth of parentheses has been removed (though this was never a serious
1150 limitation, I suspect). However, there is a downside: pcre_compile() now
1151 runs more slowly than before (30% or more, depending on the pattern). I
1152 hope this isn't a big issue. There is no effect on runtime performance.
1153
1154 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1155 newline (only possible for the last line of a file) and it was a
1156 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1157
1158 19. Added additional timing features to pcretest. (1) The -tm option now times
1159 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1160 separate command line item, by a number that specifies the number of
1161 repeats to use when timing. The default is 50000; this gives better
1162 precision, but takes uncomfortably long for very large patterns.
1163
1164 20. Extended pcre_study() to be more clever in cases where a branch of a
1165 subpattern has no definite first character. For example, (a*|b*)[cd] would
1166 previously give no result from pcre_study(). Now it recognizes that the
1167 first character must be a, b, c, or d.
1168
1169 21. There was an incorrect error "recursive call could loop indefinitely" if
1170 a subpattern (or the entire pattern) that was being tested for matching an
1171 empty string contained only one non-empty item after a nested subpattern.
1172 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1173 incorrectly, because the \d was being skipped in the check.
1174
1175 22. The pcretest program now has a new pattern option /B and a command line
1176 option -b, which is equivalent to adding /B to every pattern. This causes
1177 it to show the compiled bytecode, without the additional information that
1178 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1179 is the same as /B/I).
1180
1181 23. A new optimization is now able automatically to treat some sequences such
1182 as a*b as a*+b. More specifically, if something simple (such as a character
1183 or a simple class like \d) has an unlimited quantifier, and is followed by
1184 something that cannot possibly match the quantified thing, the quantifier
1185 is automatically "possessified".
1186
1187 24. A recursive reference to a subpattern whose number was greater than 39
1188 went wrong under certain circumstances in UTF-8 mode. This bug could also
1189 have affected the operation of pcre_study().
1190
1191 25. Realized that a little bit of performance could be had by replacing
1192 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1193
1194 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1195
1196 27. Possessive quantifiers such as a++ were previously implemented by turning
1197 them into atomic groups such as ($>a+). Now they have their own opcodes,
1198 which improves performance. This includes the automatically created ones
1199 from 23 above.
1200
1201 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1202 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1203 the first matched character to be a colon. This applied both to named and
1204 numbered groups.
1205
1206 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1207
1208 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1209 building PCRE on Windows easier, so I have included it in the distribution.
1210
1211 31. There is now a check in pcretest against a ridiculously large number being
1212 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1213 loop, the loop is abandoned.
1214
1215 32. Forward references to subpatterns in conditions such as (?(2)...) where
1216 subpattern 2 is defined later cause pcre_compile() to search forwards in
1217 the pattern for the relevant set of parentheses. This search went wrong
1218 when there were unescaped parentheses in a character class, parentheses
1219 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1220
1221 33. "Subroutine" calls and backreferences were previously restricted to
1222 referencing subpatterns earlier in the regex. This restriction has now
1223 been removed.
1224
1225 34. Added a number of extra features that are going to be in Perl 5.10. On the
1226 whole, these are just syntactic alternatives for features that PCRE had
1227 previously implemented using the Python syntax or my own invention. The
1228 other formats are all retained for compatibility.
1229
1230 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1231 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1232 also .NET compatible.
1233
1234 (b) A recursion or subroutine call to a named group can now be defined as
1235 (?&name) as well as (?P>name).
1236
1237 (c) A backreference to a named group can now be defined as \k<name> or
1238 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1239 5.10, are also .NET compatible.
1240
1241 (d) A conditional reference to a named group can now use the syntax
1242 (?(<name>) or (?('name') as well as (?(name).
1243
1244 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1245 groups (named and numbered) that are never evaluated inline, but can be
1246 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1247 is always false. There may be only one alternative in such a group.
1248
1249 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1250 as the simple (?(R). The condition is true only if the most recent
1251 recursion is that of the given number or name. It does not search out
1252 through the entire recursion stack.
1253
1254 (g) The escape \gN or \g{N} has been added, where N is a positive or
1255 negative number, specifying an absolute or relative reference.
1256
1257 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1258 some "unreachable code" warnings.
1259
1260 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1261 things, this adds five new scripts.
1262
1263 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1264 There were also incompatibilities regarding the handling of \Q..\E inside
1265 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1266 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1267
1268 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1269 matches an empty string, and forcibly breaks the loop. There were bugs in
1270 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1271 against aaaa the result was just "a" rather than "aaaa", for example. Two
1272 separate and independent bugs (that affected different cases) have been
1273 fixed.
1274
1275 39. Refactored the code to abolish the use of different opcodes for small
1276 capturing bracket numbers. This is a tidy that I avoided doing when I
1277 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1278 The new approach is not only tidier, it makes it possible to reduce the
1279 memory needed to fix the previous bug (38).
1280
1281 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1282 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1283 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1284 mode.
1285
1286 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1287 report.
1288
1289 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1290 copy construction and assignment in the C++ wrapper.
1291
1292 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1293 couple of bugs that could have given wrong results in the "--newline=crlf"
1294 case.
1295
1296 44. Added a number of casts and did some reorganization of signed/unsigned int
1297 variables following suggestions from Dair Grant. Also renamed the variable
1298 "this" as "item" because it is a C++ keyword.
1299
1300 45. Arranged for dftables to add
1301
1302 #include "pcre_internal.h"
1303
1304 to pcre_chartables.c because without it, gcc 4.x may remove the array
1305 definition from the final binary if PCRE is built into a static library and
1306 dead code stripping is activated.
1307
1308 46. For an unanchored pattern, if a match attempt fails at the start of a
1309 newline sequence, and the newline setting is CRLF or ANY, and the next two
1310 characters are CRLF, advance by two characters instead of one.
1311
1312
1313 Version 6.7 04-Jul-06
1314 ---------------------
1315
1316 1. In order to handle tests when input lines are enormously long, pcretest has
1317 been re-factored so that it automatically extends its buffers when
1318 necessary. The code is crude, but this _is_ just a test program. The
1319 default size has been increased from 32K to 50K.
1320
1321 2. The code in pcre_study() was using the value of the re argument before
1322 testing it for NULL. (Of course, in any sensible call of the function, it
1323 won't be NULL.)
1324
1325 3. The memmove() emulation function in pcre_internal.h, which is used on
1326 systems that lack both memmove() and bcopy() - that is, hardly ever -
1327 was missing a "static" storage class specifier.
1328
1329 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1330 containing an extended class (one that cannot be represented by a bitmap
1331 because it contains high-valued characters or Unicode property items, e.g.
1332 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1333 pattern, but PCRE should not loop if you do not (it no longer does).
1334 [Detail: two cases were found: (a) a repeated subpattern containing an
1335 extended class; (b) a recursive reference to a subpattern that followed a
1336 previous extended class. It wasn't skipping over the extended class
1337 correctly when UTF-8 mode was not set.]
1338
1339 5. A negated single-character class was not being recognized as fixed-length
1340 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1341 compile error "lookbehind assertion is not fixed length".
1342
1343 6. The RunPerlTest auxiliary script was showing an unexpected difference
1344 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1345 write a Perl script that can interpret lines of an input file either as
1346 byte characters or as UTF-8, which is what "perltest" was being required to
1347 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1348 can't do is switch easily at run time between having the "use utf8;" pragma
1349 or not. In the end, I fudged it by using the RunPerlTest script to insert
1350 "use utf8;" explicitly for the UTF-8 tests.
1351
1352 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1353 the end of the subject string, contrary to the documentation and to what
1354 Perl does. This was true of both matching functions. Now it matches only at
1355 the start of the subject and immediately after *internal* newlines.
1356
1357 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1358 a pointer to an int instead of a pointer to an unsigned long int. This
1359 caused problems on 64-bit systems.
1360
1361 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1362 instance of the 'standard' template library not being so standard".
1363
1364 10. There was no check on the number of named subpatterns nor the maximum
1365 length of a subpattern name. The product of these values is used to compute
1366 the size of the memory block for a compiled pattern. By supplying a very
1367 long subpattern name and a large number of named subpatterns, the size
1368 computation could be caused to overflow. This is now prevented by limiting
1369 the length of names to 32 characters, and the number of named subpatterns
1370 to 10,000.
1371
1372 11. Subpatterns that are repeated with specific counts have to be replicated in
1373 the compiled pattern. The size of memory for this was computed from the
1374 length of the subpattern and the repeat count. The latter is limited to
1375 65535, but there was no limit on the former, meaning that integer overflow
1376 could in principle occur. The compiled length of a repeated subpattern is
1377 now limited to 30,000 bytes in order to prevent this.
1378
1379 12. Added the optional facility to have named substrings with the same name.
1380
1381 13. Added the ability to use a named substring as a condition, using the
1382 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1383 are numbers (not recommended). Forward references are permitted.
1384
1385 14. Added forward references in named backreferences (if you see what I mean).
1386
1387 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1388 pattern could run off the end of the subject. For example, the pattern
1389 "(?s)(.{1,5})"8 did this with the subject "ab".
1390
1391 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1392 PCRE_CASELESS was set when matching characters that were quantified with ?
1393 or *.
1394
1395 17. A character class other than a single negated character that had a minimum
1396 but no maximum quantifier - for example [ab]{6,} - was not handled
1397 correctly by pce_dfa_exec(). It would match only one character.
1398
1399 18. A valid (though odd) pattern that looked like a POSIX character
1400 class but used an invalid character after [ (for example [[,abc,]]) caused
1401 pcre_compile() to give the error "Failed: internal error: code overflow" or
1402 in some cases to crash with a glibc free() error. This could even happen if
1403 the pattern terminated after [[ but there just happened to be a sequence of
1404 letters, a binary zero, and a closing ] in the memory that followed.
1405
1406 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1407 over the years. Originally (before any Unicode support), just the bottom 8
1408 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1409 output from "man perlunicode" includes this:
1410
1411 The regular expression compiler produces polymorphic opcodes. That
1412 is, the pattern adapts to the data and automatically switches to
1413 the Unicode character scheme when presented with Unicode data--or
1414 instead uses a traditional byte scheme when presented with byte
1415 data.
1416
1417 Sadly, a wide octal escape does not cause a switch, and in a string with
1418 no other multibyte characters, these octal escapes are treated as before.
1419 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1420 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1421 Unicode string.
1422
1423 I have not perpetrated such confusion in PCRE. Up till now, it took just
1424 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1425 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1426 translate to the appropriate multibyte character.
1427
1428 29. Applied some refactoring to reduce the number of warnings from Microsoft
1429 and Borland compilers. This has included removing the fudge introduced
1430 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1431 a warning about an unused variable.
1432
1433 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1434 characters since release 4.0, because Perl (from release 5.004) does not.
1435 [Or at least, is documented not to: some releases seem to be in conflict
1436 with the documentation.] However, when a pattern was studied with
1437 pcre_study() and all its branches started with \s, PCRE still included VT
1438 as a possible starting character. Of course, this did no harm; it just
1439 caused an unnecessary match attempt.
1440
1441 22. Removed a now-redundant internal flag bit that recorded the fact that case
1442 dependency changed within the pattern. This was once needed for "required
1443 byte" processing, but is no longer used. This recovers a now-scarce options
1444 bit. Also moved the least significant internal flag bit to the most-
1445 significant bit of the word, which was not previously used (hangover from
1446 the days when it was an int rather than a uint) to free up another bit for
1447 the future.
1448
1449 23. Added support for CRLF line endings as well as CR and LF. As well as the
1450 default being selectable at build time, it can now be changed at runtime
1451 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1452 specify that it is scanning data with non-default line endings.
1453
1454 24. Changed the definition of CXXLINK to make it agree with the definition of
1455 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1456
1457 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1458 recursions. This makes a big different to stack usage for some patterns.
1459
1460 26. If a subpattern containing a named recursion or subroutine reference such
1461 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1462 the space required for the compiled pattern went wrong and gave too small a
1463 value. Depending on the environment, this could lead to "Failed: internal
1464 error: code overflow at offset 49" or "glibc detected double free or
1465 corruption" errors.
1466
1467 27. Applied patches from Google (a) to support the new newline modes and (b) to
1468 advance over multibyte UTF-8 characters in GlobalReplace.
1469
1470 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1471 difference for some implementation of PCRE in some Windows version.
1472
1473 29. Added some extra testing facilities to pcretest:
1474
1475 \q<number> in a data line sets the "match limit" value
1476 \Q<number> in a data line sets the "match recursion limt" value
1477 -S <number> sets the stack size, where <number> is in megabytes
1478
1479 The -S option isn't available for Windows.
1480
1481
1482 Version 6.6 06-Feb-06
1483 ---------------------
1484
1485 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1486 in pcreposix.h. I have copied the definition from pcre.h.
1487
1488 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1489 because pcre.h is no longer a built file.
1490
1491 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1492 not normally included in the compiled code.
1493
1494
1495 Version 6.5 01-Feb-06
1496 ---------------------
1497
1498 1. When using the partial match feature with pcre_dfa_exec(), it was not
1499 anchoring the second and subsequent partial matches at the new starting
1500 point. This could lead to incorrect results. For example, with the pattern
1501 /1234/, partially matching against "123" and then "a4" gave a match.
1502
1503 2. Changes to pcregrep:
1504
1505 (a) All non-match returns from pcre_exec() were being treated as failures
1506 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1507 error message is output. Some extra information is given for the
1508 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1509 probably the only errors that are likely to be caused by users (by
1510 specifying a regex that has nested indefinite repeats, for instance).
1511 If there are more than 20 of these errors, pcregrep is abandoned.
1512
1513 (b) A binary zero was treated as data while matching, but terminated the
1514 output line if it was written out. This has been fixed: binary zeroes
1515 are now no different to any other data bytes.
1516
1517 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1518 used to set a locale for matching. The --locale=xxxx long option has
1519 been added (no short equivalent) to specify a locale explicitly on the
1520 pcregrep command, overriding the environment variables.
1521
1522 (d) When -B was used with -n, some line numbers in the output were one less
1523 than they should have been.
1524
1525 (e) Added the -o (--only-matching) option.
1526
1527 (f) If -A or -C was used with -c (count only), some lines of context were
1528 accidentally printed for the final match.
1529
1530 (g) Added the -H (--with-filename) option.
1531
1532 (h) The combination of options -rh failed to suppress file names for files
1533 that were found from directory arguments.
1534
1535 (i) Added the -D (--devices) and -d (--directories) options.
1536
1537 (j) Added the -F (--fixed-strings) option.
1538
1539 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1540
1541 (l) Added the --colo(u)r option.
1542
1543 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1544 is not present by default.
1545
1546 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1547 items such as (?R) or (?1), when the recursion could match a number of
1548 alternatives. If it matched one of the alternatives, but subsequently,
1549 outside the recursion, there was a failure, the code tried to back up into
1550 the recursion. However, because of the way PCRE is implemented, this is not
1551 possible, and the result was an incorrect result from the match.
1552
1553 In order to prevent this happening, the specification of recursion has
1554 been changed so that all such subpatterns are automatically treated as
1555 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1556
1557 4. I had overlooked the fact that, in some locales, there are characters for
1558 which isalpha() is true but neither isupper() nor islower() are true. In
1559 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1560 and ordfeminine) are like this. This affected the treatment of \w and \W
1561 when they appeared in character classes, but not when they appeared outside
1562 a character class. The bit map for "word" characters is now created
1563 separately from the results of isalnum() instead of just taking it from the
1564 upper, lower, and digit maps. (Plus the underscore character, of course.)
1565
1566 5. The above bug also affected the handling of POSIX character classes such as
1567 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1568 permanent tables. Instead, the bit maps for such a class were previously
1569 created as the appropriate unions of the upper, lower, and digit bitmaps.
1570 Now they are created by subtraction from the [[:word:]] class, which has
1571 its own bitmap.
1572
1573 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1574 It is created by subtracting the vertical space characters (\x09, \x0a,
1575 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1576 subtraction was done in the overall bitmap for a character class, meaning
1577 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1578 be recognized. This bug has been fixed.
1579
1580 7. Patches from the folks at Google:
1581
1582 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1583 real life, but is still worth protecting against".
1584
1585 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1586 regular expressions".
1587
1588 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1589 have it.
1590
1591 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1592 "configure" and the latter not, in order to fix a problem somebody had
1593 with compiling the Arg class on HP-UX.
1594
1595 (e) Improve the error-handling of the C++ wrapper a little bit.
1596
1597 (f) New tests for checking recursion limiting.
1598
1599 8. The pcre_memmove() function, which is used only if the environment does not
1600 have a standard memmove() function (and is therefore rarely compiled),
1601 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1602 returning a result (though PCRE never actually uses the result).
1603
1604 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1605 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1606 returned instead of calling malloc() with an overflowing number that would
1607 most likely cause subsequent chaos.
1608
1609 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1610
1611 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1612 with this option is matched, the nmatch and pmatch options of regexec() are
1613 ignored.
1614
1615 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1616 provided in case anyone wants to the the POSIX interface with UTF-8
1617 strings.
1618
1619 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1620 C++ linking (needed for some HP-UX environments).
1621
1622 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1623 (unused parameter) and in the pcre_printint() function (omitted "default"
1624 switch label when the default is to do nothing).
1625
1626 15. Added some code to make it possible, when PCRE is compiled as a C++
1627 library, to replace subject pointers for pcre_exec() with a smart pointer
1628 class, thus making it possible to process discontinuous strings.
1629
1630 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1631 much the same function. They were added by different people who were trying
1632 to make PCRE easy to compile on non-Unix systems. It has been suggested
1633 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1634 for compiling on Windows systems. I have therefore replaced it with
1635 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1636 defaults to "extern" for C or "extern C" for C++, which works fine on
1637 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1638 SCOPE with something explicit in config.h. In addition:
1639
1640 (a) pcreposix.h still had just "extern" instead of either of these macros;
1641 I have replaced it with PCRE_DATA_SCOPE.
1642
1643 (b) Functions such as _pcre_xclass(), which are internal to the library,
1644 but external in the C sense, all had PCRE_EXPORT in their definitions.
1645 This is apparently wrong for the Windows case, so I have removed it.
1646 (It makes no difference on Unix-like systems.)
1647
1648 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1649 of recursive calls to match(). This is different to MATCH_LIMIT because
1650 that limits the total number of calls to match(), not all of which increase
1651 the depth of recursion. Limiting the recursion depth limits the amount of
1652 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1653 when PCRE is compiled, and changed at run time. A patch from Google adds
1654 this functionality to the C++ interface.
1655
1656 18. Changes to the handling of Unicode character properties:
1657
1658 (a) Updated the table to Unicode 4.1.0.
1659
1660 (b) Recognize characters that are not in the table as "Cn" (undefined).
1661
1662 (c) I revised the way the table is implemented to a much improved format
1663 which includes recognition of ranges. It now supports the ranges that
1664 are defined in UnicodeData.txt, and it also amalgamates other
1665 characters into ranges. This has reduced the number of entries in the
1666 table from around 16,000 to around 3,000, thus reducing its size
1667 considerably. I realized I did not need to use a tree structure after
1668 all - a binary chop search is just as efficient. Having reduced the
1669 number of entries, I extended their size from 6 bytes to 8 bytes to
1670 allow for more data.
1671
1672 (d) Added support for Unicode script names via properties such as \p{Han}.
1673
1674 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1675 matching that character.
1676
1677 20. When matching a repeated Unicode property with a minimum greater than zero,
1678 (for example \pL{2,}), PCRE could look past the end of the subject if it
1679 reached it while seeking the minimum number of characters. This could
1680 happen only if some of the characters were more than one byte long, because
1681 there is a check for at least the minimum number of bytes.
1682
1683 21. Refactored the implementation of \p and \P so as to be more general, to
1684 allow for more different types of property in future. This has changed the
1685 compiled form incompatibly. Anybody with saved compiled patterns that use
1686 \p or \P will have to recompile them.
1687
1688 22. Added "Any" and "L&" to the supported property types.
1689
1690 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1691 but give a compile time error if the value is greater than 0xff.
1692
1693 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1694 accidentally not being installed or uninstalled.
1695
1696 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1697 made were to insert the current release number. This seemed silly, because
1698 it made things harder for people building PCRE on systems that don't run
1699 "configure". I have turned pcre.h into a distributed file, no longer built
1700 by "configure", with the version identification directly included. There is
1701 no longer a pcre.h.in file.
1702
1703 However, this change necessitated a change to the pcre-config script as
1704 well. It is built from pcre-config.in, and one of the substitutions was the
1705 release number. I have updated configure.ac so that ./configure now finds
1706 the release number by grepping pcre.h.
1707
1708 26. Added the ability to run the tests under valgrind.
1709
1710
1711 Version 6.4 05-Sep-05
1712 ---------------------
1713
1714 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1715 "--" to be printed when multiple files were scanned, even when none of the
1716 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1717 consider it to be a bug, and have restored the previous behaviour.
1718
1719 2. A couple of code tidies to get rid of compiler warnings.
1720
1721 3. The pcretest program used to cheat by referring to symbols in the library
1722 whose names begin with _pcre_. These are internal symbols that are not
1723 really supposed to be visible externally, and in some environments it is
1724 possible to suppress them. The cheating is now confined to including
1725 certain files from the library's source, which is a bit cleaner.
1726
1727 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1728 file's purpose clearer.
1729
1730 5. Reorganized pcre_ucp_findchar().
1731
1732
1733 Version 6.3 15-Aug-05
1734 ---------------------
1735
1736 1. The file libpcre.pc.in did not have general read permission in the tarball.
1737
1738 2. There were some problems when building without C++ support:
1739
1740 (a) If C++ support was not built, "make install" and "make test" still
1741 tried to test it.
1742
1743 (b) There were problems when the value of CXX was explicitly set. Some
1744 changes have been made to try to fix these, and ...
1745
1746 (c) --disable-cpp can now be used to explicitly disable C++ support.
1747
1748 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1749 backslash in a target when C++ was disabled. This confuses some
1750 versions of "make", apparently. Using an intermediate variable solves
1751 this. (Same for CPP_LOBJ.)
1752
1753 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1754 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1755 necessary on certain architectures.
1756
1757 4. Added a setting of -export-symbols-regex to the link command to remove
1758 those symbols that are exported in the C sense, but actually are local
1759 within the library, and not documented. Their names all begin with
1760 "_pcre_". This is not a perfect job, because (a) we have to except some
1761 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1762 available (and never for static libraries). I have made a note to try to
1763 find a way round (a) in the future.
1764
1765
1766 Version 6.2 01-Aug-05
1767 ---------------------
1768
1769 1. There was no test for integer overflow of quantifier values. A construction
1770 such as {1111111111111111} would give undefined results. What is worse, if
1771 a minimum quantifier for a parenthesized subpattern overflowed and became
1772 negative, the calculation of the memory size went wrong. This could have
1773 led to memory overwriting.
1774
1775 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1776
1777 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1778 operating environments where this matters.
1779
1780 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1781 PCRE options from within the C++ wrapper.
1782
1783 5. Named capturing subpatterns were not being correctly counted when a pattern
1784 was compiled. This caused two problems: (a) If there were more than 100
1785 such subpatterns, the calculation of the memory needed for the whole
1786 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1787 back references of the form \12, where the number was greater than 9, were
1788 not recognized as back references, even though there were sufficient
1789 previous subpatterns.
1790
1791 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1792 versions of gcc, e.g. 2.95.4.
1793
1794
1795 Version 6.1 21-Jun-05
1796 ---------------------
1797
1798 1. There was one reference to the variable "posix" in pcretest.c that was not
1799 surrounded by "#if !defined NOPOSIX".
1800
1801 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1802 the cross-check on the old pcre_info() function, for the benefit of the
1803 cut-down version of PCRE that is currently imported into Exim.
1804
1805 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1806 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1807 patterns that start (?i) but I don't think that matters. The use of (?i) is
1808 just an example; this all applies to the other options as well.
1809
1810 4. Since libtool seems to echo the compile commands it is issuing, the output
1811 from "make" can be reduced a bit by putting "@" in front of each libtool
1812 compile command.
1813
1814 5. Patch from the folks at Google for configure.in to be a bit more thorough
1815 in checking for a suitable C++ installation before trying to compile the
1816 C++ stuff. This should fix a reported problem when a compiler was present,
1817 but no suitable headers.
1818
1819 6. The man pages all had just "PCRE" as their title. I have changed them to
1820 be the relevant file name. I have also arranged that these names are
1821 retained in the file doc/pcre.txt, which is a concatenation in text format
1822 of all the man pages except the little individual ones for each function.
1823
1824 7. The NON-UNIX-USE file had not been updated for the different set of source
1825 files that come with release 6. I also added a few comments about the C++
1826 wrapper.
1827
1828
1829 Version 6.0 07-Jun-05
1830 ---------------------
1831
1832 1. Some minor internal re-organization to help with my DFA experiments.
1833
1834 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1835 didn't matter for the library itself when fully configured, but did matter
1836 when compiling without UCP support, or within Exim, where the ucp files are
1837 not imported.
1838
1839 3. Refactoring of the library code to split up the various functions into
1840 different source modules. The addition of the new DFA matching code (see
1841 below) to a single monolithic source would have made it really too
1842 unwieldy, quite apart from causing all the code to be include in a
1843 statically linked application, when only some functions are used. This is
1844 relevant even without the DFA addition now that patterns can be compiled in
1845 one application and matched in another.
1846
1847 The downside of splitting up is that there have to be some external
1848 functions and data tables that are used internally in different modules of
1849 the library but which are not part of the API. These have all had their
1850 names changed to start with "_pcre_" so that they are unlikely to clash
1851 with other external names.
1852
1853 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1854 a different (DFA) algorithm. Although it is slower than the original
1855 function, it does have some advantages for certain types of matching
1856 problem.
1857
1858 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1859 including restarting after a partial match.
1860
1861 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1862 defined when compiling for Windows was sent to me. I have put it into the
1863 code, though I have no means of testing or verifying it.
1864
1865 7. Added the pcre_refcount() auxiliary function.
1866
1867 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1868 match before or at the first newline in the subject string. In pcretest,
1869 the /f option on a pattern can be used to set this.
1870
1871 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1872 would behave wrongly. This has been present in PCRE since release 4.0.
1873
1874 10. A number of changes to the pcregrep command:
1875
1876 (a) Refactored how -x works; insert ^(...)$ instead of setting
1877 PCRE_ANCHORED and checking the length, in preparation for adding
1878 something similar for -w.
1879
1880 (b) Added the -w (match as a word) option.
1881
1882 (c) Refactored the way lines are read and buffered so as to have more
1883 than one at a time available.
1884
1885 (d) Implemented a pcregrep test script.
1886
1887 (e) Added the -M (multiline match) option. This allows patterns to match
1888 over several lines of the subject. The buffering ensures that at least
1889 8K, or the rest of the document (whichever is the shorter) is available
1890 for matching (and similarly the previous 8K for lookbehind assertions).
1891
1892 (f) Changed the --help output so that it now says
1893
1894 -w, --word-regex(p)
1895
1896 instead of two lines, one with "regex" and the other with "regexp"
1897 because that confused at least one person since the short forms are the
1898 same. (This required a bit of code, as the output is generated
1899 automatically from a table. It wasn't just a text change.)
1900
1901 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1902 option but starts with a hyphen. Could be a pattern or a path name
1903 starting with a hyphen, for instance.
1904
1905 (h) "-" can be given as a file name to represent stdin.
1906
1907 (i) When file names are being printed, "(standard input)" is used for
1908 the standard input, for compatibility with GNU grep. Previously
1909 "<stdin>" was used.
1910
1911 (j) The option --label=xxx can be used to supply a name to be used for
1912 stdin when file names are being printed. There is no short form.
1913
1914 (k) Re-factored the options decoding logic because we are going to add
1915 two more options that take data. Such options can now be given in four
1916 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1917
1918 (l) Added the -A, -B, and -C options for requesting that lines of context
1919 around matches be printed.
1920
1921 (m) Added the -L option to print the names of files that do not contain
1922 any matching lines, that is, the complement of -l.
1923
1924 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1925 continue to scan other files.
1926
1927 (o) The -s option was incorrectly implemented. For compatibility with other
1928 greps, it now suppresses the error message for a non-existent or non-
1929 accessible file (but not the return code). There is a new option called
1930 -q that suppresses the output of matching lines, which was what -s was
1931 previously doing.
1932
1933 (p) Added --include and --exclude options to specify files for inclusion
1934 and exclusion when recursing.
1935
1936 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1937 Hopefully, it now does.
1938
1939 12. Missing cast in pcre_study().
1940
1941 13. Added an "uninstall" target to the makefile.
1942
1943 14. Replaced "extern" in the function prototypes in Makefile.in with
1944 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1945 world, but is set differently for Windows.
1946
1947 15. Added a second compiling function called pcre_compile2(). The only
1948 difference is that it has an extra argument, which is a pointer to an
1949 integer error code. When there is a compile-time failure, this is set
1950 non-zero, in addition to the error test pointer being set to point to an
1951 error message. The new argument may be NULL if no error number is required
1952 (but then you may as well call pcre_compile(), which is now just a
1953 wrapper). This facility is provided because some applications need a
1954 numeric error indication, but it has also enabled me to tidy up the way
1955 compile-time errors are handled in the POSIX wrapper.
1956
1957 16. Added VPATH=.libs to the makefile; this should help when building with one
1958 prefix path and installing with another. (Or so I'm told by someone who
1959 knows more about this stuff than I do.)
1960
1961 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1962 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1963 match everything, including newlines. This is not POSIX-compatible, but
1964 somebody wanted the feature. From pcretest it can be activated by using
1965 both the P and the s flags.
1966
1967 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1968
1969 19. libpcre.pc was being incorrectly installed as executable.
1970
1971 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1972 it now also looks for '\r' so that it will work unmodified on Windows.
1973
1974 21. Added Google's contributed C++ wrapper to the distribution.
1975
1976 22. Added some untidy missing memory free() calls in pcretest, to keep
1977 Electric Fence happy when testing.
1978
1979
1980
1981 Version 5.0 13-Sep-04
1982 ---------------------
1983
1984 1. Internal change: literal characters are no longer packed up into items
1985 containing multiple characters in a single byte-string. Each character
1986 is now matched using a separate opcode. However, there may be more than one
1987 byte in the character in UTF-8 mode.
1988
1989 2. The pcre_callout_block structure has two new fields: pattern_position and
1990 next_item_length. These contain the offset in the pattern to the next match
1991 item, and its length, respectively.
1992
1993 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1994 insertion of callouts before each pattern item. Added the /C option to
1995 pcretest to make use of this.
1996
1997 4. On the advice of a Windows user, the lines
1998
1999 #if defined(_WIN32) || defined(WIN32)
2000 _setmode( _fileno( stdout ), 0x8000 );
2001 #endif /* defined(_WIN32) || defined(WIN32) */
2002
2003 have been added to the source of pcretest. This apparently does useful
2004 magic in relation to line terminators.
2005
2006 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2007 for the benefit of those environments where the "b" makes a difference.
2008
2009 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2010 to know about it. I have put a hack into configure.in that adds in code
2011 to set GCC=yes if CC=icc. This seems to end up at a point in the
2012 generated configure script that is early enough to affect the setting of
2013 compiler options, which is what is needed, but I have no means of testing
2014 whether it really works. (The user who reported this had patched the
2015 generated configure script, which of course I cannot do.)
2016
2017 LATER: After change 22 below (new libtool files), the configure script
2018 seems to know about icc (and also ecc). Therefore, I have commented out
2019 this hack in configure.in.
2020
2021 7. Added support for pkg-config (2 patches were sent in).
2022
2023 8. Negated POSIX character classes that used a combination of internal tables
2024 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2025 [[:^ascii]]. Typically, they would match almost any characters. The other
2026 POSIX classes were not broken in this way.
2027
2028 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2029 to find the match, as PCRE was deluded into thinking that the match had to
2030 start at the start point or following a newline. The same bug applied to
2031 patterns with negative forward assertions or any backward assertions
2032 preceding ".*" at the start, unless the pattern required a fixed first
2033 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2034
2035 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2036 starting at the last subject character, bytes beyond the end of the subject
2037 string were read.
2038
2039 11. Renamed the variable "class" as "classbits" to make life easier for C++
2040 users. (Previously there was a macro definition, but it apparently wasn't
2041 enough.)
2042
2043 12. Added the new field "tables" to the extra data so that tables can be passed
2044 in at exec time, or the internal tables can be re-selected. This allows
2045 a compiled regex to be saved and re-used at a later time by a different
2046 program that might have everything at different addresses.
2047
2048 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2049 -R library as well as a -L library.
2050
2051 14. The debugging options of pcretest (-d on the command line or D on a
2052 pattern) showed incorrect output for anything following an extended class
2053 that contained multibyte characters and which was followed by a quantifier.
2054
2055 15. Added optional support for general category Unicode character properties
2056 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2057 support. It adds about 90K to the size of the library. The meanings of the
2058 inbuilt class escapes such as \d and \s have NOT been changed.
2059
2060 16. Updated pcredemo.c to include calls to free() to release the memory for the
2061 compiled pattern.
2062
2063 17. The generated file chartables.c was being created in the source directory
2064 instead of in the building directory. This caused the build to fail if the
2065 source directory was different from the building directory, and was
2066 read-only.
2067
2068 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2069 file. No doubt somebody will tell me if they don't make sense... Also added
2070 Dan Mooney's comments about building on OpenVMS.
2071
2072 19. Added support for partial matching via the PCRE_PARTIAL option for
2073 pcre_exec() and the \P data escape in pcretest.
2074
2075 20. Extended pcretest with 3 new pattern features:
2076
2077 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2078 write the compiled pattern to the file whose name is "rest-of-line".
2079 This is a straight binary dump of the data, with the saved pointer to
2080 the character tables forced to be NULL. The study data, if any, is
2081 written too. After writing, pcretest reads a new pattern.
2082
2083 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2084 compiled pattern from the given file. There must not be any
2085 occurrences of "<" in the file name (pretty unlikely); if there are,
2086 pcretest will instead treat the initial "<" as a pattern delimiter.
2087 After reading in the pattern, pcretest goes on to read data lines as
2088 usual.
2089
2090 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2091 and 16-bit fields in a compiled pattern, to simulate a pattern that
2092 was compiled on a host of opposite endianness.
2093
2094 21. The pcre-exec() function can now cope with patterns that were compiled on
2095 hosts of opposite endianness, with this restriction:
2096
2097 As for any compiled expression that is saved and used later, the tables
2098 pointer field cannot be preserved; the extra_data field in the arguments
2099 to pcre_exec() should be used to pass in a tables address if a value
2100 other than the default internal tables were used at compile time.
2101
2102 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2103 now diagnosed as an error. Previously, most of the time, a negative number
2104 would have been treated as zero, but if in addition "ovector" was passed as
2105 NULL, a crash could occur.
2106
2107 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2108 new versions from the libtool 1.5 distribution (the last one is a copy of
2109 a file called libtool.m4). This seems to have fixed the need to patch
2110 "configure" to support Darwin 1.3 (which I used to do). However, I still
2111 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2112 workstation).
2113
2114 24. Changed the PCRE licence to be the more standard "BSD" licence.
2115
2116
2117 Version 4.5 01-Dec-03
2118 ---------------------
2119
2120 1. There has been some re-arrangement of the code for the match() function so
2121 that it can be compiled in a version that does not call itself recursively.
2122 Instead, it keeps those local variables that need separate instances for
2123 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2124 needs to "recurse". Keeping track of where control must go is done by means
2125 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2126 hide most of the details from the main code, and operates only if
2127 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2128 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2129 operating.
2130
2131 To make it easier for callers to provide specially tailored get/free
2132 functions for this usage, two new functions, pcre_stack_malloc, and
2133 pcre_stack_free, are used. They are always called in strict stacking order,
2134 and the size of block requested is always the same.
2135
2136 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2137 PCRE has been compiled to use the stack or the heap for recursion. The
2138 -C option of pcretest uses this to show which version is compiled.
2139
2140 A new data escape \S, is added to pcretest; it causes the amounts of store
2141 obtained and freed by both kinds of malloc/free at match time to be added
2142 to the output.
2143
2144 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2145 what's available on my current Linux desktop machine.
2146
2147 3. When matching a UTF-8 string, the test for a valid string at the start has
2148 been extended. If start_offset is not zero, PCRE now checks that it points
2149 to a byte that is the start of a UTF-8 character. If not, it returns
2150 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2151 this is necessary because there may be backward assertions in the pattern.
2152 When matching the same subject several times, it may save resources to use
2153 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2154
2155 4. The code for checking the validity of UTF-8 strings has been tightened so
2156 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2157 containing "overlong sequences".
2158
2159 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2160 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2161 should have been "&", but it just so happened that all the cases this let
2162 through by mistake were picked up later in the function.
2163
2164 6. I had used a variable called "isblank" - this is a C99 function, causing
2165 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2166
2167 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2168 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2169 so the version is shown; (c) stop "make test" echoing "./RunTest".
2170
2171 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2172
2173 9. The prototype for memmove() for systems that don't have it was using
2174 size_t, but the inclusion of the header that defines size_t was later. I've
2175 moved the #includes for the C headers earlier to avoid this.
2176
2177 10. Added some adjustments to the code to make it easier to compiler on certain
2178 special systems:
2179
2180 (a) Some "const" qualifiers were missing.
2181 (b) Added the macro EXPORT before all exported functions; by default this
2182 is defined to be empty.
2183 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2184 that it reads its output file name as an argument instead of writing
2185 to the standard output and assuming this can be redirected.
2186
2187 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2188 class containing characters with values greater than 255, PCRE compilation
2189 went into a loop.
2190
2191 12. A recursive reference to a subpattern that was within another subpattern
2192 that had a minimum quantifier of zero caused PCRE to crash. For example,
2193 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2194 recursion. If the recursively-called subpattern itself had a zero repeat,
2195 that was OK.
2196
2197 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2198 buffer into which it was copied (for escape processing) was still set at
2199 1024, so long lines caused crashes.
2200
2201 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2202 "internal error: code overflow...". This applied to any character class
2203 that was followed by a possessive quantifier.
2204
2205 15. Modified the Makefile to add libpcre.la as a prerequisite for
2206 libpcreposix.la because I was told this is needed for a parallel build to
2207 work.
2208
2209 16. If a pattern that contained .* following optional items at the start was
2210 studied, the wrong optimizing data was generated, leading to matching
2211 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2212 matching string must start with a or b or c. The correct conclusion for
2213 this pattern is that a match can start with any character.
2214
2215
2216 Version 4.4 13-Aug-03
2217 ---------------------
2218
2219 1. In UTF-8 mode, a character class containing characters with values between
2220 127 and 255 was not handled correctly if the compiled pattern was studied.
2221 In fixing this, I have also improved the studying algorithm for such
2222 classes (slightly).
2223
2224 2. Three internal functions had redundant arguments passed to them. Removal
2225 might give a very teeny performance improvement.
2226
2227 3. Documentation bug: the value of the capture_top field in a callout is *one
2228 more than* the number of the hightest numbered captured substring.
2229
2230 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2231 in incorrectly linking with a previously installed version. They now link
2232 explicitly with libpcre.la.
2233
2234 5. configure.in no longer needs to recognize Cygwin specially.
2235
2236 6. A problem in pcre.in for Windows platforms is fixed.
2237
2238 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2239 pcretest, it used to include the size of the study block as part of its
2240 output. Unfortunately, the structure contains a field that has a different
2241 size on different hardware architectures. This meant that the tests that
2242 showed this size failed. As the block is currently always of a fixed size,
2243 this information isn't actually particularly useful in pcretest output, so
2244 I have just removed it.
2245
2246 8. Three pre-processor statements accidentally did not start in column 1.
2247 Sadly, there are *still* compilers around that complain, even though
2248 standard C has not required this for well over a decade. Sigh.
2249
2250 9. In pcretest, the code for checking callouts passed small integers in the
2251 callout_data field, which is a void * field. However, some picky compilers
2252 complained about the casts involved for this on 64-bit systems. Now
2253 pcretest passes the address of the small integer instead, which should get
2254 rid of the warnings.
2255
2256 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2257 both compile and run time, and gives an error if an invalid UTF-8 sequence
2258 is found. There is a option for disabling this check in cases where the
2259 string is known to be correct and/or the maximum performance is wanted.
2260
2261 11. In response to a bug report, I changed one line in Makefile.in from
2262
2263 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2264 to
2265 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2266
2267 to look similar to other lines, but I have no way of telling whether this
2268 is the right thing to do, as I do not use Windows. No doubt I'll get told
2269 if it's wrong...
2270
2271
2272 Version 4.3 21-May-03
2273 ---------------------
2274
2275 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2276 Makefile.
2277
2278 2. Some refactoring to improve the quality of the code:
2279
2280 (i) The utf8_table... variables are now declared "const".
2281
2282 (ii) The code for \cx, which used the "case flipping" table to upper case
2283 lower case letters, now just substracts 32. This is ASCII-specific,
2284 but the whole concept of \cx is ASCII-specific, so it seems
2285 reasonable.
2286
2287 (iii) PCRE was using its character types table to recognize decimal and
2288 hexadecimal digits in the pattern. This is silly, because it handles
2289 only 0-9, a-f, and A-F, but the character types table is locale-
2290 specific, which means strange things might happen. A private
2291 table is now used for this - though it costs 256 bytes, a table is
2292 much faster than multiple explicit tests. Of course, the standard
2293 character types table is still used for matching digits in subject
2294 strings against \d.
2295
2296 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2297 ending in _t are). So I've renamed it as ESC_tee.
2298
2299 3. The first argument for regexec() in the POSIX wrapper should have been
2300 defined as "const".
2301
2302 4. Changed pcretest to use malloc() for its buffers so that they can be
2303 Electric Fenced for debugging.
2304
2305 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2306 to read one or more bytes before the start of the subject string. Often this
2307 had no effect on PCRE's behaviour, but in some circumstances it could
2308 provoke a segmentation fault.
2309
2310 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2311 to try to read one or more bytes before the start of the subject string.
2312
2313 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2314 UTF-8 support could misbehave in various ways if the subject string
2315 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2316 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2317 back over UTF-8 characters.)
2318
2319
2320 Version 4.2 14-Apr-03
2321 ---------------------
2322
2323 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2324
2325 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2326 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2327 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2328 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2329 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2330 and BUILD_EXEEXT
2331 Note: automatic setting of the BUILD variables is not yet working
2332 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2333 compile-time but not at link-time
2334 [LINK]: use for linking executables only
2335 make different versions for Windows and non-Windows
2336 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2337 libraries
2338 [LINK_FOR_BUILD]: new variable
2339 [OBJEXT]: use throughout
2340 [EXEEXT]: use throughout
2341 <winshared>: new target
2342 <wininstall>: new target
2343 <dftables.o>: use native compiler
2344 <dftables>: use native linker
2345 <install>: handle Windows platform correctly
2346 <clean>: ditto
2347 <check>: ditto
2348 copy DLL to top builddir before testing
2349
2350 As part of these changes, -no-undefined was removed again. This was reported
2351 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2352 in any case.
2353
2354 3. Some tidies to get rid of compiler warnings:
2355
2356 . In the match_data structure, match_limit was an unsigned long int, whereas
2357 match_call_count was an int. I've made them both unsigned long ints.
2358
2359 . In pcretest the fact that a const uschar * doesn't automatically cast to
2360 a void * provoked a warning.
2361
2362 . Turning on some more compiler warnings threw up some "shadow" variables
2363 and a few more missing casts.
2364
2365 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2366 option, a class that contained a single character with a value between 128
2367 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2368
2369 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2370 option, a class that contained several characters, but with at least one
2371 whose value was between 128 and 255 caused PCRE to crash.
2372
2373
2374 Version 4.1 12-Mar-03
2375 ---------------------
2376
2377 1. Compiling with gcc -pedantic found a couple of places where casts were
2378 needed, and a string in dftables.c that was longer than standard compilers are
2379 required to support.
2380
2381 2. Compiling with Sun's compiler found a few more places where the code could
2382 be tidied up in order to avoid warnings.
2383
2384 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2385 first of these names is deprecated in the latest Autoconf in favour of the name
2386 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2387 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2388 analogy I have changed it to CFLAGS_FOR_BUILD.
2389
2390 4. Added -no-undefined to the linking command in the Makefile, because this is
2391 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2392 linking step for the pcreposix library.
2393
2394 5. PCRE was failing to diagnose the case of two named groups with the same
2395 name.
2396
2397 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2398 literal character that is needed in the subject for a match, and scans along to
2399 ensure that it is present before embarking on the full matching process. This
2400 saves time in cases of nested unlimited repeats that are never going to match.
2401 Problem: the scan can take a lot of time if the subject is very long (e.g.
2402 megabytes), thus penalizing straightforward matches. It is now done only if the
2403 amount of subject to be scanned is less than 1000 bytes.
2404
2405 7. A lesser problem with the same optimization is that it was recording the
2406 first character of an anchored pattern as "needed", thus provoking a search
2407 right along the subject, even when the first match of the pattern was going to
2408 fail. The "needed" character is now not set for anchored patterns, unless it
2409 follows something in the pattern that is of non-fixed length. Thus, it still
2410 fulfils its original purpose of finding quick non-matches in cases of nested
2411 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2412
2413
2414 Version 4.0 17-Feb-03
2415 ---------------------
2416
2417 1. If a comment in an extended regex that started immediately after a meta-item
2418 extended to the end of string, PCRE compiled incorrect data. This could lead to
2419 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2420
2421 2. Moved to autoconf 2.53 and libtool 1.4.2.
2422
2423 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2424 the special perltest8 script is no longer needed - all the tests can be run
2425 from a single perltest script.
2426
2427 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2428 by \s. It has now been removed in PCRE. This means it isn't recognized as
2429 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2430 class [:space:] *does* include VT, thereby creating a mess.
2431
2432 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2433 space and tab.
2434
2435 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2436 its new features into the main test script, reducing the number of scripts.
2437
2438 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2439 were backward compatible, and made the (?i) apply to the whole pattern, as if
2440 /i were given. Now it behaves more logically, and applies the option setting
2441 only to what follows. PCRE has been changed to follow suit. However, if it
2442 finds options settings right at the start of the pattern, it extracts them into
2443 the global options, as before. Thus, they show up in the info data.
2444
2445 8. Added support for the \Q...\E escape sequence. Characters in between are
2446 treated as literals. This is slightly different from Perl in that $ and @ are
2447 also handled as literals inside the quotes. In Perl, they will cause variable
2448 interpolation. Note the following examples:
2449
2450 Pattern PCRE matches Perl matches
2451
2452 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2453 \Qabc\$xyz\E abc\$xyz abc\$xyz
2454 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2455
2456 For compatibility with Perl, \Q...\E sequences are recognized inside character
2457 classes as well as outside them.
2458
2459 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2460 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2461 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2462 signed/unsigned warnings.
2463
2464 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2465 option for pcretest, so I've replaced it by a simple function that does just
2466 that job.
2467
2468 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2469 "pcregrep -".
2470
2471 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2472 Java package. This provides some syntactic sugar for simple cases of what my
2473 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2474 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2475 item, you can use this simplified notation. Note that only makes sense with
2476 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2477 greediness, whatever the setting of the PCRE_UNGREEDY option.
2478
2479 13. A change of greediness default within a pattern was not taking effect at
2480 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2481 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2482 was abstracted outside.
2483
2484 14. PCRE now supports the \G assertion. It is true when the current matching
2485 position is at the start point of the match. This differs from \A when the
2486 starting offset is non-zero. Used with the /g option of pcretest (or similar
2487 code), it works in the same way as it does for Perl's /g option. If all
2488 alternatives of a regex begin with \G, the expression is anchored to the start
2489 match position, and the "anchored" flag is set in the compiled expression.
2490
2491 15. Some bugs concerning the handling of certain option changes within patterns
2492 have been fixed. These applied to options other than (?ims). For example,
2493 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2494 been the other way round. Some of this was related to change 7 above.
2495
2496 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2497 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2498 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2499 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2500
2501 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2502 mode. Unlike ".", it always matches newline, whatever the setting of
2503 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2504 assertions. Perl allows it, but it doesn't (in general) work because it can't
2505 calculate the length of the lookbehind. At least, that's the case for Perl
2506 5.8.0 - I've been told they are going to document that it doesn't work in
2507 future.
2508
2509 18. Added an error diagnosis for escapes that PCRE does not support: these are
2510 \L, \l, \N, \P, \p, \U, \u, and \X.
2511
2512 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2513 reading past the end of the pattern in cases such as /[abcd/.
2514
2515 20. PCRE was getting more memory than necessary for patterns with classes that
2516 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2517
2518 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2519 compiling PCRE for use with Virtual Pascal.
2520
2521 22. Small fix to the Makefile to make it work properly if the build is done
2522 outside the source tree.
2523
2524 23. Added a new extension: a condition to go with recursion. If a conditional
2525 subpattern starts with (?(R) the "true" branch is used if recursion has
2526 happened, whereas the "false" branch is used only at the top level.
2527
2528 24. When there was a very long string of literal characters (over 255 bytes
2529 without UTF support, over 250 bytes with UTF support), the computation of how
2530 much memory was required could be incorrect, leading to segfaults or other
2531 strange effects.
2532
2533 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2534 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2535 there was a subsequent back reference to those brackets. This meant that, for
2536 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2537 possible to check for precisely this case. All we can do is abandon the
2538 optimization if .* occurs inside capturing brackets when there are any back
2539 references whatsoever. (See below for a better fix that came later.)
2540
2541 26. The handling of the optimization for finding the first character of a
2542 non-anchored pattern, and for finding a character that is required later in the
2543 match were failing in some cases. This didn't break the matching; it just
2544 failed to optimize when it could. The way this is done has been re-implemented.
2545
2546 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2547
2548 28. Added a new feature that provides some of the functionality that Perl
2549 provides with (?{...}). The facility is termed a "callout". The way it is done
2550 in PCRE is for the caller to provide an optional function, by setting
2551 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2552 global variable. By default it is unset, which disables all calling out. To get
2553 the function called, the regex must include (?C) at appropriate points. This
2554 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2555 This provides a means of identifying different callout points. When PCRE
2556 reaches such a point in the regex, if pcre_callout has been set, the external
2557 function is called. It is provided with data in a structure called
2558 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2559 matching continues; if it returns a non-zero value, the match at the current
2560 point fails. However, backtracking will occur if possible. [This was changed
2561 later and other features added - see item 49 below.]
2562
2563 29. pcretest is upgraded to test the callout functionality. It provides a
2564 callout function that displays information. By default, it shows the start of
2565 the match and the current position in the text. There are some new data escapes
2566 to vary what happens:
2567
2568 \C+ in addition, show current contents of captured substrings
2569 \C- do not supply a callout function
2570 \C!n return 1 when callout number n is reached
2571 \C!n!m return 1 when callout number n is reached for the mth time
2572
2573 30. If pcregrep was called with the -l option and just a single file name, it
2574 output "<stdin>" if a match was found, instead of the file name.
2575
2576 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2577 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2578 pcre_exec(). This saves a malloc/free per call. The default value of
2579 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2580 when configuring.
2581
2582 32. The default maximum size of a compiled pattern is 64K. There have been a
2583 few cases of people hitting this limit. The code now uses macros to handle the
2584 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2585 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2586 configuring. Tests 2 and 5 work only with 2-byte links because they output
2587 debugging information about compiled patterns.
2588
2589 33. Internal code re-arrangements:
2590
2591 (a) Moved the debugging function for printing out a compiled regex into
2592 its own source file (printint.c) and used #include to pull it into
2593 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2594 separate copies.
2595
2596 (b) Defined the list of op-code names for debugging as a macro in
2597 internal.h so that it is next to the definition of the opcodes.
2598
2599 (c) Defined a table of op-code lengths for simpler skipping along compiled
2600 code. This is again a macro in internal.h so that it is next to the
2601 definition of the opcodes.
2602
2603 34. Added support for recursive calls to individual subpatterns, along the
2604 lines of Robin Houston's patch (but implemented somewhat differently).
2605
2606 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2607 allow it to read and process whole directories in Win32. This code was
2608 contributed by Lionel Fourquaux; it has not been tested by me.
2609
2610 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2611 used to name a group. Names consist of alphanumerics and underscores, and must
2612 be unique. Back references use the syntax (?P=name) and recursive calls use
2613 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2614 numbers. The function pcre_fullinfo() can be used after compilation to extract
2615 a name/number map. There are three relevant calls:
2616
2617 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2618 PCRE_INFO_NAMECOUNT yields the number of entries
2619 PCRE_INFO_NAMETABLE yields a pointer to the map.
2620
2621 The map is a vector of fixed-size entries. The size of each entry depends on
2622 the length of the longest name used. The first two bytes of each entry are the
2623 group number, most significant byte first. There follows the corresponding
2624 name, zero terminated. The names are in alphabetical order.
2625
2626 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2627 case instead of 255. Making it the same both with and without UTF-8 support
2628 means that the same test output works with both.
2629
2630 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2631 calling malloc() with a zero argument.
2632
2633 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2634 optimization. I've improved things by keeping a bitmap of backreferences with
2635 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2636 fact referenced, the optimization can be applied. It is unlikely that a
2637 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2638 the match to follow \n) will appear inside brackets with a number greater than
2639 31, but if it does, any back reference > 31 suppresses the optimization.
2640
2641 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2642 of disabling numbered capturing parentheses. Any opening parenthesis that is
2643 not followed by ? behaves as if it were followed by ?: but named parentheses
2644 can still be used for capturing (and they will acquire numbers in the usual
2645 way).
2646
2647 41. Redesigned the return codes from the match() function into yes/no/error so
2648 that errors can be passed back from deep inside the nested calls. A malloc
2649 failure while inside a recursive subpattern call now causes the
2650 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2651
2652 42. It is now possible to set a limit on the number of times the match()
2653 function is called in a call to pcre_exec(). This facility makes it possible to
2654 limit the amount of recursion and backtracking, though not in a directly
2655 obvious way, because the match() function is used in a number of different
2656 circumstances. The count starts from zero for each position in the subject
2657 string (for non-anchored patterns). The default limit is, for compatibility, a
2658 large number, namely 10 000 000. You can change this in two ways:
2659
2660 (a) When configuring PCRE before making, you can use --with-match-limit=n
2661 to set a default value for the compiled library.
2662
2663 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2664 a different value is set. See 45 below.
2665
2666 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2667
2668 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2669 of things that can be changed at compile time. The first argument specifies
2670 what is wanted and the second points to where the information is to be placed.
2671 The current list of available information is:
2672
2673 PCRE_CONFIG_UTF8
2674
2675 The output is an integer that is set to one if UTF-8 support is available;
2676 otherwise it is set to zero.
2677
2678 PCRE_CONFIG_NEWLINE
2679
2680 The output is an integer that it set to the value of the code that is used for
2681 newline. It is either LF (10) or CR (13).
2682
2683 PCRE_CONFIG_LINK_SIZE
2684
2685 The output is an integer that contains the number of bytes used for internal
2686 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2687
2688 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2689
2690 The output is an integer that contains the threshold above which the POSIX
2691 interface uses malloc() for output vectors. See item 31 above.
2692
2693 PCRE_CONFIG_MATCH_LIMIT
2694
2695 The output is an unsigned integer that contains the default limit of the number
2696 of match() calls in a pcre_exec() execution. See 42 above.
2697
2698 44. pcretest has been upgraded by the addition of the -C option. This causes it
2699 to extract all the available output from the new pcre_config() function, and to
2700 output it. The program then exits immediately.
2701
2702 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2703 order to support additional features. One way would have been to define
2704 pcre_exec2() (for example) with extra arguments, but this would not have been
2705 extensible, and would also have required all calls to the original function to
2706 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2707 is used for passing in "extra" data from pcre_study().
2708
2709 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2710 contains the following fields:
2711
2712 flags a bitmap indicating which of the following fields are set
2713 study_data opaque data from pcre_study()
2714 match_limit a way of specifying a limit on match() calls for a specific
2715 call to pcre_exec()
2716 callout_data data for callouts (see 49 below)
2717
2718 The flag bits are also defined in pcre.h, and are
2719
2720 PCRE_EXTRA_STUDY_DATA
2721 PCRE_EXTRA_MATCH_LIMIT
2722 PCRE_EXTRA_CALLOUT_DATA
2723
2724 The pcre_study() function now returns one of these new pcre_extra blocks, with
2725 the actual study data pointed to by the study_data field, and the
2726 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2727 before. That is, this change is entirely upwards-compatible and requires no
2728 change to existing code.
2729
2730 If you want to pass in additional data to pcre_exec(), you can either place it
2731 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2732 block.
2733
2734 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2735 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2736 times with different match limits, until it finds the minimum value needed for
2737 pcre_exec() to complete. The value is then output. This can be instructive; for
2738 most simple matches the number is quite small, but for pathological cases it
2739 gets very large very quickly.
2740
2741 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2742 returns the size of the data block pointed to by the study_data field in a
2743 pcre_extra block, that is, the value that was passed as the argument to
2744 pcre_malloc() when PCRE was getting memory in which to place the information
2745 created by pcre_study(). The fourth argument should point to a size_t variable.
2746 pcretest has been extended so that this information is shown after a successful
2747 pcre_study() call when information about the compiled regex is being displayed.
2748
2749 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2750 because what follows is always an absolute path. (Later: it turns out that this
2751 is more than cosmetic for MinGW, because it doesn't like empty path
2752 components.)
2753
2754 49. Some changes have been made to the callout feature (see 28 above):
2755
2756 (i) A callout function now has three choices for what it returns:
2757
2758 0 => success, carry on matching
2759 > 0 => failure at this point, but backtrack if possible
2760 < 0 => serious error, return this value from pcre_exec()
2761
2762 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2763 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2764 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2765 use by callout functions. It will never be used by PCRE itself.
2766
2767 (ii) The pcre_extra structure (see 45 above) has a void * field called
2768 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2769 pcre_callout_block structure has a field of the same name. The contents of
2770 the field passed in the pcre_extra structure are passed to the callout
2771 function in the corresponding field in the callout block. This makes it
2772 easier to use the same callout-containing regex from multiple threads. For
2773 testing, the pcretest program has a new data escape
2774
2775 \C*n pass the number n (may be negative) as callout_data
2776
2777 If the callout function in pcretest receives a non-zero value as
2778 callout_data, it returns that value.
2779
2780 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2781 there were some redundant $(CFLAGS) in commands that are now specified as
2782 $(LINK), which already includes $(CFLAGS).
2783
2784 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2785 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2786 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2787 one-byte characters throughout. Note that case-insensitive matching applies
2788 only to characters whose values are less than 256. PCRE doesn't support the
2789 notion of cases for higher-valued characters.
2790
2791 (i) A character class whose characters are all within 0-255 is handled as
2792 a bit map, and the map is inverted for negative classes. Previously, a
2793 character > 255 always failed to match such a class; however it should
2794 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2795
2796 (ii) A negated character class with a single character < 255 is coded as
2797 "not this character" (OP_NOT). This wasn't working properly when the test
2798 character was multibyte, either singly or repeated.
2799
2800 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2801 mode, for example: \x{100}{2,3}.
2802
2803 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2804 singly or repeated) now correctly test multibyte characters. However,
2805 PCRE doesn't recognize any characters with values greater than 255 as
2806 digits, spaces, or word characters. Such characters always match \D, \S,
2807 and \W, and never match \d, \s, or \w.
2808
2809 (v) Classes may now contain characters and character ranges with values
2810 greater than 255. For example: [ab\x{100}-\x{400}].
2811
2812 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2813 PCRE in UTF-8 mode.
2814
2815 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2816 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2817 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2818 value.)
2819
2820 53. The single man page has become too large. I have therefore split it up into
2821 a number of separate man pages. These also give rise to individual HTML pages;
2822 these are now put in a separate directory, and there is an index.html page that
2823 lists them all. Some hyperlinking between the pages has been installed.
2824
2825 54. Added convenience functions for handling named capturing parentheses.
2826
2827 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2828 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2829 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2830 are faulted.
2831
2832 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2833 calling configure. These values are used when compiling the dftables.c program
2834 which is run to generate the source of the default character tables. They
2835 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2836 you will need to set these values.
2837
2838 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2839
2840
2841 Version 3.9 02-Jan-02
2842 ---------------------
2843
2844 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2845
2846 2. If --disable-static was given, the building process failed when trying to
2847 build pcretest and pcregrep. (For some reason it was using libtool to compile
2848 them, which is not right, as they aren't part of the library.)
2849
2850
2851 Version 3.8 18-Dec-01
2852 ---------------------
2853
2854 1. The experimental UTF-8 code was completely screwed up. It was packing the
2855 bytes in the wrong order. How dumb can you get?
2856
2857
2858 Version 3.7 29-Oct-01
2859 ---------------------
2860
2861 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2862 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2863 this didn't happen under Solaris 8, where I normally test things.
2864
2865 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2866 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2867 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2868 this fix an hour or so after the initial 3.7 release.)
2869
2870
2871 Version 3.6 23-Oct-01
2872 ---------------------
2873
2874 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2875 offsets passed as NULL with zero offset count.
2876
2877 2. The config.guess and config.sub files had not been updated when I moved to
2878 the latest autoconf.
2879
2880
2881 Version 3.5 15-Aug-01
2882 ---------------------
2883
2884 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2885 had been forgotten.
2886
2887 2. By using declared but undefined structures, we can avoid using "void"
2888 definitions in pcre.h while keeping the internal definitions of the structures
2889 private.
2890
2891 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2892 user point of view, this means that both static and shared libraries are built
2893 by default, but this can be individually controlled. More of the work of
2894 handling this static/shared cases is now inside libtool instead of PCRE's make
2895 file.
2896
2897 4. The pcretest utility is now installed along with pcregrep because it is
2898 useful for users (to test regexs) and by doing this, it automatically gets
2899 relinked by libtool. The documentation has been turned into a man page, so
2900 there are now .1, .txt, and .html versions in /doc.
2901
2902 5. Upgrades to pcregrep:
2903 (i) Added long-form option names like gnu grep.
2904 (ii) Added --help to list all options with an explanatory phrase.
2905 (iii) Added -r, --recursive to recurse into sub-directories.
2906 (iv) Added -f, --file to read patterns from a file.
2907
2908 6. pcre_exec() was referring to its "code" argument before testing that
2909 argument for NULL (and giving an error if it was NULL).
2910
2911 7. Upgraded Makefile.in to allow for compiling in a different directory from
2912 the source directory.
2913
2914 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2915 options bits, the pointer it was passed was to an int instead of to an unsigned
2916 long int. This mattered only on 64-bit systems.
2917
2918 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2919 generated) instead of pcre.in, which it its source. Also made the same change
2920 in several of the .c files.
2921
2922 10. A new release of gcc defines printf() as a macro, which broke pcretest
2923 because it had an ifdef in the middle of a string argument for printf(). Fixed
2924 by using separate calls to printf().
2925
2926 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2927 script, to force use of CR or LF instead of \n in the source. On non-Unix
2928 systems, the value can be set in config.h.
2929
2930 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2931 absolute limit. Changed the text of the error message to make this clear, and
2932 likewise updated the man page.
2933
2934 13. The limit of 99 on the number of capturing subpatterns has been removed.
2935 The new limit is 65535, which I hope will not be a "real" limit.
2936
2937
2938 Version 3.4 22-Aug-00
2939 ---------------------
2940
2941 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2942
2943 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2944
2945
2946 Version 3.3 01-Aug-00
2947 ---------------------
2948
2949 1. If an octal character was given, but the value was greater than \377, it
2950 was not getting masked to the least significant bits, as documented. This could
2951 lead to crashes in some systems.
2952
2953 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2954 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2955
2956 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2957 These just pass their arguments on to (pcre_free)(), but they are provided
2958 because some uses of PCRE bind it to non-C systems that can call its functions,
2959 but cannot call free() or pcre_free() directly.
2960
2961 4. Add "make test" as a synonym for "make check". Corrected some comments in
2962 the Makefile.
2963
2964 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2965 Makefile.
2966
2967 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2968 command called pgrep for grepping around the active processes.
2969
2970 7. Added the beginnings of support for UTF-8 character strings.
2971
2972 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2973 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2974 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2975 out for the ar command.)
2976
2977
2978 Version 3.2 12-May-00
2979 ---------------------
2980
2981 This is purely a bug fixing release.
2982
2983 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2984 of ZA. This was just one example of several cases that could provoke this bug,
2985 which was introduced by change 9 of version 2.00. The code for breaking
2986 infinite loops after an iteration that matches an empty string was't working
2987 correctly.
2988
2989 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2990 when matched against abbab (for example). After matching an empty string, it
2991 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2992 caused it to match further down the string than it should.
2993
2994 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2995 was there because it doesn't seem to be needed, and it causes trouble on some
2996 systems, as it is not a Standard C header. It has been removed.
2997
2998 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2999 were reported on the Macintosh. The changes were from
3000
3001 while ((c = *(++ptr)) != 0 && c != '\n');
3002 to
3003 while ((c = *(++ptr)) != 0 && c != '\n') ;
3004
3005 Totally extraordinary, but if that's what it takes...
3006
3007 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3008 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3009 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3010 assumes the way PCRE uses memmove() (always moving upwards).
3011
3012 6. PCRE is being used in one environment where strchr() is not available. There
3013 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3014 faster code anyway.
3015
3016
3017 Version 3.1 09-Feb-00
3018 ---------------------
3019
3020 The only change in this release is the fixing of some bugs in Makefile.in for
3021 the "install" target:
3022
3023 (1) It was failing to install pcreposix.h.
3024
3025 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3026
3027
3028 Version 3.0 01-Feb-00
3029 ---------------------
3030
3031 1. Add support for the /+ modifier to perltest (to output $` like it does in
3032 pcretest).
3033
3034 2. Add support for the /g modifier to perltest.
3035
3036 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3037 matches null strings.
3038
3039 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3040 pattern. Perl treats empty patterns specially - it reuses the most recent
3041 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3042 effect.
3043
3044 5. The POSIX interface was broken in that it was just handing over the POSIX
3045 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3046 required a bigger vector, with some working space on the end. This means that
3047 the POSIX wrapper now has to get and free some memory, and copy the results.
3048
3049 6. Added some simple autoconf support, placing the test data and the
3050 documentation in separate directories, re-organizing some of the
3051 information files, and making it build pcre-config (a GNU standard). Also added
3052 libtool support for building PCRE as a shared library, which is now the
3053 default.
3054
3055 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3056 09 are not valid octal constants. Single digits will be used for minor values
3057 less than 10.
3058
3059 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3060 existing programs that set these in the POSIX interface can use PCRE without
3061 modification.
3062
3063 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3064 return all that pcre_info() returns, plus additional data. The pcre_info()
3065 function is retained for compatibility, but is considered to be obsolete.
3066
3067 10. Added experimental recursion feature (?R) to handle one common case that
3068 Perl 5.6 will be able to do with (?p{...}).
3069
3070 11. Added support for POSIX character classes like [:alpha:], which Perl is
3071 adopting.
3072
3073
3074 Version 2.08 31-Aug-99
3075 ----------------------
3076
3077 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3078 trying to match at the startoffset position, but instead was moving forward to
3079 the next newline as if a previous match had failed.
3080
3081 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3082 and could get into a loop if a null string was matched other than at the start
3083 of the subject.
3084
3085 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3086 be distinguished at compile time, and for completeness also added PCRE_DATE.
3087
3088 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3089 in GnuWin32 environments.
3090
3091
3092 Version 2.07 29-Jul-99
3093 ----------------------
3094
3095 1. The documentation is now supplied in plain text form and HTML as well as in
3096 the form of man page sources.
3097
3098 2. C++ compilers don't like assigning (void *) values to other pointer types.
3099 In particular this affects malloc(). Although there is no problem in Standard
3100 C, I've put in casts to keep C++ compilers happy.
3101
3102 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3103 should be (const char *).
3104
3105 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3106 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3107 However, I haven't made this a standard facility. The documentation doesn't
3108 mention it, and the Makefile doesn't support it.
3109
3110 5. The Makefile now contains an "install" target, with editable destinations at
3111 the top of the file. The pcretest program is not installed.
3112
3113 6. pgrep -V now gives the PCRE version number and date.
3114
3115 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3116 causing the entire string to be ignored, instead of just the last character.
3117
3118 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3119 non-matching string, it can take a very, very long time, even for strings of
3120 quite modest length, because of the nested recursion. PCRE now does better in
3121 some of these cases. It does this by remembering the last required literal
3122 character in the pattern, and pre-searching the subject to ensure it is present
3123 before running the real match. In other words, it applies a heuristic to detect
3124 some types of certain failure quickly, and in the above example, if presented
3125 with a string that has no trailing " it gives "no match" very quickly.
3126
3127 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3128 other alternatives are tried instead.
3129
3130
3131 Version 2.06 09-Jun-99
3132 ----------------------
3133
3134 1. Change pcretest's output for amount of store used to show just the code
3135 space, because the remainder (the data block) varies in size between 32-bit and
3136 64-bit systems.
3137
3138 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3139 start matching at. This allows lookbehinds to work when searching for multiple
3140 occurrences in a string.
3141
3142 3. Added additional options to pcretest for testing multiple occurrences:
3143
3144 /+ outputs the rest of the string that follows a match
3145 /g loops for multiple occurrences, using the new startoffset argument
3146 /G loops for multiple occurrences by passing an incremented pointer
3147
3148 4. PCRE wasn't doing the "first character" optimization for patterns starting
3149 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3150 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3151 the letter 'x'. On long subject strings, this gives a significant speed-up.
3152
3153
3154 Version 2.05 21-Apr-99
3155 ----------------------
3156
3157 1. Changed the type of magic_number from int to long int so that it works
3158 properly on 16-bit systems.
3159
3160 2. Fixed a bug which caused patterns starting with .* not to work correctly
3161 when the subject string contained newline characters. PCRE was assuming
3162 anchoring for such patterns in all cases, which is not correct because .* will
3163 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3164 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3165 must be retried after every newline in the subject.
3166
3167
3168 Version 2.04 18-Feb-99
3169 ----------------------
3170
3171 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3172 computation of the store needed to hold the pattern was incorrect (too large).
3173 If such patterns were nested a few deep, this could multiply and become a real
3174 problem.
3175
3176 2. Added /M option to pcretest to show the memory requirement of a specific
3177 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3178
3179 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3180 compiled in such a way that the backtracking after subsequent failure was
3181 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3182 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3183
3184
3185 Version 2.03 02-Feb-99
3186 ----------------------
3187
3188 1. Fixed typo and small mistake in man page.
3189
3190 2. Added 4th condition (GPL supersedes if conflict) and created separate
3191 LICENCE file containing the conditions.
3192
3193 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3194 Perl, that is the internal \ allows the delimiter to be included in the
3195 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3196 the final delimiter, add \ to the end of the pattern (to test the error).
3197
3198 4. Added the convenience functions for extracting substrings after a successful
3199 match. Updated pcretest to make it able to test these functions.
3200
3201
3202 Version 2.02 14-Jan-99
3203 ----------------------
3204
3205 1. Initialized the working variables associated with each extraction so that
3206 their saving and restoring doesn't refer to uninitialized store.
3207
3208 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3209 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3210 fix the problem.
3211
3212 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3213 calls, and wasn't printing the correct value for compiling calls. Increased the
3214 default value of LOOPREPEAT, and the number of significant figures in the
3215 times.
3216
3217 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3218
3219 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3220 a building problem on Windows NT with a FAT file system.
3221
3222
3223 Version 2.01 21-Oct-98
3224 ----------------------
3225
3226 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3227 to character tables built by pcre_maketables() in the current locale. If NULL
3228 is passed, the default tables are used.
3229
3230
3231 Version 2.00 24-Sep-98
3232 ----------------------
3233
3234 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3235 it any more.
3236
3237 2. Allow quantification of (?>) groups, and make it work correctly.
3238
3239 3. The first character computation wasn't working for (?>) groups.
3240
3241 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3242 end of the subject) and add 5.005's \z, which really does match only at the
3243 very end of the subject.
3244
3245 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3246
3247 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3248 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3249 localized options. All options to pcre_study() were also removed.
3250
3251 7. Add other new features from 5.005:
3252
3253 $(?<= positive lookbehind
3254 $(?<! negative lookbehind
3255 (?imsx-imsx) added the unsetting capability
3256 such a setting is global if at outer level; local otherwise
3257 (?imsx-imsx:) non-capturing groups with option setting
3258 (?(cond)re|re) conditional pattern matching
3259
3260 A backreference to itself in a repeated group matches the previous
3261 captured string.
3262
3263 8. General tidying up of studying (both automatic and via "study")
3264 consequential on the addition of new assertions.
3265
3266 9. As in 5.005, unlimited repeated groups that could match an empty substring
3267 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3268 runtime if any iteration does actually match an empty substring.
3269
3270 10. Include the RunTest script in the distribution.
3271
3272 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3273 discrepancies, some of which were old and were also with respect to 5.004. They
3274 have now been fixed.
3275
3276
3277 Version 1.09 28-Apr-98
3278 ----------------------
3279
3280 1. A negated single character class followed by a quantifier with a minimum
3281 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3282 program crashes, or just wrong answers. This did not apply to negated classes
3283 containing more than one character, or to minima other than one.
3284
3285
3286 Version 1.08 27-Mar-98
3287 ----------------------
3288
3289 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3290
3291 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3292 latter must appear before anything that relies on it in the pattern.
3293
3294
3295 Version 1.07 16-Feb-98
3296 ----------------------
3297
3298 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3299 repeat of a potentially empty string).
3300
3301
3302 Version 1.06 23-Jan-98
3303 ----------------------
3304
3305 1. Added Markus Oberhumer's little patches for C++.
3306
3307 2. Literal strings longer than 255 characters were broken.
3308
3309
3310 Version 1.05 23-Dec-97
3311 ----------------------
3312
3313 1. Negated character classes containing more than one character were failing if
3314 PCRE_CASELESS was set at run time.
3315
3316
3317 Version 1.04 19-Dec-97
3318 ----------------------
3319
3320 1. Corrected the man page, where some "const" qualifiers had been omitted.
3321
3322 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3323 input syntax.
3324
3325 3. Fixed memory leak which occurred when a regex with back references was
3326 matched with an offsets vector that wasn't big enough. The temporary memory
3327 that is used in this case wasn't being freed if the match failed.
3328
3329 4. Tidied pcretest to ensure it frees memory that it gets.
3330
3331 5. Temporary memory was being obtained in the case where the passed offsets
3332 vector was exactly big enough.
3333
3334 6. Corrected definition of offsetof() from change 5 below.
3335
3336 7. I had screwed up change 6 below and broken the rules for the use of
3337 setjmp(). Now fixed.
3338
3339
3340 Version 1.03 18-Dec-97
3341 ----------------------
3342
3343 1. A erroneous regex with a missing opening parenthesis was correctly
3344 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3345 on some systems.
3346
3347 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3348 it was reported that one broken compiler failed on the former because "code" is
3349 also an independent variable.
3350
3351 3. The erroneous regex a[]b caused an array overrun reference.
3352
3353 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3354 fail on data ending with that character. (It was going on too far, and checking
3355 the next character, typically a binary zero.) This was specific to the
3356 optimized code for single-character negative classes.
3357
3358 5. Added a contributed patch from the TIN world which does the following:
3359
3360 + Add an undef for memmove, in case the the system defines a macro for it.
3361
3362 + Add a definition of offsetof(), in case there isn't one. (I don't know
3363 the reason behind this - offsetof() is part of the ANSI standard - but
3364 it does no harm).
3365
3366 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3367 most of the places where whitespace preceded '#'. I have given up and
3368 allowed the remaining 2 cases to be at the margin.
3369
3370 + Rename some variables in pcre to eliminate shadowing. This seems very
3371 pedantic, but does no harm, of course.
3372
3373 6. Moved the call to setjmp() into its own function, to get rid of warnings
3374 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3375
3376 7. Constructs such as \d{8,} were compiling into the equivalent of
3377 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3378 outcome, but in this particular case used more store than had been allocated,
3379 which caused the bug to be discovered because it threw up an internal error.
3380
3381 8. The debugging code in both pcre and pcretest for outputting the compiled
3382 form of a regex was going wrong in the case of back references followed by
3383 curly-bracketed repeats.
3384
3385
3386 Version 1.02 12-Dec-97
3387 ----------------------
3388
3389 1. Typos in pcre.3 and comments in the source fixed.
3390
3391 2. Applied a contributed patch to get rid of places where it used to remove
3392 'const' from variables, and fixed some signed/unsigned and uninitialized
3393 variable warnings.
3394
3395 3. Added the "runtest" target to Makefile.
3396
3397 4. Set default compiler flag to -O2 rather than just -O.
3398
3399
3400 Version 1.01 19-Nov-97
3401 ----------------------
3402
3403 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3404 like /([ab]*)*/, that is, for classes with more than one character in them.
3405
3406 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3407 as /((?>a*))*/ (a PCRE_EXTRA facility).
3408
3409
3410 Version 1.00 18-Nov-97
3411 ----------------------
3412
3413 1. Added compile-time macros to support systems such as SunOS4 which don't have
3414 memmove() or strerror() but have other things that can be used instead.
3415
3416 2. Arranged that "make clean" removes the executables.
3417
3418
3419 Version 0.99 27-Oct-97
3420 ----------------------
3421
3422 1. Fixed bug in code for optimizing classes with only one character. It was
3423 initializing a 32-byte map regardless, which could cause it to run off the end
3424 of the memory it had got.
3425
3426 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3427
3428
3429 Version 0.98 22-Oct-97
3430 ----------------------
3431
3432 1. Fixed bug in code for handling temporary memory usage when there are more
3433 back references than supplied space in the ovector. This could cause segfaults.
3434
3435
3436 Version 0.97 21-Oct-97
3437 ----------------------
3438
3439 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3440
3441 2. Optimized negated single characters not to use a bit map.
3442
3443 3. Brought error texts together as macro definitions; clarified some of them;
3444 fixed one that was wrong - it said "range out of order" when it meant "invalid
3445 escape sequence".
3446
3447 4. Changed some char * arguments to const char *.
3448
3449 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3450
3451 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3452 pcretest.
3453
3454
3455 Version 0.96 16-Oct-97
3456 ----------------------
3457
3458 1. Added a simple "pgrep" utility to the distribution.
3459
3460 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3461 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3462 where "ddd" means "one or more decimal digits".
3463
3464 3. Fixed serious bug. If a pattern had a back reference, but the call to
3465 pcre_exec() didn't supply a large enough ovector to record the related
3466 identifying subpattern, the match always failed. PCRE now remembers the number
3467 of the largest back reference, and gets some temporary memory in which to save
3468 the offsets during matching if necessary, in order to ensure that
3469 backreferences always work.
3470
3471 4. Increased the compatibility with Perl in a number of ways:
3472
3473 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3474 to request this handling. The option can be set at compile or exec time.
3475
3476 (b) $ matches before a terminating newline by default; an option
3477 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3478 mode). The option can be set at compile or exec time.
3479
3480 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3481 the same as Perl's. If the decimal number it represents is less than 10
3482 or there aren't that many previous left capturing parentheses, an octal
3483 escape is read. Inside a character class, it's always an octal escape,
3484 even if it is a single digit.
3485
3486 (d) An escaped but undefined alphabetic character is taken as a literal,
3487 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3488 escapes.
3489
3490 (e) {0} is now permitted. (The previous item is removed from the compiled
3491 pattern).
3492
3493 5. Changed all the names of code files so that the basic parts are no longer
3494 than 10 characters, and abolished the teeny "globals.c" file.
3495
3496 6. Changed the handling of character classes; they are now done with a 32-byte
3497 bit map always.
3498
3499 7. Added the -d and /D options to pcretest to make it possible to look at the
3500 internals of compilation without having to recompile pcre.
3501
3502
3503 Version 0.95 23-Sep-97
3504 ----------------------
3505
3506 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3507 \x20 at the start of a run of normal characters. These were being treated as
3508 real characters, instead of the source characters being re-checked.
3509
3510
3511 Version 0.94 18-Sep-97
3512 ----------------------
3513
3514 1. The functions are now thread-safe, with the caveat that the global variables
3515 containing pointers to malloc() and free() or alternative functions are the
3516 same for all threads.
3517
3518 2. Get pcre_study() to generate a bitmap of initial characters for non-
3519 anchored patterns when this is possible, and use it if passed to pcre_exec().
3520
3521
3522 Version 0.93 15-Sep-97
3523 ----------------------
3524
3525 1. /(b)|(:+)/ was computing an incorrect first character.
3526
3527 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3528 but not actually doing anything yet.
3529
3530 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3531 as Perl does (e.g. [-az] or [az-]).
3532
3533 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3534 all possible positions.
3535
3536 5. Split up into different modules to avoid including unneeded functions in a
3537 compiled binary. However, compile and exec are still in one module. The "study"
3538 function is split off.
3539
3540 6. The character tables are now in a separate module whose source is generated
3541 by an auxiliary program - but can then be edited by hand if required. There are
3542 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3543 toupper() in the code.
3544
3545 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3546 make them global. Abolish the function for setting them, as the caller can now
3547 set them directly.
3548
3549
3550 Version 0.92 11-Sep-97
3551 ----------------------
3552
3553 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3554 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3555
3556 2. Caseless matching was not working in character classes if the characters in
3557 the pattern were in upper case.
3558
3559 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3560
3561 4. Make PCRE_ANCHORED public and accept as a compile option.
3562
3563 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3564 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3565 pass them.
3566
3567 6. Give an error if bad option bits passed at compile or run time.
3568
3569 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3570 pcretest to cause it to pass that flag.
3571
3572 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3573 options, and the first character, if set.
3574
3575 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3576
3577
3578 Version 0.91 10-Sep-97
3579 ----------------------
3580
3581 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3582 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3583
3584 2. PCRE was looping on encountering an indefinitely repeated back reference to
3585 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3586 Perl does - treats the match as successful.
3587
3588 ****

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