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Revision 491 - (show annotations) (download)
Mon Mar 1 17:45:08 2010 UTC (4 years, 8 months ago) by ph10
File size: 181657 byte(s)
Update Unicode tables to Unicode version 5.2.0.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.02 01-Mar-2010
5 ------------------------
6
7 1. The Unicode data tables have been updated to Unicode 5.2.0.
8
9
10 Version 8.01 19-Jan-2010
11 ------------------------
12
13 1. If a pattern contained a conditional subpattern with only one branch (in
14 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
15 computed the wrong minimum data length (which is of course zero for such
16 subpatterns). This could cause incorrect "no match" results.
17
18 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
19 the pattern is reset in the first branch, pcre_compile() failed with
20 "internal error: code overflow at offset...". This happened only when
21 the reset was to the original external option setting. (An optimization
22 abstracts leading options settings into an external setting, which was the
23 cause of this.)
24
25 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
26 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
27 assertion pattern did not match (meaning that the assertion was true), it
28 was incorrectly treated as false if the SKIP had been reached during the
29 matching. This also applied to assertions used as conditions.
30
31 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
32 assertion subpattern, including such a pattern used as a condition,
33 unpredictable results occurred, instead of the error return
34 PCRE_ERROR_DFA_UITEM.
35
36 5. The C++ GlobalReplace function was not working like Perl for the special
37 situation when an empty string is matched. It now does the fancy magic
38 stuff that is necessary.
39
40 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
41 removed. (These were left over from very, very early versions of PCRE.)
42
43 7. Some cosmetic changes to the code to make life easier when compiling it
44 as part of something else:
45
46 (a) Change DEBUG to PCRE_DEBUG.
47
48 (b) In pcre_compile(), rename the member of the "branch_chain" structure
49 called "current" as "current_branch", to prevent a collision with the
50 Linux macro when compiled as a kernel module.
51
52 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
53 prevent a collision with the Linux macro when compiled as a kernel
54 module.
55
56 8. In pcre_compile() there are some checks for integer overflows that used to
57 cast potentially large values to (double). This has been changed to that
58 when building, a check for int64_t is made, and if it is found, it is used
59 instead, thus avoiding the use of floating point arithmetic. (There is no
60 other use of FP in PCRE.) If int64_t is not found, the fallback is to
61 double.
62
63 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
64 2005 (difference between two addresses compared to an unsigned value).
65
66 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
67 custom one, because of the following reported problem in Windows:
68
69 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
70 under Win32.
71 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
72 therefore missing the function definition.
73 - The compiler thus generates a "C" signature for the test function.
74 - The linker fails to find the "C" function.
75 - PCRE fails to configure if asked to do so against libbz2.
76
77 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
78 messages were output:
79
80 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
81 rerunning libtoolize, to keep the correct libtool macros in-tree.
82 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
83
84 I have done both of these things.
85
86 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
87 most of the time, it *can* run out if it is given a pattern that contains a
88 runaway infinite recursion. I updated the discussion in the pcrestack man
89 page.
90
91 13. Now that we have gone to the x.xx style of version numbers, the minor
92 version may start with zero. Using 08 or 09 is a bad idea because users
93 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
94 interpreted as invalid octal numbers. I've updated the previous comment in
95 configure.ac, and also added a check that gives an error if 08 or 09 are
96 used.
97
98 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
99 causing partial matching to fail when the end of the subject matched \W
100 in a UTF-8 pattern where \W was quantified with a minimum of 3.
101
102 15. There were some discrepancies between the declarations in pcre_internal.h
103 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
104 their definitions. The declarations used "const uschar *" and the
105 definitions used USPTR. Even though USPTR is normally defined as "const
106 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
107 reported that: "This difference in casting confuses some C++ compilers, for
108 example, SunCC recognizes above declarations as different functions and
109 generates broken code for hbpcre." I have changed the declarations to use
110 USPTR.
111
112 16. GNU libtool is named differently on some systems. The autogen.sh script now
113 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
114 (FreeBSD).
115
116 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
117 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
118 comment: "Figure out how to create a longlong from a string: strtoll and
119 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
120 instance, but it only takes 2 args instead of 3!"
121
122 18. A subtle bug concerned with back references has been fixed by a change of
123 specification, with a corresponding code fix. A pattern such as
124 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
125 refers, was giving matches when it shouldn't. For example, xa=xaaa would
126 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
127 same bug. Such groups have to be quantified to be useful, or contained
128 inside another quantified group. (If there's no repetition, the reference
129 can never match.) The problem arises because, having left the group and
130 moved on to the rest of the pattern, a later failure that backtracks into
131 the group uses the captured value from the final iteration of the group
132 rather than the correct earlier one. I have fixed this in PCRE by forcing
133 any group that contains a reference to itself to be an atomic group; that
134 is, there cannot be any backtracking into it once it has completed. This is
135 similar to recursive and subroutine calls.
136
137
138 Version 8.00 19-Oct-09
139 ----------------------
140
141 1. The table for translating pcre_compile() error codes into POSIX error codes
142 was out-of-date, and there was no check on the pcre_compile() error code
143 being within the table. This could lead to an OK return being given in
144 error.
145
146 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
147 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
148 in a Windows environment.
149
150 3. The pcregrep --count option prints the count for each file even when it is
151 zero, as does GNU grep. However, pcregrep was also printing all files when
152 --files-with-matches was added. Now, when both options are given, it prints
153 counts only for those files that have at least one match. (GNU grep just
154 prints the file name in this circumstance, but including the count seems
155 more useful - otherwise, why use --count?) Also ensured that the
156 combination -clh just lists non-zero counts, with no names.
157
158 4. The long form of the pcregrep -F option was incorrectly implemented as
159 --fixed_strings instead of --fixed-strings. This is an incompatible change,
160 but it seems right to fix it, and I didn't think it was worth preserving
161 the old behaviour.
162
163 5. The command line items --regex=pattern and --regexp=pattern were not
164 recognized by pcregrep, which required --regex pattern or --regexp pattern
165 (with a space rather than an '='). The man page documented the '=' forms,
166 which are compatible with GNU grep; these now work.
167
168 6. No libpcreposix.pc file was created for pkg-config; there was just
169 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
170
171 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
172 when UCP support is not needed, by modifying the Python script that
173 generates it from Unicode data files. This should not matter if the module
174 is correctly used as a library, but I received one complaint about 50K of
175 unwanted data. My guess is that the person linked everything into his
176 program rather than using a library. Anyway, it does no harm.
177
178 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
179 was a minimum greater than 1 for a wide character in a possessive
180 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
181 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
182 character. Chaos in the form of incorrect output or a compiling loop could
183 result.
184
185 9. The restrictions on what a pattern can contain when partial matching is
186 requested for pcre_exec() have been removed. All patterns can now be
187 partially matched by this function. In addition, if there are at least two
188 slots in the offset vector, the offset of the earliest inspected character
189 for the match and the offset of the end of the subject are set in them when
190 PCRE_ERROR_PARTIAL is returned.
191
192 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
193 synonymous with PCRE_PARTIAL, for backwards compatibility, and
194 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
195 and may be more useful for multi-segment matching.
196
197 11. Partial matching with pcre_exec() is now more intuitive. A partial match
198 used to be given if ever the end of the subject was reached; now it is
199 given only if matching could not proceed because another character was
200 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
201 string "Z", which now yields "no match" instead of "partial match". In the
202 case of pcre_dfa_exec(), "no match" is given if every matching path for the
203 final character ended with (*FAIL).
204
205 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
206 if the pattern had a "must contain" character that was already found in the
207 earlier partial match, unless partial matching was again requested. For
208 example, with the pattern /dog.(body)?/, the "must contain" character is
209 "g". If the first part-match was for the string "dog", restarting with
210 "sbody" failed. This bug has been fixed.
211
212 13. The string returned by pcre_dfa_exec() after a partial match has been
213 changed so that it starts at the first inspected character rather than the
214 first character of the match. This makes a difference only if the pattern
215 starts with a lookbehind assertion or \b or \B (\K is not supported by
216 pcre_dfa_exec()). It's an incompatible change, but it makes the two
217 matching functions compatible, and I think it's the right thing to do.
218
219 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
220 so that the demonstration program is easily available in environments where
221 PCRE has not been installed from source.
222
223 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
224 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
225 library.
226
227 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
228 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
229 is not the first non-POSIX option to be added. Clearly some people find
230 these options useful.
231
232 17. If a caller to the POSIX matching function regexec() passes a non-zero
233 value for nmatch with a NULL value for pmatch, the value of
234 nmatch is forced to zero.
235
236 18. RunGrepTest did not have a test for the availability of the -u option of
237 the diff command, as RunTest does. It now checks in the same way as
238 RunTest, and also checks for the -b option.
239
240 19. If an odd number of negated classes containing just a single character
241 interposed, within parentheses, between a forward reference to a named
242 subpattern and the definition of the subpattern, compilation crashed with
243 an internal error, complaining that it could not find the referenced
244 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
245 [The bug was that it was starting one character too far in when skipping
246 over the character class, thus treating the ] as data rather than
247 terminating the class. This meant it could skip too much.]
248
249 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
250 /g option in pcretest when the pattern contains \K, which makes it possible
251 to have an empty string match not at the start, even when the pattern is
252 anchored. Updated pcretest and pcredemo to use this option.
253
254 21. If the maximum number of capturing subpatterns in a recursion was greater
255 than the maximum at the outer level, the higher number was returned, but
256 with unset values at the outer level. The correct (outer level) value is
257 now given.
258
259 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
260 PCRE did not set those parentheses (unlike Perl). I have now found a way to
261 make it do so. The string so far is captured, making this feature
262 compatible with Perl.
263
264 23. The tests have been re-organized, adding tests 11 and 12, to make it
265 possible to check the Perl 5.10 features against Perl 5.10.
266
267 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
268 pattern matches a fixed length string. PCRE did not allow this; now it
269 does. Neither allows recursion.
270
271 25. I finally figured out how to implement a request to provide the minimum
272 length of subject string that was needed in order to match a given pattern.
273 (It was back references and recursion that I had previously got hung up
274 on.) This code has now been added to pcre_study(); it finds a lower bound
275 to the length of subject needed. It is not necessarily the greatest lower
276 bound, but using it to avoid searching strings that are too short does give
277 some useful speed-ups. The value is available to calling programs via
278 pcre_fullinfo().
279
280 26. While implementing 25, I discovered to my embarrassment that pcretest had
281 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
282 study optimizations had never been tested with that matching function.
283 Oops. What is worse, even when it was passed study data, there was a bug in
284 pcre_dfa_exec() that meant it never actually used it. Double oops. There
285 were also very few tests of studied patterns with pcre_dfa_exec().
286
287 27. If (?| is used to create subpatterns with duplicate numbers, they are now
288 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
289 on the other side of the coin, they are no longer allowed to have different
290 names, because these cannot be distinguished in PCRE, and this has caused
291 confusion. (This is a difference from Perl.)
292
293 28. When duplicate subpattern names are present (necessarily with different
294 numbers, as required by 27 above), and a test is made by name in a
295 conditional pattern, either for a subpattern having been matched, or for
296 recursion in such a pattern, all the associated numbered subpatterns are
297 tested, and the overall condition is true if the condition is true for any
298 one of them. This is the way Perl works, and is also more like the way
299 testing by number works.
300
301
302 Version 7.9 11-Apr-09
303 ---------------------
304
305 1. When building with support for bzlib/zlib (pcregrep) and/or readline
306 (pcretest), all targets were linked against these libraries. This included
307 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
308 libraries. This caused unwanted dependencies to be created. This problem
309 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
310 pcretest is linked with readline.
311
312 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
313 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
314 moved outside it again, because FALSE and TRUE are already defined in AIX,
315 but BOOL is not.
316
317 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
318 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
319
320 4. The pcregrep documentation said spaces were inserted as well as colons (or
321 hyphens) following file names and line numbers when outputting matching
322 lines. This is not true; no spaces are inserted. I have also clarified the
323 wording for the --colour (or --color) option.
324
325 5. In pcregrep, when --colour was used with -o, the list of matching strings
326 was not coloured; this is different to GNU grep, so I have changed it to be
327 the same.
328
329 6. When --colo(u)r was used in pcregrep, only the first matching substring in
330 each matching line was coloured. Now it goes on to look for further matches
331 of any of the test patterns, which is the same behaviour as GNU grep.
332
333 7. A pattern that could match an empty string could cause pcregrep to loop; it
334 doesn't make sense to accept an empty string match in pcregrep, so I have
335 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
336 seems to be how GNU grep behaves.
337
338 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
339 start or after a newline", because the conditional assertion was not being
340 correctly handled. The rule now is that both the assertion and what follows
341 in the first alternative must satisfy the test.
342
343 9. If auto-callout was enabled in a pattern with a conditional group whose
344 condition was an assertion, PCRE could crash during matching, both with
345 pcre_exec() and pcre_dfa_exec().
346
347 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
348 used for matching.
349
350 11. Unicode property support in character classes was not working for
351 characters (bytes) greater than 127 when not in UTF-8 mode.
352
353 12. Added the -M command line option to pcretest.
354
355 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
356
357 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
358
359 16. Added comments and documentation about mis-use of no_arg in the C++
360 wrapper.
361
362 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
363 from Martin Jerabek that uses macro names for all relevant character and
364 string constants.
365
366 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
367 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
368 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
369 these, but not everybody uses configure.
370
371 19. A conditional group that had only one branch was not being correctly
372 recognized as an item that could match an empty string. This meant that an
373 enclosing group might also not be so recognized, causing infinite looping
374 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
375 with the subject "ab", where knowledge that the repeated group can match
376 nothing is needed in order to break the loop.
377
378 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
379 exec(), but without supplying a callout function, matching went wrong.
380
381 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
382 leak if the size of the offset vector was greater than 30. When the vector
383 is smaller, the saved offsets during recursion go onto a local stack
384 vector, but for larger vectors malloc() is used. It was failing to free
385 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
386 error, in fact).
387
388 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
389 heapframe that is used only when UTF-8 support is enabled. This caused no
390 problem, but was untidy.
391
392 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
393 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
394 included within another project.
395
396 24. Steven Van Ingelgem's patches to add more options to the CMake support,
397 slightly modified by me:
398
399 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
400 not building pcregrep.
401
402 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
403 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
404
405 25. Forward references, both numeric and by name, in patterns that made use of
406 duplicate group numbers, could behave incorrectly or give incorrect errors,
407 because when scanning forward to find the reference group, PCRE was not
408 taking into account the duplicate group numbers. A pattern such as
409 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
410
411 26. Changed a few more instances of "const unsigned char *" to USPTR, making
412 the feature of a custom pointer more persuasive (as requested by a user).
413
414 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
415 pcretest.c, inside #ifndefs, because it seems they are sometimes already
416 pre-defined.
417
418 28. Added support for (*UTF8) at the start of a pattern.
419
420 29. Arrange for flags added by the "release type" setting in CMake to be shown
421 in the configuration summary.
422
423
424 Version 7.8 05-Sep-08
425 ---------------------
426
427 1. Replaced UCP searching code with optimized version as implemented for Ad
428 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
429 stage table and inline lookup instead of a function, giving speed ups of 2
430 to 5 times on some simple patterns that I tested. Permission was given to
431 distribute the MultiStage2.py script that generates the tables (it's not in
432 the tarball, but is in the Subversion repository).
433
434 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
435 scripts.
436
437 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
438 a group with a zero qualifier. The result of the study could be incorrect,
439 or the function might crash, depending on the pattern.
440
441 4. Caseless matching was not working for non-ASCII characters in back
442 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
443 It now works when Unicode Property Support is available.
444
445 5. In pcretest, an escape such as \x{de} in the data was always generating
446 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
447 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
448 truncation.
449
450 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
451
452 7. Added two (int) casts to pcregrep when printing the difference of two
453 pointers, in case they are 64-bit values.
454
455 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
456 test 2 if it fails.
457
458 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
459 and a #define of that name to empty if it is not externally set. This is to
460 allow users of MSVC to set it if necessary.
461
462 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
463 the convenience functions in the pcre_get.c source file.
464
465 11. An option change at the start of a pattern that had top-level alternatives
466 could cause overwriting and/or a crash. This command provoked a crash in
467 some environments:
468
469 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
470
471 This potential security problem was recorded as CVE-2008-2371.
472
473 12. For a pattern where the match had to start at the beginning or immediately
474 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
475 pcre_dfa_exec() could read past the end of the passed subject if there was
476 no match. To help with detecting such bugs (e.g. with valgrind), I modified
477 pcretest so that it places the subject at the end of its malloc-ed buffer.
478
479 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
480 exec() might read past the end of the data buffer in UTF-8 mode.
481
482 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
483 the data contained the byte 0x85 as part of a UTF-8 character within its
484 first line. This applied both to normal and DFA matching.
485
486 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
487 /^[^d]*?$/8 failed to match "abc".
488
489 16. Added a missing copyright notice to pcrecpp_internal.h.
490
491 17. Make it more clear in the documentation that values returned from
492 pcre_exec() in ovector are byte offsets, not character counts.
493
494 18. Tidied a few places to stop certain compilers from issuing warnings.
495
496 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
497 supplied by Stefan Weber. I made a further small update for 7.8 because
498 there is a change of source arrangements: the pcre_searchfuncs.c module is
499 replaced by pcre_ucd.c.
500
501
502 Version 7.7 07-May-08
503 ---------------------
504
505 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
506 a string to a long long, pretend we don't even have a long long." This is
507 done by checking for the strtoq, strtoll, and _strtoi64 functions.
508
509 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
510 pre-7.6 versions, which defined a global no_arg variable instead of putting
511 it in the RE class. (See also #8 below.)
512
513 3. Remove a line of dead code, identified by coverity and reported by Nuno
514 Lopes.
515
516 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
517
518 (1) The include/exclude patterns were being applied to the whole pathnames
519 of files, instead of just to the final components.
520
521 (2) If there was more than one level of directory, the subdirectories were
522 skipped unless they satisfied the include/exclude conditions. This is
523 inconsistent with GNU grep (and could even be seen as contrary to the
524 pcregrep specification - which I improved to make it absolutely clear).
525 The action now is always to scan all levels of directory, and just
526 apply the include/exclude patterns to regular files.
527
528 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
529 --exclude_dir in the tests to avoid scanning .svn directories.
530
531 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
532 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
533 doesn't support NULs in patterns.
534
535 7. Added some missing "const"s to declarations of static tables in
536 pcre_compile.c and pcre_dfa_exec.c.
537
538 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
539 caused by fix #2 above. (Subsequently also a second patch to fix the
540 first patch. And a third patch - this was a messy problem.)
541
542 9. Applied Craig's patch to remove the use of push_back().
543
544 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
545 matching function regexec().
546
547 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
548 which, however, unlike Perl's \g{...}, are subroutine calls, not back
549 references. PCRE supports relative numbers with this syntax (I don't think
550 Oniguruma does).
551
552 12. Previously, a group with a zero repeat such as (...){0} was completely
553 omitted from the compiled regex. However, this means that if the group
554 was called as a subroutine from elsewhere in the pattern, things went wrong
555 (an internal error was given). Such groups are now left in the compiled
556 pattern, with a new opcode that causes them to be skipped at execution
557 time.
558
559 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
560 to the way PCRE behaves:
561
562 (a) A lone ] character is dis-allowed (Perl treats it as data).
563
564 (b) A back reference to an unmatched subpattern matches an empty string
565 (Perl fails the current match path).
566
567 (c) A data ] in a character class must be notated as \] because if the
568 first data character in a class is ], it defines an empty class. (In
569 Perl it is not possible to have an empty class.) The empty class []
570 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
571 The negative empty class [^] matches any one character, independently
572 of the DOTALL setting.
573
574 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
575 non-existent subpattern following a character class starting with ']' and
576 containing () gave an internal compiling error instead of "reference to
577 non-existent subpattern". Fortunately, when the pattern did exist, the
578 compiled code was correct. (When scanning forwards to check for the
579 existencd of the subpattern, it was treating the data ']' as terminating
580 the class, so got the count wrong. When actually compiling, the reference
581 was subsequently set up correctly.)
582
583 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
584 it was being rejected as not supported by pcre_dfa_exec(), even though
585 other assertions are supported. I have made pcre_dfa_exec() support
586 (*FAIL).
587
588 16. The implementation of 13c above involved the invention of a new opcode,
589 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
590 cannot be changed at match time, I realized I could make a small
591 improvement to matching performance by compiling OP_ALLANY instead of
592 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
593 on the OP_ANY path.
594
595 17. Compiling pcretest on Windows with readline support failed without the
596 following two fixes: (1) Make the unistd.h include conditional on
597 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
598
599 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
600 ncurses library to be included for pcretest when ReadLine support is
601 requested, but also to allow for it to be overridden. This patch came from
602 Daniel Bergström.
603
604 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
605 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
606 any errors with the current Unicode tables. Thanks to Peter Kankowski for
607 spotting this.
608
609
610 Version 7.6 28-Jan-08
611 ---------------------
612
613 1. A character class containing a very large number of characters with
614 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
615 overflow.
616
617 2. Patch to cut out the "long long" test in pcrecpp_unittest when
618 HAVE_LONG_LONG is not defined.
619
620 3. Applied Christian Ehrlicher's patch to update the CMake build files to
621 bring them up to date and include new features. This patch includes:
622
623 - Fixed PH's badly added libz and libbz2 support.
624 - Fixed a problem with static linking.
625 - Added pcredemo. [But later removed - see 7 below.]
626 - Fixed dftables problem and added an option.
627 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
628 HAVE_LONG_LONG.
629 - Added readline support for pcretest.
630 - Added an listing of the option settings after cmake has run.
631
632 4. A user submitted a patch to Makefile that makes it easy to create
633 "pcre.dll" under mingw when using Configure/Make. I added stuff to
634 Makefile.am that cause it to include this special target, without
635 affecting anything else. Note that the same mingw target plus all
636 the other distribution libraries and programs are now supported
637 when configuring with CMake (see 6 below) instead of with
638 Configure/Make.
639
640 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
641 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
642 exported in the Windows port". It has not yet been confirmed that the patch
643 solves the problem, but it does no harm.
644
645 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
646 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
647 with CMake, and also correct the comment about stack recursion.
648
649 7. Remove the automatic building of pcredemo from the ./configure system and
650 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
651 of a program that users should build themselves after PCRE is installed, so
652 building it automatically is not really right. What is more, it gave
653 trouble in some build environments.
654
655 8. Further tidies to CMakeLists.txt from Sheri and Christian.
656
657
658 Version 7.5 10-Jan-08
659 ---------------------
660
661 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
662 values in parens when parsing an RE using the C++ wrapper."
663
664 2. Negative specials like \S did not work in character classes in UTF-8 mode.
665 Characters greater than 255 were excluded from the class instead of being
666 included.
667
668 3. The same bug as (2) above applied to negated POSIX classes such as
669 [:^space:].
670
671 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
672 defined or documented. It seems to have been a typo for PCRE_STATIC, so
673 I have changed it.
674
675 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
676 first named subpattern) and a construct such as (?&a) would reference the
677 first named subpattern whose name started with "a" (in other words, the
678 length check was missing). Both these problems are fixed. "Subpattern name
679 expected" is now given for (?&) (a zero-length name), and this patch also
680 makes it give the same error for \k'' (previously it complained that that
681 was a reference to a non-existent subpattern).
682
683 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
684 this is right because (?- can be followed by option settings as well as by
685 digits. I have, however, made the messages clearer.
686
687 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
688 than the number used in the conditional) now cause a compile-time error.
689 This is actually not compatible with Perl, which accepts such patterns, but
690 treats the conditional as always being FALSE (as PCRE used to), but it
691 seems to me that giving a diagnostic is better.
692
693 8. Change "alphameric" to the more common word "alphanumeric" in comments
694 and messages.
695
696 9. Fix two occurrences of "backslash" in comments that should have been
697 "backspace".
698
699 10. Remove two redundant lines of code that can never be obeyed (their function
700 was moved elsewhere).
701
702 11. The program that makes PCRE's Unicode character property table had a bug
703 which caused it to generate incorrect table entries for sequences of
704 characters that have the same character type, but are in different scripts.
705 It amalgamated them into a single range, with the script of the first of
706 them. In other words, some characters were in the wrong script. There were
707 thirteen such cases, affecting characters in the following ranges:
708
709 U+002b0 - U+002c1
710 U+0060c - U+0060d
711 U+0061e - U+00612
712 U+0064b - U+0065e
713 U+0074d - U+0076d
714 U+01800 - U+01805
715 U+01d00 - U+01d77
716 U+01d9b - U+01dbf
717 U+0200b - U+0200f
718 U+030fc - U+030fe
719 U+03260 - U+0327f
720 U+0fb46 - U+0fbb1
721 U+10450 - U+1049d
722
723 12. The -o option (show only the matching part of a line) for pcregrep was not
724 compatible with GNU grep in that, if there was more than one match in a
725 line, it showed only the first of them. It now behaves in the same way as
726 GNU grep.
727
728 13. If the -o and -v options were combined for pcregrep, it printed a blank
729 line for every non-matching line. GNU grep prints nothing, and pcregrep now
730 does the same. The return code can be used to tell if there were any
731 non-matching lines.
732
733 14. Added --file-offsets and --line-offsets to pcregrep.
734
735 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
736 infinitely looping recursion. The bug was that positive lookaheads were not
737 being skipped when checking for a possible empty match (negative lookaheads
738 and both kinds of lookbehind were skipped).
739
740 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
741 inclusion of <windows.h> to before rather than after the definition of
742 INVALID_FILE_ATTRIBUTES (patch from David Byron).
743
744 17. Specifying a possessive quantifier with a specific limit for a Unicode
745 character property caused pcre_compile() to compile bad code, which led at
746 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
747 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
748 caused the error; without that there was no problem.
749
750 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
751
752 19. Added --enable-pcretest-libreadline.
753
754 20. In pcrecpp.cc, the variable 'count' was incremented twice in
755 RE::GlobalReplace(). As a result, the number of replacements returned was
756 double what it should be. I removed one of the increments, but Craig sent a
757 later patch that removed the other one (the right fix) and added unit tests
758 that check the return values (which was not done before).
759
760 21. Several CMake things:
761
762 (1) Arranged that, when cmake is used on Unix, the libraries end up with
763 the names libpcre and libpcreposix, not just pcre and pcreposix.
764
765 (2) The above change means that pcretest and pcregrep are now correctly
766 linked with the newly-built libraries, not previously installed ones.
767
768 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
769
770 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
771 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
772 UTF-8 newline character). The key issue is that the pattern starts .*;
773 this means that the match must be either at the beginning, or after a
774 newline. The bug was in the code for advancing after a failed match and
775 checking that the new position followed a newline. It was not taking
776 account of UTF-8 characters correctly.
777
778 23. PCRE was behaving differently from Perl in the way it recognized POSIX
779 character classes. PCRE was not treating the sequence [:...:] as a
780 character class unless the ... were all letters. Perl, however, seems to
781 allow any characters between [: and :], though of course it rejects as
782 unknown any "names" that contain non-letters, because all the known class
783 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
784 for example, whereas PCRE did not - it did not recognize a POSIX character
785 class. This seemed a bit dangerous, so the code has been changed to be
786 closer to Perl. The behaviour is not identical to Perl, because PCRE will
787 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
788 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
789 Perl does, and where it didn't before.
790
791 24. Rewrite so as to remove the single use of %n from pcregrep because in some
792 Windows environments %n is disabled by default.
793
794
795 Version 7.4 21-Sep-07
796 ---------------------
797
798 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
799 means that a class such as [\s] counted as "explicit reference to CR or
800 LF". That isn't really right - the whole point of the change was to try to
801 help when there was an actual mention of one of the two characters. So now
802 the change happens only if \r or \n (or a literal CR or LF) character is
803 encountered.
804
805 2. The 32-bit options word was also used for 6 internal flags, but the numbers
806 of both had grown to the point where there were only 3 bits left.
807 Fortunately, there was spare space in the data structure, and so I have
808 moved the internal flags into a new 16-bit field to free up more option
809 bits.
810
811 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
812 but did not set the internal JCHANGED flag - either of these is enough to
813 control the way the "get" function works - but the PCRE_INFO_JCHANGED
814 facility is supposed to tell if (?J) was ever used, so now (?J) at the
815 start sets both bits.
816
817 4. Added options (at build time, compile time, exec time) to change \R from
818 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
819
820 5. doc/pcresyntax.html was missing from the distribution.
821
822 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
823 compatibility, even though it is no longer used.
824
825 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
826 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
827 windows.h file is present (where different names are used). [This was
828 reversed later after testing - see 16 below.]
829
830 8. Changed all #include <config.h> to #include "config.h". There were also
831 some further <pcre.h> cases that I changed to "pcre.h".
832
833 9. When pcregrep was used with the --colour option, it missed the line ending
834 sequence off the lines that it output.
835
836 10. It was pointed out to me that arrays of string pointers cause lots of
837 relocations when a shared library is dynamically loaded. A technique of
838 using a single long string with a table of offsets can drastically reduce
839 these. I have refactored PCRE in four places to do this. The result is
840 dramatic:
841
842 Originally: 290
843 After changing UCP table: 187
844 After changing error message table: 43
845 After changing table of "verbs" 36
846 After changing table of Posix names 22
847
848 Thanks to the folks working on Gregex for glib for this insight.
849
850 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
851 unicode-properties was also set.
852
853 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
854
855 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
856 checked only for CRLF.
857
858 14. Added casts to pcretest.c to avoid compiler warnings.
859
860 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
861
862 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
863 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
864 entirely. This removes changes made in 7 above.
865
866 17. The CMake files have been updated, and there is now more information about
867 building with CMake in the NON-UNIX-USE document.
868
869
870 Version 7.3 28-Aug-07
871 ---------------------
872
873 1. In the rejigging of the build system that eventually resulted in 7.1, the
874 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
875 brackets there is not right, since it causes compilers to look for an
876 installed pcre.h, not the version that is in the source that is being
877 compiled (which of course may be different). I have changed it back to:
878
879 #include "pcre.h"
880
881 I have a vague recollection that the change was concerned with compiling in
882 different directories, but in the new build system, that is taken care of
883 by the VPATH setting the Makefile.
884
885 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
886 when the subject happened to end in the byte 0x85 (e.g. if the last
887 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
888 characters but of course it shouldn't be taken as a newline when it is part
889 of another character. The bug was that, for an unlimited repeat of . in
890 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
891 characters when looking for a newline.
892
893 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
894
895 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
896 in debug output.
897
898 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
899 long printing in the pcrecpp unittest when running under MinGW.
900
901 6. ESC_K was left out of the EBCDIC table.
902
903 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
904 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
905 limit also applies to "virtual nesting" when a pattern is recursive, and in
906 this case 1000 isn't so big. I have been able to remove this limit at the
907 expense of backing off one optimization in certain circumstances. Normally,
908 when pcre_exec() would call its internal match() function recursively and
909 immediately return the result unconditionally, it uses a "tail recursion"
910 feature to save stack. However, when a subpattern that can match an empty
911 string has an unlimited repetition quantifier, it no longer makes this
912 optimization. That gives it a stack frame in which to save the data for
913 checking that an empty string has been matched. Previously this was taken
914 from the 1000-entry workspace that had been reserved. So now there is no
915 explicit limit, but more stack is used.
916
917 8. Applied Daniel's patches to solve problems with the import/export magic
918 syntax that is required for Windows, and which was going wrong for the
919 pcreposix and pcrecpp parts of the library. These were overlooked when this
920 problem was solved for the main library.
921
922 9. There were some crude static tests to avoid integer overflow when computing
923 the size of patterns that contain repeated groups with explicit upper
924 limits. As the maximum quantifier is 65535, the maximum group length was
925 set at 30,000 so that the product of these two numbers did not overflow a
926 32-bit integer. However, it turns out that people want to use groups that
927 are longer than 30,000 bytes (though not repeat them that many times).
928 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
929 made it possible to implement the integer overflow checks in a much more
930 dynamic way, which I have now done. The artificial limitation on group
931 length has been removed - we now have only the limit on the total length of
932 the compiled pattern, which depends on the LINK_SIZE setting.
933
934 10. Fixed a bug in the documentation for get/copy named substring when
935 duplicate names are permitted. If none of the named substrings are set, the
936 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
937 empty string.
938
939 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
940 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
941 because the ] is interpreted as the first data character and the
942 terminating ] is not found. PCRE has been made compatible with Perl in this
943 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
944 cause memory overwriting.
945
946 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
947 string has been matched (to stop an infinite loop). It was not recognizing
948 a conditional subpattern that could match an empty string if that
949 subpattern was within another subpattern. For example, it looped when
950 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
951 condition was not nested. This bug has been fixed.
952
953 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
954 past the start of the subject in the presence of bytes with the top bit
955 set, for example "\x8aBCD".
956
957 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
958 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
959
960 14. Optimized (?!) to (*FAIL).
961
962 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
963 This restricts code points to be within the range 0 to 0x10FFFF, excluding
964 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
965 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
966 does: it's just the validity check that is more restrictive.
967
968 16. Inserted checks for integer overflows during escape sequence (backslash)
969 processing, and also fixed erroneous offset values for syntax errors during
970 backslash processing.
971
972 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
973 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
974
975 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
976 caused an overrun.
977
978 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
979 something other than just ASCII characters) inside a group that had an
980 unlimited repeat caused a loop at compile time (while checking to see
981 whether the group could match an empty string).
982
983 20. Debugging a pattern containing \p or \P could cause a crash. For example,
984 [\P{Any}] did so. (Error in the code for printing property names.)
985
986 21. An orphan \E inside a character class could cause a crash.
987
988 22. A repeated capturing bracket such as (A)? could cause a wild memory
989 reference during compilation.
990
991 23. There are several functions in pcre_compile() that scan along a compiled
992 expression for various reasons (e.g. to see if it's fixed length for look
993 behind). There were bugs in these functions when a repeated \p or \P was
994 present in the pattern. These operators have additional parameters compared
995 with \d, etc, and these were not being taken into account when moving along
996 the compiled data. Specifically:
997
998 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
999 length.
1000
1001 (b) An item such as \pL+ within a repeated group could cause crashes or
1002 loops.
1003
1004 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1005 "reference to non-existent subpattern" error.
1006
1007 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1008
1009 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1010 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1011
1012 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1013
1014 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1015 character were causing crashes (broken optimization).
1016
1017 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1018 \p or \P) caused a compile-time loop.
1019
1020 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1021 break. For example, the unstudied pattern [\r\n]A does not match the string
1022 "\r\nA" because change 7.0/46 below moves the current point on by two
1023 characters after failing to match at the start. However, the pattern \nA
1024 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1025 the same is true. There doesn't seem any very clean way out of this, but
1026 what I have chosen to do makes the common cases work: PCRE now takes note
1027 of whether there can be an explicit match for \r or \n anywhere in the
1028 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1029 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1030 pattern has explicit CR or LF references.
1031
1032 29. Added (*CR) etc for changing newline setting at start of pattern.
1033
1034
1035 Version 7.2 19-Jun-07
1036 ---------------------
1037
1038 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1039 which is apparently normally available under Windows.
1040
1041 2. Re-jig the pcregrep tests with different newline settings in an attempt
1042 to make them independent of the local environment's newline setting.
1043
1044 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1045
1046 4. Some of the "internals" tests were previously cut out when the link size
1047 was not 2, because the output contained actual offsets. The recent new
1048 "Z" feature of pcretest means that these can be cut out, making the tests
1049 usable with all link sizes.
1050
1051 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1052 stack recursion. This gives a massive performance boost under BSD, but just
1053 a small improvement under Linux. However, it saves one field in the frame
1054 in all cases.
1055
1056 6. Added more features from the forthcoming Perl 5.10:
1057
1058 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1059 recursion call. It refers to the nth most recently opened parentheses.
1060
1061 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1062 to be opened parentheses.
1063
1064 (c) Conditions that refer to capturing parentheses can be specified
1065 relatively, for example, (?(-2)... or (?(+3)...
1066
1067 (d) \K resets the start of the current match so that everything before
1068 is not part of it.
1069
1070 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1071
1072 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1073 reference syntax.
1074
1075 (g) (?| introduces a group in which the numbering of parentheses in each
1076 alternative starts with the same number.
1077
1078 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1079
1080 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1081 PCRE_INFO_JCHANGED.
1082
1083 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1084 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1085 for detecting groups that can match an empty string.
1086
1087 9. A pattern with a very large number of alternatives (more than several
1088 hundred) was running out of internal workspace during the pre-compile
1089 phase, where pcre_compile() figures out how much memory will be needed. A
1090 bit of new cunning has reduced the workspace needed for groups with
1091 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1092 workspace instead of running out of the 4096 that are available.
1093
1094 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1095
1096 11. Applied patch from Google to remove an optimization that didn't quite work.
1097 The report of the bug said:
1098
1099 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1100 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1101 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1102
1103 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1104 it matched the wrong number of bytes.
1105
1106
1107 Version 7.1 24-Apr-07
1108 ---------------------
1109
1110 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1111 that is more "standard", making use of automake and other Autotools. There
1112 is some re-arrangement of the files and adjustment of comments consequent
1113 on this.
1114
1115 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1116 for recursive directory scanning broke on some systems because the files
1117 are not scanned in any specific order and on different systems the order
1118 was different. A call to "sort" has been inserted into RunGrepTest for the
1119 approprate test as a short-term fix. In the longer term there may be an
1120 alternative.
1121
1122 3. I had an email from Eric Raymond about problems translating some of PCRE's
1123 man pages to HTML (despite the fact that I distribute HTML pages, some
1124 people do their own conversions for various reasons). The problems
1125 concerned the use of low-level troff macros .br and .in. I have therefore
1126 removed all such uses from the man pages (some were redundant, some could
1127 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1128 HTML has been updated to handle .nf/.fi and to complain if it encounters
1129 .br or .in.
1130
1131 4. Updated comments in configure.ac that get placed in config.h.in and also
1132 arranged for config.h to be included in the distribution, with the name
1133 config.h.generic, for the benefit of those who have to compile without
1134 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1135
1136 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1137 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1138 makevp.bat for the current PCRE, using the additional files
1139 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1140
1141 6. A Windows user reported a minor discrepancy with test 2, which turned out
1142 to be caused by a trailing space on an input line that had got lost in his
1143 copy. The trailing space was an accident, so I've just removed it.
1144
1145 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1146 that is needed.
1147
1148 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1149 as "const" (a) because they are and (b) because it helps the PHP
1150 maintainers who have recently made a script to detect big data structures
1151 in the php code that should be moved to the .rodata section. I remembered
1152 to update Builducptable as well, so it won't revert if ucptable.h is ever
1153 re-created.
1154
1155 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1156 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1157 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1158 support is not required. This saves 1.5-2K of code, which is important in
1159 some applications.
1160
1161 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1162 so as not to refer to the tables, even though these functions will never be
1163 called when UTF-8 support is disabled. Otherwise there are problems with a
1164 shared library.
1165
1166 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1167
1168 (a) It was defining its arguments as char * instead of void *.
1169
1170 (b) It was assuming that all moves were upwards in memory; this was true
1171 a long time ago when I wrote it, but is no longer the case.
1172
1173 The emulated memove() is provided for those environments that have neither
1174 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1175 is clearly not the case, as these two bugs were recently reported.
1176
1177 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1178 and Detrail to create the HTML documentation, the .txt form of the man
1179 pages, and it removes trailing spaces from listed files. It also creates
1180 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1181 case, it wraps all the #defines with #ifndefs. This script should be run
1182 before "make dist".
1183
1184 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1185 with Unicode property support.
1186
1187 (a) For a maximizing quantifier, if the two different cases of the
1188 character were of different lengths in their UTF-8 codings (there are
1189 some cases like this - I found 11), and the matching function had to
1190 back up over a mixture of the two cases, it incorrectly assumed they
1191 were both the same length.
1192
1193 (b) When PCRE was configured to use the heap rather than the stack for
1194 recursion during matching, it was not correctly preserving the data for
1195 the other case of a UTF-8 character when checking ahead for a match
1196 while processing a minimizing repeat. If the check also involved
1197 matching a wide character, but failed, corruption could cause an
1198 erroneous result when trying to check for a repeat of the original
1199 character.
1200
1201 13. Some tidying changes to the testing mechanism:
1202
1203 (a) The RunTest script now detects the internal link size and whether there
1204 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1205 values substituted by "configure". (The RunGrepTest script already did
1206 this for UTF-8.) The configure.ac script no longer substitutes the
1207 relevant variables.
1208
1209 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1210 with length and offset values. This means that the output is different
1211 for different internal link sizes. Test 2 is skipped for link sizes
1212 other than 2 because of this, bypassing the problem. Unfortunately,
1213 there was also a test in test 3 (the locale tests) that used /B and
1214 failed for link sizes other than 2. Rather than cut the whole test out,
1215 I have added a new /Z option to pcretest that replaces the length and
1216 offset values with spaces. This is now used to make test 3 independent
1217 of link size. (Test 2 will be tidied up later.)
1218
1219 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1220 segmentation fault instead of returning the appropriate error message.
1221
1222 15. In multiline mode when the newline sequence was set to "any", the pattern
1223 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1224 This doesn't seem right; it now treats the CRLF combination as the line
1225 ending, and so does not match in that case. It's only a pattern such as ^$
1226 that would hit this one: something like ^ABC$ would have failed after \r
1227 and then tried again after \r\n.
1228
1229 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1230 in an attempt to make files that differ only in their line terminators
1231 compare equal. This works on Linux.
1232
1233 17. Under certain error circumstances pcregrep might try to free random memory
1234 as it exited. This is now fixed, thanks to valgrind.
1235
1236 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1237 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1238 was because its rules for how to advance for /g after matching an empty
1239 string at the end of a line did not allow for this case. They now check for
1240 it specially.
1241
1242 20. pcretest is supposed to handle patterns and data of any length, by
1243 extending its buffers when necessary. It was getting this wrong when the
1244 buffer for a data line had to be extended.
1245
1246 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1247 CRLF as a newline sequence.
1248
1249 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1250 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1251 I have nevertheless tidied it up.
1252
1253 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1254
1255 24. Added a man page for pcre-config.
1256
1257
1258 Version 7.0 19-Dec-06
1259 ---------------------
1260
1261 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1262 moving to gcc 4.1.1.
1263
1264 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1265 sys/time.h, which is documented as needed for this function. It doesn't
1266 seem to matter on Linux, but it showed up on some releases of OS X.
1267
1268 3. It seems that there are systems where bytes whose values are greater than
1269 127 match isprint() in the "C" locale. The "C" locale should be the
1270 default when a C program starts up. In most systems, only ASCII printing
1271 characters match isprint(). This difference caused the output from pcretest
1272 to vary, making some of the tests fail. I have changed pcretest so that:
1273
1274 (a) When it is outputting text in the compiled version of a pattern, bytes
1275 other than 32-126 are always shown as hex escapes.
1276
1277 (b) When it is outputting text that is a matched part of a subject string,
1278 it does the same, unless a different locale has been set for the match
1279 (using the /L modifier). In this case, it uses isprint() to decide.
1280
1281 4. Fixed a major bug that caused incorrect computation of the amount of memory
1282 required for a compiled pattern when options that changed within the
1283 pattern affected the logic of the preliminary scan that determines the
1284 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1285 that the computed length was too small. The symptoms of this bug were
1286 either the PCRE error "internal error: code overflow" from pcre_compile(),
1287 or a glibc crash with a message such as "pcretest: free(): invalid next
1288 size (fast)". Examples of patterns that provoked this bug (shown in
1289 pcretest format) are:
1290
1291 /(?-x: )/x
1292 /(?x)(?-x: \s*#\s*)/
1293 /((?i)[\x{c0}])/8
1294 /(?i:[\x{c0}])/8
1295
1296 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1297 is now done differently.
1298
1299 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1300 wrapper classes; (b) implement a new function in the C++ scanner that is
1301 more efficient than the old way of doing things because it avoids levels of
1302 recursion in the regex matching; (c) add a paragraph to the documentation
1303 for the FullMatch() function.
1304
1305 6. The escape sequence \n was being treated as whatever was defined as
1306 "newline". Not only was this contrary to the documentation, which states
1307 that \n is character 10 (hex 0A), but it also went horribly wrong when
1308 "newline" was defined as CRLF. This has been fixed.
1309
1310 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1311 was being set to -1 for the "end of line" case (supposedly a value that no
1312 character can have). Though this value is never used (the check for end of
1313 line is "zero bytes in current character"), it caused compiler complaints.
1314 I've changed it to 0xffffffff.
1315
1316 8. In pcre_version.c, the version string was being built by a sequence of
1317 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1318 string (as it is for production releases) called a macro with an empty
1319 argument. The C standard says the result of this is undefined. The gcc
1320 compiler treats it as an empty string (which was what was wanted) but it is
1321 reported that Visual C gives an error. The source has been hacked around to
1322 avoid this problem.
1323
1324 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1325 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1326 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1327 of them did).
1328
1329 10. Originally, pcretest opened its input and output without "b"; then I was
1330 told that "b" was needed in some environments, so it was added for release
1331 5.0 to both the input and output. (It makes no difference on Unix-like
1332 systems.) Later I was told that it is wrong for the input on Windows. I've
1333 now abstracted the modes into two macros, to make it easier to fiddle with
1334 them, and removed "b" from the input mode under Windows.
1335
1336 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1337
1338 12. Added -help and --help to pcretest as an official way of being reminded
1339 of the options.
1340
1341 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1342 and pcrecpp.cc because they annoy compilers at high warning levels.
1343
1344 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1345
1346 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1347 scripts are not C programs :-) and which was not noticed because it works
1348 on Linux.
1349
1350 16. pcretest is supposed to handle any length of pattern and data line (as one
1351 line or as a continued sequence of lines) by extending its input buffer if
1352 necessary. This feature was broken for very long pattern lines, leading to
1353 a string of junk being passed to pcre_compile() if the pattern was longer
1354 than about 50K.
1355
1356 17. I have done a major re-factoring of the way pcre_compile() computes the
1357 amount of memory needed for a compiled pattern. Previously, there was code
1358 that made a preliminary scan of the pattern in order to do this. That was
1359 OK when PCRE was new, but as the facilities have expanded, it has become
1360 harder and harder to keep it in step with the real compile phase, and there
1361 have been a number of bugs (see for example, 4 above). I have now found a
1362 cunning way of running the real compile function in a "fake" mode that
1363 enables it to compute how much memory it would need, while actually only
1364 ever using a few hundred bytes of working memory and without too many
1365 tests of the mode. This should make future maintenance and development
1366 easier. A side effect of this work is that the limit of 200 on the nesting
1367 depth of parentheses has been removed (though this was never a serious
1368 limitation, I suspect). However, there is a downside: pcre_compile() now
1369 runs more slowly than before (30% or more, depending on the pattern). I
1370 hope this isn't a big issue. There is no effect on runtime performance.
1371
1372 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1373 newline (only possible for the last line of a file) and it was a
1374 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1375
1376 19. Added additional timing features to pcretest. (1) The -tm option now times
1377 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1378 separate command line item, by a number that specifies the number of
1379 repeats to use when timing. The default is 50000; this gives better
1380 precision, but takes uncomfortably long for very large patterns.
1381
1382 20. Extended pcre_study() to be more clever in cases where a branch of a
1383 subpattern has no definite first character. For example, (a*|b*)[cd] would
1384 previously give no result from pcre_study(). Now it recognizes that the
1385 first character must be a, b, c, or d.
1386
1387 21. There was an incorrect error "recursive call could loop indefinitely" if
1388 a subpattern (or the entire pattern) that was being tested for matching an
1389 empty string contained only one non-empty item after a nested subpattern.
1390 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1391 incorrectly, because the \d was being skipped in the check.
1392
1393 22. The pcretest program now has a new pattern option /B and a command line
1394 option -b, which is equivalent to adding /B to every pattern. This causes
1395 it to show the compiled bytecode, without the additional information that
1396 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1397 is the same as /B/I).
1398
1399 23. A new optimization is now able automatically to treat some sequences such
1400 as a*b as a*+b. More specifically, if something simple (such as a character
1401 or a simple class like \d) has an unlimited quantifier, and is followed by
1402 something that cannot possibly match the quantified thing, the quantifier
1403 is automatically "possessified".
1404
1405 24. A recursive reference to a subpattern whose number was greater than 39
1406 went wrong under certain circumstances in UTF-8 mode. This bug could also
1407 have affected the operation of pcre_study().
1408
1409 25. Realized that a little bit of performance could be had by replacing
1410 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1411
1412 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1413
1414 27. Possessive quantifiers such as a++ were previously implemented by turning
1415 them into atomic groups such as ($>a+). Now they have their own opcodes,
1416 which improves performance. This includes the automatically created ones
1417 from 23 above.
1418
1419 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1420 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1421 the first matched character to be a colon. This applied both to named and
1422 numbered groups.
1423
1424 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1425
1426 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1427 building PCRE on Windows easier, so I have included it in the distribution.
1428
1429 31. There is now a check in pcretest against a ridiculously large number being
1430 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1431 loop, the loop is abandoned.
1432
1433 32. Forward references to subpatterns in conditions such as (?(2)...) where
1434 subpattern 2 is defined later cause pcre_compile() to search forwards in
1435 the pattern for the relevant set of parentheses. This search went wrong
1436 when there were unescaped parentheses in a character class, parentheses
1437 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1438
1439 33. "Subroutine" calls and backreferences were previously restricted to
1440 referencing subpatterns earlier in the regex. This restriction has now
1441 been removed.
1442
1443 34. Added a number of extra features that are going to be in Perl 5.10. On the
1444 whole, these are just syntactic alternatives for features that PCRE had
1445 previously implemented using the Python syntax or my own invention. The
1446 other formats are all retained for compatibility.
1447
1448 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1449 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1450 also .NET compatible.
1451
1452 (b) A recursion or subroutine call to a named group can now be defined as
1453 (?&name) as well as (?P>name).
1454
1455 (c) A backreference to a named group can now be defined as \k<name> or
1456 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1457 5.10, are also .NET compatible.
1458
1459 (d) A conditional reference to a named group can now use the syntax
1460 (?(<name>) or (?('name') as well as (?(name).
1461
1462 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1463 groups (named and numbered) that are never evaluated inline, but can be
1464 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1465 is always false. There may be only one alternative in such a group.
1466
1467 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1468 as the simple (?(R). The condition is true only if the most recent
1469 recursion is that of the given number or name. It does not search out
1470 through the entire recursion stack.
1471
1472 (g) The escape \gN or \g{N} has been added, where N is a positive or
1473 negative number, specifying an absolute or relative reference.
1474
1475 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1476 some "unreachable code" warnings.
1477
1478 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1479 things, this adds five new scripts.
1480
1481 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1482 There were also incompatibilities regarding the handling of \Q..\E inside
1483 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1484 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1485
1486 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1487 matches an empty string, and forcibly breaks the loop. There were bugs in
1488 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1489 against aaaa the result was just "a" rather than "aaaa", for example. Two
1490 separate and independent bugs (that affected different cases) have been
1491 fixed.
1492
1493 39. Refactored the code to abolish the use of different opcodes for small
1494 capturing bracket numbers. This is a tidy that I avoided doing when I
1495 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1496 The new approach is not only tidier, it makes it possible to reduce the
1497 memory needed to fix the previous bug (38).
1498
1499 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1500 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1501 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1502 mode.
1503
1504 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1505 report.
1506
1507 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1508 copy construction and assignment in the C++ wrapper.
1509
1510 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1511 couple of bugs that could have given wrong results in the "--newline=crlf"
1512 case.
1513
1514 44. Added a number of casts and did some reorganization of signed/unsigned int
1515 variables following suggestions from Dair Grant. Also renamed the variable
1516 "this" as "item" because it is a C++ keyword.
1517
1518 45. Arranged for dftables to add
1519
1520 #include "pcre_internal.h"
1521
1522 to pcre_chartables.c because without it, gcc 4.x may remove the array
1523 definition from the final binary if PCRE is built into a static library and
1524 dead code stripping is activated.
1525
1526 46. For an unanchored pattern, if a match attempt fails at the start of a
1527 newline sequence, and the newline setting is CRLF or ANY, and the next two
1528 characters are CRLF, advance by two characters instead of one.
1529
1530
1531 Version 6.7 04-Jul-06
1532 ---------------------
1533
1534 1. In order to handle tests when input lines are enormously long, pcretest has
1535 been re-factored so that it automatically extends its buffers when
1536 necessary. The code is crude, but this _is_ just a test program. The
1537 default size has been increased from 32K to 50K.
1538
1539 2. The code in pcre_study() was using the value of the re argument before
1540 testing it for NULL. (Of course, in any sensible call of the function, it
1541 won't be NULL.)
1542
1543 3. The memmove() emulation function in pcre_internal.h, which is used on
1544 systems that lack both memmove() and bcopy() - that is, hardly ever -
1545 was missing a "static" storage class specifier.
1546
1547 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1548 containing an extended class (one that cannot be represented by a bitmap
1549 because it contains high-valued characters or Unicode property items, e.g.
1550 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1551 pattern, but PCRE should not loop if you do not (it no longer does).
1552 [Detail: two cases were found: (a) a repeated subpattern containing an
1553 extended class; (b) a recursive reference to a subpattern that followed a
1554 previous extended class. It wasn't skipping over the extended class
1555 correctly when UTF-8 mode was not set.]
1556
1557 5. A negated single-character class was not being recognized as fixed-length
1558 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1559 compile error "lookbehind assertion is not fixed length".
1560
1561 6. The RunPerlTest auxiliary script was showing an unexpected difference
1562 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1563 write a Perl script that can interpret lines of an input file either as
1564 byte characters or as UTF-8, which is what "perltest" was being required to
1565 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1566 can't do is switch easily at run time between having the "use utf8;" pragma
1567 or not. In the end, I fudged it by using the RunPerlTest script to insert
1568 "use utf8;" explicitly for the UTF-8 tests.
1569
1570 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1571 the end of the subject string, contrary to the documentation and to what
1572 Perl does. This was true of both matching functions. Now it matches only at
1573 the start of the subject and immediately after *internal* newlines.
1574
1575 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1576 a pointer to an int instead of a pointer to an unsigned long int. This
1577 caused problems on 64-bit systems.
1578
1579 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1580 instance of the 'standard' template library not being so standard".
1581
1582 10. There was no check on the number of named subpatterns nor the maximum
1583 length of a subpattern name. The product of these values is used to compute
1584 the size of the memory block for a compiled pattern. By supplying a very
1585 long subpattern name and a large number of named subpatterns, the size
1586 computation could be caused to overflow. This is now prevented by limiting
1587 the length of names to 32 characters, and the number of named subpatterns
1588 to 10,000.
1589
1590 11. Subpatterns that are repeated with specific counts have to be replicated in
1591 the compiled pattern. The size of memory for this was computed from the
1592 length of the subpattern and the repeat count. The latter is limited to
1593 65535, but there was no limit on the former, meaning that integer overflow
1594 could in principle occur. The compiled length of a repeated subpattern is
1595 now limited to 30,000 bytes in order to prevent this.
1596
1597 12. Added the optional facility to have named substrings with the same name.
1598
1599 13. Added the ability to use a named substring as a condition, using the
1600 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1601 are numbers (not recommended). Forward references are permitted.
1602
1603 14. Added forward references in named backreferences (if you see what I mean).
1604
1605 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1606 pattern could run off the end of the subject. For example, the pattern
1607 "(?s)(.{1,5})"8 did this with the subject "ab".
1608
1609 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1610 PCRE_CASELESS was set when matching characters that were quantified with ?
1611 or *.
1612
1613 17. A character class other than a single negated character that had a minimum
1614 but no maximum quantifier - for example [ab]{6,} - was not handled
1615 correctly by pce_dfa_exec(). It would match only one character.
1616
1617 18. A valid (though odd) pattern that looked like a POSIX character
1618 class but used an invalid character after [ (for example [[,abc,]]) caused
1619 pcre_compile() to give the error "Failed: internal error: code overflow" or
1620 in some cases to crash with a glibc free() error. This could even happen if
1621 the pattern terminated after [[ but there just happened to be a sequence of
1622 letters, a binary zero, and a closing ] in the memory that followed.
1623
1624 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1625 over the years. Originally (before any Unicode support), just the bottom 8
1626 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1627 output from "man perlunicode" includes this:
1628
1629 The regular expression compiler produces polymorphic opcodes. That
1630 is, the pattern adapts to the data and automatically switches to
1631 the Unicode character scheme when presented with Unicode data--or
1632 instead uses a traditional byte scheme when presented with byte
1633 data.
1634
1635 Sadly, a wide octal escape does not cause a switch, and in a string with
1636 no other multibyte characters, these octal escapes are treated as before.
1637 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1638 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1639 Unicode string.
1640
1641 I have not perpetrated such confusion in PCRE. Up till now, it took just
1642 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1643 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1644 translate to the appropriate multibyte character.
1645
1646 29. Applied some refactoring to reduce the number of warnings from Microsoft
1647 and Borland compilers. This has included removing the fudge introduced
1648 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1649 a warning about an unused variable.
1650
1651 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1652 characters since release 4.0, because Perl (from release 5.004) does not.
1653 [Or at least, is documented not to: some releases seem to be in conflict
1654 with the documentation.] However, when a pattern was studied with
1655 pcre_study() and all its branches started with \s, PCRE still included VT
1656 as a possible starting character. Of course, this did no harm; it just
1657 caused an unnecessary match attempt.
1658
1659 22. Removed a now-redundant internal flag bit that recorded the fact that case
1660 dependency changed within the pattern. This was once needed for "required
1661 byte" processing, but is no longer used. This recovers a now-scarce options
1662 bit. Also moved the least significant internal flag bit to the most-
1663 significant bit of the word, which was not previously used (hangover from
1664 the days when it was an int rather than a uint) to free up another bit for
1665 the future.
1666
1667 23. Added support for CRLF line endings as well as CR and LF. As well as the
1668 default being selectable at build time, it can now be changed at runtime
1669 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1670 specify that it is scanning data with non-default line endings.
1671
1672 24. Changed the definition of CXXLINK to make it agree with the definition of
1673 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1674
1675 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1676 recursions. This makes a big different to stack usage for some patterns.
1677
1678 26. If a subpattern containing a named recursion or subroutine reference such
1679 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1680 the space required for the compiled pattern went wrong and gave too small a
1681 value. Depending on the environment, this could lead to "Failed: internal
1682 error: code overflow at offset 49" or "glibc detected double free or
1683 corruption" errors.
1684
1685 27. Applied patches from Google (a) to support the new newline modes and (b) to
1686 advance over multibyte UTF-8 characters in GlobalReplace.
1687
1688 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1689 difference for some implementation of PCRE in some Windows version.
1690
1691 29. Added some extra testing facilities to pcretest:
1692
1693 \q<number> in a data line sets the "match limit" value
1694 \Q<number> in a data line sets the "match recursion limt" value
1695 -S <number> sets the stack size, where <number> is in megabytes
1696
1697 The -S option isn't available for Windows.
1698
1699
1700 Version 6.6 06-Feb-06
1701 ---------------------
1702
1703 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1704 in pcreposix.h. I have copied the definition from pcre.h.
1705
1706 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1707 because pcre.h is no longer a built file.
1708
1709 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1710 not normally included in the compiled code.
1711
1712
1713 Version 6.5 01-Feb-06
1714 ---------------------
1715
1716 1. When using the partial match feature with pcre_dfa_exec(), it was not
1717 anchoring the second and subsequent partial matches at the new starting
1718 point. This could lead to incorrect results. For example, with the pattern
1719 /1234/, partially matching against "123" and then "a4" gave a match.
1720
1721 2. Changes to pcregrep:
1722
1723 (a) All non-match returns from pcre_exec() were being treated as failures
1724 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1725 error message is output. Some extra information is given for the
1726 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1727 probably the only errors that are likely to be caused by users (by
1728 specifying a regex that has nested indefinite repeats, for instance).
1729 If there are more than 20 of these errors, pcregrep is abandoned.
1730
1731 (b) A binary zero was treated as data while matching, but terminated the
1732 output line if it was written out. This has been fixed: binary zeroes
1733 are now no different to any other data bytes.
1734
1735 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1736 used to set a locale for matching. The --locale=xxxx long option has
1737 been added (no short equivalent) to specify a locale explicitly on the
1738 pcregrep command, overriding the environment variables.
1739
1740 (d) When -B was used with -n, some line numbers in the output were one less
1741 than they should have been.
1742
1743 (e) Added the -o (--only-matching) option.
1744
1745 (f) If -A or -C was used with -c (count only), some lines of context were
1746 accidentally printed for the final match.
1747
1748 (g) Added the -H (--with-filename) option.
1749
1750 (h) The combination of options -rh failed to suppress file names for files
1751 that were found from directory arguments.
1752
1753 (i) Added the -D (--devices) and -d (--directories) options.
1754
1755 (j) Added the -F (--fixed-strings) option.
1756
1757 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1758
1759 (l) Added the --colo(u)r option.
1760
1761 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1762 is not present by default.
1763
1764 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1765 items such as (?R) or (?1), when the recursion could match a number of
1766 alternatives. If it matched one of the alternatives, but subsequently,
1767 outside the recursion, there was a failure, the code tried to back up into
1768 the recursion. However, because of the way PCRE is implemented, this is not
1769 possible, and the result was an incorrect result from the match.
1770
1771 In order to prevent this happening, the specification of recursion has
1772 been changed so that all such subpatterns are automatically treated as
1773 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1774
1775 4. I had overlooked the fact that, in some locales, there are characters for
1776 which isalpha() is true but neither isupper() nor islower() are true. In
1777 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1778 and ordfeminine) are like this. This affected the treatment of \w and \W
1779 when they appeared in character classes, but not when they appeared outside
1780 a character class. The bit map for "word" characters is now created
1781 separately from the results of isalnum() instead of just taking it from the
1782 upper, lower, and digit maps. (Plus the underscore character, of course.)
1783
1784 5. The above bug also affected the handling of POSIX character classes such as
1785 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1786 permanent tables. Instead, the bit maps for such a class were previously
1787 created as the appropriate unions of the upper, lower, and digit bitmaps.
1788 Now they are created by subtraction from the [[:word:]] class, which has
1789 its own bitmap.
1790
1791 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1792 It is created by subtracting the vertical space characters (\x09, \x0a,
1793 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1794 subtraction was done in the overall bitmap for a character class, meaning
1795 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1796 be recognized. This bug has been fixed.
1797
1798 7. Patches from the folks at Google:
1799
1800 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1801 real life, but is still worth protecting against".
1802
1803 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1804 regular expressions".
1805
1806 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1807 have it.
1808
1809 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1810 "configure" and the latter not, in order to fix a problem somebody had
1811 with compiling the Arg class on HP-UX.
1812
1813 (e) Improve the error-handling of the C++ wrapper a little bit.
1814
1815 (f) New tests for checking recursion limiting.
1816
1817 8. The pcre_memmove() function, which is used only if the environment does not
1818 have a standard memmove() function (and is therefore rarely compiled),
1819 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1820 returning a result (though PCRE never actually uses the result).
1821
1822 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1823 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1824 returned instead of calling malloc() with an overflowing number that would
1825 most likely cause subsequent chaos.
1826
1827 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1828
1829 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1830 with this option is matched, the nmatch and pmatch options of regexec() are
1831 ignored.
1832
1833 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1834 provided in case anyone wants to the the POSIX interface with UTF-8
1835 strings.
1836
1837 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1838 C++ linking (needed for some HP-UX environments).
1839
1840 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1841 (unused parameter) and in the pcre_printint() function (omitted "default"
1842 switch label when the default is to do nothing).
1843
1844 15. Added some code to make it possible, when PCRE is compiled as a C++
1845 library, to replace subject pointers for pcre_exec() with a smart pointer
1846 class, thus making it possible to process discontinuous strings.
1847
1848 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1849 much the same function. They were added by different people who were trying
1850 to make PCRE easy to compile on non-Unix systems. It has been suggested
1851 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1852 for compiling on Windows systems. I have therefore replaced it with
1853 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1854 defaults to "extern" for C or "extern C" for C++, which works fine on
1855 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1856 SCOPE with something explicit in config.h. In addition:
1857
1858 (a) pcreposix.h still had just "extern" instead of either of these macros;
1859 I have replaced it with PCRE_DATA_SCOPE.
1860
1861 (b) Functions such as _pcre_xclass(), which are internal to the library,
1862 but external in the C sense, all had PCRE_EXPORT in their definitions.
1863 This is apparently wrong for the Windows case, so I have removed it.
1864 (It makes no difference on Unix-like systems.)
1865
1866 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1867 of recursive calls to match(). This is different to MATCH_LIMIT because
1868 that limits the total number of calls to match(), not all of which increase
1869 the depth of recursion. Limiting the recursion depth limits the amount of
1870 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1871 when PCRE is compiled, and changed at run time. A patch from Google adds
1872 this functionality to the C++ interface.
1873
1874 18. Changes to the handling of Unicode character properties:
1875
1876 (a) Updated the table to Unicode 4.1.0.
1877
1878 (b) Recognize characters that are not in the table as "Cn" (undefined).
1879
1880 (c) I revised the way the table is implemented to a much improved format
1881 which includes recognition of ranges. It now supports the ranges that
1882 are defined in UnicodeData.txt, and it also amalgamates other
1883 characters into ranges. This has reduced the number of entries in the
1884 table from around 16,000 to around 3,000, thus reducing its size
1885 considerably. I realized I did not need to use a tree structure after
1886 all - a binary chop search is just as efficient. Having reduced the
1887 number of entries, I extended their size from 6 bytes to 8 bytes to
1888 allow for more data.
1889
1890 (d) Added support for Unicode script names via properties such as \p{Han}.
1891
1892 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1893 matching that character.
1894
1895 20. When matching a repeated Unicode property with a minimum greater than zero,
1896 (for example \pL{2,}), PCRE could look past the end of the subject if it
1897 reached it while seeking the minimum number of characters. This could
1898 happen only if some of the characters were more than one byte long, because
1899 there is a check for at least the minimum number of bytes.
1900
1901 21. Refactored the implementation of \p and \P so as to be more general, to
1902 allow for more different types of property in future. This has changed the
1903 compiled form incompatibly. Anybody with saved compiled patterns that use
1904 \p or \P will have to recompile them.
1905
1906 22. Added "Any" and "L&" to the supported property types.
1907
1908 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1909 but give a compile time error if the value is greater than 0xff.
1910
1911 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1912 accidentally not being installed or uninstalled.
1913
1914 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1915 made were to insert the current release number. This seemed silly, because
1916 it made things harder for people building PCRE on systems that don't run
1917 "configure". I have turned pcre.h into a distributed file, no longer built
1918 by "configure", with the version identification directly included. There is
1919 no longer a pcre.h.in file.
1920
1921 However, this change necessitated a change to the pcre-config script as
1922 well. It is built from pcre-config.in, and one of the substitutions was the
1923 release number. I have updated configure.ac so that ./configure now finds
1924 the release number by grepping pcre.h.
1925
1926 26. Added the ability to run the tests under valgrind.
1927
1928
1929 Version 6.4 05-Sep-05
1930 ---------------------
1931
1932 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1933 "--" to be printed when multiple files were scanned, even when none of the
1934 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1935 consider it to be a bug, and have restored the previous behaviour.
1936
1937 2. A couple of code tidies to get rid of compiler warnings.
1938
1939 3. The pcretest program used to cheat by referring to symbols in the library
1940 whose names begin with _pcre_. These are internal symbols that are not
1941 really supposed to be visible externally, and in some environments it is
1942 possible to suppress them. The cheating is now confined to including
1943 certain files from the library's source, which is a bit cleaner.
1944
1945 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1946 file's purpose clearer.
1947
1948 5. Reorganized pcre_ucp_findchar().
1949
1950
1951 Version 6.3 15-Aug-05
1952 ---------------------
1953
1954 1. The file libpcre.pc.in did not have general read permission in the tarball.
1955
1956 2. There were some problems when building without C++ support:
1957
1958 (a) If C++ support was not built, "make install" and "make test" still
1959 tried to test it.
1960
1961 (b) There were problems when the value of CXX was explicitly set. Some
1962 changes have been made to try to fix these, and ...
1963
1964 (c) --disable-cpp can now be used to explicitly disable C++ support.
1965
1966 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1967 backslash in a target when C++ was disabled. This confuses some
1968 versions of "make", apparently. Using an intermediate variable solves
1969 this. (Same for CPP_LOBJ.)
1970
1971 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1972 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1973 necessary on certain architectures.
1974
1975 4. Added a setting of -export-symbols-regex to the link command to remove
1976 those symbols that are exported in the C sense, but actually are local
1977 within the library, and not documented. Their names all begin with
1978 "_pcre_". This is not a perfect job, because (a) we have to except some
1979 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1980 available (and never for static libraries). I have made a note to try to
1981 find a way round (a) in the future.
1982
1983
1984 Version 6.2 01-Aug-05
1985 ---------------------
1986
1987 1. There was no test for integer overflow of quantifier values. A construction
1988 such as {1111111111111111} would give undefined results. What is worse, if
1989 a minimum quantifier for a parenthesized subpattern overflowed and became
1990 negative, the calculation of the memory size went wrong. This could have
1991 led to memory overwriting.
1992
1993 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1994
1995 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1996 operating environments where this matters.
1997
1998 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1999 PCRE options from within the C++ wrapper.
2000
2001 5. Named capturing subpatterns were not being correctly counted when a pattern
2002 was compiled. This caused two problems: (a) If there were more than 100
2003 such subpatterns, the calculation of the memory needed for the whole
2004 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2005 back references of the form \12, where the number was greater than 9, were
2006 not recognized as back references, even though there were sufficient
2007 previous subpatterns.
2008
2009 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2010 versions of gcc, e.g. 2.95.4.
2011
2012
2013 Version 6.1 21-Jun-05
2014 ---------------------
2015
2016 1. There was one reference to the variable "posix" in pcretest.c that was not
2017 surrounded by "#if !defined NOPOSIX".
2018
2019 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2020 the cross-check on the old pcre_info() function, for the benefit of the
2021 cut-down version of PCRE that is currently imported into Exim.
2022
2023 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2024 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2025 patterns that start (?i) but I don't think that matters. The use of (?i) is
2026 just an example; this all applies to the other options as well.
2027
2028 4. Since libtool seems to echo the compile commands it is issuing, the output
2029 from "make" can be reduced a bit by putting "@" in front of each libtool
2030 compile command.
2031
2032 5. Patch from the folks at Google for configure.in to be a bit more thorough
2033 in checking for a suitable C++ installation before trying to compile the
2034 C++ stuff. This should fix a reported problem when a compiler was present,
2035 but no suitable headers.
2036
2037 6. The man pages all had just "PCRE" as their title. I have changed them to
2038 be the relevant file name. I have also arranged that these names are
2039 retained in the file doc/pcre.txt, which is a concatenation in text format
2040 of all the man pages except the little individual ones for each function.
2041
2042 7. The NON-UNIX-USE file had not been updated for the different set of source
2043 files that come with release 6. I also added a few comments about the C++
2044 wrapper.
2045
2046
2047 Version 6.0 07-Jun-05
2048 ---------------------
2049
2050 1. Some minor internal re-organization to help with my DFA experiments.
2051
2052 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2053 didn't matter for the library itself when fully configured, but did matter
2054 when compiling without UCP support, or within Exim, where the ucp files are
2055 not imported.
2056
2057 3. Refactoring of the library code to split up the various functions into
2058 different source modules. The addition of the new DFA matching code (see
2059 below) to a single monolithic source would have made it really too
2060 unwieldy, quite apart from causing all the code to be include in a
2061 statically linked application, when only some functions are used. This is
2062 relevant even without the DFA addition now that patterns can be compiled in
2063 one application and matched in another.
2064
2065 The downside of splitting up is that there have to be some external
2066 functions and data tables that are used internally in different modules of
2067 the library but which are not part of the API. These have all had their
2068 names changed to start with "_pcre_" so that they are unlikely to clash
2069 with other external names.
2070
2071 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2072 a different (DFA) algorithm. Although it is slower than the original
2073 function, it does have some advantages for certain types of matching
2074 problem.
2075
2076 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2077 including restarting after a partial match.
2078
2079 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2080 defined when compiling for Windows was sent to me. I have put it into the
2081 code, though I have no means of testing or verifying it.
2082
2083 7. Added the pcre_refcount() auxiliary function.
2084
2085 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2086 match before or at the first newline in the subject string. In pcretest,
2087 the /f option on a pattern can be used to set this.
2088
2089 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2090 would behave wrongly. This has been present in PCRE since release 4.0.
2091
2092 10. A number of changes to the pcregrep command:
2093
2094 (a) Refactored how -x works; insert ^(...)$ instead of setting
2095 PCRE_ANCHORED and checking the length, in preparation for adding
2096 something similar for -w.
2097
2098 (b) Added the -w (match as a word) option.
2099
2100 (c) Refactored the way lines are read and buffered so as to have more
2101 than one at a time available.
2102
2103 (d) Implemented a pcregrep test script.
2104
2105 (e) Added the -M (multiline match) option. This allows patterns to match
2106 over several lines of the subject. The buffering ensures that at least
2107 8K, or the rest of the document (whichever is the shorter) is available
2108 for matching (and similarly the previous 8K for lookbehind assertions).
2109
2110 (f) Changed the --help output so that it now says
2111
2112 -w, --word-regex(p)
2113
2114 instead of two lines, one with "regex" and the other with "regexp"
2115 because that confused at least one person since the short forms are the
2116 same. (This required a bit of code, as the output is generated
2117 automatically from a table. It wasn't just a text change.)
2118
2119 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2120 option but starts with a hyphen. Could be a pattern or a path name
2121 starting with a hyphen, for instance.
2122
2123 (h) "-" can be given as a file name to represent stdin.
2124
2125 (i) When file names are being printed, "(standard input)" is used for
2126 the standard input, for compatibility with GNU grep. Previously
2127 "<stdin>" was used.
2128
2129 (j) The option --label=xxx can be used to supply a name to be used for
2130 stdin when file names are being printed. There is no short form.
2131
2132 (k) Re-factored the options decoding logic because we are going to add
2133 two more options that take data. Such options can now be given in four
2134 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2135
2136 (l) Added the -A, -B, and -C options for requesting that lines of context
2137 around matches be printed.
2138
2139 (m) Added the -L option to print the names of files that do not contain
2140 any matching lines, that is, the complement of -l.
2141
2142 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2143 continue to scan other files.
2144
2145 (o) The -s option was incorrectly implemented. For compatibility with other
2146 greps, it now suppresses the error message for a non-existent or non-
2147 accessible file (but not the return code). There is a new option called
2148 -q that suppresses the output of matching lines, which was what -s was
2149 previously doing.
2150
2151 (p) Added --include and --exclude options to specify files for inclusion
2152 and exclusion when recursing.
2153
2154 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2155 Hopefully, it now does.
2156
2157 12. Missing cast in pcre_study().
2158
2159 13. Added an "uninstall" target to the makefile.
2160
2161 14. Replaced "extern" in the function prototypes in Makefile.in with
2162 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2163 world, but is set differently for Windows.
2164
2165 15. Added a second compiling function called pcre_compile2(). The only
2166 difference is that it has an extra argument, which is a pointer to an
2167 integer error code. When there is a compile-time failure, this is set
2168 non-zero, in addition to the error test pointer being set to point to an
2169 error message. The new argument may be NULL if no error number is required
2170 (but then you may as well call pcre_compile(), which is now just a
2171 wrapper). This facility is provided because some applications need a
2172 numeric error indication, but it has also enabled me to tidy up the way
2173 compile-time errors are handled in the POSIX wrapper.
2174
2175 16. Added VPATH=.libs to the makefile; this should help when building with one
2176 prefix path and installing with another. (Or so I'm told by someone who
2177 knows more about this stuff than I do.)
2178
2179 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2180 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2181 match everything, including newlines. This is not POSIX-compatible, but
2182 somebody wanted the feature. From pcretest it can be activated by using
2183 both the P and the s flags.
2184
2185 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2186
2187 19. libpcre.pc was being incorrectly installed as executable.
2188
2189 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2190 it now also looks for '\r' so that it will work unmodified on Windows.
2191
2192 21. Added Google's contributed C++ wrapper to the distribution.
2193
2194 22. Added some untidy missing memory free() calls in pcretest, to keep
2195 Electric Fence happy when testing.
2196
2197
2198
2199 Version 5.0 13-Sep-04
2200 ---------------------
2201
2202 1. Internal change: literal characters are no longer packed up into items
2203 containing multiple characters in a single byte-string. Each character
2204 is now matched using a separate opcode. However, there may be more than one
2205 byte in the character in UTF-8 mode.
2206
2207 2. The pcre_callout_block structure has two new fields: pattern_position and
2208 next_item_length. These contain the offset in the pattern to the next match
2209 item, and its length, respectively.
2210
2211 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2212 insertion of callouts before each pattern item. Added the /C option to
2213 pcretest to make use of this.
2214
2215 4. On the advice of a Windows user, the lines
2216
2217 #if defined(_WIN32) || defined(WIN32)
2218 _setmode( _fileno( stdout ), 0x8000 );
2219 #endif /* defined(_WIN32) || defined(WIN32) */
2220
2221 have been added to the source of pcretest. This apparently does useful
2222 magic in relation to line terminators.
2223
2224 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2225 for the benefit of those environments where the "b" makes a difference.
2226
2227 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2228 to know about it. I have put a hack into configure.in that adds in code
2229 to set GCC=yes if CC=icc. This seems to end up at a point in the
2230 generated configure script that is early enough to affect the setting of
2231 compiler options, which is what is needed, but I have no means of testing
2232 whether it really works. (The user who reported this had patched the
2233 generated configure script, which of course I cannot do.)
2234
2235 LATER: After change 22 below (new libtool files), the configure script
2236 seems to know about icc (and also ecc). Therefore, I have commented out
2237 this hack in configure.in.
2238
2239 7. Added support for pkg-config (2 patches were sent in).
2240
2241 8. Negated POSIX character classes that used a combination of internal tables
2242 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2243 [[:^ascii]]. Typically, they would match almost any characters. The other
2244 POSIX classes were not broken in this way.
2245
2246 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2247 to find the match, as PCRE was deluded into thinking that the match had to
2248 start at the start point or following a newline. The same bug applied to
2249 patterns with negative forward assertions or any backward assertions
2250 preceding ".*" at the start, unless the pattern required a fixed first
2251 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2252
2253 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2254 starting at the last subject character, bytes beyond the end of the subject
2255 string were read.
2256
2257 11. Renamed the variable "class" as "classbits" to make life easier for C++
2258 users. (Previously there was a macro definition, but it apparently wasn't
2259 enough.)
2260
2261 12. Added the new field "tables" to the extra data so that tables can be passed
2262 in at exec time, or the internal tables can be re-selected. This allows
2263 a compiled regex to be saved and re-used at a later time by a different
2264 program that might have everything at different addresses.
2265
2266 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2267 -R library as well as a -L library.
2268
2269 14. The debugging options of pcretest (-d on the command line or D on a
2270 pattern) showed incorrect output for anything following an extended class
2271 that contained multibyte characters and which was followed by a quantifier.
2272
2273 15. Added optional support for general category Unicode character properties
2274 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2275 support. It adds about 90K to the size of the library. The meanings of the
2276 inbuilt class escapes such as \d and \s have NOT been changed.
2277
2278 16. Updated pcredemo.c to include calls to free() to release the memory for the
2279 compiled pattern.
2280
2281 17. The generated file chartables.c was being created in the source directory
2282 instead of in the building directory. This caused the build to fail if the
2283 source directory was different from the building directory, and was
2284 read-only.
2285
2286 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2287 file. No doubt somebody will tell me if they don't make sense... Also added
2288 Dan Mooney's comments about building on OpenVMS.
2289
2290 19. Added support for partial matching via the PCRE_PARTIAL option for
2291 pcre_exec() and the \P data escape in pcretest.
2292
2293 20. Extended pcretest with 3 new pattern features:
2294
2295 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2296 write the compiled pattern to the file whose name is "rest-of-line".
2297 This is a straight binary dump of the data, with the saved pointer to
2298 the character tables forced to be NULL. The study data, if any, is
2299 written too. After writing, pcretest reads a new pattern.
2300
2301 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2302 compiled pattern from the given file. There must not be any
2303 occurrences of "<" in the file name (pretty unlikely); if there are,
2304 pcretest will instead treat the initial "<" as a pattern delimiter.
2305 After reading in the pattern, pcretest goes on to read data lines as
2306 usual.
2307
2308 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2309 and 16-bit fields in a compiled pattern, to simulate a pattern that
2310 was compiled on a host of opposite endianness.
2311
2312 21. The pcre-exec() function can now cope with patterns that were compiled on
2313 hosts of opposite endianness, with this restriction:
2314
2315 As for any compiled expression that is saved and used later, the tables
2316 pointer field cannot be preserved; the extra_data field in the arguments
2317 to pcre_exec() should be used to pass in a tables address if a value
2318 other than the default internal tables were used at compile time.
2319
2320 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2321 now diagnosed as an error. Previously, most of the time, a negative number
2322 would have been treated as zero, but if in addition "ovector" was passed as
2323 NULL, a crash could occur.
2324
2325 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2326 new versions from the libtool 1.5 distribution (the last one is a copy of
2327 a file called libtool.m4). This seems to have fixed the need to patch
2328 "configure" to support Darwin 1.3 (which I used to do). However, I still
2329 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2330 workstation).
2331
2332 24. Changed the PCRE licence to be the more standard "BSD" licence.
2333
2334
2335 Version 4.5 01-Dec-03
2336 ---------------------
2337
2338 1. There has been some re-arrangement of the code for the match() function so
2339 that it can be compiled in a version that does not call itself recursively.
2340 Instead, it keeps those local variables that need separate instances for
2341 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2342 needs to "recurse". Keeping track of where control must go is done by means
2343 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2344 hide most of the details from the main code, and operates only if
2345 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2346 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2347 operating.
2348
2349 To make it easier for callers to provide specially tailored get/free
2350 functions for this usage, two new functions, pcre_stack_malloc, and
2351 pcre_stack_free, are used. They are always called in strict stacking order,
2352 and the size of block requested is always the same.
2353
2354 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2355 PCRE has been compiled to use the stack or the heap for recursion. The
2356 -C option of pcretest uses this to show which version is compiled.
2357
2358 A new data escape \S, is added to pcretest; it causes the amounts of store
2359 obtained and freed by both kinds of malloc/free at match time to be added
2360 to the output.
2361
2362 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2363 what's available on my current Linux desktop machine.
2364
2365 3. When matching a UTF-8 string, the test for a valid string at the start has
2366 been extended. If start_offset is not zero, PCRE now checks that it points
2367 to a byte that is the start of a UTF-8 character. If not, it returns
2368 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2369 this is necessary because there may be backward assertions in the pattern.
2370 When matching the same subject several times, it may save resources to use
2371 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2372
2373 4. The code for checking the validity of UTF-8 strings has been tightened so
2374 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2375 containing "overlong sequences".
2376
2377 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2378 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2379 should have been "&", but it just so happened that all the cases this let
2380 through by mistake were picked up later in the function.
2381
2382 6. I had used a variable called "isblank" - this is a C99 function, causing
2383 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2384
2385 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2386 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2387 so the version is shown; (c) stop "make test" echoing "./RunTest".
2388
2389 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2390
2391 9. The prototype for memmove() for systems that don't have it was using
2392 size_t, but the inclusion of the header that defines size_t was later. I've
2393 moved the #includes for the C headers earlier to avoid this.
2394
2395 10. Added some adjustments to the code to make it easier to compiler on certain
2396 special systems:
2397
2398 (a) Some "const" qualifiers were missing.
2399 (b) Added the macro EXPORT before all exported functions; by default this
2400 is defined to be empty.
2401 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2402 that it reads its output file name as an argument instead of writing
2403 to the standard output and assuming this can be redirected.
2404
2405 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2406 class containing characters with values greater than 255, PCRE compilation
2407 went into a loop.
2408
2409 12. A recursive reference to a subpattern that was within another subpattern
2410 that had a minimum quantifier of zero caused PCRE to crash. For example,
2411 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2412 recursion. If the recursively-called subpattern itself had a zero repeat,
2413 that was OK.
2414
2415 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2416 buffer into which it was copied (for escape processing) was still set at
2417 1024, so long lines caused crashes.
2418
2419 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2420 "internal error: code overflow...". This applied to any character class
2421 that was followed by a possessive quantifier.
2422
2423 15. Modified the Makefile to add libpcre.la as a prerequisite for
2424 libpcreposix.la because I was told this is needed for a parallel build to
2425 work.
2426
2427 16. If a pattern that contained .* following optional items at the start was
2428 studied, the wrong optimizing data was generated, leading to matching
2429 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2430 matching string must start with a or b or c. The correct conclusion for
2431 this pattern is that a match can start with any character.
2432
2433
2434 Version 4.4 13-Aug-03
2435 ---------------------
2436
2437 1. In UTF-8 mode, a character class containing characters with values between
2438 127 and 255 was not handled correctly if the compiled pattern was studied.
2439 In fixing this, I have also improved the studying algorithm for such
2440 classes (slightly).
2441
2442 2. Three internal functions had redundant arguments passed to them. Removal
2443 might give a very teeny performance improvement.
2444
2445 3. Documentation bug: the value of the capture_top field in a callout is *one
2446 more than* the number of the hightest numbered captured substring.
2447
2448 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2449 in incorrectly linking with a previously installed version. They now link
2450 explicitly with libpcre.la.
2451
2452 5. configure.in no longer needs to recognize Cygwin specially.
2453
2454 6. A problem in pcre.in for Windows platforms is fixed.
2455
2456 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2457 pcretest, it used to include the size of the study block as part of its
2458 output. Unfortunately, the structure contains a field that has a different
2459 size on different hardware architectures. This meant that the tests that
2460 showed this size failed. As the block is currently always of a fixed size,
2461 this information isn't actually particularly useful in pcretest output, so
2462 I have just removed it.
2463
2464 8. Three pre-processor statements accidentally did not start in column 1.
2465 Sadly, there are *still* compilers around that complain, even though
2466 standard C has not required this for well over a decade. Sigh.
2467
2468 9. In pcretest, the code for checking callouts passed small integers in the
2469 callout_data field, which is a void * field. However, some picky compilers
2470 complained about the casts involved for this on 64-bit systems. Now
2471 pcretest passes the address of the small integer instead, which should get
2472 rid of the warnings.
2473
2474 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2475 both compile and run time, and gives an error if an invalid UTF-8 sequence
2476 is found. There is a option for disabling this check in cases where the
2477 string is known to be correct and/or the maximum performance is wanted.
2478
2479 11. In response to a bug report, I changed one line in Makefile.in from
2480
2481 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2482 to
2483 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2484
2485 to look similar to other lines, but I have no way of telling whether this
2486 is the right thing to do, as I do not use Windows. No doubt I'll get told
2487 if it's wrong...
2488
2489
2490 Version 4.3 21-May-03
2491 ---------------------
2492
2493 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2494 Makefile.
2495
2496 2. Some refactoring to improve the quality of the code:
2497
2498 (i) The utf8_table... variables are now declared "const".
2499
2500 (ii) The code for \cx, which used the "case flipping" table to upper case
2501 lower case letters, now just substracts 32. This is ASCII-specific,
2502 but the whole concept of \cx is ASCII-specific, so it seems
2503 reasonable.
2504
2505 (iii) PCRE was using its character types table to recognize decimal and
2506 hexadecimal digits in the pattern. This is silly, because it handles
2507 only 0-9, a-f, and A-F, but the character types table is locale-
2508 specific, which means strange things might happen. A private
2509 table is now used for this - though it costs 256 bytes, a table is
2510 much faster than multiple explicit tests. Of course, the standard
2511 character types table is still used for matching digits in subject
2512 strings against \d.
2513
2514 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2515 ending in _t are). So I've renamed it as ESC_tee.
2516
2517 3. The first argument for regexec() in the POSIX wrapper should have been
2518 defined as "const".
2519
2520 4. Changed pcretest to use malloc() for its buffers so that they can be
2521 Electric Fenced for debugging.
2522
2523 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2524 to read one or more bytes before the start of the subject string. Often this
2525 had no effect on PCRE's behaviour, but in some circumstances it could
2526 provoke a segmentation fault.
2527
2528 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2529 to try to read one or more bytes before the start of the subject string.
2530
2531 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2532 UTF-8 support could misbehave in various ways if the subject string
2533 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2534 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2535 back over UTF-8 characters.)
2536
2537
2538 Version 4.2 14-Apr-03
2539 ---------------------
2540
2541 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2542
2543 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2544 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2545 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2546 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2547 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2548 and BUILD_EXEEXT
2549 Note: automatic setting of the BUILD variables is not yet working
2550 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2551 compile-time but not at link-time
2552 [LINK]: use for linking executables only
2553 make different versions for Windows and non-Windows
2554 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2555 libraries
2556 [LINK_FOR_BUILD]: new variable
2557 [OBJEXT]: use throughout
2558 [EXEEXT]: use throughout
2559 <winshared>: new target
2560 <wininstall>: new target
2561 <dftables.o>: use native compiler
2562 <dftables>: use native linker
2563 <install>: handle Windows platform correctly
2564 <clean>: ditto
2565 <check>: ditto
2566 copy DLL to top builddir before testing
2567
2568 As part of these changes, -no-undefined was removed again. This was reported
2569 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2570 in any case.
2571
2572 3. Some tidies to get rid of compiler warnings:
2573
2574 . In the match_data structure, match_limit was an unsigned long int, whereas
2575 match_call_count was an int. I've made them both unsigned long ints.
2576
2577 . In pcretest the fact that a const uschar * doesn't automatically cast to
2578 a void * provoked a warning.
2579
2580 . Turning on some more compiler warnings threw up some "shadow" variables
2581 and a few more missing casts.
2582
2583 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2584 option, a class that contained a single character with a value between 128
2585 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2586
2587 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2588 option, a class that contained several characters, but with at least one
2589 whose value was between 128 and 255 caused PCRE to crash.
2590
2591
2592 Version 4.1 12-Mar-03
2593 ---------------------
2594
2595 1. Compiling with gcc -pedantic found a couple of places where casts were
2596 needed, and a string in dftables.c that was longer than standard compilers are
2597 required to support.
2598
2599 2. Compiling with Sun's compiler found a few more places where the code could
2600 be tidied up in order to avoid warnings.
2601
2602 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2603 first of these names is deprecated in the latest Autoconf in favour of the name
2604 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2605 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2606 analogy I have changed it to CFLAGS_FOR_BUILD.
2607
2608 4. Added -no-undefined to the linking command in the Makefile, because this is
2609 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2610 linking step for the pcreposix library.
2611
2612 5. PCRE was failing to diagnose the case of two named groups with the same
2613 name.
2614
2615 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2616 literal character that is needed in the subject for a match, and scans along to
2617 ensure that it is present before embarking on the full matching process. This
2618 saves time in cases of nested unlimited repeats that are never going to match.
2619 Problem: the scan can take a lot of time if the subject is very long (e.g.
2620 megabytes), thus penalizing straightforward matches. It is now done only if the
2621 amount of subject to be scanned is less than 1000 bytes.
2622
2623 7. A lesser problem with the same optimization is that it was recording the
2624 first character of an anchored pattern as "needed", thus provoking a search
2625 right along the subject, even when the first match of the pattern was going to
2626 fail. The "needed" character is now not set for anchored patterns, unless it
2627 follows something in the pattern that is of non-fixed length. Thus, it still
2628 fulfils its original purpose of finding quick non-matches in cases of nested
2629 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2630
2631
2632 Version 4.0 17-Feb-03
2633 ---------------------
2634
2635 1. If a comment in an extended regex that started immediately after a meta-item
2636 extended to the end of string, PCRE compiled incorrect data. This could lead to
2637 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2638
2639 2. Moved to autoconf 2.53 and libtool 1.4.2.
2640
2641 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2642 the special perltest8 script is no longer needed - all the tests can be run
2643 from a single perltest script.
2644
2645 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2646 by \s. It has now been removed in PCRE. This means it isn't recognized as
2647 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2648 class [:space:] *does* include VT, thereby creating a mess.
2649
2650 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2651 space and tab.
2652
2653 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2654 its new features into the main test script, reducing the number of scripts.
2655
2656 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2657 were backward compatible, and made the (?i) apply to the whole pattern, as if
2658 /i were given. Now it behaves more logically, and applies the option setting
2659 only to what follows. PCRE has been changed to follow suit. However, if it
2660 finds options settings right at the start of the pattern, it extracts them into
2661 the global options, as before. Thus, they show up in the info data.
2662
2663 8. Added support for the \Q...\E escape sequence. Characters in between are
2664 treated as literals. This is slightly different from Perl in that $ and @ are
2665 also handled as literals inside the quotes. In Perl, they will cause variable
2666 interpolation. Note the following examples:
2667
2668 Pattern PCRE matches Perl matches
2669
2670 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2671 \Qabc\$xyz\E abc\$xyz abc\$xyz
2672 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2673
2674 For compatibility with Perl, \Q...\E sequences are recognized inside character
2675 classes as well as outside them.
2676
2677 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2678 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2679 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2680 signed/unsigned warnings.
2681
2682 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2683 option for pcretest, so I've replaced it by a simple function that does just
2684 that job.
2685
2686 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2687 "pcregrep -".
2688
2689 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2690 Java package. This provides some syntactic sugar for simple cases of what my
2691 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2692 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2693 item, you can use this simplified notation. Note that only makes sense with
2694 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2695 greediness, whatever the setting of the PCRE_UNGREEDY option.
2696
2697 13. A change of greediness default within a pattern was not taking effect at
2698 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2699 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2700 was abstracted outside.
2701
2702 14. PCRE now supports the \G assertion. It is true when the current matching
2703 position is at the start point of the match. This differs from \A when the
2704 starting offset is non-zero. Used with the /g option of pcretest (or similar
2705 code), it works in the same way as it does for Perl's /g option. If all
2706 alternatives of a regex begin with \G, the expression is anchored to the start
2707 match position, and the "anchored" flag is set in the compiled expression.
2708
2709 15. Some bugs concerning the handling of certain option changes within patterns
2710 have been fixed. These applied to options other than (?ims). For example,
2711 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2712 been the other way round. Some of this was related to change 7 above.
2713
2714 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2715 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2716 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2717 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2718
2719 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2720 mode. Unlike ".", it always matches newline, whatever the setting of
2721 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2722 assertions. Perl allows it, but it doesn't (in general) work because it can't
2723 calculate the length of the lookbehind. At least, that's the case for Perl
2724 5.8.0 - I've been told they are going to document that it doesn't work in
2725 future.
2726
2727 18. Added an error diagnosis for escapes that PCRE does not support: these are
2728 \L, \l, \N, \P, \p, \U, \u, and \X.
2729
2730 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2731 reading past the end of the pattern in cases such as /[abcd/.
2732
2733 20. PCRE was getting more memory than necessary for patterns with classes that
2734 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2735
2736 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2737 compiling PCRE for use with Virtual Pascal.
2738
2739 22. Small fix to the Makefile to make it work properly if the build is done
2740 outside the source tree.
2741
2742 23. Added a new extension: a condition to go with recursion. If a conditional
2743 subpattern starts with (?(R) the "true" branch is used if recursion has
2744 happened, whereas the "false" branch is used only at the top level.
2745
2746 24. When there was a very long string of literal characters (over 255 bytes
2747 without UTF support, over 250 bytes with UTF support), the computation of how
2748 much memory was required could be incorrect, leading to segfaults or other
2749 strange effects.
2750
2751 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2752 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2753 there was a subsequent back reference to those brackets. This meant that, for
2754 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2755 possible to check for precisely this case. All we can do is abandon the
2756 optimization if .* occurs inside capturing brackets when there are any back
2757 references whatsoever. (See below for a better fix that came later.)
2758
2759 26. The handling of the optimization for finding the first character of a
2760 non-anchored pattern, and for finding a character that is required later in the
2761 match were failing in some cases. This didn't break the matching; it just
2762 failed to optimize when it could. The way this is done has been re-implemented.
2763
2764 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2765
2766 28. Added a new feature that provides some of the functionality that Perl
2767 provides with (?{...}). The facility is termed a "callout". The way it is done
2768 in PCRE is for the caller to provide an optional function, by setting
2769 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2770 global variable. By default it is unset, which disables all calling out. To get
2771 the function called, the regex must include (?C) at appropriate points. This
2772 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2773 This provides a means of identifying different callout points. When PCRE
2774 reaches such a point in the regex, if pcre_callout has been set, the external
2775 function is called. It is provided with data in a structure called
2776 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2777 matching continues; if it returns a non-zero value, the match at the current
2778 point fails. However, backtracking will occur if possible. [This was changed
2779 later and other features added - see item 49 below.]
2780
2781 29. pcretest is upgraded to test the callout functionality. It provides a
2782 callout function that displays information. By default, it shows the start of
2783 the match and the current position in the text. There are some new data escapes
2784 to vary what happens:
2785
2786 \C+ in addition, show current contents of captured substrings
2787 \C- do not supply a callout function
2788 \C!n return 1 when callout number n is reached
2789 \C!n!m return 1 when callout number n is reached for the mth time
2790
2791 30. If pcregrep was called with the -l option and just a single file name, it
2792 output "<stdin>" if a match was found, instead of the file name.
2793
2794 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2795 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2796 pcre_exec(). This saves a malloc/free per call. The default value of
2797 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2798 when configuring.
2799
2800 32. The default maximum size of a compiled pattern is 64K. There have been a
2801 few cases of people hitting this limit. The code now uses macros to handle the
2802 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2803 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2804 configuring. Tests 2 and 5 work only with 2-byte links because they output
2805 debugging information about compiled patterns.
2806
2807 33. Internal code re-arrangements:
2808
2809 (a) Moved the debugging function for printing out a compiled regex into
2810 its own source file (printint.c) and used #include to pull it into
2811 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2812 separate copies.
2813
2814 (b) Defined the list of op-code names for debugging as a macro in
2815 internal.h so that it is next to the definition of the opcodes.
2816
2817 (c) Defined a table of op-code lengths for simpler skipping along compiled
2818 code. This is again a macro in internal.h so that it is next to the
2819 definition of the opcodes.
2820
2821 34. Added support for recursive calls to individual subpatterns, along the
2822 lines of Robin Houston's patch (but implemented somewhat differently).
2823
2824 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2825 allow it to read and process whole directories in Win32. This code was
2826 contributed by Lionel Fourquaux; it has not been tested by me.
2827
2828 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2829 used to name a group. Names consist of alphanumerics and underscores, and must
2830 be unique. Back references use the syntax (?P=name) and recursive calls use
2831 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2832 numbers. The function pcre_fullinfo() can be used after compilation to extract
2833 a name/number map. There are three relevant calls:
2834
2835 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2836 PCRE_INFO_NAMECOUNT yields the number of entries
2837 PCRE_INFO_NAMETABLE yields a pointer to the map.
2838
2839 The map is a vector of fixed-size entries. The size of each entry depends on
2840 the length of the longest name used. The first two bytes of each entry are the
2841 group number, most significant byte first. There follows the corresponding
2842 name, zero terminated. The names are in alphabetical order.
2843
2844 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2845 case instead of 255. Making it the same both with and without UTF-8 support
2846 means that the same test output works with both.
2847
2848 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2849 calling malloc() with a zero argument.
2850
2851 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2852 optimization. I've improved things by keeping a bitmap of backreferences with
2853 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2854 fact referenced, the optimization can be applied. It is unlikely that a
2855 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2856 the match to follow \n) will appear inside brackets with a number greater than
2857 31, but if it does, any back reference > 31 suppresses the optimization.
2858
2859 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2860 of disabling numbered capturing parentheses. Any opening parenthesis that is
2861 not followed by ? behaves as if it were followed by ?: but named parentheses
2862 can still be used for capturing (and they will acquire numbers in the usual
2863 way).
2864
2865 41. Redesigned the return codes from the match() function into yes/no/error so
2866 that errors can be passed back from deep inside the nested calls. A malloc
2867 failure while inside a recursive subpattern call now causes the
2868 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2869
2870 42. It is now possible to set a limit on the number of times the match()
2871 function is called in a call to pcre_exec(). This facility makes it possible to
2872 limit the amount of recursion and backtracking, though not in a directly
2873 obvious way, because the match() function is used in a number of different
2874 circumstances. The count starts from zero for each position in the subject
2875 string (for non-anchored patterns). The default limit is, for compatibility, a
2876 large number, namely 10 000 000. You can change this in two ways:
2877
2878 (a) When configuring PCRE before making, you can use --with-match-limit=n
2879 to set a default value for the compiled library.
2880
2881 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2882 a different value is set. See 45 below.
2883
2884 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2885
2886 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2887 of things that can be changed at compile time. The first argument specifies
2888 what is wanted and the second points to where the information is to be placed.
2889 The current list of available information is:
2890
2891 PCRE_CONFIG_UTF8
2892
2893 The output is an integer that is set to one if UTF-8 support is available;
2894 otherwise it is set to zero.
2895
2896 PCRE_CONFIG_NEWLINE
2897
2898 The output is an integer that it set to the value of the code that is used for
2899 newline. It is either LF (10) or CR (13).
2900
2901 PCRE_CONFIG_LINK_SIZE
2902
2903 The output is an integer that contains the number of bytes used for internal
2904 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2905
2906 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2907
2908 The output is an integer that contains the threshold above which the POSIX
2909 interface uses malloc() for output vectors. See item 31 above.
2910
2911 PCRE_CONFIG_MATCH_LIMIT
2912
2913 The output is an unsigned integer that contains the default limit of the number
2914 of match() calls in a pcre_exec() execution. See 42 above.
2915
2916 44. pcretest has been upgraded by the addition of the -C option. This causes it
2917 to extract all the available output from the new pcre_config() function, and to
2918 output it. The program then exits immediately.
2919
2920 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2921 order to support additional features. One way would have been to define
2922 pcre_exec2() (for example) with extra arguments, but this would not have been
2923 extensible, and would also have required all calls to the original function to
2924 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2925 is used for passing in "extra" data from pcre_study().
2926
2927 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2928 contains the following fields:
2929
2930 flags a bitmap indicating which of the following fields are set
2931 study_data opaque data from pcre_study()
2932 match_limit a way of specifying a limit on match() calls for a specific
2933 call to pcre_exec()
2934 callout_data data for callouts (see 49 below)
2935
2936 The flag bits are also defined in pcre.h, and are
2937
2938 PCRE_EXTRA_STUDY_DATA
2939 PCRE_EXTRA_MATCH_LIMIT
2940 PCRE_EXTRA_CALLOUT_DATA
2941
2942 The pcre_study() function now returns one of these new pcre_extra blocks, with
2943 the actual study data pointed to by the study_data field, and the
2944 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2945 before. That is, this change is entirely upwards-compatible and requires no
2946 change to existing code.
2947
2948 If you want to pass in additional data to pcre_exec(), you can either place it
2949 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2950 block.
2951
2952 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2953 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2954 times with different match limits, until it finds the minimum value needed for
2955 pcre_exec() to complete. The value is then output. This can be instructive; for
2956 most simple matches the number is quite small, but for pathological cases it
2957 gets very large very quickly.
2958
2959 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2960 returns the size of the data block pointed to by the study_data field in a
2961 pcre_extra block, that is, the value that was passed as the argument to
2962 pcre_malloc() when PCRE was getting memory in which to place the information
2963 created by pcre_study(). The fourth argument should point to a size_t variable.
2964 pcretest has been extended so that this information is shown after a successful
2965 pcre_study() call when information about the compiled regex is being displayed.
2966
2967 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2968 because what follows is always an absolute path. (Later: it turns out that this
2969 is more than cosmetic for MinGW, because it doesn't like empty path
2970 components.)
2971
2972 49. Some changes have been made to the callout feature (see 28 above):
2973
2974 (i) A callout function now has three choices for what it returns:
2975
2976 0 => success, carry on matching
2977 > 0 => failure at this point, but backtrack if possible
2978 < 0 => serious error, return this value from pcre_exec()
2979
2980 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2981 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2982 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2983 use by callout functions. It will never be used by PCRE itself.
2984
2985 (ii) The pcre_extra structure (see 45 above) has a void * field called
2986 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2987 pcre_callout_block structure has a field of the same name. The contents of
2988 the field passed in the pcre_extra structure are passed to the callout
2989 function in the corresponding field in the callout block. This makes it
2990 easier to use the same callout-containing regex from multiple threads. For
2991 testing, the pcretest program has a new data escape
2992
2993 \C*n pass the number n (may be negative) as callout_data
2994
2995 If the callout function in pcretest receives a non-zero value as
2996 callout_data, it returns that value.
2997
2998 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2999 there were some redundant $(CFLAGS) in commands that are now specified as
3000 $(LINK), which already includes $(CFLAGS).
3001
3002 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3003 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3004 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3005 one-byte characters throughout. Note that case-insensitive matching applies
3006 only to characters whose values are less than 256. PCRE doesn't support the
3007 notion of cases for higher-valued characters.
3008
3009 (i) A character class whose characters are all within 0-255 is handled as
3010 a bit map, and the map is inverted for negative classes. Previously, a
3011 character > 255 always failed to match such a class; however it should
3012 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3013
3014 (ii) A negated character class with a single character < 255 is coded as
3015 "not this character" (OP_NOT). This wasn't working properly when the test
3016 character was multibyte, either singly or repeated.
3017
3018 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3019 mode, for example: \x{100}{2,3}.
3020
3021 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3022 singly or repeated) now correctly test multibyte characters. However,
3023 PCRE doesn't recognize any characters with values greater than 255 as
3024 digits, spaces, or word characters. Such characters always match \D, \S,
3025 and \W, and never match \d, \s, or \w.
3026
3027 (v) Classes may now contain characters and character ranges with values
3028 greater than 255. For example: [ab\x{100}-\x{400}].
3029
3030 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3031 PCRE in UTF-8 mode.
3032
3033 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3034 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3035 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3036 value.)
3037
3038 53. The single man page has become too large. I have therefore split it up into
3039 a number of separate man pages. These also give rise to individual HTML pages;
3040 these are now put in a separate directory, and there is an index.html page that
3041 lists them all. Some hyperlinking between the pages has been installed.
3042
3043 54. Added convenience functions for handling named capturing parentheses.
3044
3045 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3046 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3047 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3048 are faulted.
3049
3050 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3051 calling configure. These values are used when compiling the dftables.c program
3052 which is run to generate the source of the default character tables. They
3053 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3054 you will need to set these values.
3055
3056 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3057
3058
3059 Version 3.9 02-Jan-02
3060 ---------------------
3061
3062 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3063
3064 2. If --disable-static was given, the building process failed when trying to
3065 build pcretest and pcregrep. (For some reason it was using libtool to compile
3066 them, which is not right, as they aren't part of the library.)
3067
3068
3069 Version 3.8 18-Dec-01
3070 ---------------------
3071
3072 1. The experimental UTF-8 code was completely screwed up. It was packing the
3073 bytes in the wrong order. How dumb can you get?
3074
3075
3076 Version 3.7 29-Oct-01
3077 ---------------------
3078
3079 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3080 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3081 this didn't happen under Solaris 8, where I normally test things.
3082
3083 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3084 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3085 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3086 this fix an hour or so after the initial 3.7 release.)
3087
3088
3089 Version 3.6 23-Oct-01
3090 ---------------------
3091
3092 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3093 offsets passed as NULL with zero offset count.
3094
3095 2. The config.guess and config.sub files had not been updated when I moved to
3096 the latest autoconf.
3097
3098
3099 Version 3.5 15-Aug-01
3100 ---------------------
3101
3102 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3103 had been forgotten.
3104
3105 2. By using declared but undefined structures, we can avoid using "void"
3106 definitions in pcre.h while keeping the internal definitions of the structures
3107 private.
3108
3109 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3110 user point of view, this means that both static and shared libraries are built
3111 by default, but this can be individually controlled. More of the work of
3112 handling this static/shared cases is now inside libtool instead of PCRE's make
3113 file.
3114
3115 4. The pcretest utility is now installed along with pcregrep because it is
3116 useful for users (to test regexs) and by doing this, it automatically gets
3117 relinked by libtool. The documentation has been turned into a man page, so
3118 there are now .1, .txt, and .html versions in /doc.
3119
3120 5. Upgrades to pcregrep:
3121 (i) Added long-form option names like gnu grep.
3122 (ii) Added --help to list all options with an explanatory phrase.
3123 (iii) Added -r, --recursive to recurse into sub-directories.
3124 (iv) Added -f, --file to read patterns from a file.
3125
3126 6. pcre_exec() was referring to its "code" argument before testing that
3127 argument for NULL (and giving an error if it was NULL).
3128
3129 7. Upgraded Makefile.in to allow for compiling in a different directory from
3130 the source directory.
3131
3132 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3133 options bits, the pointer it was passed was to an int instead of to an unsigned
3134 long int. This mattered only on 64-bit systems.
3135
3136 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3137 generated) instead of pcre.in, which it its source. Also made the same change
3138 in several of the .c files.
3139
3140 10. A new release of gcc defines printf() as a macro, which broke pcretest
3141 because it had an ifdef in the middle of a string argument for printf(). Fixed
3142 by using separate calls to printf().
3143
3144 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3145 script, to force use of CR or LF instead of \n in the source. On non-Unix
3146 systems, the value can be set in config.h.
3147
3148 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3149 absolute limit. Changed the text of the error message to make this clear, and
3150 likewise updated the man page.
3151
3152 13. The limit of 99 on the number of capturing subpatterns has been removed.
3153 The new limit is 65535, which I hope will not be a "real" limit.
3154
3155
3156 Version 3.4 22-Aug-00
3157 ---------------------
3158
3159 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3160
3161 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3162
3163
3164 Version 3.3 01-Aug-00
3165 ---------------------
3166
3167 1. If an octal character was given, but the value was greater than \377, it
3168 was not getting masked to the least significant bits, as documented. This could
3169 lead to crashes in some systems.
3170
3171 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3172 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3173
3174 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3175 These just pass their arguments on to (pcre_free)(), but they are provided
3176 because some uses of PCRE bind it to non-C systems that can call its functions,
3177 but cannot call free() or pcre_free() directly.
3178
3179 4. Add "make test" as a synonym for "make check". Corrected some comments in
3180 the Makefile.
3181
3182 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3183 Makefile.
3184
3185 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3186 command called pgrep for grepping around the active processes.
3187
3188 7. Added the beginnings of support for UTF-8 character strings.
3189
3190 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3191 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3192 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3193 out for the ar command.)
3194
3195
3196 Version 3.2 12-May-00
3197 ---------------------
3198
3199 This is purely a bug fixing release.
3200
3201 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3202 of ZA. This was just one example of several cases that could provoke this bug,
3203 which was introduced by change 9 of version 2.00. The code for breaking
3204 infinite loops after an iteration that matches an empty string was't working
3205 correctly.
3206
3207 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3208 when matched against abbab (for example). After matching an empty string, it
3209 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3210 caused it to match further down the string than it should.
3211
3212 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3213 was there because it doesn't seem to be needed, and it causes trouble on some
3214 systems, as it is not a Standard C header. It has been removed.
3215
3216 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3217 were reported on the Macintosh. The changes were from
3218
3219 while ((c = *(++ptr)) != 0 && c != '\n');
3220 to
3221 while ((c = *(++ptr)) != 0 && c != '\n') ;
3222
3223 Totally extraordinary, but if that's what it takes...
3224
3225 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3226 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3227 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3228 assumes the way PCRE uses memmove() (always moving upwards).
3229
3230 6. PCRE is being used in one environment where strchr() is not available. There
3231 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3232 faster code anyway.
3233
3234
3235 Version 3.1 09-Feb-00
3236 ---------------------
3237
3238 The only change in this release is the fixing of some bugs in Makefile.in for
3239 the "install" target:
3240
3241 (1) It was failing to install pcreposix.h.
3242
3243 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3244
3245
3246 Version 3.0 01-Feb-00
3247 ---------------------
3248
3249 1. Add support for the /+ modifier to perltest (to output $` like it does in
3250 pcretest).
3251
3252 2. Add support for the /g modifier to perltest.
3253
3254 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3255 matches null strings.
3256
3257 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3258 pattern. Perl treats empty patterns specially - it reuses the most recent
3259 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3260 effect.
3261
3262 5. The POSIX interface was broken in that it was just handing over the POSIX
3263 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3264 required a bigger vector, with some working space on the end. This means that
3265 the POSIX wrapper now has to get and free some memory, and copy the results.
3266
3267 6. Added some simple autoconf support, placing the test data and the
3268 documentation in separate directories, re-organizing some of the
3269 information files, and making it build pcre-config (a GNU standard). Also added
3270 libtool support for building PCRE as a shared library, which is now the
3271 default.
3272
3273 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3274 09 are not valid octal constants. Single digits will be used for minor values
3275 less than 10.
3276
3277 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3278 existing programs that set these in the POSIX interface can use PCRE without
3279 modification.
3280
3281 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3282 return all that pcre_info() returns, plus additional data. The pcre_info()
3283 function is retained for compatibility, but is considered to be obsolete.
3284
3285 10. Added experimental recursion feature (?R) to handle one common case that
3286 Perl 5.6 will be able to do with (?p{...}).
3287
3288 11. Added support for POSIX character classes like [:alpha:], which Perl is
3289 adopting.
3290
3291
3292 Version 2.08 31-Aug-99
3293 ----------------------
3294
3295 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3296 trying to match at the startoffset position, but instead was moving forward to
3297 the next newline as if a previous match had failed.
3298
3299 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3300 and could get into a loop if a null string was matched other than at the start
3301 of the subject.
3302
3303 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3304 be distinguished at compile time, and for completeness also added PCRE_DATE.
3305
3306 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3307 in GnuWin32 environments.
3308
3309
3310 Version 2.07 29-Jul-99
3311 ----------------------
3312
3313 1. The documentation is now supplied in plain text form and HTML as well as in
3314 the form of man page sources.
3315
3316 2. C++ compilers don't like assigning (void *) values to other pointer types.
3317 In particular this affects malloc(). Although there is no problem in Standard
3318 C, I've put in casts to keep C++ compilers happy.
3319
3320 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3321 should be (const char *).
3322
3323 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3324 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3325 However, I haven't made this a standard facility. The documentation doesn't
3326 mention it, and the Makefile doesn't support it.
3327
3328 5. The Makefile now contains an "install" target, with editable destinations at
3329 the top of the file. The pcretest program is not installed.
3330
3331 6. pgrep -V now gives the PCRE version number and date.
3332
3333 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3334 causing the entire string to be ignored, instead of just the last character.
3335
3336 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3337 non-matching string, it can take a very, very long time, even for strings of
3338 quite modest length, because of the nested recursion. PCRE now does better in
3339 some of these cases. It does this by remembering the last required literal
3340 character in the pattern, and pre-searching the subject to ensure it is present
3341 before running the real match. In other words, it applies a heuristic to detect
3342 some types of certain failure quickly, and in the above example, if presented
3343 with a string that has no trailing " it gives "no match" very quickly.
3344
3345 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3346 other alternatives are tried instead.
3347
3348
3349 Version 2.06 09-Jun-99
3350 ----------------------
3351
3352 1. Change pcretest's output for amount of store used to show just the code
3353 space, because the remainder (the data block) varies in size between 32-bit and
3354 64-bit systems.
3355
3356 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3357 start matching at. This allows lookbehinds to work when searching for multiple
3358 occurrences in a string.
3359
3360 3. Added additional options to pcretest for testing multiple occurrences:
3361
3362 /+ outputs the rest of the string that follows a match
3363 /g loops for multiple occurrences, using the new startoffset argument
3364 /G loops for multiple occurrences by passing an incremented pointer
3365
3366 4. PCRE wasn't doing the "first character" optimization for patterns starting
3367 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3368 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3369 the letter 'x'. On long subject strings, this gives a significant speed-up.
3370
3371
3372 Version 2.05 21-Apr-99
3373 ----------------------
3374
3375 1. Changed the type of magic_number from int to long int so that it works
3376 properly on 16-bit systems.
3377
3378 2. Fixed a bug which caused patterns starting with .* not to work correctly
3379 when the subject string contained newline characters. PCRE was assuming
3380 anchoring for such patterns in all cases, which is not correct because .* will
3381 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3382 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3383 must be retried after every newline in the subject.
3384
3385
3386 Version 2.04 18-Feb-99
3387 ----------------------
3388
3389 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3390 computation of the store needed to hold the pattern was incorrect (too large).
3391 If such patterns were nested a few deep, this could multiply and become a real
3392 problem.
3393
3394 2. Added /M option to pcretest to show the memory requirement of a specific
3395 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3396
3397 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3398 compiled in such a way that the backtracking after subsequent failure was
3399 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3400 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3401
3402
3403 Version 2.03 02-Feb-99
3404 ----------------------
3405
3406 1. Fixed typo and small mistake in man page.
3407
3408 2. Added 4th condition (GPL supersedes if conflict) and created separate
3409 LICENCE file containing the conditions.
3410
3411 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3412 Perl, that is the internal \ allows the delimiter to be included in the
3413 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3414 the final delimiter, add \ to the end of the pattern (to test the error).
3415
3416 4. Added the convenience functions for extracting substrings after a successful
3417 match. Updated pcretest to make it able to test these functions.
3418
3419
3420 Version 2.02 14-Jan-99
3421 ----------------------
3422
3423 1. Initialized the working variables associated with each extraction so that
3424 their saving and restoring doesn't refer to uninitialized store.
3425
3426 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3427 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3428 fix the problem.
3429
3430 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3431 calls, and wasn't printing the correct value for compiling calls. Increased the
3432 default value of LOOPREPEAT, and the number of significant figures in the
3433 times.
3434
3435 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3436
3437 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3438 a building problem on Windows NT with a FAT file system.
3439
3440
3441 Version 2.01 21-Oct-98
3442 ----------------------
3443
3444 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3445 to character tables built by pcre_maketables() in the current locale. If NULL
3446 is passed, the default tables are used.
3447
3448
3449 Version 2.00 24-Sep-98
3450 ----------------------
3451
3452 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3453 it any more.
3454
3455 2. Allow quantification of (?>) groups, and make it work correctly.
3456
3457 3. The first character computation wasn't working for (?>) groups.
3458
3459 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3460 end of the subject) and add 5.005's \z, which really does match only at the
3461 very end of the subject.
3462
3463 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3464
3465 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3466 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3467 localized options. All options to pcre_study() were also removed.
3468
3469 7. Add other new features from 5.005:
3470
3471 $(?<= positive lookbehind
3472 $(?<! negative lookbehind
3473 (?imsx-imsx) added the unsetting capability
3474 such a setting is global if at outer level; local otherwise
3475 (?imsx-imsx:) non-capturing groups with option setting
3476 (?(cond)re|re) conditional pattern matching
3477
3478 A backreference to itself in a repeated group matches the previous
3479 captured string.
3480
3481 8. General tidying up of studying (both automatic and via "study")
3482 consequential on the addition of new assertions.
3483
3484 9. As in 5.005, unlimited repeated groups that could match an empty substring
3485 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3486 runtime if any iteration does actually match an empty substring.
3487
3488 10. Include the RunTest script in the distribution.
3489
3490 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3491 discrepancies, some of which were old and were also with respect to 5.004. They
3492 have now been fixed.
3493
3494
3495 Version 1.09 28-Apr-98
3496 ----------------------
3497
3498 1. A negated single character class followed by a quantifier with a minimum
3499 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3500 program crashes, or just wrong answers. This did not apply to negated classes
3501 containing more than one character, or to minima other than one.
3502
3503
3504 Version 1.08 27-Mar-98
3505 ----------------------
3506
3507 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3508
3509 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3510 latter must appear before anything that relies on it in the pattern.
3511
3512
3513 Version 1.07 16-Feb-98
3514 ----------------------
3515
3516 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3517 repeat of a potentially empty string).
3518
3519
3520 Version 1.06 23-Jan-98
3521 ----------------------
3522
3523 1. Added Markus Oberhumer's little patches for C++.
3524
3525 2. Literal strings longer than 255 characters were broken.
3526
3527
3528 Version 1.05 23-Dec-97
3529 ----------------------
3530
3531 1. Negated character classes containing more than one character were failing if
3532 PCRE_CASELESS was set at run time.
3533
3534
3535 Version 1.04 19-Dec-97
3536 ----------------------
3537
3538 1. Corrected the man page, where some "const" qualifiers had been omitted.
3539
3540 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3541 input syntax.
3542
3543 3. Fixed memory leak which occurred when a regex with back references was
3544 matched with an offsets vector that wasn't big enough. The temporary memory
3545 that is used in this case wasn't being freed if the match failed.
3546
3547 4. Tidied pcretest to ensure it frees memory that it gets.
3548
3549 5. Temporary memory was being obtained in the case where the passed offsets
3550 vector was exactly big enough.
3551
3552 6. Corrected definition of offsetof() from change 5 below.
3553
3554 7. I had screwed up change 6 below and broken the rules for the use of
3555 setjmp(). Now fixed.
3556
3557
3558 Version 1.03 18-Dec-97
3559 ----------------------
3560
3561 1. A erroneous regex with a missing opening parenthesis was correctly
3562 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3563 on some systems.
3564
3565 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3566 it was reported that one broken compiler failed on the former because "code" is
3567 also an independent variable.
3568
3569 3. The erroneous regex a[]b caused an array overrun reference.
3570
3571 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3572 fail on data ending with that character. (It was going on too far, and checking
3573 the next character, typically a binary zero.) This was specific to the
3574 optimized code for single-character negative classes.
3575
3576 5. Added a contributed patch from the TIN world which does the following:
3577
3578 + Add an undef for memmove, in case the the system defines a macro for it.
3579
3580 + Add a definition of offsetof(), in case there isn't one. (I don't know
3581 the reason behind this - offsetof() is part of the ANSI standard - but
3582 it does no harm).
3583
3584 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3585 most of the places where whitespace preceded '#'. I have given up and
3586 allowed the remaining 2 cases to be at the margin.
3587
3588 + Rename some variables in pcre to eliminate shadowing. This seems very
3589 pedantic, but does no harm, of course.
3590
3591 6. Moved the call to setjmp() into its own function, to get rid of warnings
3592 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3593
3594 7. Constructs such as \d{8,} were compiling into the equivalent of
3595 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3596 outcome, but in this particular case used more store than had been allocated,
3597 which caused the bug to be discovered because it threw up an internal error.
3598
3599 8. The debugging code in both pcre and pcretest for outputting the compiled
3600 form of a regex was going wrong in the case of back references followed by
3601 curly-bracketed repeats.
3602
3603
3604 Version 1.02 12-Dec-97
3605 ----------------------
3606
3607 1. Typos in pcre.3 and comments in the source fixed.
3608
3609 2. Applied a contributed patch to get rid of places where it used to remove
3610 'const' from variables, and fixed some signed/unsigned and uninitialized
3611 variable warnings.
3612
3613 3. Added the "runtest" target to Makefile.
3614
3615 4. Set default compiler flag to -O2 rather than just -O.
3616
3617
3618 Version 1.01 19-Nov-97
3619 ----------------------
3620
3621 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3622 like /([ab]*)*/, that is, for classes with more than one character in them.
3623
3624 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3625 as /((?>a*))*/ (a PCRE_EXTRA facility).
3626
3627
3628 Version 1.00 18-Nov-97
3629 ----------------------
3630
3631 1. Added compile-time macros to support systems such as SunOS4 which don't have
3632 memmove() or strerror() but have other things that can be used instead.
3633
3634 2. Arranged that "make clean" removes the executables.
3635
3636
3637 Version 0.99 27-Oct-97
3638 ----------------------
3639
3640 1. Fixed bug in code for optimizing classes with only one character. It was
3641 initializing a 32-byte map regardless, which could cause it to run off the end
3642 of the memory it had got.
3643
3644 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3645
3646
3647 Version 0.98 22-Oct-97
3648 ----------------------
3649
3650 1. Fixed bug in code for handling temporary memory usage when there are more
3651 back references than supplied space in the ovector. This could cause segfaults.
3652
3653
3654 Version 0.97 21-Oct-97
3655 ----------------------
3656
3657 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3658
3659 2. Optimized negated single characters not to use a bit map.
3660
3661 3. Brought error texts together as macro definitions; clarified some of them;
3662 fixed one that was wrong - it said "range out of order" when it meant "invalid
3663 escape sequence".
3664
3665 4. Changed some char * arguments to const char *.
3666
3667 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3668
3669 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3670 pcretest.
3671
3672
3673 Version 0.96 16-Oct-97
3674 ----------------------
3675
3676 1. Added a simple "pgrep" utility to the distribution.
3677
3678 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3679 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3680 where "ddd" means "one or more decimal digits".
3681
3682 3. Fixed serious bug. If a pattern had a back reference, but the call to
3683 pcre_exec() didn't supply a large enough ovector to record the related
3684 identifying subpattern, the match always failed. PCRE now remembers the number
3685 of the largest back reference, and gets some temporary memory in which to save
3686 the offsets during matching if necessary, in order to ensure that
3687 backreferences always work.
3688
3689 4. Increased the compatibility with Perl in a number of ways:
3690
3691 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3692 to request this handling. The option can be set at compile or exec time.
3693
3694 (b) $ matches before a terminating newline by default; an option
3695 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3696 mode). The option can be set at compile or exec time.
3697
3698 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3699 the same as Perl's. If the decimal number it represents is less than 10
3700 or there aren't that many previous left capturing parentheses, an octal
3701 escape is read. Inside a character class, it's always an octal escape,
3702 even if it is a single digit.
3703
3704 (d) An escaped but undefined alphabetic character is taken as a literal,
3705 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3706 escapes.
3707
3708 (e) {0} is now permitted. (The previous item is removed from the compiled
3709 pattern).
3710
3711 5. Changed all the names of code files so that the basic parts are no longer
3712 than 10 characters, and abolished the teeny "globals.c" file.
3713
3714 6. Changed the handling of character classes; they are now done with a 32-byte
3715 bit map always.
3716
3717 7. Added the -d and /D options to pcretest to make it possible to look at the
3718 internals of compilation without having to recompile pcre.
3719
3720
3721 Version 0.95 23-Sep-97
3722 ----------------------
3723
3724 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3725 \x20 at the start of a run of normal characters. These were being treated as
3726 real characters, instead of the source characters being re-checked.
3727
3728
3729 Version 0.94 18-Sep-97
3730 ----------------------
3731
3732 1. The functions are now thread-safe, with the caveat that the global variables
3733 containing pointers to malloc() and free() or alternative functions are the
3734 same for all threads.
3735
3736 2. Get pcre_study() to generate a bitmap of initial characters for non-
3737 anchored patterns when this is possible, and use it if passed to pcre_exec().
3738
3739
3740 Version 0.93 15-Sep-97
3741 ----------------------
3742
3743 1. /(b)|(:+)/ was computing an incorrect first character.
3744
3745 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3746 but not actually doing anything yet.
3747
3748 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3749 as Perl does (e.g. [-az] or [az-]).
3750
3751 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3752 all possible positions.
3753
3754 5. Split up into different modules to avoid including unneeded functions in a
3755 compiled binary. However, compile and exec are still in one module. The "study"
3756 function is split off.
3757
3758 6. The character tables are now in a separate module whose source is generated
3759 by an auxiliary program - but can then be edited by hand if required. There are
3760 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3761 toupper() in the code.
3762
3763 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3764 make them global. Abolish the function for setting them, as the caller can now
3765 set them directly.
3766
3767
3768 Version 0.92 11-Sep-97
3769 ----------------------
3770
3771 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3772 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3773
3774 2. Caseless matching was not working in character classes if the characters in
3775 the pattern were in upper case.
3776
3777 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3778
3779 4. Make PCRE_ANCHORED public and accept as a compile option.
3780
3781 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3782 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3783 pass them.
3784
3785 6. Give an error if bad option bits passed at compile or run time.
3786
3787 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3788 pcretest to cause it to pass that flag.
3789
3790 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3791 options, and the first character, if set.
3792
3793 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3794
3795
3796 Version 0.91 10-Sep-97
3797 ----------------------
3798
3799 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3800 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3801
3802 2. PCRE was looping on encountering an indefinitely repeated back reference to
3803 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3804 Perl does - treats the match as successful.
3805
3806 ****

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