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Revision 493 - (show annotations) (download)
Tue Mar 2 11:37:21 2010 UTC (4 years, 4 months ago) by ph10
File size: 181904 byte(s)
Updated licensing terms in pcregexp.pas

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 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
10 configured.
11
12 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
13 original author of that file, following a query about its status.
14
15
16 Version 8.01 19-Jan-2010
17 ------------------------
18
19 1. If a pattern contained a conditional subpattern with only one branch (in
20 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
21 computed the wrong minimum data length (which is of course zero for such
22 subpatterns). This could cause incorrect "no match" results.
23
24 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
25 the pattern is reset in the first branch, pcre_compile() failed with
26 "internal error: code overflow at offset...". This happened only when
27 the reset was to the original external option setting. (An optimization
28 abstracts leading options settings into an external setting, which was the
29 cause of this.)
30
31 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
32 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
33 assertion pattern did not match (meaning that the assertion was true), it
34 was incorrectly treated as false if the SKIP had been reached during the
35 matching. This also applied to assertions used as conditions.
36
37 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
38 assertion subpattern, including such a pattern used as a condition,
39 unpredictable results occurred, instead of the error return
40 PCRE_ERROR_DFA_UITEM.
41
42 5. The C++ GlobalReplace function was not working like Perl for the special
43 situation when an empty string is matched. It now does the fancy magic
44 stuff that is necessary.
45
46 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
47 removed. (These were left over from very, very early versions of PCRE.)
48
49 7. Some cosmetic changes to the code to make life easier when compiling it
50 as part of something else:
51
52 (a) Change DEBUG to PCRE_DEBUG.
53
54 (b) In pcre_compile(), rename the member of the "branch_chain" structure
55 called "current" as "current_branch", to prevent a collision with the
56 Linux macro when compiled as a kernel module.
57
58 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
59 prevent a collision with the Linux macro when compiled as a kernel
60 module.
61
62 8. In pcre_compile() there are some checks for integer overflows that used to
63 cast potentially large values to (double). This has been changed to that
64 when building, a check for int64_t is made, and if it is found, it is used
65 instead, thus avoiding the use of floating point arithmetic. (There is no
66 other use of FP in PCRE.) If int64_t is not found, the fallback is to
67 double.
68
69 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
70 2005 (difference between two addresses compared to an unsigned value).
71
72 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
73 custom one, because of the following reported problem in Windows:
74
75 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
76 under Win32.
77 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
78 therefore missing the function definition.
79 - The compiler thus generates a "C" signature for the test function.
80 - The linker fails to find the "C" function.
81 - PCRE fails to configure if asked to do so against libbz2.
82
83 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
84 messages were output:
85
86 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
87 rerunning libtoolize, to keep the correct libtool macros in-tree.
88 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
89
90 I have done both of these things.
91
92 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
93 most of the time, it *can* run out if it is given a pattern that contains a
94 runaway infinite recursion. I updated the discussion in the pcrestack man
95 page.
96
97 13. Now that we have gone to the x.xx style of version numbers, the minor
98 version may start with zero. Using 08 or 09 is a bad idea because users
99 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
100 interpreted as invalid octal numbers. I've updated the previous comment in
101 configure.ac, and also added a check that gives an error if 08 or 09 are
102 used.
103
104 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
105 causing partial matching to fail when the end of the subject matched \W
106 in a UTF-8 pattern where \W was quantified with a minimum of 3.
107
108 15. There were some discrepancies between the declarations in pcre_internal.h
109 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
110 their definitions. The declarations used "const uschar *" and the
111 definitions used USPTR. Even though USPTR is normally defined as "const
112 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
113 reported that: "This difference in casting confuses some C++ compilers, for
114 example, SunCC recognizes above declarations as different functions and
115 generates broken code for hbpcre." I have changed the declarations to use
116 USPTR.
117
118 16. GNU libtool is named differently on some systems. The autogen.sh script now
119 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
120 (FreeBSD).
121
122 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
123 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
124 comment: "Figure out how to create a longlong from a string: strtoll and
125 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
126 instance, but it only takes 2 args instead of 3!"
127
128 18. A subtle bug concerned with back references has been fixed by a change of
129 specification, with a corresponding code fix. A pattern such as
130 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
131 refers, was giving matches when it shouldn't. For example, xa=xaaa would
132 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
133 same bug. Such groups have to be quantified to be useful, or contained
134 inside another quantified group. (If there's no repetition, the reference
135 can never match.) The problem arises because, having left the group and
136 moved on to the rest of the pattern, a later failure that backtracks into
137 the group uses the captured value from the final iteration of the group
138 rather than the correct earlier one. I have fixed this in PCRE by forcing
139 any group that contains a reference to itself to be an atomic group; that
140 is, there cannot be any backtracking into it once it has completed. This is
141 similar to recursive and subroutine calls.
142
143
144 Version 8.00 19-Oct-09
145 ----------------------
146
147 1. The table for translating pcre_compile() error codes into POSIX error codes
148 was out-of-date, and there was no check on the pcre_compile() error code
149 being within the table. This could lead to an OK return being given in
150 error.
151
152 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
153 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
154 in a Windows environment.
155
156 3. The pcregrep --count option prints the count for each file even when it is
157 zero, as does GNU grep. However, pcregrep was also printing all files when
158 --files-with-matches was added. Now, when both options are given, it prints
159 counts only for those files that have at least one match. (GNU grep just
160 prints the file name in this circumstance, but including the count seems
161 more useful - otherwise, why use --count?) Also ensured that the
162 combination -clh just lists non-zero counts, with no names.
163
164 4. The long form of the pcregrep -F option was incorrectly implemented as
165 --fixed_strings instead of --fixed-strings. This is an incompatible change,
166 but it seems right to fix it, and I didn't think it was worth preserving
167 the old behaviour.
168
169 5. The command line items --regex=pattern and --regexp=pattern were not
170 recognized by pcregrep, which required --regex pattern or --regexp pattern
171 (with a space rather than an '='). The man page documented the '=' forms,
172 which are compatible with GNU grep; these now work.
173
174 6. No libpcreposix.pc file was created for pkg-config; there was just
175 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
176
177 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
178 when UCP support is not needed, by modifying the Python script that
179 generates it from Unicode data files. This should not matter if the module
180 is correctly used as a library, but I received one complaint about 50K of
181 unwanted data. My guess is that the person linked everything into his
182 program rather than using a library. Anyway, it does no harm.
183
184 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
185 was a minimum greater than 1 for a wide character in a possessive
186 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
187 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
188 character. Chaos in the form of incorrect output or a compiling loop could
189 result.
190
191 9. The restrictions on what a pattern can contain when partial matching is
192 requested for pcre_exec() have been removed. All patterns can now be
193 partially matched by this function. In addition, if there are at least two
194 slots in the offset vector, the offset of the earliest inspected character
195 for the match and the offset of the end of the subject are set in them when
196 PCRE_ERROR_PARTIAL is returned.
197
198 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
199 synonymous with PCRE_PARTIAL, for backwards compatibility, and
200 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
201 and may be more useful for multi-segment matching.
202
203 11. Partial matching with pcre_exec() is now more intuitive. A partial match
204 used to be given if ever the end of the subject was reached; now it is
205 given only if matching could not proceed because another character was
206 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
207 string "Z", which now yields "no match" instead of "partial match". In the
208 case of pcre_dfa_exec(), "no match" is given if every matching path for the
209 final character ended with (*FAIL).
210
211 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
212 if the pattern had a "must contain" character that was already found in the
213 earlier partial match, unless partial matching was again requested. For
214 example, with the pattern /dog.(body)?/, the "must contain" character is
215 "g". If the first part-match was for the string "dog", restarting with
216 "sbody" failed. This bug has been fixed.
217
218 13. The string returned by pcre_dfa_exec() after a partial match has been
219 changed so that it starts at the first inspected character rather than the
220 first character of the match. This makes a difference only if the pattern
221 starts with a lookbehind assertion or \b or \B (\K is not supported by
222 pcre_dfa_exec()). It's an incompatible change, but it makes the two
223 matching functions compatible, and I think it's the right thing to do.
224
225 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
226 so that the demonstration program is easily available in environments where
227 PCRE has not been installed from source.
228
229 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
230 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
231 library.
232
233 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
234 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
235 is not the first non-POSIX option to be added. Clearly some people find
236 these options useful.
237
238 17. If a caller to the POSIX matching function regexec() passes a non-zero
239 value for nmatch with a NULL value for pmatch, the value of
240 nmatch is forced to zero.
241
242 18. RunGrepTest did not have a test for the availability of the -u option of
243 the diff command, as RunTest does. It now checks in the same way as
244 RunTest, and also checks for the -b option.
245
246 19. If an odd number of negated classes containing just a single character
247 interposed, within parentheses, between a forward reference to a named
248 subpattern and the definition of the subpattern, compilation crashed with
249 an internal error, complaining that it could not find the referenced
250 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
251 [The bug was that it was starting one character too far in when skipping
252 over the character class, thus treating the ] as data rather than
253 terminating the class. This meant it could skip too much.]
254
255 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
256 /g option in pcretest when the pattern contains \K, which makes it possible
257 to have an empty string match not at the start, even when the pattern is
258 anchored. Updated pcretest and pcredemo to use this option.
259
260 21. If the maximum number of capturing subpatterns in a recursion was greater
261 than the maximum at the outer level, the higher number was returned, but
262 with unset values at the outer level. The correct (outer level) value is
263 now given.
264
265 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
266 PCRE did not set those parentheses (unlike Perl). I have now found a way to
267 make it do so. The string so far is captured, making this feature
268 compatible with Perl.
269
270 23. The tests have been re-organized, adding tests 11 and 12, to make it
271 possible to check the Perl 5.10 features against Perl 5.10.
272
273 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
274 pattern matches a fixed length string. PCRE did not allow this; now it
275 does. Neither allows recursion.
276
277 25. I finally figured out how to implement a request to provide the minimum
278 length of subject string that was needed in order to match a given pattern.
279 (It was back references and recursion that I had previously got hung up
280 on.) This code has now been added to pcre_study(); it finds a lower bound
281 to the length of subject needed. It is not necessarily the greatest lower
282 bound, but using it to avoid searching strings that are too short does give
283 some useful speed-ups. The value is available to calling programs via
284 pcre_fullinfo().
285
286 26. While implementing 25, I discovered to my embarrassment that pcretest had
287 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
288 study optimizations had never been tested with that matching function.
289 Oops. What is worse, even when it was passed study data, there was a bug in
290 pcre_dfa_exec() that meant it never actually used it. Double oops. There
291 were also very few tests of studied patterns with pcre_dfa_exec().
292
293 27. If (?| is used to create subpatterns with duplicate numbers, they are now
294 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
295 on the other side of the coin, they are no longer allowed to have different
296 names, because these cannot be distinguished in PCRE, and this has caused
297 confusion. (This is a difference from Perl.)
298
299 28. When duplicate subpattern names are present (necessarily with different
300 numbers, as required by 27 above), and a test is made by name in a
301 conditional pattern, either for a subpattern having been matched, or for
302 recursion in such a pattern, all the associated numbered subpatterns are
303 tested, and the overall condition is true if the condition is true for any
304 one of them. This is the way Perl works, and is also more like the way
305 testing by number works.
306
307
308 Version 7.9 11-Apr-09
309 ---------------------
310
311 1. When building with support for bzlib/zlib (pcregrep) and/or readline
312 (pcretest), all targets were linked against these libraries. This included
313 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
314 libraries. This caused unwanted dependencies to be created. This problem
315 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
316 pcretest is linked with readline.
317
318 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
319 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
320 moved outside it again, because FALSE and TRUE are already defined in AIX,
321 but BOOL is not.
322
323 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
324 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
325
326 4. The pcregrep documentation said spaces were inserted as well as colons (or
327 hyphens) following file names and line numbers when outputting matching
328 lines. This is not true; no spaces are inserted. I have also clarified the
329 wording for the --colour (or --color) option.
330
331 5. In pcregrep, when --colour was used with -o, the list of matching strings
332 was not coloured; this is different to GNU grep, so I have changed it to be
333 the same.
334
335 6. When --colo(u)r was used in pcregrep, only the first matching substring in
336 each matching line was coloured. Now it goes on to look for further matches
337 of any of the test patterns, which is the same behaviour as GNU grep.
338
339 7. A pattern that could match an empty string could cause pcregrep to loop; it
340 doesn't make sense to accept an empty string match in pcregrep, so I have
341 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
342 seems to be how GNU grep behaves.
343
344 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
345 start or after a newline", because the conditional assertion was not being
346 correctly handled. The rule now is that both the assertion and what follows
347 in the first alternative must satisfy the test.
348
349 9. If auto-callout was enabled in a pattern with a conditional group whose
350 condition was an assertion, PCRE could crash during matching, both with
351 pcre_exec() and pcre_dfa_exec().
352
353 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
354 used for matching.
355
356 11. Unicode property support in character classes was not working for
357 characters (bytes) greater than 127 when not in UTF-8 mode.
358
359 12. Added the -M command line option to pcretest.
360
361 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
362
363 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
364
365 16. Added comments and documentation about mis-use of no_arg in the C++
366 wrapper.
367
368 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
369 from Martin Jerabek that uses macro names for all relevant character and
370 string constants.
371
372 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
373 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
374 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
375 these, but not everybody uses configure.
376
377 19. A conditional group that had only one branch was not being correctly
378 recognized as an item that could match an empty string. This meant that an
379 enclosing group might also not be so recognized, causing infinite looping
380 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
381 with the subject "ab", where knowledge that the repeated group can match
382 nothing is needed in order to break the loop.
383
384 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
385 exec(), but without supplying a callout function, matching went wrong.
386
387 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
388 leak if the size of the offset vector was greater than 30. When the vector
389 is smaller, the saved offsets during recursion go onto a local stack
390 vector, but for larger vectors malloc() is used. It was failing to free
391 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
392 error, in fact).
393
394 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
395 heapframe that is used only when UTF-8 support is enabled. This caused no
396 problem, but was untidy.
397
398 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
399 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
400 included within another project.
401
402 24. Steven Van Ingelgem's patches to add more options to the CMake support,
403 slightly modified by me:
404
405 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
406 not building pcregrep.
407
408 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
409 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
410
411 25. Forward references, both numeric and by name, in patterns that made use of
412 duplicate group numbers, could behave incorrectly or give incorrect errors,
413 because when scanning forward to find the reference group, PCRE was not
414 taking into account the duplicate group numbers. A pattern such as
415 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
416
417 26. Changed a few more instances of "const unsigned char *" to USPTR, making
418 the feature of a custom pointer more persuasive (as requested by a user).
419
420 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
421 pcretest.c, inside #ifndefs, because it seems they are sometimes already
422 pre-defined.
423
424 28. Added support for (*UTF8) at the start of a pattern.
425
426 29. Arrange for flags added by the "release type" setting in CMake to be shown
427 in the configuration summary.
428
429
430 Version 7.8 05-Sep-08
431 ---------------------
432
433 1. Replaced UCP searching code with optimized version as implemented for Ad
434 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
435 stage table and inline lookup instead of a function, giving speed ups of 2
436 to 5 times on some simple patterns that I tested. Permission was given to
437 distribute the MultiStage2.py script that generates the tables (it's not in
438 the tarball, but is in the Subversion repository).
439
440 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
441 scripts.
442
443 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
444 a group with a zero qualifier. The result of the study could be incorrect,
445 or the function might crash, depending on the pattern.
446
447 4. Caseless matching was not working for non-ASCII characters in back
448 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
449 It now works when Unicode Property Support is available.
450
451 5. In pcretest, an escape such as \x{de} in the data was always generating
452 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
453 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
454 truncation.
455
456 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
457
458 7. Added two (int) casts to pcregrep when printing the difference of two
459 pointers, in case they are 64-bit values.
460
461 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
462 test 2 if it fails.
463
464 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
465 and a #define of that name to empty if it is not externally set. This is to
466 allow users of MSVC to set it if necessary.
467
468 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
469 the convenience functions in the pcre_get.c source file.
470
471 11. An option change at the start of a pattern that had top-level alternatives
472 could cause overwriting and/or a crash. This command provoked a crash in
473 some environments:
474
475 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
476
477 This potential security problem was recorded as CVE-2008-2371.
478
479 12. For a pattern where the match had to start at the beginning or immediately
480 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
481 pcre_dfa_exec() could read past the end of the passed subject if there was
482 no match. To help with detecting such bugs (e.g. with valgrind), I modified
483 pcretest so that it places the subject at the end of its malloc-ed buffer.
484
485 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
486 exec() might read past the end of the data buffer in UTF-8 mode.
487
488 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
489 the data contained the byte 0x85 as part of a UTF-8 character within its
490 first line. This applied both to normal and DFA matching.
491
492 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
493 /^[^d]*?$/8 failed to match "abc".
494
495 16. Added a missing copyright notice to pcrecpp_internal.h.
496
497 17. Make it more clear in the documentation that values returned from
498 pcre_exec() in ovector are byte offsets, not character counts.
499
500 18. Tidied a few places to stop certain compilers from issuing warnings.
501
502 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
503 supplied by Stefan Weber. I made a further small update for 7.8 because
504 there is a change of source arrangements: the pcre_searchfuncs.c module is
505 replaced by pcre_ucd.c.
506
507
508 Version 7.7 07-May-08
509 ---------------------
510
511 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
512 a string to a long long, pretend we don't even have a long long." This is
513 done by checking for the strtoq, strtoll, and _strtoi64 functions.
514
515 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
516 pre-7.6 versions, which defined a global no_arg variable instead of putting
517 it in the RE class. (See also #8 below.)
518
519 3. Remove a line of dead code, identified by coverity and reported by Nuno
520 Lopes.
521
522 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
523
524 (1) The include/exclude patterns were being applied to the whole pathnames
525 of files, instead of just to the final components.
526
527 (2) If there was more than one level of directory, the subdirectories were
528 skipped unless they satisfied the include/exclude conditions. This is
529 inconsistent with GNU grep (and could even be seen as contrary to the
530 pcregrep specification - which I improved to make it absolutely clear).
531 The action now is always to scan all levels of directory, and just
532 apply the include/exclude patterns to regular files.
533
534 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
535 --exclude_dir in the tests to avoid scanning .svn directories.
536
537 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
538 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
539 doesn't support NULs in patterns.
540
541 7. Added some missing "const"s to declarations of static tables in
542 pcre_compile.c and pcre_dfa_exec.c.
543
544 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
545 caused by fix #2 above. (Subsequently also a second patch to fix the
546 first patch. And a third patch - this was a messy problem.)
547
548 9. Applied Craig's patch to remove the use of push_back().
549
550 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
551 matching function regexec().
552
553 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
554 which, however, unlike Perl's \g{...}, are subroutine calls, not back
555 references. PCRE supports relative numbers with this syntax (I don't think
556 Oniguruma does).
557
558 12. Previously, a group with a zero repeat such as (...){0} was completely
559 omitted from the compiled regex. However, this means that if the group
560 was called as a subroutine from elsewhere in the pattern, things went wrong
561 (an internal error was given). Such groups are now left in the compiled
562 pattern, with a new opcode that causes them to be skipped at execution
563 time.
564
565 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
566 to the way PCRE behaves:
567
568 (a) A lone ] character is dis-allowed (Perl treats it as data).
569
570 (b) A back reference to an unmatched subpattern matches an empty string
571 (Perl fails the current match path).
572
573 (c) A data ] in a character class must be notated as \] because if the
574 first data character in a class is ], it defines an empty class. (In
575 Perl it is not possible to have an empty class.) The empty class []
576 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
577 The negative empty class [^] matches any one character, independently
578 of the DOTALL setting.
579
580 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
581 non-existent subpattern following a character class starting with ']' and
582 containing () gave an internal compiling error instead of "reference to
583 non-existent subpattern". Fortunately, when the pattern did exist, the
584 compiled code was correct. (When scanning forwards to check for the
585 existencd of the subpattern, it was treating the data ']' as terminating
586 the class, so got the count wrong. When actually compiling, the reference
587 was subsequently set up correctly.)
588
589 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
590 it was being rejected as not supported by pcre_dfa_exec(), even though
591 other assertions are supported. I have made pcre_dfa_exec() support
592 (*FAIL).
593
594 16. The implementation of 13c above involved the invention of a new opcode,
595 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
596 cannot be changed at match time, I realized I could make a small
597 improvement to matching performance by compiling OP_ALLANY instead of
598 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
599 on the OP_ANY path.
600
601 17. Compiling pcretest on Windows with readline support failed without the
602 following two fixes: (1) Make the unistd.h include conditional on
603 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
604
605 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
606 ncurses library to be included for pcretest when ReadLine support is
607 requested, but also to allow for it to be overridden. This patch came from
608 Daniel Bergström.
609
610 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
611 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
612 any errors with the current Unicode tables. Thanks to Peter Kankowski for
613 spotting this.
614
615
616 Version 7.6 28-Jan-08
617 ---------------------
618
619 1. A character class containing a very large number of characters with
620 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
621 overflow.
622
623 2. Patch to cut out the "long long" test in pcrecpp_unittest when
624 HAVE_LONG_LONG is not defined.
625
626 3. Applied Christian Ehrlicher's patch to update the CMake build files to
627 bring them up to date and include new features. This patch includes:
628
629 - Fixed PH's badly added libz and libbz2 support.
630 - Fixed a problem with static linking.
631 - Added pcredemo. [But later removed - see 7 below.]
632 - Fixed dftables problem and added an option.
633 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
634 HAVE_LONG_LONG.
635 - Added readline support for pcretest.
636 - Added an listing of the option settings after cmake has run.
637
638 4. A user submitted a patch to Makefile that makes it easy to create
639 "pcre.dll" under mingw when using Configure/Make. I added stuff to
640 Makefile.am that cause it to include this special target, without
641 affecting anything else. Note that the same mingw target plus all
642 the other distribution libraries and programs are now supported
643 when configuring with CMake (see 6 below) instead of with
644 Configure/Make.
645
646 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
647 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
648 exported in the Windows port". It has not yet been confirmed that the patch
649 solves the problem, but it does no harm.
650
651 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
652 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
653 with CMake, and also correct the comment about stack recursion.
654
655 7. Remove the automatic building of pcredemo from the ./configure system and
656 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
657 of a program that users should build themselves after PCRE is installed, so
658 building it automatically is not really right. What is more, it gave
659 trouble in some build environments.
660
661 8. Further tidies to CMakeLists.txt from Sheri and Christian.
662
663
664 Version 7.5 10-Jan-08
665 ---------------------
666
667 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
668 values in parens when parsing an RE using the C++ wrapper."
669
670 2. Negative specials like \S did not work in character classes in UTF-8 mode.
671 Characters greater than 255 were excluded from the class instead of being
672 included.
673
674 3. The same bug as (2) above applied to negated POSIX classes such as
675 [:^space:].
676
677 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
678 defined or documented. It seems to have been a typo for PCRE_STATIC, so
679 I have changed it.
680
681 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
682 first named subpattern) and a construct such as (?&a) would reference the
683 first named subpattern whose name started with "a" (in other words, the
684 length check was missing). Both these problems are fixed. "Subpattern name
685 expected" is now given for (?&) (a zero-length name), and this patch also
686 makes it give the same error for \k'' (previously it complained that that
687 was a reference to a non-existent subpattern).
688
689 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
690 this is right because (?- can be followed by option settings as well as by
691 digits. I have, however, made the messages clearer.
692
693 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
694 than the number used in the conditional) now cause a compile-time error.
695 This is actually not compatible with Perl, which accepts such patterns, but
696 treats the conditional as always being FALSE (as PCRE used to), but it
697 seems to me that giving a diagnostic is better.
698
699 8. Change "alphameric" to the more common word "alphanumeric" in comments
700 and messages.
701
702 9. Fix two occurrences of "backslash" in comments that should have been
703 "backspace".
704
705 10. Remove two redundant lines of code that can never be obeyed (their function
706 was moved elsewhere).
707
708 11. The program that makes PCRE's Unicode character property table had a bug
709 which caused it to generate incorrect table entries for sequences of
710 characters that have the same character type, but are in different scripts.
711 It amalgamated them into a single range, with the script of the first of
712 them. In other words, some characters were in the wrong script. There were
713 thirteen such cases, affecting characters in the following ranges:
714
715 U+002b0 - U+002c1
716 U+0060c - U+0060d
717 U+0061e - U+00612
718 U+0064b - U+0065e
719 U+0074d - U+0076d
720 U+01800 - U+01805
721 U+01d00 - U+01d77
722 U+01d9b - U+01dbf
723 U+0200b - U+0200f
724 U+030fc - U+030fe
725 U+03260 - U+0327f
726 U+0fb46 - U+0fbb1
727 U+10450 - U+1049d
728
729 12. The -o option (show only the matching part of a line) for pcregrep was not
730 compatible with GNU grep in that, if there was more than one match in a
731 line, it showed only the first of them. It now behaves in the same way as
732 GNU grep.
733
734 13. If the -o and -v options were combined for pcregrep, it printed a blank
735 line for every non-matching line. GNU grep prints nothing, and pcregrep now
736 does the same. The return code can be used to tell if there were any
737 non-matching lines.
738
739 14. Added --file-offsets and --line-offsets to pcregrep.
740
741 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
742 infinitely looping recursion. The bug was that positive lookaheads were not
743 being skipped when checking for a possible empty match (negative lookaheads
744 and both kinds of lookbehind were skipped).
745
746 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
747 inclusion of <windows.h> to before rather than after the definition of
748 INVALID_FILE_ATTRIBUTES (patch from David Byron).
749
750 17. Specifying a possessive quantifier with a specific limit for a Unicode
751 character property caused pcre_compile() to compile bad code, which led at
752 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
753 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
754 caused the error; without that there was no problem.
755
756 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
757
758 19. Added --enable-pcretest-libreadline.
759
760 20. In pcrecpp.cc, the variable 'count' was incremented twice in
761 RE::GlobalReplace(). As a result, the number of replacements returned was
762 double what it should be. I removed one of the increments, but Craig sent a
763 later patch that removed the other one (the right fix) and added unit tests
764 that check the return values (which was not done before).
765
766 21. Several CMake things:
767
768 (1) Arranged that, when cmake is used on Unix, the libraries end up with
769 the names libpcre and libpcreposix, not just pcre and pcreposix.
770
771 (2) The above change means that pcretest and pcregrep are now correctly
772 linked with the newly-built libraries, not previously installed ones.
773
774 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
775
776 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
777 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
778 UTF-8 newline character). The key issue is that the pattern starts .*;
779 this means that the match must be either at the beginning, or after a
780 newline. The bug was in the code for advancing after a failed match and
781 checking that the new position followed a newline. It was not taking
782 account of UTF-8 characters correctly.
783
784 23. PCRE was behaving differently from Perl in the way it recognized POSIX
785 character classes. PCRE was not treating the sequence [:...:] as a
786 character class unless the ... were all letters. Perl, however, seems to
787 allow any characters between [: and :], though of course it rejects as
788 unknown any "names" that contain non-letters, because all the known class
789 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
790 for example, whereas PCRE did not - it did not recognize a POSIX character
791 class. This seemed a bit dangerous, so the code has been changed to be
792 closer to Perl. The behaviour is not identical to Perl, because PCRE will
793 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
794 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
795 Perl does, and where it didn't before.
796
797 24. Rewrite so as to remove the single use of %n from pcregrep because in some
798 Windows environments %n is disabled by default.
799
800
801 Version 7.4 21-Sep-07
802 ---------------------
803
804 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
805 means that a class such as [\s] counted as "explicit reference to CR or
806 LF". That isn't really right - the whole point of the change was to try to
807 help when there was an actual mention of one of the two characters. So now
808 the change happens only if \r or \n (or a literal CR or LF) character is
809 encountered.
810
811 2. The 32-bit options word was also used for 6 internal flags, but the numbers
812 of both had grown to the point where there were only 3 bits left.
813 Fortunately, there was spare space in the data structure, and so I have
814 moved the internal flags into a new 16-bit field to free up more option
815 bits.
816
817 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
818 but did not set the internal JCHANGED flag - either of these is enough to
819 control the way the "get" function works - but the PCRE_INFO_JCHANGED
820 facility is supposed to tell if (?J) was ever used, so now (?J) at the
821 start sets both bits.
822
823 4. Added options (at build time, compile time, exec time) to change \R from
824 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
825
826 5. doc/pcresyntax.html was missing from the distribution.
827
828 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
829 compatibility, even though it is no longer used.
830
831 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
832 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
833 windows.h file is present (where different names are used). [This was
834 reversed later after testing - see 16 below.]
835
836 8. Changed all #include <config.h> to #include "config.h". There were also
837 some further <pcre.h> cases that I changed to "pcre.h".
838
839 9. When pcregrep was used with the --colour option, it missed the line ending
840 sequence off the lines that it output.
841
842 10. It was pointed out to me that arrays of string pointers cause lots of
843 relocations when a shared library is dynamically loaded. A technique of
844 using a single long string with a table of offsets can drastically reduce
845 these. I have refactored PCRE in four places to do this. The result is
846 dramatic:
847
848 Originally: 290
849 After changing UCP table: 187
850 After changing error message table: 43
851 After changing table of "verbs" 36
852 After changing table of Posix names 22
853
854 Thanks to the folks working on Gregex for glib for this insight.
855
856 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
857 unicode-properties was also set.
858
859 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
860
861 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
862 checked only for CRLF.
863
864 14. Added casts to pcretest.c to avoid compiler warnings.
865
866 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
867
868 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
869 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
870 entirely. This removes changes made in 7 above.
871
872 17. The CMake files have been updated, and there is now more information about
873 building with CMake in the NON-UNIX-USE document.
874
875
876 Version 7.3 28-Aug-07
877 ---------------------
878
879 1. In the rejigging of the build system that eventually resulted in 7.1, the
880 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
881 brackets there is not right, since it causes compilers to look for an
882 installed pcre.h, not the version that is in the source that is being
883 compiled (which of course may be different). I have changed it back to:
884
885 #include "pcre.h"
886
887 I have a vague recollection that the change was concerned with compiling in
888 different directories, but in the new build system, that is taken care of
889 by the VPATH setting the Makefile.
890
891 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
892 when the subject happened to end in the byte 0x85 (e.g. if the last
893 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
894 characters but of course it shouldn't be taken as a newline when it is part
895 of another character. The bug was that, for an unlimited repeat of . in
896 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
897 characters when looking for a newline.
898
899 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
900
901 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
902 in debug output.
903
904 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
905 long printing in the pcrecpp unittest when running under MinGW.
906
907 6. ESC_K was left out of the EBCDIC table.
908
909 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
910 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
911 limit also applies to "virtual nesting" when a pattern is recursive, and in
912 this case 1000 isn't so big. I have been able to remove this limit at the
913 expense of backing off one optimization in certain circumstances. Normally,
914 when pcre_exec() would call its internal match() function recursively and
915 immediately return the result unconditionally, it uses a "tail recursion"
916 feature to save stack. However, when a subpattern that can match an empty
917 string has an unlimited repetition quantifier, it no longer makes this
918 optimization. That gives it a stack frame in which to save the data for
919 checking that an empty string has been matched. Previously this was taken
920 from the 1000-entry workspace that had been reserved. So now there is no
921 explicit limit, but more stack is used.
922
923 8. Applied Daniel's patches to solve problems with the import/export magic
924 syntax that is required for Windows, and which was going wrong for the
925 pcreposix and pcrecpp parts of the library. These were overlooked when this
926 problem was solved for the main library.
927
928 9. There were some crude static tests to avoid integer overflow when computing
929 the size of patterns that contain repeated groups with explicit upper
930 limits. As the maximum quantifier is 65535, the maximum group length was
931 set at 30,000 so that the product of these two numbers did not overflow a
932 32-bit integer. However, it turns out that people want to use groups that
933 are longer than 30,000 bytes (though not repeat them that many times).
934 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
935 made it possible to implement the integer overflow checks in a much more
936 dynamic way, which I have now done. The artificial limitation on group
937 length has been removed - we now have only the limit on the total length of
938 the compiled pattern, which depends on the LINK_SIZE setting.
939
940 10. Fixed a bug in the documentation for get/copy named substring when
941 duplicate names are permitted. If none of the named substrings are set, the
942 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
943 empty string.
944
945 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
946 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
947 because the ] is interpreted as the first data character and the
948 terminating ] is not found. PCRE has been made compatible with Perl in this
949 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
950 cause memory overwriting.
951
952 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
953 string has been matched (to stop an infinite loop). It was not recognizing
954 a conditional subpattern that could match an empty string if that
955 subpattern was within another subpattern. For example, it looped when
956 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
957 condition was not nested. This bug has been fixed.
958
959 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
960 past the start of the subject in the presence of bytes with the top bit
961 set, for example "\x8aBCD".
962
963 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
964 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
965
966 14. Optimized (?!) to (*FAIL).
967
968 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
969 This restricts code points to be within the range 0 to 0x10FFFF, excluding
970 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
971 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
972 does: it's just the validity check that is more restrictive.
973
974 16. Inserted checks for integer overflows during escape sequence (backslash)
975 processing, and also fixed erroneous offset values for syntax errors during
976 backslash processing.
977
978 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
979 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
980
981 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
982 caused an overrun.
983
984 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
985 something other than just ASCII characters) inside a group that had an
986 unlimited repeat caused a loop at compile time (while checking to see
987 whether the group could match an empty string).
988
989 20. Debugging a pattern containing \p or \P could cause a crash. For example,
990 [\P{Any}] did so. (Error in the code for printing property names.)
991
992 21. An orphan \E inside a character class could cause a crash.
993
994 22. A repeated capturing bracket such as (A)? could cause a wild memory
995 reference during compilation.
996
997 23. There are several functions in pcre_compile() that scan along a compiled
998 expression for various reasons (e.g. to see if it's fixed length for look
999 behind). There were bugs in these functions when a repeated \p or \P was
1000 present in the pattern. These operators have additional parameters compared
1001 with \d, etc, and these were not being taken into account when moving along
1002 the compiled data. Specifically:
1003
1004 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1005 length.
1006
1007 (b) An item such as \pL+ within a repeated group could cause crashes or
1008 loops.
1009
1010 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1011 "reference to non-existent subpattern" error.
1012
1013 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1014
1015 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1016 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1017
1018 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1019
1020 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1021 character were causing crashes (broken optimization).
1022
1023 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1024 \p or \P) caused a compile-time loop.
1025
1026 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1027 break. For example, the unstudied pattern [\r\n]A does not match the string
1028 "\r\nA" because change 7.0/46 below moves the current point on by two
1029 characters after failing to match at the start. However, the pattern \nA
1030 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1031 the same is true. There doesn't seem any very clean way out of this, but
1032 what I have chosen to do makes the common cases work: PCRE now takes note
1033 of whether there can be an explicit match for \r or \n anywhere in the
1034 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1035 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1036 pattern has explicit CR or LF references.
1037
1038 29. Added (*CR) etc for changing newline setting at start of pattern.
1039
1040
1041 Version 7.2 19-Jun-07
1042 ---------------------
1043
1044 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1045 which is apparently normally available under Windows.
1046
1047 2. Re-jig the pcregrep tests with different newline settings in an attempt
1048 to make them independent of the local environment's newline setting.
1049
1050 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1051
1052 4. Some of the "internals" tests were previously cut out when the link size
1053 was not 2, because the output contained actual offsets. The recent new
1054 "Z" feature of pcretest means that these can be cut out, making the tests
1055 usable with all link sizes.
1056
1057 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1058 stack recursion. This gives a massive performance boost under BSD, but just
1059 a small improvement under Linux. However, it saves one field in the frame
1060 in all cases.
1061
1062 6. Added more features from the forthcoming Perl 5.10:
1063
1064 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1065 recursion call. It refers to the nth most recently opened parentheses.
1066
1067 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1068 to be opened parentheses.
1069
1070 (c) Conditions that refer to capturing parentheses can be specified
1071 relatively, for example, (?(-2)... or (?(+3)...
1072
1073 (d) \K resets the start of the current match so that everything before
1074 is not part of it.
1075
1076 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1077
1078 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1079 reference syntax.
1080
1081 (g) (?| introduces a group in which the numbering of parentheses in each
1082 alternative starts with the same number.
1083
1084 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1085
1086 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1087 PCRE_INFO_JCHANGED.
1088
1089 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1090 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1091 for detecting groups that can match an empty string.
1092
1093 9. A pattern with a very large number of alternatives (more than several
1094 hundred) was running out of internal workspace during the pre-compile
1095 phase, where pcre_compile() figures out how much memory will be needed. A
1096 bit of new cunning has reduced the workspace needed for groups with
1097 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1098 workspace instead of running out of the 4096 that are available.
1099
1100 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1101
1102 11. Applied patch from Google to remove an optimization that didn't quite work.
1103 The report of the bug said:
1104
1105 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1106 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1107 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1108
1109 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1110 it matched the wrong number of bytes.
1111
1112
1113 Version 7.1 24-Apr-07
1114 ---------------------
1115
1116 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1117 that is more "standard", making use of automake and other Autotools. There
1118 is some re-arrangement of the files and adjustment of comments consequent
1119 on this.
1120
1121 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1122 for recursive directory scanning broke on some systems because the files
1123 are not scanned in any specific order and on different systems the order
1124 was different. A call to "sort" has been inserted into RunGrepTest for the
1125 approprate test as a short-term fix. In the longer term there may be an
1126 alternative.
1127
1128 3. I had an email from Eric Raymond about problems translating some of PCRE's
1129 man pages to HTML (despite the fact that I distribute HTML pages, some
1130 people do their own conversions for various reasons). The problems
1131 concerned the use of low-level troff macros .br and .in. I have therefore
1132 removed all such uses from the man pages (some were redundant, some could
1133 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1134 HTML has been updated to handle .nf/.fi and to complain if it encounters
1135 .br or .in.
1136
1137 4. Updated comments in configure.ac that get placed in config.h.in and also
1138 arranged for config.h to be included in the distribution, with the name
1139 config.h.generic, for the benefit of those who have to compile without
1140 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1141
1142 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1143 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1144 makevp.bat for the current PCRE, using the additional files
1145 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1146
1147 6. A Windows user reported a minor discrepancy with test 2, which turned out
1148 to be caused by a trailing space on an input line that had got lost in his
1149 copy. The trailing space was an accident, so I've just removed it.
1150
1151 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1152 that is needed.
1153
1154 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1155 as "const" (a) because they are and (b) because it helps the PHP
1156 maintainers who have recently made a script to detect big data structures
1157 in the php code that should be moved to the .rodata section. I remembered
1158 to update Builducptable as well, so it won't revert if ucptable.h is ever
1159 re-created.
1160
1161 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1162 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1163 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1164 support is not required. This saves 1.5-2K of code, which is important in
1165 some applications.
1166
1167 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1168 so as not to refer to the tables, even though these functions will never be
1169 called when UTF-8 support is disabled. Otherwise there are problems with a
1170 shared library.
1171
1172 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1173
1174 (a) It was defining its arguments as char * instead of void *.
1175
1176 (b) It was assuming that all moves were upwards in memory; this was true
1177 a long time ago when I wrote it, but is no longer the case.
1178
1179 The emulated memove() is provided for those environments that have neither
1180 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1181 is clearly not the case, as these two bugs were recently reported.
1182
1183 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1184 and Detrail to create the HTML documentation, the .txt form of the man
1185 pages, and it removes trailing spaces from listed files. It also creates
1186 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1187 case, it wraps all the #defines with #ifndefs. This script should be run
1188 before "make dist".
1189
1190 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1191 with Unicode property support.
1192
1193 (a) For a maximizing quantifier, if the two different cases of the
1194 character were of different lengths in their UTF-8 codings (there are
1195 some cases like this - I found 11), and the matching function had to
1196 back up over a mixture of the two cases, it incorrectly assumed they
1197 were both the same length.
1198
1199 (b) When PCRE was configured to use the heap rather than the stack for
1200 recursion during matching, it was not correctly preserving the data for
1201 the other case of a UTF-8 character when checking ahead for a match
1202 while processing a minimizing repeat. If the check also involved
1203 matching a wide character, but failed, corruption could cause an
1204 erroneous result when trying to check for a repeat of the original
1205 character.
1206
1207 13. Some tidying changes to the testing mechanism:
1208
1209 (a) The RunTest script now detects the internal link size and whether there
1210 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1211 values substituted by "configure". (The RunGrepTest script already did
1212 this for UTF-8.) The configure.ac script no longer substitutes the
1213 relevant variables.
1214
1215 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1216 with length and offset values. This means that the output is different
1217 for different internal link sizes. Test 2 is skipped for link sizes
1218 other than 2 because of this, bypassing the problem. Unfortunately,
1219 there was also a test in test 3 (the locale tests) that used /B and
1220 failed for link sizes other than 2. Rather than cut the whole test out,
1221 I have added a new /Z option to pcretest that replaces the length and
1222 offset values with spaces. This is now used to make test 3 independent
1223 of link size. (Test 2 will be tidied up later.)
1224
1225 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1226 segmentation fault instead of returning the appropriate error message.
1227
1228 15. In multiline mode when the newline sequence was set to "any", the pattern
1229 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1230 This doesn't seem right; it now treats the CRLF combination as the line
1231 ending, and so does not match in that case. It's only a pattern such as ^$
1232 that would hit this one: something like ^ABC$ would have failed after \r
1233 and then tried again after \r\n.
1234
1235 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1236 in an attempt to make files that differ only in their line terminators
1237 compare equal. This works on Linux.
1238
1239 17. Under certain error circumstances pcregrep might try to free random memory
1240 as it exited. This is now fixed, thanks to valgrind.
1241
1242 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1243 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1244 was because its rules for how to advance for /g after matching an empty
1245 string at the end of a line did not allow for this case. They now check for
1246 it specially.
1247
1248 20. pcretest is supposed to handle patterns and data of any length, by
1249 extending its buffers when necessary. It was getting this wrong when the
1250 buffer for a data line had to be extended.
1251
1252 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1253 CRLF as a newline sequence.
1254
1255 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1256 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1257 I have nevertheless tidied it up.
1258
1259 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1260
1261 24. Added a man page for pcre-config.
1262
1263
1264 Version 7.0 19-Dec-06
1265 ---------------------
1266
1267 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1268 moving to gcc 4.1.1.
1269
1270 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1271 sys/time.h, which is documented as needed for this function. It doesn't
1272 seem to matter on Linux, but it showed up on some releases of OS X.
1273
1274 3. It seems that there are systems where bytes whose values are greater than
1275 127 match isprint() in the "C" locale. The "C" locale should be the
1276 default when a C program starts up. In most systems, only ASCII printing
1277 characters match isprint(). This difference caused the output from pcretest
1278 to vary, making some of the tests fail. I have changed pcretest so that:
1279
1280 (a) When it is outputting text in the compiled version of a pattern, bytes
1281 other than 32-126 are always shown as hex escapes.
1282
1283 (b) When it is outputting text that is a matched part of a subject string,
1284 it does the same, unless a different locale has been set for the match
1285 (using the /L modifier). In this case, it uses isprint() to decide.
1286
1287 4. Fixed a major bug that caused incorrect computation of the amount of memory
1288 required for a compiled pattern when options that changed within the
1289 pattern affected the logic of the preliminary scan that determines the
1290 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1291 that the computed length was too small. The symptoms of this bug were
1292 either the PCRE error "internal error: code overflow" from pcre_compile(),
1293 or a glibc crash with a message such as "pcretest: free(): invalid next
1294 size (fast)". Examples of patterns that provoked this bug (shown in
1295 pcretest format) are:
1296
1297 /(?-x: )/x
1298 /(?x)(?-x: \s*#\s*)/
1299 /((?i)[\x{c0}])/8
1300 /(?i:[\x{c0}])/8
1301
1302 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1303 is now done differently.
1304
1305 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1306 wrapper classes; (b) implement a new function in the C++ scanner that is
1307 more efficient than the old way of doing things because it avoids levels of
1308 recursion in the regex matching; (c) add a paragraph to the documentation
1309 for the FullMatch() function.
1310
1311 6. The escape sequence \n was being treated as whatever was defined as
1312 "newline". Not only was this contrary to the documentation, which states
1313 that \n is character 10 (hex 0A), but it also went horribly wrong when
1314 "newline" was defined as CRLF. This has been fixed.
1315
1316 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1317 was being set to -1 for the "end of line" case (supposedly a value that no
1318 character can have). Though this value is never used (the check for end of
1319 line is "zero bytes in current character"), it caused compiler complaints.
1320 I've changed it to 0xffffffff.
1321
1322 8. In pcre_version.c, the version string was being built by a sequence of
1323 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1324 string (as it is for production releases) called a macro with an empty
1325 argument. The C standard says the result of this is undefined. The gcc
1326 compiler treats it as an empty string (which was what was wanted) but it is
1327 reported that Visual C gives an error. The source has been hacked around to
1328 avoid this problem.
1329
1330 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1331 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1332 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1333 of them did).
1334
1335 10. Originally, pcretest opened its input and output without "b"; then I was
1336 told that "b" was needed in some environments, so it was added for release
1337 5.0 to both the input and output. (It makes no difference on Unix-like
1338 systems.) Later I was told that it is wrong for the input on Windows. I've
1339 now abstracted the modes into two macros, to make it easier to fiddle with
1340 them, and removed "b" from the input mode under Windows.
1341
1342 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1343
1344 12. Added -help and --help to pcretest as an official way of being reminded
1345 of the options.
1346
1347 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1348 and pcrecpp.cc because they annoy compilers at high warning levels.
1349
1350 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1351
1352 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1353 scripts are not C programs :-) and which was not noticed because it works
1354 on Linux.
1355
1356 16. pcretest is supposed to handle any length of pattern and data line (as one
1357 line or as a continued sequence of lines) by extending its input buffer if
1358 necessary. This feature was broken for very long pattern lines, leading to
1359 a string of junk being passed to pcre_compile() if the pattern was longer
1360 than about 50K.
1361
1362 17. I have done a major re-factoring of the way pcre_compile() computes the
1363 amount of memory needed for a compiled pattern. Previously, there was code
1364 that made a preliminary scan of the pattern in order to do this. That was
1365 OK when PCRE was new, but as the facilities have expanded, it has become
1366 harder and harder to keep it in step with the real compile phase, and there
1367 have been a number of bugs (see for example, 4 above). I have now found a
1368 cunning way of running the real compile function in a "fake" mode that
1369 enables it to compute how much memory it would need, while actually only
1370 ever using a few hundred bytes of working memory and without too many
1371 tests of the mode. This should make future maintenance and development
1372 easier. A side effect of this work is that the limit of 200 on the nesting
1373 depth of parentheses has been removed (though this was never a serious
1374 limitation, I suspect). However, there is a downside: pcre_compile() now
1375 runs more slowly than before (30% or more, depending on the pattern). I
1376 hope this isn't a big issue. There is no effect on runtime performance.
1377
1378 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1379 newline (only possible for the last line of a file) and it was a
1380 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1381
1382 19. Added additional timing features to pcretest. (1) The -tm option now times
1383 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1384 separate command line item, by a number that specifies the number of
1385 repeats to use when timing. The default is 50000; this gives better
1386 precision, but takes uncomfortably long for very large patterns.
1387
1388 20. Extended pcre_study() to be more clever in cases where a branch of a
1389 subpattern has no definite first character. For example, (a*|b*)[cd] would
1390 previously give no result from pcre_study(). Now it recognizes that the
1391 first character must be a, b, c, or d.
1392
1393 21. There was an incorrect error "recursive call could loop indefinitely" if
1394 a subpattern (or the entire pattern) that was being tested for matching an
1395 empty string contained only one non-empty item after a nested subpattern.
1396 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1397 incorrectly, because the \d was being skipped in the check.
1398
1399 22. The pcretest program now has a new pattern option /B and a command line
1400 option -b, which is equivalent to adding /B to every pattern. This causes
1401 it to show the compiled bytecode, without the additional information that
1402 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1403 is the same as /B/I).
1404
1405 23. A new optimization is now able automatically to treat some sequences such
1406 as a*b as a*+b. More specifically, if something simple (such as a character
1407 or a simple class like \d) has an unlimited quantifier, and is followed by
1408 something that cannot possibly match the quantified thing, the quantifier
1409 is automatically "possessified".
1410
1411 24. A recursive reference to a subpattern whose number was greater than 39
1412 went wrong under certain circumstances in UTF-8 mode. This bug could also
1413 have affected the operation of pcre_study().
1414
1415 25. Realized that a little bit of performance could be had by replacing
1416 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1417
1418 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1419
1420 27. Possessive quantifiers such as a++ were previously implemented by turning
1421 them into atomic groups such as ($>a+). Now they have their own opcodes,
1422 which improves performance. This includes the automatically created ones
1423 from 23 above.
1424
1425 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1426 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1427 the first matched character to be a colon. This applied both to named and
1428 numbered groups.
1429
1430 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1431
1432 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1433 building PCRE on Windows easier, so I have included it in the distribution.
1434
1435 31. There is now a check in pcretest against a ridiculously large number being
1436 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1437 loop, the loop is abandoned.
1438
1439 32. Forward references to subpatterns in conditions such as (?(2)...) where
1440 subpattern 2 is defined later cause pcre_compile() to search forwards in
1441 the pattern for the relevant set of parentheses. This search went wrong
1442 when there were unescaped parentheses in a character class, parentheses
1443 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1444
1445 33. "Subroutine" calls and backreferences were previously restricted to
1446 referencing subpatterns earlier in the regex. This restriction has now
1447 been removed.
1448
1449 34. Added a number of extra features that are going to be in Perl 5.10. On the
1450 whole, these are just syntactic alternatives for features that PCRE had
1451 previously implemented using the Python syntax or my own invention. The
1452 other formats are all retained for compatibility.
1453
1454 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1455 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1456 also .NET compatible.
1457
1458 (b) A recursion or subroutine call to a named group can now be defined as
1459 (?&name) as well as (?P>name).
1460
1461 (c) A backreference to a named group can now be defined as \k<name> or
1462 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1463 5.10, are also .NET compatible.
1464
1465 (d) A conditional reference to a named group can now use the syntax
1466 (?(<name>) or (?('name') as well as (?(name).
1467
1468 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1469 groups (named and numbered) that are never evaluated inline, but can be
1470 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1471 is always false. There may be only one alternative in such a group.
1472
1473 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1474 as the simple (?(R). The condition is true only if the most recent
1475 recursion is that of the given number or name. It does not search out
1476 through the entire recursion stack.
1477
1478 (g) The escape \gN or \g{N} has been added, where N is a positive or
1479 negative number, specifying an absolute or relative reference.
1480
1481 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1482 some "unreachable code" warnings.
1483
1484 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1485 things, this adds five new scripts.
1486
1487 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1488 There were also incompatibilities regarding the handling of \Q..\E inside
1489 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1490 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1491
1492 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1493 matches an empty string, and forcibly breaks the loop. There were bugs in
1494 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1495 against aaaa the result was just "a" rather than "aaaa", for example. Two
1496 separate and independent bugs (that affected different cases) have been
1497 fixed.
1498
1499 39. Refactored the code to abolish the use of different opcodes for small
1500 capturing bracket numbers. This is a tidy that I avoided doing when I
1501 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1502 The new approach is not only tidier, it makes it possible to reduce the
1503 memory needed to fix the previous bug (38).
1504
1505 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1506 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1507 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1508 mode.
1509
1510 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1511 report.
1512
1513 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1514 copy construction and assignment in the C++ wrapper.
1515
1516 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1517 couple of bugs that could have given wrong results in the "--newline=crlf"
1518 case.
1519
1520 44. Added a number of casts and did some reorganization of signed/unsigned int
1521 variables following suggestions from Dair Grant. Also renamed the variable
1522 "this" as "item" because it is a C++ keyword.
1523
1524 45. Arranged for dftables to add
1525
1526 #include "pcre_internal.h"
1527
1528 to pcre_chartables.c because without it, gcc 4.x may remove the array
1529 definition from the final binary if PCRE is built into a static library and
1530 dead code stripping is activated.
1531
1532 46. For an unanchored pattern, if a match attempt fails at the start of a
1533 newline sequence, and the newline setting is CRLF or ANY, and the next two
1534 characters are CRLF, advance by two characters instead of one.
1535
1536
1537 Version 6.7 04-Jul-06
1538 ---------------------
1539
1540 1. In order to handle tests when input lines are enormously long, pcretest has
1541 been re-factored so that it automatically extends its buffers when
1542 necessary. The code is crude, but this _is_ just a test program. The
1543 default size has been increased from 32K to 50K.
1544
1545 2. The code in pcre_study() was using the value of the re argument before
1546 testing it for NULL. (Of course, in any sensible call of the function, it
1547 won't be NULL.)
1548
1549 3. The memmove() emulation function in pcre_internal.h, which is used on
1550 systems that lack both memmove() and bcopy() - that is, hardly ever -
1551 was missing a "static" storage class specifier.
1552
1553 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1554 containing an extended class (one that cannot be represented by a bitmap
1555 because it contains high-valued characters or Unicode property items, e.g.
1556 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1557 pattern, but PCRE should not loop if you do not (it no longer does).
1558 [Detail: two cases were found: (a) a repeated subpattern containing an
1559 extended class; (b) a recursive reference to a subpattern that followed a
1560 previous extended class. It wasn't skipping over the extended class
1561 correctly when UTF-8 mode was not set.]
1562
1563 5. A negated single-character class was not being recognized as fixed-length
1564 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1565 compile error "lookbehind assertion is not fixed length".
1566
1567 6. The RunPerlTest auxiliary script was showing an unexpected difference
1568 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1569 write a Perl script that can interpret lines of an input file either as
1570 byte characters or as UTF-8, which is what "perltest" was being required to
1571 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1572 can't do is switch easily at run time between having the "use utf8;" pragma
1573 or not. In the end, I fudged it by using the RunPerlTest script to insert
1574 "use utf8;" explicitly for the UTF-8 tests.
1575
1576 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1577 the end of the subject string, contrary to the documentation and to what
1578 Perl does. This was true of both matching functions. Now it matches only at
1579 the start of the subject and immediately after *internal* newlines.
1580
1581 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1582 a pointer to an int instead of a pointer to an unsigned long int. This
1583 caused problems on 64-bit systems.
1584
1585 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1586 instance of the 'standard' template library not being so standard".
1587
1588 10. There was no check on the number of named subpatterns nor the maximum
1589 length of a subpattern name. The product of these values is used to compute
1590 the size of the memory block for a compiled pattern. By supplying a very
1591 long subpattern name and a large number of named subpatterns, the size
1592 computation could be caused to overflow. This is now prevented by limiting
1593 the length of names to 32 characters, and the number of named subpatterns
1594 to 10,000.
1595
1596 11. Subpatterns that are repeated with specific counts have to be replicated in
1597 the compiled pattern. The size of memory for this was computed from the
1598 length of the subpattern and the repeat count. The latter is limited to
1599 65535, but there was no limit on the former, meaning that integer overflow
1600 could in principle occur. The compiled length of a repeated subpattern is
1601 now limited to 30,000 bytes in order to prevent this.
1602
1603 12. Added the optional facility to have named substrings with the same name.
1604
1605 13. Added the ability to use a named substring as a condition, using the
1606 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1607 are numbers (not recommended). Forward references are permitted.
1608
1609 14. Added forward references in named backreferences (if you see what I mean).
1610
1611 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1612 pattern could run off the end of the subject. For example, the pattern
1613 "(?s)(.{1,5})"8 did this with the subject "ab".
1614
1615 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1616 PCRE_CASELESS was set when matching characters that were quantified with ?
1617 or *.
1618
1619 17. A character class other than a single negated character that had a minimum
1620 but no maximum quantifier - for example [ab]{6,} - was not handled
1621 correctly by pce_dfa_exec(). It would match only one character.
1622
1623 18. A valid (though odd) pattern that looked like a POSIX character
1624 class but used an invalid character after [ (for example [[,abc,]]) caused
1625 pcre_compile() to give the error "Failed: internal error: code overflow" or
1626 in some cases to crash with a glibc free() error. This could even happen if
1627 the pattern terminated after [[ but there just happened to be a sequence of
1628 letters, a binary zero, and a closing ] in the memory that followed.
1629
1630 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1631 over the years. Originally (before any Unicode support), just the bottom 8
1632 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1633 output from "man perlunicode" includes this:
1634
1635 The regular expression compiler produces polymorphic opcodes. That
1636 is, the pattern adapts to the data and automatically switches to
1637 the Unicode character scheme when presented with Unicode data--or
1638 instead uses a traditional byte scheme when presented with byte
1639 data.
1640
1641 Sadly, a wide octal escape does not cause a switch, and in a string with
1642 no other multibyte characters, these octal escapes are treated as before.
1643 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1644 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1645 Unicode string.
1646
1647 I have not perpetrated such confusion in PCRE. Up till now, it took just
1648 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1649 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1650 translate to the appropriate multibyte character.
1651
1652 29. Applied some refactoring to reduce the number of warnings from Microsoft
1653 and Borland compilers. This has included removing the fudge introduced
1654 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1655 a warning about an unused variable.
1656
1657 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1658 characters since release 4.0, because Perl (from release 5.004) does not.
1659 [Or at least, is documented not to: some releases seem to be in conflict
1660 with the documentation.] However, when a pattern was studied with
1661 pcre_study() and all its branches started with \s, PCRE still included VT
1662 as a possible starting character. Of course, this did no harm; it just
1663 caused an unnecessary match attempt.
1664
1665 22. Removed a now-redundant internal flag bit that recorded the fact that case
1666 dependency changed within the pattern. This was once needed for "required
1667 byte" processing, but is no longer used. This recovers a now-scarce options
1668 bit. Also moved the least significant internal flag bit to the most-
1669 significant bit of the word, which was not previously used (hangover from
1670 the days when it was an int rather than a uint) to free up another bit for
1671 the future.
1672
1673 23. Added support for CRLF line endings as well as CR and LF. As well as the
1674 default being selectable at build time, it can now be changed at runtime
1675 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1676 specify that it is scanning data with non-default line endings.
1677
1678 24. Changed the definition of CXXLINK to make it agree with the definition of
1679 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1680
1681 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1682 recursions. This makes a big different to stack usage for some patterns.
1683
1684 26. If a subpattern containing a named recursion or subroutine reference such
1685 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1686 the space required for the compiled pattern went wrong and gave too small a
1687 value. Depending on the environment, this could lead to "Failed: internal
1688 error: code overflow at offset 49" or "glibc detected double free or
1689 corruption" errors.
1690
1691 27. Applied patches from Google (a) to support the new newline modes and (b) to
1692 advance over multibyte UTF-8 characters in GlobalReplace.
1693
1694 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1695 difference for some implementation of PCRE in some Windows version.
1696
1697 29. Added some extra testing facilities to pcretest:
1698
1699 \q<number> in a data line sets the "match limit" value
1700 \Q<number> in a data line sets the "match recursion limt" value
1701 -S <number> sets the stack size, where <number> is in megabytes
1702
1703 The -S option isn't available for Windows.
1704
1705
1706 Version 6.6 06-Feb-06
1707 ---------------------
1708
1709 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1710 in pcreposix.h. I have copied the definition from pcre.h.
1711
1712 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1713 because pcre.h is no longer a built file.
1714
1715 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1716 not normally included in the compiled code.
1717
1718
1719 Version 6.5 01-Feb-06
1720 ---------------------
1721
1722 1. When using the partial match feature with pcre_dfa_exec(), it was not
1723 anchoring the second and subsequent partial matches at the new starting
1724 point. This could lead to incorrect results. For example, with the pattern
1725 /1234/, partially matching against "123" and then "a4" gave a match.
1726
1727 2. Changes to pcregrep:
1728
1729 (a) All non-match returns from pcre_exec() were being treated as failures
1730 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1731 error message is output. Some extra information is given for the
1732 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1733 probably the only errors that are likely to be caused by users (by
1734 specifying a regex that has nested indefinite repeats, for instance).
1735 If there are more than 20 of these errors, pcregrep is abandoned.
1736
1737 (b) A binary zero was treated as data while matching, but terminated the
1738 output line if it was written out. This has been fixed: binary zeroes
1739 are now no different to any other data bytes.
1740
1741 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1742 used to set a locale for matching. The --locale=xxxx long option has
1743 been added (no short equivalent) to specify a locale explicitly on the
1744 pcregrep command, overriding the environment variables.
1745
1746 (d) When -B was used with -n, some line numbers in the output were one less
1747 than they should have been.
1748
1749 (e) Added the -o (--only-matching) option.
1750
1751 (f) If -A or -C was used with -c (count only), some lines of context were
1752 accidentally printed for the final match.
1753
1754 (g) Added the -H (--with-filename) option.
1755
1756 (h) The combination of options -rh failed to suppress file names for files
1757 that were found from directory arguments.
1758
1759 (i) Added the -D (--devices) and -d (--directories) options.
1760
1761 (j) Added the -F (--fixed-strings) option.
1762
1763 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1764
1765 (l) Added the --colo(u)r option.
1766
1767 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1768 is not present by default.
1769
1770 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1771 items such as (?R) or (?1), when the recursion could match a number of
1772 alternatives. If it matched one of the alternatives, but subsequently,
1773 outside the recursion, there was a failure, the code tried to back up into
1774 the recursion. However, because of the way PCRE is implemented, this is not
1775 possible, and the result was an incorrect result from the match.
1776
1777 In order to prevent this happening, the specification of recursion has
1778 been changed so that all such subpatterns are automatically treated as
1779 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1780
1781 4. I had overlooked the fact that, in some locales, there are characters for
1782 which isalpha() is true but neither isupper() nor islower() are true. In
1783 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1784 and ordfeminine) are like this. This affected the treatment of \w and \W
1785 when they appeared in character classes, but not when they appeared outside
1786 a character class. The bit map for "word" characters is now created
1787 separately from the results of isalnum() instead of just taking it from the
1788 upper, lower, and digit maps. (Plus the underscore character, of course.)
1789
1790 5. The above bug also affected the handling of POSIX character classes such as
1791 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1792 permanent tables. Instead, the bit maps for such a class were previously
1793 created as the appropriate unions of the upper, lower, and digit bitmaps.
1794 Now they are created by subtraction from the [[:word:]] class, which has
1795 its own bitmap.
1796
1797 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1798 It is created by subtracting the vertical space characters (\x09, \x0a,
1799 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1800 subtraction was done in the overall bitmap for a character class, meaning
1801 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1802 be recognized. This bug has been fixed.
1803
1804 7. Patches from the folks at Google:
1805
1806 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1807 real life, but is still worth protecting against".
1808
1809 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1810 regular expressions".
1811
1812 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1813 have it.
1814
1815 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1816 "configure" and the latter not, in order to fix a problem somebody had
1817 with compiling the Arg class on HP-UX.
1818
1819 (e) Improve the error-handling of the C++ wrapper a little bit.
1820
1821 (f) New tests for checking recursion limiting.
1822
1823 8. The pcre_memmove() function, which is used only if the environment does not
1824 have a standard memmove() function (and is therefore rarely compiled),
1825 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1826 returning a result (though PCRE never actually uses the result).
1827
1828 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1829 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1830 returned instead of calling malloc() with an overflowing number that would
1831 most likely cause subsequent chaos.
1832
1833 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1834
1835 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1836 with this option is matched, the nmatch and pmatch options of regexec() are
1837 ignored.
1838
1839 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1840 provided in case anyone wants to the the POSIX interface with UTF-8
1841 strings.
1842
1843 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1844 C++ linking (needed for some HP-UX environments).
1845
1846 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1847 (unused parameter) and in the pcre_printint() function (omitted "default"
1848 switch label when the default is to do nothing).
1849
1850 15. Added some code to make it possible, when PCRE is compiled as a C++
1851 library, to replace subject pointers for pcre_exec() with a smart pointer
1852 class, thus making it possible to process discontinuous strings.
1853
1854 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1855 much the same function. They were added by different people who were trying
1856 to make PCRE easy to compile on non-Unix systems. It has been suggested
1857 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1858 for compiling on Windows systems. I have therefore replaced it with
1859 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1860 defaults to "extern" for C or "extern C" for C++, which works fine on
1861 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1862 SCOPE with something explicit in config.h. In addition:
1863
1864 (a) pcreposix.h still had just "extern" instead of either of these macros;
1865 I have replaced it with PCRE_DATA_SCOPE.
1866
1867 (b) Functions such as _pcre_xclass(), which are internal to the library,
1868 but external in the C sense, all had PCRE_EXPORT in their definitions.
1869 This is apparently wrong for the Windows case, so I have removed it.
1870 (It makes no difference on Unix-like systems.)
1871
1872 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1873 of recursive calls to match(). This is different to MATCH_LIMIT because
1874 that limits the total number of calls to match(), not all of which increase
1875 the depth of recursion. Limiting the recursion depth limits the amount of
1876 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1877 when PCRE is compiled, and changed at run time. A patch from Google adds
1878 this functionality to the C++ interface.
1879
1880 18. Changes to the handling of Unicode character properties:
1881
1882 (a) Updated the table to Unicode 4.1.0.
1883
1884 (b) Recognize characters that are not in the table as "Cn" (undefined).
1885
1886 (c) I revised the way the table is implemented to a much improved format
1887 which includes recognition of ranges. It now supports the ranges that
1888 are defined in UnicodeData.txt, and it also amalgamates other
1889 characters into ranges. This has reduced the number of entries in the
1890 table from around 16,000 to around 3,000, thus reducing its size
1891 considerably. I realized I did not need to use a tree structure after
1892 all - a binary chop search is just as efficient. Having reduced the
1893 number of entries, I extended their size from 6 bytes to 8 bytes to
1894 allow for more data.
1895
1896 (d) Added support for Unicode script names via properties such as \p{Han}.
1897
1898 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1899 matching that character.
1900
1901 20. When matching a repeated Unicode property with a minimum greater than zero,
1902 (for example \pL{2,}), PCRE could look past the end of the subject if it
1903 reached it while seeking the minimum number of characters. This could
1904 happen only if some of the characters were more than one byte long, because
1905 there is a check for at least the minimum number of bytes.
1906
1907 21. Refactored the implementation of \p and \P so as to be more general, to
1908 allow for more different types of property in future. This has changed the
1909 compiled form incompatibly. Anybody with saved compiled patterns that use
1910 \p or \P will have to recompile them.
1911
1912 22. Added "Any" and "L&" to the supported property types.
1913
1914 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1915 but give a compile time error if the value is greater than 0xff.
1916
1917 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1918 accidentally not being installed or uninstalled.
1919
1920 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1921 made were to insert the current release number. This seemed silly, because
1922 it made things harder for people building PCRE on systems that don't run
1923 "configure". I have turned pcre.h into a distributed file, no longer built
1924 by "configure", with the version identification directly included. There is
1925 no longer a pcre.h.in file.
1926
1927 However, this change necessitated a change to the pcre-config script as
1928 well. It is built from pcre-config.in, and one of the substitutions was the
1929 release number. I have updated configure.ac so that ./configure now finds
1930 the release number by grepping pcre.h.
1931
1932 26. Added the ability to run the tests under valgrind.
1933
1934
1935 Version 6.4 05-Sep-05
1936 ---------------------
1937
1938 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1939 "--" to be printed when multiple files were scanned, even when none of the
1940 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1941 consider it to be a bug, and have restored the previous behaviour.
1942
1943 2. A couple of code tidies to get rid of compiler warnings.
1944
1945 3. The pcretest program used to cheat by referring to symbols in the library
1946 whose names begin with _pcre_. These are internal symbols that are not
1947 really supposed to be visible externally, and in some environments it is
1948 possible to suppress them. The cheating is now confined to including
1949 certain files from the library's source, which is a bit cleaner.
1950
1951 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1952 file's purpose clearer.
1953
1954 5. Reorganized pcre_ucp_findchar().
1955
1956
1957 Version 6.3 15-Aug-05
1958 ---------------------
1959
1960 1. The file libpcre.pc.in did not have general read permission in the tarball.
1961
1962 2. There were some problems when building without C++ support:
1963
1964 (a) If C++ support was not built, "make install" and "make test" still
1965 tried to test it.
1966
1967 (b) There were problems when the value of CXX was explicitly set. Some
1968 changes have been made to try to fix these, and ...
1969
1970 (c) --disable-cpp can now be used to explicitly disable C++ support.
1971
1972 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1973 backslash in a target when C++ was disabled. This confuses some
1974 versions of "make", apparently. Using an intermediate variable solves
1975 this. (Same for CPP_LOBJ.)
1976
1977 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1978 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1979 necessary on certain architectures.
1980
1981 4. Added a setting of -export-symbols-regex to the link command to remove
1982 those symbols that are exported in the C sense, but actually are local
1983 within the library, and not documented. Their names all begin with
1984 "_pcre_". This is not a perfect job, because (a) we have to except some
1985 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1986 available (and never for static libraries). I have made a note to try to
1987 find a way round (a) in the future.
1988
1989
1990 Version 6.2 01-Aug-05
1991 ---------------------
1992
1993 1. There was no test for integer overflow of quantifier values. A construction
1994 such as {1111111111111111} would give undefined results. What is worse, if
1995 a minimum quantifier for a parenthesized subpattern overflowed and became
1996 negative, the calculation of the memory size went wrong. This could have
1997 led to memory overwriting.
1998
1999 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2000
2001 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2002 operating environments where this matters.
2003
2004 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2005 PCRE options from within the C++ wrapper.
2006
2007 5. Named capturing subpatterns were not being correctly counted when a pattern
2008 was compiled. This caused two problems: (a) If there were more than 100
2009 such subpatterns, the calculation of the memory needed for the whole
2010 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2011 back references of the form \12, where the number was greater than 9, were
2012 not recognized as back references, even though there were sufficient
2013 previous subpatterns.
2014
2015 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2016 versions of gcc, e.g. 2.95.4.
2017
2018
2019 Version 6.1 21-Jun-05
2020 ---------------------
2021
2022 1. There was one reference to the variable "posix" in pcretest.c that was not
2023 surrounded by "#if !defined NOPOSIX".
2024
2025 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2026 the cross-check on the old pcre_info() function, for the benefit of the
2027 cut-down version of PCRE that is currently imported into Exim.
2028
2029 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2030 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2031 patterns that start (?i) but I don't think that matters. The use of (?i) is
2032 just an example; this all applies to the other options as well.
2033
2034 4. Since libtool seems to echo the compile commands it is issuing, the output
2035 from "make" can be reduced a bit by putting "@" in front of each libtool
2036 compile command.
2037
2038 5. Patch from the folks at Google for configure.in to be a bit more thorough
2039 in checking for a suitable C++ installation before trying to compile the
2040 C++ stuff. This should fix a reported problem when a compiler was present,
2041 but no suitable headers.
2042
2043 6. The man pages all had just "PCRE" as their title. I have changed them to
2044 be the relevant file name. I have also arranged that these names are
2045 retained in the file doc/pcre.txt, which is a concatenation in text format
2046 of all the man pages except the little individual ones for each function.
2047
2048 7. The NON-UNIX-USE file had not been updated for the different set of source
2049 files that come with release 6. I also added a few comments about the C++
2050 wrapper.
2051
2052
2053 Version 6.0 07-Jun-05
2054 ---------------------
2055
2056 1. Some minor internal re-organization to help with my DFA experiments.
2057
2058 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2059 didn't matter for the library itself when fully configured, but did matter
2060 when compiling without UCP support, or within Exim, where the ucp files are
2061 not imported.
2062
2063 3. Refactoring of the library code to split up the various functions into
2064 different source modules. The addition of the new DFA matching code (see
2065 below) to a single monolithic source would have made it really too
2066 unwieldy, quite apart from causing all the code to be include in a
2067 statically linked application, when only some functions are used. This is
2068 relevant even without the DFA addition now that patterns can be compiled in
2069 one application and matched in another.
2070
2071 The downside of splitting up is that there have to be some external
2072 functions and data tables that are used internally in different modules of
2073 the library but which are not part of the API. These have all had their
2074 names changed to start with "_pcre_" so that they are unlikely to clash
2075 with other external names.
2076
2077 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2078 a different (DFA) algorithm. Although it is slower than the original
2079 function, it does have some advantages for certain types of matching
2080 problem.
2081
2082 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2083 including restarting after a partial match.
2084
2085 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2086 defined when compiling for Windows was sent to me. I have put it into the
2087 code, though I have no means of testing or verifying it.
2088
2089 7. Added the pcre_refcount() auxiliary function.
2090
2091 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2092 match before or at the first newline in the subject string. In pcretest,
2093 the /f option on a pattern can be used to set this.
2094
2095 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2096 would behave wrongly. This has been present in PCRE since release 4.0.
2097
2098 10. A number of changes to the pcregrep command:
2099
2100 (a) Refactored how -x works; insert ^(...)$ instead of setting
2101 PCRE_ANCHORED and checking the length, in preparation for adding
2102 something similar for -w.
2103
2104 (b) Added the -w (match as a word) option.
2105
2106 (c) Refactored the way lines are read and buffered so as to have more
2107 than one at a time available.
2108
2109 (d) Implemented a pcregrep test script.
2110
2111 (e) Added the -M (multiline match) option. This allows patterns to match
2112 over several lines of the subject. The buffering ensures that at least
2113 8K, or the rest of the document (whichever is the shorter) is available
2114 for matching (and similarly the previous 8K for lookbehind assertions).
2115
2116 (f) Changed the --help output so that it now says
2117
2118 -w, --word-regex(p)
2119
2120 instead of two lines, one with "regex" and the other with "regexp"
2121 because that confused at least one person since the short forms are the
2122 same. (This required a bit of code, as the output is generated
2123 automatically from a table. It wasn't just a text change.)
2124
2125 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2126 option but starts with a hyphen. Could be a pattern or a path name
2127 starting with a hyphen, for instance.
2128
2129 (h) "-" can be given as a file name to represent stdin.
2130
2131 (i) When file names are being printed, "(standard input)" is used for
2132 the standard input, for compatibility with GNU grep. Previously
2133 "<stdin>" was used.
2134
2135 (j) The option --label=xxx can be used to supply a name to be used for
2136 stdin when file names are being printed. There is no short form.
2137
2138 (k) Re-factored the options decoding logic because we are going to add
2139 two more options that take data. Such options can now be given in four
2140 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2141
2142 (l) Added the -A, -B, and -C options for requesting that lines of context
2143 around matches be printed.
2144
2145 (m) Added the -L option to print the names of files that do not contain
2146 any matching lines, that is, the complement of -l.
2147
2148 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2149 continue to scan other files.
2150
2151 (o) The -s option was incorrectly implemented. For compatibility with other
2152 greps, it now suppresses the error message for a non-existent or non-
2153 accessible file (but not the return code). There is a new option called
2154 -q that suppresses the output of matching lines, which was what -s was
2155 previously doing.
2156
2157 (p) Added --include and --exclude options to specify files for inclusion
2158 and exclusion when recursing.
2159
2160 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2161 Hopefully, it now does.
2162
2163 12. Missing cast in pcre_study().
2164
2165 13. Added an "uninstall" target to the makefile.
2166
2167 14. Replaced "extern" in the function prototypes in Makefile.in with
2168 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2169 world, but is set differently for Windows.
2170
2171 15. Added a second compiling function called pcre_compile2(). The only
2172 difference is that it has an extra argument, which is a pointer to an
2173 integer error code. When there is a compile-time failure, this is set
2174 non-zero, in addition to the error test pointer being set to point to an
2175 error message. The new argument may be NULL if no error number is required
2176 (but then you may as well call pcre_compile(), which is now just a
2177 wrapper). This facility is provided because some applications need a
2178 numeric error indication, but it has also enabled me to tidy up the way
2179 compile-time errors are handled in the POSIX wrapper.
2180
2181 16. Added VPATH=.libs to the makefile; this should help when building with one
2182 prefix path and installing with another. (Or so I'm told by someone who
2183 knows more about this stuff than I do.)
2184
2185 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2186 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2187 match everything, including newlines. This is not POSIX-compatible, but
2188 somebody wanted the feature. From pcretest it can be activated by using
2189 both the P and the s flags.
2190
2191 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2192
2193 19. libpcre.pc was being incorrectly installed as executable.
2194
2195 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2196 it now also looks for '\r' so that it will work unmodified on Windows.
2197
2198 21. Added Google's contributed C++ wrapper to the distribution.
2199
2200 22. Added some untidy missing memory free() calls in pcretest, to keep
2201 Electric Fence happy when testing.
2202
2203
2204
2205 Version 5.0 13-Sep-04
2206 ---------------------
2207
2208 1. Internal change: literal characters are no longer packed up into items
2209 containing multiple characters in a single byte-string. Each character
2210 is now matched using a separate opcode. However, there may be more than one
2211 byte in the character in UTF-8 mode.
2212
2213 2. The pcre_callout_block structure has two new fields: pattern_position and
2214 next_item_length. These contain the offset in the pattern to the next match
2215 item, and its length, respectively.
2216
2217 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2218 insertion of callouts before each pattern item. Added the /C option to
2219 pcretest to make use of this.
2220
2221 4. On the advice of a Windows user, the lines
2222
2223 #if defined(_WIN32) || defined(WIN32)
2224 _setmode( _fileno( stdout ), 0x8000 );
2225 #endif /* defined(_WIN32) || defined(WIN32) */
2226
2227 have been added to the source of pcretest. This apparently does useful
2228 magic in relation to line terminators.
2229
2230 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2231 for the benefit of those environments where the "b" makes a difference.
2232
2233 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2234 to know about it. I have put a hack into configure.in that adds in code
2235 to set GCC=yes if CC=icc. This seems to end up at a point in the
2236 generated configure script that is early enough to affect the setting of
2237 compiler options, which is what is needed, but I have no means of testing
2238 whether it really works. (The user who reported this had patched the
2239 generated configure script, which of course I cannot do.)
2240
2241 LATER: After change 22 below (new libtool files), the configure script
2242 seems to know about icc (and also ecc). Therefore, I have commented out
2243 this hack in configure.in.
2244
2245 7. Added support for pkg-config (2 patches were sent in).
2246
2247 8. Negated POSIX character classes that used a combination of internal tables
2248 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2249 [[:^ascii]]. Typically, they would match almost any characters. The other
2250 POSIX classes were not broken in this way.
2251
2252 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2253 to find the match, as PCRE was deluded into thinking that the match had to
2254 start at the start point or following a newline. The same bug applied to
2255 patterns with negative forward assertions or any backward assertions
2256 preceding ".*" at the start, unless the pattern required a fixed first
2257 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2258
2259 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2260 starting at the last subject character, bytes beyond the end of the subject
2261 string were read.
2262
2263 11. Renamed the variable "class" as "classbits" to make life easier for C++
2264 users. (Previously there was a macro definition, but it apparently wasn't
2265 enough.)
2266
2267 12. Added the new field "tables" to the extra data so that tables can be passed
2268 in at exec time, or the internal tables can be re-selected. This allows
2269 a compiled regex to be saved and re-used at a later time by a different
2270 program that might have everything at different addresses.
2271
2272 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2273 -R library as well as a -L library.
2274
2275 14. The debugging options of pcretest (-d on the command line or D on a
2276 pattern) showed incorrect output for anything following an extended class
2277 that contained multibyte characters and which was followed by a quantifier.
2278
2279 15. Added optional support for general category Unicode character properties
2280 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2281 support. It adds about 90K to the size of the library. The meanings of the
2282 inbuilt class escapes such as \d and \s have NOT been changed.
2283
2284 16. Updated pcredemo.c to include calls to free() to release the memory for the
2285 compiled pattern.
2286
2287 17. The generated file chartables.c was being created in the source directory
2288 instead of in the building directory. This caused the build to fail if the
2289 source directory was different from the building directory, and was
2290 read-only.
2291
2292 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2293 file. No doubt somebody will tell me if they don't make sense... Also added
2294 Dan Mooney's comments about building on OpenVMS.
2295
2296 19. Added support for partial matching via the PCRE_PARTIAL option for
2297 pcre_exec() and the \P data escape in pcretest.
2298
2299 20. Extended pcretest with 3 new pattern features:
2300
2301 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2302 write the compiled pattern to the file whose name is "rest-of-line".
2303 This is a straight binary dump of the data, with the saved pointer to
2304 the character tables forced to be NULL. The study data, if any, is
2305 written too. After writing, pcretest reads a new pattern.
2306
2307 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2308 compiled pattern from the given file. There must not be any
2309 occurrences of "<" in the file name (pretty unlikely); if there are,
2310 pcretest will instead treat the initial "<" as a pattern delimiter.
2311 After reading in the pattern, pcretest goes on to read data lines as
2312 usual.
2313
2314 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2315 and 16-bit fields in a compiled pattern, to simulate a pattern that
2316 was compiled on a host of opposite endianness.
2317
2318 21. The pcre-exec() function can now cope with patterns that were compiled on
2319 hosts of opposite endianness, with this restriction:
2320
2321 As for any compiled expression that is saved and used later, the tables
2322 pointer field cannot be preserved; the extra_data field in the arguments
2323 to pcre_exec() should be used to pass in a tables address if a value
2324 other than the default internal tables were used at compile time.
2325
2326 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2327 now diagnosed as an error. Previously, most of the time, a negative number
2328 would have been treated as zero, but if in addition "ovector" was passed as
2329 NULL, a crash could occur.
2330
2331 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2332 new versions from the libtool 1.5 distribution (the last one is a copy of
2333 a file called libtool.m4). This seems to have fixed the need to patch
2334 "configure" to support Darwin 1.3 (which I used to do). However, I still
2335 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2336 workstation).
2337
2338 24. Changed the PCRE licence to be the more standard "BSD" licence.
2339
2340
2341 Version 4.5 01-Dec-03
2342 ---------------------
2343
2344 1. There has been some re-arrangement of the code for the match() function so
2345 that it can be compiled in a version that does not call itself recursively.
2346 Instead, it keeps those local variables that need separate instances for
2347 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2348 needs to "recurse". Keeping track of where control must go is done by means
2349 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2350 hide most of the details from the main code, and operates only if
2351 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2352 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2353 operating.
2354
2355 To make it easier for callers to provide specially tailored get/free
2356 functions for this usage, two new functions, pcre_stack_malloc, and
2357 pcre_stack_free, are used. They are always called in strict stacking order,
2358 and the size of block requested is always the same.
2359
2360 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2361 PCRE has been compiled to use the stack or the heap for recursion. The
2362 -C option of pcretest uses this to show which version is compiled.
2363
2364 A new data escape \S, is added to pcretest; it causes the amounts of store
2365 obtained and freed by both kinds of malloc/free at match time to be added
2366 to the output.
2367
2368 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2369 what's available on my current Linux desktop machine.
2370
2371 3. When matching a UTF-8 string, the test for a valid string at the start has
2372 been extended. If start_offset is not zero, PCRE now checks that it points
2373 to a byte that is the start of a UTF-8 character. If not, it returns
2374 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2375 this is necessary because there may be backward assertions in the pattern.
2376 When matching the same subject several times, it may save resources to use
2377 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2378
2379 4. The code for checking the validity of UTF-8 strings has been tightened so
2380 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2381 containing "overlong sequences".
2382
2383 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2384 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2385 should have been "&", but it just so happened that all the cases this let
2386 through by mistake were picked up later in the function.
2387
2388 6. I had used a variable called "isblank" - this is a C99 function, causing
2389 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2390
2391 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2392 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2393 so the version is shown; (c) stop "make test" echoing "./RunTest".
2394
2395 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2396
2397 9. The prototype for memmove() for systems that don't have it was using
2398 size_t, but the inclusion of the header that defines size_t was later. I've
2399 moved the #includes for the C headers earlier to avoid this.
2400
2401 10. Added some adjustments to the code to make it easier to compiler on certain
2402 special systems:
2403
2404 (a) Some "const" qualifiers were missing.
2405 (b) Added the macro EXPORT before all exported functions; by default this
2406 is defined to be empty.
2407 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2408 that it reads its output file name as an argument instead of writing
2409 to the standard output and assuming this can be redirected.
2410
2411 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2412 class containing characters with values greater than 255, PCRE compilation
2413 went into a loop.
2414
2415 12. A recursive reference to a subpattern that was within another subpattern
2416 that had a minimum quantifier of zero caused PCRE to crash. For example,
2417 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2418 recursion. If the recursively-called subpattern itself had a zero repeat,
2419 that was OK.
2420
2421 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2422 buffer into which it was copied (for escape processing) was still set at
2423 1024, so long lines caused crashes.
2424
2425 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2426 "internal error: code overflow...". This applied to any character class
2427 that was followed by a possessive quantifier.
2428
2429 15. Modified the Makefile to add libpcre.la as a prerequisite for
2430 libpcreposix.la because I was told this is needed for a parallel build to
2431 work.
2432
2433 16. If a pattern that contained .* following optional items at the start was
2434 studied, the wrong optimizing data was generated, leading to matching
2435 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2436 matching string must start with a or b or c. The correct conclusion for
2437 this pattern is that a match can start with any character.
2438
2439
2440 Version 4.4 13-Aug-03
2441 ---------------------
2442
2443 1. In UTF-8 mode, a character class containing characters with values between
2444 127 and 255 was not handled correctly if the compiled pattern was studied.
2445 In fixing this, I have also improved the studying algorithm for such
2446 classes (slightly).
2447
2448 2. Three internal functions had redundant arguments passed to them. Removal
2449 might give a very teeny performance improvement.
2450
2451 3. Documentation bug: the value of the capture_top field in a callout is *one
2452 more than* the number of the hightest numbered captured substring.
2453
2454 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2455 in incorrectly linking with a previously installed version. They now link
2456 explicitly with libpcre.la.
2457
2458 5. configure.in no longer needs to recognize Cygwin specially.
2459
2460 6. A problem in pcre.in for Windows platforms is fixed.
2461
2462 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2463 pcretest, it used to include the size of the study block as part of its
2464 output. Unfortunately, the structure contains a field that has a different
2465 size on different hardware architectures. This meant that the tests that
2466 showed this size failed. As the block is currently always of a fixed size,
2467 this information isn't actually particularly useful in pcretest output, so
2468 I have just removed it.
2469
2470 8. Three pre-processor statements accidentally did not start in column 1.
2471 Sadly, there are *still* compilers around that complain, even though
2472 standard C has not required this for well over a decade. Sigh.
2473
2474 9. In pcretest, the code for checking callouts passed small integers in the
2475 callout_data field, which is a void * field. However, some picky compilers
2476 complained about the casts involved for this on 64-bit systems. Now
2477 pcretest passes the address of the small integer instead, which should get
2478 rid of the warnings.
2479
2480 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2481 both compile and run time, and gives an error if an invalid UTF-8 sequence
2482 is found. There is a option for disabling this check in cases where the
2483 string is known to be correct and/or the maximum performance is wanted.
2484
2485 11. In response to a bug report, I changed one line in Makefile.in from
2486
2487 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2488 to
2489 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2490
2491 to look similar to other lines, but I have no way of telling whether this
2492 is the right thing to do, as I do not use Windows. No doubt I'll get told
2493 if it's wrong...
2494
2495
2496 Version 4.3 21-May-03
2497 ---------------------
2498
2499 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2500 Makefile.
2501
2502 2. Some refactoring to improve the quality of the code:
2503
2504 (i) The utf8_table... variables are now declared "const".
2505
2506 (ii) The code for \cx, which used the "case flipping" table to upper case
2507 lower case letters, now just substracts 32. This is ASCII-specific,
2508 but the whole concept of \cx is ASCII-specific, so it seems
2509 reasonable.
2510
2511 (iii) PCRE was using its character types table to recognize decimal and
2512 hexadecimal digits in the pattern. This is silly, because it handles
2513 only 0-9, a-f, and A-F, but the character types table is locale-
2514 specific, which means strange things might happen. A private
2515 table is now used for this - though it costs 256 bytes, a table is
2516 much faster than multiple explicit tests. Of course, the standard
2517 character types table is still used for matching digits in subject
2518 strings against \d.
2519
2520 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2521 ending in _t are). So I've renamed it as ESC_tee.
2522
2523 3. The first argument for regexec() in the POSIX wrapper should have been
2524 defined as "const".
2525
2526 4. Changed pcretest to use malloc() for its buffers so that they can be
2527 Electric Fenced for debugging.
2528
2529 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2530 to read one or more bytes before the start of the subject string. Often this
2531 had no effect on PCRE's behaviour, but in some circumstances it could
2532 provoke a segmentation fault.
2533
2534 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2535 to try to read one or more bytes before the start of the subject string.
2536
2537 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2538 UTF-8 support could misbehave in various ways if the subject string
2539 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2540 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2541 back over UTF-8 characters.)
2542
2543
2544 Version 4.2 14-Apr-03
2545 ---------------------
2546
2547 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2548
2549 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2550 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2551 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2552 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2553 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2554 and BUILD_EXEEXT
2555 Note: automatic setting of the BUILD variables is not yet working
2556 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2557 compile-time but not at link-time
2558 [LINK]: use for linking executables only
2559 make different versions for Windows and non-Windows
2560 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2561 libraries
2562 [LINK_FOR_BUILD]: new variable
2563 [OBJEXT]: use throughout
2564 [EXEEXT]: use throughout
2565 <winshared>: new target
2566 <wininstall>: new target
2567 <dftables.o>: use native compiler
2568 <dftables>: use native linker
2569 <install>: handle Windows platform correctly
2570 <clean>: ditto
2571 <check>: ditto
2572 copy DLL to top builddir before testing
2573
2574 As part of these changes, -no-undefined was removed again. This was reported
2575 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2576 in any case.
2577
2578 3. Some tidies to get rid of compiler warnings:
2579
2580 . In the match_data structure, match_limit was an unsigned long int, whereas
2581 match_call_count was an int. I've made them both unsigned long ints.
2582
2583 . In pcretest the fact that a const uschar * doesn't automatically cast to
2584 a void * provoked a warning.
2585
2586 . Turning on some more compiler warnings threw up some "shadow" variables
2587 and a few more missing casts.
2588
2589 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2590 option, a class that contained a single character with a value between 128
2591 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2592
2593 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2594 option, a class that contained several characters, but with at least one
2595 whose value was between 128 and 255 caused PCRE to crash.
2596
2597
2598 Version 4.1 12-Mar-03
2599 ---------------------
2600
2601 1. Compiling with gcc -pedantic found a couple of places where casts were
2602 needed, and a string in dftables.c that was longer than standard compilers are
2603 required to support.
2604
2605 2. Compiling with Sun's compiler found a few more places where the code could
2606 be tidied up in order to avoid warnings.
2607
2608 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2609 first of these names is deprecated in the latest Autoconf in favour of the name
2610 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2611 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2612 analogy I have changed it to CFLAGS_FOR_BUILD.
2613
2614 4. Added -no-undefined to the linking command in the Makefile, because this is
2615 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2616 linking step for the pcreposix library.
2617
2618 5. PCRE was failing to diagnose the case of two named groups with the same
2619 name.
2620
2621 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2622 literal character that is needed in the subject for a match, and scans along to
2623 ensure that it is present before embarking on the full matching process. This
2624 saves time in cases of nested unlimited repeats that are never going to match.
2625 Problem: the scan can take a lot of time if the subject is very long (e.g.
2626 megabytes), thus penalizing straightforward matches. It is now done only if the
2627 amount of subject to be scanned is less than 1000 bytes.
2628
2629 7. A lesser problem with the same optimization is that it was recording the
2630 first character of an anchored pattern as "needed", thus provoking a search
2631 right along the subject, even when the first match of the pattern was going to
2632 fail. The "needed" character is now not set for anchored patterns, unless it
2633 follows something in the pattern that is of non-fixed length. Thus, it still
2634 fulfils its original purpose of finding quick non-matches in cases of nested
2635 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2636
2637
2638 Version 4.0 17-Feb-03
2639 ---------------------
2640
2641 1. If a comment in an extended regex that started immediately after a meta-item
2642 extended to the end of string, PCRE compiled incorrect data. This could lead to
2643 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2644
2645 2. Moved to autoconf 2.53 and libtool 1.4.2.
2646
2647 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2648 the special perltest8 script is no longer needed - all the tests can be run
2649 from a single perltest script.
2650
2651 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2652 by \s. It has now been removed in PCRE. This means it isn't recognized as
2653 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2654 class [:space:] *does* include VT, thereby creating a mess.
2655
2656 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2657 space and tab.
2658
2659 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2660 its new features into the main test script, reducing the number of scripts.
2661
2662 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2663 were backward compatible, and made the (?i) apply to the whole pattern, as if
2664 /i were given. Now it behaves more logically, and applies the option setting
2665 only to what follows. PCRE has been changed to follow suit. However, if it
2666 finds options settings right at the start of the pattern, it extracts them into
2667 the global options, as before. Thus, they show up in the info data.
2668
2669 8. Added support for the \Q...\E escape sequence. Characters in between are
2670 treated as literals. This is slightly different from Perl in that $ and @ are
2671 also handled as literals inside the quotes. In Perl, they will cause variable
2672 interpolation. Note the following examples:
2673
2674 Pattern PCRE matches Perl matches
2675
2676 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2677 \Qabc\$xyz\E abc\$xyz abc\$xyz
2678 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2679
2680 For compatibility with Perl, \Q...\E sequences are recognized inside character
2681 classes as well as outside them.
2682
2683 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2684 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2685 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2686 signed/unsigned warnings.
2687
2688 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2689 option for pcretest, so I've replaced it by a simple function that does just
2690 that job.
2691
2692 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2693 "pcregrep -".
2694
2695 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2696 Java package. This provides some syntactic sugar for simple cases of what my
2697 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2698 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2699 item, you can use this simplified notation. Note that only makes sense with
2700 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2701 greediness, whatever the setting of the PCRE_UNGREEDY option.
2702
2703 13. A change of greediness default within a pattern was not taking effect at
2704 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2705 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2706 was abstracted outside.
2707
2708 14. PCRE now supports the \G assertion. It is true when the current matching
2709 position is at the start point of the match. This differs from \A when the
2710 starting offset is non-zero. Used with the /g option of pcretest (or similar
2711 code), it works in the same way as it does for Perl's /g option. If all
2712 alternatives of a regex begin with \G, the expression is anchored to the start
2713 match position, and the "anchored" flag is set in the compiled expression.
2714
2715 15. Some bugs concerning the handling of certain option changes within patterns
2716 have been fixed. These applied to options other than (?ims). For example,
2717 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2718 been the other way round. Some of this was related to change 7 above.
2719
2720 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2721 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2722 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2723 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2724
2725 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2726 mode. Unlike ".", it always matches newline, whatever the setting of
2727 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2728 assertions. Perl allows it, but it doesn't (in general) work because it can't
2729 calculate the length of the lookbehind. At least, that's the case for Perl
2730 5.8.0 - I've been told they are going to document that it doesn't work in
2731 future.
2732
2733 18. Added an error diagnosis for escapes that PCRE does not support: these are
2734 \L, \l, \N, \P, \p, \U, \u, and \X.
2735
2736 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2737 reading past the end of the pattern in cases such as /[abcd/.
2738
2739 20. PCRE was getting more memory than necessary for patterns with classes that
2740 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2741
2742 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2743 compiling PCRE for use with Virtual Pascal.
2744
2745 22. Small fix to the Makefile to make it work properly if the build is done
2746 outside the source tree.
2747
2748 23. Added a new extension: a condition to go with recursion. If a conditional
2749 subpattern starts with (?(R) the "true" branch is used if recursion has
2750 happened, whereas the "false" branch is used only at the top level.
2751
2752 24. When there was a very long string of literal characters (over 255 bytes
2753 without UTF support, over 250 bytes with UTF support), the computation of how
2754 much memory was required could be incorrect, leading to segfaults or other
2755 strange effects.
2756
2757 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2758 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2759 there was a subsequent back reference to those brackets. This meant that, for
2760 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2761 possible to check for precisely this case. All we can do is abandon the
2762 optimization if .* occurs inside capturing brackets when there are any back
2763 references whatsoever. (See below for a better fix that came later.)
2764
2765 26. The handling of the optimization for finding the first character of a
2766 non-anchored pattern, and for finding a character that is required later in the
2767 match were failing in some cases. This didn't break the matching; it just
2768 failed to optimize when it could. The way this is done has been re-implemented.
2769
2770 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2771
2772 28. Added a new feature that provides some of the functionality that Perl
2773 provides with (?{...}). The facility is termed a "callout". The way it is done
2774 in PCRE is for the caller to provide an optional function, by setting
2775 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2776 global variable. By default it is unset, which disables all calling out. To get
2777 the function called, the regex must include (?C) at appropriate points. This
2778 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2779 This provides a means of identifying different callout points. When PCRE
2780 reaches such a point in the regex, if pcre_callout has been set, the external
2781 function is called. It is provided with data in a structure called
2782 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2783 matching continues; if it returns a non-zero value, the match at the current
2784 point fails. However, backtracking will occur if possible. [This was changed
2785 later and other features added - see item 49 below.]
2786
2787 29. pcretest is upgraded to test the callout functionality. It provides a
2788 callout function that displays information. By default, it shows the start of
2789 the match and the current position in the text. There are some new data escapes
2790 to vary what happens:
2791
2792 \C+ in addition, show current contents of captured substrings
2793 \C- do not supply a callout function
2794 \C!n return 1 when callout number n is reached
2795 \C!n!m return 1 when callout number n is reached for the mth time
2796
2797 30. If pcregrep was called with the -l option and just a single file name, it
2798 output "<stdin>" if a match was found, instead of the file name.
2799
2800 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2801 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2802 pcre_exec(). This saves a malloc/free per call. The default value of
2803 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2804 when configuring.
2805
2806 32. The default maximum size of a compiled pattern is 64K. There have been a
2807 few cases of people hitting this limit. The code now uses macros to handle the
2808 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2809 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2810 configuring. Tests 2 and 5 work only with 2-byte links because they output
2811 debugging information about compiled patterns.
2812
2813 33. Internal code re-arrangements:
2814
2815 (a) Moved the debugging function for printing out a compiled regex into
2816 its own source file (printint.c) and used #include to pull it into
2817 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2818 separate copies.
2819
2820 (b) Defined the list of op-code names for debugging as a macro in
2821 internal.h so that it is next to the definition of the opcodes.
2822
2823 (c) Defined a table of op-code lengths for simpler skipping along compiled
2824 code. This is again a macro in internal.h so that it is next to the
2825 definition of the opcodes.
2826
2827 34. Added support for recursive calls to individual subpatterns, along the
2828 lines of Robin Houston's patch (but implemented somewhat differently).
2829
2830 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2831 allow it to read and process whole directories in Win32. This code was
2832 contributed by Lionel Fourquaux; it has not been tested by me.
2833
2834 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2835 used to name a group. Names consist of alphanumerics and underscores, and must
2836 be unique. Back references use the syntax (?P=name) and recursive calls use
2837 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2838 numbers. The function pcre_fullinfo() can be used after compilation to extract
2839 a name/number map. There are three relevant calls:
2840
2841 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2842 PCRE_INFO_NAMECOUNT yields the number of entries
2843 PCRE_INFO_NAMETABLE yields a pointer to the map.
2844
2845 The map is a vector of fixed-size entries. The size of each entry depends on
2846 the length of the longest name used. The first two bytes of each entry are the
2847 group number, most significant byte first. There follows the corresponding
2848 name, zero terminated. The names are in alphabetical order.
2849
2850 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2851 case instead of 255. Making it the same both with and without UTF-8 support
2852 means that the same test output works with both.
2853
2854 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2855 calling malloc() with a zero argument.
2856
2857 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2858 optimization. I've improved things by keeping a bitmap of backreferences with
2859 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2860 fact referenced, the optimization can be applied. It is unlikely that a
2861 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2862 the match to follow \n) will appear inside brackets with a number greater than
2863 31, but if it does, any back reference > 31 suppresses the optimization.
2864
2865 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2866 of disabling numbered capturing parentheses. Any opening parenthesis that is
2867 not followed by ? behaves as if it were followed by ?: but named parentheses
2868 can still be used for capturing (and they will acquire numbers in the usual
2869 way).
2870
2871 41. Redesigned the return codes from the match() function into yes/no/error so
2872 that errors can be passed back from deep inside the nested calls. A malloc
2873 failure while inside a recursive subpattern call now causes the
2874 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2875
2876 42. It is now possible to set a limit on the number of times the match()
2877 function is called in a call to pcre_exec(). This facility makes it possible to
2878 limit the amount of recursion and backtracking, though not in a directly
2879 obvious way, because the match() function is used in a number of different
2880 circumstances. The count starts from zero for each position in the subject
2881 string (for non-anchored patterns). The default limit is, for compatibility, a
2882 large number, namely 10 000 000. You can change this in two ways:
2883
2884 (a) When configuring PCRE before making, you can use --with-match-limit=n
2885 to set a default value for the compiled library.
2886
2887 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2888 a different value is set. See 45 below.
2889
2890 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2891
2892 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2893 of things that can be changed at compile time. The first argument specifies
2894 what is wanted and the second points to where the information is to be placed.
2895 The current list of available information is:
2896
2897 PCRE_CONFIG_UTF8
2898
2899 The output is an integer that is set to one if UTF-8 support is available;
2900 otherwise it is set to zero.
2901
2902 PCRE_CONFIG_NEWLINE
2903
2904 The output is an integer that it set to the value of the code that is used for
2905 newline. It is either LF (10) or CR (13).
2906
2907 PCRE_CONFIG_LINK_SIZE
2908
2909 The output is an integer that contains the number of bytes used for internal
2910 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2911
2912 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2913
2914 The output is an integer that contains the threshold above which the POSIX
2915 interface uses malloc() for output vectors. See item 31 above.
2916
2917 PCRE_CONFIG_MATCH_LIMIT
2918
2919 The output is an unsigned integer that contains the default limit of the number
2920 of match() calls in a pcre_exec() execution. See 42 above.
2921
2922 44. pcretest has been upgraded by the addition of the -C option. This causes it
2923 to extract all the available output from the new pcre_config() function, and to
2924 output it. The program then exits immediately.
2925
2926 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2927 order to support additional features. One way would have been to define
2928 pcre_exec2() (for example) with extra arguments, but this would not have been
2929 extensible, and would also have required all calls to the original function to
2930 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2931 is used for passing in "extra" data from pcre_study().
2932
2933 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2934 contains the following fields:
2935
2936 flags a bitmap indicating which of the following fields are set
2937 study_data opaque data from pcre_study()
2938 match_limit a way of specifying a limit on match() calls for a specific
2939 call to pcre_exec()
2940 callout_data data for callouts (see 49 below)
2941
2942 The flag bits are also defined in pcre.h, and are
2943
2944 PCRE_EXTRA_STUDY_DATA
2945 PCRE_EXTRA_MATCH_LIMIT
2946 PCRE_EXTRA_CALLOUT_DATA
2947
2948 The pcre_study() function now returns one of these new pcre_extra blocks, with
2949 the actual study data pointed to by the study_data field, and the
2950 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2951 before. That is, this change is entirely upwards-compatible and requires no
2952 change to existing code.
2953
2954 If you want to pass in additional data to pcre_exec(), you can either place it
2955 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2956 block.
2957
2958 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2959 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2960 times with different match limits, until it finds the minimum value needed for
2961 pcre_exec() to complete. The value is then output. This can be instructive; for
2962 most simple matches the number is quite small, but for pathological cases it
2963 gets very large very quickly.
2964
2965 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2966 returns the size of the data block pointed to by the study_data field in a
2967 pcre_extra block, that is, the value that was passed as the argument to
2968 pcre_malloc() when PCRE was getting memory in which to place the information
2969 created by pcre_study(). The fourth argument should point to a size_t variable.
2970 pcretest has been extended so that this information is shown after a successful
2971 pcre_study() call when information about the compiled regex is being displayed.
2972
2973 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2974 because what follows is always an absolute path. (Later: it turns out that this
2975 is more than cosmetic for MinGW, because it doesn't like empty path
2976 components.)
2977
2978 49. Some changes have been made to the callout feature (see 28 above):
2979
2980 (i) A callout function now has three choices for what it returns:
2981
2982 0 => success, carry on matching
2983 > 0 => failure at this point, but backtrack if possible
2984 < 0 => serious error, return this value from pcre_exec()
2985
2986 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2987 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2988 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2989 use by callout functions. It will never be used by PCRE itself.
2990
2991 (ii) The pcre_extra structure (see 45 above) has a void * field called
2992 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2993 pcre_callout_block structure has a field of the same name. The contents of
2994 the field passed in the pcre_extra structure are passed to the callout
2995 function in the corresponding field in the callout block. This makes it
2996 easier to use the same callout-containing regex from multiple threads. For
2997 testing, the pcretest program has a new data escape
2998
2999 \C*n pass the number n (may be negative) as callout_data
3000
3001 If the callout function in pcretest receives a non-zero value as
3002 callout_data, it returns that value.
3003
3004 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3005 there were some redundant $(CFLAGS) in commands that are now specified as
3006 $(LINK), which already includes $(CFLAGS).
3007
3008 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3009 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3010 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3011 one-byte characters throughout. Note that case-insensitive matching applies
3012 only to characters whose values are less than 256. PCRE doesn't support the
3013 notion of cases for higher-valued characters.
3014
3015 (i) A character class whose characters are all within 0-255 is handled as
3016 a bit map, and the map is inverted for negative classes. Previously, a
3017 character > 255 always failed to match such a class; however it should
3018 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3019
3020 (ii) A negated character class with a single character < 255 is coded as
3021 "not this character" (OP_NOT). This wasn't working properly when the test
3022 character was multibyte, either singly or repeated.
3023
3024 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3025 mode, for example: \x{100}{2,3}.
3026
3027 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3028 singly or repeated) now correctly test multibyte characters. However,
3029 PCRE doesn't recognize any characters with values greater than 255 as
3030 digits, spaces, or word characters. Such characters always match \D, \S,
3031 and \W, and never match \d, \s, or \w.
3032
3033 (v) Classes may now contain characters and character ranges with values
3034 greater than 255. For example: [ab\x{100}-\x{400}].
3035
3036 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3037 PCRE in UTF-8 mode.
3038
3039 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3040 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3041 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3042 value.)
3043
3044 53. The single man page has become too large. I have therefore split it up into
3045 a number of separate man pages. These also give rise to individual HTML pages;
3046 these are now put in a separate directory, and there is an index.html page that
3047 lists them all. Some hyperlinking between the pages has been installed.
3048
3049 54. Added convenience functions for handling named capturing parentheses.
3050
3051 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3052 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3053 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3054 are faulted.
3055
3056 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3057 calling configure. These values are used when compiling the dftables.c program
3058 which is run to generate the source of the default character tables. They
3059 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3060 you will need to set these values.
3061
3062 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3063
3064
3065 Version 3.9 02-Jan-02
3066 ---------------------
3067
3068 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3069
3070 2. If --disable-static was given, the building process failed when trying to
3071 build pcretest and pcregrep. (For some reason it was using libtool to compile
3072 them, which is not right, as they aren't part of the library.)
3073
3074
3075 Version 3.8 18-Dec-01
3076 ---------------------
3077
3078 1. The experimental UTF-8 code was completely screwed up. It was packing the
3079 bytes in the wrong order. How dumb can you get?
3080
3081
3082 Version 3.7 29-Oct-01
3083 ---------------------
3084
3085 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3086 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3087 this didn't happen under Solaris 8, where I normally test things.
3088
3089 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3090 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3091 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3092 this fix an hour or so after the initial 3.7 release.)
3093
3094
3095 Version 3.6 23-Oct-01
3096 ---------------------
3097
3098 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3099 offsets passed as NULL with zero offset count.
3100
3101 2. The config.guess and config.sub files had not been updated when I moved to
3102 the latest autoconf.
3103
3104
3105 Version 3.5 15-Aug-01
3106 ---------------------
3107
3108 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3109 had been forgotten.
3110
3111 2. By using declared but undefined structures, we can avoid using "void"
3112 definitions in pcre.h while keeping the internal definitions of the structures
3113 private.
3114
3115 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3116 user point of view, this means that both static and shared libraries are built
3117 by default, but this can be individually controlled. More of the work of
3118 handling this static/shared cases is now inside libtool instead of PCRE's make
3119 file.
3120
3121 4. The pcretest utility is now installed along with pcregrep because it is
3122 useful for users (to test regexs) and by doing this, it automatically gets
3123 relinked by libtool. The documentation has been turned into a man page, so
3124 there are now .1, .txt, and .html versions in /doc.
3125
3126 5. Upgrades to pcregrep:
3127 (i) Added long-form option names like gnu grep.
3128 (ii) Added --help to list all options with an explanatory phrase.
3129 (iii) Added -r, --recursive to recurse into sub-directories.
3130 (iv) Added -f, --file to read patterns from a file.
3131
3132 6. pcre_exec() was referring to its "code" argument before testing that
3133 argument for NULL (and giving an error if it was NULL).
3134
3135 7. Upgraded Makefile.in to allow for compiling in a different directory from
3136 the source directory.
3137
3138 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3139 options bits, the pointer it was passed was to an int instead of to an unsigned
3140 long int. This mattered only on 64-bit systems.
3141
3142 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3143 generated) instead of pcre.in, which it its source. Also made the same change
3144 in several of the .c files.
3145
3146 10. A new release of gcc defines printf() as a macro, which broke pcretest
3147 because it had an ifdef in the middle of a string argument for printf(). Fixed
3148 by using separate calls to printf().
3149
3150 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3151 script, to force use of CR or LF instead of \n in the source. On non-Unix
3152 systems, the value can be set in config.h.
3153
3154 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3155 absolute limit. Changed the text of the error message to make this clear, and
3156 likewise updated the man page.
3157
3158 13. The limit of 99 on the number of capturing subpatterns has been removed.
3159 The new limit is 65535, which I hope will not be a "real" limit.
3160
3161
3162 Version 3.4 22-Aug-00
3163 ---------------------
3164
3165 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3166
3167 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3168
3169
3170 Version 3.3 01-Aug-00
3171 ---------------------
3172
3173 1. If an octal character was given, but the value was greater than \377, it
3174 was not getting masked to the least significant bits, as documented. This could
3175 lead to crashes in some systems.
3176
3177 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3178 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3179
3180 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3181 These just pass their arguments on to (pcre_free)(), but they are provided
3182 because some uses of PCRE bind it to non-C systems that can call its functions,
3183 but cannot call free() or pcre_free() directly.
3184
3185 4. Add "make test" as a synonym for "make check". Corrected some comments in
3186 the Makefile.
3187
3188 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3189 Makefile.
3190
3191 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3192 command called pgrep for grepping around the active processes.
3193
3194 7. Added the beginnings of support for UTF-8 character strings.
3195
3196 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3197 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3198 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3199 out for the ar command.)
3200
3201
3202 Version 3.2 12-May-00
3203 ---------------------
3204
3205 This is purely a bug fixing release.
3206
3207 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3208 of ZA. This was just one example of several cases that could provoke this bug,
3209 which was introduced by change 9 of version 2.00. The code for breaking
3210 infinite loops after an iteration that matches an empty string was't working
3211 correctly.
3212
3213 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3214 when matched against abbab (for example). After matching an empty string, it
3215 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3216 caused it to match further down the string than it should.
3217
3218 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3219 was there because it doesn't seem to be needed, and it causes trouble on some
3220 systems, as it is not a Standard C header. It has been removed.
3221
3222 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3223 were reported on the Macintosh. The changes were from
3224
3225 while ((c = *(++ptr)) != 0 && c != '\n');
3226 to
3227 while ((c = *(++ptr)) != 0 && c != '\n') ;
3228
3229 Totally extraordinary, but if that's what it takes...
3230
3231 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3232 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3233 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3234 assumes the way PCRE uses memmove() (always moving upwards).
3235
3236 6. PCRE is being used in one environment where strchr() is not available. There
3237 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3238 faster code anyway.
3239
3240
3241 Version 3.1 09-Feb-00
3242 ---------------------
3243
3244 The only change in this release is the fixing of some bugs in Makefile.in for
3245 the "install" target:
3246
3247 (1) It was failing to install pcreposix.h.
3248
3249 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3250
3251
3252 Version 3.0 01-Feb-00
3253 ---------------------
3254
3255 1. Add support for the /+ modifier to perltest (to output $` like it does in
3256 pcretest).
3257
3258 2. Add support for the /g modifier to perltest.
3259
3260 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3261 matches null strings.
3262
3263 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3264 pattern. Perl treats empty patterns specially - it reuses the most recent
3265 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3266 effect.
3267
3268 5. The POSIX interface was broken in that it was just handing over the POSIX
3269 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3270 required a bigger vector, with some working space on the end. This means that
3271 the POSIX wrapper now has to get and free some memory, and copy the results.
3272
3273 6. Added some simple autoconf support, placing the test data and the
3274 documentation in separate directories, re-organizing some of the
3275 information files, and making it build pcre-config (a GNU standard). Also added
3276 libtool support for building PCRE as a shared library, which is now the
3277 default.
3278
3279 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3280 09 are not valid octal constants. Single digits will be used for minor values
3281 less than 10.
3282
3283 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3284 existing programs that set these in the POSIX interface can use PCRE without
3285 modification.
3286
3287 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3288 return all that pcre_info() returns, plus additional data. The pcre_info()
3289 function is retained for compatibility, but is considered to be obsolete.
3290
3291 10. Added experimental recursion feature (?R) to handle one common case that
3292 Perl 5.6 will be able to do with (?p{...}).
3293
3294 11. Added support for POSIX character classes like [:alpha:], which Perl is
3295 adopting.
3296
3297
3298 Version 2.08 31-Aug-99
3299 ----------------------
3300
3301 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3302 trying to match at the startoffset position, but instead was moving forward to
3303 the next newline as if a previous match had failed.
3304
3305 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3306 and could get into a loop if a null string was matched other than at the start
3307 of the subject.
3308
3309 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3310 be distinguished at compile time, and for completeness also added PCRE_DATE.
3311
3312 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3313 in GnuWin32 environments.
3314
3315
3316 Version 2.07 29-Jul-99
3317 ----------------------
3318
3319 1. The documentation is now supplied in plain text form and HTML as well as in
3320 the form of man page sources.
3321
3322 2. C++ compilers don't like assigning (void *) values to other pointer types.
3323 In particular this affects malloc(). Although there is no problem in Standard
3324 C, I've put in casts to keep C++ compilers happy.
3325
3326 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3327 should be (const char *).
3328
3329 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3330 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3331 However, I haven't made this a standard facility. The documentation doesn't
3332 mention it, and the Makefile doesn't support it.
3333
3334 5. The Makefile now contains an "install" target, with editable destinations at
3335 the top of the file. The pcretest program is not installed.
3336
3337 6. pgrep -V now gives the PCRE version number and date.
3338
3339 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3340 causing the entire string to be ignored, instead of just the last character.
3341
3342 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3343 non-matching string, it can take a very, very long time, even for strings of
3344 quite modest length, because of the nested recursion. PCRE now does better in
3345 some of these cases. It does this by remembering the last required literal
3346 character in the pattern, and pre-searching the subject to ensure it is present
3347 before running the real match. In other words, it applies a heuristic to detect
3348 some types of certain failure quickly, and in the above example, if presented
3349 with a string that has no trailing " it gives "no match" very quickly.
3350
3351 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3352 other alternatives are tried instead.
3353
3354
3355 Version 2.06 09-Jun-99
3356 ----------------------
3357
3358 1. Change pcretest's output for amount of store used to show just the code
3359 space, because the remainder (the data block) varies in size between 32-bit and
3360 64-bit systems.
3361
3362 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3363 start matching at. This allows lookbehinds to work when searching for multiple
3364 occurrences in a string.
3365
3366 3. Added additional options to pcretest for testing multiple occurrences:
3367
3368 /+ outputs the rest of the string that follows a match
3369 /g loops for multiple occurrences, using the new startoffset argument
3370 /G loops for multiple occurrences by passing an incremented pointer
3371
3372 4. PCRE wasn't doing the "first character" optimization for patterns starting
3373 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3374 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3375 the letter 'x'. On long subject strings, this gives a significant speed-up.
3376
3377
3378 Version 2.05 21-Apr-99
3379 ----------------------
3380
3381 1. Changed the type of magic_number from int to long int so that it works
3382 properly on 16-bit systems.
3383
3384 2. Fixed a bug which caused patterns starting with .* not to work correctly
3385 when the subject string contained newline characters. PCRE was assuming
3386 anchoring for such patterns in all cases, which is not correct because .* will
3387 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3388 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3389 must be retried after every newline in the subject.
3390
3391
3392 Version 2.04 18-Feb-99
3393 ----------------------
3394
3395 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3396 computation of the store needed to hold the pattern was incorrect (too large).
3397 If such patterns were nested a few deep, this could multiply and become a real
3398 problem.
3399
3400 2. Added /M option to pcretest to show the memory requirement of a specific
3401 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3402
3403 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3404 compiled in such a way that the backtracking after subsequent failure was
3405 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3406 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3407
3408
3409 Version 2.03 02-Feb-99
3410 ----------------------
3411
3412 1. Fixed typo and small mistake in man page.
3413
3414 2. Added 4th condition (GPL supersedes if conflict) and created separate
3415 LICENCE file containing the conditions.
3416
3417 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3418 Perl, that is the internal \ allows the delimiter to be included in the
3419 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3420 the final delimiter, add \ to the end of the pattern (to test the error).
3421
3422 4. Added the convenience functions for extracting substrings after a successful
3423 match. Updated pcretest to make it able to test these functions.
3424
3425
3426 Version 2.02 14-Jan-99
3427 ----------------------
3428
3429 1. Initialized the working variables associated with each extraction so that
3430 their saving and restoring doesn't refer to uninitialized store.
3431
3432 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3433 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3434 fix the problem.
3435
3436 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3437 calls, and wasn't printing the correct value for compiling calls. Increased the
3438 default value of LOOPREPEAT, and the number of significant figures in the
3439 times.
3440
3441 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3442
3443 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3444 a building problem on Windows NT with a FAT file system.
3445
3446
3447 Version 2.01 21-Oct-98
3448 ----------------------
3449
3450 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3451 to character tables built by pcre_maketables() in the current locale. If NULL
3452 is passed, the default tables are used.
3453
3454
3455 Version 2.00 24-Sep-98
3456 ----------------------
3457
3458 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3459 it any more.
3460
3461 2. Allow quantification of (?>) groups, and make it work correctly.
3462
3463 3. The first character computation wasn't working for (?>) groups.
3464
3465 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3466 end of the subject) and add 5.005's \z, which really does match only at the
3467 very end of the subject.
3468
3469 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3470
3471 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3472 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3473 localized options. All options to pcre_study() were also removed.
3474
3475 7. Add other new features from 5.005:
3476
3477 $(?<= positive lookbehind
3478 $(?<! negative lookbehind
3479 (?imsx-imsx) added the unsetting capability
3480 such a setting is global if at outer level; local otherwise
3481 (?imsx-imsx:) non-capturing groups with option setting
3482 (?(cond)re|re) conditional pattern matching
3483
3484 A backreference to itself in a repeated group matches the previous
3485 captured string.
3486
3487 8. General tidying up of studying (both automatic and via "study")
3488 consequential on the addition of new assertions.
3489
3490 9. As in 5.005, unlimited repeated groups that could match an empty substring
3491 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3492 runtime if any iteration does actually match an empty substring.
3493
3494 10. Include the RunTest script in the distribution.
3495
3496 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3497 discrepancies, some of which were old and were also with respect to 5.004. They
3498 have now been fixed.
3499
3500
3501 Version 1.09 28-Apr-98
3502 ----------------------
3503
3504 1. A negated single character class followed by a quantifier with a minimum
3505 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3506 program crashes, or just wrong answers. This did not apply to negated classes
3507 containing more than one character, or to minima other than one.
3508
3509
3510 Version 1.08 27-Mar-98
3511 ----------------------
3512
3513 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3514
3515 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3516 latter must appear before anything that relies on it in the pattern.
3517
3518
3519 Version 1.07 16-Feb-98
3520 ----------------------
3521
3522 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3523 repeat of a potentially empty string).
3524
3525
3526 Version 1.06 23-Jan-98
3527 ----------------------
3528
3529 1. Added Markus Oberhumer's little patches for C++.
3530
3531 2. Literal strings longer than 255 characters were broken.
3532
3533
3534 Version 1.05 23-Dec-97
3535 ----------------------
3536
3537 1. Negated character classes containing more than one character were failing if
3538 PCRE_CASELESS was set at run time.
3539
3540
3541 Version 1.04 19-Dec-97
3542 ----------------------
3543
3544 1. Corrected the man page, where some "const" qualifiers had been omitted.
3545
3546 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3547 input syntax.
3548
3549 3. Fixed memory leak which occurred when a regex with back references was
3550 matched with an offsets vector that wasn't big enough. The temporary memory
3551 that is used in this case wasn't being freed if the match failed.
3552
3553 4. Tidied pcretest to ensure it frees memory that it gets.
3554
3555 5. Temporary memory was being obtained in the case where the passed offsets
3556 vector was exactly big enough.
3557
3558 6. Corrected definition of offsetof() from change 5 below.
3559
3560 7. I had screwed up change 6 below and broken the rules for the use of
3561 setjmp(). Now fixed.
3562
3563
3564 Version 1.03 18-Dec-97
3565 ----------------------
3566
3567 1. A erroneous regex with a missing opening parenthesis was correctly
3568 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3569 on some systems.
3570
3571 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3572 it was reported that one broken compiler failed on the former because "code" is
3573 also an independent variable.
3574
3575 3. The erroneous regex a[]b caused an array overrun reference.
3576
3577 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3578 fail on data ending with that character. (It was going on too far, and checking
3579 the next character, typically a binary zero.) This was specific to the
3580 optimized code for single-character negative classes.
3581
3582 5. Added a contributed patch from the TIN world which does the following:
3583
3584 + Add an undef for memmove, in case the the system defines a macro for it.
3585
3586 + Add a definition of offsetof(), in case there isn't one. (I don't know
3587 the reason behind this - offsetof() is part of the ANSI standard - but
3588 it does no harm).
3589
3590 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3591 most of the places where whitespace preceded '#'. I have given up and
3592 allowed the remaining 2 cases to be at the margin.
3593
3594 + Rename some variables in pcre to eliminate shadowing. This seems very
3595 pedantic, but does no harm, of course.
3596
3597 6. Moved the call to setjmp() into its own function, to get rid of warnings
3598 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3599
3600 7. Constructs such as \d{8,} were compiling into the equivalent of
3601 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3602 outcome, but in this particular case used more store than had been allocated,
3603 which caused the bug to be discovered because it threw up an internal error.
3604
3605 8. The debugging code in both pcre and pcretest for outputting the compiled
3606 form of a regex was going wrong in the case of back references followed by
3607 curly-bracketed repeats.
3608
3609
3610 Version 1.02 12-Dec-97
3611 ----------------------
3612
3613 1. Typos in pcre.3 and comments in the source fixed.
3614
3615 2. Applied a contributed patch to get rid of places where it used to remove
3616 'const' from variables, and fixed some signed/unsigned and uninitialized
3617 variable warnings.
3618
3619 3. Added the "runtest" target to Makefile.
3620
3621 4. Set default compiler flag to -O2 rather than just -O.
3622
3623
3624 Version 1.01 19-Nov-97
3625 ----------------------
3626
3627 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3628 like /([ab]*)*/, that is, for classes with more than one character in them.
3629
3630 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3631 as /((?>a*))*/ (a PCRE_EXTRA facility).
3632
3633
3634 Version 1.00 18-Nov-97
3635 ----------------------
3636
3637 1. Added compile-time macros to support systems such as SunOS4 which don't have
3638 memmove() or strerror() but have other things that can be used instead.
3639
3640 2. Arranged that "make clean" removes the executables.
3641
3642
3643 Version 0.99 27-Oct-97
3644 ----------------------
3645
3646 1. Fixed bug in code for optimizing classes with only one character. It was
3647 initializing a 32-byte map regardless, which could cause it to run off the end
3648 of the memory it had got.
3649
3650 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3651
3652
3653 Version 0.98 22-Oct-97
3654 ----------------------
3655
3656 1. Fixed bug in code for handling temporary memory usage when there are more
3657 back references than supplied space in the ovector. This could cause segfaults.
3658
3659
3660 Version 0.97 21-Oct-97
3661 ----------------------
3662
3663 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3664
3665 2. Optimized negated single characters not to use a bit map.
3666
3667 3. Brought error texts together as macro definitions; clarified some of them;
3668 fixed one that was wrong - it said "range out of order" when it meant "invalid
3669 escape sequence".
3670
3671 4. Changed some char * arguments to const char *.
3672
3673 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3674
3675 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3676 pcretest.
3677
3678
3679 Version 0.96 16-Oct-97
3680 ----------------------
3681
3682 1. Added a simple "pgrep" utility to the distribution.
3683
3684 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3685 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3686 where "ddd" means "one or more decimal digits".
3687
3688 3. Fixed serious bug. If a pattern had a back reference, but the call to
3689 pcre_exec() didn't supply a large enough ovector to record the related
3690 identifying subpattern, the match always failed. PCRE now remembers the number
3691 of the largest back reference, and gets some temporary memory in which to save
3692 the offsets during matching if necessary, in order to ensure that
3693 backreferences always work.
3694
3695 4. Increased the compatibility with Perl in a number of ways:
3696
3697 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3698 to request this handling. The option can be set at compile or exec time.
3699
3700 (b) $ matches before a terminating newline by default; an option
3701 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3702 mode). The option can be set at compile or exec time.
3703
3704 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3705 the same as Perl's. If the decimal number it represents is less than 10
3706 or there aren't that many previous left capturing parentheses, an octal
3707 escape is read. Inside a character class, it's always an octal escape,
3708 even if it is a single digit.
3709
3710 (d) An escaped but undefined alphabetic character is taken as a literal,
3711 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3712 escapes.
3713
3714 (e) {0} is now permitted. (The previous item is removed from the compiled
3715 pattern).
3716
3717 5. Changed all the names of code files so that the basic parts are no longer
3718 than 10 characters, and abolished the teeny "globals.c" file.
3719
3720 6. Changed the handling of character classes; they are now done with a 32-byte
3721 bit map always.
3722
3723 7. Added the -d and /D options to pcretest to make it possible to look at the
3724 internals of compilation without having to recompile pcre.
3725
3726
3727 Version 0.95 23-Sep-97
3728 ----------------------
3729
3730 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3731 \x20 at the start of a run of normal characters. These were being treated as
3732 real characters, instead of the source characters being re-checked.
3733
3734
3735 Version 0.94 18-Sep-97
3736 ----------------------
3737
3738 1. The functions are now thread-safe, with the caveat that the global variables
3739 containing pointers to malloc() and free() or alternative functions are the
3740 same for all threads.
3741
3742 2. Get pcre_study() to generate a bitmap of initial characters for non-
3743 anchored patterns when this is possible, and use it if passed to pcre_exec().
3744
3745
3746 Version 0.93 15-Sep-97
3747 ----------------------
3748
3749 1. /(b)|(:+)/ was computing an incorrect first character.
3750
3751 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3752 but not actually doing anything yet.
3753
3754 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3755 as Perl does (e.g. [-az] or [az-]).
3756
3757 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3758 all possible positions.
3759
3760 5. Split up into different modules to avoid including unneeded functions in a
3761 compiled binary. However, compile and exec are still in one module. The "study"
3762 function is split off.
3763
3764 6. The character tables are now in a separate module whose source is generated
3765 by an auxiliary program - but can then be edited by hand if required. There are
3766 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3767 toupper() in the code.
3768
3769 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3770 make them global. Abolish the function for setting them, as the caller can now
3771 set them directly.
3772
3773
3774 Version 0.92 11-Sep-97
3775 ----------------------
3776
3777 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3778 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3779
3780 2. Caseless matching was not working in character classes if the characters in
3781 the pattern were in upper case.
3782
3783 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3784
3785 4. Make PCRE_ANCHORED public and accept as a compile option.
3786
3787 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3788 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3789 pass them.
3790
3791 6. Give an error if bad option bits passed at compile or run time.
3792
3793 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3794 pcretest to cause it to pass that flag.
3795
3796 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3797 options, and the first character, if set.
3798
3799 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3800
3801
3802 Version 0.91 10-Sep-97
3803 ----------------------
3804
3805 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3806 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3807
3808 2. PCRE was looping on encountering an indefinitely repeated back reference to
3809 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3810 Perl does - treats the match as successful.
3811
3812 ****

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